• Journal of Korea Society of Industrial Information Systems
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• v.18 no.2
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• pp.19-25
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• 2013

In this paper, we propose an approach to tracking road regions from video sequences. The proposed method segments and tracks road regions by utilizing the prior information from the result of the previous frame. For the efficiency of the system, we have a simple assumption that the road region is usually shown in the lower part of input images so that lower 60% of input images is set to the region of interest(ROI). After initial segmentation using flood-fill algorithm, we merge neighboring regions based on color similarity measure. The previous segmentation result, in which seed points for the successive frame are extracted, is used as prior information to segment the current frame. The similarity between the road region of the previous frame and that of the current frame is measured by the modified Jaccard coefficient. According to the similarity we refine and track the detected road regions. The experimental results reveal that the proposed method is effective to segment and track road regions in noisy and non-noisy environments.

• The Journal of Society for e-Business Studies
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• v.24 no.2
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• pp.1-14
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• 2019

Because of the characteristics of game software, it is important to quickly identify and reflect users' needs into game software after its launch. However, most sites such as the Google Play Store, where users can download games and post reviews, provide only very limited and ambiguous classification categories for game reviews. Therefore, in this paper, we develop an automatic classification system for game reviews that categorizes reviews into categories that are clearer and more useful for game providers. The developed system converts words in reviews into vectors using word2vec, which is a representative word embedding model, and classifies reviews into the most relevant categories by measuring the similarity between those vectors and each category. Especially, in order to choose the best similarity measure that directly affects the classification performance of the system, we have compared the performance of three representative similarity measures, the Euclidean similarity, cosine similarity, and the extended Jaccard similarity, in a real environment. Furthermore, to allow a review to be classified into multiple categories, we use a threshold-based multi-category classification method. Through experiments on real reviews collected from Google Play Store, we have confirmed that the system achieved up to 95% accuracy.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.6
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• pp.333-340
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• 2014

Despite the security weakness of reusing passwords, many Internet users are likely to use a single ID and password on various sites to avoid the inconvenience of remembering multiple credentials. This paper proposes a scheme for securely storing, retrieving, and updating randomly chosen (ID, password) pairs by using smart cards as secure and portable storages. The scheme makes a user free from remembering her (ID, password) pairs for Internet accesses. By splitting and scattering the (ID, password) pairs of a user across the user's smart card memory and a remote server's storage, it can protect the logon credentials even from the theft or loss of the smart card. Also, a user, if deemed necessary, can issue and let the server to delete all information belonging to the user. Hence even an attacker who cracked the smart card memory would not be able to obtain any (ID, password) pair of the victim thereafter. The scheme requires a user to input a site information and pass-phrase to her smart card to obtain the logon credentials, but it should be an acceptable overhead considering the benefits of not remembering the freely chosen (ID, password) pairs at all.

• Journal of the Korean Society for information Management
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• v.18 no.2
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• pp.203-230
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• 2001

The purpose of this study is to develop a document clustering model for automatic classification of knowledge. Two test collections of newspaper article texts and journal article abstracts are built for the clustering experiment. Various feature reduction criteria as well as term weighting methods are applied to the term sets of the test collections, and cosine and Jaccard coefficients are used as similarity measures. The performances of complete linkage and K-means clustering algorithms are compared using different feature selection methods and various term weights. It was found that complete linkage clustering outperforms K-means algorithm and feature reduction up to almost 10% of the total feature sets does not lower the performance of document clustering to any significant extent.

• Journal of Digital Contents Society
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• v.19 no.5
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• pp.871-880
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• 2018

Recently, the technology of recommendation of POI (Point of Interest) related technology is getting attention with the increase of big data related to consumers. Previous studies on POI recommendation systems have been limited to specific data sets. The problem is that if the study is carried out with this particular dataset, it may be suitable for the particular dataset. Therefore, this study analyzes the similarity and correlation between stores using the user visit data obtained from the integrated sensor installed in Seoul and Songjeong roads. Based on the results of the analysis, we study the preference prediction system which recommends the stores that new users are interested in. As a result of the experiment, various similarity and correlation analysis were carried out to obtain a list of relevant stores and a list of stores with low relevance. In addition, we performed a comparative experiment on the preference prediction accuracy under various conditions. As a result, it was confirmed that the jacquard similarity based item collaboration filtering method has higher accuracy than other methods.

