• 한국BIM학회 논문집
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• 제2권2호
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• pp.1-9
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• 2012

국내 공공 공동주택에 BIM 도입이 추진되었으나, BIM 기반 평가 기준 불확실성 및 관리업무 프로세스 비합리성으로 인한 참여업체의 과도한 설계 유발, 성과품 제출위주의 평가가 이루어지고 있다. 이에 본 연구에서는 공공 공동주택의 BIM 적용 설계 경기평가관리를 위해 실무자의 의견 수렴 및 시범적용을 실시하여 BIM 기술 수준 및 적용 가능성을 파악하고, 이를 통해 현실적인 평가항목 선정을 통한 평가관리 방안을 제시하고자 하였다. 첫째, 본 연구에 앞서 현재 실시되고 있는 BIM 적용 공공 공동주택의 평가 현황을 살펴본 후 사전조사를 통해 BIM이 적용 가능한 항목 15개를 예비 선정 하였다. 둘째, 예비 선정한 15개의 항목 중 BIM 기술수준 적합성, 결과 값 도출과정 명확성, 정보수준 만족 여부를 기준으로 시범적용을 실시한 결과 총 8개의 항목에서 BIM이 적용 가능한 것으로 분석되었다. 특히 현상설계 단계에서의 BIM 적용 평가 가능 항목은 3D 시각화 및 면적 관련 항목이 대부분이며, 기존에 요구되었던 사업비, 에너지/환경분석, 구조, 설비관련 항목은 후속설계 단계(기본, 실시)에 적합한 것으로 정리 할 수 있다. 본 연구의 결과는 현재 국내의 BIM 기술 수준 및 적용 가능성을 올바르게 인식하지 못하고, 무분별한 범위에서 BIM을 적용하고자 하는 현업 실태의 문제점을 지적하고, 적절한 범위에서 가장 객관적인 결과 및 BIM의 효율성을 극대화하고자 하는데 활용할 수 있는 자료를 제공하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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• pp.13-15
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• 1998

EM(Electro Magnetic) pump is used for the purpose of transporting liquid sodium coolant with electrical conductivity in the LMR(Liquid Metal Reactor). In the present study. pilot EM pump has been designed by using of equivalent circuit method which is commonly employed to analyze linear induction machines for the test of removal of residual heat. The length and diameter of the pump have fixed values of 840 mm and 101.6 mm each by taking account of geometrical size of circulation loop for the installation of EM pump. Flowrate versus developing pressure is related from Laithwaite's standard design formula and the characteristic analyses of developing force and efficiency are carried out according to change of input frequency. From the characteristic curve, input frequency of 13 Hz is determined as the design frequency. On the other hand, The annular air gap size of 6.05 mm is selected not to bring about too much hydraulic loss. Resultantly design analysis makes pump have the electrical input of 604 VA and the hydrodynamical capacity of 1.3 bars and 40 l/min.

• 신재생에너지
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• 제17권3호
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• pp.32-41
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• 2021

A groundwater source heat pump (GWHP) was developed in this study by adapting a borehole heat exchanger with closed-loop and open-loop systems in a new building. In the pilot test building, the air-conditioning on the second floor was designed to employ a closed-loop system and that on the third floor had an open-loop system. The GWHP design is based on the feasibility of groundwater resources at the installation site. For the hydrogeological survey of the study site, pumping and injection tests were conducted, and the feasibility of GWHP installation was evaluated based on the air-conditioning load demand of the building. The site was found to be satisfactory for the design capacity of the thermal load and water quality. In addition, the effect of groundwater movement on the performance of the closed-loop system was tested under three different operational scenarios of groundwater pumping. The performance of the system was sustainable with groundwater flow but declined without appropriate groundwater flow. From long-term observations of the operation, the aquifer temperature change was less than 2℃ at the observation well and 5℃ at the injection well with respect to the initial groundwater temperature. This pilot study is expected to be of guidance for developing GWHPs at fractured rock aquifers.

