• Journal of Advanced Marine Engineering and Technology
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• v.33 no.1
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• pp.144-152
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• 2009

This paper propose highly miniaturized active $90^{\circ}C$ phase difference power divider and combiner for application to wireless communication system. The conventional passive $90^{\circ}C$ power divider and combiner cannot be integrated on MMIC because of their very large circuit size. Therefore, the highly miniaturized active $90^{\circ}C$ phase difference power divider and combiner are required for a development of highly integrated MMIC. In this paper, the highly miniaturized active $90^{\circ}C$ phase difference power divider and combiner employing InGaAs/GaAs HBT were designed, fabricated on GaAs substrate. According to the results, the circuit size of fabricated active $90^{\circ}C$ phase difference power divider and combiner were $1.67{\times}0.87$ mm and $2.42{\times}1.05$ mm, respectively, which were 31.6% and 2.2% of the size of conventional passive branch-line coupler. The output gain division characteristic of proposed divider circuit showed 8.4 dB and 7.9 dB respectively, and output phase difference characteristic showed $-89.3^{\circ}C$. The output gain coupling characteristic of proposed combiner circuit showed 9.4 dB and 10.5 dB respectively, and output phase difference characteristic showed $-92.6^{\circ}C$. The highly miniaturized active $90^{\circ}C$ phase difference power divider and combiner exhibited good RF performances compared with the conventional passive branch-line coupler.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.8
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• pp.1248-1256
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• 2008

In this paper, basic characteristics of transmission line employing PPGM (periodically perforated ground metal) were investigated using theoretical and experimental analysis.According to the results, unlike the conventional PBG (photonic band gap) structures, the characteristic impedance of the transmission line employing PPGM structure showed a real value, which exhibited a very small dependency on frequency. The transmission line employing PPGM structure showed a loss (per quarter wave length) higher by $0.1{\sim}0.2\;dB$ than the conventional microstrip line. According to the investigation of the dependency of RF characteristic on ground condition, the RF characteristic of the transmission line employing PPGM structure was hardly affected by the ground condition in the frequency lower than Ku band, but fairly affected in the frequency higher than Ku band, which indicated that coplanar waveguide employing PPGM structure was optimal for RF characteristic and reduction of size. Considering above results, impedance transformer was developed using coplanar waveguide with PPGM structure for the first time, and good RF characteristics were observed from the impedance transformer. In case that {\lambda}/4$ impedance transformer with a center frequency of 9 GHz was fabricated for a impedance transformation from 20 to10 {\Omega}$, the line width and length were 20 and $500\;{\mu}m$, respectively, and its size was only 0.64 % of the impedance transformer fabricated with conventional microstrip lines. Above results indicate that the transmission line employing PPGM is a promising candidate for a development of matching and passive elements on MMIC.

• Archives of design research
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• v.16 no.3
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• pp.51-58
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• 2003

The first impression of people plays a crucial role in deciding personal image. Except for the eyes, the V zone of a suit attracts people's attention most. Therefore, a necktie has an instant and strong influence in delivering the image of a man. This research divided images of men into several factors based on necktie that plays an important role in expressing men's images. Futhermore, this research inquired into characteristics of necktie designs that can express men's images. And this research presented visually through surveys. As a result, men's images were divided into six factors of uniqueness, sociality, generosity, notability, activeness & vitality and reliability with two axes of attractiveness and capability. Afterwards, the characteristic of necktie designs suitable for each image was presented. Furthermore, the characteristic of necktie designs suitable for jobs classification was presented by relating each image to six job classifications. Applying these facts into necktie sales, consumers will be able to choose their neckties that can express proper images according to their tastes, situations and jobs. Furthermore, consumers will be able to establish better image for themselves.

