Is my outbuilding wired correctly?

Question: I have a 3-wire source power wire (red/hot, black/hot, white/neutral and bare copper/ground) leading into an outbuilding to a light switch and GFCI outlet 4x4 metal box. This 3 wire provides power to multiple lights, multiple outlets and a security light in an outbuilding.
So I just want to make sure I hooked it up correctly.
Incoming or source wires:

Black wire- I connected the source black wire to the line in on the GFCI
Red wire - I connected to the source red wire to the line in on the light switch
Neutral wire- I connected to the line in on the GFCI opposite side of the black wire.
Ground wire- I connected to a pig tail wire connected to the screw in the back of the box and also to the ground screw on the light switch and the ground screw on the GFCI.

I have 3 romex wires coming into the top of the box leading to other lights, outlets and a security light.
Out going Lights romex wire:
Going to my other lights wire I connected the black wire to the load side on the light switch and connected the ground wire to the pigtail with all the other out going ground wires and connected it to the ground screw on the back of the box. I wasn't sure if I needed to pigtail all the outgoing neutral wires and connect them to the load side of the GFCI? I believe I pigtailed the two neutrals from the outgoing lights and outgoing outlets wires and connected them to the screw on the load side of the GFCI. For the security light wire I used the push in on the load side of the GFCI. Everything is working but I'm not sure if I should have connected the white neutral going to my other lights to the load side on the light switch. Anyway they are all working with it connected to the GFCI load side for the white wires.
Outgoing outlet romex wire:
I connected the black outgoing wire to the load side of the GFCI. I connected the ground to the other outgoing grounds on a pigtail and connected to the ground screw on the box. I connected the white wire to a pigtail with the other white wire going to my lights and then connected them to the load side opposite my black hot wire on the GFCI.
Outgoing security light:
I connected the black wire for the security wire to the push in on the load on the GFCI and the white wire is also connected to the push in on the load side of the GFCI. The ground is connected to all the other outgoing grounds in a pigtail attached to the ground screw.
As stated everything is working and I have constant power to my outlets and all my lights turn on at this switch. Everything is working so I must have done something right but my only real question is should I have attached the white neutral wire going to my lights to the neutral on the light switch as well as the neutral load on the GFCI? I didn't connect the neutral back to the light switch I just put it back on the GFCI because that's where the line in neutral was. Maybe I should have pigtailed the incoming neutral and connected it to both the line in on the GFCI and the light switch? Now that I'm typing this that sounds like it may have been a better idea. Any help would be appreciated.
Answer: You should have only attached the white grounded (neutral) conductor from the cable leading to the other receptacles, to the grounded (neutral) terminal of the GFCI.  The white grounded (neutral) conductors for the lights should be connected with at pigtail to the neutral feeding the building.

Unless you want to provide GFCI protection to the security light as well, then you'll connect the wires feeding that to the load side of the GFCI.
Comment: Thanks! That's exactly what I was looking for. I like your diagrams also. I knew I had all my hot wires connected in the right places but was unsure of my neutral wires. I did have the security light on the GFCI circuit.
Comment: I also read in some of the other threads that people didn't think it was a good idea to use the quick connects on the back of the GFCI outlets. I did use these for the security light. Would it be better to pigtail them and use the screw? With all these wires coming into this 4x4 box there isn't that much room for a lot of wire connectors.
Comment: I prefer using the screw terminals, but I have nothing against the modern push terminals.

Is my outbuilding wired correctly?


What is the difference between centralised, decentralised, distributed, fully-distributed?

Question: What is the difference between centralised, decentralised, distributed, fully-distributed, partially-centralised, partially-decentralised system?
Which type or topology is the system attached in the picture below? For instance, A is a master node (coordinator) of A1, A2, A3, which makes this part a centralised system. A, B, C and D are all connected between each other, which makes this system a decentralised one. But then, what are fully-distributed, partially-centralised, partially-decentralised systems?
Comment: That's pretty broad -- asking about the difference between six different types of systems sounds potentially too broad to fit in a reasonable-sized answer, to me.  Can you research those topics, see how far you can get on your own, and then narrow down this question to ask about (say) just one or two types of systems?  I suspect you'll be more likely to get useful answers if you can do that.  Community votes, please: is this too broad?
Answer: You need to differentiate between centralization/decentralization on the one hand and distributed/non-distributed on the other hand.
Centralization
Centralization tells you where the processing gets done.
Fully centralized systems do all their processing in one place.
Distribution
Distribution has nothing to do with processing. It just relates to systems that communicate via messages.
A non-distributed system is a stand-alone PC with no clients, or a server with dumb clients.
A fully distributed system does not have a single source of truth, however that does not mean that all nodes have to be equal. You can have 'supernodes' mixed with lesser nodes and still be fully distributed.
Distribution = network
The current incarnation of distributed systems are networked systems, but of course it's perfectly possible to pass messages using a serial cable, sneakernet or carrier pigeon. Is that a distributed system?
Yes if both systems do actual work, No if one system is simply a recipient of data (printer/terminal etc).
Peripherals do not count
The passing of screen and keyboard data between the terminal and the server is not deemed substantial enough to qualify as message passing.
Caveat
The definition of distributed computing is best narrowed down in the context of a specific protocol or algorithm (e.g. bittorrent or mapreduce)
Outside that context it becomes exceedingly vague to the point of being meaningless.
The mysterious diagram
The diagram in the question seems to hint at some sort of hierarchy and thus centralisation.
Obviously the systems A,B,C and D cannot be peripherals (because they are not leaf nodes) and thus some message passing (aka network activity) ought to take place.
What the nature of the leaf nodes (A123 et al) is is unclear, but these leafs do seem subservient to A,B and C proper.
Answer: In addition to Johan's answer:
A decentralised system is a fully distributed system where all the nodes in the network are equal so that there is no "authority" node in the network. Bitcoin Network is an example of this.


Propagated pothos not growing

Question: About a month ago I planted some pothos leaves I had rooted in water, but I haven't seen any growth so far. Could I be doing something wrong or should I wait a bit longer?
Answer: The leaves look fine. Problem indications would be older leaves yellowing and dropping off.
I suggest you move to higher light conditions and go easy on the water until it does start new leaves.
Epipremnum aureum grows outside in Mexico and most tropical countries so it can take high light inside a house.
Answer: An important detail here is to be aware of the potential buds in the axils of the leaves, where the leaf joins the main stem. The pieces will consist of a leaf joined to a section of stem plus the roots that were sprouted in the water. When we pot up the rooted cutting we are asking that potential bud in the leaf axil to sprout out and make a new stem. So the only clue that something is happening is to see movement by that bud changing into a weak stem and then producing leaves of its own. If the bud is buried too deep then you see no progress; either pull back the soil/compost or repot so that the bud is in light. Then as soon as it is ready to sprout the change will be readily visible.

Propagated pothos not growing


What is the required burn to keep a satellite at a Lagrangian point?

Question: When a satellite reaches a Lagrangian point, it has a non-zero velocity $v_1$ because of the transfer orbit in which it had already been. What burn, say, $\Delta v$, one needs if the satellite is about to be kept at that Lagrangian point? Given velocity $v_2$ after the burn applied to the spacecraft, shall we have $v_2 = 0$, i.e., $\Delta v = -v_1$?
Comment: This will be a little hard to answer because satellites are usually put in orbits that move around Lagrange points (e.g. halo orbits), not exactly at them. Either way these tend to be unstable both because of orbital mechanics and because realistic orbits of the Earth, Moon, and other bodies are elliptical, not circular and so there are always perturbations. Also, satellites can try to approach these halo orbits along manifolds which can require very little delta-v to "slide into" halo orbits. It's a complicated topic.
Comment: This is a different question but you may find it interesting [Rendezvouses in halo or lissajous orbits](https://space.stackexchange.com/q/34997/12102)
Answer:
What is the required burn to keep a satellite at a Lagrangian point?

tl;dr: typical station keeping delta-v for a halo orbit around Sun-Earth L1 or L2 points are of the order of 2 to 4 meters/sec per year based on a very old spacecraft (SOHO) and a future spacecraft (JWST).

I'll address the two closest and most used Lagrange points; L1 and L2. Generally spacecraft are put in halo or Lissajous orbits associated with (around) the points, not at the points themselves. This is done both for geometrical reasons (avoid the Sun in the line of sight for antenna-pointing or blockages) but there may be orbital mechanical reasons as well. See the extensive answers to Are large halo orbits around L₁'s and L₂'s preferred over small orbits for reasons other than geometry?
I'll add a quick note, Lagrange points and halo (and other) orbits are mathematical manifestations of mathematics. They exist in a certain theoretical situation called the Circular Restricted Three Body Problem or CR3BP (or CRTBP). These concepts work approximately in the real world where orbits are not circular and there are more than three bodies.
Whether you are at L1 or L2, or in a halo orbit around them, you are really orbiting around the larger body. If you are at or near the Sun - Earth L1 (e.g. DSCOVR, SOHO) you are really in an orbit around the Sun which is in resonance with the Earth. It would normally move around the Sun a little faster than Earth, but Earth pulls it back just enough to keep it orbiting with a period of one year.
There is a subclass of halo orbits around L1 and L2 in the CR3BP model that are actually stable, though the rest aren't. However in the real world due to there being other gravitational bodies around and the orbits not being circular, none of these are really stable.
According to this answer to ** the James Webb Space Telescope (JWST) only needs a station-keeping delta-v budget of 2 to 4 meters/sec per year to stay in its halo orbit around the Sun-Earth L2 point. It accomplishes this though careful planning and construction. JWST sits just in front of the most stable halo orbit so it would ten to wander toward the Earth, but this is balanced by solar photon pressure on its giant solar thermal shield, which tends to hold it there (roughly speaking). It will also execute very tiny delta-v maneuvers ever three weeks so that the errors are tiny and never allowed to grow.
I talk a lot about SOHO (Sun-Earth L1) station keeping in Is this what station keeping maneuvers look like, or just glitches in data? (SOHO via Horizons) and in the exciting report (if you like orbital mechanics) Roberts 2002 The SOHO Mission L1 Halo Orbit Recovery
From the Attitude Control Anomalies of 1998 in Table 2 and the paragraph that follows, it says that SOHO originally needed about 2.4 meters/sec per year for station-keeping.

