Recently, the incidence and magnitude of earthquakes have been continuously increasing. NFPA 13 requires that hydroponics fire extinguishing system pipelines apply seismic isolation. Stainless steel joints have been newly developed to replace these seismic isolation joints. Therefore, in this study, a nonlinear finite element model of a pipeline with Stainless Power Joint was developed based on experimental data, and finite element analysis was performed by applying hydrostatic pressure and cyclic loading.

Core/shell CdSe/ZnS quantum dots (QDs) are synthesized by a microfluidic reactor-assisted continuous reactor system. Photoluminescence and absorbance of synthesized CdSe/ZnS core/shell QDs are investigated by fluorescence spectrophotometry and online UV-Vis spectrometry. Three reaction conditions, namely; the shell coating reaction temperature, the shell coating reaction time, and the ZnS/CdSe precursor volume ratio, are combined in the synthesis process. The quantum yield of the synthesized CdSe QDs is determined for each condition. CdSe/ZnS QDs with a higher quantum yield are obtained compared to the discontinuous microfluidic reactor synthesis system. The maximum quantum efficiency is 98.3% when the reaction temperature, reaction time, and ZnS/CdSe ratio are 270℃, 10 s, and 0.05, respectively. Obtained results indicate that a continuous synthesis of the Core/shell CdSe/ZnS QDs with a high quantum efficiency could be achieved by isolating the reaction from the external environment.

The purpose of this study was to examine the relationship of fatigue and stress in seafarers. Ninety healthy adults were recruited and cumulative fatigue, stress index and stress resistance of seafarers were measured using autonomic nervous system analysis device (SA-6000; Medicoa Co. Ltd. Korea). The stress index had a significant correlation with the degree of resistance (p<.01). Cumulative fatigue and the stress index had a strong positive correlation (r=.781) with the stress resistance, cumulative fatigue had a strong negative correlation (r=.782) (p<0.01). Furthermore, the stress index had a strong negative correlation with the degree of resistance (r=.924) (p<.01). The present study indicate that there are significant correlation between the cumulative fatigue and stress index, cumulative fatigue and stress resistance, as well as stress index and stress resistance in the seafarers (p<.01).

쓰레기 소각장이나 산업체의 폐열을 농업에 활용한 사례는 몇몇 있었다. 그러나 온배수를 농업에 활용한 사례는 전무하였으며, 치어, 종패 등을 양식하는 수산업이 대부분이었다. 본 연구에서는 화력발전소의 온배수(폐열)를 열원으로 이용하는 120 RT 규모의 냉난방시스템을 제주특별자치도 서귀포시 안덕면 소재의 5,280m2 아열대 작물(망고) 재배 온실에 설치, 10월에서 다음해 2월까지 약 5개월 동안 난방을 실시하여 난방에너지 비용 절감 효과 등 분석하였다. 난방에너지 비용 절감효과는 면세경유에 대하여 87%이였으며, 또한 발전소의 온배수를 에너지원으로 재활용함으로 서 62%의 이산화탄소 배출 저감 효과를 얻었다. 본 연구를 계기로 2015년에 해수가 수열에너지 분야로 재생에너지에 포함되었다. 해수의 표층의 열을 히트펌프를 사용하여 변환시켜 얻은 에너지라는 수열에너지 분야의 기준과 범위를 볼 때, 이는 온배수가 재생에너지에 포함되었다고 말해도 과언이 아닐 것으로 사료된다. 그 이유는 온배수도 해수임에도 불구하고 온도가 일반 해수 보다 7~8oC 높아, 일반 해수를 히트펌프의 열원으로 이용하는 것보다 온배수를 열원으로 이용했을 때 히트펌프의 성능이 높기 때문이다. 또한 같은 해 농식품부의 폐열 재이용 시설 지원 사업이 발표되어, 발전소 온배수뿐만 아니라 산업체와 소각장의 폐열을 농업에 활용하면 지원을 받을 수 있게 되었다. 이 사업에 의하여 2015년 당진시, 하동군, 제주시, 곡성군이 선정되었으며, 2016년 태안군, 서귀포시 등이 선정되어, 2016년 말 곡성군과 제주시가 공사를 완료, 농업에 폐열을 활용하고 있으며(제주시는 발전소, 곡성군은 산업체 폐열을 이용하고 있음), 기타 지역은 추진 중이다.

