• Journal of the Ergonomics Society of Korea
• /
• v.30 no.1
• /
• pp.213-220
• /
• 2011

Objective: The aim of this study was to investigate middle-aged drivers' driving performance and heart-rate as the behavior and physiological changes due to intersection types in left-turn situation. Background: In Korea, the drivers were aged 40~50s are most plentiful. In addition, the intersection traffic accidents are increasing every year. However, the researches for middle-aged drivers and intersection environments have been little. Method: In this study, three kinds of left-turning intersection types(T1, T2, T3) was used as the within-subject independent variables, three age groups(young, middle-aged, elderly) was used as the between-subject independent variables. Also, passing time, approaching velocity, speed and steering variations and heart-rate were used as dependent variables. Results: Overall, middle-aged drivers' driving behaviors were similar to those of the younger drivers. At the T2 intersection type, however, the approaching velocity of middle-aged drivers was similar to younger drivers, whereas the passing time of middle-aged drivers was similar to elderly drivers. Conclusion: These results could be interpreted that a transition driving behavior of middle-aged drivers in terms of age would be appeared on the T2 intersection type. Application: The results might help to understand the characteristics of driving behavior for middle-aged drivers.

• Nuclear Engineering and Technology
• /
• v.41 no.5
• /
• pp.617-648
• /
• 2009

Under the government supported long-term nuclear R&D program, the severe accident research program at KAERI is directed to investigate unresolved severe accident issues such as core debris coolability, steam explosions, and hydrogen combustion both experimentally and numerically. Extensive studies have been performed to evaluate the in-vessel retention of core debris through external reactor vessel cooling concept for APR1400 as a severe accident management strategy. Additionally, an improvement of the insulator design outside the vessel was investigated. To address steam explosions, a series of experiments using a prototypic material was performed in the TROI facility. Major parameters such as material composition and void fraction as well as the relevant physics affecting the energetics of steam explosions were investigated. For hydrogen control in Korean nuclear power plants, evaluation of the hydrogen concentration and the possibility of deflagration-to-detonation transition occurrence in the containment using three-dimensional analysis code, GASFLOW, were performed. Finally, the integrated severe accident analysis code, MIDAS, has been developed for domestication based on MELCOR. The data transfer scheme using pointers was restructured with the modules and the derived-type direct variables using FORTRAN90. New models were implemented to extend the capability of MIDAS.

• The Journal of the Korea Contents Association
• /
• v.14 no.1
• /
• pp.386-399
• /
• 2014

Following the heightened facilitation of information system in the education field, educational institutions encounter frequent information security infringement accidents. However there is insufficient education for persons in charge of information security duties in educational institutions. This study aims to analyze differences of knowledge and skills required for information security professionals in educational institutions by institution type, service area and duty. Based on the results of multidimensional scaling on survey data, this study presents the information security education framework for educational institutions.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.23 no.2
• /
• pp.1-6
• /
• 2015

The RSA is intended to prevent the following five types of events from becoming an accident: landing overruns, landing undershoots, landing veer-offs, takeoff overruns and takeoff veer-offs. The improved models are based on evidence from worldwide accidents and incidents that occurred during the past 27 years. The analysis utilizes historical data from the specific airport and allows the user to take into consideration specific operational conditions to which movements are subject, as well as the actual or planned RSA conditions in terms of dimensions, configuration, type of terrain, and boundaries defined by existing obstacles. This paper shows how to apply the improved models for Risk Assessment of Runway Safety Areas (Airport cooperative research program(ACRP) Report 50) into an airport and the outcome differences between the old models based on ACRP report 3-Analysis of aircraft overrun and undershoots for runway safety areas and the new models from ACRP report 50 in the specific airport.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.18 no.6
• /
• pp.301-308
• /
• 2014

A suspension bridge is a type of bridge in which the beam is suspended by load-bearing cables. There are two classifications: the self-anchored suspension bridge has the main cable anchored to the bridge girders, and the earth-anchored suspension bridge has the main cable anchored to a large anchorage. Although a suspension bridge is structurally safe, it is prone to be damaged by various actions such as hurricanes, tsunamis and terrorist incidents because its cables are exposed. If damage to a cable eventually leads to the cable rupture, the bridge may collapse. To avoid these accidents, studies on the dynamic behavior of cable bridges due to the cable rupture have been carried out. Design codes specify that the calculated DAF (dynamic amplification factor) should not exceed a certain value. However, it has been difficult to determine DAFs effectively from dynamic analysis, and thus no systematic approach has been suggested. The current study provides a guideline to determine DAFs reliably from the dynamic analysis results and summarizes the results by applying the method to an earth-anchored suspension bridge. In the study, DAFs were calculated at the location of four structural parts, girders, pylons, main cable and hangers, with variations in the rupture time.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.21 no.1
• /
• pp.80-86
• /
• 2013

