• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.16-21
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• 2008

Aero-engine, as one kind of rotating machinery with complex structure and high rotating speed, has complicated vibration faults. Therefore, condition monitoring and fault diagnosis system is very important for airplane security. In this paper, a vibration data acquisition and intelligent fault diagnosis system is introduced. First, the vibration data acquisition part is described in detail. This part consists of hardware acquisition modules and software analysis modules which can realize real-time data acquisition and analysis, off-line data analysis, trend analysis, fault simulation and graphical result display. The acquisition vibration data are prepared for the following intelligent fault diagnosis. Secondly, two advanced artificial intelligent(AI) methods, mapping-based and rule-based, are discussed. One is artificial neural network(ANN) which is an ideal tool for aero-engine fault diagnosis and has strong ability to learn complex nonlinear functions. The other is data mining, another AI method, has advantages of discovering knowledge from massive data and automatically extracting diagnostic rules. Thirdly, lots of historical data are used for training the ANN and extracting rules by data mining. Then, real-time data are input into the trained ANN for mapping-based fault diagnosis. At the same time, extracted rules are revised by expert experience and used for rule-based fault diagnosis. From the results of the experiments, the conclusion is obvious that both the two AI methods are effective on aero-engine vibration fault diagnosis, while each of them has its individual quality. The whole system can be developed in local vibration monitoring and real-time fault diagnosis for aero-engine.

• 한국사회정책
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• 제23권2호
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• pp.141-172
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• 2016

본 연구는 광주광역시 초등학교 돌봄교사 대상 심층면접을 통해 수집한 자료를 바탕으로 초등돌봄교사의 고용형태와 노동조건에 대해 살펴보고 이들의 노동경험에서 나타나는 다양한 문제들을 고찰한다. 초등돌봄교실은 초등학교 학생들의 방과후 돌봄공백을 해결하기 위한 교육부의 정책으로 2014년에 급속하게 확대되었으며, 이 과정에서 학교 비정규직인 시간제 돌봄교사들이 대거 학교현장으로 유입되었다. 여성이 다수를 차지하는 초등돌봄교사의 비정규직화는 여성 비정규직과 관련 노동에 대한 사회적 차별, 배제와 불평등 현상이 공공영역인 학교에서도 나타나고 있음을 대표적으로 보여준다. 돌봄교실의 제도화를 통해 사적영역에서 담당해온 돌봄이 가정을 벗어나 사회화된다 하더라도 돌봄노동을 수행하는 주체는 여전히 여성이 주가 되며 공적영역의 돌봄노동은 저임금과 불안정고용으로 특징지어지며 저평가된다. 공교육에서 돌봄교실의 중요성과 수요급증에 따른 확대가 강조되는 상황에서 초등돌봄교사의 고용형태와 노동조건은 오히려 더 열악해져왔다. 교육부와 각 시도교육청은 '질높고 안전한 돌봄서비스 제공'을 위한 돌봄교실의 효율적 운영을 내세우며 돌봄교사의 시간제 계약직 고용과 돌봄교실의 외주위탁운영을 확대하고 있다. 본 연구의 사례로 살펴본 광주광역시의 경우, 최근 2년동안 돌봄교사의 주15시간미만 초단시간 근로계약 체결과 돌봄교실의 외주화가 확대되면서 돌봄교실의 공공성 문제가 제기되고 있다. 주15시간미만 초단시간 근로와 외주위탁 형태로 고용된 시간제 돌봄교사들은 상시적인 고용불안에 시달리며 열악한 노동환경과 저임금, 학교 내 차별과 배제, 업무에서의 소외 등의 경험을 하고 있다. 이 과정에서 돌봄교사들의 노동은 고용의 결정권한을 가진 학교와 위탁업체에 의해 이중적으로 통제되고 있으며, 교육청과 학교는 고용형태에 따른 교사 간 서열화와 분업, 공간의 분할 및 해고 위협 등의 기제를 통해 돌봄교사들을 개별화 고립화하여 집단적 저항을 최소화하려는 시도를 하고 있다.

• 드라이브 ㆍ 컨트롤
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• 제16권3호
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• pp.51-58
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• 2019

The objective of this study was to investigate a simulation technology for the AM field based on ANSYS Inc.. The introduction of metal 3D printing AM process, and the examining of the present status of AM process simulation software, and the AM process simulation processor were done in the previous study (part 1). This present study (part 2) examined the use of the AM process simulation processor, presented in Part 1, through direct execution of Topology Optimization, Ansys Workbench, Additive Print and Additive Science. Topology Optimization can optimize additive geometry to reduce mass while maintaining strength for AM products. This can reduce the amount of material required for additive and significantly reduce additive build time. Ansys Workbench and Additive Print simulate the build process in the AM process and optimize various process variables (printing parameters and supporter composition), which will enable the AM to predict the problems that may occur during the build process, and can also be used to predict and correct deformations in geometry. Additive Science can simulate the material to find the material characteristic before the AM process simulation or build-up. This can be done by combining specimen preparation, measurement, and simulation for material measurements to find the exact material characteristics. This study will enable the understanding of the general process of AM simulation more easily. Furthermore, it will be of great help to a reader who wants to experience and appreciate AM simulation for the first time.

