• KIEE International Transactions on Electrophysics and Applications
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• v.2C no.6
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• pp.309-313
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• 2002

In this paper, we have studied minimization of the kerf-width and surface burning, which occurred after the conventional singulation process of the multi-layer BGA board with copper, polyethylene and epoxy glass fiber. The high thermal energy of a pulsed Nd:YAG laser is used to cut the multi-layer board. The most considerable matter in the laser cutting of the multi-layer BGA boards is their different absorption coefficient to the laser beam and their different heat conductivity. The cut mechanism of a multi-layer BGA board using a 2$^{nd}$ harmonic Nd:YAG laser is the thermal vaporization by high temperature rise based on the Gaussian profile and copper melting point. In this experiment, we found that the sacrifice layer and Na blowing are effective in minimizing the surface burning by the reaction between oxygen in the air and the laser beam. In addition, N2 blowing reduces laser energy loss by debris and suppresses surface oxidation. Also, the beam incidence on the epoxy layer compared to polyimide was much more suitable to reduce damage to polyimide with copper wire for the multi layer BGA singulation. When the polyester double-sided tape is used as a sacrifice layer, surface carbonization becomes less. The SEM, non-contact 3D inspector and high-resolution microscope are used to measure cut line-width and surface morphology.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.10
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• pp.101-108
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• 2001

In this study, the static and dynamic characteristics of endmilling process were modelled and the analytic realization of chatter mechanism was discussed. In this reward, We have discussed on the comparative assessment of recursive time series modeling algorithms that cal represent time machining process and detect the abnormal machining behaviors in precision endmilling operation. In this study, simulation and experimental works were performed to show the malfunctional behaviors. For this purpose, new recursive algorithm(RLSM) was adopted for the oil-line system identification and monitoring of a machining process, we can apply these new algorithms in real process for detection of abnormal chatter. Also, The stability lobe of chatter was analysed by varying parameter of cutting dynamics in regenerative chatter mechanics.

• Journal of Fashion Business
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• v.18 no.2
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• pp.14-28
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• 2014

This study analyzed the group of experts who were related to cubism, selected among the works of 2010~2013 Paris Collection based on F.G.R.(Focus Group Research). According to the results of this study, there were appeared first, 'a one-piece dress' second, 'H silhouette' third, 'cotton', in case of item distribution and frequency. The analysis was done by using the manner of expression, cubical expression, exaggeration, distortion, dismantlement, geometrical division of face, mix-match look, wraparound repetition, asymmetric structure, etc. Based on the outcomes of the analysis on figurative design elements, this study adjusted three manners appearing on cubism fashion style. First, it was 'avant garde manner' of constitution or 'dismantlement' which was compiled into multi-view representations of overlaps and viewpoints by repetitive use of color tone trimming detail. Second, it was 'geomagnetic block placement' which expresses cubism with geometric partitioning of surface and separation of panel by cutting disintegration. Finally, it was 'distortion and simplification of silhouette' which is a distortion created by constitution-line pressed thin with silhouette. It maximizes the beauty of human body outline, which was distorted by three-dimensional-manipulation, and simplified by ellipsis for another shape for the extension or expansion of detail trimming.

• Journal of Fashion Business
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• v.12 no.6
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• pp.81-92
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• 2008

The purpose of this study is to develop the applied brassiere pattern of women which are fitting for 75A. The constructing of this experimental brassiere were lower cup, upper cup, front panel and U-wing as well as a full cup embcing the entire breasts. Basing on the bra model from domestic experiment results, development of an applied design, round side type pattern, has been suggested. Thus, suggesting the round variation design bra, which is an applied design based on the basic model based on the breast volume. Based on the sizes that are in reference to Size Korea (2004) and related previous researches, the basic model that has been experimented with 11.4% polyurethane and 88.6% Nylon as the materials, has been selected as the model of research. This takes 75A, the size of which is set according to the underbust circumference and the breasts circumference, as the basic model. It is an application in terms of design, and there is no change to the cup volume or size because it has been moved only from the cutting line. The applied design changes the right side of the lower cup into an easily-movable form and attaches it to the upper cup, and the lower cup takes the right part of the upper cup to form a cup shape of round variation design. It also changes basic straight form of the wings, and alters them into U-shape.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2000.04a
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• pp.94-99
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• 2000

Bioluminescence is being used as a prevailing reporter of gene expression in microorganisms and mammalian cells. Bacterial bioluminescence draws special attention from environmental biotechnologists since it has many advantageous characteristics, such as no requirement of extra substractes, highly sensitive, and on-line measurability. Using bacterial bioluminescence as a reporter of toxicity has replaced the classical toxicity monitoring technology of using fish or daphnia with a cutting-edge technology. Fusion of bacterial stress promoters, which control the transcription of stress genes corresponding to heat-shock, DNA-, or oxidative-damaging stress, to the bacterial lux operon has resulted in the development of novel toxicity biosensors with a short measurement time, enhanced sensitivity, and ease and convenient usage. Therefore, these recombinant bioluminescent bacteria are expected to induce bacterial bioluminescence when the cells are exposed to stressful conditions, including toxic chemicals. We have used these recombinant bioluminescent bacteria in order to develop toxicity biosensors in a continuous, portable, or in-situ measurement from for air, water, and soil environments. All the data obtained from these toxicity biosensors for these environments were found to be repeatable and reproducible, and the minimum detection level of toxicity was found to be ppb (part per billion) levels for specific chemicals.

