What TV show has kids entering a video game of some sort?

Question: I've been searching the entire Internet for this show about 4 teenagers that enter a video game world where they have to fight monsters that looked like insects. Every time they had to enter the world, they'd go down in the sewers and one of the guys had a skateboard, a girl had a scooter and that's what I can remember. There was also one guy that always stayed behind to check their "health" in the game and pull them out in case they took too much damage to avoid them dying inside the game. I don't know if it was animated or not so there's not much to go on at all but hopefully someone might know what show it is?
Comment: I second Code Lyoko. Especially in the first season, most trips down to the system involved them travelling through a bunch of pipes with lots of shots of skateboarding and scootering, and the enemies in the virtual world were very bug-like.
Comment: @ConMan I think it probably is correct.  Went ahead and posted as an answer.
Answer: Possibly Code Lyoko.  This has four characters from a boarding school as well as a girl that the main character finds in a virtual world:

Jeremie Belpois, a gifted thirteen-year-old boy attending boarding school at the fictional Kadic Academy, one day discovers a quantum supercomputer in an abandoned factory near his school. Upon activating it, he discovers a virtual world called Lyoko with a young girl, Aelita, trapped inside it. Unusual events begin to occur at Kadic Academy. Jeremie learns of X.A.N.A., a rogue, malevolent artificial intelligence multi-agent system who also dwells within the supercomputer. X.A.N.A.'s goal is to conquer the real world and all human beings.
Jeremie must materialize Aelita into the real world and stop X.A.N.A. Jeremie is aided by his three best friends and classmates Ulrich Stern, Odd Della Robbia, Yumi Ishiyama as they, along with Aelita, are virtualized into Lyoko in order to save both worlds from the sinister virtual entity.

Additionally, confirming the recollection that one character stayed behind:

Because he is not very athletic and is more computer savvy, Jeremie rarely goes to Lyoko.

Further, as to the skateboard and scooter we have with respect to Jeremie:

When going to the factory, he rides a scooter. He's the main protagonist and also the youngest of the group.

Also, for Aelita:

When going to the factory, she rides a scooter.

The other three main characters all ride skateboards, also matching with part of the description of the show.
Answer: Da Boom Crew mostly matches your question.

Da Boom Crew is a Canadian/American children's television animated series, produced by Berliner Film Company in association with Jambalaya Studios in Los Angeles, California.
The series premiered on Kids' WB in September 2004. Unusual for an animated series, it was cancelled after only four episodes aired due to low ratings and viewer reception.
In the United Kingdom, all 13 episodes were broadcast on Cartoon Network UK in 2005.

....

After four foster children create a video game, suddenly a supernatural vortex appears and pulls them into a world which is really similar to their game. This show also details their adventures in this parallel world as they embark on a quest to find their missing game cartridges and stop the sadistic emperor extraterrestrial terrorist Zorch from taking control of this intergalactic dimension.

As you can see from the title card for the show, one of the characters, Jubei, uses a "hoverboard" which resembles a skateboard, and some of the bad guys are indeed insectile.
Comment: It seems slightly doubtful that it would be "the answer" given they've already accepted one, but it is good to have additional answers that also are correct to the question.
Answer: There was a show called VR Trooper. That was very similar to what you are describing. There were teens that had to enter a virtual world and fight evil.
I believe it used to be on on a Saturday morning. If I remember correctly, and a quick check on IMDB will confirm/deny this, there were three that went in, a robot that could switch between the real and virtual worlds at will, and another kid that sat and worked the console, like an operator on the matrix.
Answer: If it was a movie it could be the film Arcade
It has a bunch of friends (about 4 or 6) who go to play a prototype video game, only it turns out the video game is alive and if you get killed in the game you get trapped it it forever
The main girl has to go rescue her friends at the end because all of them end up getting trapped in the game one by one, at the hands of the main boss of the game, called Arcade
The arcade store where they go to play the video game was underground I think
The video game company that made the Arcade game give the teenagers some free samples of their home console, but for the final showdown they go back to the arcade store
Answer: Let's Samuraize, guys! You're thinking of Superhuman Samurai Syber Squad:

Here is the opening:
Answer: I've also been looking for the show that you described for a long time and have just found a show that looks 95 percent similar to it called Zixx that aired on Canadian TV for 3 seasons.

Zixx is an Intergalactic Network (simplified as the Network) agent who has crash landed onto Earth with her partner Flanngo. As luck would have it, Earth also happens to be a hotbed of activity for the evil Onccalon and the Hargokk Empire. Zixx has no intention of letting him win, so she and Flanngo need to find a way to access the Network and make sure they can get to the next level of the Keep before Onccalon's henchmen do.

Zixx: Level One promo
Comment: Hi, welcome to SF&F!  You can make this a better answer by describing how *Zixx* matches the points detailed in the question.  Check out [answer] for more info.


How would humans and aliens communicate in a combat

Question: Humans and several other alien species are allies in a universal war against another set of species. How would these different allies (us and aliens) communicate on the battlefield. It's one thing to communicate slowly when in a friendly mood. We can try to make them understand our language with signs and signals, but on a field where quick communication (like "hey, watch out. Enemy at 12'o' clock) is a necessity, how would these species communicate.
Language can be used but since it will be new to all of us, we will take time to hear it properly and understand it. What mode of communication would be the fastest on battlefield for the alien species and us?   EDIT  They will be communicating before the war. That is not the question. The question is about the fastest mode of communication on battlefield where it has to be extremely fast
Comment: This question is far too broad as it stands unfortunately.  If you can provide a list of species and their differences and similarities, as well as how their native form of communication works this would be objectively (or more at least) answerable.
Comment: I'm guessing this is about infantry ground combat? For any kind of vehicle combat, the best fix would be building a communication system that can translate information and display it in the native language for each vehicle.
Comment: Wouldn't this be solved *before* we got into battle with allies? Like, we'd have computers which talked to each others, and each species would just talk to the computer? Why would we be war-time allies with a species that we couldn't easily communicate with?
Comment: Would emotions be a valid answer for you? Something like empathy as shown by Diana Troy in Star Trek.
Comment: Emotions? How would we communicate with emotions? And how will we direct our emotions to a certain individual whom we want to warn? Wouldn't it take time for us to focus our chain on emotions on a certain individual?
Comment: i thought of something like "uhhhh youuuu need to look there!!!" in the mind of one of the Humans, and the Alien dose feel the need to look in that direktion. And with need i want to express the real desire to look there. This would work with the most of the basic Orders on a Battlefield: Attack, Help X, got to X, look at, Destroy, Fire in the hole...
Comment: Ok. This sounds reasonable. But, most of the time it might be slow since the target will first receive the emotions and then parse them and then act upon them. It won't be directly like "look there" and "Okay. Boom". That would be  a bit of mind controlling, don't you think.
Comment: think of it more like tooth pain, you cant ignore it once you feel it, and you react immediately. If you have something in your head, usualy it will be your first tought of how to get rid of it.
Comment: So mind control through emotions. That makes sense but what if some species is incapable of receiving emotions or perceive emotions like others. Or what if it is completely void of emotions.
Comment: Keep in mind that "empathy" (as in Diana Troi) has no known basis in science.
Answer: Imagine someone arriving to a country he has never been before and doesn't know language at all (even basic phrases).
That's what phrase books are for.
We and our allies would have to define a set of basic commands that'd be used on battlefield (like attack, watch out, retreat; numbers to define positions (as in question) etc.). It could be voice commands as well as gestures or any other code that can be easily and quickly recognised.
Emotions wouldn't work unless included in the set of commands, since our and aliens' psychology would be completely different.
Comment: @Namechangedtomaskidentity: Phrase book was just an example of finite subset of phrases used for basic communication. If we ever formed an alliance with another lifeform, we first have to be able communicate with them *at least* at basic level.
Comment: @Namechangedtomaskidentity: Yes, it would probably take that long to learn a phrase book.  It would take that long just to produce it AND it would likely take that long for the various combatants to actually figure out *who* is fighting or even why the fight is going on.
Comment: So you are saying that language is the only option. It will probably take days and weeks or even months for us to learn that phrase book. And who is to say that they can all speak. What if they don't speak and can only make signs and gestures.
Comment: @Namechangedtomaskidentity There are distinct contexts in which you'll want to communicate. One is strategic planning, during which you can bring people to translate what you say and you have some time to figure out what every one is saying. The other one is in the middle of the fight, and then there are very few things that you actually need to say. And every soldier could learn the twelve phrases from his phrase book.
Comment: As long as the phrase book is accurate. You don't want the aliens trying to warn of an incoming attack shouting, "My nipples explode with delight!"
Answer: Visually
So you're dropped into a battle with several aliens.  One of them hands you this funky looking visor thing - you notice that they're already all wearing them.  You want to be cool too, so you put it on.  Immediately you see your normal vision overlayed with complex, uncomprehensible goblygook.
The visor, not recognizing your species, initiates an integration step.  This is a couple of minutes where it familiarizes itself with your visual spectrum and capabilities.  Thankfully it has inward facing cameras, and the dumb AI is quickly able to detect and interpret your pupil motions and activities, using those to fine tune its display and figure out what colors you best react to.
Once it knows it can show you information, the visor initiates the familiarization step.  Obviously fake objects appear in your vision, and your prompted (again, visually) to interact with those objects - you see shadowy appendages reach out, as if they belonged to you, and move those around.  Once you take that step, it proceeds to more and more complex actions.  It takes a bit but the visor adjusts quickly and is able to motion capture your hand movements.
Once you can interact with it, the visor starts walking you through information.  A map appears in the upper right corner of your vision (the visor determined that area would be optimal, given your eye movement patterns).  You notice some dots on that, which the visor demonstrates to be your allies by high-lighting them in the same color in your field of vision and on the map.  Once you're comfortable with that, it adds more options.  You're a quick study and you start clicking and messing with the map, and you can indicate danger, or movement, or query for help - thankfully it's pretty intuitive with dropdown menus and such.
Now that you have the basics down, you're ready for combat.  You're surprised when your group is broken up into several different colors - you end up being in group pink, go figure - but you immediately see the benefit when a pink arrow indicates the direction you need to go.  You start off with the rest of your group.  After a bit you notice a weird pink dot in your group - it's a darker color, and it's flashing as you get further away, but there's no one there - and oh!  That's where you're supposed to be.  You head over there, and once you get close enough it stops flashing.  You keep an eye on it to make sure you stay on track.
Contact with the enemy is rough.  You first spot them as red dots, which you haven't seen used before.  Your group leader assigns you movement orders (pink trail), and enemy targets (high-lighted red dots).  It's tough at first paying attention to the map while also fighting, but you adjust after a few minutes.
Your first battles go ok.  You notice that as you get comfortable with the basic capabilities, it starts adding more options.  The first is False-Color Overlays - you get the option of viewing things in other parts of the light spectrum (ultraviolet, infrared, radar, microwave), and even a weird echolocation sound mode that gives you a headache.  Once you get promoted to lead a group, you also see other options appear - you can now create subgroups of your people, and you have options to assign those targets or movement orders.  You can also create more variations, or mark enemies certain ways - never with language, but you are given logical grouping options, and the visors render those appropriately to the wearer (a human might see striped enemies vs cross-hatched, for example).
Answer: Ever been to pub fight? Well, let me explain from my one, and luckily only situation where I was in such situation:

