• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.6
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• pp.70-76
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• 2016

Commercialization of surface lighting using Light Emitting Diodes (LED) has embraced the advance to Organic Light Emitting Diode (OLED) technology. This is necessary to achieve light-efficiency-improvement and longer component life. The range of application of LED lighting for both interior and outdoor lights has been gradually expanding. Automobiles and home appliances are now included. In the case of LED surface lighting in a domestic refrigerator, achieving high efficiency requires optimization of the number of LEDs in a pack. Optimization is also required in the design stage of development with regard to the conversion of the light source type from point light sources to the surface light type. This paper addresses these design problems. It presents a study of brightness variations for design solutions that differ from the existing technology in both the number of LED packages and use of Light Gathering Power (LGP) information. The intention is to facilitate production of high brightness LED surface lighting for domestic refrigerators.

• Korean Journal of Computational Design and Engineering
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• v.9 no.1
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• pp.35-43
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• 2004

It is well known that the five-axis machining has advantages of tool accessibility and machined surface quality when compared with conventional three-axis machining. Traditional researches on the five-axis tool-path generation have addressed interferences such as cutter gouging, collision, machine kinematics and optimization of a CL(cutter location) or a cutter position. In the paper it is presented that optimal CL data for a face-milling cutter moving on a tool-path are obtained by incorporating TSS(tool swept surface) model. The TSS model from current CL position to the next CL position is constructed based on machine kinematics as well as cutter geometry, with which the deviation from the design surface can be computed. Then the next CC(cutter-contact) point should be adjusted such that the deviation conforms to given machining tolerance value. The proposed algorithm was implemented and applied to a marine propeller machining, which proved effective from a quantitative point of view. In addition, the algorithm using the TSS can also be applied to avoid cutter convex interferences in general three-axis NC machining.

• Journal of the Korea Furniture Society
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• v.22 no.2
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• pp.83-90
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• 2011

In the radically changing market situation, surface materials of student furniture are a very important element to decide the consumption pattern and the market price. Thus, this study examined the characteristics of surface materials by classifying the student furniture into children's, juniors', and seniors' furniture while accessing the features of such surface materials through Glulam, veneer, poly paper, finishing foil, high pressure melamine (HPM), and low pressure melamine (LPM), and PVC vinyl. When taking a look at the surface materials that were most frequently produced in each domestic furniture company, the combined materials that used more than 2 elements (31.88%), LPM (23.19%), and Glulam (20.29%) were introduced at the market in the order. Regarding the analysis made on colors, the combination colors took more than half (55.32%) followed by brown (13.83%) and beige (11.7%) in the order. Based on the results derived from the analysis, the study suggests to stress more importance to surface materials when developing student furniture and to exert efforts for the consistent development of new materials and quality improvement, as a way to accelerate the development of the furniture industry in Korea.

• 한국금형공학회:학술대회논문집
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• 2008.06a
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• pp.135-139
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• 2008

Development of surface heating technology using hot jet impingement onto mold inner surface for improvement of pattern transcription. This study is focused on how to control the parameters related to hot jet impingement. The mass flow rate, the jet temperature and the duration of the impingement are major parameters. The nozzle design and other geometric configurations also affect the heat transfer to the surface. In terms of heat transfer analysis, the most important number is the heat transfer coefficient, which is influenced by the mass flow rate, nozzle design, distance between the nozzle tip and the surface. In summary, several parametric studies using the developed model are conducted to investigate the effects of mass flow rate, jet temperature and Heating Time in Surface heating technology using hot jet impingement onto mold.

• Korean Journal of Computational Design and Engineering
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• v.11 no.4
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• pp.246-255
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• 2006

Ribs and fans are interesting geometric entities that are derived from an ordinary $B\'{e}zier$ curve or surface. A rib itself is a $B\'{e}zier$ curve or surface with a lower degree than the given curve or surface. A fan is a vector field whose degree is also lower than its origin. First, we present methods to transform the control points of a $B\'{e}zier$ curve or surface into the control points and vectors of its ribs and fans. Then, we show that a $B\'{e}zier$ curve of degree n is decomposed into a rib of degree (n-1), a fan of degree (n-2), and a scalar function of degree 2. We also show that a $B\'{e}zier$ surface of degree (m, n) is decomposed into a rib of degree (m-1, n-1) and three fans of degrees (m-1, n-2), (m-2, n-1), and (m-2, n-2), respectively. In addition, the lengths of the fans are further controlled by scalar functions of degree 2 and (2, 2). We present relevant notations and definitions, introduce theories, and present some of design examples.

