ppxscal/embedding_network huggingface dataset:
Abstract approach to evolution equations of phase-field type and applications
Authors: Giulio Schimperna
Venue:  (1999)

A general system of abstract nonlinear parabolic equations deriving from phase-field models of heat transfer in anisotropic fluids with phase transitions is studied through a backward finite differences approximation scheme and existence and uniqueness theorems are proved. Then, applications are presented to two physical situations: first, a standard heat diffusion problem is briefly discussed mainly as a justification of the choices of the abstract setting. Second, a more interesting transmission problem between two different adjoining fluids is studied under very general compatibility hypotheses and the abstract results are adapted to provide an existence and uniqueness theorem also in this case. Moreover, through convex analysis techniques, it is performed a mathematical study of the subdifferential-type relations linking the phase fields and the temperatures to the internal energies of the fluids. EMAIL:: schimper@dragon.ian.pv.cnr.it KEYWORDS:: Phase-field models, subdifferential operators, abstract evolution equations
Approximation by fully complex multilayer perceptrons
Authors: Taehwan Kim, Tülay Adali
Venue: Neural Computation (2003)

We investigate the approximation ability of a multilayer perceptron (MLP) network when it is extended to the complex domain. The main challenge for processing complex data with neural networks has been the lack of bounded and analytic complex nonlinear activation functions in the complex domain, as stated by Liouville's theorem. To avoid the conflict between the boundedness and the analyticity of a nonlinear complex function in the complex domain, a number of ad hoc MLPs that include using two real-valued MLPs, one processing the real part and the other processing the imaginary part, have been traditionally employed. However, since nonanalytic functions do not meet the Cauchy-Riemann conditions, they render themselves into degenerative backpropagation algorithms that compromise the efficiency of nonlinear approximation and learning in the complex vector field. A number of elementary transcendental functions (ETFs) derivable from the entire exponential function ez that are analytic are defined as fully complex activation functions and are shown to provide a parsimonious structure for processing data in the complex domain and address most of the shortcomings of the traditional approach. The introduction of ETFs, however, raises a new question in the approximation capability of this fully complex MLP. In this letter, three proofs of the approximation capability of the fully complex MLP are provided based on the characteristics of singularity among ETFs. First, the fully complex MLPs with continuous ETFs over a compact set in the complex vector field are shown to be the universal approximator of any continuous complex mappings. The complex universal approximation theorem extends to bounded measurable ETFs possessing a removable singularity. Finally, it is shown that the output of complex MLPs using ETFs with isolated and essential singularities uniformly converges to any nonlinear mapping in the deleted annulus of singularity nearest to the origin.
What I Did on My Fall Vacation-A Pervasive Computing Class
Authors: Larry Rudolph
Venue: IEEE Pervasive Computing (2003)

In this issue, Larry Rudolph shares his experience in developing and teaching classes in pervasive computing at MIT and for industry. The course drew on many technologies from MIT's Project Oxygen. He describes goals for the course, the syllabus, problem sets, course components, and final projects. Please let me know your comments and suggestions for future columns.Scott Midkiff
New Access Index for Fast Execution of Conjunctive Queries over Text Data
Authors: Yuping Yang, Mukesh Singhal
Venue: Proceedings of the 1999 International Symposium on Database Engineering & Applications (1999)

Complex queries with multiple conjunctive (AND) predicates have attracted increasing attention for their importance in OLAP systems. Signature index is ideal for fast execution of queries involving multiple conjunctive predicates. However, previous signature-based methods did not separate the signatures from different attributes.We developed a signature augmented access index, MG-tree. It's main features are: (1) it is a light-weight search tree for indexing multiple attributes of text data, (2) it eliminates the mix of signatures from different attributes, so the construction and maintenance of the index is easy and search is efficient.Our analysis and experiments show that the MG-tree achieved a significant improvement in terms of access speed and storage space overhead over both tree-like indexes and previous multi-dimensional signature indexes, and is easier to build and maintain. MG-tree can be employed in practical DBMS implementations.
Simple but efficient collaboration in a complex competitive situation
Authors: Satoshi Kurihara, Kensuke Fukuda, Toshio Hirotsu, Osamu Akashi, Shinya Sato, Toshiharu Sugawara
Venue: Proceedings of the second international joint conference on Autonomous agents and multiagent systems (2003)

In this paper, we analyze a simple adaptive model of competition called the Minority Game, which is used in analyzing competitive phenomena in markets, and suggest that the core elements required for the formation of self-organization are: (i) rules that place a good constraint on each agent's behavior, and (ii) rules that lead to indirect coordination, which is called "stigmergy." Finally, we tested the points suggested by this research in solving the El Farol's bar problem, which is an extended version of the Minority Game.
A holistic design procedure for membrane structures using the SCOOP framework
Authors: K. Reimann, R. Wagner, R. Blum, M. Jentsch
Venue: Proceedings of the sixth conference on Computational structures technology (2002)

