ppxscal/embedding_network huggingface dataset:
Protection of computer systems from computer viruses: ethical and practical issues
Authors: Bruce J. Neubauer, James D. Harris
Venue: Journal of Computing Sciences in Colleges (2002)

Computer viruses, worms, and Trojan horse programs cost individuals, companies and government agencies millions of dollars every year. Traditional responses have involved use of antiviral software which remove infections or which restrict the transmission of infected communications, and firewalls. The need to rapidly respond to new or threatened attacks has increased the popularity of subscription services which allow users to quickly obtain the most up-to-date antiviral protection. However, unprotected systems can become infected and can rapidly propagate that infection to many other systems. In response, more invasive antiviral agents can be imagined. This paper addresses ethical issues related to the protection of computer systems and delivery of that protection. Five categories in a "Protection Mechanism Grid" are proposed. The categories are based upon possible protection delivery mechanisms and the options available to system owners. The practical and ethical implications of each category are addressed.
Some properties of a new product in J′n
Authors: David Carfi, Clara Germanà
Venue: Journal of Computational and Applied Mathematics (2003)

In this paper, the authors study some basic properties of the new generalized scalar product introduced recently by Carfi in the space of tempered distributions. Such properties are the analogues of some basic properties fulfilled by the scalar product of a finite dimensional pre-Hilbertian space. The interest of this circumstance lies in the fact that the space of tempered distributions has not a pre-Hilbertian natural structure, moreover it is not a finite dimensional vector space.
A context-aware experience sampling tool
Authors: Stephen S. Intille, John Rondoni, Charles Kukla, Isabel Ancona, Ling Bao
Venue: CHI '03 extended abstracts on Human factors in computing systems (2003)

A new software tool for user-interface development and assessment of ubiquitous computing applications is available for CHI researchers. The software permits researchers to use common PDA mobile computing devices for experience sampling studies. The basic tool offers options not currently available in any other open-source sampling package. However, the tool also has new functionality: context-aware experience sampling. This feature permits researchers to acquire feedback from users in particular situations that are detected by sensors connected to a mobile computing device.
Local Search Heuristics for the Single Machine Total Weighted Tardiness Scheduling Problem
Authors: H. A. J. Crauwels, C. N. Potts, L. N. Van Wassenhove
Venue: INFORMS Journal on Computing (1998)

This paper presents several local search heuristics for the problem of scheduling a single machine to minimize total weighted tardiness. We introduce a new binary encoding scheme to represent solutions, together with a heuristic to decode the binary representations into actual sequences. This binary encoding scheme is compared to the usual "natural" permutation representation for descent, simulated annealing, threshold accepting, tabu search and genetic algorithms on a large set of test problems. Computational results indicate that all of the heuristics which employ our binary encoding are very robust in that they consistently produce good quality solutions, especially when multistart implementations are used instead of a single long run. The binary encoding is also used in a new genetic algorithm which performs very well and requires comparatively little computation time. A comparison of neighborhood search methods which use the permutation and binary representations shows that the permutation-based methods have a higher likelihood of generating an optimal solution, but are less robust in that some poor solutions are obtained. Of the neighborhood search methods, tabu search clearly dominates the others. Multistart descent performs remarkably well relative to simulated annealing and threshold accepting.
Optical code division multiplexing (OCDM) and its application for peta-bit/s photonic network
Authors: Hideyuki Sotobayashi, Wataru Chujo, Ken-ichi Kitayama
Venue: Information Sciences&mdash;Informatics and Computer Science: An International Journal (2003)

Applications of optical code division multiplexing (OCDM) to multi-tera bit/s photonic network are introduced. A high spectrum efficiency OCDM/WDM transmission as a link technology, and a transparent virtual optical code/wavelength path (VOCP/VWP) network as a node technology are experimentally demonstrated.
Error estimates for fully discrete approximation to a free boundary problem in polymer technology
Authors: Min Jung Ahn, Hyun Young Lee, Mi Ray Ohm
Venue: Applied Mathematics and Computation (2003)

In this paper, we construct and analyze fully discrete method for a free boundary problem arising in polymer technology. This method is based on a Galerkin finite element formulation in space and a backward Euler time stepping technique. We derive optimal error estimates in the spatial and temporal directions in L2, H1 normed spaces.
Market Split and Basis Reduction: Towards a Solution of the Cornuéjols-Dawande Instances
Authors: K. Aardal, R. E. Bixby, C. A. J. Hurkens, A. K. Lenstra, J. W. Smeltink
Venue: INFORMS Journal on Computing (2000)

