• The Journal of Society for e-Business Studies
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• 제17권4호
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• pp.39-56
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• 2012

Technological advancements in information technology including RFID and mobile technologies have made it feasible to track the customers travel path in a store. The customer travel paths provide valuable implications to understanding the customer behaviors in a store. In our research, we develop a shopping path analysis system to track and analyze the customer travel path. The proposed system consists of RFID systems for collecting the customer paths and analysis system. The analysis system conducts clustering for identifying the distinctive shopping patterns, and analyzes the profile of a grocery, such as congestion rate, visiting rate, and staying time, etc. We show the applicability of our proposed system using the actual data obtained at a grocery in Seoul as a case study.

• Journal of Korean Society of Transportation
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• 제25권5호
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• pp.195-207
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• 2007

The urban railways connecting between the inner city and suburb of Seoul metropolitan area, has lost the competitiveness against cars because too many stops deteriorated operating speed and passenger's level of service. This paper suggests that an express train should be introduced into the urban railway system in order to sort out such a complication. There are two considerations in the present study. Firstly, train schedule problem should be taken into account. In this regard, a new model for urban railway system was developed by revising the existing models dealing with single line freight railway. Approximate branch and bound algorithm based on conflict group rather than a single conflict was adopted. Consequently, it was found that the time saving in calculating the optimal schedule is the most meaningful contribution of the algorithm. The second consideration is associated with the application of the model. A case study was carried out using the actual operation data from Ansan line. In conclusion, the operation speed of the line can increase considerably with minimal number of new sidings.

• Journal of Korean Tunnelling and Underground Space Association
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• 제16권4호
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• pp.387-402
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• 2014

In congested urban areas, constructions of tunnel structures have became necessary due to a lack of surface space. The excavation of any tunnel generated the ground disturbances of surrounding ground and displacements is major concern. Therefore, a study of tunnel stability is necessary. In this study, the authors have investigated the stability and failure pattern of tunnel through the model tunnel test. In this study, the close range photogrammetry was used to measure the ground deformation. The measured data was converted to displacement vectors and contours. And then it compared to FE analysis and empirical formula. In addition, this study presented the comparison between steel pipe reinforced model tunnel and unreinforced model tunnel. The ground deformation for both the steel pipe reinforced model tunnel and the unreinforced model tunnel was analysed.

• KIPS Transactions on Computer and Communication Systems
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• 제1권2호
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• pp.99-102
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• 2012

The performance of P2P application services may be improved by reducing unnecessary inter-network traffic through intelligent peer selection. However, since a logical link between peers in a P2P overlay network is composed of a set of physical links in an underlay network, the traffic pattern determined by the sending rates of selected peers imposes loads on each underlay links. Thus, if the sending rates are not determined carefully, the loads between underlay links may not be balanced, which means some links are underloaded while the other links are congested. In this paper, we take an optimization approach to determine the sending rates of peers strategically to avoid the inefficient use of underlay links. The proposed scheme also guarantee the minimum receiving rates of peers while minimizing the maximum link utilization of underlay links, which is beneficial both to P2P applications and an underlay network.

• Journal of the Institute of Convergence Signal Processing
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• 제7권2호
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• pp.60-64
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• 2006

In typical video streaming services such as MPEG encoded video, the transmission data sizes change depending on the frame types and the required bandwidth for QoS support also changes as time passes. Accordingly, in video streaming services using the Internet it could happen that the video services stop occasionally due to instantaneous deficiencies of the required bandwidth under unexpected congestion even if the highest priority is allocated to the service by network administration. In this paper, we investigate several methods for bandwidth allocation and traffic engineering to support MPEG video traffic and propose a new method to reduce the transmission delay and enhance the throughput, there by provisioning the QoS requirements. In the proposed scheme, LSPs are established based on temporal variation patterns of the Internet traffic and the CQ_LLQ policing scheme is applied for traffic shaping at the ingress routers. Finally we verified the performance of the proposed scheme via computer simulations using OPNET.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• 제13권4호
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• pp.30-37
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• 2014

The Electronic Toll Collection System based on Free-Flow Multi-Lane is needed to solve some yearly problems such as traffic congestion, safety accident, maintenance by hold-up of one way hi-pass system. The hi-pass communication system is first-in, first-out method in one way environment so, it can't handle various running patterns such as vehicle platoon, switching lane and passing in multi-lane environment. In this thesis we compared and analyzed the communication system of foreign countries ETCS operating system and domestic hi-pass communication system, then studied communication system which can run in multiple-way accepting existing hi-pass OBU. And we formed the communication system of Free-Flow Multi-Lane environment as a plan using incoherent of IR antenna and coherent of RF antenna. The communication system in Free-Flow Multi-Lane environment can be used not alone in parking garages but in expressways of ETCS and toll roads from now on.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• 제10권6호
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• pp.74-83
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• 2011

