ppxscal/embedding_network huggingface dataset:
Tree pattern query minimization
Authors: S. Amer-Yahia, S. Cho, L. V. S. Lakshmanan, D. Srivastava
Venue: The VLDB Journal &mdash; The International Journal on Very Large Data Bases (2002)

Tree patterns form a natural basis to query tree-structured data such as XML and LDAP. To improve the efficiency of tree pattern matching, it is essential to quickly identify and eliminate redundant nodes in the pattern. In this paper, we study tree pattern minimization both in the absence and in the presence of integrity constraints (ICs) on the underlying tree-structured database. In the absence of ICs, we develop a polynomial-time query minimization algorithm called CIM, whose efficiency stems from two key properties: (i) a node cannot be redundant unless its children are; and (ii) the order of elimination of redundant nodes is immaterial. When ICs are considered for minimization, we develop a technique for query minimization based on three fundamental operations: augmentation (an adaptation of the well-known chase procedure), minimization (based on homomorphism techniques), and reduction. We show the surprising result that the algorithm, referred to as ACIM, obtained by first augmenting the tree pattern using ICs, and then applying CIM, always finds the unique minimal equivalent query. While ACIM is polynomial time, it can be expensive in practice because of its inherent non-locality. We then present a fast algorithm, CDM, that identifies and eliminates local redundancies due to ICs, based on propagating &rdquo;information labels&rdquo; up the tree pattern. CDM can be applied prior to ACIM for improving the minimization efficiency. We complement our analytical results with an experimental study that shows the effectiveness of our tree pattern minimization techniques.
Leakage Current in Sub-Quarter Micron MOSFET: A Perspective on Stressed Delta IDDQ Testing
Authors: Oleg Semenov, Arman Vassighi, Manoj Sachdev
Venue: Journal of Electronic Testing: Theory and Applications (2003)

The effectiveness of single threshold IDDQ measurement for defect detection is eroded owing to higher and more variable background leakage current in modern VLSIs. Delta IDDQ is identified as one alternative for deep submicron current measurements. Often delta IDDQ is coupled with voltage and thermal stress in order to accelerate the failure mechanisms. A major concern is the IDDQ limit setting under normal and stressed conditions. In this article, we investigate the impact of voltage and thermal stress on the background leakage. We calculate IDDQ limits for normal and stressed operating conditions of 0.18 &mu;m n-MOSFETs using a device simulator. Intrinsic leakage current components of transistor are analyzed and the impact of technology scaling on effectiveness of stressed &Delta;IDDQ testing is also investigated.
Query containment and rewriting using views for regular path queries under constraints
Authors: Gösta Grahne, Alex Thomo
Venue: Proceedings of the twenty-second ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems (2003)

In this paper we consider general path constraints for semistructured databases. Our general constraints do not suffer from the limitations of the path constraints previously studied in the literature. We investigate the containment of regular path queries under general path constraints. We show that when the path constraints and queries are expressed by words, as opposed to languages, the containment problem becomes equivalent to the word rewrite problem for a corresponding semi-Thue system. Consequently, if the corresponding semi-Thue system has an undecidable word problem, the word query containment problem will be undecidable too. Also, we show that there are word constraints, where the corresponding semi-Thue system has a decidable word rewrite problem, but the general query containment under these word constraints is undecidable. In order to overcome this, we exhibit a large, practical class of word constraints with a decidable general query containment problem.Based on the query containment under constraints, we reason about constrained rewritings -using views- of regular path queries. We give a constructive characterization for computing optimal constrained rewritings using views.
Book Reviews
Authors: Benjamin Lev, Antanas Zilinskas, Michael O. Ball
Venue: Interfaces (2001)

