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31.
Shimon Y. Nof S. E. Elmaghraby Gavrtel Salvendy Deborah J. Seifert Tibor Vamos John A. White Hans-Jorg Bullinger A. Alan B. Pmtsker A. W. Scheer Daniel Teichroew A. B. Whinston Gary E. Whitehouse 《IIE Transactions》1989,21(1):50-65
By invitation from the Editor of IIE Transactions, a research forum was established in 1987 to develop and prepare this article. The objective: to write on the directions, needs and challenges for research by the IE com-munity in applying computer and information sciences. The motivation: realizing the major advancements in computer and information sciences in the recent decade and their significant impact on the IE profession, it is vital to examine how IE research activities can respond effectively to current and emerging needs. This article is viewed as a useful contribution to such an examination.
Forum members were invited from academia, government and industry based on their experience in and commitment to research in this area. The forum was chaired by Shimon Y. Nof and the members are the co-authors of this article.
Forum members communicated and deliberated throughout 1987 and met for a review and planning session dur-ing the IIE Conference in Washington, D.C. in May, 1987 (Forum, 1987). The following article summarizes the contributions and recommendations of the forum members, and was reviewed by four guest reviewers. The re-viewers, invited by the Editor, have provided comments that have been incorporated into this article 相似文献
Forum members were invited from academia, government and industry based on their experience in and commitment to research in this area. The forum was chaired by Shimon Y. Nof and the members are the co-authors of this article.
Forum members communicated and deliberated throughout 1987 and met for a review and planning session dur-ing the IIE Conference in Washington, D.C. in May, 1987 (Forum, 1987). The following article summarizes the contributions and recommendations of the forum members, and was reviewed by four guest reviewers. The re-viewers, invited by the Editor, have provided comments that have been incorporated into this article 相似文献
32.
This paper describes specific Cu2+-catalyzed oxidative cleavage of alpha and beta subunits of Na,K-ATPase at the extracellular surface. Incubation of right side-out renal microsomal vesicles with Cu2+ ions, ascorbate, and H2O2 produces two major cleavages of the alpha subunit within the extracellular loop between trans-membrane segments M7 and M8 and L7/8. Minor cleavages are also detected in loops L9/10 and L5/6. In the beta subunit two cleavages are detected, one before the first S-S bridge and the other between the second and third S-S bridges. Na,K-ATPase and Rb+ occlusion are inactivated after incubation with Cu2+/ascorbate/H2O2. These observations are suggestive of a site-specific mechanism involving cleavage of peptide bonds close to a bound Cu2+ ion. This mechanism allows several inferences on subunit interactions and spatial organization. The two cleavage sites in L7/8 of the alpha subunit and two cleavage sites of the beta subunit identify interacting segments of the subunits. L7/8 is also close to L9/10 and to cation occlusion sites. Comparison of the locations of Cu2+-catalyzed cleavages with Fe2+-catalyzed cleavages (Goldshleger, R., and Karlish, S. J. D. (1997) Proc. Natl. Acad. Sci. U. S. A. 94, 9596-9601) suggests division of the membrane sector into two domains comprising M1-M6 and M7-M10/Mbeta, respectively. 相似文献
33.
Coal-rank measurements and heat-flow data from three rhomb-shaped grabens along the continental portion of the Dead Sea Transform—the Hula Depression, the Sea of Galilee and the Dead Sea Graben—reveal contrasting thermal regimes. The coalification profile the Hula Depression indicates a relatively high thermal gradient, averaging 40C/km, throughout the Late Cenozoic. Similarly, a relatively high heat flow, approx 1.77 HFU, was reported in the Sea of Galilee, 35 km to the south. Coalfieation profile, heat flow data and BHT measurements on the Dead Sea Graben (200 km to the south) reveal a considerably lower thermal regime (approx 0.7 HFU, 2OC/km) that has prevailed since the mid-Miocene.
However, the differences in the thermal regime do not represent different mechanisms of basin formation. With the corroboration of hydrological and geophysical data, it is suggested that the high thermal regime in the two northern basins reflects a regional phenomenon associated with the nearby extensive Golan-Jeble Druze young volcanic terrain. Therefore, it has no relationship to the mechanism of rhomb-shaped graben formation, and should not be cited in support of kinematic models requiring a high thermal regime. 相似文献
However, the differences in the thermal regime do not represent different mechanisms of basin formation. With the corroboration of hydrological and geophysical data, it is suggested that the high thermal regime in the two northern basins reflects a regional phenomenon associated with the nearby extensive Golan-Jeble Druze young volcanic terrain. Therefore, it has no relationship to the mechanism of rhomb-shaped graben formation, and should not be cited in support of kinematic models requiring a high thermal regime. 相似文献
34.
