• JOURNAL OF ELECTRICAL WORLD
• /
• no.6 s.138
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• pp.54-61
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• 1988

• JOURNAL OF ELECTRICAL WORLD
• /
• no.8 s.140
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• pp.40-44
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• 1988

• JOURNAL OF ELECTRICAL WORLD
• /
• no.5 s.137
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• pp.54-63
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• 1988

• JOURNAL OF ELECTRICAL WORLD
• /
• no.9 s.141
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• pp.48-56
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• 1988

• JOURNAL OF ELECTRICAL WORLD
• /
• no.7 s.139
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• pp.61-70
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• 1988

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2001.05a
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• pp.249-252
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• 2001

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.483-495
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• 2011

In modern society, the range of time and space in life is continually expanding due to increase of income and diversification of life. In order to respond to these changes and to satisfy needs and to secure the mobility of citizens, the construction of transport infrastructure and public transport services should be provided continually. In particular, to ensure mobility during late-night hours, providing metropolitan public transport services is urgently needed. Due to expansion of life zone, tension of time and space of metropolitan transportation is essential to construct transport infrastructure in preparation for entry into 24-hour community. This study was based on analysis of travel resource and survey data conducted by passengers of express trains, conventional trains, and metropolitan bus. This study is to investigate use characteristics of passengers and characteristics and problems of Gyeongin-line. Moreover, this study's purpose is to suggest plans in order to improve express train operation and extend hours of the midnight express. It is also important to vitalize public transportation.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.55 no.1
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• pp.35-40
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• 2006

Heat-pump system has a special feature that provides heating operation in winter season and cooling operation in summer season with a single system. It also has a merit that absorbs and makes use of wastewater heat, terrestrial heat, and heat energy from the air. Because heat-pump system uses midnight electric power, it decreases power peak load and is very economical as a result. By using the property that energy source is converted to low temperature when losing the heat, high temperature energy source is used to provide heating water and low temperature energy source is used to provide cooling water simultaneously in summer season. This study made up a heat-pump system with 4 air heat sources and a water heat source and implemented the optimal operation algorithm that works with numbers of heat pumps to operate them efficiently. With the heat-pump system, we applied it to cooling and heating operation in summer season operation mode in a real building.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.10
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• pp.733-738
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• 2012

It is important issue to reduce the electric energy to save the operating cost of HVAC system. Even if electrical energy is the clean energy, it is difficult and takes high cost for storage of electricity. These cause the high peak load of electric energy for HVAC in summer season. In korea, government impose the electric charge with several grade for the purpose of cut-off the peak load of electricity. Government has a policy to support to design and install the heat/ice storage system using midnight electricity. In this study, analysis of cooling load and operating characteristics for ice storage system are performed. And, also economical efficiency is compared between ordinary charge system of electricity and midnight rate charge of electricity. The systematic and economical supports are needed for expansion of usage of energy saving equipments.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.19-20
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• 2015

Since 2013, Seoul Metropolitan Government (SMG) has introduced big data initiatively in administration and put into practices in transportation, safety, welfare in order to overcome limited resources and conflicting interests. For establishing a new midnight bus service, SMG prepared optimized midnight bus routes by analyzing big data from mobile phone Call Data Record (CDR) through collaboration with a telecommunication company. Despite of limited budget and resources, newly identified routes can cover over 42% of the citizen with 9 routes and less than 1% of buses compare with day time operation. In addition to solve transportation problem, SMG utilizes big data to resolve location selection problem for choosing new facility locations such as life double cropping centers and senior citizen leisure centers. As results, SMG demonstrates big data as a good tool to make policies and to build smarter city by overcome space-time limitation of resources, mediation of conflicts, and maximizes benefit of the citizen.