• 드라이브 ㆍ 컨트롤
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• 제19권4호
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• pp.46-53
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• 2022

RIn this study, a test tractor that could measure various types of agricultural operational loads was developed, and its performance was verified. This tractor could be used to measure the load generated during agricultural work and convert the related data into a database. A test tractor was developed using an 80-kW-rated load tractor, and it could measure various types of field test data, such as engine torque and rpm, wheel torque, PTO(power take-off) torque, hexometer, IMU/INS sensor, steering angle sensor, hydraulic pressure, and flow sensor data. To verify the developed test tractor, a verification test using an agriculture rotavator was performed. The test conditions were L1, L2, and L3 based on the tractor's main and sub-transmission stages, and stages 1 and 2 were selected as the PTO. In a comparison of the analyzed test data, similar tendencies in the test results of this research and other research (Kim's research) were seen. Through this, the developed test tractor was verified. In the future, we plan to conduct research on the tractor developed in this study using various attached working machines.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.1036-1038
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• 2003

Electric control of eddy coupling offers many new possibilities in process control and other industrial control applications. And a form of speed control for the load is affected for a system driven by costant frequency induction motor. This paper compare speed-torque characteristic of three types of eddy-current coupling by using the analytical method. And characteristic experiment of three types of eddy current coupling is put into operation. And then, this paper will discuss operational and magnetic field characteristic of three types model.

• 한국태양에너지학회 논문집
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• 제30권3호
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• pp.39-46
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• 2010

This study is focused on the effect of thermal load according to the various plan types in tower-type apartment in Korea. So, we chose the '』' type model in order to analyze the shading effect of the plan type. The main results are as follows. In chosen model, cooling energy demands are more sensitive than heating ones when is compared with the two methods. And there are about 10% deviations between new and conventional method. Because new method considers more detailed than conventional one about the building geometries. We also found that this building type affects to the about 3 floors from the top and it doesn't affect to the thermal load in lower floors. From these facts, we suggest new modeling method to the similar researches that will be analyzed the thermal load on the tower type apartment in Korea. Also there is no difference of the thermal load in each azimuth between simple and detailed modeling method. Consequently, we judge that this new method considered the shading effect will be used a lot to the similar analysis in tower type apartment in Korea.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2001년도 추계학술대회 학술발표 논문집
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• pp.1-4
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• 2001

Landsat TM 위성영상을 대상으로 인공신경망 모형과 RBF 신경망 모형의 토지피복분류 정확도를 평가하였다. 토지피복의 특성에 따라 세 개의 연구지역(복합토지이용, 농경지, 도시지역)을 대상으로 RBF 신경망 모형의 입력밴드 조합 및 분류 항목의 변화에 따른 민감도 분석이 수행되었다. 오염부하 원단위의 신뢰구간 및 분포를 추정하기 위하여 붓스트랩기법이 적화하였으며, 특히 토지이용이 다양한 도시지역에서 가장 큰 변화폭을 보였다.

• 대한기계학회논문집A
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• 제35권1호
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• pp.77-83
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• 2011

본 논문에서는 해상 부유식 풍력타워의 동역학 모델링이 제시되고, 다양한 해상환경하중인 풍하중, 파랑하중을 모델링하여 플랫폼의 동적 거동해석을 수행하였다. 풍하중을 모델링하기 위해 풍속은 높이에 따라 변하도록 고려하였고, 파랑하중은 상대운동 모리슨방정식을 이용하여 모델링 하였다. 동적 거동해석을 위해 동역학해석프로그램인 ADAMS 를 이용하였다. 부유식 플랫폼에 많이 쓰이는 tension leg platform 의 네 가지 타입에 대해 동적 거동특성을 비교하였다.

