ppxscal/embedding_network huggingface dataset:
TRANSPARENT REMOTE PROCEDURE CALLS (M.S. Thesis)
Authors: Michelle D Abram
Venue:  (1992)

With the vastly increased need for computing power in modern computing environments, the ability to distribute jobs across machine boundaries has become essential. The main drawback of distributed computing is the excessive complexity of network programming. One way to solve this problem is to create an environment that emulates the typical programming environment. This is the basis of remote procedure calls (RPC). A remote procedure call is the execution of a procedure that resides on a foreign host. A program at the remote site receives data from the caller, calls the procedure locally, and returns the result. To the programmer, remote procedure calls closely resemble local procedure calls. This is a well developed idea, and a number of RPC packages have been implemented. The problem with most of these packages is that complex initialization routines are required to use them. It is unnecessary to concern the programmer with the underlying connectivity and packet exchange mechanisms required to implement an RPC package. Further, these initialization requirements undermine the central goal of RPC programming: transparent distributed computing. We present a remote procedure call package that has been designed to relieve the programmer of this burden without sacrificing power.
Computer Teachers' Perceptions of Hardware and Software Trends
Authors: Ali R. Salehnia, Lonnie J. Echternacht
Venue: Journal of Computing Sciences in Colleges (1991)

The purpose of this study was to determine whether there was a difference between the perceptions of secondary school business teachers and area vocational school business teachers who teach computer/data processing courses regarding the trends and advancement of computer hardware and software technologies and their use in education programs and business education programs in 1995. Data for the study were collected by questionnaires. The null hypothesis was tested at the .05 level of significance. A significant difference among the perceptions of secondary school business teachers and area vocational school business teachers was found. Therefore, the null hypothesis was rejected.
ON THE COMPUTATIONAL COMPLEXITY OFAPPROXIMATING DISTRIBUTIONS BY PROBABILISTIC AUTOMATA
Authors: Naoki Abe, Manfred K. Warmuth
Venue:  (1990)

We introduce a rigorous performance criterion for training algorithms for probabilistic automata (PAs) and hidden Markov models (HMMs), used extensively for speech recognition, and analyze the complexity of the training problem as a computational problem. The PA training problem is the problem of approximating an arbitrary, unknown source distribution by distributions generated by a PA. We investigate the following question about this important, well-studied problem: Does there exist an *efficient* training algorithm such that the trained PAs *provably converge* to a model close to an optimum one with high confidence, after only a feasibly small set of training data? We model this problem in the framework of computational learning theory and analyze the sample as well as computational complexity. We show that the number of examples required for training PAs is moderate -- essentially linear in the number of transition probabilities to be trained and a low-degree polynomial in the example length and parameters quantifying the accuracy and confidence. Computationally, however, training PAs is quite demanding: Fixed state size PAs are trainable in time polynomial in the accuracy and confidence parameters and example length, but *not* in the alphabet size, unless RP = NP. The latter result is shown via a strong non-approximability result for the single string maximum likelihood model problem for 2-state PAs, which is of independent interest.
Aggregated Bit Vector Search Algorithms for Packet Filter Lookups
Authors: Florin Baboescu, George Varghese
Venue:  (2001)

Packet classification is important for applications such as firewalls, intrusion detection, and differentiated services. Existing algorithms for packet classification reported in the literature scale poorly in either time or space as filter databases grow in size. Hardware solutions such as TCAMs do not scale to large classifiers. However, even for large classifiers (say 100,000 rules), any packet is likely to match a few (say 10) rules. Our paper seeks to exploit this observation to produce a scalable packet classification scheme called Aggregated Bit Vector (ABV). Our paper takes the bit vector search algorithm (BV) described in \cite{lucent} (which takes linear time) and adds two new ideas, recursive aggregation of bit maps and filter rearrangement, to create ABV (which can take logarithmic time for many databases). We show that ABV outperforms BV by an order of magnitude using simulations on both industrial firewall databases and synthetically generated databases.
TLS: Ein Hardware-System fur die Ausbildung im Bereich der parallelenDatenverarbeitung
Authors: Jurgen W. Meyer, Volkhard Klinger
Venue:  (1993)

Fur die Ausbildung im Bereich der Parallelverarbeitung wurde das Transputer-Lehrsystem (TLS) konzipiert. Erfahrungen mit konventionellen Transputersystemen zeigten, da? diese fur die Lehr unzureichend ausgestattet sind. Dieser Beitrag zeigt die Notwendigkeit eines speziellen Systems zu Ausbildungszwecken auf und gibt einen Uberblick uber die wichtigsten Eigenschaften des TLS.
The Aladin Abstract Machine
Authors: Gary Meehan
Venue:  (1998)

