ppxscal/embedding_network huggingface dataset:
Multi-class Discriminant Kernel Learning via Convex Programming
Authors: Jieping Ye, Shuiwang Ji, Jianhui Chen
Venue: The Journal of Machine Learning Research (2008)

Regularized kernel discriminant analysis (RKDA) performs linear discriminant analysis in the feature space via the kernel trick. Its performance depends on the selection of kernels. In this paper, we consider the problem of multiple kernel learning (MKL) for RKDA, in which the optimal kernel matrix is obtained as a linear combination of pre-specified kernel matrices. We show that the kernel learning problem in RKDA can be formulated as convex programs. First, we show that this problem can be formulated as a semidefinite program (SDP). Based on the equivalence relationship between RKDA and least square problems in the binary-class case, we propose a convex quadratically constrained quadratic programming (QCQP) formulation for kernel learning in RKDA. A semi-infinite linear programming (SILP) formulation is derived to further improve the efficiency. We extend these formulations to the multi-class case based on a key result established in this paper. That is, the multi-class RKDA kernel learning problem can be decomposed into a set of binary-class kernel learning problems which are constrained to share a common kernel. Based on this decomposition property, SDP formulations are proposed for the multi-class case. Furthermore, it leads naturally to QCQP and SILP formulations. As the performance of RKDA depends on the regularization parameter, we show that this parameter can also be optimized in a joint framework with the kernel. Extensive experiments have been conducted and analyzed, and connections to other algorithms are discussed.
A Secure RFID Protocol based on Insubvertible Encryption Using Guardian Proxy
Authors: Kyosuke Osaka, Shuang Chang, Tsuyoshi Takagi, Kenichi Yamazaki, Osamu Takahashi
Venue: Proceedings of the 2008 Third International Conference on Availability, Reliability and Security (2008)

Radio frequency identification (RFID) has been widely deployed for manufacturing, supply chain management, etc. Unfortunately, RFID may cause privacy and security problems. To solve these problems, researchers have studied extensively on RFID security systems. Ateniese et al. proposed an RFID protocol using insubvertible encryption based on the universal reencryption. Although this protocol achieves the integrity of ciphertexts randomized by authorized users, it still leaves security problems. In this paper, we propose a secure RFID protocol based on insubvertible encryption involving guardian proxy. The guardian proxy is a personal RFID-privacy device which may be integrated into cellular phones or PDAs. By introducing the guardian proxy and other basic cryptographic primitives into RFID systems, our protocol is secure against the tag spoofing and swapping attacks. Moreover, our protocol enables ownership transfer.
Parameterized timing analysis with general delay models and arbitrary variation sources
Authors: Khaled R. Heloue, Farid N. Najm
Venue: Proceedings of the 45th annual Design Automation Conference (2008)

Many recent techniques for timing analysis under variability, in which delay is an explicit function of underlying parameters, may be described as parameterized timing analysis. The "max" operator, used repeatedly during block-based timing analysis, causes several complications during parameterized timing analysis. We introduce bounds on, and an approximation to, the max operator which allow us to develop an accurate, general, and efficient approach to parameterized timing, which can handle either uncertain or random variations. Applied to random variations, the approach is competitive with existing statistical static timing analysis (SSTA) techniques, in that it allows for nonlinear delay models and arbitrary distributions. Applied to uncertain variations, the method is competitive with existing multi-corner STA techniques, in that it more reliably reproduces overall circuit sensitivity to variations. Crucially, this technique can also be applied to the mixed case where both random and uncertain variations are considered. Our results show that, on average, circuit delay is predicted with less than 2% error for multi-corner analysis, and less than 1% error for SSTA.
Following non-stationary distributions by controlling the vector quantization accuracy of a growing neural gas network
Authors: Hervé Frezza-Buet
Venue: Neurocomputing (2008)

