• Journal of Korean Society of Transportation
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• v.29 no.5
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• pp.19-32
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• 2011

There are many investment budget drafts in the filed of a road traffic safety. The traffic safety budget is spitted into following three major areas: 1) traffic safety facility (Engineering), 2) traffic enforcement (Enforcement), and 3) traffic safety education & public relation (Education). The three area are known as so-called 3E policy. This study investigates the effect of the investment in the 3E policy on the reduction of traffic accidents analyzing the data annually collected from the 15 local governments during 1992 to 2007. The analysis employing the traffic accidents as the dependent variable reveals that the effect of the investment is higher if same amount of investment is made on areas of the traffic safety education and public relation than the area of facility improvement. The similar conclusions are resulted from the separate investigation of traffic accidents data by 6 different types. All the results consistently indicate that the current traffic safety investment being primarily made on traffic safety facility needs to shift to the areas of traffic safety education and public relation budget.

• Journal of Korean Association for Spatial Structures
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• v.1 no.1 s.1
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• pp.143-155
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• 2001

Generally, truss design has been determined by the designer's experience and intuition. But if we perform the most economical structural design we must consider not only cross-sections of members but also configurations(howe, warren and pratt types etc.) of single truss as the number of panel and truss height. The purpose of this study is to develope automated optimum design techniques for steel truss structures considering cross-sections of members and shape of trusses simultaneously. As the results, it could be possible to find easily the optimum solutions subject to design conditions at the preliminary structural design stage of the steel truss structures. In this study, the objective function is expressed as the whole member weight of trusses, and the applied constraints are as stresses, slenderness ratio, local buckling, deflection, member cross-sectional dimensions and truss height etc. The automated optimum design algorithm of this study is divided into three-level procedures. The first level on member cross-sectional optimization is performed by the sequential unconstrained minimization technique(SUMT) using dynamic programming method. And the second level about truss height optimization is applied for obtaining the optimum truss height by three-equal interval search method. The last level of optimization is applied for obtaining the optimum panel number of truss by integer programming method. The algorithm of multi-level optimization programming technique proposed in this study is more helpful for the economical design of plane trusses as well as space trusses.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.4
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• pp.21-27
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• 1999

A low order panel method based on the perturbation potential is applied for prediction of performance of blown-flap rudders. In order to improve the solution behavior at the large angle of attacks, the geometry of the trailing wake sheet is computed by aligning freely with the local flow. The effect of the wake sheet roll-up is also included with use of a high order panel method. The flow in the gap between the main component and the flap of the rudder is modeled as Couette flow. The effects of the gap and the flow jet are included in application of a kinematic and a dynamic boundary condition on the inlet and the outlet of the gap as well as on the flap and the wake. The results with the present method are compared with existing experimental data. The method is shown to be capable of determining accurately the flow characteristics even for large flap angles.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.176.2-176.2
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• 2013

Property of optical diagnostics for pulse-discharged plasma in liquid and its biological applications to proteins are investigated by making use of high voltage Marx generator. The Marx generator has been consisted of 5 stages, where each charging capacitor is 0.5 ${\mu}F$, to generate a high voltage pulse with rising time of $1{\mu}s$. We have applied an input voltage of 6 kV to the each capacitor of 0.5 ${\mu}F$. High voltage pulsed plasma has been generated inside a polycarbonate tube by a single-shot operation, where the breakdown voltage is measured to be 7 kV, current of 1.2 kA, and pulse width of ~ 1 ${\mu}s$ between the two electrodes of anode-cathode whose material is made of tungsten pin, which are immersed into the liquids. We have investigated the emitted hydrogen lines for optical diagnostics of high voltage pulsed plasma. The emission line of 656.3 nm from $H-{\alpha}$ and 486.1 nm from $H-{\beta}$ have been measured by a monochromator. If we assumed that the focused plasma regions satisfy the local thermodynamic equilibrium conditions, the electron temperature and density of the high voltage pulsed plasma in liquid could be obtained by the Stark broadening of optical emission spectroscopy. For the investigation of the influence of pulsed plasma on biological proteins, we have exposed it onto the proteins such as hemoglobin and myoglobin. The structural changes in these proteins and their analysis have also been obtained by circular dichroism (CD) and ultraviolet (UV) visible spectroscopy.

