• Title/Summary/Keyword: Micro:bit

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크롬비트의 취약점 분석을 적용한 크롬 OS 보안 강화 방안 (Chrome OS Security Strength On Applying Vulnerable Analysis of ChromeBit)

  • 이슬기;유헌창
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2017년도 춘계학술발표대회
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    • pp.319-322
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    • 2017
  • 크롬비트는 크롬 OS를 기반으로 하여 사용자 맞춤형 클라우드 서비스를 제공하는 스틱 PC이다. 기존의 크롬북이 이동성을 강조한 외부 인터넷 환경에 특화된 기기라고 할 때, 크롬비트는 스마트 TV구축 등을 비롯한 내부 인터넷 환경에 특화된 기기라고 볼 수 있다. 이처럼 크롬 OS를 실내와 실외에서 사용 가능하다는 것을 감안한다면 클라우드와 사물인터넷 등을 매개로 하는 4차 산업 혁명에 가장 근접한 OS 임에 틀림이 없다. 그럼에도 불구하고 현재 이 운영체제의 개발 속도와 더불어 보안 취약점 분석을 위한 방안은 전혀 마련되어 있지 않다. 그래서 본 논문에서는 취약점 분석 쉘 스크립트 실행을 통한 성능 향상 방안 마련과 크롬 OS의 보안 성능 개선 여부 확인을 살펴보고자 한다.

공장 자동화에 관한 소고 : 그룹 테크놀로지를 이용한 생산원가 추정 (A Bit of Factory Automation : Manufacturing Cost Estimation Using Group Technology)

  • 이성렬
    • 대한산업공학회지
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    • 제15권2호
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    • pp.77-86
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    • 1989
  • A fully automated cost estimation system(FACES) has been developed. Since speed, accuracy, and consistency are essential factors in automating a cost estimation, the use of computers in cost estimation system(CES) has grown rapidly in the last few years. FACES is a micro computer based cost estimation system that employs a manufacturing knowledge base. A Group Technology(GT) based part classification and coding(C&C) scheme is used to automate the process planning aspects of cost estimation. Variant process planning methods are employed to generate workstation routings from form features of the part. The system has been tested for an assembly of six machined parts. Results indicate that the system could provide a substantial improvement in accuracy, productivity, and performance over the more traditional full dialog approach to cost estimation. It also provides a good foundation for a factory automation by using a common GT based database through design to production.

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트로틀 앵글 제어에 의한 내연기관의 토오크 및 속도의 비선형 제어 (Nonlinear Control of Torque and Speed of S.I.Engines Using Electric Throttle Control)

  • 원문철;강병배;박문수;김태영
    • 한국자동차공학회논문집
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    • 제7권6호
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    • pp.72-81
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    • 1999
  • A nonlinear engine torque and speed control algorithm using throttle angle control is developed with an engine load torque estimation algorithm. Three 3-dimensional nonlinear engine maps as a part of the nonlinear control algorithm are obtained from steady state engine dynamometer tests. An electric throttle actuator is developed using a stepper motor and a 8 bit micro-processor. The speed control and external load estimation algorithm are tested via engine speed control experiments, and show performance good enough for using various engine torque and speed control applications.

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2중 영 벡터 모드의 2상 SRP-PWM기반 인버터 구동장치의 스위칭 소음 스펙트럼 (Switching Noise Spectrum of 2-Phase SRP-PWM Based Inverter Fed Drives with Double Zero Vector Mode)

  • 김정근;오승열;임영철;정영국
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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    • pp.283-288
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    • 2004
  • In case while modulation index (M) is more than 0.7, the spectrum of motor voltage and current of a conventional two-phase SRP scheme are not reduced considerably. To solve the problems of a conventional two-phase SRP, this paper proposes a two-phase SRP(DZSRP) with double zero vector mode which zero vector is selected as V(111) in case of $M\;\geqq\;0.7$, and zero vector is selected as V(000) if M < 0.7. For the validity of the proposed method, a 16 bit micro-controller C167 was used and the experiments were conducted with the 1.5kw induction motor under load condition. And the experimental results show that the switching noise spectrum for all the M are spread to a wide band area.

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하드와이어드 방법으로 설계된 단일 칩 마이크로 컴퓨터의 제어부 설계 (The control part of 8 bit micro computer by hardwired design)

  • 류기철;박용수;류종필;정호선;이우일
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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    • pp.1499-1502
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    • 1987
  • The control part of one-chip microcomputer has been designed with the 3um design rule for CMOS poly silicon gate and Its cells were layed out. The operation of the logic circuits were simulated with EDAS_P. The widths and lengths of circuit were determined by using PSPICE. The control part of microcomputer has designed by using hardwired methode. Results of logic simulation and circuit simulation are in good agreements with expected circuit characteristics.

