• 한국전자파학회논문지
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• 제8권1호
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• pp.35-41
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• 1997

빔폭 $10^{\circ}$, 경사각 $80^{\circ}$ 및 SLL -15 dB 이하인 직렬 급전형 마이크로스트립 배열 안테나를 설계한다. 직렬 급전형 배열은 모든 소자들을 고임피딘스인 전송선로로 상호 연결하고, 첫 번째 소자에서 급전하며, 정합부하로 종단된 진행파 안테나이다. 안테나의 방사패턴과 임피던스 정합은 인쇄된 안테나 및 배열을 설계하는데 널리 사용 되는 소프트웨어 패키지인 앙상블 4.0에 의해서 해석한다. 빔의 경사각은 소자간의 간격에 의해서 구현된다. 직렬 급전형 배열 안테나는 병렬급전구조에 비하여 급전회로망이 간단하고 급전회로망에서의 방사손실이 작은 이점이 있다. 안테나는 두께 62 mil인 RT/Duroid 기판상에 제작한다. 실험결과 이론치와 실험치가 일치함을 확인하였다.

• 천문학회보
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• 제41권1호
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• pp.54.3-55
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• 2016

DEEP-South Scheduling and Data reduction System (DS SDS) consists of two separate software subsystems: Headquarters (HQ) at Korea Astronomy and Space Science Institute (KASI), and SDS Data Reduction (DR) at Korea Institute of Science and Technology Information (KISTI). HQ runs the DS Scheduling System (DSS), DS database (DB), and Control and Monitoring (C&M) designed to monitor and manage overall SDS actions. DR hosts the Moving Object Detection Program (MODP), Asteroid Spin Analysis Package (ASAP) and Data Reduction Control & Monitor (DRCM). MODP and ASAP conduct data analysis while DRCM checks if they are working properly. The functions of SDS is three-fold: (1) DSS plans schedules for three KMTNet stations, (2) DR performs data analysis, and (3) C&M checks whether DSS and DR function properly. DSS prepares a list of targets, aids users in deciding observation priority, calculates exposure time, schedules nightly runs, and archives data using Database Management System (DBMS). MODP is designed to discover moving objects on CCD images, while ASAP performs photometry and reconstructs their lightcurves. Based on ASAP lightcurve analysis and/or MODP astrometry, DSS schedules follow-up runs to be conducted with a part of, or three KMTNet telescopes.

• 한국정보통신학회논문지
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• 제8권7호
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• pp.1524-1531
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• 2004

본 논문에서는 라운드 로빈 알고리즘을 적용한 부하균형기법을 보이고 있다. 이를 위하여 2개의 패키지(패킷 캡춰와 라운드로빈 테스트 패키지)를 구현하였으며, 이러한 구현 패키지 S/W에 의해 본 연구 실험의 가상연결구조(데이터 생성기, 가상서버, 서버1,2,3) 에서 발생하는 패킷의 량을 측정한 것으로 서버1,2,3으로 트래픽 분산여부를 파악할 수 있었으며, 구현된 라운드로빈 부하균형 모니터링 시스템의 기능으로는 데이터의 수신량, 패킷량 표현, 패킷량 그래프 표현, 라운드 로빈 테스트, 시스템 모니터링 기능이 있다. 실험결과는 들어오는 데이터의 크기가 많이 차이나지 않는 이상 라운드 로빈 알고리즘은 확실한 형태의 트래픽 분산을 가능하게 해주었다 그리고 일부분에서 오차가 심한 경우도 있지만 횟수를 거듭하고 테스트가 장기화 될수록 오차는 줄어들었다.

