• Journal of applied mathematics & informatics
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• 제28권5_6호
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• pp.1431-1437
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• 2010

We use the (G'/G)-expansion method to seek the traveling wave solution of the Seventh-order Sawada-Kotera Equation. The solutions that we get are more general than the solutions given in literature. It is shown that the (G'/G)-expansion method provides a very effective and powerful mathematical tool for solving nonlinear equations in mathematical physics.

• Journal of Power Electronics
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• 제5권4호
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• pp.257-263
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• 2005

This paper describes the development and testing results of a high density High Voltage Power Supply (HVPS) that drives microwave Traveling Wave Tubes (TWTs) of phased array transmitters for airborne EW systems. The HVPS is designed to consist of a number of modules connected in series. Among them, especially, the high-density pulse transformer module including the resonant circuit is newly designed to make the HVPS much more reliable. In addition, this paper describes the development of high voltage solid-state modulation using fast switching devices (FETs) and also represents the test results of a modulator module.

• Journal of the Optical Society of Korea
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• 제5권3호
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• pp.76-82
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• 2001

The optical response for traveling-wave Mach-Zehnder modulators without-with phased reversal is successfully derived in more concise and succinct form than any other equations before. The obtained equation is applied to a bandpass traveling-wave modulator with 3-section phase reversal and is confirmed to be in reasonable agreement with the experimental data.

• Journal of applied mathematics & informatics
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• 제30권3_4호
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• pp.635-646
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• 2012

This paper is concerned with an SIRS epidemic model with spatial diffusion and time delay representing the length of the immunity period. By using a new cross iteration scheme and Schauder's fixed point theorem, we reduce the existence of traveling wave solutions to the existence of a pair of upper-lower solutions. By constructing a newfashioned pair of upper-lower solutions, we derive the existence of a traveling wave solution connecting the uninfected steady state and the infected steady state.

• Management Science and Financial Engineering
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• 제20권1호
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• pp.17-19
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• 2014

In this paper, we consider an interesting variant of the inverse minimum traveling salesman problem. Given an instance (G, w) of the minimum traveling salesman problem defined on a metric space, we fix a specified Hamiltonian cycle $HC_0$. The task is then to adjust the edge cost vector w to w' so that the new cost vector w' satisfies the triangle inequality condition and $HC_0$ can be returned by the minimum spanning tree algorithm in the TSP-instance defined with w'. The objective is to minimize the total deviation between the original and the new cost vectors with respect to the $L_1$-norm. We call this problem the inverse metric traveling salesman problem against the minimum spanning tree algorithm and show that it is closely related to the inverse metric spanning tree problem.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제8권1호
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• pp.61-67
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• 2008

This paper introduces the multi-vehicle routing problem(MRP) which is different from the traveling sales problem(TSP), and presents the ant system(AS) applied to the MRP. The proposed MRP is a distributive model of TSP since many vehicles are used, not just one salesman in TSP and even some constraints exist. In the AS, a set of cooperating agents called vehicles cooperate to find good solutions to the MRP. To make the proposed MRP extended more, Tokyo city model(TCM) is proposed. The goal in TCM is to find a set of routes that minimizes the total traveling time such that each vehicle can reach its destination as soon as possible. The results show that the AS can effectively find a set of routes minimizing the total traveling time even though the TCM has some constraints.

• 제어로봇시스템학회논문지
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• 제9권2호
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• pp.152-158
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• 2003

A machine-vision guided inspection system with go-no gauges for inspecting eggcrate assemblies in steam generators is considered. To locate the gauge at the right place, periodic corrective actions for its position and traveling direction are required. We present a machine vision algorithm for determining inserting position and traveling direction of the go-no gauge. The overall procedure of the algorithm is composed of camera calibration, eggcrate image preprocessing, grid-height adjustment, intersection point estimation between two intersecting grids, and adjustment of position and traveling direction of the gauge. The intersection point estimation is performed by using linear regression with a constraint. A test with a real eggcrate specimen shows the feasibility of the algorithm.

• 한국경영과학회지
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• 제33권2호
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• pp.17-26
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• 2008

The traveling salesman problem is to find tours through all cities at minimum cost ; simply visiting the cities only once that a salesman wants to visit. As such, the traveling salesman problem is a NP-complete problem ; an heuristic algorithm is preferred to an exact algorithm. In this paper, we suggest an effective cost relaxation using a candidate arc set which is obtained from a regression function for the traveling salesman problem. The proposed method sufficiently consider the characteristics of cost of arcs compared to existing methods that randomly choose the arcs for relaxation. For test beds, we used 31 instances over 100 cities existing from TSPLIB and randomly generated 100 instances from well-known instance generators. For almost every instances, the proposed method has found efficiently better solutions than the existing method.

• Journal of Advanced Marine Engineering and Technology
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• 제32권2호
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• pp.351-358
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• 2008

This paper introduces a map building algorithm which can collect environmental information using ultrasonic sensors. And also this paper discusses a traveling algorithm using environmental information which leads to the map building algorithm. In order to accomplish the proposed traveling algorithm, this paper additionally discusses a path revision algorithm. For verifying the proposed algorithms, several experiments are executed using a mobile robot physically designed in this paper. The conclusion is that the proposed algorithm is very effective and is applicable to mobile robots especially requiring a low-cost environmental information.

• 대한산업공학회지
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• 제36권2호
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• pp.78-86
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• 2010

The traveling purchaser problem(TPP) is a generalization of the well-known traveling salesman problem(TSP), which has many real-world applications such as purchasing the required raw materials for the manufacturing factories and the scheduling of a set of jobs over some machines, and many others. TPP also could be extended to the vehicle routing problem(VRP) by incorporating additional constraints such as multi-purchaser, capacity, distance and time restrictions. In the last decade, TPP has received some attention of the researchers in the operational research area. However it has not received the equivalent interest as much as TSP and VRP. Therefore, there does not exist a review of the TPP. The purpose of this paper is to review the TPP and to describe solution procedures proposed for this problem. We also introduce the ILP formulation for the multiple TPP(mTPP) which is generalized type of TPP. We compare the system performance according to change from TPP to mTPP.