• Coupled systems mechanics
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• v.6 no.3
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• pp.229-249
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• 2017

A new technique to mitigate irregular buildings with soil structure interaction (SSI) effect subjected to critical seismic waves is presented. The L-shape in plan irregular building for various reasons was selected, subjected to seismic a load which is a big problem for structural design especially without separation gap. The L-shape in plan building with different dimensions was chosen to study, with different rectangularity ratios and various soil kinds, to show the effect of the irregular building on the seismic response. A 3D building subjected to critical earthquake was analyzed by structural analysis program (SAP2000) fixed and with SSI (three types of soils were analyzed, soft, medium and hard soils) to find their effect on top displacement, base shear, and base torsion. The straining actions were appointed and the treatment of the effect of irregular shape under critical earthquake was made by using tuned mass damper (TMD) with different configurations with SSI and without. The study improve the success of using TMDs to mitigate the effect of critical earthquake on irregular building for both cases of study as fixed base and raft foundation (SSI) with different TMDs parameters and configurations. Torsion occurs when the L-shape in plan building subjected to earthquake which may be caused harmful damage. TMDs parameters which give the most effective efficiency in the earthquake duration must be defined, that will mitigate these effects. The parameters of TMDs were studied with structure for different rectangularity ratios and soil types, with different TMD configurations. Nonlinear time history analysis is carried out by SAP2000 with El Centro earthquake wave. The numerical results of the parametric study help in understanding the seismic behavior of L-shape in plan building with TMDs mitigation system.

• Proceedings of the KSRS Conference
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• v.1
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• pp.52-55
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• 2006

It's used to be said that tsunami is a rare event. The recurrence time of tsunami in Sumatra area is approximately 230 years as CalTech Research Group‘s study from paleocoral. However, the tsunami occurred in Indian Ocean on 26 December 2004, 28 March 2005 and 17 July 2006, because the earthquakes still release the energy. To cope with the tsunami disaster, we have to put the much effort on better disaster preparedness. The Tsunami Reduction Of Impacts through three Key Actions (TROIKA) was suggested by Eddie N. Bernard, the director of NOAA/PMEL (Pacific Marine Environmental Laboratory). They are Hazard Assessment, Mitigation and Warning Guidance. The satellite remote sensing has potential on these actions. The medium and high resolution satellite data were used to assess the degree of damage at the six-damaged provinces on the Andaman seacoast of Thailand. Fast and reliable interpretation of the damage by remote sensing method can be used for inundation mapping, rehabilitation and housing plans for the victims. For tsunami mitigation, the satellite data can be used with GIS to construct the evacuation map (evacuation route and refuge site) and coastal zone management. It is also helpful for educational program for local residents and school systems. Tsunami is a kind of ocean wave, therefore any satellite sensors such as SAR, Altimeter, MODIS, Landsat, SPOT, IKONOS can detect the tsunami wave in 2004. The satellite images have shown the characteristics of tsunami wave approaching the coast. For warning, satellite data has potential for early warning to detect the tsunami wave in deep ocean, if there are enough satellite constellation to monitor and detect the first tsunami wave like the pressure gauge, seismograph and tide gauge with the DART buoy can do. Moreover, the new methods should be developed to analyse the satellite data more faster for early warning procedure.

• Journal of Korean Society on Water Environment
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• v.32 no.3
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• pp.243-252
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• 2016

