ppxscal/embedding_network huggingface dataset:
Smoothness of Multiple Refinable Functions and Multiple Wavelets
Authors: Rong-Qing Jia, Sherman D. Riemenschneider, Ding-Xuan Zhou
Venue: SIAM Journal on Matrix Analysis and Applications (1999)

We consider the smoothness of solutions of a system of refinement equations written in the form $$\phi = \sum\nolimits_{\ga\in\ZZ} a(\ga)\phi({2\,\cdot}-\ga),$$ where the vector of functions $\phi=(\phi_1,\ldots,\phi_r)^T$ is in $(L_p(\mbox{\smallBbb R}))^r$ and a is a finitely supported sequence of r X r matrices called the refinement mask. We use the generalized Lipschitz space $\hbox{Lip}^*(\nu, L_p(\mbox{\smallBbb R}))$, $\nu > 0$, to measure smoothness of a given function. Our method is to relate the optimal smoothness, $\nu_p(\phi)$, to the $p$-norm joint spectral radius of the block matrices $A_\gep$, $\gep = 0, 1$, given by $A_\gep = ( a(\gep+2\ga-\gb) )_{\ga,\gb}$, when restricted to a certain finite dimensional common invariant subspace $V$. Denoting the $p$-norm joint spectral radius by $\rho_p(A_0|_V,A_1|_V)$, we show that $\nu_p(\phi) \ge 1/p - \log_2 \rho_p(A_0|_V, A_1|_V) $ with equality when the shifts of $\phi_1,\ldots,\phi_r$ are stable and the invariant subspace is generated by certain vectors induced by difference operators of sufficiently high order. This allows an effective use of matrix theory. Also the computational implementation of our method is simple.When p = 2, the optimal smoothness is also given in terms of the spectral radius of the transition matrix associated with the refinement mask. To illustrate the theory, we give a detailed analysis of two examples where the optimal smoothness can be given explicitly. We also apply our methods to the smoothness analysis of multiple wavelets. These examples clearly demonstrate the applicability and practical power of our approach.
A Periodic Review Inventory Model with Demand Influenced by Promotion Decisions
Authors: Feng Cheng, Suresh P. Sethi
Venue: Management Science (1999)

In this paper, we use a Markov decision process (MDP) to model the joint inventorypromotion decision problem. The state variable of the MDP represents the demand state brought about by changing environmental factors as well as promotion decisions. The demand state in a period determines the distribution of the random demand in that period. Optimal inventory and promotion decision policies in the finite horizon problem are obtained via dynamic programming. Under certain conditions, we show that there is a threshold inventory level P for each demand state such that if the threshold is exceeded, then it is desirable to promote the product. For the proportional ordering cost case, the optimal inventory replenishment policy is a base-stock type policy with the optimal base-stock level dependent on the promotion decision.
Towards usable VR: an empirical study of user interfaces for immersive virtual environments
Authors: Robert W. Lindeman, John L. Sibert, James K. Hahn
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: the CHI is the limit (1999)

This paper reports empirical results from a study into the use of 2D widgets in 3D immersive virtual environments. Several researchers have proposed the use of 2D interaction techniques in 3D environments, however little empirical work has been done to test the usability of such approaches. We present the results of two experiments conducted on low-level 2D manipulation tasks within an immersive virtual environment. We empirically show that the addition of passive-haptic feedback for use in precise UI manipulation tasks can significantly increase user performance. Furthermore, users prefer interfaces that provide a physical surface, and that allow them to work with interface widgets in the same visual field of view as the objects they are modifying.
On Hyperbolic Triangularization: Stability and Pivoting
Authors: Michael Stewart, G. W. Stewart
Venue: SIAM Journal on Matrix Analysis and Applications (1998)

