• 전자공학회논문지 IE
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• v.49 no.2
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• pp.9-17
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• 2012

One of the problems on the application of the speech recognition system in the real world is the degradation of the performance by acoustical distortions. The most important source of acoustical distortion is the additive noise. This paper describes a spectral compensation technique based on a spectral peak enhancement scheme followed by an efficient noise subtraction scheme for noise robust speech recognition. The proposed methods emphasize the formant structure and compensate the spectral tilt of the speech spectrum while maintaining broad-bandwidth spectral components. The recognition experiments was conducted using noisy speech corrupted by white Gaussian noise, car noise, babble noise or subway noise. The new technique reduced the average error rate slightly under high SNR(Signal to Noise Ratio) environment, and significantly reduced the average error rate by 1/2 under low SNR(10 dB) environment when compared with the case of without spectral compensations.

• 전자공학회논문지 IE
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• v.49 no.2
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• pp.46-51
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• 2012

Transmit signal of Enhancement Layer in AT-DMB system is received by Coherent Detection, but in Base Layer of AT-DMB, a differential modulation and demodulation is adopted, same as the T-DMB. Especially for the coherent dectection of enhancement layer in AT-DMB system, a channel estimation must be employed. In this paper, I will show that the BER performance of Base-Layer in AT-DMB system will be improved by using the channel estimation information. The suggested method is focusing the constallations after Equalizaing to the nearlest ${\pi}$/4-shift DQPSK constallation points. Simulation results show that for the non-coding environment, the BER performance of AWGN channel, about 2-dB gain can be achieved at $10^{-4}BER$.

• 전자공학회논문지 IE
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• v.46 no.3
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• pp.42-47
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• 2009

In CDMA system, the call admission control method using the variable effective bandwidth concept is employed in this paper. The bandwidth for a new call and a handoff call is allocated by considering the number of mobile station being served and dynamically assigned by taking account of the blocking rate of new calls and the dropping rate of handoff calls. There is reserved resource for handoff call. In the case radio resource is insufficient, a new call and a handoff call stand by in buffer for constant time. When radio resource come about, the waiting call is allocated the resource. I analyze the performance of system according to existence and nonexistence of buffer by a simulation study.

• 전자공학회논문지 IE
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• v.46 no.4
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• pp.49-56
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• 2009

In this paper, stabilization inverse optimal control for nonlinear systems with structural uncertainty is considered. Based on the control Lyapunov function, a theorem for the globally asymptotic stability is presented. From this a less conservative condition for the inverse optimal control is derived. The result is used to design an inverse optimal controller for a class of nonlinear systems, that improves and extends the existing results. The class of nonlinear system considered is also enlarger. The simulation results show the effectiveness of the method.

• 전자공학회논문지 IE
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• v.45 no.3
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• pp.50-55
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• 2008

In CDMA system, the number of mobile stations which can be served simultaneously in a base station is limited by the amount of total interference received. Considering the facts, the call admission control method using the effective bandwidth concept is employed in this paper. The bandwidth for a new call and a handoff call is allocated by considering the number of mobile station being served and dynamically assigned by taking account of the blocking rate of new calls and the dropping rate of handoff calls. Also, there is reserved resource for handoff call. We analyze the performance of system according to reserved resource by a simulation study. The more a resource reserved, the less it is the dropping rate of handoff.

• Journal of Families and Better Life
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• v.9 no.1 s.17
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• pp.27-44
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• 1991

The purpose of this study is to investigate the relationship between communication pattern and conflict between old parents and their adult children. For this purose, 380 adult children are surveyed therefore the answers of survey are described by adult children only. The number of old parents turn to be 230 old fathers and 301 old mothers respectively, there numbers have included the case both parents are alive. The data were analysed several method with SPSS and the methods used for the analysis are Factor analysis, one way ANOVA, Scheffe-Test, Pearson's Correlation, Multple Regression. The results of this study are summarizd as follows ; 1) Old parents's communication patterns differ each other and under many variables. 2) In the conflicts between old parents and adult children differ each other and under many variables, too. 3) The relationship between communication patterens and conflict between old parent and adult children turn to be as follows : Two communication styles ie, the autoritarian style and insincere style increse conflicts. Frendly style have negatve affect to conflicts and decreses the conflicts. Sacrifice style is turn to have slightly affect the conflict.