• Korean Institute of Interior Design Journal
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• v.15 no.3 s.56
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• pp.75-82
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• 2006

Discussions on transparency have been being analyzed as variedly as the diversity itself in contemporary architecture. Though it is inappropriate to summarize the discussions into several specific viewpoints, as the notional classifications on transparency are varied according to the points of individual researchers, it can be said that, by approaching with the standpoint of the designers who may have various difficulties in the course of design, the meaning of this thesis lies largely in the fact that it attempted to study the architectural application techniques of transparency notion both through surface aspect which could be said to decide on the appearance of the architecture shape and through, in physical aspects as a combination of space components comprising the inner space, spatial aspect to which architectural techniques of transparency notion are applied. Through these, we conclude as follows. 1. Representation Techniques of Transparency in Surface : Transparency from surface viewpoint could be categorized into 1) emphasis on property-of-matter, 2) lightness of Literal material itself, 3) visual ambivalence, and 4) dematerialized hyper-surface. 2. Representation Techniques of Transparency in Space : In spatial viewpoint, transparency is summarized into sub-viewpoints as 1) straightforward space 2) ambiguous spacer 3) expanded space

• Microbiology and Biotechnology Letters
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• v.48 no.1
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• pp.48-56
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• 2020

This study aimed to optimize the culture conditions to improve the crude biosurfactant activity of Bacillus pumilus IJ-1, using a 3³ full-factorial design of response surface methodology (RSM). It was found that submerged fermentation of B. pumilus improved the activity of the crude biosurfactant. The factors selected for optimization were NaCl concentration, temperature, and tryptone concentration. Response surface analysis revealed that the fitted quadratic model was statistically significant and produced an adequate R² value (0.9898) and a low probability value (<0.0001). The optimum level for each factor was found to be 0.567% (w/v) NaCl, 21.851℃ and 0.765% (w/v) tryptone, respectively. Crude biosurfactant activity was found to be most affected by tryptone concentration; then temperature, and finally NaCl concentration. Our results may potentially facilitate large-scale biosurfactant production from B. pumilus IJ-1.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.7 s.250
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• pp.700-706
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• 2006

This study presents a numerical procedure to optimize the shape of dimple surface to enhance turbulent heat transfer in a rectangular channel. The response surface based optimization method is used as an optimization technique with Reynolds-averaged Wavier-Stokes analysis of fluid flow and heat transfer with shear stress transport (SST) turbulence model. The dimple depth-to-dimple print diameter ratio, channel height-to-dimple print diameter ratio, and dimple print diameter-to-pitch ratio are chosen as design variables. The objective function is defined as a linear combination of heat transfer related term and friction loss related term with a weighting factor. full factorial method is used to determine the training points as a mean of design of experiment. The optimum shape shows remarkable performance in comparison with a reference shape.

• Journal of The Korean Digital Architecture Interior Association
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• v.8 no.2
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• pp.39-46
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• 2008

Current architecture can receive support of and command various ways of expression by more advanced technology of the present time, this means the formation of changeable external design of building, and has the tendency to be interactive non-rheological shape. Accordingly surface of building is decorated not only by the basic function and the expression of information, but also by complex narrative image structure or text, so far as recognizes human as the subject of communication, and is trying the artistic expression interacting with the general public. In various expressive tendency of current architecture surface design, such an approach from a view of an interactive art trying the communication between architecture, art, and human has the meaning of suggesting the direction of directing emotional architecture giving a present to the morderners who are growing more and more an earnest desire for experiencing culture and art in their daily life.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.1-4
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• 2002

The present study aims to design a multiplayer microstrip antenna with composite sandwich construction and to estimate structural behavior of this multiplayer structure for the next generation of structural surface technology. This is termed Surface-Antenna-Structure indicating that structural surface becomes antenna. Constituent materials were selected considering electrical properties as well as mechanical properties. For the antenna performance, antenna elements inserted into structural layers were designed for satellite communication at a resonant frequency of 12.5 GHz and final demonstration article was $16\times16$ array antenna. From electrical measurements it was shown that antenna performances were in good agreement with design requirements. Structural analysis showed this antenna structure was well designed for the mechanical rigidity. All constituent materials were characterized independently. The SAS concept is the first serious attempt at integration for both antenna and composite engineers and promises innovative future communication technology.