• Journal of Korean Society of Transportation
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• v.35 no.5
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• pp.423-433
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• 2017

During recent 5 years, it was recorded that 20% of total accident frequency and 30% of total number of death have been occurred due to drowsy driving. Drowsy driving accident is result from the loss of driving ability due to driver's accumulated fatigue. Continuous driving time can be measured as a surrogate variable to quantify the level of fatigue. The main purpose of this research is to investigate statistical correlation between the proportion of continuous driving vehicle (more than 2 hours) and the number of drowsy accidents. To carry this out, continuous driving time was measured using GPS route-guidance trajectory data. Also, accident frequency, traffic volume and segment length were collected to estimate safety performance function (SPF) for Jungbunearuk expressway in Korea. Through various types of estimated SPFs, statistical correlation was analyzed based on estimated statistical indices. This research can provide theoretical background for enforcement to regulate commercial vehicle driver's continuous driving time. In addition, throughout the trajectory data expansion, it is expected that strategy for anti-drowsy driving facilities installation can be established based on the suggested methodology.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.925-932
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• 2018

This study deals with Turbo-Roundabout of Special-Roundabouts. Recently, many rotary intersections are being constructed in Korea, but the effect of the rotary intersection depends on the total entrance traffic volume and the area of the paper. The purpose of this study is to analyze the operation and accident reduction effect of turning traffic signal intersection with small traffic volume into turbo - type turning intersection. The main results are as follows. First, when the traffic volume of the main road is high, the traffic volume of the subway is less than 10 ~ 15%, or when the left turn ratio is less than 30%, it is improved when switching to the turbo type turn intersection instead of the first turn type and second turn type turn intersection Was analyzed. Second, it is considered that turbo type rotary intersection is more effective than first - type rotary intersection, and it is more effective in increasing road capacity because the area of paper is smaller than that of second - order rotary intersection. Third, the number of traffic accidents decreased by 45.9% and the number of injured persons decreased by 76.5% after the conversion of the turnover type turnover to turbo type. 100%), the number of car accidents was 0.3, and the number of casualties was 0 (100%). Finally, the positive evaluation of the user satisfaction survey showed that the improvement in safety, accessibility, and convenience was improved by 60.4%, which was improved by 16.4% to 76.8% after the conversion to the turbo type turnover.

• Education of Primary School Mathematics
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• v.20 no.1
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• pp.53-68
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• 2017

Although the table, as one of the representations for helping mathematics understanding, steadily has been shown in the mathematics textbooks, there have been little studies that focus on the table and analyze how the table may be used in understanding students' functional thinking. This study investigated the elementary school 5th graders' abilities to design function tables. The results showed that about 75% of the students were able to create tables for themselves, which shaped horizontal and included information only from the problem contexts. And the students had more difficulties in solving geometric growing pattern problems than story problems. Building on these results, this paper is expected to provide implications of instructional directions of how to use the table as 'function table'.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.632-634
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• 2021

In proportion to the development of the Internet and the increase in users, the rate of cyber-incident using it is increasing. As a countermeasure, there is a network separation method that separates the system accessible to users and the system containing key information from each other. However, in the case of tasks that require the use of the Internet network, it is exposed to cyber attacks, and there are many loopholes in the method of data transmission between networks and the management and operation of the system, resulting in infection of the closed network. In this paper, we aim to enhance the safety of the networking system by investigating the types and cases of infringement accidents in these network separation environments.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.2
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• pp.168-176
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• 2017

HNS accidents involve large-scale fires and explosions, causing numerous human casualties and extreme environmental pollution in the surrounding area. The widespread diffusion of effects should be prevented through rapid decision making. In this study, a high-quality, standardized, and digitized HNS accident databases has been generated based on the HNS standard code proposed. Furthermore, the HNS Accident Tracking System (HATS) was applied and implemented to allow for systematic integration management and sharing. In addition, statistical analysis was performed on 76 cases of domestic HNS accident data collected over 23 years using HATS. In Korea, an average of 3.3 HNS accidents occurred each year and major HNS accident factors were Springs (41 %), Aprons (51 %), Chemical Carriers (49 %), Crew's Fault (45 %) and Xylenes (12 %). (The number in parentheses is the percentage of HNS accident factors for each HNS accident classification)

