• Title/Summary/Keyword: computer modelling

Search Result 440, Processing Time 0.024 seconds

A study on An Application for Ensuring Safety of Computer Based Automatic Train Control System (컴퓨터기반 자동열차제어장치의 안전성 확보에 관한 연구)

  • Lee jongwoo;SHIN jongwoo
    • The Transactions of the Korean Institute of Electrical Engineers B
    • /
    • v.54 no.6
    • /
    • pp.261-268
    • /
    • 2005
  • This paper propose the safety design of automatic train control system which is used for controlling and monitoring train speed not to excess a permitted speed. Safety activities are shown for the computerized system to achieve a required safety requirement. The safety activities are composed of system dynamic modelling to identify potential hazards contained in the target system, to analyze sub system faults to provoke the hazards. Risks analysis are carried out to estimate losses caused from the hazards to allocate safety requirement. We Proposed design solutions for sub system to meet safety requirement.

MIL-HDBK-217D를 이용한 전자부품 및 Board의 고장율 계산에 관한 연구

  • Jo, Yeong-So;Im, Deok-Bin
    • ETRI Journal
    • /
    • v.5 no.3
    • /
    • pp.9-15
    • /
    • 1983
  • This paper describes the applicable method of part stress analysis failure rate prediction for electronic components in the MIL-HDBK-217D. The part stress analysis method requires the great amount of detailed informations, such as operating temperature, operating environment, etc. This paper calculates the failure rate of electronic components using the computer program. The program was written by Fortran V and has four basic units as follows (1) Raw data file (2) Failure rate calculation (3) Reliability modelling(Series only) (4) New data file The Functions and structure of the program are illustrated.

  • PDF

A State Estimator for servo system using discrete Kalman Filter (이산형 칼만 필터를 이용한 서보 시스템의 상태 추정자 설계)

  • Shin, Doo-Jin;Yum, Hyung-Sun;Huh, Uk-Youl;Lee, Je-Hie
    • Proceedings of the KIEE Conference
    • /
    • 1998.11b
    • /
    • pp.420-422
    • /
    • 1998
  • In this paper, we propose a position-speed control of servo system with a state estimator. And also we utilized two mass modelling in order to deals with real system accurately. The overall control system consists of two parts: the position-speed controller and state estimator. The Kalman filter applied as state - feedback controller is an optimal state estimator applied to a dynamic system that involves random perturbations and gives a linear,unbiased and minimun error variance recursive algorithm to estimate the unknown state optimally. Therefore we consider the error problem about the servo system modelling, the measurement noise at low-speed ranges a stochastic system, and implement a optimal state observer. Performance of the proposed state estimator are demonstrated by computer simulations.

  • PDF

An Iterative Analysis of Single-Hop B-MAC Networks Under Poisson Traffic

  • Jung, Sung-Hwan;Choi, Nak-Jung;Kwon, Tae-Kyoung
    • Journal of Communications and Networks
    • /
    • v.14 no.1
    • /
    • pp.40-50
    • /
    • 2012
  • The Berkeley-medium access control (B-MAC) is a lightweight, configurable and asynchronous duty cycle medium access control (MAC) protocol in wireless sensor networks. This article presents an analytic modelling of single-hop B-MAC protocol under a Poisson traffic assumption.Our model considers important B-MAC parameters such as the sleep cycle, the two stage backoff mechanism, and the extended preamble. The service delay of an arriving packet and the energy consumption are calculated by an iterative method. The simulation results verify that the proposed analytic model can accurately estimate the performance of single-hop B-MAC with different operating environments.

Comparison among different software for the evaluation of moment-curvature of R.C. columns

  • Montuori, Rosario;Nastri, Elide;Palese, Maria Ilenia;Piluso, Vincenzo
    • Computers and Concrete
    • /
    • v.24 no.3
    • /
    • pp.259-269
    • /
    • 2019
  • The work aims at the comparison among commonly used research programs concerning moment-curvature ($M-{\chi}$) diagrams of confined R.C. members. The software considered in this work are Sap2000, SeismoStruct and Opensees. The curves provided by these software, given the same modelling, have been compared to those provided by a theoretical fiber model. A parametric analysis has been led on rectangular column sections with different level of axial load and different stirrups spacing. The accuracy of the modelling of the considered structural programs has been investigated by comparing their results with those obtained by applying the theoretical fiber model.

Addressing the New User Problem of Recommender Systems Based on Word Embedding Learning and Skip-gram Modelling

  • Shin, Su-Mi;Kim, Kyung-Chang
    • Journal of the Korea Society of Computer and Information
    • /
    • v.21 no.7
    • /
    • pp.9-16
    • /
    • 2016
  • Collaborative filtering(CF) uses the purchase or item rating history of other users, but does not need additional properties or attributes of users and items. Hence CF is known th be the most successful recommendation technology. But conventional CF approach has some significant weakness, such as the new user problem. In this paper, we propose a approach using word embedding with skip-gram for learning distributed item representations. In particular, we show that this approach can be used to capture precise item for solving the "new user problem." The proposed approach has been tested on the Movielens databases. We compare the performance of the user based CF, item based CF and our approach by observing the change of recommendation results according to the different number of item rating information. The experimental results shows the improvement in our approach in measuring the precision applied to new user problem situations.

