• 조명전기설비학회논문지
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• 제25권1호
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• pp.30-41
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• 2011

This study performs the subjective evaluations of LED illumination conditions according to three types of color temperatures (7,000[K], 5,000[K], 3,000[K]) after employing LED illumination system in the classroom, Since the objective of this study is to develop an artificial lighting conditions like day light comfortable to students in the classroom, the learning effect based on three types of LED illumination conditions are analyzed. Three factors (learning intention, learning environment, learning motivation) are extracted by ANOVA and there are preference differences of LED illumination conditions between learning intention and learning environment factors. Especially, preference differences of LED illumination conditions are existed about calculation, reading and fatigue reduction. The test results of this study can be applied to obtaining high achievement of learning based on the lighting conditions.

• Journal of Advanced Research in Ocean Engineering
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• 제4권2호
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• pp.47-52
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• 2018

The Korea Offshore Wind Power (KOWP) is planning to construct offshore wind energy farms with an overall rated power of 2.5 GW in the south-western coast of the country until 2019. Various types of support structures for offshore wind turbines have been proposed in the past. Nevertheless, in South Korea, jacket structures have in general, been applied as support structures for offshore wind turbines owing to the many accumulated experiences and know-how regarding this kind of support structure. The choice of offshore structure is mainly influenced by site conditions such as seabed soil type and sea environment during installation. In installing jacket sets on the seabed, the mudmat is necessary to maintain the equilibrium of the jacket without the aid of additional devices. Hence, this study proposes the installation of skirt plates underneath the bottom frame of jackets in order to improve the installation stability of jacket structures under rougher sea conditions. To confirm the effect of skirt plates, installation stability analyses considering overturning, sliding and bearing capacity have been performed. From the results, it is shown that jacket structures with skirt plates can contribute to improving the sliding stability of the structures of new wind power farms, while providing economic benefits.

• 한국지반공학회논문집
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• 제28권4호
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• pp.55-65
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• 2012

본 연구는 지반조건에 따른 효과적인 마이크로 파일의 설치방법을 제안하기 위해 실트 또는 모래지반에서 모형시험을 수행하였다. 시험결과, 관입 전단파괴가 발생한 실트지반은 압축변위에 저항하도록 마이크로 파일을 엇갈리게 설치(${\theta}$ < $0^{\circ}$)하는 것이 효과적이며, 전면 또는 국부전단파괴가 발생한 모래인 경우 횡 방향 변위에 저항하도록 마이크로 파일을 경사지게 설치(${\theta}$ > $0^{\circ}$ 또는 ${\theta}$ < $0^{\circ}$) 하는 것이 효과적인 것으로 나타났다.

• Geomechanics and Engineering
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• 제23권6호
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• pp.523-533
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• 2020

The current study focuses on the effect of the end shape of steel pipe piles on installation effort and bearing resistance using the pressing method of installation under dense ground conditions. The effect of pile rotation on the installation effort and bearing resistance is also investigated. The model steel piles with a flat end, cone end and cutting-edge end were used in this study. The test results indicated that cone end pile with the pressing method of installation required the least installation effort (load) and showed higher ultimate resistance than flat and cutting-edge end piles. However, pressing and rotation during cutting-edge end pile installation considerably reduces the installation effort (load and torque) if pile penetration in one rotation equal to the cutting-edge depth. Inclusion of rotation during pile installation reduces the ultimate bearing resistance. However, if penetration of the cutting-edge end pile equal to the cutting-edge depth in one rotation, the reduction in ultimate resistance can be minimized. In comparing the cone and cutting-edge end piles installed with pressing and rotation, the least installation effort is observed in the cutting-edge end pile installed with penetration rate equal to the cutting-edge depth per rotation.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1995년도 추계학술발표회논문집
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• pp.53-59
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• 1995

The accurcy and the application limits of the Three-Curve Method(TCM) and Zonal Cavity Method(ZCM) are evaluated. Average illuminance values are calculated by TCM and ZCM for various lighting conditions using general Diffusing Luminaires and Direct Luminaires. These values are compared with the values from Monte-Carlo Simulation(MCS) for the same lighting conditions. Accuracy of MCS was proved by Moon's Analytical Method.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2003년도 학술대회논문집
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• pp.117-122
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• 2003

Street light facilities, which are easily accessible, can be in danger of electric shock when water percolates the facilities especially in summer. In case deteriorated facilities are not checked regularly, they can cause accidents such as electric shock. We should consider regional characteristics to prevent this kind of accidents. In this paper, we analyzed the problems according to the facilities through the research on the actual conditions. We also analyzed the facilities by region and the standards by the conditions.

