ppxscal/embedding_network huggingface dataset:
Parallelism versus memory allocation in pipelined router forwarding engines
Authors: Fan Chung, Ronald Graham, George Varghese
Venue: Proceedings of the sixteenth annual ACM symposium on Parallelism in algorithms and architectures (2004)

A crucial problem that needs to be solved is the allocation of memory to processors in a pipeline. Ideally, the processor memories should be totally separate (i.e., one port memories) in order to minimize contention; however, this minimizes memory sharing. Idealized sharing occurs by using a single shared memory for all processors but this maximizes contention. Instead, in this paper we show that perfect memory sharing of shared memory can be achieved with a collection of *two*-port memories, as long as the number of processors is less than the number of memories. We show that the problem of allocation is NP-complete in general, but has a fast approximation algorithm that comes within a factor of 3/2. The proof utilizes a new bin packing model, which is interesting in its own right. Further, for important special cases that arise in practice the approximation algorithm is indeed optimal. We also describe an incremental memory allocation algorithm that provides good memory utilization while allowing fast updates.
Retiming with Interconnect and Gate Delay
Authors: Chris Chu, Evangeline F. Y. Young, Dennis K. Y. Tong, Sampath Dechu
Venue: Proceedings of the 2003 IEEE/ACM international conference on Computer-aided design (2003)

In this paper, we study the problem of retiming of sequential circuitswith both interconnect and gate delay. Most retiming algorithms haveassumed ideal conditions for the non-logical portions of the datapaths, which are not sufficiently accurate to be used in high performancecircuits today. In our modeling, we assume that the delay ofa wire is directly proportional to its length. This assumption is reasonablesince the quadratic component of a wire delay is significantlysmaller than its linear component when the more accurate Elmore delaymodel is used. A simple experiment is conducted to illustrate thevalidity of this assumption. We present two approaches to solve thisproblem, both of which have polynomial time complexity. The firstone can compute the optimal clock period while the second one isan improvement over the first one in terms of practical applicability.The second approach gives solutions very close to the optimal (0.13%more than the optimal on average) but in a much shorter runtime.A circuit with more than 22K gates and 32K wires can be optimallyretimed in 83.56 seconds by a PC with an 1.8GHz Intel Xeon processor.
Security Fundamentals
Authors: Hector Zenil Chávez
Venue: IEEE Distributed Systems Online (2004)

A review of Practical Unix & Internet Security, 3rd edition by Simson Garfinkel, Gene Spafford, and Alan Schwartz.
Autonomic defense: thwarting automated attacks via real-time feedback control
Authors: Derek Armstrong, Sam Carter, Gregory Frazier, Tiffany Frazier
Venue: Complexity (2003)

A critical threat to organizations, and the Internet itself, is a class of automated network attacks referred to as Internet worms. This article examines the use of mathematical models and optimization algorithms--specifically a partially-observable Markov decision process (PO-MDP) based feedback control system--as the basis for implementing an autonomic defense system (ADS) that can protect organizations against Internet worms. The PO-MDP ADS introduced in this article is capable of detecting and responding to worms in real time. Furthermore, the PO-MDP ADS can ameliorate the rate of incorrect control decisions that would normally occur in the presence of sensor false alarms.
Querying at Internet scale
Authors: Brent Chun, Joseph M. Hellerstein, Ryan Huebsch, Shawn R. Jeffery, Boon Thau Loo, Sam Mardanbeigi, Timothy Roscoe, Sean Rhea, Scott Shenker, Ion Stoica
Venue: Proceedings of the 2004 ACM SIGMOD international conference on Management of data (2004)

We are developing a distributed query processor called PIER, which is designed to run on the scale of the entire Internet. PIER utilizes a Distributed Hash Table (DHT) as its communication substrate in order to achieve scalability, reliability, decentralized control, and load balancing. PIER enhances DHTs with declarative and algebraic query interfaces, and underneath those interfaces implements multihop, in-network versions of joins, aggregation, recursion, and query/result dissemination. PIER is currently being used for diverse applications, including network monitoring, keyword-based filesharing search, and network topology mapping. We will demonstrate PIER's functionality by showing system monitoring queries running on PlanetLab, a testbed of over 300 machines distributed across the globe.
An extension of the technology acceptance model in an ERP implementation environment
Authors: Kwasi Amoako-Gyampah, A. F. Salam
Venue: Information and Management (2004)

