• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.557-560
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• 2013

MANTET(Mobile Ad-Hoc Networks), which is configured and operated by each terminals with no support of communication infra-structures, is recently expanded its application fields from terrestrial communications to underwater environments with technical advances of Wi/Fi and minimized portable terminals. Underwater sensor network, undersea environment explorations and probes, information transmission for underwater area, etc., is typical application fields of underwater MANET. Especially, Performance measurement and analysis on this application fields is one of important research area and base of design, implementation and operation for underwater MANET. However, the research results are focued on various transmission parameters on network level, and its objects of analysis are also performance of network level. In this paper, transmission performances for application levels are measured and analyzed for user levels on underwater MANET. In this study, voice traffic is assumed as object application traffic, computer simulation which is based on NS-2 having additional implemented functions for underwater communications is used. on some defined scale of MANET, transmission performances according to varying traffic environments are measured and analyzed, operation conditions on underwater MANET is suggested with the analysis.

• 한국노년학
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• v.39 no.1
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• pp.109-125
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• 2019

This study examined factors that prevent older adults from using computers and/or smartphones for their health information search and health management. This study conducted face-to-face survey of a total of 240 older adults aged over 65. Based on the responses of open-ended questions, this study conducted semantic network analysis. The results showed that low level of perceived usefulness(PU) (e.g., information I want to find, detailed information, and trustworthiness) and perceived ease of use(PEOU) (e.g., how to search for information, how to install applications, and visibility) are main factors that prevent older adults from using computers and/or smartphones for their health information search and health management. Furthermore, based on the results of semantic network analysis, further hierarchical regression analysis confirmed that PU and PEOU were positively associated with intention to use mobile application. Thus, the results imply that increasing older adults' PU and PEOU can promote their intention to use mobile application.

• The Journal of Society for e-Business Studies
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• v.7 no.2
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• pp.113-128
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• 2002

This paper proposes a public oriented e-Marketplace that induces strategic coalition using database in which detail information about each firm is contained. A public oriented e-Marketplace links each firm through the type of Internet business model and constructs a trading community. We introduce a design methodology of public oriented e-Marketplace called as social network analysis. Social network analysis helps each firm's network easily visualized and completely modeled. Additionally, this paper tries to analyze the relationship among the level of competition, potential of strategic coalition, and financial performance. We demonstrate the firm to easily accept various strategic coalitions can make higher financial performance under the more competitive condition. This implies that strategic coalition through public oriented e-Marketplace provide the each firm with various opportunities.

• International Journal of Computer Science & Network Security
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• v.24 no.1
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• pp.71-84
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• 2024

This paper presents a critical analysis of the current application of big data in higher education and how Learning Analytics (LA), and Educational Data Mining (EDM) are helping to shape learning in higher education institutions that have applied the concepts successfully. An extensive literature review of Learning Analytics, Educational Data Mining, Learning Management Systems, Informal Learning and Online Social Networks are presented to understand their usage and trends in higher education pedagogy taking advantage of 21st century educational technologies and platforms. The roles of and benefits of these technologies in teaching and learning are critically examined. Imperatively, this study provides vital information for education stakeholders on the significance of establishing a teaching and learning agenda that takes advantage of today's educational relevant technologies to promote teaching and learning while also acknowledging the difficulties of 21st-century learning. Aside from the roles and benefits of these technologies, the review highlights major challenges and research needs apparent in the use and application of these technologies. It appears that there is lack of research understanding in the challenges and utilization of data effectively for learning analytics, despite the massive educational data generated by high institutions. Also due to the growing importance of LA, there appears to be a serious lack of academic research that explore the application and impact of LA in high institution, especially in the context of informal online social network learning. In addition, high institution managers seem not to understand the emerging trends of LA which could be useful in the running of higher education. Though LA is viewed as a complex and expensive technology that will culturally change the future of high institution, the question that comes to mind is whether the use of LA in relation to informal learning in online social network is really what is expected? A study to analyze and evaluate the elements that influence high usage of OSN is also needed in the African context. It is high time African Universities paid attention to the application and use of these technologies to create a simplified learning approach occasioned by the use of these technologies.

