ppxscal/embedding_network huggingface dataset:
Calculating geometric properties of three-dimensional objects from the spherical harmonic representation
Authors: Artemy Baxansky, Nahum Kiryati
Venue: Pattern Recognition (2007)

The volume, location of the centroid, and second-order moments of a three-dimensional star-shaped object are determined in terms of the spherical harmonic coefficients of its boundary function. Bounds on the surface area of the object are derived in terms of the spherical harmonic coefficients as well. Sufficient conditions under which the moments and area computed from the truncated spherical harmonic series converge to the actual moments and area are established. The proposed method is verified using a scanned head model and by recent measurements of the 433 Eros asteroid. An extension to non-star-shaped objects of genus 0 is provided. The computational complexity of our method is shown to be equal to that of the discrete spherical harmonic transform, which is O(N^2log^2N), where N is the maximum order of coefficients retained in the expansion.
MiFi: a framework for fairness and QoS assurance for current IEEE 802.11 networks with multiple access points
Authors: Yigal Bejerano, Randeep S. Bhatia
Venue: IEEE/ACM Transactions on Networking (TON) (2006)

In this paper, we present a framework for providing fair service and supporting quality of service (QoS) requirements in IEEE 802.11 networks with multiple access points (APs). These issues becomes critical as IEEE 802.11 wireless LAN are widely deployed in nationwide networks, linking tens of thousands of "hotspots" for providing both real-time (voice) and non real-time (data) services to a large population of mobile users. However, both fairness and QoS guarantees cannot be supported in the current 802.11 standard.Our system, termed MiFi, relies on centralized coordination of the APs. During any given time of the "contention-free" period only a set of non-interfering APs is activated while the others are silenced. Moreover, the amount of service granted to an AP is proportional to its load and the system's performance is optimized by employing efficient scheduling algorithms. We show that such a system can be implemented without requiring any modification of the underlying MAC protocol standard or the behavior of the mobile stations. Our scheme is complementary to the emerging 802.11e standard for QoS and guarantees to overcome the hidden node and the overlapping cell problems. Our simulations establish that the system supports fairness and hence can provide QoS guarantees for real-time traffic, while maintaining a relative high throughput.
Refining preference-based search results through Bayesian filtering
Authors: Jiyong Zhang, Pearl Pu
Venue: Proceedings of the 12th international conference on Intelligent user interfaces (2007)

Preference-based search (PBS) is a popular approach for helping consumers find their desired items from online catalogs. Currently most PBS tools generate search results by a certain set of criteria based on preferences elicited from the current user during the interaction session. Due to the incompleteness and uncertainty of the user's preferences, the search results are often inaccurate and may contain items that the user has no desire to select. In this paper we develop an efficient Bayesian filter based on a group of users' past choice behavior and use it to refine the search results by filtering out items which are unlikely to be selected by the user. Our preliminary experiment shows that our approach is highly promising in generating more accurate search results and saving user's interaction effort.
Finding probably best systems quickly via simulation
Authors: Takayuki Osogami
Venue: Proceedings of the 38th conference on Winter simulation (2006)

The performance of computer systems can in theory be optimized by selecting the system configuration having the best simulated performance. Unfortunately, it is often computationally intractable to estimate the performance of all system configurations accurately via simulation. We propose an algorithm for finding the best system configuration without estimating the performance of each system configuration accurately, so that the total simulation time is minimized. We prove that with high probability our algorithm finds the best system configuration. In addition, our algorithm has an advantage in that it only infrequently changes the system configurations to be simulated. Numerical experiments show that our algorithm improves upon existing algorithms with respect to the total simulation time and the frequency of changing the system configurations.
Low-randomness constant-round private XOR computations
Authors: Carlo Blundo, Clemente Galdi, Giuseppe Persiano
Venue: International Journal of Information Security (2006)

In this paper we study the randomness complexity needed to distributively perform k XOR computations in a t-private way using constant-round protocols in the case in which the players are honest but curious.We show that the existence of a particular family of subsets allows the recycling of random bits for constant-round private protocols. More precisely, we show that after a 1-round initialization phase during which random bits are distributed among n players, it is possible to perform each of the k XOR computations using two rounds of communication.For $$t\leq c\sqrt{n/\log n}$$, for any c < 1/2, we design a protocol that uses O(kt2log n) random bits.
Longest repeats with a block of k don't cares
Authors: Maxime Crochemore, Costas S. Iliopoulos, Manal Mohamed, Marie-France Sagot
Venue: Theoretical Computer Science (2006)

