• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1483-1493
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• 2018

Recently, more power facilities are needed to cope with the increasing electric demand. However, the additional construction of generators, transmission and distribution installations is not easy because of environmental problems and citizen's complaints. Under this circumstance, a microgrid system with distributed renewable resources emerges as an alternative of the traditional power systems. Moreover, the configuration of power system changes with more DC loads and more DC installations. This paper is written to introduce an idea of a genetic algorithm-based solution to determine the optimal capacity of the distributed generators depending on the types of system configuration: AC-link, DC-link and Hybrid-link types. In this paper, photovoltaic, wind turbine, energy storage system and diesel generator are considered as distributed generators and the feasibility of the proposed algorithm is verified by comparing the calculated capacity of each distributed resource with HOMER simulation results for 3 types of system configuration.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.193-196
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• 1997

A mobile computing environment has many difference in character from conventional communication over wired network. These include very presents distributed design system based the mobile agent for mobile computing environment. To integrate design resource, we presented ISA(Integration Service Agent, which allows a designer to build integrated application using distributed resources, and to collaborative by exchanging service. Also we propose ICM(XML based Intelligent Connection Manger) using mobile agent. And suggested new intelligent data and process transfer architecture using ICM to implement an agent based design system in mobile environment.

• Journal of the Optical Society of Korea
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• v.17 no.6
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• pp.500-505
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• 2013

In this paper, we propose a novel framework to evaluate the depth resolution of axially distributed stereo sensing (ADSS) under fixed resource constraints. The proposed framework can evaluate the performance of ADSS systems based on various sensing parameters such as the number of cameras, the number of total pixels, pixel size and so on. The Monte Carlo simulations for the proposed framework are performed and the evaluation results are presented.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.2
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• pp.141-151
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• 2013

Process planning can be defined as determining detailed methods by which parts can be manufactured from the initial to the finished stage. Process planning starts with determining the manufacturing process based on the geometric shape of the part and the machines and tools required for performing this process. Distributed process planning enables production planning to be performed easily by combining the extracted process and various manufacturing resources such as operations and tools. This study proposes an algorithm to determine the process for a feature-based model and to combine manufacturing resources for the process and implements a distributed process planning system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.5
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• pp.1093-1101
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• 2017

Microgrid as a unit component consisting a smart grid is an isolated system, which has a decentralized power supply system. This paper proposes an electrical isolation of the microgrid from the utiliy grid based on a power conditioning system, and also proposes an operation method maintaining the isolated state efficiently using diverse distributed energy resources such as renewable energy sources and energy storage system. The proposed system minimizes the influence of the grid connection on the internal load though a phase detection and synchrnoization to the utiligy grid and the microgrid can be stable even if the grid is failed.

• Journal of the Speleological Society of Korea
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• no.95
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• pp.23-33
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• 2009

This study analyzed the distribution of China's caves and cave resources in Research. The results are as follows: First, China's melting karst caves are mainly distributed in southwest widely distributed. Recently in Beijing and other northern areas found in many caves. First, China's Karst caves are mainly distributed in karst-flung southwest. Recently in Beijing and other northern areas found in many caves. Second, although China is widespread volcanic landscapes, but most of the extinct volcano, the lava caves less so. Are mainly distributed in Hainan Island, north-east there are some distribution. Third, China's recent development and evolution of the cave, analysis of the paleo-environment records of cave stalagmites, cave biology, cave tourism development, environmental aspects of cave research more active.

• Journal of the Korea Society of Computer and Information
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• v.22 no.6
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• pp.17-24
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• 2017

In recent digital broadcasting, up to 250 channels are multiplexed and transmitted. The channel transmission is made in the form of MPEG-2 Transport Stream (TS) and transmits one channel (Video, Audio). In order to check if many broadcast channels are transmitted normally, in multi-channel multi-view system, ability of real-time monitoring is required. In order to monitor efficient multi-channel, a distributed system in which functions and load are distributed should be implemented. In the past, we used an inefficient system that gave all of the functionality to a piece of hardware, which limited the channel acceptance and required a lot of resources. In this paper, we implemented a distributed multi-view system which can reduce resources and monitor them economically through efficient function and load balancing. It is able to implement efficient system by taking charge of decoding, resizing and encoding function in specific server and viewer function in separate server. Through this system, the system was stabilized, the investment cost was reduced by 19.7%, and the wall monitor area was reduced by 52.6%. Experimental results show that efficient real-time channel monitoring for multi-channel digital broadcasting is possible.

• Journal of Korean Society for Quality Management
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• v.38 no.1
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• pp.64-74
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• 2010

Since management of information resources is getting more complicated in the distributed, heterogeneous computing environment, the capability of monitoring and controlling the dispersed information resources is perceived as a critical success factor for the effective enterprise-wide information resource management. Integrated Control Architecture(ICA) provides that capability. Utilizing such architecture, we can manage corporate information resources more efficiently, perform impact analysis for changes in information resources, and alleviate the human effort by automating the monitoring of critical information resources. In this paper, we propose a conceptual framework and metamodel of ICA.

• Journal of the Korea Society of Computer and Information
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• v.22 no.8
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• pp.55-61
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• 2017

Cloud computing is cost-effective in terms of system configuration and maintenance and does not require special IT skills for management. Also, cloud computing provides an access control setting where SSO is adopted to secure user convenience and availability. As the SSO user authentication structure of cloud computing is exposed to quite a few external security threats in wire/wireless network integrated service environment, researchers explore technologies drawing on distributed SSO agents. Yet, although the cloud computing access control using the distributed SSO agents enhances security, it impacts on the availability of services. That is, if any single agent responsible for providing the authentication information fails to offer normal services, the cloud computing services become unavailable. To rectify the environment compromising the availability of cloud computing services, and to protect resources, the current paper proposes a security policy that controls the authority to access the resources for cloud computing services by applying the authentication policy of user authentication agents. The proposed system with its policy of the authority to access the resources ensures seamless and secure cloud computing services for users.

• Journal of Environmental Science International
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• v.22 no.5
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• pp.515-522
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• 2013

To investigate groundwater variation characteristics in the Hancheon watershed, Jeju Island, an integrated hydrologic component analysis was carried out. For this purpose, SWAT-MODFLOW which is an integrated surface-groundwater model was applied to the watershed for continuous watershed hydrologic analysis as well as groundwater modeling. First, ephemeral stream characteristics of Hancheon watershed can be clearly simulated which is unlikely to be shown by a general watershed hydrologic model. Second, the temporally varied groundwater recharge can be properly obtained from SWAT and then spatially distributed groundwater recharge can be made by MODFLOW. Finally, the groundwater level variation was simulated with distributed groundwater pumping data. Since accurate recharge as well as abstraction can be reflected into the groundwater modeling, more realistic hydrologic component analysis and groundwater modeling could be possible.