In cases of water pollution accidents, accurate prediction for arrival time and concentration of contaminants in a river is essential to take proper measures and minimize their impact on downstream water intake facilities. It is critical to fully understand the behavior characteristics of contaminants on river surface, especially in case of oil spill accidents. Therefore, in this study, the effects of main parameters of advection and diffusion of contaminants were analyzed and validated by comparing the results of Lagrangian particle tracking (LPT) simulation of Environmental Fluid Dynamic Code (EFDC) model with those of Global Position System (GPS)-equipped drifter experiment. Prevention scenario modeling was accomplished by taking cases of movable weir operation into account. The simulated water level and flow velocity fluctuations agreed well with observations. There was no significant difference in the speed of surface particle movement between 5 and 10 layer modeling. Therefore, 5 layer modeling could be chosen to reduce computational time. It was found that full three dimensional modeling simulated wind effects on surface particle movements more sensitively than depth-averaged two dimensional modeling. The diffusion range of particles was linearly proportional to horizontal diffusivity by sensitivity analysis. Horizontal diffusivity estimated from the results of GPS-equipped drifter experiment was 0.096 m²/sec, which was considered to be valid for applying the LPT module in this area. Finally, the scenario analysis results showed that particle movements could be stagnant when discharge from the upstream weir was reduced, implying the possibility of securing time for mitigation actions such as oil boom installation and wiping oil contaminants. The outcomes of this study can help improve the prediction accuracy of particle tracking simulation to establish the most suitable mitigation plan considering the combination of movable weir operation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.539-546
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• 2014

The purpose of this paper is to suggest policy implications for the development of climate change plan in city scale. For a comparative case study, Changwon city in Korea and Portland city in U.S.A. were chosen. Climate change plans of both cities were analysed and compared in the perspectives of framework, climate strategies, and implementation. The findings from the comparative case study are suggested for policy implications as the followings. Firstly, the framework should be more simple and clearly integrated from goal to action plans. Secondly, more caution must be exercised for the major GHG triggers and adaptation policy measures. Finally, establishment of clear timeline is the first step of leadership in climate change plan. Coordination agencies and sustainable assessment systems for monitoring each policies are essential for the successful implementation of climate change plan.

• The Journal of the Korea Contents Association
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• v.11 no.10
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• pp.267-273
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• 2011

The purpose of this paper is to suggest the types of recovery activities and the major contents of preimpact recovery plan through theoretical review. Disaster recovery is to provide immediate support during the early recovery period necessary to return vital life support systems to minimum operation levels, and continuing to provide support until the community returns to normal. Disaster researchers distinguished 4 types in recovering from disaster as follows; an emergency period, a restoration period, a reconstruction period, and a developmental reconstruction period. And recovery measures are both short-term and long-term. Short-term measures are relief and rehabilitation and long-term measures include reconstruction. Finally, to design a preimpact recovery plan, we should define a disaster recovery organization that includes major stakeholders, identify the location of temporary housing, determine how to perform essential tasks, address the licensing and monitoring of contractors and retail price controls to ensure victims are not exploited, determine how recovery tasks will be carried out at historical sites, and recognize the recovery period as a unique time to enact policies for hazard mitigation and incorporate this objecive into the recovery planning process.

• Journal of the Korean Society of Hazard Mitigation
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• v.1 no.3 s.3
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• pp.93-102
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• 2001

In this study, the characteristics of river bed profile fluctuation are become possible to be used effectively in future estimation of Taehwa river general development plan through analysis and examination according to the effects of sediment protection weir located in the area of the estuary of Taehwa river's main channel using HEC-6 model. The flow conditions needed in analysis of the characteristics of river bed profile fluctuation refer the conditions of flow which secures 95 days in a year, flood flow, and design flood examined in the estimation of Taehwa river maintenance basic plan. First, in analysis result of river bed variation range, there is no significant variation in upstream section from Samho-gyo while there are the more active erosion and sedimentation as the more flow in downstream from Samho-gyo. Next, from the result of the capacity of sediment transfer, it is analyzed that sediment transfer capacity in the area of estuary of Taehwa river has no significant difference in before and after removal of the sediment protection weir when design flood flows while it is estimated that the more flow, the bigger sediment transfer capacity. Therefore, it is thought that the installation of a suitable hydraulic structure at the lowest point of Dong-chun tributary joins from the downstream of Taehwa river can be a good device to reduce the accumulation of sediments at the lowest point of Taehwa river considering the reduction plan of sediment inflow caused by removal of the sediment protection weir.

