• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.2
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• pp.17-26
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• 2021

For the past half century, the Journal of the Korean Landscape Architecture has been leading the landscape architecture research and industry inclusively. In this study, abstracts of 1,802 articles were collected and analyzed with topic modeling and network analysis method. As a result of this paper, a total of 27 types of subjects were identified. Health and healing in the field of environmental psychology, garden and aesthetics, participation and community, modernity, place and placenness, microclimate, tourism and social equity also have been continued as important research area in this journal. Modernity, community and urban regeneration is hot topics and ecological landscape related topics were cold topics. Although there was a difference by subject, the variability of the research subjects appeared after the 2000s. In Network analysis, it shows that 'Park' is a representative keyword that can symbolize the journal, and 'landscape' is also important a leading area of the journal. Looking at the overall structure of the network, it can be seen that the journal conducts research on 'utilizing', 'using', and creating 'park', 'landscape', and 'space'. This study is meaningful in that it grasped the overall research trend of the journal by using topic modeling and network analysis of text mining.

• Transactions of the Korean hydrogen and new energy society
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• v.7 no.1
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• pp.29-37
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• 1996

Alkaline water electrolysis has been commercialized as the only large-scale method for a long time to produce hydrogen and the technology is superior to other methods such as photochemical, thermochemical water splitting, and thermal decomposition method in view of efficiency and related technical problem. However, such conventional electrolyzer do not have high electric efficiency and productivity to apply to large scale hydrogen production for energy or chemical feedstocks. Solid polymer electrolyte water electrolysis using a perfluorocation exchange membrane as an $H^+$ ion conductor is considered to be a promising method, because of capability for operating at high current densities and low cell voltages. So, this is a good technology for the storage of electricity generated by photovoltaic power plants, wind generators and other energy conversion systems. One of the most important R&D topics in electrolyser is how to minimize cell voltage and maximize current density in order to increase the productivity of the electrolyzer. A commercialized technology is the hot press method which the film type electrocatalyst is hot-pressed to soild polymer membrane in order to eliminate the contact resistance. Various technologies, electrocatalyst formed over Nafion membrane surface by means of nonelectrolytic plating process, porous sintered metal(titanium powder) or titanium mesh coated with electrocatalyst, have been studied for preparation of membrane-electrocatalyst composites. In this study some experiments have been conducted at a solid polymer electrolyte water electrolyzer, which consisted of single cell stack with an electrode area of $25cm^2$ in a unipolar arrangement using titanium mesh coated with electrocatalyst.

• The Journal of the Korea Contents Association
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• v.20 no.2
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• pp.96-104
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• 2020

As consumers' consumption activities become more active due to the activation of online shopping malls, companies are conducting item trend analyses to boost sales. The existing item trend analysis methods are analyzed by considering only the activities of users in online shopping mall services, making it difficult to identify trends for new items without purchasing history. In this paper, we propose a trend analysis method that combines data in online shopping mall services and social network data to analyze item trends in users and potential customers in shopping malls. The proposed method uses the user's activity logs for in-service data and utilizes hot topics through word set extraction from social network data set to reflect potential users' interests. Finally, the item trend change is detected over time by utilizing the item index and the number of mentions in the social network. We show the superiority of the proposed method through performance evaluations using social network data.

• Journal of Korea Society of Industrial Information Systems
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• v.26 no.1
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• pp.83-95
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• 2021

In this study, major research trends at home and abroad were compared and analyzed in order to derive key research fields in the financial security field and to suggest directions. To this end, 689 domestic and 20,736 foreign data were collected from domestic and international academic journal DB, and major research fields related to financial security were extracted through LDA analysis. After that, hot & cold topics were derived through time series linear regression analysis. As a result of the analysis, studies related to government policy issues, personal information, and accredited certification were derived as promising research fields in Korea. In the case of foreign countries, related studies were drawn to develop advanced security systems such as cryptographic protocols and quantum security. Recently, it has become possible to apply various security technologies in Korea through the abolition of public certification. Accordingly, as changes in promising research fields are expected, the results of this study are expected to contribute to the establishment and development of a successful roadmap for domestic financial security.

