• 한국디지털건축인테리어학회논문집
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• 제8권2호
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• pp.21-28
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• 2008

The main purpose of this paper is to find the phase-in of BIM adoption by focusing on the level of integration. BlM should be aimed at integration and collaboration of all parties furnishing design and construction services to increase the productivity. Therefore, the degree and depth of integration for project collaboration is very important to BlM design process. One of the key advantages of full integration is that is to facilitates the development of detailed information much earlier in the entire design process to improve collaboration among stakeholders. Such integrated use is the ultimate method, but even so, it's not the precondition of BlM. One of the key advantages of relatively low integration as a transition phase is to adopt the BlM earlier than full integration. Such transitional and non-integrated BIM can also reduce the possibility of trial and error in BlM adoption. Therefore, this paper focused on non-integrated use of BlM as a substitute of full IPD by analyzing obstacles in BIM adoption.

• Radiation Oncology Journal
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• 제10권1호
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• pp.95-100
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• 1992

LINAC 뇌정위적 방사선 수술은 multiple noncoplanar arc, 3 차원 선량 계산 및 많은 조사 변수들이 사용되기 때문에 간단한 경우에도 최적 선량분포를 얻기 위해서는 많은 시간이 요구된다. 본 논문에서는 실험적 방법과 분석적 방법을 통한 유용한 방법을 제시하기 위한 것으로서, 보다 자세한 방법 및 내용은 앞으로의 발표 논문에서 다루게 된다. 실험적 방법으로 2가지 방법에의하면, 첫번째 방법은 multiple isocenter를 이용하는 것이고, 두번째 방법은 beam's eye view와 field shaping을 이용한 conformal therapy이다. 분석적 방법은 최적 조사조건을 찾기 위하여 computer-aided design optimization 방법을 이용하는 것이다.

• Earthquakes and Structures
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• 제3권6호
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• pp.839-852
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• 2012

Earthquake records are often analyzed in various earthquake engineering problems, making time-frequency analysis for such records of primary concern. The best tool for such analysis appears to be based on wavelet functions; selection of which is not an easy task and is commonly carried through trial and error process. Furthermore, often a particular wavelet is adopted for analysis of various earthquakes irrespective of record's prime characteristics, e.g. wave's magnitude. A wavelet constructed based on records' characteristics may yield a more accurate solution and more efficient solution procedure in time-frequency analysis. In this study, a low-pass reconstruction filter is obtained for each earthquake record based on multi-resolution decomposition technique; the filter is then assigned to be the normalized version of the last approximation component with respect to its magnitude. The scaling and wavelet functions are computed using two-scale relations. The calculated wavelets are highly efficient in decomposing the original records as compared to other commonly used wavelets such as Daubechies2 wavelet. The method is further advantageous since it enables one to decompose the original record in such a way that a clear time-frequency resolution is obtained.

• 소성∙가공
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• 제26권1호
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• pp.28-34
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• 2017

Multi-pass shape rolling is performed to produce long products of arbitrary cross-sectional shapes. In the past, the multi-pass shape rolling process has been designed by the trial and error method or the experience of experts based on the empirical approach. Particularly, the design of roll caliber in shape rolling is important to improve product quality and dimensional accuracy. In this paper, the caliber design and pass schedule of multi-pass shape rolling were proposed for manufacturing piston ring wire. In order to design roll caliber, major shape parameter and dimension was determined by analysis of various caliber design. FE-simulation was conducted to verify effectiveness of proposed process design. At first, forming simulation was performed to predict shape of the product. Then, fracture of the wire was evaluated by critical damage value using normalized Cockcroft-Latham criteria. The experiment was carried out and the results are within the allowable tolerance.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.993-998
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• 2002

Ultra precision processing technology is the field which is seriously protected its technology by advanced nations. Because of this reason, this technology is very difficult to supply for domestic companies, also domestic companies are revealed the limit of technology development by itself. And then, those are depend on the technology development of advanced nation, domestic companies are not conquer application step with already developed parts. Of course, some cases of its research are succeed. those are included element technology, system technology and so on, for development of ultra precision processing system. To conquer technology holding ultra precision processing accuracy of no level, active research are needed. In this paper, stability of ultra precision cutting unit is analyzed, this unit is the kernel unit in ultra precision processing machine. According to alteration of shape and material about hinge, stability investigation is performed Through this stability investigation, trial and error is reduced in design and manufacture, at the same time, we are accumulated foundation data for un it control.

