• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2003년도 춘계종합학술대회
• /
• pp.749-752
• /
• 2003

HLA(High Level Architecture)는 미 국방성에서 제안한 분산 시뮬레이션을 위한 실시간 분산 데이터 공유를 위한 객체, 시간, 인터페이스 규격을 말한다. 이 HLA는 (1) Rules, (2) Interface Specification, (3) Object Model Template 둥의 3가지 구성요소로 정의되며, 인터페이스 명세를 구현한 것이 RTI(Run-Time Infrastructure)이다. RTI는 분산 운영체계가 응용 프로그램에게 서비스를 제공하는 것과 유사한 방법으로 Federation을 구성하고 있는 Federate들에게 상호연동에 필요한 서비스를 제공한다. 모든 서비스들이 표준에 적합하게 구현되었는지 테스트하기 위한 방법은 DMSO에서 제안한 RTI를 검증하기 위한 2단계 과정을 통해 테스트된다. 본 논문에서는 1단계 테스트를 위한 테스트 절차와 그 방법에 대해 논한다 테스트 결과를 토대로 각 영역에서 DMSO에서 제안한 Level One Test Procedures에 따라 RTI가 Interface Specification에 적합하게 구현되었는지 확인하며, 각 단계마다 올바른 명령과 예상된 결과가 나오는지 테스트하기 위한 Test Suite를 개발한다.

• 정보과학회 컴퓨팅의 실제 논문지
• /
• 제22권4호
• /
• pp.163-169
• /
• 2016

Lustre는 대용량 분산파일 시스템의 일종으로 슈퍼컴퓨팅 분야에서 널리 사용되고 있다. 최근 SSD의 등장으로 인해, 고성능 스토리지를 구성할 수 있는 하드웨어적인 발전은 이루어졌으나, 이에 따른 소프트웨어적인 발전은 아직 따라가지 못하고 있다. 본 논문에서는 SSD를 이용한 Lustre시스템의 성능을 실험을 통해 측정하고 분석하였다. 하드디스크로 구성된 Lustre와 SSD로 구성된 Lustre를 각각 비교실험을 통해, 전체 대역폭 및 메타데이터 접근 성능에 대해서 분석하고, 장단점을 비교한다. 실험결과, 1) 랜덤 접근에 강한 SSD를 메타데이터용 저장공간에 사용하는 것이 효율적이며, 2) 스레드 수가 많거나, 작은 파일이 많은 경우 SSD를 데이터 저장 디스크로 사용하는 것이 성능의 이점이 있다.

• 정보처리학회논문지D
• /
• 제14D권6호
• /
• pp.649-656
• /
• 2007

오늘날 차량네트워크(CAN)는 전기적 강인, 저가격과 접근지연 때문에 분산 임베디드 시스템에서 널리 사용되는 버스형 필드이다. 그러나 버스토폴로지에서 발생하는 의존적인 제한 때문에 차량네트워크가 어플리케이션상에서 안전적으로 사용되는지는 논쟁되어왔다. 그래서 차량네트워크(CAN) 디자인 단계 동안 데이터 버스의 부하와 최대 지연, 경쟁 우선순위와 같은 네트워크의 성능을 분석하는 것이 중요하게 되었다. 이 논문은 차량네트워크의 성능을 평가하기 위해 사용된 시뮬레이션 알고리즘과 고장 기법 기술을 적용을 소개한다. 이는 차량네트워크의 어떤 산만한 구현의 줄임과 시스템의 신뢰성을 향상 시켜 줄 것이다.

• Journal of Information Processing Systems
• /
• 제5권2호
• /
• pp.69-76
• /
• 2009

Self healing systems are considered as cognation-enabled sub form of fault tolerance system. But our experiments that we report in this paper show that self healing systems can be used for performance optimization, configuration management, access control management and bunch of other functions. The exponential complexity that results from interaction between autonomic systems and users (software and human users) has hindered the deployment and user of intelligent systems for a while now. We show that if that exceptional complexity is converted into self-growing knowledge (policies in our case), can make up for initial development cost of building an intelligent system. In this paper, we report the application of AHSEN (Autonomic Healing-based Self management Engine) to in OKKAM Project infrastructure backbone cluster that mimics the web service based architecture of u-Zone gateway infrastructure. The 'blind' load division on per-request bases is not optimal for distributed and performance hungry infrastructure such as OKKAM. The approach adopted assesses the active threads on the virtual machine and does resource estimates for active processes. The availability of a certain server is represented through worker modules at load server. Our simulation results on the OKKAM infrastructure show that the self healing significantly improves the performance and clearly demarcates the logical ambiguities in contemporary designs of self healing infrastructures proposed for large scale computing infrastructures.

• 한국사이버테러정보전학회:학술대회논문집
• /
• 한국사이버테러정보전학회 2004년도 제1회 춘계학술발표대회
• /
• pp.199-204
• /
• 2004

운영체제 및 응용프로그램들은 프로그램 개발 과정의 특성상 보안 취약성을 가지고 있다. 최근 이러한 취약성을 악용하는 침해사례가 증가하고 있으며, 그 피해의 파급효과가 더욱 커지고 있다. 패치의 분배 및 설치는 취약성을 이용하는 침해사고를 예방하기 위한 가장 중요한 요소중의 하나이다. 특정 기관이나 조직은 다양한 운영체제 및 응용프로그램을 사용하기 때문에 관리자가 매번 신속하게 모든 시스템들에 대하여 패치를 설치하기는 어려움이 있다. 본 논문에서는 중앙의 관리자가 패치관리서버를 이용하여 Windows, Linux, Solaris 클라이언트 시스템들에 대하여 안전하게 패치를 자동분배하고 설치하는 패치 자동관리시스템을 설계 및 구현하였다. 또한, 대규모 네트워크를 지원하기 위하여 확장성을 고려한 계층적인 패치 분배 구조로 설계 및 구현하였다.

