ppxscal/embedding_network huggingface dataset:
Beyond 2D images: effective 3D imaging for library materials
Authors: Michael S. Brown, W. Brent Seales
Venue: Proceedings of the fifth ACM conference on Digital libraries (2000)

Significant efforts are being made to digitize rare and valuable library materials, with the goal of providing patrons and historians digital facsimiles that capture the "look and feel" of the original materials. This is often done by digitally photographing the materials and making high resolution 2D images available. The underlying assumption is that the objects are flat. However, older materials may not be flat in practice, being warped and crinkled due to decay, neglect, accident and the passing of time. In such cases, 2D imaging is insufficient to capture the "look and feel" of the original. For these materials, 3D acquisition is necessary to create a realistic facsimile. This paper outlines a technique for capturing an accurate 3D representation of library materials which can be integrated directly into current digitization setups. This will allow digitization efforts to provide patrons with more realistic digital facsimile of library materials.
Hierarchical A Posteriori Error Estimators for Mortar Finite Element Methods with Lagrange Multipliers
Authors: Barbara I. Wohlmuth
Venue: SIAM Journal on Numerical Analysis (1999)

Hierarchical a posteriori error estimators are introduced and analyzed for mortar finite element methods. A weak continuity condition at the interfaces is enforced by means of Lagrange multipliers. The two proposed error estimators are based on a defect correction in higher-order finite element spaces and an adequate hierarchical two-level splitting. The first provides upper and lower bounds for the discrete energy norm of the mortar finite element solution whereas the second also estimates the error for the Lagrange multiplier. It is shown that an appropriate measure for the nonconformity of the mortar finite element solution is the weighted L2-norm of the jumps across the interfaces.
A Boundary Functional for the Least-Squares Finite- Element Solution of Neutron Transport Problems
Authors: Thomas A. Manteuffel, Klaus J. Ressel, Gerhard Starke
Venue: SIAM Journal on Numerical Analysis (1999)

The least-squares finite-element framework for the neutron transport equation is based on the minimization of a least-squares functional applied to the properly scaled neutron transport equation. This approach is extended by incorporating the boundary conditions into the least-squares functional. The proof of the V-ellipticity and continuity of the new functional leads to bounds of the discretization error for different regimes. For a P1 approximation of the angular dependence the resulting system of partial differential equations for the moments is explicitly derived. In the diffusion limit this system is essentially a Poisson equation for the zeroth moment and has a divergence structure for the set of moments of order 1. One of the key features of the least-squares approach is that it produces a posteriori error bounds. The use of these bounds is demonstrated in numerical examples for a spatial discretization using trilinear finite elements on a uniform tessellation into cubes.
One Dimensional SDE Models, Low Order Numerical Methods and Simulation Based Estimation: A Comparison of Alternative Estimators
Authors: Eugene M. Cleur, Piero Manfredi
Venue: Computational Economics (1999)

We evaluate the effects of several discretization schemes on alternative estimators of the drift parameters of stochastic differential equations, namely the continuous time MLE, a so-called naive estimator and an indirect estimator obtained through calibration. Two main results are evidenced: first, the importance of correctly generating data in a simulation based estimation procedure and second, the role of an indirect estimation procedure through calibration as a general strategy to be used every time the conditions of the estimation experiment are not the optimal ones.
Videoconferencing on LANs: Issues and Proposals
Authors: Alan J. Weissberger
Venue: International Journal of Network Management (1996)

Progress in video coding, microprocessor and LAN switching technologies justify PC-based LAN videoconferencing. The key benefit is an improvement in productivity and savings in time and effort. This article reviews LAN video conferencing issues and and potential solutions.
Explanation component of software system
Authors: Bruce A. Wooley
Venue: Crossroads (1998)

Explanation is an important feature that needs to be integrated into software products. Early software that filled the horizontal software market (such as word processors) contained help systems. More specialized systems, known as expert systems, were developed to produce solutions that required specific domain knowledge of the problem being solved. The expert systems initially produced results that were consistent with the results produced by experts, but the expert systems only mimicked the rules the experts outlined. The decisions provided by expert systems include no justification, thus causing users to doubt the results reported by the system. If the user was dealing with a human expert, he could ask for a line of reasoning used to draw the conclusion. The line of reasoning provided by the human expert could then be inspected for discrepancies by another expert or verified in some other manner. Software systems need better explanations of how to use them and how they produce results. This will allow the users to take advantage of the numerous features being provided and increase their trust in the software product.
Handling very large databases with informix extended parallel server
Authors: Andreas Weininger
Venue: ACM SIGMOD Record (2000)