본 연구는 4연동 벤로형 유리온실의 냉·난방 부하를 고려한 PV 시스템의 적정 패널 설치 면적을 도출하기 위하여 BES 기법을 이용하여 온실 및 PV 시스템의 에너지 모델을 설계하였으며 동적 에너지 시뮬레이션을 수행하였다. 대상 작물은 파프리카로 선정하였으며 작물의 적정생육온도를 고려하여 냉·난방장치 및 환기장치의 가동조건을 설정하였다. 2012년부터 2016년까지 총 5년 동안의 기간별 냉·난방부하 및 최대 냉·난방 부하를 환 기팬의 환기량 조건 별로 분석을 실시하였다. 온실의 냉 ·난방 부하 산정과 함께 PV 시스템의 설치 각도에 따른 전력 생산량을 분석하였으며 신재생에너지 공급의무비율을 적용하여 최적 PV 시스템 설계 방안을 도출하였다. 환기팬의 환기량 60AE·hr-1 조건에서 대상 온실의 기간 평균 냉방 부하로 인한 전력 소모량은 174,310kWh, 기간 평균 난방 부하로 인한 전력 소모량은 458,903kWh 로 총 633,213kWh의 전력 소모량이 산정되었다. PV 시스템은 설치 각도를 30o로 설정하는 조건에서 가장 높은 전력 생산량이 나타났으며 월별 최적 각도를 적용하는 조건에서는 고정형 PV 시스템보다 약 5.7% 많은 전력 을 생산하는 것으론 산정 되었다. 최종적으로 대상 온실에 적합한 PV 시스템 패널 면적을 도출한 결과, 고정형 PV 시스템은 521m2의 패널이 필요한 것으로 산정되었고, 가변형 PV 시스템의 경우 494m2의 패널이 필요한 것으로 산정되었다. 본 연구를 통하여 4연동 벤로형 유리온실의 냉·난방 부하를 고려한 PV 시스템의 필요 패널 설치 면적을 도출할 수 있었으며 PV 시스템의 온실 적용 가능성 및 경 제성 평가의 기초 자료로 활용 가능할 것으로 판단된다. 한편, 본 연구에서는 작물 특성 데이터를 확보하지 못하여 작물의 에너지 교환을 고려하지 않았다. 보다 정확한 결과를 도출하기 위해서는 현장 실험 데이터에 기반을 둔 추가 연구가 필요할 것으로 판단된다.

Dynamic numerical simulation of pile-supported slab track system embedded in a soft soil and embankment was performed. 3D model was formulated in a time domain to consider the non-linearity of soil by utilizing FLAC 3D, which is a finite difference method program. Soil non-linearity was simulated by adopting the hysteric damping model and liner elements, which could consider soil-pile interface. The long period seismic loads, Hachinohe type strong motions, were applied for estimating seismic respose of the system, Parametric study was carried out by changing subsoil layer profile, embankment height and seismic loading conditions. The most of horizontal permanent displacement was initiated by slope failure. Increase of the embedded height and thickness of the soft soil layer leads increase of member forces of PHC piles; bending moment, and axial force. Finally, basic guidelines for designing pile-supported slab track system under seismic loading are recommended based on the analysis results.

