Future Malazan novels by Steven Erikson?

Question: Does anybody have any idea of what are Steven Erikson's plans towards works set in the Malazan world? Can we expect more of Ganeos and others? Also, I believe that Erikson and Esslemont have a pact about not interfering with each other, is that true?
Comment: worth mentioning that the first of the two trilogies planned has been put on hold after book 2 and Erikson is now working on the second trilogy instead.
Answer: From a forum discussion following a signing tour (so second hand info)

Steven Erikson confirmed that he has
  signed up for 6 more Malazan novels
  for Bantam. They will not be direct
  continuations of the Malazan Book of
  the Fallen, but will be two somewhat
  self-contained trilogies, one of which
  will be the backstory of Anomander
  Rake. He also confirmed that the two
  new trilogies will be released at a
  more leisurely pace than the MBF, as
  the one-book-per-year pace is too much
  to keep up indefinitely.
He also confirmed that there are 6
  more Bauchelain and Korbal Broach
  novellas to come, to bring the total
  to 9.
Added in with the 10 volumes of the
  MBF itself and Esslemont's planned 6
  novels, that brings the total to 22
  novels, 9 novellas and 1 companion
  volume set in this world.
Answer: From wiki page of Steven Erikson :

During a 2008 question and answer session in Seattle, Washington, Erikson stated he had signed a deal to write two more trilogies and six novellas; Erikson planned to use the novellas to continue the Bauchelain and Korbal Broach storyline while one of the trilogies would be a prequel to the main series, detailing the history of Anomander Rake and Mother Dark.

From an interview at The Void

Q:Is it correct that your next project is a prequel trilogy about Anomander Rake? What's the plan? And will there be further spin-off series? You've written away from the series. Do you envisage ever ending it permanently?
A:It took me a month to think about
  writing after completing The Crippled
  God. That's the longest break I've had
  since I first started writing
  full-time. It was vaguely alarming. In
  thinking about it and in writing it,
  The Malazan Book of the Fallen
  consumed more than twenty years of my
  life, day after day, night after
  night. And suddenly… nothing. I felt
  (and still feel) I could drop dead
  tomorrow, and apart from some regret
  over those who would be saddened at my
  passing, I'd be pretty fine with that.
  I did what I wanted to do, said what I
  wanted and needed to say, completed my
  modest salute to Homer and The Iliad,
  and all that.
Eventually, things started stirring
  again (keep your thoughts out of my
  trousers!), and I started thinking
  about another modest salute, this time
  to The Bard himself, and from that
  impetus some notes started taking
  shape, and the new trilogy was
  underway.
Obviously, I won't give much away,
  only to say that it's tighter, not
  quite so sprawling, not so wide-angled
  in focus, and that structurally it's
  looking far more… traditional. Who'da
  thunk, eh?
Answer: As of March 19th, 2019 Steven Erikson is working on the Witness trilogy which is based around Karsa Orlong. The first book is almost done.  More info in this blog post.


What could make armoured trains viable in a near future setting?

Question: The armoured trains need to be made viable without just removing other aspects of warfare. Tactical pure fusion nukes with a yield of under 75kt are common. The environment of the planet is earth like. There are a few areas that are just barren flat rock & a few very dense megalopolises. Rail infrastructure is plentiful. The primary opponents are varied but the main situation for use is between developed industrial powers. The armoured trains have to be used in direct combat & be heavily armoured. They can carry other vehicles & infantry. The standard rail gauge is 1,600mm. The technology level is near future. What could allow armoured trains to work in this setting?
Comment: Even historically, when armored trains were common, they were not used in direct combat. They were used as transport, and were armed and armored to protect them from cavalry raids, poorly equipped partisans, and early aircraft strafing fire. They were never meant for frontline combat, not even in the 19th and early 20th century when they were common.
Comment: Btw, "pure fusion nukes" would be a technology which is way *way* beyond what we can currently even imagine. For fusion, you need to get the atomic nuclei together. To do that without a fission primary for enough of fusable material to have 75kt explosion.... I think anti-matter bombs would be easier without some exotic tech. And if you add this exotic fusion tech, you would transform the entire society with "unlimited" energy.
Comment: Why do you need rails for?
Comment: @SteroidSandwich (mylar-foil sunglasses and Doc Brown's hair)  "Rails? Where we're going, we don't need Rails!"
Comment: Domestic terrorism and rampant serial killers. If the situation in America continues, subway cars will need to be armored. Why bother with schools and malls, when you can shoot up an entire subway car?
Comment: @Criggie the purpose of an armoured train isn't to carry supplies, its to shoot at things, which it can't from inside a tunnel. Also if the enemy gets through at any point everything will break horribly
Comment: @OT-64SKOT The question doesn't say the trains are armed and intended to fire, the nearest is "The armoured trains have to be used in direct combat"   An armoured train that doesn't shoot would be ideal for protecting its contents up to the front line.   Would you mind clarifying that this armoured train is an offensive/attacking weapon, not a protective one ?
Comment: Does [this one](https://www.girlgeniusonline.com/comic.php?date=20141229#.YTXDheBlCdM) count?
Comment: Does your definition of Train include subways ?  If so, super-thick tunnels for Hyperloop.  Put the armour in the tunnel, not the train.
Comment: Consider https://en.wikipedia.org/wiki/Armoured_trains_of_Poland or enjoy reading Philip Pullman's https://en.wikipedia.org/wiki/The_Shadow_in_the_North
Comment: The only use I could actually imagine for a armored train is as a railgun artillery platform for a landlocked country  as it could handle  the power requirements either by schlepping along a reactor or by wire. Even so it would be incredibly vulnerable unless you have battlefield dominance. This would still be slightly relevant if there is a concept similar to MAD that that limits the use of nuclear weapons.
Comment: Unless your world is post-apocalyptic and populated by zombies not smart enough to attack rails (a la *Kabaneri of the Iron Fortress*), a train is going to be probably the worst choice for anything.
Comment: @papirtiger there have been many times throughout history where armoured trains where used extensively. Even now they're used in a very limited capacity by Russia.
Comment: @IanKemp there have been many times throughout history where armoured trains where used extensively. Even now they're used in a very limited capacity by Russia.
Comment: @OT-64SKOT Russia does have a tendency though to hamster everything even if it's not even relevant anymore. Is it actually functional or just a rusty wreck?
Comment: @OT-64SKOT Yes, the key being "history". The reason Russia is the only nation to still use such trains is that Russia is the only nation with an internal asymmetric warfare problem, and fewer/worse roads than railways.
Comment: @papirtiger my point is that up to & into world war 2 they had a use. they aren't completely useless against anything more than zombies. they can be made useful
Comment: @IanKemp my point is that up to & into world war 2 they had a use. they aren't completely useless against anything more than zombies. they can be made useful
Comment: Do you mean "viable" in the sense of "make military sense in fact" or in the sense of "those in change will favor them"? The latter opens up a lot more possibilities, many of which are arguably more interesting than the former from a storytelling perspective. One possible and always interesting for the latter — and one which is probably the most common historically — is simple stupidity. The majority of military technologies have in retrospect made little or no sense, so if your world has typical leaders (or perhaps interestingly stupid leaders) that would be enough.
Answer: If you want to stop the train you don't aim for it, you just target the railway.
No matter how thick is the armor on the train, a single bomb on the track will stop not only the one train you target, but the whole traffic on the line.
Which is a very effective way of using bombs.
If you want to prevent this, your only option is to have an underground railway, which is going to cost like a whole nuclear program if you want to cover your whole country (unless your country is a city state)
Comment: @OT-64SKOT And while the armored train is stopped, waiting for the tracks to be fixed, it's a sitting duck.  The enemy will bomb the rail ahead of it so it stops, bomb the rail behind it so it can't retreat, attack the repair crews fixing the rails (they're not armored), and then easily destroy the trapped armored train at their leisure.
Comment: You could build a train that doesn't require tracks. Now, it will require several modifications such as wheels that provide sufficient sliding friction (rubber?), have a steering mechanism to direct the train, extra motor units because you'll be accelerating a lot, perhaps even separate the individually powered units entirely so that steering failures and unexpected collisions don't damage the entire train... wait.
Comment: @JohnDvorak. Maybe even add wings and a jet engine to make it go faster
Comment: @John Dvorak: Meet the LeTourneau land train. https://www.thedrive.com/news/33645/the-incredible-story-of-the-us-armys-earth-shaking-off-road-land-trains  This was developed for hauling construction material & supplies, but adding armor wouldn't be all that hard.
Comment: @TigerGuy says "*a train that doesn't require tracks is a truck*".  No, a truck's wheels run on the ground, not along a track.  What's needed is a short length of track that gets laid in front of the vehicle, picked up from behind when passed over, and then returned to the front for reuse again.  But that's already been invented; it's called a tank.
Comment: you're telling me we could've had a nationwide underground railway network instead of a nuclear program?!
Comment: @Tiger Guy: But trucks require roads :-)  Seriously, or maybe I mean linguistically, you make a "train" by having a bunch of units following the leader.  See for instance Australia's road trains.  Or in a different context, the train of a fancy bridal gown: https://www.brides.com/story/wedding-dress-train-etiquette  Which I imagine you might armor with chain mail :-)
Comment: @OT-64SKOT, does your armoured train carry extra *bridges*?
Comment: armoured trains already have a solution for blowing the tracks, typically carrying extra rails to replace any damaged ones encountered. And sending ahead scout cars or other land vehicles to check for damaged tracks.
Comment: @JohnDvorak, a train that doesn't require tracks is a truck
Comment: @AmiralPatate You know we've had large scale wars involving railroads and aircraft.  There's no need for speculation lol.
Comment: @MadPhysicist also to make it easier to avoid obstacles and perhaps even some targeted attacks.
Comment: And they'll have it fixed in 4 hours.
Comment: @Harper-ReinstateMonica I think in 4 hours you'll be able to destroy more kilometres of rail than the enemy can ever hope to repair. Maybe even if you had to learn how to make bombs in the first place.
Comment: @Ray Butterworth: But a tank is not a train (see above), though you could make a land train with treads rather than wheels.
Comment: @TigerGuy Next you'll be telling me that a truck that doesn't require roads is an airplane!
Comment: @Ray Butterworth: But the group of (usually) 4 wheels at each end of a railroad car is called a truck (in the US, "bogie" in Britain, I think).  And there are likewise trucks - including standard pickups that you'd drive on the road - that are fitted with special wheels in order to be driven on railroad tracks.  Used for maintenance &c.
Answer: Almost impossible - rails are vulnerable
Railway lines are a very efficient means of transporting goods.  However, they are a terrible option as a propulsion for equally armed primary combatants, even without nuclear weapons being involved in the mix.