At the IPCO VI conference CornuÃ©jols and Dawande proposed a set of 0-1 linear programming instances that proved to be very hard to solve by traditional methods, and in particular by linear programming-based branch-and-bound. They offered thesemarket split instances as a challenge to the integer programming community. The market split problem can be formulated as a system of linear diophantine equations in 0-1 variables. In our study we use the algorithm of Aardal, Hurkens, and Lenstra (1998) based on lattice basis reduction. This algorithm is not restricted to deal with market split instances only but is a general method for solving systems of linear diophantine equations with bounds on the variables. We show computational results from solving both feasibility and optimization versions of the market split instances with up to 7 equations and 60 variables and discuss various branching strategies and their effect on the number of enumerated nodes. To our knowledge, the largest feasibility and optimization instances solved before had 6 equations and 50 variables, and 4 equations and 30 variables, respectively. We also present a probabilistic analysis describing how to compute the probability of generating infeasible market split instances. By generating instances the way prescribed by CornuÃ©jols and Dawande, one obtains relatively many feasible instances for sizes larger than 5 equations and 40 variables.
Protecting the Hosted Application Server
Authors: Paola Dotti, Owen Rees
Venue: Proceedings of the 8th Workshop on Enabling Technologies on Infrastructure for Collaborative Enterprises (1999)

Internet applications, are evolving from the web server to the more powerful and dynamic application server in order to support the deployment of complex applications integrated with the organization's back end systems. A key element of the application server architecture is CORBA, the Common Object Request Broker that allows applications to communicate in a transparent and interoperable manner. For this new architecture to succeed, it must guarantee a secure processing environment to the organizations.This paper explains why a conventional firewall can not be used to secure CORBA applications. It describes the architecture of CORBAgate, a gateway based on the concept of proxies and object key re-mapping. The paper compares the CORBAgate solution with the OMG specification for CORBA firewall security. Finally, the paper discusses how these elements combine to enable outsourced application services.
Rasetti-Regge Dirac bracket formulation of Lagrangian fluid dynamics of vortex filaments
Authors: Darryl D. Holm
Venue: Mathematics and Computers in Simulation (2003)

We review the Rasetti-Regge Dirac bracket (RRDB) for determining the constrained Hamiltonian dynamics of vortex filaments moving with an incompressible potential flow of superfluid helium-II in the Lagrangian fluid picture. We compare the equations for Lagrangian vortex filaments with their corresponding Eulerian vorticity dynamics in the examples of the Euler fluid, superfluid vortices, the local induction approximation (LIA), the Rosenhead regularization and a new class of alternative regularized theories including the Euler-alpha model. The RRDB formulation generalizes the Betchov-Da Rios equation for the transverse self-induction velocity of a vortex filament from LIA to the case of an incompressible fluid whose energy may expressed as an arbitrary functional of spatial vorticity. We also discuss the relation of RRDB to the Marsden-Weinstein bracket for vortex filaments and its implications under the Hasimoto transformation for physically meaningful nonlocal nonlinear Schrödinger (NLNLS) equations.
Implementing finite structures in mathematica via a skeletal topos of finite sets
Authors: Susan B. Niefield
Venue: Journal of Symbolic Computation (2003)

To implement finite structures in a symbolic computation program such as Mathematica, we consider a skeletal topos N which is equivalent to the category Setf of finite sets. Objects of N are nonnegative integers, and morphisms f : n → m are lists (f1,..., fn) of integers such that 1 ≤ fi ≤ m, for all i. A full and faithful functor from N to Setf is obtained by identifying n with the set [n] = {1,..., n} and identifying (f1,..., fn) with the function i ↦ fi. A topos structure on N (appropriate for Mathematica) is obtained by transporting the topos structure of Setf along a suitable pseudo-inverse C of the functor from N to Setf described above. The code for the Mathematica implementation included below is also available as a Mathematica Notebook.
Production and Inventory Model Using Net Present Value
Authors: Daning Sun, Maurice Queyranne
Venue: Operations Research (2002)

Using the net present value is the standard methodology in theoretical analysis, and the most frequently used method for making financial decisions. However, net present value is rarely used in production and inventory decisions. The main reasons appear to be the complexity of the formulae and the robustness of the EOQ model. We investigate the general multiproduct, multistage production and inventory model using the net present value of its total cost as the objective function. A power-of-two heuristic gives us a near optimal solution to this problem. If the base period is fixed (or varied), the solution based on the best power-of-two heuristic will be within 6.2% (or 2.1% ) of the optimal. This result is surprisingly similar to models using the long-term average cost. The average cost does not reflect the time value of money. Does this mean that decisions based on average cost are significantly inferior to those based on net present value? The answer is quite surprising. If we include discounted production cost in the holding cost, it turns out that the decision based on average cost is only 9.6% (in terms of the net present value of the total cost) worse than the decision based on the net present value. However, the reorder interval based on the average cost could be much longer than that derived using net present value. This result shows that average cost is a good approximation to the net present value when the demands are deterministic.
Emulation in Academia: Balancing Structure and Identity
Authors: Giuseppe Labianca, James F. Fairbank, James B. Thomas, Dennis A. Gioia, Elizabeth E. Umphress
Venue: Organization Science (2001)