This paper presents an extension to the technology acceptance model (TAM) and empirically examines it in an enterprise resource planning (ERP) implementation environment. The study evaluated the impact of one belief construct (shared beliefs in the benefits of a technology) and two widely recognized technology implementation success factors (training and communication) on the perceived usefulness and perceived ease of use during technology implementation. Shared beliefs refer to the beliefs that organizational participants share with their peers and superiors on the benefits of the ERP system.Using data gathered from the implementation of an ERP system, we showed that both training and project communication influence the shared beliefs that users form about the benefits of the technology and that the shared beliefs influence the perceived usefulness and ease of use of the technology. Thus, we provided empirical and theoretical support for the use of managerial interventions, such as training and communication, to influence the acceptance of technology, since perceived usefulness and ease of use contribute to behavioral intention to use the technology.
An English pronunciation learning system for Japanese students based on diagnosis of critical pronunciation errors
Authors: Yasushi Tsubota, Masatake Dantsuji, Tatsuya Kawahara
Venue: ReCALL (2004)

We have developed an English pronunciation learning system which estimates the intelligibility of Japanese learners' speech and ranks their errors from the viewpoint of improving their intelligibility to native speakers. Error diagnosis is particularly important in self-study since students tend to spend time on aspects of pronunciation that do not noticeably affect intelligibility. As a preliminary experiment, the speech of seven Japanese students was scored from 1 (hardly intelligible) to 5 (perfectly intelligible) by a linguistic expert. We also computed their error rates for each skill. We found that each intelligibility level is characterized by its distribution of error rates. Thus, we modeled each intelligibility level in accordance with its error rate. Error priority was calculated by comparing students' error rate distributions with that of the corresponding model for each intelligibility level. As non-native speech is acoustically broader than the speech of native speakers, we developed an acoustic model to perform automatic error detection using speech data obtained from Japanese students. As for supra-segmental error detection, we categorized errors frequently made by Japanese students and developed a separate acoustic model for that type of error detection. Pronunciation learning using this system involves two phases. In the first phase, students experience virtual conversation through video clips. They receive an error profile based on pronunciation errors detected during the conversation. Using the profile, students are able to grasp characteristic tendencies in their pronunciation errors which in effect lower their intelligibility. In the second phase, students practise correcting their individual errors using words and short phrases. They then receive information regarding the errors detected during this round of practice and instructions for correcting the errors. We have begun using this system in a CALL class at Kyoto University. We have evaluated system performance through the use of questionnaires and analysis of speech data logged in the server, and will present our findings in this paper.
A unified model of literal mining and link analysis for ranking web resources
Authors: Yinghui Xu, Kyoji Umemura
Venue: Proceedings of the 27th annual international ACM SIGIR conference on Research and development in information retrieval (2004)

Web link analysis has been proved to provide significant enhancement to the precision of Web search in practice. The PageRank algorithm, which is used in Google Search Engine, plays an important role on improving the quality of its resuls by employing the explicit hyperlink structure among the Web pages. The prestige of Web pages defined by PageRank is purely derived from surfer random walk on the Web graph without textual content content consideration. However, in the practical sense, user surfing behavior is far from random jumping. In this paper, we present a unified model for a more accurate page rank. User's surfing is guided by a probabilistic model that is based on literal matching between connected pages. The result shows that our proposed ranking algorithms do perform better than the original PageRank.
Object representation using 1D displacement mapping
Authors: Yi Xu, Yee-Hong Yang
Venue: Proceedings of Graphics Interface 2004 (2004)

In this paper, we propose a new method for rendering image-based objects. An object is decomposed into a set of 1D displacement textures in a preprocessing stage. During rendering, each of these 1D displacement textures is rendered to its appropriate position in 3D space, using the hardware accelerated displacement mapping approach. Our method can represent and render complex objects with accurate appearance from arbitrary viewpoints. It can also render a complex object at a high frame rate, using commodity graphics hardware. The 1D displacement texture set is reconstructed from the images with depth maps.
An Effective Methodology to Improve the Performance of the Up*/Down* Routing Algorithm
Authors: Jose C. Sancho Antonio Robles, Jose Duato
Venue: IEEE Transactions on Parallel and Distributed Systems (2004)

Networks of workstations (NOWs) are being considered as a cost-effective alternative to parallel computers. Most NOWs are arranged as a switch-based network and provide mechanisms for discovering the network topology. Hence, they provide support for both regular and irregular topologies, which makes routing and deadlock avoidance quite complicated. Current proposals use the Up*/down* routing algorithm to remove cyclic dependencies between channels and avoid deadlock. However, routing is considerably restricted and most messages must follow nonminimal paths, increasing latency and wasting resources. In this work, we propose and evaluate a simple and effective methodology to compute Up*/down* routing tables. The new methodology is based on computing a depth-first search (DFS) spanning tree on the network graph that decreases the number of routing restrictions with respect to the breadth-first search (BFS) spanning tree used by the traditional methodology. Additionally, we propose different heuristic rules for computing the spanning trees to improve the efficiency of Up*/down* routing. Evaluation results for several different topologies show that computing the Up*/down* routing tables by using the new methodology increases throughput by a factor of up to 2.48 in large networks with respect to the traditional methodology, and also reduces latency significantly.
Visualizing a Sphere Eversion
Authors: George Francis, John M. Sullivan
Venue: IEEE Transactions on Visualization and Computer Graphics (2004)