• IE interfaces
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• v.18 no.3
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• pp.221-233
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• 2005

e-Manufacturing can be referred to as a system methodology enabling the integration of manufacturing operations and IT technologies to achieve objectives of an enterprise. It is recently regarded as a powerful solution to survive in a chaotic marketplace. While conducting an e-Manufacturing project, we first needed to capture collaborative processes conducted by multiple participants in order to define functions of a system supporting them. However, pervasive process modeling techniques including IDEF3, Petri nets, and UML are not sufficient for modeling collaborative processes. Therefore, we first briefly investigate several process modeling methods including aforementioned modeling methods and ARIS focusing on the collaboration point of view. Then, we propose a new modeling method referred to as Collaborative Process Modeling (CPM) to clearly describe collaborative processes. Also, we develop and illustrate a rule for transforming collaborative process models into Marked Graph models to use the analysis power of the Petri nets. Using CPM empowers us to develop collaborative process models with simple notations, understand and facilitate the realization of the collaboration, and verify models before rushing into the development.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.04a
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• pp.118-125
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• 2000

Gloss uniformity on unprinted coated papers is oftenly called as 'Surface Feeling' in market and roles as a very important criteria when a customer choose a paper. However, there is few researches on this quality so far and even there isn't much knowledge on the characteristics of gloss variation, ie what it is, where it comes from etc. Therefore, there should be a pre-research on its characteristics, factors, measuring method or tools prior to the following development activities. In this paper, we obtained about a dozen of papers including foreign products and measured not only basic properties of them, but also various characteristics related to ununiformity. Our experiments went further to printing, but that area is excluded in this paper. Also, we investigated several instruments for measuring gloss variation by an objective way all over the world and tested with our own samples so that we tried to find out which one is best-correlated with visual appreciation and suggest its results as possible. We found out several things from these experiments including what is difference between good and bad gloss uniformity, the factors of gloss variation, and the results of measurement for gloss variation with instruments.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.04a
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• pp.180-184
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• 2008

Fire prevention strategies should be aimed at the prevention of structured fire since average annual rates of structured fire have been increased due to economic growth resulted in increasing high rise buildings and multipurpose occupancies over the past ten years. Hence, this study mainly focused on the improve method and problems in the field test of fire detector in compliances with experimental consideration. And it leads us to the flowing conclusions : Firstly, it is necessary to formulate a safety standards on field test. Nowadays, the test enforced in many ways without formulated standard. Therefore it is necessary to be complete the arrangements standardized and how to do the test with formulated safety standards. Second, it is necessary to establish the regal guidance with regard to inspection equipment, ie density, component and temperature of test equipment should be considered. Also the equipment is need to be standardized and improved. Third, fire inspector's competency in their practice should be enhanced. The problems arising from the lack of knowledge and competence regarding inspection could be settled by providing professional education to ensure proficiency in their practice. Specialized training, as has been noted, should be offered in accordance with occupancy type, scale and fire protection system in the fire facilities.

• Journal of Korean Society of Rural Planning
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• v.24 no.2
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• pp.21-29
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• 2018

Riparian management has become important as stream water quality as well as riparian ecosystem gain more public attentions. The objective of this study was to determine riparian widths based on the functions of nutrient removal and wildlife habitat protection and to apply for the Jinwee stream area as a preliminary case. Nitrogen and phosphorus filtration efficiencies were considered in water quality aspect, while the habitat radii of amphibian and reptiles were used for wildlife conservation purpose. In addition, observation of endangered species and human impact on wildlife disturbance in riparian area were also taken into account in determining riparian widths. The stream confluence zone was emphasized by doubling the riparian widths as the focal point for wildlife habitat conservation. As the results, three different levels of riparian widths were proposed depending on the major riparian functions and applied to the Jinwee stream section as the case study. The proposed method can be used to determine riparian width in other stream areas based on different functional focus, ie, water quality or riparian conservation purposes.