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排序方式: 共有977条查询结果,搜索用时 46 毫秒
891.
Jacek Wdowicki Elbieta Wdowicka 《The Structural Design of Tall and Special Buildings》1993,2(4):295-305
The paper presents a system of programs for calculating stresses and displacements in three-dimensional shear wall structures with uniform properties throughout the height. The analysis is carried out on the basis of the continuous connection method. The system allows for considering lateral and vertical loads, arbitrarily located in the plan and arbitrarily distributed along the height. The system is user-oriented and inexpensive in operation. Two numerical examples are given in the paper. 相似文献
892.
893.
The discrete logarithm problem modulo a composite??abbreviate it as DLPC??is the following: given a (possibly) composite integer n??? 1 and elements ${a, b \in \mathbb{Z}_n^*}$ , determine an ${x \in \mathbb{N}}$ satisfying a x ?=?b if one exists. The question whether integer factoring can be reduced in deterministic polynomial time to the DLPC remains open. In this paper we consider the problem ${{\rm DLPC}_\varepsilon}$ obtained by adding in the DLPC the constraint ${x\le (1-\varepsilon)n}$ , where ${\varepsilon}$ is an arbitrary fixed number, ${0 < \varepsilon\le\frac{1}{2}}$ . We prove that factoring n reduces in deterministic subexponential time to the ${{\rm DLPC}_\varepsilon}$ with ${O_\varepsilon((\ln n)^2)}$ queries for moduli less or equal to n. 相似文献
894.
Jacek Galas Dariusz Litwin Adam Czyzewski Stefan Sitarek Katarzyna Kolacz Maciej Kochanowski Maciej Socjusz 《Optical Memory & Neural Networks》2012,21(2):86-93
This paper presents the Variable Wavelength Interferometry (VAWI) technique, its applications and expected research potential of this system equipped with a femtosecond laser. The system is configured for observation and measurement of local optical parameters modified by a high power laser pulse. The VAWI measurement technique has a unique feature that can visualize and enables investigation of the immediate matter response to a single high power laser pulse just in the pulse area, which can locally modify dielectric and optical parameters of matter along the propagation path. It affects the dielectric tensor, refractive indices and it may induce birefringence. The high power laser pulse is responsible for the nonlinear effects in the optical materials like crystals, photonic crystals, optical fibers etc. The VAWI provides the ability to measure very accurately the above optical parameters along the laser pulse propagation path and neighboring regions in the VIS-NIR spectral ranges. 相似文献
895.
In this paper the problem of shape optimization of thin-walled pressure vessel heads is investigated. Shape of a meridian which minimizes the functional containing a depth and capacity of a vessel closure is sought. The meridian is approximated either by the convex Bézier polynomial or by functions with free parameters. Domes consisting of both two- and one-arc are considered. The optimal solutions are obtained using the simulated annealing algorithm. 相似文献
896.
Jacek?Kru?eleckiEmail author Rafa??Ortwein 《Structural and Multidisciplinary Optimization》2012,45(5):729-737
In this paper the problem of the optimal design of columns under combined compression and torsion is investigated. A cross-sectional area varying along the axis of the column which leads to the maximal critical loading is sought. The varying cross-section is approximated either by a function with free parameters or is determined using Pontriagin’s maximum principle. 相似文献
897.
In this paper we present problems connected with the construction of a natural language (NL) interface for a mobile robot. We determine the spatial information that should be analysed in this kind of interface, as well as indicate which information can be omitted. This study is a contribution to our long-term research program on man-machine communication. Implementation of a virtual agent (ACALA) equipped with a natural language interface is important from a methodological point of view because it permits us to observe natural language interaction between the human user and the computer-controlled system. 相似文献
898.
Mateusz Cichenski Florian Jaehn Grzegorz Pawlak Erwin Pesch Gaurav Singh Jacek Blazewicz 《Journal of Scheduling》2017,20(1):57-65
A hub-and-spoke railway system is an efficient way of handling freight transport by land. A modern rail–rail train yard consists of huge gantry cranes that move the containers between the trains. In this context, we consider a rail–rail transshipment yard scheduling problem (TYSP) where the containers arrive to the hub and need to be placed on a train that will deliver them to their destination. In the literature, the problem is decomposed hierarchically into five subproblems, which are solved separately. First, the trains have to be grouped into bundles in which they visit the yard. Next, the trains have to be assigned to tracks within these bundles, namely parking positions. Then the final positions for the containers on trains have to be determined. Next, the container moves that need to be performed are assigned to the cranes. Finally, these moves have to be sequenced for each crane for processing. In this paper, an integrated MILP model is proposed, which aims to solve the TYSP as a single optimization problem. The proposed formulation also enables us to define more robust and complex objective functions that include key characteristics from each of the above-mentioned subproblems. The strength of our proposed formulation is demonstrated via computational experiments using the data from the literature. Indeed, the results show that the TYSP can be solved without the use of decomposition techniques and more insight can be obtained from the same input data used to solve particular single decomposed subproblems. 相似文献
899.
Ireneusz KocembaAuthor Vitae Jacek RynkowskiAuthor Vitae 《Sensors and actuators. B, Chemical》2011,155(2):659-666
The article presents the results of research studies on ceramics SnO2 sensors with Pt catalysts. The role of catalysis in gas sensing mechanisms was investigated. In order to obtain samples with different catalytic activity but with identical Pt loading, the Pt/SnO2 catalysts were calcined at different temperatures (400-800 °C). Structural analysis of these samples was performed. Among the sensors manufactured with Pt/SnO2, the highest sensitivity was shown for the sensor obtained with Pt/SnO2 sample sintered at 800 °C. The correlation between catalytic activity and sensor sensitivity is given. 相似文献
900.
This paper focuses on the integration of GIS and an extension of the analytical hierarchy process (AHP) using quantifier-guided ordered weighted averaging (OWA) procedure. AHP_OWA is a multicriteria combination operator. The nature of the AHP_OWA depends on some parameters, which are expressed by means of fuzzy linguistic quantifiers. By changing the linguistic terms, AHP_OWA can generate a wide range of decision strategies. We propose a GIS-multicriteria evaluation (MCE) system through implementation of AHP_OWA within ArcGIS, capable of integrating linguistic labels within conventional AHP for spatial decision making. We suggest that the proposed GIS-MCE would simplify the definition of decision strategies and facilitate an exploratory analysis of multiple criteria by incorporating qualitative information within the analysis. 相似文献