When a satellite reaches a Lagrangian point, it has a non-zero velocity 1 because of the transfer orbit in which it had already been.

Getting to halo orbits around L1 and L2 does not always require a classical "transfer orbit". You can sneak in with very little delta-v along what is called a "stable manifold" as SOHO did for example. It's not perfectly zero delta-v, but it is very low.
It is a lot like the opposite of what would happen if you started just Earthward of the halo orbit, you would drift out along the unstable manifold. Drifting in is like drifting out but backwards in time.
This is plotted data from Horizons from Is this what station keeping maneuvers look like, or just glitches in data? (SOHO via Horizons) using a script like this: https://pastebin.com/7XULFDea written when I was just starting to learn Python. Still images combined into a GIF using ImageJ. Data from https://ssd.jpl.nasa.gov/horizons small black dots are 1 day intervals, red dot is Sun-Earth L1 and blue blob represents the various places Earth is relative to L1.
Comment: That's a very nice visualisation - do you plot it and record the screen as you change the view?
Comment: Thank you - I hadn't visited the links, I assumed they were just the source of the data.
Comment: For reference, Wind typically uses less than 1 m/s per year of fuel (usually only ~0.13 kg per maneuver, four maneuvers per year).
Comment: @honeste_vivere buried here in a comment very few will see that. Posted as a short new answer post, the page will be kicked back into the active queue and many current and future readers will see it.
Comment: @uhoh - Okay, fine ;)
Comment: @RoryAlsop yikes that was three years ago, feels like another lifetime. I've added the information for the plot here instead.
Answer: For those Lagrangian points which are unstable, L1, L2 and L3, there is no equilibrium, and any movement off the point will accelerate further away, towards the Sun or Earth. For them, you would need to counteract v1 (and any gravitational forces undergone along the way) in order to reach a rest velocity with respect to the Lagrangian point plus you would have to use thrusters to remain there.
For stable Lagrangian points, L4 and L5, you would need to simply meet the required orbit parameters. There will still be a burn to match the orbit.
Comment: L1, L2 and L3 are equilibria (in the rotating reference frame). They are just unstable in the same direction as the vector connecting the star and planet. So perturbations in the other two directions are not unstable (though the surface that is spanned by this is curved). This is also what enables halo orbits. But in general disturbances like variations in solar pressure or the gravitational pull of other planets do excite this unstable direction so one does indeed need to perform station keeping burns.
Answer: The Wind spacecraft has been orbiting the Earth-Sun L1 point since roughly May 2004.  Originally it was put into a Lissajous orbit but was recently moved into a halo orbit in late 2020.
Typically, Wind uses ~0.13-0.20 kg of fuel per maneuver and four maneuvers per year (it had ~36 kg remaining as of December 16, 2021, i.e., ~45-60 years of fuel left).  For Wind, ~0.14 kg of fuel corresponds to ~0.276 m/s of delta-v (changes slightly over time as its mass decreases with use of fuel, obviously).  It is an ecliptic spinner (i.e., the spin axis is pointed toward the south ecliptic pole) and has a banded antenna about its midsection (i.e., like a ring around the center of the cylinder of the spacecraft bus) so it doesn't need to do extra maneuvers to reorient the spacecraf for communication with Earth.  In contrast, the ACE performs maneuvers every other week or so.  The difference is that ACE is a sun-pointed spinner (i.e., its spin axis is nearly directed at the sun).  ACE needs to point in a specific direction for communication with Earth and because one of its plasma instruments is failing (so they canted the spin axis a little to rely more heavily on the less damaged anodes).  This results in it using a lot more fuel per year than Wind.
In short, the fuel usage depends on the spacecraft.
Comment: Interesting data, but it would give (me) more confidence in them if you could add direct links (papers, reports, ... where the numbers are calculated). Also, as an answer, it gives the impression that you are "beating around the bush", which I don't think it is your intention. The OP's question may be rooted in a misunderstanding. By not addressing the possible misunderstanding, the fog gets thicker, at least to me! Allows me to reword: Assuming we want to, how much would it cost to transfer to an L-point and reach v=0 (wrt Earth), momentarily? How much to transfer to a Halo/Lissajous instead?
Comment: @NgPh - At the time I submitted the 2020 Senior Review report (in the link for the Wind spacecraft), Wind still had ~52.5 kg of fuel (i.e., I think this was May 2020).  As of December 16, 2021, Wind now has ~36 kg of fuel.  In that time Wind went from a Lissajous to halo orbit, which is responsible for the bulk of that fuel delta (since 4 station keeping maneuvers per year only consume ~0.5 kg of fuel).  To reach v=0 wrt Earth, starting from Earth, would be extremely expensive and not helpful for orbit insertion (as you'd spend additional fuel inserting afterwards).


Planting too many seeds in small pot

Question: What will happen if i keep my sweet basil here?
Answer: Your plants will have to compete with each other for light, and root space. Because they are so packed and crowded, none of the plants will grow optimal this way. If you just want basil cress, you can harvest already, but if you want real and healthy basil plants you need to trim (or pull) away most of it. I think you have to leave 1-2 cm between plants at minimum.
Comment: Tiny scissors are helpful at this point. If you pull the extras, you'll lose a lot of dirt.
Answer: Ummmm, are you asking about that center pot?  Your donut shaped plants should be transplanted into 6" pots with potting soil only.  Dump the whole pot and donut out of the main pot, using serrated knife, carve a chunk about an inch wide of that donut, and put in its new pot. Lightly plant the roots in the new potting soil, add (balanced fertilizer) give plenty of light.  You'll have 7 or 8 pots worth of basil (not every single plant will live from the chunks you cut off) but just one plant per pot will give you a beautiful full basil plant.  What type of basil is this???  Why the donut thing?  Next time you buy seed make sure you get NON GMO and you have try THAI basil!!  I use this basil for everything I want basil into...
If you wanted, you should pull that center pot out, fill with potting soil then then with tweezers until you get 6 viable plants left.  This is a worthy solution if you have used only potting soil.
Comment: Basil is pretty hardy to being transplanted. I've pulled plants/roots out of pots nearly as crowded as the above pix. Bare roots. Planted them outside, and they grew into beautiful 2.5 foot plants; gallons of pesto.  Be aware that Robins love to eat Basil cotyledons, so you'll want to wait fof secondary leaves.
Answer: If we plant too many seeds in a small pot the plant wouldn't be huge it will remain small, because of this we should plant seeds in a big pot.

Planting too many seeds in small pot


How to deal with VBO and obj files for physics simulation?

Question: I'm having a hard time struggling with obj files and clothing simulations.
I first made the obj file processor class that deals with the typical obj file problem: having multiple indices for vertex position, vertex texture coordinates, and vertex normals like this f 52/49/224 57/54/224 279/270/224. I made a function that shrinks the multiple index arrays to one index array.
class VERTEX{
public:
    glm::vec3 position;
    glm::vec2 uv_coord;
    glm::vec3 normal;
};

std::vector<VERTEX> out_vertices;
std::vector<unsigned int> out_indices;

void reorderData(){
        for(int i=0;i<vertexIndices.size();i++){
            VERTEX vertex;
            // add -1 to each index as indices for obj files start from 1, not 0.
            int vi = vertexIndices[i]-1;
            int uvi = uvIndices[i]-1;
            int ni = normalIndices[i]-1;
            vertex.position = temp_vertices[vi];
            vertex.uv_coord = temp_uvs[uvi];
            vertex.normal = temp_normals[ni];
            //assign new index here for the VERTEX object
            int index = getVertexIndex(vertex);
            //If it's a new index, it means it's a new VERTEX. Store it in out_vertices.
            if(index==out_vertices.size()){
                out_vertices.push_back(vertex);
            }
            out_indices.push_back(index);
        }
    }

Then I use out_vertices and out_indices to set up the VAO, VBO, and EBO for rendering. The problem here is that in the VBO, there are multiple VERTEX objects that have the same position value.
However, in order to do physics simulation, I need a particle class that deals with calculating the force, speed, position for every loop of each cloth particle.
class particle{
public:
    glm::vec3 position;
    glm::vec3 force;
    glm::vec3 speed;
    float mass;
}

And if I just copy the the VERTEX objects' position values to the particle objects, then there will be multiple particle objects with the same position value. But this doesn't seem right as there should be only one particle object for each unique position.
So my solution at the moment is, to first make particle objects that each have unique position values. Then, after each physics loop calculating a particle's speed, force, position, I update all the VERTEX objects whose position value has changed for the corresponding 'position' object. Lastly I update the VBO.
Would this be the right approach? I am afraid that linearly searching the multiple VERTEX objects who have the same position value as the particle object is going to take a lot of time. Any help would be appreciated. Thanks in advance!

To be short what I want to seek advice about is how to seperate and handle the rendering data and the physics simulation data efficiently.
Answer: Assuming that your object is made up of triangle faces, use the center of those triangles for the position data of that particular face.
This will get rid of all duplicate vertex data.


