• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.21 no.1
• /
• pp.113-124
• /
• 2008

Distributed operation of overall structural design process, by which product optimization and process parallelization are simultaneously implemented, is presented in this paper. The database-interacted hybrid method, which selectively takes the accustomed procedure of the conventional method in the framework of the optimal design, is utilized here. The staged application of design constraints reduces the computational burden for large complex optimization problems. Two kinds of numeric and graphic processes are simultaneously implemented by concurrent engineering approach in the distributed environment of PC networks. The former is based on finite element optimization method and the latter is represented by AutoCAD using AutoLISP programming language. Numerical computation and database interaction on servers and graphic works on independent clients are communicated through message passing. The numerical experiments for some steel truss models show the validity and usability of the method. This study has sufficient adaptability and expandability, in that it is based on general methodologies and industry standard platforms.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.18 no.4
• /
• pp.123-130
• /
• 2018

Many massively multiplayer online games(MMOG) use client-server architectures that have enormous server-side bandwidth requirements. In this paper, we propose a region-based hybrid game architecture that combines the advantages of client-server and peer-to-peer architectures, so that only critical events changing game state are processed by the server. In this hybrid architecture, the central server divides the game into regions and assigns a player as a regional server to distribute important updates for that region. Thus, the central server sends state updates to the players through the regional servers. All players in the same region directly exchange updates without affecting game state. This division of labor greatly reduces server bandwidth significantly and enables it to serve larger number of concurrent players. Our experiments show that the region-based hybrid architecture with three-level hierarchy scales better than the client-server architecture, saving considerable bandwidth at the central server while requiring enough bandwidth of players acting as regional servers.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.45 no.3
• /
• pp.30-36
• /
• 2008

The multimedia that is characterized by multi-media, multi-features, multi-representations, huge volume, and varieties, is rapidly spreading out due to the increasing of application domains. Thus, it is urgently needed to develop a multimedia information system that can retrieve the needed information rapidly and accurately from the huge amount of multimedia data. For the content-based retrieval of moving picture, picture information is generally used. It is generally used when video is segmented. Through that, it can be a structural video browsing. The tasking that divides video to shot is called video segmentation, and detecting the cut for video segmentation is called cut detection. The goal of this paper is to divide moving picture using HMMD(Hue-Mar-Min-Diff) color model and edge histogram descriptor among the MPEG-7 visual descriptors. HMMD color model is more familiar to human's perception than the other color spaces. Finally, the proposed retrieval system is implemented as hardware.

• Journal of KIISE:Databases
• /
• v.32 no.6
• /
• pp.616-627
• /
• 2005

In the shared storage file system, systems can directly access the shared storage device through specialized data-only subnetwork unlike in the network attached file server system. In this shared-storage architecture, data consistency is maintained by some designated set of lock servers which use control network to send and receive the lock information. Furthermore, lease mechanism is introduced to cope with the control network failure. But when the control network is partitioned, participating systems can no longer make progress after the lease term expires until the network recovers. This paper addresses this limitation and proposes a method that allows partitioned systems to make progress under the partition of control network. The proposed method works in a manner that each participating system is rotationally given a predefined lease term periodically. It is also shown that the proposed mechanism always preserves data consistency.

• Proceedings of the Acoustical Society of Korea Conference
• /
• 1998.06c
• /
• pp.205-208
• /
• 1998

본 논문에서는 VLSI 기술에 바탕을 둔 top-down 접근 방식에 의하여 MPEG-2 오디오 부호화 알고리듬을 구현하였다. MPEG-2 오디오 부호화기의 알고리듬은 많은 연산량을 갖고 이질적인 특성을 갖고 이질적인 특성을 갖는 알고리듬들이 복합적으로 존재한다. 그러므로, 부호화기를 효과적으로 구현하기 위해서는 알고리듬 수준에서 구조적 수준에 이르기까지 많은 고찰이 이루어져야 한다. 본 논문에서는 우선 전체 부호화 알고리듬을 분석하여 이들을 다시 작업이라고 정의된 작은 부-알고리듬으로 나누었다. 다음으로, 분할된 작업들은 시간과 공간을 초대한 활용할 수 있도록 적절한 작업 순서를 부여하고, 좀 더 큰 모듈들로 모으는 클러스터링을 수행하였다. 마지막으로 이러한 분석 결과를 바탕으로, 실시간으로 동작하는 5.1 채널 MPEG-2 오디오 부호화기를 설계하였다. 설계된 시스템은 두 개의 하드웨어 블록과 한 개의 ASIP형 DSP 프로세서를 갖는 이질적인 다중 프로세서의 형태를 갖는다. 설계된 오디오 부호화기는 0.6$\mu\textrm{m}$ 표준 셀 기술을 이용하여 단일 칩으로 제작되었으며, PC에 탑재 가능한 시험 기판을 제작하여 동작을 검증하였다.

