The Neural Network Approach to Input–Output Analysis for Economic Systems

Economic practitioners in China are giving up the classical Leontief’s Input–Output analysis methods. This paper offers an alternative method of input–output analysis. The proposed method is based on the layered neural network model. It shows that neural networks method can be useful for input–output analysis for a dynamic economic system.       

Thinking About Evolution in Terms of Cellular Computing

The past five decades of molecular genetics have produced many discoveries about genome structure and function that can only be understood from an informatic perspective: – distinct sequence codes to mark the individual steps in packaging, expression, replication, transmission, repair and restructuring of DNA molecules; – modularity of data files for RNA and protein products; – combinatoric organization of signals to format the genome for differential functioning during cellular and organismal cycles; – direct participation of DNA in the execution of biological algorithms (formation of highly structured nucleoprotein complexes); – hierarchical organization of genomic subsystems to form higher level system architectures. This review will discuss aspects of genome organization and genome change that require a more formal computational analysis. We will see how modern results indicate that genome evolution has many similarities to computer system engineering. The ability of cells to control the function of natural genetic engineering systems is central to the genome’s potential as a Read–Write information storage system.     

Extended multi bottom–up tree transducers

Extended multi bottom–up tree transducers are defined and investigated. They are an extension of multi bottom–up tree transducers by arbitrary, not just shallow, left-hand sides of rules; this includes rules that do not consume input. It is shown that such transducers, even linear ones, can compute all transformations that are computed by linear extended top–down tree transducers, which are a theoretical model for syntax-based machine translation. Moreover, the classical composition results for bottom–up tree transducers are generalized to extended multi bottom–up tree transducers. Finally, characterizations in terms of extended top–down tree transducers and tree bimorphisms are presented.     

Hot embossing of microstructures: characterization of friction during demolding

Today, hot embossing and injection molding belong to the established plastic molding processes in microengineering. Based on experimental findings, a variety of microstructures have been replicated so far using the above processes. However, with increasing requirements regarding the embossing surface and the simultaneous decrease of the structure size down into the nanorange, increasing know––how is needed to adapt hot embossing to industrial standards. To reach this objective, a German–Canadian cooperation project has been launched to study hot embossing theoretically by a process simulation and experimentally. The present publication shall report about an important aspect––the determination of friction during the demolding of microstructures.     

Information assimilation framework for event detection in multimedia surveillance systems

Most multimedia surveillance and monitoring systems nowadays utilize multiple types of sensors to detect events of interest as and when they occur in the environment. However, due to the asynchrony among and diversity of sensors, information assimilation – how to combine the information obtained from asynchronous and multifarious sources is an important and challenging research problem. In this paper, we propose a framework for information assimilation that addresses the issues – “when”, “what” and “how” to assimilate the information obtained from different media sources in order to detect events in multimedia surveillance systems. The proposed framework adopts a hierarchical probabilistic assimilation approach to detect atomic and compound events. To detect an event, our framework uses not only the media streams available at the current instant but it also utilizes their two important properties – first, accumulated past history of whether they have been providing concurring or contradictory evidences, and – second, the system designer’s confidence in them. The experimental results show the utility of the proposed framework.     

On Parabolic Boundary Layers for Convection–Diffusion Equations in a Channel: Analysis and Numerical Applications

In this article we discuss singularly perturbed convection–diffusion equations in a channel in cases producing parabolic boundary layers. It has been shown that one can improve the numerical resolution of singularly perturbed problems involving boundary layers, by incorporating the structure of the boundary layers into the finite element spaces, when this structure is available; see e.g. [Cheng, W. and Temam, R. (2002). Comput. Fluid. V.31, 453–466; Jung, C. (2005). Numer. Meth. Partial Differ. Eq. V.21, 623–648]. This approach is developed in this article for a convection–diffusion equation. Using an analytical approach, we first derive an approximate (simplified) form of the parabolic boundary layers (elements) for our problem; we then develop new numerical schemes using these boundary layer elements. The results are performed for the perturbation parameter ε in the range 10⁻¹–10⁻¹⁵ whereas the discretization mesh is in the range of order 1/10–1/100 in the x-direction and of order 1/10–1/30 in the y-direction. Indications on various extensions of this work are briefly described at the end of the Introduction.Dedicated to David Gottlieb on his 60th birthday.     

An algorithm for the construction of intrinsic delaunay triangulations with applications to digital geometry processing

Summary The discrete Laplace–Beltrami operator plays a prominent role in many digital geometry processing applications ranging from denoising to parameterization, editing, and physical simulation. The standard discretization uses the cotangents of the angles in the immersed mesh which leads to a variety of numerical problems. We advocate the use of the intrinsic Laplace–Beltrami operator. It satisfies a local maximum principle, guaranteeing, e.g., that no flipped triangles can occur in parameterizations. It also leads to better conditioned linear systems. The intrinsic Laplace–Beltrami operator is based on an intrinsic Delaunay triangulation of the surface. We detail an incremental algorithm to construct such triangulations together with an overlay structure which captures the relationship between the extrinsic and intrinsic triangulations. Using a variety of example meshes we demonstrate the numerical benefits of the intrinsic Laplace–Beltrami operator.     

