ppxscal/embedding_network huggingface dataset:
Introduction of the asymmetric cryptography in GSM, GPRS, UMTS, and its public key infrastructure integration
Authors: Constantinos F. Grecas, Sotirios I. Maniatis, Iakovos S. Venieris
Venue: Mobile Networks and Applications (2003)

The logic ruling the user and network authentication as well as the data ciphering in the GSM architecture is characterized, regarding the transferring of the parameters employed in these processes, by transactions between three nodes of the system, that is the MS, actually the SIM, the visited MSC/VLR, and the AuC, which is attached to the HLR in most cases. The GPRS and the UMTS architecture carry the heritage of the GSM's philosophy regarding the user/network authentication and the data ciphering. So, the corresponding three nodes (MS, VLR, and HLR) of these systems are involved as well in the authentication and data ciphering procedures. Moreover, the methods of the conventional cryptography have been adopted by all three systems. This paper describes in brief the subscriber authentication and data ciphering, as they are recommended by the Specifications for all three aforementioned systems. Based on what the specifications define, we pinpoint the vulnerable points of the systems, exposed to third party attacks, and propose asymmetric cryptography procedures for their coverage, consisting of the introduction of public-private key pairs for the transactions between the VLR-HLR, as well as the MS-VLR. On the other hand, the nature of the services constituting a Public Key Infrastructure (PKI) renders the telecommunication operators the main candidates for the development of PKIs fully or partially fledged. The private-public key pair, stored by the PLMN operator in the SIM, for the GSM/GPRS case, or in the USIM for the UMTS case and created to deal initially with internal system functions, can easily be extended, adopted and employed in secure e/m-transactions, if bound to a digital certificate, in the case the PLMN operator supports PKI services as well.
Fitting world-wide web request traces with the EM-algorithm
Authors: Rachid El Abdouni Khayari, Ramin Sadre, Boudewijn R. Haverkort
Venue: Performance Evaluation (2003)

In recent years, various researchers have shown that network traffic that is due to world-wide web transfers shows characteristics of self-similarity and it has been argued that this can be explained by the heavy-tailedness of many of the involved distributions. Considering these facts, developing methods that are able to handle self-similarity and heavy-tailedness is of great importance for network capacity planning purposes.However, heavy-tailed distributions cannot be used so easily for analytical or numerical evaluation studies. To overcome this problem, in this paper, we approximate the empirical distributions by analytically more tractable, that is, hyper-exponential distributions. For that purpose, we present a new fitting algorithm based on the expectation-maximisation and show it to perform well both for pure traffic statistics as well as in queuing studies.
A Tool for Analyzing and Fine Tuning the Real-Time Properties of an Embedded System
Authors: David B. Stewart, Gaurav Arora
Venue: IEEE Transactions on Software Engineering (2003)

This paper describes a computer-aided software engineering (CASE) tool that helps designers analyze and fine-tune the timing properties of their embedded real-time software. Existing CASE tools focus on the software specification and design of embedded systems. However, they provide little, if any, support after the software has been implemented. Even if the developer used a CASE tool to design the system, their system most likely does not meet the specifications on the first try. This paper includes guidelines for implementing analyzable code, profiling a real-time system, filtering and extracting measured data, analyzing the data, and interactively predicting the effect of changes to the real-time system. The tool is a necessary first step towards automating the debugging and fine tuning of an embedded system's temporal properties.
Airline Yield Management with Overbooking, Cancellations, and No-Shows
Authors: Janakiram Subramanian, Shaler Stidham,  Jr., Conrad J. Lautenbacher
Venue: Transportation Science (1999)