Trains can only go where there are railways and railways can only be built slowly.  Therefore, it is practically impossible to achieve strategic surprise.
With limited exceptions at junctions, trains can only go forwards or backwards on railways.  This makes predicting their movement extremely easy and mining their path trivial.
Most importantly, railways are very easily damaged.  Dumb bombs can do it with good aiming, smart bombs and sabotage teams with explosives can do it trivially.  (Nukes are overkill and make it difficult in the long term to utilise the area.)  If combatant A cuts all the lines between combatant B's armoured trains and the area to be contested, combatant B cannot even participate in the battle.
If nuclear weapons are used and burst to one side of a train sitting on 1600 mm gauge rail, the train will be much more easily blown over than squat, tracked vehicles sitting on the ground.
Railway lines running through tunnels will be protected from observation and fire, but armoured trains in the tunnels cannot fight (except point blank against something in the same tunnel) and enemies can collapse the tunnel openings as an alternative to cutting the rails at the tunnel mouth.
The weaker side just needs to build their railways with a different gauge and their enemy's armoured trains cannot enter their territory without rebuilding the rail lines.

The only situation in which this would make even limited sense would be where the railway is protected by treaty / tradition and no one is willing to attack it.  However, given that the weapons that one armoured train would need to use against another would almost inevitably damage the track, the first party to start using such weapons would either win trivially against their tradition-bound opponents or be stomped flat by an alliance of all other powers.
Comment: @OT-64SKOT There isn't a scout car in existence that can carry enough rails to repair the damage from a serious airstrike with conventional weapons, let alone a 75kt ground burst.  Quite apart from the time required to repair the substrate that the rails need to sit on.
Comment: @Rad140 the OP specified that the trains are running on 1600 mm gauge rails.  However, even if they were road trains running on electric lines, the line infrastructure would be even more vulnerable than rails.
Comment: armoured trains already have a solution for blowing the tracks, typically carrying extra rails to replace any damaged ones encountered. And sending ahead scout cars or other land vehicles to check for damaged tracks.
Comment: Who said trains need rails? They only need to be long and powered by electric lines.
Comment: Then make the train underground
Comment: @KerrAvon2055 the scout car doesn't need to carry the rails, it just needs to be able to tell the main train to stop before it hits the damaged bit
Comment: @Rad140 you can't shoot anything from underground, defeating the purpose of an armoured train
Comment: Most nuclear silos are underground
Answer: Since modern military combat is all about air superiority, it is likely that this will stay the way in the future (upgrading to space superiority eventually). In such an environment, there is no way heavily armored ground targets work, because a single plane with a nuclear missile can simply take out the train (or the tracks). This means to realize your train-warfare future, you need to eliminate heavier-than-air flight.
Specifically, you could do this by making the atmosphere so toxic and polluted that jet turbines or light combustion engines of any type simply don't work in atmosphere because they get rapidly gunked up and destroyed by the particulate matter in the air. In one fell swoop, this eliminates fighter jets, helicopters, cruse missiles, and basically everything that lets a military project force across a long distance. Additionally, this atmospheric pollution is so bad that true stealth exists again, and it's possible to drive trains around in the smog without instantly detecting them from dozens of kilometers away.
In such an environment, warfare becomes more akin to the old-fashioned "Battleships" game, with the two sides wandering around in the fog of war, until one side spots the other, and blows them away with a railgun dart before they even know what's happening. Even better, the thick smog would heavily attenuate radio, meaning that long networks of wiring and much slower intelligence become the norm again.
It should be noted though that this smog would not eliminate heavier vehicles because the engines can be designed to handle the smog (like in a train or a large truck) and it also wouldn't do anything against vehicles that operate like a rocket and bring their own oxidizer with them instead of using the smoggy atmosphere.
Comment: But with negligible air threats, what are we armoring the trains against? If we're positing fusion-era technology, artillery probably has near-continental range notwithstanding atmospheric ickiness, and road-going transport can handle even the heaviest cargo.  Armored trains are a reasonable idea for early 20th-century technology where high-value targets (VIPs, precious materiel) need to be protected from capture (not just destruction or delay), threats are mostly insurgents, a massive rail infrastructure is already in place, and roads and road-going vehicles are less mature.
Comment: @CCTO hmm, well, rail still beats out trucking when it comes to transporting bulk on an established route. I could imagine that these mega cities consume enormous amounts of raw material (many kilotons of metal per day), and trains are needed to transport it in bulk. The enemy, obviously, wants to deny the resources but they also want them for themselves, hence trying to avoid blowing up tracks so they can use then later.
Comment: @Dragongeek : even if the enemy wants to use the railways afterwards, a short blown-up section is easy to repair. Even in WW2 it was common that a bridge was blown up during the day and repaired during the night. Still, blowing up rails and rail bridges is useful in slowing the enemy down, or blowing them up over and over can drastically slow down the transport of supplies. Still, real life armored trains were used to defend against guerillas armed with small arms, or from early aircraft which only had light machineguns. Armored trains were already obsolete in the later stages of WW2.
Comment: @vsz, I'd like a source for that claim, please. A bridge that has the rail damaged, and structure intact, maybe. A very small bridge, maybe. A significant bridge? No.
Answer: A much more sophisticated ability to repair tracks.
Railway trains that can repair tracks are a known thing. and more sophisticated material science, AI, and material science could improve this ability. A train might be designed that could replace small breaks in a railway without slowing down, causing small scale disruption to matter less.
A bit more expense, in making them capable of driving on their own to some degree.
Dual purpose vehicles are already well known. Your armored trains should be designed for limited off rail use, so that if someone nukes the track they can drive off, and have the individual carts avoid spinning off. Good AI drivers and small motors should help with this.
This would help with the repair. A train could drive over a broken track, if slower, and lay down a new track along the line, ensuring that other trains could move more quickly.
Armored AI tracks.
It's easy to imagine a track system that withdraws the track under a concrete bunker if they detect an enemy bomber or are ordered to by command because of an attack.
This would lower the risk of damage from bombs. They'd still be a threat, but they would need to be big bombs and hit completely on target, or be very fast and be a surprise.
More sophisticated anti air capacity for missiles.
Missiles from trains should ideally be a serious threat for any airplanes flying a few miles above. It should be a bad idea to just fly an airplane over a train to bomb it.
With all these, they could keep being a serious threat.
Answer: Make the war over what's on the trains
They're fighting not for land or ideologies, but for things they can only easily move by rail.
Perhaps they're carrying stocks of nuclear fuel or portable reactors, with all the heavy shielding that entails. Perhaps they're moving the nukes themselves, or some other kind of advanced weapon or technology. Things that weigh several tens of tons and would be better captured than destroyed. In addition, they're moving through a neutral country or they're operating under a cold-war style situation where a large scale deployment of forces may be undesirable.
They can't destroy the track or derail the train, as it's the only way to move the thing around and it would cripple their own ability to shift it. Much better to roll up next to it in their own train and hijack the engine. Cue heavily armored attack and defence wagons to assist in and defend against these hijacks.
Answer: Justifying Warfare on the Ground
It seems your setting is capable of fusion power, judging by your statement of:

Tactical pure fusion nukes with a yield of under 75kt are common

So the first problem you need to solve is why is warfare being conducted on the ground and not in the air.  Fusion power would provide the power necessary for flying battle platforms akin to the helicarriers seen in the Marvel movies.  Satelites with high powered lasers would also be entirely feasible with fusion power.
Flight and orbital platforms would give any side a considerable advantage over ground based forces, so why would everyone be using trains or any other ground based force?
A few suggestions to explain this:

The atmoshpere is covered with high altitude magnetic storms, making flight difficult and target acquisition almost impossible.

Ground-to-air attacks are significantly more effective than air-to-ground attacks, either through the weaponry used (which would be difficult to justify, as kinetic bombardment is extremely potent) or through defensive systems used (eg orbital bombardment shields that are effective against overhead attacks but not so effective against lateral attacks).

The planet is covered in a shield of somekind, protecting the surface from orbital attacks (which would solve orbital platforms but not flying attack platforms or fighter jets).

Thin atmosphere, which results in a poor ability to fly conventionally.

Any combination of these factors could give you a situation where ground based combat would be preferable to air based combat.  There could be other elements that make air combat unfeasible, but that is almost worth an entire question in itself.

Solving the Track Problem
Next problem you have is the tracks.
Trains require tracks to travel, and the tracks are stationary targets that would require a huge investment to protect.  Even if the entire surface of the planet is covered in train tracks, enough bombing would eventually render trains useless.
So I am proposing a train that lays its own tracks as it goes along.
Something like this: https://www.youtube.com/watch?v=tMXfU8blPMM

Why two rails when one will do?
Finally, I would recommend moving over to a monorail system, as this would be easier, faster and cheaper to build and maintain than a two rail system.
With the potential for blowing up tracks and disabling your opponents that way, repairing and rebuilding tracks would be critical.  If you can repair and rebuild faster than your opponents then you have a significant advantage.  Placing a single rail down is easier than placing down two rails an exact distance from each other.
Plus with monorails you have the option of making them maglev compatible, allowing you to send trains down your tracks at speeds far exceeding those of trains that make physical contact with the track.
Comment: Trains that lay their own tracks always reminds me of this classic: https://m.youtube.com/watch?v=jrmZIgVoQw4&t=90s
Comment: Yeah I was thinking Gromit's skills would come in useful...
Answer: As other answers have pointed out, against an opponent with modern weapons rails are vulnerable.  But this is your story, and you can find a way that is somewhat plausible.  One way would be:

Air power is very important

In the real world air power decides interstate conflicts, so this is easy.

