• Journal of Digital Convergence
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• v.11 no.11
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• pp.775-781
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• 2013

N-screen is a Service that can be provide for One Service Multi Device. If the network is changed or if the device is changed after authentication the device fits seamlessly send footage. Security threats that occur here have a problem with user authentication. In this paper proposes available in a multi-device the authentication system. Homomorphic Encryption Algorithm of authentication scheme used. Among the authentication mechanism that already exists is a simple and lightweight authentication mechanism. In addition, N-screen service that uses multiple devices is simple authentication process of the device. Review the results of proposed authentication protocol, encryption algorithm to process a small storage capacity and is easy to work in low processor. And was suitable for use with multiple devices.

• Journal of Korea Port Economic Association
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• v.27 no.2
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• pp.59-84
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• 2011

The purpose of this study is to analyze the spatial distribution and the linkage characteristics of the warehousing industry in Busan and to provide the policy implications for the warehousing industry in Korean port hinterland. We surveyed the warehousing firms in Busan. Categorizing the warehousing industry into industry types, sizes, and organization types on the basis of the survey, we attempted the point pattern analysis and the proximity analysis using the GIS. The warehousing industry in Busan had changed from a small single-unit firm to a medium or a large firm with a head office or branches. These were distributed in hinterland of North Harbor, South Harbor & Gamcheon Harbor, and Sin-Pyoung & Jang-Rim industrial complex and Sasang Industrial Complex constituting the spatial agglomeration. The warehousing industry in Busan formed the linkages with other sectors of the same logistics to provide manufacturing industries with various other services as well as storage services. The linkages were largely formed in the local scope with spatial proximity, generating the economic gains of agglomeration, which were transformed into the efficiency of the warehousing industry in the local scope to gradually expand the spatial dimensions of the linkages.

• Journal of Digital Convergence
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• v.11 no.10
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• pp.359-366
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• 2013

Due to the development and market expansion of image analysis and recognition technology, video security such as CCTV cameras and digital storage devices, are required for real-time monitoring systems and intelligent video security systems. This includes the development of more advanced technologies. A rotatable PTZ camera, in a CCTV camera system, has a zoom function so you can acquire a precise picture. However it can cause blind spots, and can not monitor two or more moving objects at the same time. This study concerns, the intelligent tracking of multiple moving objects, CCTV systems, and methods of video surveillance. An intelligent video surveillance system is proposed. It can accurately shoot broad areas and track multiple objects at the same time, much more effectively than using one fixed camera for an entire area or two or more PTZ cameras.

• Journal of the Korea Society of Computer and Information
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• v.25 no.2
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• pp.21-29
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• 2020

The use of NAND flash memory is continuously increased with the demand of mobile data in the IT industry environment. However, the erase operations in flash memory require longer latency and higher power consumption, resulting in the limited lifetime for each cell. Therefore, frequent write/erase operations reduce the performance and the lifetime of the flash memory. In order to solve this problem, management techniques for improving the performance of flash based storage by reducing write and erase operations of flash memory with using disk buffers have been studied. In this paper, we propose a CPWL to minimized the number of write operations. It is a disk buffer management that separates read and write pages according to the characteristics of the buffer memory access patterns. This technique increases the lifespan of the flash memory and decreases an energy consumption by reducing the number of writes by arranging pages according to the characteristics of buffer memory access mode of requested pages.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.3
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• pp.458-468
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• 2009

The patching technique has been used for removing initial waiting time of NVOD. The technique was applicable only to time segmented NVOD services. However, data segmented NVOD methods have been known to have less initial waiting time or use less server's bandwidths than the time segmented NVODs. Therefore, we expect that if patching is applied to a data segmented NVOD, a more efficient NVOD service will be possible. But there has not been such approach. In this paper, we propose a new VOD scheduling algorithm that combines the patching technique with a data segmented NVOD, thus it uses less server's bandwidths and removes initial waiting time, hence makes a true VOD service possible. The proposed technique also absorbs the storage overhead necessary for client buffering incurred by patching into the data segmentation policy of the NVOD scheduling, hence does not need any extra overhead of the client's resource. Therefore, it is also applicable to the case that the client has resource limits.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.8
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• pp.445-452
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• 2004

