Rate limit based on VLAN

Question: My ISP company has some PoPs in remote areas, as shown in diagram. It is currently, it's getting all prefixes from Local IX and getting only a default route from the upstream Internet provider. Currently, the internal network uses static routing, but I am planning to move it to OSPF.
Currently, all the traffic shaping is done in PoP routers so that core router doesn't get burned out, and it's done by interface-based rate limiting, one customer one interface basis.
Now my goal is to provide unlimited speed (full wire-speed) to local IX, which gives hundreds of prefixes which are constantly changing, and my service nodes (FTP, storage, local contents, etc.), while limiting Internet bandwidth by customer. Preferably, this done in the PoP routers. Again, it is not at all feasible to put separate long haul links to pop routers just for this purpose.
Is it possible to rate limit based on VLAN so that I can achieve the goal? Are there any other suggestions?
Comment: This question is really broad with opinion-based answers. You can read in the [help] on how to properly ask a question, and you should edit your question to narrow the focus and eliminate opinion-based answers.
Comment: Edited to narrow question down
Answer:
Is it possible rate limit based on vlan so I can achieve the goal ?

The answer is a qualified yes. It really depends on the capabilities of your router hardware and software. For instance, I know Cisco and Juniper routers have robust QoS features to allow traffic shaping and policing based on a variety of criteria, which include VLANs or IP address ranges.
Without knowing what equipment you are using, it is impossible to say for sure, but it is highly probable that you can do this.

Rate limit based on VLAN


What is the typical sentence for BURGLARY - OCCUPIED DWELLING UNARMED?

Question: Just asking for a friend in South Florida.
Answer: This is not a good question for two reasons:

Criminal sentencing guidelines vary by jurisdiction and can be readily found by searching for sentencing guidelines and the jurisdiction in question.
Sentencing "typically" depends on factors beyond the crime committed.  These commonly include:

whether the offender is a "first-time" or repeat offender
whether the offender was an accessory (helping the main offender) or the main offender
whether the offender committed the crime under great personal stress or duress
whether anyone was hurt, and whether the crime was committed in a manner that was unlikely to result in anyone being hurt
whether the offender was particularly cruel to a victim, or particularly destructive, etc.
whether the offender is genuinely contrite or remorseful
Comment: 3) the friend is potentially facing a serious criminal charge, and should be consulting with actual lawyers rather than random people online
Answer: According to the Florida Statutes, section 810.02, this is probably a felony in the second degree, although there are circumstances you have not covered (using a vehicle to make entry, or causing sufficient damage, or assaulting an occupant of the structure, or during a state of emergency) that could make it a felony in the first degree.  The relevant sentence is covered by either section 775.082 or section 775.084.
According to section 775.082, a felony in the first degree carries a sentence of up to 30 years in prison unless otherwise provided by statute; section 810.02 provides otherwise and first-degree burglary carries a sentence of up to life imprisonment.  A felony in the second degree carries a sentence of up to 15 years in prison.
If this is the third felony the offender is convicted of, section 75.084 (habitual felony offenders) applies and the potential sentence is life imprisonment for first-degree felony burglary, or up to 30 years for second-degree.
Comment: Good references, but not necessarily responsive to the OP: there can be quite a disconnect between _typical_ sentences and the _maximum allowed_ sentence.


Can I use a separate hosting company for a subdomain?

Question: I own a .me domain (bought with GoDaddy), where I have my web hosted using Github pages. Now, I would like to create a sub-domain or sub-page (such that subdomain.example.me or example.me/subdomain) and fill it with an external template that I want to buy using a web-provided such as Squarespace. Is is possible to do that?
Comment: Your second example is a subdirectory, not a subdomain.   It is more accurate to say `example.me/subdirectory`.
Comment: You can, and if something goes wrong, to whom will you turn?
Answer: You can do this for a subdomain (ie subdomain.example.com) - as DNS is designed (among other things) to direct different different subdomains to appropriate ip addresses.
It is only indirectly possible to have 2 servers hosting content to a site (ie in the case example.com/resource1 on a different server to example.com/ or example.com/resource2) and a lot harder to implement.  In order to do this you need to add some kind of reverse proxy or load balancer which accepts the requests and then gets them to the appropriate server. I believe Cloudflare may be able to do this  and I know that Apache can be confugured to do this using mod-proxy with proxypass rules - but setting this up requires access to the server configuration and some specialist knowledge). There are analogous mechanisms for NGINX as well as standalone proxies.
Answer: It should be relatively straight forward to configure a subdomain to point to another service like Squarespace, however, to point a subdirectory to an external host requires very different technologies and is unlikely to be possible with using only Github pages and Squarespace.
To forward the subdomain you would configure either an A record in the DNS to point to an IP address at Squarespace (or a CNAME record to point the subdomain to an already configured domain at Squarespace) and configure this hostname/subdomain at Squarespace, so that it knows to accept requests to this hostname.
However, to forward a subdirectory requires that you configure a reverse proxy at your source host (Github pages), which AFAIK Github pages does not support*1. This may also be against Squarespace's interests/T&Cs and they could potentially (attempt to) block the request.
*1 Although as noted by @davidgo in comments, you could employ an additional service that sits in front of Github pages that implements the reverse proxy.
Comment: I largely agree, but would point out it is quite possible to configure a reverse proxy at another location altogether, so it does not need to be supported by Github.    I skimmed through the Squarespace T&Cs and their Product specific terms and could not find anything against putting a proxy in front of the site.  Squarepsace havehttps://support.squarespace.com/hc/en-us/articles/213469948-Connecting-your-domain-to-CloudFlare) a specific page for connecting through Cloudflare, so I posit this is practical  (
Answer: Yes it is possible to create https://here.example.com hosted on a different server, create a subdomain name and set the DNS A record to your desired IP address.
Sub path is harder to implement and generally your host will need to setup and will most likely change an extra monthly cost to do so. Not impossible just more difficult.


Is a notarized signature required on a title search?

Question: I've noticed that in preparation for closing on a house, a title search is done.  What is the name of the document that is produced when the title search is complete?  And does that document need to be signed by an attorney?  Is a notarized signature required?  Is it customary?
Comment: Where? There are hundreds of jurisdictions to choose from.
Comment: @Greendrake - Oh.  It varies county by county?  State by state?  Country by country?  In the UK, for example, is it also called "title search"? // I made some progress on my own.  I think the resulting document is called "title abstract."
Answer:
I've noticed that in preparation for closing on a house, a title
  search is done. What is the name of the document that is produced when
  the title search is complete?

There are several kinds of products of a title search that could be produced.
The smallest and cheapest, but not usually sufficient for a closing on real estate, is an O&E for "ownership and encumbrance report" which lists the current owner of record and current debts that the property is subject to based upon a superficial, non-guaranteed search.
Another product is an abstract of title, which is a list of all recorded documents related to the title of the property, sometimes discarding documents that are "wild deeds" or are barred by adverse possession doctrines (a sort of statute of limitations that gives someone with a long chain of uninterrupted title priority over someone who has older documents that arguably given them an interest in the property).
A third product is a title commitment. This document states that the title insurance company is insuring and guaranteeing that a certain person will own the property free and clear subject to only specified encumbrances and easements of record, if certain steps are taken (i.e. if the required documents are paid at closing and the identified debts are paid in the amounts listed). Often there are lots of exceptions for easements, HOA organization documents, special taxing districts, mineral rights, water rights, etc.
In the Western U.S., normally a title commitment is the main document used at closing. In the Eastern U.S., a title abstract followed by an insured opinion letter regarding title from an attorney is more common.

And does that document need to be signed by an attorney?

In the Eastern U.S., for example, in New York State, this is restricted to attorneys. In many Western U.S. states one does not have to be an attorney to do an abstract or a title commitment or to issue title insurance, although title insurance companies generally have an attorney on staff even though most routine cases are done by title officers and paralegals who are not lawyers.

Is a notarized signature required? Is it customary?