A k-repeat is a string wk = u*k v that matches more than one substring of x, where * is the don't care letter and k > 0. We propose an O(n log n)-time algorithm for computing all longest k-repeats in a given string x = x[1..n]. The proposed algorithm uses suffix trees to fulfill this task and relies on the ability to answer lowest common ancestor queries in constant time.
Qualifying online teachers--Communicative skills and their impact on e-learning quality
Authors: Karin Tweddell Levinsen
Venue: Education and Information Technologies (2007)

Worldwide there is an increasing demand for educational institutions to offer part of their educations online and mixed mode. For institutions to comply with these demands, it is necessary to prepare teachers (and other members of the staff), to fulfil their responsibilities within the virtual environment. Teachers must be able to organize their courses pedagogically according to different conditions, i.e., subject domains, group sizes, variations within communication and interaction. Teachers must acquire knowledge and skills in handling Information and Communication Techniques (ICT) as well as pedagogical possibilities and constraints inherited in the software available. Several studies demonstrate that technical obstacles are easier to overcome than lack of communication skills. Also the consequenses of communication breakdowns tend to create serious problems that technology cannot solve. These problems concern how teachers function satisfactory as mediators and coaches in collaborative, knowledge sharing virtual environments. For example, how teachers support their students in becoming online-students and how they facilitate complex discussions on difficult topics. This is a big challenge for everybody involved in e-learning, and the challenge is not met by offering introductory courses for university teachers. Based on basis of a recent examination of concrete actions and strategies for the future within 11 Danish universities, the auther argues that there exists a severe mismatch between the organisational expectations and strategies and the competence-evolving activities that the same organisations offer to their staff. A recent case study of a university pedagogy course on e-learning for university teachers demonstrates and identifies some of the consequences of the mismatch. Finally the author suggests strategies to meet the demands of the future online university.
Minimum-length connection networks
Authors: W. D. Hart
Venue: Issue 16 (April 1974) (1974)

These notes were prompted by reading in the SIGMAP Newsletter for November 1973 the article on Minimum-Length Network problems by J. Soukup and W. F. Chow. 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
Relaxational metric adaptation and its application to semi-supervised clustering and content-based image retrieval
Authors: Hong Chang, Dit-Yan Yeung, William K. Cheung
Venue: Pattern Recognition (2006)

The performance of many supervised and unsupervised learning algorithms is very sensitive to the choice of an appropriate distance metric. Previous work in metric learning and adaptation has mostly been focused on classification tasks by making use of class label information. In standard clustering tasks, however, class label information is not available. In order to adapt the metric to improve the clustering results, some background knowledge or side information is needed. One useful type of side information is in the form of pairwise similarity or dissimilarity information. Recently, some novel methods (e.g., the parametric method proposed by Xing et al.) for learning global metrics based on pairwise side information have been shown to demonstrate promising results. In this paper, we propose a nonparametric method, called relaxational metric adaptation (RMA), for the same metric adaptation problem. While RMA is local in the sense that it allows locally adaptive metrics, it is also global because even patterns not in the vicinity can have long-range effects on the metric adaptation process. Experimental results for semi-supervised clustering based on both simulated and real-world data sets show that RMA outperforms Xing et al.'s method under most situations. Besides applying RMA to semi-supervised learning, we have also used it to improve the performance of content-based image retrieval systems through metric adaptation. Experimental results based on two real-world image databases show that RMA significantly outperforms other methods in improving the image retrieval performance.
Linux Application Development (2nd Edition)
Authors: Michael K. Johnson, Erik W. Troan
Venue:  (2004)

Develop Software that Leverages the Full Power of Today's LinuxLinux Application Development, Second Edition, is the definitive reference for Linux programmers at all levels of experience, including C programmers moving from other operating systems. Building on their widely praised first edition, leading Linux programmers Michael Johnson and Erik Troan systematically present the key APIs and techniques you need to create robust, secure, efficient software or to port existing code to Linux.This book has been fully updated for the Linux 2.6 kernel, GNU C library version 2.3, the latest POSIX standards, and the Single Unix Specification, Issue 6. Its deep coverage of Linux-specific extensions and features helps you take advantage of the full power of contemporary Linux. Along the way, the authors share insights, tips, and tricks for developers working with any recent Linux distribution, and virtually any version of Unix.Topics include Developing in Linux: understanding the operating system, licensing, and documentation The development environment: compilers, linker and loader, and unique debugging tools System programming: process models, file handling, signal processing, directory operations, and job control Terminals, sockets, timers, virtual consoles, and the Linux console Development libraries: string matching, terminal handling, command-line parsing, authentication, and more Hundreds of downloadable code samplesNew to this edition The GNU C library (glibc), underlying standards, and test macros Writing secure Linux programs, system daemons, and utilities Significantly expanded coverage of memory debugging, including Valgrind and mpr Greatly improved coverage of regular expressions IPv6 networking coverage, including new system library interfaces for using IPv6 and IPv4 interchangeably Coverage of strace, ltrace, real-time signals, poll and epoll system calls, popt library improvements, Pluggable Authentication Modules (PAM), qdbm, and much more Improved index and glossary, plus line-numbered code examples
Firmware engineering and microprogramming at the University of Cincinnati
Authors: Christos A. Papachristou
Venue: ACM SIGMICRO Newsletter (1983)

