• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.4
• /
• pp.603-610
• /
• 2018

The development of industry and the increase in the use of fossil fuels have accelerated the process of global warming and climate change, resulting in more frequent and intense natural disasters than ever before. Since electricity facilities are often installed outdoors, they are heavily influenced by natural disasters and the number of related accidents is increasing. In this paper, we analyzed the statistical status of domestic electrical fires, electric shock accidents, and electrical equipment accidents and hence analyzed the risk associated with climate change. Through the analysis of the electrical accidental data in connection with the various regional (metropolitan) climatic conditions (temperature, humidity), the risk rating and charts for each region and each equipment were produced. Based on this analysis, a basic electric risk prediction model is presented and a method of displaying an electric hazard prediction map for each region and each type of electric facilities through a website or smart phone app was developed using the proposed analysis data. In addition, efforts should be made to increase the durability of the electrical equipment and improve the resistance standards to prevent future disasters.

• Journal of Convergence for Information Technology
• /
• v.10 no.10
• /
• pp.115-122
• /
• 2020

Due to the climate change, torrential rain downpours unprecedentedly, and urban areas repeatedly suffer from the inundation damages, which cause miserable loss of property and life by flooding. Two major reasons of urban flooding are river inundation and inland submergence. However, most of previous studies ignored the comprehensive mechanism of those two factors, and showed discrepancy and inadequacy due to the linear summation of each analysis result. In this study, river inundation and inland flooding were analyzed at the same time. Petrov-stabilizing scheme was adopted to capture the shock wave accurately by which river inundation can be modularized. In addition, flux-blocking alrotithm was introduced to handle the wet and dry phenomena. Sink/source terms with EGR (Exponentially Growth Rate) concept were incorporated to the shallow water equations to consider inland flooding. Comprehensive simulation implementing inland flooding and river inundation at the same time produced satisfactory results because it can reflect the counterbalancing and superposition effects, which provided accurate prediction in flooding analysis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2009.04a
• /
• pp.108-108
• /
• 2009

The main object of this research is to minimize the shock effects which frequently result in fatal damage in wind met mast on impact of barge. The collision between wind met mast and barge is generally a complex problem and it is often not practical to perform rigorous finite element analyses to include all effects and sequences during the collision. LS-dyna generally purpose explicit finite element code, which is a product of ANSYS software, is used to model and analyze the non-linear response of the met mast due to barge collision. A significant part of the collision energy is dissipated as strain energy and except for global deformation modes, the contribution from elastic straining can normally be neglected. On applying impact force of a barge to wind met mast, the maximum acceleration, internal energy and plastic strain were calculated for each load cases using the finite element method and then compare it, varying to the velocity of barge, with one varying to the thickness of rubber fender conditions. Hence, we restrict the present research mainly to the wind met mast and also parametric study has been carried out with various velocities of barge, thickness of wind met mast, thickness and Mooney-Rivlin coefficient of rubber fender with experimental data. The equation of motion of the wind met mast is derived under the assumption that it was ignored vertical movement effect of barge on sea water. Such an analyzing method which was developed so far, make it possible to determine the proper size and material properties of rubber fender and the optimal moving conditions of barge, and finally, application method can be suggested in designing process of rubber fender considering barge impact.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.11 no.2 s.54
• /
• pp.81-94
• /
• 2007

In most experimental researches on the liquefaction phenomenon, an earthquake as a random vibration has been regraded as a sinusoidal wave or a triangular wave with an equivalent amplitude. Together with the development in the part of signal control and data acquisition, dynamic experimental equipments in the soil dynamics have also developed rapidly and further more, several real earthquakes have been simulated in the large model test such as shaking table tests and centrifuge tests. In Korea, several elementary laboratory tests to simulate the real earthquake load were performed. From these test results, it was reported that the sinusoidal wave cannot reliably reflect the soil dynamic behavior under the real earthquake motion. In this study, 4 types of dynamic motions such as the sinusoidal wave, the triangular wave, the incremental triangular wave and several real earthquake motions which were classified with shock-type and vibration-type were loaded to find something new to explain the change of the excess pore water pressure under the real earthquake load. Through the detailed investigation and comparison on all test results, it is found that the dynamic flow is generated by the soil plastic deformation and the velocity head of dynamic flow is changed the pressure head in the un-drained condition. It can be concluded that the change of the excess pore water pressure is related to the pressure head of dynamic flow. Lastly, a new hypothesis to explain such a liquefaction initiation phenomenon under the real earthquake load is also proposed and verified.

