• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.942-945
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• 2006

In order to measure the sound transmission loss(STL) of a test specimen such as windows, which is smaller than the test opening, a special partition is built into the test opening and the specimen is placed in that partition. This paper discusses how the measured STL is changed by the partition when a small-size window of high sound insulation is mounted. Theoretical and experimental investigations are carried out to quantify the effect of the filler wall. The results reveal that the smaller the window size is, the higher sound insulation performance of the filler wall is required in order to measure the accurate STL of the specimen. It is found that the insufficient sound insulation of the filler wall leads to the lower measured value of the window's STL.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2004.11a
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• pp.315-318
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• 2004

In recent days, IAQ(Indoor Air Quality) is regarded as one of the most important environmental factors as well as thermal and acoustic comfort. The purpose of this study was to estimate on effect of indoor air pollution from VOCs and formaldehyde emitted by building materials. As the results, we knew that concentration of Toluene, Xylene, Styrene and HCHO emitted from the furnitures and frame material of windows and doors are high emission factors on indoor air pollution.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.11C
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• pp.1097-1105
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• 2002

In display systems employing analog monitors, the tearing artifact such that an window screen is divided into two parts showing different scenes can occur when the change of scenes in the moving pictures is very fast, but the frame buffer's refresh rate does not match the monitor's scanning frequency. It is especially noticeable at high frame rate. DVR system is a recently popularized visual monitoring system. The tearing artifacts becomes more serious since the frame buffer's refresh rate is very high due to the requirement of multi channel display in the DVR. In this paper, we propose an improved display system for windows-based DVR systems which prevents the tearing artifacts without deterioration of display speed performance. The efficiency of the proposed display system is verified through experiments.

• Smart Structures and Systems
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• v.29 no.5
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• pp.653-660
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• 2022

Gravel scattering that is generated during operation of high-speed railway vehicle is cause to damage of vehicle such as windows, axle protector and so on. Especially, those are frequently occurred in winter season when snow ice is generated easily. Above all, damage of vehicle windows has not only caused maintenance cost but also increased psychological anxiety of passengers. Various methods such as heating system using copper wire, heating jacket and heating air are applied to remove snow ice generated on the under-body of vehicle. However, the methods require much run-time and man power which can be low effectiveness of work. Therefore, this paper shows that large-area heating system was developed based on heating coat in order to fundamentally prevent snow ice damage on high-speed railway vehicle in the winter season. This system gives users high convenience because that can remotely control the heating system using IoT-based wireless communication. For evaluating the applicability to railroad sites, a field test on an actual high-speed railroad operation was conducted by applying these techniques to the brake cylinder of a high-speed railroad vehicle. From the results, it evaluated how input voltage and electric power per unit area of the heating specimen influences exothermic performance to draw the permit power condition for icing. In the future, if the system developed in the study is applied at the railroad site, it may be used as a technique for preventing all types of damages occurring due to snow ice in winter.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.11
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• pp.25-34
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• 2019

It is important to design windows in a reasonable way considering the performance characteristics of the elements of the window rather than just to increase the thermal energy performance of the window. In this study, the Heat-transfer Coefficient as insulation performance of the windows and together with the grade of the glass's SHGC (Solar Heat Gain Coefficient) were analyzed to relate to the energy efficiency performance of the building by azimuth angle. Based on this basic study, the Heat-transfer Coefficient of windows and the SHGC rating of glass were applied to the unit plan of apartment building, and the Heating and Cooling Demand were analyzed by azimuth angle. Apartment plan types were divided into 2 types of Non-extension and extension of balcony. The designPH analysis data derived from the variant of the Heat-transfer Coefficient and SHGC, were put into PHPP(Passive House Planning Package) to analyze precisely the energy efficiency(Heating and Cooling Demands) of the building by azimuth angle. In addition, assuming the 'ㅁ' shape layout, energy efficiency performance and potential of PV Panel installation also were analyzed by floors and azimuth angle, reflecting the shading effects by surrounding buildings. As the results of the study, the effect of Heat Gain by SHGC was greater than Heat Loss due to the Heat-transfer Coefficient. So it is more effective to increase SHGC to satisfy the same Heating Demand, and increasing SHGC made possible to design windows with low Heat-transfer Coefficient. It was also revealed that the difference in annual Heating and Cooling Demands between the low, mid and high floor households is significantly high. In addition to it, the installation of PV Panel in the form of a shading canopy over the window reduces the Cooling Load while at the same time producing electricity, and also confirmed that absolute thermal energy efficiency could not be maximized without controlling the thermal bridge and ventilation problems as important heat loss factors.