We formulate and analyze a Markov decision process (dynamic programming) model for airline seat allocation (yield management) on a single-leg flight with multiple fare classes. Unlike previous models, we allow cancellation, no-shows, and overbooking. Additionally, we make no assumptions on the arrival patterns for the various fare classes. Our model is also applicable to other problems of revenue management with perishable commodities, such as arise in the hotel and cruise industries. We show how to solve the problem exactly using dynamic programming. Under realistic conditions, we demonstrate that an optimal booking policy is characterized by state- and time-dependent booking limits for each fare class. Our approach exploits the equivalence to a problem in the optimal control of admission to a queueing system, which has been well studied in the queueing-control literature. Techniques for efficient implementation of the optimal policy and numerical examples are also given. In contrast to previous models, we show that 1) the booking limits need not be monotonic in the time remaining until departure; 2) it may be optimal to accept a lower-fare class and simultaneously reject a higher-fare class because of differing cancellation refunds, so that the optimal booking limits may not always be nested according to fare class; and 3) with the possibility of cancellations, an optimal policy depends on both the total capacity and the capacity remaining. Our numerical examples show that revenue gains of up to 9% are possible with our model, compared with an equivalent model omitting the effects of cancellations and no-shows. We also demonstrate the computational feasibility of our approach using data from a real-life airline application.
On Throughput Maximization in Constant Travel-Time Robotic Cells
Authors: Milind Dawande, Chelliah Sriskandarajah, Suresh Sethi
Venue: Manufacturing Service Operations Management (2002)

We consider the problem of scheduling operations in bufferless robotic cells that produce identical parts. The objective is to find a cyclic sequence of robot moves that minimizes the long-run average time to produce a part or, equivalently, maximizes the throughput rate. The robot can be moved in simple cycles that produce one unit or, in more complicated cycles, that produce multiple units. Because one-unit cycles are the easiest to understand, implement, and control, they are widely used in industry. We analyze one-unit cycles for a class of robotic cells calledconstant travel-time robotic cells. We complete a structural analysis of the class of one-unit cycles and obtain a polynomial time algorithm for finding an optimal one-unit cycle.Constant travel-time robotic cells are used in real manufacturing operations that the authors have encountered during their interactions with companies. The results and the analysis in this paper offer practitioners (i) a tool to experiment with and study the design of a proposed robotic cell during a prototyping exercise, (ii) a lower bound on the throughput of a robotic cell to help them make an informed assessment of the ultimate productivity level, and (iii) a benchmark throughput level (for comparison purposes) for robotic cells whose operations differ slightly from those discussed in this paper.
Interface solvers and preconditioners of domain decomposition type for multiphase flow in multiblock porous media
Authors: Ivan Yotov
Venue: Scientific computing and applications (2001)

A multiblock mortar approach to modeling multiphase flow in porous media decomposes the simulation domain into a series of blocks with possibly different physical and numerical models employed in each block. Matching conditions along the interfaces are imposed through the use of mortar finite elements. A parallel domain decomposition algorithm reduces the algebraic nonlinear system to an interface problem which is solved via a nonlinear multigrid with Newton-GMRES smoothing.
Exact and approximate methods for data directed microaggregation in one or more dimensions
Authors: Gordon Sande
Venue: International Journal of Uncertainty, Fuzziness and Knowledge-Based Systems (2002)

Microaggregation is a technique for the protection of the confidentiality of respondents in microdata releases. It is used for economic data where respondent identifiability is high. Microaggregation releases the averages of small groups in which no single respondent is dominant. It was developed for univariate data. The data was sorted and the averages of adjacent fixed size groups were reported. The groups can be allowed to have varying sizes so that no group will include a large gap in the sorted data. The groups become more homogeneous when their boundaries are sensitive to the distribution of the data. This is like clustering but with the number of clusters chosen to be as large as possible subject to homogeneous clusters and a minimum cluster size. Approximate methods based on comparisons are developed. Exact methods based on linear optimization are also developed. For bivariate, or higher dimensional, data the notion of adjacency is defined even though sorting is no longer well defined. The constraints for minimum cluster size are also more elaborate and not so easily solved. We may also use only a triangulation to limit the number of adjacencies to be considered in the algorithms. Hybrids of the approximate and exact methods combine the strengths of each strategy.
Extended-Enterprise Supply-Chain Management at IBM Personal Systems Group and Other Divisions
Authors: Grace Lin, Markus Ettl, Steve Buckley, Sugato Bagchi, David D. Yao, Bret L. Naccarato, Rob Allan, Kerry Kim, Lisa Koenig
Venue: Interfaces (2000)

