ppxscal/embedding_network huggingface dataset:
Integration of self-organizing maps with spatial indexing for efficient processing of multi-dimensional data
Authors: M. Zaremba, L. St-Laurent, O. Niemann, D. Richardson
Venue: Proceedings of the 8th ACM international symposium on Advances in geographic information systems (2000)

This paper investigates the integration of a class of adaptive soft-computing techniques and architectures with helical hyperspatial codes (HHCode) - indexing technology developed at Canadian Hydrographic Services - and their use in developing automated systems for processing of complex, multi-dimensional geo-spatial information, mainly multi-spectral satellite imagery, in a broader context of knowledge extraction and representation. The soft-computing methods investigated here involve fusion of techniques used in self-organizing maps (SOM - a class of unsupervised neural networks) and fuzzy logic. The topological relationships between the features - automatically extracted by SOM from multi-spectral images - are formed into a neural network in a meaningful order. The ordered features can later be interpreted and labeled according to the specific requirements of the application. Two SOM/HHCode integration architectures are proposed and discussed in the paper: closely-coupled integration where HHCode queries control the size of the neural network - in other words, the generalization level; and an architecture where HHCode is used to encode the results of clustering by SOM as well as the topological ordering of heterogeneous data encoded in the network. Results of tests performed on multi-spectral 20-m SPOT satellite images are given.
Automatic recording agent for digital video server
Authors: Atsuyoshi Nakamura, Naoki Abe, Hiroshi Matoba, Katsuhiro Ochiai
Venue: Proceedings of the eighth ACM international conference on Multimedia (2000)

We propose and evaluate the performance of a number of methods for automatic recording of TV programs for digital video servers, which estimate the user's preference over TV programs based on her/his past viewing behavior and automatically record a selected number of TV programs believed to be of interest to the user. Our methods combine the so-called content-based filtering and social (or collaborative) filtering methods and are based on a certain class of on-line learning algorithms known as the `specialist' algorithms, recently developed in the field of computational learning theory. We empirically evaluated the performance of content-based part of the proposed methods using preference data on TV programs consisting of scores given by people on actual TV programs. The results are largely encouraging and indicate in particular that our methods are practical in terms of both the precision in predicting the user's preference and computational complexity.
Detecting video shot boundaries up to 16 times faster (poster session)
Authors: Kien A. Hua, JungHwan Oh
Venue: Proceedings of the eighth ACM international conference on Multimedia (2000)

Shot boundary detection (SBD) is the first fundamental step to managing video databases. Existing automatic SBD techniques, however, are based on sequential search, and therefore too expensive for practical use. To address this problem, we investigate a non-linear approach in which most video frames do not need to be compared. It can improve their performance substantially. Our experiments show that this idea speeds up a conventional method based on color histograms up to 16 times (five times on average) while preserving the same accuracy.
Gene-finding via tandem mass spectrometry
Authors: Ting Chen
Venue: Proceedings of the fifth annual international conference on Computational biology (2001)

We propose a new gene-finding methodology that combines high performance liquid chromatograph (HPLC)-tandem mass spectrometry experiments with a fast computer algorithm to locate coding regions and introns. Proteins are first extracted from cells and digested by enzymes, and then the resulting peptides are separated and analyzed by HPLC-tandem mass spectrometry. We designed an algorithm to find DNA coding sequences, corresponding to open reading frames (ORF), in the genome such that their translated amino acid sequences are optimally correlated with these tandem mass spectra. In this algorithm, we also allow one gap, corresponding to an intron, between two DNA coding sequences, such that their concatenation becomes one coding sequence. Finally, the algorithm assembles these candidate coding sequences and introns into gene structures. Our algorithm was implemented to predict genes on 4 contigs with a total of 123 kbps using two sets of simulated digestion- HPLC-tandem mass spectrometry data of 2523 Caenorhabditis elegans Chromosome IV proteins, digested by trypsin and Asp-N respectively. Among 15 annotated genes in the forward strand, all 98 exons are hit by the predicted no-gap coding sequences, and 60 out of 83 introns are correctly predicted. We also tested gene structure prediction in a contig containing 3 genes. Combining splicing site predictions with predicted coding sequences and introns, we found all 3 gene structures.
Recursive data structures in APL
Authors: W. E. Gull, M. A. Jenkins
Venue: Communications of the ACM (1979)

