• 대한기계학회논문집A
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• 제40권11호
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• pp.943-948
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• 2016

최근, 산업에서는 미세패턴의 효과가 입증됨에 따라 미세패턴에 대한 연구가 활발히 진행되고 있다. 그러나, 이러한 연구들은 단일 패턴에 집중되어있으며, 복합 미세패턴의 제작 및 디버링에 관한 연구는 부족한 실정이다. 따라서, 본 연구에서는 원통형 공작물에 복합 미세패턴을 제작하고, 자기 디버링을 이용하여 디버링을 실시하였다. 또한, 반응표면법을 이용하여 패턴의 높이에 대한 예측모델을 도출하고, 자기 디버링 공정을 최적화하였다. 그 결과, 패턴의 높이에 대한 예측값과 실험값을 비교하였을 때, 평균적으로 7%의 오차가 발생하는 것을 확인하였다. 또한, 검증실험을 통하여 형상 정밀도가 우수한 복합 미세패턴의 제작이 가능하고, 예측모델이 신뢰성이 있음을 알 수 있었다.

• 한국멀티미디어학회논문지
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• 제8권5호
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• pp.715-720
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• 2005

소프트웨어 개발과정에서 사용자 요구사항을 정확히 만족하기 위해서는 사용자 관점에서 요구사항을 검증하기 위한 방법이 필요하다. 이것은 사용자의 요구사항이 시스템 개발자에게 적절히 반영되어 사용자가 요구하는 고품질의 소프트웨어 시스템을 더 효과적으로 설계하고 구현할 수 있기 때문이다. 본 논문에서는 시스템 구현 전 단계에서 사용자 요구사항을 효율적으로 검증할 수 있는 RV-UI 모델 시스템을 제안한다. RV-UI 모델 시스템은 상용화된 사용자 인터페이스를 프로세스별 기능 모델로 표준화하여 구성하였고, Kano의 모델을 적용한 인터페이스를 통해 명화한 사용자 요구사항의 검증과 체계적인 요구사항의 형상관리를 가능하도록 설계 하였다.

• 한국정밀공학회지
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• 제17권7호
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• pp.124-131
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• 2000

Rapid Prototyping(RP) models are no longer used only for design verification. Currently, parts built utilizing layer manufacturing technology can be employed as functional prototypes and as patterns or tools for different manufacturing processes such as vacuum casting, investment casting, injection molding, precise casting and sand casting. This trend of Rapid Prototyping application meets the requirement of concurrent engineering and its range covers a more spreaded area. The aim of this paper is saving the manufacturing lead time and cost of plastic parts having hollow space shapes used by prototype-car. Using rapid prototype patterns, made by the Selective Laser Sintering(SLS) technique, a new approach of manufacturing resin-based blow mold is discussed. It has a great potential fur making prototype-car parts with the batch size of under 200 parts, in case of rapid modification due to a subsequent design changes in developing stage. So, the process proposed in this research shows reduction of process time and manufacturing cost when compared with the conventional process such as a Zinc Alloy fur Stamping(ZAS) mold.

• 한국농공학회논문집
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• 제55권3호
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• pp.63-73
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• 2013

The objectives of this study were to develop a hydrologic simulation model to estimate surface drainage for irrigation districts consisting of paddy and protected cultivation, and to evaluate the applicability of the developed model. The model consists of three sub-models; agricultural supply, paddy block drainage, and protected cultivation runoff. The model simulates daily total drainage as the sum of paddy field drainage, irrigation canal drainage, and protected cultivation runoff at the outlets of the irrigation districts. The agricultural supply sub-model was formulated considering crop water requirement for growing seasons and agricultural water management loss. Agricultural supply was calculated for use as input data for the paddy block sub-model. The paddy block drainage sub-model simulates paddy field drainage based on water balance, and irrigation canal drainage as a fraction of agricultural supply. Protected cultivation runoff is calculated based on NRCS (Natural Resources Conservation Service) curve number method. The Idong reservoir irrigation district was selected for surface drainage monitoring and model verification. The parameters of model were calibrated using a trial and error technique, and validated with the measured data from the study site. The model can be a useful tool to estimate surface drainage for irrigated districts consisting of paddy and protected cultivation.

• 한국철도학회논문집
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• 제13권3호
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• pp.251-256
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• 2010

본 연구에서는 충돌해석 프로그램의 해석 결과와 실제 시험결과에 대한 비교를 통하여 충돌해석 프로그램의 신뢰성에 대한 검증을 진행하였으며, 충돌해석 프로그램을 이용하여 도시철도차량에서 요구하는 차량 편성에 대한 충돌 해석 결과를 제시하였다.

