• Journal of Information Processing Systems
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• v.13 no.6
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• pp.1575-1584
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• 2017

As interest in big data has increased recently, NoSQL, a solution for storing and processing big data, is getting attention. NoSQL supports high speed, high availability, and high scalability, but is limited in areas where data integrity is important because it does not support multiple row transactions. To overcome these drawbacks, many studies are underway to support multiple row transactions in NoSQL. However, existing studies have a disadvantage that the number of transactions that can be processed per unit of time is low and performance is degraded. Therefore, in this paper, we design and implement a multi-row transaction system for data integrity in big data environment based on HBase, a column-based NoSQL which is widely used recently. The multi-row transaction system efficiently performs multi-row transactions by adding columns to manage transaction information for every user table. In addition, it controls the execution, collision, and recovery of multiple row transactions through the transaction manager, and it communicates with HBase through the communication manager so that it can exchange information necessary for multiple row transactions. Finally, we performed a comparative performance evaluation with HAcid and Haeinsa, and verified the superiority of the multirow transaction system developed in this paper.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.4
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• pp.820-822
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• 2010

Mobile WiMAX system provides various classes of traffic such as real-time and non-realtime services. These services have different QoS requirements and the QoS aware scheduling has been an important issue. Although many of scheduling algorithms for various services in OFDMA system have been proposed, it is needed to be modified to be applied to Mobile WiMAX system. Since Mobile WiMAX supports five kinds of service classes, it is important to take QoS characteristics of each class into consideration. In this paper, we propose an efficient packet scheduling algorithm to support QoS of each class. Proposed scheme selects a service class first considering QoS Characteristics of each class and choose an appropriate user in the selected class. Simulation results show that the proposed algorithm has better performance than the other algorithm.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.631-634
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• 1996

This paper describes an intelligent user interface to define simulation models from the process and resource models. It also explains an automatic program generator of discrete event simulation model for shop floor control in a flexible manufacturing system. Especially, the paper is focused on the design and development of methodology to automate simulation modeling from the system description. Describing a shop floor control system in simulation is not an easy task since it must resolve various decision problems such as deadlock resolution, part dispatching, resource conflict resolution, etc. The program generator should be capable of constructing a complete discrete simulation models for a multi-product and multi-stage flow shop containing the above mentioned problems.

• Journal of the Korea Society of Computer and Information
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• v.20 no.8
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• pp.85-92
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• 2015

Due to the advancements in the capabilities of smart devices and home networks, we are able to easily access multimedia contents stored in a home server. In this paper, we present a wireless media content sharing mechanism for home networks that utilizes UPnP-based DLNA technology. We also present a novel Peer-to-Peer content sharing system that is able to operate on the client as well as server. Our system supports multiple push/pull services simultaneously via a multi-thread technique, and our intuitive user interface facilitates ease of use. Future studies would explore the feasibility of implementing our system in a multi-hop environment or providing a community-wide service.

• Journal of the Korea Computer Industry Society
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• v.7 no.5
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• pp.481-486
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• 2006

Whereas conveniences deriving from the development of information and telecommunication technology increase, information outflow and illegal data use are also rapidly on the rise. Consequently, many studies to prevent illegal information outflow are currently under way, and the use of Smart Card is in steep jump. Recently, Java Card is diffused fast as an alternative to complement the technical problems of the Smart Card. This paper designed and Implementation the system for multi-users authentication and file access control by user through designing a Java Card applet that is used for information protection and in various application fields. For allowing a file access competence, each user's file access competence is processed via drawing up the access condition table in the applet. Therefore, illegal correction exposure and destruction of information, which become the concerns when multi-users have an access, can be prevented. In addition its application becomes possible in the system requiring multi-users certifications.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.10
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• pp.603-609
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• 2004

Procedural texture has many advantages that its representation is extremely compact and unfixed in resolution. However, it can be difficult for an end-user having no programming skill to build and debug. This paper presents a new interactive design system for procedural texture generation. The user's interactive design process based on multi-layer operations is represented with a graph structure, which consists of the data node, the operation and the output. Since our system generates automatically a shading language, a user who is not acquainted with implicit concepts can make procedural texturing by using an intuitive and flexible interface. Simulation results showed that the proposed method can make a variety of texture patterns efficiently.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.4
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• pp.8-12
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• 2009

We propose BMPA(balanced multimedia packet allocation) scheme. This scheme considers the issue of optimal sub-carrier allocation in OFDMA multicast system. When RT(real time) packets and NRT(non-real time) packets arrive at the same time, BMPA scheme gives higher weight to RT packets than NRT packets and then, it allocates sub-carriers according to the total weight sum of packets in each user. This process acts as both packet scheduler and sub-carrier allocation. Therefore, each user receives multimedia packets with reliability. With simulation results, it shows that BMPA scheme ensures long-term system throughput and, in average RT packet delay, BMPA scheme greatly outperforms multi-user water-filling algorithm.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.5
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• pp.616-621
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• 2006

Recently many cars are equipping a navigation system. The main purpose of the early system guides a user through the route. A navigation system includes various abilities by development of various technologies and it has given more convenience to user. It can play various records on the tape and announces which are useful information about each road. Also it can use various multi-media contents by DMB device during driving. However, guide function of basic and important road in the navigation system has not grown greatly yet. In this paper, we proposed recommendation method of human-friendly road considering user's condition through various information of outside environment, user's velocity intention, a driver's emotion and a preference of the road. Modules consists of hierarchical structure that can easily correct and add each algorithm and those use fuzzy logic algorithm.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.8
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• pp.58-64
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• 2012

We propose a double time reversal (TR) prefilter for high data rate and minimum interference in multi-user indoor communication system. A conventional TR prefilter degrades bit error rate (BER) performance significantly because it cannot remove the interference perfectly. As the symbol duration is close, the BER performance is deteriorated. Since the proposed scheme aims to minimize interference, high data rate is realized without the performance degradation and the complexity of receiver is reduced through an additional prefilter design. Simulation results show that the performance of the proposed scheme is improved as the number of users is increased or the data rate becomes high.

• Journal of the Korean housing association
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• v.15 no.1
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• pp.95-102
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• 2004

The purpose of this study is to actualize the planning method of the shared community space (SCS). For this, it analyzed the residents' needs for the SCS and grasped the composition system of the needs and estimated the factors considered in the planning of the SCS. This study focused on seeking out the user-oriented design criteria for the planning of the SCS. The results of this study are as follows: First, as the results subdividing the residents' needs to understand the various requirements for the SCS, the composition system was classified into the fundamental SCS and the individual SCS. The fundamental SCS's to be considered as basic facilities in the planning of the multi-family housing complex, and the individual SCS to be more suited to a particular group. Second, regarding the investigation of detail guidelines in the SCS planning, it was found that there was a difference in the considered factors and the preferred locations according to the kinds of each SCS, the types of facilities, the main users of facilities, and the contents of activities available in the facilities.