• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.4 s.56
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• pp.116-125
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• 2009

Recently, modular system are popular in construction fields, and they are increasing their marcket share. To compare modular units, bolting and welding are most popular methods. However, the temperature around a welded part might be over than 1,300$^{\circ}C and the composite member might be exposed tp the direct welding heat about 20,000$^{\circ}C. This high welding heat makes decrease of the concrete strength. If the concrete strength seriously decreases, it can affect the behavior and safty of a structure. On this study, To prevent of concrete strength decreases by welding heat, we suggested method of to insert between steel and concrete.

• Journal of the Korea Society for Simulation
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• v.20 no.4
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• pp.91-96
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• 2011

As the user's demand for ultra high-speed wireless internet has increased, the standardization, research and development of future mobile communication systems have been done for several years. IMT-Advanced system which is called fourth generation mobile communication should support the data rate of 1 Gbps for nomadic users and 100 Mbps for mobile users. Also, the system should hold call connection at the mobile speed of 350 km/h. Meanwhile, since Doppler spread is linearly proportional to mobile speed, high mobility leads to the increase of interference between subcarriers and the deterioration of detection performance consequently. In this paper, we evaluate and analyze detection probability with respect to equalization methods in time-varying channels under system parameters complying with IMT-Advanced requirements. According to computer simulation conducted by varying mobile speed and code rate, MMSE based equalization can mitigate performance degradation of IMT-Advanced system considerably in time-varying channels.

• Journal of Information Management
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• v.41 no.2
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• pp.95-110
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• 2010

We studied the methods for boosting a user participating service using KOSEN(The Global Network or Korean Scientists and Engineers) OpenLab service. OpenLab is a laboratory database of all the fields of science and technology, and it is different from other services in that basically it makes users register their information volunteerly. User participation service is not easy, so we made several strategies like promotion, event, and connection to other services. In result, we could collect about 4,300 laboratory database. Because user participation is a key concept for the Web 2.0, this study would contribute to the operation of the related services, especially to the services for scientists and engineers.

• Journal of KIISE:Information Networking
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• v.28 no.3
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• pp.377-388
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• 2001

An approach for testing multi-protocol Implementation Under Test (IUT) with a single test suite has been proposed in[1]. this paper proposes an algorithm called Multi-protocol Test Method (MPTM) for automatic test case generation based on that approach. With the MPTM, a multi-protocol IUT consisting of two protocol layers is modeled as two Finite State Machines (FSMs), and the relationships between the transitions of the two FSMs are defined as a set of transition relationships pre-execution and carried-by. The proposed algorithm is implemented and applied to a simplified TCP/IP and B-ISDN Signaling/SSCOP. MPTM is able to test the multi-protocol IUT even though the interfaces between the protocol layers are not exposed. It results in that the proposed MPTM allows the same test coverage as conventional test methods even with fewer numbers of test cases.

• Journal of Oriental Neuropsychiatry
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• v.31 no.2
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• pp.109-119
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• 2020

Objectives: The aim of this study is to review the significance of managing "Mibyeong" in geriatric health in Korean medicine and psychology. Methods: We performed a literature search using OASIS, Koreantk, RISS, DBpia, and PubMed databases. We retrieved research articles using the keywords related to mibyeong (未病), sub-health (亞健康), Korean-medicine, psychology and geriatric health. Results: Both Korean medicine and psychology emphasize biological, psychological, and social balance and well-being. In addition, both value individual personality and constitution. Mibyeong is a Korean medical concept suggesting sub-health. Elderly individuals who are in a state of Mibyeong are frail and vulnerable to disorders and illness. Since depression, chronic diseases, low physical and mental activity have fatal outcomes in frail and elderly subjects, positive psychological support and active management of Mibyeong are very important. Conclusions: Geriatric health conditions are associated with chronic disease and multiple risk factors, including physiological, psychological, social, and economic conditions. A preventive and integrative approach is essential for geriatric health as prevention is better than cure for most geriatric diseases and illnesses.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.6
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• pp.69-73
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• 2009