Air strips are more vulnerable than rails

Planes are really stuck if they cannot land, but trains can wait until the rails are repaired.
Rails are harder to damage than airstrips.  Perhaps hardened sleepers help.  Perhaps self repairing rails.  Built in IT that informs the commanders of the state of the line in real time.
You have significant investment in rail repair, some attached to the front of the train, some in the auxiliary military vehicles.
Perhaps they can "step over" short missing sections of track.

Trains make great land based aircraft carriers

If airstrips are vulnerable, make them mobile.  Mobile airstrips = trains.  This seems quite believable, as trains are the right shape already.

I can imagine a world where land combat is more like naval combat (as desert warfare was in WW2).  Your trains are the primary assets (equivalent to naval aircraft carriers), your planes are the primary weapon, and the other vehicles & infantry are there to protect the trains and repair the rails when you need to move.  Damage to rails restricts mobility but not the ability to launch aircraft.
Answer: Frame challenge:
Sure, your train can carry spare tracks to replace small sections of rail. So what happens when the enemy targets something like this:

Or uses some explosives to take down part of this ledge:

All the best automated rail laying equipment in the world with all the resupply of rails one needs is utterly useless if you don't have anything to put them on.
Comment: Indeed. Armored trains only make sense against lightly armored enemies or against enemies who refuse to damage rails or are too stupid to do so (e.g. large animals).
Answer: There is many other answers which sugest why it is hard made trains viable and how to improve that.
I would try to be optimistic and propose this (which may not be totally scientic, but at least little beleivable):

sandstorms - lot of them and lot of really tiny sand in air

visibility is low, if the sand is also iron rich, it may disable radars (not much sure about it, sounds as good excuse)
- as sideeffect there is a lot of iron around so it may be cheap and so track and armored trains, instead of (there expensive) asphalt roads

anything moving fast is eroded by the sand, the faster moving, the more eroding

aircraft can lift only a little of armor (for its weight) and cannot fly fast a long way (so carry it in the train, if needed and release it just near the target)
aicraft jet motors and/or traditional propellers have extra hard time and need even more service and fast replacement
they say, that if you fire a gun in heavy sandstorm, the bulet is eroded to nothing before it hits ground, so explosive ammunition if better also heavy armored and used on shorter range
rockets are also only short range weapons

Tactical nukes are common.

so there is a plenty of areas, which are heavily poluted

so you near protection not only agains sand, but also radioactivity and all kinds of toxic, that can get in air
armor and filters and all the protection for longer traver is heavy and clumsy
so trains are good long distance carriers, as they are really effective on rails, can carry heavy armor and weaposns and engines and filters and big load of anything you need or want (be it in war or peace for civilian purposes)
so while other vehicles (from cars, tanks to aicrafts and missiles) are more manuerable and what all, it is way easier to move them in closed trains to the place of usage, then release then and after short range action again retrive and fix them on the way to new conflict

railroads are native way for communication, if the radio is often canceled by iron rich sand

it is also easier follow the rails and stem then from sand, if neaded, than traver throught heavy terrain with heavy armor and bad navigation and limited fuel (as all-terrains in terrain have much worse economy on fuel)

also those cities may be megacities, as this is easier protect one bid city with multilevel buildings, than many small willages
local flora is accustomed to the weather, so it is more like potatoes, with main part underground
if terrain allows, there are some (or even many) oasis, protected by hills and maybe even with some trees witch use relatively still air to get more sun and with deep root also more watter - which makes oasis more permanent and good for life
so battle trains usually stops near the border and launch all other vehicles to do their work and supports them with artilery (and as rails usually leads to cities, the stabilisation of guns is easy as they usually shoots basically straight forward, enjoying cleaner air at the oasis)

it is so much like Dune or any desert, but what if such conditions are only on part of the ground (say 10%? 20%?) - and so trains are used mainly there - and those parts are typically long and divide the land to many smaller non-desert parts - so states are formed on one or more such oasis and to conquer this place are used usually Earth-like means so it is relatively simple get whole islad, but hard to expand to another. War between states are nearly over desert, so trains are used for that. There may be much railroads between two states, as railroad takes the function of Earths roads anyway
Answer: To make trains useful targets, you need indestructible tracks.
So, let's say the planet has unusual core and mantle, with superconducting properties. Massive handwaving.
This forms magnetic field lines which allow maglev trains to travel along them, gliding above the ground, with just a tiny bit of initial lift and then ground effect to keep the trains off the ground. The crest of magnetic line is narrow and if you get away from the middle, you start getting pushed to the side, so you have to follow the exact route.
The tracks might slowly shift positions, as the configuration of the superconductor structures in the mantle shift. This could be centimeters per year in stable area, meters per day on active areas, and earthquakes could break entire routes and create new ones.
Preparing this kind of natural "track" is basically just removing obstacles, maybe making some tunnels through hills and filling up valleys a bit. Destroying the track would require making huge craters, and with heavy buldozing machinery, they might still be quickly repaired, in some cases by just filling it with water. Mining the tracks could be an option, but that's why you have the armoring and special dampeners and mine detectors in the first car. Also the trains might have limited capability to move outside the tracks. Doing that would just require massive amounts of fuel to stay off the ground. The trains might also have caterpillar-like legs, which would allow them to not only stand still, but move very slowly outside the tracks.
Anyway, the core idea idea is, the train tracks need to be non-physical so they can't be destroyed, while still being "fixed" enough so you would actually have a network of tracks. Otherwise it would just be trucks (with wheels, tracks or legs) and not really trains.
Answer: A train that could only run along tracks seems unfeasible, as others have pointed out, because tracks can be destroyed. In combination the excellent suggestions of others (e.g. trains that can repair tracks, as well as go off-track), and physical conditions to make them more worthwhile (e.g. magnetic storms, sandstorms and a thin atmosphere), might be enough to justify the use of bifunctional trains that can drive on land but are more efficient on mono/birail.
Such a train would have only the same problems as a truck or wheeled vehicle when it came to regions of track that were not easily repaired.
Although tracks might often be damaged, given a huge network of tracks (even damaged ones) armored trains that could could slide on and off might be more efficient than other ground based travel options.
Adverse weather conditions above ground also lend themselves to LDutch's suggestion of a underground railway. I would add that the underground railway could have been built for another purpose before the war broke out, so it need not be a diversion of resources away from current spending on war. To prevent problems with enemy strikes causing cave ins (which trains could run into or at the best have to wait to be cleared), I would add many side tunnels that lead to the surface that a train could divert up if a cave in was detected ahead. The train would simply go over land for a short time and then dive down into the next available tunnel entrance. A decent monitoring system for cave ins of the tunnel network with lasers would allow planning for trains to go down the most undisturbed routes, and vehicles and infantry could be dropped by armored trains above ground to locations of interest.
Answer: To see the viability of armored trains, you don't have to look farther than the user of the most armored trains and one of the sole current operators of armored trains Russia.  Russia once operated armored trains in the tens and hundreds during the peak of the civil war. In modern times, armored trains are primarily designed as mobile nuclear silos with missiles and officers to launch them. Their armored train doctrine is quite mature, and spans multiple technological eras. Germany operated quite a few as well, but the allies, the winners, used almost none and such most knowledge on armored train doctrine is obscure in the west. After all, trains are the most efficient form of ground transport.
There are two basic types of armored train. The standard "train" configuration with an armored engine pulling multiple cars with troops and various weaponry. Then there are Rail Cruisers which are self powered single cars with weapons, like a tank on rails. The configuration of a train and its cars can easily define its mission.

One common use of rail cruisers was attached to either end of a standard armored train. The rail cruisers would detach to scout ahead on the rails ahead of the main train to ensure its safety and rail conditions. Rail cruisers often carried a small detachment of troopers which could be deployed to operate deserted switching or resupply stations ahead of the main train. They could also be counted on the defuse or eliminate mines laid onto the tracks.

A common configuration was to attach an empty flatbed train car or two in front of a train to trigger mines and other explosives. Following that there was a combat car, either a rail cruiser or an unpowered armored train car which could fire over the flatbed. This combat car would usually be followed by the main engine(s) and followed by cargo cars and additional combat or rail cruisers attached at the rear end. this ensures protection and flexibility for the train by itself.

The flatbeds sometimes carried rail repair materials. Rail engineers can repair rails from single bomb or rocket impacts surprisingly quickly, usually within half to a full hour or so. Such repairs usually only involve two or four rail segments at most. Bridges are much more troublesome, but smaller ones could be repaired with a few days depending on damage. In modern times there exist automated rail and track laying machines. These can repair damages in minutes if the foundations are mostly intact.

As for mission, there are three main types: Fire support, transport, and direct assault. The first two were most common, with direct assaults being very rare.
The fire support mission is probably the most useful.

During the first world war armored trains could carry large artillery pieces and as much ammunition as they wanted quickly and reposition ready-to-fire faster than vehicles or field pieces. Primitive tanks and self propelled artillery couldn't match the power of railway guns in caliber or numbers.

With the advent of rockets and missiles, trains could carry a lot of punch that hit out to much farther distance. A train with a few nukes could wipe out a small nation. Resupply would just be riding the rails back to base, usually much faster and certainly more efficient compared to air or other forms of ground resupply.

These missile or nuke carrying armored trains were very elusive. They could hide in just about any rail tunnel anywhere and rotated all over the rail network in Russia. When a war started they would either roll out to launch, or wait in their covered tunnels until enemy impact and then roll out to fire off their revenge. Compared to stationary missile silos, armored trains were very hard to plug in as targets ahead of time to missiles using analog computers as they moved to often and were sometimes not viable targets even to nukes being underground and in any stretch of tunnel, which could have multiple tunnels linked.

Air defense systems in the modern era are quite advanced. An air interception system with missiles and radar mounted on vehicles can also be put on trains. While their deployment is heavily based on rail availability, trains are much faster to reposition from or to cover. The smoothness of rails can also allow systems to fire on the move with great accuracy. A modern era armored train with a wide band radar, anti-air missiles, and a radar directed point defense autocannon would be a powerful deterrent to air threats. Low flying attack helicopters overwhelming a position would just cause the train to retreat underground to pop up at a tunnel entrance somewhere else and perhaps covered by additional defense systems.

