• Korean Journal of Social Welfare Studies
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• v.42 no.3
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• pp.267-290
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• 2011

This research attempts to analyze the effects of demographic factors, socioeconomic factors, health behaviors and social/familial supports on health inequalities among Korean elderly. For this end, this study adopts the multiple linear regression analysis to process data on population aged over 65 contained in 'The Third Korea Welfare Panel Study' published in 2008. The following are the results. First, the less educated they are, the smaller income they earn, the less they drink, the less satisfied with relationships with their family members, the more they turn out to feel depressed. Second, the less educated they are, the smaller income they earn, the less they drink, the less they are satisfied with relationship with family members, the more they benefit from social welfare services, the worse they turn out to rate their health. Based on these findings, three following suggestions could be forwarded. First, vulnerable aged groups including female elderly, low-income elderly, less-educated elderly need customized social supports. Second, new social policy for households is required to enhance elderly people's satisfaction with their family relationships with the rapid trend of a growing number of nuclear families and aging. Third, social welfare service programs need to be reevaluated to enhance their function for the aged.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.61-64
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• 2003

This study attempts to analyze both the mis-closures between triangulation points of 3 and 4 glade and permanent sites data, and accuracy of according as change the number of utilized GPS permanent sites and base lines for improvement of the accuracy in GPS surveying using permanent sites data. The result of this study show that the mis-closure between the two points and Jeonju/Chungju/Sangju/Daegu stations of NGI(National Geography Institute) are 0.0051 m, 0.0361 m, 0.0039 m and 0.0198 m respectively. It indicated that the mis-closures were less than the allowed values in the primary/secondary control point specification for GPS surveying, a mis-closure less than 30 mm for the distance less than 30 km and a mis-closure less than 1 PPM${\times}$D(km) for the distance greater than 30 km. Jinan 11 of actual surveying point for the base line 21.4911 km in Jeonju permanent site and 87.8156 km in Sangju permanent site, northing and easting for planimetric errors of Jinan 11 are 0.0120 m and 0.0113 m, northing and easting for planimetric errors of Jinan 12 are 0.0122 m and 0.0115 m.

• Journal of the Korean Institute of Telematics and Electronics
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• v.13 no.5
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• pp.1-8
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• 1976

Microwave GaAs Metal Semiconductor Field effect Transistors (MESFET) with the gate-length of two micrometers are investigated. The scattering parameters of the transistors have been measured from 1GHz to 2GHz by Hp8545 Automatic network analyzer. From the measured data, an equivalent circuit is established which consists of an ntrinsic and. extrinsic transistor elements. In this paper, GaAb MESFET Amplifier is used in conjunction with conventional microstrip techniques to match into a 50 ohms high input/output impedances system. We found that Power gain is less than 8dB and VSWR is less than 1.5 in L-Band.

• ETRI Journal
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• v.34 no.6
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• pp.807-815
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• 2012

In this paper, we propose a scheme for partially dynamic lane control for energy saving in multilane-based high-speed Ethernet. In this scheme, among the given transmission lanes, at least one lane is always operating, and the remaining lanes are dynamically activated to alleviate the network performance in terms of queuing delay and packet loss in the range of acceptance. The number of active lanes is determined by the decision algorithm based on the information regarding traffic and queue status. The reconciliation sublayer adjusts the transmission lane with the updated number of lanes received from the algorithm, which guarantees no processing delay in the media access control layer, no overhead, and minimal delay of the exchanging control frames. The proposed scheme is simulated in terms of queuing delay, packet loss rate, lane changes, and energy saving using an OPNET simulator. Our results indicate that energy savings of around 55% (or, when the offered load is less than 0.25, a significant additional savings of up to 75%) can be obtained with a queuing delay of less than 1 ms, a packet loss of less than $10^{-4}$, and a control packet exchange time of less than $0.5{\mu}s$ in random traffic.

• Journal of Power Electronics
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• v.12 no.1
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• pp.49-57
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• 2012

This paper presents performance evaluation of an Integrated Starter-Alternator (ISA) prototype with an Interior Permanent Magnet (IPM) synchronous machine under sensor-less operation. To attain a high starting torque at zero speed and in subsequent extremely low speed range, a hybrid signal injection method is proposed. At higher speed, an improved stator flux observer is used for the stator flux estimation. This observer is able to produce accurately-estimated stator flux linkage for high performance Direct Torque and Flux Control (DTFC) implementation. The sensor-less DTFC IPM synchronous machine drive takes full advantage of the capacity of the power converter and fulfills the control specifications for the ISA. The trajectory control algorithm responds rapidly and in a well behaved manner over a wide range of operating conditions. The experimental results verify the feasibility and advantages of the system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.4
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• pp.583-588
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• 2014