A mathematical study of three approaches for defining nested arrays in APL is presented. Theorems exhibiting the relationships between the definitional systems are given and illustrated through graph representations. One of the approaches is used to define an APL array to be a recursive data structure equivalent to a tree structure in which all data is stored at the leaves as homogeneous arrays of numbers and characters. An extension of APL is proposed that includes new primitive functions to manipulate the nesting level of arrays and new operators to assist in the construction of data-driven algorithms.
The ELDer project: social, emotional, and environmental factors in the design of eldercare technologies
Authors: Tad Hirsch, Jodi Forlizzi, Elaine Hyder, Jennifer Goetz, Chris Kurtz, Jacey Stroback
Venue: Proceedings on the 2000 conference on Universal Usability (2000)

The ELDeR (Enhanced Living through Design Research) Project, comprised of a team of designers and behavioral scientists, conducted a four-month study at a seniors community near Pittsburgh, PA. The purpose of the project was to understand the experiences of elders and their caregivers in order to: 1) study the eldercare experience from the perspective of primary stakeholders; 2) to assess the importance of psychological and social factors in the eldercare experience; and 3) to identify implications for product, interface, and interaction design and opportunities for new products and technologies. Our findings show that social, emotional, and environmental factors play a key role in the eldercare experience and the adoption and use of new products. We argue that designing eldercare technologies to address all of these factors lowers social and economic barriers to universal usability.
On the evolution of videotext description scheme and its validation experiments for MPEG-7
Authors: Chitra Dorai, Ruud Bolle, Nevenka Dimitrova, Lalitha Agnihotri, Gang Wei
Venue: Proceedings of the 2000 ACM workshops on Multimedia (2000)

Videotext refers to text superimposed on still images and video frames, and can be used in many MPEG-7 applications that deal with archival and delivery of images and video. It can be used to annotate and index large video and image collections, and enables text based search, automatic video logging, and video cataloging. This paper describes the joint work of IBM and Philips Research Laboratories on designing an MPEG-7 description scheme based on videotext. It describes the elements comprising the Videotext DS and discusses validation experiments performed to demonstrate the effectiveness of the DS in video browsing and classification tasks.
MCM interconnect design using two-pole approximation
Authors: J. Shao, R. M. M. Chen
Venue: Proceedings of the conference on Design, automation and test in Europe (1998)

In this paper, an optimization scheme is proposed for interconnect design with wire width and series resistance being design variables. Due to the distributed nature of interconnects, poles of such systems are transcendental and infinite in number. First, a two-pole approximation is used to capture the system behavior. Lower-order moments are employed to obtain two approximate dominant poles. Then, the two parameters, damping ratio and natural undamped frequency, are expressed as functions of the two dominant poles. Since the output response is characterized by the two parameters, the parameters are used to define the objective function and constraints, which form a constrained multivariable nonlinear optimization problem. After that, the optimization problem is solved using gradient projection method. One advantage of our approach is the ability to explicitly control the maximum overshoot of the observation points. Two numerical examples are given.
Structural Operational Semantics for a Portable Subset of Behavioral VHDL-93
Authors: Krishnaprasad Thirunarayan, Robert L. Ewing
Venue: Formal Methods in System Design (2001)

Goossens defined structural operational semantics for a subset of VHDL-87 and proved that the parallelism present in VHDL is benign. We extend this work to include VHDL-93 features such as shared variables and postponed processes that change the underlying semantic model. In the presence of shared variables, non-deterministic execution of VHDL-93 processes destroys the unique meaning property. We identify and characterize a class of portable VHDL-93 descriptions for which unique meaning property can be salvaged. We analyze the computability of the portability condition and show that portability checks are neither local nor static. Our formal specification can serve as a correctness criteria for a VHDL-93 simulator or can be used as a basis for coding a simulator.
Secure personal computing in an insecure network
Authors: Dorothy E. Denning
Venue: Communications of the ACM (1979)

A method for implementing secure personal computing in a network with one or more central facilities is proposed. The method employs a public-key encryption device and hardware keys. Each user is responsible for his own security and need not rely on the security of the central facility or the communication links. A user can safely store confidential files in the central facility or transmit confidential data to other users on the network.
Integrating object-oriented programming and protected objects in Ada 95
Authors: A. J. Wellings, B. Johnson, B. Sanden, J. Kienzle, T. Wolf, S. Michell
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (2000)

Integrating concurrent and object-oriented programming has been an active research topic since the late 1980's. There is a now a plethora of methods for achieving this integration. The majority of approaches have taken a sequential object-oriented language and made it concurrent. A few approaches have taken a concurrent language and made it object-oriented. The most important of this latter class is the Ada 95 language, which is an extension to the object-based concurrent programming language Ada 83. Arguably, Ada 95 does not fully integrate its models of concurrency and object-oriented programming. For example, neither tasks nor protected objects are extensible. This article discusses ways in which protected objects can be made more extensible.
UPLIFTS&mdash;University of Pittsburgh linear file tandem system
Authors: J. D. Canter, C. E. Donaghey
Venue: Communications of the ACM (1965)

