SP 2010: column permission

Question: If I understand well in SP (out of the box) it is not possible to define single column (fields) permission for the various users of a site. I have seen some third party solutions which can do that, but they're not free.
I have tried some workarounds to realize this, but as even the views of a lists are not permissions-customizable, i was not able to get things working.
Is there a way to realize this option or the only way is to buy something?
Answer: Even if you buy something, the third party solution won't be absolute.  All the third party solutions do is lock down the views that can be shown to the end users.  But if a user knows what they are doing, they can still get the data through Microsoft Access, Web Services, Reporting Services, and other means.
If you're looking for something to make it a little more difficult for someone to get the data, the third party tools will work.  If you're looking for a secure solution, you probably will need to store the secret data in another list, then set permissions on the other list appropriately.
Comment: "If you're looking for a secure solution, you probably will need to store the secret data in another list, then set permissions on the other list appropriately."

I'm not sure i have understand. Let's make a pratical example:
I have a "Projects" list, with a "budget" column. I want that only the users with high permission can see it.
So i have to delete the "budget" column from my "project" list, and create an additional list with just 2 columns: a lookup column to "projects - project name" and a "budget" column.

Am i right?
Comment: But then when i add an item to the projects list i have to manually go and specify the budget in the new list i suppose. That would be really a bad thing...
Comment: Yes, your understanding is correct.  And yes, it would require some custom code in order to do it, probably some event receivers to make it all happen seamlessly.  It's not a simple out of the box solution.
Answer: In terms of make vs buy anything the 3rd party solutions have implemented you can implement yourself. You need to determine the return on investment based on your requirements.
I would personally be suspicious of the 3rd party solutions I would advise to evaluate if they are truly secure by testing if the secured data is exposed by

Object Model Access
RSS Feeds
Export to Excel
SharePoint Workspace
Document Properties in Word
Full Text Search

Remember that the Full Text Search will bypass most kinds of security as the crawl typically run as a highly privileged user, renders the text in the WebPart and indexes it secure information can then leak either in the hit highlight summary.
Larbo's suggestion to store the data in a second list with appropriate item level permissions and using a lookup column to join it in is a good idea.
Additionally you might consider.
If the data is cheap to recreate or is stored somewhere else already you could implement a custom SPField to retrieve the data at runtime and render it.
If the data is expensive and the lookup column is unmanageable you couldstore the data encrypted in the list and only decrypt it at render time. Again a custom SPField should be able to do this.
Answer: you can find a usefull solution for your problem from here: http://splistsecurity.codeplex.com
each column could have a separate permission

SP 2010: column permission


How does A/B montage works?

Question: I heard about A/B montage in school, but it was only mentioned once. And I know it has something to do with two tracks, and using it for easier automation and whatever else, when the perspective in sound changes because of visual perspective changing of course etc. I would like to learn that type of workflow, but cant find it anywhere.
Answer: A/B is also called checkerboarding.  You can use it for when a scene changes or anytime you need to apply processing that is radically different than the section of audio that came right before it.  It can be used in other ways as well, such as if room tones aren't matching between shots and long fades are needed.  I'm sure you already lay out tracks like that sometimes without knowing the specific term for what your doing.
Comment: but how do you do it
Comment: The very simplified version would be that Actor/Angle/Scene A would be on track 1 and Actor Angle/Scene B would be on track 2 so that you could have your settings for track 1 and radically different (if needed) settings on track 2. It can let you use less tracks in your edit or mix because your usually just switching off between a couple tracks.  Your edit will end up looking like a checkerboard.  If you don't already have it, I'm pretty sure the John Purcell book gives a better explanation and probably has photos also.  Its a great book to have in any event if you plan on doing audio post.

How does A/B montage works?


How to find maximum and minimum right acsension and declination based on the telescope's location?

Question: If I am to apply at a telescope for viewing objects, how to determine (easily) what is the minimum and maximum possible RA and DEC visible from that telescope during that time of the year. For eg, take the telescope at paranal
(24.6258°S, 70.4310°W) and if I observe anytime from October to March.
Comment: You can see objects of all RAs - eg by looking at the relevant celestial pole. Similarly, whatever pole you can see is the maximum Dec (alternatively, subtract your latitude from 90 to get the 'maximum' Dec visible in the direction of the other pole.)
Answer: In the Southern hemisphere, the maximum declination you can see is
90-L where L is your latitude. The minimum is -90, since you can see
the south celestial pole.
As the earth rotates and revolves, you can see any right ascension
within those declinations.
The only exception is that you ordinarily can't see stars that are too
close to the Sun. However, the Sun moves enough between October and
March that all right ascensions will be visible at night sometime
between October and March.


Answering Questions With Accepted Answer

Question: Is it correct/OK/encouraged to submit an answer to a question even if an already existing answer has already been accepted?
Comment: If you think you can write an answer which adds new useful value to the post, then write your answer. But don't just post the same thing, which is already posted.
Comment: I'm new here and figuring out how to approach things so I don't go outside of what's expected, so I've thought about this issue. In my opinion, the litmus test is whether or not it's helpful. If I think my answer is better than the accepted answer or a valid alternative that is truly different, I'd be inclined to post it.
Comment: See [this](http://meta.stackoverflow.com/questions/303045/10-million-questions-lets-share-some-stories-that-the-number-doesnt-convey/303112#303112) post.
Comment: Oh, and if it's an improvement on the accepted answer, I'd comment on the answer.
Comment: This post provides some very interesting and well written life experiences.
Comment: Where is the vote to close button?  This has been asked umpteen times
Answer: Assuming that your answer is better than the accepted answer then yes, it's encouraged. There's even a gold badge for it, Populist.
Better means adding new information to the question rather than rewriting what's already been written.
Comment: That is very well explained.
Comment: @Ben Regarding 'adding new information to the question rather than rewriting what's already been written' - If a new answer provides the same information but presents it much more clearly, wouldn't that be helpful too?
Comment: It would be @Timothy, yes. My experience is that being able to do this is extremely rare and in the cases where it's happened there's only been one answer, which I edited rather than posting my own. Just in case: your answer doesn't have to be just new information, a (properly attributed - if appropriate) précis of what's gone before is also helpful so that all the information is in one place.
Answer:
Accepted answers can get unaccepted. It is not a permanent status.
The accept status is just one person's opinion abut what works for them, possibly in a situation that is much more narrowly defined than what the question appears to be about, or even other than what the question is about.
Answers are supposed to be useful to future visitors, who may have almost exactly the same question, without the specific quirks or restrictions.
Sometimes accepted answers are outright junk. If you ever happen to write one, you will be dismayed to find that you cannot delete an accepted answer; it must first be unaccepted. Meanwhile other answers are upvoted higher.
Sometimes an early answer is accepted almost instantly, before the question has had much exposure.
Answer: The OP is the one who accepts an answer - and that's all the meaning there is for this feature.
The OP likely knows best about the his/her problem. But he or she is not necessarily the expert to pick the best answer. And some users have a very short attention span and tend to favor "the fastest gun in the west". See fastest-gun. That misguided practice produces quite a few accepted answers of questionable usefulness.
If you have something useful and relevant to the question that's not in the answers so far (accepted or not) - and with enough substance to be more than a comment - by all means, write a new answer. The new answer does not have to be "better". It has to add something useful addressing the question.


How do I Connect Two SATA II Hard Drives to a Laptop?

Question: I want to copy data from an old drive to a new drive.  The laptop has a connection for only one drive.  I see a number of splitters advertised for SATA drives, but have no idea what I need.
Answer: Use a USB to SATA cable, the SATA Multipliers and related are not well supported.
Answer: What you want is a SATA port multiplier:

In reading up for another question I found some discussion on port multipliers that indicates the success is highly dependent on the chipsets in play.  In particular, the Backblaze Pod folks found that Silicon Image (SiI) chipsets SiI3132 and SiI3124 play well with the SiI3726-based port multipliers they were using, but that their motherboard's onboard Intel ICH10 ports did not.
Addonics makes several port multiplier products that works with those SiI chipsets:

You can also find SATA hubs like this one; it also appears to be based on the SiI3726 chipset:

You'll have to do some digging to find out exactly what SATA chipset your laptop uses; it's likely integrated into the system southbridge, so the Addonics products may not be appropriate.  You can probably identify your chipset from the Windows Device Manager to be sure.  If your research indicates your laptop's chipset will not play nicely with the SiI port multipliers, you're probably better off going with Chris S's USB suggestion.


