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• How do you get better working conditions? [closed]

  - by 0A0D

  I work at a business who has a software side and manufacturing side. The software we write is sold as a package along with other hardware that our customers purchase. I basically work in a warehouse. There is one door that seperates the engineers from the warehouse noise. I have asked for noise cancelling walls to be put in. I have asked multiple times over 6 months to be moved up front to one of two vacant sales offices, but they seem reluctant to let an Engineer move into a sales office. In fact, sales are the only ones with windows and they get commission though they make mistakes or overpromise to the customer. So, my question is how can I get better working conditions without necessarily having to leave my current job? It is very hard to work and concentrate. UPDATE I think I can finally close this chapter in my life. I have moved on to a large corporation which follows CMMI religiously and has even started using Agile in many of its projects. Nevertheless, there is organization, respect, and genuine care for the engineers and scientists that work for them. Pierre was right - quitting was the right answer. My life does not nearly have the amount of stress it used to have because I now work for a place that is organized and knows what it wants its engineers to do along with treating them like they should be treated.

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• Is there a simple way to make my laptop always turn on muted? [closed]

  - by tehp

  Possible Duplicate: How to mute the sound output on Windows Start up? I carry a laptop around. Sometimes I'll open it up in meetings or other quiet settings. The speaker is interrupted by the windows startup noise or Pandora refreshing it's page and starting to play a song or some other random computer noise. Is there a simple way to mute the sound on startup/resume/whatever? Kind of like the BIOS option to turn on or off the Num Lock.

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• Realtek "Microphone Effects" no longer working

  - by abc

  I have a mic plugged into my computer, and I was able to use the "microphone effects" tab here to enable/disable noise suppression and acoustic echo cancellation. Noise suppression off and acoustic echo cancellation on were the most recent settings I had on before the problem occurred. I disabled my mic in the windows 7 "recording devices" tab, then re-enabled it. When it came back, these options were grayed out, and remained so even after a reboot. I am not sure why this is or how to fix it, all other options are still the same (Settings are identical to when it was working). Any ideas whats wrong or how to fix it? edit: can't post image due to being new.

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• Fan is spinning too fast just in Windows - software?

  - by B. Roland

  I've recently replaced my fans (CPU, GPU, and bought a CHA fan). The GPU remained the same, but I've seen it when it was spinned 2 times faster, than it usual... but it is rarely. The problem is, that the CPU fan in Windows (especially 7) spinned too much, 'cos it keeps in under 40°C, and it is spinning with 3300-3600 RPM, which is too high I think. If I swich to Ubuntu, it keeps on ~40-45°C with with 2500-2800 RPM, which is a big difference in numbers, and in noise. I'm looking for a manual fan control solution, or just reduce the Windows' multipliers of fan speed control, somehow... I was bought the new fans because of the lower noise (and it does it, but not with 3.6k RMP). Thank you!

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• Computer has power but won't boot

  - by John Isaacks

  When I power on my computer it will not boot. It will not even go into bios or anything. It is as if it is not powering on at all, however the decorative casing lights turn on and the PC is making noise (like from the fans). I am reluctant to think it is the power supply since some part are getting power. I do not know what it is though? For the couple days leading up to this, the computer would make a loud noise and the screen would stop displaying anything. I had to reboot to get it to work again. Now nothing happens when I boot, except the case lights come on and it sounds like some fans are coming on. Any ideas?

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• Can I replace my notebook's fan without replacing the heat sink?

  - by kuzzooroo

  My laptop (Acer Travelmate 8204) has started making a grinding noise, which seems to be coming from the fan (not the hard drive). Some articles online mention replacing the fan, but others imply that one should replace both the fan and the heat sink. Does it make sense to replace the fan only? (addendum: does this procedure really take 3 hours for a noob, as this video implies? UPDATE: the fan certainly seems to be on the "top" layer when I open my laptop but some parts of it extend under other layers) Some additional info in response to comments: I have run MS scandisk on the hard drive a few times since the grinding started. It usually reports finding something or other but the computer's behavior doesn't change I'm pretty sure it's the fan based on where the noise is coming from. I employed the cardboard tube trick from the PC World article.