These three dudes are my friens
These four dudes are most definitely enemies
Heck! These two dudes attacked my bro! Attaaaaack!

In other words:

You have to know your enemies
You try to attack your best and your hardest to the closest enemy.
If one of your friends seems to be needing help, you provide it. Simply because you hope they will do the same for you

Even more generic: I am strongly assuming that tactical capabilities of these aliens will be same, or at least similar. And that we are fighting together some ugly dude, because, hey, we are friends and he is not. If only he paid me the shots...
EDIT
I feel like I actually did not answer the question. I strongly think, that in such situation, where any communication is slow ...
(Did I tell you that the pub fight happened in Bulgaria where I fighted together with some dudes from Germany and I am pretty poor in German and I do not understand any Bulgarian?)
You just fight and hope for the best
Motto: Even the best plan can be thrown away when dealing with enemy
EDIT2
I have been thinking about it even more and decided to post this:
Why did we decide to help them?
Your question kinda suggest this scenario:
Alien ship appears: Hello, we are race Tom from planet Bob
Humankind quickly decides who should answer and says: Uhm, hello and welcome. We are peaceful, live long and prosper
Aliens: Um, actually, there is race John from planet Mary and they are our enemies. Will you help us?
Humankind: Yeah, sure! Bring them on!
But this is very, very unlikely. It will take years to actually decide what to do in this situation. So, likely scenario is this:
Aliens appear on orbit: Hello, we are race Tom from planet Bob
Humankind: Um, we officially agreed to say: Hi!
Another alien ship appears and starts attacking Earth immediatelly
Alien Tom: Thats race John from planet Mary. They are our enemies. Will you help us?
Humankind: We are packed and loaded. Bring it on!
Comment: But, how would I communicate to my friend that hey lookout, there's an ugly dude with a heavy machine gun just behind your back and is about to blow you to pieces. Right now, I can simply say "Zohan, look out."
Answer: Ironically this has already been answered by the military: they do exactly what they do today.
Consider, combat is not a coarse art.  If your squad is not finely tuned and well oiled, the finely tuned and well oiled squad down the hall is going to shoot you and take your ground.  There is no one way to fight, so each group develops their own quirks that work well for them.
This pattern ripples all the way up the chain.  Consider navy battles between the great sailing ships of the French and English.  The English used powerful ships will well tuned guns so that, when they had the wind, they could demolish their foe.  The French used more nimble ships so that, when they didn't have the wind, they could simply flee faster than the English.
In modern combat with multiple nations, the process is simple: you don't rely on communication at the lower levels unless you have to.  When given any opportunity, you structure your army to allow the different groups to act independently, and only do language translation at higher ranking positions where there is time to do such translations.
It'd be nice to think that our military would be an even mix of human and alien with nobody discriminating between the two.  Tough cookies.  This is war, where people die.  If segregation increases survival, its what they do.
Answer: How did they become allies?  How long has it been?  If they are allies then they should already have some communications available.
We are currently working on universal translators, don't know how well they work now, but I'm sure they would be sufficient for simple commands and directions.
So, I expect computers would be doing the translation and an individual fighter pilot might not even know if their wingman is alien or human.
Answer: Visual signaling is a lot faster than verbal processing, especially with a new language. The fastest way to do this is to use short hand signals - you sometimes see this in cop shows and war movies.
This can be combined with HUD alerts. Think Google glass overlays or a standard fighter pilot cockpit. Since you're talking about aliens (but didn't specify whether we're on earth), the HUD is feasible tech. The military already has models it's working on, so it isn't really a stretch for your world.
Basically, direct visual range =hand signals, father range = translate verbal commands from allied commander to visual signal overlaid of l on HUD.
Answer: I would use radios with automatic translators.  Use a different frequency for each language.  A computer listens to each and translates anything said on that frequency into each other language and broadcasts it on the other frequencies.
One of the complications of communicating during combat is confusion, so we already need to use limited vocabulary and keep messages brief.  This will make translation easier.  Keeping the different languages on different frequencies allows the soldiers to listen to only what they'd understand, anwyay.
Radios also have the advantage that it would cut down on the amount of shouting that modern combat soldiers have to do.
One disadvantage is that communications would no longer be localized by the range of the soldier's voice, so there is the potential for lots of chatter in a combat involving hundreds or thousands of soldiers.  But we already have technology (cell phone networks) to allow us to control who we'll be listening to, including override capabilities, etc.
It would take a lot of planning and design work, but anyone with technology for interplanetary travel could definitely build a combat communication network that could meet the above needs.
See the "Old Man's War" series by John Scalzi for an example of a network similar to what I've described.  The network in his stories is humans-only, but that was a political decision, not a technological one.


proc/sys/vm/flush_mmap_pages missing in 3.9 kernel, how to get it?

Question: There was an option in redHat 5.2 called flush_mmap_pages, I could set this to zero and that would turn of writing dirty pages from a mapped memory file (so I can do it myself when I want to). However it is missing in newer kernels, I am using fedora 17 on Linux 3.9 kernel ATM and it is not there. Is there anyway to apply a kernel patch to get it back, does anybody know the last kernel version to support this kernel parameter?
Answer: If it is not present in the new kernels, it means that the maintainers decided for this section of code decided not to provide this facility.  This capability could have been moved or combined with some other capability, but you'll have to research this to find out.
I would approach patching to get some old capability very carefully if it is NOT in the current kernel.  You might well introduce some serious instability.


Is it mandatory to have published papers while applying for PhD?

Question: I've heard from people saying that while applying for PhD, you need to have past experience in researching something and should have international publications. I was like more concentrated towards practical experience and have't had any publications. If I am aspiring to do PhD and want to apply, it would be impossible if such a criteria exists!
Comment: I take it this question mainly comes up in STEM-related fields... In humanities and much of the social sciences, even applicants who already have MA degrees are pretty unlikely to have any publications.
Answer:
Is it mandatory to have published papers while applying for PhD?

No.
However, if you have any research experience (working in a lab, research you've done for classes, undergraduate thesis, capstone project, etc.), you should highlight that on your application, both in your personal statement and on your resume / CV.  More importantly, your letters of recommendation should discuss your potential for research. Your recommendation writers should know this, but it would be worthwhile to highlight this in any material you provide to them when you ask them for recommendations, and when you discuss it with them. Trust me, the more information you can give your letter writers, the better their letters will be. I explicitly ask students what their goals are when I'm writing letters of recommendation so I can tailor them appropriately, and you should make sure your letter writers understand that you're applying for a PhD and what your research goals are.

I was like more concentrated towards practical experience and have't had any publications.

If by "practical experience" you mean that you worked on an unsolved problem, then that counts as research. If you simply re-applied knowledge in order to learn how to become proficient in that field (e.g., you programmed a microcontroller to turn lights on and off via voice commands), then the research angle is harder to spin.  But, do the best you can to highlight on your applications why you believe you have the preparation to do quality research.
Answer: I agree with Chris Gregg here, and I would like to detail my personal situation, as it might be relevant here.
I am about to get my Master's degree in CS and will start my first year of PhD in October with only a four-month experience in R&D (and not really research per se) during an exchange program and with no publication. In my opinion, there are three points that played in my favour while applying :

Four-month experience is still experience, and you should highlight it in your resume and cover letters. In my case, this experience was at the roots of my choice to get a PhD; reading articles, getting to learn of tons of great ideas on a single subject, then trying to develop your own idea and finally publishing it are the reasons why I have decided to get a PhD. But more importantly, thanks to this experience, I got to know what it was like to work in the industry (through internships) and to work in research, and it allowed me to justify my choice more easily.
You have to narrow down the subjects that interest you, as a PhD is a long-term engagement. During my applications, I have specifically targeted the Human-Computer Interactions domain (HCI) and have been lucky enough to find a subject on Computer-Supported Collaborative Learning (CSCL) that is related to HCI and to learning sciences (which is great because I want to be a teacher, eventually).
Choose wisely your recommendation writers. They have to testify your ability to work in research and academia. I have been accepted for a subject only because the contact knew a PI who wrote a letter.