A notarized signature is neither required nor customary unless offered as evidence in opposition to a motion for summary judgment in a court case.
Comment: Thanks.  Let's say it's a paralegal doing the title search.  Does the paralegal have to sign the finished product or some related document?  Does an attorney have to sign -- or is it customary for the attorney to sign?
Comment: @aparente001 There is extreme regional variation, mostly east to west but with some exceptions. Title commitments are usually signed by a non-lawyer title officer who is a de facto paralegal where this is not considered practice of law (e.g. Colorado). An attorney signs title commitments and title abstracts in places like New York State.


If 100% of the energy from the sun is reflected back into space

Question: 100% of the energy from the sun is reflected back into space, it's just shifted from a low-entropy state to a high-entropy state, and from a high frequency (ultraviolet) to a low frequency (infrared). But does the total number of photons change as a result? Are there more low frequency photons, then, in order to make the same amount of energy?
Answer: Reflection, by definition, sends the same photons back. So it can't change the frequency of the photons or their number or the entropy (at least locally, it can't).
What you probably want to talk about is complete absorption and black-body re-radiation of the energy. That's something else than reflection.
Yes, if the planet is in balance, then, of course, it has to emit a higher number of photons that have a lower energy and lower frequency each because the energy of a single photon is related by $E=hf$ to the frequency. The entropy is essentially proportional to the number of photons, so it emits more entropy than it absorbs, and the entropy is increasing.
Comment: The frequency of a true reflection is altered by the doppler effect. Of course we can have a temporal energy imbalance as the planet may be heating up/cooling down on average at any given moment. Wheras with reflection (ignoring photon time of flight issues), we won't get a temporal imbalance of energy.


Change Add To Cart To Buy Now drupal Commerce

Question: Hello currently I am making a online e store using drupal Commerce so i want to change add to cart button to Buy Now So Ho Can I able To Do Help It Out
Answer: If you want to alter the text for a particular form you can alter it using hook_form_alter
Get the ID of the form for the product display where you are trying to change the text & do something like this:
function MYMODULE_form_alter(&$form, &$form_state, $form_id){//replace your module name with MYMODULE
  if(strpos($form_id, 'commerce-cart-add-to-cart-form-65') !== false){//my form ID is "commerce-cart-add-to-cart-form-65", replace it with your form ID.
    $form['submit']['#value'] = t('Buy Now');//Put the text which you want to make appear instead of "Add to cart".
  }
}

You could also use String Overrides Module to achieve the same.


Do Jehovah's Witnesses believe that their "Governing body" will rule the world after "Armageddon"?

Question: I understand that Witnesses follow an unelected body of men called a "Governing body".  However I'm unclear on whether or not they believe this governing body is in charge of the earth after their claims of Armageddon.  Is this true?
Comment: What research have you done to indicate that it *might* be?
Comment: An ex-Witness told me.  So I'm trying to see if that's true.
Comment: I voted it up. This question has potential, since it focuses on eschatology.
Answer: Read this article:

http://www.jw.org/en/publications/magazines/w20130715/who-is-faithful-discreet-slave/
This addresses your question specifically.

Often you won't get the same answer when asking random people from their congregations as some are more in touch with modern developments more than others, as you've just discovered.
Another thing is that the interpretations on core modern fulfilments often change: 2013 changed the governing body's role slightly. The "wheat and weeds" understanding also recently changed.
The answer is "No" they do not believe they will exclusively "rule the world", but are part of the 144,000 which serve as Kings and Priests under Christ, obeying him as co-rulers. They presently find themselves to to have a unique role among the anointed, that having changed to "Faithful and Discreet Slave", which dispenses food (teachings) in due season/proper time.
Comment: So the hierarchy they support now will no longer exist in this hypothetical scenario?  No Witness will have leadership over another?
Comment: 2 Corinthians 1:24 -- is the motto (Overseers not masters over our faith). There is no hierarchy.
Comment: To my understanding, having spoken to  many Witnesses, there is a heirarchy because the governing body IS unelected and dictates what literature and rules elders and followers must follow.
Comment: You are correct in many ways. We have a hierarchy, but we are individually answerable to only God and Christ. So if we were ever asked to do something contrary to bible commands then we would obey God rather than those men. In that way they aren't really leaders as much as they are guides.
Comment: Let's keep the comments restricted to clarifying the answer. A remind that the purpose of this site is to provide information about what people believe, not determine who is right and who is wrong.
Answer: We do have an unelected Governing Body. Currently there are 8 men on the body. The term "governing body" is synonymous with the "faithful and discreet slave" (Matthew 24:45)
Jehovah's Witnesses believe that 144,000 men and women will be co-rulers with Jesus in heaven and rule over the earth (Revelation 20:4). Of course they won't be humans at that time. They will be spirit creatures like Jesus; a new creation (2Co 5:16, 17). The members of the Governing Body are part of this 144,000 and will rule in heaven if they finish their earthly life in a faithful state.


Ubuntu 17.10 and rhythmbox google music plugin

Question: I'm trying to install the google music plugin for Rhythmbox(link)
Now this plugin also requires 'gmusicapi'(link)
I was able to install both these packages without any errors.
When I open Rhythmbox and try to enable the google music plugin, the player crashes.
I tried running the player in debug mode from terminal by using rhythmbox -d
When I try to enable the plugin, it throws this error: This program requires version 3.5.0 of the Protocol Buffer runtime library, but the installed version is 3.0.0.  Please update your library.  If you compiled the program yourself, make sure that your headers are from the same version of Protocol Buffers as your link-time library.
Questions:

How do I fix this? I have installed protobuf 3.5.o and my protobuf-compiler version is 3.0
I believe both are the latest
A questions about the gmusicapi: Where should I include this authentication code link
I started a python shell in Ubuntu terminal and was able to get a python list of my google play music library. But when I try to do the same in the Rhythmbox python shell, I get the same error

Please help. If someone is using the google play music plugin please assist.
Please let me know any additional debugging steps that I can follow to help me solve this problem.
PS: I'm using Ubuntu 17.10
Answer:
For Ubuntu 14.xx or Later Users
Canonical's repos package Rhythmbox 3 beginning with Ubuntu 14.04 Trusty Tahr. If you are running Ubuntu 14 or later, you will need to add the Saucy repos to your sources, and downgrade to Rhythmbox 2.99 to use this plugin.

Have you downgraded your Rhythmbox?


Type I error and type II error trade off

Question: Can someone illustrate the trade off with the help of a diagram and intuitive explanation? Thanks
Comment: Are you familiar with the story of the boy who cried wolf?
Comment: I am! I read what type 1 error and type 2 error is in the story's context.
Answer: When the boy first pretends there is a wolf and the villagers believe him, it's a Type I error. When he claims there is a wolf again, but no one takes him seriously, though it is true, it's a type II error.
The villagers can avoid type I errors by never believing the boy, but that will always cause a Type II errors when there is a wolf around. Similarly, they can always believe him and never make a Type II, but that will cause lots of Type I errors.
You can think of using how scared the boy as a kind of test statistic. If he's crying, his breathing and heart rate are elevated, he has goose bumps or piloerection (his hair is standing up), then the villagers should take his claim more seriously. Requiring all these symptoms to be present and high is analogous to using a small $\alpha$ in the graph that @slowloris posted.
Comment: That makes sense! Thanks a lot :) But could you illustrate that with a figure? I remember my professor showing me something in class about that. There were bell curves under null and alternative and we could see the trade off between type 1 and type 2 errors.
Answer: A life and death example of statistical errors
You are a paramedic and you approach the scene of a car accident. One victim is laying motionless on the road and you must assess whether the victim is dead or alive, and the victim will be treated accordingly.  Based on this information which error rate results in the most costly mistake?
Null Hypothesis - The victim's status equals a living person
Alternative Hypothesis - The victim's status is not equivalent to a living person (i.e., they are dead)
Type I error - You reject the null hypothesis when the null hypothesis is actually true.
Type II error - You fail to reject the null hypothesis when the the alternative hypothesis is true.
Cost of Type I error - You erroneously presume that the victim is dead, and they do not receive an ambulance to the hospital for a life saving medical treatment.
Cost of Type II error - You erroneously send a dead person to the hospital in an ambulance.
Answer: As you can see, the Cost of the Type I error is tremendously worse than the cost of the Type II error.
Therefore, you may consider the trade-off of these errors.  In traditional statistical hypothesis testing, you could use this cost benefit analysis to determine your alpha (Type I error rate) and beta (Type II error rate) before conducting an experiment. In our example, we would want a very small alpha (typically 0.05), but could live with a larger beta (typically 0.1 - 0.3, but we could live with >0.3 in this case).  This would, for example, dramatically effect the required sample size of your experiment because you are OK with accepting the null hypothesis incorrectly and report that dead people are actually alive.
I diagnostic testing, we can look at trade off of Type I and Type II errors in terms of the threshold we place between the distribution of a measurement taken from two populations.  Using our example, we might measure the redness of the skin, with redder skin representing a living victim.
In the figure, we can see that the best place to put a threshold between these groups is in the lowest point between the two distributions.  This location would result in the least overall error.  However, we can make a logical trade off here: By moving the threshold to the Right, the probability of a Type I error is reduced at the expense of increasing the probability of a Type II error.  In our example, this trade off is good and would likely save someone's live and our job as a paramedic.

