• 제목/요약/키워드: Simulation integration

검색결과 1,046건 처리시간 0.031초

Accuracy Improvement of Low Cost GPS/INS Integration System for Digital Photologging System

  • Kim, Byung-Guk;Kwon, Jay-Hyoun;Lee, Jong-Ki
    • Korean Journal of Geomatics
    • /
    • 제2권2호
    • /
    • pp.99-105
    • /
    • 2002
  • The accuracy of the Digital Photologging System, designed for the construction of the road Facility Database, highly depends on the positions and attitudes of the cameras from GPS/INS integration. In this paper, the development of a loosely coupled GPS/INS is presented. The performance of the system is verified through a simulation as well as a real test data processing. Since the IMU used in this study shows large systematic errors, the possible accuracy of the positions and attitudes of this low-performance IMU when combined with precise GPS positions are assigned. Currently, the integrated system shows the positional accuracy better than 5cm in real data processing. Although the accuracy of attitude based on real test could not be assigned at this time, it is expected that better than 0.5 degrees and 1.8 degrees for horizontal and down component are achievable according to the simulation result.

  • PDF

RELTSYS: A computer program for life prediction of deteriorating systems

  • Enright, Michael P.;Frangopol, Dan M.
    • Structural Engineering and Mechanics
    • /
    • 제9권6호
    • /
    • pp.557-568
    • /
    • 2000
  • As time-variant reliability approaches become increasingly used for service life prediction of the aging infrastructure, the demand for computer solution methods continues to increase. Effcient computer techniques have become well established for the reliability analysis of structural systems. Thus far, however, this is largely limited to time-invariant reliability problems. Therefore, the requirements for time-variant reliability prediction of deteriorating structural systems under time-variant loads have remained incomplete. This study presents a computer program for $\underline{REL}$iability of $\underline{T}$ime-Variant $\underline{SYS}$tems, RELTSYS. This program uses a combined technique of adaptive importance sampling, numerical integration, and fault tree analysis to compute time-variant reliabilities of individual components and systems. Time-invariant quantities are generated using Monte Carlo simulation, whereas time-variant quantities are evaluated using numerical integration. Load distribution and post-failure redistribution are considered using fault tree analysis. The strengths and limitations of RELTSYS are presented via a numerical example.

JAVA-BASED SIMULATION FOR DEVS

  • Bai, Tao;Zeng, Jianchao;Wang, Meng
    • 한국시뮬레이션학회:학술대회논문집
    • /
    • 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
    • /
    • pp.349-353
    • /
    • 2001
  • There are many excellent characters of Java-based simulation compared with existing ones in the respect of running on the Internet/Web, reuse, integration and etc.. In this paper, the main idea of design and realization of Java-based modeling and simulation software for DEVS will be discussed in detail.

  • PDF

레이더 단일 펄스를 이용한 목표물 방향과 거리 추정에 대한 연구 (A Study on Target Direction and Rage Estimation using Radar Single Pulse)

  • 이관형
    • 한국인터넷방송통신학회논문지
    • /
    • 제14권6호
    • /
    • pp.107-112
    • /
    • 2014
  • 본 논문에서는 레이더 시스템에서 단일 펄스 방식, 집적 상관 방식, 비 집적 상관 방식의 신호대 잡음비 성능에 대해서 비교 분석하였다. 그리고, 공간상에 두 목표물에 대한 방향을 추정하여 기존의 방법과 비교 분석하였다. 레이더 시스템에서 일반적으로 반사파와 전송파의 왜곡을 방지하고 감소시키기 위해서 펼스파를 이용하여 신호를 전송한다. 본 논문에서는 수신신호를 처리하는 방식으로 포락선 검파기 앞에서 처리하는 집적 상관방식과 과 포락선 검파기 뒤에서 처리하는 비 집적 상관 방식의 성능을 비교 분석하였다. 모의실험을 통하여 목표물 방향을 추정하였고, 두 목표물의 탐지 거리를 추정하여 신호대 잡음비 성능을 비교 분석하였다. 집적 상관방식의 성능이 우수함을 입증하였다.

화학공정 비정상상태 모사기 개발 I (Developement of Dynamic Process Simulator I.)

  • 이강주;윤인섭
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
    • /
    • pp.482-487
    • /
    • 1988
  • A sequential-clustered integrator based on GEAR method is developed for the purpose of dynamic simulation of chemical processes. And a single simulator structure capable of employing various integration approaches is designed and its efficiency and flexiblity is evaluated. Sequential integration method is superior to simultaneous method for the process without recycle, but simultaneous method is very powerful for the coupled process with recycle.

  • PDF

Asymptotic Comparison of Latin Hypercube Sampling and Its Stratified Version

  • Lee, Jooho
    • Journal of the Korean Statistical Society
    • /
    • 제28권2호
    • /
    • pp.135-150
    • /
    • 1999
  • Latin hypercube sampling(LHS) introduced by McKay et al. (1979) is a widely used method for Monte Carlo integration. Stratified Latin hypercube sampling(SLHS) proposed by Choi and Lee(1993) improves LHS by combining it with stratified sampling. In this article it is shown that SLHS yields an asymptotically more accurate than both stratified sampling and LHS.