• Child Health Nursing Research
• /
• v.7 no.4
• /
• pp.494-510
• /
• 2001

As a family respond to any stressful situation as a whole system, cancer diagnosis of a child, as a serious life event, could be emotional shock to destroy homeostasis of the family system. A family has a resilient capacity to adjust and adapt to stressful events. Previous studies have been focused on family stress and adaptation, but little attention has been given to family value as one of resilient factors. The data for model testing were collected from July 18, 2000 to August 30, 2000 and the analysis included 309 parents of children who are diagnosed as cancer, 18 or less years of age, and treated either hospitalized or at the outpatient clinics. The data analysis utilized SAS 6.12 and LISREL 8 for descriptive statistics, correlation, cluster analysis, factor analysis, and LISREL. The study findings are as follows. 1) Monthly income (γ=-0.28, t=-5.81) was the most important factor to explain family strain along with family support (γ=-0.11, t=-2.43), severity of children's illness (γ=0.26, t=5.22), and family stressor (γ=0.22, t=4.62). All of these factors together explained 40％ of variance in family strain. 2) Among general family value, the relationship with the parents (γ=0.28, t=4.89) and relationship with the children (γ=0.20, t=3.60) showed positive effects to family value for cancer children, while relationship with the spouse (γ=-0.19, t=-3.22) and the age of the cancer children (γ=-0.11, t=-2.21) showed negative effects. These predictors together explained 22％ of variance in family value for cancer children. 3) Family hardiness was explained mostly by family strain (γ=-0.53, t=-8.65) along with direct negative effects of family persistency and indirect negative effects of severity of children's illness, family stressor, relationship with the spouse, and the children's age. Family value for cancer children was the most important predictor with positive effect (γ=0.44, t=6.76) along with indirect effects of monthly income, relationship with the parents, relationship with the children, support from family and significant others, and confidence with the health professionals. 51％ of variance in family hardiness was explained by all of these predictors. 4) The most important predictor for family adaptation was family stressor (γ=-0.50, t=-6.85) with direct and indirect negative effects along with the severity of children's illness (γ=-0.27, t=-5.21). However, family value for cancer children showed compromised total effect (γ=-0.13, t=-1.99) with negative direct effects (γ=-0.28, t=-3.43) and positive indirect effects (γ=0.14, t=3.01). Similarly, confidence with the health professionals also showed compromised total effect (γ=0.09, t=1.99) with positive direct effects and negative indirect effects. Family hardiness showed the biggest positive direct effects while other factors such as monthly income, family stressor, family persistence, support of family and significant others, relationship with the parents, relationship with the children, and relationship with the spouse, and children's age showed indirect effects only. 39％ of variance in family adaptation was explained by all of these predictors.

• Korean Journal of Social Welfare
• /
• v.53
• /
• pp.155-178
• /
• 2003

Traditionally, the Sozialdemokratitische Partei Deutschlands(SPD) guards strictly radical welfare conception and intends to support the disabled with universal welfare-political instruments. After the oil-shock in 1973, European welfare states including Germany had experienced stark financial crisis because of economic unstability and increasing social expenditure. The political direction of SPD has been gradually changed. This transformation has been reflected automatically on the welfare policy for the disabled. In Germany, Gerhard Schroeder who leads the SPD governs since 1998. The Schroeder's new conception of welfare policy is known as the Third Way("neue Mitte") that the social economic structure intends to neo-liberalistic trend. The concern on the employment policy for the disabled has grown recently in neo-liberalistic age, but research on German employment policy for the disabled is very limited in quantity and depth. The main purpose of this study is to examine how the employment policy for the disabled of Schroeder-government has been developing in Germany. And this paper evaluates the effect of transforming policy. Based on this evaluation, this paper attempts to manifest the problem of Korean employment policy for the disabled and to find the implications of German model.

• Journal of the Korean Society of Safety
• /
• v.31 no.3
• /
• pp.8-15
• /
• 2016

