• 반도체디스플레이기술학회지
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• 제9권4호
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• pp.45-50
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• 2010

This paper explores a new approach for modeling of decision-making problems that involve uncertain, time-dependent and sequence-dependent processes which can be applied to semiconductor industry. In the proposed approach, which is based on probability theory, approximate sample paths are required to be specified by probability and statistic characteristics. Completely specified sample paths are seen to be elementary and fundamental outcomes of the related experiment. The proposed approach is suitable for modeling real processes more accurately. A case study is applied to a single item production planning problem with continuous and uncertain demand and the solution obtained by the approximate path specification method shows less computational efforts and practically desirable features. The application possibility and general plan of the proposed approach in semiconductor manufacturing process is also described in the paper.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.410-413
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• 2000

This paper suggests a methodology in which control signals for high-level synthesis are generated from SDL specification. SDL is based on EFSM(Extended Finite State Machine) model. Data path and control part are partitioned into representing data operations in the from of scheduled data flow graph and process behavior of an SDL code in forms of an abstract FSM. Resource allocation is performed based on the suggested architecture model and local control signals to drive allocated functional blocks are incorporated into an abstract FSM extracted from an SDL process specification. Data path and global controller acquired through suggested methodology are combined into structural VHDL representation and correctness of behavior for final circuit is verified through waveform simulation.

• 한국정보처리학회논문지
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• 제2권2호
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• pp.254-263
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• 1995

본 논문은 파이프라인 방식의 ASIC 데이타 경로를 제어하기 위한 무어 및 밀리식 의 시간 정지형 콘트롤러에 관한 연구이다. 조건분기(conditional branches)를 가진 데이타흐름도로 부터 무어 및 밀리식의 유한상태기(finite state machine) 콘트롤러 를 합성하는 방법을 소개한다. 콘트롤 합성은 콘트롤 명세서의 작성과 유한상태기의 합성으로 구성된다. 콘트롤 명세서를 작성하기 위한 과정들을 통해 상태표(state table)의 형태로 표현되는 유한상태기의 내역이 작성된다. 이 유한상태기를 여러 가지 다른 방식의 분할 과정과 축소화 과정을 거쳐 최소 면적을 가진 콘트롤러가 합성된다. 실험을 통해 두가지 콜트롤 방식의 특성을 비교하며 또한 두 모델의 비용과 성능의 영향 관계를 보여준다.

• 정보처리학회논문지D
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• 제14D권2호
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• pp.191-202
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• 2007

일반적으로 테스트 데이터 생성 방법들은 테스트 데이터를 자동으로 생성하기 위해서 완전한 프로그램 경로를 기술한 것을 요구한다. 이 논문에서는 프로그램 경로를 완전하게 명시하지 않아도 테스트 데이터를 자동으로 생성하는 새로운 방법을 제안한다. 이를 위해 이 논문에서는 테스트 대상 프로그램을 1차 관계 논리 언어인 Alloy로 변환하고 Alloy 분석기를 통하여 테스트 데이터를 생성하는 방법을 제안한다. 제안된 방법은 사용자로 하여금 프로그램 경로를 선택하도록 하는 부담을 덜어줄 뿐만 아니라 다양한 테스트 적합성 기준에 따라 테스트 데이터를 생성하는 일을 용이하게 한다. 간단하지만 설명에 도움이 될 수 있는 예들을 통하여 제안한 방법에 대해 설명한다.

• 한국멀티미디어학회논문지
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• 제2권2호
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• pp.200-216
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• 1999

본 연구에는 멀티미디어 타이틀의 저작과 동기화 문제를 효과적으로 명세하고 분석할 수 있으며, 타이틀의 재생을 직접 제어할 수 있는 통합모형인 BTPN모형과 패러다임들을 제시한다 타이틀내의 객체들간의 모든 관계들을 BTPN구조와 BTPN언어로 명세하는 방법과 잔여시간형 도달성그래프, 타이밍다이어그램 둥을 이용하여 BTPN을 분석하는 방법을 제시하였다. 특히, PERT/CPM방법으로부터 도입한 임계객체경로나 최 장경로 개념은 타이틀 저작 및 재생시의 불확실성을 모형화하며 재생시간의 조정도 가능하게 하고 있다.