Conserved currents in higher-spin theories

Question: After the proposal of Maldacena (AdS/CFT), there have been numerous attempts to find out gravity duals of various kinds of CFT. Klebanov and Polyakov gave one such correspondence here. The claim is this:
The singlet sector of the critical $O(N)$ model with the $(\phi^{a}\phi^{a})^{2}$ interaction is dual to the minimal bosonic theory in $AdS_4$. Of course, we have to take the large $N$ limit. Simplest such $O(N)$ invariant theory (free, with no interactions) is:
\begin{equation*}
S= \frac{1}{2}\int d^3 x \sum_{a=1}^{N}(\partial_{\mu}\phi^{a})^{2}
\end{equation*}
How do I derive the conserved currents in this theory? $\phi^{a}$ are $N$-component vector fields and NOT $N \times N$ matrix fields.
Comment: Can you post your results? I don't know anything about this Fronsdal stuff, but the c.c.'s are not so difficult to write down, namely $J_\mu = \phi^a \partial_\mu \phi^a,$ $J_{\mu \nu} = \phi^a \partial_\mu \partial_\nu \phi^a$ etc. The derivatives need to act on both fields, so they are conserved (but don't know the TeX to do this). They are traceless because $\partial^2 \phi^a = 0.$ If $\phi^a$ is real the odd spins vanish identically.
Comment: O.k. I figured it out myself. It seems this formalism was developed by Fronsdal long time back. However, another question has popped up. Spin-$s$ massless fields are given by totally symmetric tensor $\phi_{n_1 n_2..n_s}$. There is a condition though on these fields. They have to be "double traceless" i.e I contract them with $g_{\mu_1 \mu_2}g_{\mu_3 \mu_4}$. Why do I need to impose this condition?
Comment: Vibert, one can write the currents as follows, $j_{\mu_1...\mu_s}=\bar{\phi}(x) (\overleftarrow{\partial_\mu}-\overrightarrow{\partial_\mu})^s\phi(x)$. These are not traceless, the trace is given by superpotential. One can easily make them traceless, but the formulas are no so nice
Comment: Hi Debangshu, could you please mention the paper of Fronsdal that you were talking about in your comment? Thanks!
Answer: That looks weird but you have to impose the double trace constraint in order to have the right number of degrees of freedom. This is easy to see by going into light-cone and analyzing the equations of motion.


Ubercart- Assign new role on expiry

Question: I am granting users specific a role on purchase of some product( using ubercart). In doing so I have added a rule to take away their initial role(so that they do not have 2 roles and confuse the content access permissions). When the role expires, I want to grant the use back his original role. I am trying to use rules to do this. However, I am unsure on what action to call this rule.
Any suggestions? Thanks!
Answer: It seems that "I am unsure on what action to call this rule" is your remaining issue, and that by using the rules module you are already close.
However, when talking about Rules and its Event-Condition-Action concept, your issue is about what Event to use. With that in mind, I would try to use the Rules Scheduler submodule of Rules, to schedule the rule to be executed at the moment of the purchase already.
Makes sense?
Answer: You can do this with using Ubercart Roles.
In Ubercart Role there is an option to send the notification to that user whose role is expired. You can trigger a rule on that event or you can define a role expiration event if you wish to tie it to a discrete event rather than the sending of an email.
I have found a patch for Role Expire which creates a Rules event upon role expiration that you might use as a model.
First you need to create a rule, then a simple action to assign a role (Add user role action) to the expiration:user.
Comment: Thanks! Yeah I did it almost exactly like that, however I wanted the event to be triggered exactly when the role expires - whereas now it is triggered "x" days before the expiry and only when the notification is sent to user(in case of the email expiry trigger).
Comment: Also, I am not using the Role Expire module but the built in expiry system that comes within UberCart.
Answer: This problem is you can handled by drupal rules.

Ubercart- Assign new role on expiry


Average thunderstorm days for each month

Question: How can I find the average number of days with thunderstorms for each month for different cities in the United States? I'm doing a researching project for this and I need to find some links that will show me the average number of days with thunderstorms for each month for different cities in the United States.
Comment: you might take a look here https://w2.weather.gov/jetstream/tstorms_intro it does not answer your question but it is a start.
Comment: http://opendata.stackexchange.com/questions/10154/sources-of-weather-data may or may not be helpful
Answer: You should start with NOAA services. They have a Storm Events Database going back to 1950, where you can do queries for states/counties of interest. If you are more interested in lightning data, they also have some products, including raw data from a private company (you'll need access for this) and freely available derived products.
Answer: I too don't know any direct sources.  So you will likely have to do a bit of legwork.

Was going to offer that you could work a climatology together from
monthly FP6 reports using the desired NWS site (click the office on
https://sercc.com/nowdata.html, then switch to observed weather, then
select CF6 and choose the site and then indicate the month report you
want... on those reports any date with a 3 in the WX column had
thunder... then you could sum them over many reports to make a
climatology... time consuming, but I've done similar.  It would be
feasible to do a few sites, but brutal to do for many without
automating the process)
But it looks like Iowa State's IEM ADP comes through with something a
bit more robust and more reasonable in the amount of work it takes to
finish together...   Using option ADP #87 here, select the
state/country of interest, then city you want data on (you may wish to further
look into what the official observing site is for the city you want)... make
sure you have thunder as the code choice, and select group by day of
the years.  Choose your years {you may want to skip the first and
current year for better hopes of about equal data sets for each day
of the year... you also may want to avoid going back too far in time,
as it looks like records may have been less complete back towards the
1950s and earlier}, then make the plot with options.   It'll produce
a nice graphic which you may find useful.  If you want precise
numbers, you can reasonably make the true climatology by clicking
download as Excel below the plot.
(If anyone reading happens to be a little unfamiliar with Excel {Open Office likely would work fairly similar?}... I can try to run you through the remaining process I used for this graphic:
select the day and year columns together,
then filter out duplicates,
then make a Pivot Table in a new sheet with doy as Row Label
and count of year as Σ values.
After one mistake in reading, I realized you wanted monthly data... from here there may be easier ways to do the rest, but using my old Office 2007 and somewhat limited skill, I pushed through to get all dates summed by writing the formula

=ROW()-3

in cell D4 and

=IFERROR(GETPIVOTDATA("year",\$A$3,"doy",ROW()-3),0)

in cell E4.
Then expanded those cell formulas downward to row 369 (so 366 days were covered).
Then I typed the month names in F4-F15 and the formulas

=SUM(E4:E34)/50
  =SUM(E35:E63)/50
  =SUM(E64:E94)/50
  =SUM(E95:E124)/50
  =SUM(E125:E155)/50
  =SUM(E156:E185)/50
  =SUM(E186:E216)/50
  =SUM(E217:E247)/50
  =SUM(E248:E277)/50
  =SUM(E278:E308)/50
  =SUM(E309:E338)/50
  =SUM(E339:E369)/50

in G4-G15.
Select the F and G columns, add a bar graph from that, add a title, and I had:

It's certainly not readymade :-(
But it does at least seem a way you could possibly produce enough climatologies in reasonable time to get a rough idea of the country (or other parts of the world?)?
Hope you/others can find something that is already completed, but if not, hopefully this offers something a bit useful.
(Those looking to go all-out nuts and make a full dataset could download full ASOS data from Iowa State or NCDC and put together a detailed script to pull out the pieces needed.  Feel free to share the data here if you do!)


Adding Bourbon flavor to a beer

Question: So in my last beer, I added bourbon infused with vanilla bean. I started to wonder if this was "cheating" or frowned upon, as far as getting the bourbon flavor into the beer. Is there a better way to do it, or a correct way?
Answer: Jordan,
Whichever way you want to flavor a beer is fantastic!  That's part of the fun with brewing.  Unless you are concerned about following the Reinheitsgebot, don't worry about adjunct materials.  I really like the way you decided to flavor your beer.  If you're looking for further suggestions, try finding wood chips soaking them in your favorite bourbon, than throw the wood chips in a nylon sock.  Tie up the top and place it in your beer during the conditioning stage.  The flavor comes through nicely in the final product.  If you can find some wood from an old bourbon barrel this technique works well.  Just make sure you sterilize all surfaces that will come in contact with your beer by washing it with an alkaline based cleaner or under water that is at least 160 degrees Fahrenheit (71 Celsius).
-Adam-
Comment: I just soak my oak chips in a bottle of bourbon and have not ahd any issues with not boiling it. The alcohol keeps it clean. I see that others dont think this is a smart thing to do so I amy be wrong but it works for me.
Answer: Like I have said before, its the taste that matters in the end to me.  Not some sort of right or wring way to get there.
I make a winter ale with oak ships soaked in burbon.  To which I add my cinnamon and nutmeg as well.  Let it sit for a few days then put it all in secondary.
You method sounds great to me.
Answer: I don't think there's any wrong way to add bourbon flavor to your beer other than adding something that hasn't been sanitized properly ;)
Jack Daniels sells wood chips made from their old barrels for smoking on the grill but I don't see any reason why you couldn't use them to add some oak and bourbon* flavor to your brew, just be sure to sanitize them properly first.
*technically Jack Daniel's isn't bourbon since it is not made in Kentucky; but as far as ingredients and flavor are concerned, it is basically bourbon.
Comment: I found them in the grilling/barbecue section of a local grocery store. They may be a seasonal item depending where you live. People don't buy much grilling stuff when it's 0 degrees outside.
Comment: Technically, Jack Daniel's is bourbon (bourbon doesn't _have_ to be made in Kentucky, it's just that nearly all of it is). It's marketed as Tennessee whiskey, which, legally, is just bourbon made in Tennessee. The difference between Jack Daniel's and most bourbon is that it's filtered through maple charcoal, but that doesn't stop it being bourbon. /pedant
Comment: Where would one find such chips?
Answer: First, I don't think it's cheating. I think adding bourbon to beer sounds delicious!
I guess it would help to break down what you want in a "bourbon" flavor. For my Scotch Ale, I wanted something smokey and peaty and oaky. So I used smoked malt and peated malt, and oak chips.
Using a barrel that was used for bourbon would work pretty well too.. Though that's difficult at the 5 gal range.
Comment: Yeah a barrel was really not an option. I thought about soaking oak chips in bourbon, and throwing them in there, but I figured there would be more control of the flavor if the bourbon was just poured in right at bottling. We just added an ounce or two at a time and tested until it tasted right. I guess it just seemed too easy, compared to aging in a barrel like the big guys do it.

Adding Bourbon flavor to a beer


How to find ISSN number of IEEE Sponsored (or IEEE related) Events?

