• The Journal of the Korea Contents Association
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• v.12 no.8
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• pp.388-398
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• 2012

In this study, Entropy method and PROMETHEE(Preference Ranking organization METHod for Enrichment Evaluations) which is one of the multi criteria decision making methods are applied to estimate the relative inundation risk ranking of the urban sewer systems. Then, the evaluation factors were selected considering two main items to estimate the inundation risk using Entropy and PROMETHEE. In the first item considering topographical and environmental factor, average elevation, average slope, width of area, population, density of conduit were selected as the detailed factors of first item which have influence of the overflow occurrence and damage scale in urban sewer system. And, the relative reliability of sewer network was considered as the second item which can quantify the inundation appearance. Then, the reliability is estimated considering the number of overflow nodes and overflow volume simultaneously. Therefore, the suggested inundation risk evaluation method can be used as the evaluation index for sewer networks and contribute to decision making for the sewer rehabilitation policy.

• The Journal of Korean Association of Computer Education
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• v.15 no.2
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• pp.75-81
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• 2012

As the number of web users is increasing, the leakage of personal information is increasing. If some personal information is leaked, the victim can suffer from material damage or mental damage at the same time. Most of the leakages are result from the people who works for the personal information by accident or design. Hence, the Ministry of Public Administration and Security proposeed the measuring index and enumerates the details. The index is used in a system to check protection of a personal information. However, because this system is used to evaluate after the leakage, it cannot be used to construct some security system or programming a security system. To solve this problem, it needs to express the diversity of items and be able to count what assessors want to count. Thus, a summary sheet which displays the result of the tool will be presented in a radial form graph. Details will be presented as a bar graph. Therefore, it will be proposed that the tool can grasp the weak point and propose the direction of security.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.1
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• pp.231-238
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• 2017

Water supply safety index plays an important role on assessing the water supply capacity of hydrologic system. Due to the absence of consistent guidance, however, practical problems have been brought up on data period used for dam design and performance evaluation. Therefore, this study employed bivariate drought frequency analysis which is able to consider drought severity and duration simultaneously, in order to evaluate water supply capacity of multi-purpose dams. Drought characteristics were analyzed based on the probabilistic approach, and water supply capacity of five multi-purpose dams in Korea (Soyang River, Chungju, Andong, Daecheong, Seomjin River) were evaluated under the specific drought conditions. As a result, it would be possible to have stable water supply with their own inflow during summer and fall, whereas water shortage would occur even under the 1-year return period drought event during spring and winter due to low rainfall.

• Journal of Food Hygiene and Safety
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• v.27 no.1
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• pp.87-95
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• 2012

This study was investigated to determine the contamination levels of total aerobic bacteria, coliform group, $E.$ $coli$ and food-borne pathogens of side dishes from 2 traditional markets (100 samples) and 2 super markets (100 samples) located on Ulsan. The levels (range) of total aerobic bacteria was 4.75 log CFU/g (1.60~6.92 log CFU/g) in traditional market and 4.62 log CFU/g (2.00~6.46 log CFU/g) in super market, respectively. Coliform was detected in 64 and 66 samples sold at traditional markets and super markets, respectively. $E.$ $coli$ was detected in 4 and 6 samples sold at traditional markets and super markets, respectively. The food-borne pathogens, namely $Bacillus$ $cereus$ and $Listeria$ $monocytogenes$ were detected in 1 sample sold at traditional markets, respectively, and $Bacillus$ $cereus$ was detected in 4 samples sold at super markets. However, other pathogens such as $Salmonella$ spp., $Shigella$ spp., $Vibrio$ $parahaemolyticus$, $Yersinia$ $enterocolitica$, $Clostridium$ $perfringens$, $Camphylobacter$ $jejuni$ and Pathogenic $E.$ $coli$ were not detected. The $Saengchae$ and $Seasoned$ $Jeotgal$ were relatively vulnerable compared to the others in the food-borne pathogens.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.6
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• pp.1105-1123
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• 2018

The main risk factors of tunnel excavation through urban areas are ground settlement and surface sink which caused by ground conditions, excavation method, groundwater condition, excavation length, support method, etc. In the process of ground settlement assessment, the numerical analysis should be conducted considering the displacement and stress due to tunnel excavation. Therefore a technique that can simplify such process and easily evaluate the influence of tunnel excavation is needed. This study focused on the tunnelling-induced ground settlement which is main consideration of underground safety impact assessment. The parametric numerical analyses were performed considering such parameters as ground conditions, tunnel depth, and lateral distance from tunnel center line, etc. A simplified ground settlement evaluation chart was suggested by analyzing tendency of ground subsidence, lateral influence area and character by depth. The applicability of the suggested settlement evaluation chart was verified by comparative numerical analysis of settlement characteristics.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.5
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• pp.293-307
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• 2024