• 한국산업정보학회논문지
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• 제28권6호
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• pp.91-98
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• 2023

태양광 발전소의 발전량은 기상 조건, 지리적 조건, 태양광 패널 설치 조건과 높은 상관관계를 갖는다. 과거 연구들에서는 발전량에 영향을 미치는 요소를 찾아내었고, 그 중 일부는 태양광 패널이 최대 전력량을 생산할 수 있는 최적의 조건을 찾았었다. 하지만, 태양광발전소 설치 시 현실적 제약을 고려하면 최대 발전량 조건을 만족시키기는 매우 어렵다. 발전소 소유자가 태양광발전소 설치를 검토할 때 태양광 발전량을 예측하기 위해서는 발전량에 영향을 미치는 요인들의 민감도를 알아야 한다. 본 논문에서는 태양광발전소의 발전량과 날씨, 위치, 설치 조건 등 관련 요인들과의 관계를 분석하기 위한 다항회귀분석 방법을 제안한다. 분석자료는 대구, 경북에 설치·운영되는 태양광발전소 11개소로부터 수집하였다. 분석 결과 발전량은 패널 종류, 일사량, 음영 유무에 영향을 받으며 패널 설치 각도와 방향이 복합적인 영향을 주는 것으로 나타났다.

• Geomechanics and Engineering
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• 제20권2호
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• pp.147-154
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• 2020

A novel approach for predicting lateral displacement caused by pile installation in anisotropic clay is presented, on the basis of the cylindrical and spherical cavities expansion theory. The K₀-based modified Cam-clay (K₀-MCC) model is adopted for the K₀-consolidated clay and the process of pile installation is taken as the cavity expansion problem in undrained condition. The radial displacement of plastic region is obtained by combining the cavity wall boundary and the elastic-plastic (EP) boundary conditions. The predicted equations of lateral displacement during single pile and multi-pile installation are proposed, and the hydraulic fracture problem in the vicinity of the pile tip is investigated. The comparison between the lateral displacement obtained from the presented approach and the measured data from Chai et al. (2005) is carried out and shows a good agreement. It is suggested that the presented approach is a useful tool for the design of soft subsoil improvement resulting from the pile installation.

• 환경영향평가
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• 제22권4호
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• pp.361-367
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• 2013

Noise and vibration occurs during construction intermittently, but with the most arise complaints. There is a need to efficiently manage the construction noise and vibration problems because in case a residential facility that requires calmness around the construction site adversely affects the living conditions of nearby residents. The ministry of environment has mandating the installation of soundproofing facilities for the management of construction noise. In order to enforce a particular construction, the mandatory install with soundproofing facilities before the start of construction, and after construction. However, Installation guide of soundproofing facilities for construction sites were not considered affected areas by noise and there is no provision of performance evaluation for soundproofing facilities. In this study, investigated the status and problems of the installation guide for soundproofing facilities in construction sites, we propose an efficient installation guide of soundproofing facilities for the reduction construction noise.

• 한국태양에너지학회 논문집
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• 제39권1호
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• pp.77-89
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• 2019

The solar air heater has various performances according to an obstacle installed in the air duct. Many studies on thermal performance have been conducted. But many of these studies were using a kind of rib type obstacle attached at the bottom of absorbing plate, but they are so hard to be manufactured. In this study, characteristics of the heat transfer and pressure drop in the solar air heater with various horizontal rectangular obstacles was investigated by CFD (Computational Fluid Dynamics) analysis. As a result, the heat transfer performance was improved from 1.2 to 3.32 times depending on installation conditions of rectangular obstacle. The pressure drop, however, also increased with increment of heat transfer performance from 2.8 to 180 times only by changing installation conditions of rectangular obstacle. Thus, the performance factor presenting the thermal performance enhancement on the same pressure drop was also confirmed. As a result, the highest value of 0.828 as better performance factor was obtained at the lower height of rectangular obstacle and this value has started to decrease with increment of heat transfer performance. In the end, it could be confirmed that the pressure drop was carried higher than the quantity of improvement of the heat transfer performance when the heat transfer performance was increased by change of installation conditions of rectangular obstacle. Both heat transfer enhancement and pressure drop to be required for system need to be considered before the rectangular obstacles are applied to the solar air heater.