• International conference on construction engineering and project management
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• 2022.06a
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• pp.1114-1121
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• 2022

Construction laborers and crews play a critical role in achieving a safe and productive construction site. Many past research studies used top-down approaches/perspectives for studying the impact of laborers' performance on overall construction site outputs with limited flexibility in accounting for laborers' various characteristics. However, the recent reap in computational advances allowed applications of bottom-up architectures, which can potentially incorporate heterogeneous characteristics of laborers' individual behavioral and decision-making features effectively. Accordingly, agent-based modeling (ABM), as a tool to leverage a bottom-up methodological approach, has been widely adopted by recent research. Existing literature investigated the influence of changes in laborers' behaviors and interactions on either construction sites' safety performance or productivity performance individually, leaving the tradeoff between safety and productivity in this context relatively unexplored. Accordingly, this study aims to develop an agent-based framework to study the tradeoff between project safety and productivity performances resulting from changes in laborers' behaviors after attending safety trainings. Our findings via simulations indicate that proper safety trainings can improve safety performance without negatively impacting productivity performance.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.1
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• pp.12-19
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• 2005

This study investigated the productivity and growth of copepods, Sinocalanus tenellus 2 strains, Paracyclopina nana 3 strains, Apocyclops royi 2 strains, Tachidius triangularis 1 strain and Tigriopus sp. 1 strain at different temperatures $(24,\;28\;and\;32^{\circ}C)$ under 15 psu and various salinities (10, 20, 30 psu) at $28^{\circ}C$ for an individual culture. And the mass culture was carried out to evaluate the production of these copepods in the 500 mL vessel. For an individual culture of copepod, survival period of a brood female tended to increase with the decrease of temperature, but was not significantly influenced by salinity. With an increase of temperature and a decrease of salinity, maturation period of nauplii in all species tended to decrease. Total nauglii production from a broodo female at $24^{\circ}C$ was higoher than that from a brood .female at either 28 or $32^{\circ}C$ for S. tenellus and at $32^{\circ}C$ than either 24 or $32^{\circ}C$ for A. royi Haenam stram, but was not influenced by temperature for another copepods. And total nauplii production from a brood female at 10 and 20 psu tended to be higher than that from a brood female at 30 psu, expect for Tigriopus sp. and P. nana Hwajinpo strain. Total nauplii production from a brood female was the highest in Tigriopus sp. (350 nauplii) at $28^{\circ}C$ under 20 psu, followed by A. royi Haenam strain (187 nauplii) at $32^{\circ}C$ under 15 psu and P. nana Hwajinpo strain (152 nauplii) at $24^{\circ}C$ under 10 psu. In the mass culture of each copepod, P. nana was the most productive (26.6 mg dry weight) and this value was two and four times higher than productivity of Tigriopus sp. and A. royi, respectively.

• Journal of Distribution Science
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• v.14 no.7
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• pp.53-61
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• 2016

Purpose - The production efficiency of agricultural crops has been the subject of numerous studies in the field of agricultural economics. This study examines the production efficiency of emerging vineyards in the 14 northern U.S. states and aims to understand raw input and managerial factors affecting the grape production with focusing on the effect of farm size. Research design, data, and methodology - Using a unique survey dataset that was collected from 176 vineyards in 2012, we employed data envelopment analysis (DEA) for estimation of production efficiency in individual vineyards. Production efficiency is regressed on various input and managerial covariates to understand factors influencing the productivity. Results - Although there exists positive correlation between the farm size and productivity of vineyards in Northern U.S. states, we find negative relationship when the farm size is instrumented by the additional farm size expansion indicator. The negative effect is more pronounced for the recently established vineyards. Conclusions - This study suggests that there needs to be adequate managerial improvements for emerging vineyards in northern states for the achievement of increased productivity.

• Korean Journal of Ecology and Environment
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• v.52 no.3
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• pp.202-209
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• 2019

The primary productivity and production rate of photosynthetic pigment of periphyton and phytoplankton were estimated using a $^{13}C$ stable labeling technique in May 2011, in the waterfront of Lake Paldang. Primary productivity of periphyton ($28.15mgC\;m^{-2}\;d^{-1}$) was higher than phytoplankton production ($0.14mgC\;m^{-2}\;d^{-1}$). The net production rates of photosynthetic pigments(Chl a and Fucoxanthin) of periphyton were $2.53ngC\;m^{-2}\;d^{-1}$ and $0.12ngC\;m^{-2}\;d^{-1}$, respectively. On the other hand, the net production rate of pigments on phytoplankton (Chl a : $0.023ngC\;m^{-2}\;d^{-1}$, Fucoxanthin: $0.002ngC\;m^{-2}\;d^{-1}$) was lower than that of periphyton. Specific production rates of individual pigments of phytoplankton to the total primary productivity indicate the predominance of diatom (Fucoxanthin) species in phytoplankton assemblage in Lake Paldang. The net individual production rate of pigments by $^{13}C$ tracer was a useful tool to estimate the contribution of each phytoplankton class for total primary productivity, and it is possible to calculate the seasonal contribution of each phytoplankton class to the total primary productivity in the aquatic ecosystems. This study is the first report on photosynthetic pigment production rates of periphyton and phytoplankton.