• Journal of Distribution Research
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• v.12 no.2
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• pp.79-102
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• 2007

Consumers evaluate stores by comparing stores that we, in their minds, similar and are competitive with one another; and in this way, the term "consideration set of stores" is defined as those store alternatives the consumer is aware of and evaluates positively. The purpose of this study is to aid in understanding the consideration set of stores in store choice processes in apparel product purchases. More specifically, this study aims to clarify the relation between consideration set of stores and importance of store image. As a result, the respondents of quantitative study were classified into seven groups by the number of stores and store types they considered: 1) "small-road shop sets group" ; 2) "small-market sets group" ; 3) "small- department store sets group" ; 4) "small-department store/outlet sets group" ; 5) "large-department store/market sets group" ; 6) "large-department store/road shop sets group" ; and 7) "large-department store sets group". Further, significant differences among the groups in the importance of store image were observed. For example, low prices were an important factor in both the small-market considering group and large-department store/market considering group when choosing a retail store, there were also differences in the considering groups in that for the small-department store considering group, store mileage-discount cards were important whereas ample space for relaxation around the stores were important retail store selection factors for the large-department store/road shop considering group. This study may provide a useful direction to retailers in finding out who the target customers and competitive stores are and allow retailers to make proper marketing strategies.

• Journal of recreation and landscape
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• v.6 no.2
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• pp.63-71
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• 2012

As the interest in rural tourism has been increasing since the late 1990s, the research associated with rural tourism has increased, including research on the classification of rural tourism resources. The research classifying these resources has proved useful to many other studies. Although such studies have been conducted for a long time, they have expressed only experts' perspectives and been supported by statistics, without reflecting on users' opinions. Given this background, this study aims to classify rural tourism resources by focusing on the rural activities for tourists who use those tourism resources. To achieve this, each study participant proceeded to collect tourism resources by using a rural amenity resources database, and a card sorting test was conducted. Thirty-two people who had previously gone sightseeing in the rural areas were chosen as participants in the card sorting test. After the card sorting test was complete, the results were reviewed by experts. These results yielded six categories: doing nature activities, eating and cooking local dishes, putting up (overnight stays), going sightseeing/appreciating the landscape, enjoying leisure activities, and doing artistic activities. In the doing nature activities category, there were four subcategories: experiencing local resources, experiencing nature, experiencing tradition, and harvesting. This study was conducted to improve the satisfaction and understanding of the tourists who visit rural areas. Thus, the classification of rural tourism resources developed by this study will be widely used to establish the framework or contents of websites, applications, and so on, for promoting rural tourism resources and local resources.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.4
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• pp.400-404
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• 1999

The conventional mercury delay method to measure compressional wave velocity of unconsolidated sediment is inconvenient because the signal must be analyzed on the oscilloscope and the mercury column has to be calibrated between measurements. We developed an automated compressional wave velocity measurement technique by connecting an oscilloscope and a PC with a GPIB (General Purpose Interface Bus) card. The GPIB card buses signals from the oscilloscope to the PC where the signal from a sample is analyzed and compared to the input pulse thereby the compressional wave velocity of the sample is computed and recorded automatically. Differences between the mercury delay method and the automated measurement technique are negligible except the slightly greater velocity in the automated measurement technique. We concluded that the new technique can be used to measure the velocity for unconsolidated marine sediment. It also has an advantage to calculate sediment attenuation through the processing of waveform using the spectral ratio technique.

• Journal of Life Science
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• v.20 no.10
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• pp.1490-1497
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• 2010

The present study aimed to investigate the level of accumulated heavy metal in various tissues of Carassius auratus after exposure to Cadmium (Cd), histologically and physiologically. After treating C. auratus with Cd, the accumulated Cd in gill tissues was detected to be of the highest content, and showed the lowest content in integument tissues. Also, Cd content increased in a time dependent manner and showed the highest accumulation in the tissues exposed for 20 days. Antioxidant enzyme activities showedhigher activity in the gill and integument than in the kidney and liver tissues. In the case of SOD, antioxidation activity of SOD in all Cd exposed tissues was higher than in unexposed tissues. The activities of SOD and CAT also became higher after Cd exposure. Gill tissues exposed to Cd showed an increased number of mucous cells between lamella in a time dependent manner. In addition, the gills showed morphological changes such as edema, exfoliation of epithelial cells, and fusion of the secondary lamellae. Also, exposure to Cd for 20 days had an effect on gill tissues, causing membrane damage in the mitochondria and nucleus. In kidney tissues, atrophied glomerulus was observed, and the empty space in Bowman's capsule was wider.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.2 s.40
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• pp.87-93
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• 2007

Over the years, Advanced Public Transportation System (APTS) has been implemented to manage and operate public transportation system. With the expanding mass spatio-temporal data such as comprehensive spatial information of each individual passenger and public transportation vehicle, it has been required to consolidate and analyze these multiple data sets from various sources. This paper demonstrates how GIS is utilized for the consolidation of massive transit related spatio-temporal information. And it presents effective applications to improve transit planning process and support transit related decision-making activities. GIS based system is used to combine multi-agents' data in the areas of transit operation and individual transit ride and transfer management. Due to the unique comprehensiveness and the level of detail of the data provide by the Seoul Transit system, this GIS based information consolidation is the first in its class. Based on the integrated database, this paper describes the effective and efficient GIS based analysis deployed in a transportation system planning process. The data integration systems and analytic models developed in this paper can be transferred and applied by any municipal governments provided that the appropriate data is available.