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Real-Time Systems - Science topic

Explore the latest questions and answers in Real-Time Systems, and find Real-Time Systems experts.
Questions related to Real-Time Systems
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Does a PhD degree in Management really helps an employee to move towards CEO position in corporate? What is your Real-time Experience and opinion?
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Dear Doctor,
Thank you for the interesting question.
The purpose of a PhD degree in Management is to help in the advancement of the world thorough education and research. So, theoretically speaking, a PhD degree should not ideally help an employee to move towards the position of a CEO in the corporate sector. But, nowadays, man is busy in discovering corollaries of all theories, beliefs and ideas. So, these days, many CEOs and higher level management professionals are PhD degree holders. Actually, it is seen that many research scholars pursue applied researches which are readily purchased by the industry. This trend is producing many CEOs and higher level management professionals who are PhD degree holders. I guess, that is the reason for raising this question. This phenomena is breaking the classical myth that PhD degree holders are mainly for education and research.
Best regards,
Anamitra.
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Hi, I am currently working on a project which requires me to implement the ICA algorithm in real time, to be specific, I am trying to separate the noise from the audio. When I perform the algorithm in offline, it works fine despite the amplitude of the separated audio is a bit soft. However, when I implement it in real-time, the separated audio becomes very soft. Any source code that I could refer to solve this kind of problem. Thanks.
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What you are describing appear to be two different problems, one compounding the other
For the first problem
1) Which ICA implementation are you using?
For the second problem
1) For the real time capture what sampling rate are you doing the capture?
2) what are you using to capture the signal in real time(e.g. are you using ALSA on Linux or are you using Windows)?
Note that the RM Cortex-M7 of the Teensy 4.0 is a slow processor compared to an Intel or AMD
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I would be grateful if anybody could point me to published research discussing the role of public administrations in freight transport planning/policy and what data they collect and use to base their policy upon, especially if such data is from real-time systems (perhaps once summarised). Please note that my interest is for intercity freight transport particularly.
Very many thanks!
Andrea
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Prof Ken Ogden published journal papers and a book related to freight transport planning when he was working at Monash Uni.
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I am looking for a book or a paper which can help me find the relationship between these parameters.
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Delay time may (or not) be of first order. The magnitude of the error that results from identifying the observed/measured variable (affected by first order delay) with the corresponding actual (real) concentration, can be estimated accordingly eq. 2.58 of the following reference (p. 25):
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Hello
My colleagues and I intend to implement a real-time controller. So that a simple real first-order system is controlled by a controller designed in MATLAB/Simulink environment (Rapid Control Prototyping). We would be grateful if you could help with the following:
Is this possible with the help of dSPACE devices? And in that case, with what tools? For example, is the DS1202 MicroLab suitable by itself?
In general, what configuration is proposed for such a system in real-time modeling? (In the academic field)
We would also be grateful if you could suggest an example (project, article, book, schematics, etc.) in this regard. Unfortunately, with so much searching, most of what I found was just PWM generating for power electronic converters.
We are also interested in any advice and experience you have had in this field.
Thanks & Regards.
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You can easily implement the controller on TMS320F28335 microcontroller. You can see my video for more advanced controller design:
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The app itdoesn´t start correctly (0xc000007b). Press click in Accep to close it.
The app was made in VC10.
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CTRl+F5
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I am working on an Edge Framework which aims to execute tasks/processes in real-time and to offload the tasks to other neighboring Edge Servers in case the current server does not have enough resources, or likely to miss the deadline.
There are several architecture available from e.g. OpenFog Consortium or EdgeX Foundry. Additionally, simulators such as iFogSim, EdgeCloudSim (which are based on CloudSim), EmuFog, or YAFS exist. However, as far as I understood, they rely on best effort rather than real-time reaction.
Are there any existing solutions in the same direction, i.e. real-time execution in a distributed network?
Thank you,
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I would suggest considering serverless computing along with edge computing. Our recent paper will definitely help.
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And preferably a risk management system that incorporates crowd sourcing capabilities
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I have read some papers about the Model Predictive Control. As I know, MPC mainly update the optimal solutions based on the updated initial condition, i.e. repeated optimal control. As real-time optimal control also do the repeated optimal control, what is the difference between MPC and Real-time optimal control?
Please help me if you know something. Thanks.
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Dear Jingwen Zhang
real-time optimal control is an open-loop control, and MPC is a closed-loop control.
Regards
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Looking for a case study where severe influx and loss events were experienced even when a MPD system is installed and active. Interested in the sequence of events and mitigation steps.
A real well example, not theoretical discussions. A big shout out to the petroleum engineers, drilling engineers, MPD experts and wellsite folks.
Thanks in advance.
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Hi, Souvik Sen I did a quick search on onepetro.org and found some interesting papers. Kindly check through and see if you can extract some data from it.
Best regards
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I’m trying to implement EKF in my Real-time hand motion capturing algorithm. I have surveyed some paper or source code, but I can’t understand how to define a correct x state. Someone define [velocity(X);position(X);velocity(Y);position(Y)] or [acceleration(X); acceleration(Y)]in X state matrix. However I can't confirm if they are suitable for my system.
Could anyone tell me how to choose a correct X state matrix?
Some information
Input data: 3D acceleration (x,y,z).
State model:
Xk = AXk-1 + wk-1
Zk = HXk + vk
wk-1 and vk are Gaussian white noise.
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Useful answers, thank you for all
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Frameworks such as Apache Storm, Flink, Heron and Spark were developed to run on clusters or cloud. These such kinds of infrastructures do not have memory, CPU and bandwidth limitations. In contrast, computing resources at the network edge are constrained regarding their capabilities. I am aware of the Apache Edgent and Nifi frameworks. However, they were conceived to run locally on a single computing resource. If you want to run them in a distributed infrastructure, you might create your own stack of components (broker + framework).
