ppxscal/embedding_network huggingface dataset:
The Theory of 2-Regularity for Mappings with Lipschitzian Deriatives and its Applications to Optimality Conditions
Authors: A. F. Izmailov, M. V. Solodov
Venue: Mathematics of Operations Research (2002)

We study local structure of a nonlinear mapping near points where standard regularity and/or smoothness assumptions need not be satisfied. We introduce a new concept of 2-regularity (a certain kind of second-order regularity) for a once differentiable mapping whose derivative is Lipschitz continuous. Under this 2-regularity condition, we obtain the representation theorem and the covering theorem (i.e., stability with respect to "right-hand side" perturbations) under assumptions that are weaker than those previously employed in the literature for results of this type. These results are further used to derive a constructive description of the tangent cone to a set defined by (2-regular) equality constraints and optimality conditions for related optimization problems. The class of mappings introduced and studied in the paper appears to be a convenient tool for treating complementarity structures by means of an appropriate equation-based reformulation. Optimality conditions for mathematical programs with (equivalently reformulated) complementarity constraints are also discussed.
Towards semistructured data integration
Authors: Mengchi Liu, Tok Wang Ling
Venue: Web-enabled systems integration: practices and challenges (2003)

With the recent popularity of the World Wide Web, an enormous amount of heterogeneous information is now available online. As a result, information about the same real-world object often spreads over different data sources, and may be partial and inconsistent. How to obtain information as complete as possible and detect inconsistency from these sources is thus a challenge. Previous work using a simple graph-based or tree-based data model to represent heterogeneous data coming from various sites fail to provide a proper foundation for the integration of data with partial and inconsistent information. In order to integrate such data, we need a powerful data model that is more expressive than the existing graph-based and tree-based ones to account for the existence of partial and inconsistent information from different data sources. In this chapter, we propose a novel data model for such data and study how to integrate such data spread in various sources and check consistency in the meantime. We propose a new operator called integration for this purpose and discuss its semantic properties.
Spare-Capacity Assignment For Line Restoration Using a Single-Facility Type
Authors: Anantaram Balakrishnan, Thomas L. Magnanti, Joel S. Sokol, Yi Wang
Venue: Operations Research (2002)

The network restoration problem is a specialized capacitated network design problem requiring the installation of spare capacity to fully restore disrupted network flows if any edge in a telecommunications network fails. We present a new mixed-integer programming formulation for a line restoration version of the problem using a single type of capacitated facility. We examine two different models, for distinct and integrated spare-capacity systems, reflecting technologies used in synchronous transfer mode (STM) and asynchronous transfer mode (ATM) networks. The problem is NP-complete in the strong sense. We study the problem's polyhedral structure to identify strong valid inequalities that tighten the problem formulation. Our computational results on several real and randomly generated problems show that these inequalities considerably reduce the integrality gap from an average of 10% to an average of under 1%. These results indicate that strong cutting planes combined with branch-and-bound can provide efficient algorithms for solving a class of real-world problems in the telecommunications industry.
Dynamic compilation for energy adaptation
Authors: P. Unnikrishnan, G. Chen, M. Kandemir, D. R. Mudgett
Venue: Proceedings of the 2002 IEEE/ACM international conference on Computer-aided design (2002)

While previous compiler research indicates that significant improvements in energy efficiency may be possible if properly optimized code is used, the energy constraints under which a given application code should be optimized may not always be available at compile-time. More importantly, these constraints may change dynamically during the course of execution. In this work, we present a dynamic recompilation/linking framework using which the energy behavior of a given application can be optimized while the application is being executed. Our preliminary experiments indicate that large energy gains are possible through dynamic code recompilation/linking at the expense of a relatively small increase in execution time.
A Note on Coefficient Adjustment Using Sos Constraints
Authors: R. Lougee-Heimer
Venue: Operations Research (2001)

We examine two coefficient adjustment methods proposed in the literature, and we show by example that the second is not valid. We provide a modified approach that subsumes both methods, generalizing the first and correcting the second.
Can Difficult-To-Reuse Syringes Reduce the Spread of HIV Among Injection Drug Users?
Authors: Jonathan P. Caulkins, Edward H. Kaplan, Peter Lurie, Thomas O'Connor, Sung-Ho Ahn
Venue: Interfaces (1998)

Sharing of syringes by injection drug users is a principal means by which the human immunodeficiency virus (HIV) is spread. Some have suggested that distributing syringes that are difficult to reuse (DTR) would slow the spread of HIV. We developed a simple mathematical model that describes how changes in the numbers of DTR syringes or regular syringes consumed over the course of a fixed number of injections affects the proportion of injections that are potentially infectious and, thus, the transmission of HIV. It suggests that increasing consumption of either type of syringe will reduce the proportion of potentially infectious injections, but that, per syringe added, the reduction is always greater if a regular rather than a DTR syringe is added. Simil arly, introducing a certain number of DTR syringes and simultaneously reducing the consumption of regular syringes by the same number will increase, not decrease, the proportion of infectious injections. DTR syringes are more expensive than regular syringes, so there is little justification for substituting them for regular syringes.
Automatic synthesis of a subclass of schedulers in timed systems
Authors: Padmanabhan Krishnan
Venue: Theoretical Computer Science (2003)

