• 제목/요약/키워드: Locking Control

검색결과 166건 처리시간 0.03초

철도 진로 제어 연동 로직의 표준화를 위한 연구 (A Study on the Standardization for Railway Route Control Locking Logic)

  • 정승기;김명수
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 추계학술대회 논문집
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    • pp.1220-1226
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    • 2008
  • A route control in railway is one of the very important system to operate a train. An efficient train route control assures to increase train operation performance with a same railway system. The erroneous route control can accompany serious accidents which occur train collision or derailment which provokes death. A Route control carries out exactly lest the accident should take place. An interlocking table is widely used for the exact route control. The table has the problem of its exactness proving because it has been established by experts. In this paper, We tried to formalize a route control using mathematical logic. A route consists of symbolized tracks, signals, switch and crossing. It represents as a set, respectively. We proposed route setting control logic, converted the elements to set logics and construct route logics with the set logics of the elements. Finally we proposed a model which presents a prototype routes and we proved the proposed logics using the proposed method.

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ABS 장착 자동차의 제어방식에 따른 제동특성에 관한 연구 (A Study on the Braking Characteristics of Control Methods for ABS mounted Vehicle)

  • 최종환;김승수;양순용;박성태;이진걸
    • 한국정밀공학회지
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    • 제19권8호
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    • pp.203-211
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    • 2002
  • ABS (Anti-lock Braking System) is a safety device for preventing wheel locking in a sudden braking. It consists of hydraulic modulator, ECU(Electronic Control Unit) and angular velocity sensors. Its control methods are classified into three types; deceleration control, slip ratio control and deceleration/acceleration control. In this paper, ABS mounted vehicle is mathematically modeled and the proposed model is verified by actual cars experiments, and the braking characteristics of the control methods with pulse width modulation are compared and analyzed through computer simulations.

0.11-2.5 GHz All-digital DLL for Mobile Memory Interface with Phase Sampling Window Adaptation to Reduce Jitter Accumulation

  • Chae, Joo-Hyung;Kim, Mino;Hong, Gi-Moon;Park, Jihwan;Ko, Hyeongjun;Shin, Woo-Yeol;Chi, Hankyu;Jeong, Deog-Kyoon;Kim, Suhwan
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제17권3호
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    • pp.411-424
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    • 2017
  • An all-digital delay-locked loop (DLL) for a mobile memory interface, which runs at 0.11-2.5 GHz with a phase-shift capability of $180^{\circ}$, has two internal DLLs: a global DLL which uses a time-to-digital converter to assist fast locking, and shuts down after locking to save power; and a local DLL which uses a phase detector with an adaptive phase sampling window (WPD) to reduce jitter accumulation. The WPD in the local DLL adjusts the width of its sampling window adaptively to control the loop bandwidth, thus reducing jitter induced by UP/DN dithering, input clock jitter, and supply/ground noise. Implemented in a 65 nm CMOS process, the DLL operates over 0.11-2.5 GHz. It locks within 6 clock cycles at 0.11 GHz, and within 17 clock cycles at 2.5 GHz. At 2.5 GHz, the integrated jitter is $954fs_{rms}$, and the long-term jitter is $2.33ps_{rms}/23.10ps_{pp}$. The ratio of the RMS jitter at the output to that at the input is about 1.17 at 2.5 GHz, when the sampling window of the WPD is being adjusted adaptively. The DLL consumes 1.77 mW/GHz and occupies $0.075mm^2$.

