• 한국학교보건학회지
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• 제8권2호
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• pp.277-291
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• 1995

The study was designed to grasp the mental health of junior college students and identify the relation between mental health and social support. The subjects for this study were 781 sophomores attending T junior college in Taegu. The data were collected through questionnaire during the period from september 10,1993 to september 24, 1993. The results of this can be summarized as follows: In mental health the average mark was 1.94 on the basis of 5 marks. Those whose mark was more than 75% (low) had Depression(8.7%),Obsessive compulsive reaction(5.2%) Anxiety(3.6%). In social support, the average mark was 3.03 on the basis of 4 marks, which showed comparatively high support; relationship with friends was 75.4%, companionship was 75.4%, and mutual understanding was 72.3%. Many students got more than 75% in total marks. In the state of mental health, there was a significant difference depending on sex, total income, the character and the attitude toward his parents. There is also an unusual difference in social support depending on the major subjects, the character, the problem at present and the attitude toward his parents. In mental health, both male and female students got higher marks in Depression, Obsessive compulsive reaction than in any other item. In social support level all students had a high support in the relationship with friends and mutual understanding. Those who are affectionate to and dependent on their parents had a tendency to have better mental health. The simple correlation modules between social support mark and mental health one was -0.5555 and the partial correlation modules of controlling sex, age, growth place was -0.5557. There was little difference between them. In mental health items Interpersonal sensitivity was highest correlated with social support and Somatinization was lowest correlated. There was a significant correlation between mental health and social support: the higher social support were, the better mental health was. In conclusion, the study showed that the relationship between the social support and the mental health level revealed a significant correlation. In social support Expressive support (companionship support, mutual understanding support) showed a higher degree of support than instrumental support(monetary support, demand support). Therefore, in the guidance of students, it is necessary to expand expressive support considering these respects. Further multidimensional study is needed on how to improve the mental health of junior students through the social support.

• 한국표면공학회지
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• 제35권3호
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• pp.113-120
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• 2002

Injection molded plastic parts have many surface defects. These include a weld line, sink mark, flow mark, gloss, shading, scratching etc. Because these surface faults are not aesthetically acceptable, plastic parts are produced through painting or texturing. The purpose of this paper is to develop paintless molded parts using a flow control method. Computer aided injection mold filling simulations were used in order to minimize the number of defects from injection molding. Based on the numerical results, FR(Flame Retardant) HIPS was developed and the guidelines for part design, mold design, and the processing conditions were established. The effects of cost savings, improvements in productivity, and recycling were considered by reducing the number of surface faults and eliminating the painting process.

• 한국전자파학회지:전자파기술
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• 제7권1호
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• pp.22-31
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• 1996

1989년 5월 3일 발표된 EC(현 EU) Directive 89 / 336 / EEC(전자파 양립성 지령)에 의해, 1996년 1월 1일부터 EU 지역에서 생산 또는 EU 역내에 수입되는 모든 전기전자제품에 대해 CE Mark 가없이는 유통, 판매, 사용이 금지되기 시작했다. 이 지령은 EMC에 관한 각종 제품의 보호요건을 정의하고 있으며, 타제품 및 부문에 대해서도 EU 위 원회에서 제정한 각종 안전규정(Directives; 지령)에 적합할 경우, CE Mark를 부착하고, 이는 구주 역 내 국가간에 규제를 통일하고 안전성이 확보된 제품의 자유로운 유통(Free Movement of Goods)과 판매를 목적으로 한다. 이에 따라, EU위원회에서는 EMC를 비롯한 안전, 기계, 완구 등 여러 분야에 대해 각국의 규제를 조 정하고 일체화하여 현재까지 약 20종류의 EC지령을 발표하였다.

• 디자인학연구
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• 제16권3호
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• pp.143-150
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• 2003

방향이나 목적, 기준 따위를 나타내는 표지의 역할로 웹 사이트에서 활용되는 아이콘은 사용자가 정보 분류에 따른 정보, 이른바 콘텐츠를 찾는데 가장 중요한 수단이 되고 있다. 사용자는 아이콘의 시각화가 콘텐츠의 내용을 정확히 담고 있을 때 인터넷 사용의 만족을 얻게 된다. 따라서 보다 사용자가 원하는 콘텐츠를 찾는데 있어서 빠르고 편리한 기능을 수행하게 되는 아이콘의 시각화는 그 중요성이 매우 높다. 이에 본 논문은 웹 사이트에서 공통의 콘텐츠를 지칭하고 있는 아이콘의 표현방식을 조사하여 무형의 콘텐츠와 유형의 콘텐츠로 나누고 그 사례를 기호적 입장에서 분석, 유형별로 가장 적합한 시각화의 방법을 제시하였다

• 한국자동차공학회논문집
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• 제10권3호
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• pp.159-165
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• 2002

So far, an alternator pulley has been formed by cold forging and casting with a metal due to the necessity of its high strength. Various advantages such as the light weight, the low cost, and the high productivity can be obtained by the injection molding process using engineering plastics. Engineering plastics have an excellent performance in the characteristics off strength vs. weight, a good forming ability and a productivity. The object of this study is to develop an alternator pulley, which has been made with a metal, using the injection molding process based on Taguchi methods. A sink mark is considered as a characteristic parameter to improve the quality. The FEM Simulation CAE tool, Moldflow, is used for the analysis of injection molding process.