Increasing my cardio

Question: I'm trying to lose weight and I want to know the best ways to increase my cardio? I try to push my self to at least run or use the bicycle for 30 or 40 min but if I'm on the treadmill I can sprint maybe like 3 times and hold it for 3 min and the rest of the time I end up mostly walking (or speed walking).  With the bicycle it can do a little better but not much?
Comment: Possible duplicate of http://fitness.stackexchange.com/questions/3178/whats-the-most-effective-way-to-improve-cardio-endurance .
Answer: To lose weight, your diet will be the most important thing you need to work on.
As for cardio, I think that bicycle is an excellent way to start, since it is (in my opinion) better for your legs(if you feel you are overweight). I rarely do treadmill myself because of my knee.
If you feel like you have some cardiovascular endurance then you can try HIIT(High intense interval training). It can shorten your training sessions A LOT.
Basically what you do(i prefer on a bicycle or rowing machine) is use whatever you like and for, lets say 30 sec you work as hard as possible, then rest for 30 sec and do it again. Repeat this process as much as you like, you can start 6-7 times and move up to 10+. Later on you can play with the work and rest times. Like work 30 sec, rest 20 etc.
I found this being much more...fun than just cycling or rowing for an hour.
Answer: s3v3ns answer pretty much covers it, but I'd like to be more specific about the diet.
Doing cardio, even every day, will not guarantee that you lose weight (= have negative calorie balance), eating 500 kcal is much, much easier than running 500 kcal.
So I'd recommend that you write down what you eat during a week, and don't try to eat healther than normal, just write it down. In the end of the week, calculate the calorie intake you've had, and you'll see what adjustments you should make.
Comment: Sites like [myfitnesspal](http://myfitnesspal.com) will certainly help make calorie counting easier

Increasing my cardio


Can I play my old 3DS games on a new 3DS without a system transfer?

Question: My brother lost his 3DS and his super smash bros game along with it, so he is obviously pretty mad. He has a couple other games as well that he has data for (physical copies, not bought from the E shop) and he is really scared that if he buys a new model the the new 3DS and puts his game in he wont keep his characters. We just need to know if he can still play his old 3DS games on a new, new 3DS without a system transfer.
Comment: Which games? Some games store additional data on the 3DS's SD card, which would be lost if you put the game card in a 3DS with another SD card
Answer: It depends on the game.
Any game that you have a physical copy of isn't tied to your device. It can be played on any 3DS, regardless. If you bought a game on the E-Shop, it's tied to your Nintendo ID/account.
However, some games store their save data on the actual device (ex: Mario Kart 7), while other games store game data on the cartridge itself (ex: any Pokemon game). A system transfer is required for any save data that was stored on the 3DS SD card in order to restore that saved data.
Answer: Yes! My aunt plays Pokémon Moon on her New 3DS XL and it works just fine! Usually, the info of the game isn't put on the SD Card. Pokémon game cartridges have the players' progress on the cartridge. It's like how us 3DS users were able to play DS games.


Using Fragment Color to store individual bits (GLSL) may introduce issues if OpenGL does any evaluation of the floats before writing them to memory

Question: I need to be able to output individual bits from a fragment shader.
I need a lot of bits per fragment too, otherwise I will face a tremendous performance drag.
Let's say that we have a whole bunch of single-direction lights, let's say 128 of them.
Let's also say that we have already rendered their depth buffers and have a huge FBO
Well, from the player-camera's perspective, All we really need to know from the depth buffer is whether or not an individual screen pixel is in a shadow or not.
I want to do a mid-level pass in my algorithm (Trust me- I have a reason) for testing whether or not a screen pixel is in the shadow of a particular light
As in, all the pixels have boolean values for each light stored in them
The thing is, I don't want Numlights of these buffers.
I would like to pack as many lights into one of these "Boolean Buffers" as I call them as possible. I want to be memory efficient.
(NOTE: I've devised a way to mix this with the shadow map generation too, i'm really trying to reduce the amount of gpu memory my algorithm uses)
Booleans are either 1 or 0. Conveniently, computers store data as ones and zeros.
This includes the output of a fragment, which is four GLfloats.
I'm wondering if it would be possible to manipulate individual bits of a GLfloat, to the maximum bitdepth of a float.
This would allow me to run through all my depth buffers (32 buffers at a time, even) and calculate the cansee/cannotsee of all my lights, 32 at a time (OpenGL allows for 32 texture units at once)
My depth buffers are stored as textures.
My algorithm theoretically works, however ANY evaluation of the floats' values when they are being read from or written to GPU memory will cause my algorithm to fail (Although it wouldn't crash...).
E.g. if Not-a-Number floats get evaluated as all zeros in bits (rather than directly copying the bits regardless of evaluation) then my boolean buffer will fail!
My algorithm also fails if there is any sort of clamping or estimation applied to the floats.
My questions are then as such:

Are there any float values (in bits) that will be evaluated and copied incorrectly to/from GPU memory when a fragment is rendered or the texture2d call in glsl reads it?
Is there any clamping or evaluation or estimation done on the output floats of a fragment shader? What are they?
Is there a better way of outputting as many bits as possible from a fragment shader, that wouldn't have any weirdnesses? (E.g. changing the rendering mode to doubles or ints or something)

but... I would also like to tell you...
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    In case you're curious what I'm using it for...
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I'm developing a brand-new low-memory-footprint and relatively computationally efficient light and shadow rendering technique for rendering thousands of lights (my current plan is 128 per middle-pass FBO, as the bitdepth of a GLfloat is 32 and there are 4 floats output by the fragment shader... RGBA) which uses shadow mapping but I need to use middle-pass buffers filled with boolean data for whether or not a shadow can "see" a light. Using this along with of course all the light locations in the scene I can generate the lighting buffer (Stores the net color change of fragments due to lighting) using relatively few passes (For unidirectional lights, the number of passes to generate the lighting color buffer would be equivalent to 1 + Numlights(1 per light)(NumShadowmaps) + Numlights/128/32 (rounded up, next highest int)(Number of Middlepass BooleanBuffers) + Numlights/128/32/31 (rounded up, next highest int)(Number of Cumulative light color change buffer passes, 31 b/c we need to pass in the old cumulative buffer alongside all those boolean buffers)
if I was able to find someway to store more than 128 bits per fragment, say 256, then I could store even more lights! 1+Numlights + Numlights/256/32 + Numlights/256/32/31! SO MANY LIGHTS, SO FEW PASSES, SO LITTLE MEMORY! :D
The pass to generate the lighting color buffer of course gets a couple vector operations more complicated with every new light, but since the shader for my lighting color buffer automatically checks all its uniform variables to see if they are valid and only calculates what it needs to, and since I seperated out the shadowmapping process, it is not a huge impact. An additional shadowmap is usually the only additional complexity, with only shadowmaps that increase the number of middlepasses (multiples of 32) or cumulative color change passes (multiples of 128 times 31). Cumulative color change passes are additive, so there is no recursive effect or anything. We're not getting an infinite series of 1+1/32+1/(128*31)+...
if I ever manage to make it a reality, i'll see what I can do about uploading an open-source demo. I've been studying shadow algorithms for a couple weeks and very few algorithms seem to solve this apparent light-number-limit and computational complexity problem as efficiently as I do.
My solution becomes even more efficient with more unit textures allowed.
If I bothered to write much larger textures made up of a lot of smaller textures (I've heard this called "texels" but I hate the name), it could be even more efficient but I'm somewhat new to OpenGL and I don't feel like coding a huge complicated texel mess right now. it would actually decrease performance for a small number of lights too, and make the overhead for rendering the final pass larger.
Comment: "Texels" are individual pixels in a texture.  Large textures that are made up of smaller textures are "texture atlases".
Comment: I fail to understand your algorithm. You want to determine whether a screen pixel is visible to a light. But how do you intend to make that determination? How do you intend to populate this texture? If you're doing shadow mapping, then for each light, you have to render a shadow map, right? And then you have to sample from each light's shadow map, for each pixel, to determine if that pixel is within that light's shadow. That's a lot of shadow maps that have to be preserved, and that's a lot of texture sampling to convert it into a bit-map.
Comment: I *think* the idea here is that if you have a mostly static scene, you don't need to recalculate the shadow maps and sample from them all the time;  you could just calculate (shadowed/not-shadowed) once and store the result into a temporary, intermediate texture.  So further rendering could then be done without updating the shadow maps or sampling from them at all;  just sample from the buffer of shadowmap lookup results you pre-calculated.  You could even throw away the shadow maps.  Of course, if anything moves (including the camera), you kind of have to recalculate everything again.
Comment: Also, (if I've understood the intent correctly), this approach is not going to support transparencies at all.
Answer:
3) Is there a better way of outputting as many bits as possible from a fragment shader, that wouldn't have any weirdnesses? (E.g. changing the rendering mode to doubles or ints or something)

If you're using at least OpenGL 3.0, you can just use integer buffers and bypass the complexity of floats entirely.  Just bind a buffer of type GL_RGBA32UI to GL_COLOR_ATTACHMENT0, and do something like this in your shader:
#version 300
layout(location = 0) out uvec4  frag_color_uint_output;

void main(void)
{
    uint myBits = whatever; // 32 bits of data.
    uint myBits2 = whatever; // 32 bits of data.
    uint myBits3 = whatever; // 32 bits of data.
    uint myBits4 = whatever; // 32 bits of data.
    frag_color_uint_output = uvec4( myBits, myBits2, myBits3, myBits4 );
}


Copying from SPS2003 explorer view to local folder: "Edit Items" required?