In mixed traffic conditions, the conservative driving behavior of autonomous vehicles (AV) would negatively affect overall traffic performance. In order to manage mobility and safety in mixed traffic conditions, it is essential to scientifically evaluate driving behavior using autonomous driving data collected from real-world. This study proposed a methodology to evaluate the driving behavior of autonomous vehicles (AV) and manual vehicles (MV) at different types of intersections using the Waymo Open Dataset. Urban street were identified through video data, and the autonomous driving conservativeness index (ADCI) was devised to compare the difference in time-to-collision (TTC) based conflict rates between AV and MV in car following situations. The results showed that unsignalized 4-way intersections had the highest ADCI value, indicating greater conservativeness in driving behavior. This indicates the necessity of analyzing the driving behavior of each road section and deriving support measures to prevent AV from negatively affecting the overall traffic performance in mixed traffic conditions. The methodology of this study is expected to serve as foundational for analyzing factors affecting AV using real-world datasets.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.20-29
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• 2018

Owing to the changing climate and recent flood events, flood damage caused by river levee collapse and overflow is on the rise in Korea, making it necessary to enhance river levee maintenance technologies to deal with various flood damage scenarios. This paper proposes the evaluation system of a river-levee safety map to improve maintenance efficiency and disaster responsiveness. A river-levee safety map, indicating sliding, piping, visual inspection, scouring, and safety index of a levee fill material on a GIS map will enable the dangerous zone to be identified visually and the development of proactive measures to deal with it. This will maximize the river-levee maintenance efficiency, which is a break from traditional practice in that restoration measures are taken only after the damage has occurred. This study includes scouring and levee fill material in addition to previously-proposed sliding, piping and visual inspections. The research activities conducted in the study include 1) categorization of scouring and levee fill material based on document and data examination, 2) evaluation of sliding and piping at 5 locations on the left levee in the Nam river according to the duration time of the flood water level, and 3) evaluation of the characteristics of scouring and levee fill material at 9 locations on the left/right levee in the Nam River. The river levee safety map proposed in this study would be more useful and practical but further study on the manual for river management organization, repair and reinforcement methods, and budget is required.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.2
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• pp.425-433
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• 2016

In smart grid, enhancement of efficiency and interoperability of electric power system is achieved through the connection with outer network, and this induces that power grid system is threatened increasingly, becomes the main target of cyber terrorism, and is sincerely required to design the secure power system. Although SSDLC(Secure System Development Life Cycle) is used for risk management from the design phase, traditional development life cycle is somewhat limited for satisfaction of information security indicator of power control system. Despite that power control system should reflect control entities of information security considering its own characteristics, validation elements are insufficient to apply into real tasks based on existing compliance. To make design of diagnostic model and assessment process for power control system possible and to give a direction for information security and present related indicator, we propose the new risk management framework of power control system which is applied operational security controls and standard architecture presented by IEC 62351 TC 57 with enterprise risk management framework.

• Journal of the Korean Geosynthetics Society
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• v.16 no.4
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• pp.33-41
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• 2017

In this study, the increment effect of safety factor according to increasing of horizontal permeability coefficient is analyzed when geocell is installed on the slope for protection. To evaluate the horizontal permeability and reinforcement effect, the laboratory tests such horizontal permeability test were conducted. According to the laboratory test results, as the porosity rate of geocell increases, the coefficient of horizontal permeability is also increased. And also, regardless of the different types of filled materials, the coefficient of horizontal permeability is improved in a geocell reinforced ground compare with the non-reinforced ground. Laboratory test results and the rainfall intensity were applied to the numerical modeling of slope for seepage analysis and stability analysis of slope by using Soilworks, numerical analysis program. As a result of the slope stability analysis, it is confirmed that the installed geocell on the slope facilitates the drainage of water on the surface of slope. Hence, the ground water elevation is suppressed. Therefore, the safety factor of the slope is increased by the increasing of the internal friction angle, apparent cohesion, and coefficient of horizontal permeability by reinforcing the slope with geocell.

• Explosives and Blasting
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• v.22 no.1
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• pp.57-65
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• 2004

Explosive blasting in tunnel excavation produces ground vibration and air blast as its side effects, which may cause complaints from nearby residents. This study was intended to investigate the propagation characteristics of ground vibration induced by tunnel blasting and to evaluate its effects on the residential structures near the site. We have conducted field measurements for 6 blasts and acquired vibration data from 70 measuring points, some of which on positioned inside the tunnel for comparative reason. Various documentation was reviewed to determine an allowable level of peak particle velocity for the residential structures in the area and the allowable limit was set to 0.5 cm/sec. Propagation equations for peak particle velocities were derived from regression analyses using the data acquired at both the surface and the underground tunnel. Finally we proposed appropriate predictive equations for the two areas and a safe blasting criterion.