This paper treats the problem of triangularizing a matrix by hyperbolic Householder transformations. The stability of this method, which finds application in block updating and fast algorithms for Toeplitz-like matrices, has been analyzed only in special cases. Here we give a general analysis which shows that two distinct implementations of the individual transformations are relationally stable. The analysis also shows that pivoting is required for the entire triangularization algorithm to be stable.
Managing the Topological Expansion of Computer Networks in an Optimal Way
Authors: Debashis Saha, Amitava Mukherjee
Venue: International Journal of Network Management (1996)

This article describes a subgradient-based near-optimal heuristic algorithm designed for minimizing the search of links that need to be added to an existing telecommunications network to enhance the survivability and routability of the network.
Application of intelligent agent technology for managerial data analysis and mining
Authors: Ranjit Bose, Vijayan Sugumaran
Venue: ACM SIGMIS Database (1999)

Data analysis and mining technologies help bring business intelligence into organizational decision support systems (DSS). While a myriad of data analysis and mining technologies are commercially available today, organizations are seeing a growing gap between powerful storage (data warehouse) systems and the business users' ability to analyze and act effectively on the information they contain. We contend that to narrow this gap effectively, a data analysis and mining environment is needed that can bring together and make available for use many of these technologies, that can support business users with different backgrounds, and with which the users can work comfortably.This paper illustrates the design and construction of such an environment, called the Intelligent Data Miner. IDM is Web-based and it is intended to provide an organization-wide decision support capability for business users. Intelligent agent technology is used as the basis for IDM design. IDM provides several types of data access capabilities to access and analyze the data contained in a data warehouse to obtain the critical information needed by business decision-makers. It supports both predefined and ad hoc data access, data analysis, data presentation, and data mining requests from non-technical users.An operational prototype of IDM, implemented using Java and JATLite (Java Agent Template, Lite from Stanford University), allowed us to examine the feasibility of having the "agents" automatically control and coordinate activities and tasks on the business users' behalf. These agents proved to hide the complexity of data analysis and mining activities, techniques, and methods from the business users, for effective use of the warehouse data.
Pontryagin's Principle for State-Constrained Control Problems Governed by Parabolic Equations with Unbounded Controls
Authors: J. P. Raymond, H. Zidani
Venue: SIAM Journal on Control and Optimization (1998)

This paper deals with optimal control problems governed by semilinear parabolic equations with pointwise state constraints and unbounded controls. Under some strong stability assumption, we obtain necessary optimality conditions in the form of a Pontryagin's minimum principle in qualified form. A Pontryagin's principle in nonqualified form is also proved without any stability condition.
A Linux kernel module implementation of restricted Ada tasking
Authors: Hongfeng Shen, Theodore P. Baker
Venue: Proceedings of the ninth international workshop on Real-time Ada (1999)

An Ada tasking kernel is implemented as a layer beneath the Linux operating system on a PC-compatible machine. This implementation is derived from Yodaiken's Real-Time Linux kernel, with new scheduling and synchronization primitives introduced specifically to support the GNAT Ada runtime system. Primitive operations for real-time Ada tasks are directly implemented on top of the underlying hardware in the form of a loadable Linux kernel module. This design not only reduces execution overhead and improves control over execution timing for tasks, but also opens the door for a simple restricted-tasking runtime system that could be certified for safety-critical applications.
Network performance modeling with NetArchitect&thinsp;&trade; get a grip!
Authors: Michael A. Salsburg
Venue: International Journal of Network Management (1997)

This article uses the traditional &lsquo;central server model&rsquo; as a starting point and proposes additional abstractions to build an extended, &lsquo;non-central server&rsquo; model. The model is implemented in a new product called NetArchitect&thinsp;&trade;. A real&hyphen;world problem is used as an example of the methodology. &copy; 1997 John Wiley Sons, Ltd.
Invited presentation: introns and modules in ancient conserved genes (abstract only)
Authors: Walter Gilbert
Venue: Proceedings of the fourth annual international conference on Computational molecular biology (2000)