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• Adobe Photoshop Vs Lightroom Vs Aperture

  - by Aditi

  Adobe Photoshop is the standard choice for photographers, graphic artists and Web designers. Adobe Photoshop Lightroom  & Apple’s Aperture are also in the same league but the usage is vastly different. Although Photoshop is most popular & widely used by photographers, but in many ways it’s less relevant to photographers than ever before. As Lightroom & Aperture is aimed squarely at photographers for photo-processing. With this write up we are going to help you choose what is right for you and why. Adobe Photoshop Adobe Photoshop is the most liked tool for the detailed photo editing & designing work. Photoshop provides great features for rollover and Image slicing. Adobe Photoshop includes comprehensive optimization features for producing the highest quality Web graphics with the smallest possible file sizes. You can also create startling animations with it. Designers & Editors know how important precise masking is, PhotoShop lets you do that with various detailing tools. Art history brush, contact sheets, and history palette are some of the smart features, which add to its viability. Download Whether you’re producing printed pages or moving images, you can work more efficiently and produce better results because of its smooth integration across other adobe applications. Buy supporting layer effects, it allows you to quickly add drop shadows, inner and outer glows, bevels, and embossing to layers. It also provides Seamless Web Graphics Workflow. Photoshop is hands-down the BEST for editing. Photoshop Cons: • Slower, less precise editing features in Bridge • Processing lots of images requires actions and can be slower than exporting images from Lightroom • Much slower with editing and processing a large number of images Aperture Apple Aperture is aimed at the professional photographer who shoots predominantly raw files. It helps them to manage their workflow and perform their initial Raw conversion in a better way. Aperture provides adjustment tools such as Histogram to modify color and white balance, but most of the editing of photos is left for Photoshop. It gives users the option of seeing their photographs laid out like slides or negatives on a light table. It boasts of – stars, color-coding and easy techniques for filtering and picking images. Aperture has moved forward few steps than Photoshop, but most of the editing work has been left for Photoshop as it features seamless Photoshop integration. Aperture Pros: Aperture is a step up from the iPhoto software that comes with every Mac, and fairly easy to learn. Adjustments are made in a logical order from top to bottom of the menu. You can store the images in a library or any folder you choose. Aperture also works really well with direct Canon files. It is just $79 if you buy it through Apple’s App Store Moving forward, it will run on the iPad, and possibly the iPhone – Adobe products like Lightroom and Photoshop may never offer these options It is much nicer and simpler user interface. Lightroom Lightroom does a smashing job of basic fixing and editing. It is more advanced tool for photographers. They can use it to have a startling photography effect. Light room has many advanced features, which makes it one of the best tools for photographers and far ahead of the other two. They are Nondestructive editing. Nothing is actually changed in an image until the photo is exported. Better controls over organizing your photos. Lightroom helps to gather a group of photos to use in a slideshow. Lightroom has larger Compare and Survey views of images. Quickly customizable interface. Simple keystrokes allow you to perform different All Lightroom controls are kept available in panels right next to the photos. Always-available History palette, it doesn’t go when you close lightroom. You gain more colors to work with compared to Photoshop and with more precise control. Local control, or adjusting small parts of a photo without affecting anything else, has long been an important part of photography. In Lightroom 2, you can darken, lighten, and affect color and change sharpness and other aspects of specific areas in the photo simply by brushing your cursor across the areas. Photoshop has far more power in its Cloning and Healing Brush tools than Lightroom, but Lightroom offers simple cloning and healing that’s nondestructive. Lightroom supports the RAW formats of more cameras than Aperture. Lightroom provides the option of storing images outside the application in the file system. It costs less than photoshop. Download Why PhotoShop is advanced than Lightroom? There are countless image processing plug-ins on the market for doing specialized processing in Photoshop. For example, if your image needs sophisticated noise reduction, you can use the Noiseware plug-in with Photoshop to do a much better job or noise removal than Lightroom can do. Lightroom’s advantages over Aperture 3 Will always have better integration with Photoshop. Lightroom is backed by bigger and more active user community (So abundant availability for tutorials, etc.) Better noise reduction tool. Especially for photographers the Lens-distortion correction tool  is perfect Lightroom Cons: • Have to Import images to work on them • Slows down with over 10,000 images in the catalog • For processing just one or two images this is a slower workflow Photoshop Pros: • ACR has the same RAW processing controls as Lightroom • ACR Histogram is specialized to the chosen color space (Lightroom is locked into ProPhoto RGB color space with an sRGB tone curve) • Don’t have to Import images to open in Bridge or ACR • Ability to customize processing of RAW images with Photoshop Actions Pricing and Availability Get LightRoomGet PhotoShop Latest version Of Photoshop can be purchased from Adobe store and Adobe authorized reseller and it costs US$999. Latest version of Aperture can be bought for US$199 from Apple Online store or Mac App Store. You can buy latest version of LightRoom from Adobe Store or Adobe Authorized reseller for US$299. Related posts:Adobe Photoshop CS5 vs Photoshop CS5 extended Web based Alternatives to Photoshop 10 Free Alternatives for Adobe Photoshop Software