Image Source: http://grasshopper.com/blog/the-errors-of-ab-testing-your-conclusions-can-make-things-worse/
Answer: Google "illustration type 1 type 2 error" and have your pick. This site is one of many you can find a figure like the one you are asking for.


Foundation For An Underwater Dome

Question: Can I get help on how to make a foundation for an underwater dome that can hold an amount of 150,000 people? But don't try to use Wikipedia, please.
Comment: welcome. interesting concept that has been delved into in several questions on Worldbuilding SE. questions to help you define your problems a bit more: deep under water or shallow coastal water? rocky bathymetry or sand/clay bathymetry? have to take into account wave action or strong currents? are we using today's tech or far future? or possibly even past tech? Currently there is nothing defining what you are actually having a problem with or even how you would define an acceptable answer. I suggest you have a look around at other similar questions to see if they can help first. Enjoy :)
Comment: How *much* water is this dome under? A dome that's three miles underwater will require a vastly different engineering solution to one that's just three feet underwater.
Comment: Normally buildings are designed in terms of employed materials, foundation ground type and consistency, maximum solicitation. Unless you define these your question is too broad.
Comment: Holding 150 000 people like a stadium? Or a city that includes everything from housing, workplaces, schools...?
Answer: Build it without a foundation.
Your air filled huge dome will have substantial buoyancy.  It will have negative weight.  It will not sit on the bottom.  It will be like a huge helium balloon on land.  A balloon does not need a foundation.   You will need strong tethers to keep your dome from floating away.

Sink deep pilings around circumference of dome site.
Put some sort of floor on the site.  It can be anything because it serves no structural purpose.
Position dome in ocean over pilings.  Fill it with water until it is barely buoyant.
Winch it down into the piling nest.  You will need to add air as it goes down because as it gets deeper air within will be compressed and it may become less buoyant.
Once in position over floor secure it to floor and pilings and fill with air.  If interior pressure is slightly over external that will ease the load on the dome from external water but you might blow it up off the floor.  Internal pressure slightly lower than external will let water press the floor up into it and if it is close to external it is not that much load for the dome.

If you are so deep you need huge air pressure then your inhabitants will get nitrogen narcosis from the high pressure air.  You will need to either use a helium oxygen mix or lower pressure air and hope your dome can take the external pressure.

Watch to make sure pilings are not getting pulled up and loose!

Foundation For An Underwater Dome


Is it beneficial to practice derivations instead of solving problems

Question: During much of my time studying physics on my own time, I have prioritized practicing the derivations out of the book because I feel like I can learn more by trying to master the theoretical structure rather than applying the theory to solve problems. And I don't mean that I read over them, I mean that I will repetitively derive an equation anywhere from 1-10 times until I feel like I completely understand and have memorized it. However, I do not want to waste time. Is it beneficial to spend most of my study time trying to master the derivations already given, or should I mainly skim over the theory and dedicate most of my time-solving problems? I want to choose a route that will maximize the amount I learn and what will lead me to become a more efficient physicist. I don't know if it will make a difference but this question is aimed toward more advanced physics classes/students.
Answer: This is a great question.  I think many theorists (and I am one) follow this path.  For one thing that is part of our job, to derive things.  Also, I think you are correct in that by deriving things we learn at a deeper level.  However, sometimes solving specific problems allows us to apply mathematical techniques and reasoning in a different way compared to going through derivations.  Also, as a theorists I was indoctrinated into the thinking that constants didn't matter.  We tacitly set them to 1.  Later in life I regretted that.  There is great value in "knowing things", like the value of the Gravitational constant, the speed of light, etc.  But it sounds to me like you are looking for an optimal learning path.  One that takes up as little time as needed to maximize your skill set.  I am not sure that there is a perfect ratio of theory to application.  It is probably different for each person.  But I would offer some advice.  It is often said that we should play to our strengths while working on strengthening our weaknesses.  So, be honest with yourself, are you really great at deriving and sloppy at solving?  Or, is solving problems really easy and uninteresting for you?  If you can do it well no need to bother practicing. But if you are better at one than the other you might want to spend more time on the thing you are bad at.
I often had the experience of reading something abstract on QFT or another topic, deriving the numbered equations and feeling like I had mastered it.  Then when it came to doing a simple calculation I got stumped.  In some cases the approach to solving a problem or calculating something involves deciphering the presentation of the problem and fitting it into the theoretical paradigm you learned.  This is not always obvious and involves a different type of thinking.  One does not beget the other.  Also, we often find that to completely solve a problem we need to make simplifying assumptions that the theory does not necessarily teach us to do or we need some clever trick.  This is always worth learning.
When it comes to deriving the basic results, it is helpful but applying them can be more useful.  I'd say that if you want to be a theorist then you will want to learn the art of proving things, and deriving things.  This will be part of your job so it is definitely worth the effort.
Comment: IMO, the best challenges are self imposed.
Comment: What about taking up challenges? The question and your answer seem to be about what kind of practicing one should d to learn the material effectively. But isnt it also important to train solving problems when the path to a solution is unknown (i.e. not training a derivation i have seen in some book or textbook problems with given solving algorithms, but actually seeking out some challenging problems, that might not be as efficient for helping to learn the material, but will help you to learn some creativity)?
Comment: I agree, but you have to start somewhere.  One thing I used to do is make up my own problems by altering those in the text.  I would go through a lot of "what if" scenarios in my mind.  In some cases this led to unsolvable problems and frustration.  But one needs to learn to not get frustrated so it was worth it.


Is the typical value (as consumed) refer to the product after cooking or before cooking?

Question: Looking at the Typical Values under Nutrition for Morrisons Free Range Egg Noodles, does the "(as consumed) per 100g" mean that 100g of uncooked noodles provides 107 calories when it is cooked, or 100g of cooked noodles provides 107 calories?
Comment: I fry them just using heat, no oil. So can you work out how many calories it would mean if 180g (measured before they are cooked) are cooked?
Answer: Nutrition tables give the value for the product alone, as is, unless explicitly stated otherwise. Cereal sometimes describes a serving as Xg cereal plus Yg milk of a certain fat content, for example. But there should always be the "pure" values for 100g, as most food labeling laws require.
The product description confirms this by explicitly stating "as sold":

A 1/4 pack (as sold) provides... Calories 110 5.5%, Sugar trace trace, Fat 1.5g 2.1%, Saturates 0.1g 0.5%, Salt trace trace of your guideline daily

If you check the table carefully, you'll notice that for a 1/4 pack (slightly over 100g) the value for fat is 1.5g. This fits what the eggs in egg noodles would contribute, but is significantly less than what per the cooking instructions should be added for stir-frying.
If you want or need to calculate your calorie intake, weigh the product before your chosen preparation method and use basic maths to calculate the calories or other nutritional values. Any additions (like the aforementioned oil) need to be calculated separately.
Comment: @EthanFairhurst Exactly. That's how the nutrition labeling works.
Comment: Unless you somehow removed anything with calories (water has no calories), no. You can't evaporate calories.
Comment: So if I weighed 100g of these noodles before I cooked them then this provides 107 calories when cooked, forgetting any dressings or oil used to cook as I only use heat to cook these?
Comment: I also found that the mass decreased after I cooked them? Does this mean that the calories would decrease from when I initially weighed due to the decrease in mass when I have cooked?