Question: My University of Technology requires me to limit my research paper publications to certain venues, which have an associated ISSN number.  How do I find out the ISSN numbers for IEEE Sponsored events, such as in Croatia (Europe), when I can't find an ISSN number on their Web pages?  Here is the IEEE related conference URL: http://iwcmc.org/2015/?  Thanks so much!!!
Answer: You can look at this list https://www.ieee.org/documents/2005_present_list_of_titles.xls from IEEE of upcoming events, and events from 2005 to present with all corresponding publication numbers.
As a comment points out, many of the listings do not have ISSN numbers. However, you can look at line 10935 of the excel sheet and see your conference.
IWCMC.  The IEEE conference number is 34432 and ISBN 978-1-4799-5345-5
Comment: Note that most of these IEEE conference proceedings don't have an ISSN.  In my experience, journals are assigned ISSN's, but conference proceedings volumes typically have an ISBN and no ISSN.  As conference proceedings volumes go the IEEE proceedings are generally considered to be pretty good, but not nearly at the same level as the IEEE Transactions On  journals.
Comment: @BrianBorchers Your right that the document does not have many ISSN numbers, but not sure that it is true for all conferences.  As of prestige, that would depend on which conference and journal, and what your criteria is.  H-Index by googles shows many fields where conferences are ranked higher than journals.
Comment: @BrianBorchers for example ICCAS http://2014.iccas.org/ posts their ISSN number, and the conference appears in IEEE, but the list does not include an ISSN number.


What's the difference between hard and soft floating point numbers?

Question: When I compile C code with my cross toolchain, the linker prints pages of warnings saying that my executable uses hard floats but my libc uses soft floats. What's the difference?
Comment: @Nils Pipenbrinck: MIPS chips also have this issue
Comment: If it is ARM architecture please put that into the tags :-)
Comment: Related: [uses VFP register arguments](https://stackoverflow.com/questions/9753749/arm-compilation-error-vfp-registers-used-by-executable-not-object-file)  which is the modern day message.
Answer: Hard floats use an on-chip floating point unit. Soft floats emulate one in software. The difference is speed. It's strange to see both used on the same target architecture, since the chip either has an FPU or doesn't. You can enable soft floating point in GCC with -msoft-float. You may want to recompile your libc to use hardware floating point if you use it.
Comment: "It's strange to see both used on the same target architecture" This can make sense for a library to be machine-independent and bit-exact (soft float) in accuracy-critical parts and fast (hard float) in parts where small deviations don't matter.
Comment: Soft floats can be used for deterministic calculations, e.g. for physics simulation.
They will give the same results every time, on every platform, on every processor.
Comment: It happens on 32-bit ARM.
Answer: Strictly speaking, all of these answers seem wrong to me.

When I compile C code with my cross toolchain, the linker prints pages of warnings saying that my executable uses hard floats but my libc uses soft floats. What's the difference?

The Debian VFP wiki has information on the three choices for -mfloat-abi,

soft - this is pure software
softfp - this supports a hardware FPU, but the ABI is soft compatible.
hard - the ABI uses float or VFP registers.

The linker (loader) error is because you have a shared library that will pass floating point values in integer registers.  You can still compile your code with a -mfpu=vfp, etc but you should use -mfloat-abi=softfp so that if the libc needs a float it is passed in a way the library understands.
The Linux kernel can support emulation of the VFP instructions.  Obviously, you are better off to compile with -mfpu=none for this case and have the compile generate code directly instead of relying on any Linux kernel emulation.  However, I don't believe the OP's error is actually related to this issue.  It is separate and must also be dealt with along with the -mfloat-abi.
Armv5 shared library with ArmV7 CPU is an opposite of this one; the libc was hard float but the application was only soft.  It has some ways to work around the issue, but recompiling with correct options is always the easiest.
Another issue is that the Linux kernel must support VFP tasks (or whatever ARM floating point is present) to save/restore the registers on a context switch.
Comment: This is the right answer. The calling conversion for floats needs to match between your code and libc. It might still work with a mismatch, if you never never call any floating point libc functions.
Comment: +1 as this seems to be the most correct answer. I'd also add that while you might have an  FPU or not. You can also have an FPU that only supports a subset of the functions that can be expressed in a C program e.g. `1.0L / 2.0L` would not be possible on a single-precision FPU but `1.0f / 2.0f` would be. It is often the case that the compiler runtime (e.g. libgcc) will provide the 'soft' version of the missing long-double-division. However, the single-precision instructions will be 'soft' wrapped hardware instructions.
Comment: Modern GCC (~4.8+) versions support 'multi-lib', which have hard float and soft float libraries.  Earlier versions required you had a compiler built with a specific version.  Occasionally the path to the correct library is needed when linking with a 'multi-lib' gcc distribution as there are several version of the libraries (requiring a longer time to build the compiler).  Directory names might be 'hf', 'hardf', 'libhf', or 'hard-float' but they are usually under the regular 'soft' directory or a nearby location.
Answer: There are three ways to do floating point arithmetic:

Use float instructions if your CPU has a FPU. (fast)
Have your compiler translate floating point arithmetic to integer arithmetic. (slow)
Use float instructions and a CPU with no FPU. Your CPU will generate a exception (Reserved Instruction, Unimplemented Instruction or similar), and if your OS kernel includes a floating point emulator it will emulate those instructions (slowest).
Answer: It sounds like your libc was built for software floating point operations while your exe was compiled assuming hardware support for floating point. In the short term, you could force soft floats as a compiler flag. (if you're using gcc I think it's -msoft-float)
Longer term, if your target's processor has hardware support for floating point operations you'll generally want to build or find a cross toolchain with hardware float enabled for speed. Some processor families have model variants some with and some without hardware support. So, for example, just saying your processor is an ARM is  insufficient to know if you have hardware floating point support.
Answer: The computation may be done either by floating-point hardware or in software based on integer arithmetic.
Doing it in hardware is much faster, but many microcontrollers don't have floating-point hardware. In that case you may either avoid using floating point (usually the best option) or rely on an implementation in software, which will be part of the C library.
In some families of controllers, for example ARM, the floating-point hardware is present in some models of the family but not in others, so gcc for these families supports both. Your problem seems to be that you mixed up the two options.
Answer: It may be the case that softfloats leave the data in the fpu alone, whilst hardfloats require the overhead of pushing the fpu registers out to cache when the process becomes active. This is why FPU is normally disabled for the kernel at compile time, don't waste cycles pushing it in and out of memory every time someone makes a kernel call.


Jiang & Conrath when two words are the same

Question: I would like to normalize the result of Jiang & Conrath similarity measure by dividing it by the maximum value(normally should be when both synsets are the same). I am using the implementation of Jiang & Conrath similarity in wordnet. when I use two same synsets for example slap.jcn_similarity(slap, brown_ic) the answer is 1e+300. How should I deal with it to normalize the results?  what is the range of Jiang & Conrath similarity?
I read in this website(http://maraca.d.umn.edu/similarity/measures.html):
There are two special cases that need to be handled carefully when computing relatedness; both of these involve the case when jcn_distance is zero.
In the first case, we have ic(synset1) = ic(synset2) = ic(lcs) = 0. In an ideal world, this would only happen when all three concepts, viz. synset1, synset2, and lcs, are the root node. However, when a synset has a frequency count of zero, we use the value 0 for the information content. In this first case, we return 0 due to lack of data.
In the second case, we have ic(synset1) + ic(synset2) = 2 * ic(ics). This is almost always found when synset1 = synset2 = lcs (i.e., the two input synsets are the same). Intuitively this is the case of maximum relatedness, which would be infinity, but it is impossible to return infinity. Insteady we find the smallest possible distance greater than zero and return the multiplicative inverse of that distance.
I actually could not figure out the first case exactly. Is this happen when a word is not available in the corpus for example the word "wwsds"?
How should we deal with these two cases in python programming? I would be grateful if anyone can explain any python program for dealing with these cases.
Answer: You can rewrite Jiang & Conrath similarity by: 1 / log(jcn_distance). If jcn_distance is equal to 0, then by adding 'log' the result will be 0.


What is a "covenant of salt"?

Question: In Numbers 18:19, God says the holy contributions made by the people of Israel belong to Aaron and his descendants forever, as a "covenant of salt".  I've never seen this term before.  What does it mean?
Answer: A covenant of salt in the Bible
The term covenant of salt is found three times in the Old Testament:
First occurrence

Leviticus 2:13 `And every offering of your grain offering you shall
  season with salt; you shall not allow the salt of the covenant of
  your God to be lacking from your grain offering. With all your
  offerings you shall offer salt.'[NKJV]

Notice here that the offerings were to be seasoned with salt, which is identified as the salt of the covenant.
Second occurrence

Numbers 18:19 "All the heave offerings of the holy things, which the
  children of Israel offer to the LORD, I have given to you and your
  sons and daughters with you as an ordinance forever; it is a
  covenant of salt forever before the LORD with you and your descendants with you."[NKJV]

This verse is in reference to establishment of the Aaronic Priesthood.
third occurrence

2 Chronicles 13:5 "Should you not know that the LORD God of Israel
  gave the dominion over Israel to David forever, to him and his sons,
  by a covenant of salt?"

