• KIEAE Journal
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• v.13 no.1
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• pp.133-140
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• 2013

The purpose of this study was to test the effectiveness of the light-shelf system combined with IT to save lighting energy in resident space. According to the multiple variables that affected intensity of illumination, various experiments were designed and conducted. The main findings of this study were following: (1)the optimal level of light-shelf system was formulated which met the appropriate range of intensity of illumination in living-room; (2)although the mixed light-shelf system indicated a high performance, it could often provide discomforts to residents according to the degree of exposure; (3)artificial lights using light-shelf system combined with IT showed a higher effectiveness than those using fixed light-shelf system displayed. This study provided initial information of light-shelf system formative processes that could contribute to the lighting energy diminution. Future studies should focus more on multiple approaches regarding different types of resident space planning.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.4
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• pp.181-192
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• 2014

Light-shelf is one of the most efficient natural lighting systems due to the improved function of the inflow level of the outdoor natural light. However, the existing research on the light shelf limits to the rectangular parallelepiped space, so do not provide sufficient data for various shapes of spaces. Thus, this study aims at deriving proper plan and relationship of the light shelf through its performance assessment depending on the indoor space shapes and utilizing them as basic data of light shelf design. The conclusions are as follows : 1) for 6m space depth, standard intensity of illumination satisfaction depth has shown 8.3%~26.3% improvement through the adjustment of the angle and width when installing light shelf compared to no light shelf installation; 2) $-30^{\circ}$, $-20^{\circ}$ and $-10^{\circ}$ light shelves set by this study play only as a blind regardless of the shape of ceiling on the summer solstice, and it is unsuitable; and 3) this study has derived proper plan of light shelf upon space shapes based on energy reduction and indoor evenness. The study results provide expanded data of the performance assessment of the light shelves according to the different space shapes and light shelf factors, which serves as a basis of the light shelves designing.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.1
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• pp.141-150
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• 2014

Due to their accessibility and 24-hr availability, convenience stores are an integral part of daily lives. Because they sell a limited number of products and have small shelf space, shelf space allocation and inventory replenishment are important considerations for inventory management that critically affect profit. In this paper, we propose five solutions for the vendor-managed inventory problem of convenience stores that maximize profit while considering stock-out-based product substitutions. The performance of the proposed solutions is evaluated via simulation to reflect the demand uncertainty and marketing activity.

• Journal of the Korea Furniture Society
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• v.28 no.2
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• pp.95-102
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• 2017

In the process of changing from modern society to contemporary society, innovation of various fields is considered as important with rapid social change and one of the consequences of this changing movement is the innovation of living space. In this paper, based on this motive, we will study a modular shelf that can create a private space, and serve function like role of partition that delimits space in the one-room. Modular shelves can provide openness, closeness, and autonomy to individual spaces in a one-room space without space divisions. In a small one-room for residential purpose, it is able to function effectively to show the atmosphere of personal space and display small items reflecting personal taste in addition to the function of storing books and items. In addition, a modular shelves considering disassembly and movement are proposed in order to take advantage of one-room that can make different space configurations as needed. It is aim to suggest a basic modular shelves structure that used traditional Chinese wood-joints during which techniques was sturdy while reducing the use of timber. Futhermore, the purpose of this study is to study the design of shelf furniture that can add individuality.

• Korean Institute of Interior Design Journal
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• v.17 no.3
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• pp.51-58
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• 2008

Lately, in public libraries, there are various service programs for child user by corresponding to importance of reading based education and also a variety of changes by accommodating family based cultural life style. Therefore there is a need for space planning based study on unit-data room. This study gives guide-line of space planning through categorizing of space plot and furniture lay-out in child data room. The researcher, as a first step, searched web sites of 29 data rooms of 26 libraries and summarized space plots and features of data rooms through in-person visits. Then the author made a categorization standard and did a general analysis of featured data rooms through multiple categorization steps. There are Basic Type, General Type, Book-Shelf Centered Type, Book-shelf Scattered type and Multi-Functional Type out of this categorization steps. In sum, six categorizing bases, dividing infant room from child room, space zonning, position of entrance, compactness of reading space, position of book-shelf and orientation of book-shelf will be important design standards for child data-room of future libraries and an effective guide-lines for other unit data-rooms.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.9
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• pp.424-433
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• 2014

The purpose of this study is to evaluate the effectiveness in the lighting performance of mixed type light-shelf, by comparing and analyzing the internal light-shelf, external light-shelf, and mixed-type light-shelf. The performance of light-shelf was evaluated according to the angle of light-shelf at summer solstice, winter solstice, vernal equinox, and autumn equinox. The comparative analysis between the internal light-shelf, external light-shelf, and mixed-type light-shelf was carried out using the performance evaluation and analysis method. The result of performance evaluation is shown as follows. The mixed type light-shelf showed the highest lighting performance all at summer solstice, winter solstice, vernal equinox, and autumn equinox, followed by the external light-shelf and the internal light-shelf in the same order. The mixed type light-shelf was the most favorable for bringing daylight to indoors by adjusting the angle of light-shelf, and it also showed the highest lighting performance in terms of uniformity ratio of illumination which indicates the quality of light.

