ppxscal/embedding_network huggingface dataset:
Security Control for COTS Components
Authors: Qun Zhong, Nigel Edwards
Venue: Computer (1998)

Using COTS components poses serious threats to system security. The authors analyze the risks and describe how their sandbox method can confine the damage potential of COTS components. The sandbox model was originally developed for fault tolerance. Rather than eliminating actual failures, it provides a restricted environment to confine application behavior. The approach confines the damage caused if an application accidentally or maliciously misbehaves. The authors' sandbox method differs from Java's, in that it is built with OS support rather than with support from a particular language. In this article, they describe the Sendmail version of their sandbox method. Their approach requires B-level security features not found on most conventional OSs. Typically developed for government or military use, B-level-certified OSs have more sophisticated security features. The authors explain that their method does not eliminate security problems but rather mitigates the damage caused by compromised applications and thus prevents most common security breaches. Untrusted COTS components can thus be safely plugged into a system without major reengineering, provided there is a suitable security platform.
Reliable Communication for Highly Mobile Agents
Authors: Amy L. Murphy, Gian Pietro Picco
Venue: Autonomous Agents and Multi-Agent Systems (2002)

The provision of a reliable communication infrastructure for mobile agents is still an open research issue. The challenge to reliability we address in this work does not come from the possibility of faults, but rather from the mere presence of mobility, which complicates the problem of ensuring the delivery of information even in a fault-free network. For instance, the asynchronous nature of message passing and agent migration may cause situations where messages forever chase a mobile agent that moves frequently from one host to another. Current solutions rely on conventional technologies that either do not provide a solution for the aforementioned problem, because they were not designed with mobility in mind, or enforce continuous connectivity with the message source, which in many cases defeats the very purpose of using mobile agents.In this paper, we propose an algorithm that guarantees delivery to highly mobile agents using a technique similar to a distributed snapshot. A number of enhancements to this basic idea are discussed, which limit the scope of message delivery by allowing dynamic creation of the connectivity graph. Notably, the very structure of our algorithm makes it amenable not only to guarantee message delivery to a specific mobile agent, but also to provide multicast communication to a group of agents, which constitutes another open problem in research on mobile agents. After presenting our algorithm and its properties, we discuss its implementability by analyzing the requirements on the underlying mobile agent platform, and argue about its applicability.
Concepts and realization of a diagram editor generator based on hypergraph transformation
Authors: Mark Minas
Venue: Science of Computer Programming (2002)

Diagram editors which are tailored to a specific diagram language typically support either syntax-directed editing or free-hand editing, i.e., the user is either restricted to a collection of predefined editing operations, or he is not restricted at all, but misses the convenience of such complex editing operations. This paper describes DIAGEN, a rapid prototyping tool for creating diagram editors which support both modes in order to get their combined advantages. Created editors use hypergraphs as an internal diagram model and hypergraph parsers for syntactic analysis whereas syntax-directed editing is realized by programmed hypergraph transformation of these internal hypergraphs. This approach has proven to be powerful and general in the sense that it supports quick prototyping of diagram editors and does not restrict the class of diagram languages which it can be applied to.
Distributed, Collaborative Software Inspection
Authors: Vahid Mashayekhi, Janet M. Drake, Wei-Tek Tsai, John Riedl
Venue: IEEE Software (1993)

The Collaborative Software Inspection (CSI) tool, which provides a distributed, structured environment for performing inspections on all software-development products, including specifications, designs, code, and test cases, is described. The inspection environment lets geographically distributed inspection participants meet with people in other cities through workstations at their desks. The current version of all material is accessible online. Inspection products are created online, so secondary data entry to permanent records is not necessary. The inspection information is also available for review and metrics collection. To assess the effectiveness of inspection in the distributive collaborative environment and compare it with face-to-face meetings, a case-study approach with replication logic is presented.
An architectural system for retrieving messages to respond dangling questions in learning forum
Authors: Chih-Kai Chang
Venue: Computers Education (2002)

After an instructor has used a Web-based forum in a course for years, the system database will contain an accumulation of discussion messages, which may be on similar topics, from different classes within a course, Furthermore, the discussion processes of some classes may be very heuristic for other learners in the same course. In general, a Web-based forum serves as additional channels for learners to discuss learning topics in the absence of an instructor. However, an instructor may want to guide learners in reading meaningful discussion messages in previous learners' discussion records when a similar question is asked. Hence, it is necessary to model the relationships between discussion messages from different classes in the same course. Furthermore, an instructor desires no unanswered question, called a dangling question, in a Web-based forum because of the possible negative influences, such as discouraging learners to raise questions. This paper proposes a concept-mapping method, which originates from information retrieval technology, for representing the relationships between learners' questions and previous learners' discussion messages. Consequently, the methodology enables an instructor to locate easily from the system database a set of discussion messages with conceptual similarity as answers to eliminate the dangling question.
A New Approach to the Design of Reinforcement Schemes for Learning Automata: Stochastic Estimator Learning Algorithms
Authors: G. I. Papadimitriou
Venue: IEEE Transactions on Knowledge and Data Engineering (1994)