In this article we present a synthesis technique for generating schedulers for real-time systems. The aim of the scheduler is to ensure (via restricting the general behaviour) that the real-time system satisfies the specification. The real-time system and the specification are described as Alur-Dill timed automata while the synthesised scheduler is a type of timed trajectory automaton. This allows us to perform the synthesis without incurring the cost of constructing timed regions. We also note a simple constraint that the specification has to satisfy for this technique to be useful.
Building models: a direct but neglected approach to teaching computer science
Authors: John E. Howland
Venue: Journal of Computing Sciences in Colleges (2002)

The use of software models for teaching a variety of computer science topics is a valuable technique. Such models may be studied by reading and examining each model itself. Additionally, the models form the basis for experimentation. The J language is particularly well suited for modeling. It is not necessary that students be proficient in J programming to make effective use of J models and experiments with models are easily devised so that laboratory measurements may be taken. Example models for a number of computer science topics are given.
Balanced grammars and their languages
Authors: Jean Berstel, Luc Boasson
Venue: Formal and natural computing (2002)

Balanced grammars are a generalization of parenthesis grammars in two directions. First, several kind of parentheses are allowed. Next, the set of right-hand sides of productions may be an infinite regular language. XML-grammars are a special kind of balanced grammars. This paper studies balanced grammars and their languages. It is shown that there exists a unique minimal balanced grammar equivalent to a given one. Next, balanced languages are characterized through a property of their syntactic congruence. Finally, we show how this characterization is related to previous work of McNaughton and Knuth on parenthesis languages.
A Low Power Correlator for CDMA Wireless Systems
Authors: Bibhudatta Sahoo, Keshab K. Parhi
Venue: Journal of VLSI Signal Processing Systems (2003)

The complex valued matched filter correlators consume maximum power in the DS/SS CDMA receivers. These correlators accumulate 1024 samples lying in the range &minus;7 to +7. This accumulation needs 3 data bits, 1 sign bit and 10 extra bits for overflow. Hence, the correlator can be implemented as a cascade of 4-bit full adder and a 10-bit incrementer. As a ripple carry adder (RCA) consumes the least power among all the existing adder architectures, we have implemented the 4-bit adder as a RCA. Previous incrementers were implemented as ripple counters. In this paper we propose a novel incrementer which is faster than a ripple counter based incrementer. Hence, it can be operated at a reduced voltage resulting in considerable power reduction. The incrementer is implemented using multiplexers, AND gates and TSPC registers. The ripple-counter correlator and the proposed incrementer correlator were laid out in MAGIC using 0.5 &mu; CMOS technology followed by power estimation using HSPICE. It is shown that the proposed architecture requires 50% less power than a ripple counter based design.
Computational science in a liberal arts college
Authors: Angela B. Shiflet
Venue: Journal of Computing Sciences in Colleges (2002)

The field of computational science combines simulation, visualization, mathematical modeling, programming, data structures, networking, database design, symbolic computation, and high performance computing with various scientific disciplines. Although there is a critical shortage of computational scientists, as noted in a study by Charles Swanson supported by the Krell Institute, few undergraduates programs exist [6].Liberal arts colleges can help alleviate the shortage of computational scientists and can provide a solid education for students in an area that is intellectually and financially rewarding. Such institutions are ideally suited for computational science programs because their curricula expose students to a wide variety of subjects and their smaller sizes contribute to communication among departments.Wofford College has successfully implemented an Emphasis in Computational Science for interested students majoring in science or mathematics. With few undergraduate textbooks available in the field, on-line, application rich course modules serve as the textbooks for the computational science courses. [4].
Organizational Incentives and Organizational Mortality
Authors: Scott Shane
Venue: Organization Science (2001)

Despite a long tradition of research on organizational mortality, organizational theorists have not examined the effect of incentive contracting on firm survival. This paper fills this gap by examining the effect of incentive contracting on the survival of U.S. business format franchise systems over the period 1984-1996. The paper finds empirical support for several hypotheses derived from efficient contracting theory. In general, large firms that adopt policies which screen agents, signal quality, and control agents' free-riding are more likely to survive than large firms which do not adopt these policies.
The view selection problem for XML content based routing
Authors: Ashish Kumar Gupta, Dan Suciu, Alon Y. Halevy
Venue: Proceedings of the twenty-second ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems (2003)

