• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.2
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• pp.188-193
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• 2007

Tracking and erosion of Poly Methyl Methacrylate (PMMA) and the suppression mechanism of alumina trihydrate were investigated in the present study The conventional testing as IEC-60587 is widely used in surface aging measurement of outdoor insulator those testing can carry out very short time for Lab testing. Also IEC-60587 testing is able to offer the standard judgement of relative degradation level of outdoor HV system. Therefore it is very useful method compare to previous conventional tracking testing method, But surface discharges(SD) have very complex characteristics of discharge pattern so it is required estimation research to development of precise analysis method. In recent, the study of IRR-Camera is carrying out discover of temperature of power equipment through condition diagnosis and system development of degradation diagnosis. In this paper, SD occurred from IEC-60587 is measured with the surface temperature of weibull distribution in real time, the degradation grade of SD is analyzed through produced patterns in IEC-60587 using Infrared Radiation(IRR) camera.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.2
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• pp.67-79
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• 1998

Inthe study, a method to evaluate the door closing sound has been developed. Based on the factor analysis, various adjective pairs which describe meaning of the door impact sound have been differentiated. This approach, called Semantic difference(SD) method, was originally developed in linguistics research on order to compare diverse mother tongue. This paper introduces at first how the door sound os generated and transmitted. After that, a factor analysis which is a tool of SD method is implemented to door closing sound for 12 domestic and 1 foreign car models. During investigation, the examined models are categorized into small, medium and luxurious size automobiles. The adjective pairs which attritbute to the door quality have been factorized into three group : expensive/ smooth, powerful/ heavy, and modern/dull. It turns out that the first factor : expensive/ smooth plays the most important role in door closing sound quality.

• ETRI Journal
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• v.41 no.2
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• pp.145-159
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• 2019

To reduce the number of radio frequency (RF) chains in multiple input multiple output (MIMO) systems, generalized spatial modulation (GSM) techniques have been proposed in the literature. In this paper, we propose a zero-forcing (ZF)-based detector, which performs an initial pruning of the search tree that will be considered as the initial condition in a sphere decoding (SD) algorithm. The proposed method significantly reduces the computational complexity of GSM systems while achieving a near maximum likelihood (ML) performance. We analyze the performance of the proposed method and provide an analytic performance difference between the proposed method and the ML detector. Simulation results show that the performance of the proposed method is very close to that of the ML detector, while achieving a significant computational complexity reduction in comparison with the conventional SD method, in terms of the number of visited nodes. We also present some simulations to assess the accuracy of our theoretical results.

• Journal of Environmental Science International
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• v.15 no.4
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• pp.305-310
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• 2006

The color and structure of urban constructions is a factor of urban landscape and shows their characteristics. Hence the modern buildings deal with their materials and external appearance as an important factor, making up the urban image. But it was nearby impossible to evaluate the value of visual landscape with objective measuring method. Most of all, it depends on the subjective estimation of a few talented or high educated experts with a sense of beauty. Such kinds of estimation can in some cases include arbitrary interpretations. In relation to this kind of problems, it is tried here in this study to analyse the human response of brain wave pattern (EEG) with use of SD method, while the tested persons watch the urban landscape scenery constructed in a visual reality. The tested persons were 20 adult male and female with no color blindness and intact cognitive function. Light source with color filter was used for color environment in a dark soundproof chamber. The signal of EEG is analysed digitally and grouped into the ${\alpha}$ and ${\beta}$ waves. The result showed that relative power of ${\alpha}$ wave ratio increased in the natural landscape scenery with blue and green color. From these results it was possible to evaluate the human response, which is affected by urban and natural color and structure stimulation and it might be useful as an indicator of visual cognition amenity toward the design of urban construction environment.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.5
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• pp.506-514
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• 2008

