• Journal of Electrical Engineering and Technology
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• v.12 no.5
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• pp.1789-1797
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• 2017

It is necessary to charge electric vehicles in order to drive them. Thus, it is essential to have electric vehicle charging facilities in place. In the case of a household battery charger, the power similar to that consumed by a household with a basic contract power of 3kW is consumed. In addition, many consumers who own an electric vehicle will charge their vehicles at the same time. The simultaneous charging of electric vehicles will cause the load to increase, which then will lead to the imbalance of supply and demand in the distribution system. Thus, a smart charging scheme for electric vehicles is an essential element. In this paper, simulated conditions were set up using real data relating to Korea in order to design a smart charging technique suitable for the actual situation. The simulated conditions were used to present a smart charging technique for electric vehicles that disperses electric vehicles being charged simultaneously. The EVs and Smart Charging Technique are modeled using the Electro Magnetic Transients Program (EMTP).

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.4
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• pp.398-404
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• 2010

Purpose: Concerns had been voiced about an oversupply of optometrists in Korea. So, this study aimed to forecast the supply and demand for opticians for policy implications. Methods: Baseline Projection model combined with demographic method was adopted as the supply forecasting method and so was a ratio method using the number of physician and population using weight of healthcare utilization. Results: Under the 'physician to optician ratio', there would be a surplus of 83~700 opticians in 2010 and an undersupply of 15 to surplus of 6,118 opticians in 2025. Under the 'population to optician ratio', there would be a surplus of 1,055 opticians in 2010 and surplus of 9,376 opticians in 2025. Conclusions: We concluded that there would be oversupply for opticians until 2025, although the shortage and surplus of opticians might depend on the ratio's criteria. Hence, policies would need to be developed that could solve the imbalance in requirements and supply for opticians.

• Journal of the Korean Data and Information Science Society
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• v.27 no.2
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• pp.275-284
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• 2016

Accurate electricity demand forecasts is essential in reducing energy spend and preventing imbalance of the power supply. In forcasting electricity demand, we considered double seasonal Holt-Winters model and TBATS model with sliding window. We selected a specific time zone as the reference line of daily electric demand because it is least likely to be influenced by external factors. The forecasting performance have been evaluated in terms of RMSE and MAPE criteria. We used the observations ranging January 4, 2009 to December 31 for testing data. For validation data, the records has been used between January 1, 2012 and December 29, 2012.

• Korean Journal of Construction Engineering and Management
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• v.13 no.4
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• pp.100-109
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• 2012

Large road construction projects are typically partitioned into sections that are then contracted individually to contractors. Each section requires using similar heavy equipment including excavators, dump trucks and pavers, which constitute the highest cost. Normally the equipment is not shared between them, as each contractor wishes to have their equipment readily available. However, such practices result in very low utilization of these equipment. The goal of this research is to develop a programmatic resource sharing system in which contractors can share equipment depending on the changing needs of a multi-sectioned road project. This paper introduces the results of a survey performed to investigate how contractors currently manage the supply and demand of equipment and the equipment that are practical for sharing across a project. More importantly, the paper describes a set of metrics (DPR, nDPR, SDI) needed to quantify the amount of supply/demand variance occurring in each section. The metrics were used on an actual road construction project, and the results show that each section suffers from an imbalance between its monthly planned and actual utilization of equipment. The results also indicate that the sharing of the equipment can lead to potentially large savings as equipment requirements can be met within a project as to short leasing from outside vendors.

• Architectural research
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• v.18 no.2
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• pp.59-64
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• 2016

Since the massive power outages that hit across the nation in September 2011, a growing imbalance between energy supply and demand has led to a severe backup power shortage. To overcome the energy crisis which is annually repeated, a policy change for deriving energy supply from renewable energy sources and a demand reduction strategy has become essential. Buildings account for 18% of total energy consumption and have great potential for energy efficiency improvements; it is an area considered to be a highly effective target for reducing energy demand by improving buildings' energy efficiency. In this regard, retrofitting buildings to promoting environmental conservation and energy reduction through the reuse of existing buildings can be very effective and essential for reducing maintenance costs and increasing economic output through energy savings. In this study, we compared the energy reduction efficiency of national power energy consumption by unit production volume based on thermal power generation, renewable energy power generation, and initial and operating costs for a building retrofit. The unit production was found to be 13,181GWh/trillion won for bituminous coal-fired power generation, and 5,395GWh/trillion won for LNG power generation, implying that LNG power generation seemed to be disadvantageous in terms of unit production compared to bituminous coal-fired power generation, which was attributable to a difference in unit production price. The unit production from green retrofitting increased to 38,121GWh/trillion won due to the reduced energy consumption and benefits of greenhouse gas reduction costs. Renewable energy producing no greenhouse gas emissions during power generation and showed the highest unit production of 75,638GWh/trillion won, about 5.74 times more effective than bituminous coal-fired power generation.