The range of books reviewed is wide, covering theory and applications in operations research, statistics, management science, econometrics, mathematics, computers, and information systems (no software is reviewed). In addition, we include books in other fields that emphasize technical applications. Publishers who wish to have their books reviewed should send them to Professor Benjamin Lev. We list the books received; not all books received can be reviewed because space and time are limited. Those who would like to review books are urged to send me their names, addresses, and specific areas of expertise. We commission all reviews and do not accept unsolicited book reviews. Readers are encouraged to suggest books that might be reviewed or to ask publishers to send me copies of such books.
A number theoretic function and its mean value property
Authors: Liu Hongyan, Zhang Wenpeng
Venue: Smarandache Notions Journal (2002)

Let p be a prime, n be any positive integer, α(n, p) denotes the power of p in the factorization of n!. In this paper, we study the asymptotic properties of the mean value Σp≤n α(n, p) and give an interesting asymptotic formula for it.
Gemmating P systems: collapsing hierarchies
Authors: D. Besozzi, G. Mauri, G. Păun, C. Zandron
Venue: Theoretical Computer Science (2003)

We continue the analysis of P systems with gemmation of mobile membranes. We solve an open problem from Besozzi et al. (Proc. Italian Conf. on Theoretical Computer Science 2001, Lecture Notes in Computer Science, Vol. 2202, Springer, Berlin, 2001, pp. 136-153), showing that the hierarchy on the number of membranes collapses: systems with eight membranes characterize the recursively enumerable languages (seven membranes are enough in the case of extended systems). We also prove that P systems, which use only gemmation, but neither classical rewriting rules nor in/out communications, can generate the same family of languages. In this case, the hierarchy on the number of membranes collapses to level nine.
Improvement and Comparison of Heuristics for Solving the Uncapacitated Multisource Weber Problem
Authors: Jack Brimberg, Pierre Hansen, Nenad Mlandinovic, Eric. D. Taillard
Venue: Operations Research (2000)

The multisource Weber problem is to locate simultaneouslym facilities in the Euclidean plane to minimize the total transportation cost for satisfying the demand ofn fixed users, each supplied from its closest facility. Many heuristics have been proposed for this problem, as well as a few exact algorithms. Heuristics are needed to solve quickly large problems and to provide good initial solutions for exact algorithms. We compare various heuristics, i.e., alternative location-allocation (Cooper 1964), projection (Bongartz et al. 1994), Tabu search (Brimberg and Mladenovic 1996a),p-Median plus Weber (Hansen et al. 1996), Genetic search and several versions of Variable Neighbourhood search. Based on empirical tests that are reported, it is found that most traditional and some recent heuristics give poor results when the number of facilities to locate is large and that Variable Neighbourhood search gives consistently best results, on average, in moderate computing time.
Design of the Control Algorithm in a System of Production Rules with Time Parameter
Authors: O. V. German, D. V. Zan'ko
Venue: Automation and Remote Control (2003)

For the problem of designing control formalized in the system of production rules with a time parameter, consideration was given to realization and the applicability conditions for the method of equivalent substitutions. The proposed method was substantiated in formal terms and analyzed.
The effects of systemic packet loss on aggregate TCP flows
Authors: Thomas J. Hacker, Brian D. Noble, Brian D. Athey
Venue: Proceedings of the 2002 ACM/IEEE conference on Supercomputing (2002)

The use of parallel TCP connections to increase throughput for bulk transfers is common practice within the high performance computing community. However, the effectiveness, fairness, and efficiency of data transfers across parallel connections is unclear. This paper considers the impact of systemic non-congestion related packet loss on the effectiveness, fairness, and efficiency of parallel TCP transmissions. The results indicate that parallel connections are effective at increasing aggregate throughput, and increase the overall efficiency of the network bottleneck. In the presence of congestion related losses, parallel flows steal bandwidth from other single stream flows. A simple modification is presented that reduces the fairness problems when congestion is present, but retains effectiveness and efficiency.
Register write specialization register read specialization: a path to complexity-effective wide-issue superscalar processors
Authors: André Seznec, Eric Toullec, Olivier Rochecouste
Venue: Proceedings of the 35th annual ACM/IEEE international symposium on Microarchitecture (2002)