• 한국BIM학회 논문집
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• 제9권4호
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• pp.41-50
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• 2019

Digital models for a cable-stayed bridge are defined considering data-driven engineering from design to construction. Algorithms for digital object generation of each component of the cable-stayed bridge were developed. Using these algorithms, Level-3 BIM practices can be realized from design stages. Based on previous practices, digital object library can be accumulated. Basic digital models are modified according to given design conditions by a designer. Once design models are planned, various applications using the models are linked the models such as estimation, drawings and mechanical properties. Federated bridge models are delivered to construction stages. In construction stage, the models can be efficiently revised according to the changed situations during construction phases. In this paper, measured coordinates are imported to the model generation algorithms and revised models are obtained. Augmented reality devices and their applications are proposed. AR simulations in construction site and in office condition are tested. From this pilot test of digital models, it can be said that Level-3 BIM practices can be realized by using in-house modeling algorithms according to different purposes.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.1273-1278
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• 2008

A sea water source cascade heat pump was designed and tested in this study. The system was designed to perform a single stage operation in summer, as well as a cascade operation in winter to ensure the high temperature lift. A steady-state simulation model was developed to analyze and optimize its performance. The simulation results show that the R717 exhibits best performance among combinations considered in this study. A R410A also exhibits the highest performance among HFCs with the smallest compressor displacement. A 15-RT R410A-R134a pilot system was installed in the 5-story commercial building at Samcheok City by the East Sea. A scroll type R410A compressor, a reciprocating type R134a compressor, plate type condenser/ evaporator/ cascade heat exchanger and two electronic expansion valves were used to build a pilot. A titanium plate type heat exchanger is also used for the heat exchanging with a sea water. The heat source/sink water is supplied from the well below the seashore in the depth of 5 m. In the initial test of the system, supply water temperature was rising up to $67^{\circ}C$ using a sea water heat source of $9^{\circ}C$, while an ambient temperature was $4.5^{\circ}C$.

• 제어로봇시스템학회논문지
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• 제14권7호
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• pp.711-719
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• 2008

Although non-real time simulation and pilot based evaluations are available for the development of flight control computer prior to real flight tests, there are still many risky factors. The control law designed for prototype aircraft often leads to degraded performance from the initial design objectives, therefore, the proper evaluation methods should be applied such that flight control law designed can be verified in real flight environment. The one proposed in this paper is IFS(In-Flight Simulator). Currently, this system has been implemented into the F-18 HARV(High Angle of Attack Research Vehicle), SU-27 and F-16 VISTA(Variable stability. In flight Simulation Test Aircraft) programs. This paper addresses the concept of switching mechanism for FLCC(Flight Control Computer)-SWMC(Switching Mechanism Computer) using 1553B communication based on flight control law of advanced supersonic trainer. And, the fader logic of TFS(Transient Free Switch) and stand-by mode of reset '0' type are designed to reduce abrupt transient and minimize the integrator effect in pitch axis control law. It hans been turned out from the pilot evaluation in real time that the aircraft is controllable during the inter-conversion process through the flight control computer, and level 1 handling qualities are guaranteed. In addition, flight safety is maintained with an acceptable transient response during aggressive maneuver performed in severe flight conditions.

• 대한예방한의학회지
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• 제18권2호
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• pp.59-67
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• 2014

