ppxscal/embedding_network huggingface dataset:
On a concatenation problem
Authors: Henry Ibstedt
Venue: Smarandache notions (2002)

This article has been inspired by questions asked by Charles Ashbacher in the Journal of Recreational Mathematics, vol. 29.2. It concerns the Smarandache Deconstructive Sequence. This sequence is a special case of a more general concatenation and sequencing procedure which is the subject of this study. Answers are given to the above questions. The properties of this kind of sequencies are studied with particular emphasis on the divisibility of their terms by primes.
Using the Redundant Chords of the k-Fault-Tolerant Graph to Eliminate the Effect of Failed Components
Authors: V. A. Vedeshenkov
Venue: Automation and Remote Control (2003)

Studies of the structural graphs of the fault-tolerant systems designed by the methods of M.F. Karavai demonstrated that if the number of the redundant graph vertices coincides with the degree k of fault-tolerance, then the number of redundant chords grows rapidly with k. Described was a method of reconfiguration of the redundant graph which is a variant of the sliding redundantization allowing one to use the redundant chords in order to eliminate the effect of some m (> k) failed chords of the graph, its value being dependent on the structure of the objective graph, the magnitude of k, and the topology of failures. Presented were examples of realizing this method which suggest that greater values of m are more frequently obtained for the longest chords of the k-fault-tolerant graph.
Transport and dispersion of blowing dust in the Mexico Basin
Authors: M. T. López, R. Villasenor, A. I. Quintanar, V. Mora
Venue: Development and application of computer techniques to environmental studies (2002)

Most current wind erosion methods predict average annual or seasonal erosion amounts and only very approximate estimates of suspended dust emissions are available. The main objective of this investigation is to use an empirical USEPA erosion model to estimate dust emissions in the Mexico City Basin, and to compare the predicted concentrations to measured data of geological material. When the emission model is combined with a transport-dispersion model, estimates of downwind particulate concentrations compared reasonably well with measured data. To study the effect on transport and dispersion of PM, observational data from March 5 and 6 of 1997 were used to drive a diagnostic meteorological model and a transport/dispersion model to simulate the local wind circulation and PM concentration distributions. Results show good agreement with the main spatial features of the local wind circulation and windblown dust concentrations.
Design and Use of the Microsoft Excel Solver
Authors: Daniel Fylstra, Leon Lasdon, John Watson, Allan Waren
Venue: Interfaces (1998)

In designing the spreadsheet optimizer that is bundled with Microsoft Excel, we and Microsoft made certain choices in designing its user interface, model processing, and solution algorithms for linear, nonlinear, and integer programs. We describe some of the common pitfalls users encounter and remedies available in the latest version of Microsoft Excel. The Solver has many applications and great impact in industry and education.
iCAP: an informal tool for interactive prototyping of context-aware applications
Authors: Timothy Sohn, Anind Dey
Venue: CHI '03 extended abstracts on Human factors in computing systems (2003)

iCAP is a system that assists users in prototyping context-aware applications. iCAP supports sketching for creating input and output devices, and using these devices to design interaction rules, which can be prototyped in a simulated or real context-aware environment. We were motivated to build our system by the lack of tools currently available for developing rich sensor-based applications. We iterated on the design of our system using paper prototypes and obtained feedback from fellow researchers, to develop a robust system for prototyping context-aware applications.
Evaluating real-time software specification languages
Authors: Dong-Tsan Lee
Venue: Computer Standards Interfaces (2002)

In recent years, many notations and methods in real-time software engineering have been proposed. However, thorough experimentation to evaluate these notations and methods has not been carried out. This paper focuses on real-time software engineering specification languages: Unified Modeling Language (UML), Real-Time Object-Oriented Modeling Language (ROOM), Modecharts, statecharts, Mealy and Moore machines, finite state machines, classical logic, Z, ASTRAL, temporal logic, FNLOG, linear logic, Timed Communicating Sequential Processes (TCSP), Temporal Calculus of Communicating Systems (TCCS), ρ1, and Multilevel Specification. The basis for evaluating these software engineering specification languages is by using the Turing machines and Interaction machines. We classify them based on their computational capabilities.
Efficient retrieval of similar shapes
Authors: Davood Rafiei, Alberto O. Mendelzon
Venue: The VLDB Journal &mdash; The International Journal on Very Large Data Bases (2002)