As the functions and structure of the system are complicated and elaborated, various types of structures are emerging to increase reliability in order to cope with a system requiring higher reliability. Among these, standby systems with standby components for each major component are mainly used in aircraft or power plants requiring high reliability. In this study, we consider a standby system with a multi-functional standby component in which one standby component simultaneously performs the functions of several major components. The structure of a parallel system with multifunctional standby components can also be seen in real aircraft hydraulic pump systems and is very efficient in terms of weight, space, and cost as compared to a basic standby system. All components of the system have complete operation, complete failure, only two states, and the system has multiple states depending on the state of the component. At this time, the multi-functional standby component is assumed to be in a non-operating standby state (Cold Standby) when the main component fails. In addition, the failure rate of each part follows the Weibull distribution which can be expressed as increasing type, constant type, and decreasing type according to the shape parameter. If the Weibull distribution is used, it can be applied to various environments in a realistic manner compared to the exponential distribution that can be reflected only when the failure rate is constant. In this paper, Markov chain analysis method is applied to evaluate the reliability of multi-functional multi-state standby system. In order to verify the validity of the reliability, a graph was generated by applying arbitrary shape parameters and scale parameter values through Excel. In order to analyze the effect of multi-functional multi-state standby system using Weibull distribution, we compared the reliability based on the most basic parallel system and the standby system.

This study introduces the comparison of efficiency levels of photovoltaics systems by analyzing various installation systems of photovoltaics systems and optimization techniques and proposes a system using techniques In this study, the generation time and power generation of two types of photovoltaic power generation system were measured and compared. Comparing the monthly power generation time with the power generation amount, it is found that there are many fixed variable photovoltaic power generation systems with a large average daily power generation time of 0.8h and an average power generation capacity of 2,871kw from November to December. Total Fixed Variable Total Daily Power Generation Time 2.4h The power generation amount is 23,184kw, showing a large amount of electric power generation.

In this study, we conducted a comparative study on user’s perception and behavior on public system service (PSS) using institutionalism theory and MGA (multi-group analysis) methodology. In particular, this study focuses on how institutional isomorphism is applied to public system services and how MGA can be implemented correctly in a variance based SEM (structural equation model) such as PLS (partial least square). A data set of 496 effective responses was collected from pubic system users and an empirical research was conducted using three segmented models categorized by public proximity theory (public firms = 113, government contractors = 210, private contractors = 173). For rigorous group comparisons, each model was estimated by the same indicators and approaches. PLS-SEM was used in testing research hypotheses, followed by parametric and non-parametric PLS-MGA procedures in testing categorical moderation effects. This study applied novel procedures for testing composite measurement invariance prior to multi-group comparisons. The following main results and implications are drawn : 1) Partial measurement invariance was established. Multi-group analysis can be done by decomposed models although data can not be pooled for one integrated model. 2) Multi-group analysis using various approaches showed that proximity to public sphere moderated some hypothesized paths from quality dimensions to user satisfaction, which means that categorical moderating effects were partially supported. 3) Careful attention should be given to the selection of statistical test methods and the interpretation of the results of multi-group analysis, taking into account the different outcomes of the PLS-MGA test methods and the low statistical power of the moderating effect. It is necessary to use various methods such as comparing the difference in the path coefficient significance and the significance of the path coefficient difference between the groups. 4) Substantial differences in the perceptions and behaviors of PSS users existed according to proximity to public sphere, including the significance of path coefficients, mediation and categorical moderation effects. 5) The paper also provides detailed analysis and implication from a new institutional perspective. This study using a novel and appropriate methodology for performing group comparisons would be useful for researchers interested in comparative studies employing institutionalism theory and PLS-SEM multi-group analysis technique.

This study is analyse method for Industrial disester prevention of E-9 foreign workers. To do this, We adapted tp TRIZ 's creative problem solving theory and AHP, QFD. TRIZ is determined some parameters for problem solving and selected the inventive principles for each parameters. So, We made new parameters and inventive principles under theory of the TRIZ process for reduced to the foreign worker’s disaster rate. After, The derived parameters and the inventive principles are used to evaluate the importance of factors through the AHP, and determine the weight of the relation through QFD expansion. Finally. this paper applies statistical data according to the determined model process, analyzes the result and proposes improvement method for the prevention of disaster of foreign workers