• Journal of applied mathematics & informatics
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• v.20 no.1_2
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• pp.327-343
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• 2006

A general methodology is suggested to solve shelf-space allocation problem of retailers. A multi-item inventory model of breakable items is developed, where items are either complementary or substitute. Demands of the items depend on the amount of stock on the showroom and unit price of the respective items. Also demand of one item decreases (increases) due to the presence of others in case of substitute (complementary) product. For such a model, a Contractive Mapping Genetic Algorithm (CMGA) has been developed and implemented to find the values of different decision variables. These are evaluated to have maximum possible profit out of the proposed system. The system has been illustrated numerically and results for some particular cases are derived. The results are compared with some other heuristic approaches- Simulated Annealing (SA), simple Genetic Algorithm (GA) and Greedy Search Approach (GSA) developed for the present model.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.6
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• pp.275-286
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• 2014

Light shelf is an efficient system that reduces the energy consumption by bringing the natural light down to the deep spaces inside of a building. However, the existing light shelves have limits in reducing energy usage, because the direction of the light flow is determined by the external environment such as the altitude of the sun and the azimuth. This current study presents a system that increases the efficiency of the light shelf by applying the Location-Awareness technology, in which the efficiency was verified through the performance evaluation. According to the examination of the technology for the Location-Awareness within residential space, 'Zigbee' type appears to be the most appropriate. The Location-Awareness technology operates the light shelf based on both the angle control axis and the light shelf angle control axis through the modularization of the reflector surface which is less affected by the external environment. The results of the performance evaluation showed that the movable light shelf that employs the Location-Awareness technology can reduce the energy consumption for lighting by 98.3% compared to the fixed light shelf and by 97.3% compared to the movable light shelf without Location-Awareness.

• KIEAE Journal
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• v.15 no.3
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• pp.49-56
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• 2015

Purpose: Due to recent increase on energy consumption for light in building, many studies to mitigate this issue have been conducted. Various researches have been carried out to suggest light shelf as one of the solutions, but researches for its reflectivity is very few. In fact, existing research on light shelf shows that utilizing more than 90% of high-illumination materials causes imbalance of glare and illuminance. Method: Therefore this research aimed to evaluate the performance of light shelves depending on reflectivity and to identify proper solution through test-bed. Result: The results are following: 1) Increased reflectivity generally contributed to increase of indoor illuminance but degrade uniformity factor related with indoor comfort of light environment. 2) The $0^{\circ}fixed$ light shelf with 75% of reflectivity and width of 300mm and 40mm appeared to consume more energy than other shelves. Therefore, it is analyzed as unsuitable. 3) This research was conducted by calculating appropriate angle of light shelf around winter and summer solstices and vernal/autumnal equinox. Based on this, performance evaluation was undertaken depending on reflectivity of movable light shelf, which is activated by external sources and can be applied with lower reflectivity than fixed shelf. However, one exception was a movable shelf with width of 600mm that increased light energy consumption when 75% of reflectivity was applied. 4) Performance evaluation of fixed and movable light shelf showed that the shelf with 80% of reflectivity came up with suitable results, but 75% of reflectivity may be applied depending on the width and angle of the shelf. This research is meaningful in that estimation of appropriate reflectivity of light shelf can resolve the glare problem and improve light environment, and further research would be desirable under more diverse conditions to identify proper solution.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.8
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• pp.395-401
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• 2015

Recently, many research studies have been carried out on the efficiency of light-shelf daylighting systems, especially comparing performance improvements and the limitations of reflective surfaces and their lighting performance. In this study, a crystal face reflective surface is proposed. The objective of the study is to evaluate the lighting performance of a crystal face light-shelf through a performance study. The performance study was carried out in a full scale test-bed in order to calculate the light distribution and energy consumption utilizing the standard indoor illumination as an index. The conclusions of the performance study are as follows. 1) The optimal angle of incidence for daylighting for both the operable flat type light-shelf and the crystal face light-shelf are taken in the natural environment on the dates of the winter and summer solstices, as well as the autumn and spring equinoxes. 2) The application and installation of the crystal face light-shelf can produce a 29.9%~34.3% increase of light distribution within the indoor space. However, the increase of light distribution can also lead to a decrease in the uniformity ratio, a design challenge that should be considered when applying a crystal face light-shelf. 3) It is possible to achieve a 7.98%~13.3% greater reduction in energy consumption when applying a crystal face light-shelf than when applying a flat type light-shelf. The increase in the number of crystal faces should concur with the analysis of the energy reduction. A limitation of the study is that only one predetermined pattern was performance tested for a crystal face light-shelf. In order to carry out further research on crystal face light-shelves, additional performance studies are needed based on alternative patterns and designs.