ppxscal/embedding_network huggingface dataset:
On the complexity of combinatorial auctions: structured item graphs and hypertree decomposition
Authors: Georg Gottlob, Gianluigi Greco
Venue: Proceedings of the 8th ACM conference on Electronic commerce (2007)

The winner determination problem in combinatorial auctions is the problem of determining the allocation of the items among the bidders that maximizes the sum of the accepted bid prices. While this problem is in general NP-hard, it is known to be feasible in polynomial time on those instances whose associated item graphs have bounded treewidth (called structured item graphs). Formally, an item graph is a graph whose nodes are in one-to-one correspondence with items, and edges are such that for any bid, the items occurring in it induce a connected subgraph. Note that many item graphs might be associated with a given combinatorial auction, depending on the edges selected for guaranteeing the connectedness. In fact, the tractability of determining whether a structured item graph of a fixed treewidth exists (and if so, computing one) was left as a crucial open problem.In this paper, we solve this problem by proving that the existence of a structured item graph is computationally intractable, even for treewidth 3. Motivated by this bad news, we investigate different kinds of structural requirements that can be used to isolate tractable classes of combinatorial auctions. We show that the notion of hypertree decomposition, a recently introduced measure of hypergraph cyclicity, turns out to be most useful here. Indeed, we show that the winner determination problem is solvable in polynomial time on instances whose bidder interactions can be represented with (dual) hypergraphs having bounded hypertree width. Even more surprisingly, we show that the class of tractable instances identified by means of our approach properly contains the class of instances having a structured item graph.
COPS--Collaborative Peer-to-Peer Information Systems Workshop Report
Authors: Michele Angelaccio, Andrea D'Ambrogio, Berta Buttarazzi
Venue: Proceedings of the 15th IEEE International Workshops on Enabling Technologies: Infrastructure for Collaborative Enterprises (2006)

The second International Workshop on Collaborative Peer-to-Peer Information Systems, COPS06 was held in Manchester University as part of WETICE-2006. It was the second meeting devoted to the study of the emerging field of Cooperative Information Systems and P2P networks or Cooperative P2P-based Information Systems (COPS). The first edition has been focused on trust management and middleware. This tendency has been confirmed in this second edition, but other important areas have been received attention. Among these COPS for real time and multimedia applications. In addition the service oriented approach is emerging as a unifying approach to describe COPS systems in a more technical way.
Interpolated 3-D digital waveguide mesh with frequency warping
Authors: L. Savioja
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2001. on IEEE International Conference - Volume 05 (2001)

An interpolated 3-D digital waveguide mesh algorithm is elaborated. We introduce an optimized technique that improves a formerly proposed interpolated 3-D mesh and renders the 3-D mesh more homogeneous in different directions. Frequency-warping techniques are used to shift the frequencies of the output signal of the mesh in order to cancel the effect of dispersion error. The extensions improve the accuracy of 3-D digital waveguide mesh simulations enough so that in the future it can be used for acoustical simulations needed in the design of listening rooms, for example.
Learning distance function by coding similarity
Authors: Aharon Bar Hillel, Daphna Weinshall
Venue: Proceedings of the 24th international conference on Machine learning (2007)

We consider the problem of learning a similarity function from a set of positive equivalence constraints, i.e. 'similar' point pairs. We define the similarity in information theoretic terms, as the gain in coding length when shifting from independent encoding of the pair to joint encoding. Under simple Gaussian assumptions, this formulation leads to a non-Mahalanobis similarity function which is efficient and simple to learn. This function can be viewed as a likelihood ratio test, and we show that the optimal similarity-preserving projection of the data is a variant of Fisher Linear Discriminant. We also show that under some naturally occurring sampling conditions of equivalence constraints, this function converges to a known Mahalanobis distance (RCA). The suggested similarity function exhibits superior performance over alternative Mahalanobis distances learnt from the same data. Its superiority is demonstrated in the context of image retrieval and graph based clustering, using a large number of data sets.
GPS receiver design for portable applications
Authors: Won Namgoong
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 06 (2000)

