• Communications for Statistical Applications and Methods
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• 제4권3호
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• pp.847-858
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• 1997

In this note we develop a partial ordering among positive lower orthant dependent distributions with fixed marginals. This permits us to measure the degree of positive lower orthant dependence. Some basic properties and preservation results are derived.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1997년도 한국재료학회 춘계학술발표회
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• pp.36-36
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• 1997

• 충청수학회지
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• 제24권4호
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• pp.795-805
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• 2011

In this paper, we study a family of continuous bivariate distributions that possesses the negative quadrant dependence property and the generalized negatively quadrant dependent F-G-M copula. We also develop the partial ordering of this new parametric family of negative quadrant dependent distributions.

• Applied Microscopy
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• 제34권2호
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• pp.113-120
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• 2004

복합페로브스카이트 (1-x) $(Li_{1/2}Sm_{1/2})TiO_3-x (Na_{1/2}Sm_{1/2})TiO_3$ (LNST)의 미세구조를 TEM으로 관찰하였다. $0.0{\leq}x{\leq}0.6$ LNST에서는 A-site 양이온의 결핍에 의한 1/2 (001) 초격자 회절점을 형성하는 vacancy ordering을 갖고 있으며 이는 APB로 확인할 수 있었다. 그러나 x가 증가함에 따라 Li 이온의 양이 적어져서 vacancy ordering 을 만들기 어렵게 된다. $0.8{\leq}x{\leq}1.0$ 조성의 LNST의 미세구조에서도 APB가 관찰되었는데 이는 A-site에서 Na와 Sm 이온간의 1:1 chemical ordering에 의한 것으로 사료된다. LNST 전 조성에서 산소팔면체의 anti-phase tilting과 in-phase tilting 그리고 A-site 양이온의 antiparallel shift가 관찰되었는데, 이들은 ferroelastic domain으로 확인할 수 있었다.

• Archives of Pharmacal Research
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• 제15권3호
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• pp.196-203
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• 1992

Intramolecular excimer formation of 1, 3-di(1-pyrenyl)propane (Py-3-Py) and fluorescence polarization of 1, 6-diphenyl-1, 3, 5-hexatriene (DPH) were used to investigate the effects of barbiturates on the fluidity of model membranes of phosphatidycholine (SPMVPC), phosphatidylserine (SPMVPS), and phosphatidylinositol (SPMVPI) fractions of synaptosomal plasma membrane vesicles (SPMV) isolated from bovine cerebral cortex. In a dose-dependent manner, barbiturates decreased the excimer to monomer fluorescence intensity ratio (I'/I) of Py-3-Py and increased the anisotropy(r), rotational relaxation time (P), limiting anisotropy $(r_infty)$, and order parameter (S) of DPH in SPMVPC, SPMVPS and SPMVPI. This indicates that barbiturates decreased both the lateral and rotational diffusion of the probes in SPMVPC, SPMVPS and SPMVPI. The relative potencies of barbiturates in ordering the membranes were in the order: pentobarbital > hexobarbital > amobarbital > phenobarbital. This order correlates well with the anesthetic potencies of barbiturates and the potencies for enhancement of $\gamma$-aminobutyric acid-stimulated chloride uptake. Thus, it is strongly suggested that a close relationship might exist between the membrane ordering effects of barbiturates and the chloride fluxes across SPMV.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.93-96
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• 2005

We propose a computationally efficient sphere decoding (SD) algorithm with smart radius control (SRC). As a baseline algorithm for SD, we consider the modified Schnorr-Euchner (SE) algorithm [1] (hereafter, called as the MSE algorithm). In principle, the radius after zero-forcing decision feedback equalization (ZF-DFE) estimation can be reduced further if we select a new lattice vector closer to the received signal vector than the lattice vector corresponding to the ZF-DFE estimate does. In our case, we obtain such a better lattice vector by performing a sequence of alternating one-dimensional searches, starting from the ZF-DFE estimate. We then develop a novel SRC algorithm that adopts adaptively the additional radius reduction process according to the estimated signal-to-noise-power ratio (SNR) after ZF-DFE estimation. In addition, we analyze the effect of detection ordering on the complexity for SD. Column-norm ordering of the channel matrix and optimal ordering [1] are considered here. From our analyses, we see that SRC can reduce greatly the complexity for SD and the degree of complexity reduction gets significant as the SNR decreases, irrespective of detection ordering schemes used.

