• Nuclear Engineering and Technology
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• v.49 no.2
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• pp.442-449
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• 2017

Risk management of the Fukushima Daiichi Nuclear Power Station decommissioning is a great challenge. In the present study, a risk management framework has been developed for the decommissioning work. It is applied to fuel assembly retrieval from Unit 3 spent fuel pool. Whole retrieval work is divided into three phases: preparation, retrieval, and transportation and storage. First of all, the end point has been established and the success path has been developed. Then, possible threats, which are internal/external and technical/societal/management, are identified and selected. "What can go wrong?" is a question about the failure scenario. The likelihoods and consequences for each scenario are roughly estimated. The whole decommissioning project will continue for several decades, i.e., long-term perspective is important. What should be emphasized is that we do not always have enough knowledge and experience of this kind. It is expected that the decommissioning can make steady and good progress in support of the proposed risk management framework. Thus, risk assessment and management are required, and the process needs to be updated in accordance with the most recent information and knowledge on the decommissioning works.

• Science of Emotion and Sensibility
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• v.13 no.3
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• pp.501-510
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• 2010

The knowledge base on emotional information is one of the key elements in the implementation of emotion retrieval systems for contents design of Mobile devices. This study proposed a new approach to the knowledge base implementation by automatically extracting color components from full-color images. In this study, the validity of the proposed method was empirically tested. Database was developed using 100 interior images as visual stimuli and a total of 48 subjects participated in the experiment. In order to test the reliability of the proposed 'emotional information knowledge base', firstly 'recall ratio' that refers to frequencies of correct images from the retrieved images was derived. Secondly, correlation Analysis was performed to compare the ratings by the subjects to what the system calculated. Finally, the rating comparison was used to run a paired-sample t-test. The analysis demonstrated satisfactory recall ration of 62.1%. Also, a significant positive correlation (p<.01) was observed from all the emotion keywords. The paired Sample t-test found that all the emotion keywords except "casual" retrieved the images in the order from more relevant to less relevant images and the difference was statistically significant (t(9)=5.528, p<.05). Findings of this study support that the proposed 'emotional information knowledge base' established only with color information automatically extracted from images can be effectively used for such visual stimuli search tasks as commercial interior images.

• Korean Journal of Cognitive Science
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• v.24 no.2
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• pp.111-132
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• 2013

Previous research has shown that aging asymmetrically affects various functions in language. It is known that older adults show deficits in language production compared to young adults, while the performance in semantic processing is similar between older and young adults. The tip-of-the-tongue (TOT) phenomenon effectively reflects failure in retrieval of phonological knowledge. Older adults report TOTs more often than young adults and the cause of this phenomenon has been explained by two frameworks: the 'blocking hypothesis' and 'transmission deficit hypothesis'. This study examines the effect of aging on the retrival of phonological knowledge by inducing TOTs in the laboratory. Two variables were manipulated: age and word category. Participants were young and older adults, and stimuli was selected from 5 categories of words. After the participants read a definition about a target word, they reported three conditions: 'know', 'don't know', 'TOT'. The results were as follows: First, the older adults reported TOTs more often than the young adults. Second, TOTs occurred more in proper nouns such as names of persons and places. Third, in the category that TOTs occurred more often, there was a bigger age difference. Fourth, older adults reported fewer alternative words during TOT than young adults. Fifth, participants tended to report the partial information during TOT in characters. These results show the age-related difficulty in the retrieval of phonological knowledge in Korean. It is explained by the transmission deficit hypothesis and the characteristics of Korean orthography and phonology.

• Journal of the Korean Society for information Management
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• v.28 no.2
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• pp.135-158
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• 2011

The ability of the searcher to express their information problem to an information retrieval system is fundamental to the retrieval process. Query by visual example is the principal query paradigm for expressing queries in a content-based image retrieval environment yet there is little empirical evidence to support its efficacy in facilitating query formulation. The aim of this research was to investigate the usability of the query by colour method in supporting a range of information problems in order to contribute to the gap in knowledge regarding the relationship between searchers' information problems and the query methods required to support efficient and effective visual query formulation. The results strongly suggest that the query method does not support visual query formulation and that there is a significant mismatch between the searchers information problems and the expressive power of the retrieval paradigm.