A series of computer programs has been developed and is now operational for processing the National Aeronautics and Space Administration linear file system on an IBM 1401-7090 combined data processing system. The programs are noteworthy in that they create fixed length logical records and fixed length blocks from variable length source data, and format the output for optimization of processing on the IBM 7090 system. The programs are completely self-checking and test for both validity and accuracy of the input materials as provided by the National Aeronautics and Space Administration.
Distance labeling in graphs
Authors: Cyril Gavoille, David Peleg, Stéphane Pérennes, Ran Raz
Venue: Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms (2001)

We consider the problem of labeling the nodes of a graph in a way that will allow one to compute the distance between any two nodes directly from their labels (without using any additional information). Our main interest is in the minimal length of labels needed in different cases. We obtain upper bounds and (most importantly) lower bounds for several interesting families of graphs. In particular, our main results are the following: For general graphs, the length needed is &THgr;(n). For trees, the length needed is &THgr;(log2 n). For planar graphs, we show an upper bound of &Ogr;(&radic;n log n) and a lower bound of &OHgr;(n1/3). For bounded degree graphs, we show a lower bound of &OHgr;(&radic;n). The upper bounds for planar graphs and for trees follow by a more general upper bound for graphs with a r(n)- separator. The two lower bounds, however, are obtained by two different arguments that may be interesting in their own right. We also show some lower bounds on the length of the labels, even if it is only required that distances be approximated to a multiplicative factor s. For example, we show that for general graphs the required length is &OHgr;(n). We also consider the problem of the time complexity of the distance function once the labels are computed. We show that there are graphs with optimal labels of length 3 log n, such that if we use any labels with fewer than n bits per label, computing the distance function requires exponential time. A similar result is obtained for planar and bounded degree graphs.
QMESH: an interactive visualization tool for quadrilateral mesh-generation
Authors: Michael Orr
Venue: Journal of Computing Sciences in Colleges (2001)

QMesh, my undergraduate research project, involves the design, implementation, and experimental evaluation of algorithmic techniques for quadrilateral mesh-generation. A large percentage of this project is the study of techniques for converting triangulations to quadrangulations. This paper is geared towards the understanding of implementation issues that are involved in computing the triangulation of a simple polygon and its dual tree, which are necessary procedures for computing a quadrangulation.
Role-based access control on the web
Authors: Joon S. Park, Ravi Sandhu, Gail-Joon Ahn
Venue: ACM Transactions on Information and System Security (TISSEC) (2001)

Current approaches to access control on the Web servers do not scale to enterprise-wide systems because they are mostly based on individual user identities. Hence we were motivated by the need to manage and enforce the strong and efficient RBAC access control technology in large-scale Web environments. To satisfy this requirement, we identify two different architectures for RBAC on the Web, called user-pull and server-pull. To demonstrate feasibility, we implement each architecture by integrating and extending well-known technologies such as cookies, X.509, SSL, and LDAP, providing compatibility with current web technologies. We describe the technologies we use to implement RBAC on the Web in different architectures. Based on our experience, we also compare the tradeoffs of the different approaches.
At the Forge: Configuring, Tuning, and Debugging Apache
Authors: Reuven M. Lerner
Venue: Linux Journal (2000)

Reuven writes about what tools and techniques Webmasters can use when trying to configure, tune, and debug their Apache configurations. 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
The case for profile-directed selection of garbage collectors
Authors: Robert Fitzgerald, David Tarditi
Venue: Proceedings of the 2nd international symposium on Memory management (2000)

Many garbage-collected systems use a single garbage collection algorithm across all applications. It has long been known that this can produce poor performance on applications for which that collector is not well suited. In some systems, such as those that execute stand-alone compiled executables, an appropriate collector for each application can be selected from a pool of available collectors and tuned by using profile information. In a study of 20 benchmarks and several collectors, compiled with the Marmot optimizing Java-to-native compiler, for every collector there was at least one benchmark that would have been at least 15% faster with a more appropriate collector. The collectors are a copying collector, a generational copying collector, which is combined with each of 4 different write barriers, and the null collector, which allocates but never collects. A detailed analysis of storage management costs shows how they vary by application and collector.
All Lambda-Designs With \lambda = 2 p areType-1
Authors: Akos Seress
Venue: Designs, Codes and Cryptography (2001)

