OpenRaiser/Intern-Atlas huggingface dataset:
Machine Learning in Automated Text Categorization
Venue: arXiv cs.IR 2001
Year: 2001

The automated categorization (or classification) of texts into predefined categories has witnessed a booming interest in the last ten years, due to the increased availability of documents in digital form and the ensuing need to organize them. In the research community the dominant approach to this problem is based on machine learning techniques: a general inductive process automatically builds a classifier by learning, from a set of preclassified documents, the characteristics of the categories. The advantages of this approach over the knowledge engineering approach (consisting in the manual definition of a classifier by domain experts) are a very good effectiveness, considerable savings in terms of expert manpower, and straightforward portability to different domains. This survey discusses the main approaches to text categorization that fall within the machine learning paradigm. We will discuss in detail issues pertaining to three different problems, namely document representation, classifier construction, and classifier evaluation.
Vertex-Unfoldings of Simplicial Manifolds
Venue: arXiv cs.CG 2001
Year: 2001

We present an algorithm to unfold any triangulated 2-manifold (in particular, any simplicial polyhedron) into a non-overlapping, connected planar layout in linear time. The manifold is cut only along its edges. The resulting layout is connected, but it may have a disconnected interior; the triangles are connected at vertices, but not necessarily joined along edges. We extend our algorithm to establish a similar result for simplicial manifolds of arbitrary dimension.
An Asynchronous Automata Approach to the Semantics of Temporal Logic
Venue: arXiv cs.LO 2001
Year: 2001

The paper presents the differential equations that characterize an asynchronous automaton and gives their solution x:R->{0,1}x...x{0,1}. Remarks are made on the connection between the continuous time and the discrete time of the approach. The continuous and the discrete time, the linear and the branching temporal logics have the semantics depending on x and their formulas give the properties of the automaton.
Analysis of Investment Policy in Belarus
Venue: arXiv cs.CE 2001
Year: 2001

The optimal planning trajectory is analyzed on the basis of the growth model with effectiveness. The saving per capital value has to be rather high initially with smooth decrement in the future years.
Sintesi di algoritmi con SKY
Venue: arXiv cs.LO 2001
Year: 2001

This paper describes the semantics and ideas about SKY, a logic programming language intended in order to specify algorithmic strategies for the evaluation of problems.
Visual DCT - Visual EPICS Database Configuration Tool
Venue: arXiv cs.SE 2001
Year: 2001

Visual DCT is an EPICS configuration tool completely written in Java and therefore supported in various systems. It was developed to provide features missing in existing configuration tools as Capfast and GDCT. Visually Visual DCT resembles GDCT - records can be created, moved and linked, fields and links can be easily modified. But Visual DCT offers more: using groups, records can be grouped together in a logical block, which allows a hierarchical design. Additionally indication of data flow direction using arrows makes the design easier to understand. Visual DCT has a powerful DB parser, which allows importing existing DB and DBD files. Output file is also DB file, all comments and record order is preserved and visual data saved as comment, which allows DBs to be edited in other tools or manually. Great effort has been taken and many tricks used to optimize the performance in order to compensate for the fact that Java is an interpreted language.
Application of digital regulated Power Supplies for Magnet Control at the Swiss Light Source
Venue: arXiv cs.SE 2001
Year: 2001

The Swiss Light Source (SLS) has in the order of 500 magnet power supplies (PS) installed, ranging from from 3 A/20 V four-quadrant PS to a 950 A/1000 V two-quadrant 3 Hz PS. All magnet PS have a local digital controller for a digital regulation loop and a 5 MHz optical point-to-point link to the VME level. The PS controller is running a pulse width/pulse repetition regulation scheme, optional with multiple slave regulation loops. Many internal regulation parameters and controller diagnostics are readable by the control system. Industry Pack modules with standard VME carrier cards are used as VME hardware interface with the high control density of eight links per VME card. The low level EPICS interface is identical for all 500 magnet PS, including insertion devices. The digital PS have proven to be very stable and reliable during commissioning of the light source. All specifications were met for all PS. The advanced diagnostic for the magnet PS turned out to be very useful not only for the diagnostic of the PS but also to identify problems on the magnets.
SNS Timing System
Venue: arXiv cs.AR 2001
Year: 2001