35.
A. K. Shuaibov A. I. Dashchenko L. L. Shimon I. V. Shevera 《Technical Physics Letters》2002,28(8):702-704
The initiation conditions and characteristics of a volume discharge in a krypton-chlorine mixture at low pressures (P≤1.0 kPa) were studied. It is shown that a constant voltage of U ch 1.0 kV applied to a spherical anode-flat cathode system gives rise to a pulsed-periodic discharge with a pulse repetition rate of 1–50 kHz. The current-voltage characteristics of the discharge, the spectra of emission in a wavelength interval of Δ λ=130–350 nm, and oscillograms of the current and the total output emission intensity were studied as dependent on the partial composition and pressure of the krypton-chlorine mixture. It is shown that the discharge is a selective source of emission in the electronic-vibrational bands with λ=257 nm [Cl2(D′-A′)], 222 nm [KrCl(B-X)], and 200 nm [C12**]. The volume discharge in the Kr-Cl2 mixture can be used for the development of pulsed-periodic low-pressure excimer-halogen lamps. 相似文献
36.
THE MINIMUM REQUIREMENTS APPROACH TO THE URBAN ECONOMIC BASE 总被引:2,自引:0,他引:2
37.
In robotic assembly stations robots pick a series of component parts from bins and then insert and assemble them. Several approaches are described and formulated for optimizing bin organization, picking, and insertion sequence and route. Solution procedures are developed for several modes of assembly tasks. The Simple Assembly Plan problem (SAP) is defined and solved. Extensions to this problem are heuristically solved by separating the SAP problem into the Bin Assignment Problem (BAP) and the Pick-Insert Sequencing (PIS) problem. We then define and formulate a new version of the assignment problem which is termed the Minimax Assignment Problem (MAP). An algorithm for the solution of this problem is developed and tested. 相似文献
38.
Hunt RA Dance DR Pachoud M Alm Carlsson G Sandborg M Ullman G Verdun FR 《Radiation protection dosimetry》2005,114(1-3):432-435
A test phantom, including a wide range of mammographic tissue equivalent materials and test details, was imaged on a digital mammographic system. In order to quantify the effect of scatter on the contrast obtained for the test details, calculations of the scatter-to-primary ratio (S/P) have been made using a Monte Carlo simulation of the digital mammographic imaging chain, grid and test phantom. The results show that the S/P values corresponding to the imaging conditions used were in the range 0.084-0.126. Calculated and measured pixel values in different regions of the image were compared as a validation of the model and showed excellent agreement. The results indicate the potential of Monte Carlo methods in the image quality-patient dose process optimisation, especially in the assessment of imaging conditions not available on standard mammographic units. 相似文献
39.
A number of different surface chemistries have been developed in recent years to render semiconductor nanocrystals (NCs) stable in water and biocompatible. However, most of these surface modifications affect NCs' photophysical properties, calling for a method to simultaneously monitor colloidal and fluorescence properties. Fluorescence correlation spectroscopy (FCS) combined with ensemble spectroscopic methods and Monte Carlo simulations were used to interpret and derive photophysical as well as colloidal properties of four different NC surface treatments. Using a novel FCS scheme with alternating laser excitation at two different intensities, we first ruled out influences from optical gradient forces (optical trapping). We then compared concentration of emitting particles, brightness per particle, saturation intensity, blinking (intermittency), hydrodynamic radius, and propensity for aggregation of the different bioconjugated NCs. This approach was successfully applied during the development and optimization of peptide-coated NCs. 相似文献
40.
Template dependencies were introduced by Sadri and Ullman [17] to generalize existing forms of data dependencies. It was hoped that by studying a large and natural class of dependencies, we could solve the inference problem for these dependencies, while that problem was elusive for restricted subsets of the template dependencies, such as embedded multivalued dependencies. At about the same time, other generalizations of known dependency forms were developed, such as the implicational dependencies of Fagin [11] and the algebraic dependencies of Yannakakis and Papadimitriou [20]. Unlike the template dependencies, the latter forms include the functional dependencies as special cases. In this paper we show that no nontrivial functional dependency follows from template dependencies, and we characterize those template dependencies that follow from functional dependencies. We then give a complete set of axioms for reasoning about combinations of functional and template dependencies. As a result, template dependencies augmented by functional dependencies can serve as a substitute for the more general implicational or algebraic dependencies, providing the same ability to represent those dependencies that appear ‘in nature’, while providing a somewhat simpler notation and set of axioms than the more general classes. 相似文献