In this paper, we investigate which problems exist in very large real databases and describe which mechanisms are provided by Informix Extended Parallel Server (XPS) for dealing with these problems. Currently the largest customer XPS database contains 27 TB of data. A database server that has to handle such an amount of data has to provide mechanisms which allow achieving adequate performance and easing the usability. We will present mechanisms which address both of these issues and illustrate them with examples from real customer systems.
Mathematical Analysis of HIV-1 Dynamics in Vivo
Authors: Alan S. Perelson, Patrick W. Nelson
Venue: SIAM Review (1999)

Mathematical models have proven valuable in understanding the dynamics of HIV-1 infection in vivo. By comparing these models to data obtained from patients undergoing antiretroviral drug therapy, it has been possible to determine many quantitative features of the interaction between HIV-1, the virus that causes AIDS, and the cells that are infected by the virus. The most dramatic finding has been that even though AIDS is a disease that occurs on a time scale of about 10 years, there are very rapid dynamical processes that occur on time scales of hours to days, as well as slower processes that occur on time scales of weeks to months. We show how dynamical modeling and parameter estimation techniques have uncovered these important features of HIV pathogenesis and impacted the way in which AIDS patients are treated with potent antiretroviral drugs.
When bears are blue and bulls are red
Authors: Linda Alvord, Tama Traberman
Venue: Proceedings of the conference on APL '99 : On track to the 21st century: On track to the 21st century (1999)

Analysts deal with real numerical data. Often the data is collected over time. Because numbers are abstract, analysts often use graphs to make numerical data more meaningful. Real data typically fluctuates in some random fashion. However, patterns often exist in the data. An example would be the seasonal fluctuations in commodities. Analysts use a variety of techniques to help them find patterns that have the potential to improve their skill in predicting future trends. This paper suggests some ways to make some of these patterns more obvious.We are here presenting techniques to enhance traditional methods of providing information in graphs. By taking advantage of current computer technology to provide graphic images and to draw graphs, new and exciting visual images are possible. In addition, animation strategies allow us to simulate the passage of time. Finally, we add a whimsical touch.By animating the graphs of mathematical functions we illuminate aspects of the graphing process which might otherwise go unnoticed. The focus of this paper is on curve fitting. APL and J provide the matrix divide function for finding the coefficients of the constant, linear, quadratic, cubic or nth degree polynomial which best fit a collection of data.Each of these polynomials also has a polynomial derivative. These derivatives are useful for three reasons. Select a point on the x-axis. The y-value of the polynomial is the height of the polynomial for that x-value. But the y-value of the derived polynomial for the chosen x-value provides information about the original polynomial in three ways. First the y-value for the chosen x-value is the slope of the original polynomial at that point. The second useful aspect of the derivative is that positive and negative values indicate when the original polynomial is increasing or decreasing. A derivative is one degree less than the original polynomial so for example, a cubic polynomial has a quadratic polynomial derivative.Applications will demonstrate how the slope of the tangent together with the use of images and color can enhance the reader's ability to assimilate data. These enhancements give additional meaning to graphs and add life to the data.
Systematic Width-and-Length Dependent CMOS Transistor Mismatch Characterization and Simulation
Authors: Teresa Serrano-Gotarredona, Bernabé Linares-Barranco
Venue: Analog Integrated Circuits and Signal Processing (1999)

This paper presents a methodology for characterizing the random component of transistor mismatch in CMOS technologies. The methodology is based on the design of a special purpose chip which allows automatic characterization of arrays of NMOS and PMOS transistors of different sizes. Up to 30 different transistor sizes were implemented in the same chip, with varying transistors width W and length L. A simple strong inversion large signal transistor model is considered, and a new five parameters MOS mismatch model is introduced. The current mismatch between two identical transistors is characterized by the mismatch in their respective current gain factors &Delta;&beta;/&beta;, threshold voltages \Delta V_{T0}, bulk threshold parameters &Delta;&gamma;, and two components for the mobility degradation parameter mismatch \Delta \theta_{o} and \Delta \theta_{e}. These two components modulate the mismatch contribution differently, depending on whether the transistors are biased in ohmic or in saturation region. Using this five parameter mismatch model, an extraordinary fit between experimental and computed mismatch is obtained, including minimum length (1 &mu;m) transistors for both ohmic and saturation regions. Standard deviations for these five parameters are obtained as well as their respective correlation coefficients, and are fitted to two dimensional surfaces f(W, L) so that their values can be predicted as a function of transistor sizes. These functions are used in an electrical circuit simulator (Hspice) to predict transistor mismatch. Measured and simulated data are in excellent agreement.
Reflectance and texture of real-world surfaces
Authors: Kristin J. Dana, Bram van Ginneken, Shree K. Nayar, Jan J. Koenderink
Venue: ACM Transactions on Graphics (TOG) (1999)