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Spray Characteristics of Hydrotreated Biodiesel Blended Fuels

  • Kim, Duckhan;Oh, Sehun;Kim, Seonghwan;No, Soo-Young
    • 한국분무공학회지
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    • 제18권4호
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    • pp.169-175
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    • 2013
  • Hydrotreated biodiesel (HBD) would be one of the promising alternative fuels instead of current biodiesel. In this study, spray characteristics in terms of spray penetration and spray angle were conducted experimentally including calculated SMDs as well. The ambient pressures of 1, 3, and 5 MPa and injection pressures of 30, 80, and 130 MPa were introduced and the fuels employed were petro-diesel, and 2, 10, 20, 30, and 50% for hydrotreated biodiesel, respectively. The result of this study found that the more HBD blended diesels have the slightly shorter spray tip penetration lengths especially on the lowest injection pressure and at the highest ambient pressure, but have the larger spray angles and SMDs than petro-diesel. Consequently, this study found that HBD has a little bit merits and demerits of macro- and micro- spray patterns compared to petro-diesel.

Microinstruction의 부호 할당에 관한 연구 (A Study on Code Assignment to Microinstructions)

  • 오창준;이철동;유영욱
    • 대한전자공학회논문지
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    • 제25권1호
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    • pp.108-114
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    • 1988
  • We have developed a program that minimizes the chip area with effective code assignment of microinstructions when the control part of VLSI system is implemented in the PLA. While conventional algorithms are composed of one pass, the algorithm proposed in this paper is composed of two passes and it consists of three principal procedures: a procedure for the determination of the code assignment order, a procedure for the code assignment and a procedure for the reduction of the code length. especially, we have proposed a new method of folding back for the reduction of the code length. We have obtained the result of 4 bit code length and 9 product terms when 11 micro-instructions and 6 microoperations were given as a inputs. Therefore, we have certified that it could be used efficiently for the control part of the processors.

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MPC5554를 이용한 HEV용 IPMSM 벡터제어 (IPMSM Vector Control using MPC5554 for HEV)

  • 문정송;이정효;하인용;원충연
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2010년도 춘계학술대회 논문집
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    • pp.213-219
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    • 2010
  • MCU(Micro Controller Unit) used for the automobiles has been required for improving of the safety and high reliability. Also, the necessity of high performance MCU equipped with high fuel-efficiency has been risen according to increased requests of high fuel-efficiency and improving the occupants safety with the development of intelligent vehicles and future vehicles. The MPC5554 32-bit embedded controller, made by Freescale Semiconductor, specialized in the part of the power train provides the high reliability, fast interrupt process and real-time control. In This paper, the investigation on IPMSM using MPC5554 has been performed. Also SVPWM(Space Vector Pulse Width Modulation) is implemented to the servo system.

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마이크로 프로세서로 손쉽게 구현 가능한 BLDC(Burshless DC)-모터 제어 알고리즘 (BLDC(Brushless DC) Motor Control Algorithm to be easily Realized by a Micro Processor)

  • 이영주
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
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    • pp.59-62
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    • 2002
  • BLDC motor is widely used in automation areas for its good maintenance and controllability. In this paper it is designed for a speed control servo system of sinusoidal typo BLDC motor that can be easily adapted to automation systems with lower cost. Also, control parameters & periods are made adjustable according to the sensors of the motor, electric and mechanical time constant, and PI and PD control are used. The processor for the proposed system is a low cost 16bit One-Chip microprocessor. By experimental results from application to the industrial sewing machine, one of the application of BLDC motor, it can be verified that under the given reference, the system is enough as a speed and position servo without overshoots.

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2중 영벡터 모드를 갖는 2상 공간벡터 SRP기반 유도모터 구동시스템의 스위칭 소음과 전도 노이즈 (Switching Noise and Conducted Noise of Two-Phase Space Vector SRP based Induction Motor Drives with Double Zero Vector Modes)

  • 김정근;임영철;정영국
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.109-113
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    • 2004
  • In case while modulation index (M) is more than 0.7, the spectrum of motor voltage and current of a conventional two-phase SRP scheme are not reduced considerably. To solve the problems of a conventional two-phase SRP, this paper proposes a two-phase SRP(DZSRP) with double zero vector mode which zero vector is selected as V(111) in case of M $\geq$ 0.7, and zero vector is selected as V(000) if M < 0.7. For the validity of the proposed method, a 16 bit micro-controller C167 was used and the experiments were conducted with the 1.5kw induction motor under load condition. And the experimental results show that the switching noise spectrum for all the M are spread to a wide band area. Also the switching noise and conducted noise are discussed.

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