• Nuclear Engineering and Technology
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• 제48권4호
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• pp.1047-1057
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• 2016

Design engineering process for field programmable gate array (FPGA)-based reactor trip functions are developed in this work. The process discussed in this work is based on the systems engineering approach. The overall design process is effectively implemented by combining with design and implementation processes. It transforms its overall development process from traditional V-model to Y-model. This approach gives the benefit of concurrent engineering of design work with software implementation. As a result, it reduces development time and effort. The design engineering process consisted of five activities, which are performed and discussed: needs/systems analysis; requirement analysis; functional analysis; design synthesis; and design verification and validation. Those activities are used to develop FPGA-based reactor bistable trip functions that trigger reactor trip when the process input value exceeds the setpoint. To implement design synthesis effectively, a model-based design technique is implied. The finite-state machine with data path structural modeling technique together with very high speed integrated circuit hardware description language and the Aldec Active-HDL tool are used to design, model, and verify the reactor bistable trip functions for nuclear power plants.

• 로봇학회논문지
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• 제9권1호
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• pp.67-77
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• 2014

An electric motor is the one of the most important parts in robot systems, which mainly drives the wheel of mobile robots or the joint of manipulators. According to the requirement of motor performance, the controller type and parameters vary. For the wheel driving motors, a speed tracking controller is used, while a position tracking controller is required for the joint driving motors. Moreover, if the mechanical parameters are changed or a different motor is used, we might have to tune again the controller parameters. However, for the beginners who are not familiar about the controller design, it is hard to design pertinently. In this paper, we develop a nominal robust controller model for the velocity tracking of wheel driving motors and the position tracking of joint driving motors based on the disturbance observer (DOB) which can reject disturbances, modeling errors, and dynamic parameter variations, and propose the methodology for the determining the least control parameters. The proposed control system enables the beginners to easily construct a controller for the newly designed robot system. The purpose of this paper is not to develop a new controller theory, but to increase the user-friendliness. Finally, simulation and experimental verification have performed through the actual wheel and joint driving motors.

• 전자통신동향분석
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• 제32권6호
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• pp.105-115
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• 2017

This paper describes a project - based quality management model that identifies development technologies and codes while at the same time verifying the ability to implement processes that are essential in R & D projects. In order to verify the process implemented in the R & D project implementation, there are review, checking points, and evaluating methods the process performance levels for five processes such as defining requirements which is the beginning stage of system development, testing process which is the completion stage of system development, and project management and peer review process for project management and support in the proposed project-based quality management model. For development technology and code validation, the model included the documented test cases for each requirement by the developer in the requirements definition stage, debugging and testing in the design and implementation stages, static analysis and open source licence verification procedure, and system environment. After applying the model in SW development R&D project for evaluating the process performance, and verifying the development technology and the code, the developers responded that the improvement in the development technique and the code, and upgrade of process performance level for project are more than 10%.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.198-200
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• 2018

In this paper a single-stage single-phase differential type isolated AC-DC converter is proposed. This converter eliminates the requirement to use bulky electrolytic capacitor from the system and at the same time provides DC charging by employing the AC Power Decoupling waveform control method. All the switches of the converter achieve ZVS turn on during half line cycle and all diodes achieve ZCS turn off during entire line cycle. A conventional controller is implemented for PFC control and output regulation, whereas a power decoupling controller is added to compensate $2^{nd}$ harmonic ripple power. In addition, an interleaving technique is applied to increase the power range of the converter and reduce the input inductor size. In the end simulation verification is performed and results are obtained for 6.6KW.

• 한국정보과학회논문지:소프트웨어및응용
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• 제29권5호
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• pp.345-354
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• 2002

정형 명세를 이용하여 구현된 프로그램이 수행 중에 명세를 만족시키는지 모니터링하고 검사하는 기법에 대한 연구들이 기존에 많이 수행되어 왔다. 이들은 주로 요구사항 명세언어로 시제논리 혹은 그것의 확장을 사용하게 된다. 이때 대부분의 연구는 실제 구현된 시스템이 가지는 동적인 변화를 제대로 요구사항 명세에 기술하고, 검사할 수 있는 언어를 제공하지 못하고 있다. 본 연구에서는 동적 시스템의 특성 명세언어로 기존에 제안했던 HDTL을 사용하여 동적인 자바 프로그램의 수행을 모니터링하고 검사하는 프레임웍을 제안한다.