• 제어로봇시스템학회논문지
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• 제8권12호
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• pp.1048-1055
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• 2002

The problem of generating torch paths for 2D laser cutting of a stock plate nested with a set of free-formed parts is investigated. The objective is to minimize the total length of the torch path starting from a blown depot, then visiting all the given Parts, and retuning back to the depot. A torch Path consists of the depot and Piercing Points each of which is to be specified for cutting a part. The torch path optimization problem is shown to be formulated as an extended version of the standard travelling salesman problem To solve the problem, a hybrid genetic algorithm is proposed. In order to improve the speed of evolution convergence, the algorithm employs a genetic algorithm for global search and a combination of an optimization technique and a genetic algorithm for local optimization. Traditional genetic operators developed for continuous optimization problems are used to effectively deal with the continuous nature of piercing point positions. Computational results are provided to illustrate the validity of the proposed algorithm.

• 한국디지털정책학회:학술대회논문집
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• 한국디지털정책학회 2006년도 추계학술대회
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• pp.327-336
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• 2006

The odds ratio is used for assessing the disease-exposure association, because epidemiological data for case-control of cohort studies are often summarized into 2 ${\times}$ 2 tables. In this paper we define the odds ratio function(ORF) that extends odds ratio used on discrete survival event data to continuous survival time data and propose estimation procedures with censored data. The first one is a nonparametric estimator based on the Nelson-Aalen estimator of comulative hazard function, and the others are obtained using the concept of empirical odds ratio. Asymptotic properties such as consistency and weak convergence results are also provided. The ORF provides a simple interpretation and is comparable to survival function or comulative hazard function in comparing two groups. The mean square errors are investigated via Monte Carlo simulation. The result are finally illustrated using the Melanoma data.

• Journal of Platform Technology
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• 제6권3호
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• pp.3-9
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• 2018

This paper describes the design and trial development of a system that supports continuous hazard mapping by local residents in their daily life. We performed an interview survey to design our system in a model traditional town in Saga Prefecture, Japan. The results show that despite continued efforts, many practical problems remain and residents feel unsafe. Considering these results, we designed and developed a unique information and communication technology-based support system that contributes to community-based disaster prevention and reduction. The continuous resident participation and posting design are the core concept for our community-based approach. Our system continues to support making a hazard map by integrating the community-based hazard information. Local residents register information (disaster types, risk level, photographs, comments, positional information) about locations that could be dangerous in a disaster. In addition, our system enables information sharing through a Web server. We expect that this information sharing will allow local hazard information for each district to be used.

• 대한수학회논문집
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• 제17권1호
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• pp.37-51
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• 2002

Let X be a reflexive Banach space with a uniformly Gateaux differentiable norm, C a nonempty bounded open subset of X, and T a continuous mapping from the closure of C into X which is locally pseudo-contractive mapping on C. We show that if the closed unit ball of X has the fixed point property for nonexpansive self-mappings and T satisfies the following condition: there exists z $\in$ C such that ∥z-T(z)∥<∥x-T(x)∥ for all x on the boundary of C, then the trajectory tlongrightarrowz$_{t}$$\in$C, t$\in$[0, 1) defined by the equation z$_{t}$ = tT(z$_{t}$)+(1-t)z is continuous and strongly converges to a fixed point of T as t longrightarrow 1￣.ow 1￣.

• International Journal of Advanced Culture Technology
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• 제6권3호
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• pp.193-200
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• 2018

This paper describes the design and trial development of a system that supports continuous hazard mapping by local residents in their daily life. We performed an interview survey to design our system in a model traditional town in Saga Prefecture, Japan. The results show that despite continued efforts, many practical problems remain and residents feel unsafe. Considering these results, we designed and developed a unique information and communication technology-based support system that contributes to community-based disaster prevention and reduction. The continuous resident participation and posting design are the core concept for our community-based approach. Our system continues to support making a hazard map by integrating the community-based hazard information. Local residents register information (disaster types, risk level, photographs, comments, positional information) about locations that could be dangerous in a disaster. In addition, our system enables information sharing through a Web server. We expect that this information sharing will allow local hazard information for each district to be used.

• 전기학회논문지
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• 제61권3호
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• pp.451-458
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• 2012

This paper addresses the problem that policy iteration (PI) for continuous-time (CT) systems requires explorations of the state space which is known as persistency of excitation in adaptive control community, and as a result, proposes a PI scheme explorized by an additional probing signal to solve the addressed problem. The proposed PI method efficiently finds in online fashion the related CT linear quadratic (LQ) optimal control without knowing the system matrix A, and guarantees the stability and convergence to the LQ optimal control, which is proven in this paper in the presence of the probing signal. A design method for the probing signal is also presented to balance the exploration of the state space and the control performance. Finally, several simulation results are provided to verify the effectiveness of the proposed explorized PI method.

• 대한수학회지
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• 제47권5호
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• pp.1077-1095
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• 2010

The paper considers the identifiability (i.e., the unique identification) of a composite string in the class of piecewise constant parameters. The 1-D string vibration is measured at finitely many observation points. The observations are processed to obtain the first eigenvalue and a constant multiple of the first eigenfunction at the observation points. It is shown that the identification by the Marching Algorithm is continuous with respect to the mean convergence in the admissible set. The result is based on the continuous dependence of eigenvalues, eigenfunctions, and the solutions on the parameters. A numerical algorithm for the identification in the presence of noise is proposed and implemented.

• Communications for Statistical Applications and Methods
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• 제21권6호
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• pp.513-520
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• 2014

We study numerical methods to obtain the stationary probabilities of continuous-time Markov chains whose embedded chains are periodic. The power method is applied to the balance equations of the periodic embedded Markov chains. The power method can have the convergence speed of exponential rate that is ambiguous in its application to original continuous-time Markov chains since the embedded chains are discrete-time processes. An illustrative example is presented to investigate the numerical iteration of this paper. A numerical study shows that a rapid and stable solution for stationary probabilities can be achieved regardless of periodicity and initial conditions.

• 디지털융복합연구
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• 제3권2호
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• pp.39-57
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• 2005

This research is about continuous improvement in productivity for the central and local government administration. It is a comprehensive execution manual that summarizes from preparation to completion of this task. If you follow the process described in this research, you will achieve the following. l. You will motivate the innovators. 2. You will spare yourself of many trial and errors and risks thus increasing the effectiveness, 3. You will eliminate the obstacles to innovation. 4. You will continue to innovate and will be able to assess the results through visible index.

• 디지털융복합연구
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• 제3권1호
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• pp.149-163
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• 2005

Researches for NN(nearest neighbor) query which is often used in LBS system, have been worked. However. Conventional NN query processing techniques are usually meaningless in moving object management system for LBS since their results may be invalidated as soon as the query and data objects move. To solve these problems, in this paper we propose a new nearest neighbor query processing technique, called CTNN, which is possible to meet continuous trajectory nearest neighbor query processing. The proposed technique consists of Approximate CTNN technique which has quick response time, and Exact CTNN technique which makes it possible to search accurately nearest neighbor objects. Experimental results using GSTD datasets shows that the Exact CTNN technique has high accuracy, but has a little low performance for response time. They also shows that the Approximate CTNN technique has low accuracy comparing with the Exact CTNN, but has high response time.