Question: When i want to copy from a document library in a SPS2003-site, only
"View items" and "Browse directories" is not enough! If i try to copy
from explorer view to my local hard drive, I get "access denied"
error.
When I give myself "View items", "Browse directories" AND "Edit items"
it works!
The properties of the original document are not changed during copy
(of course not), so I have no idea why I need Edit Items-permission.
I can't find anything on Google that points to a solution to my
problem. I don't want to give anyone Edit items permission to just
copy files from the site.
When I make my test-account  "Administrator"  or "Web Designer" or
"Contributor" permission, it works fine.
Anyone in the company is "Reader" and can open the documents through
the list-view. But, we are migrating towards MOSS2007 and some people
with only "Reader"-permission on SPS2003 has to be able to copy the
documents using explorer view to their local drive.
So, "Readers" cannot copy files from SPS2003 to a local folder using
Explorer View; i have to grant them at least Contributor-rights...
That is strange, isn't it?
Executed steps:
- SPS2003 library -> Explorer view
- Select documents and copy with CTRL+C
- Open My Documents and paste with CTRL+C
- Explorer error: "Access denied, make sure the disk is not full or
write protected and that the file is not currently in use" when
"Reader". If "Contributor", no error occurs.
Can anyone help? I have really no idea :(
Answer: I'm Kevin and I work on SharePoint.. I asked around a bit and found out that in SPS 2003 we gated all WebDav requests with the 'edit item' permission. We relaxed this restriction in SharePoint 2007.


How does sensor size affect minimum front element size for a given f-stop and focal length?

Question: Does the sensor size affect the needed size of the front element given a focal length and f-stop? My intuition tells me that a bigger image circle would require a bigger front element to maintain the same "light density" but I can not figure out what the exact relation is.
Comment: This is another one of those questions easily answered by the thin lens equation but complicated in the light of an optical assembly. Ultimately the FOV will be determined by the focal length and the sensor size (simple trig) but location of the entrance pupil determines where in the view cone each element is located. Perhaps with further consideration a monolithic equation is possible but right now I can only think to describe the dependent relationship. Sensor irradiance and stop size are not _directly_ germane to element size, though.
Answer:
How does sensor size affect minimum front element size for a given f-stop and focal length?

It affects the width of the angle from which the entrance pupil should be visible when looking through the front of the lens.

Does the sensor size affect the needed size of the front element given a focal length and f-stop?

It affects the width of the angle from which the entrance pupil should be visible when looking through the front of the lens.
For most practical lens designs this means a larger element when using similar materials with similar refractive indices and similar shapes to construct the front elements of the lenses.
What, you may well ask, is the entrance pupil? It is basically the aperture opening as viewed through the front of the lens. The size of the physical aperture is usually magnified (either negatively or positively - i.e. reduced in size or enlarged in size) by the lens elements between the front of the lens and the physical location of the aperture. The actual physical size of the aperture diaphragm is not used to calculate f-number. The size of the entrance pupil, sometimes called the effective aperture, is what is actually used.

My intuition tells me that a bigger image circle would require a bigger front element to maintain the same "light density" but I can not figure out what the exact relation is.

The bigger front element is not required to maintain light density in the areas of the scene that are captured by both lens and sensor combinations.¹ Light density is maintained by an entrance pupil that is the same size for both lenses.¹ The bigger front element is required to collect light, at the same magnification, from a wider enough angle of view to provide an image circle larger enough to cover the larger sensor.
When both are the same focal length and f-number, lenses for larger sensors don't collect more light from the same field of view as lenses for smaller sensors. They collect "more" light only in the same proportion, in terms of area, to the respective sizes of the fields of view needed by the two respective lenses.²
Given the same exact scene, the lens for the larger sensor will collect the same amount of light from the center of its field of view that is equal to the total field of view of the lens for the smaller sensor.¹ Not only will the amount of light "collected" from that part of the lens' field of view be the same, but so will the size of the virtual image projected onto the sensor of objects in the scene that are within the field of view of the lens needed for the smaller sensor.¹
But the lens for the larger sensor will also "collect" light from the parts of its required field of view that are not within the required field of view of the lens for the smaller sensor.¹ That's where the "more light it collects" comes from - the wider parts of the scene that will be needed to provide an image circle wide enough to cover the larger sensor.²
Where some people get confused is when we view two images - taken from the same shooting positions with cameras of two different sensor sizes using lenses of the same focal length - at the same display size. The reason the same objects look larger in the image from the smaller sensor is not because the same focal length lens magnifies those objects more. It doesn't. Both lenses project the same objects onto their respective sensors at the same size.¹ It is because we have enlarged the size of the image collected by the smaller sensor more to display it at the same size as the image collected by a larger sensor.
If we enlarge the images from both sensors by the same enlargement factor, the image from the larger sensor will be larger than the image from the smaller sensor. For instance, if we enlarge an image from a full frame (FF) sensor to view it at 18x12 inches and use the same amount of enlargement (12.7X) for an image from a 1.5X APS-C camera, we will be viewing the second image at a size of  12x8 inches. The objects in both images will be the same size when the FF image is viewed at 18x12 and the APS-C image is viewed at 12x8.¹ If we then place the 12x8 image from the APS-C camera on the middle of the 18x12 image from the FF camera they will match up and it will look the same as the image from the FF sensor did before we superimposed the image from the smaller sensor onto its center (if both lenses use the same type of projections and are free from geometric distortion).¹ But when we view the image from the APS-C camera at 18x12 inches, we've used an enlargement ratio of 19.05X for the APS-C image compared to an enlargement ratio of 12.7X to view the FF image at 18x12 inches. The larger size of the same objects in the APS-C image viewed at 18x12 compared to the image from the FF camera viewed at 18x12 doesn't come from any difference in the lenses or the sensors, the larger size of the same objects is the result of our higher enlargement ratio.¹
The key to understanding the difference between the light needed to be "collected" for a larger and smaller sensor with lenses of the same focal length and apertures is to understand that the light density will be the same for both lenses.¹ It is the angle of view that must be larger for the larger sensor. The parts of the scene that are needed for both sensors will be projected by both lenses (of the same focal length) at the same size.¹ But the objects that are on the periphery just outside the smaller sensor's required angle of view will need to be projected onto the larger sensor by the lens for the larger sensor.¹ Thus the front of a lens for a larger sensor must be able to collect light from a wider angle of view than the front of a same focal length lens would need to collect for a smaller sensor.
It's pretty easy to observe. Just compare a fairly wide angle lens for a FF sensor next to a lens of the same focal length for, say, a Micro Four-Thirds sensor that is half as large linearly and one-fourth as large in area. For our example we'll use 17mm f/4.
A 17mm lens with an image circle large enough to cover an µ4/3 sensor must provide a 52° angle of view.
A 17mm lens with an image circle large enough to cover a FF sensor must provide a 104° angle of view.
From any angle within each lens' FoV (for their respective sensor sizes), the entrance pupil is the same size for the same f-number.
A 17mm f/4 FF lens has an entrance pupil 4.25mm wide.
A 17mm µ4/3 lens has an entrance pupil 4.25mm wide.
There's no difference in the size of each entrance pupil. The difference is that the µ4/3 lens only needs a front element wide enough so that the entrance pupil may be seen anywhere from within a cone 26° from the center of the lens' optical axis. This gives the lens a 52° angle of view. The FF lens, on the other hand, must provide a cone with twice the angle. The front element for that lens must be larger enough, or have a higher enough refractive power, that the entrance pupil is visible at an angle 52° from the center of the lens' optical axis. This gives the lens a 104° angle of view.
¹ Given the same scene under the same illumination, the same camera position, the same focal length, and the same f-number.
² Given the same scene under the same illumination that is constant within the entire field of view, the same camera position, the same focal length, and the same f-number.
Answer: The camera lens projects a circular image of the outside world on the surface of film or digital sensor. The resulting image will be brightest and sharpest at the center. This image falloff is typically called vignette. The film camera, loaded with negative film has the advantage. The resulting negative exhibits a vignette. Now when we print this negative by projection, using an enlarger, its lens also vignettes. I am describing the negative/positive system. It has a subtle advantage in that the vignette of the camera and the vignette of the enlarger often counter. True when printing a negative but the vignette is amplified when printing a positive (slide) on reversal paper. A digital system displays is amplification unless adjusted by software.
The optical vignette has many ingredients. The chief responsibility is due to the geometry of how the image is projected by camera lens. The edges of the projection are further away from the lens then the center. The law of the inverse square takes its toll, the edges receive less light. The light that plays on film or sensor at the edges arrives at an angle. Looking back at the lens from the boundaries, we see an oval aperture, not a circle. The oval aperture has less surface area, thus less light plays at the boundaries. Think of a flashlight beam, dead on, it's a circle. Hold the flashlight at an angle and the light plays as an oval and its less bright. This has a name "cosign error".
The wide-angle lens suffers the most from a lack of uniformity of field. The uniformity of the wide-angle lens can be improved if somehow we could mount the lens further away from film or digital sensor. Increased back focus will temper the angle of the arriving light at the boundaries. Wide-angles are thus constructed with increased back focus. An inverted telephoto design does this trick. The measuring point for focal length is the rear nodal. If a telephoto lens is reversed, we get a wide-angle plus the rear nodal is shifted forward. The result is a longer back focus and greater uniformity of image.
If the wide-angle is not designed to give higher uniformity, a 70° angle of view will result in a loss, the difference between center and margin will be more than 45%. We are also taking about loss of acuity at the boundaries.
To get more uniform coverage and acuity the back focus is lengthened. The lens barrel is constructed so that it gives a clear view, no shadowing of the full diameters of the lenses. Symmetrical lenses of medium aperture deliver larger circles of good definition. To gain a larger circle of good definition, the lens designer will sacrifice corrections for the intermediate zones (slightly off axis) to gain improved marginal definition. In other words, a good lens is a series of compromises.
Answer: The simple answer this respondent wants was developed by the Zeiss engineers at Jena before WWII. To get M=1, the focal length of the lens should be equal to the diagonal of the sensor size. So, in film terms, a 35 mm film has an image (sensor) size of 36 mm x 24 mm. The diagonal = sq rt (36^2 + 24^2) = 43 mm, exactly the focal length of the first 35 mm camera lens.
The world's reliance on calling the 50 mm lens the 'standard' actually gave M = 1.16.
Comment: @ Brian --- Please site your source -- Zeiss M=1