• Korean Journal of Labor Studies
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• v.23 no.2
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• pp.79-108
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• 2017

Using data sets from the Korean Labour and Income Panel Study (KLIPS) for the period 2003-2015, this study shows that wages of nonunion workers are positively related to the percentage of unionized workers in the same geographic region. A 10 percentage point increase in a region's union density is associated with a 4.9 percent increase in the region's average wage of nonunion workers. It is also shown that this positive spillover effect is observed for various subgroups of nonunion workers, including women, youth, low-educated workers, small firm employees, and those employed under nonstandard work arrangements. In contrast, the average wage of union workers is found to respond insignificantly to changes in a region's union density.

• The Journal of the Korea Contents Association
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• v.16 no.8
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• pp.59-70
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• 2016

This study aimed to find effective policies to cope with low birth rate in local authorities. It was analyzed the variables-a number of child-care facilities, paid parental leave, labor force participation, and total working hours-using panel analysis from 2005 to 2014. The results were as follows. First, after testing the whole years, we found that the fittest model was the fixed-effects model of 2 models(fixed-effects model, random effects model). A number of child-care facilities had positive effects, and a number of child-care facilities, and total working hours in women influenced negative effects on total fertility rate. Second, during the former time and the period of plan for low birth rate and aging society, a number of child-care facilities influenced negative effects on total fertility rate. Third, a number of child-care facilities had negative effects on total fertility rate in Busan, Daegu, and Kwangju. Paid parental leave influenced positively on total fertility rate in 5 cities and a province. Women's total working hours were a significant variable of total fertility rate in Jeju. This study found that the variables which influenced on total fertility rate were different by local authorities, and a number of child-care facilities and paid parental leave were very important variables on total fertility rate.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.3
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• pp.142-147
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• 2023

Objectives: As medical history before surgery is often based on patient reporting, there is the possibility that patients intentionally hide underlying diseases or that dentists cannot recognize abnormal health states. Therefore, more professional and reliable treatment processes are needed under the Korean dental specialist system. The purpose of this study was to elucidate the necessity of a preoperative blood testing routine prior to office-based surgery under local anesthesia. Patients and Methods: Preoperative blood lab data for 5,022 patients from January 2018 to December 2019 were assembled. Study participants were those who underwent extraction or implant surgery under local anesthesia at Seoul National University Dental Hospital. Preoperative blood tests included complete blood count (CBC), blood chemistry, serum electrolyte, serology, and blood coagulation data. Values outside of the normal range were considered an "abnormality," and the percentage of abnormalities among the total number of patients was calculated. Patients were divided into two groups based on the presence of underlying disease. The rates of abnormalities in the blood tests were compared between groups. Chi-square tests were performed to compare data from the two groups, and P<0.05 was considered statistically significant. Results: The percentages of males and females in the study were 48.0% and 52.0%, respectively. Of all patients, 17.0% (Group B) reported known systemic disease, while 83.0% (Group A) reported no specific medical history. There were significant differences between Groups A and B in CBC, coagulation panel, electrolytes, and chemistry panel (P<0.05). In Group A, the results of blood tests that required a change in procedure were identified even though the proportion was very small. Conclusion: Preoperative blood tests for office-based surgery can detect underlying medical conditions that are difficult to identify from patient history alone and can prevent unexpected sequelae. In addition, such tests can result in a more professional treatment process and build patient confidence in the dentist.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.228-237
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• 2018

