On private-key encryption using product codes

In this paper, we analyze the security of J. and R.M. Campello de Souza's private-key encryption scheme, which is based on the product codes with the capability of correcting a special type of structured errors. According to our cryptanalysis, we show that J. and R.M. Campello de Souza's scheme is insecure against chosen-plaintext attacks. A secure modified scheme is consequently proposed to enhance the security. In addition, we propose a modification of the proposed scheme which provides joint error correction and encryption.     

An integrated framework for the performance analysis of asynchronous communicating stochastic processes

In this paper we present a design framework containing a process algebra and the concurrent functional programming language Eden. In order to study properties of a specification written in our process algebraic notation, we provide a translation mechanism to generate Eden programs. Once we have a translation, we may use the Eden tools to study the performance of the (simulation of the) system. In order to add expressiveness to our design language we use a very powerful process algebra. First, we allow the specification of delays induced by general random variables. We also consider value passing. Finally, the communication between concurrent processes is asynchronous. The usefulness of our framework is presented by two examples featuring all the characteristics of our process algebraic model, we give the corresponding translations, and we provide some performance measures obtained by using Eden tools.Research supported in part by the Ministerio de Ciencia y Tecnologí a projects MASTER (TIC2003-07848-C02-01) and AMEVA (TIC2000-0701-C02-01) and by the Junta de Comunidades de Castilla-La Mancha project PAC-03-001.Accepted in revised form 15 September 2003 by M. Broy, G. Lüttgen and M. Mendler     

Exploratory Navigation Based on Dynamical Boundary Value Problems

The paper presents a general framework for concurrent navigation and exploration of unknown environments based on discrete potential fields that guide the robot motion. These potentials are obtained from a class of partial differential equation (PDE) problems called boundary value problems (BVP). The boundaries are generated from sensor readings and therefore they change as the robot moves. This framework corresponds to an extension of our previous work (Prestes, E., Idiart, M. A. P., Engel, P. and Trevisan, M.: Exploration technique using potential fields calculated from relaxation methods, in: IEEE/RSJ International Conference on Intelligent Robots and Systems, 2001, p. 2012; Prestes, E., Engel, P. M., Trevisan, M. and Idiart, M. A.: Exploration method using harmonic functions, Robot. Auton. Syst. 40(1) (2002), 25–42). Here, we propose that a careful choice of the PDE and the boundary conditions can produce efficient exploratory behaviors in sparse and dense environments. Furthermore, we show how to extend the exploratory behavior to produce new ones by changing dynamically the boundary function (the value of the potential at the boundaries) as the exploration takes course. Our framework is validated through a series of experiments with a real robot in office environments.     

Beyond contracts for concurrency

SCOOP is a concurrent programming language with a new semantics for contracts that applies equally well in concurrent and sequential contexts. SCOOP eliminates race conditions and atomicity violations by construction. However, it is still vulnerable to deadlocks. In this paper we describe how far contracts can take us in verifying interesting properties of concurrent systems using modular Hoare rules and show how theorem proving methods developed for sequential Eiffel can be extended to the concurrent case. However, some safety and liveness properties depend upon the environment and cannot be proved using the Hoare rules. To deal with such system properties, we outline a SCOOP Virtual Machine (SVM) as a fair transition system. The SVM makes it feasible to use model-checking and theorem proving methods for checking global temporal logic properties of SCOOP programs. The SVM uses the Hoare rules where applicable to reduce the number of steps in a computation. P. J. Brooke, R. F. Paige and Dong Jin Song This work was conducted under an NSERC Discovery grant.     