• 대한인간공학회지
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• 제29권4호
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• pp.595-604
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• 2010

Reaching up the present from the past, the design was reflected in our life, thereby having brought about great development in the aesthetic harmony or functional part. In the present era, it is advancing in order to seek for the better direction without being satisfied with formativeness. What comes to represent it is UX design, namely, user-experience design. If a user has confusion in using product or environmental facilities, or if a user needs to utilize by analyzing function, this cannot help being inconvenient. Only what a user's behavior is caused by which the cognitive and sensitive attributes interact without inconvenience can be said to be design for a user. Given explaining easily, UX implies to design and develop the designed product or space from the position of a client who uses. Also, it also implies to offer service of being satisfied. For one example, a work can be said that distributes logo to the upper part of web site. That is because of allowing client to be much confused if logo is distributed to the different position. The designed web site in consideration of user's position is developed much now. However, it is the real situation of being still much insufficient in the public facilities that have UX characteristics amid the living environment. There is great interest in UX of the public facilities. However, there are many cases of facing mostly for the first time. The understanding level is thought to be much different. This study examines about a concept of UX design, and about UX design, which considered from the user's position, and analyzes a case. Thus, the aim is to suggest good directivity in designing by efficiently approaching UX that can be difficult theoretically.

• Safety and Health at Work
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• 제11권1호
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• pp.80-87
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• 2020

Background: Residential and commercial cleaning is a part of our daily routine to maintain sanitation around the environment. Health care of professionals involved in such cleaning activities has become a major concern all over the world. The present study investigates the risk of musculoskeletal disorders in professional cleaners involved in floor mopping tasks. Methods: A cross-sectional study was performed on 132 mopping professionals using a modified Nordic questionnaire. The Pearson correlation test was implemented to study the association of perceived pain with work experience. The muscle strain and postural risk were evaluated by means of three-channel electromyography and real-time motion capture respectively of 15 professionals during floor mopping. Results: Regarding musculoskeletal injuries, risk was reported majorly in the right hand, lower back, left wrist, right shoulder, left biceps, and right wrist of the workers. Work experience had a low negative association with MSDs in the left wrist, right wrist, right elbow, lower back, and right lower arm (p < 0.01). Surface EMG showed occurrence of higher muscle activity in upper trapezius and biceps brachii (BB) muscles of the dominant hand and flexor carpi radialis and BB muscles of the nondominant hand positioned at the upper and lower portion of the mop rod, respectively. Conclusion: Ergonomic mediations should be executed to lessen the observed risk of musculoskeletal injuries in this professional group of workers.

• 보건교육건강증진학회지
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• 제26권4호
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• pp.105-116
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• 2009

Objectives: In recent years, pregnancy rate among female adolescents has increased and caused a variety of physical and social problems. Therefore, this study aimed to investigate sexual behavior, delinquent behavior, and pregnancy rate among Korean female adolescents. Methods: In light of the growing interest in adolescent pregnancy, this study conducted a web-based survey, titled "The 2006 Youth Health Risk Behavior Survey." The Korean Center for Disease Control (KCDC) collected questionnaire responses from 34,200 young women. The collected data were analyzed through chi-square test and logistic regression using SPSS Win 14.0 version. Results: This study analyzed main factors, which can predict pregnant experience. The statistic results showed two types of the predicting factors: (1) personal factors: sexual relations after drinking (odds 25.1), Narcotic drug taking (odds 13.0), sexual violence act (odds 7.0), part-time job(odds 2.5), drinking, smoking ; and (2) environmental factors: stepfather(odds 4.2) and natural mother. Conclusion: The influential factor identification for predicting pregnancy rate is important to develop an effective education program for preventing the adolescent pregnancy. The education programs with referring to the identified factors can contribute to reducing the unwilling pregnancy rate of young woman.

• The Journal of Korean Physical Therapy
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• 제12권2호
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• pp.107-119
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• 2000

