Quasiconcave Bilevel Programming Problem

S.R. Arora,Anuradha Gaur 한국경영과학회 2006 Management Science and Financial Engineering Vol.12 No.1

Bilevel programming problem is a two-stage optimization problem where the constraint region of the first level problem is implicitly determined by another optimization problem. In this paper we consider the bilevel quadratic/linear fractional programming problem in which the objective function of the first level is quasiconcave, the objective function of the second level is linear fractional and the feasible region is a convex polyhedron. Considering the relationship between feasible solutions to the problem and bases of the coefficient submatrix associated to variables of the second level, an enumerative algorithm is proposed which finds a global optimum to the problem.

A Paradox in an Indefinite Quadratic Transportation Problem

Arora, S. R.,Khurana, Archana 한국경영과학회 2001 Management Science and Financial Engineering Vol.7 No.2

This paper discusses a paradox in an Indefinite Quadratic Transportation Problem. Ilere, the objective function is the product of two linear functions. A paradox arises when the transportation problem admits of a total cost which is lower than the optimum cost, by transporting larger quantities of goods over the same route. A sufficient condition for the existence of a paradox is established. Paradoxical Range of Flow is obtained for any given flow in which the corresponding objective function value is less than the optimum value of the given transportation problem. It is illustrated with the help of a numerical example.

NONCONVEX BULK TRANSPORTATION PROBLEM

Arora, S. R.,Ahuja, Anu 한국경영과학회 2001 Management Science and Financial Engineering Vol.7 No.2

In the present paper, we present a method to solve a Fractional Bulk Transportation Problem(FBTP) in which the numerator is quadratic in nature and the denominator is linear. A related (FBTP) is formed whose feasible solutions are ranked to reach an optimal solution of the given problem. The method to find these feasible solutions makes use of parametric programming wherein a series of Ordinary Bulk Transportation Problems are solved by the usual methods.

A Fuzzy-Goal Programming Approach For Bilevel Linear Multiple Objective Decision Making Problem

S.R. Arora,Ritu Gupta 한국경영과학회 2007 Management Science and Financial Engineering Vol.13 No.2

This paper presents a fuzzy-goal programming (FGP) approach for Bi-Level Linear Multiple Objective Decision Making (BLL-MODM) problem in a large hierarchical decision making and planning organization. The proposed approach combines the attractive features of both fuzzy set theory and goal programming (GP) for MODM problem. The GP problem has been developed by fixing the weights and aspiration levels for generating pareto-optimal (satisfactory) solution at each level for BLL-MODM problem. The higher level decision maker (HLDM) provides the preferred values of decision vector under his control and bounds of his objective function to direct the lower level decision maker (LLDM) to search for his solution in the right direction. Illustrative numerical example is provided to demonstrate the proposed approach.

OPTIMAL CONDITIONS AND AN ALGORITHM FOR LINEAR-QUADRATIC BILEVEL PROGRAMMING

Malhotra, Neelam,Arora, S. R. 한국경영과학회 2001 Management Science and Financial Engineering Vol.7 No.1

The linear fractional - quadratic bilevel programming problem. in which the leader's objective function is a linear fractional function and the follower's objective function is a quadratic function, is studied in this paper. The leader's and the follower's variables are related by linear constraints. The derivations of the optimality conditions are based on Kuhn-Tucker conditions and the duality theory. It is also shown that the original linear fractional - quadratic bilevel programming problem can be solved by solving a standard linear fractional program and the optimal solution of the original problem can be achieved at one of the extreme point of a convex polyhedral formed by the new feasible region. The algorithm is illustrated with the help of an example.

Effect of oxygen partial pressure and annealing on nanocrystalline p-type ZnO:Sb thin films

K. Samanta,A.K. Arora,S. Hussain,S. Chakravarty,R.S. Katiyar 한국물리학회 2012 Current Applied Physics Vol.12 No.5

We have investigated the effect of oxygen partial pressure and annealing on nanocrystalline p-type Sb-doped ZnO thin films, grown by pulsed laser deposition, with hole concentration of 6.5 ×1018/cm3and mobility of 53 cm2/V-s. Uses of higher working pressure or annealing are found to reduce carrier concentration. A strong correlation is observed between carrier concentration and the violet (3.02 eV)emission related to free Zn-vacancy; stronger the violet emission, smaller the carrier concentration. In contrast to earlier suggestion of using higher oxygen pressure for obtaining p-type conductivity, the present results show a deterioration of the quality of film. We have investigated the effect of oxygen partial pressure and annealing on nanocrystalline p-type Sb-doped ZnO thin films, grown by pulsed laser deposition, with hole concentration of 6.5 ×1018/cm3and mobility of 53 cm2/V-s. Uses of higher working pressure or annealing are found to reduce carrier concentration. A strong correlation is observed between carrier concentration and the violet (3.02 eV)emission related to free Zn-vacancy; stronger the violet emission, smaller the carrier concentration. In contrast to earlier suggestion of using higher oxygen pressure for obtaining p-type conductivity, the present results show a deterioration of the quality of film.

