• 한국IT서비스학회:학술대회논문집
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• 2007.11a
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• pp.351-356
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• 2007

현재의 사실상 국제 이러닝 표준으로 자리 잡은 SCORM 2004 기술규격은 '단일 사용자 콘텐츠 학습' 환경의 '웹 기반 자기 주도적 학습'에 근거하고 있다. 즉, 학습자 그룹을 포함한 협력적인 학습과정 설계가 가능하도록 하는 규격 부분이 부재한 상태이다. 이에 SCORM 규격을 기반으로 하여 협력학습 콘텐츠를 개발하는 연구가 활발히 진행되어 왔으나, 협력학습 콘텐츠를 탑재하는 플랫폼 즉, 협력학습을 지원하기 위한 학습관리 시스템의 표준화에 대한 연구는 거의 이루어지지 않은 실정이다. 따라서, 본 논문에서는 이러닝 협력학습의 표준화를 주도하고 있는 국제 이러닝 표준기구인 ISO/IEC JTC1 SC36의 연구 자료를 토대로 협력학습을 지원 가능한 방안을 제안하여 SCORM 2004 규격의 실행환경에 협력학습과 관련된 데이터모델을 추가하여 협력학습지원 시스템을 설계하고 구현하고자 한다.

• Korean Journal of Child Studies
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• v.8 no.2
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• pp.61-71
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• 1987

The effects of token and social reinforcement on inappropriate study behaviors of nursery school children were investigated. The subjects were three nursery school boys, and the target behaviors were : 1) out-of-seat behaviors, 2) bothering other children, and 3) disruptive behaviors. The ABAB(Reversal) design was used in this experiment. It consisted of four periods : baseline, reinforcement I, reversal, and reinforcement II. During the reinforcement period, social reinforcement as well as token reinforcement was applied. In all three subjects, inappropriate study behaviors decreased during the reinforcement periods (I, II), and increased during the reversal period, showing the effects of token and social reinforcement. The subjects showed stability in three post-experimental tests, indicating that modification of inappropriate study behaviors was being maintained.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.52
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• pp.211-219
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• 1999

Sleeping is important activity in bedroom and it takes one third of our lifetime. The body pressure distribution on bed has been considered as one of the most important factors affecting sleeping comfort. The measurement contact pressure has been applied to design seat, mattress, shoes, etc., for prevention of pressure sores and improvement of products. This paper discusses the recognizing rule of sleeping posture using contact pressure. Subjects' ages are ranged from twenties to fifties. They include 29 males and 35 females. Body pressure distribution is measured in the state of stable bed when subject lies on his/her back, on his/her side and on his/her face. We made recognizing rules of sleeping posture through statistical analysis; ANOVA and regression analysis, qualitative analysis.

• Proceedings of the KAIS Fall Conference
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• 2007.11a
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• pp.330-333
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• 2007

도로교통법에 의해 건교부 측에서 2006. 6. 1일부터 유아용 카시트에 관하여 시행령이 내려졌다. 때문에 국내의 유모차 및 카시트의 판매량이 증가하고 있다. 그러나 기존의 제품은 사용이 불편하고 사용 연령층의 폭이 좁고 기능면에 비하여 단가가 높다. 본 연구는 유모차/카시트 겸용을 주 연구 과제로 하였고, 이에 따른 유아용 카시트 탈착형 다기능 유모차의 프레임 폴딩구조 및 프레임의 경량화를 설계하고 유모차 검사기준에 따른 해석을 하였다.

• Tribology and Lubricants
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• v.22 no.6
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• pp.329-334
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• 2006

In CNG (Compressed natural gas) fuel supply line, whose main components are receptacle and check valve are used to charge high pressure gas to the tank of NGV (Natural gas vehicle). It is reported that the seal is separated occasionally form valve seat and results in blockage of gas flow. In this paper, MARC is used to investigate the reasons of seal separation and suggest design improvements. The static gas pressure distributions acting on the seal which calculated using FLUENT are considered to investigate accurate seal deformation behaviors. Deformed seal shapes are obtained for various amounts of seal interference and its location, gas pressure distributions and Young's modulus of the rubber used. The results showed that the reasons of seal separation problems are verified theoretically, and suggested examples of new design method. Therefore the present numerical methods can be applied in designing and performance analysis of rubber seals adopted in high pressure fluid machineries.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.2
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• pp.72-78
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• 2011

