• Journal of the Society of Naval Architects of Korea
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• v.45 no.4
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• pp.432-440
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• 2008

Korean shipbuilders are starting to use three dimensional solid CAD systems to enhance their competitiveness in design and production. Despite many merits, three dimensional CAD systems reveal some problems in pipe-line modeling. Pipe-line modeling is heavily dependent on point data in routing. However, since the models built by sweeping or skinning operations do not have data about points and lines on the surfaces, the point data for routing are currently manually calculated by considering the diameters of the pipes and alignment conditions with other pipes. This process is inefficient and prone to errors. In order to enhance the pipe modeling, this paper presents an Offset Routing Program for a three dimensional CAD system, which aids designers to easily define the start points and to generate the pipe routings using reference objects.

• Korean Journal of Computational Design and Engineering
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• v.2 no.1
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• pp.1-10
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• 1997

Finding the optimum route of ship's pipes is complicated and time-consuming process. Experience of designers is the main tool in this process. To reduce design man-hours and human errors a design expert system shell and a geometric modeler is used to automate the design process. In this paper, a framework of the intelligent CAD system for pipe auto-routing is suggested, which consists of general-purpose expert system shell and a geometric modeler. The design expert system and the geometric modeling kernel have been integrated. The CADDS5 of Computervision is used as the overall CAD environment. The Nexpert Object of Neuron Data is used as the expert system shell. The CADDS5 ISSM is used as the interface that creates and modifies geometric models of pipes. Existing algorithms for the routing problem have been analyzed. Most of them are to solve the 2-D circuit routing problems. Ship piping system, specially within the engine room, is a complicated, large scale 3-D routing problem. Methods of expert system have been used to find the route of ship pipes on the main deck.

• Journal of Communications and Networks
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• v.10 no.3
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• pp.268-286
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• 2008

In this work, we review the routing models that use game theoretical methodologies. A very common assumption in the analysis and development of networking algorithms is the full cooperation of the participating nodes. Most of the analytical tools are based on this assumption. However, the reality may differ considerably. The existence of multiple domains belonging to different authorities or even the selfishness of the nodes themselves could result in a performance that significantly deviates from the expected one. Even though it is known to be extensively used in the fields of economics and biology, game theory has attracted the interest of researchers in the field of communication networking as well. Nowadays, game theory is used for the analysis and modeling of protocols in several layers, routing included. This review aims at providing an elucidation of the terminology and principles behind game theory and the most popular and recent routing models. The examined networks are both the traditional networks where latency is of paramount importance and the emerging ad hoc and sensor networks, where energy is the main concern.

• Journal of Communications and Networks
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• v.11 no.4
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• pp.327-336
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• 2009

Geographic routing has been considered as an attractive approach in wireless sensor networks, since it routes data packets by using location information rather than global topology information. In geographic routing schemes, packets are usually sent along the boundary of a hole by face routing to detour the hole. As result, all data flows which need to detour the hole are concentrated on the boundary of the hole. This hole detour scheme results in much more energy consumption for nodes at the hole boundary, and the energy exhaustion of hole boundary nodes enlarges the holes. This is referred to as a hole diffusion problem. The perimeter mode may also lead to data collisions on the hole boundary nodes if multiple data flows need to bypass a hole simultaneously. In this paper, we propose a hole modeling and detour scheme for geographic routing in wire-less sensor networks. Our hole modeling and detour scheme can efficiently prevent hole diffusion, avoid the local minimum problem faced by geographic routing protocols, and reduce data collisions on the hole boundary nodes. Simulation results show that the proposed scheme is superior to the other protocols in terms of control overhead, average delivery delay and energy consumption.

• KIISE Transactions on Computing Practices
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• v.23 no.2
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• pp.116-121
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• 2017

In wireless sensor networks, the multipath prefers energy efficient routing method due to the characteristic of low-power sensor which uses geographic method to transmit data packet through information of the neighbor nodes. However, when multipath meets the routing fail area called hole area, path overlap problem can occur, resulting in failed maintenance of disjoint multipath. To solve this problem, multipath research studies have been performed to exploit the modeling and detouring method in routing fail area by keeping the disjoint multipath. However, in an energy point of view, additional method like modeling can lead to a lot of energy consumption of sensor node. Moreover, lots of energy consumption of sensor node can shorten the life span of sensor network. In this study, we proposed an energy efficient geographic routing by keeping the disjoint multipath in routing fail area. The proposed scheme exploited the face routing using the geographic recovery method without additional method like modeling.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2001.10a
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• pp.89-99
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• 2001

Optimum Ship Routing can be defined as “The selection of an optimum track for a transoceanic crossing by the application of long-range predictions of wind, waves and currents to the knowledge of how the routed vessel reacts to these variables”. This paper treats the methodology how to serve optimum ship routing problem by network modeling and reveals the validity of the network model by some numerical experiments.

• Journal of the Korean Institute of Navigation
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• v.25 no.3
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• pp.211-223
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• 2001

Optimum Ship Routing can be defined as \"The selection of an optimum track for a transoceanic crossing by the application of long-range predictions of wind, waves and currents to the knowledge of how the routed vessel reacts to these variables\". This paper treats the methodology how to solve optimum ship routing problem by network modeling and reveals the validity of the network model by some numerical experiments.periments.

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.4
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• pp.543-549
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• 1986

A topologically based interconnection routing of multilayer printed circuit boards has been proposed. This study focuses on modeling the relative positioning of the interconnect paths rather than absolute positioning within a fixed coordinate system, thereby avoiding simplifications that impose restrictin on the path shapes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.4
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• pp.1376-1391
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• 2015

In bus delay-tolerant networks, the route of bus is determinate but its arrival time is indeterminate. However, most conventional approaches predict future contact without considering its uncertainty, which makes a limitation on routing performance. A novel approach is proposed by employing interval algebra to characterize the contact's uncertainty and time-varying nature. The contact is predicted by using the Bayesian estimation to achieve a better routing performance. Simulation results show that this approach achieves a good balance between delivery latency and delivery ratio.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.349-352
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• 2001

In this paper, the design of WDM network using the traffic estimation modeling is implemented. Because of the lack of data of real traffic volumes, the information of statistic data is used. Using the modeling results, the WDM channels are assinged for each node, and the network is simulated using OPNET simulation tools. Here, we investigate the shortest routing scheme using OPNET simulation tools. As a result the realistic WDM network design for Korea topology is proposed.