Network Virtual Environments (NVEs) is a virtual world where users exchanges messages via network connection. A limited visibility sphere called area of interest (AOI) is used to reduce the load created by the interactions between users. VON-Forwarding model is proposed as an effective methods to reduce network bandwidth in P2P network environment. Vorocast and Fibocast originated from Von-forwarding resolves the problems to receive the same messages repeatly. In this paper, We proposed an Extended Volocast scheme to improve the problem not to get consistency except a limited area near to the center of AOI. The proposed scheme maintains the consistency about the broad area into AOI by adjusting geometrical series $2^X$. We perform simulation experiments to show that the proposed scheme provide better performance compared to the other schemes.

• Journal of Climate Change Research
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• v.3 no.4
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• pp.271-280
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• 2012

The study aims to analyze economic viability of Integrated Gasification Combined Cycle, an innovative technology to utilize clean coal effectively and efficiently in the era of energy crisis. The study is conducted to evaluate business value of 300 MW IGCC demonstration plant technology development based on binomial option, in consideration of uncertainty of fuel price. Binomial option is one of the real option valuation methods, which is ideally suited to irreversible decision making under uncertainty. With this analysis, it shows that investment value is higher compared with economic evaluation based on discounted cash flow, since this method can measure quantity. As a result, this study is proved to be economically feasible, which have a positive impact on the next generation of IGCC and the connection with Carbon Capture and Storage.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.12
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• pp.2409-2417
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• 1994

The ODR(orthogonal double-rotation) digital lattice filters have desirable properties for VLSI implementation such as local connection, regularity and pipelinability. These filters are also known to exhibit good numerical behavior for finite precision implementation. Although these filters can be pipelined by the cut-set localization procedure, it should be noted that the maximum sample rate obtained by this technique is limited by the feedback computations. In this paper, a pipelining method for the ODR digital lattice filter is proposed, by which the sample rate can be increased at any desired level. it is also shown that the low-power CMOS digital implementation of ODR digital lattice filters can be done successfully using our pipelining method. The pipelining method is based on the properties of the Schur algoithm, constrained filter design methods, and the polyphase decomposition technique.

• Journal of the Korean Society of Hazard Mitigation
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• v.2 no.2 s.5
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• pp.95-104
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• 2002

This paper presents the pull-out failure mode on Headed Bars and prediction of tensile capacity, as governed by concrete cone failure. 17 different plate types, three different concrete strengths and three different welding types of specimens were simulated. Test variables are the reinforcing bar diameters connected to headed plate (e.g., 16mm, 19mm and 22mm), the head plate shapes (e.g., circular, square, rectangular), the dimensions of head plates (e.g., area and thickness), the types of welding scheme for connection of reinforcing bars and head plates (e.g., general welding and friction welding). Headed Bars were manufactured in different areas, which shape and thickness are based on ASTM 970-98. Calculation of Embedment length in concrete is based on CSA 23.3-94, and static tensile load was applied. Pullout capacities tested were compared to the values determined using current design methods such as ACI-349 and CCD method. If compare experiment results and existings, Headed bar expressed high strength and bigger breakdown radious than standard by wide plate area and anomaly reinforcing rod unlike anchor.

• Journal of Korea Water Resources Association
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• v.39 no.4 s.165
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• pp.363-372
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• 2006

Many methods have been used to estimate evapotranspiration. However, there is little information about the evapotranspiration from river basins with complicated topographies and variable land use. Remote sensing technique is a probable means to estimate distribution of the evapotranspiration in connection with regional characteristics of vegetation and landuse. The evapotranspiration not only depends on meteorological circumstances but also on the condition of the vegetation. The latter effect can be expressed in terms of NDVI(Normalized Difference Vegetation Index) obtained by NOAA/AVHRR datasets. In this paper, a simple method to estimate evapotranspiration of the Keum river basin is proposed based on NDVI and temperature data.