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Himadri Nath Saha, it seems to be a fascinating motivation scenario. The investments and the continuous growth of streaming games have imposed new requirements of response time (i.e., ultra-low latency). I am looking for DSP systems where latency-sensitive applications can be easily deployed on geo-distributed constrained resources avoiding creating a multi-tier of components.
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The data stream engines are characterized by receiving and processing an unbounded data stream using the available resources (i.e. memory, processors, etc.). Suppose that each data stream comes with a certain tagging, which allows you to identify the related concept with a given measure. The point is the way to recognize from previous pieces of knowledge or experiences from some repository (e.g. an Organizational Memory) patterns or situations in order to avoid risk situations or catch a given event.
In a data stream context...What do you think is the best way to represent the knowledge in order to allow dynamic reasoning on the fly at the moment in which each measure is read and matched with its concept?
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Perhaps we mean something different by the words "data stream." To me it means an unbroken time-stamped series of readings from a single sensor. That logically precludes the possibility that it " contains data coming from different kind[s] of sensors." A "different kind" of sensor would be a different sensor and come through a different stream. Your agent program can look at more than one stream and sense patterns of cross-correlation between those streams.
For example, you might look for a spike of readings from one sensor coincident with a trough of readings from another. In fact, you would prefer to have any alarms triggered by correlations among readings from multiple separate sensors to minimize false alarms.
The recent difficulty with Boeing 737 Max attack-angle sensors might have been avoided if the flight computer had watched streams from both of the sensors that were available and disengaged the MCAS if they disagreed by some given percentage while warning pilots that there was an attack-angle sensor problem.
The point is that multiple sensors "touch" the real world in different places and each provides a stream of readings reporting conditions at one of those different places. It is then a real-time computing problem to sense and understand patterns in those readings. It sounds like you may be trying to mix and match raw sensor data streams too early in your logical process.
Think of data as starting out as a broad array of multiple streams. Your data analysis (its actually a synthesis process, but people get in the habit of using wrong words) is then a series of steps funneling that data down to a single-bit result -- to trigger an alarm NOW or not. The reason I call it a synthesis process is that, while much of the data gets thrown away as irrelevant TO THAT ALARM-TRIGGER PROBLEM, the important stuff consists of logically combining observations from relevant streams via some species of pattern recognition.
I hope that makes sense and helps.
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I used two samples one is infected to HBV and another not. when I had checked the Real-time amplification data it showed HBV specific primers amplification in both samples infected or non-infected while its amplification should be only from the infected Sample.
Reaction volume = 6uL
( Sybr Green =2.5 ul, primers = 1uL(10uM), template = 1uM and ddH2O = 1.5uL)
Reaction condition ;
Initially 95 degree for 10 minutes
Denaturation at 95 degrees for 15 sec
Annealing at 56 degrees for 1 minute
Extention at 72 degrees for 30 sec
Melting Curve ; 95, 60, 95 degree for 15, 60, 15 sec respectively.
Primers Tm between 59 to 62 degree and Product length from 100 to 150
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Dear Frederic,
Thank you for your early reply.
Yes, I was every time took negative controls like Primers with water, template with water, SYBR Green with water, SYBR Green with Primers and SYBR Green with template alone, in these all wells result was undetermined like expected or fine but the problem is only the amplification detection in Control.
Thanking You
Regards
Jitendra
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Dear all,
We perform an experiment to study agglomeration of small particles in zero gravity. For this, we need to control particle size distribution in real-time (the camera framerate is 50 fps, 8-bit grey image). Can you advise enough fast algorithm for localisation, counting and measurement of particle size? See one image attached - they say, it is better to see once than to hear one hundred times.
Thank you all in advance
Daniyar Balapanov
Brussels Free University
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If you are trying to get size by application of the Stokes-Einstein equation then you need a slow algorithm not a fast one. You’ll have to track a statistical number of particles for a sufficiently long period of time to get reliable diffusion coeffients. You can to do if you buy a Nanosight NTA.
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For the temporal guarantee of some applications, many authors recommend a busload limit, but with new protocols such as CAN-FD, many changes occur. References mention that is 30%, but I believe that it changed. Please provide some recent references about it.
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Have you checked this paper?
"Typical Worst Case Response-Time Analysis and its Use in Automotive Network Design." DAC 2014.
It contains industrial data from Daimler (Mercedes).
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I have always used SYBR® Green *10,000X DMSO Solution* in my qPCR (real time) Mastermix. Has anyone used something like this instead, which appears to not contain DMSO and be designed for PCR? It's a lot more expensive. https://www.aatbio.com/products/cyber-green-sybr-green-10-000x-aqueous-pcr-solution?unit=17592, particularly compared to their version of Sybr green in DMSO https://www.aatbio.com/products/cyber-green-nucleic-acid-gel-stain-sybr-green-10-000x-dmso-solution
Thanks!
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Hi Dear Robin M Forbes-Lorman, you can use to Eva green kit for Real Time PCR. Good luck
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If a very high % of higher ed. students think: "open my brain and just pour the knowledge in" we may be doomed in discovering things for bad sciences (with no one willing to look at whole systems of understanding -- though they do not work).
There has always been a disturbing % of students (including ones who have become professors) that had this basic attitude and approach. Now, in this iPhone, etc age, it seems the % may have reached "critical mass" for hopelessness.
The good news: one or a few people could process a whole new system and investigate it (these students being among some very rare subset). These students (several) could make entire good careers out of such work. They may well occupy some seats on a plane to Oslo some day too. AND:
Frankly: analytic professors OWE THE WHOLE WORLD SUCH ANALYSIS for penance for their false persuading assertions that have messed up behavioral science FOR 100 YEARS !!
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I agree with you that independent research and study are the keys to all difficulties
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Hello Everyone
hope you all are fine
I am working on Intrusion Detection System (IDS), so to implement it on real time on my system i need some help regarding that,
how my system can decide that the packets on network in real time scenarios is either malicious or normal one.