We propose an indexing technique for the fast retrieval of objects in 2D images based on similarity between their boundary shapes. Our technique is robust in the presence of noise and supports several important notions of similarity including optimal matches irrespective of variations in orientation and/or position. Our method can also handle size-invariant matches using a normalization technique, although optimality is not guaranteed here. We implemented our method and performed experiments on real (hand-written digits) data. Our experimental results showed the superiority of our method compared to search based on sequential scanning, which is the only obvious competitor. The performance gain of our method increases with any increase in the number or the size of shapes.
Assessment of Cost Uncertainties for Large Technology Projects: A Methodology and an Application
Authors: Robin L. Dillon, Richard John, Detlof von Winterfeldt
Venue: Interfaces (2002)

Large projects, especially those planned and managed by government agencies, often incur substantial cost overruns. The tolerance, particularly on the part of members of Congress, for these cost overruns has decreased, thus increasing the need for accurate, defensible cost estimates. Important aspects of creating responsible cost estimates are accounting for the uncertainties in these estimates, expressing the estimates clearly, and communicating them to decision makers. Our method for estimating cost uncertainties can be used at all stages of a project. It combines the principles of probabilistic risk analysis with procedures for expert elicitation to incorporate uncertainties and extraordinary events in cost estimates. The Department of Energy implemented this process to select a new tritium supply source. During this implementation, we identified four key issues in modeling cost risks: how to consider correlations among cost components, how to aggregate assessments of multiple experts, how to manage communication and information sharing among experts, and what is an appropriate discount rate for cost estimates.
Nonterminal complexity of programmed grammars
Authors: Henning Fernau
Venue: Theoretical Computer Science (2003)

We show that, in the case of context-free programmed grammars with appearance checking working under free derivations, three nonterminals are enough to generate every recursively enumerable language. This improves the previously published bound of eight for the nonterminal complexity of these grammars. This also yields an improved nonterminal complexity bound of four for context-free matrix grammars with appearance checking. Moreover, we establish an upperbound of four on the nonterminal complexity of context-free programmed grammars without appearance checking working under leftmost derivations of type 2. We derive nonterminal complexity bounds for context-free programmed and matrix grammars with appearance checking or with unconditional transfer working under leftmost derivations of types 2 and 3, as well. More specifically, a first nonterminal complexity bound for context-free programmed grammars with unconditional transfer (working under leftmost derivations of type 3) which depends on the size of the terminal alphabet is proved.
Portfolio Management in An Upstream Oil and Gas Organization
Authors: Dimitris Bertsimas, Christopher Darnell, Robert Soucy, Mazen A. Skaf
Venue: Interfaces (1999)

Implementing portfolio management in an organization presents organizational and analytical challenges. A successful implementation requires an integrated solution for both the people aspects and the analytical aspects of the problem. Strategic Decisions Group (now Navigant Consulting, Strategy Consulting Practice) developed and implemented a portfolio-management process and system for a client organization inthe upstream oil and gas industry. The tailored process provides a forum for decision-focused dialogue between senior management and asset teams. The system provides the analytical support for the process and enables management to compare decisions and assets across the portfolio and determine optimal allocation of resources. The system architecture builds on a rigorous model of the asset life cycle and the key decisions in the life cycle. To further integrate portfolio management into its business processes, the organization set up an internal core team to facilitate the process and work with the asset teams on an ongoing basis. This has helped reduce the time for developing regional and business-unit portfolio strategies. The value added from strategic alternatives developed using the method is in the hundreds of millions of dollars.
Identifying high maintenance legacy software
Authors: Matthew S. Harrison, Gwendolyn H. Walton
Venue: Journal of Software Maintenance: Research and Practice (2002)

