• Journal of the Korean Applied Science and Technology
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• v.40 no.1
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• pp.24-34
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• 2023

This study sought to explore the online consumption propensity of sports goods by generation of the productive population and to provide basic data to predict the future consumption market by segmenting online consumers in the sports 4.0 market. Therefore, this survey was conducted on those who consumed sports goods among the generation-specific groups (Generation Y and above, Z) of the productive population, and a total of 478 people's data were applied to the final analysis. Data processing was conducted with SPSS statistics (ver.21.0), frequency analysis, exploratory factor analysis, correlation analysis of re-examination reliability, reliability analysis, and decision tree analysis. According to the online consumption propensity of sports goods by generation of the productive population, there is a high probability of being classified as Generation Z group if the factors of leisure, joy, and environment are high. In addition, the classification accuracy of such a model was 69.7%.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.607-610
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• 2006

The Digital Frequency Synthesizer(DFS) that generates the wideband signal with hish speed frequency hopping rate and high frequency resolution characteristics was implemented in this paper. The DFS was applied as local oscillator for direct frequency conversion IF modules of DVB-RCS, which directly generates the transmission immediate frequency signal by using DDS and wideband PLL technologies. The DDS technology provides high speed frequency hopping rate and high frequency resolution characteristics, which ate also the DVB-RCS requirement. The wideband PLL technology also provides the wideband signal generation, which is a necessity for direct frequency conversion modules. The implemented DFS provide the spurious suppression characteristic of -50 dBc, frequency resolution of 0.233 Hz and frequency hopping rate of 125 ns, respectively. Also the DFS represent the amplitude flatness of 3 dB and less in the pass-band and phase noise characteristic of -75 dBc/Hz at 1 kHz frequency offset.

• Journal of Korean Institute of Industrial Engineers
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• v.4 no.2
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• pp.83-90
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• 1978

Frequency and duration method is a well known model in the generation reserve reguirement planning area. In this paper, the model is used to measure the effect of increased failure rates of individual generating units on the capability of power system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.365-366
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• 2009

• Proceedings of the Optical Society of Korea Conference
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• 2009.10a
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• pp.92-93
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• 2009

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.113-115
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• 1998

This paper present a buck-boost PWM inverter and its application for residential system. The PWM power inverter is realized by driving a inverter constructed with a high frequency buck-boost chopper in the discontinuous conduction mode (DCM)

• Journal of Fashion Business
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• v.18 no.6
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• pp.208-221
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• 2014

The purpose of this study was to investigate the effects of the hair style, and perceiver's generation on the perception of a high schoolgirl's image. A quasi-experimental method by questionnaire was used. The subjects were 253 high schoolgirls and their mothers living in Jinju. The data were analyzed by using frequency, factor analysis, Cronbach's alpha-reliability coefficient, three-way ANOVA, and Duncan's multiple ranges test. The high schoolgirl's image was derived in five dimensions by factor analysis: schoolgirl look, prettiness, individuality, activeness, and cuteness. In the image based on the hair length, it was assessed that the short cut and the bobbed hair styles looked more like school girls. And the short cut and long hair styles were considered as showing individuality. On the other hand, the bobbed hair style was assessed as cuter than styles of other lengths. For the bangs, the short bangs were found to more school-girl look and cuter than the long bangs. The mother group, whose ages were older than that of the other group, evaluated that the stimulative pictures had more school-girl look, individuality, prettiness, activeness and cuteness, compared to how the school girl group evaluated. It was shown that the generation gap produced different opinions about the stimulative pictures. Therefore hair style, bangs style, and difference in generations were found to be the variables affecting perception of high school girl image.

• Korean Management Science Review
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• v.12 no.1
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• pp.157-173
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• 1995

Hydro-electric power generation from multi-purpose dams has been playing important roles in the electric power supply network in Korea. Although the total share of hydro power in national electricity supply now becomes very small, the peak-shaving and frequency control capability of hydro power helps the power company enormously in maintaining the quality of power. But since the company that builds and operates the multi-purpose dams in Korea has to sell all the electricity produced to the monopolistic utility, there have been various problems in justifying the investment, designing pricing mechanism, and controlling operations of the power plants. In addition, economic evaluation of the hydro power has been distorted by a variety of reasons and hence it has been very difficult to encourage effective development and utilization of national water resources. To make the problem worse, both parties are public companies with X-inefficiency problems. Thus, changing environment requires to reengineer the system that governs hydro power generation. We address the problems of Korean hydro-electric power generation system in four areas: the investment justification process, the operations decison right of the hydro power plants, the pricing of the purchased-power, and the negotiation of contract revision. Then we propose improvement directions of new hydro-electric power system in view of static and dynamic efficiency, X-inefficiency and equity.

• Journal of Communications and Networks
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• v.10 no.3
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• pp.258-267
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• 2008

In this paper, we examine what changes the next-generation wireless communication systems will experience in terms of the technologies, services, and networks and, based on that, we investigate how the inter-cell interference management should evolve in various aspects. We identify that the main driving forces of the future changes involve the data-centric services, new dynamic service scenarios, all-IP core access networks, new physical-layer technologies, and heavy upload traffic. We establish that in order to cope with the changes, the next-generation inter-cell interference management should evolve to 1) set the objective of providing a maximal data rate, 2) take the form of joint management of power allocation and user scheduling, 3) operate in a fully distributed manner, 4) handle the time-varying channel conditions in mobile environment, 5) deal with the changes in interference mechanism triggered by the new physical-layer technologies, and 6) increase the spectral efficiency while avoiding centralized coordination of resource allocation of the users in the uplink channel.

• Journal of the Microelectronics and Packaging Society
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• v.16 no.4
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• pp.5-8
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• 2009

In this paper, a high-quality low-temperature co-fired ceramic (LTCC) solenoid inductor using a solder ball and an air cavity on a silicon wafer for three-dimensional (3-D) system-in-package (SiP) is proposed. The LTCC multi-layer solenoid inductor is attached using Ag paste and solder ball on a silicon wafer with the air cavity structure. The air cavity is formed on a silicon wafer through an anisotropic wet-etching technology and is able to isolate the LTCC dielectric loss which is equivalent to a low k material effect. The electrical coupling between the metal layer and the LTCC dielectric layer is decreased by adopting the air cavity. The LTCC solenoid inductor using the solder ball and the air cavity on silicon wafer has an improved Q factor and self-resonant frequency (SRF) by reducing the LTCC dielectric resistance and parasitic capacitance. Also, 3-D device stacking technologies provide an effective path to the miniaturization of electronic systems.