Ridgelet变换及其在图象降噪中的应用

1999年,Stanford大学的E.J.Candes和D.L.Donoho教授提出了信号的一种新的多尺度表示法—Ridgelet变换,它特别适合于具有直线或超平面奇性的二维信号的描述,而且具有较高的逼近精度。随后,M.N.Do和M.Vetterli针对特定大小的离散图象给出了正交有限Ridgelet变换-FiniteRidgeletTransform(FRIT)。该文将FRIT应用于图象降噪,为了说明FRIT的优越性,将Wavelet领域中的多种降噪方法扩展应用到Ridgelet领域。试验结果表明,FRIT比起Wavelet变换更适合描述具有直线边界的图象,而且降噪效果更为明显。     

P2P cloud network services for IoT based disaster situations information

In order to cope with disaster situations properly, it is very important to identify the disaster scale and provide the accurate information of the site to the appropriate authorities including disaster site and Central Disaster Management Center, on-site command post, etc. and share the information provided. In particular, sharing information on disaster situations should control the disaster quickly to prevent the disaster situation from lasting and expanding. However, in the event of a large-scale disaster, delay is caused in the existing commercial network and therefore, the disaster situation cannot be communicated quickly and accurately. In order to determine the situation exactly in the event of a disaster, safety and connectivity of the network and flow of data are very important. Even if the stability of the network and connection of nodes are resolved in the network of each agency business operator, it is necessary to share the platform between networks for IoT/M2M communication for the smooth flow of data. Recently, the disaster safety net of combining existing disaster standard technology with Ubiquitous Technology and Smart IT such as Tetra of Europe, iDEN of the U.S., etc. has been built for disaster safety communications. In addition, systems useful for demand-centered, site-centered immediate disaster response by using Mobile, SNS, cloud computing, etc. are being built and designed to play an important role in the disaster information system especially through IoT, P2P cloud network, big data, etc. Therefore, in this paper, we proposed the P2P cloud network service for IoT based disaster situations information according to the paradigm of the changing times. The proposed service is to combine IoT/M2M network with P2P cloud service for rapid and smooth response in the event of a disaster and provide the results as social services such as SNS. To this end, the wide area wireless disaster information network system has been built in the local and each local network is connected to each other to provide disaster situations by using the server of the disaster area. At this time, each server was to be interconnected via P2P network and to be connected automatically by software-based network in P2P Cloud System. Also, the cognitive cycle was applied for selecting optimal wireless link and router of P2P Cloud-based Disaster Information Network and the danger situations of the disaster area were to be provided to the user by configuring disaster information component for providing services and building central disaster information platform managing it.     

Spatially adaptive techniques for level set methods and incompressible flow

Since the seminal work of [Sussman, M, Smereka P, Osher S. A level set approach for computing solutions to incompressible two-phase flow. J Comput Phys 1994;114:146–59] on coupling the level set method of [Osher S, Sethian J. Fronts propagating with curvature-dependent speed: algorithms based on Hamilton–Jacobi formulations. J Comput Phys 1988;79:12–49] to the equations for two-phase incompressible flow, there has been a great deal of interest in this area. That work demonstrated the most powerful aspects of the level set method, i.e. automatic handling of topological changes such as merging and pinching, as well as robust geometric information such as normals and curvature. Interestingly, this work also demonstrated the largest weakness of the level set method, i.e. mass or information loss characteristic of most Eulerian capturing techniques. In fact, [Sussman M, Smereka P, Osher S. A level set approach for computing solutions to incompressible two-phase flow. J Comput Phys 1994;114:146–59] introduced a partial differential equation for battling this weakness, without which their work would not have been possible. In this paper, we discuss both historical and most recent works focused on improving the computational accuracy of the level set method focusing in part on applications related to incompressible flow due to both of its popularity and stringent accuracy requirements. Thus, we discuss higher order accurate numerical methods such as Hamilton–Jacobi WENO [Jiang G-S, Peng D. Weighted ENO schemes for Hamilton–Jacobi equations. SIAM J Sci Comput 2000;21:2126–43], methods for maintaining a signed distance function, hybrid methods such as the particle level set method [Enright D, Fedkiw R, Ferziger J, Mitchell I. A hybrid particle level set method for improved interface capturing. J Comput Phys 2002;183:83–116] and the coupled level set volume of fluid method [Sussman M, Puckett EG. A coupled level set and volume-of-fluid method for computing 3d and axisymmetric incompressible two-phase flows. J Comput Phys 2000;162:301–37], and adaptive gridding techniques such as the octree approach to free surface flows proposed in [Losasso F, Gibou F, Fedkiw R. Simulating water and smoke with an octree data structure, ACM Trans Graph (SIGGRAPH Proc) 2004;23:457–62].     