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• Not getting desired results with SSAO implementation

  - by user1294203

  After having implemented deferred rendering, I tried my luck with a SSAO implementation using this Tutorial. Unfortunately, I'm not getting anything that looks like SSAO, you can see my result below. You can see there is some weird pattern forming and there is no occlusion shading where there needs to be (i.e. in between the objects and on the ground). The shaders I implemented follow: #VS #version 330 core uniform mat4 invProjMatrix; layout(location = 0) in vec3 in_Position; layout(location = 2) in vec2 in_TexCoord; noperspective out vec2 pass_TexCoord; smooth out vec3 viewRay; void main(void){ pass_TexCoord = in_TexCoord; viewRay = (invProjMatrix * vec4(in_Position, 1.0)).xyz; gl_Position = vec4(in_Position, 1.0); } #FS #version 330 core uniform sampler2D DepthMap; uniform sampler2D NormalMap; uniform sampler2D noise; uniform vec2 projAB; uniform ivec3 noiseScale_kernelSize; uniform vec3 kernel[16]; uniform float RADIUS; uniform mat4 projectionMatrix; noperspective in vec2 pass_TexCoord; smooth in vec3 viewRay; layout(location = 0) out float out_AO; vec3 CalcPosition(void){ float depth = texture(DepthMap, pass_TexCoord).r; float linearDepth = projAB.y / (depth - projAB.x); vec3 ray = normalize(viewRay); ray = ray / ray.z; return linearDepth * ray; } mat3 CalcRMatrix(vec3 normal, vec2 texcoord){ ivec2 noiseScale = noiseScale_kernelSize.xy; vec3 rvec = texture(noise, texcoord * noiseScale).xyz; vec3 tangent = normalize(rvec - normal * dot(rvec, normal)); vec3 bitangent = cross(normal, tangent); return mat3(tangent, bitangent, normal); } void main(void){ vec2 TexCoord = pass_TexCoord; vec3 Position = CalcPosition(); vec3 Normal = normalize(texture(NormalMap, TexCoord).xyz); mat3 RotationMatrix = CalcRMatrix(Normal, TexCoord); int kernelSize = noiseScale_kernelSize.z; float occlusion = 0.0; for(int i = 0; i < kernelSize; i++){ // Get sample position vec3 sample = RotationMatrix * kernel[i]; sample = sample * RADIUS + Position; // Project and bias sample position to get its texture coordinates vec4 offset = projectionMatrix * vec4(sample, 1.0); offset.xy /= offset.w; offset.xy = offset.xy * 0.5 + 0.5; // Get sample depth float sample_depth = texture(DepthMap, offset.xy).r; float linearDepth = projAB.y / (sample_depth - projAB.x); if(abs(Position.z - linearDepth ) < RADIUS){ occlusion += (linearDepth <= sample.z) ? 1.0 : 0.0; } } out_AO = 1.0 - (occlusion / kernelSize); } I draw a full screen quad and pass Depth and Normal textures. Normals are in RGBA16F with the alpha channel reserved for the AO factor in the blur pass. I store depth in a non linear Depth buffer (32F) and recover the linear depth using: float linearDepth = projAB.y / (depth - projAB.x); where projAB.y is calculated as: and projAB.x as: These are derived from the glm::perspective(gluperspective) matrix. z_n and z_f are the near and far clip distance. As described in the link I posted on the top, the method creates samples in a hemisphere with higher distribution close to the center. It then uses random vectors from a texture to rotate the hemisphere randomly around the Z direction and finally orients it along the normal at the given pixel. Since the result is noisy, a blur pass follows the SSAO pass. Anyway, my position reconstruction doesn't seem to be wrong since I also tried doing the same but with the position passed from a texture instead of being reconstructed. I also tried playing with the Radius, noise texture size and number of samples and with different kinds of texture formats, with no luck. For some reason when changing the Radius, nothing changes. Does anyone have any suggestions? What could be going wrong?