We consider the view selection problem for XML content based routing: given a network, in which a stream of XML documents is routed and the routing decisions are taken based on results of evaluating XPath predicates on these documents, select a set of views that maximize the throughput of the network. While in view selection for relational queries the speedup comes from eliminating joins, here the speedup is obtained from gaining direct access to data values in an XML packet, without parsing that packet. The views in our context can be seen as a binary representation of the XML document, tailored for the network's workload.In this paper we define formally the view selection problem in the context of XML content based routing, and provide a practical solution for it. First, we formalize the problem; while the exact formulation is too complex to admit practical solutions, we show that it can be simplified to a manageable optimization problem, without loss in precision. Second we show that the simplified problem can be reduced to the Integer Cover problem. The Integer Cover problem is known to be NP-hard, and to admit a log n greedy approximation algorithm. Third, we show that the same greedy approximation algorithm performs much better on a class of work-loads called 'hierarchical workloads', which are typical in XML stream processing. Namely, it returns an optimal solution for hierarchical workloads, and degrades gracefully to the log n general bound as the workload becomes less hierarchical.
Non-separable detachments of graphs
Authors: Bill Jackson, Tibor Jordán
Venue: Journal of Combinatorial Theory Series B (2003)

Let G = (V, E) be a graph and r : V → Z+. An r-detachment of G is a graph H obtained by 'splitting' each vertex v ∈ V into r(v) vertices, called the pieces of v in H. Every edge uv ∈ E corresponds to an edge of H connecting some piece of u to some piece of v. An r-degree specification for G is a function f on V, such that, for each vertex v ∈ V, f(v) is a partition of d(v) into r(v) positive integers. An f-detachment of G is an r-detachment H in which the degrees in H of the pieces of each v ∈ V are given by f(v). Crispin Nash-Williams [3] obtained necessary and sufficient conditions for a graph to have a k-edge-connected r-detachment or f-detachment. We solve a problem posed by Nash-Williams in [2] by obtaining analogous results for non-separable detachments of graphs.
Experimental partial dissolution using aqua regia on stream sediments, a case study in arid environment, Eastern Iran
Authors: M. Shiva
Venue: Iranian Journal of Science and Technology (2001)

A stream sediment geochemical investigation was carried out downstream of a known sulfide lead, zinc and copper mineralization in the arid environment of Eastern Iran. The minus 150 µm fractions of the fourteen samples were subjected to analysis by inductively coupled plasma atomic emission spectrometry (ICP-AES) after leaching in aqua regia for the determination of the elements, Pb, Zn, Cu, As, Co, Ni, Ca, Al, Mn, Fe, and Mg. The samples were also analysed by X-ray fluorescence spectrometry (XRFS) for the determination of the total contents of the elements to provide information concerning the leaching effect of aqua regia. It was clearly indicated that the increasing orders of leaching of the analysed major oxides and base metals in the stream sediments of the study area are, MnO > Fe2O3 > CaO > MgO > Al2O3 and Cu > Zn > Pb. The results also indicated that nearly 100 percent of the copper and zinc are extractable by aqua regia, whereas lead is more resistant to leaching in aqua regia than zinc and copper. The geochemical signatures of Co in the stream sediments of the area are mainly controlled by Mn-and Fe oxides.
Polynomial algorithms that prove an NP-Hard hypothesis implies an NP-hard conclusion
Authors: D. Bauer, H. J. Broersma, A. Morgana, E. Schmeichel
Venue: Discrete Applied Mathematics (2002)

A number of results in hamiltonian graph theory are of the form "P1 implies P2", where P1 is a property of graphs that is NP-hard and P2 is a cycle structure property of graphs that is also NP-hard. An example of such a theorem is the well-known Chvátal-Erdös Theorem, which states that every graph G with α ≤ κ is hamiltonian. Here κ is the vertex connectivity of G and α is the cardinality of a largest set of independent vertices of G. In another paper Chvátal points out that the proof of this result is in fact a polynomial time construction that either produces a Hamilton cycle or a set of more than κ independent vertices. In this note we point out that other theorems in hamiltonian graph theory have a similar character. In particular, we present a constructive proof of a well-known theorem of Jung (Ann. Discrete Math. 3 (1978) 129) for graphs on 16 or more vertices.
A Multiplier Adjustment Method for Dynamic Resource Allocation Problems
Authors: Tassio A. Carvalho, Warren B. Powell
Venue: Transportation Science (2000)

Dynamic fleet management problems (with a homogeneous fleet) are classically formulated as dynamic networks, or linear programs with side constraints. Recently, a new dynamic control approach was introduced, called a logistics queueing network. Instead of a large linear program, the problem is decomposed into small subproblems that are guided by two control variables that push these local problems to produce a solution that is close to a global optimum. In prior work, these control variables were updated using a subgradient approximation. In this paper, we propose a multiplier adjustment method for solving the same problem. Numerical experiments show that this method produces better solutions with greater stability. The new method is somewhat slower, and is more difficult to implement. We believe that both methods will represent reasonable choices for solving the problem.
On the Pseudo-Smarandache squarefree function
Authors: Maohua Le
Venue: Smarandache notions (2002)

