325 research outputs found

    Infrared Sensors for Autonomous Vehicles

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    The spurt in interest and development of Autonomous vehicles is a continuing boost to the growth of electronic devices in the automotive industry. The sensing, processing, activation, feedback and control functions done by the human brain have to be replaced with electronics. The task is proving to be exhilarating and daunting at the same time. The environment sensors – RADAR (RAdio Detection And Ranging), Camera and LIDAR (Light Detection And Ranging) are enjoying a lot attention with the need for increasingly greater range and resolution being demanded by the “eyes” and faster computation by the “brain”. Even though all three and more sensors (Ultrasonic / Stereo Camera / GPS / etc.) will be used together; this chapter will focus on challenges facing Camera and LIDAR. Anywhere from 2 – 8 cameras and 1 – 2 LIDAR are expected to be part of the sensor suite needed by Autonomous vehicles – which have to function equally well in day and night. Near infrared (800 – 1000nm) devices are currently emitters of choice in these sensors. Higher range, resolution and Field of view pose many challenges to overcome with new electronic device innovations before we realize the safety and other benefits of autonomous vehicles

    FPGA based Design and Simulation of Extended Golay Codec with Hardware Optimization for high speed Applications

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    In wireless communication systems the ability of the receiver to detect and correct the error from the received information is become one of the most important issue, so as to provide the processor the correct information data. To achieve this there are numbers of such methods are available to implement the hardware and software. But, length of the communication link plays an important role because the distance of the transmitter and the receiver depends on the length as length increases the distance between the transmitter and the receiver, and multiple bits of the transmitted information may change due to the effect of noise on the transmitted signal. This can cause extreme loss in many cases. This paper presents a brief of Field Programmable Gate Array (FPGA) based design and simulation of Golay Code (G23) and Extended Golay Code (G24) Encoding scheme. This paper using the Golay Encoder to work on the optimization of the time delay of the operational circuit to encode a data packet

    Runtime Support for In-Core and Out-of-Core Data-Parallel Programs

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    Distributed memory parallel computers or distributed computer systems are widely recognized as the only cost-effective means of achieving teraflops performance in the near future. However, the fact remains that they are difficult to program and advances in software for these machines have not kept pace with advances in hardware. This thesis addresses several issues in providing runtime support for in-core as well as out-of-core programs on distributed memory parallel computers. This runtime support can be directly used in application programs for greater efficiency, portability and ease of programming. It can also be used together with a compiler to translate programs written in a high-level data-parallel language like High Performance Fortran (HPF) to node programs for distributed memory machines. In distributed memory programs, it is often necessary to change the distribution of arrays during program execution. This thesis presents efficient and portable algorithms for runtime array redistribution. The algorithms have been implemented on the Intel Touchstone Delta and are found to scale well with the number of processors and array size. This thesis also presents algorithms for all to all collective communication on fat tree and two dimensional mesh interconnection topologies. The performance of these algorithms on the CM 5 and Touchstone Delta is studied extensively. A model for estimating the time taken by these algorithms on the basis of system parameters is developed and validated by comparing with experimental results. A number of applications deal with very large data sets which cannot fit in main memory, and hence have to be stored in files on disks, resulting in out of core programs. This thesis also describes the design and implementation of efficient runtime support for out of core computations. Several optimizations for accessing out of core data are presented. An extended Two Phase Method is proposed for accessing sections of out of core arrays efficiently. This method uses collective I/O and the I/O workload is divided among processors dynamically, depending on the access requests. Performance results obtained using this runtime support for out of core programs on the Touchstone Delta are presented

    The clinical and etiological profile of atrial fibrillation after echocardiography in a tertiary care centre from North India - a cross sectional observational study

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    Background: Atrial fibrillation (AF) is the most common sustained arrhythmia in clinical practice. In western countries, rheumatic heart disease (RHD) is a rare cause of atrial fibrillation but in developing countries like India it is one of the commonest cause of atrial fibrillation. We studied etiology, left atrial size and the incidence of left atrial appendage clot in patients with atrial fibrillation at our institution so that guidelines could be formulated to manage the patients of AF in the hours of emergency.Methods: 110 consecutive patients of atrial fibrillation coming to emergency, cardiology and medicine outpatient department over a period of one year were enrolled for the study. Ethical committee clearance was taken. Detailed history were taken, clinical presentation reviewed  and examination were carried out. All patients were subjected to transthoracic echocardiography and for transesophageal echocardiography if required.Results: The mean age of patients in the study was 58.42±14.27 years (range 22-90 years). Maximum numbers of patients were in the age group of 61-70 years (26.37%). Out of 110 patients with atrial fibrillation, 72 patients (65.46%) were females and 38 patients (34.54%) were males. Majority of patients presented with more than one symptom. Out of 110, 66 patients (60%) had RHD. Among RHD patients, 50 patients (45.55%) were females and 16 patients (14.55%) were males. Next common causes were hypertensive heart disease and degenerative valvular heart disease.Conclusions: In our study RHD was the most common cause of atrial fibrillation, followed by hypertensive heart disease and degenerative valvular heart disease. Mitral valve involvement was seen in all patients of RHD. Left atrial enlargement was seen in majority of patients, so left atrial enlargement could be a predictor of atrial fibrillation. Patients of left atrial enlargement are more prone to develop left atrial appendage clot

