ppxscal/embedding_network huggingface dataset:
Combinatorics of periods in strings
Authors: Eric Rivals, Sven Rahmann
Venue: Journal of Combinatorial Theory Series A (2003)

We consider the set Γn of all period sets of strings of length n over a finite alphabet. We show that there is redundancy in period sets and introduce the notion of an irreducible period set. We prove that Γn is a lattice under set inclusion and does not satisfy the Jordan-Dedekind condition. We propose the first efficient enumeration algorithm for Γn and improve upon the previously known asymptotic lower bounds on the cardinality of Γn. Finally, we provide a new recurrence to compute the number of strings sharing a given period set, and exhibit an algorithm to sample uniformly period sets through irreducible period set.
Network Ties, Reputation, and the Financing of New Ventures
Authors: Scott Shane, Daniel Cable
Venue: Management Science (2002)

Explaining how entrepreneurs overcome information asymmetry between themselves and potential investors to obtain financing is an important issue for entrepreneurship research. Our premise is that economic explanations for venture finance, which do not consider how social ties influence this process, are undersocialized and incomplete. However, we also argue that organization theoretic arguments, which draw on the concept of social obligation, are oversocialized. Drawing on the organizational theory literature, and in-depth fieldwork with 50 high-technology ventures, we examine the effects of direct and indirect ties between entrepreneurs and 202 seed-stage investors on venture finance decisions. We show that these ties influence the selection of ventures to fund through a process of information transfer.
Accurate and robust line segment extraction by analyzing distribution around peaks in Hough space
Authors: Yasutaka Furukawa, Yoshihisa Shinagawa
Venue: Computer Vision and Image Understanding (2003)

Hough transform (HT) is a well-known technique for extracting lines. However, it is difficult for most existing HT methods to extract line segments robustly from complicated images, mainly because the influence from various objects other than line segments are not taken into account. This paper proposes an accurate and robust evaluator that dynamically removes contributions of backgrounds and analyzes voting patterns around peaks in the accumulator space. In the experiments, four peak detection algorithms are tested against seven images completely automatically. Results show that our method is superior to existing methods in terms of accuracy and robustness while there are no clear differences in execution time. The proposed evaluator detects peaks after the HT and hence it can be applied to any HT that keeps the basic characteristics of the voting process.
Proposal of a new computational method for the analysis of the systematic differences in star catalogues
Authors: J. A. López, F. J. Marco, M. J. Martínez
Venue: Proceedings of the international conference on Computational methods in sciences and engineering (2003)

One of the main objects of fundamental astronomy is the determination of the celestial reference frames. The reference frames must approximate the inertial system with great accuracy. Positions of the celestial bodies can not be obtained directly from the reference system so it is necesary to built star catalogues, which materialize the reference system. The positions of the celestial bodies can be obtained from them by comparisson of the body position with the stars coorditates taken from the cataloges. The reference frame in use nowadays was adopted in Kyoto by International Astronomical Union and their main caracteristics are: a.-From the first of Jaunary 1998 the Celestial Reference System adopted by I.A.U. will be The International Celestial Reference system (ICRS) defined by the International Earth Rotation Service. b.-The corresponding Reference Frame will be the International Celestial Reference Frame (ICFR) build for the corresponding workgroup of the I.A.U. c.- The Hipparcos Catalogue is the materialization of this reference frame for visible wavelenghts. d.-The IERS , and the IAU working group will take the apropiated measures for their maitenance of the ICRF and the relations with the other reference frames.
Iterative data detection: modified message-passing algorithms and convergence
Authors: Keith M. Chugg
Venue:  (2002)

