• Nuclear Engineering and Technology
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• 제52권9호
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• pp.1926-1938
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• 2020

We validated the performance of RELAP MOD3.3 code regarding the hybrid SIT with available experimental data. The concept of the hybrid SIT is to connect the pressurizer to SIT to utilize the water inside SIT in the case of SBO or SB-LOCA combined with TLOFW. We investigated how well RELAP5 code predicts the physical phenomena in terms of the equilibrium time, stratification, condensation against Separate Effect Test (SET) data. We also conducted the validation of RELAP5 code against Integrated Effect Test (IET) experimental data produced by the ATLAS facility. We followed conventional approach for code validation of IET data, which are pre-test and post-test calculation. RELAP5 code shows substantial difference with changing number of nodes. The increase of the number of nodes tends to reduce the condensation rate at the interface between liquid and vapor inside the hybrid SIT. The environmental heat loss also contributes to the large discrepancy between the simulation results of RELAP5 and the experimental data.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제2권3호
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• pp.204-209
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• 2002

The interest of data mining in artificial intelligence with fuzzy logic has been increased. Data mining is a process of extracting desirable knowledge and interesting pattern ken large data set. Because of expansion of WWW, web data is more and more huge. Besides mining web contents and web structures, another important task for web mining is web usage mining which mines web log data to discover user access pattern. The goal of web usage mining in this paper is to find interesting user pattern in the web with user feedback. It is very important to find user's characteristic fer e-business environment. In Customer Relationship Management, recommending product and sending e-mail to user by extracted users characteristics are needed. Using our method, we extract user profile from the result of web usage mining. In this research, we concentrate on finding association rules and verify validity of them. The proposed procedure can integrate fuzzy set concept and association rule. Fuzzy association rule uses given server log file and performs several preprocessing tasks. Extracted transaction files are used to find rules by fuzzy web usage mining. To verify the validity of user's feedback, the web log data from our laboratory web server.

• 한국지능시스템학회논문지
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• 제21권6호
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• pp.724-729
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• 2011

정보 검색은 다수 자료에서 사용자가 원하는 부분을 찾는 과정을 의미한다. 일반적으로 대규모 자료 집합의 관리를 위해서는 데이터베이스가 사용되는데 인터넷과 같은 복잡한 문서구조들이 공존하는 환경에서는 한 번에 사용자가 원하는 문서를 정확히 찾아내는 것이 어렵기 때문에, 문서에 순위를 부여하여 사용자에게 제시하는 방법이 일반적으로 많이 사용된다. 본 논문에서는 자료에 포함되어 있는 단어들을 단순히 검색하는 것 뿐만 아니라 단어들 간의 순서 및 인접성을 고려한 검색방법을 용어빈도-역문헌빈도 및 n-gram 기법을 응용하여 구현하였다. 그 결과 19,000개 이상의 다수 문서 집합에서 73%의 정확율로 보다 정확한 검색이 가능하게 되었다.

• 한국콘텐츠학회논문지
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• 제9권11호
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• pp.455-464
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• 2009

현재의 논문 중심적 학술정보 탐색의 한계에서 벗어나 저자 중심적 검색을 제공하기 위해서는 저자명이 갖는 동명이인의 문제가 해결되어야 한다. 그 해법으로 제시된 저자식별은 논문에 출현한 저자명 개체에 실세계 연구자에 대응하는 식별자를 부여하는 작업이다. 최근의 선도적 저자식별 연구들은 90%를 상회하는 식별 성능을 보고하고 있으나 실질적인 학술정보서비스에서 저자식별 기능이 탑재된 예는 거의 없다. 본 논문에서는 학술정보서비스에 보다 직접적으로 기여할 수 있는 광범위한 저자식별 연구를 위해 한국과학기술정보연구원에서 새롭게 구축한 대용량 저자식별 평가셋에 대해 기술한다. 평가셋은 DBLP 데이터에 출현한 고빈도 저자명들에 대해 웹 검색을 통한 수작업 식별 과정을 거쳐 만들어졌다. 현재 881개 저자명에 대해 수집된 41,673개의 저자명개체레코드로 구성되어 있으며 총 6,921명의 실세계 저자 식별자가 존재한다.

• Structural Engineering and Mechanics
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• 제38권6호
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• pp.767-802
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• 2011

Developers of new finite elements or nonlinear solution techniques rely on discriminative benchmark tests drawn from the literature to assess the advantages and drawbacks of new formulations. Buckling benchmark tests provide a rigorous evaluation of finite elements applied to thin structures, and a complete and detailed set of reference results would therefore prove very useful in carrying out such evaluations. Results are usually presented in the form of load-deflection curves that developers must reconstruct by extracting the points, a procedure which is often tedious and inaccurate. Moreover the curves are usually given without accompanying information such as the calculation time or number of iterations it took for the model to converge, even though this type of data is equally important in practice. This paper presents ten different limit-point buckling benchmark tests, and provides for each one the reference load-deflection curve, all the points necessary to recreate the curve in tabulated form, analysis data such as calculation time, number of iterations and increments, and all of the inputs used to obtain these results.

