• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.2
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• pp.1-13
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• 2009

Although enormous data have been collected in major cities (Korea) by APTS(Advanced Public Transit Systems), most of studies related to bus schedule management evaluation have confined to headway adherence and on-time performance. Therefore, bus operation management have been very lack of using APTS data. This study uses coefficient of correlation to evaluate bus company's schedule management level. However, direct application of coefficient of correlation has inequitable problem because of many limitation(number of vehicle, headway, etc). and so variable calibration method was developed and applied to cope with these problems. Thus, demand-elastic management evaluation index was developed. For verifying the equity of developed index, it is applied to Seoul bus routes. It is expected for the developed index to contribute into the demand-elastic management of bus schedule.

• Journal of the Korea Society of Computer and Information
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• v.8 no.4
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• pp.47-56
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• 2003

According to rapidly developed mobile terminals and network in the play environment for multimedia presentation, different end-to-end QoS situations appear. Then the generation of transcoding path algorithm was reviewed to transcode a source'data satisfying the needed QoS from a destination and play it considering given transcoders and network. This method used only workload as a parameter although two parameters, workload and throughput, were needed to process multimedia stream in a transcoder, Therefore generated transcoding path with this method had additional calculation to check playability whether it was safisfed the QoS of a destination or not. To solve the problem this paper suggests T algorithm with evaluation function using isochronous property that is needed for multimedia stream to arrive a destination. That means, most playable path is selected with heuristic search based isochronous property between many transcoding paths. Using the suggested algorithm, a transcoding path can be generated faster to play the multimedia data with different end-to-end QoS in real-time transmission.

• Journal of the Korea Society of Computer and Information
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• v.16 no.12
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• pp.205-214
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• 2011

In this paper, we propose a mobile navigation application that allows a user to send location data to another user using the iPhone's GPS function and Mapkit framework. The GPS function of the iPhone detects the location of the first user and the Mapkit framework shows the first user location on Google Maps. If the second user requires guidance to a destination, the first user touches the record button on the proposed application to record his or her position. The first user can check his or her recorded location from the pin position on Google Maps, and he or she can then send the relevant information to the second user who wants to visit that location. The second user receives the location data and is guided to the destination easily by following the next position icon on the iPhone camera overlay or by following the pin position on Google Maps. Therefore, even if a user is traveling somewhere for the first time, the proposed application guides that user to his or her destination by receiving recorded location data from another user.

• The Transactions of the Korea Information Processing Society
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• v.4 no.2
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• pp.491-498
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• 1997

Geographic Infprmation System(GIS)is being apply to extended from specified ppkication to general purpose deu to the omprovement of computing power.As one part of postal Integarated Information Servies, Postalroute Optimication system(PROS) is comprsed of the composed of the shortest pathe genrator for providing fast and shortest route of postal delivery, the ischronal area generator, the boudary relacation generator, GIS engine, road map, and rdelational database , etc.This paper is related to creation algorithm of the shortest path generation (SPAWD;Shortest Path Algorithm With Direction)from PEOS model.To differ from the exsting shortest path generating methods, this paper suggests SPAWD alforithm for searching destinations of fast time between start and destination points with dirdstion.It comapares and analyzes the new algorithm with existion algorithms, and suggests directions of future studies.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.2
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• pp.429-434
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• 2017

In a graph G=(V, E) with n vertices, there is an unique box which is finally laid on each vertex. Thus each vertex and box is both numbered from 1 to n and the box i should be laid on the vertex i. But, the box ${\pi}$(i) is initially located on the vertex i according to a permutation ${\pi}$. In each step, the robot can walk along an edge of G and can carry at most one box at a time. Also when arriving at a vertex, the robot can swap the box placed there with the box it is carrying. The problem is to minimize the total step so that every vertex has its own box, that is, the shuffled boxes are sorted. In this paper, we shall find an upper bound of the minimum number of steps and show that the movement of the robot is found in $O(n^2)$ time when G is a cycle.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.4
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• pp.687-694
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• 2022

In this paper, we proposed an autonomous vehicle platform that delivers goods to a designated destination based on the SLAM (Simultaneous Localization and Mapping) map generated indoors by applying the Visual SLAM technology. To generate a SLAM map indoors, a depth camera for SLAM map generation was installed on the top of a small autonomous vehicle platform, and a tracking camera was installed for accurate location estimation in the SLAM map. In addition, a convolutional neural network (CNN) was used to recognize the label of the destination, and the driving algorithm was applied to accurately arrive at the destination. A prototype of an indoor delivery autonomous vehicle was manufactured, and the accuracy of the SLAM map was verified and a destination label recognition experiment was performed through CNN. As a result, the suitability of the autonomous driving vehicle implemented by increasing the label recognition success rate for indoor delivery purposes was verified.

• Journal of Advanced Navigation Technology
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• v.26 no.6
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• pp.393-403
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• 2022

Various studies suggest that the initial operating form of UAM, which is being presented as a solution to the urban traffic problem, will be similar to VTOL aircraft among current aircraft. In a form similar to determining the direction of the runway where fixed-wing aircraft take off and land, the vertiport where take-off and landing of VTOL aircraft takes place determines the flight direction of departure and arrival in consideration of the direction of the wind. Unlike areas where airports are generally built, in the case of downtown areas, it is expected that the characteristics of wind may continuously change depending on the environment of changing terrain or obstacles such as the construction of new buildings. In this study, long-term actual observation data for reviewing the take-off and landing directions at the city center where the location of the vertiport is expected are compared using a wind speed map, and the characteristics of the ground wind and the possibility of change in the direction of the predominant wind depending on the observation period and observation location confirmed.