• Journal of Fashion Business
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• v.14 no.3
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• pp.35-51
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• 2010

This study aims at providing data for establishing a marketing strategy which can enhance the competitiveness of Korea domestic SPA(Specialty Store Retailer of Private Label Apparel) Brands by suggesting countermeasure strategy through the observation and analysis for SPA Brands, under the current circumstance in which the systematic and scholastic discussion for the matter, is lack, despite the diastrophism in fashion industry is prospected according to the rapid growth of Global SPA Brands. For this purpose, the characteristic and current status of Global SPA Brands is examined, and the main cause of growth is analyzed by approaching to their marketing characteristic, in this study. In relation with this situation, this study suggests the provisions as below, which are drawn from the analysis on Global SPA Brands' marketing strategy, so that Korea domestic SPA Brands could achieve successive performance under fierce competition. First, to be a competitive SPA Brands a business should be able to supply products with frequent product turnover by an interval level of one week or so, the existent product planning by seasons, as a business obtains various swift informations on consumers' demand with R&D center foundation. Secondly, SPA Brands should establish a strategy that a business can create high net profit by inventory management which enables lowering inventory ratio remarkably, and a strategy for innovative product supply by small quantity batch production, along with founding a high technological logistics system. Third, SPA Brands should establish a strategy for primary cost reduction by overseas dispersed outsourcing in order to enable diverse product development and rational price setting. Fourth, fashion marketers should establish also a strategy for communication by which brand image can be delivered effectively, by firming the brand identity and by informing product characteristic and customer service totally, with the method of VMD and flagship store. Additionary, fashion marketers also should establish a strategy by developing mobile application which can provide brand image and diverse other fashion related information.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1158-1158
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• 2001

Fast and dynamic biochemical, enzymatic and morphological changes occur during the so-called generative development and during the vegetative processes in seeds. The most characteristic biochemical and compositional changes of this period are the formation and decline of storage components or their precursors, the change of their degree in polymerization and an extensive change in water content. The aim of the present study was to detect the maturation processes in seed nondestructively and to verify the applicability of near infrared spectroscopic methods in the measurement of physiological, chemical and biochemical changes in wheat seed. The amount and variation of different water “species” has been changed intensively during maturation. Characteristic changes of three water absorption bands (1920, 1420 and 1150 nm) during maturation were analysed. It was concluded that the free/bound transition of water molecules could be followed sensitively in different region of NIR spectra. Kinetic changes of carbohydrate reserves were characteristic during maturation. An intensive formation and decline of carbohydrate reserves were observed during early stage of maturation (0 -13 days, high energy demand). An accelerated formation of storage carbohydrates (starch) was detected in the second phase of maturation. Five characteristic absorption bands were analysed which were sensitive indicators the changes of carbohydrates occurred during maturation. Precursors of protein synthesis and the synthesis of reserve proteins and their kinetic changes during maturation were followed from NIR spectra qualitative and qualitatively. Dynamic formation of amino acids and the changes of N forms were detected by spectroscopic, chromatographic and by capillary electrophoresis methods. Calibration equations were developed and validated in order to measure the optimal maturation time protein and moisture content of developing wheat seeds. The spectroscopic methods are offering chance and measurement potential in order to detect fine details of physiological processes. The spectra have many hidden details, which can help to understand the biochemical background of processes.

• Journal of KSNVE
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• v.5 no.4
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• pp.543-553
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• 1995

Modern steam turbine generators are being built as a higher power and larger system, experiencing more frequent starts and stops of operation due to a constant change of power demands. Hence, they are inevitably more vulnerable to various vibrations, and more often exposed to the danger of sudden vibration accidents than ever before. Even under the circumstances, in order to secure the system reliability of steampower plants and there by to supply safely the public electricity, it is important to prevent a sudden vibration accident in one hand and even when it happens, to raise an operating efficiency of the plants throught swift and precise treatments in the other. In this study, an interactive vibration diagnostic system has been developed to make the on-site vibration diagnosis of steam turbine generators possible and convenient, utilizing a note-book PC. For this purpose, at first the principal vibration phenomena, such as various unbalance and unstable vibrations as well as rubbing, misalignment, and shaft crack vibrations, have been systematically classified as grouped parameters of vibration frequencies, amplitudes, phases, rotating speeds at the time of accident, and operating conditions or condition changes. A new complex vibration diagnostic table has been constructed from the causal relations between the characteristic parameters and the principal vibration phenomena. Then, the diagnostic system has been developed to screen and issue the corresponding vibration phenomena by assigning to each user-selected combination of characteristic parameters a unique characteristic vector and comparing this vector with a diagnostic vector of each vibration phenomenon based on the constructed diagnostic table. Moreover, the diagnostic system has a logic whose diagnosis may be performed successfully by inputing only some of the corresponding characteristic parameters without having to input all the parameters. The developed diagnostic system has been applied to perform the diagnosis of several real cases of steam turbine vibration accidents. And the results have been quite satisfactory.