In this work, we investigate the visual appearance of real-world surfaces and the dependence of appearance on the geometry of imaging conditions. We discuss a new texture representation called the BTF (bidirectional texture function) which captures the variation in texture with illumination and viewing direction. We present a BTF database with image textures from over 60 different samples, each observed with over 200 different combinations of viewing and illumination directions. We describe the methods involved in collecting the database as well as the importqance and uniqueness of this database for computer graphics. A related quantity to the BTF is the familiar BRDF (bidirectional reflectance distribution function). The measurement methods involved in the BTF database are conducive to simultaneous measurement of the BRDF. Accordingly, we also present a BRDF database with reflectance measurements for over 60 different samples, each observed with over 200 different combinations of viewing and illumination directions. Both of these unique databases are publicly available and have important implications for computer graphics.
Security issues in ATM networks
Authors: Danai Patiyoot, S. J. Shepard
Venue: ACM SIGOPS Operating Systems Review (1999)

This paper presents a survey of existing solutions aiming to secure communications over ATM network. Details are given about: the security services offered, their placement within ATM protocol reference model, the mechanism to negotiate security services, techniques to provides synchronisation and key exchange protocol. Additionally, this paper proposes a new ATM security solution.
Client-site query extensions
Authors: Tobias Mayr, Praveen Seshadri
Venue: Proceedings of the 1999 ACM SIGMOD international conference on Management of data (1999)

We explore the execution of queries with client-site user-defined functions (UDFs). Many UDFs can only be executed at the client site, for reasons of scalability, security, confidentiality, or availability of resources. How should a query with client-site UDFs be executed? We demonstrate that the standard execution technique for server-site UDFs performs poorly. Instead, we adapt well-known distributed database algorithms and apply them to client-site UDFs. The resulting query execution techniques are implemented in the Cornell Predator database system, and we present performance results to demonstrate their effectiveness. We also consider the question of query optimization in the context of client-site UDFs. The known techniques for expensive UDFs are inadequate because they do not take the location of the UDF into account. We present an extension of traditional 'System-R' optimizers that suitably optimize queries with client-site operations.
The effect of task conditions on the comprehensibility of synthetic speech
Authors: Jennifer Lai, David Wood, Michael Considine
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (2000)

A study was conducted with 78 subjects to evaluate the comprehensibility of synthetic speech for various tasks ranging from short, simple e-mail messages to longer news articles on mostly obscure topics. Comprehension accuracy for each subject was measured for synthetic speech and for recorded human speech. Half the subjects were allowed to take notes while listening, the other half were not. Findings show that there was no significant difference in comprehension of synthetic speech among the five different text-to-speech engines used. Those subjects that did not take notes performed significantly worse for all synthetic voice tasks when compared to recorded speech tasks. Performance for synthetic speech in the non note-taking condition degraded as the task got longer and more complex. When taking notes, subjects also did significantly worse within the synthetic voice condition averaged across all six tasks. However, average performance scores for the last three tasks in this condition show comparable results for human and synthetic speech, reflective of a training effect.
Type Safety in the Context of Method Updates
Authors: Zahir Tari, Xue Li, Ling Liu
Venue: Journal of Intelligent Information Systems (1999)

This paper presents a framework for checking and maintaining type safety in the presence of method evolution. A method update often affects all components of the method, including the inter face and the implementation. The type safety problem is addressed as two levels of type consistency. The first level relates to the type checking of methods in the context of the class inheritance hierarchy, and concerns the semantics of the polymorphism of methods. The second level considers the implementation parts of methods by capturing and preserving the semantics of the chain of calling relationships among relevant methods. A graph-based approach is used to achieve this two-level type consistency required at the level of class inheritance hierarchy and the level of method invocation. We demonstrate that the two levels of type consistency checking combined provide a better control of the run-time type error problems.
Optimization of constrained frequent set queries with 2-variable constraints
Authors: Laks V. S. Lakshmanan, Raymond Ng, Jiawei Han, Alex Pang
Venue: ACM SIGMOD Record (1999)