A new class of learning automata is introduced. The new automata use a stochastic estimator and are able to operate in nonstationary environments with high accuracy and a high adaptation rate. According to the stochastic estimator scheme, the estimates of the mean rewards of actions are computed stochastically. So, they are not strictly dependent on the environmental responses. The dependence between the stochastic estimates and the deterministic estimator's contents is more relaxed when the latter are old and probably invalid. In this way, actions that have not been selected recently have the opportunity to be estimated as "optimal", to increase their choice probability, and, consequently, to be selected. Thus, the estimator is always recently updated and consequently is able to be adapted to environmental changes. The performance of the Stochastic Estimator Learning Automaton (SELA) is superior to the previous well-known S-model ergodic schemes. Furthermore, it is proved that SELA is absolutely expedient in every stationary S-model random environment.
The Performance of Counter- and Correlation-Based Schemes for Branch Target Buffers
Authors: Amit Mital, Barry Fagin
Venue: IEEE Transactions on Computers (1995)

Branch target buffers, or BTBs, can be used to improve CPU performance by maintaining target and history information of previously executed branches. We present trace-driven simulation results comparing counter-based and correlation-based prediction schemes for a variety of branch target buffer sizes. We report relative performance estimates to show both the relative merits of various techniques and their effects on performance for current microprocessors. Our results indicate that counter-based schemes outperform correlation-based schemes for small buffers, but that the opposite becomes true as buffer size increases. This is due to the importance of hit ratio over prediction success in branch target buffer design. The transition point between counter- and correlation-based schemes is dependent on the size of the working set of dynamic branches for a given collection of benchmark programs.Our results also show that for small BTBs, hit ratio and hence performance decrease as the number of correlation bits increase. This is due to non-random distribution of correlation vectors causing increased collisions for BTB locations. Only when a BTB becomes large enough to capture the working set of a program¿s branch and correlation vector references do the expected benefits of correlation-based schemes manifest themselves.
A Method for Trading off Test Time, Area and Fault Coverage in Datapath BIST Synthesis
Authors: D. Berthelot, M. L. Flottes, B. Rouzeyre
Venue: Journal of Electronic Testing: Theory and Applications (2001)

This paper presents a partitioned and embedded BIST technique for data path like circuits. The BIST scheme is defined at behavioral level for full optimization of both system and BIST modes during High Level Synthesis. Test time, area overhead and fault coverage are under the scope of the method. User-given constraints on fault coverage to achieve on data path operators and on test time are used to guide the BIST insertion technique towards the lowest area overhead solution.
Run-time performance optimization of an FPGA-based deduction engine for SAT solvers
Authors: Andreas Dandalis, Viktor K. Prasanna
Venue: ACM Transactions on Design Automation of Electronic Systems (TODAES) (2002)

FPGAs are a promising technology for accelerating SAT solvers. Besides their high density, fine granularity, and massive parallelism, FPGAs provide the opportunity for run-time customization of the hardware based on the given SAT instance. In this article, a parallel deduction engine is proposed for backtrack search algorithms. The performance of the deduction engine is critical to the overall performance of the algorithm because, for any moderate SAT instance, millions of implications are derived. We propose a novel approach in which p, the amount of parallelization of the engine, is fine-tuned during problem solving in order to optimize performance. Not only the hardware is initially customized based on the input instance, but it is also dynamically modified in terms of p based on the knowledge gained during solving the SAT instance. Compared with conventional deduction engines that correspond to p = 1, we demonstrate speedups in the range of 2.87 to 5.44 for several SAT instances.
Kleitman and combinatorics: a celebration
Authors: G. W. Peck
Venue: Discrete Mathematics (2002)

A discussion of the history, the mathematics, and the charm of Daniel J. Kleitman.
Using and Determining Location in a Context-Sensitive Tour Guide
Authors: Nigel Davies, Keith Cheverst, Keith Mitchell, Alon Efrat
Venue: Computer (2001)

