• Journal of Korean Neurosurgical Society
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• v.40 no.2
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• pp.84-89
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• 2006

Objective : The purpose of this study is to compare the outcomes of two methods for stabilization and fusion : Postero-Lateral Fusion [PLF, pedicle screw fixation with bone graft] and Posterior Lumbar Interbody Fusion [PLIF, cage insertion] for spinal stenosis and recurred disc herniation except degenerative spondylolisthesis. Methods : Seventy one patients who underwent PLF [n=36] or PLIF [n=35] between 1997 and 2001 were evaluated prospectively. These two groups were compared for the change of interbody space, the range of segmental angle, the angle of lumbar motion, and clinical outcomes by Prolo scale. Results : The mean follow-up period was 32.6 months. The PLIF group showed statistically significant increase of the interbody space after surgery. However, the difference in the change of interbody space between two groups was insignificant [P value=0.05]. The range of segmental angle was better in the PLIF group, but the difference in the change of segmental angle was not statistically significant [P value=0.0l7]. Angle of lumbar motion was similar in the two groups. Changes of Prolo economic scale were not statistically significant [P value=0.193]. The PLIF group showed statistically significant improvement in Prolo functional scale [P value=0.003]. In Prolo economic and functional scale, there were statistically significant relationships between follow-up duration [P value<0.001]. change of interbody space [P value<0.001], and range of segmental angle [P value<0.001]. Conclusion : Results of this study indicate that PLIF is superior to PLF in interbody space augmentation and clinical outcomes by Prolo functional scale. Analysis of clinical outcomes showed significant relationships among various factors [fusion type, follow-up duration, change of interbody space, and range of segmental angle]. Therefore, the authors recommend instrumented PLIF to offer better clinical outcomes in patients who needed instrumented lumbar fusion for spinal stenosis and recurred disc herniation.

• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.268-273
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• 2006

This study analyzed the technological change of Korean sawmill industry affected by change of factor price. An aggregate cost function has been estimated to analyze the technological change in Korean sawmill industry between 1970 and 2003 to the technical bias and scale effect. There was substitution among labour, capital, and material, especially in more elastic relation between labour and capital. In addition, domestic sawmill industry was progressed into structure which is biased to labour saving, and capital and material using because of increase of labour price. Since Korean sawmill industry's technology still exhibits an increasing returns to the scale, the large amount of investment has contributed to productivity growth, and the future productivity growth continually depend on the scale effect for some time.

• Journal of Korea Water Resources Association
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• v.56 no.10
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• pp.679-690
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• 2023

Leakage is one of the representative abnormal conditions in Water distribution systems (WDSs). Leakage can potentially occur and cause immediate economic and hydraulic damage upon occurrence. Therefore, leakage detection is essential, but WDSs are located underground, it is difficult. Moreover, when multiple leakage occurs, it is required to prioritize restoration according to the scale and location of the leakage, applying for an optimal restoration framework can be advantageous in terms of system resilience. In this study, various leakage scenarios were generated based on the WDSs hydraulic model, and leakage detection was carried out containing location and scale using a Deep learning-based model. Finally, the leakage location and scale obtained from the detection results were used as a factor for the priority of leakage restoration, and the results of the priority of leakage restoration were derived. The priority of leakage restoration considered not only hydraulic factors but also socio-economic factors (e.g., leakage scale, important facilities).

• Journal of the Korean Operations Research and Management Science Society
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• v.14 no.1
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• pp.51-58
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• 1989

A joint economic ordering problem between supplier and customer has been formulated where a supplier has to pay the freight cost which follows the principle of economy of scale. An algorithm is given to determine order size and price simultaneously which give gains to both parties. A scenario is presented within which both parties come to a mutual agreement on the revised order size and price by utilizing quantity discount schedule.

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.20-23
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• 2003

Low-sulfidation style ore deposits, the major source of Au, Ag, and Hg, are formed from neutral-pH, reduced hydrothermal solutions close to equilibrium with their host rocks. The waters are low-salinity (〈1 wt % NaCl equiv.) but relatively gas rich (1-2 wt % $CO_2$), and are largely meteoric water. However, the contribution of magmatic components to the epithermal system, its temporal importance, and its relation to the source of ore metals are largely controversial. (omitted)

• Proceedings of the KOR-KST Conference
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• 1998.09a
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• pp.135-140
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• 1998

Social and economic development needs the support of transportation and communications and in turn the development level of society and economy affects urban traffic demand and determines the investment scale of transportation facilities. In the paper based on the analysis of the evolution of urban transportation in Shanghai in the past ten years and the economic background of that period, the urban transportation in the future development of economy is generally prospected.