A genetic approach to the design of autonomous agents for futures trading

We propose a genetic algorithm-based method for designing an autonomous trader agent. The task of the proposed method is to find an optimal set of fuzzy if–then rules that best represents the behavior of a target trader agent. A highly profitable trader agent is used as the target in the proposed genetic algorithm. A trading history for the target agent is obtained from a series of futures trading. The antecedent part of fuzzy if–then rules considers time-series data of spot prices, while the consequent part indicates the order of trade (Buy, Sell, or No action) with its degree of certainty. The proposed method determines the antecedent part of fuzzy if–then rules. The consequent part of fuzzy if–then rules is automatically determined from the trading history of the target trader agent. The autonomous trader agent designed by the proposed genetic algorithm consists of a fixed number of fuzzy if–then rules. The decision of the autonomous trader agent is made by fuzzy inference from the time-series data of spot prices. This work was presented in part at the 11th International Symposium on Artificial Life and Robotics, Oita, Japan, January 23–25, 2006     

Multichannel image segmentation using adaptive finite elements

We present an adaptive finite element algorithm for segmentation with denoising of multichannel images in two dimensions, of which an extension to three dimensional images is straight forward. It is based on a level set formulation of the Mumford–Shah approach proposed by Chan and Vese in (JVCIR 11:130–141,(2000); IEEE Trans Image Proces 10(2):266–277, (2001); Int J Comp Vis 50(3):271–293, (2002)) In case of a minimal partition problem an exact solution is given and convergence of the discrete solution towards this solution is numerically verified.     

Electroosmotic flow at a liquid–air interface

This paper presents the first experimental evidence on electroosmotic flow at a liquid–air interface. A PDMS microchannel with an opening to air was created to allow for the formation of a liquid–air interface. Polystyrene particles were used to visualize the liquid motion and the experiments found that the particle velocity at the liquid–air interface was significantly slower than the particle velocity in the bulk. This result agrees with a mathematical model that considers the effects of electrical surface charges at the liquid–air interface in electroosmotic flow.     

Anodic bonding of glass to aluminium

Anodic bonding of glass to aluminium may provide a higher degree of freedom in device design. In this paper, a systematic variation of the bonding parameters for the aluminium–glass bond is presented. Hermetic seals with strengths of 18.0 MPa can be achieved using a 50–100-nm-thick bonding aluminium layer, and bonding at 300–400°C applying a voltage of 1,000–1,500 V for 20 min. With these parameters, bond yields above 95.1% were obtained on 17 wafers. The bonds survived extensive thermal ageing without significant degradation. The possibility of bonding glass to an aluminium layer with buried, electrically isolated conductors underneath is also demonstrated.     

Locally strong coherence and inference with lower–upper probabilities

 We introduce an operational way to reduce the spatial complexity in inference processes based on conditional lower–upper probabilities assessments. To reach such goal we must suitably exploit zero probabilities taking account of logical conditions characterizing locally strong coherence. We actually re-formulate for conditional lower–upper probabilities the notion of locally strong coherence already introduced for conditional precise probabilities. Thanks to the characterization, we avoid to build all atoms, so that several real problems become feasible. In fact, the real complexity problem is connected to the number of atoms. Since for an inferential process with lower–upper probabilities several sequences of constraints must be fulfilled, our simplification can have either a “global” or a “partial” effect, being applicable to all or just to some sequences. The whole procedure has been implemented by XLisp-Stat language. A comparison with other approaches will be done by an example. The contribution of L. Galli has been essentially addressed to some aspects of the algorithm's implementation.     

A Discontinuous Galerkin Scheme Based on a Space–Time Expansion. I. Inviscid Compressible Flow in One Space Dimension

In this paper, we propose an explicit discontinuous Galerkin scheme for conservation laws which is of arbitrary order of accuracy in space and time. The basic idea is to use a Taylor expansion in space and time to define a space–time polynomial in each space–time element. The space derivatives are given by the approximate solution at the old time level, the time derivatives and the mixed space–time derivatives are computed from these space derivatives using the so-called Cauchy–Kovalevskaya procedure. The space–time volume integral is approximated by Gauss quadrature with values at the space–time Gaussian points obtained from the Taylor expansion. The flux in the surface integral is approximated by a numerical flux with arguments given by the Taylor expansions from the left and from the right-hand side of the element interface. The locality of the presented method together with the space–time expansion gives the attractive feature that the time steps may be different in each grid cell. Hence, we drop the common global time levels and propose that every grid zone runs with its own time step which is determined by the local stability restriction. In spite of the local time steps the scheme is locally conservative, fully explicit, and arbitrary order accurate in space and time for transient calculations. Numerical results are shown for the one-dimensional Euler equations with orders of accuracy one up to six in space and time.     

