• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.12
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• pp.120-127
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• 2008

HMIPv6 draws lots of attentions in recent years for providing an efficient handover and reducing the signaling overhead. HMIPv6 employs MAP(Mobility Anchor Point) in order to minimize a signaling overhead and a local mobility management. MAP completes an efficient mobility management in HMIPv6 network environment with frequent handover. However, HMIPv6 causes load concentration at a paricular MAP and may have unnecessary latency between HN(Mobile Node) and CN(Correspondent Node) within the same network. A MAP may also disturb the route optimization in HMIPv6 network because all packets must be transmitted through a MAP. In this paper, we propose a scheme to optimize the route in HMIPv6 networks according to MAP load. We configure a threshold in order to support the better service into MAP domain. The packets do not pass through MAP and are directly transmitted to AR(Access Router) if the number of current MNs attached to the MAP exceed the desired threshold. We simulate the performance of the proposed scheme and compare with HMIPv6. Resultly, the proposed scheme reduces signaling costs and mitigates concentration of a paticular MAP as well.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.67-75
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• 2020

This paper proposes a methodology for gantry route optimization in order to maximize the productivity of a odd-type surface mount device (SMD). A odd-type SMD is a machine that uses a gantry to mount electronic components on the placement point of a printed circuit board (PCB). The gantry needs a nozzle to move its electronic components. There is a suitability between the nozzle and the electronic component, and the mounting speed varies depending on the suitability. When it is difficult for the nozzle to adsorb electronic components, nozzle exchange is performed, and nozzle exchange takes a certain amount of time. The gantry route optimization problem is divided into the mounting order on PCB and the allocation of nozzles and electronic components to the gantry. Nozzle and electronic component allocation minimized the time incurred by nozzle exchange and nozzle-to-electronic component compatibility by using an mixed integer programming method. Sequence of mounting points on PCB minimizes travel time by using the branch-and-price method. Experimental data was made by randomly picking the location of the mounting point on a PCB of 800mm in width and 800mm in length. The number of mounting points is divided into 25, 50, 75, and 100, and experiments are conducted according to the number of types of electronic components, number of nozzle types, and suitability between nozzles and electronic components, respectively. Because the experimental data are random, the calculation time is not constant, but it is confirmed that the gantry route is found within a reasonable time.

• Korean Journal of Computational Design and Engineering
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• v.17 no.2
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• pp.71-78
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• 2012

Recently, the ratio of fuel cost to the operational cost of a ship is increasing according to the increase of the international oil price. Thus, many studies are being made to reduce the cost; for example, a method for acquiring the sea state information, a method for estimating fuel consumption, a method for determining the ship's optimal route, and so on. However, these studies were not incorporated together and being independently made in different fields. In this study, by improving and incorporating such studies, a method for determining a ship economic route based on the acquisition of the sea state and estimation of fuel consumption was proposed. To evaluate the applicability of the proposed method, it was applied to an optimal routing problem of the ocean area including many islands. The result shows that the proposed method can yield the economic route minimizing fuel consumption.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.2
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• pp.617-626
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• 2014

Lately, losses and damage from natural disasters have been increasing. Researchers across various fields in Korea are trying to come up with a response plan, but research for evacuation plans is still far from satisfactory. Hence this paper proposes a model that could find an optimized evacuation route for when disasters occur over wide areas. Development of the model used methods including the Dijkstra shortest path algorithm, feasible path method, genetic algorithm, and pareto efficiency. Computations used parallel computing (SPMD) for high performance. In addition, the developed model is applied to a virtual network to check the validity. Finally the adaptability of the model is verified on a real network by computating for Gumi 1stNational Industrial Complex. Computation results proved that this model is valid and applicable by comparison of the fitness values for before optimization and after optimization. This research can contribute to routing for responder vehicles as well as planning for evacuation by objective when disasters occur.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.344-351
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• 2016

In the point of view of a train operator, the main concern with a train operation is not only to maintain a time schedule, but also to decrease the energy consumption as much as possible. Generally for a manual drive, a train conductor controls the train acceleration and deceleration by controlling the notches not to exceed the regulation velocity by considering the given maximum velocity profile for an operation route. For this case, the guideline for a conductor is needed to choose the proper notches by applying the notch optimization so as to drive at the regulation velocity and minimize energy consumption simultaneously. In this paper, the real-time notch optimization plan is suggested using a genetic algorithm that optimizes the notches for the remaining route in real time when the event occurs that track information or regulation velocity profile of the remaining route changes during train operation as well as a normal operation situation. An energy saving effect and the convergence behavior of the optimal solution obtained was analyzed in a genetic algorithm.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.902-907
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• 2004