With the continuous shrinking of transistor size, processor designers are facing new difficulties to achieve high clock frequency. The register file read time, the wake up and selection logic traversal delay and the bypass network transit delay with also their respective power consumptions constitute major difficulties for the design of wide issue superscalar processors.In this paper, we show that transgressing a rule, that has so far been applied in the design of all the superscalar processors, allows to reduce these difficulties. Currently used general-purpose ISAs feature a single logical register file (and generally a floating-point register file). Up to now all superscalar processors have allowed any general-purpose functional unit to read and write any physical general purpose register.First, we propose Register Write Specialization, i.e, forcing distinct groups of functional units to write only in distinct subsets of the physical register file, thus limiting the number of write ports on each individual register. Register Write Specialization significantly reduces the access time, the power consumption and the silicon area of the register file without impairing performance.Second, we propose to combine Register Write Specialization with Register Read Specialization for clustered superscalar processors. This limits the number of read ports on each individual register and simplifies both the wakeup logic and the bypass network. With a 8-way 4-cluster WSRS architecture, the complexities of the wake-up logic entry and bypass point are equivalent to the ones found with a conventional 4-way issue processor. More physical registers are needed in WSRS architectures. Nevertheless, using WSRS architecture allows a dramatic reduction of the total silicon area devoted to the physical register file (by a factor four to six). Its power consumption is more than halved and its read access time is shortened by one third. Some extra hardware and/or a few extra pipeline stages are needed for register renaming. WSRS architecture induces constraints on the policy for allocating instructions to clusters. However, performance of a 8-way 4-cluster WSRS architecture stands the comparison with the one of a conventional 8-way 4-cluster conventional superscalar processor.
Relative invariants of some 2-simple prehomogeneous vector spaces
Authors: Takeyoshi Kogiso, Go Miyabe, Miyuki Kobayashi, Tatsuo Kimura
Venue: Mathematics of Computation (2003)

In this paper, we shall construct explicitly irreducible relative invariants of two 2-simple prehomogeneous vector spaces. Together with a preprint by the same authors, this completes the list of all relative invariants of regular 2-simple prehomogeneous vector spaces of type I.
Page Segmentation Using Document Model
Authors: Anil K. Jain, Bin Yu
Venue: Proceedings of the 4th International Conference on Document Analysis and Recognition (1997)

Transforming a paper document to its electronic version in a form suitable for efficient storage, retrieval and interpretation continues to be a challenging problem. An efficient document model is necessary to solve this problem. Document modeling involves techniques of thresholding, skew detection, geometric layout analysis and logical layout analysis. The derived model can then be used in document storage and retrieval. In this paper, we use the traditional bottom-up approach based on the connected component extraction to efficiently implement page segmentation and region identification. A new document model which preserves top-down generation information is proposed based on which a document is logically represented for interactive editing, storage, retrieval, transfer and logical analysis.Address Block Location on Complex Mail Pieces
Optimal pricing and ordering policies for retailers under order-size-dependent delay in payments
Authors: Seong Whan Shinn, Hark Hwang
Venue: Computers and Operations Research (2003)

This paper deals with the problem of determining the retailer's optimal price and order size simultaneously under the condition of order-size-dependent delay in payments. It is assumed that the length of the credit period is a function of the retailer's order size, and also the demand rate is a function of the selling price. We formulate two types of mathematical models from which algorithms are derived based on properties of an optimal solution. A numerical example is presented to illustrate the algorithms developed.
A fundamental solution method for viscous flow problems with obstacles in a periodic array
Authors: Hidenori Ogata, Kaname Amano, Masaaki Sugihara, Dai Okano
Venue: Journal of Computational and Applied Mathematics (2003)