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• SQL SERVER – Data and Page Compressions – Data Storage and IO Improvement

  - by pinaldave

  The performance of SQL Server is primarily decided by the disk I/O efficiency. Improving I/O definitely improves the performance. SQL Server 2008 introduced Data and Backup compression features to improve the disk I/O. Here, I will explain Data compression. Data compression implies the reduction in the disk space reserved by data. Therefore, data compression can be [...]

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• Microsoft lance System Center : une plate-forme unique et complète pour l'administration systèmes

  Microsoft® System Center est une plate-forme unique et complète pour l'administration des postes de travail, des serveurs, des applications et des périphériques, en environnement physique ou virtuel. Citation: La gamme de produits System Center a pour but de simplifier les opérations et les changements, de réduire les durées de dépannage et d'améliorer les capacités de planification au sein de votre entreprise dans une optique de réduction des coûts. Optimisée pour une administration système dynamique, System Center vous aide à fournir le niv...

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• Slow boot time since upgrade to 12.04 from 11.10

  - by danh28

  I have tried for quite a while now to reduce my boot time, disabled some startup items, removed packages that were causing crashes after boot, removed ureadahead pack files, reinstalled ureadahead, uninstalled ureadahead and installed e4rat....and nothing has made that much difference. e4rat made the biggest difference with a reduction of a few seconds but my boot time is still around 80 seconds. Can anyone help? Dmesg and bootchart below: dmesg bootchart

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• 5 Lessons learnt in localization / multi language support in WPF

