• 항공우주시스템공학회지
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• 제12권3호
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• pp.38-44
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• 2018

군용항공기는 다양한 임무의 수행을 통한 비행시간 누적과 예상 불가능한 외기 환경에 의한 복합적인 요인으로 구조적으로 취약한 부위에서 피로균열이 발생할 수 있다. 피로 균열은 점차 진전되어 극심한 경우 해당 구조가 파괴될 위험이 있으며 이는 비행 안전성에 큰 영향을 미칠 수 있다. 본 논문에서는 항공기 주익과 동체의 연결부위를 보호하기 위해 장착한 페어링 내부의 지지대에서 주기검사 중 균열 현상을 개선하기 위한 일련의 품질개선에 관한 연구를 수행하였다. 균열의 원인파악을 위해 주익 조립 공정에 따른 예하중 발생 여부에 대해 조사하고 파단면 분석을 수행하였다. 또한, 균열의 재발방지를 위해 지지대의 설계를 개선하는 방안을 제시하였고, 응력 및 피로 수명해석을 통해 구조 건전성을 검증하였다.

• 대한기계학회논문집
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• 제14권1호
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• pp.145-156
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• 1990

본 연구에서는 시편을 유한원판으로 하고 방형파펄스가열을 채용한 경우 이론 적인 검토와 실험측정으로서 그 방법을 적용할 때 측정장치와 컴퓨터를 직접 접속시켜 시료의 열물성치인 열확산계수와 비열 그리고 열전도계수를 보다 높은 정확도로 측정 하였다. 또한 고온에 있어서 시료표면으로부터 그 주위에 방출하는 열물질을 고헌하 였고, 초기조건및 경계조건을 실험조건과 부합되도록 가정함으로써 무차원 온도상승을 구할 수 있는 열전달 지배방정식의 해를 변수분이법으로 해석하였다. 측정에 사용했 던 시료는 내연기관, 열교환기, 기계요소, 화학반응장치 등 기계구조용 및 기계부품용 재료로서 내식성이 우수하면서, 고온도하에서 강도가 크고, 열팽창계수가 비교적 적고, 열적변형이 적은 고성능세라믹인 알루미나(Al$_{2}$O$_{3}$),탄화규소(SiC), 질화규소 (Si$_{3}$N$_{4}$) 계열을 상온에서 약 1300K 온도범위까지 열물성치를 측정하고, 동 일계통의 시료라 할지라도 화학조성을 중량비율로 첨가했을 경우 열물성치가 다르기 때문에 그들 사이의 관계에 대해서도 검토하였다.

• 대한수학교육학회지:수학교육학연구
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• 제20권3호
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• pp.203-219
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• 2010

본 연구는 창의성 신장을 위한 영재교육을 시도할 때 고려해야 하는 수업 전략을 확인하고, 이를 확률 과제에 적용하고 그 결과를 확인하는 데 목표를 둔다. 창의성 신장을 위한 수업 전략으로는 인지갈등 유발, 다양한 표현 방법 권장, 사회적 상호작용이라는 세 요소를 선택하였다. 이 전략을 Simpson의 패러독스 과제에 기초한 수업에 적용하고 그 결과를 분석하였다. Simpson의 패러독스는 이미 널리 알려져 있지만, 창의성 신장을 위한 영재교육에 적합한 형태가 아니었으므로 의도에 맞게 재구성하였다. 이를 이용하여 중학교 3학년 수학영재 8명을 대상으로 수업을 실시한 후, 창의성의 요소를 중심으로 사고 과정을 분석하였다. 분석 결과 사고 과정의 유창성, 독창성, 유연성, 정교성, 반성적 사고와 생산적 논쟁이 나타났고, 표현들 사이의 번역과 기본 가정의 탐구라는 고등 수학적 사고 과정이 나타났다.

• 동의생리병리학회지
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• 제19권1호
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• pp.1-7
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• 2005

