• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
• /
• pp.45-48
• /
• 2009

This study evaluated the influence of temperature on the PV module surface on power output characteristics, especially for an amorphous transparent thin-film PV module which was applied to a full-scale mock-up model as building integrated photovoltaic system. The tested mock-up consisted of various slopes of PV module, facing to the south. The annual average temperature of the module installed with the slope of $30^{\circ}$ revealed $43.1^{\circ}C$, resulting in $7^{\circ}C$ higher than that measured in PV modules with the slope of $0^{\circ}$and $90^{\circ}$ did. This $30^{\circ}$ inclined PV module also showed the highest power output of 28.5W (measured at 2 PM) than other two modules having the power output of 20.4W and 14.9W in the same time for $0^{\circ}$ and $90^{\circ}$ in the slope, respectively. In case of the $30^{\circ}$ inclined PV module, it exhibited very uniform distribution of power output generation even under the higher temperature on the module surface. Consequently, the surface temperature of the PV module analyzed in this study resulted in 0.22% reduction in power output in every $1^{\circ}C$ increase of the module surface temperature.

• 한국농공학회지
• /
• 제6권2호
• /
• pp.816-825
• /
• 1964

1. Outline: The flow of the siphon spillway is very intricate and affected by vacuous condition. It is an intresting problem to make vacuum rapidly in_siphon, i.e, to provoke the perfect siphonaoge with the lowest water-level of overflow. The hydraulic experiments of siphon spillway have practiced at the Masan Lake, Haenam, the province of Junnam and gained rational and economical results which cannot be odtained by calculation. 2. Experiment: The model scale was a half of that of the prototype. 3. Results and discussion: In the experiments of 14 runs, washing, overflow water level, outlet, water level of cushion, phenomenon of water flying and water pressure of every part, etc. were studied. a) The relation of overflow water-level at siphon inlet and deflector When the elevation of the deflector is 10. 65m and the form of deflector O.4m long is the hypotenuse of an $45^{\circ}$ isosceles triangle, the over flow water-level is the minimum, i. e. the siphonage was excellent. There is no effect by the rising of overflow water-Ievel between 11.95m to 1O.65m of deflector elevation (in the first plan, it is 11.05m). But the overflow water-level rises remarkably in the outside region of the above limits. b) The relation of overflow water-level, the length of cushion and standard height of the base. The reduction of the length of cushion brings the rising of overflow waterlevel, and the rising of the standard height of the base brings the rising of overflow water level. For the long cushion length and low standard height of the base, it cannot be expeted to have the falling of overflow water-level. The most satisfactory data were obtained at 5.20m of the base standard height and 6.1m of the length of cushion. The first vah,le planned was 5.70 m and 4.30m.

• 한국안전학회지
• /
• 제25권3호
• /
• pp.53-60
• /
• 2010

액화석유가스 자동차는 대도시의 대기환경 개선을 위해 적용되고 있으며 대기 오염물질을 저감시키는데 효과적인 것으로 입증되고 있다. 이와 더불어 환경 친화적인 에너지원으로서 가스의 수요가 날로 급증하고 있으며, LPG 충전소도 해마다 증가추세이다. 따라서 본 논문에서는 충전소에서 증기운폭발에 의한 화염의 영향으로 인간에게 미치는 영향을 알아보고자 한다. 이를 위하여 API에서 규정한 피해예측을 통하여 평가를 실시하였다. 폭발장소에서의 화염에 의해 미치는 영향 거리를 산출하여 거리별 복사열의 크기를 알게 되면 그 지점에서의 피해는 간단하게 예측할 수 있다. 또한 폭발장소 주변에 위치한 인간에게 미치는 영향을 PROBIT 모델에 적용하여 사고피해예측을 평가하였다. 프로빗 분석에 의하면 화염에서 30m 이격된 곳은 1도 화상에 의한 손상확률이 100%, 2도 화상에 의한 손상확률은 99.2%, 화재로 인한 사망확률은 93.4%로 나타났다.

