• Title/Summary/Keyword: slam

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Durability Prediction of Door W/H System Using FEM Analysis (전면 도어 와이어하니스 시스템의 내구 수명 예측에 관한 연구)

  • Kim, Byeong Sam;Lim, Kwangkyu
    • Journal of Auto-vehicle Safety Association
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    • v.5 no.2
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    • pp.51-56
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    • 2013
  • In vehicle's door wiring harness (W/H) system is more toward to arrange a passenger compartment than a hinge and a weatherstrip. An opening/closing member of a vehicle is attached to a vehicle by a hinge in a manner enabling easy opening and closing of the opening/closing member. Such members include doors, such as side-doors and rear doors, and other opening/closing members, such as trunk lids. This article gives some insight into the dimensioning process, with special focus on large deflection analysis of wiring harness(W/H) in vehicle's door structures for durability problem. The Finite elements analysis for door wiring harness(W/H) is used for residual stresses and dimensional stability with bending flexible. Durability test data for slam test specimens were compared with the numerical predicted fatigue life for verification. The final testing of the component combines the effects of these microstructural features with the complex stress state arising from the combined service loading and residual stresses.

Reinforcement Learning based AGV Scheduling (강화학습 기반의 AGV 스케줄링)

  • Lee, Se-Hoon;Kim, Jea-Seung;Yeom, Dae-Hoon;Mun, Hwan-Bok;Lee, Chang-Ho
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2018.07a
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    • pp.23-24
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    • 2018
  • 스마트 팩토리의 핵심 요소 중 하나인 AGV를 운용하기 위해서 스케줄링은 간과할 수 없는 문제이다. 기존의 정적인 휴리스틱 방식은 실시간으로 운용되는 스마트 팩토리에 다소 부적합한 면이 있다. 본 논문에서는 이러한 스케줄링에 관한 문제를 해결하고자 SLAM 기반의 자율주행 AGV를 운용 할 수 있는 3D 가상 환경을 설계하고 해당 환경에서 강화학습을 기반으로 한 스케줄링을 구현해 실시간으로 변화하는 공장에 적합한 동적인 스케줄링을 설계하였다.

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Performance Analysis of Bus Arbitration Schemes for Multiple-bus Multiprocessor System (다중버스 다중프로세서 시스템을 위한 버스 중재 방식의 성능 분석)

  • 김종현
    • Journal of the Korea Society for Simulation
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    • v.2 no.1
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    • pp.13-22
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    • 1993
  • In a multiple-bus multiprocessor system in which processors and memory modulus are interconnected through system buses, time delay due to bus contention degrades system performance. In order to reduce such a problem , and optimal bus arbitration scheme and its hardware are neccessary. In this study, performaces of four arbitration schemes are analyzed and compared : fixed-priority, equal-priority, rotating-priority and round-robin priority schemes. For the study, the software simulator of a multiple-bus multiprocessor system is developed by using SLAM II. Simulation results show that, when memory sccesses are evenly distributed to all memory modulus, round-robin priority scheme provides the best performance. But when a hot spot exists, the use of the fixed priority scheme results in the shortest access time.

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VQS4 Mechanism for the Priority Control in ATM Traffic (ATM 트래픽 성능향상을 위한 대기행렬구조의 제안 및 평가)

  • 안정희
    • Proceedings of the Korea Society for Simulation Conference
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    • 1998.10a
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    • pp.147-150
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    • 1998
  • ATM 환경의 다양한 QOS를 갖는 트래픽의 우선순위제어를 위해, ATM 스위치의 출력 버퍼에 저장되는 셀의 큐메카니즘을 제안하였다. 제안한 큐 방식은 가변큐공유(VQS4 : Variable Queue Sharing with 4 queue)방식으로서 기존의 고정 큐 방식의 문제점인 버스트 트래픽으로 인한 큐 오버플로우의 문제점을 개선하기 위해 CBR 큐, VBR-rt큐, VBR_nrt 큐, ABR 큐의 영역을 가변적으로 공유하여 큐 자원의 이용율을 최대화시킴으로써 순간 버스트 트래픽 유입으로 인한 셀손실율을 최소화시킬 수 있는 특성을 제공한다. VQS4 방식의 성능을 평가하기 위해 버스트 특성이 강한 트래픽 패턴을 이용하여 고정 큐를 이용한 HOL과 제안 방식인 VQS4의 셀손실률 및 평균 지연률을 비교하였으며 시뮬레이터는 Visual Slam 2.0(AweSim)을 이용하여 작성했다.

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Simulation and Evaluation of Redistribution Algorithms In Fault-Tolerant Distributed System (결함허용 분산시스템의 재분배 알고리즘의 시뮬레이션과 평가)

  • 최병갑;이천희
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.8
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    • pp.1-10
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    • 1994
  • In this paper load redistribution algorithm to allow fault-tolerance by redistributing the workload of n failure nodes to the remaining good nodes in distributed systems are investigated. To evaluate the efficiency of the algorithms a simulation model of algorithms is developed using SLAM II simulation language. The job arrival rate service rate failure and repair rate of nodes and communication delay time due to load migraion are used as parameters. The result of the simulation shows that the job arrival rate failure and repair rate of nodes do not affected on the relative efficiency of algorithms. If the communication delay time is greater than average job processing time algorithm B is better. Otherwise algorithm C is superior to the others.