I am Brasilian resident, how to buy shares on NYSE?

Question: I am having my work contract here in Brasil. I have some money (3000$) and I would like to invest it in some specific companies that are listed on NYSE. How can I do this, it seems that most brokerage houses do not allow Brazilian residents to buy shares. Any advice is welcome.
Comment: Many brokers do accept international customers (Interactive Brokers does), Brazilians should be accepted as well. Have you tried them?
Comment: This is definitely on-topic for PF.
Answer: There are some brokers in the US who would be happy to open an account for non-US residents, allowing you to trade stocks at NYSE and other US Exchanges.
Some of them, along with some facts:
DriveWealth

Competitive brokerage fees
Process for account opening is straightforward and fast
Mobile app is cool
Has support in Portuguese
Website

TD Ameritrade

Moderate fees for shares
Zero brokerage fees for some ETFs
Has support in Portuguese
Website

Interactive Brokers

Competitive brokerage fees
Competitive margin account rates
Access to some other major venues such as DAX (Germany), London, etc
Account opening is not that straightforward
Website
Answer: There are ETFs listed on the Brazilian stock market. Specifically there is one for S&P500 - SPXI11, which might fulfill your requirements, though as one commenter has observed, it doesn't answer your original question.
Comment: The question talks about "shares" and "some companies that are listed" on the New York Stock Exchange. Unless there is a significant language barrier involved (which frankly it doesn't look like to me), that seems a poor match for an investment vehicle that targets the whole S&P 500 index.
Comment: Yes, I've got you and you are right the OP does specify shares and companies. I'm just giving an option that may help or give an insight into something they can do. Sometimes it is one idea that sparks off another, that gives the final solution. It is possible they just want to be able to hedge with the $US.
Comment: If OP wants to hedge against currency risk, that's a very different question and stock market investments are generally a very poor answer; a money market fund targetting the US would likely be better in that case. But that is drifting quite far from at least my reading of the question *and* this answer, so for everyone's sanity I'll drop this here.
Comment: @MichaelKjörling Actually I thought of buying some oilservice industry shares. I think now it is good time to buy(of course if these companies survive these low oil prices)
Comment: @MikiBelavista I have proposed an edit to your question to try to clarify that.
Answer: I am not sure what a Brazilian equivalent is but you could just do an  ADR. Keep in mind that when you are investing in a foreign company there are certain currency risks that you may need to consider.
Comment: There are BDRs - "Brazilian Depositary Receipts" listed in Brazil, problems are: 1. Access to most of them is limited to "Qualified Investors"; 2. Low liquidity might be a concern


iphone <-> real world connection

Question: Any pointers on how to initiate serial communication with the iphone?  Or any other idea to interact with external hardware?
Comment: Could you clarify your question? What are you trying to do exactly?
Answer: The only supported way to connect external hardware to the iPhone is through the iPod accessory protocol, through the 30-pin connector.  Details on that program are at http://developer.apple.com/ipod/accessories.html.  It isn't a free program and the 30-pin connector only supports certain features, but it's the only option available today.
Answer: Apps compiled with the unofficial toolkit (and running on jailbroken iPhones) can supposedly access the serial port present in the dock connector.
See:
http://devdot.wikispaces.com/Iphone+Serial+Port+Tutorial
Answer: It depends on what you want to do. For an SSH terminal connection I reccomend TouchTerm (search the appstore).
I have no experience with electrical connections, but you can find the pinout of the iPod/iPhone connector here:
http://pinouts.ru/PortableDevices/ipod_pinout.shtml
You can then download the iPhone developer kit here:
http://developer.apple.com/iphone/

iphone <-> real world connection


Intrinsic gain vs. voltage gain

Question: What is the difference between intrinsic gain and just "normal" voltage gain of a circuit i.e Vout/Vin?
Answer: As I understand it, in e.g. a transistor amplifier, the intrinsic gain will refer to the transistor beta, and the voltage gain to the actual Vout/Vin.
Usually for e.g. a common emitter setup, you would not rely on the unpredictable current gain of the transistor, and add some feedback in the form of an emitter resistor. Then the voltage gain becomes roughly the ratio of the emitter and collector resistors (unless you bypass the emitter resistor for increased small signal gain)
So the intrinsic gain of the transistor might be 200, but (with an e.g. 10k/1k ratio) the actual voltage gain of the circuit ~10.
Similarly with an opamp open loop gain, you could say this is the intrinsic gain of the opamp.
Here are a couple of related links:
MOSFET intrinsic gain
Opamp discussion (see page 3 second paragraph from bottom)
Comment: so what you are saying is that the intrinsic gain is the gain internally in the device i.e a op amp or a basic gain cell, but the actual gain is the gain when you consider loads etc connected to those device?
Comment: @rrazd - not the load as such, the intrinsic gain is the "internal" gain yes, but the actual gain depends on the setup (ideally the load would not affect the gain, although you could specify e.g. a gain of x into an impedance of x) so for example an opamp with intrinsic (or open loop) gain of 100,000 could be setup for a (closed loop) gain of 10 using negative feedback. You do see unloaded vs loaded gain graphs in amplifier datasheets, but I would say the unloaded gain would be usually be used to describe the circuit itself. (unless the load is actually part of it)
Comment: @rrazd - added a couple of related links that might be helpful.
Answer: According to the book of Prof. Behzad Razavi (Fundamentals of Microelectronics):
$$A_v = -g_m \cdot r_0$$
The "intrinsic gain" of the transistor to emphasize that no external device loads the circuit, \$g_m \cdot r_0\$ represents the maximum voltage gain provided by a single transistor, playing a fundamental role in high-gain amplifiers.
Answer: As I understand it, the intrisic gain is the gain of the amplifier itself (or sometimes called the open loop gain, meaning there is no feedback loop). And the overall gain is the gain of the whole circuit with the loop (called closed loop gain)
Answer: Intrinsic Gain is just the maximum possible voltage gain of a typical transistor, regardless of the bias point. it means
\$ g_m r_o \$, that is the maximum gain of a CE (Common Emitter) amplifier.
by eliminating \$ I_C \$ it's equal to \$ V_A/V_T \$ and it hasn't any dependence to the bias point of transistor.
(Recall that \$ g_m=I_C/V_T \$ and \$ r_o=|V_A|/I_D \$, thus \$ g_m r_o=\frac{I_C|V_A|}{V_TI_C} \$.)
Comment: Could you explain why intrinsic gain doesn't depend on bias point? Intrinsic gain equals gm*ro and both gm and ro depend on bias condition.
Answer: I wanted to add the derivation for the intrinsic gain, that might help to understand it.
$$A = \frac {dV_{out}} {d_{V_in}} = \frac {dI} {dV_g} \frac {dV_d} {dI} = g_m \frac {1} {g_d} = g_m r_0$$

Intrinsic gain vs. voltage gain


QGIS Singleband pseudocolor Continuous symbology

Question: If you want to configure the symbology of a raster in QGIS using render type 'Singleband pseudocolor', you can choose out of 3 modes to generate values in the table (continuous, equal interval and quantile). Although, I do not find information on the logic behind these modes. More precisely I'd like to know how the 'Continuous' mode classifies the values. In fact, my gut feeling expects this to be the same as 'Equal Interval' but obviously it isn't...
Could someone please point me to some documentation or explain what this 'continuous' mode does exactly?
Answer: I might be late to the party, but my guess is that Continuous refers exactly to the colour ramp (that you get by clicking on the cooler ramp itself). If it has 30 defined colours, then you get 30 different values in your symbology.
With Equal interval, you define the number of values, and QGIS interpolates the values of the colour ramp.
And finally, Quantile gives you the values that separate your data into classes that have the same number of points. You can clearly see what's happening when the interpolation is set to Discrete.


Emailing hundreds of thousands of users for a newletter, company server or service?

Question: My company has a website with a lot of visitors per day.
We are planning to email hundreds of thousands of users.
I read somewhere that your email reputation is build on your domain, we have very good SEO on google, so this should not be a problem. But isn't it risky to email all these people from our server (using PHP) ? If suddenly we make a mistake or everyone just starts reporting us as spam, couldn't this lower our SEO ?