Currently, there is tremendous interest in providing ad-hoc mining capabilities in database management systems. As a first step towards this goal, in [15] we proposed an architecture for supporting constraint-based, human-centered, exploratory mining of various kinds of rules including associations, introduced the notion of constrained frequent set queries (CFQs), and developed effective pruning optimizations for CFQs with 1-variable (1-var) constraints. While 1-var constraints are useful for constraining the antecedent and consequent separately, many natural examples of CFQs illustrate the need for constraining the antecedent and consequent jointly, for which 2-variable (2-var) constraints are indispensable. Developing pruning optimizations for CFQs with 2-var constraints is the subject of this paper. But this is a difficult problem because: (i) in 2-var constraints, both variables keep changing and, unlike 1-var constraints, there is no fixed target for pruning; (ii) as we show, &ldquo;conventional&rdquo; monotonicity-based optimization techniques do not apply effectively to 2-var constraints. The contributions are as follows. (1) We introduce a notion of quasi-succinctness, which allows a quasi-succinct 2-var constraint to be reduced to two succinct 1-var constraints for pruning. (2) We characterize the class of 2-var constraints that are quasi-succinct. (3) We develop heuristic techniques for non-quasi-succinct constraints. Experimental results show the effectiveness of all our techniques. (4) We propose a query optimizer for CFQs and show that for a large class of constraints, the computation strategy generated by the optimizer is ccc-optimal, i.e., minimizing the effort incurred w.r.t. constraint checking and support counting.
Manual and gaze input cascaded (MAGIC) pointing
Authors: Shumin Zhai, Carlos Morimoto, Steven Ihde
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: the CHI is the limit (1999)

This work explores a new direction in utilizing eye gaze for computer input. Gaze tracking has long been considered as an alternative or potentially superior pointing method for computer input. We believe that many fundamental limitations exist with traditional gaze pointing. In particular, it is unnatural to overload a perceptual channel such as vision with a motor control task. We therefore propose an alternative approach, dubbed MAGIC (Manual And Gaze Input Cascaded) pointing. With such an approach, pointing appears to the user to be a manual task, used for fine manipulation and selection. However, a large portion of the cursor movement is eliminated by warping the cursor to the eye gaze area, which encompasses the target. Two specific MAGIC pointing techniques, one conservative and one liberal, were designed, analyzed, and implemented with an eye tracker we developed. They were then tested in a pilot study. This early- stage exploration showed that the MAGIC pointing techniques might offer many advantages, including reduced physical effort and fatigue as compared to traditional manual pointing, greater accuracy and naturalness than traditional gaze pointing, and possibly faster speed than manual pointing. The pros and cons of the two techniques are discussed in light of both performance data and subjective reports.
The employees' side of IS (panel session)
Venue: Proceedings of the 2000 ACM SIGCPR conference on Computer personnel research (2000)

The IS literature has almost always taken the perspective of the organization in addressing research issues. When we as researchers study productivity, benefits and competitive advantage, we almost always mean the benefits that accrue to the organization. Even such approaches as Socio-Technical systems and quality of work life have a decidedly company leaning. It is to the company's benefit that productivity etc. increase. Often, we go up one level and look at societal issues. What is left mostly untouched is the employees' side. What benefits do they get? How is an employee`s &ldquo;strategy&rdquo; and productivity that matters to the employee as an individual (as opposed to being a servant of the organization) enhanced? There is often an inherent conflict in the viewpoints and interests of the employee and the organization. In such instances, the interests of the organization almost always win out. The employee is left to suffer the negative consequences of management initiatives such as BPR and downsizing. It is appropriate that we should ask ourselves what is the individual getting out of advances in technology? Is her quality of life enhanced not as a member of the organization, but as an individual? Is she getting the benefit of productivity gains that IT brings? Is she bearing and unequal burden of IT-related negative consequences? Or worse, is she paying the price for organizational gain? The panel will try to sort through these issues. Obviously, we cannot provide many answers and solutions. But we will share our ideas and thoughts on these possibly contenious questions. Since we come from different corners of the globe, we will provide an international flavor to the issues. Essentially, we will broach three broad issues: What are the particular areas where the interests of the organization collide with those of the individual? What are we doing about it? What innovative ideas have emerged? What are we doing particularly well? What are we not doing well? What are the possible solutions to these?
Solvability of Consensus: Composition Breaks Down for NonDeterministic Types
Authors: Prasad Jayanti
Venue: SIAM Journal on Computing (1999)

Consensus, which requires processes with different input values to eventually agree on one of these values, is a fundamental problem in fault-tolerant computing. We study this problem in the context of asynchronous shared-memory systems. Prior research on consensus focused on its solvability using shared objects of specific types. In this paper, we investigate the following general question: Let T and T' be any two types. Consider the consensus problem among N processes. Suppose that this problem is unsolvable if processes may use only objects of any one type (T or T') for communication. Does it follow that the problem is unsolvable even if processes may use objects of both types? Recent results imply that the answer is positive if T and T' are both deterministic types. We prove that the answer is negative even if one of T and T' is nondeterministic.