This poster describes the timing system being designed for Spallation Neutron Source being built at Oak Ridge National lab.
User-friendly explanations for constraint programming
Venue: arXiv cs.PL 2001
Year: 2001

In this paper, we introduce a set of tools for providing user-friendly explanations in an explanation-based constraint programming system. The idea is to represent the constraints of a problem as an hierarchy (a tree). Users are then represented as a set of understandable nodes in that tree (a cut). Classical explanations (sets of system constraints) just need to get projected on that representation in order to be understandable by any user. We present here the main interests of this idea.
SNS Standard Power Supply Interface
Venue: arXiv cs.OH 2001
Year: 2001

The SNS has developed a standard power supply interface for the approximately 350 magnet power supplies in the SNS accumulator ring, Linac and transport lines. Power supply manufacturers are providing supplies compatible with the standard interface. The SNS standard consists of a VME based power supply controller module (PSC) and a power supply interface unit (PSI) that mounts on the power supply. Communication between the two is via a pair of multimode fibers. This PSI/PSC system supports one 16-bit analog reference, four 16-bit analog readbacks, fifteen digital commands and sixteen digital status bits in a single fiber-isolated module. The system can send commands to the supplies and read data from them synchronized to an external signal at up to a 10KHz rate. The PSC time stamps and stores this data in a circular buffer so historical data leading up to a fault event can be analyzed. The PSC contains a serial port so that local testing of hardware can be accomplished with a laptop. This paper concentrates on the software being provided to control the power supply. It includes the EPICS driver; software to test hardware and power supplies via the serial port and VME interface.
Hypotheses Founded Semantics of Logic Programs for Information Integration in Multi-Valued Logics
Venue: arXiv cs.LO 2001
Year: 2001

We address the problem of integrating information coming from different sources. The information consists of facts that a central server collects and tries to combine using (a) a set of logical rules, i.e. a logic program, and (b) a hypothesis representing the server's own estimates. In such a setting incomplete information from a source or contradictory information from different sources necessitate the use of many-valued logics in which programs can be evaluated and hypotheses can be tested. To carry out such activities we propose a formal framework based on bilattices such as Belnap's four-valued logics. In this framework we work with the class of programs defined by Fitting and we develop a theory for information integration. We also establish an intuitively appealing connection between our hypothesis testing mechanism on the one hand, and the well-founded semantics and Kripke-Kleene semantics of Datalog programs with negation, on the other hand.
Representation of Uncertainty for Limit Processes
Venue: arXiv cs.AI 2001
Year: 2001

Many mathematical models utilize limit processes. Continuous functions and the calculus, differential equations and topology, all are based on limits and continuity. However, when we perform measurements and computations, we can achieve only approximate results. In some cases, this discrepancy between theoretical schemes and practical actions changes drastically outcomes of a research and decision-making resulting in uncertainty of knowledge. In the paper, a mathematical approach to such kind of uncertainty, which emerges in computation and measurement, is suggested on the base of the concept of a fuzzy limit. A mathematical technique is developed for differential models with uncertainty. To take into account the intrinsic uncertainty of a model, it is suggested to use fuzzy derivatives instead of conventional derivatives of functions in this model.
Rational Competitive Analysis
Venue: arXiv cs.AI 2001
Year: 2001

Much work in computer science has adopted competitive analysis as a tool for decision making under uncertainty. In this work we extend competitive analysis to the context of multi-agent systems. Unlike classical competitive analysis where the behavior of an agent's environment is taken to be arbitrary, we consider the case where an agent's environment consists of other agents. These agents will usually obey some (minimal) rationality constraints. This leads to the definition of rational competitive analysis. We introduce the concept of rational competitive analysis, and initiate the study of competitive analysis for multi-agent systems. We also discuss the application of rational competitive analysis to the context of bidding games, as well as to the classical one-way trading problem.
Concurrent computing machines and physical space-time
Venue: arXiv cs.DC 2001
Year: 2001

