• International Journal of Highway Engineering
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• v.9 no.4
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• pp.65-74
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• 2007

There have been research and studies on rumble strip effectiveness in terms of accident reduction since rumble strips were first installed in 1950's. Research has shown that rumble strips reduce accidents from drowsy and inattentive driving. The present research statistically analyze the accident reduction effect of rumble strips based on accident reports obtained from rumble strip installed 377 places of nation wide freeway lines. Based on the results, rumble strips are effective in reducing accident frequencies 32.3%. The probable various factors inducing accidents are identified. These include drowsiness, speeding, inattentiveness, vehicle defectiveness, and short headways. It was found that rumble strips are effective in reducing A, B, C leveled accidents, and in reducing clear, cloudy, and rainy weather accidents. The results may make clear and expand probable types of accidents that rumble strips would reduce, then reduce the total accidents on freeway lines.

• Journal of KIISE:Information Networking
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• v.29 no.2
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• pp.197-203
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• 2002

This paper proposes a new agent based mechanism called a Multicast Handoff Agent (MHA) to reduce handoff latency for IP multicast. The MHA acts as a proxy for an Internet Group Management Protocol (IGMP) of Mobile Nodes (MNs) at each Base Station (BS) and keeps information for members of multicast groups in a cell. When an MN moves to a next cell, the MHA immediately sends unsolicited reports without waiting for the IGMP query. The mechanism was evaluated through simulation and analysis and compared with the IGMPv2 for micro-mobility and the IGMP traffic. Simulation results show that handoff latency for micro-mobility can be largely reduced and the IGMP control traffic on the wireless links during the duration of membership can be eliminated. Thus, this mechanism is superior to the existing mechanism in both micro-mobility and battery duration, as the need not to reply to a query conserves battery power.

• Journal of Auto-vehicle Safety Association
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• v.11 no.3
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• pp.43-47
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• 2019

Developed countries are operating an in-depth database in motor vehicle crashes nationwide. They do not rely solely on the police investigation reports that are responsible for motor vehicle crashes in each country but are developing into a useful database by expanding the categories of data through more indicators addition. In Korea, after implementing comprehensive measures to reduce traffic accident deaths in 2013, the medical centers participated in establishing the actual accident investigation system, which was called as the Korean In-Depth Accident Study (hereinafter KIDAS). This KIDAS database included more in-depth indicators as the types of accidents, types of vehicles, the injury severity, adequacy of safety devices, seating position of passengers. Although there are difficulties in establishing an actual accident investigation system including data collection due to various restrictions, if the system can cooperate with each other such as medical centers, insurance companies, police, fire and rescue services, towing companies, and car repair shops in the future, It would be expected to contribute to the development of safer vehicle, treatment system and traffic safety policy that lower the injury severity of occupant in the event of a motor vehicle crashes.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.187-194
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• 2011

Optimizing truck dispatching-intervals is imperative in ready mixed concrete (RMC) delivery process. Intervals shorter than optimal may induce queuing of idle trucks at a construction site, resulting in a long delivery cycle time. On the other hand, intervals longer than optimal can trigger work discontinuity due to a lack of available trucks where required. Therefore, the RMC delivery process should be systematically scheduled in order to minimize the occurrence of waiting trucks as well as guarantee work continuity. However, it is challenging to find optimal intervals, particularly in urban areas, due to variations in both traffic conditions and concrete placement rates at the site. Truck dispatching intervals are usually determined based on the concrete plant managers' intuitive judgments, without sufficient and reliable information regarding traffic and site conditions. Accordingly, the RMC delivery process often experiences inefficiency and/or work discontinuity. Automatic data collection (ADC) techniques (e.g., RFID or GPS) can be effective tools to assist plant managers in finding optimal dispatching intervals, thereby enhancing delivery performance. However, quantitative evidence of the extent of performance improvement has rarely been reported to data, and this is a central reason for a general reluctance within the industry to embrace these techniques, despite their potential benefits. To address this issue, this research reports on the development of a discrete event simulation model and its application to a large-scale building project in Abu Dhabi. The simulation results indicate that ADC techniques can reduce the truck idle time at site by 57% and also enhance the pouring continuity in the RMC delivery process.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.5
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• pp.200-215
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• 2023

