• The Journal of Engineering Geology
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• v.9 no.3
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• pp.187-206
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• 1999

A computer program to numerically predict the permeability tensor of fractured rocks is developed using information on discontinuities which Borehole Televiewer and Borehole Image Processing System (BIPS) provide. It uses orientation and thickness of a large number of discontinuities as input data, and calculates relative values of the 9 elements consisting of the permeability tensor by the formulation based on the EPM model, which regards a fractured rock as a homogeneous, anisotropic porous medium. In order to assess feasibility of the program on field sites, the numerically calculated tensor was obtained using BIPS logs and compared to the results of pumping test conducted in the boreholes of the study area. The degree of horizontal anisotropy and the direction of maximum horizontal permeability are 2.8 and $N77^{\circ}CE$, respectively, determined from the pumping test data, while 3.0 and $N63^{\circ}CE$ from the numerical analysis by the developed program. Disagreement between two analyses, especially for the principal direction of anisotropy, seems to be caused by problems in analyzing the pumping test data, in applicability of the EPM model and the cubic law, and in simplified relationship between the crack size and aperture. Aside from these problems, consideration of hydraulic parameters characterizing roughness of cracks and infilling materials seems to be required to improve feasibility of the proposed program. Three-dimensional assessment of its feasibility on field sites can be accomplished by conducting a series of cross-hole packer tests consisting of an injecting well and a monitoring well at close distance.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.226.1-226.1
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• 2012

위성에 탑재되어 위성의 상태를 모니터링하며, 지상으로부터 명령을 받아 위성 본연의 임무 수행이 가능하게 하는 위성비행소프트웨어는 그 개발단계에서 다양한 검증활동이 이루어진다. 설계 검증 및 리뷰, 인스펙션을 거쳐 소스 코드로 구현된 후, 단위 시험을 통해 가장 낮은 수준의 검증을 거치게 된다. 이러한 단위 시험은 개별 함수에 대해 입력에 따른 해당 출력 및 동작 여부를 검사하게 된다. 단위 시험이 하나의 함수에 대한 시험 항목이라는 점은 검증대상의 스코프가 좁다는 장점이 있으나, 다른 모듈과 연동되었을 경우에 발생할 수 있는 다양한 경우를 고려하여 테스트 케이스를 작성해야 하는 어려움이 있다. 이러한 문제점을 해결하기 위하여 단위 시험과 함께, 연관된 함수가 이미 구현되어 있는 경우, Stubbing을 하기보다는 직접 해당 함수를 사용하며, 또한 동등한 수준의 개별 함수들을 주어진 시나리오에 따라 동작하는 Compound Test를 활용, 그 결과를 확인하는 방법을 도입하였다. 이를 이용하면 단위 시험에서는 검증하기 어려운 상황별 시나리오에 따른 검증 활동을 수행할 수 있고, 또한 전체 위성비행소프트웨어를 빌드할 필요없이 테스트의 대상이 되는 함수만을 이용, 나머지 부분은 기존의 방식을 그대로 적용할 수 있어, 위성비행소프트웨어의 안전성 및 신뢰성을 보다 향상시킬 수 있다.

• Information Systems Review
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• v.18 no.1
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• pp.125-140
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• 2016

Mobile applications (apps) play a significant role in the proliferation of smartphones. According to statistics from Apple, 100 million apps were downloaded in 2008. Since then, the number of cumulative app downloads have increased exponentially. By October 2014, 85 billion apps had been downloaded worldwide. Many studies have attempted to determine the factors that drive app downloads. However, unlike previous studies, we examine the effects of app updates on app rankings. To achieve this goal, we collected data on rankings (gross rankings and category rankings), update contents, reviewer ratings, and number of reviews on apps listed in the App Store. We then categorized app updates into functionality, reliability, and convenience updates following the buying hierarchy model. We found that functionality updates had a positive effect on app gross ranking whereas reliability updates had a positive effect on category ranking. Our study is the first to explore the effects of update content on app ranking. Moreover, our study provides a practical implication for mobile app developers, who should consider app updates in their product development strategy.