• 한국소음진동공학회논문집
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• 제12권10호
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• pp.758-765
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• 2002

KITECH and ODS performed a study of internal and external noise prediction of the Korean high speed prototype test train(HSR 350X). The object of this study was 3 kinds of cars, trailer car(TT2), motorized car(TMI ) and power car(TPI) and the predicted noise was for the two different driving speeds in free field and tunnel conditions. Data of carbody design and noise sources were delivered from manufactures. Some of noise sources which were not available in the project team, were chosen by experiences of ODS. Internal noise level of each car was predicted for two cases i.e, at 300 km/h and 350 km/h. In addition sound transmission path and dominant noise sources were also investigated for each section of the car, which is circular shell typed part of whole carbody. In case of TT2, the dominating sound transmission path is the (floor in terms of structure-borne noise and air-borne noise. The main noise sources are structure-borne noise from the yaw-damper and air-borne noise from the wheel/rail contact, whereas the dominating sound transmission path of TMI are floor and sidewall below the window in terms of structure-borne noise. The main noise sources of TMI are structure-borne noise from motor/gear unit and the yaw-damper in the free field, and air-borne noise from the wheel/rail contact and structure-borne noise from motor/gear unit in the tunnel. Through the external noise prediction for the KHST test train formation, the noise form the wheel/rail contact is estimated as one of the major sources. In addition, the noise specification of sub-component was proposed for managing each sub-surpplier to reach the KHST noise requirement. The specification provide the sound power of machinery part and transmission loss of component of carbody structure. The predicted noise level in each case exceeded the required limit. Through this study, the noise characteristics of the test train were investigated by simulation, and then the actual test will be performed in near future. Both measured and calculated data will be compared and further work for noise reduction will be continued.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.917-923
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• 2002

KITECH and ODS performed a study of internal and external noise prediction of the KHST test train. The object of this study was 3 kind of cars; trailer car(TT2), motorized car(TM1) and power car(TP1) and the predicted noise was calculated for the two different driving speeds in free field and tunnel conditions. Data of carbody design and noise sources were delivered from each manufactures. Some of noise sources which were not available in project team, were chosen by experiences of ODS. Internal noise level of each car were predicted for two cases i.e, at 300 km/h and 350 km/h. In addition sound transmission path and dominant noise sources were also investigated of each section of car, which is circular shell typed part of whole carbody. In case of TT2, the dominating sound transmission path is floor in terms or structure-borne noise and air-borne noise. The main noise sources are structure-borne noise from the yaw-damper and air-borne noise from the wheel/rail contact, whereas the dominating sound transmission path of TM1 are floor and sidewall below the window in terms of structure-borne noise. The main noise sources of TM1 are structure-borne noise from motor/gear unit and the yaw-damper in the free field, and air-borne noise from the wheel/rail contact and structure-borne noise from motor/gear unit in the tunnel. Through the external noise prediction for the KHST test train formation, the noise form the wheel/rail contact is estimated as one of the major sources. In addition, the noise specification of sub-component was proposed for managing each sub-surpplier to reach the KHST noise requirement. The specification provide the sound power of machinery part and transmission loss of component of carbody structure. The predicted noise level in each case exceeded the required limit. Through this study, the noise characteristics of the test train were investigated by simulation, and then the actual test will be performed in near future. Both measured and calculated data will be compared and further work for noise reduction will be continued.

• 자동차안전학회지
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• 제12권2호
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• pp.27-32
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• 2020

This paper presents steering system requirements to ensure the stabilized lateral control of autonomous driving vehicles. The two main objectives of a lateral controller in autonomous vehicles are maintenance of vehicle stability and tracking of the desired path. Even if the desired steering angle is immediately determined by the upper level controller, the overall controller performance is greatly influenced by the specification of steering system actuators. Since one of the major inescapable traits that affects controller performance is the time delay of the steering actuator, our work is mainly focused on finding adequate parameters of high level control algorithm to compensate these response characteristics and guarantee vehicle stability. Actual vehicle steering angle response was obtained with Electric Power Steering (EPS) actuator test subject to various longitudinal velocity. Steering input and output response analysis was performed via MATLAB system identification toolbox. The use of system identification is advantageous since the transfer function of the system is conveniently obtained compared with methods that require actual mathematical modeling of the system. Simulation results of full vehicle model suggest that the obtained tuning parameter yields reduced oscillation and lateral error compared with other cases, thus enhancing path tracking performance.

• 한국정밀공학회지
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• 제13권10호
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• pp.71-77
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• 1996

This paper describes the development of on the machine measuring(OMM) system which can directlry measure the three dimensional machined dimensilnal accuracy using scanning probe in milling machine. Two algolithms, continuous path(CP) measurement using UC program and CAD data assisted point to point(PTP) measurement, were developed regarding specification of scanning probe. The OMM system was contructed to verify the developed system suing the proposed algorithm, and actually measured three kinds of machined TV shadow mask molds. The developed system was evaluated it's repeatability and compared with the current measurement system of CMM(Coording Measuring Machine) in terms of relative accuracy and time reduction and productivity increase.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.734-739
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• 2001

In this paper, we develop a six-axes machining center tool(MCT) and CAD/CAM system. The MCT consists of two mechanical parts, i.e., a X-Y-Z Cartesian coordinate typed MCT and a parallel-typed tilting table. Kinematics and singularity are accomplished to design the parallel-typed tilting table, and CAD/CAM system is developed for the six-axes MCT, which requires the commands of position as well as orientation for machining of complex shape. The CAD/CAM system has a tool path generator, a NC code generator and a graphic simulator. This paper designs the parallel-typed tilting table to meet the desired specification and presents the results of tool path, NC code and graphic simulation.