• 산업경영시스템학회지
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• 제42권2호
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• pp.28-35
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• 2019

Since guided missiles with the characteristics of the one-shot system remain stored throughout their entire life cycle, it is important to maintain their storage reliability until the launch. As part of maintaining storage reliability, period of preventive test is set up to perform preventive periodic test, in this case failure detection rate has a great effect on setting up period of preventive test to maintain storage reliability. The proposed method utilizes failure rate predicted by the software on the basis of MIL-HDBK-217F and failure mode analyzed through FMEA (Failure Mode and Effect Analysis) using data generated from the actual field. The failure detection rate of using the proposed method is applied to set periodic test of the actual guided missile. The proposed method in this paper has advantages in accuracy and objectivity because it utilizes a large amount of data generated in the actual field.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 전력전자학술대회
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• pp.537-539
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• 2019

Recently, large-scale fires have been generated as urban buildings have become more and more density. Especially, the expansion of smoke in buildings due to high-rise is an problem, and the smoke is the main cause of death in fires. Therefore, in this paper, the image-based smoke detection is proposed through deep learning-based artificial intelligence techniques to prevent possible damage if existing detectors are not detected. In addition, the detection model was not configured simply through only the smoke data set, but the data set in the haze form was additionally composed together to compensate for the accuracy.

• 응용통계연구
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• 제21권1호
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• pp.159-168
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• 2008

수익률 기간구조(term structure of interest rates, 이하 수익률곡선)는 자료의 성격이 경시적(longitudinal)이므로 만기까지 기간과 시간을 동시에 입력변수로 고려해야만 유용하고 효율적인 함수추정이 가능하다. 고러나 이러한 방법은 다루어야 하는 자료가 대용량이기 때문에 대용량 자료에 적합하고 실행속도가 빠른 추정기법을 개발하는 것이 필요하다. 한편 자료에 내재하는 자기상관성 구조 때문에 과대 적합된 추정 결과를 얻기 쉽다. 따라서 본 논문에서는 이러한 문제를 해결하기 위해서 가중 LS-SVM(least squares support vector machine, 최소제곱 서포트벡터기계)의 혼합모형을 제안한다. 미국 재무부 채권에 대한 사례연구를 통해서 추정 결과가 증권시장 붕괴 같은 이례적 사건의 현상을 잘 반영하고 있음을 확인할 수 있었다.

• Journal of Communications and Networks
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• 제15권6호
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• pp.614-634
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• 2013

The proliferation of real-time multimedia services requires huge amounts of data transactions demanding strict quality-of-service (QoS) guarantees. Multicast transmission is a promising technique because of its efficient network resource utilization. However, high head-of-line (HOL) blocking probability and lack of service-specific QoS control should be addressed for practical implementations of multicast networks. In this paper, a topology aware fanout set division (TAFD) scheme is proposed to resolve these problems. The proposed scheme is composed of two techniques that reduce HOL blocking probability and expedite packet delivery for large-delay branches regarding multicast tree topology. Since management of global topology information is not necessary, scalability of the proposed scheme is guaranteed. Mathematical analysis investigates effects of the proposed scheme and derives optimal operational parameters. The evaluation results show that the TAFD scheme achieves significant delay reduction and satisfies required delay bounds on various multicast networks.

• Advanced Composite Materials
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• 제16권3호
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• pp.245-258
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• 2007

The single-modal Weibull model has been assessed on Tyranno ZMI Si-Zr-C-O fiber if a set of shape and scale parameters accurately reproduced the effect of the size of the diameter on strength. The tensile data of a single fiber have been divided into two expedient groups as 'small diameter' group and 'large diameter' group in deriving the parameters, which should be consistent if the Weibull model accurately reproduced the size effect. However, the derived Weibull parameters were inconsistent between the two groups. Thereby the authors have concluded that the parameters of the single-modal Weibull model are dependent on the fiber diameter, so that the model is inadequate to reproduce the strength size effect. On the other hand, Weibull parameters were found consistent between the two groups by excluding the data of 'large mirror zone' sample, which was defined as the sample around 10% mirror zone area of the fracture surface. What is more, the exclusion reduced the strength variance more drastically in the 'large diameter' group than in the 'small diameter' group, even though the 'large mirror zone' samples were found identical in the percentage between the two groups. The authors therefore conclude that diameter limitation to the 'small diameter' group level can lead to drastically less distributed strength values than the estimated strength through the Weibull scaling on the present Tyranno ZMI Si-Zr-C-O fiber.