Even in WW2 automated anti-air artillery fire directors and radar trailers were somewhat common. Aircrews were trained to make speed and course corrections to fool automated flak directors used by germans. Put some on a train and they would be a large threat to bombers, who relied upon prior reconnaissance flights for target data instead of being able to ascertain most targets themselves. Back then bombers flew out to where the target was supposed to be and dropped bombs. This is why so many bombs missed their targets during that era, there were lots of navigation and recognition failures by crews. If the target moved from covered train tunnel to obscure rail sidings, trying to bomb them with overwhelming high altitude airpower would be way too expensive.

Transport is what trains are good at.
Trains are best at hauling large amounts of cargo. Armored ones would be viable if your supply lines were under attack for some reason. While probably not a good matchup versus tanks and self propelled guns, they would be fine against technicals and even air targets depending on era.

Transporting infantry and vehicles through nominally controlled terrain is what armored trains are best for. Partisan or rebel attacks in recently captured territory would play hell on unarmored transport trucks. An armored train requires explosives to interrupt, not just small arms. This is a big step up for rebels, who usually just have some guns and maybe a few AT launchers to stay mobile.

Direct assaults are a bad idea.
Not to say it won't work in a pinch, but train tracks are pretty terrible attack paths. Even more predictable than roads, except trains can't go offroad like a tank when forced.
What can make armored trains MORE viable is the a large set of mountains and tunnels. Mountains or other terrain unsuitable for ground vehicles will make trains vital no matter the era. No matter how advanced the tank, if it can't get to an area serviced by a train tunnel, it is useless. Tunnels provide cover from air observation and attacks.

By moving quickly between tunnels or "bunkers" it would be incredibly difficult for enemy artillery to counter battery and take out the guns. Trains are fast, and surfacing between two or more open areas to fire before hiding again would be incredibly frustrating. Concealed firing ports that can be opened in the top of special tunnels would make it even more infuriating. There are many examples of artillery emplaced deep within mountains, and there were notoriously hard to destroy even with air support.

Placing cover over tracks when not in use, such as camo netting or fake trees can help conceal the exposed rail sections when not in use. A small rail cruiser sent ahead to clear rails could use a sweep or plow to clean the rails of camo ahead of the main train, then stay behind to lay it all out again once it passes.


Make New Copy of Power Automate Flow

Question: I have a rather complicated Flow that I want to use as a template to deploy to multiple lists/libraries. I did a "Save As" and made a copy, then changed the trigger to point to a different library (the library is a clone of the one I developed the Flow for). When I run the Flow Checker, it gives no errors, but saving or editing a new document in the target library does not trigger the flow to run. Is there any way to get the Flow to trigger short of building a new copy from scratch?
Comment: Stupid question, but did you turn the flow on after copying? By default, it would be turned off.
Comment: Yes, I made sure the flow was turned on before trying to trigger it.
Answer: Please Check if you have specified any trigger conditions. For example, flow should only fire on a specific content type.
Comment: I would double check the Library settings (site and library) in the trigger condition, preferably deleting it and adding back in.
Answer: Here is a little trick which may help you, as you mentioned saving or editing does not trigger.
After you saving/editing, and the flow is not triggered, then edit the flow, simply do nothing and save it directly. Check if the flow has been triggered. In my end it works for a copied flow which does not trigger by item/file change.
It simply happens with some flows using automatic trigger. I am not an expert on flow so not sure what could be the reason, at least it will let you know if the flow is properly set.

Make New Copy of Power Automate Flow


Restrict one computer to only talk to one FTP

Question: I have a rip station for a few digital printers that I want to limit access, internet, usage, and anything that could cause an issue and only allow that rip station to get access/files from my FTP.  My rip station is Windows 7 64 and my FTP is Ubuntu 12.04.  What is the best way to do this?
Answer: If your FTP station has a static IP address or is on the same local network, you could simply set your firewall rules on the rip station to only allow outgoing and incoming port 21 (assuming you are using a non encrypted FTP connection) to the IP address of the FTP server.
This will probably be insufficient if you are trying to connect through the internet to a computer with a dynamic IP address, as used by most broadband connections.
If it is on the local network it may help to assign the FTP station an IP address manually rather than by DHCP, to eliminate the chance of it changing when more computers are added to the network.
Comment: everything is in a LAN. My apologies I am in no way knowledgeable in networking other than being able to configure a router and running/splicing Cat5e
Comment: that should be fine, your router probably has a local IP address such as 192.168.1.1, and then assigns each computer on the LAN 192.168.1.x. You just need to assign a particular address statically for the FTP server in the router setup, and then set the firewall rules to match on the rip station.
Comment: would it be good to learn how to assign IPs and go that route?  I dont mind learning but I dont know where to go to get quality guidance.
Comment: Yes, the hardest part is probably finding the correct page of settings in the router setup. I would search online for the make and model of your router to find the manual if you have doubts. You will probably need to tell the FTP server what its static address is once you make the change.


Direction of frictional forces on front and back wheels

Question: Why are the directions of frictional forces on the front and rear wheels of a moving car in the opposite direction, when the only the front wheels are accelerated (or only the back wheels)?
When the car accelerates, the direction of the static friction exerted by the front wheels on the surface is directed backward. But what about the wheels on the back of the car?
Comment: Does this answer your question? [Newton's third law (action and reaction) and work done with a wheel](https://physics.stackexchange.com/questions/567919/newtons-third-law-action-and-reaction-and-work-done-with-a-wheel)
Comment: @Binod you suggested an  awesome question +1 but  the answers don't suffice.
Comment: Similar: https://physics.stackexchange.com/questions/146039/the-direction-of-frictional-force-in-smooth-rolling-motion and
Comment: @Protein why not ? Bhavay's answer explains why friction force is opposite in direction?
Answer: The simplest way to figure out what friction is doing is to see what happens when you turn friction off.
Assume a car on frictionless road.With no friction at all and the car stopped, pushing down on the accelerator makes the rear  wheels spin clockwise. They spin on the frictionless surface, the front  wheels do nothing, and the car goes nowhere.
Friction on the rear  wheels opposes the spinning, so it must point in the direction the car wants to go. For the rear  wheels to roll without slipping, the friction must be static.
If we turn on friction to the rear wheels only, the car accelerates forward with the front  wheels dragging along the road without spinning. Friction opposes this motion, so it must point opposite to the way the car is going. Again, it must be static friction as tyres roll on roads.
The friction is in opposite directions on front and rear tyres this means torque output from the rear wheels must be greater than certain minimum value for car to move .
Comment: Why aren't front wheels rolling without slipping?
Comment: If we see the net forces on the car, we have forward pointed friction from the rear and backward pointed friction from the front. These are the only forces acting. Then how is the car translating forward
Comment: Aye , they are not equal in magnititudes
Answer: Assuming it is a two wheel drive car that is under power with no slipping, one pair of wheels is turned by the drive train to propel the car. The other pair of wheels is turned by the road surface, creating drag. So you have pushing and pulling, static friction in opposite directions.
Answer: Why are the direction of frictional forces on the front and rear wheels of a moving car in the opposite direction to what?
No matter.
Let the direction of the acceleration of the car be $\hat a$ and this could be in the same direction as the velocity of the car (magnitude of velocity increasing) or in the opposite direction to the velocity of the car (magnitude of velocity decreasing).
The frictional force on the bottom of the tyres touching the ground of the driving or braking wheels will be in the direction of the acceleration of the car, ie in the direction $\hat a$, and all the other tyres will have frictional forces opposite to the direction of the acceleration of the car, ie in the direction $-\hat a$.
A variation is when both the accelerator pedal and the brake pedal are being pressed at the same time, or variations of this, when the acceleration is zero which is done when a driver wants to produce smoking tyres, which is sometimes called burnout.
Most easily done on a motorbike because the front and back breaks are controlled independently and the centre of mass of the motorbike and rider can be changed relatively easily.
If the acceleration of the car is then zero with the frictional forces trying to make the car accelerate equal in magnitude but opposite in direction to the frictional forces trying to prevent the car from accelerating.
Answer: To understand why the direction of friction is opposite on front and rear wheels, you must take into account the fact that the engine of the car provides torque(turning effect) only to the rear wheels and not to the front wheels. Now,
1->  Let's press the accelerator of the car so that the engine applies a torque on the rear wheels. Note- Torque can only rotate a body and can never produce translational motion. So if the ground is frictionless(in this case friction is the only force that can act horizontally, since friction is absent, so there is no force in horizontal direction and therefore no motion in horizontal direction) , then the rear wheels will rotate about their axel and will not move forward. Note- the wheels will slip in this case.
2->  At the same time, take a look to the front wheels. There is no torque on them(since, the engine apply torque only to rear wheels) and also no net horizontal force since friction is absent(again because, friction is the only force that can act horizontally). So the front wheels are at a standstill, no rotation, no translation.
3->  Now, Let's again press the accelerator but now there is some friction. Same thing happens, the engine apply a torque on the rear wheels, the wheels will rotate(clockwise) and try to slip on the ground. Since, Friction always opposes relative slipping, so it will act such that it prevents clockwise rotation and so it is directed towards right to give a anticlockwise torque. Note that friction acts in forward direction in this case and thus accelerates the car forward.
4-> At the same time, if you look the front wheel, what's happening. The axle of the wheels is moving along with the car and so it pushes the front wheel at its centre, this force by the axle acts at the centre of the wheel so so torque is provided by it,but it give the wheel a forward motion.(Note- there is no torque till now so the wheel are moving forward "without" rotating) Due to this the wheels try to slip. Again friction will act such that it prevents relative slipping. No slipping is only possible if the wheels rotate clockwise along with moving forward. So to prevent slipping friction acts backwards to give a clockwise torque.
Hope it helped!
See these posts for a clearer knowledge:
Why do rotating bodies have friction between when the surface is accelerating?
What is the direction of the frictional force acting on a rolling wheel?


