ppxscal/embedding_network huggingface dataset:
Digital atlases and difference forms
Authors: Elizabeth L. Mansfield
Venue: Proceedings of the twenty-first international symposium on Symbolic and algebraic computation (2008)

When integrating a differential equation numerically, it can be important for the solution method to reflect the geometric properties of the original model. These include conservation laws and first integrals, symmetries, and symplectic or variational structures. Thus there is an increasingly sophisticated subject of "geometric integration" concentrating mostly on local properties of the equation. This talk is concerned with ways of ensuring that finite difference schemes accurately mirror global properties. To this end, lattice varieties are introduced on which finite difference schemes amongst others may be defined. There is no assumption of continuity, or that either the lattice variety or the difference systems have a continuum limit; our theory is more general than that of cubical complexes, and the proofs require a different foundation. We show that the global structure of a lattice variety can be determined from its digital atlas. This is important for two reasons. First, if the digital atlas has the same "system of intersections" as that of the smooth model it approximates, you are guaranteed the same global information. Secondly, since our proofs are independent of any continuum limit, global information for inherently discrete models may be obtained. The techniques used are algebraic, specifically homological algebra, which amounts to linear algebra. This talk has two meta-messages: 1) Continuity is an illusion. 2) If you want to capture analytic structures in discrete models successfully, cherchez l'algebre. No particular expertise is assumed for this talk, which is based on the paper, Difference Forms by Elizabeth L. Mansfield and Peter E. Hydon, to appear in Foundations of Computational Mathematics.
A case study of retention practices at the University of Illinois at Urbana-Champaign
Authors: Tanya L. Crenshaw, Erin Wolf Chambers, Heather Metcalf
Venue: Proceedings of the 39th SIGCSE technical symposium on Computer science education (2008)

Computer science is seeing a decline in enrollment at all levels of education. One key strategy for reversing this decline is to improve methods of student retention. This paper, based on a 10-month case study at the Department of Computer Science at the University of Illinois at Urbana-Champaign, examines two aspects of student retention at both the graduate and undergraduate levels: community identity and community relationships. Our data shows that students feel isolated from each other, faculty, and members of the greater computer science community. Given our findings, we highlight existing programs and propose new programs which improve student-community interactions. While the lessons learned might not apply at every institution, they constitute a valuable case study for improving conditions for students at large research universities.
Second-Order State-Variable Filter with Current Operational Amplifiers
Authors: David Kubanek, Kamil Vrba
Venue: Proceedings of the Third International Conference on Systems (2008)

A design of the second-order filter based on the state-variable canonic structure is described. The filter operates in current mode and offers low-pass and band-pass transfer functions simultaneously. Current operational amplifiers are used as main active building blocks. An analysis of the influence of amplifier real properties on the filter characteristics is presented. The shifts of filter poles and appearance of new parasitic zeros is observed. Computer simulation with a bipolar model of current operational amplifier was used for verification of the filter functionality.
MICRON: a framework for connection establishment in optical networks
Authors: Srinivasan Ramasubramanian, Arun K. Somani
Venue: IEEE/ACM Transactions on Networking (TON) (2008)

Traffic grooming in optical networks has gained significance due to the prevailing sub-wavelength requirement of end users. Optical networks get upgraded to the latest technology slowly with time with only a subset of nodes being upgraded to the latest technology. The networks are thus comprised of nodes employing heterogeneous switching architectures. In this paper, we develop a framework called Methodology for Information Collection and Routing in Optical Networks (MICRON) for connection establishment in optical grooming networks with heterogeneous switching architectures. We illustrate with examples the information that may be collected from the links, and operators that may be used to obtain information along a path. The information can be used to select a path dynamically depending on the network status. We complete the MICRON framework by providing a generic channel assignment procedure that could be employed to implement different channel assignment schemes. Various routing and channel assignment algorithms can be developed from the proposed framework. The framework may be easily implemented with simple traffic engineering extensions to the already existing routing protocols in the wide-area networks.
Wireless client puzzles in IEEE 802.11 networks: security by wireless
Authors: Ivan Martinovic, Frank A. Zdarsky, Matthias Wilhelm, Christian Wegmann, Jens B. Schmitt
Venue: Proceedings of the first ACM conference on Wireless network security (2008)