• Wind and Structures
• /
• 제9권2호
• /
• pp.125-146
• /
• 2006

Stonecutters Bridge of Hong Kong is a cable-stayed bridge with two single-column pylons each 298 m high and an aerodynamic twin deck. The total length of the bridge is 1596 m with a main span of 1018 m. The top 118 m of the tower will comprise structural steel and concrete composite while the bottom part will be of reinforced concrete. The bridge deck at the central span will be of steel whilst the side spans will be of concrete. Stonecutters Bridge has adopted a twin-girder deck design with a wide clear separation of 14.3 m between the two longitudinal girders. Although a number of studies have been conducted to investigate the aerodynamic performance of twin-girder deck, the actual real life application of this type of deck is extremely limited. This therefore triggered the need for conducting the present studies, the main objective of which is to investigate the performance of Stonecutters Bridge against flutter at its in-service stage as well as during construction. Based on the flutter derivatives obtained from the 1:80 scale rigid section model experiment, flutter analysis was carried out using 3-D finite element based single parameter searching method developed by the second author of this paper. A total of 6 finite element models of the bridge covering the in-service stage as well as 5 construction stages were established. The dynamic characteristics of the bridge associated with these stages were computed and applied in the analyses. Apart from the critical wind speeds for the onset of flutter, the dominant modes of vibration participating in the flutter vibration were also identified. The results indicate that the bridge will be stable against flutter at its in-service stage as well as during construction at wind speeds much higher than the verification wind speed of 95 m/s (1-minute mean).

• 한국산학기술학회논문지
• /
• 제11권6호
• /
• pp.2129-2137
• /
• 2010

본 연구는 경상남도 20개 보건소의 효율성을 평가하고, 비효율 보건소의 개선 목표치를 제시함으로써 효율성 제고에 실질적인 도움을 주고자 하였다. 효율성 평가방법으로는 자료포락분석(Data Envelopment Analysis: DEA)의 CCR, BCC 모형을 이용하여 보건소의 전체적 효율성과 사업 영역별 효율성을 평가하였다. 이를 위하여 투입변수로는 인력(의료직, 간호직, 보건직, 사무직)을 선정하였고 산출변수로는 보건소 사업(진료, 보건교육, 구강보건, 예방접종, 노인보건, 모자보건)을 선정하였다. 본 연구 결과는 기술효율성(TE) 평균은 0.868이었으며, 12개(60%) 보건소가 효율적으로 나타났다. 순수기술효율성(PTE)의 평균은 0.924이었으며, 14개(70%) 보건소가 효율적인 것으로 나타났다. 그리고 규모의 효율성(SE)의 평균은 0.933이었으며, 12개(60%)가 효율적인 것으로 나타났다. 위 연구결과를 토대로 보건사업의 체계적인 기획, 수행 및 평가를 통해 보건소가 효율적으로 운영되고 지역민에게는 최상의 의료서비스를 제공하기 위한 노력이 필요하다.

• 아시안잔디학회지
• /
• 제20권1호
• /
• pp.93-105
• /
• 2006

최근 많은 수의 골프장 건설로 인하여 국토의 상당면적이 원지형의 변화 또는 파괴되고 있으며 주변 생태계가 급속한 변이를 겪고 있다. 골프코스 건설을 위해서는 정밀하고 효율적인 설계를 요하지만 기존의 통상적 설계방식으로는 사업의 방대성으로 인한 설계자료의 처리에 한계를 가지고 있었다. 특히 공사 후의 경관 변화에 대한 예측이나 환경영향 저감대책에 대하여 적절한 대안을 제시할 적절한 수단이 없었다. 따라서 이러한 문제점을 해결하기 위하여 지형정보시스템(GIS)을 골프코스 설계에 적용하여 건설에 따른 물리적 영향을 최소화시킬 수 있는 친환경적인 골프코스 설계 기법개발에 대하여 연구하였다. 연구된 내용은 지형정보시스템을 기초자료입력 단계에서부터 최종 성과물 단계까지 적용시켜 전 설계과정을 전산화하며, 부수적으로 골프 경기의 기능적 효과 증대 토지이용의 적정성, 코스유지 관리의 용이성 등을 사전 검토할 수 있는 친환경적 전산설계기법을 개발 연구하였다.

• Journal of Preventive Medicine and Public Health
• /
• 제47권3호
• /
• pp.158-168
• /
• 2014