Ubuntu is too big for my screen

Question: I have just installed Ubuntu 13.4 on my desktop -- I am using a visio 32" tv as my monitor and have no problem with the screen size when windows is installed -- but with Ubuntu I can't see the icons on the top or bottom and the icons on the left side are only partially showing its like the Ubuntu screen is to big for my monitor -- does anybody have any advice???
Comment: How is your TV connected to your PC? That is, what cable are you using: DisplayPort, HDMI, DVI, or VGA? Also, if you try to connect it with another cable, does the problem persist?
Comment: also, check http://askubuntu.com/questions/204125/ubuntu-desktop-slightly-too-big-on-hdmi-tv
Answer: There's nothing wrong with your Ubuntu, it's a TV issue called overscan. You can fix overscan by entering TV settings, as described here: How do I fix overscan on my HDMI HDTV?.
Settings and names may vary from brand to brand and model to model.
Answer: Check your screen resolution and make sure it matches your monitors native resolution.
For a 32" TV the native resolution is most likely 1280x720.
You can access the resolution settings by doing the following:
Click on the Gear at the top right of your screen (if you can)
Select 'System Settings' then 'Displays' in the 'Hardware' section.

From there you can pull down the resolution and select the correct one to match your monitor.
If you cannot get to the top right of your screen you can get to it alternatively by:
Press the Windows key on your keyboard
Type 'Displays' without the quotes
Press the down arrow on your keyboard twice
Press 'Enter'

This should bring up the displays settings.
Comment: Hi Malte Skoruppa -- thanks for the input -- I have HDMI cables connecting the monitor to the PC -- but I did find out that my graphic card from asus does not have drivers that are copatible with ubuntu -- could this be the problem -- comes up on my "computer" data "graphic card unknown" -- looked it up something about synaptic as a download but really didn't understand??  Please advise
Answer: So this is a real zombie thread but its the first answer that came up in Google, what I also found is that if the refresh rate is incorrect but the resolution is, then the desktop appears to be larger than the screen.  I changed the refresh rate from 120 to 60 (120.02 to 59.96) and the screen was set to the correct size and resolution

Ubuntu is too big for my screen


relation between mass of black holes and tempereture?

Question: As we know, by increasing the mass or energy of a black hole, its event horizon radius will increase, but why its temperature should increase too?
Really I want the relation between mass and temperature of black hole!
Comment: $T=\frac{1}{8 \pi M}$. Check [this Wiki article on Hawking radiation](http://en.wikipedia.org/wiki/Hawking_radiation).
Comment: Really I want the physical meaning of that. Is it related to the curvature of space which occurs because of this mass?
Comment: This temperature is the temperature of BH radiation in its usual sense. Have you read the article?
Answer: Higher temperature means it's hotter for a lower mass, i.e., it emits more and higher freq radiation. Micro black holes which evaporate away quickly do so at the end in a burst as they are the hottest. You have to get the details from the paper.
The temperature is the one that would define that of a black body radiator, with the same probability density function for the radiation radiated. For black holes Hawking found that it is inversely proportional to the mass. He also determined that it is proportional to the surface gravity - defined as the acceleration that you'd have to give a body at the horizon (or right outside it) to keep it there without going in. Small black holes have a very high curvature of spacetime near them, thus a very high surface gravity and temperature, and emit at higher frequencies as they get smaller, till they dissappear in a burst.
As they get smaller they will send out more gamma ray radiation.
See about black holes temperature and thermodynamics at https://en.m.wikipedia.org/wiki/Black_hole_thermodynamics
Comment: Thak you, but as I know, curvature of spacetime depends on the mass of  objects, so for small BHs, curvature should be smaller that a large BHs, since their mass is smaller. so surface gravity should be smaller, I mean a large black hole should have large temperature, so when a BH evaporates, its temperature should decrease!
Comment: Yes, a bit counterintuitive but still right. The thing is you need to also account for distance and closer in gravity is larger. Remember at r=0 it'd be infinite and and small masses have small schwarzchild radius. So temperature definitely goes higher.


Equality field extensions

Question: How would you prove this:
If E is an extension of K and a and b are elements of E\K, a^m belongs to K, b^n belongs to K, gcd (m, n) =1, then K(ab) =K(a,b)
??
I don't know which strategy to use to prove it.
Answer: We can assume that $m$ and $n$ are minimal such that $a^m,b^n \in K$ (if not replace $m$ and $n$ by the minimal such. They will still be coprime). Since $m$ and $n$ are coprime, there exists a $k,l \in \mathbb{N}$ such that $mk = 1 + ln$. Then $$(ab)^{mk} = (b^n)^l(a^m)^kb \in K(ab)$$
so since $a^m,b^n \in K$, this shows that $b \in K(ab)$. Similarly we can show that $a \in K(ab)$ (just consider $(ab)^{nl}$) and hence $K(a,b) \subseteq K(ab)$. Since $K(ab) \subseteq K(a,b)$, they must be equal.
You could also use degrees to prove this : if you can show that both $[K(ab):K]=mn=[K(a,b):K]$, then since $K(ab) \subseteq K(a,b)$, they must be equal.
Comment: Ok, thank you very much for your answer! My previous attempts were to show what you stated below, but it is harder

Equality field extensions


Why seeds won't sprout given excess water?

Question: What would cause a seed to not sprout despite showing signs of germination given excess water? Oxygen, temperature, and light were sufficient for germination and sprouting in seeds of a slightly lesser amount of water.
Comment: What kind of seeds are we talking about here - some have special requirements
Comment: I think the answer to this question is like this.   Some seeds can sprout with this much water - even germinating underwater. The seed could sprout, but why doesn't it?  Some living things actually have adapted highly specialized conditions for growth - why should this be?  I'll try to come back later and put an answer up if this is right, and nobody else does.
Answer: You've stated in your question that oxygen was sufficient for germination, but if there's too much water this probably isn't the case. It's likely given excess water seeds will drown- that is they have not got access to sufficient oxygen to continue germination.


Estimate on Mobius function

Question: Let $\mu(n)$ be the Mobius function, how to estimate
$$\sum_{1\le i<j\le x}\mu(i)\mu(j)  $$
as $x$ goes to $\infty$? Are there some references on this?
Answer: If $S$ is your sum then
$$ \left\lvert \sum_{1\leq n\leq x}\mu(n)\right\rvert^2 = 2S+ \sum_{1\leq n\leq x}\mu(n)^2.$$
The second sum on the right is $(\frac{6}{\pi^2}+o(1))x$, and hence estimating $S$ is equivalent to estimating $\lvert \sum_{n\leq x}\mu(n)\rvert$, a classical problem of analytic number theory.
In particular, assuming the Riemann Hypothesis, the left-hand side is $O(x^{1+o(1)}$), and hence (assuming RH)
$$ S \ll x^{1+o(1)}.$$
Unconditionally we can show that $S=o(x^2)$, but cannot show $S\ll x^{2-\epsilon}$ for any $\epsilon>0$.
Comment: Yes, sorry, I was being imprecise - I meant that in terms of improving the exponent nothing better is known. The standard proof of the prime number theorem can be adapted to show that $S\ll x^2 \exp(-O(\sqrt{\log x}))$, for example, and I believe better quantitative results are known.
Comment: "The best we can conclude unconditionally is $S = o(x^2)$". What do you mean by this? I'm no analytic number theorist, but I'd be surprised if $|\sum_{n \le x} \mu(n)| \ll \frac{x}{\log\log x}$ wasn't known unconditionally.

Estimate on Mobius function


In the US are you allowed to refuse a mobile breathalyzer test?

Question: If you are stopped by the police in the US are you allowed to refuse any test to prove your sobriety? I know you have to tell the police your name, provide them with identification, insurance, and driver's license but can you refuse to give them anything else? Or is this just handing them probable cause on a silver platter?
Comment: State regulated
Comment: @GeorgeWhite Agree that there are material differences from state to state. There is not a federal right to refuse without consequences.
Answer: In the circumstance you describe, you can refuse a breathalyzer test ("opt to not take it"), and doing so would not constitute probable cause for an arrest (the results of the test can be probable cause). That is when you are on the roadside. This is Washington's "implied consent" law. One of the first things that the law says is that the test is "subject to the provisions of RCW 46.61.506", which includes the requirement that the test be performed

according to methods approved by the state toxicologist and by an
individual possessing a valid permit issued by the state toxicologist
for this purpose. The state toxicologist is directed to approve
satisfactory techniques or methods, to supervise the examination of
individuals to ascertain their qualifications and competence to
conduct such analyses, and to issue permits which shall be subject to
termination or revocation at the discretion of the state toxicologist.

There are other requirements regarding 15 minute prior observation. The legally required test is done in the police station by a specially trained technician, on an approved machine (the portable machine is not approved). The implied consent law also says that this test is "required"

if arrested for any offense where, at the time of the arrest, the
arresting officer has reasonable grounds to believe the person had
been driving or was in actual physical control of a motor vehicle
while under the influence of intoxicating liquor

You are not required to take the Portable Breath Test, which is optional (when you have been stopped) – it's the post-arrest "evidentiary" test that is obligatory, using the approved procedure. Note that failing the optional test gives probable cause for an arrest, however there can be other grounds such as failing the line-walking test. If the officer just tells you that the roadside test is mandatory, that is a defense which can be used at trial ('cuz the optional test is not mandatory). Whether or not the portable test is admissible in court depends on the state: in Kentucky it is statutorily not admissible, likewise in Washington per court ruling.
The other tests (often known as Standard Field Sobriety Test) are also optional, so ultimately it reduces to whether they already have probable cause, that is, if "the totality of the facts and circumstances known to the officers at the time of arrest would warrant a reasonably cautious person to believe a crime has been committed". It is just not clear to me what actual circumstances distinguish mere reasonable suspicion (driving slow) from probable cause, but watery eyes, slurred speech and alcohol smell will make probable cause. I don't know if driving slow and having watery eyes is probable cause – I would think not. Dunno about "smell of alcohol plus driving slow".
In Birchfield v. North Dakota, 579 US ___ we find an example of a traffic stop with ample probable cause for an arrest (smell of alcohol, bloodshot watery eyes, driving into a ditch, failing the alphabet test and massively failing the voluntary breath test). The analogous North Dakota law is largely similar to Washington law, mandating only the "approved" more technical version of the test and not the roadside test. Defendant, in that case, refused the mandatory test. A crucial difference compared to Washington law is that while suspension of driving privileges follows from refusal under Washington law, refusal in North Dakota is itself a misdemeanor per N.D.C.C. § 39-08-01. The issue for SCOTUS is whether a law criminalizing refusal to submit to a breath test (but not a blood test) violates the 4th amendment: it does not.
Comment: Is the straight line test mandatory? Is the following question. I can ask it in a separate question if you think it better to do so.
Comment: OK, I did not realise there is more than one type of breathalizer test. When I said breathalyser I meant the mobile one. I will edit m question to be more specific
Answer: It depends. According to Birchfield v. North Dakota, 136 S. Ct. 2160 - Supreme Court 2016 (emphasis mine):

