• 한국산학기술학회논문지
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• 제14권2호
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• pp.822-827
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• 2013

본 논문에서는 정지시까지 전기제동을 하는 축소모형 추진시스템을 설계하고 제작하여 실험하였으며, 정지순간 제동토오크의 제어방법을 제안하였다. 또한, 레졸바를 사용한 회전자의 위치와 속도를 추정하는 관측기에 의하여 극저속에서 속도를 검출하는 방법을 개발하였으며, 또한 정지순간 제동 토오크의 감소와 동시에 공기 브레이크의 동작을 개시하여 블렌딩 제동을 사용하는 방법과 비교하여, 정지시까지 전기제동만을 사용하는 향상된 제동방법을 제안하였다.

• Wind and Structures
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• 제30권3호
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• pp.261-273
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• 2020

This paper deals with the design, wind tunnel testing, and performance analysis of small wind turbines targeting low-power applications. Three different small-size blade designs in terms of size, shape, and twisting angle are considered and tested. We conduct wind tunnel tests while measuring the angular speed of the rotating blades, the generated voltage, and the current under varying resistive loading and air flow conditions. An electromechanical model is also used to predict the measured voltage and power and verify their consistency and repeatability. The measurements are found in qualitative agreement with those reported in previously-published experimental works. We present a novel methodology to estimate the mechanical torque applied to the wind turbine without the deployment of a torque measuring device. This method can be used to determine the power coefficient at a given air speed, which constitutes an important performance indicator of wind turbines. The wind tunnel tests revealed the capability of the developed wind turbines to deliver more than 1225 mW when subject to an air flow with a speed of 7 m/s. The power coefficient is found ranging between 26% and 32%. This demonstrates the aerodynamic capability of the designed blades to extract power from the wind.

• 공학논문집
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• 제6권1호
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• pp.83-96
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• 2004

강판파일로 지지되고 있는 미니 교대하부에, 압성토의 제거에 따른 교대의 안정성을 확보하기 위한 방법으로서 쏘일네일링 공법을 채택하였다. 네일벽체에 각종 계측기를 매설하여 벽체의 거동을 추적하였다. 또한 3차원 유한요소해석기법을 이용하여 쏘일네일 벽체와 기존 구조물사이의 상호영향과 관련된 벽체의 거동을 분석하였다. 압성토의 순차적 제거와 네일타설 등의 전 축조 시퀀스를 모델링 할 수 있는 기법을 개발하였으며 개발된 시뮬레이션 기법의 타당성을 검증하기 위해 현장에 축조된 실물 계측데이터를 이용하여 보정하였고, 압성토의 제거와 네일타설이 기존 파일의 축하중 및 휨모멘트에 미치는 영향과 네일 인장력의 변화와의 상관관계 등, 설계시 고려되어야 할 몇 가지 주요한 사항에 대한 해석결과를 구할 수 있었다.

• 한국태양에너지학회 논문집
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• 제34권4호
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• pp.91-99
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• 2014

The purpose of the study is to apprehend the preference of occupants to colors and installation locations for DSC combined windows and doors, and suggest a concept to optimize the design and function of windows and doors. A miniature model was made applying green, blue, and red colored DSC windows and doors to survey preference about DSC colors and applied location. And a survey was accomplished to 140 subjects by showing pictures of the model and the result of the survey became the basis for suggesting a concept to design DSC integrated windows and doors. Through the survey, blue color and upper part were chosen as the highest level of satisfaction in the situation of external brightness and residence. On the contrary to this, red color was chosen as the lowest level of preference when applied to both of upper and lower parts of winders and doors. Therefore, it's expected that, if various patterns of texture are developed for blue colored DSC, and installation is arranged based on upper part of windows and doors where lighting condition and comfort are less affected, then, conditions of brightness, view, and residents satisfaction will be equally fulfilled.

• Journal of Advanced Marine Engineering and Technology
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• 제39권8호
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• pp.821-827
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• 2015

This study concentrates on a wave energy converter with floaters that extracts the ocean's energy by moving up and down with the wave motion. The floater is connected to an arm structure, including a hydraulic cylinder that drives a hydraulic generator. This study focuses on a structural analysis of the floater unit, including arm and cylinder components, platform and jack-up system, along with spud columns. Previous studies have been conducted for miniature models for experimentation, but this study focuses on the full-scale model structural analysis. Static structural analysis is conducted using fine numerical grids. Due to the complexity of the whole model, it is analyzed in separate pieces. The floater unit, with arm and cylinder, are combined into one system. The platform is analyzed separately as a single system. There are four jack-up systems for each spud column; only one jack-up system is analyzed, as uniform loads are assumed on each system. There are several load cases for each system, all of which are analyzed thoroughly for stress (von Mises, shear, and normal) and deformation. Acceptable results were obtained for most of the components; unsafe components were redesigned.