A research program in firmware engineering and microprogramming is in progress at the Electrical and Computer Engineering Department of the University of Cincinnati. The group of researchers engaged in this effort is supervised by Dr. Christos Papachristou and involves his graduate assistants, Mr. Satnam Gambhir, Ms. Evelyn Melton and Mr. Pei-Ching Hwang. This research is supported in part by U.S. Army Research Office grant DAAG29-85-K-0106, gratefully acknowledged. Some preliminary results were reported at Micro-14, Micro-15 and the IEEE International Workshop on Computer Systems Organization.
Type inference for unboxed types and first class mutability
Authors: Swaroop Sridhar, Jonathan S. Shapiro
Venue: Proceedings of the 3rd workshop on Programming languages and operating systems: linguistic support for modern operating systems (2006)

Systems programs rely on fine-grain control of data representation and use of state to achieve performance, conformance to hard-ware specification, and temporal predictability. The robustness and checkability of these programs could be greatly improved if modern type systems and programming language ideas, such as polymorphism and type inference, could be applied to these programs.BitC is a higher-order programming language in the tradition of ML and Haskell, extended to incorporate both state and the expression of unboxed and low-level datatypes. State and unboxed value types interact in subtle ways with polymorphic type-inference. Unless handled with care in the language design, interactions of these features can lead to unsoundness or results that are counter-intuitive to the programmer. Because instances of value types may have mutable components, a decision must be made concerning their compatibility at copy boundaries: should structurally equivalent types that differ only in their mutability be considered compatible. The choice impacts both the amount of polymorphism that the language can preserve and the burden of type annotation imposed on the programmer.This paper presents some of these challenges and our design for how to address these issues.
Towards intelligent mapping applications: a study of elements found in cognitive maps
Authors: Gary Look, Howard Shrobe
Venue: Proceedings of the 12th international conference on Intelligent user interfaces (2007)

This paper describes a study that examines common elements found in people's mental maps of the city of Boston. The intent of the study is to understand the mental model people have of a city. Understanding this mental model will provide insight into developing mapping applications that present location information in a way that makes it easier to conceptualize and situate new location information in terms of places a person already knows. An analysis of hand-annotated maps showing the locations of prominent places in a person's mental map of Boston suggests that prominent places can be characterized by a certain set of properties and that major transit points (subway stops) play an important role in framing a person's mental map.
Dynamic power control in a fading downlink channel subject to an energy constraint
Authors: Bariş Ata, Konstantinos E. Zachariadis
Venue: Queueing Systems: Theory and Applications (2007)

A central controller chooses a state-dependent transmission rate for each user in a fading, downlink channel by varying transmission power over time. For each user, the state of the channel evolves over time according to an exogenous continuous-time Markov chain (CTMC), which affects the quality of transmission. The traffic for each user, arriving at the central controller, is modeled as a finite-buffer Markovian queue with adjustable service rates. That is, for each user data packets arrive to the central controller according to a Poisson process and packet size is exponentially distributed; an arriving packet is dropped if the associated buffer is full, which results in degradation of quality of service. The controller forwards (downlink) the arriving packets to the corresponding user according to an optimally chosen transmission rate from a fixed set A i of available values for each user i, depending on the backlog in the system and the channel state of all users. The objective is to maximize quality of service subject to an upper bound on the long-run average power consumption. We show that the optimal transmission rate for each user is solely a function of his own packet queue length and channel state; the dependence among users is captured through a penalty rate. Further, we explicitly characterize the optimal transmission rate for each user.
Finite element modeling of the nonlinear oscillations in axisymmetric acoustic resonators
Authors: A. El-Sabbagh, A. Baz
Venue: Finite Elements in Analysis and Design (2006)

Oscillation of a gas in closed resonators has gained considerable interest in the past years. In this paper, the nonlinear equations governing the behavior of the gas oscillations inside the resonator are formulated in a weak form and then modeled using the finite element method. The pressure ratios, predicted by the proposed model, are in close agreement with the exact solutions available for simple geometries such as cylindrical, exponential and linearly varying area resonators. The presented comparisons validate the accuracy of the finite element model and emphasize its potential for predicting the performance or resonators of more complex geometries which are necessary for generating high pressures from the standing waves. Also, gas flow through the boundaries of the resonator is implemented in the proposed model. The presented finite element model presents an invaluable tool for designing a new class of acoustic compressors which can be used, for example, in refrigeration and vibration control applications.
The time course of saccadic decision making: dynamic field theory
Authors: Claudia Wilimzig, Stefan Schneider, Gregor Schöner
Venue: Neural Networks (2006)

