• 대한기계학회논문집
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• 제14권5호
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• pp.1138-1146
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• 1990

본 연구에서는 이러한 지식기반 전문가 시스템을 이용하여 에너지 저장용 기 계요소인 플라이 위일의 설계를 보조해 주는 지식기반 전문가 시스템을 개발하고자 한 다. 즉 플라이 휘일의 설계, 제작 과정을 크게 개념 설계, 상세 설계 및 해석, 제작, 시험의 단계로 분류할 때 본 연구의 목적은 초기 설계 단계인 개념 설계에 도움을 주 는 시스템을 구성하는 데 있다.프로그램의 구성은 정성적인 경험, 지식을 다룰 수 있는 기호적인 (symbolic)계산과 간단한 수치적인 (numerical)계산을 함께 할 수 있는 복합시스템(hybrid system)으로 구성하고 이러한 과정을 체계적이고 조직적으로 수행 하고 지식의 첨삭이 용이하도록 전체 설계광정을 계층 구조(hierarchical structure) 화하고 설계 자료를 자료 기반화하여 관리하며 그래픽과 연계시켜 전체 지식 기반 시 스템을 총합화 하였다.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.790-793
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• 2008

현재, 국토해양부 건설기술혁신사업의 일환으로 2006년 말부터 토공자동화를 위한 '지능형굴삭시스템개발'이 진행되고 있다. 지능형 굴삭시스템의 세부핵심요소기술 중, Task Planning System(TPS)은 토공 작업의 효율성, 안전성, 경제성 등을 고려하여 토공 설계데이터와 작업환경 인식기술에 근거한 작업환경 데이터를 분석하여 최적의 작업계획을 수립하는 시스템이다. 작업계획생성 시 효율적인 토공작업을 위해서는 플랫폼 생성 시 그 위치가 최적의 점을 형성하여 중첩되는 작업영역의 크기가 줄어들어 비효율적인 작업을 제거할 수 있으며 작업 시간을 최소화할 수 있고 굴삭작업의 생산성을 극대화찰 수 있다. 또한, 최적 플랫폼 위치 선정 시 굴삭기 제원에 따른 최적화가 되어야 굴삭기의 규격에 따른 로컬 영역의 산출 알고리즘과 호환이 될 수 있다. 본 논문은 영역 분할 과정에서 산출된 로컬영역을 기준으로 굴삭기 제원에 따른 최적화된 플랫폼 위치 선정 방안에 대하여 살펴보고 검증을 통하여 효율성을 판단하고자 한다.

• Journal of Pharmaceutical Investigation
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• 제34권3호
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• pp.185-192
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• 2004

The objective of this study was to evaluate the effects of surfactant type and concentration upon dissolution rates of carbamazepine from an immediate-release tablet. The dissolution media used in this study were aqueous solutions containing 0.1-2% sodium lauryl sulfate, cetyltrimethylammonium bromide, or polysorbate 80. The solubility of carbamazepine in the dissolution media was determined at first. A dissolution study was then conducted by using the USP dissolution apparatus II (paddle method) with an agitation rate of 75 rpm. Aliquots of the dissolution media were taken at predetermined time intervals, and the amount of carbamazepine dissolved was measured spectrophotometrically at 285 nm. The dissolution data obtained were fitted into a biphasic exponential equation with four parameters. Excellent correlations were observed between the experimental data and the theoretical ones predicted by the equation. This equation permitted the calculation of $T_{50%}$ (the time required for dissolving 50% of carbamazepine) under various experimental conditions. Differentiation of the equation also led to the attainment of dissolution rates at dissolution time points. The addition of a surfactant to an aqueous solution led to increasing the solubility of carbamazepine by 3- to 12-folds, depending upon its type and concentration. This event also resulted in enhancing the magnitude of a sink condition during the dissolution study. As a result, the dissolution rate of carbamazepine was affected by the aqueous surfactant concentration in a proportional manner. Subsequently, $T_{50%}$ values declined rapidly, as the surfactant concentration increased. Such effects were observed in decreasing order of sodium lauryl sulfate, cetyltirmethylammonium bromide, and polysorbate 80. These results clearly demonstrated that it was possible to tailor a dissolution rate and $T_{50%}$ of carbamazepine by manipulating the type and concentration of a surfactant. Relevant information would be beneficial to setting up dissolution specifications for poorly water-soluble drug products.