• Journal of the Korean housing association
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• v.21 no.4
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• pp.51-58
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• 2010

In the modernization process of the city, urbanization raised a variety of social issues. Urbanization brought noticeable changes in dwelling patterns, such as drastic changes in the housing lifestyle, that revolved around the metropolitan areas of Seoul and Busan etc. before and after the expansion of economic growth. Especially in 1985, when 23.8% of the country's population was concentrated in Seoul, the imbalance of housing supply and demand caused a vast range of housing shortage. The shortage, that resulted from public sector mishandling of natural housing demand, lead to the occurrence of private sector rental housing. The occurrence of this abnormal rental housing supply, became a major cause of Korea's typical lease system called 'Co-dwelling', where the leaseholder and tenant physically lives in the same residence. The leaseholder and tenant's 'Co-dwelling' started from partial renting of traditional Korean-style housing and transformed with the transition of dwelling form and time. However, after 1985, legalization of multi-family housing, Korean rental housing started to be planned in the beginning of it's housing construction and to be produced as an independent space with separate circulation. Also in terms of facility, it changed from partial renting of a space within the residence to an assembly of small individual spaces. However, the background of this deep-rooted 'Co-dwelling' lease system, in different forms and periods of residence, is still based on the lack of public sector rental housing supply and private sector supply of rental space to utilize extra space, 'Jeonsei' payment.

• Journal of the Korea Society of Computer and Information
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• v.14 no.8
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• pp.73-80
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• 2009

It is difficult that expertise human supply and demand for industry requires by imbalance of industry necessity human and profession organs of education's Skill Mismatch. Industry can prove productivity though reeducate school graduation person in spot and master correct technology in industry special quality. This paper is research that accommodate Demand Education that industry requires and make out full text caution Curriculum Specializing Vocational High School in e-Business field. Analysis e-Business industrial classification and occupational classification. Analysis knowledge and technological level that require in industry about e-Business education and investigate and analyze the demand. Base industry, Support industry, Apply e-Business Curriculum that is examined by practical use industry to learning, Do to estimate satisfaction about Demand Education Curriculum of industry and confirm Success special quality with research and investigation and application wave. Suggested for e-Business Curriculum's basis model in this paper and school subject Curriculum. Wish to contribute in nation development through productivity elevation through e-Business education of industry request.

• Journal of Distribution Science
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• v.20 no.3
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• pp.71-82
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• 2022

Purpose: This study aims to not only measure the elderly welfare supply index but investigate spatial patterns and determinants of local elderly welfare services in South Korea. Research design, data, and methodology: The index for local elderly welfare services is measured by employing standardized scores for critical variables related to elderly welfare. The present study utilized the GIS technique and Moran's I index to examine spatial patterns of elderly welfare services. The determinants of local elderly welfare service are analyzed by a series of regression models using R. Results: Spatial imbalance and asymmetric distribution were serious in the supply of elderly welfare service. It was also confirmed that the factors affecting the level of welfare services for the elderly vary depending on the type of service. In particular, the higher the proportion of the elderly population and the social welfare budget, the lower the level of welfare services for the elderly. Conclusions: Given the circumstance of spatial mismatch between supply and demand for elderly welfare services, it is necessary to consider and provide policy tactics about how the economic benefits and welfare budgets generated in the region can contribute to strengthening the welfare service system for the elderly.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.246-249
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• 2004

While the recovery of local construction industry is picking up steam, and the number of the employed in the construction industry is on the increase, workforce supply is out of balance in its quality as well as quantity, and with economic crisis facing the country, construction and recruitment methods are in transition. In addition, rising demand in skilled workforce and a workforce in short supply have expedited wage rises and have brought broad effects on construction including productivity and construction time. Such imbalance in construction workforce supply also causes various structural changes by category. This research compares and analyzes data on annual wages of construction workforce, analyzes the state of construction workforce supply, understands recruitment structure in accordance with workforce supply conditions, and looks over characteristic changes in recruitment structure. With reflections drawn from these, this paper suggests responsive measures to future construction circumstances - changes to wages of construction workforce - as well as prospects of future construction workforce supply and measures designed for stable medium and long-term workforce supply.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.667-675
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• 2021

The purpose of this study is as follows: First, to analyze the spatial structure of Jeju by analyzing the rate of parking demand and supply; Second, to determine the parking service imbalance between regions; and third, to elucidate the causes of this spatial structural parking service imbalance and provide effective measures. Due to the rapid population and tourism growth, Jeju is suffering from traffic congestion and serious parking problems. For this, the ways to efficiently utilize the existing parking spaces were identified through spatial structure analysis based on the parking demand and supply in the Jeju area. As short-term policy, the following changes were proposed: switching to small-scale eup or myeon blocks of parking space, use of shared parking system, and repairing side streets in residential areas. As mid-to-long-term policy, it is linked to other means of transportation as follows: parking demand management policy through modal share by reorganizing public transportation routes or expanding traffic facilities; securing park-and-ride lots; and different parking pricing for different time periods. To implement these policies, each area of the public sector, private sector, and private-public partnership should develop the bond of sympathy by areas and participants.