My main question is, is it better to email from our servers, or use a service from Amazon to send the emails ?

Thank you!
Answer: First of all, if you do not have a lot of experience with e-mail distribution I can only recommend that you find a third party e-mail distributor to do that for you, especially with that amount of receivers.
Also, SEO does not matter all that much in regard of e-mail. E-mail reputation and IP network reputation matters a lot. Crossing the line is extremely easy, and undoing that action can be very cumbersome.
I have very good experience with MailChimp.com - they make abuse- and bounce handling easy, and they are strict (that's a good thing).
However! You do not mention how you collected all those e-mail addresses, but if you did not use double opt-in, they are as good as worthless. (Double opt-in means that you did send an e-mail when the users was added to the list, and asked the user to confirm this.)  You must not send newsletters to people who did not 100% agree to it. That'd be spamming.
Edit, regarding comment:
Since the headline said "for a newsletter" i automatically assumed that newsletter bulk e-mailing was what you were going to do.
For sending single e-mails individually, MailChimp is not the right tool as it is meant for bulk e-mailing. For your purpose you can take a look at Amazon SES. But no matter what you do, you still need to do a lot of reading before you are ready to start sending e-mails out.
That is, if you want to be a good guy, follow industry standards, avoid spam filters and avoid breaking spam laws.
Comment: +1 - This is definitely best offloaded to a service unless you want to make email a huge part of your business. We've used Constant Contact before, they seem ok.
Comment: Before any newsletter it will be first a reminder before any products the user purchased are expiring. I'll take a look at mailchimp, thanks!
Answer: SEO and email reputation are not linked except that you need to follow best practices for both.  Before you do the mailing ensure:

You have consent of the people you are mailing to.  Double opt-in is the current standard.  (If you have harvested addresses, you can end up on some blacklists very quickly.)
You have a has a working mechanism for users to opt out, and it is included in the mailing.
The mail is sent from a working sub-domain with a working postmaster address.
The SPF record for the sending sub-domain permits the sender to send your mail.
You have a feedback mechanism to remove addresses that bounce with a permanent status.  (If not you won't be able to get off the blacklists you got onto by harvesting addresses.)
If you are using a DKIM signature, that the validation key is available from DNS.
The sending server uses its correct identity as verifiable but rDNS validation.

It has been my experience that most e-mail distribution companies are in the business of sending e-mail.  However, they are not in the business of helping you get your mail delivered successfully.   Their servers may not be compliant with the relevant RFCs, and they don't seem to check that the appropriate DNS entries are in place for the campaign.
Their DNS and RFC compliance issues are common to most automated mailing systems.  Banks, utilities, couriers, airlines, governments, and others all seem to have the same problems.
You should ensure that the appropriate verifications have been done.  Once you have got to that point, I would consider it is pretty close to a toss-up whether you want to do it in-house or contract it out.  In either case, I would start small, verify, and scale out.
Answer: Even if you have some pretty hefty resources for sending email through your own servers (both talent and the bandwidth/power), the intricacies of SPF records, getting un-blacklisted, spam reporting standards, abuse and bounce handling, etc. take a lot of time to master.
I would highly recommend a service like MailChimp, which deals with millions of emails per day for thousands of different clients; they even have a robust API that you can integrate to do some pretty neat things (while letting them take care of the email end).
For one site I work on, we send some 20-50,000 emails per day through Amazon SES, and if you're going to do it on your own, you might want to consider using SES. You'll still have to deal with abuse reports, bounces, and SPF records, but it's a very robust service that gives you excellent pricing for a very fast and voluminous email delivery method.


Concepts as Mental Representations

Question: The SEP entry on concepts is heavily committed to an RTM functionalism characterization of concepts as mental representations. But, it makes no real mention of alternatives to this position. Are there stronger competing theories of concepts as mental representations out there?
Answer: While the following may not directly answer your question, something there may lead to one.

I suggest taking a gander at Edouard Machery's 2005 Concepts Are Not a Natural Kind; he wrote a 2011 book in this strain of thought: Doing without Concepts. I took a "Philosophy of Neuroscience" course with Machery; I wrote a final essay Concepts Contain a Natural Kind, and he graded it well (this mostly gives you a tidbit about his character).
Fauconnier and Turner's The Way We Think: Conceptual Blending And The Mind's Hidden Complexities looks very interesting to me; WP's Conceptual blending has a bit of extra content.
Grossberg's 1999 The Link between Brain Learning, Attention, and Consciousness provides a possible model of consciousness, which offers a way to separate between concepts and percepts.
Answer: Both Kant & Deleuze talk about concepts. For Kant concepts are simply that which makes Intuitions intelligible to the Understanding; they are 'empty' placeholders which when full of the stuff of Intuition they become representations: a house is a concept, my house is a representation.
Deleuze argues that concepts are the productive ideas of philosophers - it is what a philosopher have to do if he wants to philosophise.

Concepts as Mental Representations


Java: parsing ms-word document using POI/HWPF

Question: I have a ms-word document (MS-Office 2003; non-xml). Within this
document there is a string associated with a bookmark. Furthermore,
the word document contains word-macros. My goal is to read the
document with java, replace the string associated with the bookmark,
and save the document back to word format.
My first approach was using Apache POI HWPF:
<code>HWPFDocument doc = new HWPFDocument(new FileInputStream("Test.doc"));
doc.write(new FileOutputStream("Test_generated.doc"));
</code>
The problem with this solution is that the generated file does not
contain the macro anymore (File size of the original document: 32k;
file size of the generated document 19k).
Does anybody now if it's possible to retain all the original info
using POI/HWPF?
Answer: never found a solution. The customer had to pay an Aspose-license (expensive) or refrain from using macros.


command line arguments array

Question: I am having a command line arguments as like this I need to get the two as like this how is it possible
ApplicationId =1; Name =2
I like to get the two values 1,2 in single array how to do this.
Comment: You could probably help us by clarifying the question... it isn't 100% clear what the args look like or what you want to do
Answer: It isn't entirely clear to me, but I'm going to assume that the arguments are actually:
 ApplicationId=1 Name=2

the spacing etc is important due to how the  system splits arguments. In a Main(string[] args) method, that will be an array length 2. You can process this, for example into a dictionary:
    static void Main(string[] args) {
        Dictionary<string, string> options = new Dictionary<string, string>();
        foreach (string arg in args)
        {
            string[] pieces = arg.Split('=');
            options[pieces[0]] = pieces.Length > 1 ? pieces[1] : "";
        }

        Console.WriteLine(options["Name"]); // access by key

        // get just the values
        string[] vals = new string[options.Count];
        options.Values.CopyTo(vals, 0);
    }

Comment: Yep, that's pretty much what I do for utilities that require named arguments.
Answer: There's some good libraries mentioned on 631410 and 491595. I've personally used the  WPF TestAPI Library mentioned by sixlettervariables and it is indeed pretty darn good
Answer: Try
string values = "ApplicationId =1; Name =2";
string[] pairs = values.Split(';');

string value1 = pairs[0].Split('=')[1];
string value2 = pairs[1].Split('=')[1];

You'll need better error checking of course, but value1 and value2 should be "1" and "2" respectively

command line arguments array


Can I license my WordPress Theme under the GPL 3.0?

Question: I notice that WordPress uses the GPL 2+ license. Can I release my free theme under GPL 3.0, since that's the most current version? Would it create compatibility issues? Thanks!
Answer: Short answer: Yes.
I'll go through your question step by step so you can better understand why I write so:

I notice that WordPress uses the GPL 2+ license.

This depends a bit to which version you are referring. The public available, stable version 3.0.4 is licensed under GPL (no version given). That was not always exceptionally visible, but WordPress was and still is GNU GPL non-version-restricted licensed indeed.
The next versions WordPress 3.0.5 and WordPress 3.1.0 will be released under GPL v2 (or at your option any later version).

Can I release my free theme under GPL 3.0, since that's the most current version?

Regardless to which version of Wordpress you refer to, you can create a derivate out of the Wordpress code by adding your theme code and license it under GPL 3.0. That's correct.
It's your choice that counts here, you can personally decide which version to use, and it's correct that this can be version 3 of the GPL. Please name the original license for parts in the package, so it's visible where a change occurred.
If you are concerned about the most current version and why/how to choose version 3, please see Why Upgrade to GPLv3 to learn about the differences to version 2. And keep in mind that you probably want to license that derivate under GPL v3 (or at the users option any later version).

