• Journal of Mechanical Science and Technology
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• v.18 no.12
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• pp.2236-2249
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• 2004

The analysis for the three-dimensional fluid flow past tube banks arranged in equilateral-triangular form at Re$\_$max/=4,000 is carried out using a large eddy simulation technique. The governing equations for the mass and momentum conservation are discretized using the finite volume method. Parallel computational techniques using MPI (Message Passing Interface) are implemented in the present computer code. The computation time decreases linearly proportional to the number of used CPUs in the present parallel computation. We obtained the time-averaged streamwise and cross-streamwise velocities and turbulent intensities. The present numerical results are compared with the PIV experimental data and agree generally well with the experimental data.

• Journal of the Semiconductor & Display Technology
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• v.18 no.3
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• pp.42-46
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• 2019

In this paper, we introduce the novel idea to improve parallel test efficiency of semiconductor test. The idea includes the test interface card consisting of NoC structure able to transmitting test data regardless of ATE speed. We called the scheme "Multi-Clock" mode. In the proposed mode, because NoC can spread over the test data in various rates, many semiconductors are tested in the same time. We confirm the proposed idea will be promising through a FPGA board test and it is important to find a saturation point of the Multi-Clock mode due to the number of test chips and ATE channels.

• Journal of the Semiconductor & Display Technology
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• v.12 no.3
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• pp.13-18
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• 2013

Motion estimation is a key technique of modern video processing that significantly improves the coding efficiency significantly by exploiting the temporal redundancy between successive frames. Thread-level parallelism is a promising method to accelerate the motion estimation process for multithreading general-purpose processors. In this paper, we propose a parallel motion estimation algorithm which parallelizes the motion search process of the current H.264/AVC encoder. The proposed algorithm is implemented using the OpenMP application programming interface (API) and can be easily integrated into the current encoder. The experimental results show that the proposed parallel algorithm can reduce the processing time of the motion estimation up to 65.08% without any penalty in the rate-distortion (RD) performance.

• International journal of advanced smart convergence
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• v.8 no.4
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• pp.194-199
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• 2019

As the performance of the system increases, more parallelized data is being processed than single processing of data. Today's cpu structure has been developed to leverage multicore, and hence data processing methods are being developed to enable parallel processing. In recent years desktop cpu has increased multicore, data is growing exponentially, and there is also a growing need for data processing as artificial intelligence develops. This neural network of artificial intelligence consists of a matrix, making it advantageous for parallel processing. This paper aims to speed up the processing of the system by using raspberrypi to implement the cluster building and parallel processing system against the backdrop of the foregoing discussion. Raspberrypi is a credit card-sized single computer made by the raspberrypi Foundation in England, developed for education in schools and developing countries. It is cheap and easy to get the information you need because many people use it. Distributed processing systems should be supported by programs that connected multiple computers in parallel and operate on a built-in system. RaspberryPi is connected to switchhub, each connected raspberrypi communicates using the internal network, and internally implements parallel processing using the Message Passing Interface (MPI). Parallel processing programs can be programmed in python and can also use C or Fortran. The system was tested for parallel processing as a result of multiplying the two-dimensional arrangement of 10000 size by 0.1. Tests have shown a reduction in computational time and that parallelism can be reduced to the maximum number of cores in the system. The systems in this paper are manufactured on a Linux-based single computer and are thought to require testing on systems in different environments.

• Geomechanics and Engineering
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• v.21 no.6
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• pp.571-582
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• 2020

Aiming at the mechanical and structural characteristics of the contact zone composite rock, the uniaxial compression tests and numerical studies were carried out. The interaction forms and formation mechanisms at the contact interfaces of different materials were analyzed to reveal the effect of interaction on the mechanical behavior of composite samples. The research demonstrated that there are three types of interactions between the two materials at the contact interface: constraint parallel to the interface, squeezing perpendicular to the interface, and shear stress on the interface. The interaction is mainly affected by the differences in Poisson's ratio and elastic modulus of the two materials, stronger interface adhesion, and larger interface inclination. The interaction weakens the strength and stiffness of the composite sample, and the magnitude of weakening is positively correlated with the degree of difference in the mechanical properties of the materials. The tensile-shear stress derived from the interaction results in the axial tensile fracture perpendicular to the interface and the interfacial shear facture. Tensile cracks in stronger material will propagation into the weaker material through the bonded interface. The larger inclination angle of the interface enhances the effect of composite tensile/shear failure on the overall sample.