So the answer to your question is no, but prior experience in research and clear future career goals have to be emphasized in your applications in order to get not only what you want, but also what suits you.
Answer: I think a general answer to your question is "no, it's not essential (but it won't hurt!)".
It's important to bear in mind that this will be more true for some disciplines than others. In a lab science, for instance, it is fairly common for undergraduates to show up on the publications of group leaders on whose projects they have worked during some kind of internship. This is in stark contrast to a discipline such as economics, in which most students do not have any publications even at the time of completion of their PhD! Try to find out what the norms are in your discipline of choice.


Why do you need to change your position rather than just focal length to affect perspective?

Question: Why must you change your distance from an object to change your perspective of it? Why is it not sufficient to change the focal length of your lens (the zoom level) to change  your perspective?
Comment: Check out this question — the answers include some lovely animations which should clear this up for you:  [What does it really mean that telephoto lenses "flatten" scenes?](http://photo.stackexchange.com/questions/18185/what-does-it-really-mean-that-telephoto-lenses-flatten-scenes)
Comment: Because this is the way how geometry works.
Comment: [What is the difference between perspective distortion and barrel or pincushion distortion?](https://photo.stackexchange.com/q/85526/15871)
Answer: Perspective is the size relationship of objects. You might say the ratio of size of foreground objects to background objects. Perspective plays a big part when it comes to judging distances to objects. It is a major contributor to our 3D vision.
When we change our distance, the size relationships of objects at various distances change. When we change focal lengths, objects are magnified when we operate in the realm of telephoto and minimized when we deploy wide-angle.  When we zoom, the size relationships do not change as both foreground and background objects enlarge or shrink uniformly.
Answer: To quote Ansel Adams The Camera:
"...moving closer to the subject causes nearby objects to grow in apparent size more rapidly than distant ones, so their relative sizes change. In contrast, changing the lens focal length without moving the camera does not alter the relative sizes of different parts of the subject. If a nearby object doubles in size because of a lens change, then all distant objects also double in size; all parts of the subject are affected equally" (Adams, 1987, p. 101).
Answer: Perspective is all about the angles at which light rays reach the lens. If the light rays coming from the sides of one object are closer together (a smaller angle) than those coming from the sides of another, the first object will appear narrower in the photograph. This could be because the first object really is smaller, because it's farther away (like a road vanishing in the distance), or because of both factors combined. (All of the above applies to any other measurement of the object, not just width.)
If both the camera and object are stationary, those angles don't change as you change the focal length because the angles are determined solely by the relative positions of the lens and object. Changing to a longer focal length doesn't change those positions significantly. The longer focal length lens just throws away light rays that hit it at shallower angles.
Since the front of the lens moves in and out as you zoom, there probably is some slight change in perspective; but the change would be so small that it wouldn't have a practical effect on most cases.


Is there a server offering "standby" for domain name?

Question: There are a few domains I have an eye on. Right now, someone else owns those domains, but doesn't actively use them. Is there a service (if possible provided by one of the major registrar), that I can use to put myself on standby for a domain? I.e. the service would register the domain for me as soon as it becomes available?
Answer: SnapNames.com
One of the biggest firms for getting expiring domains is SnapNames.com.  I think the price is something like $59 and they'll provide you with a "SnapBack" on the domain name of your choice.
SnapNames has partnered with a large number of registrars (both large and small) to help boost their chance of success.  They attempt to register domain names with SnapBacks placed on them at the exact second that they become available.
Since they get more "tries" than you do... their chance of success over someone trying to manually grab a domain is MUCH greater.
I've used them in the past to get names for clients who forgot to renew and almost lost the domains.
Keep in mind that you're basically purchasing the CHANCE of getting a domain name.  They are partnered all over so they have a very high success rate but its NOT 100% guaranteed success.
That being said... these guys are probably your best bet if you're serious about getting the domain name.
http://www.snapnames.com
Good luck!
Answer: As KPWINC mentioned, SnapNames is great.  Another one to keep in mind would be NameJet.
If the name you are looking it is of any value, it will probably be sold through a premium partner agreement rather than just deleted where it can be picked up by any drop catcher.  These names become available through partner agreements approximately 35 days after expiration.  If they are not purchased during a partner auction, they will be deleted approximately 78 days after expiration.  When they are deleted, any drop catcher can "catch" the name for you.
Network Solutions, Enom, and some Fabulous domains will first become available at NameJet.  Moniker, Dotster, Register.com, and many others will first become available through SnapNames.  Finally, some registrars do not have partner agreements and therefore their names will only become available after deletion.
Also keep in mind that just because a name doesn't have a website that it is not necessarily unused.  Many people will have a great domain name and only use it for email.


What does "circuits" mean in Cryptography?

Question: I am not a hardcore cryptographer so this might be a really stupid question. I am looking through some papers in homomorphic encryption and discovered they describe computation as "circuits", why do they use this particular term? Isn't algorithm a more suitable word? Do "circuits" have some special meaning in cryptography?
Answer: Circuits can be expressed using very simple operations. For example, a boolean circuit consists of only two types of gates, addition and multiplication (where the input values are each 1 bit). Furthermore, (boolean) circuits can describe any computation.
This is very nice when it comes to fully-homomorphic encryption. All we have to do is provide a way to homomorphically evaluate two types of gates and voila, we can evaluate any computation homomorphically. As pointed out in a comment below, circuits have been used for more than just homomorphic encryption. Secure multiparty computation (both the secret sharing and the garbled circuits variants) uses this as well.
This makes the job for cryptographers much easier, but makes things harder on users, right. If I want my super awesome algorithm to be evaluated homomorphically, I've got to come up with a way to implement it as a boolean circuit. That means no loops, no conditionals, etc. I only get addition and multiplication. Other computation paradigms have been looked at. One early one was moving from boolean circuits to arithmetic circuits (not too big of a jump).
Update
Recent work is interested in not limiting programmers to circuits. For example this, this, and this all look at language based approaches.
P.S. Sorry for the link dump. I haven't properly read through these so I can't really comment. A question on how non-circuit approaches work could be a good question to ask. I'm betting there is someone on here who can go into detail on those.
Comment: About Turing completeness. As I recall, the reason a single circuit can not be said to be Turing complete is because the input size is fixed. However, one also talks about circuit families. Roughly speaking in a circuit family you have one circuit for each input size. To solve a problem you pick the circuit corresponding to the concrete input size. Circuit families are Turing complete. So yes you could theoretically support any algorithm supported by a Turing machine with FHE.
Comment: Ok you are right, you can of course think of it as arithmetic over GF(2). I just find it more clear to talk about XOR and AND to avoid confusion. BTW. actually XOR and AND are not functionally complete, a fact many MPC papers ignore. You also need constant TRUE (or 1) gates.
Comment: @dorafmon It is worth noting that this appears a lot in the field of MultiParty Computation (MPC, such as linear secret sharing and Garbled Circuits) as well as HE.  In addition, the circuits don't have to be boolean, there are arithmetic garbled circuits.  The basic idea is the expression should be a DAG - no loops  and conditionals are just a bit masking of the branches, each of which are evaluated.
Comment: @ThomasM.DuBuisson that (conditionals become bit masking where each branch is evaluated) is something that I think a lot of people miss. Thanks for pointing that out.
Comment: So in this sense, the FHE scheme can support any algorithm, i.e. it is Turing Complete upon encrypted data, right?
Comment: @dorafmon, not turing complete due to the size issue pointed out in the link I posted. It is a different computation model. See the beginning of [this](http://www.cs.princeton.edu/theory/complexity/circuitschap.pdf) chapter from Boaz Barak's book.
Comment: @mikeazo aha thanks! But all the (modern) processors are in this model right? Like the ones inside your laptop. if the circuits is big enough, it can give you the illusion that it is Turing complete, although it isn't.
Comment: @dorafmon Taken from [here](http://en.wikipedia.org/wiki/Talk%3ATuring_completeness#good_non-turing_complete_language:_3D_shaders) (yes it is 3d shaders, but it applies). *Shader model 3.0, which is used in the latest PC hardware and on Xbox 360, has fully general looping abilities and is Turing complete in the theoretical sense. This rather nicely highlights the difference between theory and practice, though! When people claim a device is Turing complete, what they actually mean is "if this had infinite time and infinite storage, it would be Turing complete".*
Comment: Also there is a little bit of confusion in this answer about Boolean/arithmetic circuits. In Boolean circuits the gates compute Boolean logic on bits (i.e. AND, OR, XOR, NAND and so on). In an arithmetic circuit the gates compute arithmetic operations over some field typically multiplication and addition. Usually we only care about a small number of the operation, for example, just NAND, because using NAND we can implement everything else.
Comment: @GuutBoy no confusion. In boolean circuits addition and XOR are equivalent, multiplication and AND are the same thing. You can think of it as an arithmetic circuit over GF(2). You can get NOT using the XOR (addition) gate.
Answer: IIRC, most current homomorphic encryption systems can evaluate a boolean function.  A boolean function can be implemented as a logic circuit.  The term was borrowed.
Comment: Caveat lector, I am not aware of any homomorphic encryption algorithms that are also Turing complete.  Arbitrary mathematical functions are computable over rings, but evaluation of functions involving diverging execution paths are not yet doable in anything approaching polynomial time.
Comment: @dorafmon, I found [this answer](http://cs.stackexchange.com/a/26109) and the comments to be interesting and related.
Comment: so homomorphic encryption does not support evaluating arbitrary algorithms on encrypted data? I thought it wouold.
Comment: @dorafmon : That would be completely incompatible with confidentiality, since one could evaluate an algorithm that will either halt immediately or run for a long time depending on what the data is.