• Journal of Radiation Protection and Research
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• v.47 no.4
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• pp.237-245
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• 2022

Background: The current study reports measurements of activity concentrations of radon (²²⁰Rn) and thoron (²²⁰Rn) in dwellings, followed by inhalation dose assessment of the public, and then by the development of regulation and the national radon action plan (NRAP) in Cameroon. Materials and Methods: Radon, thoron, and thoron progeny measurements were carried out from 2014 to 2017 using radon-thoron discriminative detectors (commercially RADUET) in 450 dwellings and thoron progeny monitors in 350 dwellings. From 2019 to 2020, radon track detectors (commercially RADTRAK) were deployed in 1,400 dwellings. It was found that activity concentrations of radon range in 1,850 houses from 10 to 2,620 Bq/㎥ with a geometric mean of 76 Bq/㎥. Results and Discussion: Activity concentrations of thoron range from 20 to 700 Bq/㎥ with a geometric mean of 107 Bq/㎥. Thoron equilibrium factor ranges from 0.01 to 0.6, with an arithmetic mean of 0.09 that is higher than the default value of 0.02 given by UNSCEAR. On average, 49%, 9%, and 2% of all surveyed houses have radon concentrations above 100, 200, and 300 Bq/㎥, respectively. The average contribution of thoron to the inhalation dose due to radon and thoron exposure is about 40%. Thus, thoron cannot be neglected in dose assessment to avoid biased results in radio-epidemiological studies. Only radon was considered in the drafted regulation and in the NRAP adopted in October 2020. Reference levels of 300 Bq/㎥ and 1,000 Bq/㎥ were recommended for dwellings and workplaces. Conclusion: Priority actions for the coming years include the following: radon risk mapping, promotion of a protection policy against radon in buildings, integration of the radon prevention and mitigation into the training of construction specialists, mitigation of dwellings and workplaces with high radon levels, increased public awareness of the health risks associated with radon, and development of programs on the scientific and technical aspects.

• Journal of the Society of Disaster Information
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• v.11 no.1
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• pp.55-62
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• 2015

This study suggested Nationwide Inundation Analysis method for Storm and Flood Damage Insurance Rate. Suggested modified Level-Pool method considers Zoning of urban plan to reflect real inundated area and limit inundation-boundary. Inundated area, as results of modified Level-Pool method, compared with inundation risk area on "storm and flood damage mitigation total plan". Simulated inundated area by modified Level-Pool method was more matched than results of traditional method. Therefore, modified Level-Pool method could be useful to analyze nationwide inundated area.

• Journal of Environmental Impact Assessment
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• v.18 no.1
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• pp.51-57
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• 2009

Corylopsis coreana Uyeki is endemic species in the Korean peninsula and is designated a Category Endangered Plant Species by the Wildlife Protection Act of South Korea. We developed the plan and cooperative model within the local community for the species conservation. In order to carry out this plan we first investigated the ecological characteristics of the species. The species shows patterns of discontinuous distribution and is coupled with the unusual feature of only growing on northern exposed slopes. Although Corylopsis coreana is cut the stem every year, many new sprouts are still grown from the root. Natural germination of the seed occurs only on north-facing slopes, but not on south-facing slopes at spring. That is, the species is highly influenced by soil moisture until the seedling stage has been reached. This factor limits the distribution of the species. When saplings are planted on south-facing slopes, they grow well. The information we gathered greatly helped with efforts to draw up conservation plans. In addition, when the information was shared with the local community, builders and residents showed great interest and displayed a will to help with conservation efforts. Therefore, a cooperative model within the local community was drawn up for the conservation of the species. Accordingly this model could be applied at mitigation measure at environment impact assessment.

• Journal of Radiation Protection and Research
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• v.29 no.1
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• pp.57-63
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• 2004

As a part of In-service Inspection works in a nuclear power plant, Eddy Current Testing through all the outage of nuclear power plants has been controlled by the radiation management. From the case study about the periodical ECT work, the exposed dose rate of worker has announced over the organized dose rate before the radiation work, it affects the personnel exposed dose management and radiation work permit issue. It is not easy to get some information about ECT related working hours, scope of work and how many workers to forecast the radiation working and the predict dose exposure. It should be need the data accumulation about ECT related radiation work to prepare the ALARA achievement and the radiation work plan for dose mitigation. We can discuss a few information about ECT related radiation working issue for the application of predict dose exposure on this paper.