Although originally designed for the military, the Global Positioning System (GPS) has proven invaluable in a wide variety of civilian applications. This paper describes the design of a portable GPS receiver for use in numerous emerging applications such as cellular phones that integrate GPS to comply with the FCC's enhanced 911 mandate, personal locator systems for the elderly and children, and personal navigation systems. The focus of the GPS receiver design is on achieving low-power consumption and high level of integration, which are important design goals in a portable system.
Zero-forcing blind equalization based on channel subspace estimates for multiuser systems
Authors: Junqiang Shen
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 05 (1999)

The recovery of input signals in a frequency selective fading channel is a problem of great theoretical and practical interest. We present several new blind algorithms that utilize second order statistics for multichannel equalization. The algorithms are based on the subspace extraction of a preselected block column of the channel convolution matrix. For multiuser system, user signal separation can be achieved based on partial information of the composite channel response. The equalization algorithms do not rely on the signal and noise subspace separation and therefore tend to be more robust to channel order estimation errors.
Optimization of LAMMPS
Authors: James Fischer, Vincent Natoli, David Richie
Venue: Proceedings of the HPCMP Users Group Conference (2006)

The Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) code is part of the Department of Defense High Performance Computing Modernization Program (HPCMP) Technology Insertion (TI) benchmarking suite of applications. As a component of the TI benchmarking applications, LAMMPS is a significant contributor to Computational Chemistry and Materials Science requirements within the DoD. Ensuring its optimal performance on HPCMP resources is a high priority. The CCM-KY5-003 User Productivity Enhancements and Technology Transfer (PET) project was created to profile and optimize LAMMPS to improve its performance and efficiency on two HPCMP assets, Eagle (Altix 3700) and JVN (Linux Cluster).
Role of education, science and technology in developing countries
Authors: A. Bilsel, O. Oral
Venue: Proceedings of the Frontiers in Education Conference, on 1995. Proceedings., 1995 - Volume 02 (1995)

Emphasizes the importance of a science policy which assigns the highest priority to stimulating and supporting science education and research. The impact of such a policy on economic growth is discussed, and in this context, the policies of developed and developing countries are compared. Strategies and policies for developing countries are compared and the best ones are recommended. The state of engineering education in Turkey is summarized and compared with the American curriculum, as exemplified by electrical engineering.
Approximating the statistical distribution of color histogram for content-based image retrieval
Authors: W.-J. Kuo
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 04 (2000)

With the rapid development of multimedia technologies, the problem of how to retrieve a specified image from a large amount of image databases becomes an important issue. We propose a new method by approximating the statistical distribution of color histogram for image indexing and comparison. It becomes simple to compute the distance measure of two images by the proposed method. Also, our proposed method tolerates the generally considered problems when retrieving images such as transition, scaling and rotation. The represented features of the approximated distribution of the color histogram can also be used as the indices for the image database. Experimental results show that our proposed method is quite effective not only for the performance but also better results for image indexing and retrieval.
Domain Maps: Purposes, History, Parallels with Cartography, and Applications
Authors: Peter A. Hook
Venue: Proceedings of the 11th International Conference Information Visualization (2007)

This paper discusses the history of domain maps in the context of similar developments in the field of cartography. Drawing from its underlying definitions, this paper identifies the purposes of domain maps and discusses how they might specifically be applied in the field of education and as front-ends to digital libraries.
On the hyperplanes of the half-spin geometries and the dual polar spaces DQ(2n,K)
Authors: Bart De Bruyn
Venue: Journal of Combinatorial Theory Series A (2007)

We describe relationships between locally singular hyperplanes of the dual polar space DQ(2n,K), n>=2, and hyperplanes of the half-spin geometries HS(2n-1,K) and HS(2n+1,K) for the respective hyperbolic quadrics Q^+(2n-1,K) and Q^+(2n+1,K). We use these relationships to classify all hyperplanes of HS(9,K) and to provide a method for constructing locally singular hyperplanes of DQ(2n+2,K) from locally singular hyperplanes of DQ(2n,K). Along our way, we also obtain a new proof for the fact that all hyperplanes of the half-spin geometries arise from embeddings.
The Use of Watermark and Hash Function for the Authentication of Digital Images Mapped through the use of the Wavelet Transform
Authors: Fernanda B. Coelho, Jamil Salem Barbar, Gustavo S. B. do Carmo
Venue: Proceedings of the Second International Conference on Internet and Web Applications and Services (2007)

