• Journal of KIISE:Computer Systems and Theory
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• v.28 no.8
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• pp.379-389
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• 2001

본 논문에서는 루프 반복들 간에 종속 관계가 존재하는 루프의 효율적 수행을 위한 새로운 루프 할당 기법을 제안한다. 그리고, 중앙 큐를 사용하여 공유 메모리 다중처리기에 루프 반복을 할당하는 기존 셀프 스케쥴링 기법들을 루프 캐리 종속성(loop-carried dependence)을 가진 루프의 할당에 적용하기 위해 제안한 기법을 이용한 그들의 변형에 대해 알아본다. 종속 거리를 고려하여 루프를 세 단계별로 할당하는 제안된 CDSS(Carried-Dependence Self-Scheduling) 기법 또한, 중앙 작업 큐를 기반으로 한 것이며 별도의 스케쥴러가 필요 없는 셀프 스케쥴링 알고리즘이다. 종속거리, 프로세서 수, 반복 수, 스케쥴링 연산 시간 등을 다양하게 하여 변형된 할당 기법들과 비교 분석한 결과, 제안한 기법은 양호한 부하 균형을 유지하였으며 변형된 다른 기법들에 비해 루프 수행 시간을 줄여 효율적임을 알 수 있었다. 다양한 실험 환경에서 평균적으로 제안한 CDSS, 변형된 SS, Factoring, GSS, CSS 기법 순으로 루프 수행 시간 측면에서 좋은 성능을 보였다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10a
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• pp.574-576
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• 2001

컴포넌트에 기반한 소프트웨어 개발(CBSD)에 관한 연구가 활발히 진행 중에 있다. 시스템 개발 시 컴포넌트를 활용하여 개발기간과 신뢰도를 향상시키기 위해서는 무엇보다 이들 컴포넌트의 탐색과 선택을 효과적으로 지원할 수 있는 방안이 요구된다[11]. 이를 위하여 컴포넌트 명세기법과 검색시스템에 관한 연구가 지속적으로 수행되고 있으나, 다수의 연구에서 컴포넌트의 기능과 인터페이스에만 초점을 두어 종속성에 대한 고려는 부족한 실정이다. 컴포넌트는 본질적으로 완벽하게 독립적이지 못하며 내부와 외부 요소간 종속성을 맺기 때문에 [5]. 종속성에 관한 명세와 정보제공은 컴포넌트 재사용과 활성화를 위해 필수적이다. 따라서, 본 연구에서는 XML을 이용한 자바빈즈 컴포넌트의 내부 종속성 명세기법을 제시하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.04a
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• pp.239-242
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• 2001

일반적인 응용 프로그램에서 병렬성이 많은 구조는 루프 구조이며, 루프를 병렬로 처리하기 위해 동기화가 필요하다. 본 논문에서는 다중첨자를 갖는 1차원 배열의 루프의 병렬화를 위해 다수 개의 동일한 종속값을 이용하여 종속함수를 생성하고 이를 이용하여 종속관계가 성립하지 않는 비종속 구간(Non-dependence part)을 구한다. 그리고 동일한 값을 가지는 복수개의 종속값 간의 동기화는 외부루프 분할 기법을 이용하여 간소화 한 후 단일 첨자를 갖는 루프에 동기화를 수행하는 기법을 제시한다.

• Journal of the Korean Statistical Society
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• v.6 no.2
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• pp.117-154
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• 1977

본논문에서는 첫째로 단일방정식 모형에서 종속변수가 양자택일(binary choice)의 이산확률변수일 때 이러한 이진적 종속변수(binary dependent variable)의 변동을 설명하는데 사용되는 몇 가지 모형을 소개하고 각각의 표기 및 추정방법, 추정량의 성질, 예측 및 검정 문제 등에 관하여 비교 서술하고자 한다. 둘째, 종속변수가 이산과 연속의 혼합형태일 때 앞에 소개된 모형이 어떻게 적용될 수 있는가를 살펴보며, 셋째, 선택대상 및 종속변수의 수가 증가하여 일반화된 선다형모형(multiple choice model)의 경우, 표기 및 추정방법을 단일방정식 기법을 이용하여 추가로 총람하고자 한다. 넷째, 본논문에서는 또한 내구소비재 구입에 관한 조사자료를 이용하여 실제 많이 사용되는 몇 개의 모형을 선택하여 적용하고 각각의 예측력을 분석함으로써 각 모형을 비교 검토하는데 목적이 있다.

