ppxscal/embedding_network huggingface dataset:
Geometric Visualization: How to Acquire It Using Dynamic Geometry Systems?
Authors: Cabral Lima, George Alves, Adriana Soares
Venue: Proceedings of the Third International Conference on Systems (2008)

Teaching/learning geometry is arduous for people with visualization deficiencies. We present here our recent research concerning dynamic geometry systems and their influence in learners’ mental representations of geometric objects: how the comprehension of concepts in geometry can be improved. Our psychological supports are PIAGET and VYGOTSKY researches, and our mathematical support is the VAN HIELE’s model, which deals with geometric reasoning. We also used some theories from problem resolution and knowledge representation, mainly the ones commonly used by computer and cognitive scientists. In order to evaluate our research we developed two experimental procedures: 1. with naïf learners, exploring the content of triangles: classifications, sides, etc; 2. with advanced learners, investigating contents, volume calculations, and formula deductions using the CAVALIERI’s principle. The results show that introducing dynamic geometry systems in these processes has improved learners’ performances on visualization of geometric objects and comprehension of geometric concepts.
Introducing Agile Development Practices from the Middle
Authors: Jann Thomas
Venue: Proceedings of the 15th Annual IEEE International Conference and Workshop on the Engineering of Computer Based Systems (2008)

Agile practices are widely discussed as a process that lends itself to green-field development. There is good documentation to support this and books on implementing Agile given a new project. In an organization, implementing Agile from the top down is generally accepted as the key to success. In the real world most development teams have some legacy product, and development managers make decisions on how development teams deliver software. This paper will look at introducing Agile to an existing development team with a maturing product. The problems of the development team, selling the idea to upper management, communication to customers and delivery will be discussed. The implementation of Agile practices, what was done, how it was done and next steps in implementation are the focus of this paper.
Zero-sum delta-systems and multiple copies of graphs
Authors: Yair Caro, Christian Provstgaard
Venue: Journal of Graph Theory (1999)

A main result proved in this paper is the following. Theorem. Let G be a noncomplete graph on n vertices with degree sequence d1 &ge; d2 &ge; &middot; &middot; &middot; &ge; dn and t &ge; 2 be a prime. Let m = gcd{t, di - dj: 1 &le; i < j &le; n} and set $$d =\cases{1\ \ \ if\ m = t\ and\ \ m \not\mid\ d_{i}\ for\ 1 \leq i \leq n \cr 0\ \ \ otherwise.}$$ Then R(tG, ℤt) = t(n + d) - d, where R is the zero-sum Ramsey number. This settles, almost completely, problems raised in [Bialostocki Dierker, J Graph Theory, 1994; Y. Caro, J Graph Theory, 1991]. &copy; 1999 John Wiley Sons, Inc. J Graph Theory 32: 207216, 1999
On low bound of degree sequences of spanning trees in K-edge-connected graphs
Authors: Liu Zhenhong, Xu Baoguang
Venue: Journal of Graph Theory (1998)

A graph G = (V, E) is k-edge-connected if for any subset E2 &sube; E,|E2| < k, G - E2 is connected. A dk-tree T of a connected graph G = (V, E) is a spanning tree satisfying that &forall;v &isin; V, dT(v) &le; $ [\frac{d(v)+k-1}{k}]$ + &alpha;, where [&middot;] is a lower integer form and &alpha; depends on k. We show that every k-edge-connected graph with k &ge; 2, has a dk-tree, and &alpha; = 1 for k = 2, &alpha; = 2 for k &ge; 3. &copy; 1998 John Wiley Sons, Inc. J Graph Theory 28: 8795, 1998
Constraint acquisition you can chase but you cannot find
Authors: Sven Hartmann, Sebastian Link, Thu Trinh
Venue: Proceedings of the fifth on Asia-Pacific conference on conceptual modelling - Volume 79 (2008)

