• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.675-684
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• 2020

To prevent safety accidents caused by aging pipe infrastructure and to maintain water quality, construction projects for water and sewage pipes are actively conducted across Korea. This study analyzed the criteria situations, site survey details, and regulation revisions related to the calculation of construction cost standards for pipe laying and joining work. The analysis showed that the major causes for revision are the unclear construction scope, limitations in implementing some pipe materials due to installation facility types, workforce focused on ordinary labor, limitations of manual laying work, and the lack of tool hire cost and machine expense-calculation criteria. Field studies were conducted to categorize the pipes according to their features, in addition to identifying the use of lifting heavy equipment and light equipment. In addition, excavation and testing work conducted in connection to pipe laying, as well as the use of skilled labor, were investigated. The current study clarified the work scope through new common items, provides an organization based on the pipe material, adjusted the workforce ratio to focus more on skilled labor, and developed grounds for calculating machine expenses. These revisions were estimated to save approximately 1.28% of the construction costs in each project according to an analysis of the construction cost impact study. truction costs in each project, according to an analysis of construction cost impact study.

• Asian Journal of Turfgrass Science
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• v.23 no.1
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• pp.61-76
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• 2009

The purpose of this study are to investigate the reasonable maintenance expense of golf course according to the size and management system of each golf course. The maintenance cost per hole per golfer of 29 golf courses and the maintenance cost for items and locations of 8 golf courses were analyzed. 1. As golfers per hole increased, maintenance cost per hole per golfer decreased. 2. The decisive cost factors for maintenance cost of golf course are the number of annual golfers, the total course size, the management system, and automation of course facilities. 3. Maintenance cost of golf courses contained the landscaping areas except for building and parking lots is $869^{\}/_{m^2}$ Korean won. 4. Average maintenance cost of 8 golf courses is $44,325,000^{\}/_{hole}$. 5. Labor cost marked the largest portion in the total cost. Among the items of labor cost, repair cost for green ball mark was the highest with the ratio of 26%(\4,163,000). 6. Material cost for Fairways which reaches 30% of the total area was composed of $22%{\sim}44%$ of the total cost of materials. Cost of imported fertilizers, pestcides for insects and diseases, and sands for top dressing was the highest. 7. Material cost for Green which reaches 2% of the total area was composed of $28%{\sim}36%$ of the total cost. Cost of imported products such as particle-shaped fertilizers, micro mineral fertilizers, and soil conditioners was the highest. 8. There is no difference in cost between chemical fertilizers and the environmentally friendly fertilizers even if environmentally friendly fertilizers using microorganism or chitosan materials are also expensive.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.1
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• pp.70-75
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• 2010

In Korea, standard N application level was amended from 110 to 90kg per ha for high quality rice production in 2005. So far, N application method, however, has not been considered for yield and quality based on changed standard N application level. Therefore, this experiment was conducted to find out more efficient N application method for improving rice quality or labor saving under the amended standard N application level with several varieties at three site (Suwon, Iksan, and Milyang) for two years from 2005 to 2006. Top dressing of N at 15 days before heading compared to the standard (25 days before heading) showed improved rice qualities such as 1000 grain weight and head rice ratio without changing rice yield and protein content of brown rice. In addition, there were no significant differences in yield and quality between different N split application of 70-0-30% and 50-30-20%, indicating that the former would be useful for labor saving without yield decrease and quality deterioration.

• Agricultural and Biosystems Engineering
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• v.4 no.2
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• pp.58-65
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• 2003

An understanding of the cooling requirements of horticultural commodities begins with adequate knowledge of their biological responses. All fresh horticultural products are living organisms, carrying on the many biological processes that are essential to the maintenance of life. The pre-cooling is essential technique for the construction of cold chain system, which is necessary to maintain marketing quality of fresh produces during the transportation and distribution. The purpose of this study is to develop the pressure cooling tunnel using conveyer for the reduction of labor and improvement of pre-cooling efficiency. Performance of developed facility was tested for the strawberries, tomatoes and Chinese cabbages. Cooling ratio as a result of pre-cooling efficiency was 1.57, 1.56 and 1.32 for strawberries, tomatoes, and Chinese cabbages respectively. Cooling ratio decreased with increasing the distance of heat conduction from surface to center. The cooling ratio of Chinese cabbages was lower than that of fruit because of its head and leaf. In aspect of cooling uniformity, there was no significant difference of final temperature among inlet, outlet and middle layers of cold air in fresh produces. After pre-cooling treatment, quality changes were measured for the weight loss, Vit. C content, and titratable acidity. The quality of pre-cooling treatment was better than that of non-treatment and was kept on well during long-term storage.

• Journal of the Korean Regional Science Association
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• v.31 no.3
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• pp.19-37
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• 2015

The purpose of this study is to confirm a structural relationship on factors affecting ratio of public transportation spending to a car-owning household's total transportation expenditure. For this purpose, informations of household's attributes and activities were gathered using the 13th Korean Labor and Income Panel Study (KLIPS), and information of land-use and transportation conditions on their residential locations was collected and processed. A structural equation model (SEM) on determinants affecting ratio of public transportation expenditure was constructed, based on an execution result of factor analysis using the analyzing database. The latent variables were derived as land-use/transportation characteristic, household's attribute and household's activity. In the analyzing result of the SEM, the entire latent variables were significant. And, the first two latent variables had positive influences, and the last latent variable had a negative impact. To promote public transportation use of the car-owning households, this study suggests that the policies such as enhancement of convenience in public transportation use for the household's activities and improvement of the land-use/transport conditions are required.

