A query model to synthesize answer intervals from indexed videounits

While a query result in a traditional database is a subset of the database, in a video database, it is a set of subintervals extracted from the raw video sequence. It is very hard, if not impossible, to predetermine all the queries that will be issued in the future, and all the subintervals that will become necessary to answer them. As a result, conventional query frameworks are not applicable to video databases. We propose a new video query model that computes query results by dynamically synthesizing needed subintervals from fragmentary indexed intervals in the database. We introduce new interval operations required for that computation. We also propose methods to compute relative relevance of synthesized intervals to a given query. A query result is a list of synthesized intervals sorted in the order of their degree of relevance     

Wavefront diffusion and LMSR: algorithms for dynamic repartitioningof adaptive meshes

Current multilevel repartitioning schemes tend to perform well on certain types of problems while obtaining worse results for other types of problems. We present two new multilevel algorithms for repartitioning adaptive meshes that improve the performance of multilevel schemes for the types of problems that current schemes perform poorly while maintaining similar or better results for those problems that current schemes perform well. Specifically, we present a new scratch-remap scheme called Locally-matched Multilevel Scratch-remap (or simply LMSR) for repartitioning of adaptive meshes. LMSR tries to compute a high-quality partitioning that has a large amount of overlap with the original partitioning. We show that LMSR generally decreases the data redistribution costs required to balance the load compared to current scratch-remap schemes. We present a new diffusion-based scheme that we refer to as Wavefront Diffusion. In Wavefront Diffusion, the flow of vertices moves in a wavefront from overweight to underweight subdomains. We show that Wavefront Diffusion obtains significantly lower data redistribution costs while maintaining similar or better edge-cut results compared to existing diffusion algorithms. We also compare Wavefront Diffusion with LMSR and show that these provide a trade-off between edge-cut and data redistribution costs for a wide range of problems. Our experimental results on a Gray T3E, an IBM SP2, and a cluster of Pentium Pro workstations show that both schemes are fast and scalable. For example, both are capable of repartitioning a seven million vertex graph in under three seconds on 128 processors of a Gray T3E. Our schemes obtained relative speedups of between nine and 12 when the number of processors was increased by a factor of 16 on a Gray T3E     

Graph queries for data integration using xml

A new visual language, which is called ER-QBE and uses a conceptual model semantics, is proposed for the development of XML views. ER-QBE is based on graph queries that are trees of parametric SQL queries. The ER-QBE language is characterized by formally proved completeness, its expressiveness is higher than that of well-known alternatives, and it supports both relational and object-relational databases. __________ Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 171–183, March–April 2008.     

Dynamic analysis and choice of parameters of a model of gyroscopic integrator of linear accelerations with floating platform

Problems of dynamic analysis and parametric synthesis of a discrete-continuous model of a gyroscopic integrator of linear accelerations with floating platform using methods of combined dynamic systems theory are studied. Based on theorems of stable characteristic quasipolynomials and asymptotically stable and unstable quasirational fractions, stability domains are constructed using the D-decomposition method. It is shown that the parametric synthesis of optimal parameters of the simplest integro-differential correcting block reduces considerably resonance values of amplitude-frequency characteristics, control time, and relative error.     

Optimization of an algorithm for measurements of velocity vector components using a three-wire sensor

Hot-wire measurements of velocity vector components use a sensor with three orthogonal wires, taking advantage of an anisotropic effect of wire sensitivity. The sensor is connected to a three-channel anemometric circuit and a data acquisition and processing system. Velocity vector components are obtained from measurement signals, using a modified algorithm for measuring velocity vector components enabling the minimization of measurement errors described in this paper. The standard deviation of the relative error was significantly reduced in comparison with the classical algorithm.     