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Playout synchronization mechanism for delay-sensitive multimedia applications (지연에 민감한 멀티미디어 응용을 위한 재생 동기화 메카니즘)

  • 유상신;이성근;김덕진
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.4
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    • pp.57-67
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    • 1996
  • This paper aims to support delay-sensitive multimedia applications by suggesting a mechanism in which maintains almost constant end-to-end delay thus providing the optimum playout synchronization. For this task the sum of network delay and buffering delay is entiredly managed and to eliminate little delay fluctuations and instantaneous delays at a buffer and a network, a low pass filter is used. Furthermore the correction function, which is used for maintaining the buffering level ot a reference value, is a non-linear step function, unlike the existing linear and continuous function. it has a different step sizes adapting to a traffic characteristics of a network congestion. the proposed mechanism has been confirmed of it sefficiency through SLAM-II netowrk.

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An Implementation of Stereo Image Based Sighted Guiding Device Platform for the Visually Impaired (시각장애인을 위한 스테레오 영상기반 보행환경정보안내 단말 플랫폼 개발)

  • Oh, Bonjin;Park, Sangheon;Kim, Juwan
    • IEMEK Journal of Embedded Systems and Applications
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    • v.13 no.2
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    • pp.73-81
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    • 2018
  • This paper describes a device platform which the blind can wear to keep path and to get surrounding information during their independent walking. Compared to the existing technologies, the proposed device could be used indoors and outdoors, and maps need not be provided in advance. It is composed of a glasses type device equipped with image sensors, and a portable device that analyzes sensor data for sighted guiding. RGB images and depth images are extracted to generate a walking map based on feature points. It also can cope with the risk of collision with bollard, color cone by applying vertical obstacle detection technology based on floor detection.

An ABR flow control algorithm considering propagation delay (ATM 망에서 전파 지연을 고려한 ABR 흐름 제어)

  • 박기현;김승천;김동연;이재용;이상배
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.5
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    • pp.17-26
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    • 1998
  • B-ISDN has many advantages to provide multimedia, image transfer, etc. Recently, ABR service has been proposed in order to satisfy user's various requirements in it. In this paper, we propose a new ABR flow control algorithm called CAPRO. This algorithm uses the buffer proportional to propagation delay and controls the traffic on a link-by-link basis in order to minimize the effect of propagation delay. In order to use buffer more efficienctly, we define the request cell and the control cell. Then, we analyze our algorithm using mathematical model, simulate it using SLAM system, and compare to the existing EPRCA. As a result, our algorithm has the benifit of the throughput, cell loss probability, and fairness.

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The Reconstruction of Tomographic Images using STAM System (STAM 시스템을 이용한 토모그라픽 영상 복원)

  • Hwang, Ki-Hwan;Kim, Hyun;Kim, Jong-Chan;Jun, Kye-Suk
    • The Journal of the Acoustical Society of Korea
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    • v.17 no.8
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    • pp.88-92
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    • 1998
  • 본 논문에서는 다층구조물에 대한 토모그라픽 영상을 복원하기 위해 기존의 SLAM 시스템에 쿼드러쳐 검출기와 시료회전장치를 부가하여 STAM 시스템을 구성하고 BFP 알 고리즘을 이용하여 영상복원 프로그램을 개발하였다. 본 실험에서는 시료로서 알루미늄을 사용하여 2개 층이 서로 다른 패턴을 갖는 불균질 층을 만들고 그 사이를 물로써 채워진 다 층구조물을 구성하였으며 또한 불균질 층 간격을 각각 8λ, 10λ 그리고 12λ가 되도록 제 작하였다. 이들 시료는 STAM 시스템에서 4중 프로젝션(0°, 90°, 180°, 270°)시켜 토모 그라픽 데이터를 획득하고 이를 영상처리하여 토모그라픽 영상을 복원하였다. 영상분석 결 과, 본 STAM 시스템은 4중 프로젝션시 12λ의 불균질 층 간격에서 높은 분해능의 토모그 라픽 영상을 얻을 수 있었고 각 층에 대한 위치를 결정할 수 있었다.

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Dispatching rule of automated guided vehicle to minimize makespan under jobshop condtion (Jobshop환경에서 총처리시간을 최소화하기 위한 AGV의 할당규칙)

  • Choi, Jung-Sang;Kang, In-Seon;Park, Chan-Woong
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.24 no.62
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    • pp.97-109
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    • 2001
  • This research is concerned with jobshop scheduling problem for an advanced manufacturing system like flexible manufacturing which consists of two machine centers and a single automated guided vehicle(AGV). The objective is to develop and evaluate heuristic scheduling procedures that minimize makespan to be included travel time of AGV. A new heuristic algorithm is proposed and illustrates the proposed algorithm. The heuristic algorithm is implemented for various cases by SLAM II. The results show that the proposed algorithm provides better solutions in reduction ratio and frequency than the previous algorithm.

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