• Asia pacific journal of information systems
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• v.19 no.2
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• pp.117-137
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• 2009

Recently, intelligent traffic information systems have enabled people to forecast traffic conditions before hitting the road. These convenient systems operate on the basis of data reflecting current road and traffic conditions as well as distance-based data between locations. Thanks to the rapid development of ubiquitous computing, tremendous context data have become readily available making vehicle route planning easier than ever. Previous research in relation to optimization of vehicle route planning merely focused on finding the optimal distance between locations. Contexts reflecting the road and traffic conditions were then not seriously treated as a way to resolve the optimal routing problems based on distance-based route planning, because this kind of information does not have much significant impact on traffic routing until a a complex traffic situation arises. Further, it was also not easy to take into full account the traffic contexts for resolving optimal routing problems because predicting the dynamic traffic situations was regarded a daunting task. However, with rapid increase in traffic complexity the importance of developing contexts reflecting data related to moving costs has emerged. Hence, this research proposes a framework designed to resolve an optimal route planning problem by taking full account of additional moving cost such as road traffic cost and weather cost, among others. Recent technological development particularly in the ubiquitous computing environment has facilitated the collection of such data. This framework is based on the contexts of time, traffic, and environment, which addresses the following issues. First, we clarify and classify the diverse contexts that affect a vehicle's velocity and estimates the optimization of moving cost based on dynamic programming that accounts for the context cost according to the variance of contexts. Second, the velocity reduction rate is applied to find the optimal route (shortest path) using the context data on the current traffic condition. The velocity reduction rate infers to the degree of possible velocity including moving vehicles' considerable road and traffic contexts, indicating the statistical or experimental data. Knowledge generated in this papercan be referenced by several organizations which deal with road and traffic data. Third, in experimentation, we evaluate the effectiveness of the proposed context-based optimal route (shortest path) between locations by comparing it to the previously used distance-based shortest path. A vehicles' optimal route might change due to its diverse velocity caused by unexpected but potential dynamic situations depending on the road condition. This study includes such context variables as 'road congestion', 'work', 'accident', and 'weather' which can alter the traffic condition. The contexts can affect moving vehicle's velocity on the road. Since these context variables except for 'weather' are related to road conditions, relevant data were provided by the Korea Expressway Corporation. The 'weather'-related data were attained from the Korea Meteorological Administration. The aware contexts are classified contexts causing reduction of vehicles' velocity which determines the velocity reduction rate. To find the optimal route (shortest path), we introduced the velocity reduction rate in the context for calculating a vehicle's velocity reflecting composite contexts when one event synchronizes with another. We then proposed a context-based optimal route (shortest path) algorithm based on the dynamic programming. The algorithm is composed of three steps. In the first initialization step, departure and destination locations are given, and the path step is initialized as 0. In the second step, moving costs including composite contexts into account between locations on path are estimated using the velocity reduction rate by context as increasing path steps. In the third step, the optimal route (shortest path) is retrieved through back-tracking. In the provided research model, we designed a framework to account for context awareness, moving cost estimation (taking both composite and single contexts into account), and optimal route (shortest path) algorithm (based on dynamic programming). Through illustrative experimentation using the Wilcoxon signed rank test, we proved that context-based route planning is much more effective than distance-based route planning., In addition, we found that the optimal solution (shortest paths) through the distance-based route planning might not be optimized in real situation because road condition is very dynamic and unpredictable while affecting most vehicles' moving costs. For further study, while more information is needed for a more accurate estimation of moving vehicles' costs, this study still stands viable in the applications to reduce moving costs by effective route planning. For instance, it could be applied to deliverers' decision making to enhance their decision satisfaction when they meet unpredictable dynamic situations in moving vehicles on the road. Overall, we conclude that taking into account the contexts as a part of costs is a meaningful and sensible approach to in resolving the optimal route problem.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.1
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• pp.25-43
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• 2016

This research was completed to provide fundamental data regarding the guidelines to installing and managing utility facilities & structures in wetland protected area to advance the functions and sustainable use of ecology services by preserving the ecology within wetland protected area. There were 5 on-site researching areas that were used as the main subject with these areas chosen and considered from 21 inland wetlands that have been designated and are being managed from the Ministry of Environment and by their designated dates as a wetland protected area. The utility facilities in these wetland areas were categorized by their types and a detailed on-site investigation was proceeded with investigation items chosen whereas these facilities are working by their roles from their location, size, used materials, types, information contents and etc., The results showed that regarding informational structures, several locations of information boards were distanced from the main exploring routes which did not consider the visitor's eye level which had their readability dropped and by sunlight, time lapse and water penetration, many information boards were damaged or corrupted so that it was hard to confirm the information noticed or understanding an image. Insufficient observation and educational structures were installed that considered the ecological characteristics of wild animals and their living conditions. Regarding convenience facilities, there were parking lots that were installed on the fore-land and to decrease non-point solution sources, some parking lots needed to be located in protected lowlands while some facilities' shape and colors did not harmonize with their natural surroundings, creating a sense of awareness, which will need some more consideration. As for safety facilities, they were very insufficient compared to other facilities. This means that additional safety structures are needed so that related personnel can be aware of where a visitor is located when an accident occurs. Protectional facilities strongly needed new structures and a management system to cut off entrances and do surveillance so that visitors do not go into areas outside of the managed areas and bring damages to restricted locations. Research labs needed to expand the use of automatic weather systems and water gauge equipments to build fundamental data regarding floodgates that are intimated to the forming of wetlands. Sensor cameras and other types of monitoring systems are needed to monitor the majority types of animals living in the wetlands as well.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.3
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• pp.387-395
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• 2013