Would it create compatibility issues? Thanks!

You can upgrade/convert GPL or GPL v2+ code easily to GPL v3 but not that easily the other way round. That's explained as well in the link above and not a fundamental problem.
However, GPL v3 (2007) is compatible with additional FLOSS licenses compared to GPL v2 (1991) which makes it a preferable choice if you want to mix with Apache 2.0 code, as it is compatible.
And it is well updated for nowadays day-to-day use, for example if some of your users run into licensing problems, the termination is not per-se that fatal as it is for GPL v2.
For the highest amount of flexibility you can however release your theme under the terms of the GPL and create a derivate with the current stable version. This will ensure that it is the same way compatible as any derivate available today.
For WP 3.1 you're compatible in the same sense with GPL v3+, there is actually no need to go back to GPL v2 if that is what you're asking for/what you prefer. It won't introduce any licensing trouble AFAIK.
GPL Compatibility for the WordPress.org Theme Repository
If you're asking because of the theme repository on wordpress.org you need to look there for their licensing requirements.
Guidelines state that "Themes are required to be 100% GPL-licensed, or use a GPL-compatible license. This includes all PHP, HTML, CSS, images, fonts, icons, and everything else. All of the theme must be GPL-Compatible." (Source) and a compatibility matrix is linked.
But keep in mind, it's known that part of the WordPress core project might be biased to the one or other specific GPL version and the project might want to influence on theme authors as well, so you should better ask them first.
I assume that the theme directory admins will suggest you to use GPL v2+ for your theme nowadays, but I have no clue if that is a must or not.

As always, IANAL but I hope my feedback is of some value to answer your question.
Comment: WP 3.0.4 also uses GPL v2. See the `license.txt` included with every release and also this: http://wordpress.org/about/license/
Comment: *@mercator* - Thanks for the feedback. Users can choose the terms of *any* version of the GNU GPL released by the FSF. I've made this more prominent in my answer now as well, Mark Jaquith from the WordPress project made that clear last month again. The information of the wordpress.org homepage was not that clear about the correct licensing terms so far.
Answer: You can, but it may make life more difficult for some companies that employ Armies of Lawyers®. GPL 3 is a leetle bit more hardcore than GPL 2 and them lawyer folks don't like change. It might (possibly) impact whether you can get it listed on wordpress.org/extend/themes/. I can't find anything that speaks directly to this issue, but the Review Team's page only mentions GPL 2.
Answer: From the Codex, it says that:

Licensing - WordPress is available
  under the GPL version 2 or (at your
  option) any later version

http://codex.wordpress.org/Version_3.1
Answer: I know it's been years since the question was asked, but for the benefit of others reading this:
Yes you can license your theme with GPLv3. For instance, the guidelines at wordpress.org currently state:

Your plugin must be compatible with the GNU General Public License v2,
  or any later version.

In fact, if you have included any code with the Apache license, you might have to go for version 3:

This is a free software license, compatible with version 3 of the GNU GPL.
Please note that this license is not compatible with GPL version 2, because it has some requirements that are not in that GPL version.


Confused as to when you would use JMS (or a queue in general) versus a database

Question: When you store a message in a queue, isn't it more of meta data information so whoever pulls from the queue knows how to process the data?  the actual information in the queue doesn't always hold all the information.
Say you have an app like Twitter, whenever someone posts a message, you would still need to store the actual message text in the database correct?
The queue would be more used to broadcast to other subscribers that a new message has arrived, and then those services could take further action.
Or could you actually store the tweet text in the queue also? (or you COULD, but that would be silly?)
Could a queue message have status fields, which subscribers can change as they process their part of the work flow? (or would you do that in the db?)
Just trying to get some clarification of when you would use a queue versus db.
Answer: When a process wants to farm data and the processing of that data out to another process (possibly on a different host), there are 2 strategies:

Stuff all your data into the queue item and let the receiving app worry about storing it in the database, among with whatever other processing.
Update your database, and then queue a tiny message to the other process just to notify it that there's new data to be massaged.

There are a number of factors that can be used to decide on which strategy:

If your database is fully ACID (one would hope) but your queueing system (QS) is not, your data would be safer in the DB. Even if the queue message gets lost in a server crash, you could run a script to process unprocessed data found in the DB. This would be a case for option 2.
If your data is quite large (say, 1 MB or more) then it might be cruel to burden your QS with it. If it's persistent, you'll end up writing the data twice, first to the QS's persister and later to the DB. This could be a drag on performance and influence you to go for option 1.
If your DB is slow or not even accessible to your app's front end, then option 1 it is.
If your second process is going to do something with the data but not store it in a DB, then option 1 may be the way to go.

Can't think of any more, but I hope you get the idea.
Answer: In general, a queue is used to 'smooth' out publish rate versus consume rate, by buffering incoming requests that can't be handled immediately. A queue is usually backed by some sort of non-volatile storage (such as a database table). So the distinction is not so clear cut.
Use a database when you want to perform many searches against your 'queue', or provide rich reporting.
Answer: I recommend that you look at Gregor Hophe's book, Enterprise Integration Patterns, which explains many different patterns for messaging-based approaches.
Answer: We used JMS extensively at my last job where we were passing data around from machine to machine. In the end, we were both sending and storing the data at the same time; however, we stored far less data than we sent out. We had a lot of metadata surrounding the real values.
We used JMS as simply a messaging service and it worked very well for that. But, you don't want to use JMS to store your data as it has no persistence (aside from being able to log and replay the messages perhaps).
One of the main advantages that JMS gives you is the ability to send out your messages in the correct and appropriate order and ensure that everybody receives them in that order. This makes synchronization easy since the majority of the message handling is done for you.
Answer: My understanding is Twitter will be using both DB and JMS in conjunction. First when the tweets are written it will store it in the database and this is how it will display in the message board. However since this is a publisher/subscriber model when the tweets are published it will then be sent to the subscribers. So both the items will be used.
Answer: I think your twitter example is good.  You want the database for long term data.  There wouldn't be much point in putting the tweet in the message because it has to go in the database.  However, if you were running a chat room then you could go ahead and put the message in the JMS queue because you're not storing it long term anywhere.
It's not that you can't put the tweet in the JMS it's that you need to put it in the database anyways.
Answer: I would use the queue whenever you can utilize a "fire-and-forget" pattern.  In your Twitter example, I would use the queue to post the message from the client.  The queue processor can then store it to the database when it gets to it.
If you require some sort of immediate success/failure status, then the message queue isn't for you.


Which decision tree algorithm does H2O use?

Question: Does H2O's plain random forest use CART, C4.5, 5.0, or something else? I cannot find this information. sklearn's docs say they use a modified version of CART, and I assume H2O also uses something like CART.
Answer: I have heard H20 Driverless AI uses an ensemble of xgboost and lightgbm models. In some situations it uses tensorflow neural nets as well.
Comment: I meant their vanilla random forests.


Is there a method for evaluating authenticity of revelation to other nations?