This verse is in reference to the establishment of Davidic dynasty.
What does it mean?
One commentator notes that the origin of the phraseology is unknown1, however many reliable sources believe the relevance lies in the functions of salt in a covenant meal.
For example we read:

Covenant of Salt.
Biblical phrase for a two-way agreement, the inviolability of which
  was symbolized by salt. A Middle Eastern saying, "There is bread and
  salt between us," meant that a relationship had been confirmed by
  sharing a meal. Salt symbolized the life and enduring nature of the
  alliance. In the OT salt appears in the relationship between God and
  Israel (Lv 2:13). As a purifying agent and preservative in the cereal
  offering, salt symbolized the indissoluble nature of the covenant
  between God and Israel. [Elwell, W. A., & Beitzel, B. J. (1988). In Baker encyclopedia of the Bible (p. 538). Grand Rapids, MI: Baker Book House.]

and

Covenant of salt
  As salt was regarded as a necessary ingredient of the daily food, and so of all sacrifices offered to Yahweh (Lev
  2:13), it became an easy step to the very close connection between
  salt and covenant-making. When men ate together they became friends.
  Cf. the Arabic expressions, "There is salt between us"; "He has eaten
  of my salt," which means partaking of hospitality which cemented
  friendship; cf. "eat the salt of the palace" (Ezra 4:14). Covenants
  were generally confirmed by sacrificial meals and salt was always
  present. Since, too, salt is a preservative, it would easily become
  symbolic of an enduring covenant. So offerings to Yahweh were to be by
  a statute forever, "a covenant of salt for ever before the Lord" (Num
  18:19). David received his kingdom for-ever from the Lord by a
  "covenant of salt" (2 Chron 13:5). In the light of these conceptions
  the remark of Our Lord becomes the more significant: "Have salt in
  yourselves, and be at peace with one another" [from International
  Standard Bible Encyclopedia, revised edition, Copyright © 1979 by Wm.
  B. Eerdmans Publishing Co.]

Others have suggested that:

The term "covenant of salt" is indicative of the everlasting nature of
  the relationship between the children of salt, and their Elohim
  Yahweh. When we hear the term salt, the understanding is that the
  things Yahweh addresses are eternal, enduring, never changing, and
  abiding forever. All salt covenants then are eternal, and eternally
  binding on the sons and daughters of Yisrael, regardless where they
  are to be found, and regardless of whether a physical temple stands on
  Mt. Moriyah or not.[source]

I am not convinced the term can be limited to that because:
1) The covenants that God makes with man are perpetual, see for example Gen 17:7, 2 Sam 23:5 so it seems redundant to use salt to specify the perpetual nature of the covenant.
2) The salt of the covenant was used to season all the sacrifices, many of which were eaten by the priests and those offering them. The priest ate of the grain offering, the peace offering, the sin offering and the trespass offering, and the peace offering was eaten by those offering it as well2.
The people participated in the sacrifices by the eating of them as well as the offering of them, and those sacrifices were seasoned with salt; hence I favour the emphasis provided by the Baker encyclopedia of the Bible and the Standard Bible Encyclopedia mentioned above, as one commentator notes, "It is a common phrase among Oriental people, who consider the eating of salt a pledge of fidelity, binding them in a covenant of friendship."3
Concluding thoughts
The phrase doesn't just emphasis the perpetual nature of the covenant but also the friendly nature of it as well.

1  NAC. Cole, R. D. (2000). Numbers (Vol. 3B, p. 290). Nashville: Broadman & Holman Publishers.
2 Details of these offerings can be found in the following passages:
:Burnt offering - Lev 1; 6:8-13; 8:18-21; 16:24
:Grain Offering - Lev 2; 6:14-23
:Peace Offering - Lev 3; 7:11-34
:Sin offering - Lev 4; 5:1-13; 6:24-30; 8:14-17; 16:3-22
:Trespass offering - Lev 5:14-19; 6:1-7; 7:1-6
3 Jamieson, R., Fausset, A. R., & Brown, D. (1997). Commentary Critical and Explanatory on the Whole Bible (Vol. 1, pp. 108–109). Oak Harbor, WA: Logos Research Systems, Inc.
Comment: Note that the wording of Lev 2:13 [*melaḥ bərît ʾĕlōheykā*] differs fairly markedly from Num 18:19 and 2 Chr 13:5 where *bərît melaḥ* occurs, although they are typically associated with each other. G.B. Gray's [*Numbers* commentary](https://archive.org/details/criticalexegetic00grayrich) has a [brief but illuminating discussion of 18:19](https://archive.org/stream/criticalexegetic04grayuoft#page/232/mode/2up) which is still cited in more recent commentaries, e.g. Milgrom, *[Leviticus 1-16](http://www.amazon.com/dp/0300139403/)*, p. 191. FWIW. :)
Comment: Salt is also an integral part of the kashering process of meat.  If we assume that this tradition can be traced back to Mount Sinai then it also represents a usage of salt in the relationship between man and G-d.
Answer: I do believe there was a book written about this. The point isn't that the sacrifices were seasoned with salt but instead there was an exchange of salt. Or the way I see it is God provides the salt, from the earth, and we exchange it with Him in an offering.
Let's remember this was around 3,000 years ago. Salt was like gold, rare and only for the wealthy. Similarly, sugar was too.
For traders, salt was used to pay wages. Source: Salt: A World History by Kurlansky
From what I remember, salt was carried by many travelers. They each had a pouch containing salt. When two travelers came into agreement on something, they'd seal the agreement with an exchange of salt. I give you a pinch of mine, you give me a pinch of yours, and we both place that salt in our pouches. It implies that for either of us to break the agreement, we'd have to find the salt that we gave you, to take back our agreement. Or, in other words, it was a lasting agreement.

Leviticus 2:13 Season all your grain offerings with salt. Do not leave
  the salt of the covenant of your God out of your grain offerings; add
  salt to all your offerings.

I view this as God saying that He wanted us to exchange salt with us due to that cultural tradition. That God wanted to enter into a lasting agreement with us.
Answer: Salt is by nature a preservative and also a seasoning. A Covenant is an agreement between two or more parties. With God, it's a binding ensign between the Creator and His creatures, wherewith God binds Himself and expects the other parties to comply with His will to symbolise the oath.
In Leviticus 2:13 it refers to "seasoning", one of the functions of salt -- to season means to give it taste. The "preservative" function of salt is also applicable since it is added to food items used for sacrifices so that the object of sacrifice endures and doesn't go bad.
The "preservative" function of salt is the meaning intended by the statement of King Abijah in 2 Chronicles 13:5, that the kingdom handed to David is an enduring one, "preserved" for him by a covenant.
So it can be inferred that covenant of salt means a covenant that is alive (not spoiled) and enduring.
Answer: Edward Bagby Pollard puts it this way:

solt (berith melach; halas, classical Greek hals): As salt was regarded as a necessary ingredient of the daily food, and so of all sacrifices offered to Yahweh (Leviticus 2:13), it became an easy step to the very close connection between salt and covenant-making. When men ate together they became friends. Compare the Arabic expression, "There is salt between us"; "He has eaten of my salt," which means partaking of hospitality which cemented friendship; compare "eat the salt of the palace" (Ezra 4:14). Covenants were generally confirmed by sacrificial meals and salt was always present. Since, too, salt is a preservative, it would easily become symbolic of an enduring covenant. So offerings to Yahweh were to be by a statute forever, "a covenant of salt for ever before Yahweh" (Numbers 18:19). David received his kingdom forever from Yahweh by a "covenant of salt" (2 Chronicles 13:5). In the light of these conceptions the remark of our Lord becomes the more significant: "Have salt in yourselves, and be at peace one with another" (Mark 9:50).
See http://biblehub.com/topical/c/covenant_of_salt.htm

So as others here have mentioned it is a symbol of

Friendship and Peace
An Enduring Covenant

But I'd also like to add that the New Testament adds a new perspective to the salt of the covenant. We know from Leviticus 2:13 that

And every offering of thy present shalt thou season with salt, and thou shalt never allow the salt of the covenant of thy God to be lacking from thy present; with all thine offerings thou shalt offer salt.

This concept of salt as an essential component of every offering is repeated in the New Testament too
Mark 9:49 says

For every one shall be salted with fire, and every sacrifice shall be salted with salt.

Now, in the context of the New Testament the great offering is Christ. 1 Cor 5:7 says:

Purge out therefore the old leaven, that ye may be a new lump, as ye are unleavened. For even Christ, our passover, is sacrificed for us;

And also Ephesians 5:2

and walk in charity even as the Christ also has loved us and has given himself for us as an offering and a sacrifice to God for a sweet smelling savour.

Now every sacrifice was to be offered with an additional element... salt, but where's the salt here? If Jesus is the offering, who or what is the salt? We are...
Matthew 5:13 says

Ye are the salt of the earth, but if the salt has lost its savour, with what shall it be salted? From then on it is good for nothing, but to be cast out and to be trodden under foot of men.

So here we find that in order for the sacrifice of Christ to be effective in the lives of Jesus's followers, they must be part of the sacrifice as well, they must offer themselves as part of the sacrifice. This idea is reinforced in Romans 12:1

Therefore, I beseech you brethren, by the mercies of God, that ye present your bodies in living sacrifice, holy, well pleasing unto God, which is your rational worship.

Another verse related to Jesus' followers being the salt is Luke 14:34. The context of this verse is the requirements for being Christ's disciples. We read in Luke 14:27,33-35

And whosoever does not bear his cross and come after me cannot be my disciple. [...] So likewise, any one of you that does not forsake all that he has cannot be my disciple. Salt is good; but if the salt has lost its savour, with what shall it be seasoned? It is neither good for the land, nor for the dunghill; it is cast out. He that has ears to hear, let him hear.

Once again we see the idea of a daily sacrifice of the self in being a follower of Jesus.
In summary...
In the Old Testament salt was a symbol of friendship and peace and also of an enduring covenant between two persons or groups. In the New Testament it keeps and reinforces these meanings, but also reminded his followers that they must take part in Jesus' sacrifice by "offering [themselves] as living sacrifices" to God.
Answer: Actually, the salt covenants are in the texts quoted by the OP and there were two such:

The Levitical Covenant of Salt (Lev 1-9, 16, 21-27, Num 3, 4, 8, 18, 25:10-13, Deut 33:8-11, Neh 13:29, Mal 2:4-8. This is an eternal covenant (Num 25:12, 13, Ps 106:30, Jer 33:18, 21, 22) of salt, Num 18:19.) It is a covenant between God and the tribe of Israel. The salt element was added (Num 18:19) as a symbol of its solemnity. As a memorial of this, as part of the old ceremonial system, salt was added to all offerings:

Lev 2:13 - You shall season all your grain offerings with salt. You
shall not let the salt of the covenant with your God be missing from
your grain offering; with all your offerings you shall offer salt.