In this paper a new holistic approach for the calculation process of membrane structures and its implementation into the SCOOP framework [1] is described. The relevant calculation tasks as form finding, cutting pattern generation, cutting pattern assembly and static analysis of the resulting pre-stressed structure are combined in a generalized calculation procedure.
Numerical analysis of a dental implant system in three-dimension
Authors: Bülent Ekici
Venue: Advances in Engineering Software (2002)

One of the important problems in dental implant systems is screw loosening. In order to prevent this loosening a preload is applied to the retaining screw. However, this measure has not been able to eliminate its occurrence. In this study the effect of a washer in a Branemark-type implant on the loosening conditions of the retaining screw was investigated using a finite element simulation in three-dimensional models. The simulation indicated that a washer has an important affect against loosening. This also increases the flexibility of implant system against the deformation. The application of a washer is easy and cheap.
View-Invariant Regions and Mobile Robot Self-Localization
Authors: Kristian T. Simsarian, Thomas J.Olson, N. Nandhakumar
Venue:  (1996)

This paper addresses the problem of mobile robot self-localization given a polygonal map and a set of observed edge segments. The standard approach to this problem uses interpretation tree search with pruning heuristics to match observed edges to map edges. Our approach introduces a preprocessing step in which the map is decomposed into ''view-invariant regions'' (VIRs). The VIR decomposition captures information about map edge visibility, and can be used for a variety of robot navigation tasks. Basing self-localization search on VIRs greatly reduces the branching factor of the search tree and thereby simplifies the search task. In this paper we define the VIR decomposition and give algorithms for its computation and for self-localization search. We present results of simulations comparing standard and VIR-based search, and discuss the application of the VIR decomposition to other problems in robot navigation.
Principles of inverse computation and the Universal resolving algorithm
Authors: Sergei Abramov, Robert Glück
Venue: The essence of computation: complexity, analysis, transformation (2002)

We survey fundamental concepts in inverse programming and present the Universal Resolving Algorithm (URA), an algorithm for inverse computation in a first-order, functional programming language. We discuss the principles behind the algorithm, including a three-step approach based on the notion of a perfect process tree, and demonstrate our implementation with several examples. We explain the idea of a semantics modifier for inverse computation which allows us to perform inverse computation in other programming languages via interpreters.
On the Relation between SAT and BDDs for Equivalence Checking
Venue: Proceedings of the 3rd International Symposium on Quality Electronic Design (2002)

State-of-the-art verification tools are based on efficient operations on Boolean formulas. Traditional manipulation techniques are based on Binary Decision Diagrams (BDDs) and SAT solvers. In this paper, we study the relation between the two procedures and show how the number of backtracks obtained in the Davis-Putnam (DP) procedure is linked to the number of paths in the BDD. We utilize this relation to devise a method that uses BDD variable ordering techniques to run the DP procedure. Experimental results confirm that the proposed method results in a dramatic decrease in the number of backtracks and in the time needed to prove the Boolean satisfiability problem as well.
Negotiating from Mars to Venus: gender in simulated international negotiations
Authors: Natalie B. Florea, Mark A. Boyer, Scott W. Brown, Michael J. Butler, Magnolia Hernandez, Kimberly Weir, Lin Meng, Paula R. Johnson, Clarisse Lima, Hayley J. Mayall
Venue: Simulation and Gaming (2003)

Gender analysis has emerged as an important conceptual approach to the study of decision making and conflict resolution in the international arena. Although scholars and practitioners within the field of international relations have debated the effect of gender on the negotiation and decision-making process, little systematic evidence to support their assertions has taken place. This article examines a set of data from the GLOBALED PROJECT that provides insights into the different ways men and women perceive world affairs and interact in a negotiation setting. In particular, the authors examine differences in the negotiation styles of all-female, all-male, and mixed-gender groups when negotiating over international or global issues. Findings from the GLOBALED PROJECT, a computer-mediated study of gender differences in decision-making and negotiation skills, show that there are indeed significant differences between the approaches used by various gender groupings. Although much work remains to be done in this area, this research indicates that some of the impressionistic and anecdotal characterizations of the different ways men and women approach negotiations and decision making are indeed well-grounded when examined through systemic evidence.
Classification and Comparison of Schemes for Providing Scalable IP Services Over ATM Networks
Authors: Paul Boustead, Joe Chicharo, Gary Anido
Venue: Proceedings of the 7th IEEE International Conference on Networks (1999)

