• Journal of KIISE
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• v.43 no.1
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• pp.27-33
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• 2016

Virtualization has become one of the most helpful techniques in computing systems, and today it is prevalent in several computing environments including desktops, data-centers, and enterprises. However, since I/O layers are implemented to be oblivious to the I/O behaviors on virtual machines (VM), there still exists an I/O scalability issue in virtualized systems. In particular, when a multi-queue solid state drive (SSD) is used as a secondary storage, each system reveals a semantic gap that degrades the overall performance of the VM. This is due to two key problems, accelerated lock contentions and the I/O parallelism issue. In this paper, we propose a novel approach, including the design of virtual CPU (vCPU)-dedicated queues and I/O threads, which efficiently distributes the lock contentions and addresses the parallelism issue of Virtio-blk-data-plane in virtualized environments. Our approach is based on the above principle, which allocates a dedicated queue and an I/O thread for each vCPU to reduce the semantic gap. Our experimental results with various I/O traces clearly show that our design improves the I/O operations per second (IOPS) in virtualized environments by up to 155% over existing QEMU-based systems.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.6
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• pp.77-87
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• 2007

It will need a quite long time to replace IPv4 protocol, which currently used, with IPv6 protocol completely, thus we will use both IPv4 and IPv6 together in the Internet during the period. For coexisting protocols, IETF standardized various IPv4/IPv6 transition mechanisms. However, new security problems of IPsec adaptation and IPv6 packet filtering can be raised by tunneling mechanism which mainly used in transition mechanisms. To resolve these problems, we suggested two improved schemes for packet filtering functions, which consists of an inner header filtering scheme and a dedicated filtering scheme for IPv4/IPv6 transition mechanisms. Also we implemented our proposed schemes based on Linux Netfilter framework, and we tested their filtering functions and evaluated experimental performance of our implementation on IPv4/IPv6 transition testbed. These evaluation tests indicated that our improved packet filtering functions can solve packet filtering problems of IPv4/IPv6 transition mechanisms without severely affecting system performance.

• Journal of Digital Convergence
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• v.13 no.8
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• pp.245-251
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• 2015

If a digital signage system is operated in PC mounted in the Window OS then the implementing price is very high. For resolving this problem, we used the Smartphone mounted in ARM Cortex family of multi-core processor-based mobile platform. We developed a low-power low-cost digital signage system and a remote convergence content management program based on web server. This convergence system manages advertising content to a remote control device anywhere using remote control technology. This system is one integrated system with display and is a low-power consumed and is developed in very efficient hardware interface. And condition sensors(intensity of illumination, temperature, weather, GPS etc) is equipped in the developed system. Automatic contents builder and Context-aware SMIL module is also implemented in the convergence system. We achieved over 50% power savings comparing with conventional Window OS system and 16 points multi-touch in our system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.685-688
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• 2008

A Next Generation Network (NGN) is a packet-based network able to provide services including Telecommunication Services and able to make use of multiple broadband, QoS-enabled transport technologies and in which service-related functions are independent from underlying transport-related technologies. It offers unrestricted access by users to different service providers. It supports generalized mobility which will allow consistent and ubiquitous provision of services to users in this paper. we describe the trend of standardization activity related with open services environment capabilities which had been finally approved at September 2008 in ITU-T. ITU-T SG13 is responsible for studies relating to the architecture, evolution and convergence of next generation networks including frameworks and functional architectures, signalling requirements for NGN.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.978-980
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• 2006

A Next Generation Network (NGN) is a packet-based network able to provide services including Telecommunication Services and able to make use of multiple broadband, QoS-enabled transport technologies and in which service-related functions are independent from underlying transport-related technologies. It offers unrestricted access by users to different service providers. It supports generalized mobility which will allow consistent and ubiquitous provision of services to users In this paper, we explain the trend of standardization activity related with open services in ITU-T SG13(Study Group 13). ITU-T SG13 is responsible for studies .elating to the architecture, evolution and convergence of next generation networks including frameworks and functional architectures, signalling requirements for NGN.

• 한국체육학회지인문사회과학편
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• v.55 no.5
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• pp.619-633
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• 2016

In March 26th, 2016, two major sport organizations of South Korea, Korean Olympic Committee and the Korean Council of Sports for All, have merged with the ultimate goal of improving health and wellness among Korean people through sport and physical activity participation. Integration of sport system intended to shift the paradigm from "old" to "new", and can be a catalyzer to promote Korea as a developed nation with the delivery of quality sport. This study critically reviewed the Canadian Sport for Life-Long-Term Athlete Development (CS4L-LTAD) which serves as a platform to integrate and operate sport organizations in Canada, and discussed the feasibility and adaptability of CS4L-LTAD in the Korean context. This study also introduced Integrated Model for Korea Sport System developed based on the CS4L-LTAD framework, and addressed key strategies that will drive to the successful implementation of the model. The Integrated Model for Korea Sport System offers ways to improve the quality of sport and physical activity for all Koreans by linking sport, recreation, physical education, and health, and by aligning programs and services across different settings: school, elite, and community sports. The recent restructure and redesign of Korea sport system will play vital roles in promoting the overall welfare of all Koreans, regardless of one's sex, age, disability, and sociodemographic status by providing inclusive, ethical, and holistic framework that is appropriate for the Korea sport system.

• Journal of Internet Computing and Services
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• v.16 no.5
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• pp.29-38
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• 2015

The Energy Storage System stores electricity for later use. This system can store electricity from legacy electric power systems or renewable energy systems into a battery device when demand is low. When there is high electricity demand, it uses the electricity previously stored and enables efficient energy usage and stable operation of the electric power system. It increases the energy usage efficiency, stabilizes the power supply system, and increases the utilization of renewable energy. The recent increase in the global interest for efficient energy consumption has increased the need for an energy storage system that can satisfy both the consumers' demand for stable power supply and the suppliers' demand for power demand normalization. In general, an energy storage system consists of a Power Conditioning System, a Battery Management System, a battery cell and peripheral devices. The specifications of the subsystems that form the energy storage system are manufacturer dependent. Since the core component interfaces are not standardized, there are difficulties in forming and operating the energy storage system. In this paper, the design of the profile structure for energy storage system and realization of private profiling system for energy storage system is presented. The profiling system accommodates diverse component settings that are manufacturer dependent and information needed for effective operation. The settings and operation information of various PCSs, BMSs, battery cells, and other peripheral device are analyzed to define profile specification and structure. A profile adapter software that can be applied to energy storage system is designed and implemented. The profiles for energy storage system generated by the profile authoring tool consist of a settings profile and operation profile. Setting profile consists of configuration information for energy device what composes energy saving system. To be more specific, setting profile has three parts of category as information for electric control module, sub system, and interface for communication between electric devices. Operation profile includes information in relation to the method in which controls Energy Storage system. The profiles are based on standard XML specification to accommodate future extensions. The profile system has been verified by applying it to an energy storage system and testing charge and discharge operations.