We identify established tableaux techniques as an invaluable tool for semantic knowledge acquisition in the design process of relational databases. Sample databases allow users and designers to judge, justify, convey and test their understanding of the semantics of the future database. In the case of integrity constraints such sample data can provide considerable assistance for deciding whether a constraint captures desirable information about the database or not. Since constraints can be particularly difficult to grasp in practice sample databases offer a convenient tool to confirm or reject the usefulness of potential candidate constraints. We pinpoint the Chase and analytical tableau as two tableaux techniques that are able to automatically generate sample databases for large classes of integrity constraints. The Chase can be used for generating sample data that allows us to reject candidate constraints. However, analytical tableaux enable us to find all minimal sample databases which enable us to either accept or reject a candidate constraint.
Managing Virtual Communities: Time to Turn to the Whetstone?
Authors: Martina Gillen
Venue: International Review of Law, Computers and Technology (2007)

The choice of the game 'Paper Scissors Stone' as the guiding title of this year's BILETA conference was an interesting one. Particularly, when connected to the consideration of politics, business law and changing modes of commerce. The game is one where an arbitrary set of rules has predetermined either a draw or more often a victory between otherwise unrelated items. Why should 'paper covers stone' result in the triumph of paper? Similarly if we follow this line of thought into the arena of virtual communities why should the increasingly commercial atmosphere of the Internet alter the formation and maintenance of online communities? Thus, we must be wary of assumptions imbedded in the language we use to describe and discuss phenomena, after all Chomsky has taught us that our thought processes are constrained by our language; that our conceptualisations are limited to those that we have the language to express.1
Non-traceability of large connected claw-free graphs
Authors: Wacłw Frydrych, Zdzisław Skupień
Venue: Journal of Graph Theory (1998)

Let G be a connected claw-free graph on n vertices. Let &zeta;3(G) be the minimum degree sum among triples of independent vertices in G. It is proved that if &zeta;3(G) &ge; n - 3 then G is traceable or else G is one of graphs Gn each of which comprises three disjoint nontrivial complete graphs joined together by three additional edges which induce a triangle K3. Moreover, it is shown that for any integer k &ge; 4 there exists a positive integer V(k) such that if &zeta;3(G) &ge; n - k, n > V((k) and G is non-traceable, then G is a factor of a graph Gn. Consequently, the problem HAMILTONIAN PATH restricted to claw-free graphs G = (V, E) (which is known to be NP-complete) has linear time complexity O(|E|) provided that &zeta;3(G) &ge; $\frac{5}{6}|V| - 3$. This contrasts sharply with known results on NP-completeness among dense graphs. &copy; 1998 John Wiley Sons, Inc. J Graph Theory 27: 7586, 1998
Density estimation for out-of-range events on personal mobile devices
Authors: Arjan Peddemors, Henk Eertink, Ignas Niemegeers
Venue: Proceeding of the 1st ACM SIGMOBILE workshop on Mobility models (2008)

Over the years, personal mobile devices have obtained increasing capabilities to concurrently connect to surrounding networks and nearby other devices. Good knowledge on the dynamics in the availability of these heterogeneous entities constitutes essential input for various data communication problems, ranging from the adaptation of applications on mobile devices to multi-homed situations, to the optimization of routing protocols for delay tolerant networks. In this paper, we focus on a method for the prediction in time of the loss in visibility of currently in-range network entities, as observed on a personal mobile device. We are interested in estimating the full probability density function of the time of these out-of-range events, as this allows us to ask arbitrary questions such as: what is the probability of losing connection X in the next Y minutes? To do so, we model the mobility of the user by applying kernel density estimation on previously observed mobility traces collected during a user experiment we ran with 12 participants in a six week period, logging cellular, 802.11 wireless LAN, Bluetooth, and various other events on the participant's mobile device.
Applications of newly developed spdsMCPs for first-row transition metal atoms
Authors: E. Miyoshi, Y. Osanai, M. S. Mon, H. Mori, H. Nakashima, T. Noro
Venue: Proceedings of the 1st WSEAS International Conference on Computational Chemistry (2007)

