Dynamic programming and the principle of optimality: A systematic approach     

Moshe Sniedovich 《Advances in water resources》1978,1(4):183-190

The dynamic programming recursive procedure has provided an efficient method for solving a variety of sequential decision problems related to water resources systems. In many investigations Bellman's principle of optimality is used as a proof for the optimality of the dynamic programming solutions. In this paper the dynamic programming procedure is systematically studied so as to clarify the relationship between Bellman's principle of optimality and the optimality of the dynamic programming solutions.Our main result is that although the principle is valid, in order to use it as a proof for the optimality of the dynamic programming solution certain modeling requirements should be met.The mathematical model presented in this paper provides a convenient framework for the modeling and analysis of dynamic programming problems encountered by in water resources management studies.The results derived here resolve few of the fundamental questions raised in the literature regarding the validity of Bellman's principle of oplimality and the optimality of the dynamic programming solutions.  相似文献   

Bipolar outflow on the asymptotic giant branch – the case of IRC+10011     

Dejan Vinkovi&#;  Thomas Blöcker  Karl-Heinz Hofmann  Moshe Elitzur  Gerd Weigelt 《Monthly notices of the Royal Astronomical Society》2004,352(3):852-862

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Spectral Line and Continuum Radiation Propagation in a Clumpy Medium     

John Conway  Moshe Elitzur  Rodrigo Parra 《Astrophysics and Space Science》2005,295(1-2):319-324

We discuss the propagation of spectral line and continuum radiation in a clumpy medium and give general expressions for the observed absorption or emission from a cloud population. We show that the affect of the medium clumpiness can usually be characterised by a single number multiplying the mean column opacity. Our result provides a simpler proof and generalization of the result of Martin et al. (1984). The formalism provides a simple way to understand the effects of clumping on molecular line profiles and ratios; for example, how clumping effects the interpretation of ¹³CO(1–0) to ¹²CO(1–0) line ratios. It also can be used as a propagation operator in physical models of clumpy media where the incident radiation effects the spectral line emissivity. We are working to extend the formalism to the propagation of masers in a clumpy medium, but in this case, there are special difficulties because formal expectation values are not characteristic of observations because they are biased by rare events.  相似文献   

Post-stack velocity analysis in the dip-angle domain using diffractions     

Moshe Reshef  Evgeny Landa 《Geophysical Prospecting》2009,57(5):811-821

Interval velocity analysis in complex geological areas is often considered as an unresolved problem. A novel approach to improve the velocity analysis process is to perform the analysis in a non-conventional domain and to use seismic events that are usually ignored during standard data processing and imaging. In this study, a method to analyse diffraction data for migration velocity analysis in the time- or depth-domain is presented. The method is based on the clear distinction between diffractions and reflections in the post-migration dip-angle domain. The attractive possibility to perform the analysis, using only stacked data as an input, is demonstrated on synthetic and real data examples.  相似文献   

Redefining high school catchment areas with varying effects of achievement equality     

Eliahu Stern  Moshe Michlis 《Applied geography (Sevenoaks, England)》1986,6(4)

Among the several measures being adopted to upgrade the level of education in Israel is the policy of maintaining an equal achievement level in all public high schools. Short-run allocation of elementary school graduates to schools is therefore needed. This paper presents a spatial allocation procedure which aims at improving achievement equality simultaneously with upgrading accessibility to schools. The procedure allows the mutual effect of these two factors to be varied, as well as the measurement of the real-world meaning of such variations. The advantages of the proposed procedure in comparison with the common linear programming model used in spatial planning of school districts are discussed. Allocation patterns generated for the city of Beer Sheva illustrate its use.  相似文献   

Mediterranean coasts of Israel and Sinai by D. Neev,N. Bakler,And K. O. Emery,Taylor and Francis,New York,Philadelphia, London, 1987. No. Of pages: 130     

Moshe Inbar 《地球表面变化过程与地形》1990,15(1):100-100

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Rate of seismicity of the dead sea region over the past 4000 years     

Ari Ben-Menahem  Ezra Aboodi  Moshe Vered  Robert L. Kovach 《Physics of the Earth and Planetary Interiors》1977,14(4):P17-P27

The results of two millennia of earthquake documentation, a few decades of macroseismic and instrumental routine seismological observations and five months of microearthquake monitoring, are used to estimate the rate of seismic activity of the Dead Sea fault. It is found that these vastly diverse data which combine long- and short-term tectonic processes, are in good accord with the formula: where N is the annual number of events of local magnitude M_L or greater. If this equation is extrapolated to ca. 2000 B.C., it yields a Richter magnitude M_s = 7 for the event of Sodom and Gomorrah which is believed to be associated with the strongest earthquake in the region during historical times.Comparing our findings with the results of other investigators in Turkey, Greece, Aegean Sea and Iran, we note that the b values along the Syrian-African rift zone (0.78–0.86) are smaller than those in Greece and its surrounding seas (0.94–1.16).  相似文献   

A case study of sub-basalt imaging in land region covered with basalt flows   总被引：2，自引：0，他引：2  

Moshe Reshef  Haim Shulman  Zvi Ben-Avraham 《Geophysical Prospecting》2003,51(3):247-260

In this study, a set of 20 2D seismic lines, acquired over the Golan Heights basaltic plateau, was processed and analysed. Although the data were acquired and processed by standard techniques, in some cases good-quality seismic images were obtained under several hundred metres of basalts. We describe how the seismic characteristics of the top basalt layer were defined and show the effect of the numerous widespread volcanic sources on the quality of the final images. The new data reveal the first images of the sedimentary sequence under the basalt flows, and indicate that strands of the Dead Sea Transform extend into this area. The entire region was found to be very deformed. Several attractive traps for hydrocarbon exploration were also identified on the output sections.  相似文献   

Preface Land Degradation — A Scientific 21^ST Century Challenge for Physical Geography     

Prof.  Moshe Inbar 《Geografiska Annaler: Series A, Physical Geography》2003,85(3-4):211-212

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Quantitative immunochemical evaluation of fish metallothionein upon exposure to cadmium   总被引：1，自引：0，他引：1  

Yudkovski Y  Rogowska-Wrzesinska A  Yankelevich I  Shefer E  Herut B  Tom M 《Marine environmental research》2008,65(5):427-436

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