• Journal of Korean Institute of Industrial Engineers
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• v.37 no.4
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• pp.350-357
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• 2011

In the recent, it is gradually important for airport to consider environmental aspects as sustainable development is emerged. ICAO, FAA and individual countries has tried to reduce airport noise and pollution. Thus, the effort is needed to incorporate environmental factor into productivity indicator of airport. Our paper use DEA method with the non-parametric directional output distance function(DDF) to assess productivity of 14 airports in Korea during 2008~2010. In addition to three inputs, two conventional outputs, two undesirable outputs have been considered : noise and air pollution. Results are compared from models that do not include undesirable outputs. Inclusion in the analysis of the undesirable effects of airport operations leads to greater and closer airport's efficiency scores.

• Journal of Drive and Control
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• v.19 no.4
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• pp.91-96
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• 2022

The performance and reliability of foreign servomotors and domestic servomotors for manufacturing robots were compared and verified. The mass productivity was confirmed by satisfying the requirements of the demanding companies. The servomotor was designed in consideration of mass productivity while satisfying the requirements of the demanding company. It was mounted on a real robot to check its performance and reliability. To secure mass-production performance, we designed and manufactured easy-to-manufacture parts and jigs to manufacture servomotors and achieved the goal of the mass-production evaluation of servomotors through individual performance evaluation, robot mounting test evaluation, and supplementation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6066-6075
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• 2014

The aim of this study was to analyze the productivity changes in government-funded research institutes for Economics & Humanities and Social Sciences. From Malmquist total factor productivity index analysis, the average productivity decreased 6.5% between 2006 and 2010. Further analysis showed that technical efficiency increased 4.7% annually while the technology change rate decreased 10.8% on average. Under pressure for innovation from the outside, research institutes responded to managerial efficiency improvement, which lead to increases in technical efficiency. On the other hand, for productivity improvement of government funded research institutes, they must pursue technological advances by securing an outstanding research workforce, expanding the R&D budget, and changing the R&D method. Each institute must perceive the cause of an individual institute's productivity change, and establish strategies for increasing productivity.

• Journal of the Korea Institute of Building Construction
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• v.14 no.4
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• pp.292-300
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• 2014

The construction progress control is very important because there are many unexpected factors affecting time schedule delay and cost overruns. A complicated measure including item quantity and inherent time and costs is used to monitor the progress. Another element to be considered is a productivity, which is cost effectiveness because productivity is primarily measured by the costs. Productivity is stated as constant in-place value divided by inputs such as worker-hour. The main purpose of this paper is to analyze the productivity of structural formwork using a 3D BIM. In order to achieve the research objective, an integrated model of a BIM with a daily foreman's report is developed. The quantities being extracted from a 3D model and information are integrated with manpower utilized. The developed model is applied to a case project to measure and analyze the productivity in terms of individual building and work crew team. The results are discussed and further research topics will be addressed.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.157-162
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• 2003

Piezoelectric ink jet offers a promising combination of productivity, reliability and uniformity that are appropriate for jetting organic electronic materials. Spectra is manufacturing a printhead specifically for display manufacturing. This printhead contains a robust material set and is intended to allow calibration of individual nozzles to meet uniformity requirements of+/-2% for display manufacture.

• Journal of the Korea Safety Management & Science
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• v.12 no.4
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• pp.273-278
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• 2010

As basic study on effects of the decasualization of port labor, this paper watched labor supply framework reorganization, focused on port worker in Incheon port at before decasualization(2005~2007.9) and after decasualization(2007.10~2010.5) and analyzed disposal quantity, workers, workdays, productivity, accident and disaster data that was apt to influence by the decasualization of port labor. Though commercial traffic of Incheon port was decreased in global economic depression, individual workday per month after decasualization compared with before decasualization is decreased by 3.3days from 22.7day to 19.4days, on the other hand, indivisual annual loading and unloading throughput is increased averagely 71.6%, and labour productivity, when 2005 labour productivity are 100, are increased by 67%. After decasualization, overall loading and unloading productivity is improved. But, according to loading and unloading, the number of accident and disaster are increase by 11.7% after decasualization for loading and unloading operation.