• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.141-142
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• 2019

As part of the recent low-energy policy, insulation standards for buildings are increasing every year. In addition, the conventional styrofoam heat insulation material has a problem in that the thickness of the heat insulation material to achieve the standard heat transmission rate is rapidly increased. Although the risk of spreading the structure vulnerable to fire due to insufficient spacing between buildings due to thickened insulation is increasing, the high cost of high efficiency insulation is difficult to solve. On the other hand, it is known that the method to be used as a formwork using insulation is excellent in cost reduction effect by reducing the amount of formwork used and simplifying the subsequent insulation work. The purpose of this study is to evaluate the strength characteristics of multi - layered insulation materials with appropriate strength by reducing the thickness of the insulation by appropriately combining high performance phenolic foam insulation and styrofoam insulation.

• Genomics & Informatics
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• 제6권3호
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• pp.130-135
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• 2008

The haplotypes of a 200 kb region in the human chromosome X terminal band (q28) were analyzed using the International HapMap Project Phasell data, which had been collected for three analysis panels (YRI, CEU, and CHB＋JPT). When multiple linkage disequilibrium blocks were encountered for a panel, the neighboring haplotypes that had crossover rate of 5% or more in the panel were combined to generate 'haploid' configurations. This resulted in 8, 7, and 5 'haploid' configurations for the panels of YRI, CEU, and CHB＋JPT, respectively. The multiple sequence alignment of these 'haploids' was used for the calculation of allele-sharing distances and the subsequent principal coordinate analysis. Two 'haploids' in CEU and CHB＋JPT were hypothesized as 'parental' in light of the observations that the successive recombinants of these haploids can model two other haploids in CEU and CHB＋JPT, and that their configurations were consistent with those in YRI. This study demonstrates the utility of haplotype phylogeny in understanding population evolution.

• Structural Engineering and Mechanics
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• 제4권6호
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• pp.601-612
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• 1996

To simulate the large-scale failure evolution with current computational facilities, a simple approach, that catches the essential feature of failure mechanisms, must be available so that the routine use of failure analysis is feasible. Based on the previous research results, a simple analysis procedure is described in this paper for failure simulation. In this procedure, the evolution of localization is represented by a moving surface of discontinuity, and the transition between continuous and discontinuous failure modes are described via the moving jump forms of conservation laws. As a result, local plasticity and damage models, that are formulated based on thermodynamic restrictions, are still valid without invoking higher order terms, and simple integration schemes can be designed for the rate forms of constitutive models. To resolve localized large deformations and subsequent cracking, an efficient structural solution scheme is given for Static and dynamic problems.

• 전자공학회논문지B
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• 제33B권9호
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• pp.97-106
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• 1996

In this paper, we propose a face recognition algorithm using the hidden markov model and neural networks (HMM-NN). In the preprocessing stage, we find edges of a face using the locally adaptive threshold (LAT) scheme and extract features based on generic knowledge of a face, then construct a database with extracted features. In the training stage, we generate HMM parameters for each person by using the forward-backward algorithm. In the recognition stage, we apply probability vlaues calculated by the HMM to subsequent neural networks (NN) as input data. Computer simulation shows that the proposed HMM-NN algorithm gives higher recognition rate compared with conventional face recognition algorithms.

• Nuclear Engineering and Technology
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• 제32권6호
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• pp.595-604
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• 2000

Flow-Accelerated Corrosion Behavior of SA106 Gr.C steel in room temperature alkaline solution simulating the CANDU primary water condition was studied using Rotating Cylinder Electrode. Systems of RCE were set up and electrochemical parameters were applied at various rotating speeds. Corrosion current density decreased up to pH 10.4 then it increased rapidly at higher pH. This is due to the increasing tendency of cathodic and anodic exchange half-cell current. Corrosion potential shifted slightly upward with rotating velocity. Passive film was formed from pH 9.8 by the mechanism of step oxidation and the subsequent precipitation of ferrous species into hydroxyl compound. Above pH 10.4, the film formation process was active and the film became stable. Corrosion current density showed increment in pH 6.98 with the rotating velocity, while it soon saturated from 1000 rpm above pH 9.8. This seems that activation process which represents formation of passive film on the bare metal surface controls the entire corrosion process

