• Title/Summary/Keyword: locking system

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Space maintainer using CAD/CAM system without a band: a case report (CAD/CAM 시스템을 이용하여 band 없이 공간유지 장치를 제작한 증례)

  • Eun-Sook Kang
    • Journal of Dental Rehabilitation and Applied Science
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    • v.40 no.2
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    • pp.100-106
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    • 2024
  • Early interceptive orthodontic interventions are often started in the developing dentition to guide normal occlusion. The simplest way to prevent eruption failure from deciduous tooth loss is to fix a space maintainer such as a band and loop. Band and loop space maintainer has several problems like cement loss, demineralization, locking of the adjacent tooth, and needs to take a pickup impression of the band. Computer-assisted design/computer-assisted manufacturing (CAD/CAM) space maintainer without band was developed to solve these problems. This case report describes successful eruption of the mandibular second premolar using CAD/CAM without a band.

A Study on a Fuzzy Controller for the Electronic Braking Force Distribution System (전자식 차량 제동력 배분 시스템을 위한 퍼지제어기의 연구)

  • 김승대;김훈모
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.6
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    • pp.220-229
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    • 2000
  • In the brake systems a proportioning valve which reduces the brake pressure at each wheel cylinder for anti-locking of rear wheels is closely related with the safety of vehicles. But, it is impossible for a present proportioning valve to exactly control brake pressure because mechanically it is an open loop control system. So, in this paper we describe a electronic brake pressure distribution system using a fuzzy controller in order to exactly control brake pressure using a close loop control system. The object of electronic brake pressure distribution system is to change an cut-in pressure and an valve slop of proportioning valve in order to obtain better good performance of brake system than with mechanical system.

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Architecture design and FPGA implementation of a system control unit for a multiprocessor chip (다중 프로세서 칩을 위한 시스템 제어 장치의 구조설계 및 FPGA 구현)

  • 박성모;정갑천
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.34C no.12
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    • pp.9-19
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    • 1997
  • This paper describes the design and FPGA implementation of a system control unit within a multiprocessor chip which can be used as a node processor ina massively parallel processing (MPP) caches, memory management units, a bus unit and a system control unit. Major functions of the system control unit are locking/unlocking of the shared variables of protected access, synchronization of instruction execution among four integer untis, control of interrupts, generation control of processor's status, etc. The system control unit was modeled in very high level using verilog HDL. Then, it was simulated and verified in an environment where trap handler and external interrupt controller were added. Functional blocks of the system control unit were changed into RTL(register transfer level) model and synthesized using xilinx FPGA cell library in synopsys tool. The synthesized system control unit was implemented by Xilinx FPGA chip (XC4025EPG299) after timing verification.

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Development of a Sliding-Plug Entrance Door System for Urban Electric Transit Unit to Reduce Inside Noise Level (전동차 소음저감을 위한 슬라이딩플러그 출입문 개발)

  • 서승일;임영호;신동국
    • Journal of the Korean Society for Railway
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    • v.5 no.2
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    • pp.112-117
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    • 2002
  • Reduction of noise level in the cabin of urban transit unit is an important issue to enhance the comfortability of passengers. It is made clear that a cause of increased noise level in cabin is the imperfect airtightness of entrance doors. In this study, the sliding-plug door system is developed to reduce the noise level of cabins by securing the airtightness of entrance door. The sliding-plug door system is composed of air-driven engine, swing arms, guide rails, guide rollers and locking devices. It is economical owing to using the previous door engine system. It is also adequate for the platform system of our subway station. It was tested to prove the reliability of system and was applied to standard urban transit unit. The effectiveness of noise reduction in cabin resulting form the sliding-plug door system was confirmed by test results.

An Efficient Dispatching Rule for AGVs in Automated Manufacturing Systems (자동생산시스템에서의 효율적인 AGV 운영규칙에 관한 연구)

  • Lee Yeong-Hae;Han Sang-Don
    • Journal of the military operations research society of Korea
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    • v.17 no.2
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    • pp.90-99
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    • 1991
  • In this paper a dispatching rule, $D^{*}$, for AGV operations in automated manufacturing system is proposed to improve the performance measures. And the algorithm is compared with existing heuristic rules via simulation to evaluate its capabilities. It is shown that the proposed rule enhances mean flow time, makespan and throughput, and avoids the locking phenominon which can be fatal to the operation of automated manufacturing systems.