In this paper, an original method extended from growing neural gas (GNG-T) [B. Fritzke, A growing neural gas network learns topologies, in: G. Tesauro, D.S. Touretzky, T.K. Leen (Eds.), Advances in Neural Information Processing Systems 7, MIT Press, Cambridge, MA, 1995, pp. 625-632] is presented. The method performs continuously vector quantization over a distribution that changes over time. It deals with both sudden changes and continuous ones, and is thus suited for the video tracking framework, where continuous tracking is required as well as fast adaptation to incoming and outgoing people. The central mechanism relies on the management of the quantization resolution, that copes with stopping condition problems of usual GNG inspired methods. Application to video tracking is presented.
Transcendence: enabling a personal view of the deep web
Authors: Jeffrey P. Bigham, Anna C. Cavender, Ryan S. Kaminsky, Craig M. Prince, Tyler S. Robison
Venue: Proceedings of the 13th international conference on Intelligent user interfaces (2008)

A wealth of structured, publicly-available information exists in the deep web but is only accessible by querying web forms. As a result, users are restricted by the interfaces provided and lack a convenient mechanism to express novel and independent extractions and queries on the underlying data. Transcendence enables personalized access to the deep web by enabling users to partially reconstruct web databases in order to perform new types of queries. From just a few examples, Transcendence helps users produce a large number of values for form input fields by using unsupervised information extraction and collaborative filtering of user suggestions. Structural and semantic analysis of returned pages finds individual results and identifies relevant fields. Users may revise automated decisions, balancing the power of automation with the errors it can introduce. In a user evaluation, both programmers and non-programmers found Transcendence to be a powerful way to explore deep web resources and wanted to use it in the future.
A coordinate gradient descent method for nonsmooth separable minimization
Authors: Paul Tseng, Sangwoon Yun
Venue: Mathematical Programming: Series A and B (2008)

We consider the problem of minimizing the sum of a smooth function and a separable convex function. This problem includes as special cases bound-constrained optimization and smooth optimization with &#x2113;1-regularization. We propose a (block) coordinate gradient descent method for solving this class of nonsmooth separable problems. We establish global convergence and, under a local Lipschitzian error bound assumption, linear convergence for this method. The local Lipschitzian error bound holds under assumptions analogous to those for constrained smooth optimization, e.g., the convex function is polyhedral and the smooth function is (nonconvex) quadratic or is the composition of a strongly convex function with a linear mapping. We report numerical experience with solving the &#x2113;1-regularization of unconstrained optimization problems from Mor&#x00e9; et&#x00a0;al. in ACM Trans. Math. Softw. 7, 17&#x2013;41, 1981 and from the CUTEr set (Gould and Orban in ACM Trans. Math. Softw. 29, 373&#x2013;394, 2003). Comparison with L-BFGS-B and MINOS, applied to a reformulation of the &#x2113;1-regularized problem as a bound-constrained optimization problem, is also reported.
Analytical techniques for soft error rate modeling and mitigation of FPGA-based designs
Authors: Hossein Asadi, Mehdi B. Tahoori
Venue: IEEE Transactions on Very Large Scale Integration (VLSI) Systems (2007)

Radiation-induced soft errors are the major reliability threat for digital VLSI systems. In particular, field-programmable gate-array (FPGA)-based designs are more susceptible to soft errors compared to application-specific integrated circuit implementations, since soft errors in configuration bits of FPGAs result in permanent errors in the mapped design. In this paper, we present an analytical approach to estimate the soft error rate of designs mapped into FPGAs. Experimental results show that this technique is orders of magnitude faster than the fault injection method while more than 96% accurate. We also present a highly reliable and low-cost soft error mitigation technique which can significantly improve the availability of FPGA-mapped designs. Experimental results show that, using this technique, the availability of an FPGA mapped design can be increased to more than 99.99%.
Stark effect of electrons in semiconducting rectangular quantum boxes
Authors: Guozhu Wei, Sheng Wang, Guangyu Yi
Venue: Microelectronics Journal (2008)