• ETRI Journal
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• 제31권3호
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• pp.348-350
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• 2009

To fit the limited volume and power consumption of the passive radio frequency transmission system of the electronic time fuze, an improved coded mark inversion (CMI) is proposed in this letter. From the performance analysis, the energy transmission efficiency of this encoding method is at least 50% higher than that of CMI and NRZ. Finally, the experiment results show that by adopting this improved CMI, the change of DC voltage through magnetic coupling is lower than 0.2 V when the accuracy of data transmission is above 99.5%.

• 대한전자공학회논문지
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• 제26권10호
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• pp.1462-1470
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• 1989

This paper aims at investigating the Demand Assigned Multiple Access(DAMA) system for the packet-switched Satellite Communication. An onboard processor of the multisport beam satellite incorporates the ground controller to macimize the packet transmissions for each slot. 'Request Following' trnasmission mode is introduced as a transmission strategy of ground station under the control of its zone controller. The combined scheme of reservation channel access and contention channel access was proposed by Lee & Mark[3] for improving the Delay-Throughput performance. Our scheme provides less communication delay of approximately max. 200msec for achieving the corresponding throughput than the Lee & Mark's work does. Delay versus Throughput curves as well as Delay versus Traffic parameter curves are obtained. Numerical results obtained through the analysis and by the computer simulation show that the proposed scheme provides the low average packer delay even under the condition that the number of transponders (M)is below the half of the number of zones(N).

• 한국정보처리학회논문지
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• 제5권7호
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• pp.1896-1907
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• 1998

확장된 마크흐름선도(EMFG: Extednded Mark Flow Graph)는 기존의 MFG를 개선한 그래프로서, 회로변수식에 의해 실제회로로 쉽게 구현가능하므로 이산제어시스템의 모델링과 설계 및 구현의 강력한 도구로 사용될 수 있다. 본 논문은 EMFG의 트랜지션들이 점화하는 과정 및 트랜지션들이 점화완료하였을 때 각 박스들의 마크수 변화를 부울함수식과 벡터를 사용하여 표현하였다. 또한 시스템의 상태변화를 쉽게 판단할 수 있게 하는 EMFG의 동작알고리듬을 제안하였으며, 제안된 알고리듬은 3-비트 증가계수기를 설계한 EMFG와 시간트랜지션이 포함된 가상의 EMFG에서 잘 수행되었다. EMFG의 동작이 부울함수로 해석가능해짐으로 인해 시스템의 분석 및 설계가 용이하며 컴퓨터를 이용한 자동화된 시스템의 분석과 설계가 가능하다.

• 소성∙가공
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• 제16권1호
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• pp.3-8
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• 2007

Novel compression molding system for preform has been developed in this study. The preforms for injection blow molding and injection stretch blow molding are being manufactured by injection molding. However it contains gate mark that affects the bottom crack in the PET bottle. The compression molded preform does not contain gate mark, thus the appearance quality of bottle has been increased and the residual stress near gate(bottom of the bottle) has been reduced. The thickness distributions, haze, and transmittance are well accepted for the preform. Also, flow characteristics of the resin between a core and cavity could be analyzed through computer simulation.

• 유변학
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• 제9권1호
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• pp.27-32
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• 1997

GM 은 Amorphopallus Konjac K. Koch의 tuber의 주성분으로알카리 응고제를 첨가 함에 따라 열적으로 안정한 gel을 형성한다. GM에 침전제로 메탄올을 사용하여 4단계로 분 별하였고 각 분별물(F.1, F.2, F.3, F.4)들은 Mark-Houwink 식을 이용하여 분자량을 산출하 였다. Ubbelohde를 이용한 농도에 따른 환산점도로부터 고유 점성도값을 구한 결과 분자량 이 높은 분별물이 분자량이 낮은 분별물에 비하여 직선으로부터 벗어남을 알수 있었다. 또 한 고유점성도는 분자량이 증가할수록 증가하였고, 분자량 분포 범위가 broad하게 나타났다. GM용액의 frequency와 shear rate에 따른 viscosity를 측정한결과 낮은 frequency에서는 loss modulus(G＂)가 storage modulus(G＂)보다 큰 값을 가졌으나 높은 frequency에서는 G ＇가 G＂보다 크게 나타났다. 이 현상은 분자들의 얽힘에 관한 시간 의존도로써 설명할수 있다. 즉높은 frequency에서는 탄소 사슬간의 얽힘들이 진동기간내에 분자결합이 끊어지기 에 충분한 시간을 갖지 못하여 그 조직이 교차 결합을 한 gel처럼 행동하게 되고 한편 낮은 frequency에서는 탄소사슬들의 얽힘이 풀리고 흐르기에 충분한 시간을 갖게된다. Shear rate에 따른 viscosity값과 frequency에 대한 dynamic viscosity값은 거의 유사한 변화를 나 타내었다.