We study the correlation between introns and modules, compact regions of protein structure, in genes whose products have a known 3-dimensional structre and which are homologous between bacteria and eukaryotes. Using two definitions of modules, we show that phase zero introns, those that lie between the codons, are significantly correlated with the boundaries of modules while introns that lie in phases one and two, that interrupt the codons are not so correlated. Furthermore, intron positions that are philogenetically ancient, matching between two kingdomes, are more correlated with module boundaries than are other positions. We will discuss the significance of these findings, which suggest that some of the phase zero introns are residues of the original construction of the genes while the phase one and two introns may have been added later in evolution. 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
Relaxing the Triangle Inequality in Pattern Matching
Authors: Ronald Fagin, Larry Stockmeyer
Venue: International Journal of Computer Vision (1998)

Any notion of &ldquo;closeness&rdquo; in pattern matching should have the property that if A is close to B, and B is close to C, then A is close to C. Traditionally, this property is attained because of the triangle inequality (d(A, C) &le; d(A, B) + d(B, C), where d represents a notion of distance). However, the full power of the triangle inequality is not needed for this property to hold. Instead, a &ldquo;relaxed triangle inequality&rdquo; suffices, of the form d(A, C) &le; c(d(A, B) + d(B, C)), where c is a constant that is not too large. In this paper, we show that one of the measures used for distances between shapes in (an experimental version of) IBM&lsquo;s QBIC1 (&ldquo;Query by Image Content&rdquo;) system (Niblack et al., 1993) satisfies a relaxed triangle inequality, although it does not satisfy the triangle inequality.
An exercise in evaluating significance of software quality criteria
Authors: Stanisław Szejko
Venue: ACM SIGCSE Bulletin (1999)

The paper presents an exercise in mapping user requirements to software quality model in order to disclose the product quality characteristics the developer should take special care of. House of Quality of the Quality Function Deployment method [1,2] has been adapted for dealing with system requirements.
Chat circles
Authors: Fernanda B. Viégas, Judith S. Donath
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: the CHI is the limit (1999)

Although current online chat environments provide new opportunities for communication, they are quite constrained in their ability to convey many important pieces of social information, ranging from the number of participants in a conversation to the subtle nuances of expression that enrich face to face speech. In this paper we present Chat Circles, an abstract graphical interface for synchronous conversa-tion. Here, presence and activity are made manifest by changes in color and form, proximity-based filtering intuitively breaks large groups into conversational clusters, and the archives of a conversation are made visible through an integrated history interface. Our goal in this work is to create a richer environment for online discussions.
Statistical Models for Text Segmentation
Authors: Doug Beeferman, Adam Berger, John Lafferty
Venue: Machine Learning (1999)

This paper introduces a new statistical approach to automatically partitioning text into coherent segments. The approach is based on a technique that incrementally builds an exponential model to extract features that are correlated with the presence of boundaries in labeled training text. The models use two classes of features: topicality features that use adaptive language models in a novel way to detect broad changes of topic, and cue-word features that detect occurrences of specific words, which may be domain-specific, that tend to be used near segment boundaries. Assessment of our approach on quantitative and qualitative grounds demonstrates its effectiveness in two very different domains, Wall Street Journal news articles and television broadcast news story transcripts. Quantitative results on these domains are presented using a new probabilistically motivated error metric, which combines precision and recall in a natural and flexible way. This metric is used to make a quantitative assessment of the relative contributions of the different feature types, as well as a comparison with decision trees and previously proposed text segmentation algorithms.
WebView materialization
Authors: Alexandros Labrinidis, Nick Roussopoulos
Venue: ACM SIGMOD Record (2000)

A WebView is a web page automatically created from base data typically stored in a DBMS. Given the multi-tiered architecture behind database-backed web servers, we have the option of materializing a WebView inside the DBMS, at the web server, or not at all, always computing it on the fly (virtual). Since WebViews must be up to date, materialized WebViews are immediately refreshed with every update on the base data. In this paper we compare the three materialization policies (materialized inside the DBMS, materialized at the web server and virtual) analytically, through a detailed cost model, and quantitatively, through extensive experiments on an implemented system. Our results indicate that materializing at the web server is a more scalable solution and can facilitate an order of magnitude more users than the virtual and materialized inside the DBMS policies, even under high update workloads.
Weak Univalence and Connectedness of Inverse Images of Continuous Functions
Authors: M. Seetharama Gowda, Roman Sznajder
Venue: Mathematics of Operations Research (1999)