Question: Are we provided with a method, measure or test for the validity or authenticity of prophecy or revelation given to other nations, speaking more specifically about revelations given to non-Jewish prophets in a message independent of Judaism.
Comment: What methods do we have for testing revelation to our nation?
Answer: There is a Midrash that says that since the time of Balaam (and in response to a prayer of Moses) there would never again be a gentile prophet. In which case the test is: if the gentile says he's a prophet, he's lying.
Comment: @mevaqesh Please don't edit to change others' transliteration schemes. The standard on MY is that there is no standard, so long as it is (somewhat) intelligible, and were everyone to edit according to their whim, then Eiyn laDhDhabhar Soap.
Comment: Vayikra Rabba 1:10-12? Referencing Song of Songs?
Comment: This idea is based on Bavli Brachot 7a, where it says that, in response to Moshe's prayer, the Shechinah will not rest on non-Jews,


Starship and Raptor

Question: All these SN-flights...seems that Raptor and the surrounding system is still in development and is pretty unreliable. So why go through all the trouble of flying until the Raptors are more mature?
Comment: You can do all calculations and controlled tests you want, but the second you use it real environment 100 issues will show up.
Comment: The engines are as "mature" as possible without subjecting them to flight-path stresses.
Comment: How do you mature a rocket without testing?
Comment: The general approach of SpaceX to developing Starship seems to be prototyping and "seeing what sticks". The SN flights are just that - test flight. What better place to use the new engines and see how they behave?
Comment: @Mu3 SpaceX did a lot of static test firings and a whole lot of simulation runs at various degrees of fidelity. The problem with static test firings and simulations is that neither perfectly models the conditions under which the spacecraft will operate. At some point it's essential to transition to test flights. SpaceX has chosen to make that transition earlier than do more traditional launch providers.
Answer: The Raptor engines themselves work fine on the test stand.
The current challenge SpaceX is facing seems to be in getting the fuel tankage and pressurization system to work properly in the dynamic environment of the Starship's terminal flip maneuver. I can't think of a way to realistically test that non-destructively without building a gigantic rig that physically secures and tilts a Starship, and that probably would cost at least as much as building a couple of additional Starships, and wouldn't tell them if the rest of the system works.
Answer: A traditional space program would spend a lot of time and money would to make sure that as far as possible, a test flight would work as planned and an expensive prototype wouldn't be lost. SpaceX doesn't work like that. Although they undoubtedly do a lot of prior simulation work, they are prepared to fly at a much earlier stage in the design and build the prototypes as cheaply as possible in the expectation that many will be lost. Early Starship flights are in fact more experiments than test flights.
The traditional development approach is "failure is not an option". The SpaceX approach is "if it's not failing, you're not pushing hard enough" or move quickly and break things to find out what the problem is, don't study the problem theoretically for too long. The only mistakes that are failures are the ones where nothing is learned and SpaceX monitor what happens with their prototypes very closely.
Sometimes it pays to test multiple things in one go for example Starship prototype SN8 was considered a great success because everything worked except the final landing. Any number of other problems could have emerged concerning the stability of the control system during descent or the ability to manage the throttling and shut down of engines or many other things. But they all worked or at least worked well enough so they get a tick in the box all at once.
Raptor is "good enough" to fly as far as SpaceX is concerned and Elon Musk is also in a very great hurry to get to Mars and is not worried about breaking things or spending money to do so.
Answer: Let me counter with a question: why would they not?
What else would they do with the 12 Starships and 60 Raptors do that they have already built, if they're not flying them? Hang them on the wall and admire them?
If you have the vehicles and the engines, why would you just build them to scrap them?

Starship and Raptor


What is difference between arm64 and armhf?

Question: Raspberry Pi Type 3 has 64-bit CPU, but its architecture is not arm64 but armhf.
What is the difference between arm64 and armhf?
Comment: armhf = hardware floating point instructions + 32-bit instruction set. 64-bit ARM supports hardware floating point and NEON by default, so no need to specify a qualifier like 'hf'. As mentioned below, RPi foundation hasn't added support yet for 64-bit mode on the Pi3.
Comment: Please note that Arch linux community division dedicated to ARM platform (https://archlinuxarm.org)  already has support for Aarch64 on Rpi3. You can download an image for Rpi3.
Answer: armhf stands for "arm hard float", and is the name given to a debian port for arm processors (armv7+) that have hardware floating point support.
On the beaglebone black, for example:
:~$ dpkg --print-architecture
armhf

Although other commands (such as uname -a or arch) will just show armv7l
:~$ cat /proc/cpuinfo
processor       : 0
model name      : ARMv7 Processor rev 2 (v7l)
BogoMIPS        : 995.32
Features        : half thumb fastmult vfp edsp thumbee neon vfpv3 tls
...

The vfpv3 listed under Features is what refers to the floating point support.
Incidentally, armhf, if your processor supports it, basically supersedes Raspbian, which if I understand correctly was mainly a rebuild of armhf with work arounds to deal with the lack of floating point support on the original raspberry pi's. Nowdays, of course, there's a whole ecosystem build up around Raspbian, so they're probably not going to abandon it. However, this is partly why the beaglebone runs straight debian, and that's ok even if you're used to Raspbian, unless you want some of the special included non-free software such as Mathematica.
Comment: Note that debian and raspbian apparently mean different things by armhf: https://raspberrypi.stackexchange.com/a/87403/103374
Comment: Raspbian: "armhf": ARMv6 + VFPv2 ---- Debian:"armhf": ARMv7
Answer: Update: Yes, I understand that this answer does not explain the difference between arm64 and armhf. There is a great answer that does explain that on this page. This answer was intended to help set the asker on the right path, as they clearly had a misunderstanding about the capabilities of the Raspberry Pi at the time of asking.
Where are you seeing that the architecture is armhf? On my Raspberry Pi 3, I get:
$ uname -a
armv7l

Anyway, armv7 indicates that the system architecture is 32-bit. The first ARM architecture offering 64-bit support is armv8. See this table for reference.
You are correct that the CPU in the Raspberry Pi 3 is 64-bit, but the Raspbian OS has not yet been updated for a 64-bit device. 32-bit software can run on a 64-bit system (but not vice versa). This is why you're not seeing the architecture reported as 64-bit.
You can follow the GitHub issue for 64-bit support here, if you're interested.
Comment: on my system it's uname -i
Answer: It's important to realize which commands are reporting on your kernel software architecture and which refer to hardware. Until recently, Raspberry Pi did not write 64-bit OS releases, so the 64-bit hardware 3b+ for example, ran a 32-bit OS. This can lead to some confusion when you run commands to print architecture. Don't draw the wrong conclusion, though. You'll notice on the Raspberry Pi OS release page that the new 64-bit release is compatible with older Pi 3 hardware, which have 64-bit ARM processors.
Comment: To add to the confusion, Raspberry is now loading a 64-bit kernel on Rpi 4's by default. Even if the OS is 32-bit (you can force it to load through config.txt on Rpi 3's). Not that there is anything wrong as the 32-bit OS appears to work fine with a 64-bit kernel for the most part (some people have reported issues). Unfortunately, it means you cannot use "uname -a" to learn what OS architecture you are running. After some searching, I finally learned that "file /lib/systemd/systemd" is a reliable way to determine if the OS is 32-bit or 64-bit.


Determine power requirements and limitations for an old shortwave radio

Question: I picked up an old Novico shortwave radio at a garage sale. Missing was the wall plug adapter. The battery pack runs at 9v, but I'd like to find an AC wall converter that I can modify that will let me run without batteries. Is there a relatively easy way to determine what kind of voltage/amps are needed without going over the limits? Thanks in advance!
Comment: What does the F stand for and don't say "find" lol
Comment: Is it a 9V battery like the single battery or is it a bunch of AA cells wired to 9V total? You can get a clue from the type of battery it uses.
Comment: You stated the voltage. You can measure the current using an ammeter. Whatever you read, double it, and then go look for such a unit. Do be sure to check the polarity of the entry jack used for the wall adapter, too. Assuming it doesn't directly accept AC, and requires DC, the polarity does matter.
Comment: @Andyaka when I  was at university the lecturer said "fine" was the accepted translation,  (the other 4 letter word would not be accepted)
Answer: Since you know the voltage, you can safely power the radio.  Use a 9 V bench supply or something, and measure the current.  If this radio has its own speakers or is intended to drive speakers directly, then run it at maximum volume to get close to the likely worst case current.
Then get a 9 V regulated wall wart or power supply that can supply a bit more and round up to the next higher available current.  For example, if you measure 421 mA worst case, get at least a 750 mA or 1 A power supply.  The difference from 500 mA to 1 A won't cost much extra.
Comment: Hmm switch mode power supply interference and short wave radios might not be a good mix.


How to give log in credential for internet through command line

Question: My GUI for backtrack is not working. I want to connect to internet. I gave the required static IP address to my machine. but the problem is I have to give username and password through the browser before accessing the internet. Now here, I don't have any browser. How can I give the log in credentials through command line in backtrack machine? Is it possible?
Answer: A couple of options to try: lynx, links, wget, curl.
Also, why backtrack?