Objectives: To identify and evaluate the trend of meal-skipping rates among Korean adolescents with their contributing causes and the influence of household income level on meal skipping. Methods: Using 2008, 2010, and 2012 data from the Korea Youth Risk Behavior Web-based Survey of 222 662 students, a cross-sectional study with subgroup analysis was performed. We calculated odds ratios for skipping each meal 5 or more times in a week by household socio-economic status using a multiple logistic regression model. The secular change in the meal-skipping rates by the students' family affluence scale was analyzed by comparing the meal-skipping students within each subgroup and odds ratios for the same event over time. Results: Through 2008 to 2012, most of the meal-skipping rates generally showed a continuous increase or were almost unchanged in both sexes, except for breakfast skipping in several subgroups. Students in low-income households not living with both parents had the highest meal-skipping rates and odds ratios for frequent meal skipping. In a time-series subgroup analysis, the overall odds ratios for the same event increased during 2008 to 2012, with a slight reduction in the gap between low and higher income levels with regard to meal skipping during 2010 to 2012. Conclusions: Household socio-economic status and several other factors had a significant influence on Korean adolescent meal-skipping rates. Although the gap in eating behavior associated with household socio-economic differences is currently decreasing, further study and appropriate interventions are needed.

• Geomechanics and Engineering
• /
• 제16권3호
• /
• pp.257-271
• /
• 2018

In this paper, the effect of the homogenization models on buckling and free vibration is presented for simply supported functionally graded plates (FGM) resting on elastic foundation. The majority of investigations developed in the last decade, explored the Voigt homogenization model to predict the effective proprieties of functionally graded materials at the macroscopic-scale for FGM mechanical behavior. For this reason, various models have been used to derive the effective proprieties of FGMs and simulate thereby their effects on the buckling and free vibration of FGM plates based on comparative studies that may differ in terms of several parameters. The refined plate theory, as used in this paper, is based on dividing the transverse displacement into both bending and shear components. This leads to a reduction in the number of unknowns and governing equations. Furthermore the present formulation utilizes a sinusoidal variation of displacement field across the thickness, and satisfies the stress-free boundary conditions on the upper and lower surfaces of the plate without requiring any shear correction factor. Equations of motion are derived from Hamilton's principle. Analytical solutions for the buckling and free vibration analysis are obtained for simply supported plates. The obtained results are compared with those predicted by other plate theories. This study shows the sensitivity of the obtained results to different homogenization models and that the results generated may vary considerably from one theory to another. Comprehensive visualization of results is provided. The analysis is relevant to aerospace, nuclear, civil and other structures.

• 한국컴퓨터정보학회논문지
• /
• 제20권5호
• /
• pp.91-98
• /
• 2015

본 연구는 국내 중-대형 SW개발 프로젝트 현장에 적용되고 있는 PMS의 주요 기능 및 적용효과에 대하여 소개하고, PMS적용의 중요성과 개선 필요성을 제시하고자 한다. PMS는 CMMI, PMBOK와 같은 글로벌 모델이 권고하는 모범 사례를 기반으로 주요 기능이 구현되었으며, 각 시스템이 목표로 하는 산업분야와 시스템을 구성하는 솔루션에 종속된 특화기능을 보유하고 있다. PMS적용에 따른 효과는 정성적, 정량적 효과로 구분할 수 있다. 대표적인 정성적 효과로는 SW개발 기업의 이미지 및 경쟁력 향상이며, 아울러 대표적인 정량적 효과로는 프로젝트 수행 현장의 관리 노력 절감에 따른 재무적 효과이다. 소프트웨어 프로젝트 수행과 관련한 법적, 환경적 변화에 따라 PMS적용에 대한 고객의 요구에 따른 수요는 증가될 것이므로 프로젝트 관리 분야의 글로벌한 변화추세에 따른 지속적 개선이 요구된다.

• 한방비만학회지
• /
• 제4권1호
• /
• pp.161-183
• /
• 2004

Context : Oriental medicine deals with mind cardinally and effectiveness of CBT on weight control is well-known. but there is no well-structured psychotherapy for weight control like CBT in Oriental medicine so far. Therefore It is necessary to develop new cognitive program based on the theory of Oriental medical. Objective: This study examined whether Yangsung program based on new cognitive weight regulation model is effective on weight loss, self esteem and self control. Design and setting: 44 women were assigned randomly to 2 groups; experimental group(n=24) and control group(n=10). experimental group had 11 sessions consisted of cognitive therapy, meditation, general diet and exercise education. Control group had personal interview with general diet and exercise education and ear acupuncture once a week for two months. All subjects were weighed and evaluated with Rosenberg self esteem scale, and three factor eating questionnaires at the beginning of the program and at the end of the program. Result: Experimental group reported significant changes of weight, self esteem, restraint eating, disinhibition and hunger(p<0.01). Compared with control group, more significant(p<0.05) Weight reduction and self-esteem enhancement were reported in experimental group than control group. There is no significant difference between two groups in changes of restraint eating, disinhibition and hunger.