We have examined newly developed relativistic model core potentials (MCPs) for the first row transition-metal atoms from Sc to Zn, in which 3s and 3p electrons are treated explicitly together with the 3d and 4s electrons. By adding suitable correlating functions, we demonstrated that the present MCP basis sets show excellent performance in describing the electronic structures of atoms and molecules, bringing about accurate excitation energies for atoms and very good molecular spectroscopic constants.
Estimating value in service systems: a case study of a repair service system
Authors: N. S. Caswell, C. Nikolaou, J. Sairamesh, M. Bitsaki, G. D. Koutras, G. Iacovidis
Venue: IBM Systems Journal (2008)

The economic structure of service systems has steadily increased in complexity in recent years. This is due not only to specialization in direct material production and services offered, but also in the ownership and management of resources, the role of intangible assets such as process knowledge, and the context in which goods and services are consumed. This increase in complexity represents both a challenge and an opportunity in a service-oriented economy. In this paper, we offer a descriptive structure for the analysis of this complexity which combines graph theory and network flows with economic tools. Our analysis is based on publicly observable information and can be used to analyze service systems in terms of the value they deliver, how they deliver it, and how value can be discovered and increased. We show how this analysis can be applied (in the example of a car manufacturer and its service system for suppliers and dealerships) to improve customer satisfaction and provide options and analysis models for outsourcing decision makers.
A CMOS quadrature oscillator based on a non linear system
Authors: Arturo Prieto Fuenlabrada, Ana Maria Patricia Ortiz Moreno, Joel García Delgado, Carlos Celaya Borges, Jorge Illescas Chávez, Esteban Torres León
Venue: Proceedings of the 2nd WSEAS International Conference on Computer Engineering and Applications (2008)

A CMOS quadrature oscillator based on a classical non linear system of differential equations is presented. First the state space portrait is formulated and analyzed from a set of non linear first order equations. The behavioral response of the system was simulated with ideal macromodels, models suited for program simulators like Spice. Ideal macromodels are mapped to analog structural integrated blocks (general purpose designs). A CMOS prototype was designed. Simulated results are presented.
Inter and intra-document contexts applied in polyrepresentation for best match IR
Authors: Mette Skov, Birger Larsen, Peter Ingwersen
Venue: Information Processing and Management: an International Journal (2008)

The principle of polyrepresentation offers a theoretical framework for handling multiple contexts in information retrieval (IR). This paper presents an empirical laboratory study of polyrepresentation in restricted mode of the information space with focus on inter and intra-document features. The Cystic Fibrosis test collection indexed in the best match system InQuery constitutes the experimental setting. Overlaps between five functionally and/or cognitively different document representations are identified. Supporting the principle of polyrepresentation, results show that in general overlaps generated by three or four representations of different nature have higher precision than those generated from two representations or the single fields. This result pertains to both structured and unstructured query mode in best match retrieval, however, with the latter query mode demonstrating higher performance. The retrieval overlaps containing search keys from the bibliographic references provide the best retrieval performance and minor MeSH terms the worst. It is concluded that a highly structured query language is necessary when implementing the principle of polyrepresentation in a best match IR system because the principle is inherently Boolean. Finally a re-ranking test shows promising results when search results are re-ranked according to precision obtained in the overlaps whilst re-ranking by citations seems less useful when integrated into polyrepresentative applications.
Noise and information
Authors: John I. Tait
Venue: Proceedings of the second workshop on Analytics for noisy unstructured text data (2008)

In this extended abstract I examine the notion of noise and its application to Information Retrieval and urge the reader to consider noise as an intrinsic property of information, not merely a problem to be eliminated.
Test-Bed Evaluation of Ingress Queuing for Improved Packet Delivery
Authors: Lars Landmark, Knut Øvsthus, Øivind Kure
Venue: Proceedings of the Fourth International Conference on Networking and Services (2008)

In addition to bit errors and packet collisions, packets in ad hoc networks are lost due to missing routes and unreachable next hop nodes. The latter is costly, since these packets consume scarce network resources as they are retransmitted up to transmission-threshold times before being discarded. In this paper we demonstrate, through experimental test beds and simulation, the advantage of ingress queuing. By comparing the experimental results with the simulation we illustrate the difference between actual behaviour and the behaviour of the system abstraction. The latter has value in itself, since simulation by far is the preferred methodology in ad hoc networks.
A networked robot system for wireless network emulation
Authors: Tzi-cker Chiueh, Rupa Krishnan, Pradipta De, Jui-Hao Chiang
Venue: Proceedings of the 1st international conference on Robot communication and coordination (2007)

