• Journal of the Korean Professional Engineers Association
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• v.42 no.4
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• pp.62-67
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• 2009

Labor productivity issues within the construction industry are receiving increasing attention. With the improvement in the standard of living, domestic laborers are avoiding 3D (Difficult, Dirty, and Dangerous) jobs by degrees. Because of this situation, the problem of insufficient labor is exacerbating in several basic industries. In particular, insufficient labor is a serious problem in the construction sector, where the workers are ageing and labor costs are increasing. In this study, we adopt a systematic approach to identify factors that influence labor productivity and analyze the causality between the factors and their ripple effects with the aim that the results of the study will help improve labor productivity and ensure its effective management.

• Korean Journal of Construction Engineering and Management
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• v.6 no.5 s.27
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• pp.69-77
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• 2005

Change is inevitable and is a reality of construction projects. Most construction contracts include change clauses and allowing contractors an equitable adjustment to the contract price and duration caused by change. However, the actions of a contractor can cause a loss of productivity and furthermore can result in disruption of the whole project because of a cumulative or ripple effect. Because of its complicated nature, it becomes a complex issue to determine the cumulative impact (ripple effect) caused by single or multiple change orders. Furthermore, owners and contractors do not always agree on the adjusted contract price for the cumulative Impact of the changes. A number of studies have attempted to quantify the impact of change orders on project costs and schedule. Many of these attempted to develop regression models to quantify the loss. However, regression analysis has shortcomings in dealing with many qualitative or noisy input data. This study develops ANN models to classify and quantify the labor productivity losses that are caused by the cumulative impact of change orders. The results skew that ANN models give significantly improved performance compared to traditional statistical models.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.10a
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• pp.35-38
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• 2004

Global competitive pressures are asking industrial companies to find the best way to meet their customer's requirements, reduce the costs of products, and increase productivity. Quality improvement has been proposed and implemented as a primary means of achieving these purposes. The quality improvement usually includes a goal of reducing the costs due to poor quality. While these costs of poor quality (COPQ) are not known precisely, they are known to be very high. Also, they may be underestimated by the hidden costs due to non-value activities, such as potential lost sales, costs of redesign due to quality reasons, and extra manufacturing costs due to defects, etc. In any manufacturing or service operation, all actions and resource expenditures of a company should be focused on creating value for customers. Any activity or resource of not creating the value for customers could be regarded as waste, which consequently causes the COPQ. Some companies did use dashboards to understand and identify value added or non-value added activities in order to reduce or eliminate wastes. These dashboards must be properly designed to consider inherent differences in manufacturing or service operations among business organizations. In addition, a structured quality improvement program such as the Six Sigma must support these dashboards. In this paper, a case study of designing dashboards for evaluating and reporting the COPQ in business units is presented.

• Journal of the korean Society of Automotive Engineers
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• v.14 no.6
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• pp.113-126
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• 1992

Recently the multi-kind, small-amount manufacturing system has been replacing the mass manufacturing system, and domestic machining inustry also is eager to absorb the new technology because of its high productivity and cost reduction. The optimization of the cutting condition has been a vital problem in the machining industry, which would help increase the productivity and raise the international competitiveness. It is intended in this study to investigate the machining costs per unit time which is essential to the analysis of the optimal cutting condition, to computer the cutting speed that lead to the minimum machining costs and the maximum production to suggest the cutting speed range that enables efficient speed cutting, and to review the machining economy in relation to cutting depth and feed. Also considered are the optimal cutting speed and prodution rated in rrelation with feed. It is found that the minimum-cost cutting speed increases and the efficient cutting speed range is reduced as machining cost per unit time increases since the cutting speed for maximum production remains almost constant. The machining cost is also lowered and the production rate increases as the feed increases, and the feed should be selected to satisfy the required surface roughness. The machining cost and production rate are hardly affected by the cutting depth if the cutting speed stays below 100m/min, however, they are subject to change at larger cutting depth and the high-efficient speed range also is restricted. It can be established an adaptive optimal cutting conditions can be established in workshop by the auto-selection progam for optimal operation. It is expected that this method for choosing the optimal cutting conditions might contribute to the improvement of the productivity and reduced the cost. It is highly recommended to prepare the optimal cutting conditionthus obtained for future use in the programing of G-function of CNC machines. If proper programs that automatically select the optimal cutting conditions should be developed, it would be helpful to the works being done in the machine shops and would result in noticeable production raise and cost reduction.

• Korean Journal of Social Welfare
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• v.69 no.3
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• pp.9-33
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• 2017

This study estimated the socioeconomic costs of child poverty. Based on previous studies, the present study organized component categories for direct and indirect costs of child poverty, and estimated the cost of each category in 2015 through the collection of existing data and Delphi survey techniques among experts. The total socioeconomic costs of child poverty were compared to Korea's GDP. The results of this study were as follows. First, the socioeconomic costs of child poverty in Korea in 2015 ranged from 55 trillion KW(3.5% of GDP) to 99 trillion KW(6.5% of GDP). Second, the indirect socioeconomic costs of child poverty are much higher than the direct costs. Third, among the total cost categories, costs related to productivity loss and unemployment accounted for the largest portion of both the socioeconomic costs based upon absolute poverty and relative poverty. Crime costs are the second largest. Based on these results, we discussed the importance of early intervention for children in poverty; implementation of two-generation program that intervenes simultaneously with parents and children; and long-term, continuous and integrated intervention for high-risk groups such as poor children.