Since Turbo codes were introduced, numerous works have focused on iterative decoding (ID), a technique in which soft information (also known as extrinsic information) is exchanged among Soft Input Soft Output (SISO) modules. A SISO module can be viewed as the probabilistic inverse of a constituent FSM at the encoder. It has been shown that the application of such ID techniques to a system consisting of a network of FSMs achieves very good iteration gain. The extrinsic information is refined at each iteration, becoming more reliable. The modifications needed to the ID algorithm change with application. For example, in the unknown channel case, ID has to be made adaptive, for implementation, the complexity has to be reduced. In this work, several modified ID algorithms are introduced and their performance and complexity are considered. For systems with time-varying channels, several ways to add the adaptivity to the SISO module are presented. A simple stopping criteria is also presented to reduce the average complexity of iterative decoding. In the recent past, an analytical tool was developed to explain the superior performance of these ID algorithms. This development was based on the message passing algorithms and the corresponding graphical representations (e.g., Bayesian networks, Factor graphs, Tanner graphs, etc.) of the codes (e.g., Turbo codes, Low Density Parity Check (LDPC) codes etc.). This tool, known as the Density Evolution (DE), gives the asymptotic capacity of ID and explains many characteristics of ID, including convergence of performance and preferred structures for the constituent codes. In this work, several variations of the density evolution concept, which were independently developed in the literature, are used to analyze common code structures. It is shown that those ideas yield results that agree well with simulation results. In particular, the performance gain due to scaling of the extrinsic information is analyzed by these density evolution techniques. The expected scaling gain by density evolution matches well with the achievable scaling gain from simulation results. Finally, in an attempt to optimally decode codes with cycles, a conceptual cycle cutting problem is introduced. This cycle cutting problem is a generalization of the optimal decoder of a single cycle tail-biting convolutional code, and can be realized by imposing constraints on a single or multiple nodes in the graphical representation of codes. This modified message passing algorithm, referred to Constrained Iterative Decoding (CID), is applied to the Serially concatenated Convolutional Code (SCCC) and the LDPC code.
Large and moderate deviations for infinite-dimensional autoregressive processes
Authors: André Mas, Ludovic Menneteau
Venue: Journal of Multivariate Analysis (2003)

We consider large and moderate deviations for the empirical mean and covariance of hilbertian autoregressive processes. As an application we obtain moderate deviations principles for the eigenvalues and associated projectors of the empirical covariance.
An approach for implicitly detecting information needs
Authors: Ryen W. White, Joemon M. Jose, Ian Ruthven
Venue: Proceedings of the twelfth international conference on Information and knowledge management (2003)

Searchers can have problems devising queries that accurately express their, often dynamic, information needs. In this paper we describe an adaptive approach that uses unobtrusive monitoring of interaction to help alleviate such problems and support searchers in their seeking. The approach we propose implicitly selects terms to better represent information needs, gathers evidence on potential changes in these needs, and uses this evidence to tailor the result presentation accordingly. A user evaluation of an interface implementing our approach, presented in [7], shows it can select terms that approximate current information needs and provide evidence to track changes in these needs.
On the monotonicity of games generated by symmetric submodular functions
Authors: Fedor V. Fomin, Dimitrios M. Thilikos
Venue: Discrete Applied Mathematics (2003)

Submodular functions have appeared to be a key tool for proving the monotonicity of several graph searching games. In this paper, we provide a general game theoretic framework able to unify old and new monotonicity results in a unique min-max theorem. Our theorem provides a game theoretic analogue to a wide number of graph theoretic parameters such as linear-width and cutwidth.
Studying streaming video quality: from an application point of view
Authors: Zhiheng Wang, Sujata Banerjee, Sugih Jamin
Venue: Proceedings of the eleventh ACM international conference on Multimedia (2003)

An important aspect of improving streaming application performance is the streaming quality evaluation process. In this paper we introduce a set of alternative objective streaming video quality metrics, which are suitable for large scale deployment. Derived from an existent media application, our metrics are designed to capture the application behaviors disrupting the streaming video quality. We also present a set of experiments to demonstrate the effectiveness of these metrics.
A visually grounded natural language interface for reference to spatial scenes
Authors: Peter Gorniak, Deb Roy
Venue: Proceedings of the 5th international conference on Multimodal interfaces (2003)