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A simulation study on the dynamics of an antiskid brake systems for automotive vehicles (자동차용 미끄럼 방지 제동 장치의 동특성에 관한 시뮬레이션 연구)

  • 김경훈;조형석;홍예선
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10a
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    • pp.315-320
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    • 1988
  • This paper considers modelling and control of ABS(Anti-skid Brake System) which avoids dangerous wheel locking due to excessive brake pressure during the vehicle braking. The brake pressure is controlled by on and off's of solenoid valves via the variation of the wheel circumferential deceleration measured using tacho-sensors. The dynamic model between the brake pressure and the wheel acceleration of a vehicle is mathematically derived. The computer simulation shows that the threshold value of the on-off control is critical to the performance of the ABS.

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A study on the Frequency control of HF Synthesizer using a Phase-Locked Loop (PLL을 이용한 HF 대 합성기의 주파수 조정에 관한 연구)

  • Song, Weon-Yong;Kim, Kyung-Gi
    • Proceedings of the KIEE Conference
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    • 1987.11a
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    • pp.86-89
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    • 1987
  • This paper treats with the design and fabrication of a frequency synthesizer for the generation of intermediate frequency of a HF band transceiver. The synthesizer is designed to control frequencies using a phase-locked loop and it is shown that method improved the performance of frequency accuracy and locking time then that of the crystal-reference system.

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Stereo Object Tracking System using Block-based MSE Algorithm af Optical BPEJTC (블록기반의 MSE 알고리즘과 광 BPEJTC를 이용한 스테레오 물체 추적 시스템)

  • 고정환;이재수;김은수
    • Proceedings of the Optical Society of Korea Conference
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    • 2001.02a
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    • pp.68-69
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    • 2001
  • 스테레오 물체 추적을 위해서는 추적 물체의 현재 위치를 추출하는 것이 선행 되어야한다. 입력된 좌측 영상과 이전 프레임에서 얻은 윈도우 마스크(window mask)의 기준 영상간에 식 (1)의 MSE 알고리즘을 적용하였다. 여기에서 윈도우 마스크의 기준 영상은 초기에만 추적을 원하는 물체를 마스크로 잡아(locking) 초기화 시켜 주면, 이후에는 스스로 계속 갱신(update)하게 된다. (중략)

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Strength Analysis for Compressed Coil Spring in the Gage - Adjustable Wheelset System (궤간 가변 윤축의 압축스프링에 대한 강도해석)

  • Kim, Chul-Su;Ahn, Seung-Ho;Chung, Kwang-Woo;Jang, Seung-Ho;Jang, Kook-Jin;Kim, Jung-Kyu
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.1012-1017
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    • 2007
  • To reduce the cost and the time of transport in Eurasian railroad networks such as TKR(Trans-Korea Railway), TCR(Trans-China Railway) and TSR(Trans-Siberia Railway) owing to the problem of different track gauges (narrow/standard/broad gauge), it is important to develop the gauge - adjustable wheelset system to adapt easily to these gauges. Moreover, this system accomplishes periodically a conversion operation from the gauge variable segment between different gauge. Gauge adjustable compression coil spring during conversion process accomplishes repetitively a central role for operation mechanism between flange and locking part. Therefore, to assure the safety of the gauge-adjustment wheelset system, it is necessary to stress analysis of the optimized spring in the system. In this study, it was performed to optimal design of the spring for stress analysis by using the genetic algorithm.

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A Study on Efficient Interface between Point Machine and Interlocking System for High Speed and Conventional Railroad (고속 및 일반철도용 연동장치와 선로전환기간 효율적 인터페이스 방안 연구)

  • Lee, Jae-Ho;Kang, Shin-Ju
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.12
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    • pp.1747-1751
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    • 2014
  • Interlocking system along with point machine for efficient route control secures safety of train operation by interchanging information each other. However, various types of interlocking system and point machine operating on bender specific interface bring obstacles to effective maintenance and safety. In this paper, we have investigated on interface methods to suggest standard interface module applicable to various operating system