• Journal of the Korean Society of Child Welfare
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• no.53
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• pp.25-50
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• 2016

For child abuse prevention in Korea, this study estimated the socioeconomic costs of child abuse. Based on previous studies, the present study organized component categories for estimable direct and indirect costs of child abuse, and estimated the cost of each category in 2014 through the collection of existing data and through Delphi survey techniques among experts. The total socioeconomic costs of child abuse were compared to Korea's GDP. The results of this study were as follows. First, the socioeconomic costs of child abuse in Korea in 2014 ranged from 389.9 billion KW(0.03 percent compared to GDP) to 76 trillion KW(5.1 percent compared to GDP). Second, the indirect socioeconomic costs of child abuse are much higher than the direct costs. Third, costs related to productivity loss and unemployment accounted for the largest proportion of the total costs. In addition, the proportion of the child protection budget in Korea was very low compared to developed countries. These findings suggest that there is a need to increase Korea's child protection budget and to take urgent action to detect unrevealed child abuse cases. Furthermore, in order to reduce indirect costs, it is important to provide abused children with early professional treatment.

• Journal of Preventive Medicine and Public Health
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• v.48 no.4
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• pp.180-187
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• 2015

Objectives: Metabolic syndrome is an important etiologic factor in the development of certain types of cancers. The economic cost of the treatment of cancer has been steadily increasing. We therefore estimated the economic burden of cancers attributable to metabolic syndrome in Korea. Methods: We reviewed metabolic syndrome-related cancers and relative risk and then calculated population attributable fractions. We analyzed insurance claims data for metabolic syndrome-related cancers in 2012 in order to estimate the direct costs associated with these cancers, including hospitalization, outpatient visits, transportation costs, and caregivers' costs as well as indirect costs such as loss of productivity due to cancer treatment and premature death. Results: In 2012, 18 070 patients in Korea had cancers attributable to metabolic syndrome. The economic burden was USD 199.8 million and the direct and indirect costs were USD 124.5 million and USD 75.3 million, respectively. Conclusions: We estimated the economic burden of cancers attributable to metabolic syndrome in Korea and the efforts are necessary to reduce this burden.

• Journal of the Korean Operations Research and Management Science Society
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• v.29 no.3
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• pp.79-98
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• 2004

Despite its contribution to the Korean medical service industry the question of how efficiently the Korean public hospitals have operated has been unresolved. This study gauges and analyzes the overall efficiency and the Malmquist productivity index in the industry over the period 1992 through 2001. In addition to cost efficiency. we also measure technical, allocative, pure technical and scale efficiencies. Furthermore. the Malmquist index is decomposed into efficiency and frontier changes. We identify several important factors which seem to have strong relationship with various inefficiency estimates. The results indicate that on average the public hospitals has wasted a significant amount of resources and costs over the period. Unlike many other industries, the low level of cost efficiency of the public hospital industry is mainly due to allocative inefficiency rather than technical inefficiency. The Maimquist productivity indices seem both due to the frontier change and efficiency change, but with more effect by the former. The results also indicate that the turnover of hospital beds has played an important role in determining efficiency and productivity of this important industry.

• Journal of the Korea Institute of Building Construction
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• v.12 no.6
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• pp.636-647
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• 2012

Construction projects have become so large, complicated and incredibly high-tech that process management is currently considered one of the most important issues. Unlike typical manufacturing industries, most major construction activities are performed in the open air and thus are exposed to various environmental factors. Many studies have been conducted with the goal of establishing efficient techniques and tools for overcoming these limitations. Productivity analysis and prediction, one of the related research subjects, must be considered when evaluating approaches to reducing construction duration and costs. The aim of this research is to present a quantified impact analysis of construction delay factors on construction productivity of a steel staircase system, which has been widely applied to high rise building construction. It is also expected to improve the process by managing the factors, ultimately achieving an improvement in construction productivity. To achieve the research objectives, this paper analyzed different delay factors affecting construction duration by means of multiple regression analysis focusing on steel staircase systems, which have critical effects on the preceding and subsequent processes in structure construction. Statistical analysis on the multiple linear regression model indicated that the environment, labor and material delay factors were statistically significant, with 0.293, 0.491, and 0.203 as the respective quantified impacts on productivity.

• Fibers and Polymers
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• v.7 no.2
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• pp.146-157
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• 2006

Traditional spinning systems have reached profitability limits in developed countries due to high production costs and low system productivity. Pneumatic spinning is seen as a developing system, because productivity is much higher than conventional systems. This study evaluates one of the main problems to increase productivity in pneumatic spinning, where air mass-flow is dragged by the drafting cylinders. This flow interacts with the incoming fibres deviating them from their expected path. Via laser anemometry, airflow velocity distribution around drafting cylinders has been measured and it has been found that vorticity is created at the cylinder's inlet. Extensive CFD simulation on the air flow dragged by the cylinders has given a clear insight into the vortex created, producing valuable information on how cylinder design affects the vorticity created. Several drafting cylinder designs have been tested without giving any improvement in productivity. However, the use of a drafting cylinder with holes in it produced good results to the problem of air currents, strongly reducing them and therefore allowing a sharp increase in yarn quality, as well as an increase in productivity. An extensive study on vortex kinematics has been undertaken, bringing with it a better understanding of vortex creation, development and breakdown.