• Journal of KIISE:Computer Systems and Theory
• /
• v.26 no.6
• /
• pp.683-692
• /
• 1999

관계형 데이터베이스 시스템에서 결합 연산자는 데이터베이스 질의를 구성하는 연산자들 중 가장 많은 처리시간을 요구한다. 따라서 이러한 결합연산자를 효율적으로 처리하기 위해 많은 병렬 알고리즘들이 소개되었다. 그 중 하이브리드 해쉬 결합 알고리즘은 가장 우수한 것으로 알려져왔다. 그러나 이 알고리즘은 여러 노드로 데이터를 분할하는 과정에서 데이터의 편중 문제가 발생하며, 이는 전체 시스템의 성능을 크게 저하시키게된다. 본 논문에서는 이러한 데이터 편중문제를 해결한 변형된 하이퍼퀵 정렬을 이용한 병렬 결합 알고리즘을 non-equijoin을 위한 알고리즘으로 확장하였다. 또한 T805로 연결된 하이퍼큐브 구조 시스템에서 시뮬레이션하여 얻은 결과를 수치 계산적 비용모델의 결과와 비교를 통해 변형된 하이퍼 퀵 정렬을 이용한 병렬 결합 알고리즘의 성능을 분석하고 , 비용모델의 타당성을 입증하였다.

• The KIPS Transactions:PartA
• /
• v.10A no.1
• /
• pp.43-48
• /
• 2003

Two-dimensional packing algorithm can be used for allocating submeshes in mesh multiprocessor systems. Previously, we developed an efficient packing algorithm called TP heuristic, and showed how the results of the packing could be used for allocating submeshes. In this paper, we present theoretical performance bounds for TP heuristic. We also present a parallel version of the algorithm that consumes reduced time when it is executed by multiple processors in mesh multiprocessors.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.9
• /
• pp.2827-2835
• /
• 2000

In recent years, much attention has been focused on improving I/O devices' processing speed which is essential in such large data processing areas as multimedia data processing. And studies on high-performance parallel file systems are considered to be one of such efforts. In this paper, an efficient disk allocation scheme is proposed for high-performance parallel file systems. In other words, the concept of a parallel disk file's parallelism is defined using data declustering characteristic of a given parallel file. With the concept, an efficient disk allocation scheme is proposed which calculates the appropriate degree of data declustering on disks for each parallel file in order to obtain the maximum throughput when more than one parallel file is used at the same time. Since, calculation for obtaining the maximum throughput is too complex as the number of parallel files increases, an approximate disk allocation algorithm is also proposed in this paper. The approximate algorithm is very simple and especially provides very good results when I/O workload is high. In addition, it has shown that the approximate algorithm provides the optimal disk allocation for the maximum throughput when the arrival rate of I/O requests is infinite.

• ICROS
• /
• v.15 no.3
• /
• pp.31-39
• /
• 2009

본 고에서는 병렬 영상처리를 이용한 고속 머신 비전(Machine Vision) 기술의 동향에 관해 다룬다. 머신 비전에서 사용되는 대표적인 고속 상용 영상처리 라이브러리인 MIL, HALCON, IPP에 대해 소개하고 현재 활발히 연구되고 있는 SSE, OpenMP, CUDA와 같은 병렬 처리 기술에 대하여 알아 본다. 이러한 병렬 처리 기술을 실제 영상처리 알고리즘에 적용하여 그 성능을 고속 상용 영상처리 라이브러리의 성능과 비교하여 소개된 병렬 처리 기술을 실제 PCB 기판 자동검사와 같은 머신 비전에 적용한 연구사례에 대해서 알아본다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 1997.11a
• /
• pp.214-220
• /
• 1997

DES 암호 알고리즘은 정보의 기밀성 서비스와 무결성 서비스 실현을 위해 널리 사용되고 있다. DES를 하드웨어로 실현이 곤란한 분야에서는 소프트웨어로 구현하여 사용되고 있으나 처리 속도의 문제로 인해 사용하지 못하는 경우도 존재한다. 본 논문에서는 소프트웨어의 처리 속도 문제를 해결하기 위해 DES 암호 알고리즘의 치환 연산과 대치 연산을 병렬로 처리하는 방법을 제시하여 고속으로 정보를 실시간으로 보호하고자 하는 분야에 적용할 수 있도록 하였다.

• The KIPS Transactions:PartA
• /
• v.9A no.2
• /
• pp.217-224
• /
• 2002

Many systems handle 3D-image were used. High-performance computer systems and techniques of compressing images to handle 3D-image were used. But there will be cost Problems, if GIS system is implemented, using the high-performance system. And if GIS system is implemented, using the techniques of compressing images, there will be some loss of a image. It will take a long processing time to handle 3D-images using a general PC because the size of 3D-image files are very huge. The parallel algorithm presented in the paper can improve speed to handle 3D-image using parallel computer system. The system uses the method of displacing images from nodes to screens, dividing a 3D-image into multiple sub images on multiple nodes. The performance of the presented algorithm showers improving speed by experiments.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.14 no.2
• /
• pp.57-68
• /
• 2004

We present a new parallel algorithm for extending the domain of a UOWHF. Our algorithm is based on non-complete l-ary tree and has the same optimal key length expansion as Shoup's which has the most efficient key length expansion known so far. Using the recent result [8], we can also prove that the key length expansion of this algorithm and Shoup's sequential algorithm are the minimum possible for any algorithms in a large class of "natural" domain extending algorithms. But its prallelizability performance is less efficient than complete tree based constructions. However if l is getting larger then the parallelizability of the construction is also getting near to that of complete tree based constructions.tructions.

• Journal of the Korea Society of Computer and Information
• /
• v.19 no.4
• /
• pp.9-16
• /
• 2014

This paper proposes a linear scratch detection and restoration algorithm using pixel data comparison in a single frame or consecutive frames. There exists a high parallelism in that a scratch detection and restoration algorithm needs a large amount of comparison operations. The proposed scratch detection and restoration algorithm is designed with a GPU for fast computation. We test the proposed algorithm in sequential and parallel processing with the set of digital videos in National Archive of Korea. In the experiments, the scratch detection rate of consecutive frames is as fast as about 20% for that of a single frame. The detection and restoration rates of a GPU-based algorithm are similar to those of a CPU-based algorithm, but the parallel implementation speeds up to about 50 times.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.40 no.1
• /
• pp.1-9
• /
• 2003

The CNN-UM algorithm which performs the analog parallel subtraction of images has been developed and its application study to the moving target detection has been done. The CNN-UM is the state of the art computation architecture with high computational potential of analog parallel processing. It is one of the strong candidates for the next generation of computing system which fulfills requirement of the real-time image processing. One weakness of the CNN-UM is that its analog parallel processing function is not fully utilized for the inter frame processing. If two subsequent image frames are superimposed with opposite signs on identical capacitors for short time period, the analog subtraction between them is achieved. The Principle of such temporal inter-frame processing algorithm has been described and its mathematical analysis has been done. Practical usefulness of the proposed algorithm has also been verified through the application for moving target detection.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.10 no.5
• /
• pp.97-103
• /
• 2010

There are many algorithms for 2D to 3D graphic conversion technology which have the high complexity and large scale of iterative computation. So in this paper propose parallel algorithm and high speed graphics accelerator architecture using Park's MAMS(Multiple Access Memory System) for Phong Shading, one of many 3D algorithms. The Proposed SIMD processor architecture is simulated by HDL and simulated and got 30 times faster result. It means any kinds of 3D algorithm can make parallel algorithm and accelerated by SIMD processor with Park's MAMS for real time processing.