Anyone here who is having an idea of Real time Feature Selection/Extraction/Detection (on run time not on Offline/Virtual bed test setup ). Any good method/Algorithm/any good Journal reference might help me?
your little help would be appreciated
Regards
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i do a study for a gene expression in HCC patients compared to healthy person using real time pcr. i have analyzed ct for gene of interest and house keeping gene in each sample either HCC or healthy persons. i have calculated delta ct for each sample by subtracting ct of housekeeping gene from ct of gene of interest. now i want to calculate delta delta ct. i didn't make a calibrator through my run. some colleagues suggested to consider the sample (either from patients or healthy) of highest ct is my calibrator to be subtracted from all the samples to calculate delta delta ct. i have add my result in excel sheet.
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Hi,
You should first take a look to your housekeeping gene CT .
A CT above 30 make no sense, it should be in the range of 22-28
Then, the CT in your patient groupe above 40 may indicate that you have almost no CDNA in your sample.
Can you give more information about your RNA extraction in patient and healthy ?
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There is a set of data from an emission measurement sensor sorted by the time they were measured.
Now I need to know how I can find the time pattern when a sensor goes out of calibration?
I want to use a real time model for calibration of emission measurement sensors in automobiles.
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You can conduct time-series analyses with ARIMA-GARCH models and use residuals or standardized residuals to examine any outlier effect. Also, you can examine change/break-points in these residual series with several statistical techniques. A proper ARIMA-GARCH model should provide you normally distributed residuals with no serial correlation.
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Machine learning; Real-time prediction; Accident analysis
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The basic idea is to detect changes in pitch, roll, and yaw by the sensor.
You can use the Kalman Filter for the real-time prediction.
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Is it possible to use intelligent techniques in real-time systems?
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It depends on your fitness function and required
If you use AND colony B colony in every time it searches about the best solution, while other algorithms like Fuzzy and neural networks have moods they are off-line mood (training) this is not in the time of taking decision, but when u use it (off-line mode) it is a very fast comparing to the ordinary method.
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Does anyone have any experience with real-time GIS applications using open source tools and software? The aim is visualization of sensor data and moving objects. What kind of solutions are available? ESRI has ArcGIS GeoEvent Server but is there something similar available in open source field?
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you can read in this paper
PDF] Integrating Spatial Data Infrastructures (SDIs) with Volunteered Geographic Information (VGI) for creating a Global GIS platform
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What is the approximate cost of Real Time PCR 
How much is the tuned around time?
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A frequent application is power electronics rapid prototyping, but many other are possible. A closer look for actual applications in the industry seems to be rare. This discussion can be highly useful for tackling practical applications.
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Real-time simulators are very important in many areas, where real plants are very expensive. Regarding powers systems, I have particular interests in the field of wind energy. It is not easy to have an experimental real multi-MW wind turbine. Therefore, we are developing a real time simulator with a PLC as hardware in the loop.
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I faced some problem in constructing a standard curve for my gene of interest. The GOI is somehow a low copy number genes. Therefore, I'm going to increase the starting amount of cDNA by 500 ng per tube reaction (which mean during DNase treatment , the starting total amount of RNA will be 5 ug). 
I am doing qPCR using two step kit . I used iScript Reverse Transcription by Biorad to transcribed to the cDNA, but I am wondering whether I need to increase this reverse transcript volume as the volume of cDNA concentration will be increase to the total of 5 ug? I am still new to this real-time world.
Attached herewith is the protocol sheet for your reference. Thank you.
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Thank you Nevin and Laurence. I did it and yes it is ok. I did test the reverse sample by conventional PCR and I get the expected band.
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Our lab has been looking for this answer for a few years now. Currently, we can collect heart rate data but it cannot be accessed until post-test. We are looking for suggestions on a method to obtain this data and be able to view it in real-time.
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Frank,
Are you able to access the raw data?
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I have regarding the real-time communication with KRC 4 KUKA controller questions:
Is the thought correct, that if I use RSI-XML interface, I need time calculated by interpolation cycle rate x amount of the frames to send all frames within one IPO-rate? 
Is it correct, that within 1 IPO-Cycle rate, I can send data and get them back?
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Ja, Sie sind mit einem Vorbehalt richtig. Die Interpolationszyklusrate ist nicht dieselbe wie die Übertragungsrate.
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Dear all,
I want to  expire data in  database ( its ok with expireAfterSeconds), but i want to use with collection.update>> data are always send data to database in real-time so TTL  must be working on update data.. can i do that??
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Hi
MongoDB  or higher supports TTL (Time-To-Live) indexes. TTL Monitor is a separate thread that runs periodically (usually every minute) and scans a collection, that has a TTL index defined, for any expired documents and removes them in the background.
Application of TTL indexes can be in Shopping Carts, Login sessions, Event logs etc where the data needs to be retained only for a certain period of time.
Try to see also this link it must be usefull in your implementation : https://www.codeproject.com/Tips/467689/MongoDB-Time-To-Live-TTL-Collections
Best regards 
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Hi,
I have treated breast cancer cell line (MCF7) with miRNA mimic. I want to calculate the fold change of miRNA expression between untreated and treated cells. However, the Ct value of miRNA in untreated sample is "undetermined" using real-time qPCR because maybe the miRNA is too low in MCF7. I only have the Ct value of miRNA after treatment with mimic. 
How do I calculate the fold change between untreated and treated? 
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You can use more RNA or cDNA in your experiments so that you can prepone Ct value of miRNA in untreated cells. Also, you can increase the number of cycles of your qPCR. 
If you do not use Taqman probes, I strongly recommend to use it instead of SYBR green method. The accuracy and sensitivity of probes are much greater than SYBR.
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There is only a few reference about Bluetooth high speed (HS) 3.0. My question is why technology is not intreated by researchers?