Because the impact of breath tests on privacy is slight, and the need for BAC testing is great, the Fourth Amendment permits warrantless breath tests incident to arrests for drunk driving. Blood tests, however, are significantly more intrusive, and their reasonableness must be judged in light of the availability of the less invasive alternative of a breath test. Respondents have offered no satisfactory justification for demanding the more intrusive alternative without a warrant. In instances where blood tests might be preferable — e.g., where substances other than alcohol impair the driver's ability to operate a car safely, or where the subject is unconscious — nothing prevents the police from seeking a warrant or from relying on the exigent circumstances exception if it applies. Because breath tests are significantly less intrusive than blood tests and in most cases amply serve law enforcement interests, a breath test, but not a blood test, may be administered as a search incident to a lawful arrest for drunk driving. No warrant is needed in this situation.

So it seems like it depends on:

Whether the police have a warrant.
Whether the police have enough evidence to make an arrest, and can thus perform a breath test incident to the arrest.
Whether the police have some other valid exception to the warrant rule.
Whether the police are demanding a blood test or a breath test.
What you consider "allowed" to include. In some states, you can technically refuse in some circumstances, but your refusal can come with penalties, like your license gets revoked, and the refusal may be used against you in a criminal prosecution.
The law in your state.


Minecraft Monster Spawner Glitch?

Question: Recently in my new Minecraft world I've been caving and finding some peculiar monster spawners. The cage and flame particles are all there, but there is no monster inside of the cage, and no mobs spawn out of it. If anybody has a fix for this, please answer. Also, I would rather not restart on a new world, as I've already put numerous hours into this one. Also, the glitched spawners were not only in this one mineshaft. There were spawners like this in other caves too. I am currently playing on normal difficulty, and other mobs spawn normally

Answer: From my research in Mojang's Bug Database, I have determined that your empty spawners are bugs. Some links which include reports about the bugs are listed.
Each of these bugs occured in Minecraft Pocket Edition.
Bug MCPE-9783: Empty mob spawners emit fire particles
Bug MCPE-8699: Can't see mob or particles in spawner
Bug MCPE-8902: Monster spawner / no mini mob spinning around in the monster spawner
These links elaborate and prove that this is a bug.
Please tell me if you are not using Minecraft Pocket Edition, and I will do more research.
Comment: I think the picture shows Java Edition since it has a screenshot prompt.
Answer: Are you playing in Peaceful? Because in peaceful this will happen. If you are playing in Easy+, contact Mojang, and file a bug-report.
Comment: He's in Normal difficulty, not Peaceful.
Comment: In Peaceful, the entity will simply not spawn from from the spawner.

Minecraft Monster Spawner Glitch?


Auto-post to multiple sites like Posterous?

Question: I'd like to be able to autopost from my wordpress site (private wordpress.org, not on wordpress.com) to multiple sites with one plugin/hack from within wordpress. I'd like my posts to be able to be auto-posted (linked to) on facebook, identi.ca, twitter, posterous, etc. without multiple plugins. I've looked everywhere for a good plugin and they all seem to be site specific (for example just a twitter plugin). I need a one-stop shop like posterous, but since i have my own site i don't want the links going to posterous when they could be coming back to my official site. is this at all possible as of yet? if not, someone should step up and code it. thanks!
Comment: I doubt you will find one plugin that covers all services you want. People usually develop a plugin for a need they have themselves, and this might not include everything you need. However, there could be some plugins that use a similar interface, so it doesn't look like they come from different places. And the *someone* that should step up could also be you of course!
Comment: haha...maybe i will. i got some learnin' to be done. thanks for the push. i'll do some research.
Answer: You can use the ping.fm service with the plugin Shorten2Ping.
Comment: yeah. still the same problem. it would all link back to ping.fm and not my site.
Answer: You can try dlvr.it
you just need the rss of your blog and it will be published to facebook, linkedin, googlebuz, Twitter and more....
I've been using it for months
Comment: oh wow. that looks nice. do they take credit like as in saying "via dlvr.it" or anything like that? I was considering @Jan Fabry's advice and just making one for wordpress, but if dlvr.it is transparent, i'm all for it.
Comment: It shows on facebook, it is very small and it doesn't bother, at least me.. :), in twitter it doesn't show any credit. don't know about other social networks.
I think that most of them if not all have take the credit :)


Econometrics: What will happen if I have a biased estimator (either positively or negatively biased) when constructing the confidence interval

Question: Suppose that the OLS estimator for $\beta_j$ is in fact biased. How would this affect the use of confidence intervals as hypothesis testing tools (assuming a two-tailed test)? That is, what sort of erroneous conclusions would be made?
Answer: In either direction of the bias, you need to expect your confidence interval not to have the desired coverage properties.
Recall that, in general, a well-calibrated $1-\alpha$-level CI has the property that the intervals calcaluted from the recipe will cover the true value in $(1-\alpha)\cdot100$% of the cases it is computed. That result however hinges on the condition that the distribution of the estimator from which the CI is constructed is "correct." That is generally not the case when the estimator is biased.
In that case, the point estimates, and hence the CIs constructed around the point estimates, will tend to cluster around the expected value of the estimator, which, due to its bias, is not the true value.
Through duality between tests and confidence intervals, you then need to expect your test to reject too frequently: the confidence interval collects the hypotheses you would not have rejected---if the true value is in that set too rarely, you reject too often.
Here is a little simulation illustrating the issue for the case of the LS estimator of the coefficient $\phi$ of an AR(1) model $Y_t=\phi Y_{t-1}+u_t$. It is well-known (see e.g. here) that this estimator is biased (downward), in particular for small $T$ and large $\phi$ when the regression also includes a constant.
library(dynlm)

ar.coeff <- 0.9 # the true AR(1)-coefficient used to generate data
reps <- 1000
coverage <- rep(NA,reps)
CI <- matrix(NA,reps,2)
for (i in 1:reps){
  y <- arima.sim(list(ar=ar.coeff), n=30) # simulate data from AR(1)-process
  CI[i,] <- confint(dynlm(y~L(y)))[2,]    # fit AR(1)-model and extract confidence interval
  coverage[i] <- ar.coeff > CI[i,1] & ar.coeff < CI[i,2] # check if CI covers true value
}

The coverage hovers around values like
> mean(coverage)
[1] 0.873

instead of the 95% one might hope for.
Here is a plot of the confidence intervals for 60 draws from the underlying AR process, showing that these sometimes lie "too far to the left."

R code:
plot(ar.coeff,0, cex=2, col="red", pch=19, xlim=c(0,1.2), ylab="confidence intervals", yaxt='n', xlab="")
segs <- 60
segments(CI[1:segs,1],seq(-1,1,length.out = segs),CI[1:segs,2],seq(-1,1,length.out = segs), col="grey")
abline(v=ar.coeff, lty=2)

Comment: i was asking more like the Bj +- c*se(Bj) that kind of confidence interval
Comment: `confint` does precisely that. You are right in that my example only refers to bias in the coefficient estimates and not in the s.e.s, but as the example shows, that is sufficient to exhibit undercoverage of the CIs.
Answer: So I was thinking since CI= Bj +- c*se(Bj)
When there is a positive bias, the se would be higher than normal (without bias). So not only will Bj shift to the right, due to the positive bias, but the width of the CI will also increase. Thus, this will lead us to include more Bjs, which might be from the lower significance level, and in turn make us fail to reject the null hypothesis of Bj.
And when there is a positive bias, the se would be higher than normal (without bias) as will. Though Bj will shift to the left, due to the negative bias, the width of the CI will still increase, because the increased value of se. Similar logic, this will lead us to include more Bjs, which might be from the lower significance level, and in turn make us fail to reject the null hypothesis of Bj.
But I am not sure whether this is correct.


Read text file from google drive

Question: I have simple text file in my google drive and it is publicly shared. When I read it
   InputStream is = new URL(url).openStream();

The following is read. I assume my file is google doc format. Is there anyway I can read it as a text or convert it to text?
   <!DOCTYPE html><meta name="google" content="notranslate"><meta http-equiv="X-UA-
   Compatible" content="IE=edge;"><meta name="viewport" content="width=device-width, initial-
   scale=1.0, maximum-scale=1.0, minimum-scale=1.0, user-scalable=0"/>

Read text file from google drive


Why "meinem" is used in "Er glaubt meinem Kind"?

Question: I saw this sentence in Duolingo. Is this supposed to be dative? If so, why?
Answer: From Wiktionary:

[3] »jemandem glauben« (Dativ): sich auf jemanden vertrauensvoll verlassen

The verb glauben can take both an accusative and dative object. The something you believe is accusative, the person who you believe is dative.

Ich glaube dir[dative] das[accusative] nicht.

The dative form of mein is meinem. Again, Wiktionary is quite a good help.
Thus, it's correct to say:

Er glaubt meinem Kind.
Answer: This is a possessive pronoun, dative, "male" grammar-gender.
See: http://www.mein-deutschbuch.de/lernen.php?menu_id=77
Comment: OP already used "possessive pronoun" as tag, "suggested" dative himself. The only information you added is wrong, because "Kind" is neuter, not masculine. And you didn't say **why**; which is the actual question.