  • PDF

직접적분법과 확률론적 유한요소법을 이용한 구조물의 확률론적 동적 해석 (Developing A Stochastical Dynamic Analysis Technique for Structures Using Direct Integration Methods)

  • 이정재
    • 한국농공학회지
    • /
    • 제36권1호
    • /
    • pp.54-62
    • /
    • 1994
  • The expanding technique of the Stochastic Finite Element Method(SFEM) is proposed in this paper for adapting direct integration methods in stochastical dynamic analysis of structures. Grafting the direct integration methods and the SFEM together, one can deal with nonlinear structures and nonstationary process problems without any restriction. The stochastical central diffrence and stochastic Houbolt methods are introduced to show the expanding technique, and their adaptabilities are discussed. Results computed by the proposed method (the Stochastic Finite Element Method in Dynamics: SFEMD) for two degree-of-free- dom system are compared with those obtained by Monte Carlo Simulation.

  • PDF

Simulation Based Production Using 3-D CAD in Shipbuilding

  • Okumoto, Yasuhisa;Hiyoku, Kentaro;Uesugi, Noritaka
    • International Journal of CAD/CAM
    • /
    • 제6권1호
    • /
    • pp.3-8
    • /
    • 2006
  • The application of three-dimensional (3-D) CAD has been popularized for design and production and digital manufacturing has been spreading in many industrial fields. By simulation of the production process using 3-D digital models, which are the core of CIM (Computer Integrated Manufacturing) system, the efficiency and safety of production are improved at each stage of work, and optimization of manufacturing can be achieved. This paper firstly describes the concept of "simulation based production" in shipbuilding and also digital manufacturing; the 3-D CAD system is indispensable for effective simulation because ship structure is three dimensionally complex. By simulation, "computer optimized manufacturing" can be possible. The most effective fields of simulation in shipbuilding are in jobs where many parties have to cooperate, while existing two-dimensional drawings are hardly observed the whole structures due to interference between structures or equipment of complex shape. In this paper some examples of the successful application in IHIMU (IHI Marine United Inc.) are shown: assembly of a pipe unit, erection of a complex hull block, carriage of equipment, installation of a propeller, and access in an engine room.

Three-dimensional finite element simulation and application of high-strength bolts

  • Long, Liji;Yan, Yongsong;Gao, Xinlin;Kang, Haigui
    • Steel and Composite Structures
    • /
    • 제20권3호
    • /
    • pp.501-512
    • /
    • 2016
  • High-strength structural bolts have been utilized for beam-to-column connections in steel-framed structural buildings. Failure of these components may be caused by the bolt shank fracture or threads stripping-off, documented in the literature. Furthermore, these structural bolts are galvanized for corrosion resistance or quenched-and-tempered in the manufacturing process. This paper adopted the finite element simulation to demonstrate discrete mechanical performance for these bolts under tensile loading conditions, the coated and uncoated numerical model has been built up for two numerical integration methods: explicit and implicit. Experimental testing and numerical methods can fully approach the failure mechanism of these bolts and their ultimate load capacities. Comparison has also been conducted for two numerical integration methods, demonstrating that the explicit integration procedure is also suitable for solving quasi-static problems. Furthermore, by using precise bolt models in T-Stub, more accurately simulate the mechanical behavior of T-Stub, which will lay the foundation of the mechanical properties of steel bolted joints.

Simulation of Regional Climate over East Asia using Dynamical Downscaling Method

  • Oh, Jai-Ho;Kim, Tae-Kook;Min, Young-Mi
    • 한국수자원학회:학술대회논문집
    • /
    • 한국수자원학회 2002년도 학술발표회 논문집(II)
    • /
    • pp.1187-1194
    • /
    • 2002
  • In this study, we have simulated regional climate over East Asia using dynamical downscaling For dynamic downscaling experiments for regional climate simulation, MM5method. with 27 km horizontal resolution and 18 layers of sigma-coordinate in vertical is nested within global-scale NCEP reanalysis data with 2.5。${\times}$2.5。 resolution in longitude and latitude. In regional simulation, January and July, 1979 monthly mean features have been obtained by both continuous integration and daily restart integration driven by updating the lateral boundary forcing at 6-hr intervals from the NCEP reanalysis data using a nudging scheme with the updating design of initial and boundary conditions in both continuous and restart integrations. In result, we may successfully generated regional detail features which might be forced by topography, lake, coastlines and land use distribution from a regional climate. There is no significant difference in monthly mean features either integrate continuously or integrate with daily restart. For climatologically long integration, the initial condition may not be significantly important. Accordingly, MM5 can be integrated for a long period without restart frequently, if a proper lateral boundary forcing is given.

  • PDF