In 1994, IBM began to reengineer its global supply chain. It wanted to achieve quick responsiveness to customers with minimal inventory. To support this effort, we developed an extended-enterprise supply-chain analysis tool, the Asset Management Tool (AMT). AMT integrates graphical process modeling, analytical performance optimization, simulation, activity-based costing, and enterprise database connectivity into a system that allows quantitative analysis of extended supply chains. IBM has used AMT to study such issues as inventory budgets, turnover objectives, customer-service targets, and new-product introductions. We have implemented it at a number of IBM business units and their channel partners. AMT benefits include over $750 million in material costs and price-protection expenses saved in 1998.
Estimating Bounds on the Reliability of Diverse Systems
Authors: Peter Popov, Lorenzo Strigini, John May, Silke Kuball
Venue: IEEE Transactions on Software Engineering (2003)

We address the difficult problem of estimating the reliability of multiple-version software. The central issue is the degree of statistical dependence between failures of diverse versions. Previously published models of failure dependence described what behavior could be expected ¿on average¿ from a pair of ¿independently generated¿ versions. We focus instead on predictions using specific information about a given pair of versions. The concept of ¿variation of difficulty¿ between situations to which software may be subject is central to the previous models cited, and it turns out to be central for our question as well. We provide new understanding of various alternative imprecise estimates of system reliability and some results of practical use, especially with diverse systems assembled from pre-existing (e.g., ¿off-the-shelf¿) subsystems. System designers, users, and regulators need useful bounds on the probability of system failure. We discuss how to use reliability data about the individual diverse versions to obtain upper bounds and other useful information for decision making. These bounds are greatly affected by how the versions' probabilities of failure vary between subdomains of the demand space or between operating regimes¿it is even possible in some cases to demonstrate, before operation, upper bounds that are very close to the true probability of failure of the system¿and by the level of detail with which these variations are documented in the data.
ActionWorkflow in Use: Clark County Department of Business License
Authors: Raul Medina-Mora, Kelly W. Cartron
Venue: Proceedings of the Twelfth International Conference on Data Engineering (1996)

In this paper we present the basic concepts of ActionWorkflow and a study of a successful implementation in Clark County Department of Business License. The Image/Workflow System reengineers a labyrinthine licensing system into simplistic processes that are more customer oriented, yield superior productivity, establish a work-in-progress tracking mechanism, and archive the resulting licensing processes permanently on an unalterable optical storage system.
Modeling and Solving the Crew Rostering Problem
Authors: Alberto Caprara, Paolo Toth, Daniele Vigo, Matteo Fischetti
Venue: Operations Research (1998)

The Crew Rostering Problem (CRP) aims at determining an optimal sequencing of a given set of duties into rosters satisfying operational constraints deriving from union contract and company regulations. Previous work on CRP addresses mainly urban mass-transit systems, in which the minimum number of crews to perform the duties can easily be determined, and the objective is to evenly distribute the workload among the crews. In typical railway applications, however, the roster construction has to take into account more involved sequencing rules, and the main objective is the minimization of the number of crews needed to perform the duties. In this paper we propose a basic model for CRP, and describe a Lagrangian lower bound based on the solution of an assignment problem on a suitably defined graph. The information obtained through the lower bound computation is used to drive an effective algorithm for finding a tight approximate solution to the problem. Computational results for real-world instances from railway applications involving up to 1,000 duties are presented, showing that the proposed approach yields, within short computing time, lower and upper bound values that are typically very close. The code based on the approach we propose won the FARO competition organized by the Italian railway company, Ferrovie dello Stato SpA, in 1995.
Grid programming: some indications where we are headed
Authors: D. Laforenza
Venue: Parallel Computing (2002)

Grid computing enables the development of large scientific applications on an unprecedented scale. Grid-aware applications, also called meta-applications or multi-disciplinary applications, make use of coupled computational resources that are not available at a single site. In this light, the Grids let scientists solve larger or new problems by pooling together resources that could not be coupled easily before. It is well known that the programmer's productivity in designing and implementing efficient distributed/parallel applications on high-performance computers is still usually a very time-consuming task. Grid computing makes the situation worse. Consequently, the development of Grid programming environments that would enable programmers to efficiently exploit this technology is an important and hot research issue.After an introduction on the main Grid programming issues, this paper will review the most important approaches/projects conducted in this field worldwide.
Intelligent filtering with genetic algorithms and fuzzy logic
Authors: María J. Martín-Bautista, María-Amparo Vila, Daniel Sánchez, Henrik L. Larsen
Venue: Technologies for constructing intelligent systems: Tasks (2002)