Resource-depletion attacks against IEEE 802.11 access points (APs) are commonly executed by flooding APs with fake authentication requests. Such attacks may exhaust an AP's memory resources and result in denied association service, thus enabling more sophisticated impersonation attacks accomplished by rogue APs. This work introduces the concept of wireless client puzzles, a protection method which assists an AP to preserve its resources by discarding fake requests, while allowing legitimate clients to successfully join the network. Rather than conditioning a puzzle's solution on computational resources of highly heterogeneous clients, the puzzles utilize peculiarities of a wireless environment such as broadcast communication and signal propagation which provide more invariant properties. Using an implementation of the proposed scheme, we demonstrate its effectiveness within a realistic scenario. Based on the insights from the implementation a simulation is used to extend the threat model and to scale up the scenario. Simulations verify our implementation results and show that the impact of flooding rate is decreased by 75% even if an attacker changes its position or manipulates its signal strength, while ≈ 90% of the legitimate stations are still able to successfully associate during an attack.
TWAREN Optical Network Laboratory and Lightpath Control System
Authors: Shu-Cheng Lin, Hui-Min Tseng, Yi-Cheng Chang, Hui-Lan Lee, Te-Lung Liu, Chu-Sing Yang, C. Eugene Yeh
Venue: Proceedings of the 22nd International Conference on Advanced Information Networking and Applications - Workshops (2008)

With the explosive growth of the Internet, various applications are developed. Their common feature is the desire for higher network bandwidth than before. Network backbone has been upgraded from 155Mbps with ATM technology to Gigabit Ethernet or 10 Gigabit Ethernet to meet this trend. Besides, some next-generation e-science applications such as video streaming, high-quality images, and grid computing also need the optical network to provide higher bandwidth with QoS guarantee. In the past, national research and education networks (NRENs) around the world strive for developing the control layer of optical network. TWAREN [2] establishes an optical network laboratory to investigate the next-generation network with optical technology. The laboratory supports not only SDH and next-generation SDH functions, but also DWDM functions which offer a hybrid network platform for domestic and international research projects. In our on-going LightPath control project, we develop a control system with automatic lightpath re-establishment function to manage optical devices in our laboratory. We will integrate our control system with TWAREN NOC to facilitate the network operation and reduce the cost of operator in our project planning.
Context-controlled flow visualization in augmented reality
Authors: Mike Eissele, Matthias Kreiser, Thomas Ertl
Venue: Proceedings of graphics interface 2008 (2008)

A major challenge of novel scientific visualization using Augmented Reality is the accuracy of the user/camera position tracking. Many alternative techniques have been proposed, but still there is no general solution. Therefore, this paper presents a system that copes with different conditions and makes use of context information, e.g. available tracking quality, to select adequate Augmented Reality visualization methods. This way, users will automatically benefit from highquality visualizations if the system can estimate the pose of the realworld camera accurately enough. Otherwise, specially-designed alternative visualization techniques which require a less accurate positioning are used for the augmentation of real-world views. The proposed system makes use of multiple tracking systems and a simple estimation of the currently available overall accuracy of the pose estimation, used as context information to control the resulting visualization. Results of a prototypical implementation for visualization of 3D scientific flow data are presented to show the practicality.
Machine learning method for knowledge discovery experimented with otoneurological data
Authors: Kirsi Varpa, Kati Iltanen, Martti Juhola
Venue: Computer Methods and Programs in Biomedicine (2008)

We have been interested in developing an otoneurological decision support system that supports diagnostics of vertigo diseases. In this study, we concentrate on testing its inference mechanism and knowledge discovery method. Knowledge is presented as patterns of classes. Each pattern includes attributes with weight and fitness values concerning the class. With the knowledge discovery method it is possible to form fitness values from data. Knowledge formation is based on frequency distributions of attributes. Knowledge formed by the knowledge discovery method is tested with two vertigo data sets and compared to experts' knowledge. The experts' and machine learnt knowledge are also combined in various ways in order to examine effects of weights on classification accuracy. The classification accuracy of knowledge discovery method is compared to 1- and 5-nearest neighbour method and Naive-Bayes classifier. The results showed that knowledge bases combining machine learnt knowledge with the experts' knowledge yielded the best classification accuracies. Further, attribute weighting had an important effect on the classification capability of the system. When considering different diseases in the used data sets, the performance of the knowledge discovery method and the inference method is comparable to other methods employed in this study.
continuous and digital nonlinear chaotic systems: energy-metric approach, simulation and implementation
Authors: Milan Stork, Josef Hrusak, Daniel Mayer
Venue: Proceedings of the 9th International Conference on Circuits (2005)

In the contribution a new approach to problems of nonlinear system analysis, synthesis and design, including generation of different classes of deterministic, chaotic, pseudo-chaotic and hyper-chaotic signals is presented. The proposed method insists on a new abstract formulation of the energy conservation principle, based on the idea of introducing a proper state-space metric as measure of total energy, accumulated in the state space of a system representation. The fundamental idea is illustrated by examples.
Development and evaluation of multidimensional tactons for a wearable tactile display
Authors: Pierre Barralon, Ginna Ng, Guy Dumont, Stephan K. W. Schwarz, Mark Ansermino
Venue: Proceedings of the 9th international conference on Human computer interaction with mobile devices and services (2007)