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Hi Ali
The most likely reason that there is little interest in researching Bluetooth 3.0 (although there are more than 20,000 articles in Google Scholar from a search query of Bluetooth 3), is because the technology is old (released in 2009), limited range (5 - 30m), slow (1Mbps), still had an annoying range of bugs, including connectivity issues, and all the good bits like Enhanced Data Rate (EDR), which doubled effective data transfer rate and High Speed (HS), which can increase theoretical speed to 24 Mbps utilising a co-located 802.11 link, are optional. Wifi was far more powerful, with greater range, and simpler connectivity.
Bluetooth 4.0 became a much better proposition when it was released in 2010, which included Classic Bluetooth, Bluetooth High Speed and Bluetooth Low Energy protocols. By the time Bluetooth 4.2 was released in 2014, it specifically targeted IoT devices, which made it far more interesting, although it too, has been superceded by Bluetooth 5.0 which was released in 2016, offering quadruple the range, double the speed, and providing an eight-fold increase in data broadcasting capacity of low energy Bluetooth connections, in addition to adding functionality for connectionless services like location-relevant information and navigation.
For low data accumulation IoT applications, Bluetooth 5.0 will be very interesting, due to the low energy consumption, cheap costs and ease of data aggregation and onward transfer, so I would expect this is where researchers will be looking for the future.
Hope this helps.
Regards
Bob
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For example, task periods and computation times can be generated using Stafford's Randomfixedsum algorithm especially for tasks that have implicit deadlines. Can the same algorithm be used to generate arbitrary deadlines? Or, are there other accepted methods of doing so?
Thanks for your reply.
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I am trying to optimize my simulator by leveraging real-time compilation. My code is pretty long and complex, but I identified a specific __device__ function whose performances can be strongly improved by removing all global memory accesses.
Does CUDA allow the dynamic compilation and linking of a single __device__ function (not __global__), in order to "override" an existing function?
Additional information:
- The function is a normal __device__ function.
- It is not part of a class nor structure.
- The difference is not the data type, so I cannot rely on templates.
- I actually must change the calculations performed in the function (i.e., propensity calculations) according to the model that I am simulating.
Thank you very much indeed for your answers
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for override part:
I had conducted basic code  test and I found it does support override you can use the following to test it as well:
define in your cuh (header file )
__device__ int test_Max_override(int, int );
__device__ int test_Max_override(int, int,int );
in your implantation file 
__device__ int test_Max_override(int x, int y){
if(x>y)return x;
return y;
}
__device__ int test_Max_override(int x, int y, int z){
if(x>y && x>z) return x;
if(y>x && y>z) return y;
if(z>x && z>y) return z;
}
while it is defined as __device__ than it should be called from global or other __device__ function i.e. you can not call it from host function. 
I assume this override with number of arguments; it will also work with different arguments  data type by modifying one of above with different datatype . 
Related to global variables performance you may explore using __shared__ which will be within the scope of the grid-block.
I am not for "real-time compilation (e.g., using NVRTC) to dynamically create a "__device__" function"  point if I understand it correctly, I assume you can use system call system(" YOUR EXEC COMMAND")from your code to execute NVRTC with your cuda files as work around. 
I hope this answer your question. 
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Application in fault diagnosis and determine abnormality when used with multivariate statistical process monitoring for manufacturing in real-time or by doing post-processing of historical data. Detail review of typical application cases.
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Real-time Internet Traffic Classification
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Good morning.
I am performing some Real-Time screening in 96well plates using bacterial lisates as enzyme source.
Some wells shows an amplification curve that after a while goes down (see picture).
Which could be the reason? Could be a low yield of expression (and so amount of the enzyme) the reason or instead should be something reagarding the screening system?
Thank you!
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Thank you,
I am re-expressing the plate and re-preparing lysates! I was thinking about some contaminations in the plate that give right OD but not of my clones....
I am using SYBR Green I!
I hope it will work! :)
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Actually, I am planning to use the concept of priority inheritance in distributed real-time database systems but I am not sure about which one of these two options( Priority Ceiling Protocol and Priority Inheritance Approach) will be best and on what basis.
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BTW, the source for the advantages I listed are section 11.8-11.9 in 
Burns, A & Wellings, A 2009, Real-Time Systems and Their Programming Languages, 4th edition, Addison-Wesley.
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The ZigBee protocol has been created and ratified by member companies of the ZigBee Alliance. Over 300 leading semiconductor manufacturers, technology firms, OEMs and service companies comprise the ZigBee Alliance membership. The ZigBee protocol was designed to provide an easy-to-use wireless data solution characterized by secure, reliable wireless network architectures.
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Dear Ali,
You may also want to check this survey out. The scope may be a little broader, but still...
P. Suriyachai, U. Roedig and A. Scott, "A Survey of MAC Protocols for Mission-Critical Applications in Wireless Sensor Networks," in IEEE Communications Surveys & Tutorials, vol. 14, no. 2, pp. 240-264, Second Quarter 2012.
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Need a decent simulator for the following tasks:
1. to schedule real time tasks
2. access to processor power model
3. No VM is required
Your help is highly appreciated...
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Hello Manojit, I think that StarPU+Simgrid is exactly that you are looking for: http://starpu-simgrid.gforge.inria.fr/
There are a lot of support! And a very good documentation!
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We need dye calibration for our step-one real-time system. One of our friends have a calibration kit with single used. can we reuse it or not.
Thank you for your attention.
Mohsen 
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Thanks Mayadhar for your kind attention.
Mohsen
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The system contains multi-processor with different types (Cpu, Gpu, and may contain soft-core)
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Maybe not the "implementation", but the considerations of these "old" publications are still valid :)
Looking at your list some things seem to be clear:
1. video preprocessing is best scheduled on CUDA. The same could apply to feature extraction (from the video stream). This could be an application with or without explicit scheduling - depending on the computing power available.
2. image processing would also fit the CUDA, but could as well be executed on DSP or CPU (if the image rate is not too high).3. Operating systems with explicit scheduling are typically implemented on CPUs. This may also be the unit to implement the voter - presuming that the more specialized execution units make their results available eg. memory mapped.
