• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.316-320
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• 2008

A light rail transit, using a linear induction motor, is generally composed with reaction plates along railroad track and the three phase primary on the vehicle. This linear induction motor is driven to keep clearance between the primary and the secondary of the ground for preventing any contact. Therefore efficiency and power factor is very low. In addition, the reaction plate installed on the ground throughout entire railway is impossible to keep uniform gap and it may cause system deterioration. In this paper, A rotary-type small-scale model of a linear induction motor for various characteristic analysis is designed. Thrust force, normal force and input current of the model by air-gap variation have been analyzed by using a Finite Element Method (FEM). The effects of air-gap variation on system performance have been considered by analysis results.

• 한국식품저장유통학회지
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• 제1권1호
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• pp.37-43
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• 1994

A microcomputer system consisting of 16-bit microcomputer, PCL-711S interface board, censors, and converters have been set up in order to automatically measure temperature, humidity and weight loss which are major variables of storage of apple. This system was operated by PC-LabDAS software. It has been possible to measure continuously the weight loss of Fuji apple stored in CA with the weight converter made by a miniature load cell and a strain amplifier. The temperature was checked by a k-type thermocouple and Pt 100 $\Omega$ RTD, and humidity by PQ653JAl humidity sensor. It has been possible to set up a linear equation which showers high correlationship between the estimate of temperature, weight humidity and the output of the converter in that r2 is more than 0.99. Transpiration rate, a significant factor of quality deterioration for CA storage of apple, can be estimated with these values.

• Journal of Korean Vacuum Science & Technology
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• 제5권1호
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• pp.25-32
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• 2001

Baffles have been used in cryopumps to prevent 300 K thermal radiation from reaching freely cryopanels whose temperature must be kept steadily below certain levels(4 K, 20 K or something) depending on the gas to be pumped. There are two conflicting requirements in designing a baffle such that the transmission of particles(gas molecules) should be maximized, while that of the thermal radiation(photons) minimized. The transmission probability of gas molecules or photons through chevron type baffles, influenced by the detailed geometry of blades, the reflection mode, and the absorption property of the surface, was analyzed parametrically. The effects of geometrical discrepancy between the fabricated baffle and the designed one, resulting in unexpected deterioration in the performance of the baffle, were also investigated by taking into account the gaps(or overlaps) between the baffle blades and the asymmetry in the blade arms.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.32-33
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• 2021

The corrosion of the embedded steel rebars and the consequent deterioration of the reinforced concrete structure has become a challenging concern to the construction industries for the fiscal deficit. However, corrosion inhibitors are potential and being widely used for corrosion mitigation to solve such problems. This study has been focused on the mixed type of corrosion inhibitor where one component of the corrosion inhibitor is organic and another one is inorganic material. 0.1 (M) triethanolamine (TEA) and 0.01 (M) sodium hexametaphosphate (SHMP) have been mixed in distilled water to produce the mixed inhibitor. Studies of the steel rebar corrosion in chloride contaminated (3.5 wt.% NaCl) concrete pore (CCCP) solution has been conducted using different concentrations of corrosion inhibitor. Electrochemical impedance spectroscopy (EIS) method is involved to understand the corrosion behaviour of the steel rebars at different exposure durations.

• 한국작물학회지
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• 제51권3호
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• pp.209-214
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• 2006

본 연구는 콩의 초기 유묘생육기간 동안의 lipoxygenase가 결여된 진품콩, 진품콩 2호와 정상적인 태광콩의 lipoxygenase 활성 변화를 비교 검토하여 알아보기 위하여 실시하였다. Lipoxygenase 결여 콩 품종의 초기 생육 및 lipoxygenase 활성 변화에서 유묘의 생체중은 진품콩 2호와 태광콩이 진품콩 보다 증대되는 경향이었고 하배축의 길이는 진품콩과 진품 콩 2호가 태광콩보다 서서히 증가하였지만 하배축의 두께는 진품콩과 진품콩 2호가 태광콩보다 두껍게 증가하는 경향이었다. 자엽의 lipoxygenase 활성 변화는 유형 I lipoxygenase 활성에서 진품콩과 태광콩이 계속 감소하는 경향이었지만 진품콩 2호는 활성이 나타나지 않았다. 유형 II lipoxygenase 활성에서 태광콩은 발아 2일째부터 계속 증가하다가 발아 4일 째에서 5일째 사이에 최대의 활성이 나타났고 발아 5일째부터 다시 감소하는 경향이었다. 하배축의 유형 I lipoxygenase 활성에서는 진품콩과 태광콩이 발아 l일째부터 급격히 감소하였다. 하배축의 유형 II lipoxygenase 활성은 3 품종 모두 나타나지 않았다.