The Lancaster Guide project, initiated in 1997, explores the issues that arise from developing and deploying context-sensitive applications--specifically, a tour guide for the city of Lancaster, UK. Motivated by the work on Georgia Tech's CyberGuide, the authors envisioned a system that could provide tailor-made tours for visitors by adapting its behavior to changes in a user's location. In contrast to the CyberGuide project, the Lancaster Guide adopted a network-centric approach. In Guide, the systems obtain information through a high-speed wireless network deployed throughout the target city. After implementing the Guide system in 1999, the authors ran a series of field trials involving members of the general public to explore their reactions to using these methods of locating and identifying objects. Two Guide features generated particular interest among researchers and engineers developing similar systems: the choice of positioning technology--beacons that broadcast using an IEEE 802.11 wireless network combined with user input--and the techniques used for generating custom tours for electronic city-guide systems. To work effectively, Guide relies not only on technology but also on assistance from users. This partnership offers in-creased accuracy while fostering a relationship between end users and the Guide system. The authors seek to create a more engaging and compelling experience than might otherwise be possible if they relied on technology alone. They believe their techniques are applicable to a wide range of location-based applications, especially those that use cellular location systems. Work continues on porting the Guide system to the Compaq IPAQ PDA, which would allow exploration of system development and usability issues for a new class of devices.
Fundamental Concepts in Programming Languages
Authors: Christopher Strachey
Venue: Higher-Order and Symbolic Computation (2000)

This paper forms the substance of a course of lectures given at the International Summer School in Computer Programming at Copenhagen in August, 1967. The lectures were originally given from notes and the paper was written after the course was finished. In spite of this, and only partly because of the shortage of time, the paper still retains many of the shortcomings of a lecture course. The chief of these are an uncertainty of aim&mdash;it is never quite clear what sort of audience there will be for such lectures&mdash;and an associated switching from formal to informal modes of presentation which may well be less acceptable in print than it is natural in the lecture room. For these (and other) faults, I apologise to the reader.There are numerous references throughout the course to CPL [1&ndash;3]. This is a programming language which has been under development since 1962 at Cambridge and London and Oxford. It has served as a vehicle for research into both programming languages and the design of compilers. Partial implementations exist at Cambridge and London. The language is still evolving so that there is no definitive manual available yet. We hope to reach another resting point in its evolution quite soon and to produce a compiler and reference manuals for this version. The compiler will probably be written in such a way that it is relatively easyto transfer it to another machine, and in the first instance we hope to establish it on three or four machines more or less at the same time.The lack of a precise formulation for CPL should not cause much difficulty in this course, as we are primarily concerned with the ideas and concepts involved rather than with their precise representation in a programming language.
A Survey of Automated Timetabling
Authors: A. Schaerf
Venue: Artificial Intelligence Review (1999)

The timetabling problem consists in scheduling a sequence of lectures between teachers and students in a prefixed period of time (typically a week), satisfying a set of constraints of various types. A large number of variants of the timetabling problem have been proposed in the literature, which differ from each other based on the type of institution involved (university or school) and the type of constraints. This problem, that has been traditionally considered in the operational research field, has recently been tackled with techniques belonging also to Artificial Intelligence (e.g., genetic algorithms, tabu search, and constraint satisfaction). In this paper, we survey the various formulations of the problem, and the techniques and algorithms used for its solution.
Using Heavy-Ion Radiation to Validate Fault-Handling Mechanisms
Authors: Johan Karlsson, Peter Liden, Peter Dahlgren, Rolf Johansson, Ulf Gunneflo
Venue: IEEE Micro (1994)

Fault injection is an effective method for studying the effects of faults in computer systems and for validating fault-handling mechanisms. The approach presented involves injecting transient faults into integrated circuits by using heavy-ion radiation from a Californium-252 source. The proliferation of safety-critical and fault-tolerant systems using VLSI technology makes such attempts to inject faults at internal locations in VLSI circuits increasingly important.
Formal Models of Communication Services: A Case Study
Authors: Alan Feteke
Venue: Computer (1993)

Formal methods can play an important role in exploring new communication systems services. The telecommunications and data communications communities have long accepted the need for formally describing protocols, but only recently have they considered formally describing a service by abstracting specifications from a particular protocol that provides that service. Specifying a service at an abstract level meets two important needs: standardization and customization. The author presents a simplified atomic multicast as an example service and input/output automata for the formal model. He shows how to represent the service specification, a protocol, and implementations of that protocol. He also sketches how to prove the correctness of the protocol and implementation, that is, how to show that the specified service is actually provided.
Learning Concepts in Parallel Based Upon the Strategy of Version Space
Authors: T. P. Hong, S. S. Tseng
Venue: IEEE Transactions on Knowledge and Data Engineering (1994)

