• Journal of Information Management
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• v.32 no.2
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• pp.40-53
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• 2001

The purpose of this study is to explore the current situation and problems in standardizing knowledge information and information technology in the KISTI, and collect the basic data necessary for establishing the national information infrastructure. Through a survey and interviews with nine departments of the Information Services Sector of the KISTI, data were collected regarding the management and exchange of information and the operation of communication networks. According to the analysis of fifty KISTI databases and their operation, tasks to be first standardized include Classification of ST resources, Metadata, Date modeling, Data format, DBMS, ST terminology, and Retrieval protocol.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.6
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• pp.131-136
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• 2020

In vehicular communications environment, content pre-caching can reduce the delay time from the user to the content server. However, the problem of where and how much pre-caching is still not solved. In this paper, based on the movement probability of the vehicle, we propose a method for pre-caching by distributing the optimized amount of content to each base station candidate that the vehicle will move as follows. First, the movement probability of each vehicle was learned using Markov Model. And the amount of content to be distributed and pre-cached was optimized based on the wireless environment. In experiments based on NS-3, the proposed strategy maintained the least delay compared to the existing protocol, leading to the most traffic-saving results.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.35T no.1
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• pp.111-119
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• 1998

To predict propagation environments of antenna radiation pattern, it is very important for deceision of service area, selection of the best station location and design of cell etc. By analyzing the propagation prediction model that is varied acceding to the kind of antenna, beam angle, terrain and obstacles, we expect that the economic operating of communication networks, calling quality and service of subscriber will be enhanced. It was measured the fields strength to propose the optimal propargation predicted model of the zone of Seji base station in Naju-city. The simulations of field test are 4 types Hata model, the Egri model, the Carey model and the proposed model. Finally the proposed model are more close agreement with experimental test than other models.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.2
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• pp.115-122
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• 2012

We present here a new class of activation functions for neural networks, which herein will be called CosGauss function. This function is a cosine-modulated gaussian function. In contrast to the sigmoidal-, hyperbolic tangent- and gaussian activation functions, more ridges can be obtained by the CosGauss function. It will be proven that this function can be used to aproximate polynomials and step functions. The CosGauss function was tested with a Cascade-Correlation-Network of the multilayer structure on the Tic-Tac-Toe game and iris plants problems, and results are compared with those obtained with other activation functions.

• Bulletin of the Korean Chemical Society
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• v.32 no.3
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• pp.939-942
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• 2011

Conductive carbon films were prepared at room temperature by unbalanced magnetron sputtering (UBMS) on silicon substrates using argon (Ar) gas, and the effects of post-annealing temperature on the structural, tribological, and electrical properties of carbon films were investigated. Films were annealed at temperatures ranging from $400^{\circ}C$ to $700^{\circ}C$ in increments of $100^{\circ}C$ using a rapid thermal annealing method by vacuum furnace in vacuum ambient. The increase of annealing temperature contributed to the increase of the ordering and formation of aromatic rings in the carbon film. Consequently, with increasing annealing temperature the tribological properties of sputtered carbon films are deteriorated while the resistivity of carbon films significantly decreased from $4.5{\times}10^{-3}$ to $1.0{\times}10^{-6}\;{\Omega}-cm$ and carrier concentration as well as mobility increased, respectively. This behavior can be explained by the increase of sp2 bonding fraction and ordering $sp^2$ clusters in the carbon networks caused by increasing annealing temperature.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.9
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• pp.844-848
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• 2001

This paper introduces unmaned fully automation systems, which are applied for the CSTR(Continuously Stirred Tank Reactor) and SBR (Sequencing Batch Reactor) wastewater treatment system. The pilot plant is constructed in the country side which is little far from a main city. So networks and wireless modules are employed for the data transmission. The SBR plant has a local control and the remote monitoring system which is contained communication parts which consist of ADSL (Asymmetric Digital Subscriber Line) network and CDMA (Code Division Multiple Access) Wireless module. Remote control and monitoring systems are constructed at laboratory in a metropolis.

• Journal of the Korean Data and Information Science Society
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• v.21 no.6
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• pp.1125-1136
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• 2010

Lately there exist increasing demands for online abnormality monitoring over trajectory stream, which are obtained from moving object tracking devices. This problem is challenging due to the requirement of high speed data processing within limited space cost. In this paper, we present a FADA (Fuzzy Anomaly Detection Algorithm) which constructs normal profile by computing mobility feature information from the GPS (Global Positioning System) logs of mobile devices in MANETs (Mobile Ad-hoc Networks), computes a fuzzy dissimilarity between the current mobility feature information of the mobile device and the mobility feature information in the normal profile, and detects effectively the anomaly behaviors of mobile devices on the basis of the computed fuzzy dissimilarity. The performance of proposed FADA is evaluated through simulation.

• Journal of electromagnetic engineering and science
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• v.11 no.4
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• pp.239-249
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• 2011

In this paper, we propose a reliable $8{\times}8$ up-down switching polar relay code based on 3GPP LTE standard, motivated by 3GPP LTE down link, which is 30 bps/Hz for $8{\times}8$ MIMO antennas, and by Arikan's channel polarization for the frequency selective fading (FSF) channels with the generator matrix $Q_8$. In this scheme, a polar encoder and OFDM modulator are implemented sequentially at both the source node and relay nodes, the time reversion and complex conjugation operations are separately implemented at each relay node, and the successive interference cancellation (SIC) decoder, together with the cyclic prefix (CP) removal, is performed at the destination node. Use of the scheme shows that decoding at the relay without any delay is not required, which results in a lower complexity. The numerical result shows that the system coded by polar codes has better performance than currently used designs.

• Journal of Korea Game Society
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• v.11 no.6
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• pp.13-22
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• 2011

In the digital media environment, the convergence is in the progress creating the new service and contents by users and developing the new needs of users by the service and contents as well. Social games are actualizing the new meaning of convergence. shows not only a new situation blurring the boundary of work and leisure, labor and playing and private and public sector, but how meaningful it is to make connection of social interactions and social assets a solid network. As the most popular social game text, reveals how the personal connections and personal networks constructs the social capital by making the ritual communication more interesting and flexible to the social gamers.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.8 no.4
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• pp.239-247
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• 2008

In a resource-limited wireless communication environment, various approaches to meet the ever growing application requirements in an efficient and transparent manner, are being researched and developed. Amongst many approaches, cross layer technique is by far one of the significant contributions that has undoubtedly revolutionized the way conventional layered architecture is perceived. In this paper, we propose a Universal Cross Layer Framework based on vertical layer architecture. The primary contribution of this paper is the functional architecture of the vertical layer which is primarily responsible for cross layer interaction management and optimization. The second contribution is the use of optimization cycle that comprises awareness parameters collection, mapping, classification and the analysis phases. The third contribution of the paper is the decomposition of the parameters into local and global network perspective for opportunistic optimization. Finally, we have shown through simulations how parameters' variations can represent local and global views of the network and how we can set local and global thresholds to perform opportunistic optimization.