Eze 43:24 - You shall present them before the LORD, and the priests
shall sprinkle salt on them and offer them up as a burnt offering to
the LORD.

The Davidic or Royal Covenant of Salt (2 Sam 7, 23:5, 1 Kings 6:11, 12, 8:25, 1 Chron 17:11-14, 2 Chron 6:14-16, 7:17, 18, 13:5, Ps 89:4, 29, 34, 39, 132:11, 12, Jer 33:17, 21, Eze 37:15-28. This is an eternal covenant; 2 Sam 23:5, 1 Kings 9:5, 2 Chron 13:5, Eze 37:25, 26, Jer 33:17, 21 or salt, 2 Chron 13:5.) It a covenant between God and the royal line of David through whom the (humanly speaking) the Messiah would be born. The salt element was added (2 Chron 13:5) as a symbol of its solemnity.

Thus, there are no records of any private covenants between people involving salt - the only covenants of salt are divine covenants between God's people and God, initiated by God.

What is a "covenant of salt"?


Is it better to submit temporary fix/answer as an answer or edit it in the question

Question: Is it reasonable to answer your own question with a temporary solution? I have a solution that kind of works, but it is lacking some "features". Or otherwise, put the solution in the question? If so, then where in the question would be OK: top or bottom part?
Comment: @Nathan is the capital OK the right? because if you read it, it feels like **screaming**, so I normally use ok.
Comment: Yes. "OK" is one of the few words in the English language that's conventionally written in all-caps, always. It's sort of an acronym, although we don't know for sure what words were used to form it. The same word can also be written "okay" (which follows normal casing rules), but "ok", "Ok", and other variants are all wrong.
Comment: @NathanTuggy Thanks for a reasonable explanation.
Answer: The question goes in the question box, and answers (including workarounds) belong in the answer box.
A workaround is a legitimate attempt to "answer" the question, so it should be posted in the answer box. The fact a more complete answer may come along later should not discourage you from posting it there.
You should not post any information about how you solved your own problem in the question. That box should only contain the question. Including information about your attempts to solve the problem on your own DO belong in the question, but these are never a solution, per se, but rather unsuccessful attempts to find one.


Google drive hacked

Question: Someone hacked my google drive and restricted me from viewing my own files. I have their user name, LaLa LaLa. How do I find out who that person is? No Email address beside it like usual.
Comment: change your password
Answer: It's not clear what you mean by "restricted me from viewing my own files" but in any case the first that you should do is to follow the instructions on Make your account more secure.
Then

Disable the file synchronization with your devices.
Check your devices for malware
Try to recover accesible versions of your files. For details checkout View activity & file versions

Google drive hacked


Can I connect the "headphone out" of a ZOOM effects pedal (A3/G3) to a set of 2.1 stereo powered speakers and get decent sound?

Question: Is there anything I should be wary of? I'm planning to buy a guitar and kinda in doubt whether I should go for dedicated amp (like a blackstar id:core series) or get an effects pedal like a zoom g3/a3 and connect it to my speakers. Any advice please?
Comment: Not sure the pedal can power speakers on its own. Usually these can be plugged into an amp, then speaker. Headphone sockets will power headphones rather than full blown speakers.
Comment: Is it a *powered* 2.1 system, like you'd use with e.g. a computer?
Comment: Its this : http://www.sony.co.in/product/srs-d9 , a standard 2.1 stereo stuff that you'd plug in to your desktop/laptop.
Comment: Then yes, it will work fine.
Comment: @jonrsharpe I have my doubts that it will be "fine" as in playable, listenable, audible above a backing tracks and pleasurable. It will *kind of* work, in the same way that peeing in a bottle can kind of work if you just can't pull the truck over.
Answer: If your stereo has an "aux" input, of the kind you'd plug a separate CD player into, then yes, you can connect the output of most multi-effects pedals to this.
It's likely, in fact, that the output is labeled "headphone/line out". But any headphone output can be used as a "poor man's line out".
Answer: Be wary of the headphone output levels in the pedal and the actual volume on the system in order to:
1) get a clean sound.
2) reduce the risk of blowing a speaker when using a heavy distortion or high gain effect.
It is common sense even when connecting to an amp but extra care is needed when using systems the way they are not intended to.
The Zoom G3 has a L/Mono/Phone output, so it can give you a nice line out signal, additionally you can connect the pedal in stereo using the L and R outputs and the correct plug adapters (from 1/4"phone plugs to RCA plugs) or with the stereo Phone output using a cable with an stereo 1/4" plug (or miniplug with an adapter) and the 2 RCA plugs to connect to the stereo.   system
http://www.zoom.co.jp/products/g3/spec/
Answer: Yes, it can be done but I don't think it's worth it.
Two possible outcomes:
A. You'll spend your whole life either wondering whether it's you that can't play or if it's your plastic box that sounds bad and hollow and gritty. you'll probably not be able to understand what's wrong with your playing and you won't improve much, especially in terms of control, phrasing and dynamics.
B. You'll get bored of the little box's hollow sound pretty fast and conclude that playing guitar ain't much fun after all. You'll try to resell the whole thing but will discover quick that there's no market for that.

My advice is: a musical instrument is a musical instrument, not a device.
You money is best spent on - well, lessons, you have a teacher, right? - and on a modeling amp like the Vox Valvetronix series, you can get the AD15VT model used for well under $100 and it sounds great for all styles, from blues to metal.

It is especially good for a credible AC-30 emulation (if you are into jangly rock like R.E.M. or are after Brian May's sound) and for hard blues a la Stevie Ray Vaughan.
I know because I have one and it has made me fall in love with guitar again, after an emulator connected to my monitors sucked all love of guitar out of me.
Its high gain emulations aren't the best, but nothing, say, a DS-2 can't cure if you are so inclined.
Then again, get a teacher first and maybe see if he/she can help you choosing a good starter amp.
Just in case I haven't made myself clear:

get a teacher
get a teacher
get a teacher

Defer all equipment-buying decisions to after you've gotten yourself a good teacher - especially because a teacher will help you choose a guitar and amp that doesn't suck and help you get it set up, and believe me that there's plenty of unplayable, crappy pieces of wood out there.
Comment: Oh, also those Sony speakers are of little audiophile value anyway, as is pretty much any 2.1 rig with plastic 2" drivers that defer frequencies well above 80Hz to the "sub" (which isn't a sub anymore). Avoid like the plague except for use in the (home) office.
Comment: couldn't find any of that. So i bought a Blackstar id:Core 40. Sounds good! how do u think that compares with the vox ?
Comment: And, yeah, my amp has an emulated out, and even with a decent pair of headphones (m50) it sounds quiet and hollow.


Does Karp reducibility yield a total order?

Question: Or with other words, do we have that for every language $A$ and $B$, $A \leq_p B$ or $B \leq_p A$?
Answer: Far from it. Indeed, any countable distributive lattice embeds as a sub-partial-order of $\leq_p$, even if we only consider those degrees in between two given fixed languages (K. Ambos-Spies, Sublattices of the polynomial time degrees, Inform. & Control 65(1):63-84, 1985).
Answer: As a trivial counterexample, one may consider $A=\varnothing$ and $B=\{0,1\}^*$. Neither is reducible to the other, since $x\in A$ is always wrong and $y\in B$ is always true.


How long does it take to sync a node or a Daedalus wallet? What factors does it depend on?

Question: How long does it take to sync (download the blockchain) to a Daedalus Wallet or node. What factors does this depend on (download bandwidth, size of blockchain, upload bandwidth of the source (node))?
Answer: It all depends on your hardware, mostly CPU and network connection (yours and your peers), but on most newer hardware you should be able to sync it within a day right now.
Answer: As you also asked for a wallet, also note that after your local full node fetched and verified all blocks from the network, your wallet software (Daedalus) may has to restore an existing wallet, and so walk through the whole UTXO history (all blocks)
The more wallets you restore/update the same time the longer it will take
Answer: Also can be factor that how many relay nodes the wallet connects to. Right now by default that is only one node - the IOHK server. and that can sometimes not enough since it can be overloaded because lot of wallets can connect to that server simultaneously.
This limitation will be solved by the p2p node discovery will be introduced later this year..
btw, here is a workaround how to define more relays for the wallet:
https://forum.cardano.org/t/workaround-to-fix-daedalus-connecting-to-network-and-syncing-issue/59780?u=laplasz
Comment: Note that IOHK is running several nodes and you are not connecting to only one.
Comment: @MarekMahut-StakeNuts the topology file of the wallet contains only 1 address, so the node will establish a connection only with that address.
Comment: That one addresses resolves to a lot of different nodes. Also, `cardano-node` topology specifies the valency of this address. In other words, it specifies to how many nodes it should connect to from the specified hostname.
Comment: the valency is 1 for the default hostname. Yes, it can be different IP, but only 1 connection will established.
Answer: On 1st November 2021, I synced Daedalus Mainnet wallet for approximately 9 hours, and, on 2nd November 2021, Daedalus Testnet wallet for 1 hour.
Answer: Daedalus is a full cardano-node exe with a pretty GUI.
When you first start it up, it will connect to nodes defined in topology file, default relays-new.cardano-mainnet.iohk.io
So the syncing performance depends on various factors:

Your bandwidth and your peer's bandwidth
Your CPU performance
Your RAM (every peer in your topology will consume RAM)
Network status (it can be slower when operations occur on the ledger)

Remember that you can add some of your favorite peers in the topology, but not too much to not overload RAM.


