• KIEAE Journal
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• 제14권6호
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• pp.5-13
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• 2014

Various studies on lighting energy savings are conducted, given that lighting energy consumption accounts 23.5% of building energy consumption. Especially, external type light shelf's efficiency is acknowledged; however, its application is limited in Korea, where high rise building ratio is high, due to high wind pressure. This study delves into natural lighting system to cope with wind pressure, and proposes the punching plate-installed light shelf. This study actually draws lighting energy output, according to whether the punching plate is applied through the test-bed, and verifies the effectiveness of the punching plate-installed light shelf. The conclusion is presented below: First) The result of performance evaluation of light shelf with the punching plate in winter solstice showed that the awning area decreased as the opening ratio increased so that the indoor distributed illumination tended to increase, and $-40^{\circ}$ which was advantageous for awning was determined as the proper angle. Second) The light shelf with the punching plate in spring/autumn equinox shows improved lighting according to the angle, and the appropriate angle of light shelf with the punching plate has increased to $15^{\circ}$ and $20^{\circ}$ according to the opening ratio in comparison to $5^{\circ}C$ which is the appropriate angle of light shelf with no punching plate due to the reflection area reduced by the reflecting plate with holes. Third) The result of performance evaluation of light shelf with the punching plate in summer solstice showed that the lighting performance tended to decrease as the opening ratio increased. 4) The light shelf with the punching plate incurs a 50% energy loss in comparison to the light shelf with no punching plate. However, its effectiveness has been proven in the aspects that it can bring a 50% energy saving in comparison to the case with no installation of light shelf and that it can be designed in response to wind pressure on the high floors.

• Structural Monitoring and Maintenance
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• 제10권3호
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• pp.207-220
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• 2023

The safety of bridges are critical in our transportation infrastructure. Bridge design and analysis require complex structural analysis procedures to ensure their safety and stability. One common method is to calculate the maximum moment in the girders to determine the appropriate bridge section. Girder distribution factors (GDFs) provide a simpler approach for performing this analysis. A GDF is a ratio between the response of a single girder and the total response of all girders in the bridge. This paper explores the significance of GDFs in bridge analysis and design, including their importance in the evaluation of existing bridges. We utilized Bridge Weigh-in-motion (B-WIM) measurements of five simple supported girder bridge in Indonesia to develop a simple GDF provisions for the Indonesia's bridge design code. The B-WIM measurements enable us to know each girder strain as a response due to vehicle loading as the vehicle passes the bridge. The calculated GDF obtained from the B-WIM measurements were compared with the code-specified GDF and the American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) bridge design specification. Our study found that the code specified GDF was adequate or conservative compared to the GDF obtained from the B-WIM measurements. The proposed GDF equation correlates well with the AASHTO LRFD bridge design specification. Developing appropriate provisions for GDFs in Indonesian bridge design codes can provides a practical solution for designing girder bridges in Indonesia, ensuring safety while allowing for easier calculations and assessments based on B-WIM measurements.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.82-86
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• 2004

To cope with the challenge from global market characterized by frequent changes in requirements, manufacturing enterprise should be able to promptly adjust its manufacturing system accordingly. Therefore, it is important to provide manufacturing system designer with an appropriate methodology to (re-)design a manufacturing system subject to requirements change. Axiomatic design theory focuses design activity mainly on functional consideration rather than physical, and has been known as effective especially in the conceptual design phase. This paper introduces an approach to apply the axiomatic design principle to manufacturing system design. It is shown that a new design solution can be reached quickly by finding design parameters for the added or revised functional requirements and thus achieving a set of functional requirements as well as design parameters that satisfy the independence axiom. Some illustrative examples are also given.

• 한국산학기술학회논문지
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• 제18권12호
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• pp.685-696
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• 2017

성당의 공간이미지를 조성함에 있어, 시각을 통해 심성을 변화시키는 가장 중요한 요인은 빛이라고 할 수 있다. 그리고 공간의 깊이는 빛에 의한 음영에 의해 만들어진다. 미사와 같은 종교적 행사가 행해지는 장소에 있어서 음영에 의한 깊이의 변화와 위계설정은 집중도와 신비로움 또는 성스러움의 분위기를 확보하는 데에 중요한 계획조건이 된다고 할 수 있다. 따라서 빛이 가진 종교적 의미와 인간 감성에 미치는 영향은 매우 크다고 할 수 있으며, 이에 본 연구에서는 성당의 예배공간 조명계획에 대한 요소 중 '조도'를 그 중요요소로 보았다. 조도는 시각적 환경조성에서 미묘한 공간구성상의 차이를 통해 대상과 공간의 형태, 명료함을 부여함으로써 표현된다. 조명을 통해 공간분위기를 적정한 수준에서 관리하게 되고, 공간의 존재를 확인함에 조도의 역할은 필수적이라고 할 수 있을 것이다. 이에 따라, 관련 기준을 종합 분석하여 조도의 기준과 범위를 설정하고, 현대적인 디자인 적용이 시작되었다고 할 수 있는 80년대 이후 서울 강남지역에 건립된 성당들을 대상으로 조도와 관련된 요소들을 분석하고 각 성당의 전례공간과 회중석의 조도를 측정하여 이를 비교분석함으로써 적정수준의 적용여부를 검토확인하고 이를 추후 계획지침으로 활용하도록 제안하고자 하였다.