• Journal of Korea Trade
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• v.25 no.5
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• pp.58-73
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• 2021

Purpose - In the context of economic globalization and the continuous development of international trade, as countries around the sea peninsula, port construction is particularly important. Based on the research on the influencing factors of port logistics development based on the allocation analysis, QCA (Qualitative Comparative Analysis) provides the basis for the planning and policy of port logistics development and has important theoretical value and practical significance for improving the level of port logistics management, reducing logistics operating costs and increasing economic benefits. In the tide of global integration for the development of port logistics, promote the growth of foreign trade economy of the city. It is also of great significance to the development and progress of commerce and trade. Design/methodology - Based on the relevant data samples of various ports in South Korea, this paper uses fsQCA (fuzzy set Qualitative Comparative Analysis) to integrate and analyze the influence mechanism of port logistics development and extracts five influencing factors of port logistics development, including the port's scale and infrastructure in the hard environment, port-neighboring enterprises in the soft environment, hinterland economy and government support. Findings - The five factors are unable to separately constitute the necessary and sufficient conditions of port logistics development, only a combined model can influence lake port logistics development. The scale and infrastructure of the port itself and port-neighboring ring enterprises are the main core conditions, which work together on the port, affect the throughput capacity of the port, and promote the development of port logistics. When the port-neighboring enterprises are not complete and the scale is low, the growth of port throughput will be restrained and the development of port logistics will be affected, whether the hinterland economic benefits are general, the development of port-neighboring enterprises is insufficient, or the government supports are limited. Originality/value - Through the research on the development of port logistics in South Korea from the perspective of configuration, this paper finds the configuration influence of hard environment and soft environment on the development of port logistics, which has important theoretical and practical significance for better promoting the development of port logistics in South Korea.

• Journal of the Korea Institute of Building Construction
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• v.19 no.6
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• pp.567-575
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• 2019

Statistics show that while the number of fires has decreased over the last decade, losses of human life and economic property due to fire have increased. Moreover, the number of large-scale fires that have occurred in recent years has resulted in heightened public anxiety. This study aims to identify a specific period of the year most vulnerable to fire, and fire trends, such as damage of fire to humans, to the economy, and different building types. For this purpose, we analyzed human and economic damages using statistics related to fire from 2007 to 2017 and provided a monthly distribution of fire damages both to humans and to the economy by building type. We also identified the relationship between the human damage and the economy damage, and compared the economic losses per casualty by building type. The human damage in residential buildings occupied the highest portion, whereas the economic damage of industrial buildings represented more than a half of all economic damage due to fire. The economic damage per casualty was shown highest for industrial buildings and has also increased rapidly in recent years.

• Journal of Families and Better Life
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• v.9 no.1 s.17
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• pp.241-257
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• 1991

The objectives of this study are : to measure the level of rent burden. to examine the independent influences of the variables related to rent burden. to measure the level of family economic problem perception. to examine the differences in the level of family economic problem perception due to rent burden, household characteristics, housing characteristics and rent incresing. For these purpose, a survey is conducted using questionaires. The data used in this study included 369 renters living in Seoul. Statistics uses for data analysis were Frequency Distribution. Percentile, men, Pearson's Correlation, Partial Correlation, One-way ANOVA, Breakdown and Multiple Regression Analysis. Major findings are as follows : The average score of rent burden was 35.87, Therefore rent burden of large cities, rental households is very heavy. Family income, housing facility quality, rent type, and rent incresing have independent influences on rent burden. The average of family economic problem perception is above the mid-point of the scale. The level of family economic problem perception differs due to rent burden, family income, family life cycle, family size, occupation of household head, education leval of household head and homemaker, rent type, housing type, housing size, housing facility quality and rent increases. If the level of rent burden is below 25, family economic problem perception is adequate.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.4
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• pp.63-75
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• 2009

Recently personal information security breaches by unauthorised access, mistakenly disclosure or stolen become more frequent and the scale of the economic loss of such incidents is growing. Assessing economic loss of personal information security breaches is needed for decision making of information security investment This paper presents a framework to analyze economic impact of personal information security breaches and develops formula for each element to empirically calculate the economic loss. We also compared annual economic loss of Korea with that of Japan to develop some implications.