• Journal of the Semiconductor & Display Technology
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• v.23 no.2
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• pp.50-54
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• 2024

In this paper, we propose a theoretical method to systematically analyze the power conversion efficiency of a single-phase PFC switching rectifier. Boost-type PFC was organized in order of highest correlation with load current using steady-state analysis results and introduced the concept of loss factor. The loss factors for each major element are summarized and presented in a table. This paper makes it easier to understand the internal loss and power conversion efficiency of the rectifier for loss factors. Lastly, to confirm the validity of the efficiency analysis results reflecting the loss factors, loss and efficiency analysis of the 2.5kW PFC rectifier was performed. The results were compared with data from a 2.5kW PFC circuit for evaluation. As a result, the usefulness of power conversion efficiency analysis reflecting the loss factors proposed in this paper was confirmed.

• Transportation Technology and Policy
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• v.7 no.2
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• pp.31-38
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• 2010

• Journal of the Korean Mathematical Society
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• v.27 no.2
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• pp.239-244
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• 1990

• Proceedings of the Korean Nuclear Society Conference
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• 2003.10a
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• pp.227.1-227.1
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• 2003

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.381-384
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• 1987

• The Research Journal of the Costume Culture
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• v.23 no.4
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• pp.661-672
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• 2015

In this study, nine scarf designs expected to be effective for accent design for the fashion style of new senior women were suggested by reflecting purchase behavior and scarf preference after conducting surveys and an analysis by targeting 136 new senior women in order to propose scarf design-matching with the preferences of new seniors. As a result of the study on the scarf purchase features of new seniors, it was revealed that the purchase time for scarves was mainly autumn and winter, even though it is regardless of season, and in spring and summer, they seldom purchased scarves. The purchase frequency was four times a year, and what they first thought of at the time of purchase was represented in the order of color, design, and the material of the scarf. They most preferred department stores, mixed and achromatic colors, cotton and silk fabrics, natural and geometric patterns, and long scarves of a rectangular shape. In the case of the consumer attributes of scarves, it was revealed that $50^{th}$ desired more individuality-oriented, unique scarf designs than $60^{th}$, and $60^{th}$ desired scarf designs with convenient management considering others' attention compared with $50^{th}$. As concepts for scarf designs, the aspects of individuality, co-existence, and maturity were extracted by reflecting the features of new senior women, and a total of nine scarf designs were suggested by developing three sub-designs for each concept.

• The Research Journal of the Costume Culture
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• v.23 no.4
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• pp.569-580
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• 2015

The recent fashion market failed to satisfy the needs of female customers in their 30s who are demanding a slim jacket that makes the wearer look young and slim. Accordingly, the slim-fit jackets of domestic brands targeting the women in their 30s were collected to conduct look and movement fitting evaluations based on the standard somatotype, and a slim-fit tailored jacket prototype was developed based on the present findings. This research aims to increase the satisfaction level of the slim-fit jacket customers reflecting a variety of somatotypes of women in their 30s. The research process was developing jacket patterns fully reflecting the properties in terms of extra space and design lines for different somatotypes of women in their 30s based on the jacket pattern formulated through the advanced research, and then suggesting pattern design methods for the different somatotypes. In this sense, this research attempted to identify the problems concerning the slim-fit tailored jacket fitting for different somatotypes of women in their 30s. The main aim was to suggest ways to improve the customers' satisfaction level regarding the fit, and enable the manufacturers to produce a well-fitting jacket reflecting the peculiarities of each somatotype.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2038-2047
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• 2011

This paper presents a framework for production planning for a Slim MES(Manufacturing Execution System) of module operations in TFT-LCD(Thin Film Transistor-Liquid Crystal Display) production lines. There are differences in the line configurations and functions among the module operations in the TFT-LCD production systems. This paper presents the framework for the customized MES reflecting these differences. First, a production process is figured out through the analysis of the TFT-LCD module operations. Next, a mathematical modeling is presented reflecting the constraints of shop floors and an optimal schedule is presented through a case example. And a scheduling process using the dispatching rules reflecting the status of shop floors is presented and the performances are measured and compared. Finally, a design process for the Slim MES framework is presented.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.20 no.3
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• pp.291-299
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• 2008

The present study is to estimate the effects of diffracted wave fields in a harbor and around harborentrance due to random waves, when a navigation channel is dredged in the vicinity of the a harbor entrance. The cross sections of harbor boundary are considered to be partial or full reflection in this study. The numerical simulation has been performed by the boundary element method, which is to discrete segments of pit- and harbor- boundary with the algorism of auto generated elements. The incident wave conditions are specified using discretized forms of the Mitsuyasu's frequency spectrum and directional function. The results of the present numerical simulation agreed well with those of the published experimental data. It is shown that the ratios of wave height reduction are about 20% for the case of fully reflecting boundary, and 10% for the case of partially reflecting boundary by the effect of placing a pit, respectively.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.5
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• pp.153-160
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• 2010

We optimized the Si(substrate)/$SiO_2$(cladding)/$Si_3N_4$(antiresonant cladding)/$SiO_2$(core)/air multi-layers rib-optical waveguides of antiresonant reflecting optical waveguide (ARROW) for integrated optical biosensor structure utilizing beam propagation method (BPM). Thickness of anti-resonant cladding was derived to minimize the propagation loss and leaky field mode deeply related with evanescent mode was theoretically derived. Depth, width, refractive index and cladding thickness of anti-resonant cladding were numerically calculated into 2.3${\mu}m$, 5${\mu}m$, 1.488, and 0.11${\mu}m$ respectively to minimize propagation loss using the BPM simulation tool. Finally one- and two-dimensional propagation characteristics of ARROW was confirmed.