• Steel and Composite Structures
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• 제12권5호
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• pp.427-444
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• 2012

This paper presented a new aerial platform-AERORail for rail transport and its structure evolution based on the elastic stiffness of cable; through the analysis on the cable properties when the cable supported a small service load with high-tensile force, summarized the theoretical basis of the AERORail structure and the corresponding simplified analysis model. There were 60 groups of experiments for a single naked cable model under different tensile forces and different services loads, and 48 groups of experiments for the cable with rail combined structure model. The experimental results of deflection characteristics were compared with the theoretical values for these two types of structures under the same conditions. It proved that the results almost met the classical cable theory. The reason is that a small deflection was required when this structure was applied. After the tension increments tests with moving load, it is verified that the relationships between the structure stiffness and tension force and service load are simple. Before further research and applications are made, these results are necessary for the determination of the reasonable and economic tensile force, allowable service load for the special span length for this new platform.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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• pp.67-70
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• 2010

This study investigates the physical properties of the acrylic emulsion mortar according to variable composition set of redispersible emulsion powders. This materials have to be composed of many types of binders and chemical additives. So it is difficult to decide suitable mixing proportion of composition materials. The redispersible emulsion powders using "2, 4, 6, 8kg" of EVA polymers dispersion ranges are prepared with acrylic emulsion mortars and were tested for basic characteristics such as flexural, and compressive strength, wheel load. Through experiments we found that the improved formula to satisfy the standard of wheel load by EVA polymers, and the masration rangs between about 2.0% to 2.6% which the white portland cenmet and EVA polymers is good for resistauce wheel load.

• Computers and Concrete
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• 제25권3호
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• pp.215-224
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• 2020

In the present study, according to the important of porosity in low specific weight in comparison of high stiffness of carbon nanotubes reinforced composite, buckling and free vibration analysis of sandwich composite beam in two configurations, of laminates using differential quadrature method (DQM) is studied. Also, the effects of porosity coefficient and three types of porosity distribution on critical buckling load and natural frequency are discussed. It is shown the buckling loads and natural frequencies of laminate 1 are significantly larger than the results of laminate 2. When configuration 2 (the core is made of FRC) and laminate 1 ([0/90/0/45/90]_s) are used, the first natural frequency rises noticeably. It is also demonstrated that the influence of the core height in the case of lower carbon volume fractions is negligible. Even though, when volume fraction of fiber increases, the critical buckling load enhances smoothly. It should be noticed the amount of decline has inverse relationship with the beam aspect ratio. Investigating three porosity patterns, beam with the distribution of porosity Type 2 has the maximum critical buckling load and first natural frequency. Among three elastic foundations (constant, linear and parabolic), buckling load and natural frequency in linear variation has the least amount. For all kind of elastic foundations, when the porosity coefficient increases, critical buckling load and natural frequency decline significantly.

• 한국화재소방학회논문지
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• 제11권1호
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• pp.37-45
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• 1997

본 연구에서는 국내 10개 설계 사무소 건물을 대상으로 화재하중 분석방법과 현재의 화재하중 분포 를 제시하였다. 조사범위는 건물 완공 후 거주자가 반입한 이동성 물품(이하 이동하중)으로 제한하였 다. 조사결과는 평면배치, 바닥면적, 사용인원 및 가연물의 특성에 따른 이동하중과의 관련성과 함께 미국의 조사 결과와 비교 분석하였다. 현재 국내 사무소 건물의 이동하중은 95% 신뢰도 기준으로 36.13kg/$m^2$ 에서 52.41kg/$m^2$ 사이에 분포하며 평균 화재하중은 44.27kg/$m^2$ 으로 나타났다. 한 미간의 분포는 미국이 평균 66. 84kg 1m2로 한국의 44.27kg/$m^2$ 에 비해 상당히 높게 나타났다. 본 연구결과는 향후 건불의 화재위험도 분류 및 화재 실험시 가연물량 기준에 적용되며 내화설계의 기준 결정을 위한 기초자료로 활용될 것으로 기대된다.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2006년도 정기학술발표대회 논문집
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• pp.519-522
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• 2006

본 연구는 LCA(Life Cycle Assessment, 전과정평가) 개념을 바탕으로 토목시설의 환경성 평가를 위한 의사결정시 유용한 정보를 제공하기 위하여 사례대상으로 선정된 다목적댐 비상여수로의 위치 및 형식별로 발생 가능한 환경오염물질에 대한 환경부하량을 예측하고자 하였다. 이를 위해 LCA 기법의 이론을 고찰하고, 제안된 토목시설물의 사례대상인 다목적댐 비상여수로에 적용하기 위해 전과정 동안 발생하는 환경오염물질에 대한 환경부하량을 산출하고, 예측결과를 통하여 비상여수로의 환경성을 평가하고 친환경적인 최적대안을 도출하였다.