We developed a novel wearable tactile display system as an alternative to the visual and audio displays routinely used by anesthesiologists to monitor patients in the operating room (OR). Visual displays and auditory alarms can be distracting or insufficient in their alarm transmission whereas a tactile display, which utilizes the sense of touch, can act as an effective conduit for alert delivery. A sophisticated alarm scheme is essential to convey the complex array of physiological information available in current monitoring systems; therefore, to report all relevant alerts to the attending anesthesiologist, it is essential that an augmenting or replacement display system be at least as effective and efficacious as conventional systems. Using multidimensional Tactons, we designed a tactile alert scheme consisting of 36 unique stimuli and evaluated the accuracy and response time in stimuli recognition using a tactile prototype worn as a belt. We observed an overall accuracy of 81% and a response time of 4.8 seconds. 4.18 bits (18.07 tokens) of messages were successfully communicated without loss of information. These results demonstrate that the novel tactile display represents an effective and potentially work-load-reducing method to convey vital information non-visually and non-aurally.
Using Web resources to construct multilingual medical thesaurus for cross-language medical information retrieval
Authors: Wen-Hsiang Lu, Ray S. Lin, Yi-Che Chan, Kuan-Hsi Chen
Venue: Decision Support Systems (2008)

Due to the language barrier, non-English users are unable to retrieve the most updated medical information from the U.S. authoritative medical websites, such as PubMed and MedlinePlus. However, currently, there is no any cross-language medical information retrieval (CLMIR) system that can help Chinese-speaking consumers cross the language barrier in finding useful English medical information. A few CLMIR systems utilize MeSH (Medical Subject Headings) to help overcome the language barrier. Unfortunately, the traditional Chinese version of MeSH is currently unavailable. In this paper, we employ a semi-automatic term translation method to construct a Chinese-English MeSH by exploiting abundant multilingual Web resources, including Web anchor texts and search-result pages. Through this method, we have developed a Chinese-English Mesh Compilation System to assist knowledge engineers in compiling a Chinese-English medical thesaurus with more than 19,000 entries. Furthermore, this thesaurus has been used to develop a prototypical system for cross-language medical information retrieval, MMODE, which can help consumers retrieve top-quality English medical information using Chinese terms.
A numerically stable fragile watermarking scheme for authenticating 3D models
Authors: Wei-Bo Wang, Guo-Qin Zheng, Jun-Hai Yong, He-Jin Gu
Venue: Computer-Aided Design (2008)

This paper analyzes the numerically instable problem in the current 3D fragile watermarking schemes. Some existing fragile watermarking schemes apply the floating-point arithmetic to embed the watermarks. However, these schemes fail to work properly due to the numerically instable problem, which is common in the floating-point arithmetic. This paper proposes a numerically stable fragile watermarking scheme. The scheme views the mantissa part of the floating-point number as an unsigned integer and operates on it by the bit XOR operator. Since there is no numerical problem in the bit operation, this scheme is numerically stable. The scheme can control the watermark strength through changing the embedding parameters. This paper further discusses selecting appropriate embedding parameters to achieve good performance in terms of the perceptual invisibility and the ability to detect unauthorized attacks on the 3D models. The experimental results show that the proposed public scheme could detect attacks such as adding noise, adding/deleting faces, inserting/removing vertices, etc. The comparisons with the existing fragile schemes show that this scheme is easier to implement and use.
Migrating to optimal RBAC with minimal perturbation
Authors: Jaideep Vaidya, Vijayalakshmi Atluri, Qi Guo, Nabil Adam
Venue: Proceedings of the 13th ACM symposium on Access control models and technologies (2008)

Devising a complete and correct set of roles has been recognized as one of the most important and challenging tasks in implementing role based access control. A key problem related to this is the notion of goodness - when is a set of roles good? Recently, the role mining problem (RMP) has been defined as the problem of discovering an optimal set of roles from existing user permissions. Several different objectives for optimality have been proposed. However, one problem with these definitions is that often organizations already have a deployed set of roles and wish to optimize this set. Even if an optimal set of roles is discovered, if this is widely different, it is impossible to simply throw out the deployed roles and start using the new ones as this may disrupt organizational processes and separation of duty constraints that are defined on roles. Essentially, what is missing is taking role migration cost into account when defining optimality, which would allow us to come up with the best suited set of roles. In this paper, we define a fundamentally different Role Mining Problem that takes the problem of deployed roles into account. We define the Minimal Perturbation RMP as the problem of discovering an optimal set of roles from existing user permissions that are similar to the currently deployed roles. In order to do this, we discuss the concept of similarity of roles and propose suitable definitions. Solutions also need to be parameterized to set relative weight of similarity and minimality to find the optimal set. We propose a heuristic solution based on the previously developed FastMiner algorithm that meets these requirements. We demonstrate the effectiveness of the algorithm through our experimental results.
Truthful multipath routing for ad hoc networks with selfish nodes
Authors: Yongwei Wang, Venkata C. Giruka, Mukesh Singhal
Venue: Journal of Parallel and Distributed Computing (2008)

