• 대한기계학회논문집
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• 제12권1호
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• pp.72-80
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• 1988

본 연구에서는 부분예혼합-확산계를 모델로 하여 이론해석을 통해 화염의 구조를 밝히고, 예혼합화염을 near-stoichiometry로 설정하여 내부지역에서 2차 반응으로 해석하고, 확산화염으로 부터 예혼합화염으로의 천이를 규명하는데 그 목적이 있다.

• 대한기계학회논문집
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• 제18권11호
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• pp.2967-2972
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• 1994

The multiple character of the contact interaction and the collective behavior of elementary microcontacts play a significant role in all the processes occurring in the surface layers, including the failure due to friction and wear. The array of metal spheres compressed between flat plates has been used for simulation of the contact behavior of multiple contact of solids under normal loading. An experimental design has been made providing regular array of the spheres at the same size with different spatial order. Measurement of electrial contact resistance has been made using the equipment providing the adequate accuracy in the range of micro Ohms. The data on electrical contact resistance have been compared with theoretical predictions using the multiple contact model of constriction resistance. The effect of single spots number and array on conductivity of contact has been evaluated.

• Elastomers and Composites
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• 제39권4호
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• pp.294-300
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• 2004

혼합폐플라스틱과 폐타이어분말을 혼합하여 복합체를 구성하고 그 기계적인 물성을 조사하였다. 수지-고무분말 사이의 계면접착력을 증대시키고자 두 요소와 친화성을 가질 것으로 예상되는 trans-octylene rubber(TOR)를 소량 첨가하였다. 고무분말의 투입량이 많아질수록 인장강도와 압축강도는 플라스틱자체보다 저하되었으며 파단신장률과 충격강도는 증가되었다. 상용화제 TOR이 첨가되면 인장강도와 충격강도 및 압축강도는 크게 향상되었으나 신장률은 변화가 없었다. 이러한 물성의 변화는 TOR의 화학적인 이중성에 기인한다고 여겨진다.

• Computers and Concrete
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• 제24권1호
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• pp.51-61
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• 2019

Compressive ability is one of the most important mechanical properties of concrete material. The compressive failure process of concrete is pretty complex with internal tension, shear damage and friction between cracks. To simulate the complex fracture process of concrete at meso level, methodology for meso-structural analysis of concrete specimens is developed; the zero thickness cohesive elements are pre-inserted to simulate the crack initiation and propagation; the constitutive applied in cohesive element is established to describe the mechanism of crack separation, closure and friction behavior between the fracture surfaces. A series of simulations were carried out based on the model proposed in this paper. The results reproduced the main fracture and mechanical feature of concrete under compression condition. The effect of key material parameters, structure size, and aggregate content on the concrete fracture pattern and loading carrying capacities was investigated. It is found that the inner friction coefficient has a significant influence on the compression character of concrete, the compression strength raises linearly with the increase of the inner friction coefficient, and the fracture pattern is sensitive to the mesostructure of concrete.

• 한국지반신소재학회논문집
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• 제16권4호
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• pp.221-230
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• 2017

선행 연구에서 PVP를 이용하여 수용성 폴리머 파우치를 개발하였다. 그러나 개발된 재료의 용융점이 매우 낮아 재료의 성형 시 문제점이 많아 대량생산 시 필요한 성형, 제작이 불가능하였기에 성형성이 우수한 새로운 재료 조합을 이용하여 폴리머 파우치를 개발하였다. 새롭게 선정된 PEG의 수용성 변화 및 지반공동 내 보강 시 파우치의 기계적 물성을 만족해야한다. 따라서 PEG와 LLDPE, TALC 블렌딩 비율에 따른 특성평가를 실시하였는데 각 원료의 비율에 따라 발생하는 성질이 다르기 때문에 실험을 통해 적정 비율을 찾는 것이 중요하기 때문이다. 이러한 블렌딩을 통해 수용성 특성은 유지하며 인장 및 충격강도가 증진된 폴리머 파우치를 개발하였다. 최종 개발된 제품을 이용하여 직접전단 실험을 실시한 결과, 폴리머 파우치의 지반강도 효과를 확인할 수 있었다.

