作者：
Russkova, TatianaRAS
SB VE Zuev Inst Atmospher Opt 1 Academician Zuev Sq Tomsk 634055 Russia
The parallel Monte Carlo algorithms developed for numerical simulation of the polarized radiative transfer in the Earth's atmosphere are discussed. The results of their testing in the aerosol atmosphere and cloud ...
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ISBN:
(数字)9781510622920
ISBN:
(纸本)9781510622920
The parallel Monte Carlo algorithms developed for numerical simulation of the polarized radiative transfer in the Earth's atmosphere are discussed. The results of their testing in the aerosol atmosphere and cloud layer as well as the results of calculation of the Stokes vector in an environment with spatially inhomogeneous clouds are presented. Problems of improving the efficiency of the Monte Carlo simulation by transition from sequential CPU computations to parallel GPU computations are discussed. The acceleration rate of the radiation codes achieved by parallelizing computational algorithms on a graphics processor is given. It is shown that the changeover of computing from conventional PCs to the architecture of graphics processors gives remarkable increase in performance and fully reveals the capabilities of the technology used.
This paper presents EASYPAP, an easy-to-use programming environment designed to help students to learn parallel programming. EASYPAP features a wide range of 2D computation kernels that the students are invited to par...
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ISBN:
(纸本)9781728174457
This paper presents EASYPAP, an easy-to-use programming environment designed to help students to learn parallel programming. EASYPAP features a wide range of 2D computation kernels that the students are invited to parallelize using Pthreads, OpenMP, OpenCL or MPI. Execution of kernels can be interactively visualized, and powerful monitoring tools allow students to observe both the scheduling of computations and the assignment of 2D tiles to threads/processes. By focusing on algorithms and data distribution, students can experiment with diverse code variants and tune multiple parameters, resulting in richer problem exploration and faster progress towards efficient solutions. We present selected lab assignments which illustrate how EASYPAP improves the way students explore parallel programming.
With the proliferation of multicore processors, there is an urgent need for tools and methodologies supporting parallelization of existing applications. In this paper, we present a novel tool for aiding programmers in...
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ISBN:
(纸本)9780769531090
With the proliferation of multicore processors, there is an urgent need for tools and methodologies supporting parallelization of existing applications. In this paper, we present a novel tool for aiding programmers in parallelizing programs. The tool, Embla, is based on the Valgrind framework, and allows the user to discover the data dependences in a sequential program, thereby exposing opportunities for parallelization. Embla performs an off-line dynamic analysis, and records dependences as they arise during program execution. It reports an optimistic view of parallelizable sequences, and ignores dependences that do not arise during execution. Moreover since the tool instruments the machine code of the program, it is largely language independent. Since Embla finds the dependencies that occur for particular executions, the confidence one would assign to its results depend on whether different executions yield different (bad) or largely the same (good) dependencies. We present a preliminary investigation into this issue using 84 different inputs to the SPEC CPU2006 benchmark ***. The results indicate that there is a strong correlation between coverage and finding dependencies;executing the entire program is likely to reveal all dependencies.
The biggest difficulty that students face when learning programming is in developing the necessary cognitive skills that allows them to apply what they have learnt. It is generally accepted that programming is one of ...
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ISBN:
(纸本)9781467376846
The biggest difficulty that students face when learning programming is in developing the necessary cognitive skills that allows them to apply what they have learnt. It is generally accepted that programming is one of those things that can only be learnt by doing and actively engaging with it. parallel programming is a prime example of a programming area that students commonly struggle with. A major inhibitor is due to some of its abstract concepts, making it difficult to grasp a true understanding of the underlying principles in a traditional classroom setting. This paper discusses the underlying principles that motivated the development of Active Classroom Programmer (ACP), a tool for students to learn effective programming strategies with the guidance of their instructor. ACP aims to increase students skills in applying programming topics, by immediately engaging them with the newly introduced material. This is especially important in parallel programming, as the topics quickly progress onto the many parallelisation caveats (such as thread-safety, race conditions, and so on). While laboratory or homework exercises provide students with valuable hands-on experience (to apply newly taught concepts), this opportunity generally arrives too late after the material is presented in the lesson. To address this, a collection of parallel programming exercises are being developed for the NSF/IEEE-TCPP Curriculum Initiative on parallel and Distributed Computing (as an Early Adopter award), with the help of ACP. Instructors are welcome to utilise any of the developed exercises, or even request a private ACP account for their own courses to program with their students.
View-Oriented parallel programming(VOPP) is a novel programming style based on Distributed Shared Memory, which is friendly and easy for programmers to use. In this paper we compare VOPP with two other systems for par...
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ISBN:
(纸本)9783540754435
View-Oriented parallel programming(VOPP) is a novel programming style based on Distributed Shared Memory, which is friendly and easy for programmers to use. In this paper we compare VOPP with two other systems for parallel programming on clusters: LAM/MPI, a message passing system, and TreadMarks, a software distributed shared memory system. We present results for ten applications implemented and optimized using all the three systems. Experimental results demonstrate that VOPP is almost as efficient as Message Passing Interface when running on up to 32 processors, which means there is significant performance improvement compared with TreadMarks. The factors contributing to the performance of VOPP are discussed and analyzed. VOPP is still slower than MPI when the number of processes is large because of extra messages for separate synchronization and lack of bulk transfer mechanisms.