A Study on the Implementation of GPSS Program on a Parallel Computer (GPSS 프로그램의 병렬화에 관한 연구)

  • 윤정미
    • Journal of the Korea Society for Simulation
    • /
    • v.8 no.2
    • /
    • pp.57-72
    • /
    • 1999
  • With the rapidly increasing complexity of decision-marking or system development in the fields of industry, management, etc., modelling techniques using simulation has become more highlighted. Particularly, the advent of parallel computer systems not only has opened a new horizon of parallel simulation, but also has greatly contributed to the speed-up of the execution of simulation. The implementation of parallel simulation, however, is not a easy job for those who accustomed to the existing computer systems. And it is also necessarily confronted with the problem of synchronization conflict in the process. Thus, how to allow a wider community of users to gain access to parallel simulation while solving synchronization conflicts has become an important issue in simulation study. As a method to solve these problems, this paper is primarily concerned with the implementation of GPSS which is a generally used simulation language for discrete event simulation, onto a parallel computer using C-LINDA. For that, this paper, is to suggest a model and algorithm and to experiment it using a case.

  • PDF

A Cooperative Workflow Modelling System (협동 워크플로우 모델링 시스템)

  • Han, Soo-Young;Sung, Tae-Hyuk;Park, Min-Jae;Kim, Kwang-Hoon
    • Proceedings of the Korean Information Science Society Conference
    • /
    • 2007.06b
    • /
    • pp.80-84
    • /
    • 2007
  • 기업 업무의 절차와 규모가 복잡해지고 증가함에 따라 한 사람이 기업의 모든 업무 프로세스를 모델링하고 관리하는 것이 어려워지고 있다. 기존의 워크플로우 모델링 방식은 한 명(또는 소수)의 디자이너가 맡아 왔다. 하지만 본 논문에서 제시하는 역할(Role) 기반의 프로세스 모델링은 각 역할에 해당되는 디자이너 그룹이 프로세스를 정의하기 때문에 모델링 작업을 단순화 시킬 수 있었으며 기존의 워크플로우 시스템들이 지원하지 못 했던 워크플로우 모델링 작업을 실시간으로 지원할 수 있게 되었다. 또한 본 워크플로우 모델링 시스템을 통한 모델링 결과는 국제 표준화 워크플로우 정의 언어(Process Definition Language)를 제공함으로써, 기존의 워크플로우 시스템들과의 상호호환성을 제공 하고자 하였다.

  • PDF

Experimental Designs for Computer Experiments and for Industrial Experiments with Model Unknown

  • Fang, Kai-Tai
    • Journal of the Korean Statistical Society
    • /
    • v.31 no.3
    • /
    • pp.277-299
    • /
    • 2002
  • Most statistical designs, such as orthogonal designs and optimal designs, are based on a specific statistical model. It is very often that the experimenter does not completely know the underlying model between the response and the factors. In computer experiments, the underlying model is known, but too complicated. In this case we can treat the model as a black box, or model to be unknown. Both cases need a space filling design. The uniform design is one of space filling designs and seeks experimental points to be uniformly scattered on the domain. The uniform design can be used for computer experiments and also for industrial experiments when the underlying model is unknown. In this paper we shall introduce the theory and method of the uniform design and related data analysis and modelling methods. Applications of the uniform design to industry and other areas are discussed.

Intrusion Detection using Attribute Subset Selector Bagging (ASUB) to Handle Imbalance and Noise

  • Priya, A.Sagaya;Kumar, S.Britto Ramesh
    • International Journal of Computer Science & Network Security
    • /
    • v.22 no.5
    • /
    • pp.97-102
    • /
    • 2022
  • Network intrusion detection is becoming an increasing necessity for both organizations and individuals alike. Detecting intrusions is one of the major components that aims to prevent information compromise. Automated systems have been put to use due to the voluminous nature of the domain. The major challenge for automated models is the noise and data imbalance components contained in the network transactions. This work proposes an ensemble model, Attribute Subset Selector Bagging (ASUB) that can be used to effectively handle noise and data imbalance. The proposed model performs attribute subset based bag creation, leading to reduction of the influence of the noise factor. The constructed bagging model is heterogeneous in nature, hence leading to effective imbalance handling. Experiments were conducted on the standard intrusion detection datasets KDD CUP 99, Koyoto 2006 and NSL KDD. Results show effective performances, showing the high performance of the model.