• Journal of Environmental Science International
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• v.5 no.2
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• pp.229-241
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• 1996

This study was performed to find the most desirable emission reduction for each mobile source pollutant and the optimal control strategy at a given level of expenditures in Pusan City in 2000 by using the interactive s-constraint method developed by Chang-Hyo Lee and Hyung-Wook Kim, which isone of the mathematical programming models. The most desirable emission reduction is 7093 ton/year for particulate (TSP), 4871 ton/year for NOx, 5148 ton/year for HC and 36779 ton/year for CO. The optimal control strategy is as follows; 1. As to passenger car and taxi, limiting VKT (vehicle kilometers travelled) in congested areas will be necessary. In addition to this, improving vehicie inspection Program should be enforced. 2. As to small-gasoline bus, traffic adaptive control system will be necessary. 3. As to small-diesel bus, non-adjustable engine parameters will have to be applied. .4. As to heal bus and heart truck, catalytic trap oxidizer and limiting VKT in congested areas will do necessary. 5. As to motorcycle, 2-cycle motorcycles should be converted to 4-cycle motorcycles.

• Journal of KIISE:Information Networking
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• v.41 no.4
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• pp.177-185
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• 2014

It has been occurred many times that wireless sensor networks (WSNs) had congested areas because all the sensing data collected by multiple sensor nodes are delivered to one sink node. Typically, in order to control congested areas, it used to reduce the traffic by increasing the sensing period or discarding packets. However, those schemes have a disadvantage that it loses the reliability when delivering sensing data. Moreover, there are no schemes considering case of having poor quality of links between nodes in practical terms. In this paper, we suggest a scheme not to reduce the traffic but to distribute the traffic by changing routing paths depends on the traffic and the quality of links. Also, it can be seen that the reliability of delivering of the sensing data is improved with the experiments improving collection rates and shortening end-to-end delay.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.6
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• pp.100-109
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• 2021

Flooding usually brings in disruptions and aggravated congestions to the roadway network. Hence, right information should be provided to road users to avoid the flood-impacted areas and for city officials to recover the network. However, the information about individual link congestion may not be conveyed to roadway users and city officials because too many links are congested at the same time. Therefore, more significant information may be desired, especially in a disastrous situation. This information may include 1) which places to avoid during flooding 2) which places are feasible to drive avoiding flooding. Hence, this paper aims to develop a framework to identify the flood-impacted areas in a roadway network and their criticality. Various impacted clusters and their spatiotemporal properties were identified with field data. From this data, roadway users can reroute their trips, and city officials can take the right actions to recover the affected areas. The information resulting from the developed framework would be significant enough for roadway users and city officials to cope with flooding.

• Journal of Navigation and Port Research
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• v.32 no.7
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• pp.521-527
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• 2008

The Istanbul Strait is one of the important waterways in the world. And its southern entrance has a highly congested local traffic. Till now there are several studies regarding how the Istanbul Strait is dangerous to navigate and how those dangers can be mitigated. But there is no study regarding local traffic which is posing great collision risk. In a certain traffic area, marine traffic safety assessment parameters are traffic volume, frequency of collision avoidance maneuver, traffic density, traffic flow and potential encounter, In this paper local traffic volume, traffic flow and potential encounter number of local traffic vessels and possibility of collision are investigated in order to find degree of danger at the southern entrance of the Istanbul Strait. Finally by utilizing those, risky areas are determined for southern entrance of the Istanbul Strait. Results have been compared to a previous study regarding risk analysis at congested areas of the Istanbul Strait (Aydogdu, 2006) and consistency of the results were presented.

• Korean Journal of Remote Sensing
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• v.31 no.4
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• pp.331-336
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• 2015

In this study, a numerical model developed for sunshine duration based on GIS data was used. This model considers blocking caused by topography and buildings and it is properly applicable to evaluation of sunshine duration environment in urban areas. The model reasonably well predicted the solar altitude and azimuth angels, compared to those provided by Korea Astronomy and Space Science Institute (KASI). The developed model was applied to evaluation of sunshine duration environment around the Seonleung Park located near a building-congested area in Seoul. The model well reproduced shadow caused by buildings and/or topography in the numerical domain at 09:00 on August 1, 2015. In addition, the model was applied to finding a suitable measurement sites for pyrheliometer around the Seonleung Park. The model was also usefully applied to finding a suitable site for pyrheliometer in an urban area.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.99-103
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• 2003

