• Journal of Digital Contents Society
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• v.18 no.1
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• pp.149-158
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• 2017

Big data have been presenting us with exciting opportunities and challenges in economic development. For instance, in the agriculture sector, mixing up of various agricultural data (e.g., weather data, soil data, etc.), and subsequently analyzing these data deliver valuable and helpful information to farmers and agribusinesses. However, massive data in agriculture are generated in every minute through multiple kinds of devices and services such as sensors and agricultural web markets. It leads to the challenges of big data problem including data collection, data storage, and data analysis. Although some systems have been proposed to address this problem, they are still restricted either in the type of data, the type of storage, or the size of data they can handle. In this paper, we propose a novel design of a platform for collecting and analyzing agricultural big data. The proposed platform supports (1) multiple methods of collecting data from various data sources using Flume and MapReduce; (2) multiple choices of data storage including HDFS, HBase, and Hive; and (3) big data analysis modules with Spark and Hadoop.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.12B
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• pp.1418-1425
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• 2009

This paper proposes a novel FTL (Flash Translation Layer) algorithm based on sector-level mapping to reduce the number of total erase operations in flash memory accesses. The proposed algorithm can reduce the number of erase operations by utilizing the sector-level mapping table when writing data at flash memory. Sector-level mapping technique reduces flash memory access time and extendsthe life time of the flash memory. In the algorithm, wear-leveling is implemented by selecting victim blocks having the minimal number of erase operations, when empty spaces for write are not available. To evaluate the performance of the proposed FTL algorithm, experiments were performed on several applications, such as MP3 players, MPEG players, web browsers and document editors. The proposed algorithm reduces the number of erase operations by 72.4% and 61.9%, when compared with well-known BAST and FAST algorithms, respectively.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.4 s.22
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• pp.31-39
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• 2002

In this paper, we propose Media CIS system architecture which provides geographical information of geo-features in video sequences by using 3D geographical database and GPS-related data resulted from 4S-Van. We introduce a novel interoperable geographical data service concept, so-called, Virtual World Mapping (VWA) that can map 3D graphic world with real-world video to provide geographical information. Our proposed method can easily retrieve geographical information and attributes to reconstruct 3D virtual space according to certain frame in video sequences. Our proposed system architecture also has an advantage that can provide geographical information service with video stream without any image processing procedures. In addition to, describing the details of our components, we present a Media GIS web service system by using GeoVideo Server, which performs VWM technique.

• The Journal of the Korea Contents Association
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• v.12 no.12
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• pp.733-741
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• 2012

In recent, many consumers visit the online shopping malls or price comparison sites to collect the information on the product category that they are interested in. However, the volumes of the data provided by such web sites are often too enormous, and significant number of consumers have trouble in making purchase decision based on the plethora of products and sellers. In this context, modern online shopping agents need to process the retrieved information in more intelligent way before providing them to the users. This paper proposes a novel approach for identifying the main price ranges hidden in a single product category. To this end, the price of an item in the category is represented as a row vector and k-means clustering analysis is applied to the price vectors to produce the clusters that consists of the product items with similar price vectors. Then, the main price ranges of the product category can be identified from the result of clustering analysis. In general, the price is one of the most important factors in the consumers' purchase decision, and the identified main price ranges will be helpful for the online shoppers to find appropriate items effectively.

• Steel and Composite Structures
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• v.24 no.5
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• pp.549-559
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• 2017

As few multi-tower single-box multi-cell cable-stayed bridges with corrugated steel webs have been built, analysis is mostly achieved by combining single-girder model, beam grillage model and solid model in support of the design. However, such analysis methods usually suffer from major limitations in terms of the engineering applications: single-girder model fails to account for spatial effect such as shear lag effect of the box girder and the relevant effective girder width and eccentric load coefficient; owing to the approximation in the principle equivalence, the plane grillage model cannot accurately capture shear stress distribution and local stress state in both top and bottom flange of composite box girder; and solid model is difficult to be practically combined with the overall calculation. The usual effective width method fails to provide a uniform and accurate "effective length" (and the codes fail to provide a unified design approach at those circumstance) considering different shear lag effects resulting from dead load, prestress and cable tension in the construction. Therefore, a novel spatial grid model has been developed to account for shear lag effect. The theoretical principle of the proposed spatial grid model has been elaborated along with the relevant illustrations of modeling parameters of composite box girder with corrugated steel webs. Then typical transverse and longitudinal shear lag coefficient distribution pattern at the side-span and mid-span key cross sections have been analyzed and summarized to provide reference for similar bridges. The effectiveness and accuracy of spatial grid analysis methods has been finally validated through a practical cable-stayed bridge.