Concrete computing machines, either sequential or concurrent, rely on an intimate relation between computation and time. We recall the general characteristic properties of physical time and of present realizations of computing systems. We emphasize the role of computing interferences, i.e. the necessity to avoid them in order to give a causal implementation to logical operations. We compare synchronous and asynchronous systems, and make a brief survey of some methods used to deal with computing interferences. Using a graphic representation, we show that synchronous and asynchronous circuits reflect the same opposition as the Newtonian and relativistic causal structures for physical space-time.
Media Objects in Time - A Multimedia Streaming System
Venue: arXiv cs.NI 2001
Year: 2001

The widespread availability of networked multimedia potentials embedded in an infrastructure of qualitative superior kind gives rise to new approaches in the areas of teleteaching and internet presentation: The distribution of professionally styled multimedia streams has fallen in the realm of possibility. This paper presents a prototype - both model and runtime environment - of a time directed media system treating any kind of presentational contribution as reusable media object components. The plug-in free runtime system is based on a database and allows for a flexible support of static media types as well as for easy extensions by streaming media servers. The prototypic implementation includes a preliminary Web Authoring platform.
A Concrete Final Coalgebra Theorem for ZF Set Theory
Venue: arXiv cs.LO 2001
Year: 2001

A special final coalgebra theorem, in the style of Aczel's, is proved within standard Zermelo-Fraenkel set theory. Aczel's Anti-Foundation Axiom is replaced by a variant definition of function that admits non-well-founded constructions. Variant ordered pairs and tuples, of possibly infinite length, are special cases of variant functions. Analogues of Aczel's Solution and Substitution Lemmas are proved in the style of Rutten and Turi. The approach is less general than Aczel's, but the treatment of non-well-founded objects is simple and concrete. The final coalgebra of a functor is its greatest fixedpoint. The theory is intended for machine implementation and a simple case of it is already implemented using the theorem prover Isabelle.
Generic Automatic Proof Tools
Venue: arXiv cs.LO 2001
Year: 2001

This book chapter establishes connections between the interactive proof tool Isabelle and classical tableau and resolution technology. Isabelle's classical reasoner is described and demonstrated by an extended case study: the Church-Rosser theorem for combinators. Compared with other interactive theorem provers, Isabelle's classical reasoner achieves a high degree of automation.
Ununfoldable Polyhedra with Convex Faces
Venue: arXiv cs.CG 2001
Year: 2001

Unfolding a convex polyhedron into a simple planar polygon is a well-studied problem. In this paper, we study the limits of unfoldability by studying nonconvex polyhedra with the same combinatorial structure as convex polyhedra. In particular, we give two examples of polyhedra, one with 24 convex faces and one with 36 triangular faces, that cannot be unfolded by cutting along edges. We further show that such a polyhedron can indeed be unfolded if cuts are allowed to cross faces. Finally, we prove that ``open'' polyhedra with triangular faces may not be unfoldable no matter how they are cut.
Lower Bounds for Matrix Product
Venue: arXiv cs.CC 2002
Year: 2002

We prove lower bounds on the number of product gates in bilinear and quadratic circuits that compute the product of two $n \cross n$ matrices over finite fields. In particular we obtain the following results: 1. We show that the number of product gates in any bilinear (or quadratic) circuit that computes the product of two $n \cross n$ matrices over $F_2$ is at least $3 n^2 - o(n^2)$. 2. We show that the number of product gates in any bilinear circuit that computes the product of two $n \cross n$ matrices over $F_p$ is at least $(2.5 + \frac{1.5}{p^3 -1})n^2 -o(n^2)$. These results improve the former results of Bshouty '89 and Blaser '99 who proved lower bounds of $2.5 n^2 - o(n^2)$.
The Dynamics of AdaBoost Weights Tells You What's Hard to Classify
Venue: arXiv cs.LG 2002
Year: 2002

