• 한국화재소방학회논문지
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• 제29권5호
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• pp.51-56
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• 2015

본 연구에서는 설계프로그램의 공학적 분석의 수단 또는 가치공학 측면에서 원가절감 등의 목적으로 최적설계 이론과 공학적 이론을 접목시킨 최적설계법을 가스계 소화설비 중 청정소화약제 소화설비의 약제방출량 산출에 응용하였다. 청정소화약제 소화설비의 설계이론과 최적설계 이론을 바탕으로 약제방출량을 최적화시킬 수 있는 최적설계인자를 도출하였고, 이를 설계인자로 구축된 소화설비의 소화성능시험으로 최적설계법의 적합성 여부를 검증함으로써 다른 소화설비에도 최적설계법을 접목할 수 있는 기틀을 마련하였다. 방출헤드의 약제방출량 최적화는 방출헤드 및 배관의 내경, 약제도달시간, 유량과 압력변화 등의 소화약제 유동특성에 대한 제한조건에 의해 결정됨을 확인하였고, 방출헤드의 방출압력과 약제도달시간의 편차는 배관의 압력변화만큼 발생되고 상관관계가 있음을 알 수 있었다.

• 디지털융복합연구
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• 제19권1호
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• pp.389-399
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• 2021

본 논문의 연구배경은 플로우 이론을 적용한 u-융합정보시스템이 관광객의 만족도 측정이 부족하기 때문에 연구를 시작하게 되었다. 본 연구의 목적 및 연구 방법은 다음과 같다. 첫째는 플로우 관계정보 표시형식 알고리즘 제안이다. 둘째는 이 알고리즘과 플로우 이론을 접목시켜 콘텐츠 정보품질과 관광객의 성격 유형에 따라 패턴 알고리즘을 생성한 것이다. 본 연구의 기대효과는 플로우 관계정보 표시형식과 관광객의 성격 유형에 따라 패턴 알고리즘을 생성함으로서 u-융합정보시스템의 성공요인을 도출한 것이다. 본 논문의 한계성은 한 지역을 한정적으로 하였으며 데이터의 부족과 소규모 지역으로 객관성이 떨어진다. 추후, 다른 관광지에 제시하는 방법 적용 후, 분석을 통해 효용성을 평가할 필요가 있다. 향후 과제는 전문가 집단의 데이터 보완이 필요하고 여러 지역의 객관성이 보완되어야 할 것이다.

• 대한기계학회논문집B
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• 제28권10호
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• pp.1238-1246
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• 2004

Momentum exchange theory has been generally used for an analysis of the regenerative turbomachines due to its direct description of the complicate circulatory flow. However, because its application is limited only to linear region and its model equations are incomplete on three variables, it needs further refinements. In the present study it is improved by introducing a central pivot of circulatory flow. Also, by assuming linear circulatory velocity distribution, mean radii of inlet and outlet flows through the impeller are newly suggested. By applying control volume analysis to both linear region and the acceleration region, the governing equation on the circulatory velocity is derived. As a result, systematic performance analysis on the entire region of the incompressible regenerative turbomachines can be carried out based on the proposed model equations.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 1998년도 유체기계 연구개발 발표회 논문집
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• pp.64-69
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• 1998

In this study, a preliminary design method of the axial fan was systematically established based on the two-dimensional cascade theory. Flow deviation, lift coefficient, distribution of velocity and pressure coefficient on blade surfaces were predicted by an inviscid theory of Martensen method, which was also applied to select an airfoil of required performance in the present design process. The aerodynamic performance of designed blades can be predicted quickly and reasonably by using the through-flow calculation method in the preliminary design process. It would be recommendable to adopt three-dimensional viscous flow calculation at the final design refinement stage.

• Korea-Australia Rheology Journal
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• 제21권4호
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• pp.245-268
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• 2009

Recent developments in dilute polymer solution rheology are reviewed, and placed within the context of the general goals of predicting the complex flow of complex fluids. In particular, the interplay between the use of polymer kinetic theory and continuum mechanics to advance the microscopic and the macroscopic description, respectively, of dilute polymer solution rheology is delineated. The insight that can be gained into the origins of the high Weissenberg number problem through an analysis of the configurational changes undergone by a single molecule at various locations in the flow domain is discussed in the context of flow around a cylinder confined between flat plates. The significant role played by hydrodynamic interactions as the source of much of the richness of the observed rheological behaviour of dilute polymer solutions is highlighted, and the methods by which this phenomenon can be incorporated into a macroscopic description through the use of closure approximations and multi scale simulations is discussed.

