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A Study on the Modelling and Control Method of an Anti - lock Brake System

  • Ki, Lim-Chul;Hoon, Song-Jeong;Suck, Boo-Kwang
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.112-112
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    • 2001
  • An Anti-lock Brake System ABS is developed to increase the stability of vehicle and to reduce the stopping distance when braking manoeuvres by measuring the wheel and vehicle speed. An ABS mathematical model which describes the dynamics of vehicle and calculate the stopping distance, is explained in this paper. To proceed this study, a mathematical model is produced with simulink software package. Although the model considered here is relatively simple, it retains the essential dynamics of the system. The results are evaluated at the various driving or road conditions. The results from mathematical model show that ABS reduces the stopping distance at the various road conditions. This mathematical model could be ...

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Feedback Control of a Circular Cylinder Wake with Rotational Oscillation (주기적 회전을 이용한 원봉 후류의 되먹임 제어)

  • Lee S. B.;Baek S.-J.;Sung H. J.
    • 한국전산유체공학회:학술대회논문집
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    • 2005.04a
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    • pp.51-56
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    • 2005
  • A new feedback control system based on system identification is proposed and preliminarily tested on Van der Pol equation which has a similar characteristic to circular cylinder. The same principle is applicable to circular cylinder in a uniform flow for suppresing the vortex shedding. The feedback controller is designed to impose feedback signal at the phase which is located outside the range of lock-on. The lift coefficient (CL) is employed as a feedback signal and the control forcing is given by a rotational oscillation of the cylinder. By applying the feedback control system, the lift coefficient is reduced.

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Study of Shape Optimization for Automobile Lock-up Clutch Piston Design with B-spline Curve Fitting and Simplex Method (B-spline Curve Fitting 과 심플렉스법을 적용한 자동차 록업클러치 피스톤 형상최적설계에 관한 연구)

  • Kim, Choel;Hyun, Seok-Jeong;Son, Jong-Ho;Shin, Se-Hyun
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1334-1339
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    • 2003
  • An efficient method is developed for the shape optimization of 2-D structures. The sequential linear programming is used for minimization problems. Selected set of master nodes are employed as design variables and assigned to move towards the normal direction. After adapting the nodes on the design boundary, the B-spline curves and mesh smoothing schemes are used to maintain the finite element in good quality. Finally, a numerical implementation of optimum design of an automobile torque converter piston subjected to pressure and centrifugal loads is presented. The results shows additional weight up to 13% may be saved after the shape optimization.

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Equivalent Circuit Constants and Characteristics Calculation of LIM by Lock test (구속시험에 의한 선형 유도 전동기의 등가회로 정수 산정 및 특성 계산)

  • 김규탁;강규홍;최태희;이정규
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.43 no.4
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    • pp.580-586
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    • 1994
  • The equivalent circuit of linear induction motor is generally expressed as the same that of rotary induction motor. However, it is almost impossible to perform the no-load test for LIM, because it needs a special equipment for synchronous speed. Therefore, a new method is reqnired to calculate the performance of the LIM without the no-load test. In this paper, The new method which does not need no-load test for the chanracteristics analysis of LIM is proposed. The equivalent circuit of LIM is chosen and the method if determining its constants from results of the lock test is discussed. The calculated results were satisfied by compare with experimental and conventional method results.

EQUIVALENT CIRCUIT AND CHARACTERSTICS CALCULATION OF LIM BY THE LOCK TEST (구속 시험에 의한 선형 유도 전동기의 등가회로 및 특성계산)

  • Kim, Gyu-Tak;Kang, Gyu-Hong;Choi, Tae-Hee;Lee, Jung-Gyu
    • Proceedings of the KIEE Conference
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    • 1993.07a
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    • pp.6-8
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    • 1993
  • In this paper, we proposed a new method which does not need no load test for the characteristics analysis of linear induction motor. A new equivalent circuit of LIM is chosen and a method of determining its constants from results of the lock test is discussed. The calculated results were satisfactorily agreed with experimental results and conventional method.

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Study on Current Limiting Characteristics of a Flux-locktype SFCL using Series Connected Two Coils with Twice Triggering Operation

  • Han, Tae-Hee;Ko, Seok-Cheol;Lee, Byongjun;Lim, Sung-Hun
    • Journal of Electrical Engineering and Technology
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    • v.9 no.3
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    • pp.777-781
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    • 2014
  • The current limiting characteristics of the flux-lock type superconducting fault current limiter (SFCL) using series connected two coils with twice triggering operation, which consists of series connected two coils and two superconducting (SC) modules with the inserting resistance, was analyzed. The feature of the suggested SFCL is that it can limit the fault current by triggering either one SC module or two SC modules comprising the SFCL depending on the amplitude of the fault current. To verify the current limiting operation of the suggested SFCL, the short-circuits in the fault location with the different fault currents were tested and its useful operations were described through the analysis on the tested results.