  - by MarkPearl

  For the last few months I have been secretly working away at the second version of an application that we initially released a few years ago. It’s called MaxCut and it is a free panel/cut optimizer for the woodwork, glass and metal industry. One of the motivations for writing MaxCut was to get an end to end experience in developing an application for general consumption. From the early days of v1 of MaxCut I would get the odd email thanking me for the software and then listing a few suggestions on how to improve it. Two of the most dominant suggestions that we received were… Support for imperial measurements (the original program only supported the metric system) Multi language support (we had someone who volunteered to translate the program into Japanese for us). I am not going to dive into the Imperial to Metric support in todays blog post, but I would like to cover a few brief lessons we learned in adding support for multi-language functionality in the software. I have sectioned them below under different lessons. Lesson 1 – Build multi-language support in from the start So the first lesson I learnt was if you know you are going to do multi language support – build it in from the very beginning! One of the power points of WPF/Silverlight is data binding in XAML and so while it wasn’t to painful to retro fit multi language support into the programing, it was still time consuming and a bit tedious to go through mounds and mounds of views and would have been a minor job to have implemented this while the form was being designed. Lesson 2 – Accommodate for varying word lengths using Grids The next lesson was a little harder to learn and was learnt a bit further down the road in the development cycle. We developed everything in English, assuming that other languages would have similar character length words for equivalent meanings… don’t!. A word that is short in your language may be of varying character lengths in other languages. Some language like Dutch and German allow for concatenation of nouns which has the potential to create really long words. We picked up a few places where our views had been structured incorrectly so that if a word was to long it would get clipped off or cut out. To get around this we began using the WPF grid extensively with column widths that would automatically expand if they needed to. Generally speaking the grid replacement got round this hurdle, and if in future you have a choice between a stack panel or a grid – think twice before going for the easier option… often the grid will be a bit more work to setup, but will be more flexible. Lesson 3 – Separate the separators Our initial run through moving the words to a resource dictionary led us to make what I thought was one potential mistake. If we had a label like the following… “length : “ In the resource dictionary we put it as a single entry. This is fine until you start using a word more than once. For instance in our scenario we used the word “length’ frequently. with different variations of the word with grammar and separators included in the resource we ended up having what I would consider a bloated dictionary. When we removed the separators from the words and put them as their own resources we saw a dramatic reduction in dictionary size… so something that looked like this… “length : “ “length. “ “length?” Was reduced to… “length” “:” “?” “.” While this may not seem like a reduction at first glance, consider that the separators “:?.” are used everywhere and suddenly you see a real reduction in bloat. Lesson 4 – Centralize the Language Dictionary This lesson was learnt at the very end of the project after we had already had a release candidate out in the wild. Because our translations would be done on a volunteer basis and remotely, we wanted it to be really simple for someone to translate our program into another language. As a common design practice we had tiered the application so that we had a business logic layer, a ui layer, etc. The problem was in several of these layers we had resource files specific for that layer. What this resulted in was us having multiple resource files that we would need to send to our translators. To add to our problems, some of the wordings were duplicated in different resource files, which would result in additional frustration from our translators as they felt they were duplicating work. Eventually the workaround was to make a separate project in VS2010 with just the language translations. We then exposed the dictionary as public within this project and made it as a reference to the other projects within the solution. This solved out problem as now we had a central dictionary and could remove any duplication's. Lesson 5 – Make a dummy translation file to test that you haven’t missed anything The final lesson learnt about multi language support in WPF was when checking if you had forgotten to translate anything in the inline code, make a test resource file with dummy data. Ideally you want the data for each word to be identical. In our instance we made one which had all the resource key values pointing to a value of test. This allowed us point the language file to our test resource file and very quickly browse through the program and see if we had missed any linking. The alternative to this approach is to have two language files and swap between the two while running the program to make sure that you haven’t missed anything, but the downside of dual language file approach is that it is much a lot harder spotting a mistake if everything is different – almost like playing Where’s Wally / Waldo. It is much easier spotting variance in uniformity – meaning when you put the “test’ keyword for everything, anything that didn’t say “test” stuck out like a sore thumb. So these are my top five lessons learnt on implementing multi language support in WPF. Feel free to make any suggestions in the comments section if you feel maybe something is more important than one of these or if I got it wrong!

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• Microsoft propose Windows 7 Professionnel à 85 Euro pour les étudiants

  Promotion : Windows 7 professionnel à 85€ pour les étudiants Windows 7 fait souvent l'objet de diverses remises et réduction rendant ainsi son prix plus abordable. Cette fois-ci, ce sont les étudiants qui sont à l'honneur : Microsoft leur propose en effet d'acquérir une licence Windows 7 Professionnel pour 85€. Vous êtes étudiants et vous souhaitez profiter de l'offre ? Cliquez-ici pour accéder au site de Microsoft et bénéficier de ce prix réduit. _ _ _ _ _ Voir aussi :

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• New customer references for Exadata projects

  - by Javier Puerta

  Denver Regional Transportation District (USA)  Exadata, BI Suite EE, Oracle Linux, Oracle ACSDenver Regional Transportation District Deploys Engineered System in One Week for a Four-Fold Reduction in Database Operations and Management Resources Published: August 21, 2012 Balubaid Group (Saudi Arabia) Exadata, SPARC M4000, Solaris, OBIEE 11gBalubaid Group of Companies Reduces Help-Desk Complaints by 75%, Improves Business Continuity and System Response Published August 21, 2012 All customer reference collateral can be found on Oracle.com/customers. Search by content type, product, industry, region, and even keywords.