    Runtime Array Redistribution in HPF Programs

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    This paper describes efficient algorithms for runtime array redistribution in HPF programs. We consider block(m) to cyclic, cyclic to block(m) and the general cyclic(x) to cyclic(y) type redistributions. We initially describe algorithms for one-dimensional arrays and then extend the methodology to multidimensional arrays. The algorithms are practical enough to be easily implemented in the runtime library of an HPF compiler and can also be directly used in application programs requiring redistribution. Performance results on the Intel Paragon are discussed

    Parallel netCDF: A Scientific High-Performance I/O Interface

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    Dataset storage, exchange, and access play a critical role in scientific applications. For such purposes netCDF serves as a portable and efficient file format and programming interface, which is popular in numerous scientific application domains. However, the original interface does not provide an efficient mechanism for parallel data storage and access. In this work, we present a new parallel interface for writing and reading netCDF datasets. This interface is derived with minimum changes from the serial netCDF interface but defines semantics for parallel access and is tailored for high performance. The underlying parallel I/O is achieved through MPI-IO, allowing for dramatic performance gains through the use of collective I/O optimizations. We compare the implementation strategies with HDF5 and analyze both. Our tests indicate programming convenience and significant I/O performance improvement with this parallel netCDF interface.Comment: 10 pages,7 figure

    Quantifying the Performance Benefits of Partitioned Communication in MPI

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    Partitioned communication was introduced in MPI 4.0 as a user-friendly interface to support pipelined communication patterns, particularly common in the context of MPI+threads. It provides the user with the ability to divide a global buffer into smaller independent chunks, called partitions, which can then be communicated independently. In this work we first model the performance gain that can be expected when using partitioned communication. Next, we describe the improvements we made to \mpich{} to enable those gains and provide a high-quality implementation of MPI partitioned communication. We then evaluate partitioned communication in various common use cases and assess the performance in comparison with other MPI point-to-point and one-sided approaches. Specifically, we first investigate two scenarios commonly encountered for small partition sizes in a multithreaded environment: thread contention and overhead of using many partitions. We propose two solutions to alleviate the measured penalty and demonstrate their use. We then focus on large messages and the gain obtained when exploiting the delay resulting from computations or load imbalance. We conclude with our perspectives on the benefits of partitioned communication and the various results obtained

    Testosterone levels in men with type 2 diabetes mellitus

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    Background: To study testosterone levels in men with type 2 diabetes mellitus in age group of 30-50 years.Methods: In this cross sectional study of 193 type 2 diabetes men aged between 30-50 years, total and free testosterone levels were calculated along with other relevant clinical variables like hypertension, BMI, dyslipidemia, peripheral neuropathy, retinopathy.Results: The study group had study out of 193 patients 34.7% have low total testosterone levels, 29.53% have low free testosterone levels and 23.3% have both low and free testosterone levels. Maximum number of patients with low total testosterone levels were in the age group between 46-50 years (41.0%) and with low free total testosterone levels were in the age group between 36-40 years (41.8%).Conclusions: Type 2 diabetes mellitus is associated with low levels of total and free testosterone. Obesity and dyslipidemia are also associated with low testosterone levels

    Efficient Algorithms for Array Redistribution

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    Dynamic redistribution of arrays is required very often in programs on distributed memory parallel computers. This paper presents efficient algorithms for redistribution between different cyclic(k) distributions, as defined in High Performance Fortran. We first propose special optimized algorithms for a cyclic(x) to cyclic(y) redistribution when x is a multiple of y, or y is a multiple of x. We then propose two algorithms, called the GCD method and the LCM method, for the general cyclic(x) to cyclic(y) redistribution when there is no particular relation between x and y. We have implemented these algorithms on the Intel Touchstone Delta, and find that they perform well for different array sizes and number of processors
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