In this paper, a multi-step optimization using a G.A. (Genetic Algorithm) with variable penalty function is introduced to the structural design optimization of a 5-head route machine. Our design procedure consist of two design optimization stage. The first stage of the design optimization is static design optimization. The following stage is dynamic design optimization stage. In the static optimization stage, the static compliance and weight of the structure are minimized simultaneously under some dimensional constraints and deflection limits. On the other hand, the dynamic compliance and the weight of the machine structure are minimized simultaneously in the dynamic design optimization stage. As the results, dynamic compliance of the 5-head router machine was decreased by about 37％ and the weight of the structure was decreased by 4.48％ respectively compared with the simplified structure model.

• International Journal of Naval Architecture and Ocean Engineering
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• v.5 no.2
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• pp.246-262
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• 2013

With increases in international oil prices, the proportion of fuel cost to the operational costs of a ship is currently increasing. To reduce fuel cost, a method for determining an economical route for a ship based on the acquisition of the sea state and the estimation of fuel consumption is proposed. The proposed method consists of three items. The first item is to acquire the sea state information in real time. The second item is to estimate the fuel consumption of a ship according to the sea state. The last item is to find an economical route for minimal fuel consumption based on the previous two items. To evaluate the applicability of the proposed method, it was applied to routing problems in various ocean areas. The result shows that the proposed method can yield economical ship routes that minimize fuel consumption. The results of this study can contribute to energy savings for environmentally friendly ships.

• International Journal of Computer Science & Network Security
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• v.22 no.3
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• pp.285-291
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• 2022

WSN is the major component for information transfer in IoT environments. Source Location Privacy (SLP) has attracted attention in WSN environments. Effective SLP can avoid adversaries to backtrack and capture source nodes. This work presents a Two-Level Randomized Sector-based Routing (TLRSR) model to ensure SLP in wireless environments. Sector creation is the initial process, where the nodes in the network are grouped into defined sectors. The first level routing process identifies sector-based route to the destination node, which is performed by Ant Colony Optimization (ACO). The second level performs route extraction, which identifies the actual nodes for transmission. The route extraction is randomized and is performed using Simulated Annealing. This process is distributed between the nodes, hence ensures even charge depletion across the network. Randomized node selection process ensures SLP and also avoids depletion of certain specific nodes, resulting in increased network lifetime. Experiments and comparisons indicate faster route detection and optimal paths by the TLRSR model.

• Proceedings of the Korea Contents Association Conference
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• 2004.05a
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• pp.351-356
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• 2004

The binding update of the Mobile IPv6 which does a route optimization in basic by the node which moves frequently brings about the signaling traffic increase of binding update. It supplements this the MAP(Mobile Anchor Point) for to let, and Hierarchical Mobile IPv6 which considers a macro mobility and a micro rambling regional mobility was proposed. But Mobile IPv6 when transmitting the packet, always does to pass by the mP, the packet intensive actual condition of the MAP to occur it does not guarantee a route optimization. In this study, It accomplishes the course improvement which considers the mobility of mobile node and it interprets the relaxation quality of packet intensive actual condition with the MAP

• Proceedings of the Korea Information Processing Society Conference
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• 2008.05a
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• pp.1035-1038
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• 2008

Network mobility (NEMO) has been studied extensively due to its potential applications in military and public transportation. NEMO Basic Support Protocol (NBSP) [1], the current NEMO standard based on mobile IPv6, can be readily deployed using the existing mobile IPv6 infrastructure. However, for Nested network mobility, multi-level tunnel and too many Binding Update packets results in substantial performance overhead, generally known as route sub-optimality, especially in the bottleneck root mobile router (root-MR) and Access Router. In this paper, we propose a route optimization mechanism for nested network mobility management to reduce the overhead of root-MR. In this system, Mobile Router (MR) has a cache that stores Mobile Network Nodes' (MNN) information, Correspondent Nodes' (CN) information for every MNN，and the attachments information with its subnet MRs. Home Agent performs Binding Update with CNs responsible for MRs. Through this mechanism, the number of tunnel is limited between CN and MR and the overhead of root-MR is reduced obviously.