Force-clamp spectroscopy with a small dithering of AFM tip, and its application to explore the energy landscape of single avidin-biotin complex

We have recently developed a new method for directly measuring the spring constant of single molecules and molecular complexes on a real-time basis [L.A. Chtcheglova, G.T. Shubeita, S.K. Sekatskii, G. Dietler, Biophys. J. 86 (2004) 1177]. The technique combines standard force spectroscopy with a small dithering of tip. Changes in the amplitude of the oscillations are measured as a function of the pulling-off force to yield the spring constant of the complex. In this report, we present the first results of combination of this approach with the force-clamp spectroscopy. The standard atomic-force microscope has been supplemented with an electronic unit, which is capable of realizing an arbitrary force function, and permits the force-loading regime to be interrupted at any time. Using this method, the time needed to rupture a single bond can be measured as a function of the force that is required to maintain the complex in a stretched condition. The energy landscape of the avidin-biotin complex is explored and discussed.     

Relating time complexity of protein folding simulation to approximations of folding time

Finkelstein and Badretdinov [A.V. Finkelstein, A.Y. Badretdinov, Rate of protein folding near the point of thermodynamic equilibrium between the coil and the most stable chain fold, Fold. Des. 2 (1997) 115-121] approximated the folding time of protein sequences of length n by exp(λ⋅n2/3±χ⋅n1/2/2)ns, where λ and χ are constants close to unity. Recently, Fu and Wang [B. Fu, W. Wang, A ²O(n1−1/d⋅logn) time algorithm for d-dimensional protein folding in the HP-model, in: J. Daz, J. Karhumäki, A. Lepistö, D. Sannella (Eds.), Proceedings of the 31st International Colloquium on Automata, Languages and Programming, in: Lecture Notes in Comput. Sci., vol. 3142, Springer-Verlag, Heidelberg, 2004, pp. 630-644] published an exp(O(n1−1/d)⋅lnn) algorithm for d-dimensional protein folding simulation in the HP-model, which is close to the folding time approximation by Finkelstein and Badretdinov and can be seen as a justification of the HP-model for investigating general complexity issues of protein folding. We propose a stochastic local search procedure that is based on logarithmic simulated annealing. We obtain that after (m/δ)^a⋅D Markov chain transitions the probability to be in a minimum energy conformation is at least 1−δ, where m?b(d)⋅n is the maximum neighbourhood size (b(d) small integer), a is a small constant, and D is the maximum value of the minimum escape height from local minima of the underlying energy landscape. We note that the time bound is instance-specific, and we conjecture D<n1−1/d as a worst case upper bound. We analyse experimentally on selected benchmark problems for the d=2 case.     

Learning about psychological professions with the world-wide web

Abstract Teaching with the world-wide web is becoming a common practice in modern education. The web serves two main interrelated functions, namely, retrieval and publication of information. To enhance learning and motivation, the student-as-teacher (SAT) principle was adopted in the study reported in this paper. Students were given the role of teacher of high school students and the general public about the subject matter they learned on a course. To achieve this goal, the students created educational web sites featuring two selected psychological professions. Being the major assignment for the course, the web sites created by students received higher scores than the assignments of their peers who learned the same materials through traditional pedagogical approaches. Course evaluation confirmed that the web implementation of the SAT principle enhanced learning, increased motivation and provided a transfer-able skill, without compromising accomplishment of major course goals.     

Distributed Symbolic Bounded Property Checking

In this paper we describe an algorithm for distributed, BDD-based bounded property checking and its implementation in the verification tool SymC. The distributed algorithm verifies larger models and returns results faster than the sequential version.The core algorithm distributes partitions of the state set to computation nodes after reaching a threshold size. The nodes proceed with image computation on the nodes asynchronously. The main scalability problem of this scheme is the overlap of state set partitions. We present static and dynamic overlap reduction techniques.     

Identification of stable models in subspace identification by usingregularization

In subspace identification methods, the system matrices are usually estimated by least squares, based on estimated Kalman filter state sequences and the observed inputs and outputs. For a finite number of data points, the estimated system matrix is not guaranteed to be stable, even when the true linear system is known to be stable. In this paper, stability is imposed by using regularization. The regularization term used here is the trace of a matrix which involves the dynamical system matrix and a positive (semi) definite weighting matrix. The amount of regularization can be determined from a generalized eigenvalue problem. The data augmentation method of Chui and Maciejowski (1996) is obtained by using specific choices for the weighting matrix in the regularization term