Recently, several circumferential cracks were found in the control rod drive mechanism (CRDM) nozzles of U.S. nuclear power plants. According to the accident analyses, coolant leaks were caused by primary water stress corrosion cracking (PWSCC). The tensile residual stresses caused by welding, corrosion sensitive materials, and boric acid solution cause PWSCC. Therefore, an exact estimation of the residual stress is important for reliable operation. In this study, finite element simulations were conducted to investigate the effects of the tube geometry (thickness and radius) on the residual stresses in a J-groove weld for different CRDM tube locations. Two different tube locations were considered (center-hole and steepest side hill tube), and the tube radius and thickness variables ($r_o/t$=2, 3, 4) included two different reference values ($r_o$=51.6, t=16.9mm).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.593-596
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• 2018

The speed of vehicles has remained a significant factor that influences the severity of accidents and traffic accident rate in many parts of the world including South Korea. This behavior where drivers drive at speeds which exceed a posted safe threshold is known as 'speeding'. Over the past twenty years, the Korean National Police Agency (NPA) has become aware of an increased frequency of drivers who are speeding. Therefore, fixed-type ASE systems [1] have been installed on hazardous road sections of many highways. These system monitor vehicle speeds using a camera. However, the use of ASE systems has changed the behavior of the drivers. Specifically, drivers reduce speed or avoid the route where the cameras are mounted. It is not practical to install cameras at every possible location. Therefore, it is challenging to thoroughly explore the location where speeding occurs. In view of these problems, the author of this paper designed and implemented a prototype visualization system in which point and color are used to show vehicle location and associated over-speed information. All of this information was used to create a comprehensive visualization application to show information about vehicle driving. In this paper, we present an approach detecting vehicles moving at speeds which exceed a threshold and visualizing the points those violations occur on a map. This was done using vehicle trajectory data collected in Daegu city. We propose steps for exploring the data collected from those sensors. The resulting mapping has two layers. The first layer contains the dynamic vehicle trajectory data. The second underlying layer contains the static road networks. This allows comparing the speed of vehicles on roads with the known maximum safe speed of those roads, and presents the results with a visualization tool. We also compared data about people who drive over threshold safe speeds on each road on days and weekends based on vehicle trajectories. Finally, our study suggests improved times and locations where law enforcement should use monitoring with speed cameras, and where they should be stricter with traffic law enforcement. We learned that people will drive over the speed limit at midnight more than 1.9 times as often when compared with rush hour traffic at 8 o'clock in the morning, and 4.5 times as often when compared with traffic at 7 o'clock in the evening. Our study can benefit the government by helping them select better locations for installation of speed cameras. This would ultimately reduce police labor in traffic speed enforcement, and also has the potential to improve traffic safety in Daegu city.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5060-5065
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• 2012

The purpose of this study was to report the incidence of drowning accident in order to prevent and decrease the accidents of drowning. Data were obtained on all accidents of drowning accidents occurred from January to December 2007 were identified by using the Emergency Activity Daily Report Data from the National Emergency Management Agency (NEMA). The age, weather, date, location, time and case of the drowning accident were examined. The Chi-square test was used to compare each group. All comparisons were made at the p<0.05 level of significance. The result show that the age of drowning accidents for victims aged 20-29 was 27.9%, and for victims aged 30-39 years, 18.7%. In reguard to the age group, drowning accidents during recreational aquatic activity was age 20-39; 51(44.8%). In reguard to the locations, the number of drowning accidents in a lake or reservoir during recreational aquatic activity was 62(53.4%). The number of drowning accidents in a lake or reservoir during etc was 51(58%). In reguard to the days, the number of drowning accidents on Saturday during recreational aquatic activity was 30(25.8%), on Sunday 32(27.6%). The weather of drowning accidents during recreational aquatic activity was sunny 60(51.8%), rainy 40(34.4%), cloudy 16(13.8%). The season of drowning accidents during recreational aquatic activity was summer 53(45.7%). In reguard to season, two groups are significantly different. Drowning is a leading cause of injury related accidents. Understanding the characteristics of drowning is the first step to developing prevention strategies that may be beneficial for people of all ages and under nearly all circumstances are increased swimming ability, lifeguard staffing, providing life jackets, and public education activities.