Recommendation for a binary dataset for Computational Biology open access (as in a dataset with 1 and 0 that can be used to apply ML techniques?

Question: I have a couple of modified ML methods that I want to test with biological binary data - specifically binary gene expression data - e.g. https://eprints.soton.ac.uk/69359/1/Thesis.pdf that might include a variable that could be used to be the target variable in ML classification. What I mean by binary data is the features are all either 0 or 1, so I expect a large dataset e.g this thesis. I am looking for any suggestions.
Comment: Please [edit] your question and make it a bit more specific What kind of "biological data" do you need? How large a dataset? What do you mean by "binary"? Are you referring to the format of the data or do you want something that can only have two states?
Answer: Kaggle has a cats v dogs dataset if you want to try your hand at biological image classification: https://www.kaggle.com/c/dogs-vs-cats
The DREAM challenge competitions are usually specifically oriented to solving biological classification or learning problems with ML: http://dreamchallenges.org/


Transparent Artboard

Question: I'm trying to send a file for a label as a PDF and the text is white. Is there a way that I can make the art board transparent so that she can see it without me saving it for web?
Comment: I quickly skimmed the answers and I don't think any of them mentioned that by default the white background you see in the artboard is just the way AI (and Indesign and Acrobat) choose to show you the document. So unless you specifically create a white background beneath the artwork, the white background you see is not part of the artwork, it's just a background color for convenience sake. In all of these apps you can turn on the Transparency Grid, which basically allows you to see if what you see is really transparent or not.
Comment: Most people won't be designing stuff with the transparency grid on the whole time. it would be very distracting. The white background works way better. Also when you are looking at.. let's say a text document in Acrobat, it would be pretty difficult to read the text with the transparency grid on. It's there if you need it, but the default is the white background. So... There likely is no background in the pdf even though it looks like it at first glance. — Obviously, if you export the image in a format that doesn't support transparency, then it will absolutely have a background color.
Answer: The proper way to send a single color file for reproduction is to send black artwork. Then the printer will put white ink on the press. You don't need to send white artwork. For commercial printing white equals not there or invisible.
If you really, really, really want to send white artwork, then send a negative of the artwork. That is, add a black background. That will allow the print provider to merely create a reverse and use that for production.
Talk to the print provider. Chances are very high you don't need white artwork.
In either case, for commercial printing, PDFs never need to have a transparent background.
Comment: Thanks that what I normally would do but the client wants to upload it to a printing website that uses pdfs and a "logo maker". I guess I will send it to her and provide instructions...
Answer: If your client is using Acrobat Reader to preview the image, she can click Edit > Preferences > Page Display, and select the option to show the transparency grid.
As far as printing in white is concerned, are you absolutely sure about that?  Have you discussed this with your printer?  Most printing processes do not involve printing in white ink.
Answer: Since version 1.4, PDFs support transparency. The white background is usually added automatically by the application that you use to view the document, not by the one that was used to create it.
For example, in Acrobat settings do Cmd+K > Page display > Transparency grid to see a transparency grid similar to Photoshop's.
You can open the documentin Photoshop to confirm that the background should really be transparent.
Answer: No you can't that's not how PDFs work. Additionally printers can't print white unless you are printing on an offset or sheet-fed set-up.
So if you background isn't a color the white will not show up at all.

Transparent Artboard


High School Level Math Books?

Question: I am in grade 11 in Canada, going to be taking Functions next semester. In grade 12 I will be taking both Advanced Functions and Calculus/Vectors. Are there any good books that I could buy to prepare for these courses and get a good grip on the concepts that I will see in grade 11 and 12 math?
Comment: Just out of curiousity, what does a course in "functions" typically cover?  Elementary Algebra?  Trig (/transcendental functions)?  Set Theory?  I'm just curious because we don't have a course called "Functions" down here in the States.
Comment: @Bye_World Functions covers Quadratic/Exponential/Sinusoidal functions, as well as focuses on Trig ratios, discreet functions, and equivalent algebraic expressions. Here's a link if you'd like more information; http://ontariomath.wikispaces.com/file/view/Math%20MCR3U%20curr.pdf/380065162/Math%20MCR3U%20curr.pdf
Answer: One option would be to read Functions and Graphs by I. M. Gelfand, E. G. Glagoleva, and E. E. Shnol and Trigonometry by I. M. Gelfand and Mark Saul.  Gelfand's books Algebra and The Method of Coordinates are worth reading, if less relevant to what you want to study.
Another good option are the texts Mathematics 1: Japanese Grade 10, Algebra and Geometry:  Japanese Grade 11, and Basic Analysis:  Japanese Grade 11 edited by Kunihiko Kodaira.
The texts mentioned above are challenging, but the exposition is clear.  You can use them to build conceptual understanding and develop your problem-solving skills.

High School Level Math Books?


Animal Crossing new leaf dream suite

Question: How do I get the dream suite if I already found Isabelle sleeping like one or two months ago but I didn't go to the mayors chair afterwards? Do I get a second chance of somehow?
Answer: You should still be able to go to the mayor's chair, and choose it from the list of public works projects.

Animal Crossing new leaf dream suite


How does current sink help in biasing the differential amplifier?

Question:
Here M1 and M2 are differential pairs with analog input. When source resistor is used Rs M1 and M2 when Vgs is less than 0.7 Vt threshold M1 and M2 will be in cut off region and Vo1 and Vo2 will be in Vdd potential .
But this is solved using current sink with specific value of current.
Here to work  in negative cycle M1 and M2 source potential is should go to negative according to the simulation it is and it should theoretical (i am not sure whether its negative).
When i replaced current sink with diode connected nmos transistor it didn't behave as current sink.
I have attached simulations

But the question is how does this replacement of current sink solve the biasing of the mosfet problem and whats happening in that source potential

How is that source node behaving with resistor (Rs) common mode input and in differential mode input the M1 and M2 plus how does current sink solve the problem?
Answer: If you are using enhancement-mode transistors, then the input transistor drains need to be below ground.  A current source will do that; a FET (which can't generate voltages) cannot.


How to fix persistant cracks on this section of the wall and why do they show up even after repainting?

Question: There is a section of the wall in the bedroom that even though been repainted several times by actual painters, within weeks the cracks would resurface again. im trying to figure out if there is an easy temporary fix since im not painting the room again, and what should i take into consideration next time i decide to repaint the room? This is concrete or whatever, not drywall. Here is what some of the cracks look like:
Comment: You can tell the crack has been patched, because the texture is different than the rest of the wall. You say, "this is concrete...not drywall."  If so, you're probably looking at a "cold joint" or there's expansion or contraction occurring in the second pic. Something different is causing the "patch" appearance in the first pic. To fix this you'd need to isolate the area (so the wall can move without damaging the coating/paint) around the cracked area and then re-patch, texture and paint.
Comment: Yes the crack was there before it was patched. This is just one example, the while section of the wall, it's paint is barely holding onto the wall, and a line of cracks runs straight up. The first pic though happened after i pulling out blu-tack. How do I isolate, repatch? Would that require I tear down old paint?
Comment: Yes, I think the only way to solve the issue is to start with the prep of the wall. All buildings move, we just try to limit the movement and have them move together, (as opposed to differential settlement.) To keep painting over a crack without fixing the original crack is a lot like what @brhans says about scotch tape...
Answer: Your 1st picture shows an issue where you have a layer of paint which is not well adhered to the surface underneath (and probably more layers painted on top of that).
This is like putting a piece of scotch-tape onto a dusty surface and expecting it to stick.
More and more layers of paint will never fix this.
You'd need to strip/scrape/peel all of the old paint off until you get back down to something solid and start the paint journey over again from scratch.
While doing this you'll probably also find what's under that crack in the 2nd picture - there's likely still movement on each side of the crack, but it might be possible to manage this once you know what's under there...
Comment: Whoever last painted the room probably assumed that the previous paint job was done properly - in which case simply covering the old with the new is the standard procedure. If this is the wall's 1st coat of paint, then somebody did something wrong - difficult to say exactly what - maybe wrong kind of paint, maybe needed a primer (or better primer).
Comment: I didn't paint this room a professional did. What did he do wrong? Do I have to redo it, can I just wait for a couple of years if it's that big if a problem?