The purpose of this study is to design a model with the structural stability so as not to lose the operational function due to structural plastic or fail of a sliding blast door by blast pressure to this aim, a numerical simulation was performed using full-size experiments and M&S (Modeling & Simulation) of the sliding blast door. The sliding blast door ($W3,000{\times}H2,500mm$) under the blast load is in the form of a sliding type 2-way metal grill, which was applied by a design blast pressure (reflected pressure $P_r$) of 17 bar. According to the experimental results of a real sliding blast door under blast load, the blast pressure reached the sliding blast door approximately 4.3 ms after the explosion and lasted about 4.0 ms thereafter. The maximum blast pressure($P_r$) was 347.7 psi (2,397.3 kPa), it is similar to the UFC 3-340-02 of Parameter(91 %). In addition, operation inspection that was conducted for the sliding blast door after real test showed a problem of losing the door opening function, which was because of the fail of the Reversal Bolt that was installed to prevent the shock due to rebound of the blast door from the blast pressure. According to the reproduction of the experiment through M&S by applying the blast pressure measurement value of the full-size experiments, the sliding blast door showed a similar result to the full-size experiment in that the reversal bolt part failed to lose the function. In addition, as the pressure is concentrated on the failed reversal bolt, the Principal Tensile Failure Stress was exceeded in only 1.25 ms after the explosion, and the reversal bolt completely failed after 5.4 ms. Based on the result of the failed reversal bolt through the full-size experiment and M&S, the shape and size of the bolts were changed to re-design the M&S and re-analyze the sliding blast door. According to the M&S re-analysis result when the reversal bolt was designed in a square of 25 mm ($625mm^2$), the maximum pressure that the reversal bolt receives showed 81% of the principal tensile failure stress of the material, in plastic stage before fail.

• Explosives and Blasting
• /
• v.36 no.4
• /
• pp.1-8
• /
• 2018

This numerical study was intended to evaluate the applicability of the half charge blasting to mining and tunnelling. The half charge blasting is a method that two separate rounds are sequentially blasted for the rock burdens in which long blast holes have already been drilled at one operation. The aim of the method is to decrease the construction cost and period in mining and tunnelling projects as well as to increase the blasting efficiency. Several numerical analyses were conducted by using the Euler-Lagrange solver on ANSYS AUTODYN to identify the effects of the suggested method on the blasting results in underground excavations. The overall performance of the suggested method was also compared to an ordinary blasting method. The analysis model was comprised of the Eulerian parts (explosive, air, and stemming materials) and the Lagrangian parts (rock material). As a result, it was found that, owing to the air decks formed in the bottom parts of the long blast holes, the first round of the suggested method presented a higher shock pressure and particle velocities in the vicinity of the blast holes compared to the ordinary blasting method.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.35 no.2
• /
• pp.131-140
• /
• 2022

Installing Continuous Welded Rail (CWR) is one of the economical ways to resolve the challenges of noise, vibration, and the open-deck steel railway bridge impact, and the SSF method using the interlocking sleeper fastener has recently been developed. In this study, the method employed for determining the optimum vertical stiffness of the sleeper pad installed under the bridge sleeper, which is utilized to adjust the rail height and absorb shock when the train passes when the interlocking sleeper fastener is applied, is presented. To determine the optimal vertical stiffness of the sleeper pad, related existing design codes are reviewed, and, running safety, ride comfort, track safety, and bridge vibration according to the change in the vertical stiffness of the sleeper pad are estimated via flexible multi-body dynamic analysis,. The flexible multi-body dynamic analysis is performed using commercial programs ABAQUS and VI-Rail. The numerical analysis is conducted using the bridge model for a 30m-long plate girder bridge, and the response is calculated when passing ITX Saemaeul and KTX vehicles and freight wagon when the vertical stiffness of the sleeper pad is altered from 7.5 kN/mm to 240 kN/mm. The optimum stiffness of the sleeper pad is calculated as 200 kN/mm under the conditions of the track components applied to the numerical analysis.

• Economic Analysis
• /
• v.27 no.3
• /
• pp.1-32
• /
• 2021

This study empirically analyzes whether bank capital channel and risk-taking channel for monetary policy work for domestic banks in South Korea by analyzing the impact of the expansionary monetary policy on the rate spread between deposit and loan, capital ratio, and loan amount. For the empirical analysis, the Uhlig (2005)'s sign-restricted SVAR(Structural Vector Auto-Regression) model is used. The empirical results are as follows: the bank's interest rate margin increases, the capital ratio improves, risk-weighted asset ratio increases, and the amount of loans increases in response to expansionary monetary shock. This empirical results confirm that bank capital channel and risk-taking channel work in domestic banks, similar to the previous research results. The implications of this study are as follows. Although the expansionary monetary policy has the effect of improving the bank's financial soundness and profitability in the short term as bank capital channel works, it could negatively affect the soundness of banks by encouraging banks to pursue risk in the long run as risk-taking channel works. It is necessary to note that the capital ratio according to the BIS minimum capital requirement of individual banks may cause an illusion in supervising the soundness of the bank. So, the bank's aggressive lending expansion may lead to an inherent weakness in the event of a crisis. Since the financial authority may have an illusion about the bank's financial soundness if the low interest rate persists, the authority needs to be actively interested in stress tests and concentration risk management in the pillar 2 of the BIS capital accord. In addition, since system risk may increase, it is necessary to conduct regular stress tests or preemptive monitoring of assets concentration risk.