• Journal of KIISE:Information Networking
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• v.32 no.1
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• pp.80-88
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• 2005

In ubiquitous spaces, a user wants to be provided with a VOD service while moving one space to another freely. Since the traditional VOD system is dependent on user location, the VOD server transmits video data to a single client during a session. If the user moves to another space, he/she should close the old session and make a new request for the same video. However, the location-aware VOD system supports user mobility by closing and opening the session automatically. That is, the VOD system automatically perceives the movement of a user and allows the server to change the data flow so that a client near the user can receive the video data. This paper proposes a location-aware VOD service architecture and a session handoff scheme to provide a mobile user with continuous video delivery and implements a location-aware VOD prototype system based on Jini and Java. In experiment, we show that the proposed handoff scheme has a smaller handoff delay than the other handoff scheme.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.20 no.1
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• pp.21-26
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• 2014

Background: This study was aimed to determine the effects of deep abdominal muscle exercises (DAME) and thoracic mobility exercises (TME) on pulmonary function. Methods: This study was conducted with 22 college students who are in their 20s and have no problem carrying out activities of daily living. All subjects were randomly assigned to either the DAME group (11) or the TME group (11) to undertake the exercises for 2 weeks. To measure pulmonary function of subjects, forced vital capacity (FVC), forced exploratory volume in 1 second (FEV1) and peak expiratory flow (PEF) were measured using chest graph. Chest expansion of subjects was also measured with tape ruler. These measurements were performed on the first day before the exercise program started and on the next day after the 2-week exercise program was completed. A paired-t test was performed to compare the differences in pulmonary function before and after the exercise program, and an independent t-test was performed to compare the two groups. Results: The results of this study were as follows: 1) In comparison of pre- and post-exercise changes in the DAME and TME groups, both groups showed significant increase in chest expansion and PEF after the exercise program, compared with the baseline data (p<.05). Both groups also demonstrated improvements in FVC and FEV1 after the exercise program, compared with the baseline data. However, the differences were not statistically significant (p>.05). 2) The comparison of the DAME and TME groups revealed no significant differences in chest expansion, FVC, FEV1 and PEF (p>.05). Conclusion: It is therefore concluded that both DAME and TME were effective in improving pulmonary function.

• Journal of the Korean Society of Physical Medicine
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• v.14 no.1
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• pp.101-110
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• 2019

PURPOSE: This study was conducted to analyze the effects of virtual reality inspiratory muscle training and conventional inspiratory muscle training on diaphragm movement and pulmonary function in patients with thoracic restriction. METHODS: This study measured diaphragm movement, forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), peak expiratory flow (PEF), and thoracic mobility (upper, middle, and lower trunk) under two different conditions. Forty young women between 19 and 24 years of age who had no history of orthopedic symptoms for the last 6 months were divided into experimental and control groups. The experimental group performed virtual reality inspiratory muscle training and diaphragm breathing, and the control group performed conventional inspiratory muscle training and diaphragm breathing. RESULTS: The control group showed a significant increase in all dependent variables except for lower trunk mobility and PEF. The experimental group showed a significant increase in all dependent variables except for lower trunk mobility. Particularly, the experimental group showed significant increases in diaphragm movement (p<.05), FVC (p<.05), FEV1 (p<.05), and PEF (p<.05) relative to the control group. CONCLUSION: We recommend inspiratory muscle training with a virtual reality program over conventional training to improve diaphragm movement and pulmonary function in patients with thoracic restriction.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.2
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• pp.1-7
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• 2019

Recently, multimedia streaming service has been activated, and the demand for high-quality multimedia convergence contents services is predicted to increase significantly in the future. The issues of the increasing network load due to the rise of multimedia streaming traffic must be addressed in order to provide QoS guaranteed services. To do this, an efficient network resource management and mobility support technologies are needed through seamless mobility support for heterogeneous networks. Therefore, in this paper, an MIH technology was used to recognize the network situation information in advance and reduce packet loss due to handover delays, and an ACLMIH-FHPMIPv6 is designed that can provide an intelligent interface through introducing a hierarchical mobility management technique in FPMIPv6 integrated network.

• Transactions of the Korean hydrogen and new energy society
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• v.35 no.3
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• pp.290-299
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• 2024

In this study, a theoretical study was conducted on the pre-cooling temperature of hydrogen gas and the heat exchanger area in a small-scale liquefied hydrogen system. The small-scale liquefaction system was built and liquid hydrogen production experiments were performed. In this process, the temperature of precooled hydrogen gas was measure to be about 120 K, and then the possibility of a cause was analyzed through pressure analysis of hydrogen gas and container, and analysis of the amount of liquid hydrogen produced. It was found that some reasonable results were obtained from the theoretical approaches. Based on this theoretical approach, we aim to improve the production of liquid hydrogen by optimizing the heat exchange area according to flow rate.