The purpose of this study is to develop an index to measure regional creativity factors from previous research, as well as to empirically analyze the relationship between regional creativity and regional growth. We conduct panel analysis on the balanced panel data of regional creativity in fifteen Korean cities and provinces during 2008-2012. The result of hypothesis testing are as follows: First, amongst factors of regional creativity, sub-factors such as creative personnel and intangible asset (of the basic asset factor), creative enterprise (of the economic agent factor), and convergence and creative industries (of the core industry factor) showed significant influential relationships with GRDP (Gross Regional Domestic Product) as positive. Concerning the systemization factor, all sub-factors showed no significant relationship with GRDP. Second, amongst the factors, creative personnel (of the basic asset factor), start-up and entrepreneurship (of the systemization factor), creative enterprise (of the economic agent factor), the regional space factor, and convergence industry (of the core industry factor) showed significant positive relationships with employment rate. However, tangible and intangible creative asset (of the basic asset factor), convergence management and administration (of the systemization factor), Large/middle/small enterprises and central government/municipalities (of the economic agent factor), and creative industry (of the core industry factor) showed no significant relationship with employment rate. The results of this study will provide insight into the current situation for regional creativity, and review the process and short and long term performance. In addition, it will be a basic means to lead the central government's policy of strengthening local autonomy and decentralization.

• Journal of Animal Science and Technology
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• v.58 no.4
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• pp.14.1-14.9
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• 2016

Background: Peroxisome proliferator-activated receptor gamma (PPARG), CCAAT/enhancer binding protein alpha (CEBPA) and retinoid X receptor alpha (RXRA) are nuclear transcription factors that play important roles in regulation of adipogenesis and fat deposition. The objectives of this study were to characterise the variability of these three candidate genes in a mixed sample panel composed of several cattle breeds with different meat quality, validate single nucleotide polymorphisms (SNPs) in a local crossbred population (Angus - Hereford - Limousin) and evaluate their effects on meat quality traits (backfat thickness, intramuscular fat content and fatty acid composition), supporting the association tests with bioinformatic predictive studies. Results: Globally, nine SNPs were detected in the PPARG and CEBPA genes within our mixed panel, including a novel SNP in the latter. Three of these nine, along with seven other SNPs selected from the Single Nucleotide Polymorphism database (SNPdb), including SNPs in the RXRA gene, were validated in the crossbred population (N = 260). After validation, five of these SNPs were evaluated for genotype effects on fatty acid content and composition. Significant effects were observed on backfat thickness and different fatty acid contents (P < 0.05). Some of these SNPs caused slight differences in mRNA structure stability and/or putative binding sites for proteins. Conclusions: PPARG and CEBPA showed low to moderate variability in our sample panel. Variations in these genes, along with RXRA, may explain part of the genetic variation in fat content and composition. Our results may contribute to knowledge about genetic variation in meat quality traits in cattle and should be evaluated in larger independent populations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.9-20
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• 2019

The number of natural disasters in Korea, such as earthquakes, is increasing. As a result, there is growing need for temporary residences or shelters for disaster conditions. The aim of this study was to produce post-disaster refugees housing differentiated from existing shelters using lightweight composite panels. To accomplish this, the structural performance of lightweight composite panels was validated, and an in-plane shear strength test was conducted according to the ASTM E72 criteria among the performance test methods for panels. As a result of the experiment, the maximum load for each specimen under an in-plane shear load was determined. All the experiments ended with the tear of the panel's skin section. The initial stiffness of the specimens was consistent with that predicted by the calculations. On the other hand, local crushing and tearing, as well as the characteristics of the panel, resulted in a decrease in stiffness and final failure. Specimens with an opening showed a difference in stiffness and strength from the basic experiment. The maximum load and the effective area were found to be proportional. Through this process, the allowable shear stress of the specimens was calculated and the average allowable shear stress was determined. The average ultimate shear stress of the lightweight composite panels was found to be $0.047N/mm^2$, which provides a criterion of judgement that could be used to expect the allowable load of lightweight composite panels.