How can I get an image image printed so it retains the detail I see zooming in on screen?

Question: If I take a photo in raw, edit it a little in Lightroom, then upload it to flickr, when I click on the photo in flickr to open it then click on it again to enlarge it, there seems to be quite a lot of detail. When I take the same file to a high street photo printers I am always disappointed. Can I get a print that has the same amount of detail, and if so where?
Comment: I've spent the past 3 months researching a printer for my work - to cut a very long story short - & not really surprisingly; the more you pay, the better the result. [Not necessarily because of processing differences, but attention to detail.]
Comment: What size are the prints you have had printed?
Answer: Viewing size determines visible detail.  The visible detail will depend on the viewing size.  If you print an image 6x4 inches size, it is always 4 inches tall.  Substitute 10x8 inches if you wish, but a print cannot show more detail than its size.
If you view it enlarged to full screen size on your monitor, depending on the monitor, it might be 10 or 11 inches tall.  That can show much more detail.  And if you zoom in on it larger, to show only half of previous content, the overall total (unseen) size might be 20 or 22 inches then.  Much more fine detail becomes visible at that size. Enlargement certainly does help viewing.
We think of digital resolution as pixels per inch.  However, there is definitely a limit, and in common viewing situations/distances, our eye cannot resolve more than maybe 300 pixels per inch.  If we condense 1000 pixels into an inch (in a small print), our eye cannot benefit from it, we cannot see that detail then.
Comment: Looking at an ≈22MP image at 100% magnification (zoomed all the way in) on a 23" HD (1920x1080) monitor is like looking at a small piece of a 60x40" print!
Comment: Well, you could print a larger print, or enlarge a smaller portion of it, etc. But yes, to see all of your pixels, you do have to spread them out enough to where the eye can see their detail.  Just saying, viewing a small size image cannot show all that viewing a large size image could show.
Comment: thank you for your reply ,but does this mean I can only ever look at one of photos in such detail on a computer monitor and not have a physical copy
Answer: If you print a photo at "passport photo" size, of course you won't see all the detail that the image holds; it's too small. Solution... print larger. Now, of course I don't presume you are printing at passport photo size, but the logic is the same.
(Of course there are limits - you can't just choose any arbitrary print size, because your image is composed of only so many pixels to begin with.)


Commonly taught method divides by zero

Question: I just saw this question and the two answers. Now I am very sure that if many teachers see these answers they would accept them. Unfortunately they are deeply flawed. The second one is clearly invalid in saying $\int -\frac{1}{x}\ dx = -\ln(x) + c$. But if we ignore that, the remainder is equivalent to the other solution. But most teachers would not have even realized that they have not followed the rules of arithmetic and divided by zero! I believe this method of solving separable differential equations is widespread, having been taught it by my own teachers in the past. How do we correct this problem? As I point out in the later part of this answer, actually solving differential equations rigorously is no trivial task, but difficulty does not justify using wrong methods. So my question is more of a math-educator-educator question, in that I feel educators are not sufficiently aware of the problems in their own reasoning simply because they have rote-learnt and rote-taught these methods, and I'm wondering how best to tackle this problem, since clearly students at the high-school level will not be capable of handling the correct reasoning. I'm totally not in favour of lying to the students or sweeping problems under the carpet by something like "The method works for some kinds of differential equations under certain conditions, which will be the only type I will give you, so just follow the method blindly and don't ask questions!", as I firmly believe in not telling students to suppress correct rules of arithmetic just to permit incorrect mathematics that happen to get the right answer only sometimes (like for analytic functions).
Comment: @RyanG: Your linked post is actually **not rigorous**. Please read very carefully the full post I linked regarding actual rigour in solving differential equations.
Comment: I did in fact only read it cursorily. Since I misunderstood your point I have de-linked the post.
Comment: @RyanG: Ok thank you for your response. By the way, you may be interested in reading the comments [starting from here](https://math.stackexchange.com/posts/comments/6391533) on a similar post I wrote on Math SE giving some details of what would be necessary in a rigorous proof. Feel free to ask me any questions about that in [the linked chat-room](https://chat.stackexchange.com/transcript/77161/basic-mathematics).
Answer: The method is mathematically incorrect, but whether it is wrong or not, depends on whether people know what they're doing or not.
The possible division by zero is a mistake, yes. But it is a mistake one can ignore if in the end you get a solution to the differential equation. To make it full proof, what I do is the following sequence of steps.

Possibly divide by zero;
Find a candidate solution (after dividing by zero);
Check that the candidate solution is indeed a solution, rendering the division by zero issue a non-issue. (This is step is often implied, not written and unspoken, in my mind this is the most important step);
If the goal is to find all solutions to a problem, use Picard–Lindelöf or one of its variations to conclude that the solutions previously found are the only ones. (This step is also rarely mentioned and in conjunction with the third step is also extremely important);

So to answer the question "How do we correct this problem?", just make sure steps 3 and 4 are made apparent instead of latent.

A personal comment. In my experience as a student, this was never made clear to me. It was something I had to discover on my own and I've never really seen anyone but me make the steps this clear, not even in books. I often opt to avoid this method if the differential equation can be solved by the integrating factor method, because this method is quite elementary, no need to use big theorems like the solution uniqueness or do weird things like division by zero.
Comment: You're right that the last step is the almost always missing one. I also opt to use methods that avoid division by zero and advanced theorems like Picard-Lindelof, the latter because it does not make sense to me to appeal to high-level mathematics when students and teachers cannot even get the basic arithmetic and logic right. Like you I also discovered these on my own when I actually tried to rigorously solve that kind of differential equation. But how to solve the problem of teachers not knowing (or not wanting to know) the correct methods?
Comment: Hard to believe? Most high-school teachers have no idea how to justify most of what they teach! In many cases this is not so problematic since they are simply using a **true** formula or **valid** method. In this case this is bad because the method is simply wrong. I too thought it may not be on-topic but I saw there is a tag for "questions about educating teachers" so that is why I eventually decided to post my question. =)
Comment: @user21820 It's hard to believe that whoever teaches this stuff doesn't know about it. I assume they just don't care enough about the details. I believe this is a serious problem and one which is present is many courses, analysts seem to be particularly prone to this sort of abuse, it's nothing new. How to solve this problem? I don't know and I think it's not on-topic here on MESE.
Comment: @user21820 I'm sorry. I just assumed this was at university level. Where I come from differential equations are only taught at this level. And lecturers   at this level (where I come from) are very competent. I can't comment on what happens in other countries though.
Comment: That's nice. I too feel that perhaps we shouldn't be attempting to teach it at high-school level, at least until logical foundations are firm. But then I wonder why it wasn't made clear to you as a student? Same happened to me in university level, and it was not that my lecturers knew but ignored the details. Rather I believe they never bothered to think rigorously when they applied 'well-known' methods, so they were not even aware of the gaps. I believe they also did not have a rigorous theory of differentiation **compatible** with "$\frac{dy}{dx}$" notation, so it compounded the problem.
Comment: "Well-known" such as "separable differential equations" ("just separate the "$dy$" and "$dx$" and add integral signs to both sides").. Another was substitution. If one attempted to use the epsilon-delta definitions it would become extremely messy and non-intuitive to manipulate. On the other hand, it is not an easy task to give a consistent interpretation to the Leibniz notation so that it respects both intuition and rigour without using non-standard analysis. I did so recently when coming up with my own teaching material from scratch, so I can understand the difficulty in handling it right.
Answer: First off, it's not necessarily wrong; there are other formalisms than pointwise manipulation of functions, and are arguably closer to actual practice too, even if not explicitly stated.
That aside, even in the formalism of pointwise manipulation of functions, the methods are still correct, just missing their final steps. Both of the sample answers can be described as solving the problem on the domain of nonzero $x$ (although, the integrating factor version is a little quirky and was probably a mistake rather than taking advantage of the quirk to arrive at the simplified form of the integrating factor).
The missing final step is to see which solutions on the domain $x \neq 0$ extend to a solution on the domain of all reals. An error made by both of the posts is that $c$ is meant to be locally constant; on the domain $x \neq 0$ that means $c$ potentially has two different values: one on $x>0$ and one on $x<0$.
(although it does turns out they have to be the same if you want to extend a solution on nonzero $x$ to a differentiable function on all reals)
I imagine the best thing is not to try and tell students "don't do that", but instead show them how to "do that, but correctly". And give them problems where there are new solutions. e.g. a small tweak to the same problem
$$ x y' - 2y = x^3 $$
has total solution, if the domain of $x$ is all real numbers,
$$ y = \begin{cases} x^3 + c_- x^2 & x \leq 0
\\x^3 + c_+ x^2 & x \geq 0 \end{cases}$$
where $c_-$ and $c_+$ can each be any constant.
Even with a boundary condition like $y = 0$ when $x=-1$, there can still be infinitely many solutions, such as
$$ y = \begin{cases} x^3 + x^2 & x \leq 0 \\ x^3 + c x^2 & x \geq 0 \end{cases} $$
Maybe at first give them a problem that helps remind them; e.g.