• Journal of the Korean Society of Costume
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• v.24
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• pp.217-233
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• 1995

The ultimate purpose of this study is to suggest the most effective marketing strategy for the clothing consumer market based on the new generation consumer's clothing selection behavior analysis. In this thesis, it is appempted to make a progress in the new gen-eration consumer's clothing life style types, in clothing purchase behavior analysis among the clothing life style, and also in the marketing strategy for marketers. The subjects selected for the final analysis are 412 the new gerneration women of age 20 thru 34 in seoul and satellite town area. Data were processed the spss package program. As for the analytic method, factor analysis, clustering analysis, XCross-tubulation, F-test with ANOVA, frequency and percentage were applied in the survey. The major findings are as following : life style is classified into four types : The characteristic fashion-directory type(25.7%) ; The reason traditional type(9.0%) ; The sen-sitivity fashion-following type(11.0%) ; The community brand-conscious type(54.3%). 2 Clothing life style types characteristic of the new generation consumer proved that clothing life style types are a significant difference according to the life style, the fashion consciousness and the average monthly spend-ing on clothing. 3. There is an important discrimination according to the clothing life style types in their clothing purchase behavior such as infor-mation usage, clothing choice criterion and brand loyalty. 4. Based on the result of our analysis and the review of literature, the marketing strategy is suggested that characteristic and new design development is efficient way to consumer's purchase need. Therefore apparel industary which pursue an added value must frame marketing strategy on the basis of the target consumer's sensitivity characteristic according to the life style and fashion consciousness.

• Journal of the Optical Society of Korea
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• v.20 no.4
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• pp.500-509
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• 2016

Integrating spheres play a central role in the radiometric calibration of remote sensors. With the development of the wide field of view (FOV) remote sensors, aperture diameters of remote sensors are becoming larger and larger. To satisfy the radiometric calibration requirements of full FOV and full aperture, an 8000mm diameter large aperture integrating sphere uniform source with a variable exit port was designed and manufactured. This integrating sphere will be used for pre-launch test and radiometric calibration of remote satellites. In this paper, optical theories were used to design the output spectral radiance. The LightTools software based on ray-tracing simulation method was used to determine the best combination and distribution of inner light sources. A spectral experiment was made to verify the spectral radiance design. To reduce the influence of longtime power-on, a new characteristic measurement method was developed to obtain the radiation characteristic of the integrating sphere, which could greatly improve the measuring efficiency. This method could also be applied to measure other large aperture uniform sources. The obtained results indicate that the spatial uniformity is 98.35%, and the angular uniformity at center position is 98.78%.

• The Journal of Korean Association of Computer Education
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• v.19 no.4
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• pp.11-20
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• 2016

In this paper, I developed a assesment indicator to evaluate SW program developed by students in SW education. The SW education carry out in elementary school, middle school and high school from 2016. But the assesment indicator to evaluate SW program had not been developed until now. Therefore, I tried to develop the assesment indicator that have harmoniously educational characteristic and SW qualitative characteristic. First of all, I had set the 15 attributes for assesment and developed the 36 criteria for 15 attributes. And the validity of 15 attributes and 36 criteria for assesment had been reviewed by 39 SW educational experts. As a result, the 15 attributes and 36 criteria for assesment were determined to which that have validity. I expect that the assesment indicator developed in this paper will raise the reliability of evaluation in SW education. And the assesment indicator may be used at SW competition conference for teenagers.

• Journal of Korea Water Resources Association
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• v.41 no.6
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• pp.605-617
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• 2008

This study developed a flood index which evaluates runoff characteristics. Runoff characteristics expressed in a hydrograph were reflected in the flood index in the form of characteristic factors such as a rising curve gradient, a peak discharge, a flood response time, and a flood discharge volume prior to peak. This study applied the standardization method to estimate the relative severity of the characteristic factors by transforming the distribution of characteristic factors into the standard normal distribution. The flood index developed in this study is a comprehensive flood index (CFI) which makes up for the weak points of a flash flood index (FFI) in determining relative severities. The CFI was applied to Han River basin and Selma River basin, and was compared with the FFI based on the correlation analysis and the regression analysis. The CFI could comprehensively evaluate flood runoff characteristics because the CFI is not dominated by a specific characteristic factor, and the CFI could explain more efficiently the relationship between rainfall and runoff than the FFI.