• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.8-9
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• 2019

The rebar work is a labor intensive construction work with a high labor cost ratio. It is difficult to manage the productivity, construction time, and safety of rebar work. The problem of productivity decreased in rebar construction is due to a lack of workers according to the aged workers. Partial prefabrication rebar can be an alternative solution to productivity decreased in rebar work. The characteristic of partial prefabrication method is that time consuming component such as stirrup of beam assemble in factory and others assemble in site. Therefore, in this study, the time required for each rebar assembly method is measured and analyzed to confirm the possibility of productivity improvement.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.35
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• pp.61-70
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• 1995

The objective of this study is In develope on productivity improvement program, which named PPM(Participative Productivity Management). This program consists of 3 stages which are Goal setting and sharing. Productivity measurement and evaluation, and Gain sharing. Each concepts of NGT(Nominal Group Technique), Objectives matrix method and Gain sharing was applied to form this frame. This program rewards members of an organization for their contributions to improve business results. It also fits perfectly with today's participative management philosophies. Furthermore, the company and its employees could be partners a win-win situation, and one more barrier to a high-involvement culture should be eliminated.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.177-178
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• 2020

In the construction industry, expectations for the Precast Concrete(PC) construction method are rising due to demands for high quality and productivity and social and environmental issues. However, although technical problems that occurred in the early stages of technology introduction have been solved, research related to proper construction management for PC construction methods has been relatively neglected and the advantages of PC construction methods have not been fully utilized. In this study, each group involved in PC works was surveyed to identify important management tasks affecting productivity of PC works to improve PC contruction management system. Based on factor analysis, 22 tasks were calssified into 5 management groups. The results of this study will be used to present a framework for the application of automation and information technology to improve the productivity of PC works.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.785-789
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• 2021

Paprika productivity is different even in the same quality greenhouse and in the same region. These differences are known to due to differences in various environmental factors. This study was conducted to investigate the difference in the level of various environmental factors between high-productivity (HPF) and low-productivity (LPF) greenhouses. The largest difference between the two greenhouses in the daily or weekly average values of major environmental factors was the CO₂ concentration, but the LPF was higher than the HPF, so it was not determined as a factor for the difference in productivity. Correlation analysis among 14 environmental factors showed a high correlation among irradiation or related factors in moisture. The regression coefficients of the linear regression model between vapor pressure deficit and relative humidity were -0.0202kpa in HPF and -0.0262kpa in LPF. In particular, in February and March, the vapor pressure deficit in LPF was 1.5kpa or more, and the cumulative vapor pressure deficit compared to the cumulative irradiation at the early period of cultivation increased rapidly. The reason for the low productivity in LPF is thought to be that the plant was affected by moisture stress due to high vapor pressure deficit and transpiration under low irradiation conditions in the early period of cultivation and in winter.

• Korean Journal of Soil Science and Fertilizer
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• v.7 no.1
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• pp.35-42
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• 1974

From the results of countrywide two year N. P. K simple trial with newly bred IR 667-Suwon 214 and leading local varieties for comparison soil productivity (yield without fertilizer) and fertilization productivity (yield increase with fertilizer) were investigated. 1. IR667 showed higher yield than leading local by 19% in 1971 and by 12% in the year of low temperature stress, 1972. High yielding capacity of IR667 was attributed to greater number of spikelet per panicle. The coefficient of variation in yield was smaller in IR667 but the leading locals showed higher yield in 23(1971) and 30% (1972) of the fields. 2. IR667 required more nitrogen, especially phosphorus and potassium. Fertilization efficiency (yield increment per unit fertilizer) in IR667 was-about 4kg higher in nitrogen but smaller in phosphorus and almost the same in potassium. 3. Soil productivity was higher in IR667 but percent contribution of soil productivity to total productivity (field productivity) was lower. 4. Percent contribution of fertilization productivity to field productivity was 19 to 33, of which 5 was due to phosphorus and potassium. 5. The greater the soil productivity, the greater the field productivity becomes, but the much greater the percentage contribution of soil productivity becomes. 6. Fertility saturation point at which fertilization efficiency is nil, was propoesd as a soil productivity (or field productivity) limit.

• Korean Journal of Construction Engineering and Management
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• v.22 no.1
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• pp.55-62
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• 2021

The productivity of rebar-work and form-work was analyzed with data collected from an actual high-rise construction project, and the actual utilization rates of three tower cranes were also investigated. It was found that the average productivity of the form-work increased from 12.00~8.71(㎡/man·day) in the underground and above-ground/lower-floor to 11.94~20.73(㎡/man·day) in the standard floor. Comparing the productivity of core area to outer, the former was found to be about 11% higher. Moreover, the rebar-work productivity of the outer area(1.12 ton/man·day) was approximately 9.6% higher than that of the core area for the standard floor. The average utilization rates of three TC were surveyed to be about 63.49%, and it was revealed that rainy weather(6.1%), strong winds(6.1%), holidays(17.8%), TC lifting work(5.8%), and other failures and repairs(0.07%) were the causes of non-operation. These research results are expected to be beneficial data in planning and managing the process of high-rise RC construction works in the future.