• 한국전산유체공학회:학술대회논문집
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• 2006.05a
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• pp.408-411
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• 2006

• Journal of the Korea Computer Graphics Society
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• v.18 no.3
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• pp.1-7
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• 2012

In this paper, we propose a method to compute the interface between protein molecules. When a molecules is represented as a set of spheres with van der Waals radii, the distance from a spatial point p to the molecule corresponds to the distance from p to the closet sphere. The molecular interface is composed of equi-distant points from two molecules. Our algorithm decomposes the space into a set of voxels, and then constructs a voxel map by storing the information of spheres intersecting each voxel. By using the voxel map, we compute the distance between a point and the molecule. We also use GPU for the parallel processing, and efficiently approximate the interface of a pair of molecules.

• The Transactions of the Korea Information Processing Society
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• v.6 no.2
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• pp.485-496
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• 1999

Comparing with sequential programming, parallel programming has additional complexity due to the consideration of parallelism, communication and synchronization of processes. A synergism between users and compliers should be established, each assisting the other to produce high quality parallel programs. On the above underlying philosophy, we developed a parallel Object-Oriented specification language, POOSL, as preliminary works. However, it is still likely to hard for users to write parallel program because users have to consider grammar of POOSL and to write text-based parallel program. It would be more desirable to provide users wit visual environment for effective parallel programming. Therefore, we propose a visual programming environment. VEPO(Visual environment for Parallel Object-Oriented Programming), based on POOSL in order that users can develop parallel programs more easily and conveniently. It aims at supporting a programming environment in which users can represent their programs more naturally and visually I parallel manner with object-oriented concept and essential steps during parallel program development such as program specification, compilation, execution and animation of execution are integrated. VEPO has useful features for parallel processing. Especially, complicated parallel codes for synchronization and communication of processes are automatically generated in the translation phase, so users can be relieved of writing error-prone parallel codes. The system is targeted to the transputer-based parallel system, MC-3. The graphic user interface of VEPO was implemented using Visual C++. Visual programs descirbed on VEPO are translated into Inmos C and executed on MC-3.

• ETRI Journal
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• v.27 no.1
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• pp.81-88
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• 2005

In this paper, interface circuits that are suitable for point-to-point interconnection with an over 1 Gbps data rate per pin are proposed. To achieve a successful data transfer rate of multi-gigabits per-second between two chips with a point-to-point interconnection, the input receiver uses an on-chip parallel terminator of the pass gate style, while the output driver uses the pullup and pulldown transistors of the diode-connected style. In addition, the novel dynamic voltage level converter (DVLC) has solved such problems as the access time increase and valid data window reduction. These schemes were adopted on a 64 Mb DDR SRAM with a 1.5 Gbps data rate per pin and fabricated using a 0.10 ${\mu}m$ dual gate oxide CMOS technology.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.241-246
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• 2001

Vortices terminating at free surface have been investigated extensively. Most of investigations, however, are focused on surface parallel vortices and little has been known about surface normal vortex or columnar vortex. Visualized experimental results utilizing LIF technique are discussed for the purpose of characterization of columnar vortex interacting with a clean and a contaminated free surfaces and a solid body interface in the present investigation. The results reveal that surface tension changes due to surface contamination although bulk viscosity remains constant and eventually the behavior of a columnar vortex interacting with a contaminated free surface and a solid body interface are totally different from the clean free surface case.