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Coolant Material Effect on the Heat Transfer Rates of the Molten Metal Pool with Solidification

  • Cho, Jae-Seon;Kune Y. Suh;Chung, Chang-Hyun;Park, Rae-Joon;Kim, Snag-Baik
    • Proceedings of the Korean Nuclear Society Conference
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    • 1998.05a
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    • pp.812-817
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    • 1998
  • Experimental studies on heat transfer and solidification of the molten metal pool with overlying coolant with boiling were performed The simulant molten pool material is tin (Sn) with the melting temperature of 232$^{\circ}C$. Demineralized water and R113 are used as the working coolant. This work examines the crust formation and the heat transfer characteristics of the molten metal pool immersed in the boiling coolant. The Nusselt number and the Rayleigh number in the molten metal Pool region of this study are compared between the water coolant case and the R113 coolant case. The experimental results or the water coolant are higher than those for R113. Also, the empirical relationship of the Nusselt number and the Rayleigh number is compared with the literature correlations measure from mercury. The present experimental results are higher than the literature correlations. It is believed that this discrepancy is caused by the effect of heat loss to the environment on the natural convection heat transfer in the molten pool.

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Correlation-based Robust Blind Watermarking (상관도 기반의 강인한 블라인드 워터마킹)

  • Joo, Snag-Hyun;Seo, Yong-Seok
    • The KIPS Transactions:PartB
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    • v.10B no.5
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    • pp.479-484
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    • 2003
  • We propose a blind watermarking method that embeds a binary pseudo-random sequence (watermarks), (-1, 1), into wavelet dc components, while most watermarking techniques embed watermarks in the middle frequency range for robustness and fidelity. In our scheme, the watermarks are embedded into particular locations to be selected by a key, where some watermark embeddings are skipped to avoid severe degradation in quality. Our robustness is compared to some results registered to the ChechMark [1] that is one of the most popular benchmarking tools.

A Study on Mouth Features Detection in Face using HMM (HMM을 이용한 얼굴에서 입 특징점 검출에 관한 연구)

  • Kim, Hea-Chel;Jung, Chan-Ju;Kwag, Jong-Se;Kim, Mun-Hwan;Bae, Chul-Soo;Ra, Snag-Dong
    • Proceedings of the Korea Information Processing Society Conference
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    • 2002.04a
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    • pp.647-650
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    • 2002
  • The human faces do not have distinct features unlike other general objects. In general the features of eyes, nose and mouth which are first recognized when human being see the face are defined. These features have different characteristics depending on different human face. In this paper, We propose a face recognition algorithm using the hidden Markov model(HMM). In the preprocessing stage, we find edges of a face using the locally adaptive threshold scheme and extract features based on generic knowledge of a face, then construct a database with extracted features. In training stage, we generate HMM parameters for each person by using the forward-backward algorithm. In the recognition stage, we apply probability values calculated by the HMM to input data. Then the input face is recognized by the euclidean distance of face feature vector and the cross-correlation between the input image and the database image. Computer simulation shows that the proposed HMM algorithm gives higher recognition rate compared with conventional face recognition algorithms.

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A Study on an Adaptive Membership Function for Fuzzy Inference System

  • Bang, Eun-Oh;Chae, Myong-Gi;Lee, Snag-Bae;Tack, Han-Ho;Kim, Il
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1998.10a
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    • pp.532-538
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    • 1998
  • In this paper, a new adaptive fuzzy inference method using neural network based fuzzy reasoning is proposed to make a fuzzy logic control system more adaptive and more effective. In most cases, the design of a fuzzy inference system rely on the method in which an expert or a skilled human operator would operate in that special domain. However, if he has not expert knowledge for any nonlinear environment, it is difficult to control in order to optimize. Thus, using the proposed adaptive structure for the fuzzy reasoning system can controled more adaptive and more effective in nonlinear environment for changing input membership functions and output membership functions. The proposed fuzzy inference algorithm is called adaptive neuro-fuzzy control(ANFC). ANFC can adapt a proper membership function for nonlinear plant, based upon a minimum number of rules and an initial approximate membership function. Nonlinear function approximation and rotary inverted pendulum control system ar employed to demonstrate the viability of the proposed ANFC.

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Analysis on the Relation between Induced Longitudinal Voltage and Induced Noise Voltage caused by Electrified Railway system (고속전철시설에 의한 전력유도현상의 종전압과 잡음전압의 관계 분석)

  • Cho, Mun-Hwan;Lee, Snag-Mu;Cho, Pyung-Dong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2011.10a
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    • pp.589-592
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    • 2011
  • Induced longitudinal voltage and induced noise voltage are used in the analysis on the power induction phenomenon and it is well known that these are in the subordinate relationship. But sometimes. there is a confusing situation that these voltages have not exact subordinate relationship in the actual measurement fields. So. we have analyze the correlation between induced longitudinal voltage and induced noise voltage by using tile actual measured data in the fields of 30 urban areas and 30 rural areas.