The high-pass transportation information system directly collects section information by using probe cars and therefore can offer more reliable information to drivers. However, because the running condition and features of probe cars and statistical processing methods affect the reliability of the information and particularly because the section travel time is greatly influenced by whether there has been delay by signals on urban roads or not, there can be much deviation among the collected individual probe data. Accordingly, researches in multilateral directions are necessary in order to enhance the credibility of the section information. Yet, the precedent studies related to high-pass information provision have been conducted on the highway sections with the feature of continuous flow, which has a limit to be applied to the urban roads with the transportational feature of an interrupted flow. Therefore, this research aims at analyzing the features of high-pass transportation data on urban roads and finding a proper processing method. When the characteristics of the high-pass data on urban roads collected from RSE were analyzed by using a time-space diagram, the collected data was proved to have a certain pattern according to the arriving cars' waiting for signals with the period of the signaling cycle of the finish node. Moreover, the number of waiting for signals and the time of waiting caused the deviation in the collected data, and it was bigger in traffic jam. The analysis result showed that it was because the increased number of waiting for signals in traffic jam caused the deviation to be offset partially. The analysis result shows that it is appropriate to use the mean of this collected data of high-pass on urban roads as its representative value to reflect the transportational features by waiting for signals, and the standard of judgment of delay and congestion needs to be changed depending on the features of signals and roads. The results of this research are expected to be the foundation stone to improve the reliability of high-pass information on urban roads.

• Korean Journal of Environment and Ecology
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• 제31권2호
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• pp.266-274
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• 2017

The purpose of this study was to analyze the number of visitors to the top of Seoseokdae in Mudeungsan National Park, in which visitors are concentrated, and their visiting patterns, thereby suggesting measures to manage the visitors. The number of annual visitors and the numbers of regional and seasonal visitors to Mudeungsan National Park, which affect the concentration of visits to Seoseokdae were analyzed using the data produced by an automatic digitizing device. A field study was conducted to examine the number of seasonal and periodic visitors to Seoseokdae and their visiting patterns. In 2015, the number of visitors was 2,563,651 and 83.9% of the visitors visited via the Jeungsimsa and Wonhyosa area that is near Gwangju City. This area is close to the Seoseokdae area and it is easy to hike between the areas. Therefore, there was an influx of most visitors to Seoseokdae into the Jeungsimsa and Wonhyosa area. In terms of seasonal visitors, the largest number of visitors came in the fall, followed by the summer, spring, and winter in order. However, the seasonal differences were not notable. There was no statistically significant correlation between the number of visitors and meteorological factors. This result may have been because Gwangju citizens frequently visit Mudeungsan regardless of period and weather. Visitors can get to Seoseokdae via the trails into Wonhyosa and Jangbuljae. A slightly larger number of visitors used the trail into Jangbuljae in the fall and winter, whereas a larger number of visitors used the trail into Wonhyosa in the summer. In general, there is a large influx of visitors into Jangbuljae, a strategic visiting point. However, a slightly larger number of visitors may have chosen the trail into Wonhyosa in the summer because they could hike under the shade of trees. In the summer, visitors stayed in Seoseokdae for a short time with a low level of crowdedness. On the other hand, in the fall and winter, visitors stayed in the area longer because they had lunch and rested. During the time, the number of momentary maximum visitors peaked, causing extreme crowdedness. Therefore, some visitors showed the visiting pattern of entering the grassland outside the designate zone. Because this behavior can damage the grassland on the top of Seoseokdae, which can lead to soil erosion, intensive visitor management may be necessary.

• Journal of Korea Multimedia Society
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• 제7권8호
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• pp.1066-1077
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• 2004

Dramatic increase in the number of Internet users want highly qualified service of continuous media contents on the web. To solve these problems, we present two network caching schemes(PPC, PPCwP) which consider the characteristics of continuous media objects and user access pattern in this paper. While there are plenty of reasons to create rich media contents, delivering this high bandwidth contents over the internet presents problems such as server overload, network congestion and client-perceived latency. PPC scheme periodically calculates the popularity of objects based on the playback quantity and determines the optimal size of the initial fraction of a continuous media object to be cached in proportion to the calculated popularity. PPCwP scheme calculates the expected popularity using the series information and prefetches the expected initial fraction of newly created continuous media objects. Under the PPCwP scheme, the initial client-perceived latency and the data transferred from a remote server can be reduced and limited cache storage space can be utilized efficiently. Trace-driven simulation have been performed to evaluate the presented caching schemes using the log-files of iMBC. Through these simulations, PPC and PPCwP outperforms LRU and LFU in terms of BHR and DSR.

• Journal of Korean Society of Transportation
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• 제18권5호
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• pp.83-97
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• 2000

The traffic management schemes through traffic signal control and information provision could be effective when the link-level data and trip-level data were used simultaneously in analysis Procedures. But, because the trip-level data. such as origin, destination and departure time, can not be obtained through the existing surveillance systems directly. It is needed to estimate it using the link-level data which can be obtained easily. Therefore the objective of this study is to develop the model to estimate O-D demand using only the link flows in highway network as a real time. The methodological approaches in this study are kalman filer, least-square method and normalized least-square method. The kalman filter is developed in the basis of the bayesian update. The normalized least-square method is developed in the basis of the least-square method and the natural constraint equation. These three models were experimented using two kinds of simulated data. The one has two abrupt changing Patterns in traffic flow rates The other is a 24 hours data that has three Peak times in a day Among these models, kalman filer has Produced more accurate and adaptive results than others. Therefore it is seemed that this model could be used in traffic demand management. control, travel time forecasting and dynamic assignment, and so forth.