• 한국전산구조공학회논문집
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• 제16권1호
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• pp.105-111
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• 2003

승용차의 휠은 타이어와 차체 무게를 지지하며, 회전력과 정지력을 노면으로 전달한다. 휠의 경량화는 차량의 연료효율에 효과적이므로, 스틸휠이 무게를 최소화하도록 디스크 홀이 형상을 최적화 하였다. 설계모델은 Pro/ENGINEER를 사용하여 설정하고, 설계모델의 해석은 ANSYS를 이용하였다. 범용 소프트웨어간의 직접적인 자료의 전달이 어려우므로 두 프로그램을 병합 사용하기 위해, 반응표면법을 이용한 근사함수를 구하였다. 5수준의 요인배치법의 실험값을 사용하여 최대응력과 최대 변위를 추출하였다. 초기 모델은 14인치 승용차용 스틸휠을 사용하였고, 디스크 홀의 폭을 설계변수로 선택하였다. 순차이차계획법과 활성화제약조건을 사용하는 PLBA(Pahenichny-Lim-Belegundu-Arora) 알고르즘을 이용하여 최적해를 구하였다.

• 치위생과학회지
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• 제11권6호
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• pp.583-588
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• 2011

본 연구는 2010년 11월 충북지역 일부 중학생을 대상으로 흡연, 스트레스, 구강건강 및 분야별 건강증진행위 실천정도를 파악하고자 이루어졌으며 다음과 같은 결론을 얻었다. 1. 중학생의 33.8%가 흡연 경험이 있었으며, 처음 흡연시기와(24.1%) 습관적 흡연 시기가(10.4%) 초등학교 고학년 시기에 가장 많아 흡연연령이 점차 낮아지고 있는 추세이다. 2. 스트레스에 따른 중학생의 건강생활실천 수행정도를 비교한 결과, 스트레스가 낮은 그룹이 구강건강을 제외한 모든 항목에서 건강생활실천 수행정도가 높았으며 유의한 차이가 나타났다(p<.05). 구강건강상태도 스트레스가 낮은 그룹이 우식치아수도 적게 나타나 유의한 차이가 있었으며, 구강환경관리능력(PHP)은 유의한 수준은 아니었으나 스트레스가 높은 그룹이 구강환경관리가 잘 되지 않는 것으로 조사되었다. 3. 부모의 양육방식이 자율적일수록 스트레스가 낮은 것으로 조사되었으며(p<.05), 스트레스가 낮은 그룹이 학교생활 만족도가 높은 것으로 조사되었다(p<.05). 4. 중학생의 건강증진행위에 영향을 미치는 변인의 영향력을 살펴본 결과, 표준화 계수 ${\beta}$의 견지에서 정신 건강이 가장 영향력을 미치는 변인으로 나타났다.

• 대한영양사협회학술지
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• 제22권4호
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• pp.272-291
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• 2016

The purpose of this study was to investigate health-related habits, dietary habits, depression, stress, satisfaction of body weight, mini-dietary assessment (MDA) and dietary behaviors according to self-rated health among 255 university students in Kyungnam province. Statistical analyses were performed using the SPSS software package (version 19.0). The average ages of the subjects were 21.1 years. Participants were asked their self-rated health and 109, 105 and 41 students answered themselves as "healthy", "normal" and "unhealthy", respectively. The pocket money (P<0.05) was related with self-rated health, and meal frequency (P<0.01) of healthy group was higher than that of the unhealthy group. The self-reported depression level (P<0.01) and the score of depression (P<0.05) of the healthy group were lower than those of the unhealthy group. The self-reported stress level of the healthy group (P<0.05) was higher than that of the unhealthy group. The scores of nutritional behavior (P<0.05) and MDA (P<0.01) of the healthy group were higher than those of the unhealthy group. The scores for intakes of meat, fish, egg or beans, cereals and vegetables except kimchi, fruits, balanced diet and various foods were higher in the healthy group than in the unhealthy group. Our results suggest that pocket money, high meal frequency, low depression, satisfaction of present body weight, and good dietary behavior might influence good perception of self-rated health.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2003년도 추계 학술대회논문집
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• pp.200-205
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• 2003