What can I do about no VOC paint that stinks after it has dried?

Question: We just painted with brand new, but gone-bad NO VOC paint (Dunn Edwards in a dark teal). It went on smelling like good paint but when it dried it has a chemical sour smell mixed with vomit and dead animal. We live in the desert (Sedona) so humidity is not an issue.  Headaches and nausea are not fun. We sealed all offending walls with 2 coats of sealer primer (BIN Advanced) and another top coat of paint, as suggested by paint company, and it did not fix the smelly problem.  Then we got desperate. We have burned two boxes of nag champa incense, as well as cinnamon candles for days. We have washed the walls down with backing soda.... vinegar.... and natures miracle. Everything we do alters the smell, but does not clear it up.  Other rooms we painted with lighter tan color of same paint are perfect.  The windows have been open for days with exhaust fans going, and we are being held prisoner in the only warm room that doesn't stink. Once the room warms up the smell comes back.   After reading dozens of blogs on this issue and hearing over and over that paint company's do not own up to having a fix to this bad no-VOC paint issue, it looks like we may to have to tear down dry wall!   HELP .... Any suggestions out there would be helpful before I rip my home apart.
Comment: Heating the room to 120°F for a while, say 8 hours, should speed any odious drying process. Either a portable heater or the Sedonia summer could do that for you. Air the room out well when done.
Answer: I can't speak to your problem directly but I have had a lot of success with Kilz Oil based primer. It is far from Low VOC and will come with a very strong odor initially. After the paint dries thoroughly the oil smell will subside and you can put on the top coat. I have used this primer to seal pet urine stains on sub floors that otherwise would have had to be removed to get rid of the smell.
Comment: That makes sense, oil based products tend to be much more capable.  Huge compromises must be made to have paint be water-based, and even more compromises to reduce VOC to modern SCAQMD levels.
Answer: So this happen to me last night and I was freaking out!!!!!!!!!!!!!! I googled it and I cam across yours and another persons question. I also tried everything. Then I read someone saying it contains mold in the paint. so I told myself ill try bleach before I have to go out and buy the oil base primer. Well, it took 75% of the smell and I just did another run thru the walls. I will try this several times today. I know this is a little late but maybe if someone happens to get this disgusting paint problem they can try this. I hope that it takes it away enough where I don't have to buy more and can save that money. Good Luck to me and anyone else who might come across this....


Add Nodes to MAAS for JUJU Bundle

Question: This question is similar to Can juju add-machine be used to prepare a machine for service deployment?, with some differences; however. I am trying to find the fastest way of deploying juju bundles on target nodes. I suppose the proper way of doing so is to bring the required number of target nodes to "Ready" state, and while they are powered off, deploy the bundle, turn the nodes on and let them eventually get to "allocated" state. To speed up the process, I typically issue a number of "juju add-machine" to upload the desired image to the target nodes that are already in "Ready" state and let them get allocated. To allow for a bundle to provision existing machines, I then select the allocated nodes and stop them, from MAAS drop down menu. This puts the desired nodes in "Ready" state, once again, while powered on. Deploying a bundle will provision the nodes, and puts them in "allocated" state. This generally works well. The only snag is that upon reboot, target node goes through pxe boot again, wiping out all the charms and juju deamon. Is there a better way of doing this?
Answer: You can use constraints in a bundle to limit the type of machine that each service (unit) gets deployed to, but options are somewhat limited. Telling Juju to co-locate two or more services on a given machine is definitely doable. I suggest taking a look at Juju Deployer's placement documentation to get an idea of what is possible, and how you can edit the bundle file.
Comment: So, to clarify: If I am to edit yaml file to target specific machines, it would imply that machines ought to have been assigned to a pool, already. (Correct?) Does this imply that the above procedure, for pool assignment, is proper?

Add Nodes to MAAS for JUJU Bundle


Why is the result of ('b'+'a'+ + 'a' + 'a').toLowerCase() 'banana'?

Question: I was practicing some JavaScript when one of my friends came across this JavaScript code:

document.write(('b' + 'a' + + 'a' + 'a').toLowerCase());

The above code answers "banana"!
Can anyone explain why?
Comment: That second plus is an unary operator: `+"a"` is `NaN`.
Comment: And for those eager for more. See [full fun list](https://github.com/denysdovhan/wtfjs)
Comment: In a console, write `+'a'` by itself and see what happens.
Comment: Strongly related: https://stackoverflow.com/q/9032856/
Comment: Also related: [What is the explanation for these bizarre JavaScript behaviours mentioned in the 'Wat' talk for CodeMash 2012?](https://stackoverflow.com/questions/9032856/what-is-the-explanation-for-these-bizarre-javascript-behaviours-mentioned-in-the)
Comment: This also works: `'b' + 'a' + - 'a' + 'a'`
Comment: What about this? `'CoNaN' - 'Co'`
Pretty straightforward, right :)
Answer: +'a' resolves to NaN ("Not a Number") because it coerces a string to a number, while the character a cannot be parsed as a number.

document.write(+'a');

To lowercase it becomes banana.
Adding NaN to "ba" turns NaN into the string "NaN" due to type conversion, gives baNaN.
And then there is an a behind, giving baNaNa.
The space between + + is to make the first one string concatenation and the second one a unary plus (i.e. "positive") operator.
You have the same result if you use 'ba'+(+'a')+'a', resolved as 'ba'+NaN+'a', which is equivalent to 'ba'+'NaN'+'a' due to type juggling.

document.write('ba'+(+'a')+'a');
Answer: 'b' + 'a' + + 'a' + 'a'

...is evaluated as....
'b' + 'a' + (+'a') + 'a'

(see: operator precedence)
(+'a') attempts to convert 'a' to a number using the unary plus operator. Because 'a' is not a number, the result is NaN  ("Not a Number"):
'b'  +  'a'  +  NaN  + 'a'

Although NaN stands for "Not a Number", it's still a numeric type; when added to strings, it concatenates just as any other number would:
'b'  +  'a'  +  NaN  + 'a'  =>  'baNaNa'

Finally, it's lowercased:
'baNaNa'.toLowerCase()      =>  'banana'

Answer: ('b' + 'a' + + 'a' + 'a').toLowerCase()

For clarity, let's break this down into two steps. First, we get the value of the parenthesized expression and then we apply the toLowerCase() function on the result.
Step one
'b' + 'a' + + 'a' + 'a'

Going L-R, we have:

'b' + 'a' returns ba, this is regular concatenation.
ba + + 'a' attempts to concatenate ba with + 'a'. However, since the unary operator + attempts to convert its operand into a number, the value NaN is returned, which is then converted into a string when concatenated with the original ba - thus resulting in baNaN.
baNaN + 'a' returns baNaNa. Again, this is regular concatenation.

At this stage, the result from step one is baNaNa.

Step two
Applying .toLowerCase() on the value returned from step one gives:

banana

There are many similar puns in JavaScript that you can check out.
Answer: It's just because of  + operator.
We can get further knowledge from chunk it.
=> ( ('b') + ('a') + (++) + ('a') + ('a'))
=> ( ('b') + ('a') + (+) + ('a') + ('a')) // Here + + convert it to +operator
Which later on try to convert next character to the number.