• Korean Journal of Environment and Ecology
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• v.30 no.2
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• pp.146-154
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• 2016

In this study, understanding the habitats on spot-billed duck that wintering-breed in the korea, which using the GPS-Mobile based Telemtry (WT-200), I tried to take advantage as the basic data of the protection and management of the habitats of the waterbirds of Korea. Study area is Gyeonggi-do Bokhacheon, Chonmichon, Chungcheongnam-do Gokugyochon, Chungcheongbuk-do Byeongcheoncheon, Jeollabuk-do Mangyunggang, which Five rivers and Jeju Island reservoir, I have attached the tracking of the location(WT -200) to the twenty-five spot-billed ducks. among twenty five ducks, twelve ducks moved to overseas countries, the arrival site was China, North Korea, Russia. Moving average distance was 683km, the largest distance was 1,238km. The average northbound starting date was April 26. The average daily movement distance of thirteen ducks remaining in the domestic country is $1.0{\pm}0.89km$, maximum travel distance was 23.8km. The average daily movement distance of wintering prior to average going north dating is a 0.9km, is the largest 14.6km, the breeding season is an average 1.3km, maximum was 14.4km. Spot-billed duck used the rivers in domestic country most frequently, following was rice field, a filed, reservoir. It used the river most frequently during the wintering period, in the breeding season it used paddy paddies most frequently. While wintering, during the day and night's utilization rate was the highest in the river, but utilization rate was incleased on filed, paddy filed at night. During breeding season, daytime and night's utilization rate was the highest but, utilization rate was increased on river and utilization rate was decreased on river. In accordance with time change, spot-billed duck showed different tendency in paddy fields, and they utilized the filed adjacent to rivers mostly.

• Journal of Korean Society of Transportation
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• v.23 no.2
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• pp.117-130
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• 2005

In both deteministic user Optimal Traffic Assignment Model (UOTAM) and stochastic UOTAM, travel time, which is a major ccriterion for traffic loading over transportation network, is defined by the sum of link travel time and turn delay at intersections. In this assignment method, drivers actual route perception processes and choice behaviors, which can become main explanatory factors, are not sufficiently considered: therefore may result in biased traffic loading. Even though there have been some efforts in Stochastic UOTAM for reflecting drivers' route perception cost by assuming cumulative distribution function of link travel time, it has not been fundamental fruitions, but some trials based on the unreasonable assumptions of Probit model of truncated travel time distribution function and Logit model of independency of inter-link congestion. The critical reason why deterministic UOTAM have not been able to reflect route perception cost is that the route perception cost has each different value according to each origin, destination, and path connection the origin and destination. Therefore in order to find the optimum route between OD pair, route enumeration problem that all routes connecting an OD pair must be compared is encountered, and it is the critical reason causing computational failure because uncountable number of path may be enumerated as the scale of transportation network become bigger. The purpose of this study is to propose a method to enable UOTAM to reflect route perception cost without route enumeration between an O-D pair. For this purpose, this study defines a link as a least definition of path. Thus since each link can be treated as a path, in two links searching process of the link label based optimum path algorithm, the route enumeration between OD pair can be reduced the scale of finding optimum path to all links. The computational burden of this method is no more than link label based optimum path algorithm. Each different perception cost is embedded as a quantitative value generated by comparing the sub-path from the origin to the searching link and the searched link.

• Journal of Yeungnam Medical Science
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• v.24 no.1
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• pp.41-54
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• 2007

Background : The causes of chest pain vary but the leading cause of chest pain is ischemic heart disease. Mortality from ischemic chest pain has increased more than two fold over the last ten years. The purpose of this study was to determine the data necessary for rapid treatment of patients with signs and symptoms of ischemic chest pain in the emergency department (ED). Materials and Methods : We interviewed 170 patients who had ischemic chest pain in the emergency department of Yeungnam University Hospital over 6 months with a protocol developed for the evaluation. The protocol used included gender, age, arriving time, prior hospital visits, methods of transportation to the hospital, past medical history, final diagnosis, and outcome information from follow up. Results : Among 170 patients, there were 118 men (69.4%) and the mean age was 63 years. The patients diagnosed with acute myocardial infarction (AMI) were 106 (62.4%) and with angina pectoris (AP) were 64 (37.6%). The patients who had visited another hospital were 68.8%, twice the number that came directly to this hospital (p<0.05). The ratio of patients who visited another hospital were higher for the AMI (75.5%) than the AP (59.4%) patients (p<0.05). The median time spent deciding whether to go to hospital was 521 minutes and for transportation was 40 minutes. With regard to patients that visited another hospital first, the median time spent at the other hospital was 40 minutes. The total median time spent before arriving at our hospital was 600 minutes (p>0.05). The patients who had a total time delay of over 6 hours was similar 54.8% in the AMI group and 57.9% in the AP group (p>0.05). As a result, only 12.2% of the patients with an AMI received thrombolytics, and 48.8% of them had a simultaneous percutaneous coronary intervention (PCI). In the emergency department 8.5% of the patients with an AMI died. Conclusion : Timing is an extremely important factor for the treatment of ischemic heart disease. Most patients arrive at the hospital after a long time lapse from the onset of chest pain. In addition, most patients present to a different hospital before they arrive at the final hospital for treatment. Therefore, important time is lost and opportunities for treatment with thrombolytics and/or PCI are diminished leading to poor outcomes for many patients in the ED. The emergency room treatment must improve for the identification and treatment of ischemic heart disease so that patients can present earlier and treatment can be started as soon as they present to an emergency room.