• Journal of Korean Library and Information Science Society
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• v.39 no.4
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• pp.51-69
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• 2008

This study tired to develop the web credibility evaluation model by calculating weighted values and sensitivities of indicators which presented on preceding researches using Analytic Hierarchy Process. "Expert Choice 2000" was used as the tool for analysing AHP. 25 experts are answered for this questionnaire who are selected by judgement sampling method, one of the non-probability sampling method. Also, sensitivity analyses was performed to graphically see how the alternatives change with respect to the importance of the indicators or sub-indicators. The main results are summarized as followings; i) importance analysis in first level factors: trust-worthiness(0,606), expertness(0.222), safety(0.173), ii) importance analysis in second level factors: trustfulness (0.519), reputation(0.087), usefulness (0.102), timeliness(0,093), competency(0.027), security(0.115), reliability(0,058). iii) some of the importance analysis in third level factors: the site provides comprehensive information that is attributed to a specific source(0.252), the site has articles that list citations and references(0.153), the site contains user opinions and reviews(0.072), etc. iv) sensitivity analyses showed that the importance of the indicators or sub-indicators are slightly changed with respect to the alternatives change.

• Journal of Intelligence and Information Systems
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• v.22 no.3
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• pp.23-43
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• 2016

As a result of the growth of Internet data and the rapid development of Internet technology, "big data" analysis has gained prominence as a major approach for evaluating and mining enormous data for various purposes. Especially, in recent years, people tend to share their experiences related to their leisure activities while also reviewing others' inputs concerning their activities. Therefore, by referring to others' leisure activity-related experiences, they are able to gather information that might guarantee them better leisure activities in the future. This phenomenon has appeared throughout many aspects of leisure activities such as movies, traveling, accommodation, and dining. Apart from blogs and social networking sites, many other websites provide a wealth of information related to leisure activities. Most of these websites provide information of each product in various formats depending on different purposes and perspectives. Generally, most of the websites provide the average ratings and detailed reviews of users who actually used products/services, and these ratings and reviews can actually support the decision of potential customers in purchasing the same products/services. However, the existing websites offering information on leisure activities only provide the rating and review based on one stage of a set of evaluation criteria. Therefore, to identify the main issue for each evaluation criterion as well as the characteristics of specific elements comprising each criterion, users have to read a large number of reviews. In particular, as most of the users search for the characteristics of the detailed elements for one or more specific evaluation criteria based on their priorities, they must spend a great deal of time and effort to obtain the desired information by reading more reviews and understanding the contents of such reviews. Although some websites break down the evaluation criteria and direct the user to input their reviews according to different levels of criteria, there exist excessive amounts of input sections that make the whole process inconvenient for the users. Further, problems may arise if a user does not follow the instructions for the input sections or fill in the wrong input sections. Finally, treating the evaluation criteria breakdown as a realistic alternative is difficult, because identifying all the detailed criteria for each evaluation criterion is a challenging task. For example, if a review about a certain hotel has been written, people tend to only write one-stage reviews for various components such as accessibility, rooms, services, or food. These might be the reviews for most frequently asked questions, such as distance between the nearest subway station or condition of the bathroom, but they still lack detailed information for these questions. In addition, in case a breakdown of the evaluation criteria was provided along with various input sections, the user might only fill in the evaluation criterion for accessibility or fill in the wrong information such as information regarding rooms in the evaluation criteria for accessibility. Thus, the reliability of the segmented review will be greatly reduced. In this study, we propose an approach to overcome the limitations of the existing leisure activity information websites, namely, (1) the reliability of reviews for each evaluation criteria and (2) the difficulty of identifying the detailed contents that make up the evaluation criteria. In our proposed methodology, we first identify the review content and construct the lexicon for each evaluation criterion by using the terms that are frequently used for each criterion. Next, the sentences in the review documents containing the terms in the constructed lexicon are decomposed into review units, which are then reconstructed by using the evaluation criteria. Finally, the issues of the constructed review units by evaluation criteria are derived and the summary results are provided. Apart from the derived issues, the review units are also provided. Therefore, this approach aims to help users save on time and effort, because they will only be reading the relevant information they need for each evaluation criterion rather than go through the entire text of review. Our proposed methodology is based on the topic modeling, which is being actively used in text analysis. The review is decomposed into sentence units rather than considering the whole review as a document unit. After being decomposed into individual review units, the review units are reorganized according to each evaluation criterion and then used in the subsequent analysis. This work largely differs from the existing topic modeling-based studies. In this paper, we collected 423 reviews from hotel information websites and decomposed these reviews into 4,860 review units. We then reorganized the review units according to six different evaluation criteria. By applying these review units in our methodology, the analysis results can be introduced, and the utility of proposed methodology can be demonstrated.