A major barrier to advancing modern wireless networking research is the lack of an effective wireless network simulation platform that simultaneously offers high fidelity, scalability, reproducibility and ease of use. MiNT [8], [7] is an innovative wireless network emulation platform that is specifically designed to satisfy all these desirable properties. To support reconfigurable network topology and wireless node mobility, MiNT is built on a networked robot system that carries wireless networking equipments and is designed to be completely tetherless, capable of supporting 24X7 operation, and low-cost. This paper describes the design, implementation and evaluation of this networked robot system. Each robot node in MiNT is an iRobot's Roomba, which is modified to house an embedded PC equipped with multiple wireless networking interfaces and to re-charge the embedded PC through Roomba's built-in self-charging mechanism. For robot navigation and movement, MiNT's networked robot system supports a computer vision-based robot positioning mechanism and a collision avoidance-driven trajectory planning component. Finally, MiNT provides an interactive control interface and visualization interface to give users real-time visibility into and full control over the MiNT testbed.
Exact free vibration analysis of axially moving viscoelastic plates
Authors: S. Hatami, H. R. Ronagh, M. Azhari
Venue: Computers and Structures (2008)

In this paper, an exact finite strip method is developed for the free vibration analysis of axially moving viscoelastic plates. Using the differential equation that governs the vibration of plates traveling at a constant axial speed, and utilizing the rheological models to model the viscoelastic behavior of materials, the exact stiffness matrix of a finite strip of plate is extracted in the frequency domain. Terms of this matrix are implicit functions of the eigenvalues of free vibration, in-plane forces, viscoelasticity parameters, axial speed and the geometry of the plate. By assembling the stiffness matrices of these finite strips, the global stiffness matrix of a plate moving on intermediate rollers is obtained, from which the eigenvalues defining the free vibration of the plate are extracted within the domain of complex numbers using a suitable algorithm. These values (that represent the exact frequencies of the plate vibration and damping) can be used as a benchmark to evaluate the accuracy of other numerical techniques. Finally, by presenting a set of numerical examples, the effects of axial speed and viscoelastic parameters on the free vibration of moving plates are examined in this paper.
Multi-agent system for dynamic manufacturing scheduling using meta-heuristics
Authors: Ana Madureira
Venue: Proceedings of the 4th WSEAS International Conference on Applied Mathematics and Computer Science (2005)

In this paper we will model a Manufacturing System by means of a Multi-Agent Systems, where each agent may represent a processing entity. This work has as objective to deal with the complex problem of Dynamic Scheduling in Manufacturing Systems. We want to prove that a good global solution for a scheduling problem may emerge from a community of machine agents solving locally their schedules and cooperating with other machine agents that shares some relations between the operations/jobs. The proposed approach is in line with reality and away from the approaches that deal with static and classic or basic Job-Shop scheduling problems. In fact, in real world, where problems are essentially of dynamic and stochastic nature, the traditional methods or algorithms are of very little use. This is the case with most algorithms for solving the so-called static scheduling problem for different setting of both single and multimachine systems arrangements. This reality, motivated us to concentrate on tools, which could deal with such dynamic, disturbed scheduling problems, for multi-machine manufacturing settings, even though, due to the complexity of these problems, optimal solutions may not be possible to find.
Coordinated inter-cell resource allocation approach for better frequency reuse in OFDMA cellular systems
Authors: Seong Keun Oh, Ki Tae Kim
Venue: Proceedings of the 2nd international conference on Ubiquitous information management and communication (2008)

