• Journal of Labour Economics
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• v.36 no.2
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• pp.37-65
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• 2013

This study compares the return to seniority and experience among different groups of workers. Skilled workers in large company appear to enjoy the biggest seniority premium, while non-regular workers and small company workers hardly have any. Trade union did not have significant effect. Return to experience increased especially in large firms. Nonparametric model specification test shows that the biases for returns to seniority and experience of 30 years to be between -25~29%, and -42%~6%, respectively.

• Annals of Clinical Neurophysiology
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• v.12 no.1
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• pp.1-2
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• 2010

Chronic non-specific low back pain (CLBP) is one of the major health problems casting substantial amount of economic expenses and negative impact on quality of life onto an individual as well as society. On contrary to public familiarity, the ways of management of CLBP are diverse and there is yet no general consensus about which approach is better than others or to whom the specific management should be applied. Some hold the negative point of view on the efficacy of the invasive maneuver such as epidural injection because there is no controlled clinical trial (RCT) yielding better long term outcome of those invasive managements over conservative ones. But the experts of interventional or surgical treatment stress the methodological difficulty in performing RCT and assert that those invasive treatments can bring the prompt and complete resolution of low back pain and restoration of function in appropriately selected cases. These seemingly opposite views on the invasive management on CLBP are rather complimentary each other than to be contradictory.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.7-10
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• 2003

In the field of financial technology, it is the U.S. initiative, and Japan is obliged to flattery in many respect. Currently Japan is in a too much defenseless situation that the economic structure is based on U.S. theory, In the conventional stochastic theory, it is also face that the prediction sometimes does not hit in the actual problem because it assumes a known probability distribution, none of which illustrates the real situation. A new research and development of management prediction support system is proposed based on fuzzy measures, that deals with the ambiguous, subjective evaluation by the people living in the real world well. Especially, the system will support venture, small and medium companies.

• Environmental Analysis Health and Toxicology
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• v.4 no.1_2
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• pp.55-65
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• 1989

Nevertheless the serious environmental pollution in Korea has been discussed in concern with health effect, the significant effect are not determined easily. Toxicological method has been used to establish safe levels of exposure for environmental pollutants to have threshold health effect below which significant effects are unlikely to occur. However the conventional method cannot to establish safe levels of exposure for non-threshold pollutants have been used to express comprehensive pollution degree, not in detailed toxic effects. Acceptable exposure or risk levels are decides by policymakers who consider descriptions and estimates of risks together with social and economic benefits. This paper focuses on the concept development of risk assessment and describes some risks of environmental pollution based on the surveyed date in Korea. The current concepts of risk assessment in policy descisions can be explored and areas for possible improvement, given current scientific knowledge are identified. The experience of foreign countries can provide a realistic basis for evaluating the existing data of environmental pollutants. To improve the environmental quality, risk regulation should be managed as soon as possible in Korea.

• Microbiology and Biotechnology Letters
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• v.25 no.2
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• pp.218-223
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• 1997

For the utilization of animal blood produced in slaughter for the cultivation of lactic acid bacteria, the nitrogen sources in a complex(MRS) medium were replaced by blood plasma proteins. Focusing the purpose on the industrial production of a probiotics, the hydrolytic activities of three industrially applicable proteases were compared for the effective digestion of the proteins, and Alcalase(the product of Novo Nordisk) was selected with comparatively high activity. The growth of Streptococcus thermophilus KCCM12020 was best among the four strains of lactic acid bacteria tested. With Alcalase-digested proteins in the medium, the growth rates and the final cell concentrations were higher than those with non-digested proteins. The cell mass produced in the medium containing blood proteins as nitrogen sources, $2.5{\times}10^9$ CFU/ml, was significantly high and about 70% of that in MRS medium, showing a great possibility for the utilization of animal blood proteins as economic nitrogen sources in the production of cell mass of lactic acid bacteria.

• KIEE International Transactions on Power Engineering
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• v.3A no.1
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• pp.42-46
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• 2003

The economic operation of a utility in a deregulated environment brings about optimization problems different from those in vertically integrated one［1］. While each utility operates its own generation capacity to maximize profit, the market operator (or system operator) manages and allocates all the system resources and facilities to achieve the maximum social welfare. This paper presents a sequential application of non-cooperative and cooperative game theories in analyzing the entire power transaction process.

• Earthquakes and Structures
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• v.7 no.4
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• pp.401-414
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• 2014

The economic consequences of large earthquakes require a revolutionary change in the seismic performance objective of residential and commercial buildings. The majority of total construction costs consist of non-structural and architectural costs. Therefore, the aim of this research is to upgrade current Life Safety performance objectives and to offset adverse effects on country's economy after an occurrence of large earthquakes. However, such a proposal cannot easily prove the feasibility of cost-benefit analysis in structural design. In this paper, six generic reinforced concrete frames and dual system structures designed based on Turkish Seismic Code were used in cost analysis. The study reveals that load bearing structural systems with Immediate Occupancy performance level in seismic zones can be achieved with negligible costs.

• Transactions of Materials Processing
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• v.8 no.3
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• pp.284-293
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• 1999

The rigid-plastic finite element analysis requires a large amount of computation time due to its non-linearity. For economic computation, mismatching refinement, and efficient domain decomposition method with different mesh density for each sub domain, is developed. A modified velocity alternating scheme for the interface treatment is proposed in order to obtain good convergence and accuracy. As a numerical example, the axisymmetric extrusion process is analyzed. The results are discussed for the various velocity update schemes form the viewpoint of convergence and accuracy. The three-dimen-sional extrusion process with rectangular section is analyzed in order to verify the effectiveness of the proposed method. Comparing the results with those of the conventional method of full region analysis, the accuracy and the computational efficiency of the proposed method are then discussed.

• Journal of the Korean Home Economics Association
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• v.39 no.12
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• pp.141-158
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• 2001

The purpose of this study was identifying the essential concept of home of middle class and aged housewives by using a critical incident methodology. All 30 subjects participated in structured interviews designed to elicit statements describing the attributes of home and non-home environment. The qualities of comfort, place-attachment, self-expression, fundamental values and personal identity, social relationships, economic value, and a suitable physical structure were associated with home environments, and were absent in residences which were not regarded as homes.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.5 no.7
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• pp.33-42
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• 1982

The standard theory of production treats human and non-human inputs in the same way. Inert Areas Theory drops this assumption. One distinction is obvious. Human capital, the source of human inputs, can not be purchased outright by firms. Usually what is purchased are units of labor time. What is critical is directed effort, at or beyond some level of skill. Direct effort, however, involves choice and motivation, and these are the critical variables left out of the standard theory. Leibenstein introduces the concept of "inert areas" by which he means "a set of effort positions whose associated levels of utility are not equal but in which the action required to go from a lower to a higher utility level involves a utility cost that is not compensated for by the gain in utility." This idea is used when discussing the behavior of firm's management.f firm's management.