• Journal of the Semiconductor & Display Technology
• /
• v.20 no.4
• /
• pp.83-88
• /
• 2021

Cloud services have become the core infrastructure of the digital economy as a basis for collecting, storing, and processing large amounts of data to trigger artificial intelligence-based services and industrial innovation. Recently, cloud services have been spotlighted as a means of responding to corporate crises and changes in the work environment in a national disaster caused by COVID-19. While the cloud is attracting attention, the speed of adoption and diffusion of cloud services is not being actively carried out due to the lack of trust among users and uncertainty about security, performance, and cost. This study compares and analyzes the "Cloud Service Quality and Performance Management System" and the "Cloud Service Certification System" and suggests complementary points and improvement measures for the cloud service quality and performance management system.

• Journal of Korean Society of Disaster and Security
• /
• v.12 no.1
• /
• pp.1-9
• /
• 2019

The basic analysis of Soil and structural mechanics for the bridge substructure affected by the flow of water is sufficient in the construction of such bridges, but the stability of scour resulting from hydraulic phenomena is insufficient. In addition, it is not enough to estimate the scour depth of the bridge which reflects the watershed characteristics of the domestic river because it uses the formula for calculating the scour depth of the overseas piers in calculating the scour depth of the bridge. In this study, the application of the CSU (1993) formula, which is currently applied to the national river design criteria, was reviewed between the two formulas after calculating the scour after calculating the scour by applying another bridge deck scour calculation formula to take into account the uncertainty in the calculation of scour. In this study, in addition to the CSU (1993) formula, which is currently applied to Korean river design criteria, another scour depth calculation formula is applied to calculate uncertainty in scour depth calculation, was reviewed between the two formulas. The review confirmed that the SSE (%) showed a difference of at least 2.08%, up to 91.23%, and SSEn(%) at least 0.19%, up to 415.91%, when compared to the measured depth of the pier based on the hydraulic model experiment and the depth of the pier calculated with the nine scour depth formulas in use. In other words, it is confirmed that there are many differences between the scouring formulas of piers. The results of this study are expected to be used to estimate scour depth in future river design.

• Journal of Korea Water Resources Association
• /
• v.30 no.6
• /
• pp.691-698
• /
• 1997

The risk assessment model for dam and levee is applied to a river where two adjacent dams are located in the upstream of the watershed. "A" dam is proven to be safe with 200-year precipitation and unsafe with PMP condition, whereas "B" dam to be safe with 200-year precipitation and PMP condition. The computed risk considering the uncertainties of the runoff coefficient. initial water depth and relevant data of the dam and spillway turn out to be equivalent results in Monte-Carlo and AFOSM method. In levee risk model, this study addresses the uncertainty of water surface elevation by Manning's equation. Monte-Carlo simulation with the variations of Manning's roughness coefficient is calculated by assuming that it follows atriangular distribution. The model can be used for preparing flood risk maps, flood warning systems, and establishing nation's flood disaster protection plan.

• Journal of Information Technology Applications and Management
• /
• v.15 no.3
• /
• pp.195-208
• /
• 2008

In an emergency management case, evaluating the economic value of information technology investments is a challenging problem due to the effects of decision making, uncertainty of disasters, and difficulty of measurements. Risk assessment and recovery process, one of the major functions in emergency management, consists of (1) measurement of damages or losses, (2) recovery planning, (3) reporting and approving budgets, (4) auctioning off recovery projects to constructors, and (5) construction for the recovery. Specifically and of our interest, measurement of damages or losses is often a costly and time-consuming process because the wide range of field surveys should be performed by a limited pool of trained agents. Managers, therefore, have to balance accuracy of the field survey against the total time to complete the survey. Using information technologies to support field survey and reporting has great potential to reduce errors and lowers the cost of the process. However, existing cost benefit analysis framework may be problematic to evaluate and justify the IT investment because the cost benefit analysis often include the long-run benefit of IT that is difficult to quantify and overlook the impact of managerial control upon the investment outcomes. Therefore, we present an alternative cost-centric control model that conservatively quantifies all cost savings to replace benefits in cost benefit analysis and incorporate the managerial control. The model provides a framework to examine how managerial decision making and uncertainty of disaster affect the economic value of IT investments. The current project in Emergency Agency in South Korea is introduced as a case to apply the cost-centric control model. Our work helps managers to better evaluate and justify IT-related investment alternatives in emergency management.