Classical guitar techique to play artificial harmonics while striking three bass strings

Question: Is there a technique that would allow me to play something like this? I have my pinky and ring finger free, but i don't know if i could possibly play it with them. I'm just stuck at this point. Striking all the strings with my thumb doesn't produce the right sound. I have to somehow pick them.
Comment: I must ask, are you certain the tab is correct? If you know the name of the piece, we might find that the tab is inaccurate. If it is correct,you could research how other performers handled this. In fact, you might even be able to do that without our help if your ear is good enough!
Comment: Why can't you use your pinky or ring finger to play the harmonic? I assume you are talking about your plucking hand here. It seems perfectly doable to me.
Answer: I used my ring finger. I do not strike all the strings with my thumb though. Particularly because artificial harmonics produce less volume and you don't wanna "make" more sound by striking the muted strings.
For the first cord I pluck the E string with my thumb and the other three with my I M and ring finger of my left hand. The two other cords I pluck the three base notes with the thumb and the e string with my ring finger of my left hand.
The left hand movement is kind of like when you want to pluck only both E string. As examples: Black bird from the Beatles or fast car from Tracy. Only in this case you let the thumb "slide" through the strings and pluck the three base strings.
Make sure to master the left hand movement before trying the artificial harmonics, just play the 8th fret at first. once you feel comfortable, then you
ll just have to lift the finger a bit for the artificial harmonics.
Comment: I think you're describing a Natural Harmonic. For this to be an Artificial Harmonic, you should fret the string at the 8th fret and touch the string with the right hand (presumably at the 20th fret).


Difference between Monte Carlo and Quantum Monte Carlo methods?

Question: What are the differences between Classical Monte Carlo methods and Quantum Monte Carlo methods in condensed matter physics? If one want to study strongly correlated systems with Quantum Monte Carlo method, does he/she need to study Classical Monte Carlo method first? (just like if you want to study quantum mechanics you shall study classical mechanics first?)
Comment: My understanding (although since I don't work in the field, I could be wrong) is that *Monte Carlo* algorithms are an extremely broad class of algorithms that use randomization, while thaere are a handful of fairly specific classes of algorithms called *Quantum Monte Carlo* methods, these are a subset of Classical Monte Carlo algorithms. There is no reason you should study the Classical Monte Carlo method before starting on one of the classes of Quantum Monte Carlo algorithms.
Comment: Let me expand on my comment a bit. Suppose you are interested in the [Path Integral Quantum Monte Carlo](http://en.wikipedia.org/wiki/Path_integral_Monte_Carlo) method. One can view this as a classical Monte Carlo method applied to the evaluation of a path integral. It would be a good idea to study the specific classical Monte Carlo techniques that are used in this algorithm, but there are also zillions of classical Monte Carlo techniques which have nothing to do with this Quantum Monte Carlo method, and studying those might be wasting your time.
Comment: This might be one to send to [scicomp.SE].
Answer: That depends on what you want to achieve and what literature you have access to. Monte Carlo (MC) and Quantum MC are based on the same methods. Usually textbooks describe MC first and then build on this to explain QMC. One good resource to start is this book: Thijssen: Computational Physics. It does not cover everything in depth but gives a good overview.
Another good resource is this course website. It's free and includes many many code examples.
From the way I learned about those things, I would answer your question with: yes, you should at least take a look at MC before you start with Quantum MC.
EDIT: I just found this resource as well. A good intro to Quantum MC.
Answer: Quantum statistical mechanics is just classical statistical mechanics in one additional dimension. This is because the path-integral formulation of quantum mechanics allows you to expand the partition function of your model (which is classically just a probability distribution) as a sum over "space-time" configurations of your degrees of freedom weighted with a path action.
Now, it is very important to understand that not every model, when expanded in the path integral formulation, has a real path action, and this means that the weight of a space-time configuration $\sim e^{-S}$ doesn't need to be a real, positive-definite number. If that's the case, then there is no notion of a probability distribution to sample, and you cannot use Monte Carlo methods. This is called the "sign problem."
If such a probability distribution does exist, then you can use Monte Carlo methods, which don't care what distribution you're trying to sample, just that it is, in fact, a probability distribution.
So the bottom line is, learn the path-integral formulation and classical Monte Carlo, because classical Monte Carlo is the only Monte Carlo there is.
Answer: There are some concepts which is quite confusion to starters, though the concepts themselves are quite simple:
Classical Monte Carlo method: simulating classical statistical model with Monte Carlo method on classical computer,i.e., the PC we use daily;
Quantum Monte Carlo method: simulating quantum statistical model with Monte Carlo method on classical computer;
Quantum simulation: studying a quantum system by setting up a real quantum system, usually with cold atoms.


Does taking levels in a UA prestige class count against the level limit of 20?

Question: In Wizards of the Coasts article "Prestige Classes and Rune Magic" states that it uses the normal D&D multiclassing rules. Comparing it to what I know of D&D 3.5e prestige classes consist usually of four levels. Does this mean that in 5e, a character can only have 16 levels in a base class and 4 in the prestige instead of 20 levels in a base class and 4 in the prestige?
Comment: This is tagged d&d 5e but you talk about 3.5 prestige classes in the body.  What's going on there?
Comment: The majority of 3.5E prestige classes are 5 or 10 levels...
Comment: Did you read the PHB and the DMG?
Comment: I apologize I only briefly went over prestige in 3.5 to compare it to what Unearthed Arcana release as I never played anything other than 5e
Answer: Your question boils down to two ingredients: Do prestige classes work like normal multiclassing, and does D&D 5e still have a level limit of 20?

Do prestige classes work like normal multiclassing? Yes:

Mechanically, a prestige class is a character class that requires the same training and focus as any other class. You enter a prestige class by way of the normal multiclassing rules.

Does D&D 5e still have a level limit of 20? Yes.
The prestige class rules offered in the playtest material in Unearthed Arcana do not include any change to the base game's level limit, which is level 20.

As a side note, the first prestige class we've seen (the Rune Scribe) offers 5 levels to multiclass into, not 4. It bears repeating that experience with mechanically unrelated games can be misleading and should generally be ignored when looking at how D&D 5e works.


Would tied strips of webbing have similar strength to a climbing rope?

Question: i have a bunch of several-feet-length strips of webbing (polypropyrene) and was wondering if tied together, it can maybe be used as a climbing rope?
Comment: I'm not trying to put you down or make you feel bad, but your question definitely shows a lack of knowledge and experience in roped climbing. Briefly, the reason why this will not work is that knots won't pass through a belay device. If you're going to go out climbing, please make sure you have someone more experienced and knowledgeable with you.
Comment: @Ben  -The fact they would not go though the belay is a life saving benefit. I would be more worried about what happens to a human body when subjected to a fall in harness on a static 'rope'
Comment: Perhaps this question should be modified to "Can webbing be used in place of a climbing rope?" because the poster is not really asking about strength.
Answer: If your intending to top-rope with it, or unimaginably lead climb on it, then absolutely not... ever.
Polypropylene not only has a super low melting point, but the fibres are a really large diameter, which means they are super susceptible to abrasion, i.e. your rope cutting. It lastly won't stretch when loaded, which is all around bad news in climbing!
The only ropes you should ever be using for this type of climbing is those with a UIAA stamp of approval. You can typically find a tag at the end of the rope with various information, including it's certification - but put simply: No tag, no climbing.

That said, if you are going to hang it up in your garage or some place similar and use it as a gymnastic climbing rope like the image below, go right ahead! You may even benefit from the knots you'll have to tie every foot.
Answer: A climbing rope, as in sport-climbing, is also known as a dynamic rope - it stretches when you fall. If you use polypropylene strips and fall 5 metres, even if they are strong enough not to break, the same force acts on your body as if you fell 5 metres onto solid ground. If this weren't a problem, climbers would all be using steel cable which is stronger than any rope. Fall 5 metres into a dynamic rope on the other hand and you'll barely notice, falling during a climbing session is something you get used to and not dangerous if properly secured.
There may well be situations where you can use polypropylene strips, paracord or similar for rappelling or as "hand rails", but that's not the same thing.
Comment: It's not the fall that kills you. It's the sudden stop at the end.


When does the temporary editing ban get lifted?

Question: I recently got banned for editing posts and wanted to know if I will be notified when the ban is lifted or what measures can I take to lift the ban soon.
Comment: @KrishMunot so you've got 2 days left of a 7 day ban then...
Comment: You should have received a notice when the ban expires when you attempt to make a suggested edit. Anyway, the system will automatically lift the ban in 2 days.
Comment: Recently the implementation has been made for maximum of 20 posts. Check what happened to your recent edits. 4+ rejected edits in a span of one week.
Comment: @JonClements: Its been 5 days since I got banned. No actions yet.
Answer: As indicated by Jon Clements's comment, when you attempt to suggest an edit, a notice will be displayed containing the ban's expiration date.
In your case, the ban was for 7 days and was automatically lifted after that. You'll not be notified when it is lifted, but you'll find that you're no longer blocked when trying to suggest an edit.
For moderator-imposed bans, there are no measures for you to take to lift the ban any sooner. While banned, you are invited to review your past edit actions to make sure you don't make the same mistakes again. You might also study other material like How do I make a good edit?


What's wrong with my SWTOR launcher?

Question: So, when I try to load up the Star Wars The Old Republic launcher, it doesn't load up, but it says "Unable to load application configuration". How do I fix this? (By the way, I know nothing about computers)
Answer:
Right click on the shortcut and choose Properties →  Compatibility.  Set the compatibility mode to the previous version of Windows (XP SP3 if you're using 7, and 7 SP1 if you're using 8/8.1), and set it to run as Administrator.
Make sure you have the Visual C++ runtime installed (the game includes it under in the install folder under "extras", by default: C:\Program Files (x86)\Electronic Arts\BioWare\Star Wars - The Old Republic\extras\vc2008redist_x86.exe).  You should also install QuickTime and run Windows Update.
Add firewall and antivirus exceptions for launcher.exe (in the main install folder) and swtor.exe (under install folder\swtor\retailclient).
Reboot and try running the game.

If all that doesn't work, follow the steps here: Why won't my SWTOR Launcher open?

What's wrong with my SWTOR launcher?