Solve the equation $x y' - 2y = x^3$ such that $y = 0$ when $x = -1$ and $y = 3$ when $x = 1$.

and later give them problems where you just have one boundary condition, but still expect to be given the full solution. And give them problems of the sort with no solutions too, since they should be able to recognize and prove that!
A specific kind of problem of this type might be useful, since it requires a new kind of reasoning and actually comes up in real problems is something like
$$ x y'' + y' = 1 $$
where the general solution is
$$ x + a \log|x| + b $$
(where $a,b$ are locally constant on the domain of nonzero $x$)
but one has to deduce that getting a solution on all $x$ requires selecting $a = 0$.
Comment: Indeed as I show in my linked example it is possible to use the usual method to solve the differential equation on certain separate domains and then piece them together. As for your last example, the best way is to use $(xy')' = xy'' + y' = 1$ which gives $xy' = x+c$ for some constant c. For it to be satisfied when $x = 0$, we must have $c = 0$ and hence $x = 0$ or $y' = 1$. Trivially we get $y = x+b$ for some $b$ for each domain with $x$ on one side of $0$, and the two $b$s must be the same to meet smoothly at $x = 0$.
Answer: I believe this also happens when doing partial fraction decomposition.  Often students are encouraged to plug in values of x that would lead to division by zero, but this is never really mentioned or clarified.
Comment: Well at least many teachers who teach partial fraction decomposition will show what happens when you equate with the guessed form and cross-multiply to determine the coefficients. That incorrect so-called cover-up method does not even work for general partial fractions so it should not even be taught.

Commonly taught method divides by zero


How to automate the Shape Builder tool in Adobe Illustrator CS6 for mass welding?

Question: The obvious answer is "use the Shape Builder" tool, but...

The problem is that I actually have a blob of ~5000 shapes that all need to be welded together as one, and drawing all the lines across all the shapes needed to connect Shape Builder is incredibly tedious. What I really want is "just automate Shape Builder and weld together every selected space that is the same fill color." Is there a way to do that?
Answer: Select all shapes that you want make one. Then in the Pathfinder panel (Window >> Pathfinder) click shape mode "Unite". Holes (=compound paths) will survive and the common stroke, too. Your example is united in less than 1 second including the selection. (Note: The Pathfinder Panel has nothing to do with Effects >> Pathfinder.)
If there happens to be differently colored objects here and there that you want to keep separate, you can select one red shape and take the rest along by Select > Same > Fill Color.
ADD: If we watch the example more careful and assume that there's no error we noticet that white shapes have lost their strokes.
That's no problem, if they were separate objects. One can select all white and remove the black stroke. But if they were holes, a little tinkering is needed:

After uniting the red shapes the holes are intact. They must become strokeless separate objects. They must be done all at the same time because there's maybe hundreds of them.
Draw a big strokeless white rectangle, arrange it to back. I made an yellow rectangle to make it visible.
Duplicate (=copy and paste in place) the red shape, subtract the top red shape from the rectangle in pathfinder, ungroup the result, delete the outer remainder of the rectangle
Copy the pieces in the holes (select by the same color) to the clipboard, change their color to red in the drawing
Unite the red shape and the hole fills
Paste in place the pieces from the clipboard
Comment: I would like to point out that you can also do box selection if you hold **Shift** down with shape builder. Though yes in this c ase Pathfinder is the way to go. Though combining all same colors is called **Merge** which is closer to what OP asks. Merge however will not work all that well with stroked things.
Comment: This is a very complete answer. Thank you. I will make a slight edit to stress the difference between the Pathfinder Panel and Effects >> Pathfinder.
Answer: Select all your shapes... then Pathfinder Panel > Merge
Merge will combine all objects with the same fill color into one object. If you select objects with different fill colors, each separate fill color will result in separate merged objects. You may need to reapply any stroke after the operation.
For more descriptions regarding the Pathfinder Operations see here: In Pathfinder window, what is the difference between a shape mode and a pathfinder?
The Shape Builder tool was added later to illustrator as an "on-the-fly" pathfinder tool. It essentially does what the Pathfinder panel options do, but more as a brush than a single button click.
Comment: @SRM the effect can also do this if you apply it to a group or layer
Comment: But unlike pathfinder it can actually remove strokes, as strokes ;)
Comment: This answer is false. I cannot reply with an image so I will edit my question to show -- nothing happens when I select objects and choose merge.
Comment: Oh. Wait. "Pathfinder PANEL". What is that? (goes searching) Ah. Totally different than "Effects >> Pathfinder >> Merge." Thank you.
Comment: Glad you found it @SRM The Panel (View >Pathfinder) does things much differently than the Effects Menu item. I actually rarely use the menu effects for Pathfinder.


What's the simplest set-up to demonstrate soiless plant growth to middle school students?

Question: I'm looking for a simple, inexpensive way to demonstrate that soil is not needed for plant growth to middle school students.  I plan to germinate bean seeds in cotton, but where do I take it from there?
Answer: You can take a glass mason jar, a bean seed, and a moist paper towel. Place the seed between the paper towel and the glass. If you press the paper towel so that it lines the inside of the glass jar, the seed with grow and the students can see this process through the glass.


What is a good brand for teflon pans?

Question: I am going to buy a new teflon pan and seem to run into bad luck with cheaply made ones which flake off too quickly. Also can any good brand teflon pan withstand automatic dishwashers?
Comment: More important than a brand recommendation is understanding that Teflon is not designed for certain uses, in particular high temperatures. Before you pick a brand you want to refer back to this entry: http://cooking.stackexchange.com/questions/2287/is-teflon-dangerous.
Comment: That's right, I only really plan to use it for scrambled eggs.
Comment: I use All-Clad professionally in the kitchen. As long as the pan is hot before I add the food, I use the straight stainless steel.
Comment: @Zombies- you miss the point, if your pans are flaking and falling apart "too quickly" maybe it is _operator error_ (using them in an a manner not consistent with what the manufacturers recommend) rather than being cheaply made. If you attempt to use a Ferrari for off-roading, it didn't fall apart because it was cheap manufacturing.
Answer: It is not a good idea to combine ANY teflon pan with an automatic dishwasher, regardless of what the manufacturer says.
But fortunately for you, I have handy the Cook's Illustrated from October 2010, which did a nonstick skillet (aka frying pan aka saute pan) review.  According to them, even the best nonstick coatings won't survive more than a year or two of heavy use.  This makes proper care all the more important. Brand also isn't a good indicator of coating quality, because many pan manufacturers buy coatings from the same suppliers.  To quote the article:

Most cookware manufacturers don't make their own nonstick coating; they buy it from suppliers offering a menu of options, from basic to premium, and spray it on their pans.  It's similar to painting a room; the quality of nonstick coating is determined not only by what's in it but also by how carefully it's applied and cured, and how many coats the manufacturer decides to put on.

They found the Tefal (T-Fal in the States) Professional Total Nonstick Fry Pan ($35) had a nonstick coating that outperformed the other pans by a significant margin, probably due to its 5-layer nonstick coating (most pans use 2-3 layers).  The only fly in the ointment was its handle, which had rivets that loosened after abuse.  But, for $35 that isn't bad, doubly because it outperformed the $150+ All-Clad nonstick pans they used normally.
If you're looking for something cheaper than that, I'd suggest you look at construction and not brand.  Pick a heavy pan (for its size), with either solid, thick-gauge aluminum OR a multi-ply construction.  This combination ensures the pan will heat evenly and rapidly (crucial for eggs), and is resistant to warping (important if you use an electric range). If you're cooking eggs, avoid hard-anodized aluminum interiors, as they don't help prevent adhesion of eggs, and just cost more.  The nonstick layer should look thick and smooth, not slightly textured.
My most-used frying pan (the default egg pan) is a small T-Fal that cost all of $7. The important thing is that it has the right construction and I treat it correctly; I'm careful not to scratch the surface with utensils, I never use a scouring pad on it, and it can't go near the dishwasher.  This makes more of a difference than picking a fancy brand.
Comment: A great answer Bob.
Comment: Offtopic: Does the brand I know as Tefal sell in the States under T-Fal, or is a competitor able to get away with the name without a trademark lawsuit? Or did you just "shorten" the name as not to discuss brands openly?
Comment: @rumtscho: Edited b/c I'd forgotten about that. Tefal sells as T-Fal in the States as a result of a branding conflict with Dupont, who claim it is too similar to "teflon".  This makes sense as it is a combination of "TEFlon and ALuminum".  Also, if anyone feels the need, I can go into the particular testing methodology Cook's Illustrated used.  It is fairly rigorous and objective, I just left out the details for brevity.
Comment: +1 for Tefal. I'm lucky to have a factory store near though, otherwise they'd be outside my budget :)
Comment: no problem with dishwasher and Tefal for me, but I don't need salt in my dishwasher because of our water type, which makes a difference.

What is a good brand for teflon pans?


FTP Logs in IIS 7.5

Question: I know this is weird, but the thruth is that I can't find the FTP logs in one IIS 7.5 Server.
In the IIS Management Console, I've gone to the server, click on FTP Logging that appears inside FTP group (with other options like FTP Messages and FTP Request filtering). Seems that the configured folder for logs is:

C:\InetPubFolder\logs\LogFiles

If I go there, I can find a lot of folders with the structure W3SVC#, where # it's a number. They all contain logs, but they are HTTP logs, plenty of GET and POST verbs.
Am I missing something?
The server contains a lot of domains and It's hard to find.
UPDATE:
Don't Know if this helps, but the IIS is working with Plesk. It's curious, but I can't find FTP sites as I did with IIS6. If I do a telnet to 21 port appears:
220 Microsoft FTP Service
Answer: try sending a file to the ftp server.  It may not have 'initialized' and created the logging directory.  Also, make sure that logging is turned 'on' - it might be configured, but not enabled.
Comment: Thanks a lot James!. Sorry, it doesn't make a difference. In theory, a lot of webs are making use of the FTP right now.