• Journal of Convergence for Information Technology
• /
• v.9 no.11
• /
• pp.125-133
• /
• 2019

In this paper, probabilistic flood risk maps were produced for levee break caused by possible flood scenarios. The results of the previous studies were employed for flood stages corresponding to hydrological extreme event quantified uncertainties and then predicted the location of a levee breach. The breach width was estimated by combining empirical equation considered constant width and numerical modeling considered uncertainties on compound geotechnical component. Accordingly, probabilistic breach outflow was computed and probabilistic inundation map was produced by 100 runs of 2D inundation simulation based on reliability analysis. The final probabilistic flood risk map was produced by combining probabilistic inundation map based on flood hazard mapping methodology. The outcomes of the study would be effective in establishing specified emergency actin plan (EAP) and expect to suggest more economical and stable design index.

• Structural Engineering and Mechanics
• /
• v.90 no.1
• /
• pp.19-26
• /
• 2024

In recent years, an increasing number of experimental studies have shown that the practical application of mature active control systems requires consideration of robustness criteria in the design process, including the reduction of tracking errors, operational resistance to external disturbances, and measurement noise, as well as robustness and stability. Good uncertainty prediction is thus proposed to solve problems caused by poor parameter selection and to remove the effects of dynamic coupling between degrees of freedom (DOF) in nonlinear systems. To overcome the stability problem, this study develops an advanced adaptive predictive fuzzy controller, which not only solves the programming problem of determining system stability but also uses the law of linear matrix inequality (LMI) to modify the fuzzy problem. The following parameters are used to manipulate the fuzzy controller of the robotic system to improve its control performance. The simulations for system uncertainty in the controller design emphasized the use of acceleration feedback for practical reasons. The simulation results also show that the proposed H∞ controller has excellent performance and reliability, and the effectiveness of the LMI-based method is also recognized. Therefore, this dynamic control method is suitable for seismic protection of civil buildings. The objectives of this document are access to adequate, safe, and affordable housing and basic services, promotion of inclusive and sustainable urbanization, implementation of sustainable disaster-resilient construction, sustainable planning, and sustainable management of human settlements. Simulation results of linear and non-linear structures demonstrate the ability of this method to identify structures and their changes due to damage. Therefore, with the continuous development of artificial intelligence and fuzzy theory, it seems that this goal will be achieved in the near future.

• Journal of the Society of Disaster Information
• /
• v.11 no.1
• /
• pp.121-133
• /
• 2015

A classical commercial insurance, which is used widely as the risk management methods for risk transferring and risk financing, includes the factors of interests, gambling and uncertainty, In 1985 Islamic Fiqc Academy declared that the classical commercial insurance violates the Islamic fundamental principles and beliefs, alteratively recommending a mutual insurance and takaful. A basic principle of takaful is the mutual aid in the Islamic community. On the basis of mutual aid, takaful participants (insurance policyholder) establishes the takaful fund, which is cooperation fund by participant contribution. Takaful fund is separated from shareholders' fund, and the profit and loss of takaful fund are responsible for takaful policyholder. Ownership and operation right of takaful belong to the takaful participants. In takaful, takaful company takes a role of agent or management operator. Comparing to the classical insurance, takaful has the rights of profit dividend, voting of executives, access to accounting books etc. which are additional favors for business company or individuals as takaful participants. Business companies and individuals should consider to use takaful to transfer risk and to enjoy takaful's additional advantages.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.25 no.5
• /
• pp.1-13
• /
• 2022