• Journal of KIISE:Databases
• /
• v.32 no.2
• /
• pp.177-192
• /
• 2005

In this paper, we introduce a structural redundancy method. It reduces the query processing cost incurred when reconfiguring an XML document from divided XML data in shredding XML documents into relations. The fundamental idea is that query performance can be enhanced by analyzing query patterns and replicating data essential for the query performance. For the practical and effective structural redundancy, we analyzed three types of ID, VALUE, and SUBTREE replication. In addition, if given XML data and queries are very large and complex, it can be very difficult to search optimal redundancy set. Therefore, a heuristic search method is introduced in this paper. Finally, XML query processing cost arising by employing the structural redundancy, and the efficiency of proposed search method arc analyzed experimentally It is manifest that XML read query is performed more quick]y but XML update query is performed more slowly due to the additional update consistency cost for replicas. However, experimental results showed that in-place ID replication is useful even in having excessive update cost. It was also observed that multiple-place SUBTREE replication can enhance read query performance remarkably if only update cost is not excessive.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.11a
• /
• pp.593-596
• /
• 2002

정보추출이란 자연어로 작성된 문서 집합에서 원하는 정보를 선택하여 구조화된 표현으로 생성하는 것을 말한다. 문장 단위로 정보 추출 작업을 수행할 때 추출되는 정보를 보유한 문장을 이벤트 문장이라고 정의하고 이러한 이벤트 문장의 구조를 분석하여 최종적으로 유용한 정보를 추출하기 위해서는 이벤트 문장의 구조를 파악하기 위해 이벤트 문장을 단문으로 분할하여 구조를 분석한다. 본 연구에서는 단문 구조 분석을 위해 일반적인 한국어 문장의 특성과 용언의 조사 정보를 이용하고 이러한 정보로 분석할 수 없는 문장에 대해서는 공기 정보를 사용한다. 사용되는 공기 정보는 개체명이 많이 사용되는 이벤트 문장의 특성을 이용하기 위하여 개체명으로 확장된 명사(개체명)-조사-용언의 공기 정보를 구축하여 사용한다. 개체명 확장된 공기 정보는 일반 공기 정보에 비해 이벤트 문장에서 F-Measure 기준으로 약 2%의 성능향상을 보인다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.9 no.6
• /
• pp.1395-1401
• /
• 2005

Mobile manipulator is a robot that has mobility and manipulability with the combination of the task robot and mobile robot. One of the most important feature of the Mobile Manipulator is redundant freedom. Using the redundant freedom, Mobile Manipulator can move various mode, perform dexterous motion. It can have the wider workspace and better performance in avoidance of singularity and obstacle than the fixed base structured robot. Cooperation control using the Mobile Manipulator improves the performance of the robot with redundant freedom in workspace. In this paper, configuration control of the Mobile Manipulator has been studied using Task Segment and TOMM(Task-Oriented Manipulability Measure). For verifying the proposed algorithm, we implemented a mobile manipulator, PURL-II, which is composed of a mobile robot with 3DOF and a task robot with SDOF.

• Korean Journal of Optics and Photonics
• /
• v.24 no.6
• /
• pp.311-317
• /
• 2013

It was reported in Nature and the Wall Street Journal on June 20th, 2012 that scientists at Duke university have developed a gigapixel camera, capable of over 1,000 times the resolution of a normal camera. According to the reports, this super-resolution camera was motivated by the need of US military authorities to surveil ground and sky. We notice the ripple effect of this technology has spread into the area of national defense and industry, so that this research has started to realize the super-resolution camera as a frontier research topic. As a result, we can understand the optical structure of a super-resolution camera's lens system to be composed of a front, monocentric objective of a single lens plus 98 rear, multiscale camera lenses. We can also obtain the numerical ranges of specification factors related to the optical structure, such as the diameter of the aperture, and the focal length.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2023.07a
• /
• pp.67-68
• /
• 2023

본 논문에서 제안한 Multi Agent Multi Action은 기존의 대화형 시스템 방식인 Single Agent Single Action 구조에 비해 확장성을 갖춘 대화 시스템을 구현하는 방식이다. 시스템을 여러 에이전트로 분할하고, 각 에이전트가 특정 액션에 대한 처리를 담당함으로써 보다 유연하고 효율적인 대화형 시스템을 구현할 수 있으며, 다양한 작업에 특화된 에이전트를 그룹화함으로써 작업의 효율성을 극대화하고, 사용자 경험을 향상 시킬 수 있다.