• 한국광학회지
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• 제31권2호
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• pp.96-104
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• 2020

주간 무인 감시를 위하여 가시광 파장 범위인 400~700 nm에서 렌즈와 거울의 기능을 동시에 갖는 구멍 없는 하이브리드 렌즈를 활용한 반사굴절식 전방위 줌 광학계를 설계하고 그 성능을 분석하였다. 하이브리드 렌즈는 렌즈에 구멍을 뚫는 작업이 없고 광학 부품의 수량을 줄일 수 있기 때문에 전방위 줌 광학계의 제작과 조립에서 많은 장점을 갖는다. 이 광학계에서 결상된 도넛 형태의 상에서 안쪽의 압축된 낮은 공간주파수의 상 영역을 확대하여 보기 위해서 줌 렌즈의 기능을 추가한 전방위 광학계의 최적화 설계를 진행하였다. 그 결과 최적화 설계된 광학계의 변조전달함수, 스폿 다이어그램 분석, 공차 분석을 통해 이 광학계의 성능을 분석한 결과로부터 설계 목표 사양을 만족함을 알 수 있었다. 줌 광학계를 주밍할 때 -30~50℃의 온도 변화에 따른 비열화 해석을 한 결과, 적절한 렌즈의 재질을 선정하여 온도 변화에도 상 거리 변화가 거의 없는 광학계임을 확인하였다.

• 대한지역사회영양학회지
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• 제8권1호
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• pp.62-70
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• 2003

This article aims to summarize the development and application of menu engineering technique, 'Menu Engineering Modified by Preference (MEMP)'. The site selected for this project was a foodservice operation in Yonsei University residence hall. Sales and food costs data were collected from the daily sales reports for 1 month, and the survey of food preference was conducted during May, 1999. Statistical data analysis was completed using the SAS/Win 6.12 for descriptive analysis. The calculation for menu analysis were carried out with MS 2000 Excel spreadsheet program. This MEMP technique developed had 6 category criteria and 2 dimensions of the contribution margin (CM) and the menu mix modified% (MMM%) . The MMM% was calculated by the sales volumes and also weighted by food preference. The CM and MMM% for each item were compared with a mean menu CM as well as a 70% rule. Four possible classifications by MEMP were fumed out as 'STAR', 'PLOWHORSE', 'PUZZLE', 'DOG'. 'STAR' items were the most popular and profitable items and required to maintain rigid specifications for quality. The decision actions for 'PLOWHORSE' menu items which were relatively popular, but yield a low menu average CM included combining a plowhorse item with lower cost products and reducing the frequency of serving or serving size. There was a need for 'PUZZLE' items to be changed in the menu combination, improve recipe, and promote menu. The last DOG' items were desired to be deleted. This study demonstrates that menu information can be interpreted more easily with MEMP. The use of MEMP is therefore an effective way to improve management decisions about menu of university residence hall foodservice.

• 한국추진공학회지
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• 제17권4호
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• pp.1-9
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• 2013

능동형 대함 유도탄 기만기의 추진 시스템 요구 조건 및 저장성 액체 이원추진제 로켓 엔진의 적용 가능성을 파악하기 위해 개념 설계를 수행하였다. 이미 미국과 오스트레일리아에서 공동 개발하여 운용 중인 Nulka의 제원을 통해 시스템의 기본적인 무게, 크기 등을 가정하였고, 1,000 N 급 과산화수소/케로신 로켓 엔진과 가압식 추진제 공급 방식으로 추진 시스템을 가정하였다. 이를 바탕으로 최적 궤적을 설계하였고 그 결과를 통해 하부 시스템들의 무게 분포를 예측하고 실현 가능성을 확인하였다. 그 결과, 100초 이상의 운용 시간, 엔진 재점화, 그리고 최대 지상 추력 1,000 N의 경우 최소 35%까지의 추력 제어 성능이 추진 시스템의 요구 조건으로 도출 되었다.

• Nuclear Engineering and Technology
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• 제53권10호
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• pp.3344-3351
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• 2021

The Rare Isotope Science Project was launched in 2011 in Korea toward constructing the Rare isotope Accelerator complex for ON line experiments (RAON). RAON will house several experimental systems, including the Muon Spin Rotation/Relaxation/Resonance (μSR) facility in High Energy Experimental Building B. This facility will use 600-MeV protons with a maximum current of 660 pμA and beam power of 400 kW. The key μSR features will facilitate projects related to condensed-matter and nuclear physics. Typical experiments require a few million surface muons fully spin-polarized opposite to their momentum for application to small samples. Here, we describe the design of a muon transport beam line for delivering the requisite muon numbers and the electromagnetic-component specifications in the μSR facility. We determine the beam-line configuration via beam-optics calculations and the transmission efficiency via single-particle tracking simulations. The electromagnet properties, including fringe field effects, are applied for each component in the calculations. The designed surface-muon beamline is 17.3 m long, consisting of 2 solenoids, 2 dipoles affording 70° deflection, 9 quadrupoles, and a Wien filter to eliminate contaminant positrons. The average incident-muon flux and spin rotation angle are estimated as 5.2 × 10⁶ μ⁺/s and 45°, respectively.