• 대한기계학회논문집A
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• 제20권5호
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• pp.1426-1435
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• 1996

In this paper. a network theory for generaltransmission systme was extended considering the direction of power flow. Also, a modified network model was suggested for a node with 4 shafts in order to verify the power flow. Based on the extended network theory, a simulation program was developed to analyze a hydro-mecaanical tranmission(HMT) system consistion of two hydrostatic pump motors, severeal planetary gear trains steer differential gear. The simulation result showed that the extendednotwork analysis program develped can predict the power circulation as well as the magnitude of torque and speed for each transmission element and can be used design tool for genaral power transmission system.

• 대한기계학회논문집B
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• 제22권11호
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• pp.1603-1609
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• 1998

Numerical solutions of Stokes flow through periodic arrays of cylinders were sought using Darcy's law and homogenization theory. Drag and lift forces of each cylinder were computed for various attack angles and pitch-to-diameter ratios. It was found that drag force decreased as principal pressure gradient direction deviated from array direction and that drag force increased exponentially as pitch-to-diameter ratio approached unity. Similar tendency was found in lift force except that lift force increased and then decreased in quadratic manner as attack angle varied.

• Educational Technology International
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• 제12권2호
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• pp.1-18
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• 2011

This study intends to examine the effects of motivational scaffolding in Computer-Supported Collaborative Learning (CSCL). This study was focused on the following two questions. Do motivational scaffolding lead to positive effects on the process in CSCL? Do motivational scaffolding lead to positive effects on the outcome in CSCL? In order to identify strategies for motivational scaffolding, we reviewed the "Flow Theory." Based on literature reviews, principles and strategies were drawn for the motivational scaffolding. An experimental study was conducted in order to investigate the effects of motivational scaffolding on process and outcome. In this study, 87 undergraduate students were divided into two different groups (control group, experimental group). Motivational scaffolding was provided to experimental group. The process was analyzed by examining learners' satisfaction in process. The outcome was analyzed by examining learners' satisfaction in product, group coherence, and quality of product. The difference between the two groups was statistically significant. From these results, we concluded that motivational scaffolding led to positive effects on process and outcome in CSCL environment.

• 재활치료과학
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• 제10권3호
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• pp.71-81
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• 2021

서론 : 본 연구는 대상자의 신체기능과 활동 및 참여를 위해 다양한 치료적 중재를 실시하는 작업치료 분야에 몰입경험 이론의 소개를 목적으로 한다. 본론 : 작업치료 영역에서의 몰입경험 이해를 위해 국내·외 문헌고찰을 통한 몰입경험의 개념과 특징, 단계와 뇌과학적 특성, 측정방법 및 관련 연구들을 정리하였다. 작업치료에서 대상자의 몰입경험은 '시간이 흐르는 것을 잊으면서 하고 있는 치료 활동에 완전하게 빠져드는 심리적 상태'로 정의할 수 있다. 대상자는 과제에 대한 명확한 목표를 인식하며, 도전과 기술 수준이 높은 상태로 균형을 이룰 때에 몰입을 경험하게 된다. 선행 연구에서 몰입을 경험한 대상자는 주의 및 집중, 집행 기능, 상지기능, 일상생활활동 수행 증진과 긍정적인 경험에 긍정적 변화가 있음을 확인하였다. 결론 : 국내 작업치료 영역에서 다양한 치료적 중재에 대상자의 몰입경험이 고려된다면 치료 결과의 효과는 보다 촉진될 것이라 생각되어진다.

• 공학교육연구
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• 제20권4호
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• pp.61-66
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• 2017

Automatic flow control system composed by hardware and software was designed and fabricated to be used as teaching tool of feedback control theory in university experimental class. This system includes hardwares like data acquisition board, flow measuring device, transmitters, and the pneumatic valve, and software like LabView program for the monitoring and control of flow rates. The system was designed as the student can see the control effect of not only set point but also disturbance changes. Also the LabView program was composed for the calculation of controller parameters of both Ziegler-Nichols and Cohen-Coon tuning. The students can apply both tuning constants and compare the control performances. This system will provide the easy way for the students to understand the function and specification of control hardwares, and to raise the programing ability of control software.