• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.3
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• pp.99-106
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• 2023

In this paper, we propose subregion-based area of interest management techniques for MMORPG(massively multiplayer online role playing games) integrating P2P(peer-to-peer) networking and cloud computing. For the crowded region, the proposed techniques partition it into several subregions and assign a player to manage each subregion as a coordinator. These techniques include a load balancing mechanism which regulates communication and computation overhead of such player below the specified threshold. We also provide a mechanism for satisfying the criterion, where subregions overlapped with each player's view must be switched quickly and seamlessly as the view moves around in the game world. In the proposed techniques where an efficient provisioning of resources is realized, they relieve a lot of computational power and network traffic, the load on the servers in the cloud by exploiting the capacity of the players effectively. Simulation results show that the MMORPG based on cloud and P2P architecture can reduce the considerable bandwidth at the server compared to the client server architecture as the available resources grow with the number of players in crowding or hotspots.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6D
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• pp.675-683
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• 2009

A Basic experimental study for the development of vibration-power generation system from the vibration energy of urban infrastructure, such as a railroad, highway, and bridges, was carried out to harvest electricity from moving vehicles. Starting with the proposal of vibration power generator which converts vibration energy to an electric power by using self-induction technology, the research explains the basic concept of self-induction technology and the dynamic characteristics of a ibration power generator. Also, in order to analyze the correlation of an electromotive force from vibration power generator which depends on external force and vibration speeds, many indoor experiments with various variables were achieved. Based on the experimental results, a vibration power generator system's ability were analyzed. With those results, basic data of vibration power generator system to acquire the maximum available power was confirmed.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.2
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• pp.73-86
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• 2018

The increase in the number of private automobiles has incurred various traffic problems. Globally, studies on MaaS(Mobility as a Service) has already been initiated to mobilize the use of public transportation in reducing private passenger cars in roads. This study aims to analyze the passenger's optimal route considering the transfer between different transportation modes through simulation, and analyze the effect of available route through the connected transportation modes. Sejong Special Self-Governing City was chosen as the study area due to its extensive transportation network. As a result of the analysis, the predominant obtainable route is derived either from using public transportation (i.e. bus and subway) only or by bicycle. However, it is also possible to use the car sharing and public bicycle to reach their final destination efficiently when paths that can be traversed were more scrutinized. When various transportation information and location-based services are introduced in smart phone applications, they can provide very useful information to passengers, and also promote social problems such as traffic congestion and environmental issues in the future.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.2
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• pp.273-280
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• 2010

This study aims to research into a plan for the spatial design on the major facilities in new-town region in Mongolia by using the spatial analytical technique in GIS. In case of Mongolian region, the demand for new-town development is rapidly increasing around Ulaanbaatar, where is the capital. On the other hand, the adequately relevant ground or the spatial-design technique is failing to be applied. This study extracted the region available for developing new down by using spatial analytical technique in GIS, and researched into the spatial-design plan for housing complex, filtration plant, sewage disposal plant, power plant, general park, crematory. The housing complex in the targeted region could be known to be adequate to be positioned around watercourse and road. It could be known to be adequate for filtration plant, which is the source of drinking water, to be located in the upper-stream region of a river, which is secured good quality of water, and for sewage disposal plant to be located in the lower-stream region available for minimizing occurrence of contamination. It is judged to be required for a proposed site of power plant to be located in the upper-stream region, for the park unit, which is space of the living culture, to be repaired and expanded the existing facilities, and for traffic network to be expanded through predicting demand along with new-town development. It is judged to be probably needed to be reflected even the flexible aspect for changing design through surveying the feasibility and economic efficiency on the future spatial design.

• Journal of Korean Society of Transportation
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• v.18 no.2
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• pp.91-101
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• 2000

The optimal congestion charge in transportation economics corresponds to the solution to the welfare maximization Problem for users of a certain road link where congestion takes Place. This congestion charge is in nature the optimal Price of the transportation facility, which is derived by the Partial equilibrium analysis on that facility. Therefore it is not certain that this congestion charge can maximize the well-being of all the users of the total transportation network, since the analysis does not count the impact of the congestion charge on traffic volumes of other links. This study suggests an alternative approach to estimate the optimal congestion charge. The key difference of this study from Previous ones is to derive the solution through the general equilibrium analysis on a market where several transportation facilities as well as Private goods are available to consumers. This approach shows a set of solutions a little different from the Previous one, which are explained below. The optimal congestion charge is derived for two different cases. One is the situation of which the congestion charge is levied on every transportation facility In this case, the optimal solution of each facility should equate the marginal utility of every user to the marginal cost of the corresponding facility. This analysis result in general equilibrium coincides with the Previous analysis result in partial equilibrium. However this result cannot apply to another case of which the charge is imposed only on a certain transportation facility. In this case, the optimal charge on a certain transportation facility should be less than the optimal congestion charge of partial equilibrium analysis.

