• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.10
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• pp.885-894
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• 2012

Currently, Demand of data traffic has rapidly increased by popular of smart device. It is very difficult to accommodate demand of data traffic by limited resource of base station (BS). To solve this problem, method has proposed that the Device-to-Device (D2D) reduce frequency overload of the BS and all of the user equipment (UE) inside the BS and neighbor BS don't allow communicating directly to BS. However, in LTE-Advance system cellular link and sharing radio resources of D2D link, the strong interference of the cellular network is still high. So we need to eliminate or mitigate the interference. In this paper, we use the transmission power control method and Soft Frequency Reuse (SFR) resource allocation method to mitigate the interference of the cellular link and D2D link. Simulation results show that the proposed scheme has high performance in terms of Signal to Noise Ratio (SINR) and system average throughput.

• Journal of Digital Convergence
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• v.14 no.11
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• pp.289-295
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• 2016

Subway is a future-oriented means of transportation that can be safely and quickly mass transport many passengers than buses and taxis. Congestion growth due to the increase of the metro users is one of the factors that hinder citizens' rights to comfortably use the subway. Accordingly, congestion prediction in the subway is one of the ways to maximize the use of passenger convenience and comfort. In this paper, we monitor the level of congestion in real time via the existing congestion on the metro using multiple regression analysis and big data processing, as well as their departure station and arrival station information More information about the transfer stations offer a personalized congestion prediction system. The accuracy of the predicted congestion shows about 81% accuracy, which is compared to the real congestion. In this paper, the proposed prediction and recommendation application will be a help to prediction of subway congestion and user convenience.

• Journal of the Korea Society of Computer and Information
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• v.1 no.1
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• pp.65-82
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• 1996

The assurance of software product. which Is different to other products. is very complex because of Its characteristics. The use of objective development standards or guidelines and the confirmation to meet user's requirements are Important to achieve the software quality system. Moreover correct understanding of qualitv standards and continuous applications of check-points for qualify audit are necessary. ISO 9000 series. which are International standards. were made for the qualify assurance. Among them. ISO 9000-3 is the quality management and quality assurance standards for applying ISO 9001 to the design. development. supply. installation and maintenance of software. The newly revised ISO/CD 9000-3：1995 contains a lot of enforced changes within ISO 9001 framework - quality standards for manufactured products. This paper analyses the revised ISO 9000-3 by comparing it to ISO 9001. and derives quality audit points to use for qualify audit In future.

• The KIPS Transactions:PartD
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• v.10D no.6
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• pp.949-960
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• 2003

Main memory database systems use the different implementation techniques to sturucture and organize the user dta and system catalogs, since traditional database systems are optimized for the characteristics of disk storage environment. We present, in this paper, the design considerations for our main memory database system $ALTIBASE^{TM}$ that is currently applied to the time-critical applications. We focus on the design issues of storage manager in $ALTIBASE^{TM}$. The major components are introduced, and features and characteristics of transaction management and recovery method are described. We also present the database replication mechanism and its conflict resolution mechanism for high availability and performance. In order to evaluate our transaction performance, we show various experimental reports as measured by the TPS.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.35-45
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• 2017

This study aims to explore the effect of quality factors and learning styles on users' satisfaction in e-Learning context. For this purpose, statistical methods such as reliability test, factor analysis, ANOVA, regression analysis were carried out using the survey data from university students. The quality factors of e-Learning were classified into contents, system, service, and interpersonal activities while learning styles were classified into positive-cooperative, self-directed, environmental-dependent, and passive styles. The results showed that each quality factors of e-Learning has a strong positive effect on user satisfaction, and self-directed group has higher satisfaction than other groups. Learning styles have moderating effects on the quality-satisfaction relationship, and especially, the group of passive learning style has a strong moderating effect on the interpersonal activities. Theoretical and practical implications and future research directions are drawn from these findings.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.4
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• pp.141-152
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• 2013

The applications and concerned technologies of cloud computing services, one of major trends in the information communication technology, are widely progressing and advancing. OpenStack, one of open source cloud computing platforms, is comprised of several service components; using these, it can be possible to build public or private cloud computing service for a given target application. In this study, a remote sensing image analysis processing service on cloud computing environment has designed and implemented as an operational test application in the private cloud computing environment based on OpenStack. The implemented service is divided into instance server, web service, and mobile app. A instance server provides remote sensing image processing and database functions, and the web service works for storage and management of remote sensing image from user sides. The mobile app provides functions for remote sensing images visualization and some requests.

• Journal of the Korea Convergence Society
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• v.9 no.2
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• pp.241-250
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• 2018

Online recruitment services have emerged as one of the most popular Internet services, providing job seekers with a comprehensive list of jobs and a search engine. But many recruitment services suffer from shortcomings due to their reliance on traditional client-pull information access model, in manay cases resulting in unfocused search results. Worldjob+, being operated by The Human Resources Development Service of Korea, addresses these problems and uses Splunk, a platform for analyzing machine data, to provide a more proactive and personalised services. It focuses on enhancing the existing system in two different ways: (a) using personalised automated matching techniques to proactively recommend most preferrable profile or specification information for each job opening announcement or recruiting company, (b) and to recommend most preferrable or desirable job opening announcement for each job-seeker. This approach is a feature-free recommendation technique that recommends information items to a given user based on what similar users have previously liked. A brief discussion about the potential benefit is also provided as a conclusion.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.407-409
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• 2017

Many traditional retailers are losing money due to loss and accidents in managing their carts. Therefore, we intend to solve these problems by installing a raspberry pie with various functions in order to efficiently manage the cart. First, use ultrasonic sensors to measure the distance between the cart and the object, use vibration sensors to vary the number of vibration sensors, change the number of vibrations to the user, and use Beacon to transmit the cart in real time. It also contributes to consumers' spending patterns and revenue generation by identifying consumers' consumption patterns. Problems with lost are also resolved by issuing an audible warning (outside of Mart) if a distance is removed (outside of Mart).

• The KIPS Transactions:PartA
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• v.14A no.1 s.105
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• pp.1-14
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• 2007

MPICH-G2 is an MPI implementation to solve complex computational problems by utilizing geographically dispersed computing resources in grid environments. However, the computation nodes in MPICH-G2 are exposed to the external network due to the lack of supporting the private IP clusters, which raises the possibility of malicious security attacks. In order to address this problem, we propose MPICH-GP with a new relay scheme combining NAT(Network Address Translation) service and an user-level proxy. The proxy running on the front-end system of private IP clusters forwards the incoming connection requests to the systems inside the clusters. The outgoing connection requests out of the cluster are forwarded through the NAT service on the front-end system. Through the connection path between the pair of processes, the requested MPI jobs can be successfully executed in grid environments with various clusters including private IP clusters. By simulations, we show that the performance of MPICH-GP reaches over 80% of the performance of MPICH-G2, and over 95% in ease of using RANK management method.

• Journal of Digital Convergence
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• v.11 no.11
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• pp.775-781
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• 2013

N-screen is a Service that can be provide for One Service Multi Device. If the network is changed or if the device is changed after authentication the device fits seamlessly send footage. Security threats that occur here have a problem with user authentication. In this paper proposes available in a multi-device the authentication system. Homomorphic Encryption Algorithm of authentication scheme used. Among the authentication mechanism that already exists is a simple and lightweight authentication mechanism. In addition, N-screen service that uses multiple devices is simple authentication process of the device. Review the results of proposed authentication protocol, encryption algorithm to process a small storage capacity and is easy to work in low processor. And was suitable for use with multiple devices.