• Genomics & Informatics
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• 제7권1호
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• pp.1-12
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• 2009

An alternative way of constructing ancestral graphs, which is different from the coalescent-based approach, is proposed using population linkage disequilibrium (LD) data. The main difference from the existing method is the construction of the ancestral graphs based on variants instead of individual sequences. Therefore, the key of the proposed method is to use the order of allele ages in the graphs. Distinct from the previous age-estimation methods, allele ages are estimated from full haplotype information by examining the number of generations from the initial complete LD to the current decayed state for each two variants depending on the direction of LD decay between variants. Using a simple algorithmic procedure, an ancestral graph can be derived from the expected allele ages and current LD decay status. This method is different in many ways from previous methods, and, with further improvement, it might be a good replacement for the current approaches.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.236-239
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• 2002

Surface states of silicone polymer treated by plasma were investigated by the analysis by x-ray photoelectron spectroscopy (XPS) and surface voltage decay. Plasma treatment causes the silica-like oxidative layer, which is confirmed with XPS, and lowers surface resistivity with increasing the plasma treatment time. Using the decay time constant of surface voltage, the calculated surface resistivity was compared with the value directly measured by a voltage-current method. A good agreement between two methods was obtained. In addition, we estimated the thermal activation energy for surface conduction, Based on our results, we could understand the relationship between surface chemical states and surface electrical properties.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1569-1571
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• 1999

In this work, we have performed the application experiment for real distribution line to diagnose the underground power cables using DC voltage decay measurement system. We have also performed the Isothermal Relaxation Current test for the same distribution line using KDA-l. We could confirmed possibility of grading the insulation aging state of underground power cables. Therefore, we conclude that it is possible to apply DC voltage decay method to the real distribution line.

• 한국산림과학회지
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• 제79권2호
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• pp.138-143
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• 1990

낙엽송 성숙임분(成熟林分)(1925년(年) 식재(植栽))내(內)에서 해면버섯균(菌)과 꽃송이버섯균(菌)의 자실체(子實體)가 발생(發生)된 부후피해목(腐朽被害木)을 벌채(伐採)하여 심재부후피해(心材腐朽被害)을 조사(調査)하였다. 벌근단면상(伐根斷面上)에 수(髓)를 중심(中心)하여 나타난 부후단면적율(腐朽斷面積率)은 19.2~74.4%, 부후(腐朽)높이는 수고(樹高) 1.2~5.5m, 부후재적율(腐朽材積率)은 2.2~13.4%였고, 심재부(心材部)에 부후(腐朽)가 나타나는 높이까지를 손실재(損失材)로 보면 전체재적(全體材積)의 27.2%(13.1~37.1%)가 부후(腐朽)된 것으로 나타났다. 양균종간(兩菌種間)의 피해(被害)크기 비교(比較)에서는 꽃송이버섯균(菌)에 의(依)한 피해(被害)가 해연버섯균(菌)에 의(依)한 피해(被害)보다 더 심(甚)하였다. 또한 부후재부(腐朽材部)의 압축강도(壓縮强度)($52{\sim}77kg/cm^2$)와 비중(比重)(0.40~0.47)은 건전목(健全木)의 건전재(健全材)에 비(比)하여 각각(各各) 최고(最高) 77% 및 39%가 감소(減少)한 것으로 나타났고, 부후재부(腐朽材部)가 있는 높이까지의 육안건전재부(肉眼健全材部)의 강도(强度)와 비중(比重)도 최고(最高) 42% 및 26%가 감소(減少)한 것으로 나타났다. 한편 부후피해목(腐朽被害木)과 건전목(健全木)의 연년(連年) 생장량(生長量) 비교(比較)에서, 흉고직경(胸高直徑) 생장량(生長量)은 식재(植栽) 8-14년후(年後)부터 재적(材積) 생장량(生長量)은 식재(植材) 12-21년후(年後)부터 건전목(健全木)에 뒤떨어지는 것으로 나타났다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1156-1158
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• 1995

Charge decay, thermally stimulated current(TSC), charging and discharging currents(I) are measured for negatively corona-charged polymers. In this study, we will make an experiment in charge decay on polymer surface, TSC, polarity effect and the others in order to analysis it's mechanism. Especially polyvinylidene fluoride(PVDF) film is the best functional material which has been so far. Therefore, It's worthy of notice to investigate it's characteristic. And then some other functional polymers will be focused on. An experimental result was missed out for the shortage of setting. So, this thesis will be explained on the theory and direction of reseach hereafter.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 추계학술대회 논문집
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• pp.365-368
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• 1995

Charge decay, thermally stimulated current (TSC), charging and discharging currents(I) are measured for corona-charged composite insulating materials. In this study, We will make an experiment in charge decay on composite material surface, TSC, polarity effect and the others in order to analysis its mechanism. Especially, Fiber glass Reinforced Plastics(FRP) is the best composite material which has been so far. Therefore, Its worthy of notice to investigate its characteristic. And then some other materials will be focused on. This experiment measured characteristic of charge decay, dependence of discharging-time and other electrostatic characteristics on FRP.