The Architectural Patterns for parallel programming is a collection of patterns related with a method for developing the coordination structure of parallel software systems. These architectural patterns take as input ...
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ISBN:
(纸本)9781450363877
The Architectural Patterns for parallel programming is a collection of patterns related with a method for developing the coordination structure of parallel software systems. These architectural patterns take as input information (a) the available parallel hardware platform, (b) the parallel programming language of this platform, and (c) the analysis of the problem to solve, in terms of an algorithm and data. In this paper, it is presented the application of the architectural patterns along within the Coordination stage, as part of the Pattern -based parallel Software Design Method, which aims for developing a coordination structure for solving the Laplace Equation. The Coordination stage here takes the information from the Problem Analysis presented in Section 2, selects an architectural pattern for the coordination in Section 3, and provides some elements about its implementationin Section 4.
Correctly synchronizing multithreaded programs is challenging, and errors can lead to program failures (e.g., atomicity violations). Existing memory consistency models rule out some possible failures, but are limited ...
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Correctly synchronizing multithreaded programs is challenging, and errors can lead to program failures (e.g., atomicity violations). Existing memory consistency models rule out some possible failures, but are limited by depending on subtle programmer-defined locking code and by providing unintuitive semantics for incorrectly synchronized code. Stronger memory consistency models assist programmers by providing them with easier-to-understand semantics with regard to memory access interleavings in parallel code. This dissertation proposes a new strong memory consistency model based on ordering-free regions (OFRs), which are spans of dynamic instructions between consecutive ordering constructs (e.g. barriers). Atomicity over ordering-free regions provides stronger atomicity than existing strong memory consistency models with competitive performance. Ordering-free regions also simplify programmer reasoning by limiting the potential for atomicity violations to fewer points in the program’s execution. This dissertation explores both software-only and hardware-supported systems that provide OFR serializability.
The married women who educate simultaneously, are faced to many challenges for managing their time. Since they have multiple and even conflicting roles, their academic achievement or their family life may be at *** pa...
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The married women who educate simultaneously, are faced to many challenges for managing their time. Since they have multiple and even conflicting roles, their academic achievement or their family life may be at *** parallel planning:a total time management model made by authors,can improve their academic achievement or not?A model which tries firstly to improve some skills about and secondly put together all important tasks .The main goal of this study was determining the effectiveness of instructing and employing this model in academic achievement in the case of married women. For doing so,a single case has been selected, multiple baseline(across subjects) design. The sample included 5, married female subjects who were selected in a purposive sampling way among Payame Noor University 2013 students. The cases average age was 24.2 years. Each subject had atleast 11 instructional, practical and monitoring sessions during 18 weeks. Study had two phases of baseline and treatment(instruction).Subjects entered in instruction respectively in 4 th ,5 th ,6 th ,7 th &8 th session. In each session, each subject responded to totally 18 shortanswer exams(with 20 questions) based on her thermic lesson design, along baseline and instruction phase. The scores reported in a 100point scale and finally graphs and visual analysis prepared on the basis of data. Comparison of the scores of baseline and instruction phase,demonstrated a clear improvement in each subjects’ scores. Based on findings parallel programming instruction was effective on academic achievement.
Currently, the need to learn parallel applications topics in students has become an important issue due to the rapid growth in the parallel computing field. In fact, this topic has been included in Computer Science cu...
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Currently, the need to learn parallel applications topics in students has become an important issue due to the rapid growth in the parallel computing field. In fact, this topic has been included in Computer Science curriculum, but students present difficulties to design MPI parallel applications efficiently. We present a novel methodology for teaching parallel programming centered on improving parallel applications written by students through their experiences obtained during classes. The methodology integrates theoretical and practical sections which are focused on teaching two parallel paradigms, master/Worker and SPMD. These paradigms were selected due to their different communication and computation behaviors, which generate challenges for students when they wish to improve performance application metrics. Our methodology allows students to discover their own errors and how to correct them. In addition, students analyze the issues and advantages in the application designed in order to enhance the performance metrics. Applying this methodology gave us a significant progress in parallel applications designed by students, where we have observed an improvement of around 47% in the students' skill about parallel programming when they design parallel applications. (C) 2010 Published by Elsevier Ltd.
In this paper, TOPAS(1) -a new parallel programming environnient for distributed systems - is presented. TOPAS automatically analyzes data dependence among tasks and synchronizes data, which reduces the time needed fo...
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ISBN:
(纸本)0769517307;0769517315
In this paper, TOPAS(1) -a new parallel programming environnient for distributed systems - is presented. TOPAS automatically analyzes data dependence among tasks and synchronizes data, which reduces the time needed for parallel program developments. TOPAS also provides supports for scheduling, dynamic load balancing and fault tolerance. Experiments show simplicity and efficiency of parallel programming in TOPAS environment with Jault-tolerant integration, which provides graceful performance degradation and quick reconfiguration time for application recovery.
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