• 조명전기설비학회논문지
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• 제20권2호
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• pp.75-80
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• 2006

본 논문은 전력 케이블의 절연체인 XLPE 시료에 상용주파수 교류전압을 인가하였을 때, 절연열화에 의한 보이드방전 펄스신호와 AE신호 및 트리진전 특성을 검출하고 관찰하였다. 또한 XLPE 절연체의 트리 채널내 인가전압에 따라 보이드방전 펄스신호와 AE신호를 각각 관측하였다. 실험 결과 전력 케이블의 절연체인 XLPE 시료의 보이드 존재 유 무에 따른 트리진전 형상은 보이드 존재시에는 수지형으로 성장하였으나, 무보이드시에는 수초형으로 성장하였다. XLPE 절연체내의 트리진전 특성은 보이드 존재시에는 열화시간이 경과함에 따라 급격히 증가하였으나, 무보이드시에는 열화 시간이 경과함에 따라 트리의 성장 형상은 감소되는 것으로 나타났다. 전력 케이블 절연체인 XLPE의 트리 채널내 보이드방전에 의한 AE신호의 주파수 스펙트럼으로 분석한 결과, AE신호의 크기에 따라 변화되었으며 그 주파수 영역은 대략 1.0[MHz] 이하의 분포인 것으로 관측되었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2568-2574
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• 2005

Control architecture of the action based robot engineering can be divided into two types of deliberate type - and reactive type- controller. Typical deliberate type, slow in reaction speed, is well suited for the realization of the higher intelligence with its capability to forecast on the basis of environmental model according to time flow, while reactive type is suitable for the lower intelligence as it fits to the realization of speedy reactive action by inputting the sensor without a complete environmental model. Looking at the environments in the application areas in which robots are actually used, we can see that they have been mostly covered by the uncertain and unknown dynamic changes depending on time and place, the previously known knowledge being existed though. It may cause, therefore, any deterioration of the robot performance as well as further happen such cases as the robots can not carry out their desired performances, when any one of these two types is solely engaged. Accordingly this paper aims at suggesting Goal-oriented Geometric Model(GGM) Based Intelligent System Architecture which leads the actions of the robots to perform their jobs under variously changing environment and applying the suggested system structure to the navigation issues of the robots. When the robots do perform navigation in human life changing in a various manner with time, they can appropriately respond to the changing environment by doing the action with the recognition of the state. Extending this concept to cover the highest hierarchy without sticking only to the actions of the robots can lead us to apply to the algorithm to perform various small jobs required for the carrying-out of a large main job.

• Nuclear Engineering and Technology
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• 제51권3호
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• pp.709-718
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• 2019

The international nuclear industry has undergone a lot of changes since the Fukushima, Chernobyl and TMI nuclear power plant accidents. However, there are still large and small component deficiencies at nuclear power plants in the world. There are many causes of electrical equipment defects. There are also factors that cause component failures due to human errors. This paper analyzed the root causes of failure and types of human error in 300 cases of electrical component failures. We analyzed the operating experience of electrical components by methods of root causes in K-HPES (Korean-version of Human Performance Enhancement System) and by methods of human error types in HuRAM+ (Human error-Related event root cause Analysis Method Plus). As a result of analysis, the most electrical component failures appeared as circuit breakers and emergency generators. The major causes of failure showed deterioration and contact failure of electrical components by human error of operations management. The causes of direct failure were due to aged components. Types of human error affecting the causes of electrical equipment failure are as follows. The human error type group I showed that errors of commission (EOC) were 97%, the human error type group II showed that slip/lapse errors were 74%, and the human error type group III showed that latent errors were 95%. This paper is meaningful in that we have approached the causes of electrical equipment failures from a comprehensive human error perspective and found a countermeasure against the root cause. This study will help human performance enhancement in nuclear power plants. However, this paper has done a lot of research on improving human performance in the maintenance field rather than in the design and construction stages. In the future, continuous research on types of human error and prevention measures in the design and construction sector will be required.

