• 한국정밀공학회지
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• 제20권9호
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• pp.142-150
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• 2003

MDO is one of the efficient methods for huge and multi -functional system design. This paper describes a design collaboration framework with MDO in networked design environment. A prototype of web -based integrated design system was implemented to show sharing and exchange of models and analysis information between MDO modules and collaborative design stations. Server System consists of MDO modules for optimization and modeling module for 3D modeling operation. Client system provide user with graphic interface for shape modeling and system operation. We believe that the proposed approach can be extended to solve real complex multidisciplinary design problems.

• 전자공학회논문지A
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• 제33A권6호
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• pp.206-219
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• 1996

This paper describes a data structure and evaluation algorithm to improve the perofmrances MOS logic-with-timing simulation in computation and accuracy. In order to efficiently simulate the logic and timing of driver-load networks, (1) a tree data structure to represent the mutual interconnection topology of switches and nodes in the driver-lod network, and (2) an algebraic modeling to efficiently deal with the new represetnation, (3) an evaluation algorithm to compute the linear resistive and capacitive behavior with the new modeling of driver-load networks are developed. The higher modeling presented here supports the structural and functional compatibility with the linear switch-level to simulate the logic-with-timing of digital MOS circuits at a mixed-level. This research attempts to integrate the new approach into the existing simulator RSIM, which yield a mixed-klevel logic-with-timing simulator MIXIM. The experimental results show that (1) MIXIM is a far superior to RSIM in computation speed and timing accuracy; and notably (2) th etiming simulation for driver-load netowrks produces the accuracy ranged within 17% with respect ot the analog simulator SPICE.

• 전기학회논문지
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• 제57권9호
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• pp.1642-1651
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• 2008

The dynamic behavior of power systems is affected by the interactions between linear and nonlinear components. To analyze those complicated power systems, the linear approaches have been widely used so far. Especially, a synchronous generator has been designed by using linear models and traditional techniques. However, due to its wide operating range, complex dynamics, transient performances, and its nonlinearities, it cannot be accurately modeled as linear methods based on small-signal analysis. This paper describes an application of the Takaki-Sugeno (T-S) fuzzy method to model the synchronous generator in a single-machine infinite bus (SMIB) system. The T-S fuzzy model can provide a highly nonlinear functional relation with a comparatively small number of fuzzy rules. The simulation results show that the proposed T-S fuzzy modeling captures all dynamic characteristics for the synchronous generator, which are exactly same as those by the conventional modeling method.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.1076-1082
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• 2003

As functional requirement of massive digital information storage devices are on a trend for the higher data transfer rate and lower cost, many different technical efforts are being tested and implemented in the industry. FDB(Fluid Dynamic Soaring) is one of the major breakthroughs in rotor design in terms of TMR budget. Although FDB analysis based on Reynolds' equation is well established and popularly being used for DB design especially for the estimation of bearing stiffness, there are obvious limitations in the approach due to the inherent assumptions. A generalized analysis tool employing the full Navier-Stokes equation and the energy balance is to be beneficial for detailed FDB design In this publication, an efficient geometry modeling method is presented that provides fully integrated inputs for general FVM/FDM codes. By virtue of the flexibility of the presented method, many different detailed FDB design and analysis are carried over with ease.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 1999년도 추계학술대회
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• pp.565-574
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• 1999

In reverse engineering area, it is rapidly developing reconstruction of surfaces from scanning or digitizing data, but geometric models of existing objects unavailable many industries. This paper describes new methodology of reverse engineering area, good strategies and important algorithms in reverse engineering area. Furthermore, proposing reconstruction of surface technique is presented. A method find base geometry and blending surface between them. Each based geometry is divided by triangular patch which are compared their normal vector for face grouping. Each group is categorized analytical surface such as a part of the cylinder, the sphere, the cone, and the plane that mean each based geometry surface. And then, each based geometry surface is implemented infinitive surface. Infinitive average surface's intersections are trimmed boundary representation model reconstruction. This method has several benefits such as the time efficiency and automatic functional modeling system in reverse engineering. Especially, it can be applied 3D scanner and 3D copier.

• 한국소프트웨어감정평가학회 논문지
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• 제17권1호
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• pp.93-99
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• 2021

최근 COVID-19 등의 영향으로 온라인 교육에 대한 요구가 급증하고 있다. 공학계열의 온라인 교육에 있어 가장 큰 어려움 중의 하나는 실험관련 교과목을 어떻게 효율적으로 온라인상에서 수행할 수 있느냐는 것이다. 본 연구에서는 전기전자정보통신 분야 교육에서 필수적으로 요구되는 마이크로컨트롤러 응용 학습을 위해 사용할 수 있는 가상실험 시스템 구축을 위해 반드시 필요한 마이크로컨트롤러 기능 모델링에 대해 기술하고, 자바언어로 구현하여 가상 실험에 적용함으로써 그 유용성을 검증하였다.