The damages caused by landslides are increasing worldwide due to climate change. In Korea, damages from landslides occur frequently, making it necessary to develop the effective response strategies. In particular, there is a lack of countermeasures against landslides in cultural heritage areas. The purpose of this study was to spatially analyze the relationship between Buyeo-gun's cultural heritage and landslide susceptible areas in Buyeo-gun, Chungcheongnam-do, which has a long history. Nine spatial distribution models were used to evaluate the landslide susceptibility, and the ensemble method was applied to reduce the uncertainty of individual model. There were 17 cultural heritages belonging to the landslide susceptible area. As a result of calculating the area ratio of the landslide susceptible area for cultural heritages, the cultural heritages with 100% of the area included in the landslide susceptible area were "Standing statue of Maae in Hongsan Sangcheon-ri" and "Statue of King Seonjo." More than 35% of "Jeungsanseong", "Garimseong", and "Standing stone statue of Maitreya Bodhisattva in Daejosa Temple" belonged to landslide susceptible areas. In order to effectively prevent landslide damage, the application of landslide prevention measures should be prioritized according to the proportion belonging to the landslide susceptible area. Since it is very difficult to restore cultural properties once destroyed, preventive measures are required before landslide damage occurs. The approach and results of this study provide basic data and guidelines for disaster response plans to prevent landslides in Buyeo-gun.

• Earthquakes and Structures
• /
• v.22 no.5
• /
• pp.503-515
• /
• 2022

This paper presents the development of seismic fragility curves for a precast reinforced concrete bridge instrumented with a structural health monitoring (SHM) system. The bridge is located near an active seismic fault in the Dominican Republic (DR) and provides the only access to several local communities in the aftermath of a potential damaging earthquake; moreover, the sample bridge was designed with outdated building codes and uses structural detailing not adequate for structures in seismic regions. The bridge was instrumented with an SHM system to extract information about its state of structural integrity and estimate its seismic performance. The data obtained from the SHM system is integrated with structural models to develop a set of fragility curves to be used as a quantitative measure of the expected damage; the fragility curves provide an estimate of the probability that the structure will exceed different damage limit states as a function of an earthquake intensity measure. To obtain the fragility curves a digital twin of the bridge is developed combining a computational finite element model and the information extracted from the SHM system. The digital twin is used as a response prediction tool that minimizes modeling uncertainty, significantly improving the predicting capability of the model and the accuracy of the fragility curves. The digital twin was used to perform a nonlinear incremental dynamic analysis (IDA) with selected ground motions that are consistent with the seismic fault and site characteristics. The fragility curves show that for the maximum expected acceleration (with a 2% probability of exceedance in 50 years) the structure has a 62% probability of undergoing extensive damage. This is the first study presenting fragility curves for civil infrastructure in the DR and the proposed methodology can be extended to other structures to support disaster mitigation and post-disaster decision-making strategies.

• Journal of the Society of Disaster Information
• /
• v.20 no.2
• /
• pp.379-389
• /
• 2024

Purpose and Method: Crowed Events can lead to sudden accidents caused by unpredictable variables. Therefore, focusing on the '10.29 Itaewon accident' among the representative cases, we examined the accident as the process of occurrence. In addition, improvement measures were suggested through analysis of related legal systems. Result: In the Itaewon accident, a "colony wave phenomenon" occurred due to "ultra-high-density cluster stay". In addition, cluster destruction occurred from a weak location in the cluster due to clusters and pressures in different directions to avoid this. Looking at the laws related to the safety management of Crowed Events, the laws and regulations differ depending on the location and type. Due to the complementary nature of the approach to the legal blind spot, the legal system that uses similar terms of the same concept and is not systematic is causing uncertainty in the application and interpretation of the law. Conclusion: Crowd control and on-site management should be carried out for events when the cluster density is expected to reach 8 people/m² or reached. Consistency should be maintained through the unified application of legislation to related legislation.