The dynamical evolution of weights in the Adaboost algorithm contains useful information about the role that the associated data points play in the built of the Adaboost model. In particular, the dynamics induces a bipartition of the data set into two (easy/hard) classes. Easy points are ininfluential in the making of the model, while the varying relevance of hard points can be gauged in terms of an entropy value associated to their evolution. Smooth approximations of entropy highlight regions where classification is most uncertain. Promising results are obtained when methods proposed are applied in the Optimal Sampling framework.
A computer scientist looks at game theory
Venue: arXiv cs.GT 2002
Year: 2002

I consider issues in distributed computation that should be of relevance to game theory. In particular, I focus on (a) representing knowledge and uncertainty, (b) dealing with failures, and (c) specification of mechanisms.
A Modal Logic Framework for Multi-agent Belief Fusion
Venue: arXiv cs.AI 2002
Year: 2002

This paper is aimed at providing a uniform framework for reasoning about beliefs of multiple agents and their fusion. In the first part of the paper, we develop logics for reasoning about cautiously merged beliefs of agents with different degrees of reliability. The logics are obtained by combining the multi-agent epistemic logic and multi-sources reasoning systems. Every ordering for the reliability of the agents is represented by a modal operator, so we can reason with the merged results under different situations. The fusion is cautious in the sense that if an agent's belief is in conflict with those of higher priorities, then his belief is completely discarded from the merged result. We consider two strategies for the cautious merging of beliefs. In the first one, if inconsistency occurs at some level, then all beliefs at the lower levels are discarded simultaneously, so it is called level cutting strategy. For the second one, only the level at which the inconsistency occurs is skipped, so it is called level skipping strategy. The formal semantics and axiomatic systems for these two strategies are presented. In the second part, we extend the logics both syntactically and semantically to cover some more sophisticated belief fusion and revision operators. While most existing approaches treat belief fusion operators as meta-level constructs, these operators are directly incorporated into our object logic language. Thus it is possible to reason not only with the merged results but also about the fusion process in our logics. The relationship of our extended logics with the conditional logics of belief revision is also discussed.
Data Mining the SDSS SkyServer Database
Venue: arXiv cs.DB 2002
Year: 2002

An earlier paper (Szalay et. al. "Designing and Mining MultiTerabyte Astronomy Archives: The Sloan Digital Sky Survey," ACM SIGMOD 2000) described the Sloan Digital Sky Survey's (SDSS) data management needs by defining twenty database queries and twelve data visualization tasks that a good data management system should support. We built a database and interfaces to support both the query load and also a website for ad-hoc access. This paper reports on the database design, describes the data loading pipeline, and reports on the query implementation and performance. The queries typically translated to a single SQL statement. Most queries run in less than 20 seconds, allowing scientists to interactively explore the database. This paper is an in-depth tour of those queries. Readers should first have studied the companion overview paper Szalay et. al. "The SDSS SkyServer, Public Access to the Sloan Digital Sky Server Data" ACM SIGMOND 2002.
BSML: A Binding Schema Markup Language for Data Interchange in Problem Solving Environments (PSEs)
Venue: arXiv cs.CE 2002
Year: 2002

We describe a binding schema markup language (BSML) for describing data interchange between scientific codes. Such a facility is an important constituent of scientific problem solving environments (PSEs). BSML is designed to integrate with a PSE or application composition system that views model specification and execution as a problem of managing semistructured data. The data interchange problem is addressed by three techniques for processing semistructured data: validation, binding, and conversion. We present BSML and describe its application to a PSE for wireless communications system design.
Another perspective on Default Reasoning
Venue: arXiv cs.AI 2002
Year: 2002

The lexicographic closure of any given finite set D of normal defaults is defined. A conditional assertion "if a then b" is in this lexicographic closure if, given the defaults D and the fact a, one would conclude b. The lexicographic closure is essentially a rational extension of D, and of its rational closure, defined in a previous paper. It provides a logic of normal defaults that is different from the one proposed by R. Reiter and that is rich enough not to require the consideration of non-normal defaults. A large number of examples are provided to show that the lexicographic closure corresponds to the basic intuitions behind Reiter's logic of defaults.
Interface agents: A review of the field
Venue: arXiv cs.MA 2002
Year: 2002

