• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.5
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• pp.197-202
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• 2018

The world's ageing population continues to rise rapidly while fertility levels have dropped to low rates in many developed and developing countries, and life expectancy is expected to extend compared to previous decades. Because of demographic changes, a new concept of technology should be introduced. Ambient Assisted Living(AAL) is an innovative form of technology that can be used to provide elderly people with quality of life, to live longer and independently, to monitor and assist elderly, and improve social communication. As far as an AAL system are working, however, the dataset size is continuously increasing. As the AAL data increases in size, therefore, the problem of effectively managing it becomes more difficult. In this paper, therefore, we propose a data management scheme for AAL system on the characteristics of the collected AAL data. Simulation results show that the proposed data management scheme allows achieving space efficiencies higher.

• 전자공학회논문지 IE
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• v.49 no.2
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• pp.58-64
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• 2012

In this paper, we proposed a distributed gateway for ubiquitous healthcare system. We also designed and implemented protocol conversion and processing algorithms to exchange a seamless information, the bio signals between the databases and the receiving devices from ZigBee to gateway and from the gateway to database and network. The distributed gateway system consists of the bio signal acquisition, ZigBee modules, distributed databases, and gateways. The bio signals detected by the ZigBee module are sent to the gateway. The distributed gateway analyzes the data being transferred, sends those to the receiving devices, and lets the authorized personnel access. The proposed system can be utilized in various fields including activity analysis for the elderly, security systems, home network service, and so on.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.4
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• pp.1-7
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• 1999

The demands for the various type of directional coupler, which is for the sampling of the signal levels in mobile communication baseband or transceiver systems, are growing. The proposed dual directional coupler, which has three parallel coupled transmission lines, can provide the dual coupling and good isolation characteristics between the coupling ports. In this paper, the novel analysis method and the design equation of even and odd mode for the dual directional coupler, which is employing the asymmetrically coupled transmission lines, are proposed. Using the proposed method, the dual directional coupler for PCS system has been designed and fabricated. We obtained the desired coupling value and the high directivity of 40dB. Measured results show the validity of this design method.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.5
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• pp.479-484
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• 2016

In this paper, a design of DC level shifter transmitting and receiving control and data signal which have various DC level through daisy chain interface between master IC and slave is introduced in the cell voltage monitoring (CVM). Circuit designed with a latch structure have a function to operate in high speed and for output of variable DC level through transmission gate. As a result of the simulation and the measurement, it was confirmed that control and data signal could be transferred according to the change of DC level from 0V to 30V. Delay time was measured about 170ns. but, it was considered as a negligible tolerance due to a parasitic capacitance of measuring probe and test board.

• The Korean Journal of Community Living Science
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• v.15 no.2
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• pp.167-177
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• 2004

The number of foodborne salmonellosis was estimated by using microbial risk assessment(MRA) methodology and the possibility of application was studied through comparison with previous results. The contamination levels of Salmonella sp. were estimated by using published domestic studies(1997∼2000) and monitoring data (1999∼2001) from food-safety related institutes. Data on food consumption came from the 2001 National Health and Nutrition Survey, and dose-response models from studies in other countries. Simulation results showed that there were 753,368 cases of salmonellosis in Korea in 1 year, which is about 115 times that reported in previous years and lower than the WHO's estimation increase. From these results, microbial risk assessment is likely to be available for estimation of the number of foodborne illnesses and determination of the order of priority in food-safety management. Butthe verification methods are not established and most of the data on contamination levels of foodborne bacteria, food consumption, and dose-response relationships have not been established. In addition, the actual conditions of circulation, storage and cooking must be studied further.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.3
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• pp.1-7
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• 2010

Cognitive Radio, which adaptively utilizes the vacant licensed spectrum band, is considered as an effective way to alleviate the scarcity of spectrum resource shortage. In order to guarantee the non-interference transmission of primary system, spectrum sensing, especially in quiet period, is proposed. However, it is insufficient to avoid the unacceptable interference caused by Cognitive Radios, because the primary user may appear anytime that is unpredictable. In this paper, we address the deficiency of conventional spectrum sensing and propose a novel Cognitive Radio receiver structure with monitoring function block to detect the appearance of primary user in a real-time manner. Simulations prove that the proposed eigenvalue based detection method together with the two-threshold decision procedure performs properly.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.3
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• pp.233-239
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• 2004

Smart material is used in various applications such as for glass frame, for medical instruments and for a part of sensors. Smart composite materials ran be applied to a part of aircraft and to the on-line monitoring system for industrial structures, using the shape memory effect. However, it is very difficult to simulate and analyze the shape memory effect in smart composites. In this paper, a two dimensional axisymmetric model was proposed to analyze the smart composite of one fiber and matrix using the finite element method(FEM). The finite element analysis was carried out in two renditions of the room temperature(293K) and a higher temperature (363K). The results we.e compared with the experimental results to confirm the validity of the analysis. In addition, the acoustic emission(AE) technique was used to study the microscopic damage behavior and the effect of pre-strains on TiNi/A16061 shape memory alloy composite.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.12
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• pp.568-575
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• 2008

Server consolidation by sever virtualization can make one physical machine(PM) to run several virtual machines simultaneously. Although It is attractive in cost, it has complex workload behaviors. For that reason, efficient resource management method is required. Dynamic relocation of virtual machine(VM)[3,4] by live migration[1,2] is one of resource management methods. We proposed SCOA(Server Consolidation Optimizing Algorithm) : a fine-grained load balancing mechanism worked on this dynamic relocation mechanism. We could obtain accurate resource distribution information through pointed physical machines on multi dimensional resource usage coordination, so we could maintain more balanced resource state. In this paper, we show the effectiveness of our algorithm by comparison of experimental results between SCOA and sandpiper[3] by software simulation.

• Journal of Korea Multimedia Society
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• v.13 no.1
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• pp.38-46
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• 2010

A stable game managing system is absolutely needed to accept simultaneous interlacing of many users for on- line game system. The proposed P2P on-line game system in this paper is able to get stable and real-time game managing within limited time stamp utilizing through reorganizing peers according to synchronous time which can be avoid congestion on one region, it is possible to synchronize for game nodes within limited time stamp utilizing. Reorganizing M-tree which leads 10 distribute loads. The system manages each region unit, and it is execute no matter how big game sizes are. Thus to ensure such as the problems of expand server and stabilization or message transmission. Also, prove efficiency of the suggested system through the simulation.

• Journal of Korea Multimedia Society
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• v.14 no.8
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• pp.1041-1049
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• 2011

According to the development of society and infrastructure, effective underground facility management is growing more important them ever. In the process various monitoring systems are studied and developed for water works pipe-network. Especially, RTD-1000 system with the based on Pc. Reflector-monitoring device is constructed and steered by several local governments. But, this system have to be improved result from based on PC system structure at the point of resource management, heat, power consumption and size. In this paper, RTD-2000 is proposed are a substitution of improved RTD-1000 with many respect and portable one. This system is designed and implemented with ARM-9 development kit based on WinCE and LCD eliminate TDR(Time Domain Reflector-Meter). Various surveillance programs based on windows are mounted on RTD-1000 are replaced with dedicated embedded application softwares. Simulation and evaluation for performance comparison are performed for the prove of effectiveness of RTD-2000.