• The Research Journal of the Costume Culture
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• v.22 no.4
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• pp.619-631
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• 2014

This study proposes an educational direction to be followed by the clothing departments of Korea's specialized high schools in order to help achieve high levels of job placements and to strengthen their students' competitiveness. A comparison was made of the curricula in Korea's specialized high schools and in several fashion schools in other countries including the United States, Italy, France, Taiwan, and Japan. To this end, publicly available educational records were retrieved from domestic school documentation, vocational high school portals, and domestic/overseas school web sites, and were then reviewed. The archival data extracted from these sources shows that the curricula of the three chosen domestic schools uniformly focus on foundational courses such as general computer skills, general design, accounting principles, design principles, and drawing, as well as practical courses such as the design of western clothing, fashion design, fashion CAD, management of clothing material, design of Korean clothing, and knitting. Unlike these standardized courses, it was found that overseas fashion schools provide a more technically-advanced and design-focused education based on the interests of the individual student. Moreover, their education system nurtures the students' creativity through adequate field experience and history/language education. The findings of this study suggest that Korean specialized high schools should find a way to accommodate their students' interests and to provide them with personalized fashion education by adopting a more flexible curriculum. An educational line that considers the individual student's aptitudes and career path will help foster creativity and novel ideas, which, in turn, will contribute to the development of the fashion industry.

• Journal of KIISE:Software and Applications
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• v.32 no.5
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• pp.378-384
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• 2005

In this paper, we describe a novel method of spam-filtering to improve the performance of conventional spam-filtering systems. Conventional systems filter emails by investigating words distribution in email headers or bodies. Nowadays, spammers begin making email accounts in web-based email service sites and sending emails as if they are not spams. Investigating the email accounts of those spams, we notice that there is a large difference between the automatically generated accounts and ordinaries. Based on that difference, incoming emails are classified into spam/non-spam classes. To classify emails from only account strings, we used decision trees, which have been generally used for conventional pattern classification problems. We collected about 2.15 million account strings from email service sites, and our account checker resulted in the accuracy of $96.3\%$. The previous filter system with the checker yielded the improved filtering performance.

• Journal of KIISE
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• v.44 no.11
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• pp.1165-1177
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• 2017

Many developers utilize specific APIs to develop software, and to identify the use of a particular API, a developer can refer to a website that provides the API or can retrieve the API from the web. However, the site that provides the API does not necessarily provide guidance on how to use it while it can be partially provided in many other cases. In this paper, we propose a novel system JACE (Java AST collocation-pattern extractor) as a method to reuse commonly-used code as a supplement. The JACE extracts the API call nodes, collocation patterns and analyzes the relations between the collocations to extract significant API patterns from the source code. The following experiment was performed to verify the accuracy of a defined pattern: 794 open source projects were analyzed to extract about 15M API call nodes. Then, the Eclipse plug-in test program was utilized to retrieve the pattern using the top 10 classes of API call nodes. Finally, the code search results from reference pages of the API classes and the Searchcode [1] were compared with the test program results.

• Smart Media Journal
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• v.4 no.4
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• pp.93-100
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• 2015

Markets of e-book and app book in Korea see novel as genre literature and webtoon account for 80 percents in sales so that market share is too based towards some specific fields. In readiblily and easy-to-buy convenience, different from paper books mostly sold off-line, app books are more advantageous but it works as a weak point to take long to publicly spread them before they are generally accepted. Meanwhile, the sales of the e-book market in Korea has been steeply risen. Further, the market is not only restricted to genre literature but also has come into the stage that various experimental challenges are issued in the field of publication contents. This study is aimed at developing the sightseeing app book as a future web-mobile platform with planning and develping the first app book dealing with localized contents based on Busan tour contents, making up for its defect that it offers only current simple information and then suggesting a strategy that the travelers' app book should be available for constant utilization connected to purchase by charged download.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.12C
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• pp.1251-1264
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• 2002

Currently, audio streaming services such as on-demand service and live service support only a limited number of clients. They also suffer from a lack of stability and degradation of service quality due to their inefficient use of network resources. Futhermore, since the streaming services usually do not consider dynamic services, they are very inconvenience to use. In order to resolve these drawbacks, we propose a novel audio streaming system based on MPEG-2 AAC file format which are facilitated with the network bandwidths efficiently. The proposed system supports QoS for audio streaming as well as guarantees a stability while streaming service is undergoing. Moreover, the system provides a dynamic interface which enables us to use the streaming service more easily and to manage streaming servers with convenient manner. On the contrary, most of the current available static interface streaming services are mainly depending only on a single fixed web page between client and server, which in consequence lead us to use unflexible static service environment. Our implementation results show the proposed system improves the performance compared to those of the currently existing systems that use MP3 file format. It also provides some benefits such as a stability of service and a easy to management of streaming servers.