Whether you need "partitioned" scheduling (which I'm interpreting as "unix/win style scheduling) depends on a lot of issues as "software/driver availability", communication requirements etc. Thinking of at least 2 CPUs one might run on unix, the other on a AUTOSAR like OS (non-partitioned), which is more suitable for hard real-time operations.
As you see, you not only have quite a number of execution units - you are also free to implement a multi-OS system to best serve your needs :)
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Hi
I'm looking for a simulator for real-time multiprocessor systems to build and test my own schedulers. The simulator should support resource sharing and provide a GUI.
Thanks
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Hello,
You could have a look at Cheddar: http://beru.univ-brest.fr/~singhoff/cheddar/
I am a member in the team working with and developing Cheddar at the moment.
It supports multiprocessor and resource sharing (by Priority Inheritance Protocol, Priority Ceiling Protocol).
There is a lab work about resource sharing in Cheddar, which is available in French at: http://beru.univ-brest.fr/~singhoff/cheddar/contribs/educational/ubo/ETR15/tp.html.
Best regards,
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As far as I know it is highly unreccomended to set a proccess priority on MS Windows as Real-TIme, however on which cases it would be reccomended ?
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I would not mix realtime with quick processing. By defiition real time enables you only getting a guaranteed answering time. A guaranteed answer every 10 second would be also a real time process. So real time enables you that something is definitely happening also if the computer is very busy. So real time is something very usefull for data acquisition processes or to handle break conditions in a certain time window.
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Can we use SysML to analyse and to design real-time systems?
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The answer to your question is definitely yes. However, since SysML is a general purpose notation, the problem for new users of SysML is usually understanding HOW to use it.
To this end, I can suggest a few papers.
If you are interested in using SysML for modeling requirements (according to Jackson's problem frames approach), look at [1][2].
If you are interested in a case study, in [3] you can find the description of a railroad crossing and its traffic light controller.
Design issues are discussed in [5] and [6].
A fairly complete treatment of the subject can be found in [4], the PhD thesis of Pietro Colombo, a student of mine who worked quite extensively on how to use SysML.
[1] Colombo, Pietro, et al. "A methodological framework for SysML: a Problem Frames-based approach." Software Engineering Conference, 2007. APSEC 2007. 14th Asia-Pacific. IEEE, 2007.
[2] Colombo, Pietro, Vieri del Bianco, and Luigi Lavazza. "Towards the integration of SysML and problem frames." Proceedings of the 3rd international workshop on Applications and advances of problem frames. ACM, 2008.
[3] Colombo, Pietro, Ferhat Khendek, and Luigi Lavazza. "Requirements analysis and modeling with Problem Frames and SysML: A case study." Modelling Foundations and Applications. Springer Berlin Heidelberg, 2010. 74-89.
[4] Pietro Colombo. "A SysML-based approach to requirements analysis and specification of real-time systems." PhD Thesis, University of Insubria (2009).
[5] Colombo, Pietro, Ferhat Khendek, and Luigi Lavazza. "Generating early design models from requirements analysis artifacts using problem frames and SysML." Modelling Foundations and Applications. Springer Berlin Heidelberg, 2011. 97-114.
[6] Colombo, Pietro, Ferhat Khendek, and Luigi Lavazza. "Bridging the gap between requirements and design: An approach based on Problem Frames and SysML." Journal of Systems and Software 85.3 (2012): 717-745.
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Recently there have been some releases of ARM version of windows (Windows RT).
Is the Win-RT mature enough to start developing real time application on it ?
Where does Windows Stands w.r.t linux and Adroid or any other RT operating system?
What are the Pros and Cons of Windows RT?
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refer the below link
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Dear all,
             I would like to deploy the Simulink PLC Coder generated Structured Text code in Siemens PLC. Right now, I have tried the 'plcdemo_simple_subsystem' example and deployed the generated Structured text code in Siemens S7-318-2-DP PLC. Now, I want to know that how can we assign real/process I/Os to the I/Os in the code? Besides, the code also consists of transfer function, so how is it possible to use the code with real time system? Your help will be very much appreciated. Thank you.
Regards,
Ankur Gajjar
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I am looking for an efficient way to interface a Telosb mote with a real time Simulink simulation using the USB port. Although Simulink includes several block for this purpose, all of them require to know before hand the number of bytes that are expected to be read or sent to the serial port.
Unfortunately, I am using a packet protocol of variable length, so I have programmed an simple function that takes care of the job. The drawback is that this function must be called each tick of the real-time simulation clock, as opposed to called when the operating system (Windows) receives new data through the serial port. 
What I am looking for is for a way to call my function every time Windows receives new serial data. 
I would appreciate any suggestions on this matter.
Arturo
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You are interested in an asynchronous mode operation of serial read in Simulink.  A basic description can be found here:
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my doubt is that AC tachogenerator is producing triangular voltage wave, i am giving that voltage signal to ADC port of the Dspace, for the closed loop operation need to convert that signal into speed form. i am having problem to find the frequency of the signal. if anyone having idea about this please help me.
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Dear Vikrant,
You should be able to setup dsapce ds-1104 with Control Desk Developer Version which allows you to view and control frequencies of the signal in Matlab/Simulink for a real time interface. The following doc may help you to understand how to do it. - Ning
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I have some tasks, which are further divided into runnables. Runnables execute as task instances. Runnables have dependencies within the tasks and also to other tasks's runnables. I have the information of deadlines and periods of tasks and the execution order of tasks and runnables i.e I can extract the data flow but the only point where I am stucking is that how can I get the information IF the task instances are executing within the period i.e obeying the deadlines and if not executing withtin the deadline then that task instance will execute in the next cycle or next period.
Any ideas ? Suggestions ?
p.s I dont have timing information for the execution of runnables.