EQUIVALENT CIRCUIT AND CHARACTERISTICS CALCULATION OF LIM BY THE LOCK TEST (구속 시험에 의한 선형 유도 전동기의 등가회로 및 특성계산)

  • Kim, Gyu-Tak;Kang, Gyu-Hong;Choi, Tae-Hee;Lee, Jung-Gyu
    • Proceedings of the KIEE Conference
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    • 1993.07b
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    • pp.540-542
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    • 1993
  • In this paper, we proposed a new method which does not need no load test for the characteristics analysis of linear induction motor. A new equivalent circuit of LIM is chosen and a method of determining its constants from results of the lock test is discussed. The calculated results were satisfactorily agreed with experimental results and conventional method.

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A Study on Optimizing LRU lock for Improving Parallel I/O Throughout in Manycore CPU Systems (매니코어 CPU 시스템에서의 병렬 I/O 성능 향상을 위한 LRU 최적화 기법 연구)

  • Byun, Eun-Kyu;Bang, Jiwoo;Gu, Gibeom;Oh, Kwang-Jin
    • Proceedings of the Korea Information Processing Society Conference
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    • 2022.11a
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    • pp.2-4
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    • 2022
  • 매니코어 CPU 시스템에서의 병렬 I/O 는 현재의 리눅스 시스템의 LRU 관리 방법의 한계로 확장성에 문제를 가지고 있다. 본 연구에서는 이 문제를 해결했던 하기 위한 개선된 FinerLRU 를 제안한다. LRU 락을 최대 코어 개수만큼 증가시키고 세분화된 Lock 관리를 통해 버퍼 캐시를 사용하는 파일 시스템의 병렬 I/O 성능을 향상시킨다. 리눅스 5.18.11 에 제안한 방법을 구현하였으며, 64 개의 물리적 코어와 256 개의 논리적 코어를 가지는 Intel Knights Landing 프로세서를 이용한 실험을 통해 두 배 가량의 성능 향상을 얻을 수 있음을 확인하였다.

A Study on Defense Technique Against Use-After-Free Attacks Using MTE (MTE 를 활용한 사용 후 해제 공격 방어기법 연구)

  • Yunseong Hwang;Junseung You;Yunheung Paek
    • Proceedings of the Korea Information Processing Society Conference
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    • 2024.05a
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    • pp.279-282
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    • 2024
  • The Use-after-free (UAF) bug is a long-standing temporal memory safety issue. To prevent UAF attacks, two commonly used approaches are lock-and-key and pointer nullification. Recently, ARM architecture supports the Memory Tagging Extension (MTE) that implemented a lock-and-key mechanism using a 4-bit tag during memory access. Previous research proposed a virtual address tagging scheme utilizing MTE to prevent UAF attacks. In this paper, we aimed to measure a simplified version of the previously proposed virtual address tagging scheme on real machines supporting MTE by implementing a simple module and conducting experiments.

Design and Implement a Smart Control System of Door Security Guard (도어 안전고리 스마트 제어시스템 설계 및 구현)

  • Lee, Hyo Seung;Oh, Jae Chul
    • Smart Media Journal
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    • v.6 no.1
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    • pp.61-67
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    • 2017
  • A large number of people living in modern times prefer remaining unmarried or living alone independently for the reason of their own will or another person's will. This is because they dislike being interfered with by other persons or because there is a financial problem. This behavior has become mainstream in persons working for professional jobs, persons having a strong disposition toward individual activity or college students. In particular, career women pursuing their own comfortable life have the tendency to prefer single life. However, sometimes, they become a target of crime that targets and makes bad use of this point. For these reasons. Consequently, sometimes, they additionally install and use a security system such as door security guard at front door and so on. It is not so difficult to lock the door security guard at the front door. However, it is apt to be forgotten. And when they are on the bedspread before falling asleep, in case they should check whether the door security guard is locked or in case they should lock it, they should get up, go to the entrance, and check and lock the door security guard. They often don't lock the door security guard due to their feeling that it is all right because of annoyance and inconvenience. This paper is intended to work for safety from crime such as illegal housebreaking by more conveniently using the door security guard after designing and implementing a system that can remotely control the door security guard, using a smartphone as a method of resolving this annoyance and keeping life more safe.