For example
const string =  '10';

You can convert a string into number by 2 ways:

Number(string);
+string;

So back to the original query;
Here it tries to convert the next char ('a') to the number but suddenly we got error NaN,
( ('b') + ('a') + (+'a') + ('a'))
( ('b') + ('a') + NaN + ('a'))

But it treats as a string because the previous character was in the string.
So it will be
( ('b') + ('a') + 'NaN' + ('a'))

And last it converts it to toLowerCase(), So it would be banana
If you are put number next to it, Your result will be change.
( 'b' + 'a' +  + '1' + 'a' )

It would be 'ba1a'

const example1 = ('b' + 'a' + + 'a' + 'a').toLowerCase(); // 'banana'
const example2 = ('b' + 'a' + + '1' + 'a').toLowerCase(); // 'ba1a'
console.log(example1);
console.log(example2);
Answer: This line of code evaluates an expression and then calls a method based on the returned value.
The expression ('b' + 'a' + + 'a' + 'a') is solely composed of string literals and addition operators.

String Literals "A string literal is zero or more characters enclosed in single or double quotes."
The Addition operator ( + ) "The addition operator either performs string concatenation or numeric addition."

An implicit action taken is the call for ToNumber on a string

ToNumber Applied to the String Type "ToNumber applied to Strings applies grammar to the input String. If the grammar cannot interpret the String as an expansion of StringNumericLiteral, then the result of ToNumber is NaN."

The interpreter has rules of how to parse the expression, by breaking it down into its components of left and right hand expressions.

Step 1: 'b' + 'a'
Left Expression: 'b'
 Left Value: 'b'
Operator: +  (one of the expression sides is a string, so string concatenation)
Right Expression: 'a'
 Right Value: 'a'
Result: 'ba'

Step 2: 'ba' + + 'a'
Left Expression: 'ba'
 Left Value: 'ba'
Operator: +  (one of the expression sides is a string, so string concatenation)
Right Expression: + 'a' (this evaluates the Math Value of the character 'a' assuming that it is a positive number from the + sign -- the minus sign would have also worked here indicating a negative number -- which results in NaN)
 Right Value: NaN  (because the operator is string concatenation, toString is called on this value during concatenation)
Result: 'baNaN'

Step 3: 'baNaN' + 'a'
Left Expression: 'baNaN'
 Left Value: 'baNaN'
Operator: +  (one of the expression sides is a string, so string concatenation)
Right Expression: 'a'
 Right Value: 'a'
Result: 'baNaNa'

After this the grouping expression has been evaluated, and toLowerCase is called which leaves us with banana.
Answer: Using + will convert any value to Number in JavaScript!
So...
The main thing here to know first and learn from is using + before any value in JavaScript, will convert that value to a number, but if that value can not be converted, JavaScript engine will return NaN, which means, not a number (can not be converted to a number, mate!) and the rest of story as below:
Answer:
Read more about NaN at W3Schools or Mozilla Developer Network
Answer: See the magic here. Second plus is an unary operator which gives 'NaN'

console.log(('b' + 'a' + + 'a' + 'a').toLowerCase());
console.log(('b' + 'a' + + 'a' + 'a'));
console.log(('b' + 'a' + 'a' + 'a').toLowerCase());


Iconography for a "Pokemon moves list"?

Question: I've been trying to find an icon that represents a Pokémon moves list for an app I'm developing, mind you this is an Android app and the icon will go directly to the ActionBar on a opaque background so it will have to be completely white and really simple, I've thought of a boxing glove of some sort or crossing swords, and I'm leaning towards the glove but I'm not totally convinced, in the games there usually no icon relating to moves other than the ones that represent if the move is physical or special.
Comment: Hi Vincent, you see, I'm trying to make an icon for a link that opens a window where a list of Pokemon moves (attacks or spells if you will) is shown with their different parameters.
Comment: Hi Eddnav, welcome to GDSE and thanks for your question. Could you please clarify a little for those amongst us who -- gasp! :) -- have never played Pokémon? I *am* a video gamer, but I have no clue what you're trying to make an icon for. Thanks!
Answer: Maybe something like this:

But adding a pokeball...
Comment: This is brilliant, it certainly conveys a Pokémon move.
Answer: The most recognizable thing in the poké universe is the poké ball, and the start of every poké battle is throwing the poké ball.
As an icon, how about a poké ball popping open? Something like an iconographic version of this?

Iconography for a "Pokemon moves list"?


What is the difference between a Restricted Profile and a User in Android 4.3?

Question: Android 4.3 introduced a new feature called Restricted Profiles. What is a restricted profile, and how is it different from a User?
Answer: With 4.3, Android apparently has three types of user:

primary user (admin, owner)
secondary users
restricted profiles

Primary user is the first user created for the device, when setting it up.
All users (the primary user and secondary users) have pretty much equal control of the system - they can alter all the system settings, create more users, etc. but they cannot access the data or the apps* of the other users.
Since all users can only access their own data, they can also be linked to different accounts. Likewise, they could also use a same account if you set it up for each user individually. However, this doesn't make the device aware of the different users using the same account - each user has their own "link" to the account, unaware of the others.
A restricted profile is different. Like users, it has its own settings, and own data. However uses the primary user's accounts and installed apps. The primary user controls which of these are enabled for the profile.
Further, these profiles can be given parental-type restrictions to content - such as blocking all content defined as "mature". (Note: This requires support from the apps providing the content in order to work.)
* - Google Play app-store does sort-of support some inter-user data - when you install an app that another user already has, the same app code is used by both users. This means it doesn't need to be downloaded a second time, and doesn't take up extra space. It also means that when one of the users updates the app, it is updated for everyone. However, only thing shared between the users is the app code, the users cannot access each other's data.
More information on developer.android.com, see specifically: Support for Restricted Profiles.
Comment: Disclosure: This answer compiled based on information provided in an [answer to my question](http://android.stackexchange.com/questions/50223/converting-an-existing-user-to-a-restricted-profile/50483#50483) by the OP.
Answer: The main difference is that with a restricted profile the 'main' user can prevent the restricted profile from running certain apps, installing certain apps, changing system settings etc. whereas a 'User' can do almost anything that the main user can. Android Police has a post looking at restricted profiles, and you can find information from Google here.


Memcache alternative for cpanel hosting

Question: Memcache is the best caching API for php, but it is not available on most of the hosting providers. Are there any alternatives to memcache which are available for most hosting providers(e.g. Godaddy)?
Answer: Several of my web applications and web hosting provider uses Advanced PHP Cache, also known as APC,  instead of Memcache. From my experiences of using both, APC has improved performance more.
I would make sure to ask your web hosting provider if they are/can use APC.
Answer: For non shared hosting, I would say Varnish will be your best option. It is a reverse proxy and cache content as well. This would result in improved performance of apache, reduce server load and would result in faster page loading times. There is an interesting discussion at Drupal regarding various caching options for it. In fact, most of them apply to any php based system. You may find them useful.

Memcache alternative for cpanel hosting


How to provide link to styled image in a services feed

Question: On our Drupal 7 site, we use the the services module to provide a feed for our internal news to pick up. With services, you create a view for all the data to provide. It is current giving the location of the original image for our images field (File: Path) that comes out http://oursite.com/sites/default/files/post.jpg. We want to provide a link to the styled image (already resized) that should look like https://oursite.com/sites/default/files/styles/downpage_art/public/field/image/solar_panels700x425.jpg?itok=P4VrgCIH. I don't see this as an option in the view we have for our feed.
Answer: I think the Image URL Formatter module will help.

Image URL formatter module offers 3 options that are not contained by views:

support Image styles
support multivalues, there is a "Multiple field settings" when image field is multivalue.
Comment: The module looked promising but the results came out as an empty array looking something like this:
array (
  0 =>
  stdClass::__set_state(array(
     'url' => 'http://oursite.com/sites/default/files/post.jpg',
     'caption' => 'Dick Post',
     'mimetype' => 'image/jpeg',
     'users_file_managed_mail' => 'email@example.com',
     'id' => '28815',
     'alt' => 'post',
     'title_text' => 'post',
     'fid' => '28815',
     'node_file_usage_nid' => '8900',
     'Images' =>
    array (
    ),
  )),
Answer: I'd recommend utilizing the Views Datasource module or the Services Views module. Both will allow you to set up a View to be consumed over a RESTful API. You can then use the View to easily select your image field(s), and the image style(s) to use.
Otherwise you'll need to implement hook_menu(), and create a custom item with a page_callback. That page callback can then programmatically generate an image style URL, and output it with drupal_json_output.


What is the meaning of そう君と二人 in the sentence below?