There are several approaches for the provision of scalable backbone IP over cell based networks including Multi-Protocol Label Switching (MPLS) and Multi-Protocol Over ATM (MPOA). This paper provides a classification that highlights the major differences between the various approaches. We classify approaches according to Cut-through flow classification, path determination and forwarding granularity. This framework is used in conjunction with a comparative performance analysis to examine the strengths and weaknesses of popular approaches concentrating on MPLS and MPOA. We conclude that a new hybrid solution called Destination-Site Label Switching provides promising performance particularly in terms of flow classification and forwarding granularity.
Multidimensional detective
Authors: A. Inselberg
Venue: Proceedings of the 1997 IEEE Symposium on Information Visualization (InfoVis '97) (1997)

The display of multivariate datasets in parallel coordinates, transforms the search for relations among the variables into a 2-D pattern recognition problem. This is the basis for the application to visual data mining. The knowledge discovery process together with some general guidelines are illustrated on a dataset from the production of a VLSI chip. The special strength of parallel coordinates is in modeling relations. As an example, a simplified economic model is constructed with data from various economic sectors of a real country. The visual model shows the interelationship and dependencies between the sectors, circumstances where there is competition for the same resource, and feasible economic policies. Interactively, the model can be used to do trade-off analyses, discover sensitivities, do approximate optimization, monitor (as in a process) and provide decision support.
The Complexity of Resolution Procedures for Theorem Proving in the Propositional Calculus
Authors: Zvi Galil
Venue:  (1975)

A comparative study on the complexity of various procedures for proving that a set of clauses is contradictory is described. All the procedures either use the resolution rule in some form or are closely related to procedures which do. Among the procedures considered are 1. resolution 2. regular resolution 3. Davis Putnam procedure 4. resolution with extension 5. bounded (and iterated bounded) resolution 6. enumeration procedures 7. semantic trees. The results include: a. exponential lower bounds for the run-time of most of the procedures, b. realtions between the various procedures, c. implications to the comlexity of integer programming routines.
Conditional Messaging: Extending Reliable Messaging with Application Conditions
Authors: Stefan Tai, Thomas Mikalsen, Isabelle Rouvellou, Stanley M. Sutton Jr.
Venue: Proceedings of the 22 nd International Conference on Distributed Computing Systems (ICDCS'02) (2002)

Standard messaging middleware guarantees the delivery of messages to intermediary destinations like message queues, but does not guarantee the receipt or the processing of a message by final recipients. Conditional messaging is an extension to standard messaging middleware that addresses this shortcoming by allowing an application to define, monitor, andevaluate various conditions on messages, such as time constraints on the receipt or the processing of message by a set of final recipients. In this paper, we introduce the notion of conditional messaging, and present the design and implementation of a flexible and reliable system that supports conditional messaging for use in Java 2 Enterprise Edition and message queuing environments. Our solution uniquely shifts the responsibilities for implementing the management of conditions on messages from the application to the middleware. We further discuss the grouping of multiple conditional messages into atomic units-of-work, which can also integrate requests to transactional resources like distributed objects using object middleware. Conditional messaging serves to implement various kinds of backward dependencies for distributed object transactions that integrate messaging.
The Swedish Core Language Engine
Authors: Bjorn Gamback, Manny Rayner
Venue:  (2001)

The paper describes a Swedish-language customization (S-CLE) of the SRI Core Language Engine, A shorter version of this paper appears in L.Ahrenberg (ed.): Papers from the Third Nordic Conference on Text Comprehension in Man and Machine , Link Sweden, 1992. which has been developed at SICS from the original English-language version by replacing English-specific modules with corresponding Swedish-language versions. The S-CLE is intended to be used as a building block in a broad range of applications, such as data-base query system, machine translation systems, NL front-ends, speech-to-text/text-to-speech systems, and so on. Examples of the first two types of application already exist. The main part of the S-CLE is an extensive Swedish grammar that is compiled into parsing and generation modules. The grammar formalism is a type of unification grammar loosely based on Generalized Phrase Structure Grammar (GPSG). Generation is performed using the Semantic-Head-Driven algorithm. Analysis turns sentences into ``Quasi-Logical Form'''' (QLF), a logical-form representation, while generation works in the opposite direction. Intermediate stages include processing of morphology, syntax and semantics. For knowledge-base applications, a separate module can convert QLFs into conventional scoped logical forms. After two-and-a-half years of work (approximately 45 person months), the first prototype system has a vocabulary of about 1900 words and covers a fairly broad range of possible grammatical constructions. Based on our experience in this project, we present in this paper detailed arguments to support the claim that customization of an English-language NLP system is a highly cost-effective way of constructing Swedish language systems with corresponding functionality.
Can software agents influence human relations?: balance theory in agent-mediated communities
Authors: Hideyuki Nakanishi, Satoshi Nakazawa, Toru Ishida, Katsuya Takanashi, Katherine Isbister
Venue: Proceedings of the second international joint conference on Autonomous agents and multiagent systems (2003)