Objective : This study was to examine the effects of Doin-Angyo program, evidenced by East Asian Medicine literatures, on stress among smoking adolescents. Method : This study was a prospective community trial using a one-group, pretest-posttest design. As an intervention, Doin-Angyo program was implemented for 10 minutes per session, 3 days a week, for 6 weeks to smoking students who attend a Girl's high school. Psychological stress was measured by self-report questionnaire and physiological stress was measured by salivary cortisol. The final sample for the questionnaire included 18 participants. In addition, pre- and post-salivary cortisol levels of 24 adolescents participating in the last session were compared in order to identify the acute effects of Doin-Angyo program in reducing stress. Results : There were no significant differences in overall stress-test results from the comparisons before and after the intervention. However, we found a significant going-down of the stress level(p = .032) in the question, "About School-work" among six sub-category questions. From the salivary cortisol tests in the last session, we found, in comparison with the standard salivary cortisol density level, $0.3{\mu}g/dL$, the density level tended to go down(p = .062) when higher than the standard, and it went up(p = .001) when lower than the standard, after 10 minute session. Conclusion : The results of this pilot study supported the partial effect of Doin-Angyo program in reducing the stress levels. The study protocol and results can be used to elaborate the community trials design aiming to prove the effect of Korean Medicine based health promotion modalities.

• 한국산학기술학회논문지
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• 제12권10호
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• pp.4600-4605
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• 2011

본 논문은 스프링 프레임워크 2.5의 동일한 플랫폼 환경에서 하이버네이트 3.2와 아이바티스 2.3에 대하여 기능별 수행 속도를 비교하여 프로젝트 규모별 장단점을 분석해 보는데 그 목적이 있다. 현재까지 경량 컨테이너 구조로 많이 사용되고 잘 알려진 구조로 스프링 프레임워크이 있다. 또한 데이터베이스의 생산성을 높여주기 위한 기법으로 ORM이 있다. 현재 많이 사용되는 ORM 도구로 하이버네이트와 아이바티스가 있다. 따라서 본 연구에서는 동일한 스프링 프레임워크 2.5 환경을 기반으로 하이버네이트 3.2와 아이바티스 2.3에서 파일럿 시스템을 설계하고 구현하여 CRUD별 수행 속도를 비교함으로써 프로젝트의 적용에 평가 지표를 제공하고자 한다.

• 한국수학교육학회지시리즈A:수학교육
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• 제47권4호
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• pp.487-503
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• 2008

In this paper, descriptive assessment method for middle school mathematics was evaluated by developing a framework for designing and grading problems for descriptive assessment and analyzing the effectiveness of the problems. The new descriptive assessment problems were developed by reviewing the current 7th National Mathematics Curriculum of Korea and aligned mathematics textbooks to define a set of problem design principles and evaluation framework for the assessment strategy. The developed problems were first pilot tested and then revised based on the feedback from the test. The final version was field tested by 100 students in 7th grade middle school. After the field test, the problems were graded by two middle school math teachers and one math education researcher to determine the overall correlation between graders and also to analyze effectiveness of the evaluation framework of the test. This result of this study is expected to assist in the further development of descriptive problems and grading framework by providing a reference work for teachers to better understand the process and the limitations of executing the new assessment strategy.

• 한국지반환경공학회 논문집
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• 제11권4호
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• pp.51-59
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• 2010

본 연구는 준설 매립된 느슨한 상태의 실트질 사질토층이 얕게 분포해 있는 지역에 건물 조성 및 건축물 시공을 위한 기초설계사례에 관한 연구로, 연구 대상지는 군산, 인천지역의 준설 매립지로 심도 E.L(-)10m 전후에 느슨한 실트질 사질토층이 분포해 있으며, 하부 말뚝기초의 지지층은 E.L(-)20m 전후로 출현하고 있어 얕은 기초공법 적용 시 기초지반 보강을 위한 지반개량이 필요한 지역이다. 따라서 이에 적용 가능한 기초처리 공법들을 비교 검토한 결과 구역별 설계하중 조건을 고려하는 동다짐 공법이 가장 적합한 공법으로 선정되었다. 본 연구에서는 이를 검증하기 위한 방법으로 현장시험시공을 통해 시공결과에 대한 확인시추조사 및 평판재하시험 등을 실시하여 지반개량효과를 분석하였으며, 동다짐 공법에 의해 지지력에 대한 안정성이 확보됨을 확인하였다.