• 대한기계학회논문집B
• /
• 제28권10호
• /
• pp.1184-1192
• /
• 2004

Experimental investigations were carried out in an atmospheric pressure, optically accessible and laboratory-scale dump combustor operating on methane gas. The objective of this study was to obtain the phase-resolved gas temperatures at different phases of the oscillating pressure cycle during unstable combustion. CARS temperature measurements were made at several spatial locations under lean premixed conditions to get the information on temperature field within the combustor. Also the effect of incomplete fuel-air mixing on phase-resolved temperature fluctuation was investigated. Results including phase-resolved averaged temperature, normalized standard deviation and temperature probability distribution functions (PDFs) were provided in this paper. Temperature PDFs gave an insight on the flame behavior. And strong correlation between phase-resolved temperature profile and pressure cycle was observed. Results of the phase-resolved high temperature gave an additional information on the perturbation of equivalence ratio at flame as well as the effect of mixing quality on NOx emission characteristics.

• 경영정보학연구
• /
• 제10권1호
• /
• pp.193-211
• /
• 2008

ERP(Enterprise Resource Planning) 시스템의 성공적인 도입 및 운영에 있어 교육은 핵심성공 요인 중 하나로 밝혀져 있다. 그러나 ERP시스템 벤더와 도입 기업 모두 실제 프로세스 처리 사례의 정형화된 정보를 제공하지 못해 사용자에게 효과적인 비즈니스 프로세스 교육 방안을 제시 못하고 있는 실정이다. 또한, ERP 시스템에 대한 벤더의 불완전한 테스팅은 결국 불충분하고 비효과적인 사용자 교육으로 이어지고 있다. 본 논문에서는 ERP 시스템의 테스팅과 교육용 시나리오를 작성하기 위한 프레임웍인 SF-ETT (Scenario Framework for ERP Testing and Training)를 제시하고 있다. SF-ETT는 uniERPII를 위한 통합 테스트 시나리오 프로젝트를 통해 정립된 프랙티스 기반 ERP 테스팅 시나리오 작성 프레임웍을 확장하여 설계된 것이다. SF-ETT는 ERP 시스템의 사용자가 실질적으로 이해하는 비즈니스 프로세스의 실체를 기반하여 구성되어 프랙티스(Practice) 정의, 표기 방법, 프레임웍 구조를 제시한다.

• 한국도서관정보학회지
• /
• 제45권3호
• /
• pp.349-369
• /
• 2014

본 연구는 경기도 31개 지방자치단체 도서관 행정조직의 편성과 운영형태를 조사하여 문제점을 제시하고, 이를 토대로 도서관 행정조직체계의 개선방안을 제시하고자 한다. 분석결과 본청에 직속으로 편성된 도서관 조직은 거의 없었으며, 대부분 사업소 등의 외청으로 편성되어 있었다. 또한 도서관 관련 조직이 도서관사업소 등의 독립적인 조직으로 구성되어 있는 경우도 있지만, 타 업무나 조직 하에 배속되어 있는 경우가 매우 많았으며 셋째, 해당 지방자치단체의 봉사대상 인구수나 도서관 직원 수, 도서관 수를 감안했을 때 이에 부합하지 않는 직급의 도서관 행정조직을 구성한 곳도 많았다. 넷째, 도서관 정책담당 부서의 설치가 미비하였다. 다섯째, 도서관 운영체제(중앙관-거점관-분관)가 효율적으로 구성되지 못하였다.

• 대한의용생체공학회:의공학회지
• /
• 제29권6호
• /
• pp.502-511
• /
• 2008

This study was designed to develop a new algorithm to extract the voluntary EMG and the evoked EMG from a mixed EMG generated when the muscle is stimulated both voluntarily and by electrical stimulation in the FES system. The proposed parallel filter algorithm consists of three phases: (1) Fourier transform of the mixed EMG, (2) multiplication of the transformed signal to two frequency functions, and (3) inverse Fourier transform. Four incomplete spinal cord injured patients participated in the experiments to evaluate the algorithm by measuring the knee extensor torque and the EMG signals from the quadriceps. Two functions of the algorithms were evaluated: (1) extraction of the evoked EMG and (2) the voluntary EMG from the mixed EMG. The results showed that the algorithm enabled us to separate the two EMG components in real time from the mixed EMG. The algorithm can and will be used for estimating the voluntary torque and the evoked torque independently through an artificial neural network based on the two EMG components, and also for generating a trigger signal to control the on/off time of the FES system.

• 수산해양기술연구
• /
• 제53권1호
• /
• pp.19-40
• /
• 2017

A scientific and objective sound exposure criterion for underwater sound damage on fish has been required since there has been many disputes between an underwater sound maker and a fish damage receiver. The existing criteria are still incomplete scientifically owing to a degree of variability of underwater sounds, diversity of fish hearing sensitivity and damage types, etc. This study reviews existing studies on a hearing mechanism of fish species, manmade underwater sound characteristics and sound exposure assessment parameters, and recent sound exposure criteria. A governing equation for damage coverage estimation and damage coverage dependency on sound source level, ambient noise and transmission loss are also reviewed and interpreted based on sound exposure environments. The foreign and Korean (National Environmental Dispute Medication Commission) criteria are reviewed and compared based on scientific aspects. In addition, the deficit and limit of Korean criteria are presented. The objective of this study is to give a direction for related researches and legislation of sound exposure criteria on fish.