Multiple path routing protocols are shown to be performance-effective alternatives over single-path routing for ad hoc networks. They provide better resistance to link breakage and load balancing. However, these protocols typically assume a cooperative network setting. In practice nodes in an ad hoc network may behave selfishly and may not be willing to forward packets for other nodes freely. One way to stimulate nodes' cooperation is to reimburse forwarding nodes according to their cost such that these nodes get enough incentive. However, selfish nodes may cheat over their cost to maximize their payoff. This necessitates the need for a truthful protocol which maximizes a node's payoff only when it reveals its true cost. In this paper, we present GTMR, a generic mechanism to transform any table-driven multipath routing protocol into a truthful one, and prove that it guarantees truthfulness. Further, we present TMRP - a truthful multipath routing protocol based on AOMDV protocol as an instance of GTMR. A prominent feature of TMRP is that it incurs only 2n control packets for a route discovery and does not require new types of control messages over AOMDV. To the best of our knowledge, this is the lowest overhead incurred for any truthful routing protocols. TMRP can also achieve load balancing without compromising truthfulness. We conduct an extensive simulation study to evaluate the performance of TMRP. Simulation results show that TMRP provides high packet delivery ratio and has low overhead and low end-to-end delay without compromising the overpayment to the nodes.
'Divert: mother-in-law': representing and evaluating social context on mobile devices
Authors: Kristijan Mihalic, Manfred Tscheligi
Venue: Proceedings of the 9th international conference on Human computer interaction with mobile devices and services (2007)

In this paper we examine the role of social context --- for example social relationships or mood --- in the use of mobile phones. A mobile system that uses information on social context can provide a less obtrusive and a more natural way of interaction: it could play a cheery and joyful tone when a friend calls, or divert the call for the mother-in-law. We present a model of social context, along with its implementation in a prototype based on Semantic Web ontologies. The empirical evaluation, based on experience sampling, with participants during a field trial shows that communicated content, relationship types, and mood have an impact on the usage of mobile devices. Based on the findings, we argue that the design of future mobile services needs to be informed by social context to a greater extent.
A Novel Test Generation Methodology for Adaptive Diagnosis
Authors: Rajsekhar Adapa, Edward Flanigan, Spyros Tragoudas
Venue: Proceedings of the 9th international symposium on Quality Electronic Design (2008)

This paper presents a automatic test pattern generationtechnique to improve the diagnostic resolution of a giventest set. Each test pattern generated by existing techniquesdetects a large number of faults. Identifying the faulty candidatefrom a large set of possible fault candidates is extremelydifficult and time consuming. A novel framework toadaptively generate additional patterns for diagnosing thefaulty location is presented. The additional patterns prunea set of fault free candidates from the possible fault candidates.The proposed technique improves the diagnostic resolutionwhere each new pattern detects only a small numberof faults and each fault is detected by few patterns. Theproposed method is applicable to any fault model and distinguishesa large number of faults with a small number ofpatterns. For simplicity we demonstrate the effectiveness ofthe approach on the path delay fault model.
Product recommendation approaches: Collaborative filtering via customer lifetime value and customer demands
Authors: Ya-Yueh Shih, Duen-Ren Liu
Venue: Expert Systems with Applications: An International Journal (2008)

Recommender systems are techniques that allow companies to develop one-to-one marketing strategies and provide support in connecting with customers for e-commerce. There exist various recommendation techniques, including collaborative filtering (CF), content-based filtering, WRFM-based method, and hybrid methods. The CF method generally utilizes past purchasing preferences to determine recommendations to a target customer based on the opinions of other similar customers. The WRFM-based method makes recommendations based on weighted customer lifetime value - Recency, Frequency and Monetary. This work proposes to use customer demands derived from frequently purchased products in each industry as valuable information for making recommendations. Different from conventional CF techniques, this work uses extended preferences derived by combining customer demands and past purchasing preferences to identify similar customers. Accordingly, this work proposes several hybrid recommendation approaches that combine collaborative filtering, WRFM-based method, and extended preferences. The proposed approaches further utilize customer demands to adjust the ranking of recommended products to improve recommendation quality. The experimental results show that the proposed methods perform better than several other recommendation methods.