• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.141-143
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• 2019

Vessel Traffic Service (VTS) increases the efficiency of maritime traffic in terms of reducing marine accidents and the efficient use of port facilities. This means that ports and waterways have their own capacities and can be safely adapted to their capacity through proper traffic management of the VTS. Proper traffic management can reduce the number of vessels and unnecessary waiting in ports, which can lead to economic benefits of ups and port terminals. On the other hand, Korean ports and waterways have restrictions on the maximum speed for safety, but there is no restriction on the minimum speed. However, ships that operate at low speeds in ports and waterways may be able to occupy long periods of operational routes, which may impede efficient port operation. Therefore, the purpose of this study is to propose the minimum speed of ship for efficient port and waterway use. To this end, we reviewed the current laws and systems and proposed the appropriate minimum speed in the waterway using the theory of queue.

• International Journal of Highway Engineering
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• v.14 no.3
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• pp.77-85
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• 2012

Most of Automatic Accident Detection Algorithm has a problem of detecting an accident as traffic congestion. Actually, center's managers deal with accidents depend on watching CCTV or accident report by drivers even though they run the Automatic Accident Detection system. It is because of the system's detecting errors such as detecting non-accidents as accidents, and it makes decreasing in the system's overall reliability. It means that Automatic Accident Detection Algorithm should not only have high detection probability but also have low false alarm probability, and it has to detect accurate accident spot. The study tries to verify and evaluate the effectiveness of using Gaussian Mixture Model and individual vehicle tracking to adapt Accident Detection Algorithm to Center Management System by measuring accident detection probability and false alarm probability's frequency in the real accident.

• Journal of the Korean Society for Railway
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• v.18 no.5
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• pp.471-480
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• 2015

Reliance on road transport in domestic logistics can lead to intensified congestion and greenhouse gas emissions due to the rise in oil prices, any increase in logistics costs can have a high social cost. The government policy on Low Carbon Green Growth is seeking to take advantage of the railway system. However, existing railway transport logistics systems, for reasons such as low speed, low track capacity constraints, and the impossibility of implementing a Door to Door system, make it difficult to activate a railway logistics program. As a result of this study, a national R&D project to develop a High-Speed Passenger/Baggage Mixed Train(Hy-SoBex) utilizing the rail capacity constraints to overcome the difficulties of linking an air cargo and freight railway logistics system, we propose a variety of service models and select the optimal service model.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.1
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• pp.287-295
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• 2017

Recently, MTC (Machine Type Communication) is known as an important part to support IoT (Internet of Things) applications. MTC provides network connectivities between MTC devices without human intervention. In MTC, a large number of devices try to access over communication resource with a short period of time. Due to the limited communication resource, resource contention becomes severe and it brings about access failures of devices. To solve the problem, it needs to regulate device accesses. In this paper, we present an efficient access management scheme. We measure the number of devices which try to access in a certain time period and predict the change of the number of devices in the next time period. Using the predicted change, we control the number of devices which try to access. To verify our scheme, we conduct experiments in terms of success probability, failure probability, collision probability and access delay.

• Journal of Korean Society of Transportation
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• v.35 no.1
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• pp.50-62
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• 2017

As the use of private cars increases along with the technological advancement in the automobile industries and their capabilities to supply, a wide range of issues are followed including the increase in traffic congestion costs, pavement damages and more. In spite of consistent effort to resolve such urban traffic problems, the modal share rate of private cars continuously increases, thus it is becoming more important to explore the ways to enable drivers to take reasonable measures, in self-motivated manner, by taking part of the transportation demand management policy rather than to rely on the strict enforcement of control policy. Considering that the urban transportation infrastructures are in much better shape than before, it is necessary to implement Mobility Management (MM) that induces reasonable usage of private cars by promoting the change in one's consciousness and behavior through communication. Hence, the research studies the factors that influence the mobility through the survey targeting the citizens of Busan on their awareness on the former transportation demand management policy, to explore the ways to motivate the citizens' involvement in reducing the use of private cars as a measure of Mobility Management.