• Korean Chemical Engineering Research
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• 제60권1호
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• pp.12-19
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• 2022

소형 이송형 고분자전해질 연료전지 (PEMFC)에 많이 사용되는 cathode 개방형 PEMFC 스택은 내구성이 약한 문제점이 있다. 13개의 셀로 이루어진 PEMFC 스택의 가속 내구성 평가를 통해 스택의 열화 원인을 찾고 cathode 개방형 스택의 내구성 향상에 기여하고자 하였다. Cathode가 대기에 개방되어 있고, 기밀 유지가 어려운 cathode 개방형 스택의 구조적 문제점 때문에 시동/정지 (SU/SD)시 수소/공기 경계가 형성되어 cathode를 열화시킨다. 본 연구에서는 cathode 개방형 스택에 SU/SD 1,800회 반복 후 초기 성능의 54%가 감소하여 비교적 짧은 시간에 내구성을 평가할 수 있었다. 스택 해체 후 각 셀을 2등분하여 성능분석하였다. 전체적으로 공기 유입이 용이한 anode 출구부 MEA가 유입부 MEA보다 전극 열화가 더 심해서 SU/SD시 수소/공기 경계 형성이 주요 열화 원인임을 확인했다.

• Applied Biological Chemistry
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• 제17권1호
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• pp.54-62
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• 1974

전국(全國)에 걸쳐 수집한 62개(個)의 변질미(變質米) 시료(試料)를 외관상(外觀上)의 변색(變色)으로 그 유형(類型)을 구별(區別)하고 그 원인(原因)이 되는 균군(菌群)을 분리(分離) 조사(調査)하여 다음과 같은 결과(結果)를 얻었다. 1. 62개(個)의 변질미(蠻質米)는 그 변색(變色)의 외관(外講)으로 황적색(黃赤色) 적황적색(赤黃赤色), 담적색(淡赤色), 적회색(赤灰色), 농회색(濃灰色) 및 바구미(米)의 7개유형(個類型)으로 분류(分類)하였다. 2. 62개(個)의 시료(試料)에서 곰장이류 5속(屬) 44종(種), 효모류(酵母類) 1속(屬) 1종(種), 세균류(細菌類) 4속(屬) 14종(種)을 분리(分離)하였다. 3. 분리(分離)된 총균군중(總菌群中) 72.4%는 곰팡이류(類)이었으며 27.6%가 세균류(細菌類)이었다. 곰팡이 유중(類中)에는 Asp. glaucus군(群)이 38%, Asp. candidus가 14%, Asp. oryzae가 12%, Asp. versicolor가 8%로 거의 대부분이며 기타의 Aspergillus, Penicillum, Rhizopus, Scopulariopsis 그리고 Trichoderma등(等)이 있었으며 세균류중(細菌類中)에 는87%가 Bacillus이었으며 Pseudomonas가 10%, 기타 Baveiacterium과 Staphylococus등(等) 분리(分離)되었다. 4. 변색(變色)과 균군(菌群)의 관계(關係)는 절대적(絶對的)은 아니지만 황적색(黃赤色)에서는 Pen. islandicum, 담황적색(淡養赤色)에서는 Asp. candidus, Asp. clavatus, 담적색(淡赤色)에서는 Asp. glaucus, Asp. candidus, Asp. versicolor, Asp. fumigatus등(等)이, 담회황색(淡灰黃色)에는 Asp. oryzae, 담회색(淡灰色)과 농회색(濃灰色)에서는 Asp. glaucus 및 Pencillium종류(種類)가 주(主)로 분리(分離)되었다. 5. 유독성(有毒性) 물질생성균(物質生成菌)은 Asp. glaucus, Pen. islandicum, Pen. citrinum, Asp. flavus, Asp. ochraceus등(等)이 있으나 그 출현빈도(出現頻度)는 중요(重要)한 것이 아니었다. 그러나 Pen. islandicum은 높은 생육밀도를 보여서 문제(問題)가 될 수 있겠다.