The Aladin Abstract Mac hine (AAM) provides a completely abstract definition of a functional language. There are no primitives built into Aladin, instead primitives are in tended to be programmed in any language, functional or imperative and imported in to the AAM. In this report we develop an efficient operational semantics for the AAM using the original denotational semantics as our starting point. We then use this semantics to develop an implementation of Aladin, using the Java language, with the ability to write programs in an Aladin scripting language that we develop, and primitives written in C/C++, Java and Ginger.
AN ABSTRACT USER INTERFACE MODEL FOR THE SEPARATION OFTHE INTERFACE FROM THE APPLICATION (M.S. Thesis)
Authors: Sadhana Jain
Venue:  (1990)

A distributed heterogeneous environment is created when a variety of different computer systems are connected and interacting with each other over a network. In such a situation, it is often desirable to make the same program work in environments using different I/O devices, window systems, and processors. The purpose of this thesis was to make it easy for application developers to write programs compatible with different environments. An interactive application program has two components, its functionality (sometimes called computational component) and its user interface. The only component that changes in a different environment is the user interface. The functionality of a program remains the same. If the user interface is intertwined with the functionality, the whole program will need to be rewritten when the program is moved to a new environment. If the functionality and the user interface are developed independently, only the user interface will need to be changed in a different environment. In this thesis the design of an User Interface Abstraction Model is presented. The model facilitates dialogue independence between the functionality and the user interface by providing an interface abstraction. Dialogue independence means that the design decisions affecting the computational component can be changed independent of the user interface. The interface abstraction creates a buffer between the two components using abstract data types. The data types support choices from a list for tables and selections. The design of the User Interface Abstraction Model is validated by the implementation of an `Image Browser'' application in two different environments: the X Window System and a character-based terminal environment. Only the user interface required changes in a different environment; the computational component remained unaltered. 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 Measured Access Characteristics of World-Wide-Web Client Proxy Caches
Authors: Bradley M. Duska, David Marwood, Michael J. Feeley
Venue:  (1997)

The growing popularity of the World Wide Web is placing tremendous demands on the Internet. A key strategy for scaling the Internet to meet these increasing demands is to cache data near clients and thus improve access latency and reduce network and server load. Unfortunately, research in this area has been hampered by a poor understanding of the locality and sharing characteristics of Web-client accesses. The recent popularity of Web proxy servers provides a unique opportunity to improve this understanding, because a small number of proxy servers see accesses from thousands of clients. This paper presents an analysis of access traces collected from seven proxy servers deployed in various locations throughout the Internet. The traces record a total of 47.4 million requests made by 23,700 clients over a twenty-one day period. We use a combination of static analysis and trace-driven cache simulation to characterize the locality and sharing properties of these accesses. Our analysis shows that a 2- to 10-GB second-level cache yields hit rates between 24% and 45% with 85% of these hits due to sharing among different clients. Caches with more clients exhibit more sharing and thus higher hit rates. Between 2% and 7% of accesses are consistency misses to unmodified objects, using the Squid and CERN proxy cache coherence protocols. Sharing is bimodal. Requests for shared objects are divided evenly between objects that are narrowly shared and those that are shared by many clients; widely shared objects also tend to be shared by clients from unrelated traces.
A Study and Project-Based Evaluation of The Software Engineering Evaluation System (SEES)
Authors: Arthur James D., Frakes William, Gupta Sanjay, Cannon Martha, Groener Markus, Kahn Zakia
Venue:  (1997)

The purpose of this document is to describe the design and execution of the quasi-experiment conducted in the Department of Computer Science, Virginia Tech, in accordance with the procedures described in the document "An Experimental Design for Evaluating SEES" prepared for NASA under contract NAS1-19610, Task 17. (Hereafter, that report is called the general design document.) The quasi-experiment serves three important purposes. First, the quasi-experiment is the proof of concept of the general experiment design. It shows that the procedures defined in the general experiment design can be implemented. Second, provides details for setting up a true experiment: identifying the research hypothesis, designing the investigation, selecting various variables, procedures, and controls, measuring the variables, and evaluating the results. Third, any insights revealed during the course of the quasi-experiment can be incorporated in the costly true experiment, thus providing a cost-effective experimental methodology. This report contains sufficient information so that the quasi-experiment can be replicated at an appropriate level of abstraction. We also document and interpret all the results of the quasi-experiment.
Critical and future trends in data mining: a review of key data mining technologies/applications
Authors: Jeffrey Hsu
Venue: Data mining: opportunities and challenges (2003)