Applies the technique of parallel processing to concept learning. A parallel version-space learning algorithm based upon the principle of divide-and-conquer is proposed. Its time complexity is analyzed to be O(k log/sub 2/n) with n processors, where n is the number of given training instances and k is a coefficient depending on the application domains. For a bounded number of processors in real situations, a modified parallel learning algorithm is then proposed. Experimental results are then performed on a real learning problem, showing that our parallel learning algorithm works, and being quite consistent with the results of theoretical analysis. We conclude that when the number of training instances is large, it is worth learning in parallel because of its faster execution.
Ubiquitous Spatial-Information Services Using Cell Phones
Authors: Shigeru Shimada, Masaaki Tanizaki, Kishiko Maruyama
Venue: IEEE Micro (2002)

Discover how 2G and 2.5G cell phones can help provide ubiquitous spatial-information services. with 3G cell phones just on the horizon, this approach promises to be practical and convenient.
PRIMA: a case study of using information visualization techniques for patient record analysis
Authors: D. L. Gresh, D. A. Rabenhorst, A. Shabo, S. Slavin
Venue: Proceedings of the conference on Visualization '02 (2002)

We have created an application, called PRIMA (Patient Record Intelligent Monitoring and Analysis), which can be used to visualize and understand patient record data. It was developed to better understand a large collection of patient records of bone marrow transplants at Hadassah Hospital in Jerusalem, Israel. It is based on an information visualization toolkit, Opal, which has been developed at the IBM T.J. Watson Research Center. Opal allows intelligent, interactive visualization of a wide variety of different types of data. The PRIMA application is generally applicable to a wide range of patient record data, as the underlying toolkit is flexible with regard to the form of the input data. This application is a good example of the usefulness of information visualization techniques in the bioinformatics domain, as these techniques have been developed specifically to deal with diverse sets of often unfamiliar data. We illustrate several unanticipated findings which resulted from the use of a flexible and interactive information visualization environment.
On complementary and independent mappings on databases
Authors: Arthur M Keller, Jeffrey D Ullman
Venue: Proceedings of the 1984 ACM SIGMOD international conference on Management of data (1984)

We define the notion of independent views to indicate whether the range values of the two views may be achieved independently The concept of complementary views indicates when the domain element can be uniquely determined by the range values of the two complementary views We consider the relationship between independent and complementary views In unrestricted domains, a view (but not the identity or empty view) can have more than one complementary, independent view Databases, however, are more restricted domains They are finite power sets A view is monotonic if it preserves inclusion However, in finite power sets when all views are monotonic, if a given view has another view which is independent and complementary, then this view is unique.
The Expressive Power of Temporal Relational Query Languages
Authors: Abdullah Uz Tansel, Erkan Tin
Venue: IEEE Transactions on Knowledge and Data Engineering (1997)

We consider the representation of temporal data based on tuple and attribute timestamping. We identify the requirements in modeling temporal data and elaborate on their implications in the expressive power of temporal query languages. We introduce a temporal relational data model where N1NF relations and attribute timestamping are used and one level of nesting is allowed. For this model, a nested relational tuple calculus (NTC) is defined. We follow a comparative approach in evaluating the expressive power of temporal query languages, using NTC as a metric and comparing it with the existing temporal query languages. We prove that NTC subsumes the expressive power of these query languages. We also demonstrate how various temporal relational models can be obtained from our temporal relations by NTC and give equivalent NTC expressions for their languages. Furthermore, we show the equivalence of intervals and temporal elements (sets) as timestamps in our model.
Efficient fitting of long-tailed data sets into phase-type distributions
Authors: Alma Riska, Vesselin Diev, Evgenia Smirni
Venue: ACM SIGMETRICS Performance Evaluation Review (2002)

We propose a new technique for fitting long-tailed data sets into phase-type (PH) distributions. This technique fits data sets with non-monotone densities into a mixture of Erlang and hyperexponential distributions, and data sets with completely monotone densities into hyperexponential distributions. The method first partitions the data set in a divide and conquer fashion and then uses the Expectation-Maximization (EM) algorithm to fit the data of each partition into a PH distribution. The fitting results for each partition are combined to generate the final fitting for the entire data set. The new method is accurate, efficient, and allows one to apply existing analytic tools to analyze the behavior of queueing systems that operate under workloads that exhibit long-tail behavior, such as queues in Internet-related systems.