• Journal of Preventive Medicine and Public Health
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• v.38 no.3
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• pp.241-251
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• 2005

There has been an enormous increasing trend of widening gap of social inequalities since economic crisis at the end of 1997 in Korea. Since then, Korean society has deteriorated in economic and social conditions; the unemployment rate, temporary or casual workers and absolute poverty have increased. This paper presents the origin of inequalities in work and health in Korea. The origin of inequalities in work begins with the relationship between the capitalist and labourers in the capitalist mode of production. The conception and execution are dissolved in the work process in the capitalist mode of production. Thus, captitalists become control over ther labour process from workers. An alienation of the work process from the workers. The distribution of work is the majour source if inequalities in many countries as well as Korea. This paper presents the increasing tendency of unhealthy states such as mortality, early death, morbidity, physical work load, workplace injury amongst the under-privileged: ordinary workers, unemployed people, casual workers and socially deprived people in Korea.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.04a
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• pp.13-18
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• 1994

Most widened bridges have been constructed by the joining-construction method that makes new and existing bridge structurally single structure. However, joing-construction method has several problems in design and construction viewpoint. Therefore, this study is conducted in order to investigate structural behavior of widened RC slab and traffic-induced vibration of existing bridge during placing and curing of new concrete by the prototype flexural fatigue test. From the results of this study, it is shown that stress-concentration and slip occur between concrete and reinforcing rod at joint section but the reduction of load carrying capacity and of fatigue strength is negligible according to the traffic-induced vibration as well as the difference of construction method. A reasonable construction method for the bridge widening which takes into account the effects of the traffic-induced vibration and S-N curve for the widened bridge are also proposed.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.468-472
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• 2007

For small capacity rectifier circuits such as these for consumer electronics and appliances, capacitor input type rectifier circuits are generally used. Consequently, various harmonics generated within the power system become a serious problem. Various studies of this effect have been presented previously. The absence of switching devices makes systems more tolerant to over-load, and brings low radio noise benefits. We propose a power factor correction scheme using a LC resonant in commercial frequency without switching devices. In this method, It makes a sinusoidal wave by widening conduction period using the current resonance in commercial frequency, Hence, the harmonic characteristics can be significantly improved, where the lower order harmonics, such as the fifth and seventh orders are much reduced. The result are confirmed by the theoretical and expermental implementations

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.290-293
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• 2002

For small capacity rectifier circuits such as these for consumer electronics and appliances, capacitor input type rectifier circuits are generally used. Consequently, various harmonics generated within the power system become a serious problem. Various studies of this effect have been presented previously. However, most of these employ switching devices, such as FETs and the like. The absence of switching devices makes systems more tolerant to over-load, and brings low radio noise benefits. We propose a power factor connection scheme using a LC resonant in commercial frequency without switching devices. In this method, It makes a sinusoidal wave by widening conduction period using the current resonance in commercial frequency, Hence, the harmonic characteristics can be significantly improved, where the lower order harmonics, such as the fifth and seventh orders are much reduced. The result are confirmed by the theoretical and experimental implementations.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.77-80
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• 2004

In bridge deck systems, deflections and cracking can be controlled by longitudinal and transverse prestressing, There are some benefits, longitudinal cracking control, the thickness reduction of deck slab, the widening of deck width and the reduction of the cross section area, in transversely post-tensioned concrete box girder bridges. However, it has been not sufficient to study the structural behaviors of transversely post-tensioned concrete box girder. Therefore, It is needed to predict the structural behaviors by prestressing and static loading. In this study, the analytical and experimental load tests are carried out to study the effect of transverse prestressing on concrete box girder. For these objectives, four test specimens are fabricated with various tendon spacing and steel ratio of top slab. The analytical and experimental studies are performed to estimate effects of the prestressing and failure tests.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1235-1237
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• 2003

For small capacity rectifier circuits as these for consumer electronics and appli capacitor input type rectifier circuits are gen used. Consequently. various harmonics gen within the power system become a serious pro Various studies of this effect have been pres previously. However. most of these employ swit devices, such as FETs and the like. The absen switching devices makes systems more toleran over -load, and brings low radio noise benefits propose a power factor correction scheme using resonant in commercial frequency without swit devices. In this method. It makes a sinusoidal by widening conduction period using the cu resonance in commercial frequency. Hence, harmonic characteristics can be significantly imp where the lower order harmonics. such as the and seventh orders are much reduced. The resu confirmed by the theoretical and experm implementations.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2003.11a
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• pp.403-406
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• 2003