In this study, there are examined to the grounding of lightning protection system and electrical continuity tests in the field. The standard for lightning protection system is different design or construction according to the characteristics of the structure. Ground is measured and compared at least four locations. According to the measured results in the field, the sampled values of the ground resistance are measured $5{\Omega}$ or less and the difference between each value is suitable as $0.2{\Omega}$ or less. The values of the electrical continuity test between ground and metal bodies are measured 3 groups such as isolated portion, the mechanical contacted portion, and the electrical continuity portion measuring $0.2{\Omega}$ or less. It is measured to be less than $0.2{\Omega}$ at all in metal bodies of underground. A metal body installed inside the structure is not isolated, but the resistance values are higher than $0.2{\Omega}$. Therefore, It must be carried out the structure having lightning protection system confirm the LPL(lightning protection level) and design the strategy.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.1
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• pp.1-9
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• 2004

This study is focused on finding out the character of urban recreation forest and investigating facilities regulations of forest resources around urban areas to meet future recreation needs. The method of this study is to compare urban recreation forests with similar facilities like urban parks and natural recreation forests. By this way, this study not only identifies the characteristics of urban recreation forest as emerging recreational facility, but also outputs regulations that can be adapted to real environment. Urban recreation forest is defined as follows: It has forest with good natural landscape and easy access. It makes emotion rich and its function is focused on outdoor recreation nature education, and experiences for family group mainly within a day or on weekends. This study suggests that the minimal area of urban recreation forest should be over 100,000$m^2$, with a facility ratio less than 20%. Building coverage should be less than 7% when the urban recreation forest is under 300,000$m^2$, less than 5％ when 300,000∼500,000$m^2$, and less than 3％ when over 500,000$m^2$ The limits of building height is 3 stories, or under 12m. This study finds out the character, the needs of urban recreation and the criterion for project feasibility. significance of the result is supplying theoretical basement on related regulation. Based on the results, further study will establish landscape management method and legislation & application in a detailed examination.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.347-350
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• 2006

The high efficiency full-bridge LLC resonant converter using a contact-less transformer is proposed for the photovoltaic power generation system. For the series resonance with a series capacitor, the LLC resonant converter utilizes the leakage inductance and magnetizing inductance of a contact-less transformer. Unlike the conventional series resonant converter operated to the continuous resonant current at above resonance frequency, the proposed converter operates to the discontinuous resonant current at the narrow frequency control range below resonance frequency. Due to the discontinuous mode resonant current, the proposed converter can be achieved the zero voltage switching (ZVS) in the primary switches and the zero current switching (ZCS) in the secondary rectification diodes without any auxiliary circuit. In this paper, the experimental results of the proposed full-bridge LLC resonant converter using a contact-less transfonner are verified on the simulation based on the theoretical analysis and the 150W experimental prototype.

• The Korean Journal of Community Living Science
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• v.13 no.3
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• pp.39-51
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• 2002

There are many concerns about the smoking among adolescents. Smoking status, smoking habit and dietary habit of high school students were studied using anonymous questionnaires. One hundred fifteen of 380 students(30.3%) have experienced smoking and 58.3% of them initiated it in the middle school, mostly because of the curiosity. The most plausible reasons for smoking were for stress reduction and feel bored. The students who smoked cigarettes were not likely to eat properly and their dietary habits were generally inadequate. The smoking group had less consideration of food balance, more skipping breakfast, more irregular meal time, less snack, and less frequent intake of vegetables. Also one-day dietary records obtained from 24hr recall showed less diverse food intake in smoking students. Considering the risk of poor eating behavior in smoking, nutritional care should be taken to emphasize as well as the smoking prevention and health programs, and more attention needs to be given to the relationship between smoking and the attitude and the behavior of smoking students toward their health, including proper eating habits. Since the results revealed that the majority of smoking students had previously attempted or thought about quitting to smoke, proper support programs that are more comprehensive and not temporal need to be developed.

• Korean Journal of Child Studies
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• v.32 no.4
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• pp.83-97
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• 2011

The purpose of this study was to examine the relationship between socioeconomic status, maternal involvement in learning, parenting behavior and children's self-determination motivation. The participants of this study consisted of 333 fifth- and sixth-grade elementary school children and their mothers living in Seoul. The results of this study indicated that mothers with a higher educational attainment reported greater autonomy support behavior and involvement in their offspring's learning. Conversely, mothers with low incomes were found to use psychological control and were also found to be involved in learning to a lesser degree. Hierarchical multiple regression analysis indicated that children whose mothers were less involved in learning showed higher levels of self-determination motivation. Additionally, maternal support for autonomy and psychological control had a number of moderating effects on the association between maternal involvement in learning and the child's self-determination motivation. Specifically, children tended to exhibit significantly lower levels of self-determination motivation when mothers were more involved in learning among those who received less support in terms of autonomy. Conversely, children had significantly higher levels of self-determination motivation when mothers were less involved in learning when it came to those children who were under less psychological control.