• Journal of applied mathematics & informatics
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• 제7권3호
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• pp.1059-1068
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• 2000

In this paper we introduce a new concept of weakly positive upper orthant dependence POD of hitting times of stochastic processes. This concept is weaker than the positively orthant dependent and it is closed under a certain statistical operations of W POD ordering. Examples are given to illustrate these concepts.

• Communications for Statistical Applications and Methods
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• 제16권6호
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• pp.1023-1029
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• 2009

Oh (2009) has proposed a likelihood ratio test for comparing two agreements for dependent observations based on the concept of marginal homogeneity and marginal stochastic ordering. In this paper we consider the comparison of more than two agreement measures. Simple ordering and simple tree ordering among agreement measures are investigated. Some test procedures, including likelihood ratio test, are discussed.

• International Journal of Reliability and Applications
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• 제7권2호
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• pp.127-140
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• 2006

AIn this paper we introduce and study a multivariate notions of mean inactivity time (MIT) functions. Basic properties of these functions are derived and their relationship to the multivariate conditional reversed hazard rate functions is studied. A partial ordering, called MIT ordering, of non-negative random vectors is introduced and its basic properties are presented. Its relationship to reversed hazard rate ordering is pointed out. Finally, using the MIT ordering, a bivariate and multivariate notions of IMIT (increasing mean inactivity time) class is introduced and studied.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제10권3호
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• pp.171-176
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• 2003

The purpose of this paper is to Show the relationships between three forms of the axiom of choice and well-ordering in an elementary topos.

• 대한산업공학회지
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• 제8권1호
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• pp.3-12
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• 1982

Three types of repair-ordering polices for the production facility with r-out-of-n configuration are considered. Policies are characterized by states of the system and two types of lead times ; regular lead time and expedited lead time. Optimum repair-ordering policy is determined by minimizing the cost rate for the system. Optimum policy consists of the type of policies and repair-ordering time. Variations of the optimum policies are observed with respect to variations of lead times and associated ordering costs and downtime cost, respectively.

• 한국경영과학회지
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• 제23권4호
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• pp.21-31
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• 1998

Ordering is used to reduce the amount of fill-ins in the Cholesky factor of an symmetric definite matrix. One of most efficient ordering methods is the minimum degree ordering method. In this paper. we propose the two techniques to improve the performance of the minimum degree ordering which are implemented using clique storage structure. One is node absorption which is a generalized version of clique absorption. The other technique is using the lower bounds of degree to suspend the degree updates of nodes. finally, we provide computational results on the problems on NETLIB. These results show that the proposed techniques reduce the number of degree updates and the computational time considerably.

• 지식경영연구
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• 제10권2호
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• pp.35-48
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• 2009

The paper proposes a quantitative causal ordering map (QCOM) to combine qualitative and quantitative methods in a framework. The procedures for developing QCOM consist of three phases. The first phase is to collect partially known causal dependencies from experts and to convert them into relations and causal nodes of a model graph. The second phase is to find the global causal structure by tracing causality among relation and causal nodes and to represent it in causal ordering graph with signed coefficient. Causal ordering graph is converted into QCOM by assigning regression coefficient estimated from path analysis in the third phase. Experiments with the prediction model of Korea stock price show results as following; First, the QCOM can support the design of qualitative and quantitative model by finding the global causal structure from partially known causal dependencies. Second, the QCOM can be used as an integration tool of qualitative and quantitative model to offerhigher explanatory capability and quantitative measurability. The QCOM with static and dynamic analysis is applied to investigate the changes in factors involved in the model at present as well discrete times in the future.

• 한국경영과학회지
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• 제4권1호
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• pp.25-31
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• 1979

We consider the optimal ordering policy for a single-product two-stage inventory system where the main assumptions are as follows: (i) constant continuous demand only at stage 2, (ii) constant input (production) rate at stage 1, (iii) instantaneous delivery (transportation) from stage 1 to stage 2, (iv) backlogging is allowed only at stage 2, (v) an infinite planning horizon. Costs considered are ordering and linear holding costs at both stages, and linear shortage cost only at stages 2. By solving 9 different case problems, we have observed the general from of the optimal ordering policies for our model which minimizes the total cost per unit time. It is noticeable from this observation that the questionable but more often than not adopted assumption by many authors in determining the optimal potimal policy for multistage inventory systems, that the ordering (lot) sizes at each stage remain constant thruout the planning horizon, is not valid.

• Applied Microscopy
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• 제27권2호
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• pp.217-223
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• 1997

New type of ordering along 1110] direction was found In BZT sintered at $1400^{\circ}C$ for 90 hours by using X-ray diffraction analysis and high resolution transmission electron microscopy. The wavelength of the modulated structure was 0.9 nm which is three times larger than the interplanar distance of (110) plane. New type of ordering is considered to be formed as a result of Zn vancacy ordering and new structural model was proposed. The computer simulated electron diffraction and the structural images are in good agreement with those obtained by experiments.

• Journal of Magnetics
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• 제10권1호
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• pp.28-32
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• 2005

The magnetic properties and ordering behavior of Nb-doped FePt alloy films prepared by dc-magnetron sputtering were investigated. It was found that Nb addition retarded the ordering reaction from the disordered face-centered-cubic (fcc) Al phase to the ordered face-centered-tetragonal (fct) L1₀ phase. The tetragonality (c/a ratio) of the ordered fct L1₀ phase increased with the Nb concentration. Nb addition hampered c-axis contraction during ordering, probably because the larger Nb atoms occupy Pt sites. Consequently, the coercivity and magnetocrystalline anisotropic energy of Nb-doped FePt alloy films are lower than those of un-doped FePt film under equivalent annealing conditions.