Many user interfaces, from graphic design programs to navigation aids in cars, share a virtual space with the user. Such applications are often ideal candidates for speech interfaces that allow the user to refer to objects in the shared space. We present an analysis of how people describe objects in spatial scenes using natural language. Based on this study, we describe a system that uses synthetic vision to "see" such scenes from the person's point of view, and that understands complex natural language descriptions referring to objects in the scenes. This system is based on a rich notion of semantic compositionality embedded in a grounded language understanding framework. We describe its semantic elements, their compositional behaviour, and their grounding through the synthetic vision system. To conclude, we evaluate the performance of the system on unconstrained input.
On Dominating Sets and Independent Sets of Graphs
Authors: Jochen Harant, Anja Pruchnewski, Margit Voigt
Venue: Combinatorics, Probability and Computing (1999)

For a graph G on vertex set V = {1, &hellip;, n} let k = (k1, &hellip;, kn) be an integral vector such that 1 &le; ki &le; di for i &isin; V, where di is the degree of the vertex i in G. A k-dominating set is a set Dk &sube; V such that every vertex i &isin; V&setmn;Dk has at least ki neighbours in Dk. The k-domination number &gamma;k(G) of G is the cardinality of a smallest k-dominating set of G.For k1 = &middot; &middot; &middot; = kn = 1, k-domination corresponds to the usual concept of domination. Our approach yields an improvement of an upper bound for the domination number found by N. Alon and J. H. Spencer.If ki = di for i = 1, &hellip;, n, then the notion of k-dominating set corresponds to the complement of an independent set. A function fk(p) is defined, and it will be proved that &gamma;k(G) = min fk(p), where the minimum is taken over the n-dimensional cube Cn = {p = (p1, &hellip;, pn) &#x2223; pi &isin; &Ropf;, 0 &le; pi &le; 1, i = 1, &hellip;, n}. An &Oscr;(&Delta;22&Delta;n-algorithm is presented, where &Delta; is the maximum degree of G, with INPUT: p &isin; Cn and OUTPUT: a k-dominating set Dk of G with &#x2223;Dk&#x2223;&le;fk(p).
Notes on elation generalized quadrangles
Authors: Stanley E. Payne, Koen Thas
Venue: European Journal of Combinatorics (2003)

Let S be a finite generalized quadrangle of order (s, t), s, t > 1. An "elation about a point p" of S is an automorphism fixing p linewise and fixing no point which is not collinear with p. An elation that generates a cyclic group of elations is called a "standard elation". One of the problems already considered in Payne and Thas (Finite Generalized Quadrangles (1984)) is to determine just when the set of elations about the point (∞) is a group. The purpose of this paper is to provide an example where this is not the case, and then to show that for a flock generalized quadrangle the usual group of elations about (∞) is the complete set of standard elations about (∞).
MAC-layer anycasting in ad hoc networks
Authors: Romit Roy Choudhury, Nitin H. Vaidya
Venue: ACM SIGCOMM Computer Communication Review (2004)

A wireless ad hoc network is formed by a group of wireless hosts, without the use of any infrastructure. To enable communication, hosts cooperate among themselves to forward packets on behalf of each other. A key challenge in ad hoc networks lies in designing efficient routing strategies. While several routing protocols have been proposed, most of them aim to select one optimal route between the source and destination. The MAC layer at each intermediate node is then required to forward packets to the next downstream node on that route. We argue that choosing a single optimal route at the network layer may not be sufficient. Knowledge of short-term channel conditions at the MAC layer can play an important role in improving end-to-end performance. Instantaneous interference, channel contention, power constraints and other considerations may be taken into account along with the network layer's long-term view. This paper proposes MAC layer anycasting- a forwarding strategy that combines the guidelines from the network layer, with MAC layer knowledge of the local channel. We describe some applications of MAC-layer anycasting, and discuss the performance related tradeoffs.
Maximum-norm estimates for resolvents of elliptic finite element operators
Authors: Nikolai Yu. Bakaev, Vidar Thomée, Lars B. Wahlbin
Venue: Mathematics of Computation (2003)