The Canard rotor/wing (CRW) aircraft concepts offer great potential for application by allowing the use of a common propulsion system for high-speed cruise and low-speed powered lift. Using the rotor for lift in both flight modes increases its utility. In the hovering mode, the exhausted gas from an gas turbine engine is accelerated through the duct system and it provides the tipjet power for rotor system enough to lift the aircraft. In the cruise mode, the rotor is fixed and the exhausted gas is extracted through the main nozzle, such that the aircraft is able to flight with high speed. The duct system was designed using 1-D fanno line flow theory and empirical data. However, the empirical data of the pressure loss coefficient for various bending and dividing ducts were not enough to design our duct system adaptively. Therefore, using 3-D CFD analysis we obtained the pressure loss coefficient for our duct models and chose the appropriate bending or diving duct type. In this paper, we used the CFD-ACE+ software package for the CFD analysis and the modeling of duct system. Through the 3-D CFD analysis, we investigated also the pressure loss and the velocity distributions of the designed whole duct system as well as the blade duct. Comparing the 3-D CFD result with 1-D analysis result, we lessened the uncertainty of the designed duct system and speculated the problem that was not concerned in design state.

• Computers and Concrete
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• 제2권6호
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• pp.423-437
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• 2005

In this study two single-bay, three-storey space frames, one with brick masonry infill in the second and third floors representing a soft-storey frame and the other without infill were designed and their 1:3 scale models were constructed according to non-seismic detailing and the similitude law. The models were excited with an intensity of earthquake motion as specified in the form of response spectrum in Indian seismic code IS 1893-2002 using a shake table. The seismic responses of the soft-storey frame such as fundamental frequency, mode shape, base shear and stiffness were compared with that of the bare frame. It was observed that the presence of open ground floor in the soft-storey infilled frame reduced the natural frequency by 30%. The shear demand in the soft-storey frame was found to be more than two and a half times greater than that in the bare frame. From the mode shape it was found that, the bare frame vibrated in the flexure mode whereas the soft-storey frame vibrated in the shear mode. The frames were tested to failure and the damaged soft-storey frame was retrofitted with concrete jacketing and, subjected to same earthquake motions as the original frames. Pushover analysis was carried out using the software package SAP 2000 to validate the test results. The performance point was obtained for all the frames under study, therefore the frames were found to be adequate for gravity loads and moderate earthquakes. It was concluded that the global nonlinear seismic response of reinforced concrete frames with masonry infill can be adequately simulated using static nonlinear pushover analysis.

• Advances in aircraft and spacecraft science
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• 제1권2호
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• pp.197-218
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• 2014

Quite a demanding task frequently arises in space engineering, when dealing with the cargo accommodation of modules and vehicles. The objective of this effort usually aims at maximizing the loaded cargo, or, at least, at meeting the logistic requirements posed by the space agencies. Complex accommodation rules are supposed to be taken into account, in compliance with strict balancing conditions and very tight operational restrictions. The context of the International Space Station (ISS) has paved the way for a relevant research and development activity, providing the company with a remarkable expertise in the field. CAST (Cargo Accommodation Support Tool) is a dedicated in-house software package (funded by the European Space Agency, ESA, and achieved by Thales Alenia Space), to carry out the whole loading of the Automated Transfer Vehicle (ATV). An ad hoc version, tailored to the Columbus (ISS attached laboratory) on-board stowage issue, has been further implemented and is to be used from now on. This article surveys the overall approach followed, highlighting the advantages of the methodology put forward, both in terms of solution quality and time saving, through an overview of the outcomes obtained to date. Insights on possible extensions to further space applications, especially in the perspective of the paramount challenges of the near future, are, in addition, presented.

• 한국컴퓨터정보학회논문지
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• 제19권2호
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• pp.221-231
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• 2014

본 연구는 전략적 제휴와 연계를 추구하는 장기 지속적인 그린IT 전략의 필요성을 제시하였다. 그린IT 기업의 사회적 압력과 환경지향성과 환경매력도가 장기 지속적 그린IT 전략에 어떠한 영향을 미치는지, 장기 지속적 그린 IT 전략이 환경성과에 어떠한 영향을 미치는가를 알아보기 위한 연구모형을 설정하였다. 선행연구에서 종속변수로 사용되던 장기지속성을 본 논문에서는 매개변수로 설정하였다. 그린IT 기업을 대상으로 설문조사를 실시하였고, 통계패키지를 이용하여 실증적으로 분석하였다. 사회적 압력과 환경지향성과 환경매력도와 환경성과 사이의 관계에서 장기지속성이 매개효과가 있음을 검증하였다.