Question: My question is what そう君と二人 means in this sentence:

そう君と二人で冷たい月に手を伸ばして
(Sō kimi to futari de tsumetai tsuki ni te wo nobashite)

I know that tsumetai tsuki ni te wo nobashite means something among the lines of "reach out your hand toward the cold moon", but I just can't seem to figure out what to do with そう君と二人. As far as I know, it means "So you and 2 people(...)", though I don't really know how I should convey it into the full sentence.
Answer: 「そう」, in this context, means "yes", not "so".  (For fairness, one could argue that "yes" and "so" are related as they are both used for affirmation.)  It is the introspective kind of "yes" that one uses to affirm and/or remember an event involving oneself.
This 「そう」 is quite often used in song lyrics, light poetry, romantic letters, etc.
「君{きみ}と二人{ふたり}」 means "you and I" or "the two of us".  It does not mean "you and 2 people" as you stated.
So, the whole line means:
"Yes, the two of us reach(ed) out our hands toward the cold moon."
(It is impossible to decide on the tense because 「伸{の}ばして」 is not an natural sentence ending.  More context needed to decide on the tense here.)
Comment: I would consider that phrase to be 「君と二人で」, not just 「君と二人」 - 'together with you (君と) as a pair (二人で)'.
Comment: No, 「君」 does not me "us". 「君と二人」 means "us" (It's more along the lines of "together with you").
Comment: Ooow, okay... Now I understand. So 「君」 can sometimes also be plural, meaning 'us' or 'we'. And thanks for the detailed explanation on the word 「そう」, I never thought it could just plainly mean 'yes'. You were very helpful, l'électeur. Though, I hope you don't mind helping me one more time with this piece of text: 「仕組まれてる」。

「仕組ま」or「仕組む」means to plan (something), but what does 「れてる」 mean. Is it another form of the verb Shikumu?
Comment: About the tense, this sentence is preceded by 「もう逃げない この場所で」(Not being able to escape from this place anymore), so I'm guessing it's the present.
Comment: Hmm, I see. Thanks for the elaboration, Jimmy. Is there a chance you know what 「仕組まれてる」means too?


Connecting a linux client into active directory

Question: I have a linux server (opensuse 12.1) running OTRS 3.0.10.
And a primary domain controller running Windows Server 2008R2.
I've followed the howto page here and here.
Obviously the Net::LDAP perl module is installed.
However I cannot actually connect to AD.
Here's an excerpt from my configuration file in OTRS:
/srv/otrs/Kernel/Config.pm
#Enable LDAP authentication for Customers / Users
  $Self->{'Customer::AuthModule'} = 'Kernel::System::CustomerAuth::LDAP';
  $Self->{'Customer::AuthModule::LDAP::Host'} = '10.0.1.26';
  $Self->{'Customer::AuthModule::LDAP::BaseDN'} = 'ou=D1OU,ou=D1Users,dc=domain,dc=org,dc=za';
  $Self->{'Customer::AuthModule::LDAP::UID'} = 'sAMAccountName';

#The following is valid but would only be necessary if the
#anonymous user do NOT have permission to read from the LDAP tree
  $Self->{'Customer::AuthModule::LDAP::SearchUserDN'} = 'otrs';
  $Self->{'Customer::AuthModule::LDAP::SearchUserPw'} = 'Password';

#CustomerUser
#(customer user database backend and settings)
    $Self->{CustomerUser} = {
      Module => 'Kernel::System::CustomerUser::LDAP',
      Params => {
      Host => '10.0.1.26',
      BaseDN => 'OU=D1OU,OU=D1Users,DC=domain,DC=org,DC=za',
      SSCOPE => 'sub',
      UserDN =>'otrs',
      UserPw => 'Password',
    },

# customer unique id
    CustomerKey => 'sAMAccountName',
    # customer #
    CustomerID => 'mail',
    CustomerUserListFields => ['sAMAccountName', 'cn', 'mail'],
    CustomerUserSearchFields => ['sAMAccountName', 'cn', 'mail'],
    CustomerUserSearchPrefix => '',
    CustomerUserSearchSuffix => '*',
    CustomerUserSearchListLimit => 250,
    CustomerUserPostMasterSearchFields => ['mail'],
    CustomerUserNameFields => ['givenname', 'sn'],
    Map => [

      # note: Login, Email and CustomerID needed!
      # var, frontend, storage, shown, required, storage-type
      #[ 'UserSalutation', 'Title', 'title', 1, 0, 'var' ],
      [ 'UserFirstname', 'Firstname', 'givenname', 1, 1, 'var' ],
      [ 'UserLastname', 'Lastname', 'sn', 1, 1, 'var' ],
      [ 'UserLogin', 'Login', 'sAMAccountName', 1, 1, 'var' ],
      [ 'UserEmail', 'Email', 'mail', 1, 1, 'var' ],
      [ 'UserCustomerID', 'CustomerID', 'mail', 0, 1, 'var' ],
      [ 'UserPhone', 'Phone', 'telephonenumber', 1, 0, 'var' ],
      #[ 'UserAddress', 'Address', 'postaladdress', 1, 0, 'var' ],
      #[ 'UserComment', 'Comment', 'description', 1, 0, 'var' ],
    ],
  };

And here's the error I'm getting:

ERROR: OTRS-CGI-10 Perl: 5.14.2 OS: linux Time: Mon Apr 30 10:50:52
  2012
Message: 0000208D: NameErr: DSID-0310020A, problem 2001 (NO_OBJECT),
  data 0, best match of:
          'DC=domain,DC=org,DC=za' ^@
Traceback (13338):     Module:
  Kernel::System::CustomerUser::LDAP::CustomerUserDataGet (v1.62) Line:
  614    Module: Kernel::System::CustomerUser::CustomerUserDataGet
  (v220.127.116.11) Line: 283    Module: Kernel::System::CustomerAuth::Auth
  (v18.104.22.168) Line: 166    Module:
  Kernel::System::Web::InterfaceCustomer::Run (v22.214.171.124) Line: 203
  Module:
  ModPerl::ROOT::ModPerl::Registry::srv_otrs_bin_cgi_2dbin_customer_2epl::handler
  (unknown version) Line: 46    Module: (eval) (v184.108.40.206) Line: 204
  Module: ModPerl::RegistryCooker::run (v18.104.22.168) Line: 204    Module:
  ModPerl::RegistryCooker::default_handler (v184.108.40.206) Line: 170
  Module: ModPerl::Registry::handler (v1.99) Line: 31

I have a primary domain controller at 10.0.1.26 which is called: servername.domain.org.za.
The pre-windows2000 domain name is MYSERVER which is also the pre-Windows2000 server name.
I created a user otrs which resides in the OU (organizational unit) D1OU/D1Users and is a member of the group Domain users and which has a non-expiring password (not 'password' of course, but something stronger).
What I tried
I've tried to get Winbind to talk to active directory, but it refuses unless I use the pre-Windows2000 credentials (MYSERVER works, domain.org.za does not work).
Other than that Winbind gets the data out of Active Directory with no problems.
How do I fix this?
I don't have a problem with supplying pre-windows2000 domain specs in the Config.pm file, but I don't know the format.
I would love to put proper LDAP params in, but perhaps I'm missing something.
So the question is, what do I need to change in Config.pm to get OTRS to authenticate against my AD?
Answer: You may have better luck using Centrify or PowerBroker Open to handle the windows authentication. It should work if OTRS uses PAM.


Can sub GHZ frequency can be used in space communciation?

Question: Is it possible for a sub GHZ frequency (Say 300 Mhz) can be used for space communication for small satellites such as a cubesat? What are the advantages and disadvantages for this.
Answer: Most cubesats communicate in a combination of VHF and UHF for both uplink and downlink.
Advantages:

Better link budget (lower free-space attenuation).
Cheaper ground station (radio equipment, cables, antennas).
Lots of support worldwide in amateur bands (144 and 430 MHz bands).
No need for directional antennas (and fine attitude control) on the spacecraft.

Disadvantages:

Limited bandwidth (in the order of 10 kbps maximum).

