• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1784-1787
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• 2005

This paper presents the development and testing of a power conditioning system(PCS) for application to a 100kW Molten Carbonate Fuel Cell(MCFC) generation system. The MCFC generation system is a part of a four year government funded research project that began in 2001. This paper presents the results of various tests and performance verification of the 100kW PCS using a DC power system that simulates the DC output of the MCFC fuel cell. Performance of the DC/DC, DC/AC converters were verified, and basic control functions such as grid connection, protection and characteristics of each components were tested. The tests were performed under light load and rated load conditions to verify the operation efficiency, power quality effects, and stability of the PCS.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1788-1790
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• 2005

In this paper, an operating characteristics of a 50 kW gird-connected photovoltaic(PV) power system was analysed from 2000 to 2004. The construction of the PV system includes a 3-phase inverter for grid connection, PV module, distribution box, and data monitoring system. The major results of the demonstration test of the 50 kW class gird-connected PV system showed that efficiency of PV system was 11.13%, and the conversion efficiency of the inverter was 92% at a 50% load.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1696-1698
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• 2005

In this paper, a model that can be used to represent all types of variable speed wind turbines in power system simulations is presented. Wind turbine characteristic equation of a wind turbine is implemented in the RTDS, and the real data of weather conditions are interfaced to the RTDS for the purpose of real time simulation of grid-connection wind power system. The outcomes of the simulation demonstrate the effectiveness of the proposed simulation scheme in this paper. The results show that the cost effective verifying for the efficiency and stability of WPGS.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.10
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• pp.1103-1109
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• 2013

This paper presents an optimal capacity design of a Hybrid generation system based on economical evaluation for various loads. Optimal sizes of a standalone and grid connection wind- PV hybrid systems were designed for normal, residential and industrial loads using HOMER (Hybrid Optimization Model for Electronic Renewable). Their economical evaluation were performed and compared with a diesel generation system that covers the same loads. The results showed that the stand alone hybrid generation system can be more economical than a diesel generation system for long term operation.

• Earthquakes and Structures
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• v.16 no.3
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• pp.253-263
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• 2019

The efficacy of a galvanized steel wire mesh (GSWM) as an alternative material for the rehabilitation of RC beam-column connections damaged due to reversed cyclic loading was investigated. The repair mainly uses epoxy resin infused under pressure into the damaged zone and then confined using three types of locally available GSWM mesh. The mesh types used herein are (a) Weave type square mesh with 2mm grid opening (GWSM-1) (b) Twisted wire mesh with hexagonal opening of 15 mm (GSWM-2) and (c) welded wire mesh with square opening of 25 mm (GSWM-3). A reduced scale RC beam-column connection detailed as per ductile detailing codes of Indian Standard was considered for the experimental investigation. The rehabilitated specimens were also subjected to similar cyclic displacement. Important parameters related to seismic capacity such as strength, stiffness degradation, energy dissipation, and ductility were evaluated. The rehabilitated connections exhibited equal or better performance and hence the adopted rehabilitation strategies could be considered as satisfactory. Confinement of damaged region using GSWM-1 significantly enhanced the seismic capacity of the connections.

• International Journal of Computer Science & Network Security
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• v.21 no.3
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• pp.1-10
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• 2021

In recent decades, the heterogeneous and dynamic behavior of Internet traffic has placed new demands on the adaptive resource allocation of the optical network infrastructure. However, the advent of multifiber elastic optical networks has led to a higher degree of spectrum fragmentation than conventional flexible grid networks due to the dynamic and random establishment and removal of optical connections. In this paper, we propose heuristic routing and dynamic slot allocation algorithms to minimize spectrum fragmentation and reduce the probability of blocking future connection requests by considering the power consumption in elastic multifiber elastic optical networks.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.10
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• pp.311-318
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• 2016

IoT(Internet of Things areas) rich information based on the user easy access to service creation must be one of the power system of specificity due following: The IoT spread obstacle to the act be, and 'Smart Grid information of this is not easy under power plants approach the Directive on the protection measures, particularly when stringent security policies IoT technologies applied to Advanced Metering Infrastructure sector has been desired. This is a situation that occurs is limited to the application and use of IoT technologies in the power system. Power Information Network is whilst closed network operating is has a smart grid infrastructure, smart grid in an open two-way communication for review and although information security vulnerabilities increased risk of accidents increases as according to comprehensive security policies and technologies are required and can. In this paper, the IoT platform architecture design of information systems as part of the power of research and development IoT-based energy information platform aims. And to establish a standard framework for a connection to one 'Sensor-Gateway-Network-platform sensors Service' to provide power based on the IoT services and solutions. Framework is divided into "sensor-gateway" platform to link information modeling and gateways that can accommodate the interlocking standards and handling protocols variety of sensors Based on this real-time data collection, analysis and delivery platform that performs the role of the relevant and to secure technology.

• Journal of the Korean Society of Radiology
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• v.5 no.3
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• pp.127-134
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• 2011

In this paper we propose an improved PV generation systems. Improved systems for temperature and humidity controlled heating and air conditioning offers a pleasant environment within the building, set up chopper and consists of a PWM voltage type inverter. The proposed system is stable modulation for a one-chip microprocessor using the synchronous signal and control signals was treated. The proposed system is a PWM voltage type inverter and phase of the synchronous to the grid voltage to detect the system voltage and inverter output to drive the statue, so surplus power to connection was able to, certain buildings such as buildings or hospitals, temperature and humidity sensor is applied to the good dynamic characteristic could be obtained. In addition, the system was applied to the high power factor and low-frequency harmonics by maintaining the output load and grid to power to be supplied to a stable control could get a good result.

• Journal of KIISE:Information Networking
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• v.29 no.3
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• pp.265-275
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• 2002

A default server strategy is a very popular scheme for managing location and state information of mobile hosts in cellular networks. But the communication cost increases if the call requests are frequent and the distant between the default server and the client is long. Still more any connection to a mobile host cannot be established when the default server of the destination mobile host fails. These problems can be solved by replicating default server and by letting nearest replicated default server process the query request which is sent from a client. It is important to allocate replicated default servers efficiently in networks and determine the number of replicated default servers. In this paper, we suggest and evaluate a default server replication strategy to reduce communication costs and to improve service availabilities. Furthermore we propose and evaluate an optimized allocation algorithm and an optimal replication degree for replicating: dofault servers in nn grid networks and binary tree networks.

• The Journal of the Korea Contents Association
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• v.12 no.11
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• pp.511-518
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• 2012

In this study, the trend in green technology was observed and the domain of the green technology area that will be actively studied in the future was found by establishing knowledge map in green technology area and comparing and analyzing green technology information in Korea and overseas in time series. For the purpose of this study, network analysis was conducted for the keyword of green technology information provided by green technology information portal site (www.gtnet.go.kr) operated by Korea Institute of Science and Technology Information. Network analysis was conducted using keyword, and change of study subject was found by dividing the analysis result into periods. In the result of network analysis on top 100 keywords from total English keyword, it was found that renewable energy related areas such as solar energy and biomass had high centrality. When the main keyword trend by year was studied, centrality of solar cell, nanotechnology, smart grid, and fuel cell were found to increase, showing that research and development in generation and use of renewable energy are actively made.