A continuous function f with domain X and range f(X) in Rn is weakly univalent if there is a sequence of continuous one-to-one functions on X converging to f uniformly on bounded subsets of X. In this article, we establish, under certain conditions, the connectedness of an inverse image f-1(q). The univalence results of Radulescu-Radulescu, More-Rheinboldt, and Gale-Nikaido follow from our main result. We also show that the solution set of a nonlinear complementarity problem corresponding to a continuous P0-function is connected if it contains a nonempty bounded clopen set; in particular, the problem will have a unique solution if it has a locally unique solution.
Traversable interfaces between real and virtual worlds
Authors: Boriana Koleva, Holger Schnädelbach, Steve Benford, Chris Greenhalgh
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (2000)

Traversable interfaces establish the illusion that virtual and physical worlds are joined together and that users can physically cross from one to the other. Our design for a traversable interface combines work on tele-embodiment, mixed reality boundaries and virtual environments. It also exploits non-solid projection surfaces, of which we describe four examples. Our design accommodates the perspectives of users who traverse the interface and also observers who are present in the connected physical and virtual worlds, an important consideration for performance and entertainment applications. A demonstrator supports encounters between members of our laboratory and remote visitors.
A recursive algorithm for low-power memory partitioning
Authors: Luca Benini, Alberto Macii, Massimo Poncino
Venue: Proceedings of the 2000 international symposium on Low power electronics and design (2000)

Memory-processor integration offers new opportunities for reducing the energy of a system. In the case of embedded systems, one solution consists of mapping the most frequently accessed addresses onto the on-chip SRAM to guarantee power and performance efficiency. This option is especially effective when memory access patterns can be profiled and studied at design time (as in typical real-time embedded systems).In this work, we propose an algorithm for the automatic partitioning of on-chip SRAM in multiple banks that can be independently accessed. Starting from the dynamic execution profile of an embedded application running on a givenprocessor core, we synthesize a multi-banked SRAM architecture optimally fitted to the execution profile. The algorithm provides a globally optimum solution to the problem under realistic assumptions on the power cost metrics, and with constraints on the number of memory banks.Results, collected on a set of embedded applications for the ARM processor, have shown average energy savings around 42%.
The string B-tree: a new data structure for string search in external memory and its applications
Authors: Paolo Ferragina, Roberto Grossi
Venue: Journal of the ACM (JACM) (1999)

We introduce a new text-indexing data structure, the String B-Tree, that can be seen as a link between some traditional external-memory and string-matching data structures. In a short phrase, it is a combination of B-trees and Patricia tries for internal-node indices that is made more effective by adding extra pointers to speed up search and update operations. Consequently, the String B-Tree overcomes the theoretical limitations of inverted files, B-trees, prefix B-trees, suffix arrays, compacted tries and suffix trees. String B-trees have the same worst-case performance as B-trees but they manage unbounded-length strings and perform much more powerful search operations such as the ones supported by suffix trees. String B-trees are also effective in main memory (RAM model) because they improve the online suffix tree search on a dynamic set of strings. They also can be successfully applied to database indexing and software duplication.
Outcome of Case Management and Comprehensive Support Services Following Policy Changes in Mental Health Care Delivery
Authors: Robert J. Rydman, Dennis Trybus, Nikolai Butki, Linda M. Kampe, James A. Marley
Venue: Journal of Medical Systems (1999)