We present here a fundamental solution method for two-dimensional viscous flow problems with obstacles in a two-dimensional periodic array. Our problem is mathematically a boundary value problem of the Stokes equations with periodic boundary conditions, to which it is difficult to give a good approximation by the ordinary fundamental solution method. We propose a fundamental solution method for our problem based on the periodic fundamental solution obtained by Hasimoto (J. Fluid Mech. 5 (1959) 317). In our method, the solution is approximated by using a linear combination of the periodic fundamental solutions.
G-Networks: Development of the Theory of Multiplicative Networks
Authors: P. P. Bocharov, V. M. Vishnevskii
Venue: Automation and Remote Control (2003)

This is a review on G-networks, which are the generalization of the Jackson and BCMP networks, for which the multi-dimensional stationary distribution of the network state probabilities is also represented in product form. The G-networks primarily differ from the Jackson and BCMP networks in that they additionally contain a flow of the so-called negative customers and/or triggers. Negative customers and triggers are not served. When a negative customer arrives at a network node, one or a batch of positive (ordinary) customers is killed (annihilated, displaced), whereas a trigger displaces a positive customer from the node to some other node. For applied mathematicians, G-networks are of great interest for extending the multiplicative theory of queueing networks and for practical specialists in modeling computing systems and networks and biophysical neural networks for solving pattern recognition and other problems.
A partitioning method for efficient system-level diagnosis
Authors: Gwangil Jeon, Yookun Cho
Venue: Journal of Systems and Software (2002)

We propose a partitioning method for an adaptive distributed system-level diagnosis in arbitrary network topologies. It utilizes a biconnected component as a partitioning unit. In an adaptive distributed system-level diagnosis, testing assignment algorithm is performed before each node performs actual diagnosis to reduce the number of tests in the system. Existing testing assignment algorithms adopt non-partitioning approach covering the whole system, so they incur unnecessary extra message traffic and time. In our method, the whole system is partitioned into small groups (biconnected components), and testing assignment is performed within each group. By exploiting the property of an articulation point of a biconnected component, initial testing assignment of our method performs better than non-partitioning approach by reducing the number of nodes involved in testing assignment. It also localizes the testing reassignment caused by system reconfiguration within the related biconnected components only. It is shown that our system-level diagnosis method is correct, and the number of messages required for testing assignment of our method is smaller than that of the previous non-partitioning methods. Comparisons with other partitioning approach are also presented.
Possibilistic information theory: a coding theoretic approach
Authors: Andrea Sgarro
Venue: Fuzzy Sets and Systems (2002)

We define information measures which pertain to possibility theory and which have a coding-theoretic meaning. We put forward a model for information sources and transmission channels which is possibilistic rather than probabilistic. In the case of source coding without distortion we define a notion of possibilistic entropy, which is connected to the so-called Hartley's measure; we tackle also the case of source coding with distortion. In the case of channel coding we define a notion of possibilistic capacity, which is connected to a combinatorial notion called graph capacity. In the probabilistic case Hartley's measure and graph capacity are relevant quantities only when the allowed decoding error probability is strictly equal to zero, while in the possibilistic case they are relevant quantities for whatever value of the allowed decoding error possibility; as the allowed error possibility becomes larger the possibilistic entropy decreases (one can reliably compress data to smaller sizes), while the possibilistic capacity increases (one can reliably transmit data at a higher rate). We put forward an interpretation of possibilistic coding, which is based on distortion measures. We discuss an application, where possibilities are used to cope with uncertainty as induced by a "vague" linguistic description of the transmission channel.
In Search of Strategic Operations Research/Management Science
Authors: Peter C. Bell, Chris K. Anderson
Venue: Interfaces (2002)