Every day, enormous amounts of information are generated from all sectors, whether it be business, education, the scientific community, the World Wide Web (WWW) or one of many readily available off-line and online data sources. From all of this, which represents a sizable repository of data and information, it is possible to generate worthwhile and usable knowledge. As a result, the field of Data Mining (DM) and knowledge discovery in databases (KDD) has grown in leaps and bounds and has shown great potential for the future (Han & Kamber, 2001). The purpose of this chapter is to survey many of the critical and future trends in the field of DM, with a focus on those which are thought to have the most promise and applicability to future DM applications.
Cooperative Caching of Dynamic Content on a Distributed Web Server
Authors: Vegard Holmedahl, Ben Smith, Tao Yang
Venue:  (1998)

In this technical report we propose a new method for improving the average response time of Web servers by cooperatively caching the results of requests for dynamic content. The work is motivated by our recent study of access logs from the Alexandria Digital Library server at UCSB, which demonstrates that approximately a 30 percent decrease in average response time could be achieved by caching dynamically generated content. We have developed a distributed Web server called Swala, in which the nodes cooperatively cache the results of CGI requests. We use a two-level cache table consistency protocol and a replicated global cache directory to maximize the system performance and minimize overhead in responding to dynamic Web requests. Our experiments show that the single-node performance of Swala without caching is comparable to the Netscape Enterprise server, that considerable speedups are obtained using caching, and that the cache hit rate is substantially higher with cooperative cache than with standalone cache.
Some Representational Issues in Default Reasoning
Authors: Raymond Reiter, Giovanni Criscuolo
Venue:  (1980)

Although most commonly occurring default rules are normal when I viewed in isolation, they can interact with each other in ways that lead to the derivation of anomalous default assumptions. In order to deal with such anomalies it is necessary to re-represent these rules, in some cases by introducing non-normal defaults. The need to consider such potential interactions leads to a new concept of integrity, distinct from the conventional integrity issues of first order data bases. .br The non-normal default rules required to deal with default interactions all have a common pattern. Default theories conforming to this pattern are considerably more complex than normal default theories. For example, they need not have extensions, and they lack the property of semi-monotonicity. .br Current semantic network representations fail to reason correctly with defaults. However, when viewed as indexing schemes on logical formulae, networks can be seen to provide computationally feasible heuristics for the consistency checks required by default reasoning.
ESTIMATING THE RELIABILITY OF HOSTS USING THE INTERNET
Authors: D. D. E. Long, J. L. Carroll, C. J. Park
Venue:  (1991)

Modeling the reliability distributed systems, whether through analysis or simulation, requires a good understanding of the reliability of the components. Careful modeling allows highly fault-tolerant distributed data bases and similar applications to be constructed at the least cost. It is often assumed that the failure and repair rates of components are exponentially distributed. This hypothesis is testable for failure rates, though the process of gathering and reducing the data to a usable form can be difficult. By applying an appropriate test statistic, some of the samples were found to have a realistic chance of being drawn from an exponential distribution, while others can be confidently classed as non-exponential. For this study, data were collected from a large number of hosts via the Internet with no special privileges or monitoring facilities. Over 350,000 hosts were considered, and more than 68,000 of these that were judged likely to respond were queried. These hosts were sampled several times over the course of two months to obtain up-times, and finally to determine average host availability. A rich collection of information was gathered in this fashion, allowing estimates of availability, mean-time-to-failure (MTTF) and mean-time-to-repair (MTTR) to be derived. The results reported here correspond with those seen in practice.
Probability-One Homotopy Algorithms for Full and Reduced Order H-squared/H-to Infinity Controller Synthesis
Authors: Yuzhen Ge, Layne T. Watson, Emmanuel G. Collins, Dennis S. Bernstein
Venue:  (1994)

Homotopy algorithms for both full- and reduced-order LQG controller design problems with an H-to infinity constraint on disturbance attenuation are developed. The H-to infinity constraint is enforced by replacing the covariance Lyapunov equation by a Riccati equation whose solution gives an upper boundary on H-squared performance. The numerical algorithm, based on homotopy theory, solves the necessary conditions for a minimum of the upper bound on H-squared performance. The algorithms are based on two minimal parameter formulations: Ly, Bryson, and Cannon''s 2X2 block parametrization and the input normal Riccati form parametrization. An over-parametrization formulation is also proposed. Numerical experiments suggest that the combination of a globally convergent homotopy method and a minimal parameter formulation applied to the upper bound minimization gives excellent results for mixed-norm H-squared/H-to infinity synthesis. The nonmonocity of homotopy zero curves is demonstrated, proving that algorithms more sophisticated that standard continuation are necessary.
Efficient Cross-domain Mechanisms for Building Kernel-less Operating Systems
Authors: Dave Probert, John Bruno
Venue:  (1996)

