Symport and antiport are biological ways of transporting molecules through membranes in "collaborating" pairs;in the case of symport the two molecules pass in the same direction, in the case of antiport the ...
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We study the shape matching problem under the Hausdorff distance and its variants. Specifically, we consider two sets A, B of balls in d, d = 2, 3, and wish to find a translation t that minimizes the Hausdorff distanc...
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We study the shape matching problem under the Hausdorff distance and its variants. Specifically, we consider two sets A, B of balls in d, d = 2, 3, and wish to find a translation t that minimizes the Hausdorff distance between A + t, the set of all balls in A shifted by t, and B. We consider several variants of this problem. First, we extend the notion of Hausdorff distance from sets of points to sets of balls, so that each ball has to be matched with the nearest ball in the other set. We also consider the problem in the standard setting, by computing the Hausdorff distance between the unions of the two sets (as point sets). Second, we consider either all possible translates t (as is the standard approach), or consider only translations that keep the balls of A + t disjoint from those of B. We propose several exact and approximation algorithms for these problems. Since the Hausdorff distance is sensitive to outliers, we also propose efficient approximation algorithms for computing the minimum root-mean-square (rms) and the minimum summed Hausdorff distance, under translation, between two point sets in Rd. In order to obtain a fast algorithm for the summed Hausdorff distance, we propose a deterministic efficient dynamic data structure for maintaining an Ε-approximation of the 1-median of a set of points, under insertion and deletion.
The motion planning problem of a nonholonomic multibody system is investigated. Nonholonomicity arises in many mechanical systems subject to nonintegrable velocity constraints or nonintegrable conservation laws. When ...
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The motion planning problem of a nonholonomic multibody system is investigated. Nonholonomicity arises in many mechanical systems subject to nonintegrable velocity constraints or nonintegrable conservation laws. When the total angular momentum is zero, the control problem of system can be converted to the motion planning problem for a driftless control system. In this paper, we propose an optimal control approach for nonholonomic motion planning. The genetic algorithm is used to optimize the performance of motion planning to connect the initial and final configurations and to generate a feasible trajectory for a nonholonomic system. The feasible trajectory and its control inputs are searched through a genetic algorithm. The effectiveness of the genetic algorithm is demonstrated by numerical simulation.
The cutting triangular cycles of lines in space were investigated. It was shown that a collection of lines in 3-space can be cut into a subquadratic number of pieces, such that all depth cycles defined by triples of l...
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The cutting triangular cycles of lines in space were investigated. It was shown that a collection of lines in 3-space can be cut into a subquadratic number of pieces, such that all depth cycles defined by triples of lines are eliminated. A long-standing open problem in computational geometry, motivated by hidden-surface removal in computer graphics, was solved.
In many laboratory and space dusty plasmas, shape of the grains is not sphere. It seems that the grains structure is an important parameter when it is comparable to length of in homogeneity or wavelength. But in this ...
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In many laboratory and space dusty plasmas, shape of the grains is not sphere. It seems that the grains structure is an important parameter when it is comparable to length of in homogeneity or wavelength. But in this article it is shown that in any case nonsphericity leads to some important effects. It is found that the magnetic field applied on grain surface current results net torque. This torque in the presence of neutral gas current changes angular momentum distribution function of dust grains to a shifted one around suppressed angular velocity. This anisotropy in distribution function leads to important inst.bilities.
In order to be able to compare adaptive codes and codes for a known source more precisely, it is important to know the exact expression of an O(1/n) term. Obtaining the exact expression for this and subsequent terms d...
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In order to be able to compare adaptive codes and codes for a known source more precisely, it is important to know the exact expression of an O(1/n) term. Obtaining the exact expression for this and subsequent terms describing the average behavior of adaptive block codes is shown.
In [4] a new relativization notion — stringent relativization — has been introduced for investigating a fine relationship between complexity classes. But considering "stringent relativization" is meaningfu...
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In this paper we define and study the notion of digital flatness. We extend to dimension two various definitions and classical results about digital lines and rays. In particular, we resolve a conjecture of Maurice Ni...
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The use of computer simulations has revolutionized the way engineers design and improve products and affects all design stages from concept to realization. As a consequence optimization has become an important tool fo...
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ISBN:
(纸本)9781624101007
The use of computer simulations has revolutionized the way engineers design and improve products and affects all design stages from concept to realization. As a consequence optimization has become an important tool for the engineer to realize better designs without the need of extensive prototype building. One of the algorithms that has shown an important ability to deal with this type of optimization is known as sequential approximate optimization. In sequential approximate optimization a series of local minimizations are performed over local response surface approximations of the system. In a previous work the authors developed an interior point approach for trust region managed sequential approximate optimization. The interior point approach insures that approximate feasibility is maintained throughout the optimization process. In the case of an infeasible design point, a relaxation of the constraints allows the algorithm to operate without modification. The relaxation is controlled by and homotopy parameter. A primary advantage resides in the fact that all the constraints influence the optimization, since the relaxation fades at the same time for all violated constraints. Adjustment of the parameter was performed in an heuristic fashion. In this paper the authors present a robust methodology to update the homotopy parameter based on the theory of probability one homotopies for nonlinear programming. Results show that the method is robust and effective in its implementation.
Multi-agent systems comprise entities whose individual decision making behavior may depend on one another's. Game-theory provides apposite concepts to reason in a math.matically precise fashion about such interact...
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Multi-agent systems comprise entities whose individual decision making behavior may depend on one another's. Game-theory provides apposite concepts to reason in a math.matically precise fashion about such interactive and interdependent situations. This paper concerns a logical analysis of the game-theoretical notions of Nash equilibrium and its subgame perfect variety as they apply to a particular class of extensive games of perfect information. Extensive games are defined as a special type of labelled graph and we argue that modal languages can be employed in their description. We propose a logic for a multi-modal language and prove its completeness with respect to a class of frames that correspond with a particular class of extensive games. In this multimodal language (subgame perfect) Nash equilibria can be characterized. Finally, we show how this approach can formally be refined by using Prepositional Dynamic Logic (PDL), though we leave completeness as an open question.
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