이질형 통합 데이타베이스 시스템의 전역 트랜잭션을 위한 병행수행 제어기법 (Concurrency Control for Global Transaction Management in Integrated Heterogeneous Database System)

  • 이규웅
    • 정보처리학회논문지D
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    • 제8D권5호
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    • pp.473-482
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    • 2001
  • 이질형 통합 데이타베이스 시스템은 비정형 데이타를 비롯하여 관계형 데이타베이스 시스템의 정형 데이타에 이르기까지, 지역적으로 여러곳에 산재해 있는 유용한 정보를 통합하여 일관된 인터페이스를 통한 접근을 제공하는 통합 데이타베이스 시스템이다. 통합된 데이타 자원들은 서로 다른 질의 처리 능력을 제공할 뿐 아니라, 지역 자치성(local autonomy)요구사항 때문에 전역적 트랜잭션 처리를 위한 지역 시스템의 상호 협조 운영이 불가능하여, 전역적 직렬성(global serializability)을 만족하는 전역 트랜잭션 관리기의 설계가 없다. 본 논문에서는 이질형 통합 데이타베이스 시스템의 전역 트랜잭션 관리 문제점 중에서 가장 잘 알려진 간접충돌의 문제를 해결하기 위해, 전역 무결성 제약사항의 특징을 이용한 전역 트랜잭션 모델을 정의한다. 전역 트랜잭션 모델을 기반으로 지역-로킹 연산과 이에 다른 프로토콜을 제안하고, 제안된 프로토콜이 전역 트랜잭션을 보장함을 증명한다. 또한 본 논문에서 제안된 지역 -로킹 병행수행 제어 방법은 보다 현실적인 간접충돌의 범위를 정의함으로써, 기존의 제안된 방법보다 높은 병행성 정도(concurrency degree)를 보장함을 지역 접근에 대한 경쟁률 분석을 통해 살펴본다.

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보안성을 갖춘 NFC 통신 및 생체정보 기반의 운전자 인증 및 차량 제어 시스템 제안 (Suggestion of Secure Driver Authentication and Vehicle Control System based on NFC Communication and Biometric Information)

  • 박태환;서화정;임지환;김호원
    • 한국정보통신학회논문지
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    • 제22권4호
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    • pp.700-707
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    • 2018
  • 자동차는 편리한 운송 기반 시설로써 우리생활에 폭넓게 활용되고 있으며, 운전자에 의해 차량의 모든 동작이 결정된다는 특징으로 운전자에 대한 적합한 인증이 중요하다. 특히 음주운전에 따른 다양한 사고로 인해 음주 시동 잠금장치 장착제도에 대한 도입 논의가 활발하며, 이러한 음주 시동 잠금장치 장착에 있어서 많은 비용과 시간이 소모된다는 단점이 있다. 장애인 및 국가유공자인 운전자에 대한 할인 혜택 제공에 있어서 사용자의 불편함 해소를 위한 적합한 사용자 인증이 필요한 상황이다. 이러한 문제점을 해결하고자 본 논문에서는 사용자의 스마트폰을 이용한 NFC 통신과 생체정보 기반의 운전자 인증을 통한 음주운전 방지, 장애인 및 국가유공자 혜택을 제공하는 효율적인 차량제어 및 사용자 인증 시스템을 제안하고자 한다.

Electronic Control of Braking Force Distribution for Vehicles Using a Direct Adaptive Fuzzy Controller

  • Kim, Hunmo;Kim, Seungdae;Sung, Yoon-Gyeoung
    • Journal of Mechanical Science and Technology
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    • 제15권1호
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    • pp.66-80
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    • 2001
  • In brake systems, a proportioning valve(P. V), which reduces the brake line pressure on each wheel cylinder for the anti-locking of rear wheels, is closely related to the safety of vehicles. However, it is impossible for current P. V. s to completely control brake line pressure because, mechanically, it is an open loop control system. In this paper we describe an electronic brake force distribution system using a direct adaptive fuzzy controller in order to completely control brake line pressure using a closed loop control system. The objective of the electronic brake force distribution system is to change the cut-in-pressure and the valve slop of the P. V in order to obtain better performance of the brake system than with mechanical systems.