FTP Logs in IIS 7.5


programming a 2006 Chevy Malibu key

Question: I have followed the steps several times to program my 2006 Chevy Malibu but for some reason the keys will not program and the security light does not go off I have also let it sit for more than 10 minutes the security light still doesn't go off are there any other suggestions or should I just try letting it wait longer for the key to try to program
Comment: What steps are you doing? Also are you sure you got the correct key. I realize it fits mechanically but if you didn't get the correct smart key it won't work.
Answer: Further to Larry's question 'What are doing?' have you tried another one of your keys for the vehicle? With your second key, lock the doors with it via the lock. Then open the door with it via the lock. Does it work now? If not lock the doors with the button on the key. Unlock the the doors with the button on the key. Does it work now? The above little run around is because sometimes cycling the system can do a reset. If at the end of cycling the keys it will still not turn off your immobiliser to start the engine then you are having a problem with: 1. The chip in the key is either lost or corrupt, or 2. The inductance winding in the steering coluum has failed, or 3. The vehicles ECU has failed or the vehicles instrument panel has failed. If the system does not respond to the run around then you will need a system scan to establish the exact fault area.

programming a 2006 Chevy Malibu key


How is Wordpress child related to Buddypress child theme

Question: I am new to both. I have installed and created twentytwelve on my local server. I am about to use Buddypress and create its child theme, too. Question is, how these child themes are related to each other now, in terms of editing? What happens if I edit one of them? I have difficulties grasping this concept (I understand the child theme creation, though).
Comment: Can you clarify your question please? I'm not sure what your problem is.
Answer: Your question is not very clear, but you should for the most part think of themes as being very much distinct. There is only one relationship between themes-- that between a parent theme and a child theme.
Themes in general are not related. Child themes in general are not related. Themes do not share code or settings. The exception is that two child themes with the same parent share that parent's code (PHP, Javascript, CSS),  but not typically any settings (though you can make that work). And the child theme can overwrite parts of the parent's code-- the point of a child theme--, so obviously that code is not shared.
If you edit a parent theme then anything in the child that depends on the code you edited will be effected. The reverse is not true. Editing a child does not effect the parent. If you edit a child the edit has no effect on any other child themes of the same parent.
Some theme frameworks may muddy this distinction, however.


Is it better the use the present or the past tense for a novel written in the first person

Question: I just started a book, but i cant decide if its better to use the present or the past tense (written in the first person)
Comment: The fact that you're not sure means that you should be using the past tense. It's the default for a reason.
Comment: You may be interested in [Reasons for confusion over tenses in a story](https://writers.stackexchange.com/q/29751/2533). It's not the same question as yours, but it seems somewhat related.
Answer: It depends on what you are trying to do. Present tense creates tension because the reader doesn't know what is going to happen -- is the narrator going to live after the bomb explosion, for example? However, past tense can be advantageous if you want the reader to think that the narrator has learned from experience. Is the storyteller giving you the benefit of his/her wisdom after a long series of events? Is this a retrospective, or is it happening now?
A personal opinion only: I find it very difficult to write first-person present tense for anything longer than a very short story because anything I write seems rather false and 'pushed'. Of course, this is my limitation, but you might want to consider how many well-respected authors write this way before you take it on yourself.
Answer: You are almost certainly going to use both, since it is almost impossible to say very much without making reference to actions past, present, and future. But I think what you are really asking is, should you write in the narrative present or the narrative past.
The narrative present means that you are narrating events as they occur, as if you were walking down the street giving a running commentary on you life. "On the left I am passing the butcher shop. Now I am crossing the street."
The narrative past means that you are narrating events after they happened, the way you would normally narrate events, for instance if someone asked you how was your day?
Both the narrative present and the narrative past involve the use of multiple tenses:

Now I am passing the butcher shop where Dave met his wife. They are going to knock it down next month to build a Starbucks like they did last year on Main Street.

The narrative past is the default mode of storytelling in the western tradition (and probably in all the other traditions as well). The use of the narrative present is a device for obtaining certain effects. For instance, it can give the narrative breathless quality or suggests a sense of inevitability to events. Use it is your are trying to achieve such an effect and have some clear idea of how to do so.
Answer: There is no correct answer to this - the two tenses have different effects.
It is generally believed that the present tense is more immediate and gives a stronger sense of tension.
Whereas the past tense is more standard and tells the story in a more straightforward way. Personally I think you can build just as much tension in the past tense as in the present.
I would recommend writing the past tense if you're not that experienced, because it is the default standard for most fiction, and I believe it's best to focus on the story, rather than getting preoccupied by the format, when you're first writing a novel.
When you've written your first novel in a reasonably straightforward way, you will have learned an awful lot and you will be much better informed about whether you want to use one of the more unusual structures in your next novel, such as present tense. At that point you will be able to answer it for yourself, because you will know the impact it will have on your story.
One final note - because writing in past tense is so integrated into our psyche, you may find it harder to write in the present tense and will find that you often slip back into past tense without realising. Catching all these instances could be very tedious, but not catching them will make your writing look unprofessional. Just another reason to stick to past tense unless you have a damn good reason not to!
Answer: There is much ado about this question on the internet, with vehement opinions, but the simple truth is that readers don't much notice either way.
If you wonder about which tense you should use, the common sense answer is that you should use whichever tense you feel most comfortable with when you write. Try each for a day, and you will know.


Best drum sticks size for practice pad?

Question: Is it worth it to practice with some sticks a little heavier/lighter than the ones that I actually play with?
Answer: I'm not a drummer but I've talked about this with the drummer in my band a bit.  So I have some insight but not enough experience to truly provide full detail or necessarily be able to answer follow up questions, though I will try.
Practicing with different stick sizes can be quite useful, typically on the side of practicing with heavier sticks.  The heavier sticks will work your muscles harder and develop more strength and endurance than lighter sticks.  When you transition back to the lighter sticks, they should end up feeling almost weightless, allowing you to play high intensity parts for much longer before losing your chops.  I couldn't speak to there being any value to practicing with lighter sticks than you're usually playing with, though I can imagine ways that it could potentially be useful but I won't speculate on that.
The hardest part about doing this will be transitioning back and forth between the sticks.  If you end up on the practice pad with heavy sticks more often than on the kit with lighter sticks, you may end up playing worse, or the sticks could feel so light that they pretty much fall out of your hands.  So you would want to make sure that you're comfortable with that transition before you start implementing and find yourself struggling through a gig.  If you are indeed on the pad more than the kit, I would recommend using the lighter sticks while practicing also, switching back and forth or ending with the lighter sticks, so that your hands and brain get used to that switch and it can become a subconscious thing.  It may actually be good to have several different stick sizes and move around between all of them.  This may not have a huge impact, I'm not sure, but could potentially develop a stronger sense of control that doesn't rely on the sticks themselves.
My drummer plays in lots of different styles of bands, from relatively heavy Rock to traditional Jazz, so he actually uses different sticks for each genre, occasionally switching for specific songs for a single band.  He's mentioned occasional issues with using his preferred sticks for our band after a period of time playing more consistently with another band but he adjusted quickly enough that it wasn't a major issue and could be avoided altogether by practicing with the different sticks more consistently.
As a last note on the subject, this concept can also apply to other instruments.  Jaco Pastorius mentioned in an instructional video that he would switch out the neck on his Fender Jazz Bass for a Fender P-Bass neck when practicing because the P-Bass neck required a little more work on the hands and the Jazz neck then felt easier to play for gigs.  With the speed and dexterity required to perform like Jaco, I imagine this was a very helpful exercise.
Again, I'm not a drummer and am only providing advice based on what I've been told.  So as much as I trust my drummer's thoughts on the subject, it's definitely a good idea to hear some first hand advice from actual drummers and potentially ask a teaching professional.
Answer: Larger sticks will help.
Metal sticks are also good for stick control on the pad as they can be less forgiving - just make sure that you don't use them all the time. Check out JoJo Mayer's DVD Advanced Stick control for the Modern Drummer - he talks about using metal sticks for practicing on there.
Hope that helps
J
Comment: I also use marching sticks. I have three different pairs including the Ralph H sticks mentioned. Looking for even heavier!
I hope you are using a practice pad for these as heavy sticks for marching will destroy a regular kit drum.
Comment: @Gary There are weighted sticks- e.g. the Ralph Hardimon "Hammer" model (not the regular Ralph Hardimon model!)  Also, using regular marching sticks (e.g. the regular Ralph Hardimon model) will not destroy a drum kit, although the heads will wear faster.  The heavier ones still won't break the kit, but the head might not last long at all.
Answer: This depends on what you are practicing.
I believe heavier are better for working out the muscles. I'm using the Ralph Hardimon series from Vic Firth, for example, simply because these are the heaviest I found so far. The important thing is that they have an excellent balance and rebound so they don't feel heavy. I believe heavy sticks helped me to work out the weak hand faster.
Once your grip is firm, you'll be able to play any sticks and adjust your dynamics accordingly.
It might not be good to practice with heavy sticks all the time. They have a purpose and are to be used to strengthen the muscles.
Ideally, you would practice with the sticks you play with.
After working out the muscles for several months, I went to 2B sticks for general practice. They are the heaviest of the "normal"-size sticks. The transition to 5- or 7-size is not noticeable and they still help work out the muscles.

Best drum sticks size for practice pad?


Can I use a NFC ring as an Oyster card?