Comments on ‘Inversion of A Generalized Vandermonde Matrix’ by M.E.A. El-Mikkawy, 80 (2003) 759–765

In this paper, we give the comments on the article ‘Inversion of a Generalized Vandermonde Matrix’ by M.E.A. El Mikkawy, Int. J. Computer Math. 80 (2003), pp. 759–765. The article gives an algorithm for the elementary symmetric function's calculation which contains a severe error. In these comments, we have proposed necessary corrections of that algorithm.     

On the estimation of the general parameter

In this paper, we first discuss the origin, developments and various thoughts by several researchers on the generalized linear regression estimator (GREG) due to Deville and Särndal [Deville, J.C., Särndal, C.E., 1992. Calibration estimators in survey sampling. J. Amer. Statist. Assoc. 87, 376-382]. Then, the problem of estimation of the general parameter of interest considered by Rao [Rao, J.N.K., 1994. Estimating totals and distribution functions using auxiliary information at the estimation stage. J. Official Statist. 10 (2), 153-165], and Singh [Singh, S., 2001. Generalized calibration approach for estimating the variance in survey sampling. Ann. Inst. Statist. Math. 53 (2), 404-417; Singh, S., 2004. Golden and Silver Jubilee Year-2003 of the linear regression estimators. In: Proceedings of the Joint Statistical Meeting, Toronto (Available on the CD), 4382-4380; Singh, S., 2006. Survey statisticians celebrate Golden Jubilee Year-2003 of the linear regression estimator. Metrika 1-18] is further investigated. In addition to that it is shown that the Farrell and Singh [Farrell, P.J., Singh, S., 2005. Model-assisted higher order calibration of estimators of variance. Australian & New Zealand J. Statist. 47 (3), 375-383] estimators are also a special case of the proposed methodology. Interestingly, it has been noted that the single model assisted calibration constraint studied by Farrell and Singh [Farrell, P.J., Singh, S., 2002. Re-calibration of higher order calibration weights. Presented at Statistical Society of Canada conference, Hamilton (Available on CD); Farrell, P.J., Singh, S., 2005. Model-assisted higher order calibration of estimators of variance. Australian & New Zealand J. Statist. 47 (3), 375-383] and Wu [Wu, C., 2003. Optimal calibration estimators in survey sampling. Biometrika 90, 937-951] is not helpful for calibrating the Sen [Sen, A.R., 1953. On the estimate of the variance in sampling with varying probabilities. J. Indian Soc. Agril. Statist. 5, 119-127] and Yates and Grundy [Yates, F., Grundy, P.M., 1953. Selection without replacement from within strata with probability proportional to size. J. Roy. Statist. Soc. Ser. 15, 253-261] estimator of the variance of the linear regression estimator under the optimal designs of Godambe and Joshi [Godambe, V.P., Joshi, V.M., 1965. Admissibility and Bayes estimation in sampling finite populations—I. Ann. Math. Statist. 36, 1707-1722]. Three new estimators of the variance of the proposed linear regression type estimator of the general parameters of interest are introduced and compared with each other. The newly proposed two-dimensional linear regression models are found to be useful, unlike a simulation based on a couple of thousands of random samples, in comparing the estimators of variance. The use of knowledge of the model parameters in assisting the estimators of variance has been found to be beneficial. The most attractive feature is that it has been shown theoretically that the proposed method of calibration always remains more efficient than the GREG estimator.     

Multivariate quasi-interpolation in L p (ℝ d ) with radial basis functions for scattered data

In this paper, quasi-interpolation for scattered data was studied. On the basis of generalized quasi-interpolation for scattered data proposed in [Z.M. Wu and J.P. Liu, Generalized strang-fix condition for scattered data quasi-interpolation, Adv. Comput. Math. 23 (2005), pp. 201–214.], we have developed a new method to construct the kernel in the scheme by the linear combination of the scales, instead of the gridded shifts of the radial basis function. Compared with the kernel proposed in [Z.M. Wu and J.P. Liu, Generalized strang-fix condition for scattered data quasi-interpolation, Adv. Comput. Math. 23 (2005), pp. 201–214.], the new kernel, which is still a radial function, possesses the feature of polynomial reproducing property. This opens a possibility for us to propose a different technique by obtaining a higher approximation order of the convergence.     