We sought to create a social embodied conversational agent to support group interactions, using 'balance theory' from social science research on human-human relations. We conducted an experiment to evaluate the social ECA's effectiveness in a group situation, depending upon how strongly it mediated the conversation among group members. First, we confirmed that it could win favorable feelings from subjects by showing an agreeing attitude to them and, conversely, unfavorable feelings by showing a disagreeing attitude. Next, we validated balance theory as a rule governing both agent-human relations and human relations if the social ECA highly mediated the conversation. We found that the social ECA's effectiveness was very low if it did not control turn-taking, and if the human pair had a chance to converse extensively with one another. Conversation analysis corroborated these results.
Neural Network Design and the Complexity of Learning
Authors: Stephen J. Judd
Venue:  (1988)

We formalize a notion of learning that characterizes the training of feed-forward networks. In the field of learning theory, it stands as a new model specialized for the type of learning problems that arise in connectionist networks. The formulation is similar to Valiant''s [Va184] in that we ask what can be feasibly learned from examples and stored in a particular data structure. One can view the data structure resulting from Valiant-type learning as a ''sentence'' in a language described by grammatical syntax rules. Neither the words nor their interrelationships are known a priori. Our learned data structure is more particular than Valiant''s in that it must be a particular ''sentence''. The position and relationships of each ''word'' are fully specified in advance and the learning system need only discover what the missing words are. This corresponds to the problem of finding retrieval functions for each node in a given network. We prove this problem NP-complete and thus demonstrate that learning in networks has no efficient general solution. Corollaries to the main theorem demonstrate the NP-completeness of several sub-cases. While the intractability of the problem precludes its solution in all these cases, we sketch some alternative definitions of the problem in a search for tractable sub-cases. One broad class of subcases is formed by placing constraints on the network architecture; we study one type in particular. The focus of these constraints is on families of ''shallow'' architectures which are defined to have bounded depth and unbounded width. We introduce a perspective on shallow networks, called the Support Cone Interaction (SCI) graph, which is helpful in distinguishing tractable from intractable subcases: When the SC1 graph has tree-width O (log n), learning can be accomplished in polynomial time; when its tree-width is n omega (1) we find the problem NP-complete even if the SC1 graph is a simple 2-dimensional planar grid. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Domain-independent text segmentation using anisotropic diffusion and dynamic programming
Authors: Xiang Ji, Hongyuan Zha
Venue: Proceedings of the 26th annual international ACM SIGIR conference on Research and development in informaion retrieval (2003)

This paper presents a novel domain-independent text segmentation method, which identifies the boundaries of topic changes in long text documents and/or text streams. The method consists of three components: As a preprocessing step, we eliminate the document-dependent stop words as well as the generic stop words before the sentence similarity is computed. This step assists in the discrimination of the sentence semantic information. Then the cohesion information of sentences in a document or a text stream is captured with a sentence-distance matrix with each entry corresponding to the similarity between a sentence pair. The distance matrix can be represented with a gray-scale image. Thus, a text segmentation problem is converted into an image segmentation problem. We apply the anisotropic diffusion technique to the image representation of the distance matrix to enhance the semantic cohesion of sentence topical groups as well as sharpen topical boundaries. At last, the dynamic programming technique is adapted to find the optimal topical boundaries and provide a zoom-in and zoom-out mechanism for topics access by segmenting text in variable numbers of sentence topical groups. Our approach involves no domain-specific training, and it can be applied to texts in a variety of domains. The experimental results show that our approach is effective in text segmentation and outperforms several state-of-the-art methods.
Refinement in a Type Extension Context
Authors: Peter Bancroft, Ian Hayes
Venue:  (1996)

This paper extends the methods of the refinement calculi to allow the derivation of an Oberon implementation. The use of records, pointers, opaque types and type extension distinguishes this work from previous examples. A case study for a stack abstract data type illustrates the method, which involves three data refinement steps. Firstly, a sequence of integers is refined to a sequence of integer records with pointers. Secondly, the sequence of records is refined to a linked list accessed through a start pointer. Finally, this is refined to a generic implementation that is close to Oberon code. Pointers are facilitated by declaring an explicit local data store for each stack variable. The advantage of Oberon over Modula-2 is the ability to separate the final code into two modules - a generic stack that maintains the linked List property and an integer instantiation of the stack, using type extension. This separation of concerns (isolation of the linked data structure properties) is the main benefit of the approach.