Zoning technology of disk improved the performance of disk subsystem with increase of storage capacity and average transfer bandwidth. SCAN disk scheduling with double buffering is used to utilize the performance of zoned disk in multimedia system. However, this method has a problem that generates jitter when the number of steams increases. In this article, we propose the novel approach, pre-buffering policy, to overcome this problem. Pre-buffering avoids jitter by buffering the lack of data before starting service, which is estimated from the current cycle length and the maximum cycle length. We can calculate cycle length, data sire needed in each cycle and the possible lack of data caused by the increase of the number of streams using the numerical model of disk subsystem. Pre-buffering can be applied for multimedia systems and contribute to provide clients with high quality service without jitter.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2586-2592
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• 2014

Lost fishing gears become a major cause of marine pollution, and many policy and technical efforts have been conducted for that. For efficient retrieving lost fishing gears in underwater, It is important to know the current position. Using GPS in the sub-sea environment is impossible and localization requires the use of special systems, and mobility due to water currents for underwater localization also has to be considered. In this paper, described with respect to the system for a self-generated location informations without using an external signal, such as a GPS and Sonar and storing them. Using the characteristics of the geomagnetic and INS principle, proposed informations and a way for estimating self position during movement. Embedded based system suggested and implemented in this study is tested for validating it's functionality.

• New & Renewable Energy
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• v.8 no.4
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• pp.21-29
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• 2012

The extensible supply of New & Renewable energy resources desperately needs to counter the high dependence on imported energy, recent high oil prices and the Climate Change Conference, and the government has operated the 'Renewable Portfolio Standard' (RPS) as one of the renewable energy policy from 2012. By analyzing the operation case of combined heat and power plant using the woodchip biomass, we drew the price of wood chip fuel, plant capacity factor, electricity selling price, heat selling price and LCOE value. After analyzing the economic feasibility of 3MWe combined heat and power plant based on the operating performance, the minimum of economic feasibility has appeared to be secured according to the internal rate of return (IRR) is 6.34% and the net present value (NPV) is 3.6 billion won as of 20 years life time after installation, and after analyzing the cases of the economic feasibility of the price of wood chip, plant capacity factor, electricity and heat selling price are changed, the economic feasibility is valuable when the price of wood chip is over 64,000 won/ton, NPV is minus, and the capacity factor is above 46.9%, the electricity selling price is 116 won/kWh and the heat selling price is above 75,600 won/Gcal. When going over the new installation hereafter, we need the detailed review of the woodchip storage and woodchip feeding system rather than the steam-turbine and boiler which have been inspected many times, the reason why is it's hard to secure the suitable quality (constant size) of woodchip by the lack of understanding about it as a fuel because of the domestic poor condition and the calorific value of woodchip is seriously volatile compared with other fuels.

• Advances in concrete construction
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• v.4 no.1
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• pp.15-26
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• 2016

In Algeria, wastes are often stored in such conditions that do not meet standards. Today and more than ever, we really must implement an environmentally management of wastes. Recovery of waste in Algeria has a considerable delay due to the absence of a policy favorable to the development of waste management. But many researchers have shown the possibility to reuse dredged sediments in road construction. Through Europe, recent research works have been already performed on dam sediments. Present study fits into the context of the valorization of dredged sediments from Fergoug dam. They are found in considerable quantities and mainly composed of mineral phases, organic matters and water. The reservoir sedimentation poses problems for the environment and water storage, dredging becomes necessary. Civil engineering is a common way of recycling for such materials. Dredged sediments have not the required mechanical characteristics recommended by the standards as GTR guide (LCPC-SETRA 1992). So as to obtain mechanical performance, dredged sediment can be treated with cement, lime, or replaced materials like quarry sand. An experimental study has been conducted to determine physical and mechanical characteristics of sediments dredged from dam. Then different mixtures of sediment and/or quarry sand with hydraulic binders are proposed for improving the grain size distribution of the mixes. Finally, according these mixtures, different formulations have been tested as alternative materials with dredged sediments.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.8
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• pp.432-437
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• 2013

The increase of greenhouse gas emission and decrease of fossil fuel are being caused by the indiscreet consumption of energy by people. Recently, green policy has been globally implemented to reduce energy consumption. This paper studied the research to reduce the energy consumption in buildings, by using the heat storage properties of PCM. PCM has to prevent leakage from the liquid state. Therefore, we prepared form stable PCM, by using the vacuum impregnation method. Three kinds of organic PCMs were impregnated into the structure of porous material. The characteristics of the composites were determined by using SEM, DSC, FTIR and TGA. SEM morphology showed the micro structure of silica fume/PCM. Also, thermal properties were examined by DSC and TGA analyses; and the chemical bonding of the composite was determined by FTIR analysis.