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91.
T. K. Kar Swarnakamal Misra B. Mukhopadhyay 《Journal of Applied Mathematics and Computing》2006,22(1-2):387-401
This paper deals with the problem of a ratio-dependent prey-predator model with combined harvesting. The existence of steady states and their stability are studied using eigenvalue analysis. Boundedness of the exploited system is examined. We derive conditions for persistence and global stability of the system. The possibility of existence of bionomic equilibria has been considered. The problem of optimal harvest policy is then solved by using Pontryagin’s maximal principle. 相似文献
92.
Multi-item inventory models with two storage facility and bulk release pattern are developed with linearly time dependent
demand in a finite time horizon under crisp, stochastic and fuzzy-stochastic environments. Here different inventory parameters—holding
costs, ordering costs, purchase costs, etc.—are assumed as probabilistic or fuzzy in nature. In particular cases stochastic
and crisp models are derived. Models are formulated as profit maximization principle and three different approaches are proposed
for solution. In the first approach, fuzzy extension principle is used to find membership function of the objective function
and then it’s Graded Mean Integration Value (GMIV) for different optimistic levels are taken as equivalent stochastic objectives.
Then the stochastic model is transformed to a constraint multi-objective programming problem using Stochastic Non-linear Programming
(SNLP) technique. The multi-objective problems are transferred to single objective problems using Interactive Fuzzy Satisfising
(IFS) technique. Finally, a Region Reducing Genetic Algorithm (RRGA) based on entropy has been developed and implemented to
solve the single objective problems. In the second approach, the above GMIV (which is stochastic in nature) is optimized with
some degree of probability and using SNLP technique model is transferred to an equivalent single objective crisp problem and
solved using RRGA. In the third approach, objective function is optimized with some degree of possibility/necessity and following
this approach model is transformed to an equivalent constrained stochastic programming problem. Then it is transformed to
an equivalent single objective crisp problem using SNLP technique and solved via RRGA. The models are illustrated with some
numerical examples and some sensitivity analyses have been presented. 相似文献
93.
Inventory of differential (both good and defective) items purchased in a lot for two shops under a single management is considered here. In the primary shop, the lot is received and separated, only good units are sold and shortages are allowed which are backlogged from the good units specially purchased at the beginning of the next cycle. The separated defective units are continuously trasnsferred and sold at a reduced price from the secondary shop. This inventory model is formulated and illustrated numerically for three scenarios depending upon the time periods of the shops. 相似文献
94.
95.
P. F. Moulton W. Künzel U. Dürr A. Beimowski G. Huber D. Pruss V. V. Laptev I. A. Shcherbakov Y. V. Zharikov B. Struve J. M. Eggleston T. Kane R. L. Byer J. Unternahrer R. G. Harrison M. R. Taghizadeh A. K. Kar P. K. Gupta D. J. Jackson J. J. Wynne J. J. Rocca J. D. Meyer Zeng-qi Yu G. J. Collins 《Applied physics. B, Lasers and optics》1982,28(2-3):233-239
96.
Manoranjan Das Raymund M. Golding Stanley E. Livingstone 《Transition Metal Chemistry》1978,3(1):112-117
Summary The magnetic moments of the iron(III) chelates of the fluorinated monothio--diketones RC(SH)=CFICOCF3 (R = 2-thienyl, -naphthyl, Ph, p-McC6H4, p-FC6H4,p-ClC6H4, m-MeC6H4, m-CIC6H4 m-BrC6H4) have been measured over a temperature range. The moments vary from 5.49 to 2.16 B.M. at room temperature and are temperaturedependent, falling to as low as 1.82 B.M. at 83 K. The quadrupole splittings from the Messbauer spectra at room temperature are within the range 0.70 to 1.80 mm/s, whereas at 77 K they lie within the range 1.70 to 1.95 mm/s. These results indicate that the iron atom is in an intermediate effective crystal field, which depends to a small extent on the temperature and the substituent R and increases in the order: C4H3S < -C10 < p-XC6H4 < Ph < m-XC6H4 (X = Me, F, CI or Br). Also the results indicate the degree of bonding asymmetry of the iron atom. 相似文献
97.
The local-field correction near the surface of a dipolar crystal has been studied by explicitly computing the non-retarded electric field produced by a finite array of classical point dipoles induced by a time-varying electric field. Crystals of simple cubic, f.c.c. and b.c.c. structures are considered, and results presented for the self-consitent dipole moment and the local electric field at a lattice point. The utility of the method and its possible applications are discussed. 相似文献
98.
99.
The weak objectification and Bell/CHSH inequalities are studied for a particular type of set of states of two spin-1/2 particles.
The restriction on interference term which allows Bell/CHSH inequalities to be satisfied are found out. 相似文献
100.
S. Kar Y. K. Ho 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,57(1):13-19
The doubly excited 1,3D○ resonance states of Ps- associated
with N=3, N=4 and N=5 Ps thresholds have been investigated using highly
accurate correlated wave functions with exponents generated by a quasirandom
process. Resonance parameters (both resonance positions and widths) are
extracted in the framework of the stabilization method and the complex
coordinate rotation method. In addition to many Feshbach resonances below
the various Ps thresholds, we have identified two 1
D○ shape
resonances with one each lying above the N=3 and N=4 thresholds, respectively,
and two 3
D○ shape resonances with one each lying above the N=3 and
N=5 thresholds, respectively. The 1
D○ shape resonance associated
with N=3 Ps threshold and some other Feshbach resonances are reported for the
first time in the literature. 相似文献