• International conference on construction engineering and project management
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• 2022.06a
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• pp.945-951
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• 2022

The major objective of this research is to evaluate performance of improved intersections for response time to emergency vehicle preemption. Smart technologies have been introduced to civil infrastructure systems for resilient communities. The technologies need to evaluate their effectiveness and feasibility to confirm their introduction. This research focuses on the performance of emergency vehicle preemption, represented by response time, when smart intersections are introduced in a community. The response time is determined by not only intersections but also a number of factors such as traffic, distance, road conditions, and incident types. However, the evaluation of emergency response has often ignored factors related to emergency vehicle routes. In this respect, this research synthetically analyzes geospatial and incident data using each route of emergency vehicle and conducts before-and-after evaluations. The changes in performance are analyzed by the impact of smart intersections on response time through Bayesian regression models. The result provides measures of the project's performance. This study will contribute to the body of knowledge on modeling the impacts of technology application and integrating heterogeneous data sets. It will provide a way to confirm and prove the effectiveness of introducing smart technologies to our communities.

• Wind and Structures
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• v.20 no.4
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• pp.527-548
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• 2015

Aeroelastic wind tunnel experiments were conducted for conventional and tapered super-tall building models to investigate the effect of taper on fundamental aeroelastic behaviors in various incident flows. Three incident flows were simulated: a turbulent boundary-layer flow representing urban area; a low-turbulent flow; and a grid-generated flow. Results were summarized focusing on the effect of taper and the effect of incident flows. The suppression of responses by introducing taper was profound in the low-turbulence flow and boundary-layer flow, but in the grid-generated flow, the response becomes larger than that of the square model when the wind is applied normal to the surface. The effects of taper and incident flows were clearly shown on the normalized responses, power spectra, stability diagrams and probability functions.

• Geomechanics and Engineering
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• v.31 no.2
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• pp.183-195
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• 2022

Under the effects of the near-field earthquakes, the incident angle of the incoming wave could be different. In this study, the influences of some parameters such as incident angle, basin edge, peak ground acceleration level of the bedrock motion as well as different clay types with different consistency on the amplification behavior of the shallow basins are investigated. To attain this goal, the numerical analyses of the basins filled with three different clay types are performed using a fully nonlinear method. The two dimensional models of the basins are subjected to a set of strong ground motions with different peak ground acceleration levels and three different incident angles of 30◦, 45◦ and 90◦ with respect to the horizontal axes. The results show the dominant effect of the obliquely subjected waves at most cases. The higher effect of the 45◦ incident angle on the basin response was concluded. In the other part of this study, the spectral amplification curves of the surface points were compared. It was seen that the maximum spectral amplification of different surface points occurs at different periods. Also, it is affected by the increase in the peak acceleration level of the incoming motions.

• Earthquakes and Structures
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• v.22 no.4
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• pp.373-386
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• 2022

The development of performance-based design methodologies requires a reasonable definition of a displacement-response spectrum. Although ground motions are known to be significantly affected by the resonant-like amplification behavior caused by multiple wave reflections within the surface soil, such a soil-resonance effect is seldom explicitly considered in current-displacement spectral models. In this study, an analytical approach is developed for the construction of displacement-response spectra by considering the soil-resonance effect. For this purpose, a simple and rational equation is proposed for the response spectral ratio at the site fundamental period (SRTg) to represent the soil-resonance effect based on wave multiple reflection theory. In addition, a bilinear model is adopted to construct the soil displacement-response spectra. The proposed model is verified by comparing its results with those obtained from actual observations and SHAKE analyses. The results show that the proposed model can lead to very good estimations of SRTg for harmonic incident seismic waves and lead to reasonable estimations of SRTg and soil displacement-response spectra for earthquakes with a relatively large magnitude, which are generally considered for seismic design, particularly in high-seismicity regions.

• Journal of Navigation and Port Research
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• v.41 no.5
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• pp.345-352
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• 2017

Recently, a new port reserves deep water depth for safe navigation and mooring, following the trend of larger ship building. Larger port facilities include long and huge breakwaters, and mainly adopt vertical type considering low construction cost. A vertical breakwater creates stem waves combining inclined incident waves and reflected waves, and this causes maneuvering difficulty to the passing vessels, and erosion of shoreline with additional damages to berthing facilities. Thus, in this study, the researchers have investigated the response of stem waves at the vertical breakwater near the entrance channel and applied numerical models, which are commonly used for the analysis of wave response at the harbor design. The basic equation composing models here adopted both the linear parabolic approximation adding the nonlinear dispersion relationship and nonlinear parabolic approximation adding a linear dispersion relationship. To analyze the applicability of both models, the research compared the numerical results with the existing hydraulic model results. The gap of serial breakwaters and aligned angles caused more complicated stem wave generation and secondary stem wave was found through the breakwater gap. Those analyzed results should be applied to ship handling simulation studies at the approaching channels, along with the mooring test.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.1
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• pp.86-99
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• 2021