Question: I've been looking into converting a MIFARE (Oyster card) into a ring. I found this NFC ring on kickstarter, will that work as an Oyster card? Or are they different technologies?
Comment: NFC ring doesn't say, but the key thing is going to be getting TFL to do the initial programming of it!
Comment: One thing you should be aware of is that technically this would be an unsupported media used as a payment tool which easily may become a reason for suspecting you in fraud and you looking for a lawyer. Yes, I know that it's the same thing, just looking as a ring, but the fare inspectors and the police couldn't care less.
Comment: Surely it wouldn't matter so long as their just readers got the right signals. There lies the rights issues
Comment: TfL definitely do not like people doing this, even if it merely involves removing the chip from the Oyster and using that in a ring.
Comment: @sharptooth I would travel with the transit card as well and present that to ticket inspectors. I've been asked to show my card to a person about once a year. I just want the ring to get through the gates.
Answer: The short answer is "no". The NFC ring will not contain the application-specific cryptographic keys required by Oyster.
NFC "rings", like other NFC-capable contactless payment tokens, contain a tamper-resistant microprocessor with cryptographic acceleration and a small amount of secure memory storage. These chips and associated induction antenna coil are together referred to as "tags", "smart cards", or "secure elements", regardless of the physical form factor of the surrounding plastic package (e.g. card, key chain dongle, ring, watchband).
Among the secrets stored inside the chip are symmetric cryptographic keys used to encrypt the observable traffic between the chip in the card and the turnstile reader. Without this secret key, any data you might place in your key ring, even if in exactly the right application format, would nevertheless have the wrong authentication key. The turnstile will not succeed in authenticating your key ring and will not be able to read the memory contents.
During manufacturing of the chips (during wafer-sort and test phase), the devices are automatically tested before the wafer is sawn into dice. During this testing step, the initial contents of the secure memory can be programmed according to the needs of high-volume customers. The chips are then sawn and delivered (securely) to a separate factory that produces the "inlays" (the combination of antenna coil, chip, encased in suitable packaging of plastic, plasticized paper, mylar, fluffy toy, rubber wristband, etc...)
The Oyster card uses MIFARE Classic or MIFARE Plus chips from NXP Semiconductor (MIFARE Classic family). MIFARE Plus works the same as MIFARE Classic but uses AES encryption rather than NXP proprietary encryption used in Classic. Newer applications use ISO/IEC 14443-4 standardized application cards (like payment cards from V/M/Amex, and NXP offers a proprietary extension of these called DESFire for transit agency issued cards).
The Oyster MIFARE cards are programmed at the factory (or by the system operator from blank devices) and are activated upon enrollment to the system. The readers at the turnstiles and behind the glass window or in the fare adjustment machines all have matching chipsets called "SAM" (Secure Access modules) with matching secret keys stored in their own secure memory. The reader uses the SAM to generate and validate challenge-response codes and to deduct or top-up fare balances or redeem one-time tickets.
The keys required by each application are generated in the factory and programmed as described above. Alternatively, blank cards can be programmed with "transport keys" that are not secret and enable anyone to use the chip. Your NFC key ring comes that way. Once you key the chip, you can change the two keys to whatever you want them to be and program your application settings into the chip. However, you will have no way of replicating the unique keys required by Oyster: Even if you were to discover the keys in the Oyster card, they would be the wrong keys for your NFC keyring which has a separate and unchangeable UID. The keys in each card are unique to that card, derived from the card serial number and encrypted according to an application diversification rule and master key set (AN10922—Symmetric Key Diversification). So even brute force cracking one card to discover its keys will not enable you to crack any others.
In the case of MIFARE the application platform two keys are needed. The Key A and the Key B. Key B can be thought of as the "admin" key--used to top-up change keys, replace otherwise read-only data. The Key A is the key used by the turnstiles to challenge the card. The MIFARE application in the card supports only a limited set of primitive operations and so the SAM must interrogate and update the card according to Oyster-defined logic after authenticating to the card using one of the two secret keys.
There is nothing different about an Oyster card electrically from any other MIFARE device. If TfL chose to, they could provision their application to any randomly presented MIFARE device of appropriate memory size, after first erasing it. The problem becomes one of veracity of the token. If Oyster issues the card or ticket, they can rely on a secure supply chain to ensure only legitimate cards are used to hold and redeem value. However, they can't prove where your device came from — it might be a microprocessor emulating a MIFARE device, encased in an ID-1 form plastic card like Oyster cards, but with backdoor logic that might be used to undermine Oyster system controls. There is no positive return for TfL investing against this risk, however small.
So the "no" above is really a policy choice by TfL, not a technical limitation.
Once mobile NFC becomes more accepted by TfL, they will have a way of provisioning a different kind of secure application to the phone, rather than relying on MIFARE emulation. Contactless payment cards issued by Visa, MasterCard, American Express and the other payment brands, use an ISO/IEC standard physical and logical protocol that has been adapted for use in mobile phones as "NFC". The compatibility of the radio and logical protocols, together with suitable security hardware or cloud-based tokenization, will enable the mobile phone to hold an Oyster-compatible digital token that will function at turnstiles and at the glass windows.
TfL must upgrade their reader systems and SAMs (nearly in entirety) to enable the use of open-loop payment cards, issued by banks, in addition to closed-loop Oyster tokens issued by TfL. This switch to ISO 14443-4 payment readers has taken awhile. But it works already on busses and they have promised conversion of Tube should be done by 16 September 2014.

Another way to pay
  You can use your contactless payment card to travel on buses. From 16 September 2014 you'll also be able to use it on Tube, tram, DLR, London Overground and most National Rail services in London. http://www.tfl.gov.uk/fares-and-payments/contactless

This conversion is the first step in enabling consumer-owned security tokens to substitute for agency-issued tokens. And is a HUGE cost savings for TfL. Just accepting V/M contactless cards will save enormous amounts on issuing and replacing cards and on system management. And it is a practical improvement for riders who will no longer have to top-up an Oyster card or adjust a fare—these tasks are now performed automatically.
So it may not be too long from now before you can use an "NFC ring" or "watch" to open a turnstile at your favorite station. You can already use your branded payment card and may as well use your NFC payment enabled phone.
Comment: Except MiFare classic can and has been easily cracked, with cards cloned...
Comment: @passerby, you are perhaps confusing the ability to spend hours cracking a single card with the more difficult task of an exploitable attack on a population of cards. The latter has not been demonstrated. And as I point out here, learning the keys for one card will not help you learn the keys for another.

But more importantly to the poster of the question, he wants to use an existing legitimate MIFARE card with its own UUID. The UUID of his NFC ring will not match the required issuer range of the Oyster and so will not work. Crack or no crack.
Comment: With all the new NFC/RFID/-rings that's coming to market now, this answer should really be turned into a blogpost and posted to HN...
Answer: One solution might be simply transfering the chip from a functional card. But it is forbidden by conditions of carriage, chapter 5:
<code>All photocards and Oyster photocards remain our property and must not be intentionally
damaged, altered or tampered with in any way.
</code>
Unless TFL officialy offers such rings to its customers, it is pretty much a dead end.
Edit:
Another possibility might be transfering the contents of such card. But with technology in use today, duplication is impossible. It might be possible to emulate UID, but you can not transfer the stored application and electronic ticket. So far Desfire EV1 has not been cracked. And I doubt the 'special NFC tag inlay' has all the hardware required to emulate a Desfire card.
And the ring is not a real product after all (at the time of posting).
Edit:
And just using a blank emulated card will not work either, because it must have the public transportation application officially installed.
Comment: I don't see how the quote you posted interferes with OP's goals. The Oyster card can't be modified. This statement says nothing about duplicating the effects of the Oyster Card.
Comment: Both true, both irrelevent to the technical aspects of the question. Not an answer, this is a comment at best. -1
Comment: @Passerby Answer updated.
Answer: Most likely you won't be able to use an oyster card unless it has been supplied by TFL. You may be able to dissolve an existing card (in acetone) to get at the chip and antenna.  The antenna is a long wire which is usually looped around the edge of the inside of the oyster card a few times.  You could cut this and try attaching the oyster chip to the antenna in a ring.  People have made magic wands and gloves like this.  Of course

acetone is dangerous
TfL might not like any of this but you wouldn't be getting free travel so maybe they wouldn't send you to their prison
it may be that none of this works very well

Contactless payment by debit/credit card is being accepted soon, so if you fancy ruining your credit/debit card then you could try that too.  I'd imagine banks have even less sense of humour than TfL
Answer: Can you? Technically, you can. The MiFare wikipedia page has most of what you need to know:

In March 2008 the Digital Security[23] research group of the Radboud University Nijmegen made public that they performed a complete reverse-engineering and were able to clone and manipulate the contents of an OV-Chipkaart which is a MIFARE Classic card.[24] For demonstration they used the Proxmark device, a 125 kHz / 13.56 MHz research instrument.[25] The schematics and software are released under the free GNU General Public License by Jonathan Westhues in 2007. They demonstrate it is even possible to perform card-only attacks using just an ordinary stock-commercial NFC reader in combination with the libnfc library.

Oyster cards, using the MiFare Classic Card system, are  essenttially standard encrypted nfc tags. MiFare is designed by NXP, who is a big pusher of the NFC standard. MIfare classic is also very weak.
Now should you? As others have mentioned, TfL is comprimise of a bunch of myopic paranoid bastards. Again, see the Oyster card wikipedia page.
If I were you, I'd clone my valid card, and carry that card with me regardless, as a precaution.
Comment: If the card was Mifare Classic, then maybe. But these were discontinued four years ago.

Can I use a NFC ring as an Oyster card?


Is it possible to develop apps with Kendo UI to submit to iOS App Store?

Question: The number of platforms I have to develops apps for is increasing and It brings me lots of stress to learn new technologies for each target platform. I found out that Telerik's Kendo UI is very good to build websites that look and feel native on mobile platforms (e.g. iOS and Android). My question is, is it possible to build HTML5 apps to deploy them on iTunes App Store and Google Play? Please note that I am eager to know the possibility of creating apps (complete apps bundled in standard format of Apple and Google for distribution in their respective mobile app markets) but not websites.
Answer: Yes, you can build applications with Kendo UI Mobile and PhoneGap and publish them to an app store (i.e. Apple App Store).
Answer: The best advice I can give you is to ask the folks who make Kendo UI.
In general, though, unless the framework targets the web browser specifically, then it's likely their tools compile whatever front-end HTML-like code you've written to native code for the target devices. So unless the native code violoates some other rule pertaining to the "app store" in question, then there shouldn't be an issue. The only other option is to bundle some sort of browser-like thing that acts like a VM for the target device.