The Stark shift of the electronic energy levels in semiconducting rectangular quantum boxes with different sizes is investigated by the use of variational solutions to the effective-mass approximation for electric fields of various orientations with respect to the center axis of the box. The asymptotic expansions of the Stark shift are given in the limits of low and high fields, respectively; they clearly indicate that the Stark shift is a quadratic function of the electric field for low electric fields and is an approximate linear function of the electric field for high electric fields. Likewise, our results also show that the largest Stark shift is obtained for the field directed along the diagonal in a cubic box, and is found for the low field directed along a side of the box and for the high field along the diagonal in a rectangular one. The large Stark shift of the electron and hole trapped in a quantum box leads to an obvious reduction of the interband recombination.
Theoretical Analysis of T-lymphocytes Electroporation Model
Authors: Jianjun Chen, Xianqing Luo, Jun Wang, Honghua Liao, Wenli Zhou, Ling Zhang, Heyou Han, Jun Yu
Venue: Proceedings of the 2008 International Conference on BioMedical Engineering and Informatics - Volume 02 (2008)

The paper describes a general method for analysis of time courses of transmembrane voltage induced by time-varying electric fields.Using this method, a response to time-varying fields can be studied. We apply it to different field shapes used for electroporation: rectangular pulses and trains pulses. Using the described method, the course of induced transmembrane voltage is investigated for each selected pulse shape. All the studies are performed at different pulse durations, For all the pulse shapes investigated, this slows down the process of transmembrane voltage inducement. Thus, longer pulses have to be used to attain the desired voltage amplitude, as the influence of the fast, short-lived phenomena on the induced voltage is diminished.
A Decision Support System for Performance Appraisal
Authors: P. D. D. Dominic, Izzatdin Abdul Aziz, K. N. Goh
Venue: Proceedings of the Fifth International Conference on Information Technology: New Generations (2008)

Intense competition is forcing companies to develop innovative strategies to capture customer needs and improve customer satisfaction in the external business environment. Performance appraisal and employee satisfaction is high on the agenda of many companies around the world and with the growing number of improvement models now available. Employee care has to be taken to adopt an approach that will yield the modest attractive return on investment in an internal business environment. Employee performanceappraisal is a subject of great interest in most organizations. This is because performance appraisal decisions have effects and consequences on workers’ compensation and recognition. To deal with this performance appraisal business process, the authors proposed a Decision Support System (DSS) which consists of a mathematical model to evaluate the performance appraisal for individual and for departments in an organization. The findings of this paper provide important direction for the development of employee relation in an organization.
A computer environment for beginners' learning of sorting algorithms: Design and pilot evaluation
Authors: Maria Kordaki, Micael Miatidis, George Kapsampelis
Venue: Computers Education (2008)

This paper presents the design, features and pilot evaluation study of a web-based environment -the SORTING environment- for the learning of sorting algorithms by secondary level education students. The design of this environment is based on modeling methodology, taking into account modern constructivist and social theories of learning while at the same time acknowledging the role of hands-on experience, the significance of students' expressing their previous knowledge, the importance of interlinked multiple representation systems (MRS) and the role of constructive feedback on student learning. Although SORTING supports student learning of typical sorting algorithms such as Bubble-sort, Quick-sort and Selection-sort, it can also be adapted to integrate more sorting algorithms. The analysis of the data emerging from the pilot evaluation study of SORTING has shown that students used all the representation systems (RS) provided and found them attractive and easy to use. On the whole, student interactions within SORTING helped them to become aware of both the intuitive and the typical sorting procedures used, to conceptualize them, to overcome learning difficulties, to correct themselves and to make connections between different representations of the sorting algorithms used.
Composcan: adaptive scanning for efficient concurrent communications and positioning with 802.11
Authors: Thomas King, Mikkel Baun Kjærgaard
Venue: Proceeding of the 6th international conference on Mobile systems, applications, and services (2008)

