作者：
Marianna TcherpakovDianne SheltonZe'ev RonaiAgne's DelaunayLimor BrodayYukiko HayashiMassimiliano MirabellaKenneth D.BrombergTakayuki KadoyaXiao-Bo QiuStephen N.JonesSignal Transduction Program
Burnham Institute for Medical Research La Jolla CA 92037 Department of PathologySchool of Medicine University of California La Jolla San Diego CA 92093 USA Dept Cell and Developmental Biology Sackler School of Medicine Tel Aviv University Tel Aviv Israel National Institute of Neuroscience NCNP 4-1-1 Tokyo 187-8502 Japan Laboratory of Gene Expression Institute of Cell Biology and Tissue Engineering San Raffaele Biomedical Science Park Rome 00128 Italy Dept Pharmacology and Systems Therapeutics Mount Sinai School of Medicine New York NY 10029 USA Department of Cell Biology University of Massachusetts Medical School Worcester MA 01655 USA
Several different procedures are presented to produce smooth interpolating curves on the two-sphere S 2 . The first class of methods is a combination of the pull back/push forward technique with unrolling data from S ...
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ISBN:
(纸本)1424401704;9781424401703
Several different procedures are presented to produce smooth interpolating curves on the two-sphere S 2 . The first class of methods is a combination of the pull back/push forward technique with unrolling data from S 2 into a tangent plane, solving there the interpolation problem, and then wrapping the resulting interpolation curve back to the manifold. The second method results from converting a variational problem into a finite dimensional optimisation problem by a proper discretisation process. It turns out that the resulting curves look very similar. The main difference though is that the first approach gives closed form solutions to the interpolation problem, whereas the second method results in a finite number of points. These points then require further treatment, e.g., one could connect them by geodesic arcs, i.e., by great circle segments, to get an approximate solution to the variational problem. Although the result would not be smooth, it seems to be the best that one can get if the discretisation process is combined with a sufficiently cheap interpolation procedure
This paper investigates a novel procedure to calculate smooth interpolation curves of the rotation group SO 3 , which is commonly considered as the standard representation of rigid-body's orientations. The algorit...
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This paper investigates a novel procedure to calculate smooth interpolation curves of the rotation group SO 3 , which is commonly considered as the standard representation of rigid-body's orientations. The algorithm is a combination of rolling and wrapping with the pull back/push forward technique. One remarkable advantage of this approach is that interpolation curves are given in closed form, which brings convenience for implementations on real-time control systems. A numerical example along with some visualization results is presented as well
Agents and interactions between them are two key roles in modeling artificial transportation systems. This paper presents a formal theory to describe interactions between agents, which, together with the well develope...
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Agents and interactions between them are two key roles in modeling artificial transportation systems. This paper presents a formal theory to describe interactions between agents, which, together with the well developed models to describe components as agents, completes the first step towards establishing the formal structure for artificial transportation systems. By describing individual agents and the interactions between them as independent simple sequence processes and directive communication channels respectively, we models the whole system as one sequential communications system, which is one special type of Petri net. The theory is flexible enough to model diversified interactions between agents, and the resultant model possesses favorable properties. A case study of modeling road network has been conducted for the purpose of illustration
Vision-based pedestrian detection techniques for smart vehicles have emerged as a hot research topic in the field of vehicular electronics and driving safety. A vision-based system can recognize pedestrians in front o...
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Vision-based pedestrian detection techniques for smart vehicles have emerged as a hot research topic in the field of vehicular electronics and driving safety. A vision-based system can recognize pedestrians in front of the moving vehicle, then warns the driver of the dangerous situation loudly or slows the vehicle down automatically to protect both drivers and pedestrians. In general, the vision-based pedestrian detection process can be divided into three consecutive steps: pedestrian detection, pedestrian recognition, and pedestrian tracking. In this paper, a great variety of methods associated with these three steps is introduced and compared in detail. In addition, the implementation of vision-based pedestrian detection on vehicles is also presented. In the end, we analyze the difficulties and the research trend in the future.
The Akaike information criterion, AIC , is a widely used tool for model selection. AIC is derived as an asymptotically unbiased estimator of a function used for ranking candidate models which is a variant of the Kullb...
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The Akaike information criterion, AIC , is a widely used tool for model selection. AIC is derived as an asymptotically unbiased estimator of a function used for ranking candidate models which is a variant of the Kullback-Leibler divergence between the true model and the approximating candidate model. Despite the Kullback-Leibler's computational and theoretical advantages, what can become a nuisance in model selection applications is its lack of symmetry. Simple examples can show that reversing the role of the arguments in the Kullback-Leibler divergence can yield substantially different results. In this paper, three new functions for ranking candidate models are proposed. These functions are constructed by symmetrizing the Kullback-Leibler divergence between the true model and the approximating candidate model. The operations used for symmetrizing are the average, geometric and harmonic means. It is found that the original AIC criterion is an asymptotically unbiased estimator of these three different functions. A simulation study based on polynomial regression is also provided to compare the different proposed ranking functions with the AIC asymptotic estimation.
We consider N-stage serial production/distribution systems with stationary demand at the most downstream stage. First, we study classical Clark-Scarf model with both average cost and discounted cost criteria. The opti...
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We consider N-stage serial production/distribution systems with stationary demand at the most downstream stage. First, we study classical Clark-Scarf model with both average cost and discounted cost criteria. The optimal echelon base-stock levels are obtained in terms of only probabilistic distributions of leadtime demand. This analysis yields a novel approach for developing bounds and simple heuristics for optimal echelon base-stock polices. In addition to deriving known bounds, we develop several new upper bounds for both average cost and discounted cost models. Second and more important, we extend this idea to a more general model with two transportation modes between stages: the regular and expedited shippings (Lawson and Porteus (2000)). The optimal inventory policy for this system is known to be echelon base-stock policy, which can be computed through minimizing 2N nested convex functions recursively. We again develop simple newsvendor type of lower and upper bounds for the optimal control parameters, as well as a simple near optimal heuristic. Extensive numerical results show that the heuristics for both models perform well. The bounds and heuristic enhance the accessibility and implementability of the optimal policies in supply chains with single and dual transportation modes.
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