• The KIPS Transactions:PartD
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• v.18D no.1
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• pp.1-8
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• 2011

The cache structure, which is designed for assuring fast accesses to frequently accessed data, resides on the various levels of computer system hierarchies. Many studies on this cache structure have been conducted and thus many page-replacement algorithms have been proposed. Most of page-replacement algorithms are designed on the basis of heuristic methods by using their own criteria such as how recently pages are accessed and how often they are accessed. This data-retrieval process in computer systems is analogous to human memory retrieval process since the retrieval process of human memory depends on frequency and recency of the retrieval events as well. A recent study regarding human memory cognition revealed that the possibility of the retrieval success and the retrieval latency have a strong correlation with the frequency and recency of the previous retrieval events. In this paper, we propose a novel page-replacement algorithm by utilizing the knowledge from the recent research regarding human memory cognition. Through a set of experiments, we demonstrated that our new method presents better hit-ratio than the LRFU algorithm which has been known as the best performing page-replacement algorithm for DBMS caches.

• The Korean Journal of Applied Statistics
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• v.13 no.1
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• pp.1-10
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• 2000

정보화사회에서 효율적인 정보검색(information retrieval)은 각종 의사결정에 매우 중요하다. 주어진 정보검색 문제가 있을 때 과거에 검색되었던 자료는 그 적절성 여부에 대한 평가를 데이터베이스에 첨가하여 지식베이스(knowledge base)화 할 수 있다. 본 연구는 이 지식베이스에 대한 논리적 패턴을 분석하여 새로운 정보의 '적정성(relevance)' 여부를 판별하는 확률화 정보검색 모형을 만들고 이에 대한 실험을 하였다.

• Phonetics and Speech Sciences
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• v.6 no.1
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• pp.119-125
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• 2014

Many studies have reported an age-related decline in the ability to spell words correctly. The aim of this study was to investigate the deterioration on retrieving orthographic knowledge in 64 normal elderly Korean persons. The subjects were 64 in total: they were composed of 22 persons in their 50s, 20 persons in their 60s, and 22 persons in their 70s or older. We instructed them to write from a dictation of 60 words stimuli (20 regular words, 20 irregular words, 20 nonwords). Older adults made more errors than younger adults, and the age-related decline in performance was greater for irregular than regular and nonwords. With respect to the error pattern in the irregular words, the subjects showed more phonological plausible errors than phonological implausible errors. The number of self-correction was high in nonwords. Based on the results, we found that aging differentially affects the retrieval of orthographic knowledge on regular, irregular and nonwords.

• Journal of the Korean Society for information Management
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• v.17 no.4
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• pp.47-65
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• 2000

This study aims lo enhance the perfor~nance 01 concept-based information retr~eval through the use of the lraditional thesaurus which, clearly delmes relalions among terms. To achwe lhls, thc study purports to construcl relation-value-based, relalion-bad, and inlegated kumwledge bases tluough the use ol ihc lhcsau~ub. To cornpale and a~alyze retrieval perlor~nance among knowledge bases, two methods weue al~plied. Sequential bnb algorithm is ap~lied to the I-clation-ualue-based and intzgralcd knowledge base while heuristic bnb algorithm is applied to the relal~on-based knowlcdgc base.

• Journal of Information Management
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• v.24 no.3
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• pp.1-30
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• 1993

Providing users who intend to retrieve document information in korean natural language with direct access to retrieval systems, a korean question processing system was developed in which korean natural language was translated into boolean search statements, which are the most frequently used in current information retrieval systems.

• Journal of Information Management
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• v.36 no.1
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• pp.103-124
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• 2005

This paper investigates knowledge management architecture which is related to the efficient storage, search, and retrieval of knowledge. It is important considerations that should be taken account in any knowledge management system. This study reviews literature and practices of the theory of current status of knowledge management architecture (KMA). Based on the review of the current practice, the characteristics and emphasis of the KMA applications are identified. It tries to suggest how the KMA should facilitate for effective and desirable directions of the KMA.