One of the methods to alleviate traffic congestion is to increase the efficiency of the roads by providing traffic condition information on road user and distributing the traffic. For this, reliability must be guaranteed, and quantitative real-time traffic speed prediction is essential. In this study, and based on analysis of traffic speed related to traffic conditions, historical data correlated with traffic flow were used as input. We developed an LSTM model that predicts speed in response to normal traffic conditions, along with a CNN-LSTM model that predicts speed in response to incidents. Through these models, we try to predict traffic speeds during the hour in five-minute intervals. As a result, predictions had an average error rate of 7.43km/h for normal traffic flows, and an error rate of 7.66km/h for traffic incident flows when there was an incident.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.3
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• pp.487-498
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• 2023

Security incidents using vulnerabilities in cloud services occur, but it is difficult to collect and analyze traces of incidents in cloud environments with complex and diverse service models. As a result, the importance of cloud forensics research has emerged, and infringement response scenarios must be designed from the perspective of cloud service users (CSUs) and cloud service providers (CSPs) based on representative security threat cases in the public cloud service model. This simulated hacking-based proactive cloud infringement response framework can be used to respond to the cloud service critical resource attack process from the viewpoint of vulnerability detection before cyberattacks occur on the cloud, and can also be expected for data acquisition. Therefore, in this paper, we propose a framework for preventive cloud infringement based on simulated hacking by analyzing and utilizing Cloudfox, a cloud penetration test tool.

• Fire Science and Engineering
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• v.24 no.2
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• pp.9-20
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• 2010

This study indicates direction on establishment of the operational plan for disaster mitigation and its implementation for maintaining business continuity of the local company of the first step, and seeks plans for maintaining their continuity through the establishment of early counter system constructed for achieving lasting safe at the any disaster. For achieving it, we investigated the standard of disaster management selected by the government called "Incident Preparedness and Operational Continuity Plan" Guideline, and investigated a guideline to be easily applied to domestic companies. And, we also studied on how to build the operational plan of disaster mitigation and apply IT techniques to A corporation. Especially, this study indicates the models of establishment of risk assessment, impact analysis, prevention and mitigation plan, response management plan for the establishment of plan among 5 main steps on "Incident Preparedness and Operational Continuity Management" Guideline. We devised the plan to activate the disaster mitigation activity throughout the country. It shows the skills to be prepared to upgrade the level of disaster response in this study.

• Convergence Security Journal
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• v.22 no.2
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• pp.27-42
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• 2022

In the era of the Fourth Industrial Revolution, digital transformation to increase the effectiveness of industry is becoming more important to achieving the goal of industrial innovation. The digital new deal and smart defense are required for digital transformation and utilize artificial intelligence, big data analysis technology, and the Internet of Things. These changes can innovate the industrial fields of national defense, society, and health with new intelligent services by continuously expanding cyberspace. As a result, work productivity, efficiency, convenience, and industrial safety will be strengthened. However, the threat of cyber-attack will also continue to increase due to expansion of the new domain of digital transformation. This paper presents the risk scenarios of cyber-attack threats in the Fourth Industrial Revolution. Further, we propose a preemptive intrusion response model to bolster the complex security environment of the future, which is one of the fundamental alternatives to solving problems relating to cyber-attack. The proposed model can be used as prior research on cyber security strategy and technology development for preemptive response to cyber threats in the future society.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.6
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• pp.1123-1130
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• 2020

This study aims to classify the severity in car crashes using five classification learning models. The dataset used in this study contains 21,013 vehicle crashes, obtained from Korea Expressway Corporation, between the year of 2015-2017 and the LightGBM(Light Gradient Boosting Model) performed well with the highest accuracy. LightGBM, the number of involved vehicles, type of accident, incident location, incident lane type, types of accidents, types of vehicles involved in accidents were shown as priority factors. Based on the results of this model, the establishment of a management strategy for response of highway traffic accident should be presented through a consistent prediction process of accident severity level. This study identifies applicability of Machine Learning Models for Predicting of the Severity of Car Traffic Accidents on a Highway and suggests that various machine learning techniques based on big data that can be used in the future.