Monte Carlo methods for computing the capacitance of the unit cube

It is well known that there is no analytic expression for the electrical capacitance of the unit cube. However, there are several Monte Carlo methods that have been used to numerically estimate this capacitance to high accuracy. These include a Brownian dynamics algorithm [H.-X. Zhou, A. Szabo, J.F. Douglas, J.B. Hubbard, A Brownian dynamics algorithm for calculating the hydrodynamic friction and the electrostatic capacitance of an arbitrarily shaped object, J. Chem. Phys. 100 (5) (1994) 3821–3826] coupled to the “walk on spheres” (WOS) method [M.E. Müller, Some continuous Monte Carlo methods for the Dirichlet problem, Ann. Math. Stat. 27 (1956) 569–589]; the Green’s function first-passage (GFFP) algorithm [J.A. Given, J.B. Hubbard, J.F. Douglas, A first-passage algorithm for the hydrodynamic friction and diffusion-limited reaction rate of macromolecules, J. Chem. Phys. 106 (9) (1997) 3721–3771]; an error-controlling Brownian dynamics algorithm [C.-O. Hwang, M. Mascagni, Capacitance of the unit cube, J. Korean Phys. Soc. 42 (2003) L1–L4]; an extrapolation technique coupled to the WOS method [C.-O. Hwang, Extrapolation technique in the “walk on spheres” method for the capacitance of the unit cube, J. Korean Phys. Soc. 44 (2) (2004) 469–470]; the “walk on planes” (WOP) method [M.L. Mansfield, J.F. Douglas, E.J. Garboczi, Intrinsic viscosity and the electrical polarizability of arbitrarily shaped objects, Phys. Rev. E 64 (6) (2001) 061401:1–061401:16; C.-O. Hwang, M. Mascagni, Electrical capacitance of the unit cube, J. Appl. Phys. 95 (7) (2004) 3798–3802]; and the random “walk on the boundary” (WOB) method [M. Mascagni, N.A. Simonov, The random walk on the boundary method for calculating capacitance, J. Comp. Phys. 195 (2004) 465–473]. Monte Carlo methods are convenient and efficient for problems whose solution includes singularities. In the calculation of the unit cube capacitance, there are edge and corner singularities in the charge density distribution. In this paper, we review the above Monte Carlo methods for computing the electrical capacitance of a cube and compare their effectiveness. We also provide a new result. We will focus our attention particularly on two Monte Carlo methods: WOP [M.L. Mansfield, J.F. Douglas, E.J. Garboczi, Intrinsic viscosity and the electrical polarizability of arbitrarily shaped objects, Phys. Rev. E 64 (6) (2001) 061401:1–061401:16; C.-O. Hwang, M. Mascagni, Electrical capacitance of the unit cube, J. Appl. Phys. 95 (7) (2004) 3798–3802; C.-O. Hwang, T. Won, Edge charge singularity of conductors, J. Korean Phys. Soc. 45 (2004) S551–S553] and the random WOB [M. Mascagni, N.A. Simonov, The random walk on the boundary method for calculating capacitance, J. Comp. Phys. 195 (2004) 465–473] methods.     

Discussion about parameterization in the asymptotic numerical method: Application to nonlinear elastic shells

The Asymptotic Numerical Method (ANM) is a family of algorithms for path following problems based on the computation of truncated vectorial series with respect to a path parameter “a” [B. Cochelin, N. Damil, M. Potier-Ferry, Méthode Asymptotique Numérique, Hermès-Lavoisier, Paris, 2007]. In this paper, we discuss and compare three concepts of parameterizations of the ANM curves i.e. the definition of the path parameter “a”. The first concept is based on the classical arc-length parameterization [E. Riks, Some computational aspects of the stability analysis of nonlinear structures, Computer Methods in Applied Mechanics and Engineering, 47 (1984) 219–259], the second is based on the so-called local parameterization [W. C. Rheinboldt, J. V. Burkadt, A Locally parameterized continuation, Acm Transaction on mathematical Software, 9 (1983) 215–235; R. Seydel, A Tracing Branches, World of Bifurcation, Online Collection and Tutorials of Nonlinear Phenomena (http://www.bifurcation.de), 1999; J. J. Gervais, H. Sadiky, A new steplength control for continuation with the asymptotic numerical method, IAM, J. Numer. Anal. 22, No. 2, (2000) 207–229] and the third is based on a minimization condition of a rest [S. Lopez, An effective parametrization for asymptotic extrapolation, Computer Methods in Applied Mechanics and Engineering, 189 (2000) 297–311]. We demonstrate that the third concept is equivalent to a maximization condition of the ANM step lengths. To illustrate the performance of these proposed parameterizations, we give some numerical comparisons on nonlinear elastic shell problems.     