Localization information of an object can be a very useful element for many application areas. Presently, GPS is typically used for it, but many researches on the wireless localization technology are going on recently actively using mobile communication network, wireless sensor network, and ad hoc network in order to overcome the limitations of the GPS such as indoor, cost, power consumption, and etc. Therefore, this article surveys the most representative wireless localization techniques, which can be deployed in the wireless networks, and their principles and performances are analyzed based on the researched papers. In a conclusion, selection of a localization technique should consider the key design elements to a given application from the design elements such as localization environment, accuracy, time to fix, computation amount, implementation ease, and etc.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.415-420
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• 2007

The objective of this study analyzes the influence of shimmy & shake phenomena due to tire design parameters which are RFV(radial force variation), DB(dynamic balance), RRO(radial run out) and air pressure. These parameters are inspection items for Q.C. after tires are manufactured. In order to analyze these parameters on this study, vehicle driving tests were achieved. The test modes are two type which are constant speed and coast-down driving. On this tests the dynamic characteristics of shimmy & shake are measured by the 3-axises accelerometers at the various positions that are knuckle(left & right), rack pinion, seat and steering wheel. In according to analyzed results, the longitudinal vibration of knuckle parts affects the lateral vibration of rack pinion and this vibration affects the lateral vibration of steering wheel that is the shimmy phenomena. Also the over and under DB by comparison with normal DB and the increment of RRO affect the occurrence of shimmy & shake phenomena.

• Journal of the Korea Furniture Society
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• v.18 no.4
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• pp.296-306
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• 2007

As life style changes, the demand for stacking chairs are increasing as the use of event halls or outside furniture where people gather in crowd is increasing. Early stacking chairs were mainly made to pile up a great amount and store, but in modern days it also has a decorative purpose. Besides, the development of various new materials and applied technology of furniture manufacture, the structure and design of stacking chair is becoming more interesting. Basically, according to the structure of the leg, the form and method of piling up is decided. The structure of the leg means the location of the leg connected to the seat, and according to the location, it can be piled up as upper, front, or rotational type. Such is the way how stacking chairs are classified according to the location of the leg, with its basis; the structure of stacking chair is reviewed. Now, chair for piling up is overcoming its simple function, which aesthetic beauty or arrangement of color after piling up is being considered. Also, according to storing, moving, and the place of use, various designs are demanded. As people's interest in stacking chair is increasing, various research regarding design should continue.

• The Korean Journal of Emergency Medical Services
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• v.17 no.3
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• pp.73-86
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• 2013

Purpose: The purpose of this study is to provide the basic data for the ergonomic design of first-aid activity space(FAS) for a future ambulance suitable for the performance of 119 EMT. Methods: Questionnaire was filled out by the 124 EMT in 119 centers. The questionnaire consisted of 3 sub factors including the satisfaction and compatibility of the FAS. The satisfaction and compatibility was analyzed based on characteristics of the subjects. Results: The satisfaction rate of the FAS within the ambulance was an average of 2.23, and the compatibility category got an overall average score of 2.26. The lowest ranked criteria in the satisfaction and compatibility factor was the functionality of storage space showing 1.93 and 1.88, respectively. The best position of the paramedic seat was the top side of the patient, near the head, which is suitable for patient assessment and treatment. Conclusion: During patient transportation of 119 EMTs, for efficient work process, a layout design of the FAS should be based on ergonomics that satisfied the performance function.

• Journal of Power System Engineering
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• v.21 no.6
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• pp.56-61
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• 2017

The check valves are mechanical valves that permit fluids to flow in only one direction, preventing flow from reversing. It is classified as one way directional valves. There are various types of check valves that used in a marine application. A lift type check valve uses the disc to open and close the passage of fluid. The disc lift up from seat as pressure below the disc increases, while drop in pressure on the inlet side or a build up of pressure on the outlet side causes the valve to close. An important concept in check valves is the cracking pressure which is the minimum upstream pressure at which the valve will operate. On the other hand, optimization is a process of finding the best set of parameters to reach a goal while not violating certain constraints. The AMESim software provides NLPQL(Nonlinear Programming by Quadratic Lagrangian) and genetic algorithm(GA) for optimization. NLPQL is the implementation of a SQP(sequential quadratic programming) algorithm. SQP is a standard method, based on the use of a gradient of objective functions and constraints to solve a non-linear optimization problem. A characteristic of the NLPQL is that it stops as soon as it finds a local minimum. Thus, the simulation results may be highly dependent on the starting point which user give to the algorithm. In this paper, we carried out optimization design of the check valve with NLPQL algorithm.