Legacy software maintenance is a significant cost item for many engineering organizations. This study is a preliminary report on work to investigate maintenance data, usage, and source code for legacy software used by an engineering design company to support a variety of functions, including electromagnetic, thermal, mechanical loading, vibration, and aerodynamic analysis. The results verify the applicability to legacy engineering software of previous research that concluded that size and structural metrics alone are not good indicators of high maintenance costs. Unlike previous research, the study also evaluates the effect of program usage on maintenance cost. Over the three-year period of this study of 71 legacy engineering programs, 11 of the programs (15%) accounted for 80% of all maintenance and 67% of all program runs. The highest maintenance programs were not always the largest programs or the worst structured programs. 49 % of the programs accounted for only 1% of total maintenance but 42 % of the total lines of code (LOC) thus invalidating LOC as an indicator for maintenance cost. While additional work is needed to validate these findings across other organizations and other code sets, these preliminary results provide strong evidence that expected program usage can be a useful indicator of long-term maintenance cost.
Schur function analogs for a filtration of the symmetric function space
Authors: L. Lapointe, J. Morse
Venue: Journal of Combinatorial Theory Series A (2003)

We work here with the linear span Λt(k) of Hall-Littlewood polynomials indexed by partitions whose first part is no larger than k. The sequence of spaces Λt(k) yields a filtration of the space Λ of symmetric functions in an infinite alphabet X. In joint work with Lascoux [4] we gave a combinatorial construction of a family of symmetric polynomials {Aλ(k)[X; t]}λ1 ≤ k, with N[t]-integral Schur function expansions, which we conjectured to yield a basis for Λt(k). Our primary motivation for this construction is to provide a positive integral factorization of the Macdonald q, t-Kostka matrix. More precisely, we conjecture that the connection coefficients expressing the Hall-Littlewood or Macdonald polynomials belonging to Λt(k) in terms of the basis {Aλ(k)[X; t]}λ1 ≤ k are polynomials in N [q, t]. We give here a purely algebraic construction of a new family {sλ(k)[X; t]}λ1 ≤ kof polynomials in Λt(k) which we conjecture is identical to {Aλ(k)[X; t]}λ1 ≤ k. We prove that {sλ(k) [X; t]}λ1 ≤ k is in fact a basis of Λt(k) and derive several further properties including that sλ(k)[X; t] reduces to the Schur function sλ[X] for sufficiently large k. We also state a number of conjectures which reveal that the polynomials {sλ(k)[X; t]}λ1 ≤ k are in fact the natural analogues of Schur functions for the space Λt(k).
Testing the ecological rationality of base rate neglect
Authors: Peter M. Todd, Adam S. Goodie
Venue: Proceedings of the seventh international conference on simulation of adaptive behavior on From animals to animats (2002)

What simple learning rules can allow agents to cope with changing environments? We tested whether a rule that neglects base rates of events in the world -- something that is usually considered irrational -- could be as successful as Bayesian inference that combines base rates and cue accuracies - the usual standard of rationality-in making cue-based predictions about events in time-varying environments. We focused on environments in which base rates change more frequently than cue accuracies, a condition that, we argue, is common in the real world. Five strategies (Bayesian combination, cue accuracy alone, adjusted cue accuracy, base rates alone, and a Least Mean Square learning rule) were compared across "lifetimes" of 10,000 predictions, in which base rates and cue accuracy independently changed every 10, 50, 100, 500, 1000, or 5000 events. The results confirmed that simple strategies that are typically deemed irrational (base rate neglect and its opposite, conservatism) can rival the typical standard of rationality, Bayesian combination of information, by producing ecologically rational decisions in appropriately varying environments.
B-trees with relaxed balance
Authors: Kim S. Larsen, Rolf Fagerberg
Venue: Proceedings of the 9th International Symposium on Parallel Processing (1995)