• 한국막학회:학술대회논문집
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• 한국막학회 1999년도 The 7th Summer Workshop of the Membrane Society of Korea
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• pp.55-58
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• 1999

Nafion supported catalytic membranes were found to be active, stable and selective in th partial oxidation of propane to oxygenates with H2O2 under mild condition. Addition of Fe2+ in liquid phase enhances the reaction rate. Reaction proceeds according to a radical mechanism based on th electrophilic activation of propane on superacid sites and subsequent reaction of the activated paraffin with OH radicals. The use of a catalytic membrane, which allow separation of the intermediate products from the liquid phase containing the oxidant, was found to be effective to perform selective partial oxidation of propane with high yields to oxygenated products.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 A
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• pp.436-438
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• 1993

A rule based fuzzy expert system in self-tune PID controllers is presented in this paper. The rule base. the core of the expert system, is extracted from the Wills' tuning map and the author's knowledge about the implicit relations between PID gains and controlled output response. The overall control system consists of the relay feedback scheme and the expert system, where the one is responsible for initial tuning and the other for subsequent tuning. The PID control system with the proposed fuzzy expert system, shows better convergence rate and control performances than those of a Litt in spite of the fact that the two rule bases are extracted from the same maps provided by Wills.

• 한국분말재료학회지
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• 제15권2호
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• pp.87-94
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• 2008

In order to investigate a nitriding process of spent oxide fuel and the subsequent change in thermal properties after nitriding, simulated spent fuel powder was converted into a nitride pellet with simulated fission product elements through a carbothermic reduction process. Nitriding rate of simulated spent fuel was decreased with increasing of the amount of fission products. Contents of Ba and Sr in simulated spent fuel were decreased after the carbothermic reduction process. The thermal conductivity of the nitride pellet was decreased by an addition of fission product element but was higher than that of the oxide fuel containing fission product elements.

• 한국수정란이식학회지
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• 제11권2호
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• pp.179-191
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• 1996

In-vitro culture has provided new inforrnation on mechanisms of oocytes rnaturation and results obtained in vitro have led to new questions. In porcine, follicular and oocyte size have the crucial importance for the oocytes maturation. The addition of hormones to the culture medium was found to accelerate and facilitate meiotic maturation. The presence of some factors in serum trigger the resumption of meiosis and support the maturation of oocytes in vitro. The maturation rate of porcine oocytes was also increased by supplementation of porcine follicular fluid to the culture medium. The growth factors can stimulate nuclear maturation and enhances cytoplasnic maturation of oocytes by interaction with gonadotropins. The maturation-promoting factor brings about GVBD and the subsequent maturational events in oocytes. However, cAMP can block the spontaneous meiotic maturation of oocytes in culture. The understanding of these influences is a prerequisite to enhancing in vitro maturation of porcine oocytes.

• Bulletin of the Korean Chemical Society
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• 제20권6호
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• pp.696-700
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• 1999

A method has been developed for the determination of trace anion impurities in concentrated hydrogen peroxide. The method involves on-line decomposition of hydrogen peroxide, ion chromatographic separation and subsequent suppressed-type conductivity detection. H2O2 is decomposed in Pt-catalyst filled Gore-Tex membrane tubing and the resulting aqueous solution containing analytes is introduced to the injection valve of an ion chromatograph for periodic determinations. The oxygen gas evolving within the membrane tubing escapes freely through the membrane wall causing no problem in ion chromatographic analysis. Decomposition efficiency is above 99.99% at a flow rate of 0.4mL/min for a 30% hydrogen peroxide concentration. Analytes are quantitatively retained. The analysis results for several brands of commercial hydrogen peroxides are reported.