In Chinese philosophy, the concept of Yin and Yang, in the era of the Early China, applies to many more philosophical categories than merely the relationship between the sunny side and the shady side of the sun. A whole series of possible interactions between the Yin and Yang in life is contained in the Chinese Book of Changes, the I Ching. The philosophical theory and the origin of natural sciences of the I Ching is imbued in the Nei Ching. having absorbed and developed the essence of Book of Changes, the Nei Ching reflects the spirit of science. Under the influence of Book of Changes, as well as its idea of Yin and Yang, peculiar at the time, the Nei Ching adapts the essences of the theory of Yin and Yang. The contribution made by the Nei Ching to the development of the philosophical concepts of Yin and Yang lies in that it combines those philosophical concepts with medicine and makes this the basic theory of Chinese medicine. In the Nei Ching, the Yin and Yang theory asserts that the human body is an organic whole, and there exists an organic connection between all tissues and structures. Therefore, the Yin and Yang functions as an essential life that plays a major role of the organic interrelation, the mutual control, and the mutual assistance. Yet, at the same time, each of them can be divided into the opposite aspects of yin and yang. Yin and yang depend on each other for existence. Without yin, there would be no yang, Without yang, there would be no yin. Neither can exist in isolation. Thus the interrelation of Yin and Yang is premised on the two opposite forces and aspects as the underlying cause of all change of Yin and Yang.

• 한국강구조학회 논문집
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• 제11권4호통권41호
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• pp.339-350
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• 1999

이 연구에서는 강교량 주부재의 연결에 주로 사용되는 횡방향 맞대기 용접부를 대상으로 입체결함의 일종인 블로우홀을 인위적으로 도입하고 블로우홀의 크기 및 형상에 따른 피로특성을 정량적으로 평가하기 위해서 일련의 실험을 실시하였다. 정적실험결과 블로우홀을 가진 횡방향 맞대기 용접부의 정적강도는 블로우홀의 크기 및 형상에 관계없이 일정한 경향을 나타내었다. 피로실험결과 블로우홀을 가진 횡방향 맞대기 용접부의 피로강도는 용접루트부 내부에 존재하는 블로우홀의 기하학적 형상이나 결함률에 크게 영향을 받으므로 이로부터 결함률과 피로강도 사이의 상관관계를 정량적으로 규명하였다. 또한 피로균열성장속도와 응력확대계수범위 사이의 관계로부터 블로우홀을 가진 횡방향 맞대기 용접부의 피로수명을 정확하게 산정할 수 있었다.

• 한국관광식음료학회지:관광식음료경영연구
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• 제13권1호
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• pp.29-41
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• 2002

Controlling food materials, is getting more significant in hotel management nowadays as the selling of food beverage continue to rise. F&B managers have been required to have new management of the food materials by a fierce competition, an increase in cost, the shortened span of product life and customer's demand that is becoming more various and sophisticated since Korea was placed under the influence of IMF. I'm going to analyze the factors that cause waste and loss through a series of the process to purchase inspect, store food materials, make a product with that materials and sell the product in order to make more profits by making the circulation of the food materials easier and more efficiently. I studied how 3 chain hotels of A group purchase, store the food materials and control stock. I made up questionnaires about the circulation and control of food materials to 107 cooks in order to know what the cooks who are working at the hotel regard as a real problem and a practical solution. This research indicates that purchasing, producing and selling departments don't establish the mutual connection, a professional purchasing manager is strongly needed and there is difficulty in predicting the proper timing to supply. Also the research shows that A hotel group controls the food materials by analyzing the amount of consumption, stock, setting up the period of validity and uses slowly moving food materials in stock mainly by introducing the menu that aims at four seasons. As a result, the research suggests that we should introduce the concept of food producing factory, as it were, Central Kitchen that is based on the network among various kitchens to improve the flow of the food materials.

• 항공우주정책ㆍ법학회지
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• 제7권
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• pp.151-175
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• 1995

In recent years, questions have arisen under several forms with respect to the need for adapting present legal order established under the Chicago Convention and relevant customary rules into newly developed environment surrounding the international air transport industry. Major feature of such trends included in opinions for modification of the present legal order might be defined as more liberalistic approach to this industry. In this respect, many scholars and lawyers in this field agree with a view that a theoretical tie between an aircraft/air liners and a register - State lies in political and strategical concern of the State so that each aircraft/air liners has been attributed a single nationality. In the context of such concern, each aircraft/air liners has been related with each register-State in the form of "genuine connection". However, present and near future development of air transport industry and its world - wide market requires some modification of such single nationality regime. Taking into account such circumstances, States as creator of present legal order are in the process of establishing new legal order where air liners with multi - nationality are capable of satisfying to such needs. As adopting a series of liberalization package for air transport industry in european continent, European Union adopts a concept of "community air carrier", by which an air space of each member State is open to each other, especially through the grant of cabotage right. A serious concern may arise in such grant because the Article 7 of the Chicago Convention prohibits such grant on an exclusive basis. While many theoretical opinions have been put forward concerning the interpretation of that article, a case of European Union shall be a good test of the range of its application. It is anticipated that future development around this issue shaH furnish us a major feature of the liberalization of international air transportation and an adaptation process of present legal order.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2000년도 추계 학술대회지
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• pp.3-11
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• 2000