The mathematical process of everting a sphere (turning it inside-out allowing self-intersections) is a grand challenge for visualization because of the complicated, ever-changing internal structure. We have computed an optimal minimax eversion, requiring the least bending energy. Here, we discuss techniques we used to help visualize this eversion for visitors to virtual environments and viewers of our video The Optiverse.
Evaluating content-based filters for image and video retrieval
Authors: Michael G. Christel, Neema Moraveji, Chang Huang
Venue: Proceedings of the 27th annual international ACM SIGIR conference on Research and development in information retrieval (2004)

This paper investigates the level of metadata accuracy required for image filters to be valuable to users. Access to large digital image and video collections is hampered by ambiguous and incomplete metadata attributed to imagery. Though improvements are constantly made in the automatic derivation of semantic feature concepts such as indoor, outdoor, face, and cityscape, it is unclear how good these improvements should be and under what circumstances they are effective. This paper explores the relationship between metadata accuracy and effectiveness of retrieval using an amateur photo collection, documentary video, and news video. The accuracy of the feature classification is varied from performance typical of automated classifications today to ideal performance taken from manually generated truth data. Results establish an accuracy threshold at which semantic features can be useful, and empirically quantify the collection size when filtering first shows its effectiveness.
Experience with Evaluating Human-Assisted Recovery Processes
Authors: Aaron B. Brown, Leonard Chung, William Kakes, Calvin Ling, David A. Patterson
Venue: Proceedings of the 2004 International Conference on Dependable Systems and Networks (2004)

We describe an approach to quantitatively evaluatinghuman-assisted failure-recovery tools and processes in theenvironment of modern Internet- and enterprise-class serversystems. Our approach can quantify the dependabilityimpact of a single recovery system, and also enables comparisonsbetween different recovery approaches. Theapproach combines aspects of dependability benchmarkingwith human user studies, incorporating human participantsin the system evaluations yet still producing typical dependability-related metrics as results. We illustrate our methodology via a case study of a system-wide undo/redo recoverytool for e-mail services; our approach is able to expose thedependability benefits of the tool as well as point out areaswhere its behavior could use improvement.
Using bayesian priors to combine classifiers for adaptive filtering
Authors: Yi Zhang
Venue: Proceedings of the 27th annual international ACM SIGIR conference on Research and development in information retrieval (2004)

An adaptive information filtering system monitors a document stream to identify the documents that match information needs specified by user profiles. As the system filters, it also refines its knowledge about the user's information needs based on long-term observations of the document stream and periodic feedback(training data) from the user. Low variance profile learning algorithms, such as Rocchio, work well at the early stage of filtering when the system has very few training data. Low bias profile learning algorithms, such as Logistic Regression, work well at the later stage of filtering when the system has accumulated enough training data.However, an empirical system needs to works well consistently at all stages of filtering process. This paper addresses this problem by proposing a new technique to combine different text classification algorithms via a constrained maximum likelihood Bayesian prior. This technique provides a trade off between bias and variance, and the combined classifier may achieve a consistent good performance at different stages of filtering. We implemented the proposed technique to combine two complementary classification algorithms: Rocchio and logistic regression. The new algorithm is shown to compare favorably with Rocchio, Logistic Regression, and the best methods in the TREC-9 and TREC-11 adaptive filtering tracks.
Clustering classifiers for knowledge discovery from physically distributed databases
Authors: Grigorios Tsoumakas, Lefteris Angelis, Ioannis Vlahavas
Venue: Data Knowledge Engineering (2004)

Most distributed classification approaches view data distribution as a technical issue and combine local models aiming at a single global model. This however, is unsuitable for inherently distributed databases, which are often described by more than one classification models that might differ conceptually. In this paper we present an approach for clustering distributed classifiers in order to discover groups of similar classifiers and thus similar databases with respect to a specific classification task. We also show that clustering distributed classifiers as a pre-processing step for classifier combination enhances the achieved predictive performance of the ensemble.
Static optimization of conjunctive queries with sliding windows over infinite streams
Authors: Ahmed M. Ayad, Jeffrey F. Naughton
Venue: Proceedings of the 2004 ACM SIGMOD international conference on Management of data (2004)