The most commonly used method for space management in the industry is development of site plans. These plans outline how to manage material deliveries, staging areas, and crane locations for construction sites in suburban area but not in congested urban areas. This study focuses on how to efficiently manage space for construction facilities on high-rise buildings in congested urban areas where normally space for facilities around a building footprint is not available. The limitations of available horizontal space create a need to explore vertical expansion of facilities. This raises new aspects of vertical facility handling and flow that need to be considered in the facility design problem. The construction facilities layout plan method provides layout planners with a valuable technique to develop efficient sequences of work that optimally defines how to efficiently utilize the construction facilities and minimize the travel of specific facilities effort on multiple-floor buildings. A genetic algorithm-based heuristic will be presented for generating block layouts for multiple-floor la)rout problems.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.12
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• pp.828-835
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• 2011

The purpose of this study is to analyze and evaluate the 3 types of indoor ventilation methods such as natural, mechanical, and hybrid ventilation in high-rise building which is affected by stack effect and outdoor air pressure. For the evaluation of the ventilation capacity, CFD simulation was performed in a typical high-rise residential building. The results of the simulations are as follows: 1) Natural ventilation method is not enough to the regulation. 2) In case of mechanical ventilation, congested area is occurred but meets the regulation. 3) In case of hybrid ventilation with stack effect, all the areas of indoor meet the regulation and congested area is reduced. 4) In case of high-rise building, the differences of ventilation rate among houses in the building are not large because the mechanical ventilation is main factor.

• KIEAE Journal
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• v.6 no.3
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• pp.35-42
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• 2006

The apartment buildings now covers more than 50% of the total residential types in Korea and the urban residential area becomes increasingly congested with newly constructed high-rise apartment buildings. Judicial precedents require, for securing the solar rights in the residential area, that the consecutive sunshine duration should be at least two hours from 9:00 to 15:00 or the accumulative sunshine duration should be at least four hours from 8:00 to 16:00 as of the winter solstice. Disputes are increasing, however, on infringed solar rights and view rights for the neighboring structures as cases occur where the requirement cannot be satisfied in congested residential areas. The sunshine duration scan be assessed by measuring it on the site of the dispute, but it is impracticable to actually measure it for every case on the winter solstice, only one day out of the whole year. At a trial, therefore, 3D computer simulation is used to calculate the sunshine duration and determine the extent of infringement for submission of the evaluation to be used as the basis of the judgment. The simulation, however, may have an error in its result up to the program characteristics and the accuracy of the input data such as the structure shape and height, the distance between structures, and the ground level. This study, therefore, used a self-developed VIEW program with Autodesk VIZ 2006 to provide a simulation method for solar access evaluation, and verified its efficacy by comparing the results with the actual measurements.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.1
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• pp.241-269
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• 2012

Wireless networks composed of multimedia-enabled resource-constrained sensor nodes have enriched a large set of monitoring sensing applications. In such communication scenario, however, new challenges in data transmission and energy-efficiency have arisen due to the stringent requirements of those sensor networks. Generally, congested nodes may deplete the energy of the active congested paths toward the sink and incur in undesired communication delay and packet dropping, while bit errors during transmission may negatively impact the end-to-end quality of the received data. Many approaches have been proposed to face congestion and provide reliable communications in wireless sensor networks, usually employing some transport protocol that address one or both of these issues. Nevertheless, due to the unique characteristics of multimedia-based wireless sensor networks, notably minimum bandwidth demand, bounded delay and reduced energy consumption requirement, communication protocols from traditional scalar wireless sensor networks are not suitable for multimedia sensor networks. In the last decade, such requirements have fostered research in adapting existing protocols or proposing new protocols from scratch. We survey the state of the art of transport protocols for wireless multimedia sensor networks, addressing the recent developments and proposed strategies for congestion control and loss recovery. Future research directions are also discussed, outlining the remaining challenges and promising investigation areas.

• Journal of Navigation and Port Research
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• v.47 no.4
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• pp.212-219
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• 2023

Vessel Traffic Service (VTS) area presents a complex traffic pattern due to ships entering or leaving the port to utilize port facilities, as well as ships passing through the coastal area. To ensure safe and efficient management of maritime traffic, VTS operators continuously monitor and control vessels in real time. However, during periods of high traffic congestion, the workload of VTS operators increases, which can result in delayed or inadequate VTS services. Therefore, it would be beneficial to predict traffic congestion and congested areas to enable more efficient traffic control. Currently, such prediction relies on the experience of VTS operators. In this paper, we defined vessel traffic congestion from the perspective of a VTS operator. We proposed a method to generate traffic networks using historical navigational data and predict traffic congestion and congested areas. Experiments were performed to compare prediction results with real maritime data (Daesan port VTS) and examine whether the proposed method could support VTS operators.