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I am not certain I clearly understand your question. From what I get, you should perform Worst Case Execution Time (WCET) analysis on the code of your runnables, which gives you a conservative estimate of the worst possible execution time of your runnables. Then using this, you must define or choose a scheduling policy (unless you are working with an OS which imposes one). Such policies include Rate Monotonic, Deadline Monotonic, Earliest Deadline First etc. and usually come with analytic criterion which help you figure out if your system is schedulable in the worst case under these policies (i.e. if any possible execution of your system respects the timing constraints placed on your tasks). Usually, such criterion work only for task systems without dependencies between the task instances, but there also exist techniques that allow you to build schedules (or test the schedulability of the system) even in the presence of dependencies. If you want I can point you to some publications tackling this problem of real-time scheduling with dependencies.
I hope this will help you.
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Can someone suggest the real time primers sequence for detection of expression of SGT1, RAR1, MEK2 and MAPKKKa and pathogenesis related proteins?
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what is your model?
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While the traditional approach is to have a single numerical solver that employs a s uniform step sizing in all parts of models, the alternative, using particular solvers with particular step sizes in different segments of models with different dynamic behaviors is getting more attention. I would like to ask what methods and tools are frequently employed in research community, particularly for the cases that in which MATLAB/Simulink, modelica or Scilab/Xcos is used and realtime execution is a requirement.
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From a practical implementation standpoint, you might consider the free Gnu Scientific Library: https://www.gnu.org/software/gsl/manual/html_node/Numerical-Integration.html . Look for "adaptive integration". Also, at a higher level, see: https://www.gnu.org/software/gsl/manual/html_node/Ordinary-Differential-Equations.html
I plan to incorporate this into our emerging MaxSim project based on Max/Msp. So far, we have employed Runge Kutta variants (RK1,2,4), but GSL looks promising.
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I have a model in NuSMV and I want to verify that is it giving me the correct result for my input. Generally, we hard code the value in NuSMV.
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Try to run the NuSMV interactively, using for example simulation commands with -i option, then you can choose one of the possible next states (values of variables).
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Hello Everyone,
I am interested in finding out if anyone of your institutions has implemented Data Distribution Service (DDS) technology whether open source or proprietary for REAL-TIME systems?
Really would appreciate your response.
Thanks
Tim 
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At this point I can't distribute any more than what you will find on prismtech's website in their open source version. Our approach is designed to enable people who want to program in python (ie with lower barrier to entry) to be able to prototype systems, so not to need C++ to do that. 
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Usually when we write code for microcontrollers, the code is compiled into a .hex file which is then dumped into the hardware using some other software like Flash Magic.
How can we do this for VxWorks programs? How can I dump a downloadable kernel module onto hardware?
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Use Workbench from Windriver.
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In my experiment, I extracted HCV RNA and used conventional PCR and defined an obvious band, so I took the same sample for real time PCR and the results were negative, this happened twice with 2 different samples with same RNA conc.
What could be the reasons, knowing that I have to quantify my RNA in the sample and the only available tool is real time?
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Hi Mariam, it would help to add more details about your experiment so we can see where the problem lies:
(i) Do you have real-time (q)PCR positive controls and did they amplify right in your experiments? If so, this at least rules out problems with your real-time assay.
(ii) How did you carry out your RT step for the conventional PCR? Did you use gene specific primers / oligo-dT / random hexamers or a mixture?
(iii) Similarly how did you carry out your RT for the qPCR? If it's a 1-step procedure are you using the same RT enzyme (or similar) for conventional and qPCR? / If 2-step, are you using the cDNA generated from (ii) for your qPCR?
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What would be the advantages of employing a Cloud system as a platform to run a hard real-time system where timing predictability is important as the correctness of the system? In this case, what are the main challenges? As an example, guaranteeing timing requirements on the internet is one of the prominent challenges that is discussed in several papers but how about other challenges?
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I can't see a hard real-time application that could take any advantage in a cloud. The major obstacle is that if you really have a system, where real-time tasks have to interact, running it on a cloud would have severe restrictions over timing conditions. 
The latencies involved with data transfer among tasks would make unfeasible to run hard real-time tasks, which usually have a short deadline when compared with the time spent transferring data.
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The order of the numerator polynomial is less than that of the denominator. Why?
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From a mathematical point of view, a linear time-invariant model can be described by a transfer function with the numerator degree greater than the denominator degree, that is with more zeroes than poles. However such a model would not be physically realizable, that is you cannot built it by using "physical" components. The reason is that, such a model would be an anti-causal system, i. e. the output at time t would depend on the input values after time t.
There are some applications involving "artificial" systems, in which anti-causal systems play a role. This is the case, for example, of image analysis and elaboration, where when processing, let's say frame "i", you have stored in memory the frames before and after "i", so you can take into account past and future frames.
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I’ve been trying to implement LQR with state-observer in real-time. Since, I couldn’t manage to implement it using MATLAB real-time workshop, I had to write the C code for LQR and state observer. However, it seems like the C code isn’t working at all and I can’t get my head around it. My first question is, when I design my state-feedback matrix and observer matrix in MATLAB before using it in my C code, do I have to design them (K and L) in discrete-time. I appreciate if someone can give me some advice how to implement LQR+observer in real-time using either MATLAB or C, as I don’t really know why I keep getting issues with implementation.
Best regards
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Looks like you have been given some good advice already, just wanted to add a few suggestions.
There are typically two ways to implement a control law like this, directly as a discrete time filter, or as a continuous time filter which you solve using a numerical integration scheme, such as the Euler or Runge-Kutta method. The last method is what is standard in for example Simulink if you try to solve a continuous time filter there, and will typically be a more computationally demanding.
I would suggest using a discrete time implementation, but you have to make sure you are using gains that are suitable for discrete time, as already mentioned. Newer versions of MATLAB has the 'dlqr', 'lqrd', and 'kalmd' functions, that might be useful for this.
Also, you can run your C code as a so-called S-function inside Simulink. This can be very useful in debugging your code. Set up your model of the system as a regular LTI system block, and your LQR and observer implemented in C in an S-function block.
Hope this helps...
