• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.165.2-165.2
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• 2010

The objective of this study is to analyze the energy saving rate by retrofitting multi air conditioner from conventional type to high efficient type using Energyplus 4.0 which was developed for simulating a building energy by D.O.E. Generally, Multi air conditioner system was installed for both the cooling and the heating in a building. However, it was difficult to estimate the energy saving rate in the case of retrofitting multi air conditioner from conventional type to high efficient type. In the present study, annual energy consumptions of them were evaluated for same building and climate condition.

• Journal of Environmental Science International
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• v.12 no.2
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• pp.111-117
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• 2003

This paper investigates preliminarily spatial distribution soil organic matter (SOM), nitrogen (N) and phosphorus (P) and its environmental influence in wetland soil of different vegetation landscape in the Yellow River Mouth. The result shows the SOM and total nitrogen (TN), efficient N, efficient P in top layer soils of different vegetation district have significantly different content, The SOM is shown as Calamagrostis epigeios wetlands > Phragmites cmmunis wetlands > Tamarix chinensi wetlands above tidal > Suaeda salsa wetlands in high tidal > Tamarix chinensi wetlands in high tidal > tidal flats, the arrange of the TN and efficient N content is the same except that the content in Suaeda salsa wetlands in high tidal is heavier than Tamarix chinensi wetlands in high tidal. In different vegetation landscape wetland types the vertical change of soil nutrients are obvious except for p, gradually decrease from the upper to the lower. This case reflects the function of the vegetation on the wetland development of soil and proves the wetland soil has the characteristic of new born and bad degree of development. SOM, TN, efficient N and efficient P content in wetland soils have significantly positive correlation, but TP have no correlation with them but efficient p. The contents of TN in wetland soils range from 58~1480 mg/kg, total average content 408 mg/kg, average content of above 30 cm is 625 mg/kg. The range of TP content in the soil is 372~1042 mg/kg, total average is 569 mg/kg, average content of above 20 cm is 611 mg/kg. According the P it occurs mainly as calcium phosphates, and the validity is lower, therefore, N and P in the new born wetlands cannot produce serious impact on the environments at present.

• KIEAE Journal
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• v.13 no.5
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• pp.97-102
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• 2013

Many countries over the world have acknowledged the global warming problem by greenhouse gas emission and tried to solve the problem. The Korean government has also taken many actions such as The Act on Low Carbon, Green Growth and on Promoting Green Building in that architectural building section takes 1/4 of national greenhouse gas emission. Under the situation that buildings constructed 15 years ago when insulation standards were reinforced take about 74%, The Plan on Vitalizing Green Remodeling, finally established on July 2013, will induce energy-efficient remodeling of deteriorated buildings. Using the energy simulation by the Visual DOE 4.0 program, this paper proposed the ways of energy-efficient remodeling of deteriorated high school buildings by measuring energy saving performance of factors that were drawn from the previous study. The factors considered are insulation, window's SHGC, south louver, system efficiency, and indoor setting temperature. Among them, all factors except SHGC proved contribution to reducing energy use at deteriorated high school buildings, compared with the baseline energy consumption.

• ETRI Journal
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• v.23 no.2
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• pp.61-70
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• 2001

In this paper, we propose an efficient method for personal identification by analyzing iris patterns that have a high level of stability and distinctiveness. To improve the efficiency and accuracy of the proposed system, we present a new approach to making a feature vector compact and efficient by using wavelet transform, and two straightforward but efficient mechanisms for a competitive learning method such as a weight vector initialization and the winner selection. With all of these novel mechanisms, the experimental results showed that the proposed system could be used for personal identification in an efficient and effective manner.