B-trees with relaxed balance have been defined to facilitate first updating on shared-memory asynchronous parallel architectures. To obtain this, rebalancing has been uncoupled from the updating such that extensive locking can be avoided in connection with updates. We analyze B-trees with relaxed balance, and prove that each update gives rise to at most [log/sub a/(N/2)]+1 rebalancing operations, where a is the degree of the B-tree, and N is the bound an its maximal size since it was last in balance. Assuming that the size of nodes are at least twice the degree, we prove that rebalancing can be performed in amortized constant time. So, in the long run, rebalancing is constant time on average, even if any particular update could give rise to logarithmic time rebalancing. We also prove that the amount of rebalancing done at any particular level decreases exponentially going from the leaves towards the root. This is important since the higher up in the tree a lock due to a rebalancing operation occurs, the larger a subtree which cannot be accessed by other processes for the duration of that lock. All of these results are in fact obtained for the more general (a, b)-trees, so we have results for both of the common B-tree versions as well as 2-3 trees and 2-3-4 trees.
Personal Versus Market Logics of Control: A Historically Contingent Theory of the Risk of Acquisition
Authors: Patricia H. Thornton
Venue: Organization Science (2001)

This paper develops and tests a theory of the historical contingency of the risk of acquisition using data from the higher education publishing market from 1958-1990. Interviews and historical analyses are combined to identify two forms of capitalism--personal and market, and in particular to publishing, to identify the institutional logics identified with each form of capitalism (an editorial and a market logic). Hazard-rate models are used to test for differences in the effects of these two logics on the organization and market determinants of acquisition. Publishers with relational network forms of organization in production and distribution were at a higher risk of acquisition in the market period but not in the editorial period. Competition in the product market increased the risk of acquisition in the market period, but not the editorial period. The covariates explaining the risk of acquisition change as a consequence of the evolution of capitalism and as a result of a firm's strategic and structural conformity with the institutional logic of the prevailing form of capitalism.
Play It Again, Sam? Optimal Replacement Policies for a Motion Picture Exhibitor
Authors: Sanjeev Swami, Martin L. Puterman, Charles B. Weinberg
Venue: Manufacturing Service Operations Management (2001)

Every week, motion picture exhibitors must decide whether to keep or replace the movies playing in their theaters in light of the past week's sales data. This decision is complex because of the dynamic decision environment, the uncertainty of demand, the complex revenue-sharing terms between the retailer and the distributor, the need to commit to new movies for several weeks, and the competitive release patterns of movies. We formulate this problem as a Markov Decision Process (MDP) model, using it to obtain replacement policies for the exhibitor. We examine the effect of differences in quality and quantity of available movies, and their respective release dates on the returns from model-based normative solutions. We also show that two practical heuristics are significantly outperformed by the optimal policy for the MDP model. We conclude by applying the model to industry data.
A Min-Max-Sum Resource Allocation Problem and Its Applications
Authors: Selcuk Karabati, Panagiotis Kouvelis, Gang Yu
Venue: Operations Research (2001)

In this paper we consider a class of discrete resource-allocation problems with amin-max-sum objective function. We first provide several examples of practical applications of this problem. We then develop a branch-and-bound procedure for solving the general case of this computationally intractable problem. The proposed solution procedure employs a surrogate relaxation technique to obtain lower and upper bounds on the optimal objective function value of the problem. To obtain the multipliers of the surrogate relaxation, two alternative approaches are discussed. We also discuss a simple approximation algorithm with a tight bound. Our computational results support the effectiveness of the branch-and-bound procedure for fairly large-size problems.
Quasiprimitivity: structure and combinatorial applications
Authors: Cheryl E. Praeger
Venue: Discrete Mathematics (2003)

A permutation group is said to be quasiprimitive if every nontrivial normal subgroup is transitive. Every primitive permutation group is quasiprimitive, but the converse is not true. Quasiprimitive group actions arise naturally in the investigation of many combinatorial structures, such as arc-transitive graphs, and line-transitive finite geometries. We describe some of the properties shared by finite primitive and quasiprimitive permutation groups, and some of their differences. We also indicate some of the recent major combinatorial applications of finite quasiprimitive groups.
Learning by redoing
Authors: Trevis J. Rothwell
Venue: Ubiquity (2003)