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Tunable Photonic Microwave Delay Line Filter Based on Fabry-Perot Laser Diode

  • Heo, Sang-Hu;Kim, Junsu;Lee, Chung Ghiu;Park, Chang-Soo
    • Current Optics and Photonics
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    • 제2권1호
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    • pp.27-33
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    • 2018
  • We report the physical implementation of a tunable photonic microwave delay line filter based on injection locking of a single Fabry-Perot laser diode (FP-LD) to a reflective semiconductor optical amplifier (RSOA). The laser generates equally spaced multiple wavelengths and a single tapped-delay line can be obtained with a dispersive single mode fiber. The filter frequency response depends on the wavelength spacing and can be tuned by the temperature of the FP-LD varying lasing wavelength. For amplitude control of the wavelengths, we use gain saturation of the RSOA and the offset between the peak wavelengths of the FP-LD and the RSOA to decrease the amplitude difference in the wavelengths. From the temperature change of total $15^{\circ}C$, the filter, consisting of four flat wavelengths and two wavelengths with slightly lower amplitudes on both sides, has shown tunability of about 390 MHz.

SMA을 이용한 3차원 형상제시기의 와이어프레임 구동 유닛 (Wire frame drive unit ofa SMA-based 3D shape display)

  • 추용주;김영민;송재복;박신석
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2006년도 춘계학술대회 논문집
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    • pp.439-440
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    • 2006
  • This research proposes a novel method of shape display to present 3-dimensional objects. Shape displays allow us to feel the actual volume of the object, unlike conventional 2D visual displays of 3D objects. The proposed method employs a wire frame structure to present 3D objects. The wire frame is composed of small units driven by shape memory alloy(SMA) actuators. The drive unit is analogous to the agonist-antagonist system of animal musculoskeletal systems, where the SMA actuators serve as agonist and antagonist muscles. The force in the SMA actuator is controlled by electrical current. The drive unit is equipped with the locking mechanism so that it can sustain the external force exerted by the user as well as the own weight of the wire frame structure. By controlling the current into the SMA actuator and locking mechanism, we call control the angle of the drive unit. A chain of drive units enables presentation of 2 dimensional objects. 3 dimensional presentations are possible by collecting the chains of drive units.

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2차원 형상 제시를 위한 SMA에 기반한 와이어프레임 구조의 개발 (Development of SMA-based Wireframe Structure for 2D Shape Display)

  • 추용주;송재복
    • 한국정밀공학회지
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    • 제25권5호
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    • pp.82-88
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    • 2008
  • This paper proposes a novel method of 2 dimensional shape display. Shape displays allow us to feel tile actual volume of the object, unlike conventional 2D visual displays of 3D objects. The proposed method employs a wireframe structure to present 2D or 3D objects. The wireframe is composed of small units driven by shape memory alloy (SMA) actuators. The drive unit is analogous to the agonist-antagonist system of animal musculoskeletal systems, where the SMA actuators serve as agonist and antagonist muscles. The force in the SMA actuator is controlled by electrical current. The drive unit is equipped with the locking mechanism so that it can sustain the external force exerted by the user as well as the own weight of the wireframe structure. By controlling the current into the SMA actuator and locking mechanism, we can control the angle of the drive unit. A chain of drive units enables presentation of 2 dimensional objects. 3 dimensional presentations are possible by collecting the chains of drive units.

Fractional-N 방식의 주파수 합성기 설계 (A design of fractional-N phase lock loop)

  • 김민아;최영식
    • 한국정보통신학회논문지
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    • 제11권8호
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    • pp.1558-1563
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    • 2007
  • 논문은 fractional-N 방식의 주파수 합성기(PLL)를 낮은 차수의 ${\Delta}{\Sigma}$변조기로 더욱 높은 성능의 PLL로 설계하기 위하여 대역폭 가변 방식의 PLL과 ${\Delta}{\Sigma}$방식의 fractional-N PLL의 구조를 합성한 새로운 방식의 PLL을 제안한다. Matla으로 대역폭 가변을 이용한 ${\Delta}{\Sigma}$방식의 fractional-N PLL의 시뮬레이션을 수행하여 제안된 구조의 특성을 관찰하였다. 본 논문의 대역폭 가변 PLL은 HSPICE 0.35um CMOS 공정을 이용하여 시뮬레이션 하였고, 그 결과 제안된 PLL은 빠른 록이 가능하고 fractional spur를 20dB 정도 낮출 수 있었다.