In this paper we discuss various problems and conjectures concered the pseudo-Smarandache squarefree function.
Thermal Testing of Analogue Integrated Circuits: A Case Study
Authors: J. Altet, A. Ivanov, A. Wong
Venue: Journal of Electronic Testing: Theory and Applications (2003)

This paper discusses the use of temperature as a test observable for analogue circuits, presenting a generic configuration for analogue circuit thermal testing. As a case study, static temperature analysis is performed over a two-stage operational amplifier in view of extracting temperature waveforms at different locations on the circuit under test, both under fault-free conditions as well as in the presence of bridging faults. Exhaustive thermal analysis of all the likely bridging faults is presented, establishing the detectability ratio of this fault set using temperature under different sensing scenarios.
Automatic Parallelization and Scheduling of Programs on Multiprocessors using CASCH
Authors: Ishfaq Ahmad, Yu-Kwong Kwok, Min-You Wu, Wei Shu
Venue: Proceedings of the international Conference on Parallel Processing (1997)

The lack of a versatile software tool for parallel program development has been one of the major obstacles for exploiting the potential of high-performance architectures. In this paper, we describe an experimental software tool called CASCH (Computer Aided SCHeduling) for parallelizing and scheduling applications to parallel processors. CASCH transforms a sequential program to a parallel program with automatic scheduling, mapping, communication, and synchronization. The major strength of CASCH is its extensive library of scheduling and mapping algorithms representing a broad range of state-of-the-art work reported in the recent literature. These algorithms are applied for allocating a parallelized program to the processors, and thus the algorithms can be interactively analyzed, tested and compared using real data on a common platform with various performance objectives. CASCH is useful for both novice and expert programmers of parallel machines, and can serve as a teaching and learning aid for understanding scheduling and mapping algorithms.
Automated testing of virtual reality application interfaces
Authors: Allen Bierbaum, Patrick Hartling, Carolina Cruz-Neira
Venue: Proceedings of the workshop on Virtual environments 2003 (2003)

We describe a technique for supporting testing of the interaction aspect of virtual reality (VR) applications. Testing is a fundamental development practice that forms the basis of many software engineering methodologies. It is used to ensure the correct behavior of applications. Currently, there is no common pattern for automated testing of VR application interaction. We review current software engineering practices used in testing and explore how they may be applied to the specific realm of VR applications. We then discuss the ways in which current practices are insuficient to test VR application interaction and propose a testing architecture for addressing the problems. We present an implementation of the design written on top of the VR Juggler platform. This system allows VR developers to employ standard software engineering techniques that require automated testing methods.
Restless Bandits, Linear Programming Relaxations, and a Primal-Dual Index Heuristic
Authors: Dimitris Bertsimas, José Niño-Mora
Venue: Operations Research (2000)

We develop a mathematical programming approach for the classicalPSPACE-hard restless bandit problem in stochastic optimization. We introduce a hierarchy ofN (whereN is the number of bandits) increasingly stronger linear programming relaxations, the last of which is exact and corresponds to the (exponential size) formulation of the problem as a Markov decision chain, while the other relaxations provide bounds and are efficiently computed. We also propose a priority-index heuristic scheduling policy from the solution to the firstorder relaxation, where the indices are defined in terms of optimal dual variables. In this way we propose a policy and a suboptimality guarantee. We report results of computational experiments that suggest that the proposed heuristic policy is nearly optimal. Moreover, the second-order relaxation is found to provide strong bounds on the optimal value.
Asymptotics of multiple orthogonal polynomials associated with the modified Bessel functions of the first kind
Authors: Els Coussement, Walter Van Assche
Venue: Journal of Computational and Applied Mathematics (2003)

We consider polynomials which are orthogonal with respect to weight functions which are defined in terms of the modified Bessel functions Iv and Iv+1. These multiple orthogonal polynomials Pv,cn of type II were introduced earlier by the authors. The aim of this paper is to study some asymptotics of these polynomials, such as Plancherel-Rotach asymptotics. As a consequence of these results, we obtain the accumulation set of the scaled zeros of Pnv,c. We also give a Mehler-Heine-type formula for these polynomials which is valid on compact subsets of C. Hence, we obtain a more precise result about the asymptotic behavior of the small zeros of Pnv,c.
Polynomial factorization over F2
Authors: Joachim von zur Gathen, Jürgen Gerhard
Venue: Mathematics of Computation (2002)

We describe algorithms for polynomial factorization over the binary field F2, and their implementation. They allow polynomials of degree up to 250 000 to be factored in about one day of CPU time, distributing the work on two processors.