We describe a set of efficient cross-domain mechanisms that allow operating systems to be implemented as cooperating applications, eliminating the need for a monolithic kernel. Our implementation, called SPACE, can achieve higher-performance than kernel-based systems by allowing applications to build customized system services and tailor system interfaces for performance. On the SPARC architecture we have measured minimal application-to-application system service calls that are 5 times faster than Solaris getpid(), and customized thread creation that is 50 times faster than minimal Solaris threads. SPACE unifies exception handling and cross-domain calls into a single mechanism that allows applications to efficiently interface to the underlying hardware. Conventional memory-management hardware is used to provide multiple protection domains within each address space. Cross-domain calls are implemented by portals, which map an exception in one domain to a handler in another. Portals are accessible on a per-domain basis, providing capability-based access to system services. The portals are implemented by synthesizing code according to templates for each portal type. The portal types are designed to minimize state saving and eliminate the dynamic binding overhead of generic cross-domain implementations.
On a Lower Bound for the Redundancy of Reliable Networks with Noisy Gates
Authors: Nicholas Pippenger, George D. Stamoulis, John N. Tsitsiklis
Venue:  (1990)

We prove that a logarithmic redundancy factor is necessary for the reliable computation of the parity function by means of a networks with noisy gates. This result is the same as one claimed by Dobrushin and Ortyukov in 1977, but the proof they gave appears to be incorrect.
On the Benefits of a Maintainability Methodology
Authors: John A. Lewis, Sallie M. Henry
Venue:  (1990)

A metrics methodology can dramatically reduce the problems associated with software maintenance. However, several issues must be addressed in order to develop and use these techniques successfully. This paper defines a metrics methodology which is designed to deliberately integrate maintainability into software as it is being developed. The benefits of using this approach are discussed. Then several issues which complicate the development and use of the methodology are examined. Previous maintenance studies which incorporate the methodology into two different commercial environments are used to demonstrate the difficulties in implementation and contrast the differences in approach.
An Engineering Model of Subcognition
Authors: Donald Michie
Venue:  (1992)

Symbolic and neural modes are discussed from the point of view of implementing the "intuitive" processes which mediate real-time control skills. The engineering preference is to transcend rather than emulate those limitations which are inherent in the brain''s subsymbolic modes of operation. A main payoff lies in recovering, from performance data, symbolic representations of intuitive real-time skills. Practical illustrations are reviewed using recent case studies.
Fishspear: A Priority Queue Algorithm
Authors: M. J. Fischer, M. S. Paterson
Venue:  (1992)

The Fishspear priority queue algorithm is presented and analyzed. Fishspear is comparable to the usual heap algorithm in its worst case running time, and its relative performance is much better in many common situations. Fishspear also differs from the heap method in that it can be implemented efficiently using sequential storage such as stacks or tapes, making it potentially attractive for implementation of very large queues on paged memory systems.
DNESYS--An Expert System for Automatic Extraction of Drainage Networks from Digital Elevation
Authors: Jianzhong Qian, Roger W. Ehrich, J. B. Campbell
Venue:  (1988)

The determination of drainage networks and drainage basins is one of the more tedious yet important uses of topographic maps, and geographic information systems are now used extensively as a manual aid to facilitate that task. However, the wide availability of digital elevation maps has stimulated attempts to automate the process even further. In this paper, the problems that arose in earlier programs to map drainage systems are analyzed in detail. An expert system called the Drainage Network Extraction System (DNESYS) is described which uses both local operators and global reasoning to extract drainage networks and ridge lines. A stream representation called a parameterized directed graph (PDG) is constructed to model a drainage system. The construction of a model begins with an initial pixel labeling procedure. Then a network tracing and property measurement procedure converts the 2-D low-level labeling information into a symbolic database for high -level processing. By applying Dempster- Shafer evidence theory, evidence collection and uncertain reasoning are performed against the DNESYS knowledge-base that contains the drainage system model and the organized expert knowledge. By discarding erroneous information and supplying missing information, DNESYS produces a complete PDG which can be converted into the final drainage system.
UNLOADING JAVA CLASSES THAT CONTAIN STATIC FIELDS
Authors: Charlie E. McDowell, E. A. Baldwin
Venue:  (1997)

In Java the definition of a "program" is a bit fuzzy. A Java applet is essentially a Java application (i.e. program) that can be executed by a Java enabled Web browser (i.e. an OS). An applet running inside of a browser was intended to be analogous to a conventional application running under on OS, hence the netcentric "browser is your OS" model. However, as currently implemented this analogy breaks down with regard to the system resources allocated for classes and in particular for static fields in classes (i.e. class variables) when the class was loaded as part of an applet. Without class unloading, a long running Java application such as a browser is like an OS that does not release memory resources allocated for application code space when the application terminates. With class unloading, as currently implemented, the semantics of static fields in classes are broken. In this paper we detail the problem and provide a solution. The solution combines restricting when classes can be unloaded, with a greater use of non-default class loaders.