With the rapid advance of autonomous driving technology, the related vehicle market is experiencing explosive growth, and it is anticipated that the era of fully autonomous vehicles will arrive in the near future. However, along with the development of autonomous driving technology, questions regarding its safety and reliability continue to be raised. Concerns among technology adopters are increasing due to media reports of accidents involving autonomous vehicles. To promote the improvement of the safety of autonomous vehicles, it is essential to analyze previous accident cases and identify their causes. Therefore, in this study, we aimed to analyze the factors influencing the severity of autonomous vehicle accidents using previous accident cases and related data. The data used for this research primarily comprised autonomous vehicle accident reports collected and distributed by the California Department of Motor Vehicles (CA DMV). Spatial information on accident locations and additional traffic data were also collected and utilized. Given that the primary data used in this study were accident reports, a Poisson regression analysis was conducted to model the expected number of accidents. The research results indicated that the severity of autonomous vehicle accidents increases in areas with low lighting, the presence of bicycle or bus-exclusive lanes, and a history of pedestrian and bicycle accidents. These findings are expected to serve as foundational data for the development of algorithms to enhance the safety of autonomous vehicles and promote the installation of related transportation infrastructure.

• The Journal of the Korea Contents Association
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• v.9 no.5
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• pp.50-60
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• 2009

Recently, the traffic card is gradually utilized and its several supplementary services have been significantly developed. Particularly, since it is possible to pay fees for buses, taxies, subways, parking and tollgates with only one traffic card, new payment method for economically processing has been focused. This paper presents a new receipt management system which allows possibly paying with several digital cards through PC interfacing terminals. The proposed system is mainly composed of three parts: terminals, middleware, and management servers. A terminal part includes processing module for payment/charging and credit/check/debit cards, etc and its operation is fulfilled through a middleware part. A main task of a middleware part is to connect a terminal part to managing servers through middleware applications. Additionally, processing of several receipt items and monitoring of the terminals to product statistical reports based on the processed result are carried out in the middleware. A management sever part is accomplished for collecting all of transaction histories against users and charging items over allowed province and managing statistical information. The proposed system is currently utilized in the Nam-GU district office and the Nam-GU district health center, Busan, S. Korea, respectively for testing its effectiveness. We conclude from this demonstration that the system is more useful and efficient than the previous processing method especially in that variable payment ways are provided and consumption burden is reduced.

• The Journal of Korean Obstetrics and Gynecology
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• v.35 no.4
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• pp.19-36
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• 2022

Objectives: This study was conducted to find out the general public's perception of Korean Medicine (KM) treatment for traffic accident (TA) patients during pregnancy. Methods: A self-developed questionnaire was distributed to outpatients and inpatients between the ages of 19 and 70 at KM hospitals located in Bucheon. The subjects were asked whether they thought KM treatment could be applied to TA patients during pregnancy. The perceptions of acupuncture, pharmacupuncture, herbal medicine, and Chuna treatment during pregnancy were also investigated. Results: 87.50% answered that KM treatment could be applied to TA patients during pregnancy. Most respondents thought that musculoskeletal symptoms of TA could be treated with KM (85.71%). 93.75%, 87.50%, 56.25%, and 52.08% of the respondents said they were willing to recommend acupuncture, pharmacupuncture, herbal medicine, and Chuna treatment to patients after TA during pregnancy. The respondents answered that acupuncture (95.83%), pharmacupuncture (91.67%), herbal medicine (62.50%), and Chuna (66.67%) is effective for pain controlling during pregnancy, and acupuncture (8.33%), pharmacupuncture (12.50%), herbal medicine (45.83%), and Chuna (39.58%) could be affect the risk of premature birth, miscarriage or birth defects. Conclusions: Acupuncture and pharmacupunture treatment are perceived positively, whereas herbal medicine and Chuna treatment are perceived negatively by the general public for the TA patients during pregnancy. In order to establish the correct awareness of KM treatment for TA patients during pregnancy, more clinical studies and case reports on the efficacy and safety of KM treatment during pregnancy are required.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2174-2177
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• 2003