• 한국해양공학회지
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• 제32권6호
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• pp.427-432
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• 2018

Tidal current power is one of the energy sources of the ocean. Electricity can be generated by converting the flow energy of the current into the rotational energy of a turbine. Unlike tidal barrage, tidal current power does not require dams, which have a severe environmental impact. A floating-type tidal current power device can reduce the expensive support and installation cost, which usually account for approximately 41% of the total cost. It can also be deployed in relatively deep water using tensioned wires. The dynamic behavior of a floater and turbine force are coupled because the thrust and moment of the turbine affect the floater excursion, and the motion of the floater can affect the incoming speed of the flow into the turbine. To maximize the power generation and stabilize the system, the coupled motion of the floater and turbine must be extensively analyzed. However, unlike pile-fixed devices, there have been few studies involving the motion analysis of a moored-type tidal current power device. In this study, the commercial program OrcaFlex 10.1a was used for a time domain motion analysis. In addition, in-house code was used for an iterative calculation to solve the coupled problems. As a result, it was found that the maximum mooring load of 200 kN and the floater excursion of 5.5 m were increased by the turbine effect. The load that occurred on the mooring system satisfied the safety factor of 1.67 suggested by API. The optimum mooring system for the floating tidal current power device was suggested to maximize the power generation and stability of the floater.

• 한국BIM학회 논문집
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• 제12권4호
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• pp.19-31
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• 2022

With the development of 3D-based CAD (Computer Aided Design), attempts at freeform building design have expanded to small and medium-sized buildings in Korea. However, a standardized system for continuous utilization of shape data and BIM conversion process implemented with 3D-based NURBS is still immature. Without accurate review and management throughout the Freeform building project, interference between members occurs and the cost of the project increases. This is very detrimental to the project. To solve this problem, we proposed a continuous utilization process of 3D shape information based on BIM parameters. Our process includes algorithms such as Auto Split, Panel Optimization, Excel extraction based on shape information, BIM modeling through Adaptive Component, and BIM model utilization method using ID Code. The optimal cutting reference point was calculated and the optimal material specification was derived using the Panel Optimization algorithm. With the Adaptive Component design methodology, a BIM model conforming to the standard cross-section details and specifications was uniformly established. The automatic BIM conversion algorithm of shape data through Excel extraction created a BIM model without omission of data based on the optimized panel cutting reference point and cutting line. Finally, we analyzed how to use the BIM model built for automatic conversion. As a result of the analysis, in addition to the BIM utilization plan in the general construction stage such as visualization, interference review, quantity calculation, and construction simulation, an individual management plan for the unit panel was derived through ID data input. This study suggested an improvement process by linking the existing research on atypical panel optimization and the study of parameter-based BIM information management method. And it showed that it can solve the problems of existing Freeform building project.

• 한국인터넷방송통신학회논문지
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• 제22권3호
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• pp.139-143
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• 2022

본 연구에서는 전자기 유도 발전(EMG) 기법 중 RFPM의 설계사양을 설정하고 특성 계산에 필요한 유한요소해석(FEM, 2D)을 통하여 이에 적합한 시험 시제품을 제작하였다. 또한 시험용 프로토타입의 측정, 분석을 하기위하여 전용 검사장치를 설계, 제작하였다. 검사장치로 시험품을 측정하였으며, 그 결과를 분석하여 실제 인체 운동 에너지를 이용하여 웨어러블 IT 기기의 배터리에 충전이 가능한 만큼 출력전력이 생성되어 적용할 수 있는 방법을 제시하고자 한다. 시험결과, 회전수 780.9rpm, 토크 0.264kgf/cm, 부하전류 73.6~73.9mA의 조건에서 출력 1.679W, 효율 79.31%로 측정되었다. 따라서 초소형 RFPM 진자 발전기의 출력으로 웨어러블 기기에 충전이 가능한 것으로 분석되었다.