• The KIPS Transactions:PartC
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• v.12C no.4 s.100
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• pp.597-602
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• 2005

In this study, file size for measurement and the service system's billing data were submitted to a comparative analysis by performing a verification test on the billing system of three major mobile communication services providers, based on the wireless Internet service packet. As shown in the result of the verification test, there were some differences in the billing data due to transmission overhead, according to the network quality that is affected by the wireless environment of mobile operators. Consequently, the packet analysis system was proposed as a means of applying consistent packet billing to all service providers being compared. If the packet analysis system is added to supplement the current billing system various user requirements can be met. Billing by Packet among mobile operators and differentiated billing based on the content value are available, since the packet data can be extracted through protocol analysis by service, and it can be classified by content tape through traffic data analysis. Furthermore, customer's needs can be satisfied who request more information on the detailed usage, and more flexible and diverse billing policies can be supported like application of charging conditions to the non-charging packet handling. All these services are expected to contribute to the popularization of the wireless Internet service, since user complaints about the service charge could be reduced.

• Archives of design research
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• v.20 no.1 s.69
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• pp.45-54
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• 2007

Recent research regarding local traditions, cultural heritage, and sightseeing resources that represent local characteristics for the purpose of local promotion has been actively advanced. Yangyeongsi in Daegu, South Korea is Doing developed as a core location in order to revitalize regional culture. The unique tradition and functions of this city area have been preserved. Previous research "The Fundamental Research of Revitalization for Yangyeongsi in Daegu for the Local Promotion" undertaken by the author revealed a lack of fundamental research available to establish an understanding of how to revitalize Yangyeongsi. The research methodology designed this by, (1)a site investigation and verification of previous research (2)a deep analysis of Yangyeongsi to uncover potential improvement opportunities (3) assessment of essential elements and appropriate directions for revitalization of the traditional market (4) application of the environment design improvement process to the local design center. The design proposal is that, firstly, space assessment will De improved by the maintenance and expansion of fundamental facilities. Secondly, space application can be maximized by servicing the complex road network through a traffic flow plan. In addition, consideration for the local characteristics will promote unity and identification with the region. Lastly, revitalization and industrialization development of sightseeing resources and secure streets and event spaces will promote enjoyable experiences for visitors. Research results were submitted to the local authority and applied to the future policy plan. Continuous research on revitalization and analysis of the local characteristics are recommended in order to benefit local promotion.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.12
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• pp.34-43
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• 2007

Recently, in addition to the sharp increase of mobile nodes, various kinds of wireless technologies are available for mobile nodes. If IPv6 technology is applied to the network, multi-homing terminals which have several public IP addresses on one interface will be common. Accordingly, there are many research activities on mobility management for multi-interface, multi-homming nodes. In this paper we propose an extended fast handover mechanism for multi-interface MIPv6 environments that uses multi-interface FBU (MFBU) message instead of the existing FBU message. The MFBU message has the "tunnel destination" mobility option that points a specific tunnel destination other than NAR, and "T" flag that indicates the existence of tunnel destination option. The proposed mechanism can improve the TCP performance by mitigating packet reordering during FMIPv6 handover that can cause unnecessary congestion control due to 3 duplicate ACKs. In this paper, we implemented a multi-Interface MIPv6 simulator by extending a single-interface MIPv6 simulator in NS-2, and showed that the performance of TCP traffic is improved by using the proposed multi-interface fast MIPv6.

• Journal of Korean Society of Transportation
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• v.22 no.7 s.78
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• pp.155-159
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• 2004

Recently, there are many trials about Artificial neural networks : ANNs structure and studying method of researches for forecasting traffic volume. ANNs have a powerful capabilities of recognizing pattern with a flexible non-linear model. However, ANNs have some overfitting problems in dealing with a lot of parameters because of its non-linear problems. This research deals with the application of a variety of model selection criterion for cancellation of the overfitting problems. Especially, this aims at analyzing which the selecting model cancels the overfitting problems and guarantees the transferability from time measure. Results in this study are as follow. First, the model which is selecting in sample does not guarantees the best capabilities of out-of-sample. So to speak, the best model in sample is no relationship with the capabilities of out-of-sample like many existing researches. Second, in stability of model selecting criterion, AIC3, AICC, BIC are available but AIC4 has a large variation comparing with the best model. In time-series analysis and forecasting, we need more quantitable data analysis and another time-series analysis because uncertainty of a model can have an effect on correlation between in-sample and out-of-sample.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.1
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• pp.95-107
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• 2017

In this study, a preliminary study was undertaken for development of a tunnel incident automatic detection system based on a machine learning algorithm which is to detect a number of incidents taking place in tunnel in real time and also to be able to identify the type of incident. Two road sites where CCTVs are operating have been selected and a part of CCTV images are treated to produce sets of training data. The data sets are composed of position and time information of moving objects on CCTV screen which are extracted by initially detecting and tracking of incoming objects into CCTV screen by using a conventional image processing technique available in this study. And the data sets are matched with 6 categories of events such as lane change, stoping, etc which are also involved in the training data sets. The training data are learnt by a resilience neural network where two hidden layers are applied and 9 architectural models are set up for parametric studies, from which the architectural model, 300(first hidden layer)-150(second hidden layer) is found to be optimum in highest accuracy with respect to training data as well as testing data not used for training. From this study, it was shown that the highly variable and complex traffic and incident features could be well identified without any definition of feature regulation by using a concept of machine learning. In addition, detection capability and accuracy of the machine learning based system will be automatically enhanced as much as big data of CCTV images in tunnel becomes rich.