• 전자공학회논문지SC
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• 제46권4호
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• pp.64-69
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• 2009

본 논문은 모바일 디스플레이모듈의 signal integrity와 power integrity의 시뮬레이션 방법에 관한 것이다. 본 제안 방법은 커넥터, FPCB, 드라이버IC를 포함하는 회로모듈 해석에 사용할 수 있다. 최근에 모바일 디스플레이 업계의 시리얼 인터커넥션기술에 대한 필요성 대두로 시스템오동작 방지 및 전자기파 발생을 억제하기 위해 신호선과 전원전압에 대한 섬세한 컨트롤이 필요하다. S파라미터와 Z파라미터 분석으로 주파수 도메인과 시간 도메인에서의 상관관계를 분석한다. 멀티포트 매크로를 이용하여 시간 도메인에서 sigh integrity를 power integrity에 함께 분석할 수 있다.

• 드라이브 ㆍ 컨트롤
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• 제12권4호
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• pp.54-59
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• 2015

Due to the tendency to use high speed pneumatic cylinders to improve productivity, cushioning devices are adopted to decelerate the piston motion of pneumatic cylinders to reduce noise, vibration, and impact. This paper presents a comparison of the cushion characteristics of a high speed pneumatic cylinder with a relief valve type cushioning device. The system parameters selected are the damping coefficient, Coulomb friction, heat transfer coefficient, and cracking pressure of the relief valve in the air cushioning device. The integral of the time multiplied square error (ITSE) is used to quantitative measure the cushioning performance to assess the effect of varying these. The cushioning performance achieved good results when the ITSE is a minimum value. In a comparison of the piston displacement and velocity with the variations in system parameters, the heat transfer coefficients are not as significantly affected as the other. Also, the cracking pressure of the relief valve is mainly affected by the pressure and temperature in the cushion chamber.

• 드라이브 ㆍ 컨트롤
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• 제15권1호
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• pp.16-27
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• 2018

Hydraulic torque load simulator is essential to test and qualify the performance of various angle control systems. Typically a flapper-type second stage servovalve is applied to the load simulator, but here the direct drive servovalve, which is a kind of one-stage valve and affected by the large flow force, is applied. Since the torque load is applied not to the stationary shaft but to the rotating shaft of the angle control system, the controlled torque of load simulator is not accurate due to the rotating speed of the angle control system. A feedforward compensator is designed and applied to minimize the disturbance-like effect. A mathematical model is derived and linearized to analyze the stability, accuracy and responsiveness of the torque load simulator. The parameter effects of a controller, servovalve, hydraulic motor, rotating spring shaft are analyzed and summarized. The goodness of the linear analysis is verified by the digital computer simulations using both the linear and nonlinear mathematical models.

• 한국통신학회논문지
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• 제17권12호
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• pp.1423-1436
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• 1992

이 논문에서는 멀티태스킹을 지원하는 CAT인터페이스를 구현하였다. 컴퓨터와 계측기를 연결하기 위해 인터페이스 카드를 제작하고 구현하였다. OOP와 CUI를 사용한 컨트롤과 디스플레이는 C++로 프로그램되었다. 스펙트럼 분석기와 전력계가 제어할 계측기로 선택되었다. 9개의 모듈이 여러가지 자원을 공유하도록 구성되었다. 또한, 여러대의 계측기를 동시에 측정하기 위해 멀티태스킹이 구현되었다. 멀티태스킹은 시간분할 DOS환경에서 수행되었다. 멀티태스킹은 프로세싱 기법으로 트레드 방식을 사용하였고 스케줄링으로 라운드 로빈방식을 사용하였다. 다른 목적계측기를 위해서는 목적 계측을 구동할 소프트웨어만 합하면, 시스템은 더 많은 계측기를 컴퓨터에 의해 동시 측정할 수 있다. 사용자는 전문가적인 지식없이 시간과 오차를 줄일 수 있다.

• 한국정보과학회논문지:시스템및이론
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• 제33권12호
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• pp.859-866
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• 2006

그리드 포탈 서비스는 기존의 어플리케이션 기반 그리드 서비스가 갖는 시간적 공간적 제약을 극복하여 보다 유연한 연구 환경을 제공한다. 그러나 사용자 인터페이스와 같은 사용자 요구 사항은 개발 기간 동안 불분명하기도 하고 자주 변하기도 한다. 그러므로 그리드 서비스를 위한 사용자 인터페이스를 만들고 유지 관리하는 비용을 줄일 수 있는 방안이 필요하다. 본 논문에서는 유저 인터페이스 개발이 보다 쉽고 코드의 재사용률을 증가시킬 수 있는 객체 기반의 컨트롤 모델을 제안한다. 이 모델에서는 프레젠테이션 페이지의 구조를 보다 명확히 기술할 수 있고 액션들을 구현하는 것이 보다 쉽고 간단하다.