This study seeks to expand our understanding of interorganizational emulation decisions made by top administrators in a broad sample of American colleges and universities. We analyze their emulation choices and show that these decision makers tend to emulate universities similar to their own. Our findings suggest, however, that the choice of emulation target within one's industry is not simply a matter of choosing the most structurally similar organization, but rather that identity-related attributes, such as reputation, organizational image, and organizational identity, also play a significant role in the emulation decision. The data also show that industry subgroups based on emulation decisions (strategic reference groups) differ in both structural and identity-related attributes. Further, interorganizational emulation decisions based on tactics of upward comparison (e.g., emulating universities with better reputations) are associated with greater strategic change, while downward comparisons are associated with greater perceived external threat. Finally, the data show that top management's perceptions of the university's level of environmental threat are related to their choice of a more coarse-grained or fine-grained set of attributes when determining the emulation target. We discuss some of these findings' implications for theory and practice.
Representations of the all_different Predicate of Constraint Satisfaction in Integer Programming
Authors: H.P. Williams, Hong Yan
Venue: INFORMS Journal on Computing (2001)

The use of predicates to state constraints in Constraint Satisfaction is explained. If, as an alternative, the traditional approach of Integer Programming (IP) is used, it is desirable to model these constraints so as to give as tight a linear programming relaxation as possible. One of the most commonly used predicates is the"all_different" predicate. Different applications of this are described together with different IP formulations. The facet defining constraints for the convex hull are then described and proved to be facet defining.
L&#x221E; convergence of interpolation and associated product integration for exponential weights
Authors: H. S. Jung
Venue: Journal of Approximation Theory (2003)

investigate convergence in a weighted L∞ norm of Hermite, Hermite, and Grünwald interpolations at zeros of orthogonal polynomials with respect to exponential weights such as Freud, Erdös, and exponential weight on (-1, 1). Convergence of product integration rules induced by the various approximation processes is deduced. We also give more precise weight conditions for convergence of interpolations with respect to above three types of weights, respectively.
Can Milne's method work well for the Coulomb-like potentials ?
Authors: Tadashi Yano, Yasuo Ezawa, Takeshi Wada, Hiroshi Ezawa
Venue: Journal of Computational and Applied Mathematics (2003)

We extend the improved Milne's (Milne-spline) method for obtaining eigenvalues and eigenfunctions to the cases of long-range and singular potentials, for which we have conjectured that it is difficult to apply the method. Contrary to our conjecture it turned out that the method is valid also for Coulomb potential and repulsive 1/xn(n = 2,3,...) type potential. Further we applied the method for two cases, for which the solutions are not known, in order to investigate the stability of the multi-dimensional universe. It has been shown that the extra-dimensional (internal) space of our universe is not stable in classical Einstein gravity as well as canonically quantized one. Two possibilities for stabilization were investigated: (i) noncanonically quantized Einstein gravity and (ii) canonically quantized higher curvature gravity. It has been suggested that the space is stable by qualitative and approximate methods. Exact analytical treatment is very difficult, so that numerical investigation is highly desirable. Numerical investigation shows that the space is stable with sufficient reliability.
Reliability assessment through probabilistic refinement
Authors: Elena A. Troubitsyna
Venue: Nordic Journal of Computing (1999)

The paper presents an approach to reasoning about probabilistic systems that are to be implemented in a parallel or distributed manner. The approach allows us to obtain a quantitative assessment of the reliability of a system under construction. We base our reasoning on the application of refinement and in particularly data refinement techniques to the specification of systems containing a level of overall system reliability. Performing refinement of such a probabilistic specification we not only ensure the correctness of the system design but also establish a quantitative link between the overall system reliability and reliabilities of components from which the system is to be implemented. We illustrate the approach by designing a system that models data transmission over an unreliable medium.
A vision-based head tracking system for fully immersive displays
Authors: A. Hogue, M. Robinson, M. R. Jenkin, R. S. Allison
Venue: Proceedings of the workshop on Virtual environments 2003 (2003)

Six-sided fully immersive projective displays present complex and novel problems for tracking systems. Existing tracking technologies typically require tracking equipment that is placed in locations or attached to the user in a way that is suitable for typical displays of five or less walls but which would interfere with the immersive experience within a fully enclosed display. This paper presents a novel vision-based tracking technology for fully-immersive projective displays. The technology relies on the operator wearing a set of laser diodes arranged in a specific con guration and then visually tracking the projection of these lasers on the external walls of the display outside of the user's view. This approach places minimal hardware on the user and no visible tracking equipment is placed within the immersive environment. This paper describes the basic visual tracking system including the hardware and software infrastructure.
Interactive fuzzy programming for two-level nonconvex programming problems with fuzzy parameters through genetic algorithms
Authors: Masatoshi Sakawa, Ichiro Nishizaki
Venue: Fuzzy Sets and Systems (2002)