• Journal of Biosystems Engineering
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• 제29권3호
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• pp.233-242
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• 2004

본 연구의 주요 목적은 자동 쌀 진공포장기의 3차원 기능적 가상시작기 모델을 개발하여 포장기의 구동시스템을 설계하고 개발하고자 하였다. 개발한 3차원 가상시작기는 주로 압축판부, 테이프부착부 및 진동판부로 구성되었다. 가상시작기의 민감도 분석을 수행하기 위해 제품포대의 두께변수를 이용하여 3차원 가상시작기를 파라미터화하였다 자동 진공포장기의 최대 처리능력 6포/분, 포대규격: 45cm${\times}$35cm을 충족하기 위해 각 주요부를 구동하는 모터 작동제어로직(motion control function)을 적절하게 설계하였다. 설계한 작동제어로직에 의하여 각 모터를 구동할 때 필요로 하는 적정 동력은 각각 100W, 25W 및 90W로 결정하였다. 연구결과를 요약하면 다음과 같다. 자동 진공포장기의 실제 시작기를 제조한 후 설계한 작동제어로직을 각 구동모터에 적용하여 시뮬레이션의 결과를 검증하였다. 개발한 3차원 가상시작기 모델을 시뮬레이션하여 선정한 모터들은 각 주요부를 원활하게 구동할 수 있었다. 제안한 작동제어로직은 주요부의 요구된 작동 시권스를 만족시켰으며 이때 자동진공포장기의 처리능력은 6.7 포/분이었다. 개발한 자동 쌀 진공포장기의 포장성공률은 92.6%이었다.

• 대한간호학회지
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• 제40권4호
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• pp.533-541
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• 2010

Purpose: This study was designed to test structural equation modeling of the quality of life of stroke survivors in order to provide guidelines for development of interventions and strategies to improve their quality of life. Methods: The participants in the study were patients who visited the neurology outpatient department of a tertiary hospital in Seoul between June 25 and October 15, 2009. Data collection was carried out through one-on-one interviews. Demographic factors, functional independence, social support, nutritional status, post-stroke biobehavioral changes and quality of life were investigated. Results: The final analysis included 215 patients. Fitness of the hypothetical model was appropriate (${\chi}^2$=111.5, p=.000, GFI=.926, AGFI=.880, RMSA=.068, NFI=.911, CFI=.953). Functional dependency, social support and post-stroke biobehavioral changes were found to be significant explaining variance in quality of life. Post-stroke biobehavioral changes had the strongest direct influence on quality of life. Nutritional status had an indirect effect on the quality of life. Conclusion: To improve the quality of life of stroke survivors, comprehensive interventions are necessary to manage post-stroke biobehavioral changes, and strengthening social support networks that can contribute to enhancing the quality of life of stroke survivors.

• 한국군사과학기술학회지
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• 제10권2호
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• pp.21-30
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• 2007

A practical method to design the input shaping which generates control command is proposed in this paper, We suggest an experimental technique considering human operator's target tracking error to improve aiming accuracy which significantly affects hit probability. It is known that stabilization performance is one of the most important factors for ground combat vehicle system. In particular, stabilization error of the manual target tracking system mounted on moving vehicle directly affects hit probability. To reduce this error, we applied input command shaping method using preprocessing filtering and functional curve fitting. First of all, we construct the human operator model to consider effects of human operator on our system. Input shaping curve is divided into several regions to get rid of the above problems and to improve the system performance. At example design part, we chose three steps of functional command curve and determine the parameters of the function by the proposed design method. In order to verify the proposed design method, we carried out the experiments with real plant of a fighting vehicle.

• 한국BIM학회 논문집
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• 제11권3호
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• pp.55-66
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• 2021

Recently, Building Information Modeling(BIM) has become a hot topic in the construction industry such as quantity calculation, interference check, process management, and construction cost management. It is also trying to convert the existing 2D design to 3D design and introduce the BIM in various fields, thus, many new deliverable are being presented but there are many issues due to the lack of standard guides on the preparation and delivery criteria for such new deliverable and how to utilize performance data. Therefore, In order to develop the electronic delivery process, we analyzed the process related to the delivery of BIM digital models presented in domestic and international BIM guidelines and the delivery of products from the Korea National Railway. The analysis focused on the list of achievements, delivery process, quality review standards, and the utilization code system of the Korea National Railway through BIM guidelines and the National Railroad Service's business procedures. Based on these analysis results, it presents a plan to construct an functional module of electronic delivery.