• 패션비즈니스
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• 제8권6호
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• pp.68-77
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• 2004

Hollow filament yarns provide better warmth to the touch, lighter in weight, increased opacity, and subtle luster compared to the regular synthetic filament yarns. However, luster properties of textile fibers or fabrics are often difficult to characterize, partly due to the fineness of the surface texture, the anisotropic nature of the weave structure, the complexity of the fiber array comprising a yarn, and the fiber structure itself. In this study, the fabric surface luster image was analyzed using image analysis methods after image acquisition. The hollow filament fiber was modeled using a three-dimensional modeling software. It was then ray-traced for comparing the virtual luster images of the hollow fiber and the regular fiber models based on shading models including photon mapping. The luster object size of the actual hollow filament fabric was smaller than that of the regular filament fabric. The shape of the luster object of the hollow filament fabric was dual peak type while that of the regular filament was single.

• KIEAE Journal
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• 제6권3호
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• pp.11-18
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• 2006

Attention on daylighting should be focused not so much on a simple maximization of the natural light available in a space, as on improving the quality of lighting by ensuring as even but intense distribution of illumination in inner areas. An architectural means of optimal daylight distribution is by using so-called light shelf systems, horizontal shading and redirecting devices. The overall performance of the daylighting system can be improved by the incorporation with electric lighting control devices. This paper aims to exemplify the benefit of daylighting in term of economic consideration. In such a case a reasonable technique to compare system costs is by life-cycle costing. Stated simply, a life-cycle cost represents the total cost of a system over its entire life cycle, that is, the sum of first cost and all future costs. Four different electric lighting system designs are proposed and a lighting control system that is continuously operating according to the level of daylight in the space has been adapted. The result shows clearly that although denser layout of lighting fixtures might be more effective to interface to the level of daylight ceaselessly changeable, its economic benefit may not meet the expected criterion the reason of increased initial investment and maintenance cost for the fixtures and control devices.

• 한국실내디자인학회논문집
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• 제18권6호
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• pp.28-35
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• 2009

The purpose of this study is to analyze the state-of-the-art housing cases with passive cooling technologies and to explore the feasibilities for their applications in domestic housing design. Nineteen Leadership in Energy and Environmental Design housing cases from 2002 to 2007 were selected and analyzed their used passive cooling technologies. Besides traditional passive cooling technologies such as site planning according to the sun direction, the use of thermal mass, insulation, shading, below-ground spaces and ventilation, the relatively new technology trends were detected as followings; the use of high performance envelope, operable windows, and geo-thermal energy as the cooling source of heat pumps, increased areas of photovoltaic cells, and the education of the owner and tenants about the adopted passive cooling technologies in a building. Especially, the education may have not been focused in the domestic design despite of its effectiveness on the appropriate operations of passive cooling technologies. The results of this study show their positive adaptations would be beneficial to domestic housing design to reduce energy costs and have cooler housing environments in summer.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.25-26
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• 2007

In this paper, we studied the shadow effect which is one of environmental cause for hot-spot phenomenon on PV by considering electrical effects. We fabricated PV module in case of existence and nonexistence of bypass diode. And maximum output power and thermal distribution was analyzed by shadowing solar cell by increase of 5%. From the results, the PV module's(without bypass diode) maximum output power was reduced by hot-spot gradually. But the PV module's(with bypass diode) maximum output power had no reduction by operation of bypass diode, though solar cell is shadowed more than 60%. The solar cell temperature of PV module(without bypass diode) was $10^{\circ}C$ higher compared to module's one. This is a reason for shortening of durability of PV module.

• 한국태양에너지학회 논문집
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• 제28권5호
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• pp.36-48
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• 2008

This study examines the influence of control algorithms on dimming performance to determine appropriate control setting when direct/indirect lighting is controlled by a daylight dimming system. Computer simulation were performed for a small office with double skin envelope under various daylight conditions. A retractable fabric shading and Venetian blind were applied for internal and external envelopes under three CIE standard sky conditions. Unshielded and partially-shielded photosensors were used, and three control algorithms were applied for the sensors. In general, dimming level was too excessive due to the direct impact of light from lighting fixture to the photosensor. Providing insufficient lighting output, the unshielded photosensor completely failed to secure required illuminance under any daylight condition. When a partially-shielded photosensor was applied under clear sky, three setting points functioned effectively. Less sensitivity for the partially-shielded photosensor was effective to control the dimming system optimally with reasonable energy saving. However, the daylight dimming control system for direct/indirect lighting does not appear to be energy effective when photosensors without enough shielded area is installed on ceiling where light from fixtures reaches directly.