This paper formulates two-level nonconvex programming problems with fuzzy parameters by considering the experts' vague or fuzzy understanding of the nature of the parameters in the problem-formulation process, and presents an interactive fuzzy programming method through genetic algorithms. Using the level sets of fuzzy parameters characterized as fuzzy numbers, the corresponding nonfuzzy two-level nonconvex programming problem is introduced. The fuzzy goals of the decision makers for the nonconvex objective functions at both levels are quantified by eliciting the corresponding membership functions. In our interactive method, having specified the level sets of the fuzzy parameters, by updating the satisfactory degree of the decision maker at the upper level with considerations of overall satisfactory balance between both levels, an overall satisfactory solution is derived efficiently through genetic algorithms which are effective for nonconvex programming problems. An illustrative numerical example for two-level nonconvex programming problems with fuzzy parameters is provided to demonstrate the feasibility and efficiency of the proposed method.
Value iteration methods in risk minimizing stopping problems
Authors: Yoshio Ohtsubo
Venue: Journal of Computational and Applied Mathematics (2003)

We consider an optimal stopping problem with a discrete time Markov process where the criterion function is a threshold probability. We give the fundamental properties of optimal values and optimal stopping times, but the optimal value and the optimal stopping time depend upon the threshold value. We also obtain the properties of optimal values with respect to the threshold value, and a value iteration method is given.
Analysis and Algorithms for the Transtainer Routing Problem in Container Port Operations
Authors: Ananthapadmanabhan Narasimhan, Udatta S. Palekar
Venue: Transportation Science (2002)

The problem of minimizing the time taken to load the containers from the container stack yard onto the ship is called the transtainer routing problem. We first do a theoretical investigation of the problem to understand the structural properties of the problem. We then use these results to prove that the problem isNP-Complete. The problem is then formulated as an integer program. A branch-and-bound based enumerative method is developed to obtain an exact solution to the problem. An algorithm to solve the matching problem on a line at the root node of the branch-and-bound tree is developed. Several lower bounds to prune the size of the tree are also developed. A result which states that there cannot exist a polynomial time heuristic with a bounded worst case unlessP =NP is proved. Based on this result, an enumerative heuristic with a worst-case performance ratio of 1.5 is designed. Computational tests on randomly generated problems are conducted to evaluate the exact and heuristic algorithms.
On (2n, 2, 2n, n) relative difference sets
Authors: Yutaka Hiramine
Venue: Journal of Combinatorial Theory Series A (2003)

In this article, we show that a (2n, 2, 2n, n) relative difference set in a group G of order 4n exists only if a Sylow 2-subgroup of G is non-cyclic and n is even unless n = 1. we also construct (2n, 2, 2n, n) relative difference sets relative to non-normal subgroups.
Space-time variograms and a functional form for total air pollution measurements
Authors: S. De Iaco, D. E. Myers, D. Posa
Venue: Computational Statistics Data Analysis (2002)

A space-time functional form for some contaminants is obtained and used for estimating total air pollution (TAP) in the district of Milan, Italy, during selected high-risk days of 1999. This functional form is determined through a space-time product-sum variogram model for TAP measurements and the dual form of kriging, i.e., radial basis functions. Data for nitric oxide (NO), nitrogen dioxide (NO2) and carbon monoxide (CO) collected in Milan district, Italy are used to generate a combined indicator of traffic pollution, called TAP. In a previous study the weightings were obtained by multiple principal component analyses of the daily concentration levels. It was found that the first component explains approximately 70% of the total variance for each day and this component is treated as samples defined over space and time. A systematic pattern, which follows the corridor along which survey stations, characterized by heavy traffic are located, has been observed for TAP throughout Milan district, for all days considered. Note that the pollution data set is just an illustration for the new statistical method proposed.
GOOFI: Generic Object-Oriented Fault Injection Tool
Authors: Joakim Aidemark, Jonny Vinter, Peter Folkesson, Johan Karlsson
Venue: Proceedings of the 2001 International Conference on Dependable Systems and Networks (formerly: FTCS) (2001)

Abstract: In this paper, we present a new fault injection tool called GOOFI (Generic Object-Oriented Fault Injection). GOOFI is designed to be adaptable to various target systems and different fault injection techniques. The tool is highly portable between different host platforms since it relies on the Java programming language and a SQL compatible database. The current version of the tool supports pre-runtime Software Implemented Fault Injection and Scan-Chain Implemented Fault Injection.