The availability of components that do a myriad of tasks could lead programmer complacency
A domain-theoretic semantics of lax generic functions
Authors: Hideki Tsuiki
Venue: Theoretical Computer Science (2003)

The semantic structure of a polymorphic calculus λm is studied. λm is defined over a hierarchical type structure, and a function in this calculus, called a generic function, can be composed from more than one lambda expression and the ways it behaves on each type are weakly related in that it lax commutes with the coercion functions defined from the subtypes to the supertypes.Since laxness is intermediate between ad hocness (behaviors on each type are not related) and coherency (commuting with the coercion functions), λm has syntactic properties lying between those of calculi with ad hoc generic functions and coherent generic functions studied in Tsuiki (Math. Struct. Comput. Sci. 8 (1998) 321). That is, although λm allows self application and thus is not normalizing, it does not have any unsolvable terms. For this reason, all the semantic domains are connected by mutually recursive equations and, at the same time, they do not have the least elements. We solve them by considering fibrations and expressing the equations as a recursive equation about fibrations. We also show the adequacy theorem for λm following the construction of Pitts and use it to derive some syntactic properties.
Breathers on a background: periodic and quasiperiodic solutions of extended discrete nonlinear wave systems
Authors: P. G. Kevrekidis, M. I. Weinstein
Venue: Mathematics and Computers in Simulation (2003)

In this paper we investigate the emergence of time-periodic and time quasiperiodic (sometimes infinitely long-lived and sometimes very long-lived or metastable) solutions of discrete nonlinear wave equations: discrete sine Gordon, discrete φ4 and discrete nonlinear Schrödinger equation(DNLS). The solutions we consider are periodic oscillations on a kink or standing wave breather background. The origin of these oscillations is the presence of internal modes, associated with the static ground state. Some of these modes are associated with the breaking of translational invariance, in going from a spatially continuous to a spatially discrete system. Others are associated with discrete modes which bifurcate from the continuous spectrum. It is also possible that such modes exist in the continuum limit and persist in the discrete case. The regimes of existence, stability and metastablilty of states as the lattice spacing is varied are investigated analytically and numerically. A consequence of our analysis is a class of spatially localiszed, time quasiperiodic solutions of the discrete nonlinear Schrödinger equation. We demonstrate, however, that this class of quasiperiodic solutions is rather special and that its natural generalizations yield only metastable quasiperiodic solutions.
An enhanced role model for alleviating the role-binding anomaly
Authors: Joon-Sang Lee, Doo-Hwan Bae
Venue: Software&mdash;Practice Experience (2002)

Roles and role models have received much attention as useful concepts for developing highly reusable and dynamically evolvable systems. Role models belong to the category of collaboration-based development techniques, but most of the existing approaches to role models do not explicitly incorporate the core principle of collaboration-based developments as an essential property of their primary design goals. Consequently, the existing approaches still suffer from a problematic phenomenon that the structural and behavioral constraints defined in a role system can be violated during the role-binding stage. We call such a problematic phenomenon the role-binding anomaly. In order to alleviate the role-binding anomaly, we propose an enhanced role model, in which all role instances and core objects can exist by themselves, namely, they can be developed, executed, and tested independently. Roles and core classes can be bound to each other at the instance level. In addition, the role system describes and encapsulates the behavior for dynamic reconfigurations among role instances. The enhanced role model is designed so as to be meaningful with respect to software engineering principles, rather than dynamic evolution. It also facilitates role model implementation using general programming languages (i.e. not supporting dynamic specialization) such as Java. To illustrate how the proposed role model makes such benefits, we develop a set of Java classes necessary for implementing the enhanced role model in the form of a Java package role, and present a simplified automatic teller machine system as an example application.