• Environmental and Resource Economics Review
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• v.24 no.2
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• pp.411-433
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• 2015

This paper decomposed energy productivity changes across 14 Korean manufacturing industries into 5 components, technological catch-up(EC), technological progress(TC), and changes in labor-energy ratio(LC), capital-energy ratio(KC) and energy mix(EMC). Then we also figured out the possible relationship between energy productivity change and export growth rate across the industries. It is found that (1) technological progress, changes in capital-energy ratio and energy mix contribute to energy productivity growth in Korea during the sample period, (2) technological progress is the primary driving forces for energy productivity growth, (3) increase in export growth rate had a positive impact on energy productivity growth excepting a part of energy-intensive industries.

• Journal of Environmental Policy
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• v.7 no.3
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• pp.121-140
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• 2008

The impervious cover ratio has been used as an important measure for tracing water environment characteristics in watershed. Impervious cover is divided into total impervious cover and effective impervious cover, and its size varies depending on the land use characteristics of a watershed. Total impervious cover can be easily measured using existing land use maps or land cover map, while it takes a considerable amount of time and labor to measure the effective impervious cover, as water flow should be identified at each site. This study is intended to calculate the total impervious cover and effective cover of a sample site, compare their characteristics, and find a method to apply effective and total impervious cover ratios toward watershed management. The analysis of the sample site showed that the effective impervious cover rate(39.7%) was less than the total impervious cover rate(43%). This suggests that it would be acceptable, in terms of time and cost, if total impervious cover is applied as the representative impervious cover ratio of a watershed considering that it was used as basic data to analyze the effect that impervious cover has on the water environment.

• Journal of Preventive Medicine and Public Health
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• v.40 no.5
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• pp.397-403
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• 2007

Objectives: The prevalence of metabolic syndrome has recently increased, Payments from the Korea Labor Welfare Corporation for compensation for mortality in workers caused by cardiovascular and cerebrovascular diseases have also increased in Korea in recent years. The association of metabolic syndrome and cardiocerebrovascular disease has been investigated by several researchers in recent studies, This study was conducted in an attempt to characterize the relationship between metabolic syndrome and Korean cardiocerebrovascular disease risk assessment, and to provide basic data to group health practices for the prevention of cardiocerebrovascular disease. Methods: Health examinations were previously conducted for 1526 male researchers at a private laboratory. The prevalence by age and the odds ratio of metabolic syndrome scores into the "cardiocerebrovascular risk group" (sum of low, intermediate, and high risk groups) of the Korean cardiocerebrovascular disease risk assessment were assessed, in an effort to elucidate the associations between metabolic syndrome and cardiocere brovascular disease risk assessment. Results: The prevalence of metabolic syndrome and inclusion in the cardiocerebrovascular risk group was 11,7% and 22.1% respectively. The severity of metabolic syndrome and cardiocerebrovascular risk assessment showed that individuals in their 40's and 50's were at higher risk than those in their 30's (p<0,001). The age-adjusted odds ratio of metabolic syndrome to cardiocere brovascular risk group inclusion was 5.6. Conclusions: An active prevention program for cardiocerebrovascular disease needs to begin in the 40's, as the prevalence of metabolic syndrome and the risk group of cardiocerebrovascular risk assessment peak in the 40's age group. The odds ratio between metabolic syndrome and the cardiocerebrovascular risk group was high, which indicates that metabolic syndrome scores should be utilized as guidelines during the consultation and behavioral modification program for the workplace prevention of cardiocerebrovascular diseases in group health practices.

• Journal of the Korea Safety Management & Science
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• v.19 no.3
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• pp.129-135
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• 2017

The respective delivering vehicle loaded with the own cargo moves into the respective delivery area. At the base, the delivery points D1 and D2, for example, have the same starting point but the destination is different. The average delivering time of the delivery vehicle is mostly more than 8 hours a day. Therefore, the efficiency of delivery is generally low. In this study, the deliveries will be forwarded from a base station to a delivery point where cross docking will be applied to a single vehicle, and will be distributed from the cross docking point through cross docking. If the distribution is implemented, one vehicle will not have to be operated from the base to the cross docking point. In that case, logistics cost will be reasonably saved by the reduction of transportation cost and labor time. If one vehicle only runs from the base to the cross docking point, each vehicle will be operated in two shifts, and the vehicle operation can be efficiently implemented. This research model is based on the assumption that the 3 types of ratios between the traffic volume of the vehicles starting at the base and the vehicles waiting at the cross docking point are set to the first ratio of 30% to 70%, the second ratio of 50% to 50% and the final ratio of 70% to 30%. As a result of the study, The delivery time in the cross docking point is much higher than that in present on the condition that the cargo volume in the D2 area is more than 50%. Likewise, the delivery time is slightly higher on the condition that the cargo volume is less than 50%. Time is reduced in terms of 50% model like AS-IS model.

• Journal of Labour Economics
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• v.42 no.1
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• pp.1-42
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• 2019

In this study we find that relatively high minimum wages should make the employment ratios of youth, old, and woman lower very significantly in those regions concerned, futhermore, make the overall employment ratios of those regions lower also by using a proxy variable, the Regional Minimum Wages-Half Median Wages Ratio which represents well the very stable differential structure of wage distributions among regions in Korea. In large Cities those effects become much stronger. But we find also that those effects on the rates of regional unemployment are somewhat double-faced except the case of youth because of the probable generating of many discouraged unemployed among the old and women. So, we can conclude that because of the differential regional economic situations it is not sustainable to increase the overall minimum wages uniformly and excessively and strongly necessary to explore ways toward introducing the proper system of regional minimum wages.