Self-check redundant words

Question: I find myself using redundant words. (Ask a question: To ask is to pose a question, so question is redundant.) Apart from experience, is there any method to self-check?
Comment: It depends on what you consider redundant. "Pizza pie" is redundant as pizza is pie in Italian. It depends on how much you want to clean up your work but also note that a lot of redundant things could be idiomatic to cultural phrasing. For example as you stated with the "ask me a question" it does not sound redundant even though it technically is. So I would just say be cautious on how much you normalize what you are trying to write. It may end up sounding too formal, too foreign from actual conversation dialect that it throws people off.
Comment: Incidentally, the deliberate inclusion of unnecessary words can be a rhetorical effect called pleonasm: https://en.wikipedia.org/wiki/Pleonasm
Comment: For ways to actually check, as I said it just depends on what you find redundant. If you are looking for some form of software, there are a ton out there that will review your writing and flag things. Of course it may not catch everything. The best way to self check is to go through it yourself and or find someone/hire someone to help you with it.
Comment: Simply having a person/people to do proofreading for you is usually good enough.  This can be family or friends, and any editor you send your writing to for printing is going to do that as well, even if they send it to a junior writer to do it for them.  Just make sure that whomever you have do your proofreading knows that you are looking for grammar, spelling, and other language errors, *not* help with the plot or other "suggestions".  With the exception being if you accidentally contradict yourself or do another "glitch", like having a character take a drink from a cup they don't have.
Answer: I doubt there's any mechanical way to do this reliably, like a piece of software.
Some redundancies are necessary to make a complete sentence. Like your example, "May I ask a question?" You could say that "question" is redundant, as what else could one ask except a question. But how would you leave it out? "May I ask?" That just sounds awkward and incomplete. "May I ask something?" Okay, but what's the "something" that you're going to ask? Presumably a question. So what was gained by being vague? Etc.
Sometimes we are deliberately redundant for emphasis. "He was strong and powerful." Well, "strong" and "powerful" here are basically synonyms. We say it in two different ways just to make the point more forcefully.
You have to weed out the redundancies that are just a waste of time from those that have a purpose.
Comment: I would also like to emphasize with your example of "strong and powerful" that they could also be entirely 2 different traits. Strong is usually referred to in a physical sense. Powerful as a character trait is usually related to their political stature. So while they are synonyms, they also usually refer 2 different aspects of personality.
Comment: @ggiaquin16 Very late reply: Sure, it depends on the context. "Powerful" could refer to physical strength, political influence, economic influence, hey, even magic powers in some contexts. If you mean two different things by "strong" and "powerful", then yeah, they're not redundant. If you used both to refer to the same attribute, then they are.
Answer: I would recommend checking out ProWritingAid.com. It's an online editing tool that points out many areas of writing similar to what you mentioned, so it might do what you're looking for.
Edit: I don't have any affiliation with this company other than being a happy customer of theirs for several years now. In the past (and currently) I've used this tool to see redundancies, wordy sentences and overused adjectives in my own writing and improve based off what I learned from the tool.
Hope this helps.
Answer: Let yourself be redundant in your first draft. Just write it as it comes out of your head.
You'll go through your work many times in revision. If you're especially concerned about redundancies, do a pass focusing completely on that. (I revise on paper with a pencil, marking things to fix throughout. Sometimes reading it aloud makes the rhythms of your work more apparent.)
When you have your readers review your work, ask one or more of them to focus on redundancy as well.
Answer: If you were writing in German, the softwares Papyrus Autor (since 1992, Germany) and Patchwork (since 2014, Austria), both very similar in functionality to Scrivener, offer an advanced style analysis tool that marks up register, repetitions, filler, overly long sentences, and other stylistic weaknesses. The style analysis was proposed to the developers of Papyrus by German author Andreas Eschbach, who explains it on his website, both in general and in Papyrus.
I understand that probably none of you write in German, but I posted this answer anyway to show that a solution is theoretically possible, both programmatically and manually. You may want to try Google Translate to read Eschbach's article and see if his method seems plausible to you, although I must admit that that translation is terrible and requires quite a bit of hard thinking to make sense of.

Self-check redundant words


GPS Tracking by SMS

Question: I have a GPS Tracker which sends the GPRMC string of the NMEA 0183 protocol, at fixed periodicity, to a predefined number as SMS. I am looking for a software which can port these incoming SMS to a COM port to plot them dynamically to Google Earth or a custom GIS application, and use the name of the sending GPS as a label on the map. THe software should be capable of simultaneously tracking multiple GPS trackers simultaneously.
Comment: This question makes a lot more sense if you get rid of "port these incoming SMS to a COM port to "... Can you clarify what the COM port is doing in your concept? Why can't the SMS-receiving software plot directly to google earth? That would be a 10kB android application...
Comment: I'm curious about your tracker, did you build it yourself or buy one?
Comment: @Sparr I think the COM port is an implementation detail. Most if not all SMS gateway software communicate with the hardware through COM ports ( which may be virtual or real ).
Comment: @R.K. what "hardware" are we talking about here?
Comment: Cell phones or 3G modems. They usually connect to the PC via a USB cable but the computer still communicates with them through virtual COM ports if I'm not mistaken.
Answer: Kannel is the most known sms gateway (Free and Open Source), it runs both in Linux and Windows. You can connect it with a GSM modem or a mobile phone to send or receive sms (or MMS). If you have a GPS who can connect to GSM you have the solution. AND of course it connected with Mysql or Postgresql and more DB. From a database you can send the data to a web system.
Kannel: Open Source WAP and SMS gateway
Answer: Would Gammu SMS Daemon http://wammu.eu/smsd/ be a start?

Gammu SMS Daemon is a program that periodically scans GSM modem for received messages, stores them in defined storage and also sends messages enqueued in this storage. It is perfect tool for managing big amounts of received or sent messages and automatically process them.
You can currently store received messages in files or in various databases. MySQL and PostgreSQL are supported natively and wide range of others (including SQLite) through libdbi (libdbi backend is currently not available in Windows builds).
Comment: I'm using gammu-smsd with sqlite3 and it's been running for 4 years now using SIEMENS MC35i , any kind of terminal GSM modem speaking a decent protocol will probably work with it. This is a good suggestion.  I also have to add it's running on ubuntu linux on a minimac.
Answer: Check out SlingshotSMS.  It's a minimal SMS server which connects GSM modems to websites and applications via a simple HTTP interface. Here's a sample architecture.

You could do away with the Drupal backend and write your own. It's also portable so you can run it from a flash drive.

THe software should be capable of simultaneously tracking multiple GPS
  trackers simultaneously.

If I understand it correctly, those would be different numbers sending to your tracker? If so, you could just filter them by sender so you would be able to distinguish them.

GPS Tracking by SMS


Is it possible to deploy RDS in multiple region in AWS with read and write replica

Question: I have an application that I need to make it accessible across 4 regions, I saw blogs and other posts in the internet that speaks about the read replica of AWS RDS MySQL Server, is it possible to enable write operations in the regions so that the data can be in sync and be writable across all the regions.
Answer: You can look at Aurora Global Database for this. Based on this news announcement, you can also configure the setup, so you can write to your local db cluster and this is forwarded to your primary region.
Of course there would be some lag in write requests, essentially of the length of time it takes to write to the primary region and replicate the data changes back to the replica in your local region. Nonetheless this is likely easier to handle (and with the same methods in a web application), as if you wrote to the primary region yourself and checked if the data had arrived back in local replica.


Does a switch MAC address table sync across all switches in the same VLAN?

Question: Ok, I have read up about this 16K limit for the MAC address table, or better known as the CAM table, on certain switches. Lets say I have 14 different edge switches with that 16K limit, and I have VLAN 200 set up across all of these same switches, would I expect to see the tables "sync" across all of the switches for that VLAN? For example, if one switch fills up with 10K mac addresses, would I expect to see these same MAC addresses in the CAM table across all switches in that VLAN? Could this be something that differs by configuration and/or vendor implementation?
Answer: Synchronizing MAC address tables across switches doesn't make any sense. Each switch maintains its own MAC address table.
For instance, suppose you have Switch 1 and Switch 2 connected together of their ports 24, and MAC address 0123.4567.89ab comes into Switch 1 port 5. On switch 1, the MAC address table would reflect that MAC address 0123.4567.89ab is connected to port 5. If any frames from the host with that MAC address find their way to Switch 2, the MAC address table of Switch 2 will have MAC address 0123.4567.89ab coming into port 24. If no frames from MAC address 0123.4567.89ab get sent to Switch 2, then Switch 2 will not have 0123.4567.89ab in its MAC address table.
If you synchronize MAC address table across those two switches, then how would you propose to resolve the port conflict where 0123.4567.89ab is on port 5 of one switch, but it is on port 24 of the other switch?
The closest thing you could have is with switch stacks, where multiple switches are connected in a stack, and the stack looks like a single switch. You configure the stack, not the individual switches, and things like STP and MAC address tables are done as if the stack was a single switch.
Comment: Since each switch maintains its own table, there will be no port conflict. For Switch 1, the MAC address only comes into port 5, but for Switch 2 the MAC address only comes into port 24. If the host changes position, say it now connects to Switch 2 on port 7, the first frame coming into Switch 2 port 7 with that MAC address will change the Switch 2 MAC address table. If it happens to switch among multiple ports in a very short time, you will get warnings about a flapping MAC address.
Comment: So, to avoid a duplicate mac scenario per access port, if the frame does make its way to a neighboring switch and gets stored, its shows up in the  trunk port (port 24) of the switch cam table? Is that how it can show up on both switches AND avoid a port conflict?
Answer: Switches don't normally1 sync MAC tables, they independently build them based on the Source MAC addresses and ingress ports of frames they see.
However pretty much all devices send out broadcast (or effectively broadcast) packets first (DHCP, ARP etc). When a broadcast packet is sent from a MAC address that packet will be processed by every switch in the VLAN and hence it's MAC address will be recorded by every switch in the VLAN.
So under normal circumstances you would expect all the switches on a VLAN to have pretty much the same list of MAC addresses in their switching table for that VLAN. Obviously the ports associated with those MAC addresses will be different.
1 There are exceptions to this, some protocols for virtual Ethernet networks explicitly advertise the location of MAC addresses. https://datatracker.ietf.org/doc/html/draft-ietf-bess-evpn-overlay-04