An assessment of policy toward the care of seriously mentally ill (SMI) persons residing in a suburban Chicago community was undertaken. Results indicated the SMI population was classically &ldquo;underserved.&rdquo; Few alternatives to a state inpatient hospital were being utilized. A policy change in SMI care was instituted by the local community mental health board which included implementation of the Unified Services Program (USP). The features of the USP were: centralized case management and outreach&semi; and an expansion of service philosophy into a comprehensive, multidisciplinary service model of mental health delivery. Methods: This study examined SMI service utilization, quality of life, and satisfaction with care outcomes following 12 months of USP exposure. Fifty percent of USP caseloads were randomly sampled for study participation. USP study results were compared to a large SMI population with similar exposures in another state. Results: 100% of USP SMI reported to be satisfied or very satisfied with their place of residence compared to the state hospital&semi; and 100% were satisfied or very satisfied with the USP overall. Eighty two to 100% of the study participants rated their status as better than before enrolling in USP. SMI utilized USP services, and service combinations which they find useful (88 to 100%)&semi; and felt they could not access their services without USP case managers or outreach. Compared to New York State SMI, study SMI reported similar scores, but superior ratings on &ldquo;services/facilities.&rdquo; Conclusion: The study supports use of the USP for SMI living in the community, and also identified areas for programmatic improvement.
Spike Based Normalizing Hebbian Learning in an Analog VLSI Artificial Neuron
Authors: Ph. Häfliger, M. Mahowald
Venue: Analog Integrated Circuits and Signal Processing (1999)

Recent neurophysiological results indicate that changes in synaptic efficacy are dependent on co-occurrence of a pre and a postsynaptic spike at the synapse [5,8]. There are only a few models of parts of the nervous system that use temporal correlation of single spikes in learning [1]. In most models of artificial neural networks neurons communicate by analog signals representing frequencies, and their learning rules are also defined on these continuous signals. Timing of single spikes is not used, nor is it represented. This simplification has proven useful in many applications and it makes simulations in software simpler and faster. Spiking systems have been avoided because they are computationally more difficult. However, by implementing spiking and learning artificial neurons in analog VLSI it is possible to examine the behavior of these more detailed models in real time. This is why ourselves and others [4] have started to use silicon models of spiking learning neurons. We have formulated one possible mechanism of weight normalization: a Hebbian learning rule that makes use of temporal correlations between single spikes. We have implemented it on a CMOS chip and demonstrate its normalizing behavior.
An adaptive on-chip voltage regulation technique for low-power applications
Authors: Nicola Dragone, Akshay Aggarwal, L. Richard Carley
Venue: Proceedings of the 2000 international symposium on Low power electronics and design (2000)

In this paper we present a completely on-chip voltage regulation technique which promises to adjust the degree of voltage regulation in a digital logic chip in the face of process induced delay variations so as to minimize energy dissipation while always guaranteeing the target operatingfrequency. For this purpose the delay of a critical path replica of the circuit being regulated is constantly compared with the target delay provide the regulator with the information needed to select the optimum voltage levels. The proposed solution is even more attractive in that no external components are required. Based on this scheme, a completely on-chip voltage regulator has been fabricated in a commercial 0.5&mgr;m CMOS process and used to generate the inner rail voltages for a DSP multiplier-accumulator (MAC) implemented in mixed swing QuadRail. Measured results indicate that the voltages generated by the regulator offer a very high degree of load regulation thus verifying the fast response time of the on-chip output buffer.
Compact roundtrip routing in directed networks (extended abstract)
Authors: Lenore J. Cowen, Christopher G. Wagner
Venue: Proceedings of the nineteenth annual ACM symposium on Principles of distributed computing (2000)

The first sublinear average space universal compact routing schemes for directed networks are presented. For each integer k &ge; 1, they use O(k log n) size addresses; O(kn 1/k+1)-sized routing tables on average at each node; and achieve roundtrip routes of stretch at most 2k+1-1 in any (weighted) directed network. We extend our results to yield universal compact roundtrip routing schemes with the stronger requirement that they use sublinear maximum space at every node. These schemes also use O(k log n) size addresses and achieve roundtrip routes of stretch at most 2k+1 - 1 in any (weighted) directed network, and they bound the maximum sized table at each node by O(kn 3k+1/2&middot;3k).