• 문화기술의 융합
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• 제4권3호
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• pp.241-246
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• 2018

영상 기기의 기계적인 문제로 인해 실험 데이터에 발생한 잡음으로 인한 인식 오류를 최소화하기 위해서 영상복원 과정을 거친다. 영상 복원 방법은 실험 데이터를 구성하는 각각의 픽셀에 대해 Direct Neighbor와 Indirect Neighbor의 개수와 위치를 조사해서 잡음을 해결한다. 결과적으로, 영상 복원 과정을 통해 실험 데이터에 발생한 잡음을 최대한 제거하고, 영역 단위로 학습 데이터와 실험 데이터의 차이를 계산해서 잡음에 의한 인식 오류 가능성을 낮춤으로써 만족할만한 인식 결과를 얻을 수 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.104-106
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• 2003

In recent years for propulsion of cooling fan in cars are more used electrical motors than the engine direct coupled type. But the electrical motor which is now used has the brush and the commutator. Because of the brush and the commutator the electrical motor has short life time, low efficiency and mechanical- electrical noise. Therefore it is tried to develope brushless dc motor. The motor is located in the hot air from the radiator. The motor temperature increases high and the increasing of the motor temperature rolls big in its character. The cooling fan motor has relative small in size and input voltage is low. For 300 w output power must be the current of the motor high which causes high copper loss. In this paper will be tested and analysed characteristics of a dc motor which is now used for cooling fan and a BLDC motor will be designed with same character of the brushed motor and with considering of improvement of the efficiency. After design the motor should be analysed and tested.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 추계 학술논문 발표대회
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• pp.63-66
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• 2008

Not only mechanical properties, bonding properties, electro chemical properties, etc. but also fire safety is required in patch repair materials such as polymer modified cement mortar (PCM) which are used to deteriorated reinforced concrete structure. Unfortunately, it is very difficult to choice the appropriate repair materials because there are not enough information about fire safety properties of PCM. In this study, The combustion characters of PCM were evaluated through the heat release rate test and non-combustibility test. The pyrogenicity test uses the cone calorimeter based on the oxygen consumption method. The non-combustibility test is from the temperature change inside the furnace during the test. The effect of the types of polymer and polymer content were evaluated from the series of test. The results are like followings. 1) The higher the W/C of PCM, the lower the gross calorific value and heat generation rate in the heat release rate test. The amount of heat generation of PCM is like the order of VVA, EVA, and SBR in this study. 2) Some materials such as E45-100, E50-100, E60-100, S50-50, and S50-100 were estimated as not appropriate building materials in the non combustibility test.

• Geomechanics and Engineering
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• 제6권2호
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• pp.139-151
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• 2014

Mudstone is a very common rock that, when in contact with water, can exhibit considerable volume change and breakdown. This behavior of mudstone is frequently encountered in geotechnical engineering and has a considerable influence on infrastructure stability. This is particularly important in the present work, which focuses on mitigating the harmful properties of mudstone. The samples studied are of Permian Age mudstone from Shandong Province, China. Modification tests using organic silicone additive material were carried out. The mechanisms of physical properties modification of mudstone were comparatively studied using corresponding test methods, and the modification mechanism of organic silicone additive material acting on mudstone was analyzed. The following conclusions were drawn. The surface texture and characters of mudstone changed dramatically, surface character turns from hydrophilic to hydrophobic after organic silicone additive material modification. The changes in the surface character indicate a reduction in the water sensitivity of mudstone. After modification, the shape of porosity and fracture of mudstone changed unremarkable, and the total and free expansion ratios decreased obviously, whereas the strength increased markedly.

• 한국컴퓨터정보학회지
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• 제2권1호
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• pp.45-54
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• 1995

본 연구는 ASCII 코드중에서 잘 쓰이지 않는 코드를 반달점(ˇ)으로 할당, 글꼴을 제작하여, 사용자가 국어 로마자 표기법 기본원칙을 모르더라도 한글단어, 문장, 문서를 문자열(string)로 입력받아 알고리즘화된 음운법칙을 적용하여 소리글자로 자동 변환 후 현행 정부 표준안인 국어 로마자 표기법 테이블에서 대응 글자를 참조하여 기계화 코드 변환이 가능토록 설계하였으며, 예외어 처리, 화면색상 및 풀다운 팝업 메뉴 방식을 지원, 마우스 활용 방식을 채택, 사용자 편리성을 제공하였으며, 다양한 서체, 글꼴 확대 및 축소, 이단ㆍ혼합 인쇄기능 등을 고려 C언어를 이용하여 구현하였다.