• 교육녹색환경연구
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• 제22권1호
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• pp.13-27
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• 2023

본 연구는 학교공사의 공사기간을 산정할 때 공사 목적물의 품질 및 공사의 안전성과 경제성을 확보하며 공사의 규모와 학사의 일정, 지역여건(민원발생) 등을 고려한 해당 지역 또는 교육청에 최적화된 공사유형별 적정 공사기간 산정을 위해 A교육청의 학교시설 환경개선 공사사례를 바탕으로 공사기간 연장 사유 등의 사례를 분석하였다. 공사기간 사례 분석을 위해 A교육청 관할의 학교공사 분석 기상자료개방포털 자료 분석, 2단계 통계분석을 종합적으로 검토하여 학교시설 적정공사기간을 산정하는 것으로 설정하였다. 향후 학교시설 적정공사기간 산정을 다양한 사례 분석을 통해 합리적이고 체계적인 방법으로 산정하여 공사기간을 설정하는 것이 필요하다.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2001년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2001
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• pp.276-283
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• 2001

Performance-based design concepts require the next generation of codes. To implement the main concepts several design methodologies have been proposed. This paper reviews the framework of Korea Seismic Code and shows necessary modification for adoption of appropriate design methods. The selection of design earthquake levels with the introduction of risk factor is discussed for proper risk levels for all earthquake hazards. Displacement-based design, energy-based design, comprehensive design, and force-strength design methods are reviewed as one of possible next generation design methods. This paper proposes the direction of reconstruction for design earthquake levels with performance matrix, introduction of new design methods, and emphasis on non- structural components.

• 한국CDE학회논문집
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• 제14권2호
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• pp.105-114
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• 2009

A design needs various experience and design knowledge through a whole design process. Despite of all efforts and time, it is not easy to introduce a product that meets all customer's needs and expectation in time. To achieve the product goal, designers need a set of sequential process to find appropriate design parameters and ensure customers' needs and requirements. In this research we propose a design methodology for the initial design of an excavator front group with existing QFD(Quality Function Deployment) and Axiomatic Design to satisfy customer's requirements. It turns out that the proposed methodology can support designers more effectively, objectively, and systematically.

• KIEAE Journal
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• 제17권3호
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• pp.83-90
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• 2017

Purpose: With the increase in the energy consumption in the building sector, many studies have recently been conducted to address this issue. Due to its efficiency, diverse studies on a light-shelf, which is a natural lighting system, are in progress. However, there has been no research on the external illumination that determines the performance of a light-shelf. Therefore, the present study aimed to prepare the external illumination standard for securing the lighting performance of a light-shelf through the light-shelf performance evaluation based on a 1:1 scale testbed, and to suggest a height-adjustable light-shelf based on an open and closed concept for the case in which the lighting performance of the light-shelf significantly deteriorates, by collecting the external illumination. Method: In this study, a 1:1 scale testbed was established for performance evaluation, and the external illumination standard for securing the performance of the light-shelf was prepared by comparing the lighting performance of the light-shelf depending on the open and closed condition of the light-shelf and the external illumination. Result: 1) In this study, a light-shelf that can be opened or closed depending on the external illumination was suggested. As a result, the prospect right can be secured by creating the condition where there is no light-shelf installation by moving the light-shelf to the top of the window when the lighting performance is not secured. 2) In the summer solstice, the external illuminations appropriate for lighting energy reduction were more than 75,000 lx and 60,000 lx for the light-shelf width of 0.3 m and 0.6 m, respectively. 3) In the intermediate period, the external illumination appropriate for lighting energy reduction was 60,000 lx. In the winter solstice, making the condition where there is no light-shelf installation by closing the light-shelf would be appropriate. 4) Based on the aforementioned results, the external illumination standard for the opening and closing of the height-adjustable light-shelf based on an open and closed concept suggested in this study was 60,000 lx, and the light-shelf with a width of 0.6 m would be advantageous for lighting energy reduction.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.936-938
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• 2011

This paper suggests the slot wedge shape for reducing the cogging torque of a gearless type direct-drive permanent magnet synchronous generator with open slot shape. To achieve this, we are designed the appropriate specifications of the permanent magnet synchronous generator by selected the appropriate material of slot wedge and various slot wedge shapes. The PMSG models were analyzed by finite element method. Finally, we have suggested appropriate material of slot wedges and its shape which has benefit to further reducing cogging torque and preventing decreasing of the generating power.

• Journal of the Korean Data and Information Science Society
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• 제14권3호
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• pp.545-551
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• 2003

Robust design is to identify appropriate settings of control factors that make the system's performance robust to changes in the noise factors that represent the source of variation. In this paper we propose how to simultaneously optimize multiple quality characteristics using the principal component analysis of multivariate statistical analysis. An example is illustrated to compare it with already proposed method.