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Inmon, Kimball, Hefesto or another? I'm currently building a data warehouse to pave the way for data mining, the goal of this work is to improve the process of decision-making in education policy. This requires knowing what the best architecture is.
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Its depend on what do you need, no matter what the architecture, its go back to the purpose to build datawarehouse where we need to deliver database environment which can create best sql performance when access data from datawarehouse
you can create star schema or snowflake, top down or bottom up, its depend on how best performance your sql to access datawarehouse rather than from oltp.
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I can see RNA bands in an electrophoresis gel. It is noteworthy that the color of RNA is light brown. By the way, I am sure about the activity of the enzyme in cDNA synthesis and about the primers.
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How did u know that u are not producing cDNA ?
might be u used an olgo dt Primer that not transcripe ur gene
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Leak detection systems that use in smart home for detect moisture.
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I do not recommend use such sensors as long as the detect water/no water and the conductivity depends a lot of ions at the water, I should recommend to use a specific one as in the attached url
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The main advantage of not using a kernel is that you are not biasing the shape of your signal to be similar to an arbitrary, pre-selected shape. By using LPC you make only the assumption that the signal can be modelled from its past behaviour. In terms of computing, the Yule-Walker approach is quite efficient for LPC, and althought some authors question it, I found that it always gave me good results fof the signals I used (Doppler ultrasound derived blood flow velociy and heart rate variability). Best of luck.
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What are the principal architectural similarities and differences betweel real-time and multimedia operating systems? What distinctive requirements does each have? What operating systems are typically used with each?
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Hi Sam!
There is no short answer to your question and often the two terms are used together especially for multimedia OS.
One needs to understand the intention of the software here to answer your question here. There is no bullet item list possible. But to explain in short, I would like to say that "Real time OS may have multimedia support but multimedia centric OS need not specifically have real time features". Many may object this statement but consider from expectation or user experience perspective. Real time systems are designed for fastest possible response to an event or request. And that is the expectation. While multimedia os is designed to support multiple media. Now, unless one really thinks that multimedia means audio and video, multimedia need not be real time even if acceptable user experience is considered. Media can be looked in certain context. Support for different storage media like floppy, cd, dvd etc. can be considered as multimedia. From software perspective support for more than one media is multimedia e.g. text and different image formats such as .tiff, .jpg, .bmp etc.
Now, coming to generally considered meaning of multimedia - text, image, audio and video. Of this, for good user experience, audio and video need to be near real time (what Maria calls in her answer above as soft real time). Everything revolves here around user experience as far as multimedia capabilities are concerned.
Architecturally, multithreading, parallel processing, multiprogramming, dedicated memory for frame buffers, graphics co-processors at hardware level are desirable traits in multimedia OS. But for real time (consider for medical needs such as some critical health param monitoring equipment in ICU) clear data path on hardware for fastest processing is desired. There features like multithreading at software may or may not be needed but parallel processing, VLIW (very large instruction word), hardware multithreading etc. are desirable features at hardware level and support from real time OS to fully explore the hardware capabilities.
There is much more to talk about it but I guess, this will help you separate out two concepts with the thin boundary line especially from multimedia OS perspective. True real time systems are separate class altogether.
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Could somebody please provide me with some practical examples of real-time systems and also some resources that study the control of real-time systems? Thank you.
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Actually, real-time systems are usually close-loop controlled systems as exampled by the above answers. If you are a beginner in this topic, it is better for you to know some initial knowledge about control theory by attending some courses or reading some relative books. I think you will have a good view of this topic after that.
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Please help me find a real-time operating system (preferably open source) to start off with. Searching through Google provides a lot of options and I am very confused by the different platforms.
My requirement is only that it has to run code in a real-time operating system that spawns 4 threads. All these threads have a different set of code and are completely independent. They don't cause any IO requests. For example, thread 1 generates a number series, thread 2 multiplies a large matrix, and so on. If we consider that each of these threads takes 4, 5, 7, and 9 seconds to complete if executed serially, can the same results be achieved and guaranteed if all the threads are running simultaneously?
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The predictability of a real-time system is not related to multi-threaded applications; most of the real-time applications ARE multi-threaded in the sens that the application contains a number of threads or tasks that should be executed in a concurrent manner. In order to guarantee the execution time real-time systems use a scheduler; the scheduler may be part of the operating system or it may be part of the application. In case the application is executed on a single processor (more precisely one CPU, or core) there are a number of classical scheduling algorithms such as Rate Monotonic (RM) or Earliest Deadline First (EDF) that can find a feasible schedule that can guarantee the fulfillment of deadlines. In case of multiprocessor systems the scheduling problem is a little bit more complicated but there are solutions for particular task or thread setup.
In your case with 4 threads, if you want to achieve the same execution time as in a sequential case probably you have to use a multicore platform (e.g. quad-core).
Another parameter which significantly influence the schedulability of a set of tasks (and consequently if the WCE T- worst case execution time - of each thread is guaranteed) is the periodicity of threads or tasks - how often the threads are activated.
Most of the scheduling algorithms that offer guarantees regarding execution time are taking into consideration the periods of the threads.
So, as conclusion it is not a question of operating system, is more about a good scheduling strategy.
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How can we show that a code runs real-time?
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It depends what you mean with "show". The way Christos suggests gives you a test for a specific run. Even if you run it several times it is possible that you never catch the worst case execution time. If you aiming for some "not so hard" real-time, that may be fair enough. However, real tilme usually refers to a guarantee that the worst case is *always* not worse than a given bound. Thus, to go for this objective you should provide a proof (or at least demonstrate plausibility) that your code's run time is always bound. I.e., you should check that:
- all loops performs at most a certain givenn number of iterations;
- all recursions have a given maximal deph;
- in general your longest code path has a given maximal length;
- all blockings (locks, I/O) have a given maximal duration;
- all code blocks have a maximal runtime even in case of cache misses, wrong jump
predictions, etc.;
- in case of multiprocessing/multithreading the scheduling should guarantee
at least the calculated WCET before the deadline.