• Journal of information and communication convergence engineering
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• v.10 no.2
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• pp.141-148
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• 2012

This paper presents a simple but efficient scheme incorporating a reputation-based approach and a cross-layer approach, called the SIM scheme, for maintaining reliable connectivity and high performance in ad-hoc wireless networks. The SIM scheme incorporates the following two things: an ad-hoc routing scheme with a reputation-based approach exploiting the game theory concept based on an evolutionarily stable strategy, and a cross-layer approach between the network layer and the transport layer employing a reputation-based approach.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.233-240
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• 1998

In the design of the high-speed railway vehicles of low noise and vibration characteristics, it is desirable to develop efficient and systematic procedures for analyzing large structures. In this paper, some finite-element modelling techniques and an efficient analytical method are proposed for this purpose. The analytical method is based on substructuring approach such as a free-interface method and a generalized synthesis algorithm. In final, the proposed approaches are applied to the finite-element modelling, modal analysis and subsequent model updating procedures of the high-speed railway intermediate trailers.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.805-808
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• 2004

In this study, several properties are improved when high efficient inorganic type agent and organic-inorganic type agent are applied. Especially high efficient inorganic type agent can improve the properties of concrete such as water-resisting capability more effect than organic-inorganic type agent applied.

• Journal of Electrical Engineering and Technology
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• v.11 no.1
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• pp.125-134
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• 2016

We propose an efficient high voltage level shifter for a high side Buck converter driving a light-emitting diode (LED) lamp. The proposed circuit is comprised of a low voltage pulse width modulation (PWM) signal driver, a coupling capacitor, a resistor, and a diode. The proposed method uses a property of a PWM signal. The property is that the signal repeatedly transits between a low and high level at a certain frequency. A low voltage PWM signal is boosted to a high voltage PWM signal through a coupling capacitor using the property of the PWM signal, and the boosted high voltage PWM signal drives a p-channel metal oxide semiconductor (PMOS) transistor on the high side Buck converter. Experimental results show that the proposed level shifter boosts a low voltage (0 to 20 V) PWM signal at 125 kHz to a high voltage (370 to 380 V) PWM signal with a duty ratio of up to 0.9941.

• 한국정보컨버전스학회:학술대회논문집
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• 2008.06a
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• pp.145-150
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• 2008

This thesis explores the problem of reconstructing a three-dimensional(3D) scene given a set of images or image sequences of the scene. It describes efficient methods for the 3D reconstruction of static and dynamic scenes from stereo images, stereo image sequences, and images captured from multiple viewpoints. Novel methods for image-based and volumetric modelling approaches to 3D reconstruction are presented, with an emphasis on the development of efficient algorithm which produce high quality and accurate reconstructions. For image-based 3D reconstruction a novel energy minimisation scheme, Iterated Dynamic Programming, is presented for the efficient computation of strong local minima of discontinuity preserving energyy functions. Coupled with a novel morphological decomposition method and subregioning schemes for the efficient computation of a narrowband matching cost volume. the minimisation framework is applied to solve problems in stereo matching, stereo-temporal reconstruction, motion estimation, 2D image registration and 3D image registration. This thesis establishes Iterated Dynamic Programming as an efficient and effective energy minimisation scheme suitable for computer vision problems which involve finding correspondences across images. For 3D reconstruction from multiple view images with arbitrary camera placement, a novel volumetric modelling technique, Embedded Voxel Colouring, is presented that efficiently embeds all reconstructions of a 3D scene into a single output in a single scan of the volumetric space under exact visibility. An adaptive thresholding framework is also introduced for the computation of the optimal set of thresholds to obtain high quality 3D reconstructions. This thesis establishes the Embedded Voxel Colouring framework as a fast, efficient and effective method for 3D reconstruction from multiple view images.

• Journal of the Korean Society of Combustion
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• v.21 no.1
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• pp.18-30
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• 2016

Pyro-process of solids is the way to heat solid materials under high temperature. In this processing, energy efficient use is one of the main concerns due to its high energy consumption of bulk materials. To calculate the energy use of processes, heat & mass balance in simplified 0-dimensional model was performed. Energy calculation by this simplified model can lead to confusion due to simplification. Thus, it is necessary to understand considerations of energy analysis. In this study, cement manufacturing as a very common example of pyro-processing of solids, was introduced for explaining considerations of energy analysis for energy efficient use.