• Journal of the Korean Vacuum Society
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• v.16 no.4
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• pp.267-272
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• 2007

Al-doped ZnO (AZO) thin films were grown on glass substrates by radio-frequency magnetron sputtering. The effects of oxygen flow ratio, which was used for a sputtering gas, on the AZO thin films were investigated by using the X-ray diffraction (XRD), atomic force microscopy (AFM), and Hall effects measurement. The AZO thin film, deposited with oxygen flow ratio of 0% at the growth temperature of $400^{\circ}C$, showed a strongly c-axis preferred orientation and the lowest resistivity of $6.9{\times}10^{-4}{\Omega}cm$. The ZnO (002) diffraction peak indicated a tendency to decrease substantially with increasing the oxygen flow ratio. Furthermore, as the oxygen flow ratio was decreased, the carrier concentration and the hall mobility were increased, but the electrical resistivity was decreased.

• Journal of Korea Soil Environment Society
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• v.1 no.2
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• pp.73-81
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• 1996

The self-diffusion coefficients of chloride and tritiated water ranged from 4.8 $\times$ 10-7 to 7.2 $\times$ 10-7 cm2/sec and 5.5 $\times$ 10-5 to 1.6 $\times$ 10-4 cm2/sec for three different depths of soil constituents at about 50% water content by volume, respectively Mobility of solute and water was conducted under steady-state flow conditions in a field soil consisting of 70 cm of clay to silty clay over a medium sand. A steady-state water flow conditions was maintained by applying irrigation water at a constant flux of 2cm per day. The water labeled with chloride and tritium was leached into the plot during the steady-state condition for 87 days. The positions of tritium and chloride as a function of soil depth and the time was measured by extracting samples of the soil solution with suction probes. Extremes in solute displacement occurred at equal and different depths within the plot. An analysis of these measurements indicated the observations of the pore-water velocity and the apparent diffusion coefficient were log normally disturbed. Twenty-four soil suction probes, used to identify the rate at which a solute was displaced in the soil, will yield an estimate of the mean pore-water velocity of this soils within a range of approximately 5% of its true value providing the effects of potential solute-soil interaction are taken into account.

• Journal of the Economic Geographical Society of Korea
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• v.16 no.2
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• pp.167-181
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• 2013

The cross-border flow of workers in EU having the freedom of labor mobility and residence plays a role in the border labor markets as a structural factor of regulation. The regulation role of the cross-border flow of workers on the Grand R$\acute{e}$gion, which is the border among the France-Belgium-Luxemburg-Germany, is as follows. First, the cross-border flow of workers regulates the regional surplus and lack of labor in quantity and quality. Second, the border labor markets are regulated by the regionally segmented supply and demand of labor and are modulated by the flexible employment like a part-time and temporary employment. Third, the residence of the cross-border workers concentrates on the adjacent regions to the border. And the atypical cross-border workers, who have their residence in the neighboring country but works in the existing country, are rising rapidly.

• Journal of the Korea Society of Computer and Information
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• v.19 no.1
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• pp.43-55
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• 2014

SPDY is the new protocol proposed by Google to complement problems of HTTP(Hypertext Transfer Protocol)/1.1 and to improve web speed. In this paper, we evaluated the performance of SPDY protocol in a variety environment. By this evaluation, we examined the characteristics of the SPDY protocol and compared the differences between the existing protocol and SPDY protocol. And we took a closer look at the Flow Control of SPDY. Through this, we analyzed the problem of SPDY. It improved performance at 3G network environment, but failed to improve performance at high speed WLAN and mobility environments. We also verified that Flow Control does not work well. And finally we proposed directions for improvement of this protocol.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.330-337
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• 2005

This study was investigated to elucidate the pesticide mobility in three different soil textures(Heongseong sandy loam; Chuncheon, loam; Taeback, silty clay loam) and four different gravel contents(0, 20, 40, 60%) of Taebaek soil using soil column. Carbofuran, which ranks the highest water solubility among 7 pesticides(carbendazim, carbofuran, chlorpyrifos, cypermethrin, dimethomorph, diniconazole and endosulfan) was defected over 87% in leachate samples within all soil types from early sampling time. Amount of 5 residual pesticides excluding carbendazim and carbofuran were ordered silty clay loam > loam > sandy loam, indicating pesticide residues are related to percentage of clay contents in soils. Comparing the amount of residual pesticides in soil column(upper, middle and lower layer), 6 pesticides apart from carbofuran were found in the range of $50{\sim}92%$ on the upper layer of silty clay loam and loam. Mobility of pesticides either in soil or leachate samples is dependant on water solubility of pesticide and clay content of soil. The results obtained from four different gravel contents of Tacback soil were similar to the results of three different soil textures. Also it was found that more the gravel contents, faster the flow velocity of leachate water. These results possibly provide an idea to select proper pesticides and to reduce soil and water contamination at alpine and sloped-land.