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1.
This paper is concerned with demand-driven production scheduling in a commercial environment where smoothed production plans generation over a rolling horizon is desirable as new observations of demand are received through time. Demands are assumed to be normally distributed and dependent on the previous observed levels. The method of chance constraint of Charnes and Cooper is extended to multi-product production planning with variable workforce, back-ordered inventory, and nonstationary stochastic demand process. Bayesian procedures for revising the chance constraints and several variants of linear-programming-based production planning models are presented. In all cases the proposed methodology ensures that demands are satisfied, at a given level of confidence, while achieving smooth production. 相似文献
2.
3.
The subject of spectral distribution methods where one derives and applies the locally smoothed forms of observables in nuclei
is briefly reviewed. It is well understood that the local forms (with respect to energy) of the level density function, expectation
values and strength densities are Gaussian, linear (or ratio of Gaussians) and a bivariate Gaussian respectively. To accomodate
symmetries in the above forms, one has to deal with multivariate distributions in general; for example the angular-momentum
(J) decomposition leads to a bivariate Gaussian form for the level density. These results extend to indefinitely large spaces
by method of partitioning and they generate convolution forms. The origin of these remarkable spectral properties is discussed
and shell model examples are given to substantiate their applicability to nuclear systems. Spectral distribution theory is
a practical, usable theory because the smoothed forms are defined in terms of traces of low particle-rank operators, and the
trace information propagates. Finally we discuss the application of the spectral methods for a wide range of nuclear problems;
these include binding energies, orbit occupancies, electromagnetic andβ-decay sum rule quantities, analysis of operators, symmetry breaking, numerical level densities, and determination of bounds
on time-reversal non-invariant part of nucleon-nucleon interaction. 相似文献
4.
Rao DP Sivakumar SV Mandal S Kota S Ramaprasad BS 《Journal of chromatography. A》2005,1069(1):141-151
The separation of propylene-propane mixture is an energy intensive operation commercially practiced using cryogenic distillation. The separation by pressure swing adsorption has been studied as an alternative. A fixed-bed pressure swing adsorption yields the heavy component as a pure product. The product recovery and the productivity are not high. In a moving-bed process, because of the counter-current solid-gas contact, the separation achieved is similar to that of the fractionation by distillation. Although the moving-bed operation offers the upper limit for the performance of a cyclic adsorptive process, due to mechanical complexities in the handling of solids the 'simulated' moving-bed is preferred. By moving the inlet and outlet ports of streams located along the length of the bed, a moving-bed process can be realized in a fixed bed. We describe here a 'moving-port' system which permits injection or withdrawal of the fluid along the axial direction in a fixed bed. A fixed bed embedded with the moving-port systems emulates a simulated moving-bed adsorber. The proposed adsorber can fractionate a binary gas mixture into two product streams with high purities. It is similar to the Sorbex process of UOP but does not have the eluent as an additional separating agent. A parametric study indicates that high purity products and a higher productivity by an order of magnitude can be achieved with simulated moving-beds compared to the fixed beds. 相似文献
5.
6.
Beryllium can be precipitated from homogeneous solution as a dense and easily filterable precipitate by the hydrolysis of urea, in the presence of sulphate. The method has been applied to the gravimetric determination of beryllium as oxide. The nature of the precipitate thus obtained has been examined by thermogravimetric, infrared, photomicrographic and X-ray methods. 相似文献
7.
A simple method for the measurement by neutron activation analysis of the isotopic abundance shifts of44Ca and41K in compounds of low volatility is described. Extraction and measurement procedures for the radioactive argon isotopes (37Ar,39Ar and41Ar produced by (n, α) and (n, p) reactions are also given. The results obtained demonstrate that the accuracy for the measurement
of δ44Ca is better than by the mass spectrometric method; in the case of δ41K measurement the accuracy is the same as that obtained with the mass spectrometer. Interfering reactions which yield other
rare gases, and their relative contribution to the error in the measurement of δ values are also discussed. 相似文献
8.
C. S. Sastri H. Petri G. Erdtmann 《Journal of Radioanalytical and Nuclear Chemistry》1977,38(1-2):157-164
A method is described to determine traces of V, Fe, Ni, Zn, Nb and Mo in high purity matrices of niobium, tantalum and tungsten
by non-destructive 14 MeV3He activation analysis. The influence of nuclear and γ-ray interferences in the determination of these elements is discussed. 相似文献
9.
P. Rajaram B. Viswanathan G. Aravamudan V. Srinivasan M.V.C. Sastri 《Thermochimica Acta》1973,7(2):123-129
The reaction of MoO3 with various oxides of manganese (MnO, Mn2O3, Mn3O4 and MnO2) and with MnCO3 has been studied in air and nitrogen atmospheres employing DTA, TG and X-ray diffraction methods, with a view to elucidating the conditions for the formation of MnMoO4. Thermal decomposition of MnCO3 has also been studied in air and nitrogen atmospheres to help understand the mechanism of the reaction between MnCO3 and MoO3. The studies reveal that, whereas MnO, Mn2O3 and MnO2 react smoothly with MoO3 to form MnMoO4, Mn3O4 does not react with MoO3 in the temperature range investigated (48O–6OO°C). An equimolar mixture of MnCO3 and MoO3 reacts in air to yield MnMoO4, while only a mixture of Mn3O4 and MoO3 remains as final product when the same reaction is carried out in nitrogen. Marker studies reveal that manganese ions are the main diffusing species in the reaction between MoO3 and manganese oxides that result in MnMoO4. 相似文献
10.
Summary Copper phthalocyanine tetrasulphonic acid has been found to work satisfactorily as an inside indicator in the cerimetric titration of hydro-quinone and metol. It has the advantage that the indicator correction in titrations with 0.01 N solutions of ceric sulphate is much less than with the ferroin indicator, amounting to only 0.02 ml for two drops of the indicator solution.Part II: See Z. analyt. Chem. 163, 1 (1958). 相似文献