• Nuclear Engineering and Technology
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• 제31권6호
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• pp.66-82
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• 1999

The national long-term R&D program, updated in 1997, requires Korea Atomic Energy Research Institute(KAERI) to complete by the year 2006 the basic design of Korea Advanced Liquid Metal Reactor(KALIMER), along with supporting R&D work, with the capability of resolving the issue of spent fuel storage as well as with significantly enhanced safety. KALIMER is a 150 MWe pool-type sodium cooled prototype reactor that uses metallic fuel. The conceptual design is currently under way to establish a self-consistent design meeting a set of major safety design requirements for accident prevention. Some of the current emphasis includes those for inherent and passive means of negative reactivity insertion and decay heat removal, high shutdown reliability, prevention of and protection from sodium chemical reaction, and high seismic margin, among others. All of these requirements affect the reactor design significantly and involve extensive supporting R&D programs. This paper summarizes some of the results of conceptual engineering and design analyses performed for the safety of HAMMER in the area of inherent safety, passive decay heat removal, sodium water reaction, and seismic isolation.

• 천문학회보
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• 제37권2호
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• pp.119.2-119.2
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• 2012

Charged particle energization is an outstanding problem in space physics. This paper investigates the nonlinear dynamics of Alfve'n-cyclotron waves accompanying particle heating processes and the drift Alfv'en-cyclotron (or EMIC) instability associated with a current disruption event on 29 January 2008 observed with THEMIS satellite by means of a particle-in-cell simulation. The simulation shows that the drift Alfv'en-cyclotron instabilities are excited in two regimes, a relatively low frequency mode propagating in a quasi-perpendicular direction while the second high-frequency branch propagating in a predominantly parallel propagation direction, which is consistent with observation as well as earlier theories. It is shown that parametric decay processes lead to an inverse cascade of Alfv'en-cyclotron waves and the generation of ion-acoustic waves by decay instability. It is also shown that the nonlinear decay processes are accompanied by small perpendicular heating and parallel cooling of the protons, and a pronounced parallel heating of the electrons.

• Journal of the Korean Physical Society
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• 제73권11호
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• pp.1625-1630
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• 2018

The recent neutrino experiment results show a preference on normal mass ordering of neutrinos. The global efforts to search for neutrinoless double beta decays undergo a broad gap with the approach to the prediction in three-neutrino framework based on the normal ordering. Current research is to show that it is possible to find a neutrinoless double beta decay signal even with normal ordered neutrino masses. We propose the existence of light sterile neutrino as a solution to the higher effective mass of electron neutrino expected by experiments under operation. A few short-baseline oscillation experiments gave rise to exclusion bound to the mass of sterile neutrino and its mixing with the lightest neutrino. It is demonstrated that results of neutrinoless double beta decays can also narrow down the ranges of the mass and the mixing angle of sterile neutrino.

• 보존과학회지
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• 제38권4호
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• pp.265-276
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• 2022

A long-term monitoring investigation at Sarushima Battery (Kanagawa, Japan), which is one of the modernization heritages was conducted from 2017.06 to 2020.12. The investigation of the temperature and relative humidity (RH), measurement of the amount of brick decay, and X-ray diffraction analysis of the brick decay was conducted to understand in detail the environment in which the historical brick structure, the state of deterioration, identify the factors of deterioration. Furthermore, it was discussed whether the suitability of these investigation methods for assessing the status, identifying the level of deterioration and the factors that led to deterioration at the historical brick heritages. It was found that the brick deterioration at the site progressed especially in two periods: in April, and from June to August. These periods coincided with the period when the RH inside the structure decreased, and the Toyo-gumi bricks were in the process of absorbing moisture. Several different types of salts were detected in brick decay, especially thenardite, which is considered highly hazardous and destructive during periods when the amount of brick decay increased. Therefore, the RH in the structure and the salts present in the bricks were identified as one of the factors in the deterioration of the bricks at the site. The methods used in this study are appropriate as the initial survey methods for investigating the current conditions and identifying the causes of deterioration because it is possible to understand the environment within the modernization heritages, grasp the details of deterioration progression, and identify the characteristics of deterioration progression and its factors through long-term investigation using the simple methods.