• Journal of Korea Multimedia Society
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• v.17 no.8
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• pp.946-952
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• 2014

Mobility prediction is one of hot topics using location history information. It is useful for not only user-level applications such as people finder and recommendation sharing service but also for system-level applications such as hand-off management, resource allocation, and quality of service of wireless services. Most of current prediction techniques often use a set of significant locations without taking into account possible location information changes for prediction. Markov-based, LZ-based and Prediction by Pattern Matching techniques consider interesting locations to enhance the prediction accuracy, but they do not consider interesting location changes. In our paper, we propose an algorithm which integrates the changing or emerging new location information. This approach is based on Active LeZi algorithm, but both of new location and all possible location contexts will be updated in the tree with the fixed depth. Furthermore, the tree will also be updated even when there is no new location detected but the expected route is changed. We find that our algorithm is adaptive to predict next location. We evaluate our proposed system on a part of Dartmouth dataset consisting of 1026 users. An accuracy rate of more than 84% is achieved.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.10
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• pp.2294-2300
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• 2013

As smartphones have become widely used, topics of smartphone become a hot research subject in IT technologies. Many applications have been developed for the smartphone and the application market has become more and more increasing. However here are few studies or application developments on Korea's traditional games. In this paper we developed Korea's traditional board game Gonu. People who are young or old can play the game. We expect that many applications which related with Korean culture are developed on the smartphone environment.

• Journal of Information Technology Applications and Management
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• v.15 no.1
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• pp.261-270
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• 2008

Wireless Mesh Networks (WMNs) have emerged as one of the new hot topics in wireless communications. WMNs have been suggested for use in situations in which some or all of the users are mobile or are located in inaccessible environments. Unconstrained transmission in a WMN may lead to the time overlap of two or more packet receptions, called collisions or interferences, resulting in damaged useless packets at the destination. There are two types of collisions; primary collision, due to the transmission of the stations which can hear each other, and hidden terminal collision, when stations outside the hearing range of each other transmit to the same receiving stations. For a WMN, direct collisions can be minimized by short propagation and carrier sense times. Thus, in this paper we only consider hidden terminal collision while neglecting direct collisions. To reduce or eliminate hidden terminal collision, code division multiple access (CDMA) protocols have been introduced. The collision-free property is guaranteed by the use of spread spectrum communication techniques and the proper assignment of orthogonal codes. Such codes share the fixed channel capacity allocated to the network in the design stage. Thus, it is very important to minimize the number of codes while achieving a proper transmission quality level in CDMA WMNs. In this paper, an efficient heuristic code assignment algorithm for eliminating hidden terminal collision in CDMA WMNs with general topology.

• Journal of the Korean Data and Information Science Society
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• v.20 no.1
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• pp.125-137
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• 2009

Smart card has a small sized micro computer chip. This chip contains processor, RAM, ROM, clock, bus system and crypto-co-processor. Hence it is more expensive, complicated and secure chip compared with RFID tag. The main application area of smart card is e-banking and secure communications. There are two kinds of smart card platforms; open platform and closed one. Java card is the most popular open platform because of its security, platform independency, fast developing cycle. However, the speed of Java card is slower than other ones, hence there have been hot research topics to improve the performance of Java card. In this paper, we propose an efficient transaction buffer management to improve the performance of Java card. The experimental result shows the advantage of our method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.776-779
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• 2012

Recently one of the hot topics of IT field is big data. The security's meaning changed a lot, so security tools which were used to protect the limit area traditionally, now don't have any effectiveness. In the age of Cloud Computing, big data will do the best work. This paper discusses the technology related to big data and the intelligent security system utilizing big data.

• Journal of Biomedical Engineering Research
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• v.20 no.3
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• pp.283-290
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• 1999

Because MR(Magnetic Resonance) slice images have much information of functions about body organs, it is very effeclive for diagnoses lo analyze and visualize MR slice images. A visuahzation process is composed of medical image acquisition, preprocessmg, segmentation, inlerpolation, rendering. Segmentation and interpolation among thenl ,1re currenl hot topics because of MR slice image imperfections. This paper proposes a method for segmentalion, mlerpolation respectively and addresses 3 D-visualizmg of a head. We segmented head tissues uomg otructural knowledge of head studied by clinical experiments sequentially. We improved the dynamic elastic inlerpolation to Utilize in concave conlour. We compared the proposed segmentation method and the interpolation method with other methods.