We define a framework for static optimization of sliding window conjunctive queries over infinite streams. When computational resources are sufficient, we propose that the goal of optimization should be to find an execution plan that minimizes resource usage within the available resource constraints. When resources are insufficient, on the other hand, we propose that the goal should be to find an execution plan that sheds some of the input load (by randomly dropping tuples) to keep resource usage within bounds while maximizing the output rate. An intuitive approach to load shedding suggests starting with the plan that would be optimal if resources were sufficient and adding "drop boxes" to this plan. We find this to be often times suboptimal - in many instances the optimal partial answer plan results from adding drop boxes to plans that are not optimal in the unlimited resource case. In view of this, we use our framework to investigate an approach to optimization that unifies the placement of drop boxes and the choice of the query plan from which to drop tuples. The effectiveness of our optimizer is experimentally validated and the results show the promise of this approach.
Common-Mode Response Overlapping vs. Shaping in Rail-to-Rail Op-Amp Input Stages
Authors: J. Francisco Duque-Carrillo, Juan M. Carrillo, Guido Torelli, José L. Ausín
Venue: Analog Integrated Circuits and Signal Processing (2004)

In this paper, a circuit technique&mdash;common-mode (CM) response overlapping&mdash;for maintaining the small-signal behavior of rail-to-rail amplifiers nearly constant over the whole input CM range, is introduced. This technique modifies the CM response of the rail-to-rail input stage adequately by means of two constant input floating voltage sources, which are adjusted by using a static tuning section. Its performance is compared with a second technique&mdash;CM response shaping&mdash;, which is also based on two variable input floating voltage sources, but relies on a dynamic feedback tuning loop. Experimental results obtained from two 3-V 0.8-&mu;m CMOS single-stage rail-to-rail amplifiers, which operate with CM response overlapping and shaping, respectively, are provided.
Fair blind threshold signatures in wallet with observers
Authors: Wen-Shenq Juang, Horng-Twu Liaw
Venue: Journal of Systems and Software (2004)

In this paper, we propose efficient fair blind (t,n) threshold signature schemes in wallet with observers. By these schemes, any t out of n signers in a group can represent the group to sign fair blind threshold signatures, which can be used in anonymous e-cash systems. Since blind signature schemes provide perfect unlinkability, such e-cash systems can be misused by criminals, e.g. to safely obtain a ransom or to launder money. Our schemes allow the judge (or the judges) to deliver information allowing anyone of the t signers to link his view of the protocol and the message signature pair.
Efficient dynamic traffic grooming in service-differentiated WDM mesh networks
Authors: Harsha V. Madhyastha, C. Siva Ram Murthy
Venue: Computer Networks: The International Journal of Computer and Telecommunications Networking (2004)

In this paper, we address the issue of traffic grooming in arbitrary WDM mesh networks. We present a novel groomer architecture wherein a combination of grooming at two different granularities is utilized to make the setup cost-effective without compromising on efficiency. We put forward an efficient algorithm for dynamic routing and wavelength assignment of sub-wavelength connections. We also propose a means of rerouting connections dynamically to facilitate increase in the average call acceptance ratio. Rerouting in the dynamic scenario has never been considered before. The connections, which may have arbitrary bandwidth requirements, are considered to be service-differentiated based on the need for protection. We show the advantage of employing segmented backup in place of end-to-end backup as well as the benefits of the rerouting mechanism we propose through extensive simulation results.
Articulating Autonomously Distributed Electronic Product Catalogues for Constructing Dynamic CONEX Net
Authors: Jingzhi Guo, Chengzheng Sun, David Chen
Venue: Proceedings of the E-Commerce Technology for Dynamic E-Business, IEEE International Conference (2004)

The integration of ad hoc electronic product catalogues (EPCs) is an important issue in constructing dynamic global electronic markets. A particular issue in this integration process is that millions of ad hoc EPCs are autonomously distributed around the world on Internet and fully behave in their own ways. This leads to the unknown sources of their schemas and semantics and cannot adopt traditional product ontologies to mediate heterogeneous product information. To investigate the specific issues, this paper articulates both semantic conflict relations of ad hoc EPCs and their unique uneven distribution properties. By these articulations, it has developed a novel ConexNet on which uneven distributed and autonomous EPCs are aligned and linked in a semantic conflict-free way. Features are provided to examine how ConexNet is made to resolve semantic conflicts. Measuring criteria are proposed to evaluate the quality of ConexNet.