• 한국태양에너지학회 논문집
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• 제39권2호
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• pp.11-22
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• 2019

The first case of the Central Environmental Dispute Mediation Committee, which recently decided to repay the builder for damaging the solar power plant due to the obstruction of the sunshine of new buildings, came out. Even if the Respondent complies with the provisions of the Building Act, the decision of the Complainant can be considered to have been made in light of the fact that the applicant's power plant has suffered from sunlight damage. However, since the extent of the damage may differ depending on the weather, the decision is reserved, and there is room for additional disputes on a regular basis because the loss of power generation to be continuously generated is not reflected in the future. Therefore, in this study, we try to find the direction of dispute adjustment by summarizing the issues related to the generation of power generation due to the influence of shading through the analysis of the case of dispute related to sunlight related to the PV system.

• 한국BIM학회 논문집
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• 제11권2호
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• pp.54-59
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• 2021

In the process of designing a building, the process of expressing the designer's ideas through images is essential. However, it is expensive and time consuming for a designer to analyze every individual case image to generate a hypothetical design. This study aims to visualize the basic design draft sketch made by the designer as a real image using the Generative Adversarial Network (GAN) based on the continuously accumulated architectural case images. Through this, we proposed a method to build an automated visualization environment using artificial intelligence and to visualize the architectural idea conceived by the designer in the architectural planning stage faster and cheaper than in the past. This study was conducted using approximately 20,000 images. In our study, the GAN algorithm allowed us to represent primary materials and shades within 2 seconds, but lacked accuracy in material and shading representation. We plan to add image data in the future to address this in a follow-up study.

• Current Photovoltaic Research
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• 제10권4호
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• pp.133-137
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• 2022

The economic feasibility of a photovoltaic (PV) system is greatly influenced by the initial investment cost for system installation. Also, electricity generation by PV system is highly important. The profits competitiveness of PV system will be maximized through intelligent operation and maintenance (O&M). Here, we developed a microconverter which can maximize electricity generation from PV modules by tracking the maximum power point of PV modules, and help efficient O&M. Also, the microconverter mitigates current mismatch caused by shading, hence maximize power generation. The microconverters were installed PV modules and demonstrated through the field tests. Power outputs such as voltage, string current were measured with variuos weather environments and partial shadings. We found that PV modules with the microconvertors shows 12.05% higher power generation compared to the reference PV modules.

• 한국음향학회지
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• 제41권6호
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• pp.637-646
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• 2022

임의의 곡면 배열에서 단위 빔 형성에 사용되는 부배열은 조향 방위마다 기하학적 형상이 다르다. 이 때문에 조향 방위 별 부배열의 빔 패턴은 항상 균일하지 않다. 본 논문에서는 볼록 최적화를 이용한 빔 형성 기법을 곡면 배열에 적용하고, 조향 방위별 빔 성능의 균일성이 향상되는 것을 보였다. 시뮬레이션은 절단 구면 형상의 곡면 배열에 대해 수행되었다. 고각 3 dB 빔 폭의 표준 편차가 크게 감소하였으나 반대급부로 지향 지수도 감소하는 것을 관찰했다. 이를 완화시키기 위한 하나의 방법으로 쉐이딩 함수를 이용한 최적화 기법을 제안한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1591-1596
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• 1991

The present paper describes a method of recognizing a polyhedron employing the notion of network constraint analysis. Typical difficulties in three-dimensional object recognition, other than shading, reflection, and hidden line problems, include the case where appearances of an object vary according to observation points and the case where an object to be recognized is occluded by other objects placed in its front, resulting in incomplete information on the object shape. These difficulties can, however, be solved to a large extent, by taking account of certain local constraints defined on a polyhedral shape. The present paper assumes a model-based vision employing an appearance-oriented model of a polyhedron which is provided by placing it at the origin of a large sphere and observing it from various positions on the surface of the sphere. The model is actually represented by the sets of adjacent faces pairs of the polyhedron observed from those positions. Since the shape of a projected face gives constraint to that of its adjacent face, this results in a local constraint relation between these faces. Each projected face of an unknown polyhedron on an acquired image is examined its match with those faces in the model, producing network constraint relations between faces in the image and faces in the model. Taking adjacency of faces into consideration, these network constraint relations are analyzed. And if the analysis finally provides a solution telling existence of one to one match of the faces between the unknown polyhedron and the model, the unknown polyhedron is understood to be one of those memorized models placed in a certain posture. In the performed experiment, a polyhedron was observed from 320 regularly arranged points on a sphere to provide its appearance model and a polyhedron with arbitrarily postured, occluded, or imposed another difficulty was successfully recognized.