• Journal of the Korean Geotechnical Society
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• v.20 no.1
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• pp.121-129
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• 2004

In this study, a slope stability chart for assessing stability of homogeneous simple soil slopes is proposed. Most existing slope stability charts are based on limit equilibrium method, which is not rigorous in mechanical standpoint. Meanwhile, limit analysis based on the principle of virtual work and the bound theorems of plasticity is suitable for evaluating the stability of geotechnical structures such as slope due to its simplicity in computation and mechanical rigor. Numerical limit analysis taking advantage of finite elements and linear programming can consider various slope conditions and, in addition, find the optimum stability solution with effeciency. In this study, a numerical limit analysis program in terms of effective stress is developed and a mechanically rigorous slope stability chart is proposed by performing stability analyses for various slope conditions. Pore pressure ratio, commonly used in stability charts, is applied to consider the effects of pore pressure for effective stress analysis. As a result of comparison between proposed stability chart and Spencer's stability chart, it was found that Spencer's chart solutions are biased to lower bound which means conservative in design.

• KDI Journal of Economic Policy
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• v.13 no.3
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• pp.31-53
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• 1991

본고(本稿)에서는 구조적(構造的) 재정수지(財政收支) 분석(分析)을 통하여 1972년 이후의 중앙정부(中央政府) 재정운용(財政運用)을 경기조절적(景氣調節的) 측면(側面)에서 평가(評價)하고 향후(向後) 정책방향(政策方向)을 모색해 보고자 하였다. 분석결과에 의하면 구조적(構造的) 재정수지(財政收支)는 1970년대 중반까지 계속 적자(赤字)를 보여 왔으나, 1970년대 후반 이후의 재정적자축소노력(財政赤字縮小努力)으로 인해 1980년대에는 실제재정수지(實際財政收支)의 적자(赤字)에도 불구하고 구조적(構造的)으로는 흑자기조(黑字基調)로 반전하였던 것으로 나타났다. 그러나 1988년 이후 중앙정부(中央政府) 세출규모(歲出規模)의 빠른 증대로 인하여 구조적(構造的) 재정수지(財政收支)는 다시 적자기조(赤字基調)가 심화되고 있는 것으로 나타났다. 또한 재정(財政)의 경기조절적(景氣調節的) 역할(役割)을 평가해 볼 경우, 세입(歲入)의 자동조절적(自動調節的) 변화분(變化分)은 경기변동(景氣變動)에 의해 발생되는 명목(名目)GNP갭의 15~18%를 흡수함으로써 총수요안정(總需要安定)에 중요한 역할을 하는 것으로 나타난 반면, 구조적(構造的) 재정기조(財政基調)의 변화(變化)는 1980년대 초반을 제외하고는 경기동행적(景氣同行的) 추세(趨勢)를 보이고 있는 것으로 나타나 그동안 재정부문(財政部門)의 경기조절적(景氣調節的) 역할수행(役割遂行)이 미흡했던 것으로 판단된다. 따라서 향후(向後) 재정적자문제(財政赤字問題)의 대두를 방지하기 위해서는 예산운용(豫算運用)의 효율화(效率化) 추진(推進) 및 담세율제고(擔稅率提高) 등의 수지개선노력(收支改善努力)이 요구되며, 아울러 과다한 추경편성(追更編成)의 지양(止揚) 등으로 재정(財政)의 경기조절적(景氣調節的) 역할(役割)을 강화해야 할 것으로 판단된다.

• Korean Journal of Construction Engineering and Management
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• v.13 no.4
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• pp.48-59
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• 2012

Gangform, compared to the traditional forms, is a systemized form which can reduce construction duration and cost by the advantage of using it repeatedly. However, transportation and climbing process of the Gangform is highly dependant on the performance of tower crane. Gangform climbing process takes one day out of six to seven days of a structural work cycle. Tower cranes can not be used in other lifting works when they lift the Gangform during the structural work cycle, causing the delay in the construction project. Numerous efforts and researches have been done in domestic and international industry to solve such limitations of Gangform climbing process. Especially, "A Study on the Development of Automatic Gangform Climbing System for Apartment Housing Construction"has suggested a conceptual model which can climb the Gangform system without a tower crane. In this paper, the technical and economical feasibilities of previously proposed Automatic Gangform climbing system are examined by evaluating its structural stability and lifting load reduction effect.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.21 no.2
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• pp.22-48
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• 1995

