• Journal of Korea Water Resources Association
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• v.53 no.12
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• pp.1183-1192
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• 2020

Economic analysis is a basic step in establishing disaster mitigation measures, but it is difficult to verify the results due to uncertainty. Therefore, the scope of investigation and analysis is wide. However, it is difficult to predict the amount of damage caused by flooding because the collection of relevant data is limited in the ungauged basin. In this study, distributed runoff analysis and flooding analysis were performed, and a method of estimating the amount of flood damage in the ungauged basin was proposed using collectible social and economic indicators and flood analysis results. For distributed runoff analysis and flooding analysis, GRM (Grid based Rainfall-runoff Model) and G2D (Grid based 2-Dimensional land surface flood model) developed by Korea Institute of Civil engineering and Building Technology were used. The method of substituting collectible social and economic indicators into the simple method and improvement method was used to estimate the amount of flood damage. As a result of the study, it was possible to estimate the amount of flood damage using satellite data and social and economic indicators in the ungauged basin.

• Journal of Digital Contents Society
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• v.19 no.4
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• pp.771-777
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• 2018

This study proposes a big data based risk analysis framework to analyze more comprehensive disaster risk and vulnerability. We introduce a distributed and parallel framework that allows large volumes of data to be processed in a short time by using open-source disaster risk assessment tool. A performance analysis of the proposed system presents that it achieves a more faster processing time than that of the existing system and it will be possible to respond promptly to precise prediction and contribute to providing guideline to disaster countermeasures. Proposed system is able to support accurate risk prediction and mitigate severe damage, therefore will be crucial to giving decision makers or experts to prepare for emergency or disaster situation, and minimizing large scale damage to a region.

• Journal of the Earthquake Engineering Society of Korea
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• v.28 no.1
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• pp.47-57
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• 2024

Recently, in newly constructed apartment buildings, the exterior wall structures have been characterized by thinness, having various openings, and a significantly low reinforcement ratio. In this study, a nonlinear finite element analysis was performed to investigate the crack damage characteristics of the exterior wall structure. The limited analysis models for a 10-story exterior wall were constructed based on the prototype apartment building, and nonlinear static analysis (push-over analysis) was performed. Based on the finite element (FE) analysis model, the parametric study was conducted to investigate the effects of various design parameters on the strength and crack width of the exterior walls. As the parameters, the vertical reinforcement ratio and horizontal reinforcement ratio of the wall, as well as the uniformly distributed longitudinal reinforcement ratio and shear reinforcement ratio of the connection beam, were addressed. The analysis results showed that the strength and deformation capacity of the prototype exterior walls were limited by the failure of the connection beam prior to the flexural yielding of the walls. Thus, the increase of wall reinforcement limitedly affected the failure modes, peak strengths, and crack damages. On the other hand, when the reinforcement ratio of the connection beams was increased, the peak strength was increased due to the increase in the load-carrying capacity of the connection beams. Further, the crack damage index decreased as the reinforcement ratio of the connection beam increased. In particular, it was more effective to increase the uniformly distributed longitudinal reinforcement ratio in the connection beams to decrease the crack damage of the coupling beams, regardless of the type of the prototype exterior walls.

• Structural Engineering and Mechanics
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• v.15 no.3
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• pp.285-297
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• 2003

Complementing recent advances made in the field of structural health monitoring and damage detection, the concept of a wireless sensing network with distributed computational power is proposed. The fundamental building block of the proposed sensing network is a wireless sensing unit capable of acquiring measurement data, interrogating the data and transmitting the data in real time. The computational core of a prototype wireless sensing unit can potentially be utilized for execution of embedded engineering analyses such as damage detection and system identification. To illustrate the computational capabilities of the proposed wireless sensing unit, the fast Fourier transform and auto-regressive time-series modeling are locally executed by the unit. Fast Fourier transforms and auto-regressive models are two important techniques that have been previously used for the identification of damage in structural systems. Their embedment illustrates the computational capabilities of the prototype wireless sensing unit and suggests strong potential for unit installation in automated structural health monitoring systems.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.4 s.235
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• pp.511-517
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• 2005

Fretting fatigue is often the root cause of the nucleation of cracks at attachments of structural components. Since fretting fatigue damage accumulation occurs over relatively small volumes, the subsurface cyclic plastic strain is expected to be rather non-uniformly distributed in polycrystalline materials. The scale of the cyclic plasticity and the damage process zones is often on the order of microstructure dimensions. Fretting damage analyses using cyclic crystal plasticity constitutive models have the potential to account for the influence of size, morphology, and crystallographic orientation of grains on fretting damage evolution. Two-dimensional plane strain simulations of fretting fatigue are performed using the cyclic properties of Ti-6Al-4V. The crystal plasticity simulations are compared to an initially isotropic $J_{2}$ theory with nonlinear kinematic hardening as well as to experiments. The influence of initially isotropic versus textured microstructure in the presence of crystallographic slip is studied.