Let Ω be a convex domain with smooth boundary in Rd. It has been shown recently that the semigroup generated by the discrete Laplacian for quasi-uniform families of piecewise linear finite element spaces on Ω is analytic with respect to the maximum-norm, uniformly in the mesh-width. This implies a resolvent estimate of standard form in the maximum-norm outside some sector in the right halfplane, and conversely. Here we show directly that such a resolvent estimate holds outside any sector around the positive real axis, with arbitrarily small angle. This is useful in the study of fully discrete approximations based on A(θ)-stable rational functions, with θ small.
Predicting Telecommuter Productivity
Authors: Derrick J. Neufeld, Yulin Fang
Venue: Proceedings of the Proceedings of the 37th Annual Hawaii International Conference on System Sciences (HICSS'04) - Track 1 - Volume 1 (2004)

Productivity of remote workers is of critical concern to organizations contemplating telecommuting work arrangements. This paper suggests a general theoretical framework for understanding telecommuter productivity. Based on semi-structured interviews with 32 telecommuters, we found that telecommuting productivity was positively associated with beliefs and attitudes, social factors, and situational factors, and unassociated with individual factors. Implications and future research directions are discussed.
MODD: A New Decision Diagram and Representation for Multiple Output Binary Functions
Authors: Abusaleh M. Jabir, Dhiraj K. Pradhan
Venue: Proceedings of the conference on Design, automation and test in Europe - Volume 2 (2004)

This paper presents a new decision diagram (DD), called MODD, for multiple output binary and multiple-valued functions. This DD is canonic and can be made minimal with respect to a given variable order. Unlike other reported DDs, our approach can represent arbitrary combination of bits at the word-level. The preliminary results show that our representation can result in considerable memory saving [1].
Height of minor faces in plane normal maps
Authors: O. V. Borodin, D. V. Loparev
Venue: Discrete Applied Mathematics (2004)

The height of a face in a plane graph is the greatest degree of a vertex incident with this face. Under appropriate necessary conditions we prove that any plane normal map has a 3-face of height at most 20, or a 4-face of height at most 11, or else a 5-face of height at most 5. The bounds 20 and 5 are shown to be the best possible.
A tuple-oriented algorithm for deduction in a fuzzy relational database
Authors: Ignacio J. Blanco, Maria J. Martin-Bautista, Olga Pons, M. Amparo Vila
Venue: International Journal of Uncertainty, Fuzziness and Knowledge-Based Systems (2003)

In this paper, we define the concept of generalized rule for making classical deduction with imprecise data, stored both data and rules in a fuzzy relational database represented in the GEFRED model. We propose a way of measuring the imprecision related to the calculation of a fact based on the matching degree of the facts in the database and the facts calculated while expanding the rules. In order to achieve this, classical algorithms for deduction are not appropriated and we propose the modifications that have to be applied on a classical tuple-oriented algorithm in order to design a new algorithm for deducing from imprecise data with generalized rules.
Economics of point accelleration
Authors: Eric William Burger, Guido Dedene
Venue: Proceedings of the conference on European design automation (1990)

This paper examines point accelerators from the economic point of view. Point accelerators are devices that speed-up a specific part of the design process. Examples are simulation, routing, and graphics accelerators. The paper presents a general mathematical model for the economics of point accelerators. One conclusion of the model is that for many users there is no economic justification for point acceleration. On the other hand, by using opportunity cost models the paper shows the utility of point accelerators for specific groups of users. These users are those that require the most performance possible and those that have a narrow scope, such as PCB service houses. In addition, the paper examines the effect of using accelerators on multiple process. In this case, the result is that the increase in productivity is more than the increases attributable to the individual productivity increases expected from each acceleration step.
Optimal streaming of layered video: joint scheduling and error concealment
Authors: Philippe de Cuetos, Keith W. Ross
Venue: Proceedings of the eleventh ACM international conference on Multimedia (2003)