Some principles of coordinated decision making in distributed systems

Conclusion The proposed approach leads to flexible decision support algorithms and procedures that easily adapt to changing requirements. The application of the proposed principles is illustrated in [12] with the object of allowing for the specific features of the problem and accelerating convergence of distributed decision support systems. The application of these principles to the construction of various control procedures and decision support scheme is demonstrated in [13–19]. At the present time, in connection with active transition to the market and operation in a rapidly changing reality, we can expect an increase in demand for algorithms, procedures, and schemes that divide the domains of competence, sharply delineate the domains of responsibility, and clearly separate the fields of action of the “center” and the “periphery” [11]. The need for such procedures will also be felt in financial management support [26–27] and in macro/micro economic modeling and forecasting [20–26]. This is due to the fact that in our rapidly changing world we are often unable to identify several separate criteria for optimization. We are often forced to look for a decision which is admissible by a whole range of formal and informal criteria and is stable under small perturbations of both the criteria and the external conditions [28–30]. Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 161–175, March–April, 1996.     

Pattern-based abstraction for verifying secrecy in protocols

We present a method based on abstract interpretation for verifying secrecy properties of cryptographic protocols. Our method allows one to verify secrecy properties in a general model allowing an unbounded number of sessions, an unbounded number of principals, and an unbounded size of messages. As abstract domain we use sets of so-called super terms. Super terms are obtained by allowing an interpreted constructor, which we denote by Sup , where the meaning of a term Sup (t) is the set of terms that contain t as subterm. For these terms, we solve a generalized form of the unification problem and introduce a widening operator. We implemented a prototype and were able to verify well-known protocols such as, for instance, Needham–Schroeder–Lowe (0.03 s), Yahalom (12.67 s), Otway–Rees (0.01 s), and Kao–Chow (0.78 s).     

Eine verteilte Autorisierungsinfrastruktur unter Berücksichtigung von Datenschutzaspekten

Traditionelle Verfahren der Rechtezuweisung (Autorisierung) und Zugriffskontrolle sind nur eingeschr?nkt geeignet, die Anforderungen an das Management der Nutzerprivilegien und an die Durchsetzung einer Sicherheitsstrategie in skalierbaren und hoch flexiblen verteilten Systemen umzusetzen. Dafür besser geeignet sind Sicherheitsinfrastrukturen, genauer AAIs – authentication and authorization infrastructures – und PMIs – privilege management infrastructures – die in der Lage sind, umfassende Sicherheitsdienstleistungen in einer F?deration von Systemen aus unterschiedlichen Dom?nen anzubieten. Dieser Beitrag enth?lt die Darstellung einer datenschutzorientierten AAI im Umfeld von eGovernment, die attributbasierte Zugriffskontrolle, eine XACML-Sicherheitsarchitektur zur Umsetzung und eine besondere Berücksichtigung der Datenschutzaspekte bei der Weitergabe der Nutzerattribute beinhaltet.     

On body shapes providing maximum depth of penetration

The problem of maximization of the depth of penetration of rigid impactor into semi-infinite solid media (concrete shield) is investigated analytically and numerically using two-stage model and experimental data of Forrestal and Tzou (Int J Solids Struct 34(31–32):4127–4146, 1997). The shape of the axisymmetric rigid impactor has been taken as an unknown design variable. To solve the formulated optimization problem for nonadditive functional, we expressed the depth of penetration (DOP) under some isoperimetric constraints. We apply approaches based on analytical and qualitative variational methods and numerical optimization algorithm of global search. Basic attention for considered optimization problem was given to constraints on the mass of penetrated bodies, expressed by the volume in the case of penetrated solid body and by the surface area in the case of penetrated thin-walled rigid shell. As a result of performed investigation, based on two-term and three-term two stage models proposed by Forrestal et al. (Int J Impact Eng 15(4):396–405, 1994), Forrestal and Tzou (Int J Solids Struct 34(31–32):4127–4146, 1997) and effectively developed by Ben-Dor et al. (Comp Struct 56:243–248, 2002, Comput Struct 81(1):9–14, 2003a, Int J Solids Struct 40(17):4487–4500, 2003b, Mech Des Struct Mach 34(2): 139–156, 2006), we found analytical and numerical solutions and analyzed singularities of optimal forms.     

An approach to determining Shor’s dual quadratic estimates

For a general quadratic problem, an analog is formulated as a homogeneous quadratic problem. The estimates ψ* constructed based on Shor’s dual quadratic estimates for these problems are proved to be equal. It is shown that, for the case of a homogeneous quadratic problem, finding ψ* is reduced to an unconstraint minimization problem for a convex function. The study was partially sponsored by the grant UKM2-2812-KV-06 (CRDF Cooperative Grants Program). __________ Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 89–99, March–April 2008.     

Spectral characterization of mixing properties of annular MHD micromixers

We develop a quantitative analysis of mixing regimes in an annular MHD-driven micromixer recently proposed by Gleeson et al. as a prototype for biomolecular applications. The analysis is based on the spectral properties of the advection–diffusion operator, with specific focus on the dependence of the dominant eigenvalue–eigenfunction on the Peclet number and on the system geometry. A theoretical prediction for the dominant eigenvalue encompassing all mixing regimes is developed and validated by comparison with numerical simulations. The theoretical prediction is extended to an open inflow–outflow version of the reactor, which shows the occurrence of new regimes associated with the existence of a nonuniform axial flow.