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Development of Power Plant Location Selection Simulator using Geographical Information Systems(GIS) (지리정보시스템을 통한 발전소 부지선정 시뮬레이터 개발)

  • Jun, Jin-Young;Nho, Yoon-Hui;Jung, Ji-Snag;Cho, Min-Ji;Kim, Byung-Gyu
    • Proceedings of the Korea Information Processing Society Conference
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    • 2014.11a
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    • pp.654-657
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    • 2014
  • 우리나라는 산업의 급속성장과 최근 서비스업 분야의 전력소비량이 매우 급증하면서 전력난 문제의 심각성을 더해가고 있으며 계속해서 많은 화두가 되고 있다. 그에 따라 정부에선 매년 신규 발전소의 건설계획을 세우고 있으며 건설계획 중 신규 발전소의 입지선정에는 복잡한 환경영향평가 과정을 거치게 된다. 본 논문에서는 이러한 복잡한 환경영향평가 항목들에 대한 자세한 정보들을 지도에 시각화 해주는 방법을 제안하고, 시각화된 정보들을 통하여 여러 개의 신규 발전소의 입지 후보들을 선출한 뒤 각각의 후보 입지의 평가항목들에 대한 점수를 산정하여 비교분석하고 문서화해주는 시뮬레이터 소프트웨어를 개발하였다. 본 기술로 인해 신규 발전소의 입지선정 비용을 절감시킬 수 있으며, 다양한 분야에서의 지리정보시스템의 활용 범위를 재고 해볼 수 있을 것으로 예상된다.

Eveluation of line probe assay in detecting rifampicin resistance of mycobacterium tuberculosis

  • Park, Young-Kil;Cho, Snag-Hyun;Kuk, Na-Byoung;Song, Chul-Yong;Bai, Gill-Han;Kim, Sang-Jae
    • Journal of Microbiology
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    • v.35 no.3
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    • pp.177-180
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    • 1997
  • The purpose of this study was to evaluate the efficiency of Line Probe Assay (LiPA) in detecting the rpoB gene mutation of clinically isolated Mycobacterium tuberculosis (MTB) and to compare the level of resistance to the various rifamycins with their mutation sites. The mutation in the rpoB gene was found in 84 (97.6%) out of 86 rifampicin (RMP) resistant strains as determined by LiPA. No mutation was observed in 2 RMP resistant strains and in any of 38 RMP susceptible strains tested. Only one of 3 strains with .DELTA.5/R5, one of 2 strains with .DELTA.3, and one of 3 strains with .DELTA.2/R2 LiPA profile showed a slightly lower level of resistance to the rifapentine than the other strains. Although we could not find correlations between mutation sites in the rpoB gene and the level of susceptibility to the various rifamycins, the LiPA is recommended as a fast screening tool for detection of RMP resistant MTB.

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SOrganic matter insulation by type of Study on pH change according to underwater settling period (유기질 단열재 종류별 수중정치기간에 따른 pH 변화에 관한 연구)

  • Hong, snag-hun;You, Nam Gyu;Seo, Eun-Seok;Kim, Han-nah;Kim, Bong-Joo;Jung, Ui-In
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.11a
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    • pp.87-88
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    • 2019
  • Research has been conducted in many fields for the zero energy of domestic buildings. Among them, the development of insulation has become an essential element. Accordingly, researches are being made to improve the performance of organic insulating materials, and PF boards having the lowest thermal conductivity among organic insulating materials have been in the spotlight. However, problems have arisen due to the problems of durability of insulation materials such as PF boards and past acidification, and the durability of insulation materials is deteriorated when moisture or water enters due to crack gaps during the insulation of the basement layer or the external insulation method. In regard to the durability of the insulation, when the organic insulators of different kinds were placed in water, the pH was weakly basic in all organic insulation materials except PF, and the PF was about 4 pH. As a result, the PF should be continuously reviewed, and further analysis should be carried out to determine what causes acidification.

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Evaluation of Indoor Air Quality Performance of Paste According to Carbon Black Replacement Ratio (카본블랙 치환율에 따른 페이스트의 실내 공기질 성능 평가)

  • Kim, Yeon-Ho;Lee, Snag-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.11a
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    • pp.135-136
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    • 2020
  • Recently, there is a problem that is most important in constructing buildings and building materials. It is a harmful substance generated in buildings. These harmful substances are CO2, radon and formaldehyde, volatile organic compounds generated from building materials. These are bad for the human body, may have a negative effect and cause large illnesses such as cancer. Recently built apartments have a high density, so there is a problem that harmful substances do not escape well. As a result, people's interest in indoor air quality is growing and in order to solve this problem and various researches are being conducted on the materials used for concrete pouring to find out how much the materials used adsorb harmful substances. this study uses carbon black as a material that can adsorb these harmful substances. The purpose of this study is to measure the bending strength, compressive strength, and to determine whether the paste containing carbon black can improve indoor air quality.

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