Only a few cubesats have S or X band downlinks, and always as high-bandwidth extension to the main TT&C downlink.
Comment: Why would VHF have lower free-space attenuation? I think all radio communications obey the inverse-square law, regardless of frequency. (Perhaps excepting ELF communications, where the wavelength is a significant fraction of the Earth's circumference, so it's no longer accurate to model it as a point source)
Comment: A common misconception -- the problem is that a lower frequency also requires a larger antenna for the same gain. See http://en.wikipedia.org/wiki/Free-space_path_loss#Frequency_dependency and [Is free space path loss dependent on frequency?](http://ham.stackexchange.com/q/3692/218)
Comment: Free-space path loss is proportional to $f^2$ http://en.wikipedia.org/wiki/Free-space_path_loss
Comment: My friends where telling me that the lower frequency would be hard to penetrate threw the ionosphere, so if i use a low frequency such as a 300Mhz and my antina has a gain of 5.53 Dbm with a transmitting power of 100Mw would it be possible to receive signal from an altitude of 250Km in near earth orbit?
Answer: Certainly possible. 300 MHz is not a very low frequency for satellites. There are a great many amateur satellites operating on the 2m band, around 145.8 MHz.
Going much lower, there are allocations for satellites on the 10 meter band, from 29.3 to 29.51 MHz. There are fewer amateur satellites operating here, but they do exist.
In fact, early in space exploration history, HF was used regularly for communications. For example, Yuri Gagarin in Vostok 1 sent several reports via HF.
HF for space communication has the same advantages and disadvantages as it does for terrestrial communication, more or less.
The big advantage: HF supports skywave propagation, so you may get propagation beyond line of light. There are layers of the ionosphere that are high enough to still be above some low Earth orbits. For example, Vostok 1's orbit varied between 168 and 327 km; the F layer is around 300 km.
Also, lower frequencies require less sophisticated technology, generally. Of course this is becoming less of a concern in modern times since microwave radios are commodity items now.
The big disadvantage of HF is that antennas are larger and frequency allocations are more expensive and less available. As an example, the 70cm amateur allocation in the US goes from 420 to 450 MHz and is 30 MHz wide. You could fit the entire HF spectrum in that. Commercial availability of spectrum is similarly rarer at lower frequencies.
Additionally, high-speed communications are more difficult at HF due to the higher fractional bandwidth required. As an extreme example, ELF communications can take several minutes to send just a few characters.
Answer: It's really a trade-off between transfer speeds and available transmit power. Higher your transmit power, the higher you can set your downlink carrier. You also get better transfer speeds because you can encode more information in a higher carrier frequency, using FSK or whatever. Some applications employ a sub-GHz downlink using LoRa modulation, not compromising on data rates.
Most amateur satellites and CubeSats are constrained by a lack of power to them, unlike traditional satellites that have some sort of solar array or power generation to power high frequency downlinks. Assuming you device a way to power it, you'd still have to clear through legals to use these GHz bands like X. Forcing most amateur radio (HAM) into the sub-GHz band as a result.
LoRa however, though my decent understanding of the concept, operates over a similar spectrum of FSK but employs chrip spread spectrum or CSS for short, using a chirp signal to encode information. The parameters of this chirp dictate the spectrum (through spread factor) and data rate. The people who make LoRa applications market it as the low-power counterpart to DSSS and other spread spectrum modulation techniques. It's got an advantage over traditional FSK in the fact that it's frequency and bandwidth can be scaled, allowing a significant increase in data rate - more spread spectrum = more data per unit time, with the same sub-GHz frequencies.
In my applications, I usually settle for something like 433 MHz, FSK/LoRa. Transceivers are readily available at this bandwidth and so are amplifiers and matched antennas. I personally feel like this gives me the perfect benefit of a decent data rate with conservative power requirements, and acceptable attenuation unlike the K bands that can't stand a rainy day
Comment: Huh? Why is a higher power necessary for a higher downlink frequency? And doesn't FSPL _increase_ with frequency? And how does spread-spectrum increase data rate?
Comment: @PhilFrost-W8II oops! Sorry, it does increase free-space attenuation, I'd mistyped it. About the power, it's not necessary but I meant it as a requirement to improve reception. Spread spectrum uses a large bandwidth allowing an increase in data rate - kind of like CDMA I guess where you'd encode multiple streams of data and layer them upon another in the frequency domain. The receiver would then demultiplex the individual streams and translate them into their time domain
Answer: Back in the day (long ago) we used to regularly tune in a weather satellite at 136 MHz.
So it is certainly possible.
There is no technological barrier other than size and power requirements.  Not to mention that stringing a wire (tether) behind a satellite is nowhere near as simple as unwinding wires behind aircraft.  There is a lot of physics involved.
Here is an interesting story of when they tried out the concept:
NASA Unveils A Satellite On a Tether 12 Miles Long
One of the engineers thought it might serve as an ELF antenna to communicate with submarines.


Nikon D3300 autofocus issue

Question: I just bought a Nikon D3300 from a guy from eBay. (Actually not eBay, but a Dutch website, same concept). It came with 3 lenses: an 18-55mm kit lens, a Tamron 18-270mm f/3.5-6.3, and a 50mm f/1.8 lens, all containing autofocus motors. As soon as I reach past 50mm in the zoom range, the camera stops autofocusing completely. It works perfectly fine as soon as I zoom out under 50mm. This is the same on both the kit lens and Tamron superzoom lens. They still try to focus since I hear a clicky sound which you always hear when auto focussing, but it won't move the focus ring. Anybody knows what's wrong with it?
Comment: Just to make sure - this is in full daylight, not indoors etc where they may struggle with not enough light [the Tamron especially]?
Comment: Possibly same as https://photo.stackexchange.com/questions/91579/why-is-my-nikon-18-300-lens-not-focusing-at-higher-focal-lengths?
Comment: Yes, they do. Just tried in full sunlight, The Tamron refused to autofocus. The kitlens still tried, because it moved and in the viewfinder I saw it getting blurry and unblurry etc. The Tamron only made a clicky noise but the focus ring didn't move at all..
Comment: Does the focus ring physically move with the two zoom lenses when using AF at focal lengths wider than 50mm? If so, have you tried to manually focus the lens with the AF turned on?
Comment: The focussing on the Tamron lens seems to work when I move the focus ring myself when the auto focus is trying to move the focus ring. It will come "lose" for a couple seconds but will get stuck again. It's not specifically above 50mm, it was just coincidence. The issue happens at any zoom. @MichaelClark
Answer: It sounds like someone has been moving the focusing ring on lenses with geared autofocus (AF) motors when AF is turned on. This can damage the autofocus mechanisms of certain types of autofocus lenses. It depends on which type of AF motor technology the lens in question uses.
Geared AF Motors
Lenses with geared AF motors must be switched to manual focus (MF) using the AF/MF switch to be manually focused without risking damage to the AF system of such lenses. This is because there is a hard mechanical connection between the AF motor and the focusing ring. Most such lenses will rotate the focusing ring when AF is moving the focusing elements. You should never attempt to manually focus such lenses when AF is turned on!
If your 18-55mm kit lens was the one included with the D3300 in a kit when it was new, it could be either the AF-S 18-55mm VR II included with earlier D3300 cameras or the newer AF-P type (see below) included with later D3300 cameras in some countries or in "gray market" kits. If the person who sold you the D3300 included an older AF-S 18-55mm kit lens and kept the newer 18-55mm AF-P lens, your lens is one with a geared AF motor.
If your Tamron 18-270mm lens is the 'PZD' version, it has a geared mechanism connecting the AF motor to the focusing elements.
SWM Lenses
Lenses such as the AF-S Nikkor 50mm 1:1.8 G use a type of motor to move the focus elements known as a Silent Wave Motor (SWM). The technology was first developed by Canon, who refers to it as an UltraSonic Motor (USM). It has since been adopted by many lensmakers and is known by such monikers as Supersonic Wave Drive (SWD) - Olympus, Supersonic Drive Motor (SDM) - Pentax, Supersonic Motor (SSM) - Pentax, Hyper-Sonic Motor (HSM) - Sigma, and Ultrasonic Silent Drive (USD) - Tamron.
The design uses rings vibrating at very high frequencies to produce the torque needed to move the lens' focus elements. Because these rings are not directly geared to each other, when the focus ring on an SWM lens is turned it allows them to slip in relation to each other without risk of damage to the focus motor. Most such lenses will not move the focusing ring when the AF motor is moving the focusing elements. It is also quite normal with this type of lens to be able to continue to move the focus ring indefinitely even after the focus elements in the lens have reached the end of their travel at either infinity or the lens' minimum focus distance.
Stepping/Linear Motor AF
A newer type of AF motor is called 'stepping motor AF'. Canon introduced their version, the 'STM', in 2012. Nikon's first F mount lens with a stepper motor, designated AF-P, was introduced in 2016. Pentax calls their stepper lenses PLM.
Another approach very similar to the stepper motor is the linear electromagnetic (LEM) AF motor used by Sony and Panasonic.
In most such lenses, the focusing elements are always moved by electrical signals to the AF motor. Even moving the focusing ring to manually focus the lens turns a switch that sends an electrical command, via the camera body, to the AF motor to actually move the focusing elements of the lens. These are sometimes referred to as 'focus-by-wire' AF systems. Nikon calls their lenses with stepper motors 'AF-P' lenses. Only Nikon DSLRs made since about 2013 work at all with AF-P lenses. AF-P lenses can not even be manually focused when mounted on older Nikon bodies.
Comment: The lens says Piezo Drive, which I guess means PZD then? The weird thing is that it works occasionally but stops working quickly after. Is there anything I can do to fix the issue?

Nikon D3300 autofocus issue


What is the connectivity between on-center & off-center bipolar cells?