• International Journal of Advanced Culture Technology
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• 제8권1호
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• pp.62-70
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• 2020

As an effective means of price discrimination, some suppliers offer trade credit to the distributors in order to stimulate the demand for the product they produce. The availability of the delay in payments from the supplier enables discount of the distributor's selling price from a wider range of the price option in anticipation of increased customer's demand. Since the distributor's lot-size is affected by the demand for the customer, the distributor's lot-size and the selling price determination problem is interdependent and must be solved at the same time. Also, in many common business transactions, the distributor pays the shipping cost for the order and hence, the distributor's ordering cost consists of a fixed ordering cost and the shipping cost that depend on the order quantity. In this regard, we deal with the joint lot-size and price determination problem when the supplier allows delay in payments for an order of a product. The positive effects of credit transactions can be integrated into the EOQ (economic order quantity) model through the consideration of retailing situations, where the customer's demand is a function of the distributor's selling price. It is also assumed that the distributor's order cost consists of a fixed ordering cost and the variable shipping cost. We formulate the distributor's mathematical model from which the solution algorithm is derived based on properties of an optimal solution. A numerical example is presented to illustrate the algorithm developed.

• 한국결정성장학회지
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• 제13권5호
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• pp.230-234
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• 2003

GaAs (001) 기판과 완충층을 사용한 ZnTe/GaAs(001) 기판 위에 고농도의 Zn 조성을 가지는 $Cd_xZn_{1-x}$Te/GaAs, $Cd_xZn_{1-x}$Te/ZnTe/GaAs 에피층 구조를 성장시켰다. 이때 $Cd_xZn_{1-x}$Te 에피층에서의 CuPt형의 규칙상 형성, 미세구조적 특성과 광발광특성을 X-선회절과 전자회절상, 고분해능 투과전자현미경, 그리고 저온 광발광 측정 장치를 이용하여 연구하였다.

• Industrial Engineering and Management Systems
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• 제4권2호
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• pp.145-157
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• 2005

There are a lot of raw materials, work-in-processes and finished goods in manufacturing industry. Here, the less stock of materials and work-in-processes manufacturing industry has, the worse the rate of the production is. Inversely, the more manufacturing industry has, the more expensive the cost to support them is. Thus, it is important for us to balance them efficiently. In general, inventory problems are to decide appropriate times to produce goods and to determine appropriate quantities of goods. Therefore, inventory problems require as more useful information as possible. For example, there are demand, lead time, ordering point and so on. In this paper, we deal with an optimal ordering policy on both way substitutable two-commodity inventory control system. That is, there is a problem of how to allocate the produced two kinds of goods in a factory to m areas so as to minimize the total expected inventory cost. The demand of each area is probabilistic, and we adopt the exponential distribution as a probability density function of demand. Moreover, we provide numerical examples of the problem.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제5권1호
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• pp.85-100
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• 2001

In this paper we propose a block-type parallel preconditioner for solving large sparse nonsymmetric linear systems, which we expect to be scalable. It is Multi-Color Block SOR preconditioner, combined with direct sparse matrix solver. For the Laplacian matrix the SOR method is known to have a nondeteriorating rate of convergence when used with Multi-Color ordering. Since most of the time is spent on the diagonal inversion, which is done on each processor, we expect it to be a good scalable preconditioner. Finally, due to the blocking effect, it will be effective for ill-conditioned problems. We compared it with four other preconditioners, which are ILU(0)-wavefront ordering, ILU(0)-Multi-Color ordering, SPAI(SParse Approximate Inverse), and SSOR preconditioner. Experiments were conducted for the Finite Difference discretizations of two problems with various meshsizes varying up to 1024 x 1024, and for an ill-conditioned matrix from the shell problem from the Harwell-Boeing collection. CRAY-T3E with 128 nodes was used. MPI library was used for interprocess communications. The results show that Multi-Color Block SOR and ILU(0) with Multi-Color ordering give the best performances for the finite difference matrices and for the shell problem only the Multi-Color Block SOR converges.