Internet is exposed to network attacks as Internet has a security weakness. Network attacks which are virus, system intrusion, and deny of service, put Internet in the risk of hacking, so the damage of public organization and banking facilities are more increased. So, it is necessary that the security technologies about intrusion detection and controlling attacks minimize the damage of hacking. Router is the network device of managing traffic between Internets or Intranets. The damage of router attack causes the problem of the entire network. The security technology about router is necessary to defend Internet against network attacks. Router has the need of access control and security skills that prevent from illegal attacks. We developed integrated security management framework for secure networking and kernel-level security engine that filters the network packets, detects the network intrusion, and reports the network intrusion. The security engine on the router protects router or gateway from the network attacks and provides secure networking environments. It manages the network with security policy and handles the network attacks dynamically.

• Journal of Communications and Networks
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• v.16 no.1
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• pp.81-91
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• 2014

This paper proposes hidden-node aware grouping (HAG) algorithm to enhance the performance of institute of electrical and electronics engineers (IEEE) 802.15.4 networks when they undergo either severe collisions or frequent interferences by hidden nodes. According to the degree of measured collisions and interferences, HAG algorithm dynamically transforms IEEE 802.15.4 protocol between a contention algorithm and a contention-limited one. As a way to reduce the degree of contentions, it organizes nodes into some number of groups and assigns each group an exclusive per-group time slot during which only its member nodes compete to grab the channel. To eliminate harmful disruptions by hidden nodes, especially, it identifies hidden nodes by analyzing the received signal powers that each node reports and then places them into distinct groups. For load balancing, finally it flexibly adapts each per-group time according to the periodic average collision rate of each group. This paper also extends a conventional Markov chain model of IEEE 802.15.4 by including the deferment technique and a traffic source to more accurately evaluate the throughput of HAG algorithm under both saturated and unsaturated environments. This mathematical model and corresponding simulations predict with 6%discrepancy that HAG algorithm can improve the performance of the legacy IEEE 802.15.4 protocol, for example, even by 95% in a network that contains two hidden nodes, resulting in creation of three groups.

• Journal of Chest Surgery
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• v.21 no.3
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• pp.471-478
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• 1988

We evaluated forty cases of traumatic diaphragmatic injuries that we have experienced from Jan. 1972 to Dec. 1987. 28 patients were male and 12 were female[M:F=2.3:1]. The age distribution was ranged from 4 to 71 years with mean age of 26. The diaphragmatic injuries were due to blunt trauma in 27 cases[traffic accident 22, fall down 3, others 2] and penetrating trauma in 13 cases[stab wound 11, gun shot 1, other 1]. In the blunt injury,14 cases of 17 were diagnosed and treated within 24 hours in the left diaphragmatic injury but only 3 cases of 7 cases in the right diaphragmatic injury were diagnosed and treated within 24 hours. All cases except one in penetrating injury were diagnosed and treated within 12 hours. In the blunt injury, the rupture site was located in the left in \ulcorner7 cases and in the right in 7 cases. In the penetrating injury, the rupture site was located in the left in 11 cases and in the right in 2 cases. The repair of 37 cases were performed with thoracic approach in 20 cases, thoracoabdominal approach in 12 cases and abdominal approach in 5 cases. Over all mortality was 17.5%[7/40] and postoperative mortality was 11%[4/37]. The causes of death were hypovolemic shock[3], combined head injury[2], acute renal failure[1] and septic shock with ARDS[1].