• The Korea Journal of Herbology
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• v.35 no.1
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• pp.19-25
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• 2020

Objects : The daily dose of Pinelliae Tuber in ≪Treatise on Cold Damage Diseases≫ is half seung in volume, two and half ryang in weight, and fifteen in total number. But the daily dose should be a whole number. So I found out the background of this setting and correct solution. Methods : I searched Classics of Traditional Medicine, found out the background of the daily dose setting, solution. Results : The daily dose of Pinelliae tuber in ≪Hangdi's Internal Classic Miraculous Pivot≫, ≪Bohenggyuljangbuyongyakbeobyo≫ is half seung. ≪Treatise on Cold Dameage Diseases≫ followed the same daily dose of that because it referred to these books. In ≪Synopsis of Prescription of the Golden Chamber≫, the daily dose of that is half seung, one or two seung. The half seung of the Pinelliae Tuber is thirty three mL, but the diameter is 1~1.5 cm that accurate measurement by volume is difficult. The daily dose by weight is correct considering the unity of marking of the daily dose, accuracy of measurement, the fact that Pinelliae Tuber is currently distributed by cutting. So, two ryang is correct which is thirteen gram. Conclusions : Considering the traditionality, the convenience of measurement, the daily dose of Pinelliae Tuber in the ≪Treatise on Cold Damage Diseases≫ is half seung, but considering the unity, accuracy, current state of distribution, it is correct that the daily dose of it is two ryang. It corresponds to thirteen gram.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.195-196
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• 2021

The pore distribution of the cement mortar mixed with carbon nanotubes was found to have a large number of pores at (370~80)㎛, and the distribution ratio was larger as the carbon nanotubes were mixed. However, the pores with a fine particle diameter of (10-0.5) ㎛ were found to be larger as the carbon nanotubes were incorporated. However, the distribution of pores of the test specimens of conductive cement mortar with deterioration damage was found to be distributed in a number of particle diameters of (500 to 100) ㎛ and (10 to 0.5) ㎛. It is judged that the particle diameter of the internal pores increased due to the damage. However, as the mixing ratio of the test specimen with carbon nanotubes increased, the distribution of voids was relatively lower than that of plain, and it was judged to have excellent resistance to deterioration damage.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.3
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• pp.246-253
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• 2011

This paper presents estimation of deterministic damage extents and locations due to collision and grounding which are defined by ABS guideline and DNV ship rules. It is noted that the overall extents of damages from DNV are larger than those from ABS. Nonlinear FEAs are carried out to predict residual longitudinal strength of hull girder with asymmetric severe damages. The accuracy of the applied FEA procedure is proved by comparing FEA result with test result of a 1/3-scaled frigate. The investigated vessels are a VLCC and a large-sized bulker for which evenly distributed heeling angles from $0^{\circ}$(sagging) to $180^{\circ}$(hogging) by $30^{\circ}$ due to damage-induced flooding are taken into account. The reduction ratios of the ultimate residual strength for the damaged cases to those for the intact sagging case are shown. It is proved that the grounding damage case under DNV assumption reveals most critical the residual strength. The design formulas are presented to assure minimum residual ultimate moment after damage.

• Magazine of the Korean Society of Agricultural Engineers
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• v.25 no.4
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• pp.61-68
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• 1983

In order to study the disaster of typhoons which hit the Korean peninsula a period of 22 years from 1959 through 1980 was covered to collect necessary data with respect to attack of typhoons and their damage. Centering around the Korean peninsula, typhoons which attacked between 1959 and 1980 were grouped according to their treking routes and damage for detailed analyses. The results are summarized as follows: 1. The average annual damage of typhoons in the Korean peninsula was found to be 1.27 from June to September. The monthly distributions were found to be 53.6% in August, 28.6% in September and 14.2% in July. 2. About an half (56.4%) of the typhoons which hit the Korean peninsula passed through the western coast and 27.3% through the southern and 14.6% through the eastern. Typhoons of the we8tern coast were divided by their treking routes as 25.5% in CWE type (Jul., Aug., Sep.), 14.6% in WE type (Jul., Aug.), 16.3% in W type (Jul.). 3. The minimum SLP averaged 976.6mb and ordere:l by the treking routes as E$_1$$_1$ and CWE types are higher 20mb than S, E or WE types. 4. The Korean peninsula was damaged by all number of the typhoons in WE or S type, by a third at number of its in E or WE and WI type. 5. The annual probabilities of typhoon-disasters were 0.773 for once or more, 0. 409 for twice or more, and 0.091 for three times or more. Hearvy damage experienced in the Korean peninsula are found to have an annual. 6. Amount of the damage by the treking routes in ordered S>WE>CWE>E>W$_1$, and heavy storms experienced in the Xorean peninsula are found to have accompanied the WE and S types during the months of August and September. 7. The average annual damages were found to be 110 at the death-tall, 45, 000 at the sufferers and 10.5 billion at the property damage. 8. Seventy-sex percent of the all damage in the Korean peninsula distributed on the district from the 36th Parallel south and included Chie Ju island.