• The Korean Journal of Mycology
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• v.37 no.1
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• pp.65-72
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• 2009

For the breeding purpose, in this study we attempted to select a new Lentinula edodes strain by comparing mycelial growth rate, fruit-body quality and mushroom productivity per substrate weight of hybrid strains with parent strains. Nineteen hybrid strains were made by cross of di-karyotic and mono-karyotic to develop strains suitable for sawdust cultivation of L. edodes. Among the nineteen strains, ten were selected by comparing mycelial growth rate on PDA media and wood rot on sawdust-based substrates. The most mushroom harvesting was achieved by 100 days incubation from KFRI 960, KFRI 961, KFRI 962, KFRI 963, KFRI 964, KFRI 971, KFRI 973 and 125 days from KFRI 968, 970. Experiment of incubation periods with the ten strains showed that there were productivity differences between 100 and 150 days incubations. Through comparison of hybrid strains' mushroom productivity it was found that there was no difference in mushroom productivity through crossing high temperature types with high temperature types, crossing low temperature types with high temperature types and crossing unknown temperature types with high temperature types, but there was difference through crossing middle temperature types with high temperature types. Hybrid strains showed better productivity compared with parent strains. Fruiting temperature type analysis of hybrid strains confirmed that strains of high temperature types have a dominant character.

• Journal of Environmental Science International
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• v.15 no.12
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• pp.1087-1091
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• 2006

This paper describes the current spatial patterns of the net primary productivity (NPP) of the terrestrial vegetation and carbon emission (C) in the world due to the burning of fossil fuels in order to clarify the amount of expansion of human activity. The C/NPP value varies spatially from almost zero to several tens of thousand times the local NPP. C/NPP is higher under the condition of extensive human activities due to a high human population density or when the local NPP is extremely low in severe climatic zones. In contrast, the low C/NPP areas are distributed mainly in sparsely populated districts, loading to a low impact of human activity. Although the area where C/NPP is less than 10% accounts for about 70% of the entire land area, one-third of these areas cannot contribute to carbon absorption because of low NPP with a shortage of climatic resources. Since more than half of the areas of the remaining areas are agricultural land and forest ecosystems with high NPP, the possible afforestation area was evaluated to be maximum of $30{\times}10^{6}\;km^{2}$; here only sequestrate carbons that correspond to 2% of the global total NPP are present. These analyses revealed that presently most of the areas where the NPP is high are those exclusively used by humans and that it is difficult for large-scale forest plantations to absorb a substantial amount of the carbon emitted annually by humans.

• Asia-Pacific Journal of Business
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• v.13 no.1
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• pp.277-288
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• 2022

Purpose - This study analyzed the determinants of local unemployment rate in Korea using panel data from 16 metropolitan cities and provinces from 2000 to 2018. Design/methodology/approach - We use a dynamic spatial panel model that considers characteristics of the regional unemployment rate such as the common factors effect, spatial dependence, and serial correlations. Findings - The local unemployment rate is affected by the past and present values of the national unemployment rate. And it is significantly affected by the past local unemployment rate and the past neighboring unemployment rate because spatial dependence and serial correlations are clearly present. In addition, when the industrial structure diversity and labor productivity were high, the regional unemployment rate decreased, and when the education level was high, the regional unemployment rate increased. Research implications or Originality - In order to reduce regional unemployment rate, it is necessary to plan and establish regional customized industrial structure policies under the stance of diversification rather than specializing the regional industrial structure and accompany improvement of the quality of education with the number of years of education. In addition, the redistribution of labor from low labor productivity sectors to high labor productivity sectors through technology development will help to reduce the local unemployment rate.

• Korean Journal of Poultry Science
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• v.51 no.2
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• pp.27-37
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• 2024

The poultry plays a crucial role in the animal industry, providing humans with efficient, high-quality animal protein. The rapid growth and short generational intervals of broilers offer significant benefits compared to other economic animals. This growth and increased muscle mass in modern commercial broilers result from advancements in breeding. However, the high productivity of contemporary broilers indicates they are approaching their physiological limits, with excessive fat accumulation becoming a significant industry issue. This not only reduces lean meat yield and feed efficiency but also negatively impacts consumers, especially due to problematic abdominal fat, which consumes more energy than lean meat production. Laying hens, reared for extended periods, maintain high productivity, producing a substantial number of eggs. This productivity in laying hens, akin to broilers, stems from genetic selection and breeding. For egg production, laying hens require physiological support for necessary nutrients. In this context, yolk fat accumulation is a critical physiological process. Lipoproteins, essential in avian lipid metabolism, are vital for yolk and body fat accumulation. Understanding these lipoproteins and their metabolism is key to developing healthier, more productive animals, offering economic benefits to farmers and improved nutritional quality to consumers. This review focuses on the physiological aspects of dietary fat transport, fatty acid biosynthesis in the liver, fat accumulation in the abdomen and muscles, and lipid deposition in egg yolks in chickens. It also highlights recent research trends in the regulation of fat metabolism in poultry.