This study is fulfilled from September 1st to December 31st in 1999 and the object of investigation are all 289 students belong to 5 universities managing amateur Ssirum team in Kyungnam, Kyungpook. Pusan and Seoul(158 people) and 6 high schools(131 people). And these results were derived from percentage and cross analysis of Person Chi-square test ann interview and 47 questioned paper based on this purpose of study. 1. There were no significant differences between high school students and university students in the comprehension of physical therapy and injury occurrence by technique. 2. According to the relation between satisfaction of life as a player and injured part, the injury of soft tissue ranked high among satisfied and unsatisfied people. and the satisfaction or unsatisfaction of practicing place also derived same result. 3. $46.8\%$ of Ssirum players got the injury of soft tissue during practice. the articular injury and bone injury in regular sequence. But there were no relations between the time of injury and the sort of injury. 4. There were no statistical differences ortho sort of injury by technique.(p=0.399). 5. According to the part of injury by using techniques, the injury of soft tissue ranked high$(50.0\%)$, articular injury ranked high$(42.6\%)$ in the leg technique, bone injury ranked high in the leg technique, and nerve injury ranked high in hand technique. 6. The injury of soft tissue ranked high during the practice$(46.8\%)$, practice on the purpose of a match$(50.0\%)$ and match$(41.7\%)$ but there were no relations between the time of injury and son of injury. 7. The part of injury by technique ranked high in the soft tissue$(50.0\%)$, articular injury by leg technique$(42.6\%)$, bone injury in leg and waist technique and nerve injury in hand technique high. 8. The time of injury ranked high during the practice$(65.7\%)$, and $66.1\%$ of injury occurred in the afternoon. 9. During the practice, the cold weather ie related on the rate of injury because $67\%$ of injury occurred in winter, but there are no statistical significance. 10. There were no relations between the satisfaction of place far practice and time of injury. 11. The particular part of injury occurred very much during the match between defense and offense. 12. In the relation between the degree of understanding of physical therapy and the experience of physical therapy, the people who know physical therapy had much experiences of physical therapy(p=.000) And independent of the physical therapy experiences, the effectiveness of physical therapy therapy to players was $48.8\%$, no idea was 42.65 and no effectiveness was $8.7\%$(p=.000). 13. $59.6\%$ of the people admitting the physical therapy effectiveness answered they would follow the order of the doctor and $56.6\%$ of the people not admitting the physical therapy effectiveness answered no.

• 공학교육연구
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• 제20권2호
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• pp.3-8
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• 2017

This study examined a difference in a change of understanding and recognition on STEAM Education before and after participating in STEAM Education of university students majoring in teaching profession of engineering system who took part in 'STEAM Education of being made together with undergraduates for 2016' as part of the project for a center of supporting STEAM pre-service teachers. As a result, the pre-service teachers majoring in teaching profession of engineering system could be confirmed to have been improved the understanding and sympathy level with STEAM education as a whole following the execution of the program. Comparing it with other majoring system, the pre-service teachers majoring in teaching profession of engineering system were shown to be a little low in pre-perception or satisfaction, but were indicated later to have high intention of participation in STEAM education. This suggests that the pre-service teachers majoring in teaching profession of engineering system recognize the importance of STEAM education in the engineering education, but are feeling pressure about interpersonal communication. Accordingly, it is time that there is a need to have a system of officially providing the implementation of STEAM education and an opportunity of experience in the education for pre-service teachers aiming at the engineering education for future generation.

• 한국실내디자인학회논문집
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• 제15권5호
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• pp.60-67
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• 2006

An architecture is a result from representation of design knowledge by architect's creative thinking, and operated only in his internal organization system. Design knowledge based upon the experience that they have achieved in the past as well as the informations they have accumulated over the time. In this point of view, the Schema that formed by problems settlement and process repetitions for the best conclusion, not only play an important part in the designer's thinking system about a specific problem but also appeared by distinctive features. This research looks to achieve a new design method by finding out how architects express traditionality in the contemporary house through schema. This research analyze contemporary house built in seoul of 1990's. The result are as followings. First, Schema is a 'frame' that already exist in the architect's thinking, will make a good guide about express the traditionality. Second, We found out several distinctive characters in the form and the space. The form is divided in five types. It is an condensed form of roof image, the metamorphosis of form grammar, the change of part details, the representation of design principle and the directly expression. Lastly, In the space, it is the borrow of the connection method of inside and external space, the three parts composition of the space, the adaptation of 'Madang' and the Independent composition of the space due to 'Chae'

• Journal of Mechanical Science and Technology
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• 제19권9호
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• pp.1773-1780
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• 2005

The process of mould design in the foundry industry has been based on the intuition and experience of foundry engineers and designers. To bring the industry to a more scientific basis the design process should be integrated with scientific analysis such as heat transfer. The production by foundry techniques is influenced by the geometry configuration, which affects the solidification conditions and subsequent cooling. Numerical simulation and/or experiments make possible the selection of adequate materials, reducing cycle times and minimizing production costs. The main propose of this work is to study the heat transfer phenomena in the mould considering the phase change of the cast-part. Due to complex geometry of the mould, a block unstructured grid and a generalized curvilinear formulation engaged with the finite volume method is described and applied. Two types of boundary conditions, diffusive and Newtonian, are used and compared. The developed numerical code is tested in real case and the main results are compared with experimental data. The results showed that the solidification time is about 6 seconds for diffusive boundary conditions and 14.8 seconds for Newtonian boundary conditions. The use of the block unstructured grid in combination with a generalized curvilinear formulation works well with the finite volume method and allows the development of more efficient algorithms with better capacity to describe the part contours through a lesser number of elements.