• The Research Journal of the Costume Culture
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• v.8 no.1
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• pp.53-64
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• 2000

The purpose of this study is to help efficient use of marking system and more competitive products manufacture through the actual investigation into manufacturing process of apparel products. For lack of the previous study on marking, fundamental survey was performed on systematic research for pattern marking in ready-made production line Data were collected from 36 companies using Apparel CAD/CAM through questionnaire and interview. The data were analyzed by using Frequency and Crosstabs utilizing SPSS. The results were as follows : 1. Marking situation in clothing companies were examined ; 24 companies(66.7%) use computer marking, and 12 companies(33.3%) have both computer marking and hand marking. Besides only 9 companies out of 36(25.0%) have CAM in cutting process. 2. The efficiency in marking methods was also studied and the expense-saved ways were presented. we have found there is no difference in a way of the textural efficiency but the working methods of hand marking and computer marking. 3. Merits and demerits in marking methods were investigated. In case of marking two men's wear (Jacket and Pants), it takes 38 minutes by hand whereas it takes 15 minutes by computer ; for two women's wear (Jacket and Skirt) 49 minutes by hand, and 16 minutes by computer. 4. Most of the markers have less than 5 years experiences and among them most women are less experienced. They are in the mid-twenties after college graduations.

• Journal of the Korean Home Economics Association
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• v.41 no.6
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• pp.157-166
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• 2003

The purpose of this study was to provide information on how to improve the current design of infant coveralls through analysis of the design preferences of Korean consumer. In order to compile the information about preferences with the detail design of infant coveralls, a questionnaire was administered to mothers of 241 infants (aged under 36 months) living in Seoul, and analyzed using the SPSS WIN.10.0 program. The results of this study were as follows : 1) Results of buying conditions and design preference of infant coverall : To the question asking what kind of materials they preferred according to the season as material for infant coverall, the respondents preferred cotton hit as the materials for summer, but padding material for winter. The most favored design type were a flat collar, regular bodice type without cutting line, a raglan sleeves, snap front fastener, elastic band cuffs. 2) There is significant difference in preferred material and design among the month of age groups. 3) Analysis of the differences in preferred material and detail design according to gender In preferred material, it seemed as if girl baby group prefer cotton knit material, while boy baby group prefer padding material. There is definite difference in preferred neckline type, girl baby group prefer flat collar, while boy baby group prefer stand collar.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.6
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• pp.453-459
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• 2015

In this paper, we propose a new digit recognition method based on opened enclosure. In the proposed method, each digit is divided into two parts, an upper part and a lower part, which are based on a cutting line that is modified depending on the number of intersection points. In the simulation, the performance evaluation through the data acquisition and application of the proposed algorithm was carried out and the result was presented.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5843-5849
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• 2015

This study analyzes the factor demand structure of sweet persimmon as a part of finding out cost cutting measures. Income and cost data from 2001~2013 Agricultural Income Survey are used for placing the translog cost function and estimating price elasticies and cross elasticities of labor, capital and intermediate input. The result shows that own price elasticities of all factors are small in absolute terms. Additionally the result indicates capital and intermediate input cannot be a substitution for labor, which is a top-line cost-share. It means that the demand for labor cconstitutionally can't be reduced in a short time. This implies that cost reduction should be done focusing on intermediate input, particularly on fertilizer and materials which have higher price elasticity of demand.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.5
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• pp.38-45
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• 2004

As optical communication is being substituted for telecommunication, the demand of a large variety of fiber optic components is increasing. V-groove substrates, one of the module components, are used to connect optical fibers to optical planar circuits and to arrange fibers. Their applications are multi-channel optical connectors and optical waveguide fiber coupling, etc. Because these substrates are a critical part of the splitter in a multiplexer and a multi fiber connector, precise and reliable fabrication process is required. For precisely aligning core pitch between fibers, machined core pitch tolerance should be within sub-microns. Therefore, these are generally produced by state-of-the-art micro-fabrication like MEMS. However, most of the process equipment is very expensive. It is also difficult to change the process line for custom designs to meet specific requirements using various materials. For various design specifications such as different values of the V angle and low-priced process, the fabrication method should be flexible and low cost. To achieve this goal, we have suggested a miniaturized machine tool with high accuracy positioning system. Through this study, it is shown that this cutting process can be applied to produce V-groove subtracts. We also show the possibility of using a miniaturized machining system for producing small parts.