In an effort to decrease aviation accident worldwide, development of aviation safety management has been sought through aviation index and standardization, both by establishing SMS(Safety Management System). It also needs to be done in the domestic. both study on SMS which ICAO recommends and setting the top priority safety goal, each differently classified by nations. Accordingly, defining safety index and developing continuous monitoring approach. Aircraft accident reporting system in Air Force does not operate in a open approach method due to its uniqueness related to mission achievement. Therefore, limits of utilizing the recent worldwide aircraft data sharing and analyzing results to prevent accident is inevitable. This paper introduces an overview of ECCAIRS 5 which become the standard for the recent worldwide aviation safety reporting and data exchange system. Also using ECCAIRS 5, aircraft accident cases of the Air Force are classified such as accident type, year, month, occurrence category, and flight phase. The result of the study will provide a guide line for utilizing the civil system in prevention of future military aviation accidents.

• International Journal of Highway Engineering
• /
• v.19 no.6
• /
• pp.147-153
• /
• 2017

PURPOSES : This research aims to estimate the occurrence of hydroplaning on roads based on the road alignment types and rainfall intensity in Seoul. METHODS : Three types of data were used for estimation of hydroplaning in this study. The Inner Circulation Road (12.5 km) to the Bukbu Expressway (7.4 km) in Seoul was selected as the test road and data was collected for road information using a probe-vehicle. Precipitation was observed from Automatic Weather System in Seoul. These data were interpolated by applying Inverse Distance Weighted Methodology for hydroplaning estimation. Finally, the water depth information of the roads was observed using an RCM411 device. RESULTS : This study demonstrated that the cross slope with small-angle-tilt or vertical section with large-angle-tilt are the primary factors causing hydroplaning on the roads. The flow velocity on steep slope is high; however, large drainage lengths result in hydroplaning on the roads. CONCLUSIONS : This result can contribute towards the reduction of car accidents on rainy days. Furthermore, information regarding hydroplaning can be delivered to drivers more rapidly and precisely in the future.

• Smart Media Journal
• /
• v.5 no.3
• /
• pp.81-87
• /
• 2016

In line with the sharp increase of container traffic from globalization, ships have become larger with an aim of improving the maritime transport capacity in addition to the growing interest in monitoring danger areas on ships considering the quantity increase of ships, along with the tightening of international standard for ship safety by IMO(international Maritime Organization). Korea established a location based ship accident forecasting and preventing system in 2012 by Korea Coast Guard, however its poor response in ship accidents has been pointed out in the wake of the recent disaster of Sewol ferry. To resolve this problem, this study attempts to design a wearable type, instant emergency response system that has DGPS to issue an alert on danger areas and automatically send ship's location and operation information in emergency situation.

• Journal of Ocean Engineering and Technology
• /
• v.38 no.3
• /
• pp.124-136
• /
• 2024

As the number of offshore wind-power installations increases, collision accidents with vessels occur more frequently. This study investigates the risk of collision damage with operating vessels that may occur during the operation of an offshore wind turbine. The floater used in the collision study is a 15 MW UMaine VolturnUS-S (semi-submersible type), and the colliding ships are selected as multi-purpose vessels, service operation vessels, or anchor-handling tug ships based on their operational purpose. Collision analysis is performed using ABAQUS and substantiation is performed via a drop impact test. The collision analyses are conducted by varying the ship velocity, displacement, collision angle, and ship shape. By applying this numerical model, the extent of damage and deformation of the collision area is confirmed. The analysis results show that a vessel with a bulbous bow can cause flooding, depending on the collision conditions. For damage caused by collision, various collision angles must be considered based on the internal stiffener arrangement. Additionally, the floater can be flooded with relatively small collision energy when the colliding vessel has a bulbous bow.

• Journal of Korean Society of Transportation
• /
• v.24 no.1 s.87
• /
• pp.39-52
• /
• 2006

This study divided the large-scale traffic accident locations into its own characteristics by using Cluster Analysis. Also, Quantification II and Classification and Regression Tree methods were used enabling evaluation for the amount of affecting influence by the crash type. After these analyses, we tested the fitness of the results and suggested the simplification of the quantification index. With the results from the discussed procedure, obvious differences were observed by groups according to the characteristics of crash type from the Discrimination and Classification analysis of divided four groups. Thus, measures and supplementary measures for the traffic accidents could be suggested in groups systematically. However, a lot of missing values in variables caused a huge loss of data and made this study difficult for more detailed analysis, With this difficulty. recording mandatory log files with a standardized format is also recommended to Prevent this Problem in advance.