• Journal of Korean Society of Transportation
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• v.30 no.5
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• pp.3-10
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• 2012

This study dealt with traffic accidents occurring within roundabouts. The objective was to develop roundabout accident models for different driving types by using simultaneous equations. In pursuing the above, this study used a statistical program SPSS 17.0 to accommodate data from 148 accidents occurred within 39 roundabouts of Korea. In addition, the 2SLS(2 stage least square) estimation method was adopted to calibrate the models. The main results are as follows. First, both the number of accidents and the EPDO were evaluated to have bilateral relationships. Second, all 6 different simultaneous equation models according to driving types were found to be statistically significant. Third, the developed models were compared to each other with respect to either common or specific variables. Finally, variables such as ADT, conflicting rate, heavy vehicle ratio, circulatory roadway width, number of circulatory roadway lane, approach lane width, average approach lanes, parking places, and bus stops were selected as independent variables for the models.

• Journal of Navigation and Port Research
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• v.37 no.2
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• pp.123-128
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• 2013

In spite of advanced navigational devices and reinforced mandatory standards of officers' education, the number of ship's accidents are increasing. The accidents caused by minor license officers are more than the number of accidents caused by superior license officers. There are many cases of collisions in the past 5 years released on Marine Accidents Inquiry Agency. Especially, officer's negligence from the consequences of the neglect of any precaution which may be required by the ordinary practice of seamen is the main reason behind ship's collisions. For reducing ship's accidents caused by human error, this paper suggests to develop effective training program using analysis date of domestic and foreign education system as a reference.

• The Journal of the Korea Contents Association
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• v.11 no.11
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• pp.274-285
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• 2011

This study deals with an analysis into the details of medical treatment and expenses by items of treatment as well as the factors related to the ratio between the medical treatment and expenses for 1583 patients who were hospitalized in and discharged from 2 general hospitals located at a city under the coverage of car insurance during the year 2009. As a result, there was statistically significant difference in the details of medical treatment and expenses by items of treatment as well as their composition ratio depending on the individual characters as sex, age and the number of days staying in hospital. Each medical institution should conduct a close analysis of its patients under the car insurance program as well as the factors related to medical expenses with a view to utilize them as basic data for mapping out plans for effective operation of its organization in consideration of the characters as a medicalinstitution.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.3
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• pp.615-625
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• 2015

This paper proposes new methods and examples for improving fraud detection rules based on banking customer's transaction behaviors focused on anomaly detection method. This study investigates real example that FDS(Fraud Detection System) regards fraudulent transaction as legitimate transaction and figures out fraudulent types and transaction patterns. To understanding the cases that FDS regard legitimate transaction as fraudulent transaction, it investigates all transactions that requied additional authentications or outbound call. We infered additional facts to refine detection rules in progress of outbound calling and applied to existing detection rules to improve. The main results of this study is the following: (a) Type I error is decreased (b) Type II errors are also decreased. The major contribution of this paper is the improvement of effectiveness in detecting fraudulent transaction using transaction behaviors and providing a continuous method that elevate fraud detection rules.

• Journal of The Korean Association For Science Education
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• v.36 no.6
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• pp.877-893
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• 2016

The purpose of this study was to investigate a mentor-teacher qualification standard to support professional development for beginning secondary science teachers. The participants were four mentee teachers and four mentor-teachers. The relationship between the development of beginning science teachers teaching practice and characteristics of the mentoring and interactions was investigated by analyzing conversations between mentor and mentee teachers during the collaborative mentoring. Three mentoring conversation records and transcripts during mentoring program were collected. An analytical framework of mentoring conversations was used in the analysis of mentoring conversations and RTOP was used for lesson analysis to determine the development of teaching practice. The results show that the types of interactions during mentoring varied according to the mentoring teams. Mentors who encouraged reflective thinking induced a higher level of teaching in their mentees. The mentor qualification standard was determined from the relationship between the characteristics of the interaction and the improvement in beginning teacher's teaching practice. To be an effective mentor, the mentor should be able to 1) lead the interaction in a manner that encourages the exchange of opinions, 2) induce reflective thinking and ability to achieve reflective practice following reflective thinking, 3) provide clear explanations and suggest detailed methods, 4) lead conversations that encourage reflective thinking with questions about teaching supported techniques.