• 한국자동차공학회논문집
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• 제20권2호
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• pp.64-69
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• 2012

Head injury is one of the most common cause of deaths in car-to-pedestrian collisions. To reduce the severity of such injuries, many international safety committees have performed headform impact test for pedestrian protection. In this paper, an adult headform impactor model is developed based on the finite element (FE) method and validated through the numerical simulation. The skin material of headform impactor is known as polyvinyl chloride skin (PVC) and its material was assumed as viscoelastic. The viscoelastic parameters of headform skin are identified by a series of trial and error methods. The new developed FE adult headform impactor is verified by the drop test and FE JARI adult headform impactor provided by Madymo program.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 추계학술대회 논문집
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• pp.224-227
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• 2001

The preform design in metal forging plays a key role in improving product quality, such as ensuring defect-free property and proper metal flow. In industry, preforms are generally designed by the iterative trial-and-error approach, but this approach leads not only to significant tool cost but also to the down-time of the production equipment. It is thus necessary to reduce the time and the man-power through an effective method of perform design. In this paper, the equi-potential lines designed in the electric field are introduced to find the preform shape. The equi-potential lines obtained by the arrangement of the initial and final shapes are utilized for the design of the preform, and then applied for obtaining a fine preform in the foging process of the ball-joint socket.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2123-2125
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• 2001

In thermal power plant, the efficiency of a combined power plant with a gas turbine increases, exceeding 50%, while the efficiency of traditional steam turbine plants is approximately 35% to 40%. Up to the present time, the PID controller has been used to operate this system. However, it is very difficult to achieve an optimal PID gain without any experience, since the gain of the PID controller has to be manually tuned by trial and error procedures. This paper focuses on the neural network tuning of the 2-DOF PID controller with a separated 2-DOF parameter (NN-Tuning 2-DOF PID controller), for optimal control of the Gun-san gas turbine generating plant in Seoul. Korea. In order to attain optimal control, transfer function and operating data from start-up, running, and stop procedures of the Gun-san gas turbine have been acquired, and a designed controller has been applied to this system. The results of the NN-Tuning 2-DOF PID are compared with the PID controller and the conventional 2-DOF PID controller tuned by the Ziegler-Nichols method through experimentation. The experimental results of the NN-Tuning 2-DOF PID controller represent a more satisfactory response than those of the previously-mentioned two controller.

• 정보처리학회논문지D
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• 제8D권2호
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• pp.175-180
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• 2001

본 논문은 미래의 소프크웨어 공장 수나 고장시간 예측 정확성을 얻기 위해, 뉴로-피지 시스템을 이용할 경우 최적의 검증 데이터 할당 비율에 대한 연구이다. 훈련 데이터가 주어졌을 때, 과소 적합과 과잉 적합을 회피하면서 최적의 일반화 능력을 얻기 취해 Early Stopping 방법이 일반적으로 사용되고 있다. 그러나 훈련과 검증 데이터로 얼마나 많은 데이터를 할당갈 것인가는 시행착오법을 이용해 경험적으로 해를 구해야만 하며, 과다한 시간이 소요된다. 최적의 검증 데이터 양을 구하기 위해 규칙 수를 증가시키면서 다양한 검증 데이터 양을 할당하였다. 실험결과 최소의 검증 데이터로도 좋은 예측 능력을 보였다. 이 결과는 뉴로-퍼지 시스템을 소프트웨어 신뢰성 분야에 적용시 실질직언 지침을 제공할 수 있는 것이다.

• 대한유전성대사질환학회지
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• 제4권1호
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• pp.13-17
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• 2004

저자들은 생후 28일된 발열, 간종대, 출혈성 경향, 구토, 잦은 보챔, 전신의 황달 증상을 보이던 환아를 MS-MS 이용한 신생아 대사 이상 검사와 혈중 아미노산 분석, 뇨중 유기산 분석을 통하여 hereditary tyrosinemia type I으로 진단하였다. 저 페닐알라닌/타이로신 식이와 NTBC 사용으로 국내 첫 타이로신혈증 I 치료 성공례를 경험하였다.