This study was investigated to search for the effects of the structure of each component in four-component O/W microemulsion system on its formation region, droplet size and stablilty. The results was that the more number of OH site, the shorter carbon chain length of polyol, the larger formation region of microemulsion was showed. The small microemulsion droplet was obtained on condition that the polatry of oil was large and carbon chain length of hydrophobic group of surfactant was long. In using satrated hydrocarbon (such as liquid paraffin, squalane) as dispersed phase, the stability of microemulsion was better than aromatic oil phase.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.20 no.1
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• pp.42-48
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• 2008

A system of risk assessment is developed by using the reliability analysis which evaluate quantitatively both stability and performance of sloped-coastal structures according to several scenarios of sea-level rise. By using reliability functions on armor unit and run-up, the probabilities of failure can be straightforwardly calculated with respect to several design parameters such as nominal diameter of armor unit, slope of coastal structure, and freeboard height. By comparing the results before and after sea-level rise, it may be possible to exactly assess some ranges of decrease of stability and performance of sloped-coastal structure with respect to sea-level rise. Therefore, it can also be possible to make a decision which parameters should be repaired or strengthened in order to maintain the original stability and performance of sloped-coastal structures. Finally, The present results may be useful for designing some kinds of new sloped-coastal structures including the effect of sea-level rise.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.8
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• pp.8-12
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• 2005

This paper designed electronic ballast inverter circuit using the PSpice simulation and it compared with practical ballast about electrical characteristics. Used electronic ballast driving type is self-exciting half bridge inverter we have got much the same electrical result both simulation and experiment of practical electronic ballast.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1562-1563
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• 2007

본 논문에서는 퍼지 선형추론 기반 지능형 Dimming Converter의 새로운 구조 및 설계 방법론을 제안하고 일련의 수치적인 실험을 통하여 모델 및 시스템을 평가한다. 기존의 형광 램프용 디밍 전자식 안정기는 전용의 디밍 IC를 사용하여 전자식 안정기 대비 최대 83%의 램프 및 안정기의 수명 연장을 가능하게 했다. 하지만 이러한 장점은 사용자가 수동제어를 해야만 하는 불편함 뿐만 아니라, 수동 제어가 불가능 할 경우 램프의 에너지 절약 및 수명 연장이라는 실효를 얻을 수 없다. 따라서 본 논문에서는 퍼지 선형추론 기반의 지능형 이론 및 조도센서를 사용하여 최적의 능동적 디밍제어가 가능한 시스템을 제안하고 제안된 시스템을 안정기에 적용하고 기존 전자식 안정기대비 성능평가를 통하여 지능형 Dimming Converter의 우수성을 보인다.

• The Journal of Society for e-Business Studies
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• v.20 no.4
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• pp.61-76
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• 2015

In general, we have utilized the hierarchical concept tree as a crucial data structure for indexing huge amount of textual data. This paper proposes a generality rank-based method that can automatically develop hierarchical concept structures with the Wikipedia data. The goal of the method is to regard each of Wikipedia articles as a concept and to generate hierarchical relationships among concepts. In order to estimate the generality of concepts, we have devised a special ranking function that mainly uses the number of hyperlinks among Wikipedia articles. The ranking function is effectively used for computing the probabilistic subsumption among concepts, which allows to generate relatively more stable hierarchical structures. Eventually, a set of concept pairs with hierarchical relationship is visualized as a DAG (directed acyclic graph). Through the empirical analysis using the concept hierarchy of Open Directory Project, we proved that the proposed method outperforms a representative baseline method and it can automatically extract concept hierarchies with high accuracy.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.329-332
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• 2001

The stability of red pigment isolated from RF101 was determined over a period of storage for the pH, light, temperature and various metal ions. The absorption maximum of red pigment was 510nm. Red pigment was stable from pH 5 to pH 9 and in dark conditions. It was also stable against temperature below $25^{\circ}C$ and in $K^+$, $Ca^{2+}$, $Mg^{2+}$, Antibacterial activity of RF101 showed growth-inhibitory activity against plant pathogens Agrobacterium spp.

• Journal of the Korean Geotechnical Society
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• v.23 no.10
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• pp.33-45
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• 2007

In this study, the blast-induced vibration effects on the structural stability of the adjacent tunnel were estimated with respect to the allowable peak particle velocity (PPV). The blasting distance from the tunnel satisfying the allowable PPV was estimated based on the analytical solutions, United States Bureau of Mines (USBM) suggestions, and the equations used in the subway in Seoul. The allowable blasting distance was estimated by using finite difference analysis (FDA) and the behavior of the concrete lining and rock bolts was examined and the stability of those was estimated during the blast. Research results show that the blast-induced vibration effects on the structural stability are negligible for the concrete lining but relatively large for the rock bolts.