A \lambda-design is a family B_1,B_2,\ldots,B_v of subsets of X=\{ 1,2,\ldots,v \} such that | B_i \cap B_j | = \lambda for all i \neq j and not all B_i are of the same size. Ryser's and Woodall's \lambda-design conjecture states that each \lambda-design can be obtained from a symmetric block design by a certain complementation procedure. Our main result is that the conjecture is true when \lambda is twice a prime number.
A new integration algorithm for ordinary differential equations based on continued fraction approximations
Authors: I. M. Willers
Venue: Communications of the ACM (1974)

A new integration algorithm is found, and an implementation is compared with other programmed algorithms. The new algorithm is a step-by-step procedure for solving the initial value problem in ordinary differential equations. It is designed to approximate poles of small integer order in the solutions of the differential equations by continued fractions obtained by manipulating the sums of truncated Taylor series expansions. The new method is compared with the Gragg-Bulirsch-Stoer, and the Taylor series method. The Taylor series method and the new method are shown to be superior in speed and accuracy, while the new method is shown to be most superior when the solution is required near a singularity. The new method can finally be seen to pass automatically through singularities where all the other methods which are discussed will have failed.
A tool for simulation and fast prototyping of embedded control systems
Authors: Luigi Palopoli, Guiseppe Lipari, Luca Abeni, Marco Di Natale, Paolo Ancilotti, Fabio Conticelli
Venue: Proceedings of the ACM SIGPLAN workshop on Languages, compilers and tools for embedded systems (2001)

This paper presents a set of C++ libraries, called RTSIM, aimed at realizing a joint simulation of a continuous plant and of a real-time embedded controller. The libraries permit a separate specification of the functional behaviour of the controller and of the software platform to be used for its deployment. In particular, it is possible to provide an accurate modeling of the concurrent architecture of the control tasks and of the run-time support offered by the operating system for the real-time scheduling of the shared resources (CPU, memory buffers, network links). In this way, its is possible to compare different scheduling solutions by evaluating their simulated performance in the domain of the control application. Moreover, the tool can be utilized to tune up such design parameters as the activation frequencies of the tasks. The application of the tool is shown on a meaningful robotic case-study.
N-Dimensional Phase Approximation in the L_\infty-Norm
Authors: Wasfi S. Kafri, Wael Hashlamoun
Venue: Multidimensional Systems and Signal Processing (2000)

The phase functions of N-dimensional (N-D) digital all-pass filters are investigated to approximate a prescribed phase response in a frequency region. The set of phase functions of the all-pass filters have common properties with some nonlinear approximating functions. This similarity answers the question of characterization of minimal approximation in the set of phase functions. The optimal approximation is characterized by known theorems of Tschebycheff Approximation Theory. Among the main tools of the theory, the Global and Local Kolmogoroff Criteria, are shown to give necessary and sufficient conditions for best approximations in the phase functions of N-D all-pass filters. Moreover, this best approximation in the phase functions is shown to be a global minimum. The approximation on discrete point sets ( H- sets) in a compact multidimensional domain is studied. Optimal N-dimensional approximation is not unique, an inherent property of functions of several variables.
Space Curve Representation and Recognition Based on Wavelet Transform Zero-Crossings
Authors: Quang Minh Tieng, W. W. Boles
Venue: Journal of Mathematical Imaging and Vision (2000)

A method to construct a representation of space curves based on the zero-crossings of the dyadic wavelet transform is introduced. The principal axes of inertia of these space curves, referred to as objects, are considered as the reference system. The representation is translation, rotation and size invariant. Instances of objects in images are recognised by matching their representations with those of the models. A string-matching technique is adapted and used for this purpose. Experimental results show that the representation is robust and efficient in extracting and matching object information.
Patent protection of computer programs
Authors: Morton C. Jacobs
Venue: Communications of the ACM (1964)

Recently, the computer industry has been exploring anew the question of whether programs for operating an electronic digital computer are or should be patentable.
Recursive computation of certain derivatives a study of error propagation
Authors: Walter Gautschi, Bruce J. Klein
Venue: Communications of the ACM (1970)

A brief study is made of the propagation of errors in linear first-order difference equations. The recursive computation of successive derivatives of ex/x and (cos x)/x is considered as an llustration.
Asymptotic Analysis of Congested Communication Networks
Authors: J. Frédéric Bonnans, Mounir Haddoucomo
Venue: Mathematics of Operations Research (2000)

This paper is devoted to the mathematical study of a routing problem in telecommunication networks, when the cost function is the average delay of communications. We establish asymptotic expansions for the value function and solutions in the vicinity of a congested nominal problem. The study is strongly related to the one of a partial inverse barrier method for linear programming.