This paper presents a method for inserting a watermark in digital images through the mapping of its features using the wavelet transform. To achieve the lowest computational cost and provide security, the lifting scheme was chosen instead of filter banks, and hash functions with symmetric keys, respectively.
Looking for a haystack: selecting data sources in a distributed retrieval system
Authors: David B. Leake, Michael Gasser
Venue:  (2006)

The Internet contains billions of documents and thousands of systems for searching over these documents. Searching for a useful document can be as difficult as the proverbial search for a needle in a haystack. Each search engine provides access to a different collection of documents. Collections may be large or small, focused or comprehensive. Focused collections may be centered on any possible topic, and comprehensive collections typically have particular topical areas with higher concentrations of documents. Some of these collections overlap, but many documents are available from only a single collection. To find the most needles, one must first select the best haystacks. This dissertation develops a framework for automatic selection of search engines. In this framework, the collection underlying each search engine is examined to determine how properties such as central topic, size, and degree of focus affect retrieval performance. When measured with appropriate techniques, these properties may be used to predict performance. A new distributed retrieval algorithm that takes advantage of this knowledge is presented and compared to existing retrieval algorithms.
2-D binary locally monotonic regression
Authors: A. Restrepo
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 06 (1999)

We introduce binary locally monotonic regression as a first step in the study of the application of local monotonicity for image estimation. Given an algorithm that generates a similar locally monotonic image from a given image, we can specify both the scale of the image features retained and the image smoothness. In contrast to the median filter and to morphological filters, a locally monotonic regression produces the optimally similar locally monotonic image. Locally monotonic regression is a computationally expensive technique, and the restriction to binary-range signals allows the use of Viterbi-type algorithms. Binary locally monotonic regression is a powerful tool that can be used in the solution of image estimation, image enhancement, and image segmentation problems.
A Distributed Cache Coherence Protocol for Hypercube Multiprocessors
Authors: Yeimkunn Chang, Laxmi N. Bhuyan, Akhilesh Kumar
Venue: Proceedings of the 1994 International Conference on Parallel Processing - Volume 01 (1994)

This paper proposes a distributed directory cache coherence protocol and compares the performance of the proposed protocol with fully mapped and single linked list protocols for the hypercube multiprocessors. The directories of shared blocks are maintained as a tree structure which is motivated by the similarity of the indirect binary n-cube to the direct binary n-cube. The proposed protocol also takes advantage of the wormhole routing technique. Compared to the fully mapped and single linked list schemes, the proposed protocol reduces the memory reference latency and the network traffic.
Histogram-Based Dimensionality Reduction of Term Vector Space
Authors: Krzysztof Ciesielski, Mieczyslaw A. Klopotek, Slawomir T. Wierzchon
Venue: Proceedings of the 6th International Conference on Computer Information Systems and Industrial Management Applications (2007)

One of the most vital problems of free-text document processing is the curse of dimensionality. The paper presents a dimensionality reduction algorithm based on informed feature selection. Terms describing the document are based on histogram-like statistics which can be computed as well as incrementally updated at low complexity. The document representation can adapt to changing document collection characteristics. Along with the fundamental concepts we present an empirical verification of the approach.
PCA-PMC: a novel use of a priori knowledge for fast parallel model combination
Authors: R. Sarikaya
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 02 (2000)

This paper describes an algorithm to reduce computational complexity of the parallel model combination (PMC) method for robust speech recognition while retaining the same level of performance. Although, PMC is effective in composing a noise corrupted acoustic model from clean speech and noise models, the intense computational complexity limits its use in real-time use. The novel approach here is to encode the clean models using principal component analysis (PCA) and pre-compute the prototype vectors and matrices for the means and covariances in the linear spectral-domain using rectangular DCT and inverse DCT matrices. Therefore, transformation into the linear spectral domain is reduced to finding the projection of each vector in the eigen space of means and covariances followed by a linear combination of vectors and matrices obtained from the projections. Furthermore, the eigen space allows a better trade-off for reducing computational complexity versus accuracy. The computational savings are demonstrated both analytically and through experimental evaluations. Experiments using context independent phone recognition with TIMIT data shows that the new PMC framework can outperforms the baseline method by a factor of 1.9 with the same level of accuracy.
Stereo Matching and 3D Visualization for Gamma-Ray Cargo Inspection
Authors: Zhigang Zhu, Yu-Chi Hu
Venue: Proceedings of the Eighth IEEE Workshop on Applications of Computer Vision (2007)