• Journal of Energy Engineering
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• v.25 no.4
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• pp.207-213
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• 2016

In this study, a thermal flow analysis was performed using the commercial code, ANSYS-FLUENT to reduce room temperature in a turbine building of power plant. The selected control volume of the operating floor and deaerator floor for the turbine building was respectively modelled. The skylight windows at the deaerator floor were employed for ventilation windows. Through the study, in the first we found that all window close of the deaerator floor is one alternative for reducing the temperature of the operating floor. The next thing we knew that for windows open at the front of the deaerator floor, the temperature of deaerator zone and crane zone can be respectively reduced to $1.5^{\circ}C$ and $1.6^{\circ}C$. In addition, for windows close at the rear of the deaerator floor, the temperature of deaerator zone and crane zone can be respectively reduced to 1.4 and $0.5^{\circ}C$. Therefore, it was concluded that a better choice is to open the front windows at deaerator floor to reduce the temperature of the entire deaerator floor having high temperature.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.1
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• pp.16-21
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• 1999

The analysis of distribution line faults is essential to the proper protections of the power system. A high impedance fault test, which was carried in Korean electric power systems, it was found that a arcing phenomenon occurred during the high level portion of conductor voltage in each cycle. In this paper, we propose a new method for detection of high impedance faults, which uses the arcing fault current difference during high voltage and low voltage portion of conductor voltage waveform. To extract this difference, we diveded one cycle fault current into equal spanned four data windows according to the magnitude of voltage waveform and applied fast fourier transform(FFT) to each data window. The frequency spectrum of current wavefrom in each portion are used as the inputs of neural network and is trained to detect high impedance faults. The proposed method shows improved accuracy when applied to staged fault data and fault-like load.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.12
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• pp.1492-1497
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• 1999

High impedance fault(HIF) is defined as fault the general overcurrent relay can not detect or interrupt. Especially when HIF occur in residential areas, energized high voltage conductor results in fire hazard, equipment damage or personal threat. This paper proposes the model of the high impedance fault in transmission line using the ZnO arrester and resistance to be implemented within EMTP. The performance of the proposed model is tested on a typical 154[kV] korean transmission line system under various fault conditions. Wavelet transform is efficient and useful for the detection of high impedance fault in power system, because it uses variable windows according to frequency. In this paper, HIF detection method using wavelet transform can distinguish HIF form similar fault like arcfurance load, capacitor bank switching and line switching.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.379-381
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• 2002

Mitsubishi Electric Corporation has marketed a series of multimedia CRTs enabling bright picture windows in a high-resolution date display screen. The key components of the multimedia CRTs named Diamondtran $M^2$ are a high-gm (low drive-voltage) electron gun and an aperture grille mask. A high-gm electron gun has been developed by designing a beam forming region with high-gm configuration combining with a high current-density cathode. The development of next generation high-gm guns are also introduced

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.1
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• pp.1-12
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• 2004

In this paper, we present an identificable face (n face) detection method robust to color degradation and partial veiling. This method is composed of three parts: segmentation of face candidate regions, extraction of face candidate windows, and decision of veiling. In the segmentation of face candidate regions, face candidate regions are detected by finding skin color regions and facial components such as eyes, a nose and a mouth, which may have degraded colors, from an input image. In the extraction of face candidate windows, face candidate windows which have high potentials of faces are extracted in face candidate regions. In the decision of veiling, using an eigenface method, a face candidate window whose similarity with eigenfaces is maximum is determined and whether facial components of the face candidate window are veiled or not is determined in the similar way. Experimental results show that the proposed method yields better the detection rate by about $11.4\%$ in test DB containing color-degraded faces and veiled ones than a conventional method without considering color degradation and partial veiling.