• The KIPS Transactions:PartB
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• v.9B no.4
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• pp.429-436
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• 2002

In order to apply the artificial neural network to the practical application, it is needed to implement it with the hardware system. It is most promising to make it with the hybrid VLSI among various possible technologies. When we Implement a trained network into the hybrid neuro-chips, it is to be performed the process of the quantization on its neuron outputs and its weights. Unfortunately this process cause the network's outputs to be distorted from the original trained outputs. In this paper we analysed in detail the statistical characteristics of the distortion. The analysis implies that the network is to be trained using the normalized input patterns and finally into the solution with the small weights to reduce the distortion of the network's outputs. We performed the experiment on an application in the time series prediction area to investigate the effectiveness of the results of the analysis. The experiment showed that the network by our method has more smaller distortion compared with the regular network.

• Structural Engineering and Mechanics
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• v.18 no.3
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• pp.303-314
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• 2004

An artificial neural network (ANN) application is presented for flexural and axial vibration analysis of elastic beams with various support conditions. The first three natural frequencies of beams are obtained using multi layer neural network based back-propagation error learning algorithm. The natural frequencies of beams are calculated for six different boundary conditions via direct solution of governing differential equations of beams and Rayleigh's approximate method. The training of the network has been made using these data only flexural vibration case. The trained neural network, however, had been tested for cantilever beam (C-F), and both end free (F-F) in case the axial vibration, and clamped-clamped (C-C), and Guided-Pinned (G-P) support condition in case the flexural vibrations which were not included in the training set. The results found by using artificial neural network are sufficiently close to the theoretical results. It has been demonstrated that the artificial neural network approach applied in this study is highly successful for the purposes of free vibration analysis of elastic beams.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.500-504
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• 1995

A neural network based upon the back propagation algorithm was designed and applied to acoustic power spectra of electrohydraulic total artificial hearts in order to diagnose mechanical failure of devices. The trained network distinguished spectra of the mechanically damaged device from those of the undamaged device with overall success rate of 63%. Moreover, the network correctly classified more than 70% of spectra in the frequency bands of 0-100 Hz and 700-950 Hz. Consequently, the neural network analysis was useful for the diagnosis of mechanical failure of a total artificial heart.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.2
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• pp.232-241
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• 2010

This paper describes the development of robust contingency analysis program for Korean Energy Management System. The important function of contingency analysis is to determine the bus/branch model for contingency, and to calculate the state of the power network based on the network model and topology output. In the proposed method, the bus/branch models for contingencies are determined exactly using a fast linked-list method based on the application common model database. To calculate the state of the power system included contingency, the full-decoupled powerflow approach, the partial powerflow method for contingencies and the proposed contingency screening algorithm are also used to contingency analysis. To verify the performance of the developed processor, we performed a file-based test using several structured input data and online test using the database which resides on memory. The results of these comprehensive tests showed that the developed processors can accurately calculate the power system contingency state from online data and can be applied to Korea Power Exchange system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.427-430
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• 2010

MOST Network는 오디오와 비디오 데이터를 실시간으로 전송하는 동기식데이터 영역과 패킷데이터를 전송하는 비동기식 데이터 영역, 네트워크 관리를 위한 명령, 상태, 진단 정보를 전송하는 control Channel로 구성되어 있다. 본 논문에서는 비동기식 데이터 영역과 Control Channel의 데이터를 캡처 및 분석하는 모듈을 설계 및 구현한 후 실제 MOST 네트워크를 구축하여 검증해 보았다. 구현한 시스템을 바탕으로 고가의 장비를 별도로 보유하지 않더라도 MOST Network의 비동기식 데이터 영역과 Control Channel의 데이터를 확인할 수 있으며, 분석이 가능한 시스템을 제안하였다.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.3
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• pp.357-366
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• 2006

In order to compute pressure variation for a water distribution system, an expression for the friction factor as a function of Reynolds number and the relative roughness needs to be properly incorporated in computational algorithm. Considering Moody s friction variation, Developed Unsteady Network Analyzer (UNA) has been modified to match computational results with EPANET 2.0. Substantial improvement can be found in the application of Improved UNA to both an hypothetical pipeline network and a real system located in Ulsan City. Random number generator is employed to represent the uncertainty of water use in real pipeline network. Comparisons of application between EPANET 2.0 and improved UNA 2.0 indicate advantages and potentials of this approach.