For small capacity rectifier circuits such as these for consumer electronics and appliances, capacitor input type rectifier circuits are generally used. Consequently, various harmonics generated within the power system become a serious problem. Various studies of this effect have been presented previously. However, most of these employ switching devices, such as FET and the like. The absence of switching devices mattes systems more tolerant to over-load and brings low radio noise benefits. We propose a power factor correction scheme using a LC resonant in commercial frequency without switching devices. In this method It makes a sinusoidal wave by widening conduction period using the current resonance in commercial frequency, Hence, the harmonic characteristics can be significantly improved, where the lower order harmonics, such as the fifth and seventh orders are much reduced The result are confirmed by the theoretical and experimental implementations.

• Smart Structures and Systems
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• v.13 no.6
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• pp.1015-1039
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• 2014

The widening project on Freeway No.1 in Taiwan has a total length of roughly 14 kilometers, and includes three special bridges, namely a 216 m long-span bridge crossing the original freeway, an F-bent double decked bridge in a co-constructed section, and a steel and prestressed concrete composite bridge. This study employed in-situ monitoring in conjunction with numerical modeling to establish a real-time monitoring system for the three bridges. In order to determine the initial static and dynamic behavior of the real bridges, forced vibration experiments, in-situ static load experiments, and dynamic load experiments were first carried out on the newly-constructed bridges before they went into use. Structural models of the bridges were then established using the finite element method, and in-situ vehicle load weight, arrangement, and speed were taken into consideration when performing comparisons employing data obtained from experimental measurements. The results showed consistency between the analytical simulations and experimental data. After determining a bridge's initial state, the proposed in-situ monitoring system, which is employed in conjunction with the established finite element model, can be utilized to assess the safety of a bridge's members, providing useful reference information to bridge management agencies.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.204-206
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• 2002

For small capacity rectifier circuits such as these for consumer electronics and appliances. capacitor input type rectifier circuits are generally used Consequently. various harmonics generated within the power system become a serious Problem. Various studies of this effect have been presented previously. However. most of these employ switching devices, such as FETs and the like. The absence of switching devices makes systems more tolerant to over -load, and brings low radio noise benefits. We propose a power factor correction scheme using a LC resonant in commercial frequency without switching devices. In this method. It makes a sinusoidal wave by widening conduction period using the current resonance in commercial frequency. Hence, the harmonic characteristics can be significantly improved. where the lower order harmonics. such as the fifth and seventh orders are much reduced. The result are confirmed by the theoretical and expermental implementations.

• Journal of Korean Society on Water Environment
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• v.24 no.5
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• pp.543-549
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• 2008

Human activities and land-use practices are intensely widening the urban areas. High impervious surface areas cover much of urban landscapes and are the primary pollutant sources which can lead to water quality and habitat degradation in its watershed. As the urban areas expand, transportation land-use such as parking lots, roads, service areas, toll-gates in highways and bridges also increase. These land-uses are significant in urban pollution due to high imperviousness rate and vehicular activities. To regulate the environmental impacts and to improve the water quality of rivers and lakes, the Ministry of Environment (MOE) in Korea developed the Total Pollution Load Management System (TPLMS) program. The main objective is to lead the watershed for a low impact development. On a local scale, some urban land surfaces can be emitting more pollution than others. Consequently, in urban areas, the unit loads are commonly employed to estimate total pollutant loadings emitted from various land-uses including residential, commercial, industrial, transportation, open lands such as parks and golf courses, and other developed land like parking areas as a result of development. In this research, unit pollutant loads derived specifically from transportation land-uses (i.e. branched out from urban areas) will be provided. Monitoring was conducted over 56 storm events at nine monitoring locations during three years. Results for the unit pollutant loads of transportation land-use are determined to be $399.5kg/km^2-day$ for TSS, $12.3kg/km^2-day$ for TN and $2.46kg/km^2-day$ for TP. The values are higher than those of urban areas in Korean MOE and US highways. These results can be used by MOE to separate the pollutant unit load of transportation landuses from urban areas.