• Korean Journal of Construction Engineering and Management
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• v.22 no.2
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• pp.12-20
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• 2021

Unsafe working environments slow down working speed in that it takes a lot of time to respond in case of an accident, greatly reducing the productivity of construction work. Therefore, proper safety management that does not impede the productivity of construction works is a very important factor for successful construction project. However especially in mega project, the mutual effects of safety management and productivity are complex. Therefore, this study establishes a causal model between safety management and productivity influencing factors based on effectiveness metrics, and analyzes the effect of increased site congestion due to excessive personnel input, irregular safety measures and inefficient change of work schedules. The result of this study, is expected to contribute to enhancing the competitiveness of the construction industry as the basis for establishing a safety management plan that can secure appropriate productivity.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.4
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• pp.44-51
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• 2005

In this study, the method of extracting road centerline's coordinate and road facilities is presented using RC helicopter photogrammetry system. From the survey of extracted road centerline, the errors turned out to be -0.117m ~ 0.103m on the X-axis and -0.014m ~ 0.009m on the Y-axis when RC Helicopter photogrammetry system utilized. By application of this system, hereafter, not only management of road facilities but also construction of DB would be enable which need positioning and design of alignment on the access is not easy area such as traffic congestion or toparchy area.

• Journal of Korean Society of Transportation
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• v.14 no.1
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• pp.51-67
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• 1996

The optimal path-finding problem becomes complicated when multiple variables are simultaneously considered such as physical route length, degree of congestion, traffic capacity of intersections, number of intersections and lanes, and existence of free ways. Therefore, many researchers in various fields (management science, computer science, applied mathematics, production planning, satellite launching) attempted to solve the problem by ignoring many variables for problem simplification, by developing intelligent algorithms, or by developing high-speed hardware. In this research, an integration of expert system technique and case-based reasoning in high level with a conventional algorithms in lower level was attempted to develop an optimal path-finding system. Early application of experienced driver's knowledge and case data accumulated in case base drastically reduces number of possible combinations of optimal paths by generating promising alternatives and by eliminating non-profitable alternatives. Then, employment of a conventional optimization algorithm provides faster search mechanisms than other methods such as bidirectional algorithm and $A^*$ algorithm. The conclusion obtained from repeated laboratory experiments with real traffic data in Seoul metropolitan area shows that the integrated approach to finding optimal paths with consideration of various real world constraints provides reasonable solution in a faster way than others.

• Journal of the Korea Society of Computer and Information
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• v.10 no.6 s.38
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• pp.227-232
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• 2005

A network of Packet based switch Mode will be required to carry the traffics(CVR,VBR, UBR, ABR) generated by a wide range of services. Packet based Network services the quality-of-Service (QoS) management of traffic sources and bandwidth. Besides efficiency and throughput services are achieved in the multimedia traffic sent in the network. In this paper. the scheduler transmits the safe packet, drop the unsafe packet and evaluate unsafe packet as the requirement of the delay avoiding the network congestion for improving the QoS of the multimedia network In this paper. we Propose the scheduling algorithm which evaluates and drops the packet . The suggested model performance of the switch is estimated and simulated in terms of the delay by computer.

• Korean Journal of Veterinary Service
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• v.28 no.1
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• pp.31-38
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• 2005

To examine the prevalence and type of lesions in urinary bladder of Korean cattle, a random sampling survey was performed at a Jeonju abattoir in September 2000 and January 2001. Collected urinary bladder were examined grossly and histopathologically and the patterns of disease were investigated with season and sex. Of 735 cattle(99 bulls and 246 cows in September and 141 bulls, 3 steers, and 246 cows in January) surveyed, $26.3\%$ cattle with evident lesions were found. The most common gross finding was urolithiasis of urinary bladder($23.8\%$). Other lesions included hemorrhage($5.9\%$), congestion($4.1\%$), hematuria($2.7\%$), pyuria($0.7\%$), hyperplasia($0.5\%$). Urinary calculi collected in this study contained 80 to $90\%$ of calcium oxalate and 10 to $20\%$ of struvite, with or without $20\%$ of cystine and $10\%$ of uric acid. This study on urolithiasis and pathology of urinary bladder of slaughtered Korean cattle revealed subclinical aspects and management problem in Korean beef product.