We consider streaming layered video (live and stored) over a lossy packet network in order to maximize the video quality that is rendered at the receiver. We propose a framework, called joint scheduling and error concealment (Joint S+EC), in which packet scheduling decisions at the sender explicitly account for the error concealment mechanism at the receiver. We show how the theory of infinite--horizon, average--reward Markov decision processes (MDPs) with average--cost constraints can be applied to the joint scheduling and error concealment problem for low--delay transmission channels. The formulation allows for a wide variety of performance metrics, including metrics that take quality variation into account. We demonstrate the framework and MDP solution procedure using MPEG--4 FGS video traces. The main conclusions are (1) Joint S+EC optimal policies perform better than Disjoint S+EC optimal policies, and (2) the performance of the optimal Disjoint S+EC policy is not significantly better than very simple static policies.
General urn models with several types of balls and Gaussian limiting fields
Authors: Michael Drmota, Danièle Gardy, Bernhard Gittenberger
Venue: Random Structures Algorithms (2004)

We study a system of m urns, where several types of balls are thrown, and an additive valuation is assigned to each urn depending on its state. Examples are the join models studied in a database context, and some models with two types of balls. The object of our investigation is the evolution of the valuation with time, when a ball is thrown at each time unit. By means of a generating function approach we show the weak convergence of the valuation process to a Gaussian field.
Using certes to infer client response time at the web server
Authors: David Olshefski, Jason Nieh, Dakshi Agrawal
Venue: ACM Transactions on Computer Systems (TOCS) (2004)

As businesses continue to grow their World Wide Web presence, it is becoming increasingly vital for them to have quantitative measures of the mean client perceived response times of their web services. We present Certes (CliEnt Response Time Estimated by the Server), an online server-based mechanism that allows web servers to estimate mean client perceived response time, as if measured at the client. Certes is based on a model of TCP that quantifies the effect that connection drops have on mean client perceived response time by using three simple server-side measurements: connection drop rate, connection accept rate and connection completion rate. The mechanism does not require modifications to HTTP servers or web pages, does not rely on probing or third party sampling, and does not require client-side modifications or scripting. Certes can be used to estimate response times for any web content, not just HTML. We have implemented Certes and compared its response time estimates with those obtained with detailed client instrumentation. Our results demonstrate that Certes provides accurate server-based estimates of mean client response times in HTTP 1.0/1.1 environments, even with rapidly changing workloads. Certes runs online in constant time with very low overhead. It can be used at websites and server farms to verify compliance with service level objectives.
A Real Options Approach for Prioritization of a Portfolio of Information Technology Projects: A Case Study of a Utility Company
Authors: Indranil Bardhan, Sugato Bagchi, Ryan Sougstad
Venue: Proceedings of the Proceedings of the 37th Annual Hawaii International Conference on System Sciences (HICSS'04) - Track 8 - Volume 8 (2004)

The valuation of information technology (IT) investments is particularly challenging because it is characterized by long payback periods, uncertainty, and changing business conditions. Corporate budgeting methods use accounting-based criteria like return on investment (ROI), internal rate of return (IRR), and payback period which were designed for projects with no option features. However, the uncertainties underlying IT investment decisions and the inability of traditional DCF methods to incorporate the impact of flexibility on project valuation force executives to rely on gut instinct when finalizing IT investment decisions. As corporations struggle with these issues, the valuation and prioritization of IT projects raises several challenges. In a survey of senior IT executives from 50 large firms with significant business-to-business experience, conducted by Forrester Research [11], respondents mentioned that they often struggled to prioritize project funding requests and lacked a method to coordinate funding decisions across their organizations.