• Genomics & Informatics
• /
• 제6권2호
• /
• pp.57-63
• /
• 2008

The Korean HapMap Project has been carried out for the last 5 years since it started in June, 2003. The project generated data for a sum of 1,764,000 Korean SNPs and formally registered the data to the dbSNP of NCBI (The dbSNP website. 2008). We have developed a series of software programs for association studies as well as for the comparison and analysis of Korean HapMap data with four other populations (CEPH, Yoruba, Han Chinese, and Japanese populations). The KHapmap Browser was developed and integrated to provide haplotype retrieval and comparative study tools of human ethnicities for comprehensive disease association studies (http://www.khapmap.org). On that basis, GBrowse was adopted in the KHapmap Browser for inherent Korean genetic data, and a provision of extended services was pledged with the distributed sequence annotation system (DAS). The dynamic linking service of the KHapmap Browser to other tools in our intranetwork environment provides many enhanced functions over GBrowse without DAS. KHapmap Browser is expected to be an invaluable tool for the study of Korean and international Hapmap data.

• Geomechanics and Engineering
• /
• 제20권1호
• /
• pp.29-41
• /
• 2020

It is extremely important to obtain rock strength parameters for geological engineering. In this paper, the evolution of sandstone cohesion and internal friction angle with plastic shear strain was obtained by simulating the cyclic loading and unloading tests under different confining pressures using Particle Flow Code software. By which and combined with the micro-crack propagation process, the mesoscopic mechanism of parameter evolution was studied. The results show that with the increase of plastic shear strain, the sandstone cohesion decreases first and then tends to be stable, while the internal friction angle increases first, then decreases, and finally maintains unchanged. The evolution of sandstone shear strength parameters is closely related to the whole process of crack formation, propagation and coalescence. When the internal micro-cracks are less and distributed randomly and dispersedly, and the rock shear strength parameters (cohesion, internal friction angle) are considered to have not been fully mobilized. As the directional development of the internal micro-fractures as well as the gradual formation of macroscopic shear plane, the rock cohesion reduces continuously and the internal friction angle is in the rise stage. As the formation of the macroscopic shear plane, both the rock cohesion and internal friction angle continuously decrease to a certain residual level.

• International Journal of Aeronautical and Space Sciences
• /
• 제16권3호
• /
• pp.463-474
• /
• 2015

Future Ground Control Stations (GCSs) for Unmanned Aerial Vehicles (UAVs) teleoperation targets better situational awareness by providing extra motion cues to stimulate the vestibular system. This paper proposes a new virtual environment for long range Unmanned Aerial Vehicle (UAV) control via Non-Line-of-Sight (NLoS) communications, which is based on motion platforms. It generates motion cues for the teleoperator for extra sensory stimulation to enhance the guidance performance. The proposed environment employs the distributed component simulation over GSM network as a simulation platform. GSM communications are utilized as a multi-hop communication network, which is similar to global satellite communications. It considers a UAV mathematical model and wind turbulence effects to simulate a realistic UAV dynamics. Moreover, the proposed virtual environment simulates a Multiple Axis Rotating Device (MARD) as Human Machine Interface (HMI) device to provide a complete delay analysis. The demonstrated measurements cover Graphical User Interface (GUI) capabilities, NLoS GSM communications delay, MARD performance, and different software workload. The proposed virtual environment succeeded to provide visual and vestibular feedbacks for teleoperators via GSM networks. The overall system performance is acceptable relative to other Line-of-Sight (LoS) systems, which promises a good potential for future long range, medium altitude UAV teleoperation researches.

• 한국CDE학회논문집
• /
• 제12권4호
• /
• pp.308-320
• /
• 2007

A multi-agent and web based engineering framework concerning the automation of fatigue durability analysis for welded bogie frame of railway vehicles is presented. Mostly, this kind of design or analysis includes complex workflow, huge amounts of information processing, and problem solving. Macro programs of I-DEAS, APDL of ANSYS, and in-house fatigue code are utilized for parametric geometry representation, automatic mesh generation, static stress analysis, fatigue durability analysis, post-processing, and data sorting. The engineering framework is implemented on the JADE. Since every task requires a fairly complex process and specialized knowledge, the multi-agent based framework is very useful to keep the independency among several disciplines or tasks and to use distributed hardware and software resources. All engineering programs are integrated by XML wrapper. Related database of the engineering framework and web based user interfaces are also developed. A parametric study is carried out to take into account the effect of geometrical change of transom support bracket on its cumulative fatigue damage. The developed engineering framework reduced remarkably the time and costs required in designing and solving engineering problems.

• 전기학회논문지
• /
• 제65권5호
• /
• pp.902-910
• /
• 2016

This paper presents the overall measurement system for on-line test of super-speed maglev train. The super-speed maglev train is composed of vehicle, propulsion, power, and so on. In order to evaluate and diagnose for sub-system, we made overall measurement system. Just like the other measurement system, it is designed to distributed type. The hardware is consist of SCXI, PXI, Terminal, UPS, and so forth. It is installed on a train, control room, power room and track to collect lots of signals. The software controls hardware system, monitors main data such as inverter current, converter voltage. Using the measurement system, we evaluated a lot of performances for vehicle, track, and so forth. Through the developed system have improved reliability and safety for super-speed maglev train.