• International Journal of Contents
• /
• 제2권2호
• /
• pp.17-24
• /
• 2006

The work presented in this paper is divided into two parts. The first part presents finite urn problems which generate truncated negative binomial random variables. Some combinatorial identities that arose from the negative binomial sampling and truncated negative binomial sampling are established. These identities are constructed and serve important roles when we deal with these distributions and their characteristics. Other important results including cumulants and moments of the distributions are given in somewhat simple forms. Second, the distributions of the maximum of two chi-square variables and the distributions of the maximum correlated F-variables are then derived within the negative binomial sampling scheme. Although multinomial theory applied to order statistics and standard transformation techniques can be used to derive these distributions, the negative binomial sampling approach provides more information and deeper insight regarding the nature of the relationship between the sampling vehicle and the probability distributions of these functions of chi-square variables. We also provide an algorithm to compute the percentage points of these distributions. We supplement our findings with exact simple computational methods where no interpolations are involved.

• 지능정보연구
• /
• 제9권2호
• /
• pp.19-38
• /
• 2003

In this research, we propose the mechanism to develop self-evolving expert systems (SEES) based on data mining (DM), fuzzy neural networks (FNN), and relational database (RDB)-driven forward/backward inference engine. Most researchers had tried to develop a text-oriented knowledge base (KB) and inference engine (IE). However, this approach had some limitations such as 1) automatic rule extraction, 2) manipulation of ambiguousness in knowledge, 3) expandability of knowledge base, and 4) speed of inference. To overcome these limitations, knowledge engineers had tried to develop an automatic knowledge extraction mechanism. As a result, the adaptability of the expert systems was improved. Nonetheless, they didn't suggest a hybrid and generalized solution to develop self-evolving expert systems. To this purpose, we propose an automatic knowledge acquisition and composite inference mechanism based on DM, FNN, and RDB-driven inference engine. Our proposed mechanism has five advantages. First, it can extract and reduce the specific domain knowledge from incomplete database by using data mining technology. Second, our proposed mechanism can manipulate the ambiguousness in knowledge by using fuzzy membership functions. Third, it can construct the relational knowledge base and expand the knowledge base unlimitedly with RDBMS (relational database management systems) module. Fourth, our proposed hybrid data mining mechanism can reflect both association rule-based logical inference and complicate fuzzy relationships. Fifth, RDB-driven forward and backward inference time is shorter than the traditional text-oriented inference time.

• 한국통신학회논문지
• /
• 제29권6A호
• /
• pp.589-599
• /
• 2004

소프트웨어의 신뢰성을 정량적으로 평가하는 데 있어서 대다수의 모델이 발생된 소프트웨어 고장의 발생원인에 대한 완전한 수정을 요구하는 완전 디버깅 환경을 가정하고 있다. 그러나 실제 개발자가 디버깅 작업을 수행할 때 완전한 수정이 불가능하기 때문에. 새로운 결함이 삽입되는 경우가 많다. 즉, 결함 수정은 불완전 환경에 처한다. 본 논문에서는 결함 수정시 신규 결함의 삽입 가능성을 고려하고 불완전 디버깅 환경에 대한 소프트웨어 신뢰도 성장모델을 제안하고 소프트웨어 동작 환경 하에서 발생된 소프트웨어 고장과 시험 전 소프트웨어 내의 고유 결함에 의한 고장과 동작 중에 랜덤하게 삽입된 결함에 의해 발생되는 고장 등 2종류의 결함을 고려하여 비동차포아송과정(NHPP)에 의한 소프트웨어 고장발생 현상을 기술한다. 또 소프트웨어 신뢰성 평가에 유용한 정량적인 척도를 도출하고 실측 데이터를 이용하여 적용한 결과를 제시하고 기존 모델과의 적합성을 비교, 분석한다.

• 한국정보과학회논문지:소프트웨어및응용
• /
• 제36권4호
• /
• pp.273-282
• /
• 2009

소프트웨어 프로젝트 데이터를 이용한 각종 분석 예측 모델 생성시 직면하는 문제 중 하나는 데이터에 포함된 결측값이며 이에 대한 효과적인 방안은 결측값 대치 법이다. 대표적인 결측값 대치법인 K 최근접 이웃 대치법은 대치과정에서 결측값을 포함하는 인스턴스의 관측정보를 활용하지 못한다는 단점이 있다. 본 연구에서는 이러한 단점을 극복하기 위해 K 최근접 이웃 대치법과 최대 우도 추정법을 결합한 새로운 소프트웨어 프로젝트 수치 데이터용 결측값 대치법을 제안한다. 또한 결측값 대치법의 정확도를 비교하기 위한 새로운 측도를 함께 제안한다.

• 한국정보시스템학회지:정보시스템연구
• /
• 제26권2호
• /
• pp.165-183
• /
• 2017

Purpose The purpose of this study is to identify the related factors of cautious purchasing for buyers who have purchased products in online shopping mall. First, we focus on the prevention focus, which is one of the personal characteristics, that affect the cautious purchase, and analyze the satisfaction of purchasing according to cautious purchase. Furthermore, we investigate the influence of emotional intelligence (self-awareness and social-awareness) on the process of cautious purchasing and satisfaction. Design/methodology/approach In order to verify the hypotheses, this study surveyed individuals who purchase products on the Internet for about 2 months from August to September 2016. A total of 250 copies were returned, but 20 questionnaires that were incomplete were excluded. Thus, the final 230 samples were analyzed. Structural equation modeling (SEM) was used for hypothesis testing. Findings The result of this study showed that the cautious purchasing is stronger for the buyers with the prevention focus. And consumers who purchase carefully have higher satisfaction after purchasing. In addition, emotional intelligence in the cautious purchasing process has a positive moderating effect. Based on the results of this study, the theoretical and practical implications are suggested.