• 드라이브 ㆍ 컨트롤
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• 제11권1호
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• pp.1-7
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• 2014

This paper presents a novel concept of wave energy converter for electric generation from the ocean wave energy. In this paper, a Multi-Point Absorbing Wave Energy Converter, shortened as MPAWEC by using Secondary Control Hydrostatic Transmission (SCHST) was proposed. The power take-off (PTO) system in the proposed MPAWEC includes multi heaving buoys to drive hydraulic pumps placed at different points. The application of SCHST in MPAWEC gives some advantages, such as longevity of hydraulic components; more energy is harvested; the variation of the pressure in the accumulator limited; therefore the accumulator volume is reduced and the output speed is more stable, etc. A PID controller was designed for speed control of the hydraulic motor. The simulation results indicated that the speed of the generator was ensured with the relative error as 0.67%; the efficiency of the proposed system was 71.4%.

• 한국자동차공학회논문집
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• 제22권2호
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• pp.17-22
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• 2014

Recently, the quick heating performance is an important issue in the car because engine power becomes so high. So car makers have been adapted the additional heating devices as like PTC(Positive Temperature Coefficient) heater. And the quick cooling performance is also important issue because its result is used in the IQS(Initial Quality Study). In this paper, control of the HVAC(Heating, Ventilation and Air Conditioning) intake door has been studied for the quick heating and cooling performance. Heating performance is improved $4.0^{\circ}C$ at $-20^{\circ}C$ ambient temperature after 20 minutes. And cooling performance is improved $1.5^{\circ}C$ at $35^{\circ}C$ ambient temperature after 10 minutes. In addition, intake door control system brings on the cost reduction because the flab door can be eliminated. This intake door control system has been adapted to the new developing cars.

• 드라이브 ㆍ 컨트롤
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• 제15권3호
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• pp.43-48
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• 2018

The hydraulic control valve, used in the CPB (cold-pad-Batch) cold dyeing system, passes through a pressurized material that absorbs the dye. The hydraulic control of the hydraulic control panel shall be driven in a uniform and precisely controlled manner, as it interferes directly with the dyschromatism. In this study, an acceleration test model was employed to verify the durability of the hydraulic control of the hydraulic control panel, which was manufactured by the scenic model, and the pre-roll angle was analyzed before the performance of acceleration test. Based on the change in the amount of deformation of the padder roll the durability of the padder roll was analyzed along with verification of the durability of the skin and the rubber coating in contact with the fabric. Furthermore, the accelerated test method used for hydraulic controlled multi-cell padder rolls was verified.

• 드라이브 ㆍ 컨트롤
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• 제9권4호
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• pp.8-13
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• 2012

Recently, researches about the eco-friendly vehicles such as hybrid electric vehicle, fuel cell vehicle and electric vehicle have been actively carried out. The regenerative braking system is a key technology to improve the vehicle energy utilization efficiency because it transforms the kinetic energy to the electric energy through the electric motor. This new braking system requires cooperative control between electric controlled brake and regenerative brake. Therefore, it is necessary to establish fault-diagnosis and fail-safe evaluation criteria to secure reliability of the regenerative braking system. In this paper, the failure types and causes in regenerative braking system were analyzed. The transient behavior characteristics were examined based on fault-diagnosis and fail-safe upon failure of regenerative braking system.

• 드라이브 ㆍ 컨트롤
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• 제10권2호
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• pp.23-29
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• 2013

The excavator is used in a variety of construction environments. There are many kinds of risk like falling rocks or harmful dust. The excavator cabin protects the operator not only from these harmful environments but also provides a comfortable working environment. By the way, the excavator cabin consumes a lot of energy for cabin air conditioner. For this reason, the research is required to reduce energy consumption. This study suggests the air conditioning system for excavator using forced exhaust. First, the forced exhaust system simulated by AMESim tool and surveyed the applicability. Using AMESim simulation, it was investigated the effect of cabin inside temperature by intake flow rate and intake air temperature. The experiment executed using the 1.5 ton excavator and field tested according to the intake flow rate. Finally, verified the applicability on the air conditioning system for excavator using forced exhaust.