Comparative Profitability of Genres in Movie History

Question: I'd like to see a list of genres based in order of profitability throughout movie history. I suspect the horror genre is the most profitable genre going back all the way to the early days of movies, but I'd like confirmation. I suspect Westerns might have been the most profitable genre from the 1920s-1960s, but not as profitable since the 1970s. Same with Musicals. Horror has been profitable in every era of movie history.
Comment: @Pouya Well, absolutely for sure, but they also cost an entire country's wealth to produce in the first place, whereas some stupid handheld ghost house crap costs 3 million and makes 300 million. (Which shows that some more specifics about the exact statistics asked for might be required here.)
Comment: I'm somehow certain that for the last decade, the damn dumb superhero movies are the most profitable.
Answer: When comparing profits, cost matters. One site I found says that it is NOT the big budget action adventures that return the most profit to the investors.
Documentaries can have phenomenal returns on investment, because they can be made for a fraction of what a movie costs. The documentary "Tarnation" returned 266,416.97% profit! "Super Size Me" returned 22,614.90%. There are NO documentaries at the bottom of profit-ville.
Horrors and Thrillers are 2 more genres that are big profit makers. "Paranormal Activity" cost $15,000 to make, and raked in $161,830,890 for a return of 539,336.30%! The upshot is:
1 profit maker genre: Horror
2 Documentaries
Drama has a # of movies at the bottom of the "return on investment" list. Drama, romance & comedies - those genres are in the middle somewhere, with some being at the bottom.
As for Action Adventure, In the top 20 movies that have the best ROI, you won't see any of the blockbusters you'd imagine, and "Mad Max" is the only film of its kind in the top 20.
http://www.investopedia.com/financial-edge/0410/movie-genres-with-the-best-roi.aspx
Answer: This would be an excellent thesis topic for someone, but I think a short answer was aptly provided in the opening scroll of Student Bodies (1981)...

This film is based on a true story: last year, more than 30 horror
  films were made in America. None of them lost money.

Cheap to make, same ticket price as a blockbuster with a budget 50-100 times higher.
Comment: While that's very interesting and relevant, it only talks about 1980, and not the history of the movie industry.


Doubts about editing?

Question: I have been working on a novel, and I've gone around four chapters in. I keep re-reading the first chapters, and I am tempted to edit them. Should I wait until I at least have a finished first draft to start editing, or should I edit as I go?
Comment: Possible duplicate: http://writers.stackexchange.com/questions/3513/write-to-the-finish-or-edit-as-you-go?rq=1
Comment: What goal do you think you'll accomplish by editing now? Will editing now make it easier for you to continue writing, harder, or no difference? Is there anything you think you gain by preferring to do one of them before the other, or does it make no difference?
Answer: I suggest you keep going. What you're doing right now isn't editing; it's nervous grooming. You want what you have on the page to be "perfect" so much that it's stopping you from writing anything else.
Write the rest of the book. Put it aside for a few weeks so you can come back to it with fresh eyes. Then do an editing pass.
If you want to re-read what you wrote in your last session just to get your head back into the space of your story, and you fix a few bitty things along the way, that's fine, but don't hack away wholesale if you only have a few chapters done. Move forward.
Answer: It's fine to go back and edit, if you're focusing on arc or major plot points. If one of your first key scenes needs to be completely rewritten, have the events change, etc, then going back and doing substantive editing is totally fine. But worrying about flow, word choice, etc is line editing, and you can get stuck in analysis paralysis.
I suggest using Scrivener, which is an awesome tool. Even if you're stuck with Word, you can still skip all over the book, adding whatever scene is stuck in your head, just not as easily. That assumes you have at least a sense of the overall character arcs in your book. Scrivener has a handy annotation tool, so if there's a small but important detail that's changed or needs to be added, you just type in a reminder for later and get back to new scenes.
If you're going to line edit, do it the next day to get yourself back in the flow of the story, and then move on. The main goal is to keep your word count increasing steadily every week. Feel free to skip a day or two, as long as you keep a consistent average pace. Just 750 words a day gets you 90K words in 4 months. A month to plan and a month to edit means you can turn out a second draft every six months. Of course critiques and edits will drag on voer time.
If you're not a plotter at all, and instead just write a bunch of words having no idea what your story is about or what will happen, and later try to corral the 300 or so pages later into a coherent plot with appropriate pacing and arcs, I highly recommend you plunge on ahead. But if you do even minimal planning, you should be able to go back and make annotations or important changes without interrupting your flow.
Make what changes you need to have the story make sense, write short notes for everything else, and then get writing a new scene. Good luck!
Answer: There are many different approaches here.
Some people prefer to write the whole book in one, in order, all the way to completion, then come back and edit it all in one pass. This prevents you from procrastinating, and perhaps gives your book a certain cohesiveness and poetry.
At the other end of the scale, some might prefer to work on multiple parts of the book as they go, depending on what comes to them. If a scene or line of dialog comes clear, go and write it. If it's suddenly obvious how to edit a chapter, and your words are coming freely, edit that chapter. This gives you flexibility and fun, but can lead to logical inconsistencies and procrastination.
There are a plethora of other approaches, you have to pick the one that works for you. Be self-aware. Watch out for perfectionism. See what inspires you. See what makes it fun. If you enjoy your characters and can project this onto the page, it will be enjoyable to read.
How I write (which is not necessarily how you should write)
I generally have multiple strands on the go at any one point. Some chapters are just sketches: a few hundred words of dialog and intent. Some are written but not edited. Some are part way edited. Some need to be refactored to take into account a new character trait, tense change or piece of imagery. Some are complete. Nothing is in order.
I use TODOs all over the place to remind myself to come back. I use Markdown and Git to keep track of the confusion and make sure nothing gets lost on the way. I trade meta-critiques with other authors to help find logical inconsistencies.
It's messy, hacky & slow, but lots of fun.
Answer: Don't edit as you're writing your first draft!
Here are the two main reasons...
The priority is to get the first draft finished
Going back and editing earlier chapters is an excellent way to never get to the final one. On first draft you just need to steam through to the end. At this stage the important thing is getting the bones of the story out, and tweaking and editing is a distraction.
You will learn so much during the course of your novel, you may end up discarding entire scenes
It will be wasted time spending hours, days or even weeks fine tuning the perfect words, sentences and metaphors when you might have to chuck the entire scene wholesale. Even worse, with that much sunk effort, you may be tempted to keep scenes that need to be cut, because you can't bear the thought of that time being waster, or those darlings never seeing the light of day.

Doubts about editing?


What is the correct way to make "Brazil style" BBQ meat?

Question: I'm interested in cooking some meat Brazilian style, like they do at those BBQ restraunts where the meat is served on trays in small slivers.
Is there an effective way to do this without a huge turning slow cooker thingy (sorry don't know correct name/terminology).
Answer: Not sure if there is a correct way. It's basically skewered hunks of meat on a wood fired BBQ
You can do your own Churrasqueira by using a Weber "kettle" style BBQ or a B.D.S. (Big Drum Smoker). Use long steel skewers (or swords!) for your meat and BBQ away
Thick steaks of beef and lamb work well. Also try chicken drumsticks and some small Chorizo (spicy sausage)
Don't marinate the meat, but toss some coarse salt onto the meat surface before and during cooking. Don't go crazy with it, but it seems to absorb the roasting flavours and really boost the taste
Use a smoky fire, if your wood won't smoke add some fresh wood or herbs that do. Try lavender bush (wood and flower), grape vine or kiwifruit vine cuttings, or any other fresh cut aromatic wood
Watch the amount of fat dripping onto the hot coals; too much will make the meat taste bad. Shield the coals as required or trim off large chunks of fat
There is no need for motorised skewers that takes the fun out of it. Occasionally turn the meat by hand while enjoying your favourite beverage, and "chewing the fat" with a friend
Serve by taking a skewer to the diners plate, and hold skewer nearly vertically above plate. Use an extra sharp carving knife and slice onto the plate with a downwards cut so juices and other slicing splatter goes onto the plate and not onto the diners
If you are having a Churrasco party, give each diner a flippable symbol (e.g. red/green) to indicate to the server (probably you) "GIVE ME MORE!", or "I am stuffed". Serve a round of each meat as their outer layer becomes done
Coolest Churrasco cooker I could find

The rails on the top are what the skewers rest on
Following the car theme, some more cool Churrasco cookers here http://autozine.com.br/inusitados/churrasqueiras-automotivas
Comment: I lol'd at your "cooker", but I bet it would produce the perfect flavour.
Comment: You only need to rub the coarse salt on the meat and then give it a good shake to remove any excess salt. NEVER add herbs or spices to the fire, brazilians only use charcoal made from wood or wood itself always keeping the flames at a minimum.
Comment: @Fábio 'Herbs' as in the whole woody plant. as in whole Lavender etc, which burns slowly and smoky
Answer: Step 1. Pull out your sword.
Step 2. Slice off hunk of meat...
...
To simulate the technique at home, I'd go with something along the lines of kebabs.
Comment: That wasn't a joke. Don't you all have swords in the kitchen? :-)
Comment: +1 for using humour with your cooking. It's important to enjoy the process.
Comment: @talon8 - yes, yes I do.  Makes a good pizza cutter