Stability of conformable stochastic systems depending on a parameter

In this work, we study the almost sure exponential stability ( A.S.E.S ) and the exponential stability in p-th moment ( E.S.P.M ) of conformable stochastic systems depending on a parameter (CSSP) by using the Lyapunov methods and the classical stochastic analysis techniques. In the last section, we apply the main result for an illustrative example.     

Modeling and analysis of transaction execution in database systems

The controlled-generator model of P.J. Ramadge and W.M. Wonham (1988) is used to formulate the concurrent execution of transactions in database systems as a control problem for a partially observed discrete-event dynamical system. The control objectives of this problem (for concurrency control and recovery) and the properties of some important transaction scheduling techniques are characterized in terms of the language generated by the controlled process and in terms of the stage of an ideal complete-information scheduler. Results about the performance of these techniques are presented     

Efficient algorithms for NMR quantum computers with small qubits

The security of the RSA cryptosystems is based on the difficulty of factoring a large composite integer. In 1994, Shor showed that factoring a large composite is executable in polynomial time if we use a quantum Turing machine. Since this algorithm is complicated, straightforward implementations seem impractical judging from current technologies. In this paper, we propose simple and efficient algorithms for factoring and discrete logarithm problem based on NMR quantum computers. Our algorithms are easier to implement if we consider NMR quantum computers with small qubits. A part of this work was done while both authors were with NTT Communication Science Laboratories. Noboru Kunihiro, Ph.D.: He is Assistant Professor of the University of Electro-Communications. He received his B.E., M.E. and Ph.D. in mathematical engineering and information physics from the University of Tokyo in 1994, 1996 and 2001, respectively. He had been engaged in the research on cryptography and information security at NTT Communication Science Laboratories from 1996 to 2002. Since 2002, he has been working for Department of Information and Communication Engineering of the University of Elector-Communications. His research interest includes cryptography, information security and quantum computations. He was awarded the SCIS’97 paper prize. Shigeru Yamashita, Ph.D.: Associate Professor of Graduate School of Information Science, Nara Institute of Science and Technology, Nara 630-0192, Japan. He received his B.E., M.E. and Ph.D. degrees in information science from Kyoto University, Kyoto, Japan, in 1993, 1995 and 2001, respectively. His research interests include new type of computer architectures and quantum computation. He received the 2000 IEEE Circuits and Systems Society Transactions on Computer-Aided Design of Integrated Circuits and Systems Best Paper Award.     

基于最大秩距离码的私钥加密方案

Jordan和Rao基于纠错码提出了一种私钥加密方案,通过安全性分析可知,基于大数选举方法,此方案中的秘密矩阵能有效地获得。Gabidulin于1985年提出了秩距离码及最大秩距离码的理论,由于秩范数和秩距离码的特点,利用秩距离码构造密码系统,可用比较小的参数获得比较大的工作因子。Gabidulin,Paramonov和Tretjakov基于最大秩距离码提出了一种新的McEliece公钥密码系统,该文基于最大秩距离码提出了与其稍有不同的一种私钥加密方案。讨论了它的可行性及安全性,并证明了它比基于最大秩距离码的上述公钥密码系统更安全。     