"As fast as I want to" vs. "As fast as I'd want to/ like"

Question: I've recently corrected a text that one of my students wrote. One of his sentences was, "Sometimes it's annoying that I don't learn new things as fast as I want..."
I replaced as fast as I want with as fast as I'd want to/ as fast as I'd like to. However, he asked me for an explanation and I am stuck.
Am I wrong? Are both constructions correct? If not, does anyone have an explanation as to why the first is incorrect?
Answer: Both your student's phrase and yours are valid (which means you were wrong to correct his).  There are numerous other variants—you could include "would" (the 'd) or not, you could include "to" or not, and you could use "like" or "want" pretty much interchangeably. All of them work out grammatically and with about the same meaning.
I don't know how to meaningfully explain why these are all correct—unlike something that's incorrect, where I could point to a flaw, here I'm just left looking at both and thinking "there's nothing wrong with any of these."
Comment: See my own answer for a linguistic distinction between the two.
Answer: "As fast as I want (to)" means "As far as I want to ''at this moment''".
"As fast as I'd want to" (or "I'd like to") tends to bear the added implication that this is "as fast as I would ''ever'' want to."
In more sensitive contexts, the second option may also bear a note of moral judgment: "The speed limit is as fast as I'd want to drive" suggests that one may have moral scruples against breaking the law.
However, if one is a habitual speeder, but today the weather conditions are particularly foul, your passenger may wonder at your reluctance to go faster.
"The speed limit is as fast as I want to drive, given the fact there are sheets of water on the road and my wipers are going as fast as they can."


How can I implement a flag module with caches but won't affect cache the flagging nodes?

Question: According to a post here, I have installed flag module to implement product comparison. However I found that the CPU usage is very high 80-90%, then I tried to install boost and Views content cache to improve the performance. The result is good, CPU usage drop to around 10%, but when I flag(add) or unflag(remove) the node from the views, it not work.
Answer: Views Content Cache has a patch for flags support, although I don't know how well it will work with Boost.
Try using the Views Flag Refresh module, it's supposed to tell the view when to refresh, don't know if it will play nice with the other modules though.


How do you decide between a topic-based and an audience-based main navigation?

Question: Any hints from past experience?
Any best practices?
Any research on the subject?
Comment: You might want to elaborate a bit on your problem. Like it stands, you question is rather broad and thus hard to answer.
Answer: A topic based navigation can be done, but is not preferred, if you are unaware of the audience - such as a public website where users don't have to login to see content. Audience-based navigation on public web sites would have to be generic in the form of "I'm a parent" or "I'm unemployed" or even "I'm retired", but still you'd have to put every audience type in there.
Especially this is valid in government sites:

Why It's Important
Focus groups and other feedback indicate that citizens do not know—nor do they want to know—how the government is organized to get the information and services they want. Creating navigation according to organizational structure is not the best way to design a website for citizens.

However, where you know the user, as in a public web site where users are signed in or even better in an intranet, audience based navigation is preferred. You could base navigation on which cooperation sites the user participates in showing only "my projects" as one example. Another would be to display content, such as news, based on audience such as you organisational belonging.
Just keep in mind that audience based navigation is much harder to implement and maintain, but for the user you could make a big difference if you only display navigation elements valuable to "me" as a user based on my properties.

Because navigation by organizational structure has traditionally been less effective for web users, you should use this as an alternative— not primary—form of navigation.

Reference: Organize Content Based on Audience Needs
Comment: Thanks for the reference. I now clearly understand the severe drawbacks of organizational structure. Still there seems to be no perfect choice (between topic- and audience-based navigation) for a public (anonymously accessed website).
Comment: @BenoîtPointet That's true - it's almost always a choics between pros and cons!
Answer: I redesigned a community college site's IA recently with task-based navigation for a student audience - it has been quite helpful since students were the greatest audience of the site by far. The other audience channels were left as they are (Business and Community, Employees, etc.) but with a huge percentage of visitors interested in specific tasks on the website, setting up the navigation so students could complete specific high-traffic tasks was very beneficial to that audience. I have written up a case study on my personal site so you may find some answers there.
Comment: Hi C Lin.  Welcome to the UX SE!  Can you summarize the content of the link here to avoid link-rot?  It's interesting that you studied this--can you tell us what specifically you found?


Trick to run different pre/post build events when building with MSBuild or from Visual Studio IDE

Question: Don't ask me why, but does anyone know any trick to put in the pre/post build event command that will run different commands if the project is being built from command line with MSBuild or from inside the Visual Studio IDE?
Comment: Also see https://stackoverflow.com/questions/2731502/in-msbuild-is-it-possible-to-determine-if-im-running-in-visual-studio
Comment: @Darien Pardinas, any update for this question? Could you get any useful info from the answer and the comment?
Answer: The easiest solution would be to define build targets that are conditioned on the $(BuildingInVisualStudio) property that visual studio sets to true when buildinging.
<Target Name="SpecialPreBuild" BeforeTargets="BeforeBuild" Condition="'$(BuildingInVisualStudio)' != 'true'">
  <Exec Command="some-command.exe --magic" />
  <Copy SourceFiles="foo.txt" DestinationFolder="bin\$(Configuration)\bar" />
</Target>

<Target Name="SpecialPostBuild" AfterTargets="AfterBuild" Condition="'$(BuildingInVisualStudio)' != 'true'">
  <Exec Command="some-other-command.exe --magic" />
</Target>

If you want to skip these targets in other IDEs / editors as well, you could introduce a custom property as well and change the Condition attributes above to
Condition="'$(PerformSpecialLogic)' == 'true'"

That way no "default" builds will execute these targets and you could build with the following arguments in your build script / CI definition:
msbuild /p:PerformSpecialLogic=true

Comment: Couldn't you just use the existing `$(BuildingInVisualStudio)` property?
Comment: @MartinUllrich This link https://learn.microsoft.com/en-us/visualstudio/msbuild/visual-studio-integration-msbuild?view=vs-2017 mentions `$(BuildingInsideVisualStudio)`, while your answer mentions `$(BuildingInVisualStudio)`. Are those two the same, and if yes, why the latter is not documented? Thanks.
Comment: I've seen that before but couldn't find good (/recent) documentation on that to make sure it is "public". @stijn Do you know any? Don't want to add it without source..
Comment: I'm also not sure if R#'s build calls / Rider / VS/Mac / OmniSharp (VSCode) also set this property. At least I couldn't find it in the OmniSharp source.
Comment: See https://msdn.microsoft.com/en-us/library/ms171468(en-us).aspx. No idea if other environments set it, and while it's not bad you want to take them into account, the OP doesn't ask about them so it might not matter for him.
Comment: @stijn do you want to add another answer? i'd delete this one afterwards.
Comment: No need for that. Your answer with the custom property is also viable, and I'd just be duplicating code like yours and changing a single property name. Just edit your answer, mentioning that when using VS one can swap PerformSpecialLogic with the built-in BuildingInVisualStudio property. And add the link as well. Then the answer is complete, seems easier for future visitors.


How often should I update statistics

Question: Is running a nightly job that updates the statistics way too much? Can that affect the system's performance?
Answer: It depends.  How long does a nightly update take?  Is the update happening at a slow query period/  is auto create statistics still enabled?
Each database has two options related to statistics: auto create statistics and auto update statistics. Typically, both should be left enabled for databases. Statistics are automatically updated when certain thresholds within SQL Server are met (e.g a percentage of row changes that the stat was based on). Once the threshold is reached, SQL Server will automatically update the statistic(s) defined in the table.
If your maintenance window allows it you should certainly update statistics nightly since the auto update system is certainly not perfect.
Comment: Thank you Jim B. I just ran the job on a smaller server without any load and it took 11 minutes to run. It should be much faster on the actual DB server. The job runs at 4 AM when no one should be on.

How often should I update statistics


No reply so I went ahead

Question: I am trying to find the word that means that follows:  A question or instruction is given, but no reply is made.  The assumption is that since no one has replied that it is okay to go ahead.  For example "Can I have next Tuesday off as annual leave?"  Since the manager did not come back and say "No", my assumption was that it was okay.  I know that there is a word for this, but cannot remember what it is.
Comment: You might be thinking of [acquiescence](http://dictionary.reference.com/browse/acquiescence), but as Dan Bron warned you, don't rely on it here (or elsewhere). The reign of "no means no" was short-lived. "Yes means (& requires a) yes" is now the standard.
Comment: The standard (jocular) phrase is "***silence is consent***". But ... it's dangerous. You've been warned.
Comment: *No news is good news.*
Answer: This is not a single word, but you are applying implied consent:

Implied consent is consent which is not expressly granted by a person, but rather inferred from a person's actions and the facts and circumstances of a particular situation (or in some cases, by a person's silence or inaction).
Wikipedia

No reply so I went ahead


How does one decompile and recompile a database application?

Question: I have an Access database application and I would like to know the proper way of decompiling and recompiling it.
Comment: In your previous question http://stackoverflow.com/questions/3258488/ms-access-2003-form-does-not-open-help/3260422#3260422 you accepted an answer that includes information on decompiling and recompiling.
Answer: To Decompile an Access database you'll need to create a shortcut with the following elements:

Path to the MS Access Executable (MSACESS.exe)
Path to the database you would like to decompile
The /decompile flag

All together, then, the shortcut would look something like the following:
"C:\Program Files\Microsoft Office\Office\MSACCESS.EXE" "C:\users\tim\documents\Mydatabase.mdb" /decompile

Obviously, the paths will be different on your system.
I'd recommend making a backup of your database before running this command.
If you have any startup code in your database you should hold down the shift key to bypass the startup code execution.
Once the database opens, you can compact and repair the database to ensure optimal performance.
After the compact and repair, you can recompile the VBA code by opening any module and using the Debug Compile [DatabaseName] command.
If this is something you want to do frequently, you can create an "Access Decompile" shortcut in your SendTo Menu. Once you have this shortcut in the SendTo Menu you'll be able to right-click on any Access database and select "Send To --> Access Decompile", which is much easier than having to create a shortcut to the specific database.
Follow these steps to customize the Send To menu with an Access Decompile shortcut

Create a shortcut to the Access executable.

Append the /decompile flag in the Target for the shortcut. The shortcut will look like this:
"C:\Program Files\Microsoft Office\Office\MSACCESS.EXE" /decompile

Open Windows Explorer and paste the following into the address bar:
%APPDATA%\Microsoft\Windows\SendTo

Copy the shortcut you created into the SendTo Folder.