Making a saccadic eye movement involves two decisions, the decision to initiate the saccade and the selection of the visual target of the saccade. Here we provide a theoretical account for the time-courses of these two processes, whose instabilities are the basis of decision making. We show how the cross-over from spatial averaging for fast saccades to selection for slow saccades arises from the balance between excitatory and inhibitory processes. Initiating a saccade involves overcoming fixation, as can be observed in the countermanding paradigm, which we model accounting both for the temporal evolution of the suppression probability and its dependence on fixation activity. The interaction between the two forms of decision making is demonstrated by predicting how the cross-over from averaging to selection depends on the fixation stimulus in gap-step-overlap paradigms. We discuss how the activation dynamics of our model may be mapped onto neuronal structures including the motor map and the fixation cells in superior colliculus.
A data-oriented approach to integrate emotions in adaptive dialogue management
Authors: Johannes Pittermann, Angela Pittermann
Venue: Proceedings of the 12th international conference on Intelligent user interfaces (2007)

During the past years the involvement of emotions in dialogue design has attracted much interest in current research on intelligent human-computer interfaces. We focus on the implementation of a flexible and robust dialogue system which integrates emotions and other influencing parameters in the dialogue flow. In order to achieve a higher degree of adaptability we propose a simplified stochastic approach to model the dialogue manager's behavior based on the user's input and dialogue-influencing parameters like emotions.
Computing large-amplitude progressive Rossby waves on a sphere
Authors: T. G. Callaghan, L. K. Forbes
Venue: Journal of Computational Physics (2006)

We consider the flow of a thin layer of incompressible fluid on a rotating sphere, bounded internally by the surface of the sphere and externally by a free surface. Progressive-wave solutions are sought for this problem, without tangent plane simplifications. A linearized theory is derived for small amplitude perturbations about a base westerly flow field, allowing calculation of the linearized progressive wavespeed. This result is then extended to the numerical solution of the full model, to obtain highly non-linear large-amplitude progressive-wave solutions in the form of Fourier series. A detailed picture is developed of how the progressive wavespeed depends on wave amplitude. This approach reveals the presence of non-linear resonance behaviour, with different disjointed solution branches existing at different values of the amplitude. Additionally, we show that the formation of localized low pressure systems cut off from the main flow field is an inherent feature of the non-linear dynamics, once the amplitude forcing reaches a certain critical level.
Simultaneous coupling of fluids and deformable bodies
Authors: Nuttapong Chentanez, Tolga G. Goktekin, Bryan E. Feldman, James F. O'Brien
Venue: Proceedings of the 2006 ACM SIGGRAPH/Eurographics symposium on Computer animation (2006)

This paper presents a method for simulating the two-way interaction between fluids and deformable solids. The fluids are simulated using an incompressible Eulerian formulation where a linear pressure projection on the fluid velocities enforces mass conservation. Similarly, elastic solids are simulated using a semi-implicit integrator implemented as a linear operator applied to the forces acting on the nodes in Lagrangian formulation. The proposed method enforces coupling constraints between the fluid and the elastic systems by combining both the pressure projection and implicit integration steps into one set of simultaneous equations. Because these equations are solved simultaneously the resulting combined system treats closed regions in a physically correct fashion, and has good stability characteristics allowing for relatively large time steps. This general approach is not tied to any particular volume discretization of fluid or solid, and we present results implemented using both regular-grid and tetrahedral simulations.
Taking hold of TV: learning from the literature
Authors: Richard Harper, Tim Regan, Mark Rouncefield
Venue: Proceedings of the 18th Australia conference on Computer-Human Interaction: Design: Activities, Artefacts and Environments (2006)

In this paper, we report the findings of a literature review into the experience of and the prospects for mobile TV, in particular multimedia experiences enabled over mobile phone-type devices and networks. The review shows that there will be a niche market for broadcast 'TV content' but that, more interestingly, 'mobile TV' might consist of a new content genre, affording new forms of shared, coproximate experiences.
Customer Relationship Management
Authors: William Wagner, Michael Zubey
Venue:  (2006)

Course Technology ILT manuals facilitate your learning by providing structured interaction with the software itself. It provides text to explain difficult concepts, the hands-on activities are the focus of our courses. The basic approach of setting expectations, delivering instruction, and providing summary and review afterwards. Coverage includes- To use Course Technology ILT manuals in general. To use course objectives to properly set your expectations for the course. Re-key this course after class.