The Asian summer monsoon has a profound social and economic impact in East Asia and its surrounding countries. The monsoon is basically a response of the atmosphere to the differential heating between the land mass of the Asian continent and the adjacent oceans. The atmospheric response, however, is quite complicated due to the interactions between the atmospheric heat sources, land-sea contrast, and topography, The occurrence of extreme summertime floods in Korea, Japan, and China in 1998 and 1999 has highlighted the range of variability of the East Asian summertime monsoon circulation and spurred interest in investigating the cause of such extreme variability. While ENSO is often considered a prime mechanism responsible for the unusual hydrological disasters in East Asia, understanding of the connection between ENSO and the East Asian monsoon is hampered by their dynamic complexities. Along with a recent phenomenon of weather abnormalities observed in many parts of the globe, Korea has seen its share of increased weather abnormalities such as the record-breaking heavy rainfalls due to a series of flash floods in the summers of 1998 and 1999, following devastating Yangtze river floods in China. A clear regime shift is found in the tropospheric mean temperature in the northern hemisphere middle latitudes and the surface temperature over the Asian continent during the summer with a sudden warming since 1977. Either decadal climate variation or climate regime shift in the Asian continent is evident and may have altered the characteristics of the East Asian summer monsoon. Considering the summertime rainfall amount in Korea is overall increased lately, the 1998/99 heavy rainfalls may not be isolated episodes related only to ENSO, but could be a part of long-term climate variation. The record-breaking heavy summer rainfalls in Korea may not be direct impact of ENSO. Instead, the effects of decadal climate variation and ENSO may be coupled to each other and also to the East Asian summer monsoon system, while their individual impacts are difficult to separate.

• 한국기술사회:학술대회논문집
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• 한국기술사회 1986년도 한일기술사 합동 심포지움
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• pp.60-65
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• 1986

기술혁신의 물결은 크게 일본의 산업계로 불어닥치고 있으며, 종래와 같은 공학계만의 학과로서는 당할 길이 없을 만큼 기술영역의 기술업무가 주요부분을 점유할 것으로 예측된다. 기술이전을 원활화시키기 위해서는 기술이전의 각 단계에서 각각의 과학기술인재가 유효하게 활용되어야할 필요가 더욱 중요하게 된다. 산업기술의 이전에는 민간기술자의 유효한 활용이 불가결한 것이며, 민간기술용역이 중요시되고 있는 것이다. 선단기술의 개발은 일본에서는 석유파동이래 상품혁신시대로 접어들어 기존의 기술진행에 대한 작은 기술개선이 생산성향상과 직결되고 있는 점을 중요시해야 할 것이다. 필자는 기술사로서 경험한 기술개발의 사례에서 산업고고학의 필요성을 통감한 것이다. 지녹기술의 개발수법을 연구하고 그 사례를 들어 기술사로서의 역할을 말한바 있다. 더욱 일본정부가 실시하고 있는 공업기술이전연구소의 계획실적에 언급하고 나아가서는 한국에 대한 의견을 말하고 고도한 기술도입에 따른 체제와 기술사의 적임에 관해서 조언하고 싶다.

• Steel and Composite Structures
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• 제18권6호
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• pp.1423-1450
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• 2015

The paper presents the details and results of an experimental study on bolted end-plate joints of industrial type steel building frames. The investigated joints are commonly used in Lindab-Astron industrial buildings and are optimized for manufacturing, erection and durability. The aim of the research was to provide an experimental background for the design model development by studying load-bearing capacity of joints, bolt force distribution, and end-plate deformations. Because of the special joint details, (i.e., joints with four bolts in one bolt-row and HammerHead arrangements), the Eurocode 3 standardized component model had to be improved and extended. The experimental programme included six different end-plate and bolt arrangements and covered sixteen specimens. The steel grade of test specimens was S355, the bolt diameter M20, whereas the bolt grade was 8.8 and 10.9 for the two series. The end-plate thickness varied between 12 mm and 24 mm. The specimens were investigated under pure bending conditions using a four-point-bending test arrangement. In all tests the typical displacements and the bolt force distribution were measured. The end-plate plastic deformations were measured after the tests by an automatic measuring device. The measured data were presented and evaluated by the moment-bolt-row force and moment-distance from centre of compression diagrams and by the deformed end-plate surfaces. From the results the typical failure modes and the joint behaviour were specified and presented. Furthermore the influence of the end-plate thickness and the pretension of the bolts on the behaviour of bolted joints were analysed.