Question:
Do rod-photoreceptors only form synapses with on-center bipolar cells (and on-center ganglion cells in the next step)? If so, why is that?
Why do rod-cells only connect to on-center cells, while the cones connect to both on- and off?
Am I correct in saying that what happens in the bipolar cell as a response to light stimulus on a photoreceptor depends on i) Wether it is an on-center or off-center bipolar cell - and of course where the light stimuli is focused on the bipolar cell (periphery or center), or ii) What kind of receptors the on-center and off-center bipolar cells have? This is the part where I get really confused, because I read somewhere that what kind of receptors On/Off-center bipolar cell have, is not something set in stone? So saying that On-center bipolar cells have AMPA receptors and will, as a result of that, react in a specific way to less Glutamat release would be wrong?
How does this release of neurotransmitter works together with central / periphery stimuli. Let me try and use an example, You have an on-center bipolar cell. What will happen if light is focused on the center of this cell's receptive field? And what will happen if it is focused on the periphery? Let's just say that the light hitting the center of this cell's receptive field causes it to be depolarized. But is it really the light hitting the center which causes this effect, or is it the decrease in Glutamate release from the photoreceptor that causes this effect? If the latter, then what does it really matter if the light hits the periphery or the center of the bipolar cell's receptive field? The photoreceptor is hyperpolarized by light either way and less Glutamate will be released no matter what.
Also, in order for this to make sense, the light that enters the eye is absorbed by the photoreceptors pigmentmolecules, but some of the light also has to hit the receptive field of the bipolar cell in order to decide which signal to be transmitted? So not all of the light is absorbed by the photoreceptors then?
If the light hits the periphery of an On-center bipolar cell, you will have an inhibitory effect, is that right? And the other way around, if the light hits the center of the cells receptive field, you will get an excitatory effect? But I am curious as to how this also has to do with the kind of receptor that the on-center bipolar cell has (AMPA or MGluR6).
Comment: Please limit yourself to one clear question per post.
Comment: I suggest that you split this up into several simpler questions.
Answer: First off, the post is quite lengthy and contains various sub-questions. I will answer the first two questions in detail, but only after starting with an abstracted overview of photoreception in the retina. By the looks of it, your basic understanding of photoreceptors and secondary visual neurons is incorrect. Clearing the general neurophysiological workings of the retina up should get you on your way in understanding questions 3 - 6.
Synopsis of information flow in the retina: sensation of light
In Fig. 1 a schematic of the retina is shown. It basically consists of three layers. Layer one contains the photoreceptors, namely the rods and the cones. These primary sensory neurons absorb the light with photopigments and generate electrical signals in response to that. The photoreceptors, in turn connect to the second layer, namely bipolar cels, horizontal cells and amacrine cells. These cells are responsible for the center-surround structure of the receptive field of the last layer of cells (Fig. 2), namely the retinal ganglion cells in the front of the retina, whose axons pass across the surface of the retina and form the optic nerve (Kolb, 2017).

Fig. 1. Retina. source: Quasar Group
Note that there are no light-sensitive cells in the retina besides the rods and cones (barred the retinal melanopsin ganglion cells, but please forget that for the sake of simplicity). This one detail should basically clarify the sub-questions 3 - 6 in your post. The first two questions I will address next.

Fig. 2. ON and OFF center responses. source: McGill University
Regarding the retinal bipolar system and your first two questions:

Do rod-photoreceptors only form synapses with on-center bipolar cells (and on-center ganglion cells in the next step)?
  and
Why do rod-cells only connect to on-center cells, while the cones connect to both on- and off?

Rod bipolar cells in the mammalian retina are of the ON type. In contrast to the cone system, rod bipolar cell signals are split into ON and OFF components by amacrine cells. The cone system piggybacks then on the cone system; Rod ON signals flow from rod bipolars to amacrine cells to ON cone bipolar cells. Rod OFF signals are generated between amacrine cells and OFF cone bipolar cells (Nelson & Connaughton, 2017). See Fig. 3 for an overview of the retinal connectivity between rod and cone bipolar cells.

Fig. 3. Retinal circuitry. source: Nelson & Connaughton (2017)
References
- Gouras, Color Vision: In: Webvision: The Organization of the Retina and Visual System (2017)
- Kolb, Simple Anatomy of the Retina. n: Webvision: The Organization of the Retina and Visual System (2017)
- Nelson & Connaughton, Bipolar Cell Pathways. In: Webvision: The Organization of the Retina and Visual System (2017)
Comment: This is a great answer, I think it's worth adding that there are more than just ON/OFF Bipolar cells, about 11 according to Nelson and Connaughton. There's a bit more about specific types of OFF bipolar cells here: https://www.ncbi.nlm.nih.gov/pubmed/26500507. So it's possible that the different classes of bipolar cells have slightly different receptors, or respond slightly differently, so "not set in stone".


Combined Grappling Dummy and Bob punching bag for practice

Question: I would like to practice at home both grappling and punching. For punching there is a boxing bag or Bob and for grappling there are grappling dummies such as bubba dummy and the like. I would like to know if there is a dummy that combines the two: punching bag with legs, hands and face such as Bob and grappling such as bubba dummy?
Comment: I know these exist - I'm interested in hearing from anyone who has had some experience with any of these and what the pros/cons are etc.
Comment: You could always go full throttle on a standing one and take it down to the ground to grapple.  I don't think that will keep good form though as much as a good anger management outlet...
Comment: In my experience EVERY grappling dummy doubles as a punching bag. Thick leather outer, dense inner padding. Do you have one that doesn't fit this criteria?
Comment: Thanks, @coinbird. I would like to use the dummy the same as Bob. It means that it will be able to stay on its own and have balance while boxing. In addition, I'll be able to use it for grappling.
Answer: I thought someone might write in on here with an alternate, but apparently not.  So this is how you can make your own.

Get a very simple weighted standing bag like Bob, but you just need the bottom part so I recommend going cheaper.
Get a bubba dummy
Take off the top part of the weighted standing bag so you just have the bottom heavy part and the top part is missing.  You may need to literally just cut it off.
You then bind some industrial PVC into the base so that it's stationary.  Depending on what type of weight is utilized the binding substance may vary.
You carefully cut into the bubba dummy between the legs to ensure that the PVC can be inserted into it.  Please note that depending on the material it may be best to have the post with the weighted bottom a slightly smaller size PVC and put a slightly larger size PVC into the bubba dummy and then slide the PVC together.  Naturally this will add a hardness to the grappling part, even though the base of the bubba dummy will be there.  If it works well without the additional PVC and the hole in the bottom of bubba dummy then no worries.

Once you have this you can slide the bubba dummy on and off of the weighted punching stand.  This will allow you to punch and kick him and then pull him to the ground and grapple.
Note: Be sure to secure the plastic PVC to the weighted bottom and bubba dummy with a glue or substance that binds the PVC to they respective parts.  You don't want it slipping off.
Note2: The dummy will likely spin as hit when added to the weighted base.  You may want to add some pins to keep it from spinning, but then it might likely decrease your attack to grapple transitions as well.  The spinning might mimic actual human body reactions to hits which seems like the goal of this in the first place, if so no worries and enjoy.
Good luck
P.S. Not exactly what you describe, but this seems for both punch and grapple punch and grapple


What libraries provide an implementation of multigrid?

Question: I am working on numerical method of Multigrid. What's the available implementation(solver) (actually used in scientific computation) of multigrid method?
Comment: Are you asking about which libraries provide multigrid implementations, or are you asking about which multigrid methods are actually used in practice?
Comment: @WolfgangBangerth I am asking libraries used in practice(with MPI openMP or CUDA whatever). Can you give any?
Answer: There are many libraries that provide widely used implementations of multigrid methods. Most of the available finite element libraries do to the best of my knowledge (certainly the one I work on, deal.II, does). There are also widely used implementations of algebraic multigrid methods, most notably from the ML and hypre packages that you can most easily access via the Trilinos and PETSc projects.


How did Annie know Armin was lying?

Question: When Armin approaches Annie in an alley to ask her to help Eren escape, Annie agrees but puts on her ring (with the blade). Armin later realizes that she knew from that moment that he was lying. How?
Answer: The answer is in chapter 31.

Annie noticed that Armin is not looking at her like before. Maybe she detected hints of fear on Armin's eyes, which means Armin knows that Annie is the Female Titan.
Answer: There were also no people on the entire route Annie notices and even says it. Also, Armin and co wanted Annie to come with them underground where they would subdue her. If Mikasa wasn't there she would have done it no problem because she knows she would beat Eren and Armin. She might know that titan shifters can't transform with no sunlight, as seen when even tried to turn into a titan in the well but couldn't. With Mikasa there, hand to hand combat is iffy for her but take away her trump card and add Eren? She wasn't having it and called their bluff and was able to see through the lie.

How did Annie know Armin was lying?