• Archives of Plastic Surgery
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• v.34 no.3
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• pp.365-370
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• 2007

Purpose: There are many reports about facial bone fractures, but limited to retrospective data of a single hospital. Etiology and severity of the facial bone fracture have been changed and treatment method and materials have been advanced. In order to reflect those changes and provide up-to-date data of the facial bone fractures in Daegu, we gathered the data and analyzed the epidemiologic study. Methods: The medical records of 1058 fractures in 895 patients were gathered from 5 general hospitals in Daegu during last year and these data were analyzed by following parameters: age, sex, place of residence, occupation, cause of injury, time of injury, location of fracture, length of in-hospital stay, time of operation, treatment method, associated injury, complication. Statistical analysis was performed using the Chi-square test. Results: Most commonly involved age group was 20s(26%) and the sex ratio was 3.4:1(male predominance). Fractures were occurred more in unban and white-color workers. Among variable etiology of injury, traffic accident was the most common cause. Time of injury was heighest at 6 to 7 P.M., on Sunday, in July. Locations of fractures were following sequence: nasal, zygoma, mandible, orbit, maxilla. Mean length of in-hospital stay and time of operation after injury were 6.3 and 3.2 days, respectively. In treatment methods, operative methods were dominant than conservative management and general anesthesia were favored than local anesthesia. Associated injuries were noticed in 188 cases(21.2%) and complications were in 94 cases(8.9%) and among them, ocular problem were common. Conclusion: Compared to previous studies, mean age of occurrence was lowered and the etiologies showed age-specific pattern and reflected the change of lifestyle. In young age groups, sports injury, violence were more dominant and the other hand, traffic accident and fall were dominant in older groups.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.2
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• pp.26-33
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• 2009

New equipment that is useful for driving is developing every day. Navigation is one of the most popular equipment among them. Telematics market including navigation is getting bigger and bigger. However, traffic accident from using telematics equipment is also increasing. Drivers may lose glance using navigation, and driver's workload will also grow by driver's distraction. This thesis is base on the study about the influence on the drivers' workload by using the telematics equipment. Previous study of drivers' workload used psychological method and behavior test method, but it was less connection with telematics equipment. The main object of this thesis is measuring the workload according to the telematics usage by HMI (Human Machine Interface) in the virtual reality. Therefore, we developed GPS simulator, and made an experiment of whether using the navigation or not on the highway and an experiment of the location of navigation in downtown. The result of these experiments is that workload when driver used navigation was higher than when driver didn't use navigation. In addition, workload was different according to the location, and HUD (Head-Up Display) was especially higher than other locations but also its information delivery ability was the best.

• Journal of Korean Society of Transportation
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• v.20 no.1
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• pp.121-130
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• 2002

Purpose of this paper is proposing technical evaluation method for safety on two-lane rural highways, this method can contribute to an establishment of the safety evaluation criteria and eventually contribute to the highway safety. In this study, accident data and field data(grade, radius, speed factor) are collected and are analyzed. And new technical evaluation method is proposed by problem in review of existent methods and analysis result. Property of new method is verified by comparing with existent one. Following are results of this study. 1) Proposed technical evaluation method is Proposed by using difference of speed variance and difference of acceleration. 2) In range of field survey, proposed method is more proper than existent one by comparing. 3) Headways under 6 second affect speed of next vehicle. 4) A point with the lowest speed in curve is placed about 35m from the beginning point. 5) Correlation of speed variance and severity of highway(EPDO) is statistically significant. For using proposed method, more tests are needed on other locations with various geometries. Moreover, advanced study is needed about classifying and giving the weight of each criterion.

• Korean Journal of Veterinary Service
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• v.33 no.4
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• pp.401-409
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• 2010

From 2006 through 2007, the highest need for the most urgent attention in Gangwon-do Wild Animal Rescue Center was wildlifevehicle collisions (WVC). The Korean Ministry of Environment reported 6543 WVC's in 2005 and 5565 cases of WVC's in 2006. In this study, data from the Gangwon-do Wild Animal Rescue Center was utilized to analyze WVC incidents and the movement of wildlife near roadways in Korea. From 2006 through the first half of 2008, the portable GPS device recorded accident location of the injured wildlife. Attempts were made to track and monitor the movements of four raccoon dogs and five Korean water deers near the roads. One raccoon dog and one Korean water deer were successfully tracked and monitored. Their locations were transmitted to cell phones. The amount of WVC's was highest amongst the roads near the forests of Gangwon-do. The devices installed on the nearby roads did not protect the wildlife from WVC's. Results using the CDMA-type GPS collar showed that wildlife often crossed the road even with devices installed to prevent this from crossing roads. This research analyzed the behaviors of different wildlife animals and WVC's. New preventative measures need to be established to avoid roadkill. It is suggested that new streets be built or for an appropriate speed limit be implemented.

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.655-658
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• 2006

Mesothelial cyst is a rare mediastinal tumor and usually presents in the right cardiophrenic angle. However, it sometimes occurs in atypical locations and it’s locating in the posterior mediastinum, especially, is very rare. A large cystic mass of the posterior mediastinum between pericardium and vertebral body was incidentally recognized in a patient of a 30-year-old woman admitted due to traffic accident. Even though it was very large in size measuring 18 em at longest diameter and is extending mainly to the left pleural cavity, she had no symptomatic complaints. Complete excision was performed through video-assisted thoracoscopic surgery with a additional small working window, which was necessary for dissecting the deepest point to the right pleural cavity. She is in good condition without recurrence on long-term follow-up.