• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.2
• /
• pp.583-595
• /
• 2014

Currently, Korean transportation policies are aiming for increase of safety and environment-friendly and efficient operation, by avoiding construction and expansion of roads, and upgrading road alignments and facilities. This is revealed by that there have been 22 road expansion projects (30%) and 50 road improvement projects (70%) under the 3rd Five-Year Plan for National Highways ('11~'15), while there were 53 road expansion projects (71%) and 22 road improvement projects (29%) under the 2nd Five-Year Plan for National Highways. For more effective road improvement projects, there is a need of choosing projects after an objective and scientific safety assessment of each road, and assessing safety improvement depending on projects. This study is intended to develop a model for this road safety analysis and assessment. The major objective of this study is creating a road safety analysis and assessment model appropriate for Korean society, based on the HSM (Highway Safety Manual) of the U.S. In order to build up data for model development, the sections thought to have identical geometrical structure factors in 5 lines, Cheonbuk province, were divided as homogeneous sections, and representative values of geometric structures, facilities, traffic volume, climate conditions and land usage were collected from the 1,452 sections divided. In order to build up data for model development, the sections thought to have identical geometrical structure factors in 5 lines, Cheonbuk province, were divided as homogeneous sections, and representative values of geometric structures, facilities, traffic volume, climate conditions and land usage were collected from the 1,452 sections divided. The collected data was processed correlation analysis of each road element was implemented to see which factor had a big effect on traffic accidents. On the basis of these results, then, an accident model was established as a negative binomial regression model.Using the developed model, an Crash Modification Factor (CMF) which determines accident frequency changes depending on safety performance function (SPF) predicting the number of accident occurrence through traffic volume and road section expansion, road geometric structure and traffic properties, was extracted.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.19 no.3
• /
• pp.119-131
• /
• 2009

The world's widely used key exchange protocols are open cryptographic communication protocols, such as TLS/SSL, whereas in the financial field in Korea, key exchange protocols developed by industrial classification group have been used that are based on PKI(Public Key Infrastructure) which is suitable for the financial environments of Korea. However, the key exchange protocols are not only vulnerable to client impersonation attacks and known-key attacks, but also do not provide forward secrecy. Especially, an attacker with the private keys of the financial security server can easily get an old session-key that can decrypt the encrypted messages between the clients and the server. The exposure of the server's private keys by internal management problems, etc, results in a huge problem, such as exposure of a lot of private information and financial information of clients. In this paper, we analyze the weaknesses of the cryptographic communication protocols in use in Korea. We then propose two key exchange protocols which reduce the replacement cost of protocols and are also secure against client impersonation attacks and session-key and private key reveal attacks. The forward secrecy of the second protocol is reduced to the HDH(Hash Diffie-Hellman) problem.

• Information Systems Review
• /
• v.22 no.3
• /
• pp.119-142
• /
• 2020

This study aims to examine the role of IT features as heuristic cues in choosing a content on YouTube. According to the heuristic-systematic model, people tend to rely on heuristic cues when they have to choose and process useful information quickly so that they could save time and reduce demands for thinking. Based on this line of reasoning, this study posits that YouTube users rely on certain IT features as heuristic cues in choosing contents before they actually watch them. Based on the prior literature and interviews with YouTube users, we develop a research model in which social endorsement, self-presentation, and interactivity are identified as potential determinants of users' attitude toward contents, which in turn influence their intention to watch them. To empirically test the research model, we conduct a laboratory experiment and a follow-up survey. The results of data analysis show that social endorsement for the content, YouTube creator's self-presentation, and interactivity have significant and positive effects on their attitude toward the content, leading to their intention to watch it. This study suggests that IT features on YouTube could be wisely utilized to increase the chance that users choose a particular content out of many competing contents when they search certain information on YouTube.

• Journal of agriculture & life science
• /
• v.50 no.3
• /
• pp.119-127
• /
• 2016

The current disinfection method of vehicles being applied in South Korea has various shortcomings. So, the epidemic has generated continuously at livestock farms. It is very important to develop an effective disinfection system for reduction of the epidemic. And various basic data is required for this development. Therefore, this study was performed to identify the nozzle type and proper discharge pressure of sprayers. The experiment was conducted from January 10, 2012 until February 28, 2012. All the performance measurement experiments were repeated five times. The subjects of experiment were the A, B and C company's products. The sprayed capacity, angle of spray and the covering area ratio were measured for each product. As a result, the sprayed capacity, angle of spray and the covering area ratio were increased as the discharge pressure of the sprayer was increased. In conclusion, the conical shaped of the nozzle is considered more appropriate than V-shaped, and the proper discharge pressure is expected to be at least 20kg/㎠.