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• Quels sont les apports de la virtualisation pour les PME ? Microsoft présente les avantages et ses solutions pour la technologie

  Découvrez les solutions de Microsoft en matière de virtualisation et les apports pour votre PME Les techniques de virtualisation peuvent permettre d'optimiser pratiquement tous les domaines de l'infrastructure informatique (système d'exploitation, applications, serveurs, base de données, etc.). Définie comme une technologie permettant de mutualiser sur une seule machine plusieurs systèmes d'exploitation et/ou plusieurs applications, comme s'ils fonctionnaient sur des machines distinctes, la virtualisation se positionne aujourd'hui comme un levier d'amélioration du rendement et de réduction des couts pour les PME. Pourquoi choisir la virtualisation ? Comment mener un proj...

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• Mean filter in MATLAB without loops or signal processing toolbox

  - by Doresoom

  I need to implement a mean filter on a data set, but I don't have access to the signal processing toolbox. Is there a way to do this without using a for loop? Here's the code I've got working: x=0:.1:10*pi; noise=0.5*(rand(1,length(x))-0.5); y=sin(x)+noise; %generate noisy signal a=10; %specify moving window size my=zeros(1,length(y)-a); for n=a/2+1:length(y)-a/2 my(n-a/2)=mean(y(n-a/2:n+a/2)); %calculate mean for each window end mx=x(a/2+1:end-a/2); %truncate x array to match plot(x,y) hold on plot(mx,my,'r')

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• How can I delete bad Visual Studio templates?

  - by Sung Meister

  How do you remove following noise templates, that don't even work?

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• is it legal/ethical to use source code provided in academic papers, or talks given at trade events l

  - by lucid

  so, is it legal to use source code from papers and such: like this paper on perlin noise: [url]http://mrl.nyu.edu/~perlin/paper445.pdf[/url] links to this source code: [url]http://mrl.nyu.edu/~perlin/noise/[/url] and stam's famous talk on fluid dynamics, includes source code throughout, annotated with instructions like "add these macros to the beginning of your code" [url]http://www.dgp.toronto.edu/people/stam/reality/Research/pdf/GDC03.pdf[/url] I'm just not sure if it's legal to copy and paste this to use in your own commercial code. if I were to make my own implementation, it would end up being close to identical, since I'd probably use the source code as a reference. I know very little about copyright law, including how it applies in these situations, and I can never find usage and licensing terms for these. Nor did googling any terms I could think of provide me the specific answer I need. does anyone know for sure what the rules/laws are here, or where I can find the answer?

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• Extrapolation using fft in octave

  - by CFP

  Using GNU octave, I'm computing a fft over a piece of signal, then eliminating some frequencies, and finally reconstructing the signal. This give me a nice approximation of the signal ; but it doesn't give me a way to extrapolate the data. Suppose basically that I have plotted three periods and a half of f: x -> sin(x) + 0.5*sin(3*x) + 1.2*sin(5*x) and then added a piece of low amplitude, zero-centered random noise. With fft/ifft, I can easily remove most of the noise ; but then how do I extrapolate 3 more periods of my signal data? (other of course that duplicating the signal). The math way is easy : you have a decomposition of your function as an infinite sum of sines/cosines, and you just need to extract a partial sum and apply it anywhere. But I don't quite get the programmatic way... Thanks!