We propose a coordinated inter-cell resource allocation (CICRA) approach that can reuse efficiently the radio spectrum through inter-cell interference (ICI) management over a cluster of adjoining cells in some coordinated manner. In this, the entire radio spectrum is assigned to all the cells within the cell cluster. We use a set of coordinated cell-specific resource allocation sequences in order to manage ICI. The set of sequences should be designed and assigned in a coordinated manner over all cells within the cell cluster, so that ICI from nearer interfering cells could be preferentially avoided and the average ICI level according to the loading factor (LF) could be monotonic and minimally incremented. By the virtue of such ICI-managing mechanism, the CICRA approach can govern efficiently the average ICI level only through individual resource allocation without intervention among cells. In this paper, we would apply the CICRA approach to orthogonal frequency division multiple access (OFDMA) cellular systems. A system-level simulator for an OFDMA cellular system covering surrounding cells up to 3rdtier has been implemented. Simulation results show that the proposed CICRA approach can improve noticeably the system performance in terms of both the outage probability and spectral efficiency as compared with the classical UFR scheme and the soft frequency reuse (SFR) scheme over the entire LF range.
Optimal control in radiative transfer
Authors: Michael Herty, René Pinnau, Mohammed Seaïd
Venue: Optimization Methods Software (2007)

A tracking-type optimal control problem for the radiative transfer equation (RTE) is studied, where we consider the source term in the RTE as control variable. Necessary and sufficient optimality conditions are derived. Numerical methods for the model equation and its adjoint are presented. Computational results based on a steepest descent method are given for two test examples underlining the feasibility of our approach.
Performance Evaluation of IEEE 802.15.4 Beacon-Enabled Association Process
Authors: Fan Zhang, Furong Wang, Bin Dai, Yafang Li
Venue: Proceedings of the 22nd International Conference on Advanced Information Networking and Applications - Workshops (2008)

Currently, the research of IEEE 802.15.4 rarely relates to the network initialization. However the network establishment and the device association are also the important part of IEEE 802.15.4. This paper analyzes network initialization flows in detail and develops an improved association scheme named Simple Association Process (SAP). It is introduced to reduce redundant primitives, avoid collisions and decrease association delay. Comparing SAP with the original IEEE 802.15.4 protocol, the number of association service primitives in SAP is 31.3% less than in the original protocol, and the simulation results show that the association time decreases 64.5%. SAP will get better performance as the number of devices increases and the interval time of association request decreases. It can be widely used in home networks and sensor network applications.
N-flips in even triangulations on the sphere
Authors: Atsuhiro Nakamoto, Tadashi Sakuma, Yusuke Suzuki
Venue: Journal of Graph Theory (2006)

A triangulation is said to be even if each vertex has even degree. For even triangulations, define the N-flip and the P2-flip as two deformations preserving the number of vertices. We shall prove that any two even triangulations on the sphere with the same number of vertices can be transformed into each other by a sequence of N- and P2-flips. &copy; 2005 Wiley Periodicals, Inc. J. Graph Theory
Scatter search and bionomic algorithms for the aircraft landing problem
Authors: J. E. Beasley
Venue: Proceedings of the 4th WSEAS International Conference on Applied Mathematics and Computer Science (2005)

The problem of deciding how to land aircraft approaching an airport involves assigning each aircraft to an appropriate runway, computing a landing sequence for each runway and scheduling the landing time for each aircraft. The objective is to achieve effective runway use. The multiple runway case of the static Aircraft Landing Problem is considered. Two heuristic techniques are presented: Scatter Search and the Bionomic Algorithm, population heuristic approaches that have not been applied to this problem before. Computational results are presented for test problems involving up to 500 aircraft and 5 runways.
A comprehensive model for web search evaluation
Authors: Rashid Ali, M. M. Sufyan Beg
Venue: Proceedings of the 5th WSEAS International Conference on Circuits, Systems, Electronics, Control & Signal Processing (2006)

Web searching is such an activity that its importance can just not be ignored in the current scenario. But as there are a number of search engines available, there must be some procedure to evaluate them. In this paper, architecture of a comprehensive web search evaluation system is discussed. We use a number of objective evaluation techniques to supplement the subjective evaluation based on user feedback. The user feedback is obtained implicitly by watching the actions of user on search results in response to his query. These techniques are combined using Modified Shimura technique of Rank aggregation. The aggregated ranking is then compared with the original ranking given by the search engine. The correlation coefficient thus obtained is averaged for a set of queries. We show our experimental results pertaining to seven public search engines and fifteen queries.