Two-Dimensional Nanosheets Produced by Liquid Exfoliation of Layered Materials

Coleman, J. N.,Lotya, M.,O'Neill, A.,Bergin, S. D.,King, P. J.,Khan, U.,Young, K.,Gaucher, A.,De, S.,Smith, R. J.,Shvets, I. V.,Arora, S. K.,Stanton, G.,Kim, H.-Y.,Lee, K.,Kim, G. T.,Duesberg, G. S.,H American Association for the Advancement of Scienc 2011 Science Vol.331 No.6017

<P>If they could be easily exfoliated, layered materials would become a diverse source of two-dimensional crystals whose properties would be useful in applications ranging from electronics to energy storage. We show that layered compounds such as MoS(2), WS(2), MoSe(2), MoTe(2), TaSe(2), NbSe(2), NiTe(2), BN, and Bi(2)Te(3) can be efficiently dispersed in common solvents and can be deposited as individual flakes or formed into films. Electron microscopy strongly suggests that the material is exfoliated into individual layers. By blending this material with suspensions of other nanomaterials or polymer solutions, we can prepare hybrid dispersions or composites, which can be cast into films. We show that WS(2) and MoS(2) effectively reinforce polymers, whereas WS(2)/carbon nanotube hybrid films have high conductivity, leading to promising thermoelectric properties.</P>

Genetic Diversity of Magra Sheep from India Using Microsatellite Analysis

Arora, R.,Bhatia, S. Asian Australasian Association of Animal Productio 2006 Animal Bioscience Vol.19 No.7

Genetic diversity of Magra - a lustrous carpet wool breed of India, was investigated by means of 25 ovine microsatellite markers proposed by the Food and Agriculture Organization and the International Society for Animal Genetics (FAO-ISAG). All used microsatellites amplified well and exhibited polymorphisms. A wide range of genetic variability was observed as allele number from 3 (BM6506, OarCP20) to 10 (CSSM31), observed heterozygosity from 0.200 (BM6506) to 0.947 (OarHH35), expected heterozygosity from 0.368 (CSSM47) to 0.864 (BM1314) and Polymorphism Information Content (PIC) from 0.347 (CSSM47) to 0.849 (BM1314). This supported the utility of these microsatellite loci in the measurement of genetic diversity indices in Indian sheep too. Various average genetic variability measures viz., allele diversity (5.7), observed heterozygosity (0.597), expected heterozygosity (0.694) and mean PIC (0.648) values showed high genetic variability despite accumulated inbreeding as reflected by the high average inbreeding coefficient ($F_{IS}=0.159$) due to the unequal sex ratio of the breeding animals.

Evaluation of Genetic Effects of Demographic Bottleneck in Muzzafarnagri Sheep from India Using Microsatellite Markers

Arora, R.,Bhatia, S. Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.1

Genetic variability is an important component in the ability of populations to adapt in the face of environmental change. Severe human impacts reduced Muzzafarnagri sheep of India from 500,000 in 1972 to 10,989 in 1973-74. Here we report for the first time the effect of this population decline on levels of genetic variability at 13 FAO recommended ovine microsatellite loci and contrast levels of variability to that in a breed from the same geographical region, which differed in numbers, by an order of magnitude (Marwari sheep). Of the 13 loci, 100% were polymorphic in both breeds. A high degree of genetic variation was observed within populations in terms of both allele diversity (number of alleles per locus, >4) and gene diversity (expected heterozygosity, >0.5), which implied that there is still a substantial amount of genetic diversity at the nuclear loci in a declining population. Nevertheless, overall low number of alleles per locus and relatively less abundance of low frequency alleles in Muzzafarnagri sheep suggested that genetic variability has been comparatively reduced in this population. Bottleneck analysis indicated that a genetic bottleneck did not occur during the most recent decline. In addition, we found that the differentiation among populations was moderate ($F_{ST}$= 11.8%). This study on assessment of genetic effects of the population declines in ovines is a step towards identification of genetically impoverished or healthy populations, which could prove to be a useful tool to facilitate conservation planning in this important species of small ruminants.

Efficient Fuzzy Ranking for Keyword Search on Graphs (Short Paper)

Arora, N.R.,Lee, W.,Leung, C.K.-S.,Kim, J.,Kumar, H. SPRINGER-VERLAG 2012 Lecture Notes in Computer Science Vol.7446 No.-