• Spatial Information Research
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• v.17 no.3
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• pp.361-370
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• 2009

As the increasing interests of spatial information for different application area such as disaster management, there are many researches and development of indoor spatial data models and real-time evacuation management systems. The application requires to determine and optical paths in emergency situation, to support evacuees and rescuers. The optimal path in this study is defined to guide rescuers, So, the path is from entrance to the disaster site (room), not from rooms to entrances in the building. In this study, we propose a time-dependent optimal routing algorithm to develop real-time evacuation systems. The network data that represents navigable spaces in building is used for routing the optimal path. Associated information about environment (for example, number of evacuees or rescuers, capacity of hallways and rooms, type of rooms and so on) is assigned to nodes and edges in the network. The time-dependent optimal path is defined after concerning environmental information on the positions of evacuees (for avoiding places jammed with evacuees) and rescuer at each time slot. To detect the positions of human beings in a building per time period, we use the results of evacuation simulation system to identify the movement patterns of human beings in the emergency situation. We use the simulation data of five or ten seconds time interval, to determine the optimal route for rescuers.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.6
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• pp.52-59
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• 2008

Most pier performance analysis results for ad-hoc routing protocols have been based upon the model which each node in the network moves independently without restriction. In most real environments, however, it is very common for a group or multiple groups to move under the direction of group leader or group leaders instead of each node's independent movement. This paper presents the performance analysis of routing protocols for mobile ad-hoc network under group mobility environment. The comparative simulations have been made between a table-driven protocol, DSDV, and two on-demand protocols, AODV and DSR, under a group mobility model, RPGM, which is suitable for the practical applications such as military tactical operation. Multiple group movements are also included. The results show that the protocol performances for single group movement are very similar to node independent movement case. However some differences have been observed by varying pause time and connectivity.

• Journal of Internet Computing and Services
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• v.23 no.5
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• pp.135-143
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• 2022

As the world has implemented social distancing and telecommuting due to the spread of COVID-19, real-time streaming sessions based on routing protocols have increased dependence on the Internet due to the activation of video and voice-related content services and cloud computing. BGP is the most widely used routing protocol, and although many studies continue to improve security, there is a lack of visual analysis to determine the real-time nature of analysis and the mis-detection of algorithms. In this paper, we analyze BGP data, which are powdered as normal and abnormal, on a real-world basis, using an anomaly detection algorithm that combines statistical and post-processing statistical techniques with Rule-based techniques. In addition, we present an interactive spatio-temporal analysis plan as an intuitive visualization plan and analysis result of the algorithm with a map and Sankey Chart-based visualization technique.

• Journal of Korea Water Resources Association
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• v.33 no.3
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• pp.341-350
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• 2000

The objectives of this study are to develop a state-space form of stochastic dynamic storage function routing model and to test the model performance for real-time flow forecast. The selected study area is the main Han River starting from Paldang Dam site to Indogyo station and the 13 flood events occurred from 1987 to 1998 are selected for computing model parameters and testing the model performance. It was shown that the optimal model parameters are quite different depending on Hood events, but the values used on field work also give reasonable results in this study area. It is also obvious that the model performance from the stochastic-dynamic model developed in this study gives more accurate and reliable results than that from the existing deterministic model. Analysis for allowable forecast lead time leads that under the current time step the reasonable predicted downstream flows in 5 hours time advance are obtained from the stochastic dynamic model on relatively less lateral inflow event in the study area.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.11a
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• pp.252-255
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• 2003

This article concerns the event management of the transportation and delivery system in the real time environment. Until now mainstream researches in the transportation and delivery area have largely focused how to create optimized vehicle routing schedule fast and stably, although the execution and event management area has a lot of opportunities which could make logistics efficient and especially customers satisfied. This paper suggests to-be model processes how to execute vehicle routing schedule correctly and when events are occurred how to cope with them effectively. To embody such ideas GIS, GPS and Mobile technologies are attached on optimizing scheduler engine, TMS, WMS, ATP and Monitoring system.

• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.185-194
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• 2008

The objective of this paper is to design the dynamic route guidance system(DRGS) and develop an ant algorithm based on routing mechanism for finding the multiple shortest paths within limited time in real traffic network. The proposed ant algorithm finds a collection of paths between source and destination considering turn-restrictions, U-turn, and P-turn until an acceptable solution is reached. This method can consider traffic constraints easily comparing to the conventional shortest paths algorithms.

• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.2
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• pp.13.2-20
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• 1995

An water balance model was formulated to simulate the change in water levels at the estuary reservoir from sluice gate releases and the inflow hydrographs, and an one-di- mensional flood routing model was formulated to simulate temporal and spatial varia- tions of flood hydrographs along the estuarine river. Flow rates through sluice gates were calibrated with data from the estuary dam, and the results were used for a water balance model, which did a good job in predicting the water level fluctuations. The flood routing model which used the results from two hydrologic models and the water balance model simulated hydrographs that were in close agreement with the observed data. The flood forecasting model was found to be applicable to real-time forecasting of water level fluc- tuations with reasonable accuracies.

• Magazine of the Korean Society of Agricultural Engineers
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• v.36 no.3
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• pp.67-73
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• 1994

This paper is to validate the proposed models for the real-time forecasting for the Keum river estuary dam such as tidal-level forecasting model, one-dimensional unsteady flood routing model, and Kalman filter models. The tidal-level forecasting model was based on semi-range and phase lag of four tidal constituents. The dynamic wave routing model was based on an implicit finite difference solution of the complete one-dimensional St. Venant equations of unsteady flow. The Kalman filter model was composed of a processing equation and adaptive filtering algorithm. The processng equations are second ordpr autoregressive model and autoregressive moving average model. Simulated results of the models were compared with field data and were reviewed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.10
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• pp.4054-4071
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• 2015

Named-Data Networking (NDN) is one of the promising approaches for the Future Internet to cope with the explosion and current usage pattern of Internet traffic. Content provider mobility in the NDN allows users to receive real-time traffic when the content providers are on the move. However, the current solutions for managing these mobile content providers suffer several issues such as long handover latency, high cost, and non-optimal routing path. In this paper, we survey main approaches for provider mobility in NDN and propose an optimal scheme to support the mobile content providers in the large-scale NDN domain. Our scheme predicts the movement of the provider and uses state information in the NDN forwarding plane to set up an optimal new routing path for mobile providers. By numerical analysis, our approach provides NDN users with better service access delay and lower total handover cost compared with the current solutions.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1986.04a
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• pp.119-124
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• 1986

This paper describes the development of the KORNET that may be regarded as the latest public packet-swiched computer communication network. The KORNET project included the development of the network management center (NMC), a network concentrator. For the KORNET we use the virtual circuit(VC) method, a distributed adaptive routing algorithm, and a dynamic buffer management algorithm. The NMC acts as a nerve center of the network, performing such function as network monitoring, subscriber and network management and routing management, etc. As for the NNP and NC hardware, we have implemented them with the 16-bit multitask/multiprocessor technology using MC68000 microprocessors. Softwares have been developed using C language is required for real time processing. All the network protocols we have developed comply completely with the latest CCITT recommendations including X.25, X,3 , X.28 and X.29.