• 한국정밀공학회지
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• 제22권7호
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• pp.27-37
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• 2005

Direct writing technology on the silicon wafer surface is used to reduce the size of the chip as the miniature trend in electronic circuit. In order to improve the productivity and efficiency, the real time quality estimation is very important in each semiconductor process. In laser marking, marking quality is determined by readability which is dependant on the contrast of surface, the line width, and the melting depth. Many researchers have tried to find theoretical and numerical estimation models fur groove geometry. However, these models are limited to be applied to the real system. In this study, the estimation system for the line width during the laser marking was proposed by process monitoring method. The light intensity emitted by plasma which is produced when irradiating the laser to the silicon wafer was measured using the optical sensor. Because the laser marking is too fast to measure with external sensor, we build up the coaxial monitoring system. Analysis for the correlation between the acquired signals and the line width according to the change of laser power was carried out. Also, we developed the models enabling the estimation of line width of the laser marking through the statistical regression models and may see that their estimating performances were excellent.

• 산업기술연구
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• 제18권
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• pp.405-415
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• 1998

This thesis is an experimental and numerical research on bearing capacity acting retaining walls close to rigid slopes with stiff angles. Experiments were performed with changing the roughness of adjacent slope to the wall, its inclination, distance between wall and slope. Vertical stress and applied surcharge loads were measured by miniature earth cells and a load cel respectively. Stress distribution Vertical Settlement of surcharge load of rigid model footing were measured by LVDTs. Bearing capacities of surcharge loads were compared with theoretical estimations by using several different methods of limit equilibrium and numerical analysis. For limit equilibrium methods, the modified silo and the wedge theories, proposed by Chung sung gyo and Chung in gyo (1994) were used to analyze test results Based on those modified theories, the particular solution with the boundary condition of surcharge loads on the surface of backfill was obtained to find the stress distributions acting in the backfill and to compare with test results. From results of surcharge test with model wall being very close to the slope, analyzed results by the modified silo theory and to be in the better agreements than other methods.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.111-112
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• 2020

As buildings in South Korea become more skyscrapers, the risk of fire is also emerging. Thus, regulations, regulations, and guidelines are being improved to prevent the spread of smoke in the event of a fire in high-rise buildings, but research on smoke flow and pressure distribution in vertical spaces is insufficient. Therefore, in this study, the temperature of each floor in the vertical space according to the size of the fire is measured through the miniature model experiment, and the pressure difference is calculated to establish the basic data for the improvement of the performance of domestic air supply facilities in the future. Thus, a scale model of one-sixth the size of the actual building was produced to measure the temperature, and the pressure difference was derived by substituting the value for the expression. The pressure difference varies depending on the size of the cause of the fire, and it is believed that the differential pressure and conditions of the building should be taken into account before calculating the supply volume for the analysis of the pressure difference according to the size of the cause of the fire in the event of fire.

• 한국방사선학회논문지
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• 제8권3호
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• pp.117-121
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• 2014

심장의 모양 및 혈관에 관한 의료학적 지식습득은 의료인 및 의료기사들과 같은 의료전문인들에게는 필수적 요구사항이다. 심장의 모형을 통한 의료지식의 습득은 환자의 생명과도 직결되는 중요한 사항이기 때문에 보다 정확한 의료지식이 필요하다. 따라서 심장모양 및 심장혈관질환에 대한 다양한 의료교구재의 연구 및 개발이 필요하다. 이번 연구에서 만들어진 심장 및 심장혈관의 투시 모형장비를 사용하여 심장 혈류의 투시조영시의 볼 수 있는 방사선학적 사진 영상을 미리 습득할 수 있으며, 또한 투시 조영 중 환자의 자세의 따른 심장의 위치와 모형을 미리 예측해 볼 수도 있다. 결론적으로 우리가 고안한 심장혈관 투시 장비를 사용하여 심장혈관의 해부학적 지식을 미리 습득함으로서 면허 취득 후에 임상생활에 있어서의 심장혈류에 관한 정확한 이해에 도움을 줄 수 있을 것으로 사료된다.

• Journal of Korean Neurosurgical Society
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• 제61권5호
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• pp.539-547
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• 2018

Traumatic spinal cord injury (SCI) research has recently focused on the use of rat and mouse models for in vivo SCI experiments. Such small rodent SCI models are invaluable for the field, and much has been discovered about the biologic and physiologic aspects of SCI from these models. It has been difficult, however, to reproduce the efficacy of treatments found to produce neurologic benefits in rodent SCI models when these treatments are tested in human clinical trials. A large animal model may have advantages for translational research where anatomical, physiological, or genetic similarities to humans may be more relevant for pre-clinically evaluating novel therapies. Here, we review the work carried out at the University of British Columbia (UBC) on a large animal model of SCI that utilizes Yucatan miniature pigs. The UBC porcine model of SCI may be a useful intermediary in the pre-clinical testing of novel pharmacological treatments, cell-based therapies, and the "bedside back to bench" translation of human clinical observations, which require preclinical testing in an applicable animal model.