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• problems in trying ieee 802.15.4 working from msk

  - by asel

  Hi, i took a msk code from dsplog.com and tried to modify it to test the ieee 802.15.4. There are several links on that site for ieee 802.15.4. Currently I am getting simulated ber results all approximately same for all the cases of Eb_No values. Can you help me to find why? thanks in advance! clear PN = [ 1 1 0 1 1 0 0 1 1 1 0 0 0 0 1 1 0 1 0 1 0 0 1 0 0 0 1 0 1 1 1 0; 1 1 1 0 1 1 0 1 1 0 0 1 1 1 0 0 0 0 1 1 0 1 0 1 0 0 1 0 0 0 1 0; 0 0 1 0 1 1 1 0 1 1 0 1 1 0 0 1 1 1 0 0 0 0 1 1 0 1 0 1 0 0 1 0; 0 0 1 0 0 0 1 0 1 1 1 0 1 1 0 1 1 0 0 1 1 1 0 0 0 0 1 1 0 1 0 1; 0 1 0 1 0 0 1 0 0 0 1 0 1 1 1 0 1 1 0 1 1 0 0 1 1 1 0 0 0 0 1 1; 0 0 1 1 0 1 0 1 0 0 1 0 0 0 1 0 1 1 1 0 1 1 0 1 1 0 0 1 1 1 0 0; 1 1 0 0 0 0 1 1 0 1 0 1 0 0 1 0 0 0 1 0 1 1 1 0 1 1 0 1 1 0 0 1; 1 0 0 1 1 1 0 0 0 0 1 1 0 1 0 1 0 0 1 0 0 0 1 0 1 1 1 0 1 1 0 1; 1 0 0 0 1 1 0 0 1 0 0 1 0 1 1 0 0 0 0 0 0 1 1 1 0 1 1 1 1 0 1 1; 1 0 1 1 1 0 0 0 1 1 0 0 1 0 0 1 0 1 1 0 0 0 0 0 0 1 1 1 0 1 1 1; 0 1 1 1 1 0 1 1 1 0 0 0 1 1 0 0 1 0 0 1 0 1 1 0 0 0 0 0 0 1 1 1; 0 1 1 1 0 1 1 1 1 0 1 1 1 0 0 0 1 1 0 0 1 0 0 1 0 1 1 0 0 0 0 0; 0 0 0 0 0 1 1 1 0 1 1 1 1 0 1 1 1 0 0 0 1 1 0 0 1 0 0 1 0 1 1 0; 0 1 1 0 0 0 0 0 0 1 1 1 0 1 1 1 1 0 1 1 1 0 0 0 1 1 0 0 1 0 0 1; 1 0 0 1 0 1 1 0 0 0 0 0 0 1 1 1 0 1 1 1 1 0 1 1 1 0 0 0 1 1 0 0; 1 1 0 0 1 0 0 1 0 1 1 0 0 0 0 0 0 1 1 1 0 1 1 1 1 0 1 1 1 0 0 0; ]; N = 5*10^5; % number of bits or symbols fsHz = 1; % sampling period T = 4; % symbol duration Eb_N0_dB = [0:10]; % multiple Eb/N0 values ct = cos(pi*[-T:N*T-1]/(2*T)); st = sin(pi*[-T:N*T-1]/(2*T)); for ii = 1:length(Eb_N0_dB) tx = []; % MSK Transmitter ipBit = round(rand(1,N/32)*15); for k=1:length(ipBit) sym = ipBit(k); tx = [tx PN((sym+1),1:end)]; end ipMod = 2*tx - 1; % BPSK modulation 0 -> -1, 1 -> 1 ai = kron(ipMod(1:2:end),ones(1,2*T)); % even bits aq = kron(ipMod(2:2:end),ones(1,2*T)); % odd bits ai = [ai zeros(1,T) ]; % padding with zero to make the matrix dimension match aq = [zeros(1,T) aq ]; % adding delay of T for Q-arm % MSK transmit waveform xt = 1/sqrt(T)*[ai.*ct + j*aq.*st]; % Additive White Gaussian Noise nt = 1/sqrt(2)*[randn(1,N*T+T) + j*randn(1,N*T+T)]; % white gaussian noise, 0dB variance % Noise addition yt = xt + 10^(-Eb_N0_dB(ii)/20)*nt; % additive white gaussian noise % MSK receiver % multiplying with cosine and sine waveforms xE = conv(real(yt).*ct,ones(1,2*T)); xO = conv(imag(yt).*st,ones(1,2*T)); bHat = zeros(1,N); bHat(1:2:end) = xE(2*T+1:2*T:end-2*T); % even bits bHat(2:2:end) = xO(3*T+1:2*T:end-T); % odd bits result=zeros(16,1); chiplen=32; seqstart=1; recovered = []; while(seqstart<length(bHat)) A = bHat(seqstart:seqstart+(chiplen-1)); for j=1:16 B = PN(j,1:end); result(j)=sum(A.*B); end [value,index] = max(result); recovered = [recovered (index-1)]; seqstart = seqstart+chiplen; end; %# create binary string - the 4 forces at least 4 bits bstr1 = dec2bin(ipBit,4); bstr2 = dec2bin(recovered,4); %# convert back to numbers (reshape so that zeros are preserved) out1 = str2num(reshape(bstr1',[],1))'; out2 = str2num(reshape(bstr2',[],1))'; % counting the errors nErr(ii) = size(find([out1 - out2]),2); end nErr/(length(ipBit)*4) % simulated ber theoryBer = 0.5*erfc(sqrt(10.^(Eb_N0_dB/10))) % theoretical ber