• The Journal of Korean Association of Computer Education
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• v.8 no.1
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• pp.93-103
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• 2005

Since the most program execution time is consumed in a loop structure, extracting parallelism from sequential loop programs is critical for the faster program execution. Conventional studies for extracting the parallelism are focused mostly on a uniform data dependence distance. In this paper, we proposed data dependency elimination method for a nested loop and extended data dependency elimination method to extract parallelism from the loop with procedure calls. The data dependency elimination method and the extended data dependency elimination method can be applied to uniform and non-uniform data dependency distance. We compared our method with conventional methods using CRAY-T3E for the performance evaluation. The results show that the proposed algorithms are very effective.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.5
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• pp.59-65
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• 2011

In this paper, we present a reduced-order parameter-dependent robust $H_{\infty}$ filter design method for discrete-time singular systems with polytopic uncertainties. A BRL(bounded real lemma) for parameter-dependent singular systems is derived from a parameter-dependent Lyapunov function. On the basis of the obtained BRL, low order robust $H_{\infty}$ filter design method is presented by polytopic approach, new reduced-order method, and LMI(linear matrix inequality) technique. Finally, a numerical example is presented to illustrated the feasibility of the proposed method.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.11
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• pp.1995-2005
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• 2000

The use of heterotrophic denitrification as an alternative method for supplying alkalinity during sulfur-utilizing autotrophic denitrification was evaluated by examining the effects of external carbon source (both type and concentration) and HRT on denitrification efficiency. Concentrations of $NO_3{^-}-N$ and $COD_{Cr}$ of nitrified landfill leachate used for experiment were 700-900mg/L and 900-2500mg/L. respectively, All experiment was conducted with sulfur packed bed reactors (SPBRs) which were operated at $35^{\circ}C$. The fraction of $NO_3{^-}-N$ removed by heterotrophic denitrification ($HDNR_{fraction}$) to balance the alkalinity consumption by autotrophic denitrification varied with the type of external carbon source. When methanol and sodium acetate was added at theoretical HDNRfraction value. 100% denitrification was achieved without alkalinity addition. However, glucose and molasses require $HDNR_{fraction}$ value greater than theoretical value for complete denitrification. The EBCT and volumetric loading rate at which 100% denitrification efficiency could be achieved were 6.76 h and $2.84kg-NO_3{^-}-N/m^3{\cdot}d$, respectively, based on the fact that 100% denitrification occurred within the bottom 11.5 cm layer of the SPBR. The maximum nitrogen removal rate occurred with 89% removal efficiency at loading rate of $5.05kg-NO_3{^-}-N/m^3{\cdot}d$. However, at short EBCT, clogging of SPBR was observed with excess growth of heterotrophic denitrifiers. This problem may be eliminated by back washing or by separating of heterotrophic denitrification from sulfur-utilizing denitrification.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1A
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• pp.237-246
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• 2006

In order to evaluate the seismic performance of damaged reinforced concrete members, particularly bridge piers, an inelastic time-dependent element is proposed. The proposed element enables increased characteristics due to structural intervention(i.e., repair or retrofitting) to be accurately reflected to the degraded strength and stiffness of the members. The inelastic time-dependent element having both birth and death time can freely be activated within the user-defined time intervals during static and dynamic time-history analysis. Comparative studies are carried out for reinforced concrete bridge piers that are repaired and retrofitted. Analytical predictions using the developed element show reasonable correlation with experimental results. Also conducted is a nonlinear time-history analysis of a reinforced concrete bridge under multiple earthquakes. The comparative analytical results prove the validation of current development. In all, it is concluded that the present element is capable of providing salient features for the healthy evaluation of seismic performance and hence seismic stability assessment of RC bridge piers being repaired and retrofitted.

• Communications for Statistical Applications and Methods
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• v.3 no.3
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• pp.247-251
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• 1996

독립인 두 쌍의 확률변수에 대한 두 쌍의 복합형태는 비상관 종속인 순서쌍들과 독립인 쌍들로 나타낼수 있다.

• Journal of the Korean Society of Groundwater Environment
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• v.2 no.2
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• pp.85-92
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• 1995

This study was conducted to find out the relationship between microflora in groundwater and its physico-chemical environmental factors at the 59 sites, where distributed at 3 cities and 18 counties in Jeonranam-Do, Korea. The average values of environmental factors were as followings; pH 6.9, temperature 20.1 $^{\circ}C$, dissolved oxygen 6.5 mg/1, the depth of wells 80.1 m, and nitrate 10.7 mg/1. The average value of microbial population size; Heterotrophic bacteria-NA (HPC-NA) and heterotrophic bacteria-YEPD (HPC-YEPD) were 1.4${\times}$10$^3$CFU/ml and 0.59${\times}$10$^3$ CFU/ml respectively HPC-YEPD numbers were 42.1% of HPC-YEPD. Coliform bacteria were detected at 16 sites, and its average numbers were 6.7 CFU/ml. General fungi were detected at 14 sites, and its had average numbers were 3.9 CFU/ml. The correlation coefficient was calculated value as relation index between the microbial population sizes and environmental factors in groundwater. In case of HPC-NA, the correlation coefficient value with dissolved oxygen was 0.087 But it showed negative correlation coefficient with other factors. In case of HPC-YEPD, the correlation coefficient value with pH, temperature and nitrate were 0.0957, 0.0019 and 0.0151 respectively. It was concluded that the population size of HPC-NA were influenced by the order of temperature, dissolved oxygen, pH and the depth of wells and that HPC-YEPD were influenced by the order of pH, dissolved oxygen, nitrate, the depth of wells and temperature.