In this paper, stereo matching and 3D visualization issues are studied for a linear pushbroom stereo model built for 3D gamma-ray (or x-ray) cargo inspection. A fast and automated stereo matching algorithm based on free-form deformable registration is developed to obtain 3D measurements of the objects under inspection. For facilitate stereo matching, an adaptive window min-max method is used to enhance the contrasts and boundaries of the challenging gammaray images. For fast implementation, a multi-resolution approach is also applied. A user interface is designed for interactive 3D measurements and visualization of the objects in interests. Experimental results are presented for real gamma-ray images of a 3D cargo container and the objects inside. The 3D measurements could add more value to today's cargo inspection techniques.
Synthesis of array architectures for block matching motion estimation: design exploration using the tool DG2VHDL
Authors: J. Bonk
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 04 (1999)

We present a design case study using DG2VHDL a tool which bridges the gap between an abstract graphical description of a DSP algorithm and its concrete hardware description language (HDL) representation, DG2VHDL automatically translates a dependence graph (DG) into a synthesizable, behavioral VHDL entity that can be input to industrial strength behavioral compilers for producing silicon implementations of the algorithm (FPGAs, ASICs). Full search block matching motion estimation was selected for its current applications (MPEG, HDTV, video conferencing) as well as for the richness of literature and architectural exploration over the last decade. We will not only demonstrate here that the behavioral VHDL code produced automatically by the tool leads, after behavioral synthesis, to an efficient distributed memory and control modular array architecture, but will also provide comparative statistics for several new FS-BMA architectures derived for real-time motion estimation.
Security vulnerabilities in DNS and DNSSEC
Authors: Suranjith Ariyapperuma, Chris J. Mitchell
Venue: Proceedings of the The Second International Conference on Availability, Reliability and Security (2007)

We present an analysis of security vulnerabilities in the Domain Name System (DNS) and the DNS Security Extensions (DNSSEC). DNS data that is provided by name servers lacks support for data origin authentication and data integrity. This makes DNS vulnerable to man in the middle (MITM) attacks, as well as a range of other attacks. To make DNS more robust, DNSSEC was proposed by the Internet Engineering Task Force (IETF). DNSSEC provides data origin authentication and integrity by using digital signatures. Although DNSSEC provides security for DNS data, it suffers from serious security and operational flaws. We discuss the DNS and DNSSEC architectures, and consider the associated security vulnerabilities.
A system to aid blind people in the mobility: A usability test and its results
Authors: Edoardo D'Atri, Carlo Maria Medaglia, Alexandru Serbanati, Ugo Biader Ceipidor, Emanuele Panizzi, Alessandro D'Atri
Venue: Proceedings of the Second International Conference on Systems (2007)

Blind people need to become as independent as possible in their daily life in order to guarantee a fully social inclusion. Mobility means the possibility of freely moving, without support of any accompanying person, at home, in public and private buildings, and in open spaces, as the streets of the town. Mobile and wireless technologies, and in particular the ones used to locate persons or objects, can be used to realize navigation systems in an intelligent environment. Such systems open new opportunities to improve the speed, easiness, and safety of the visually impaired persons mobility. Using these technologies together with Text To Speech systems and a mobilebased database the authors developed a cost effective, easy-to-use orientation and navigation system: RadioVirgilio/SesamoNet1. The cost effectiveness is due to the recovery of RFID identity tags from cattle slaughtering: these tags are then borrowed to create a grid used for navigation. In this paper the results of an usability analysis of this guide system are presented. A preliminary experiment involving a small group of experts and a blind person is described. In order to evaluate the usability, three cognitive walkthrough sessions have been done to discuss the system's basic functionality and to highlight the most critical aspects to be modified.
Telekom's MAGENTA algorithm for en-/decryption in the Gigabit/sec range
Authors: K. Huber
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 06 (1996)

The Deutsche Telekom is currently considering the development of an en-/decryption module for widespread (internal) usage. For this purpose a block-cipher algorithm has been developed by the Deutsche Telekom. The algorithm named MAGENTA which stands for Multifunctional Algorithm for General-purpose Encryption and Network Telecommunication Applications, is based on the shuffle signal-flow structure combined with non-linear operations. The module is planned to operate in the Gigabit/sec range for fast networks. For such high data rates there is a need of block-cipher hardware.