This paper reviews the origins of interface agents, discusses challenges that exist within the interface agent field and presents a survey of current attempts to find solutions to these challenges. A history of agent systems from their birth in the 1960's to the current day is described, along with the issues they try to address. A taxonomy of interface agent systems is presented, and today's agent systems categorized accordingly. Lastly, an analysis of the machine learning and user modelling techniques used by today's agents is presented.
The structure of broad topics on the Web
Venue: arXiv cs.IR 2002
Year: 2002

The Web graph is a giant social network whose properties have been measured and modeled extensively in recent years. Most such studies concentrate on the graph structure alone, and do not consider textual properties of the nodes. Consequently, Web communities have been characterized purely in terms of graph structure and not on page content. We propose that a topic taxonomy such as Yahoo! or the Open Directory provides a useful framework for understanding the structure of content-based clusters and communities. In particular, using a topic taxonomy and an automatic classifier, we can measure the background distribution of broad topics on the Web, and analyze the capability of recent random walk algorithms to draw samples which follow such distributions. In addition, we can measure the probability that a page about one broad topic will link to another broad topic. Extending this experiment, we can measure how quickly topic context is lost while walking randomly on the Web graph. Estimates of this topic mixing distance may explain why a global PageRank is still meaningful in the context of broad queries. In general, our measurements may prove valuable in the design of community-specific crawlers and link-based ranking systems.
Sufficiently Fat Polyhedra are not 2-castable
Venue: arXiv cs.CG 2002
Year: 2002

In this note we consider the problem of manufacturing a convex polyhedral object via casting. We consider a generalization of the sand casting process where the object is manufactured by gluing together two identical faces of parts cast with a single piece mold. In this model we show that the class of convex polyhedra which can be enclosed between two concentric spheres of the ratio of their radii less than 1.07 cannot be manufactured using only two cast parts.
Source Routing and Scheduling in Packet Networks
Venue: arXiv cs.NI 2002
Year: 2002

We study {\em routing} and {\em scheduling} in packet-switched networks. We assume an adversary that controls the injection time, source, and destination for each packet injected. A set of paths for these packets is {\em admissible} if no link in the network is overloaded. We present the first on-line routing algorithm that finds a set of admissible paths whenever this is feasible. Our algorithm calculates a path for each packet as soon as it is injected at its source using a simple shortest path computation. The length of a link reflects its current congestion. We also show how our algorithm can be implemented under today's Internet routing paradigms. When the paths are known (either given by the adversary or computed as above) our goal is to schedule the packets along the given paths so that the packets experience small end-to-end delays. The best previous delay bounds for deterministic and distributed scheduling protocols were exponential in the path length. In this paper we present the first deterministic and distributed scheduling protocol that guarantees a polynomial end-to-end delay for every packet. Finally, we discuss the effects of combining routing with scheduling. We first show that some unstable scheduling protocols remain unstable no matter how the paths are chosen. However, the freedom to choose paths can make a difference. For example, we show that a ring with parallel links is stable for all greedy scheduling protocols if paths are chosen intelligently, whereas this is not the case if the adversary specifies the paths.
The tip-of-the-tongue phenomenon: Irrelevant neural network localization or disruption of its interneuron links ?
Venue: arXiv cs.CL 2002
Year: 2002

On the base of recently proposed three-stage quantitative neural network model of the tip-of-the-tongue (TOT) phenomenon a possibility to occur of TOT states coursed by neural network interneuron links' disruption has been studied. Using a numerical example it was found that TOTs coursed by interneron links' disruption are in (1.5 + - 0.3)x1000 times less probable then those coursed by irrelevant (incomplete) neural network localization. It was shown that delayed TOT states' etiology cannot be related to neural network interneuron links' disruption.