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• HMM for perspective estimation in document image, can't understand the algorithm

  - by maximus

  Hello! Here is a paper, it is about estimating the perspective of binary image containing text and some noise or non text objects. PDF document The algorithm uses the Hidden Markov Model: actually two conditions T - text B - backgrouond (i.e. noise) It is hard to understand the algorithm itself. The question is that I've read about Hidden Markov Models and I know that it uses probabilities that must be known. But in this algorithm I can't understand, if they use HMM, how do they get those probabilities (probability of changing the state from S1 to another state for example S2)? I didn't find anything about training there also in that paper. So, if somebody understands it, please tell me. Also is it possible to use HMM without knowing the state change probabilities?

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• Voice Communication over TCP/IP

  - by Micha

  Hello, I'm currently developing application using DirectSound for communication on an intranet. I've had working solution using UDP but then my boss told me he wants to use TCP/IP for some reason. I've tried to implement it in pretty much the same way as UDP, but with very little success. What I get is basically just noise. 20% of it is the recorded sound and the rest is just weird noise. My guess for the reason is that TCP needs to read all the accepted data several times until it gets the final sound I can play. Now two questions: Am I on the right tracks? Is it even good idea to use TCP/IP for this kind of application (voice conferencing of sorts)? I'm doing it in C# but I don't think this is language specific.

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• MATLAB: filter noisy EKG signal

  - by kristia

  What is the best filter to use to remove noise from an ECG signal with matlab?

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• What is SVD(singular value decomposition)

  - by shiva

  How does it actually reduce noise..can you suggest some nice tutorials?

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• So - vuvuzelas. any programming equivalents ?? [closed]

  - by jim

  Hi All, I'm sure we've all been exposed over the past few days to the delights of the vuvuzela (see http://news.bbc.co.uk/1/hi/magazine/8738604.stm). In an attempt to mask the waspish 'parp' from our living rooms, tv sound engineers are devising all sorts of filters to try and 'calm' the abhoration :). some tho say that it simply 'adds to the ambience' and that masking it out would be a denial of its 'additive' character. Now, on a programming related front, have you had to mask any extraneous 'noise' in a piece of work that you've picked up from someone else (or perhaps even your own!!)?? If so how 'inspired' was your remedy and how did you creatively 'reverse' it out once the noise had subsided and/or the pitch changed. :) tongue firmly in cheek... jim

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