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I would like to know in the windriver platform what project type (Downloadable Kernel Module, BSP image etc) should be selected for VxWorks Device driver development. And how?
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Thank you.
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Ballistic impact events occur in microsecond time frame. Flash x-rays are usually not 3D and have a substantial reset time between images. Ideally, it would be most beneficial to have microsecond temporal resolution as well as 3D micron spatial resolution for a continuous interrogation of a millisecond or more. Tough requirement but something to dream for.
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The Laboratory for Ballistic Research of TNO (The Netherlands) has X-ray cinematography equipment and experience with high speed x-ray filming ballistic events. At this moment TNO is installing state-of-the-art X-ray source and imaging equipment and we are happy to work with third parties that want to use this rather unique piece of equipment. This would allow one to get up to 100 images with up to 500.000 fps time resolution. The X-ray source is very powerful and we aim for penetration of up to 100 mm (4 inches) of alumina ceramic tiles.
Earlier work with an older source provided images of projectile deformation in fabrics, as well as penetration in polymers and magnesium plates.
This is 2D-information only, however most of the normal impact processes can be considered axisymmetric and 2D-information is sufficient here.
For time resolved visualization of dynamic fracturing of ceramics during projectile impact we have another set-up that works up to 1.000.000 frams per second and shows timing and duration of several crack types in ceramic targets.
Once again, we welcome third parties to make use of our capabilities
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We are in the process of setting up a lab experiment in which an inverted pendulum mounted on a cart is to be swung up by a feedback controller. Measurements should be taken every 7ms, and the control signal is to be transmitted every 70ms.
We chose to implement the controller (in C) on Phidgets' single board computer, which runs Debian Linux (SBC3, see http://www.phidgets.com). The measurements are received by interface cards (also bought from Phidgets) which are connected to the SBC via USB.
Problems:
A) We are currently unable to schedule measurements so that they are taken every 7ms. In fact, using the sleep command of C our sampling times vary wildly between 3ms and 15 ms. That's a problem, since our observer (for the angular velocity of the rod and the cart's velocity) is designed for a fixed sampling rate. We have verified that the computational resources required by the controller and the observer are not responsible for these variations.
B) We are also unable to transmit the control signal on time, as it happens that the controller is unexpectedly inactive for at least 200ms. Increasing the priority of the process that runs the controller relaxes the problem somewhat, but the "dead times" are still too long and too frequent to successfully run the experiment.
Questions:
1) What are the chances that we can solve the problems described above by installing a suitable real time linux system on our SBC? Is there a specific OS you can recommend?
2) Is it a problem that the measurements are transmitted via USB to the SBC? If so, is it possible to tune the USB interface so as to better comply with real time requirements?
3) If the setup we are currently using (SBC plus interfaces via USB) turns out to be inappropriate for the above experimental setting, what alternatives could you recommend?
Thanks.
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Gunther,
There is at least this usable RT implementation of the USB stack:
- Linux/RTAI
It must be possible to get it working on a Phidget SBC 3; check READMEs for detail on support/patches of the hardware you are using.
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In Distributed Real Time Systems Fault detection and recovery techniques, are they reliable or not?
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SInce the question sounds a bit "strange" to me, I try to reword it:
"Do (usual) fault detection and recovery techniques invalidate the timeliness requirements of real-time systems?"
If this meets your question's intention, there is still no general question. All FT techniques introduce a redunadency, either a space redundency (e.g., additional resources), or a time redunadency (e.g., more complex algorithms), mostly both.
Whether the time redundency does hurt the time behavior depends on the actual timing constraints and the system's goal: E.g., a wrong result before a deadline may equally useless as a belatet correct result.
Sorry, if I've missed the point of your question. Maybe then you should expatiate your problem.
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Before starting a HIL simulation, what kind of simulation "MUST" be done? Is doing MIL, SIL and PIL necessary before HIL or just optional?
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HIL is normally costly and the number of tests that can be done is few compared to a software alone test. An extensive SIL or PIL will help remove bugs. Normally SIL and PIL are digital tests and the thresholds can be very low for an automated pass/fail. HIL test have a higher threshold and therefore may not catch all errors in software. I have seen cases passing at HIL failing miserabely in a SIL with a major catastropic error.
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I am searching for a simulation environment for power consumption at the sensor node level, or a simulation environment which is configurable and suitable for different sensor node modules (processors, sensors, communication device etc.).
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Sorry to put in this way, but I consider what you're asking for an almost impossible task.
The main reason is: the real power consumption is driven by an incredibly large number of elements, ranging from the radio to the OS polling the sensors, with the actual number crunchng performed by the CPU.
Studying all these elements together is an almost impossible task. The only "real" way to do that would be to have a real node and measure its power consumption. Some papers did exactly that (and it's not that hard, provided you have the right tools).
If you can't afford a real testbed, I'd try at least to split the problem in sub-parts. As an example, you can calculate the energy requirements of most sensors from their datasheets.
The processor power consumption is heavily dependent on the OS, so again it's a matter of how you write your programs (there TOSSIM might help, but it's limited to TinyOS, I don't know if Cooja can give you some numbers, and again it's limited to Contiki).
For the radio part, a big part is dependent on the MAC layer. Contrary to popular beliefs there are a number of different MACs compliant with 802.15.4 specifications, again with completely different energy consumptions.
So, the bottom line is: there are some tools available, but none is flexible enough to allow complete freedom. Unless you go for a real device (but in this case you'll have the numbers for THAT device, a different one might have a different CPU... and you'll have the same problem as before.
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Has anybody used a cycle-accurate simulator for multicore architectures suitable for real-time systems other than gem5? Basic requirements are the ability to output timestamps for executed instructions as well as statistics on cache hits, misses, and other hardware-accelerator events of interest to timing analysis.
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Did you check the "Extensions" page of Simplescalar. Long back I did use a multiprocessor simulator from RICE university.