The Access Decompile Shortcut will now be available for use.

To invoke the Access Decompile shortcut, right click on an Access Database in Windows Explorer and select "Send To --> Access Decompile". Be sure to hold the shift key down to bypass any startup code in the database.
Comment: To find the path to MSACCESS.EXE, run this in a console: `reg query "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\MSACCESS.EXE" /ve`
Answer: @Tim Lentine's practical instructions are good, but he leaves out the actual steps required for a decompile to be worth doing:

backup your database.

compact your database.

using the shortcut created with Tim's instructions, open your database.

close that instance of Access.

open a new instance of Access and open the database you just decompiled, but BE SURE YOU BYPASS ALL STARTUP CODE (i.e., hold down the shift key). If you don't do that, then you might as well go back to step 3 and try again, since if the startup code runs, your code will recompile before you are ready to do so.

compact the decompiled database (and be sure you hold down the shift key so that it bypasses the startup code; see #5).

open the VBE and on the Debug menu, choose COMPILE [name of project].

on the file menu, save the project.

compact again.

Why are all these steps necessary?
Because you want to not just decompile the VBA, you want to make sure that all the data pages where the compiled p-code was stored are completely discarded before you recompile.
I also recommend:

in VBE options, turn off COMPILE ON DEMAND

in the VBE, add the COMPILE button to your toolbar.

compile often with that button on the toolbar, after every two or three lines of code.

Decompile is not something you should use all the time, but during heavy-duty coding, I might do a decompile a couple of times a day. And I generally decompile/recompile as the last step before releasing an app into production use.
Last of all, read Michael Kaplan's article on the subject to understand it better.
Comment: @Paul - It shouldn't be necessary because a data-only database will presumably not contain any VBA code. (BTW, you'll have to forgive David for not responding; he passed away several years ago.)
Comment: The parenthetical in step 6 seems to be the key. I've done all of these steps from multiple websites and shift-clicking when opening finally gave me an option to compile in the VBE.
Comment: This may *sound* like a daft question, but should I use decompilation even if the database is a data only database?
Comment: @GordThompdon: Oh! No! That's definitely a fatal exception. Thanks for answering in his stead.
Answer: The accepted answer is great, but it's a little impractical to create a shortcut for every database.
You can save this as a powershell module.
#for use with MSAccess 2010

Function Decompile-AccessDB{
    param ([string]$dbFileName)

    [string]$argument = '"' + $dbFileName + '"' + "/Decompile"
    Start-Process -FilePath 'C:\Program Files (x86)\Microsoft Office\Office14\MSACCESS.EXE' -ArgumentList $argument
}

Then call it like this:
Decompile-AccessDB -Path "C:\Path\to\some.accdb"

This allows you to quickly and easily decompile any db from the power shell command line.
Note that you still need to hold down the Shift key when you run this to bypass the application startup.
Comment: Dynamically get the full path  to the access executable this way: `(Get-ItemProperty -Path "Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\MSACCESS.EXE").'(default)'`
Answer: The other answers here all seem a little complex to my taste.
To decompile an Access database:
Open the Run dialog from the start menu, or hit Win + R
Type in: MSACCESS.EXE /decompile (a proper installation should open up the Access application, you could also provide the full path to MSACCESS.EXE), and press OK.
Access now opens. Open up your DB in the Access window that just opened. That will decompile it.
Comment: This is a simple approach but I'd like some further clarification.  Are you saying that opening MSACCESS.EXE with the /decompile switch, without passing a filename, and *then* opening a database file from that instance will force a decompile on that database?  Does this also mean that any other database I open from that instance of Access will also decompile when it opens?  I'm not used to opening database files this way.  I had always thought that the `/decompile` switch was applying to the file being opened, not the Access instance being opened.  How can we know for sure?
Comment: @Ben One way is just to use it and check. I've extensively used this technique when one of my databases when debugging a bug causing VB project corruption and hard crashes on startup, requiring decompilation often. But you can easily verify how it works by first compiling multiple databases, then open an Access instance using the decompile flag, and then see if you can compile them again (if they're compiled and nothing changed, that shouldn't be possible). You'll see that only the first database opened will get decompiled.
Answer: I wrote a VBS script to automate the process of decompiling. It's silly that Microsoft hasn't integrated this into Access, considering it is a necessity when developing VBA-heavy applications.
The script locates MSACCESS.exe and runs Access with the decompile flag on a database located in the parent directory of the script, whose name is given in the code.
Option Explicit
Dim MSAccPath
Dim RegKey
Dim WSHShell
Dim currentDirectory

' Get MSACCESS.exe directory
RegKey = "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\" _
    & "CurrentVersion\App Paths\MSACCESS.EXE\Path"
Set WSHShell = WScript.CreateObject("WScript.Shell")

' Get parent directory
MSAccPath = WSHShell.RegRead(RegKey)
currentDirectory = WSHShell.CurrentDirectory

' Decompile
WSHShell.Run Chr(34) & MSAccPath & "MSACCESS.EXE" & Chr(34) & " " & Chr(34) & currentDirectory & "\..\testdb.accdb" & Chr(34) & " /decompile"

' Clear shell var
Set WSHShell = Nothing

Simply paste this text into a document with a .vbs extension and double-click it to run. Access will launch, decompile the compiled P-code ("packed" code), and automatically recompile the VBA source back into P-code.
Answer: Or simply you can create a shortcut on your Desktop (with the /Decompile Flag) and drag drop your Access application holding SHIFT to bypass any code


Reference to Quasilinear Parabolic PDE

Question: I'm studying the viscosity solutions to the Hamilton-Jacobi equations by Evans's book. If we apply the method of vanishing viscosity and add the regularizing term, we get the following quasilinear parabolic equation:
$$
u_t^{\varepsilon} + H(D_x u^\varepsilon, x) = \varepsilon \Delta u^\varepsilon \\
u^\varepsilon(x,0) = g$$
Evans simply puts it that these turn out to have smooth solutions. I've been wondering why that is true. I tried to find something in the book by Ladyzhenskaya "Linear and Quasilinear Equations of Parabolic Type", but seems like there the theory is much more general than I need, so it would take me a lot of time to pass through.
Could anybody give me some reference or explanation of this fact? In this case $H$ is a smooth function, and $g$ is continuous.
Answer: See Lemma 4.3 and the surrounding discussion in [1]. There, Evans uses a result of Friedman's in [2]. The paper [2] can be downloaded here.

[1] Evans, Lawrence C., On solving certain nonlinear partial differential equations by accretive operator methods, Isr. J. Math. 36, 225-247 (1980). ZBL0454.35038.
[2] Friedman, Avner, The Cauchy problem for first order partial differential equations, Indiana Univ. Math. J. 23, 27-40 (1973). ZBL0243.35014.
Comment: Thank you! This is exactly what I was looking for. These theorems basically provide another way to ensure the existence of the viscosity solution, defined by this vanishing viscosity method, which basically differ from the dynamic programming method, that Evans uses later in the chapter of PDE.
Comment: @Proton: no worries. In general, if you obtain an answer to your question, consider accepting it (though it is entirely reasonable to wait some time before doing so).

Reference to Quasilinear Parabolic PDE


Is it possible for each layer to give incomplete data to the lower layer?

Question: In network-based models such as OSI or TCP / IP, is it possible for data in each layer to be delivered incompletely to the lower layer?
For example, might layer 3 send data to the second layer without writing an IP?
If yes, please explain about the items that do not include IP address or MAC address?
Comment: If you use IP as the third layer, each packet has a source and destination address in the IP header. I don't see how these addresses can be removed from the header. You can put put random numbers in them, or zeros, or 0xffffffff, but something is in those fields. Whether it makes sense and the packet goes somewhere is a different question. However, at least in the OSI model you could use something else than IP as the third layer. In this case, layer 3 headers have no IP addresses.
Comment: Why is it incomplete? The second layer doesn't _care_ whether its payload contains an IP address or not.
Comment: @user1686 I know the second layer does not matter to the IP address. I mean, if the third layer does not specify the IP, it sends the data to the next layer?
Comment: I'm not sure I'm getting the point of the question. L3 can do anything it needs to do. Are you asking about specific protocols acting as L3, or are you asking about the general concept of "layer 3" in general? I mean, IP _will_ always include an IP header, but there exist layer-3 protocols that aren't IP to begin with, and there's really no requirement that the L2 payload even _be_ a L3 protocol; it could directly be an application protocol.
Answer: Theoretically yes, practically the question doesn't really make much sense.
In layman's terms, when a layer 3 packet is encapsulated into a layer 2 frame, the whole packet is "used". There is no data taken out or added from "within" the packet. So if it the data gets passed on to the next layer and it doesn't have an IP address it didn't have an IP address to begin with. But the packet would get encapsulated anyway.
A packet without an IP is not a "valid" packet so it probably would have been rejected at some point prior to the encapsulation form layer 3 to layer 2 but that all depends on the actual implementation of the software involved in the communication process.


Custom File field in custom group used by CiviCRM entity group not saving

Question: I attached a new custom group to entity type group and added a field of type file. When editing the group settings and fill in a file, it is posted without errors and notification bubble confirms success. But there is no file uploaded.
No error logs even with debugging enabled, file tmp folder is checked and I successfully tried another custom file field attached to entity contact.
Just tried on https://dmaster.demo.civicrm.org/ - same misbehavior.
Looked at the code and it seems that the posted file info is not getting into the params array. Although the posted name is of correct format custom_123_21313 the packages/HTML/QuickForm/Controller.php->exportValues gets "MAX_FILE_SIZE" as key for the custom field. Could it be that https://lab.civicrm.org/dev/core/-/blob/master/CRM/Group/Controller.php 's overridden custom file field preparation causes this error?
Civi and Drupal are current versions.
Core Team, do you have a clue? How may I investigate further? Where is the $_POST stuff prepared prior to postProcess in CRM/Group/Form/Edit.php?
Comment: Opened an issue: https://lab.civicrm.org/dev/core/-/issues/2859
Answer: This does not work and has never.