Using 802.11 concurrently for communications and positioning is problematic, especially if location-based services (e.g., indoor navigation) are concurrently executed with real-time applications (e.g., VoIP, video conferencing). Periodical scanning for measuring the signal strength interrupts the data flow. Reducing the scan frequency is no option because it hurts the position accuracy. For this reason, we need an adaptive technique to mitigate this problem. This work proposes ComPoScan which, based on movement detection, adaptively switches between light-weight monitor sniffing and invasive active scanning to allow positioning and to minimize the impact on the data flow. The system is configurable to realize different trade-offs between position accuracy and the level of communication interruption. We provide extensive experimental results by emulation on data collected at several sites and by validation in several real-world deployments. Results from the emulation show that the system can realize different trade-offs by changing parameters. Furthermore, the emulation shows that the system works independently of the environment, the network card, the signal strength measurement technology, and number and placement of access points. We also show that ComPoScan does not harm the positioning accuracy of a positioning system. By validation in several real-world deployments, we provided evidence for that the real system works as predicted by the emulation. In addition, we provide results for ComPoScan's impact on communication where it increases throughput by a factor of 122, decreases the delay by a factor of ten, and the percentage of dropped packages by 73 percent.
Ranking opinionated blog posts using OpinionFinder
Authors: Ben He, Craig Macdonald, Iadh Ounis
Venue: Proceedings of the 31st annual international ACM SIGIR conference on Research and development in information retrieval (2008)

The aim of an opinion finding system is not just to retrieve relevant documents, but to also retrieve documents that express an opinion towards the query target entity. In this work, we propose a way to use and integrate an opinion-identification toolkit, OpinionFinder, into the retrieval process of an Information Retrieval (IR) system, such that opinionated, relevant documents are retrieved in response to a query. In our experiments, we vary the number of top-ranked documents that must be parsed in response to a query, and investigate the effect on opinion retrieval performance and required parsing time. We find that opinion finding retrieval performance is improved by integrating OpinionFinder into the retrieval system, and that retrieval performance grows as more posts are parsed by OpinionFinder. However, the benefit eventually tails off at a deep rank, suggesting that an optimal setting for the system has been achieved.
Circular partitions with applications to visualization and embeddings
Authors: Krzysztof Onak, Anastasios Sidiropoulos
Venue: Proceedings of the twenty-fourth annual symposium on Computational geometry (2008)

We introduce a hierarchical partitioning scheme of the Euclidean plane, called circular partitions. Such a partition consists of a hierarchy of convex polygons, each having small aspect ratio, and satisfying specified volume constraints. We apply these partitions to obtain a natural extension of the popular Treemap visualization method. Our proposed algorithm is not constrained in using only rectangles, and can achieve provably better guarantees on the aspect ratio of the constructed polygons. Under relaxed conditions, we can also construct circular partitions in higher-dimensional spaces. We use these relaxed partitions to obtain improved approximation algorithms for embedding ultrametrics into d-dimensional Euclidean space. In particular, we give a polylog(Delta)-approximation algorithm for embedding n-point ultrametrics into R^d with minimum distortion (Delta denotes the spread of the metric). The previously best-known approximation ratio for this problem was polynomial in n [Badoiu et al. SoCG 2006]. This is the first algorithm for embedding a non-trivial family of weighted graph metrics into a space of constant dimension that achieves polylogarithmic approximation ratio.
Simulation for Wireless Sensor Networks with Intelligent Nodes
Authors: Frantisek Zboril Jr., Frantisek Zboril
Venue: Proceedings of the Tenth International Conference on Computer Modeling and Simulation (2008)

