• 수도
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• s.67
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• pp.39-50
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• 1994

• Journal of Energy Engineering
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• v.17 no.3
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• pp.125-138
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• 2008

In order to diversify energy source and to utilize it effectively, it requires to construct an integrated energy management system in a wide area. This research paper explores the core technology of network construction using wide area energy and applies the technology to the field. In specific, it examines the business model by developing l) construction technology of optimum integrated system for thermal supply on wide area network related IT technology, 2) technology of unutilized energy as heat pump using exhaust gas latent heat, and 3) thermal transportation and storage technology using various sources, and by evaluating the applicability and marketability of the model in the field.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.2
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• pp.33-43
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• 2012

Digital signage is referred to as a smart electronic display system that delivers multimedia-based information and advertisements to customers. Typically, the digital signage starts its playback after downloading a list of multimedia contents from network storage to its local disk. However, a way of downloading the entire contents before its playback entails a long initial delay time. In this paper, we formulate a problem of the initial delay time and provide a solution to compute a minimally demanded initial delay time according to a given network bandwidth and qualities/sizes of the multimedia contents. In addition, we analyze the performance of the proposed solution with various multimedia contents on digital signage.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.169-177
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• 2014

It is essential to support the image and video analysis technology such as motion detection since the DVR and NVR storage were adopted in the real time visual surveillance system. Especially the network camera would be popular as a video input device. The traditional CCTV that supports analog video data get be replaced by the network camera. In this paper, we present the design and implementation of video surveillance system that provides the real time motion detection by the video storage server. The mobile application also has been implemented in order to provides the retrieval functionality of image analysis results. We develop the video analysis server with open source library OpenCV and implement the daemon process for video input processing and real-time image analysis in our video surveillance system.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.3
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• pp.32-38
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• 2015

In this paper, we propose a smallcell local caching algorithm under user's context in smallcell environment. The proposed system reduces traffic to core network and the network cost, but increases it's performance. The proposed algorithm precache suitable files using smallcell's regional characteristics and target's personality. It can adjusts a storage allocation to make effective usage of our limited cache storage capacity. In order to evaluate the performance of the proposed cache algorithm, we define the cache efficiency, the decrement of core network traffic. The simulation results show that the proposed algorithm can improve performance by about 200% compared to existing web cache scheme.

• Journal of Electrical Engineering and Technology
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• v.5 no.4
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• pp.552-560
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• 2010

This paper presents an application of layered Artificial Neural Network controller to study load frequency control problem in power system. The objective of control scheme guarantees that steady state error of frequencies and inadvertent interchange of tie-lines are maintained in a given tolerance limitation. The proposed controller has been designed for a two-area interconnected power system. Only one artificial neural network controller (ANN), which controls the inputs of each area in the power system together, is considered. In this study, back propagation-through time algorithm is used as neural network learning rule. The performance of the power system is simulated by using conventional integral controller and ANN controller, separately. For the first time comparative study has been carried out between SMES and CES unit, all of the areas are included with SMES and CES unit separately. By comparing the results for both cases, the performance of ANN controller with CES unit is found to be better than conventional controllers with SMES, CES and ANN with SMES.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.5
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• pp.619-627
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• 1999

To support multimedia services between network domains with different environments, it is required to map the functionalities in many aspects. In this paper, we implemented interworking gateway which provides protocol conversion and QoS(Quality of Service) adaptation to interwork DAVIC services based on ATM(Asynchronous TRansfer Model )network and Internet AV services. The interworking gateway converts RTSP(Real-Time Streaming Protocol ) message into DSM-CC(Digital Storage Media Command & Control) messages to control the stream that is served in ATM network, and transmits data stream by using RTP(Real-Time Transport Protocol) The interworking gateway provides QoS adaptation functionalities by QoS monitoring and MPEG filtering to meet the variation of network bandwidth.

• The KIPS Transactions:PartA
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• v.8A no.4
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• pp.375-384
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• 2001

The shared disk file systems use a technique known as file system journaling to support recovery of metadata on the SAN(Storage Area Network). In the existing journaling technique, the metadata that is dirtied by one host must be updated to disk space before some hosts access it. The system performance is decreased because the disk access number is increased. In this paper, we describe a new recovery technique using a global buffer to decrease disk I/O. It transmits the dirtied metadata into the other hosts through Fibre Channel network on the SAN instead of disk I/O and supports recovery of a critical data by journaling a data as well as metadata.

• Journal of Korea Spatial Information System Society
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• v.8 no.3
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• pp.105-115
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• 2006

A sensor network which uses DCS(Data-Centric Storage) stores the same data into the same sensor node. Thus it has a hot spot problem when the sensor network grows and the same data arise frequently. In the past researches of the sensor network using DCS, the hot spot problem caused by growing the sensor network was ignored because they only concentrated on managing stored sensor data efficiently. In this paper, we proposed a non-equal region split method that supports efficient scalability on storing multi-dimensional sensor data. This method can reduce the storing cost, as the sensor network is growing, by dividing whole space into regions which have the same number of sensor nodes according to the distribution of sensor nodes, and storing and managing sensor data within each region. Moreover, this method can distribute the energy consumption of sensor nodes by increasing the number of regions according to the size of the sensor network, the number of sensor nodes within the sensor network, and the quantity of sensor data. Therefore it can help to increase the life time and the scalability of the sensor network.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.2
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• pp.93-103
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• 2009

In this paper, we propose a USIM-based Authentication Scheme for 3GPP Network Access. The proposed scheme improves the problems of existing authentication protocol in 3GPP Network such as sequence number synchronization problem, the storage overhead of authentication data, and bandwidth consumption between Serving Network and Home Network. Our proposal is based on the USIM-based Authentication and Key Agreement Protocol that is defined in 3GPP Specification. In our scheme, mobile nodes share a SK with Serving Network and use a time stamp when mobile nodes are performing an authentication procedure with Serving Network. By using time stamp, there is no reason for using sequence number to match the authentication vector between mobile nodes and networks. So, synchronization problem can be solved in our scheme. As well as our scheme uses an authentication vector, the storage overhead of authentication data in Serving Network and bandwidth consumption between networks can be improved.