• Culinary science and hospitality research
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• v.22 no.5
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• pp.325-338
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• 2016

This research aimed to setup the innovativeness, dependability of information, reliability, and sufficiency of information of a mobile eating out application as the precedence factor, and also aimed to present useful information regarding the mobile eating out application by verifying the effect on the continuous use satisfaction levels and long-term orientation for this mobile eating out application. The data collection carried out from February 1 to February 28, 2016, with 441 questionnaires collected from a total distribution of 500 copies, of which 396 were retained. SPSS 22.0 was employed for factor analysis and the reliability verification, while AMOS 22.0 was used for the covariance structure analysis meant to verify the presented research hypothesis. The results are as follows. First, there was found a significant positive effect (+) on continuous use from innovativeness and dependability. On the other hand, sufficiency and reliability appeared not to have a significant effect. Second, there was a positive increase in long-term orientation as continuous use increased. Third, long-term orientation increased in relation to innovativeness. On the other hand, sufficiency, dependability and reliability appeared not to have a significant effect on long term orientation. Accordingly, the useful implications for the eating out application based on the analysis results has been presented.

• Journal of the Korea Society of Computer and Information
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• v.5 no.4
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• pp.131-139
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• 2000

The Purpose of this study is to suggest usefulness of design review for new products development in business administration and quality control. DR(Design Review) is systematic activities for good design quality. It is application to whole product life cycle. Some examples of their applied are presented.

• Geophysics and Geophysical Exploration
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• v.13 no.3
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• pp.277-285
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• 2010

For regional earthquakes in the Korean Peninsula, the seismic Lg waves have the largest amplitude. Our researches in South Korea found that more reasonable low ${Q_{Lg}}^{-1}$ was obtained as the inter-station distances increase. The other methods such as coda normalization method and multiple lapse time window method also produced that the low ${Q_{Lg}}^{-1}$ is related to the values of seismically inactive region.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1180-1183
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• 2015

최근 스마트폰 사용자의 증가와 함께 무선 인터넷 보급률이 높아지면서, 언제 어디서나 위치에 구애받지 않고, 네이버 웹툰, 다음 웹툰 등으로 실시간 웹툰 서비스의 이용이 증가하고 있다. 웹툰데이터의 가치와 신뢰성도 점점 높아지고 있어, 각종 영화 애니메이션 게임 등 콘텐츠 사업에 많은 데이터가 사용되고 있다. 본 논문에서는 나이, 성별, 선호 카테고리, 선호 웹툰 플랫폼 등과 같은 개인 성향을 이용하여 협업필터링 방법을 적용하고, 기존에 웹툰에 대한 리뷰를 개인 감정에 관련된 온톨로지를 이용하여 각각의 사용자들이 보고 싶어하는 웹툰을 자동적으로 추천해주는 웹툰 추천 시스템을 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.11a
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• pp.651-654
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• 2020

유튜브 등의 1인 미디어 플랫폼 열풍과 반대로, 이에 대한 엄격한 방송 규약은 존재하지 않아 생기는 여러 사회적 문제가 대두되고 있다. 이러한 1인 미디어 시청자는 원하는 정보를 찾기 위해 영상 제공자가 제공하는 정보에만 의존하여 영상을 선택하고 내용을 확인하여야 한다. 그 결과 의도한 주제와 맞지 않은 영상을 시청하게 되는 비효율성을 해결하기 위해, 본 연구에서는 용어 신뢰도 기반 유튜브 영상 필터링 웹 서비스(YouChoose)를 제안한다. YouChoose는 유튜브 리뷰 영상의 음성을 자연어 처리 기법을 이용하여 사전 처리하고 신뢰도를 도출해 사용자에게 제공함으로써 검색 시 의도와 일치하는 영상을 직접 시청 전에 추천 받을 수 있도록 한다.