At coverage boundaries of cellular systems including the recent WiBro standard which operate with full frequency reuse for increased spectral efficiency, interference signals from the base stations(BS) of adjacent cells degrade the receiver performance. In this paper, a detection method for multiple-antenna mobile stations(MS) is proposed for downlink performance improvement at coverage boundaries of cellular systems. For the performance verification, we obtain the probability density function(pdf) of the effective signal-to-interference and noise ratio(SINR) according to the variation of the interference signals from adjacent cells as well as the number of MS antennas, and calculate the transmission efficiency. We also verify the performance of proposed method with simulation results, to demonstrate a significant performance improvement is achieved over the maximal ratio combining(MRC) and spatial demultiplexing(SD) methods in terms of the effective SINR and the spectral efficiency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.459-462
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• 2002

The conventional thermal insulator and power transformer testing is widely used in surface aging measurement of outside insulator because those testing can carry out very short time in Lab testing. Also thermal testing is able to offer the standard judgement of relative degradation level of outside HV machine. There it is very useful method compare to previous conventional thermal testing method and effective Lab testing method. But surface discharges(SD) have very complex characteristics of discharge pattern so it is required estimation research to development of precise analysis method. In recent, the study of IRR-camera is carrying out discover of temperature of power equipment through condition diagnosis and system development of degradation diagnosis. In this study, thermal testing of Power transformer is measured with partial temperature distribution in real time.

• JSTS:Journal of Semiconductor Technology and Science
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• v.10 no.1
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• pp.11-19
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• 2010

Register transfer level power macromodeling is well known as a promising technique for accurate and efficient power estimation. This paper proposes effective approaches based on the tablebased method for the RTL power macro-modeling. The new parameter SD, which characterizes the distribution of switching activities for each gate in the circuit, is one of the contributions. The new parameter SD has strong correlation with power consumption. We also propose an accurate table reference method considering the circuit characteristics. The table reference method is applicable for every table-based method and outputs more accurate power value. The experimental results show that the combination of the proposed methods reduces max error 30.36% in the best case, comparing conventional methods. The RMS error is also improved 1.70% in the best case.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.08a
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• pp.69-72
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• 2002

The conventional thermal insulator and power transformer testing is widely used in surface aging measurement of outside insulator because those testing can carry out very short time in Lab testing. Also thermal testing is able to offer the standard judgement of relative degradation level of outside HV machine. There it is very useful method compare to previous conventional thermal testing method and effective Lab testing method. But surface discharges(SD) have very complex characteristics of discharge pattern so it is required estimation research to development of precise analysis method. In recent, the study of IRR-camera is carrying out discover of temperature of power equipment through condition diagnosis and system development of degradation diagnosis. In this study, thermal testing of power transformer is measured with partial temperature distribution in real time.

• Proceedings of the KSPS conference
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• 2005.11a
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• pp.159-162
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• 2005

Identification is the process automatically identify who is speaking on the basis of information obtained from speech waves. In training phase, each speaker models are trained using each speaker's speech data. GMMs (Gaussian Mixture Models), which have been successfully applied to speaker modeling in text-independent speaker identification, are not efficient in insufficient training data environment. This paper proposes speaker modeling method using MLLR (Maximum Likelihood Linear Regression) method which is used for speaker adaptation in speech recognition. We make SD-like model using MLLR adaptation method instead of speaker dependent model (SD). Proposed system outperforms the GMMs in small training data environment.

• Journal of Home Health Care Nursing
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• v.14 no.2
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• pp.76-82
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• 2007

Purpose: The purpose of this study was to provide the data for improving home care services through investigating the recognition of home care services by nurses, doctors and general employees. Method: The data were collected from 231 nurses, 103 doctors and 157 general employees who were working at a general hospital in Seoul from Sept 11 to Sept 24, 2006 and analyzed using descriptive statistics and ANOVA. Results: The recognition on necessity of home care services was lower in doctors(M=2.73, SD=.39) and general employees (M=2.83, SD=.31) than nurses(M=3.13, SD=.39). In terms of the recognition on content of home care services, the affirmative percentages of most items were lower in doctors and general employee than nurses. The recognition on effects of home care services was also lower in doctors(M=2.90, SD=.32) and general employees(M=2.99, SD=.31) than nurses(M=3.26, SD=.35). Conclusion: This study indicates that the continuous educations and advertisements on home care services are necessary to facilitate home care services in general hospitals.