We define strategic OR/MS as "OR/MS work that leads to a sustainable competitive advantage." We found evidence of strategic OR/MS in the literature of strategic information systems (SIS) and OR/MS. We examined 30 early examples of SIS, many of which contained OR/MS work. Many of the most successful had high OR/MS content, while the least successful contained none. The inclusion of OR/MS work may be a key to sustaining an advantage from information technology. We also examined the Edelman Prize finalist articles published between 1990 and 1999. We found that 13 of the 42 private sector applications meet our definition of strategic OR/MS.
On the numerical solution of differential-algebraic equations by Padé series
Authors: Ercan Çelik, Mustafa Bayram
Venue: Applied Mathematics and Computation (2003)

In this paper, the solution for a differential-algebraic equation (DAE) can be expanded up to arbitrary order using MAPLE computer algebra systems (Frank, MAPLE V, CRC Press, Boca Raton, FL, 1996). First we calculate Power series of the given equations system then transform it into Padé series form, which gives an arbitrary order for solving DAE numerically.
Graphical Interface to Link Virtual Instruments through a Web Browser
Authors: Adriana Paula Borges, Mauricio O. Perez Lisboa, F. Javier Ramirez Fernandez
Venue: Proceedings of the 13th Brazilian Symposium on Computer Graphics and Image Processing (2000)

We present a graphical interface developed to maintain a communication between instruments of measurement and software that controls the instruments through a local area network. We implemented the algorithm initially proposed to test the real possibility of using the newest tools to control events remotely.
Checking the temporal integrity of interactive multimedia documents
Authors: I. Mirbel, B. Pernici, T. Sellis, S. Tserkezoglou, M. Vazirgiannis
Venue: The VLDB Journal &mdash; The International Journal on Very Large Data Bases (2000)

When authoring multimedia scenarios, and in particular scenarios with user interaction, where the sequence and time of occurrence of interactions is not predefined, it is difficult to guarantee the consistency of the resulting scenarios. As a consequence, the execution of the scenario may result in unexpected behavior or inconsistent use of media. The present paper proposes a methodology for checking the temporal integrity of interactive multimedia document (IMD) scenarios at authoring time at various levels. The IMD flow is mainly defined by the events occurring during the IMD session. Integrity checking consists of a set of discrete steps, during which we transform the scenario into temporal constraint networks representing the constraints linking the different possible events in the scenario. Temporal constraint verification techniques are applied to verify the integrity of the scenario, deriving a minimal network, showing possible temporal relationships between events given a set of constraints.
Rewriting P systems with conditional communication
Authors: Paolo Bottoni, Anna Labella, Carlos Martín-Vide, Gheorghe Păun
Venue: Formal and natural computing (2002)

A membrane system (P system) is a model of computation inspired by some basic features of the structure and behaviour of living cells. In this paper we consider systems with string-objects processed by rewriting, with the communication controlled by conditions on the contents of the strings. Symbols, snbstrings (in an arbitrary place, or as a prefix/suffix), or the shape of the whole string are used as permitting and as forbidding conditions when moving strings from a membrane to a neighboring membrane. Many of the obtained variants lead to new characterizations of recursively enumerable languages (as expected, these characterizations indicate a trade-off between the number of membranes and the strength of the communication conditions used). Several open problems are also formulated.
The Security of Confidential Numerical Data in Databases
Authors: Rathindra Sarathy, Krishnamurty Muralidhar
Venue: Information Systems Research (2002)

Organizations are storing large amounts of data in databases for data mining and other types of analysis. Some of this data is considered confidential and has to be protected from disclosure. When access to individual values of confidential numerical data in the database is prevented, disclosure may occur when a snooper uses linear models to predict individual values of confidential attributes using nonconfidential numerical and categorical attributes. Hence, it is important for the database administrator to have the ability to evaluate security for snoopers using linear models. In this study we provide a methodology based on Canonical Correlation Analysis that is both appropriate and adequate for evaluating security. The methodology can also be used to evaluate the security provided by different security mechanisms such as query restrictions and data perturbation. In situations where the level of security is inadequate, the methodology provided in this study can also be used to select appropriate inference control mechanisms. The application of the methodology is illustrated using a simulated database.