A local-density based spatial clustering algorithm with noise

Density-based clustering algorithms are attractive for the task of class identification in spatial database. However, in many cases, very different local-density clusters exist in different regions of data space, therefore, DBSCAN method [M. Ester, H.-P. Kriegel, J. Sander, X. Xu, A density-based algorithm for discovering clusters in large spatial databases with noise, in: E. Simoudis, J. Han, U.M. Fayyad (Eds.), Proceedings of the Second International Conference on Knowledge Discovery and Data Mining, Portland, OR, AAAI, Menlo Park, CA, 1996, pp. 226–231] using a global density parameter is not suitable. Although OPTICS [M. Ankerst, M.M. Breunig, H.-P. Kriegel, J. Sander, OPTICS: ordering points to identify the clustering structure, in: A. Delis, C. Faloutsos, S. Ghandeharizadeh (Eds.), Proceedings of ACM SIGMOD International Conference on Management of Data Philadelphia, PA, ACM, New York, 1999, pp. 49–60] provides an augmented ordering of the database to represent its density-based clustering structure, it only generates the clusters with local-density exceeds certain thresholds but not the cluster of similar local-density; in addition, it does not produce clusters of a data set explicitly. Furthermore, the parameters required by almost all the major clustering algorithms are hard to determine although they significantly impact on the clustering result. In this paper, a new clustering algorithm LDBSCAN relying on a local-density-based notion of clusters is proposed. In this technique, the selection of appropriate parameters is not difficult; it also takes the advantage of the LOF [M.M. Breunig, H.-P. Kriegel, R.T. Ng, J. Sander, LOF: identifying density-based local outliers, in: W. Chen, J.F. Naughton, P.A. Bernstein (Eds.), Proceedings of ACM SIGMOD International Conference on Management of Data, Dalles, TX, ACM, New York, 2000, pp. 93–104] to detect the noises comparing with other density-based clustering algorithms. The proposed algorithm has potential applications in business intelligence.     

Pruning boosted classifiers with a real valued genetic algorithm

Ensemble classifiers and algorithms for learning ensembles have recently received a great deal of attention in the machine learning literature (R.E. Schapire, Machine Learning 5(2) (1990) 197–227;N. Cesa-Bianchi, Y. Freund, D. Haussler, D.P. Helbold, R.E. Schapire, M.K. Warmuth, Proceedings of the 25th Annual ACM Symposium on the Theory of Computing, 1993, pp. 382–391; L. Breiman, Bias, Technical Report 460, Statistics Department, University of California, Berkeley, CA, 1996; J.R. Quinlan, Proceedings of the 14th International Conference on Machine Learning, Italy, 1997; Y. Freund, R.E. Schapire, Proceedings of the 13th International Conference on Machine Learning ICML96, Bari, Italy 1996, pp. 148–157; A.J.C. Sharkey, N.E. Sharkey, Combining diverse neural nets, The Knowledge Engineering Review 12 (3) (1997) 231–247). In particular, boosting has received a great deal of attention as a mechanism by which an ensemble of classifiers that has a better generalisation characteristic than any single classifier derived using a particular technique can be discovered. In this article, we examine and compare a number of techniques for pruning a classifier ensemble which is overfit on its training set and find that a real valued GA is at least as good as the best heuristic search algorithm for choosing an ensemble weighting.     

Hardware/software optimization for array & pointer boundary checking against buffer overflow attacks

Malicious intrusions by buffer overflow attacks cause serious security problems and pose serious threats for networks and distributed systems such as clusters, Grids and P2P systems. Array & pointer boundary checking is one of the most effective approaches for defending against buffer overflow attacks. However, a big performance overhead may occur after boundary checking is applied. Typically, it may cause 2–5 times slowdown [T.M. Austin, E.B. Scott, S.S. Gurindar, Efficient detection of all pointer and array access errors, in: Proceedings of the ACM SIGPLAN ’94 Conference on Programming Language Design and Implementation, 1994, pp. 290–301; R.W.M. Jones, P.H.J. Kelly, Backwards-compatible bounds checking for arrays and pointers in c programs, in: The Third International Workshop on Automated and Algorithmic Debugging, 1997, pp. 13–26]. In this paper, we propose a hardware/software method to optimize the performance of array & pointer boundary checking by designing a special boundary checking instruction. The experimental results show that our method can effectively reduce the overhead of array & pointer boundary checking.