Purpose of simulations is mostly to prove correctness of system behavior by execution of a simulation model. Here we bring an approach how the simulation can be useful in the process of realization of systems with intelligent sensor nodes. To make models of these systems we adapted idea of distributed multi-agent system with particular demands that overcomes ordinary multi-agent systems. The work is focused onto mobility, agent size and interoperability. We bring experiences with implementation of agents for sensors with programmable ATMEL microcontrollers and usage of simulation in the process of realization of this type of networks.
Pipelining computations in a tree of processors
Authors: S. R. Kosaraju
Venue: Proceedings of the 30th Annual Symposium on Foundations of Computer Science (1989)

The computational power of a tree of processors is investigated. It is demonstrated that a tree of processors can solve certain problems impressively fast by exploiting the internal pipelining capabilities. Efficient tree algorithms are designed for two different problems: selection and maintaining dictionaries. It is shown that an O(log n)-height tree of processors can find the kth smallest element of n numbers in deterministic O((log n)/sup 2+o(1)/) steps, an impressive improvement over previous results. The main tools are the development of a new sampling technique and an elegant internal pipelining strategy. A lower bound is established for this selection problem. Another variant of the sampling technique reduces the storage requirement of R.M. Karp et al.'s (1986) tree searching algorithm while maintaining its speed. It is established that dictionary operations can be performed with a pipelined interval of O(1) and a response time of O(height of the tree), which again improves a known result and settles an open problem. This is based on being able to make the tree operate like a complete tree view from the root.
Transport Protocols for Wireless Sensor Networks: State-of-the-Art and Future Directions
Authors: Justin Jones, Mohammed Atiquzzaman
Venue: International Journal of Distributed Sensor Networks (2007)

Characteristics of wireless sensor networks, specifically dense deployment, limited processing power, and limited power supply, provide unique design challenges at the transport layer. Message transmission between sensor nodes over a wireless medium is especially expensive. Care must be taken to design an efficient transport layer protocol that combines reliable message delivery and congestion control with minimal overhead and retransmission. Sensor networks are created using low cost, low power nodes. Wireless sensors are assumed to have a finite lifetime; care must be taken to design and implement transport layer algorithms that allow maximum network lifetime. In this paper we present current and future challenges in the design of transport layers for sensor networks. Current transport layer protocols are compared based on how they implement reliable message delivery, congestion control, and energy efficiency.
Clustering in mobile ad hoc networks through neighborhood stability-based mobility prediction
Authors: Charalampos Konstantopoulos, Damianos Gavalas, Grammati Pantziou
Venue: Computer Networks: The International Journal of Computer and Telecommunications Networking (2008)

Clustering for mobile ad hoc networks (MANETs) offers a kind of hierarchical organization by partitioning mobile hosts into disjoint groups of hosts (clusters). However, the problem of changing topology is recurring and the main challenge in this technique is to build stable clusters despite the host mobility. In this paper, we present a novel clustering algorithm, which guarantees longer lifetime of the clustering structure in comparison to other techniques proposed in the literature. The basis of our algorithm is a scheme that accurately predicts the mobility of each mobile host based on the stability of its neighborhood (i.e., how different is its neighborhood over time). This information is then used for creating each cluster from hosts that will remain neighbors for sufficiently long time, ensuring the formation of clusters that are highly resistant to host mobility. For estimating the future host mobility, we use provably good information theoretic techniques, which allow on-line learning of a reliable probabilistic model for the existing host mobility.
Mining E-Commerce Data to Analyze the Target Customer Behavior
Authors: Yuantao Jiang, Siqin Yu
Venue: Proceedings of the First International Workshop on Knowledge Discovery and Data Mining (2008)

In the advent of the information era, e-commerce has developed rapidly and has become significant for every business. With the advanced information technologies, firms are now able to collect and store mountains of data describing their myriad offerings and diverse customer profiles, from which they seek to derive information about their customers' needs and wants. Traditional forecasting methods are no longer suitable for these business situations. This research used the principles of data mining to cluster customer segments by using K-Means algorithm and data from web log of various e-commerce websites. Consequently, the results showed that there was a clear distinction between the segments in terms of customer behavior.