We present two different approaches combining fuzzy information retrieval of documents with genetic algorithms, and the pre-processing stage of classification called feature selection. The differences between these approaches lie basically in the target of the fitness function selected. In the first approach, the Term-Oriented Model, the fitness function is based on a measure to find the most discriminatory terms, by rewarding not only the terms from the good documents, but also those from the bad ones, if they are considered as good partial classifiers. However, the aim of the Document-Oriented Model, as traditionally, is to rank the documents by relevance. So, the best chromosome represents the optimal query. The fuzzy weighting scheme used in this model considers also the discriminatory terms by introducing the knowledge about the user preferences in the genes, but rewarding the genes belonging to the good documents.
LFSR Characteristic Polynomials for Pseudo-Exhaustive TPG with Low Number of Seeds
Authors: Dimitri Kagaris, Spyros Tragoudas
Venue: Journal of Electronic Testing: Theory and Applications (2003)

A fully scanned digital circuit can be tested pseudo-exhaustively by first introducing a number of extra bypass storage cells to limit the test-phase input dependency of each test-phase output and then using a Linear Feedback Shift Register (LFSR) to feed the chain of the original scan cells and the extra cells. For the design of the LFSR, the goal is to minimize the pseudo-exhaustive test length with low hardware overhead. If the LFSR uses a primitive characteristic polynomial then it requires only one seed, but the candidate primitive polynomials may all fail to satisfy the target test length. In this paper, we present a methodology that enlarges the list of candidate polynomials, if the prescribed number of seeds is more than one. Experimental results show that the new candidate polynomials are often instrumental in satisfying the given test length and seed restriction.
Migration control for mobile agents based on passport and visa
Authors: Sheng-Uei Guan, Tianhan Wang, Sim-Heng Ong
Venue: Future Generation Computer Systems (2003)

Research on mobile agents has attracted much attention as this paradigm has demonstrated great potential for the next-generation e-commerce. Proper solutions to security-related problems become key factors in the successful deployment of mobile agents in e-commerce systems. We propose the use of passport and visa (P/V) for securing mobile agent migration across communities based on the SAFER (secure agent fabrication, evolution, and roaming) for e-commerce framework. P/V not only serve as up-to-date digital credentials for agent-host authentication, but also provide effective security mechanisms for online communities to control mobile agent migration. Protection for mobile agents, network hosts, and online communities is enhanced using P/V. We discuss the design issues in detail and evaluate the implementation of the proposed system.
Constructing complex minds through multiple authors
Authors: Mark Humphrys, Ciarán O'Leary
Venue: Proceedings of the seventh international conference on simulation of adaptive behavior on From animals to animats (2002)

The World-Wide-Mind (WWM) was introduced in [Humphrys, 2001]. For a short introduction see [Humphrys, 2001a]. Briefly, this is a scheme for putting animat "minds" online (as WWM "servers") so that large complex minds may be constructed from many remote components. The aim is to address the scaling up of animat research, or how to construct minds more complex than could be written by one author (or one research group).The first part of this paper describes how a number of existing animat architectures could be implemented as WWM servers. Any unified mind can easily map to a single WWM server. So most of the discussion here is on action selection (or behavior or goal selection), where each module could be a different WWM server (written by a different author).The second part of this paper describes the first implementation of WWM servers and clients, and explains in particular how to write a WWM server. Most animats researchers are programmers but not network programmers. Almost all protocols for remote services (CORBA, SOAP, etc.) assume the programmer is a networks specialist. This paper rejects these solutions, and shows how any animats researcher can put their animat "mind" or "world" online as a server by simply converting it into a command-line program that reads standard input and writes to standard output.
SAMAA: a software for air quality modelling and analysis
Authors: C. Gueguen, A. Mangin
Venue: Development and application of computer techniques to environmental studies (2002)

SAMAA is a user friendly software developed to simulate air pollution events at medium and regional scale. Five modules compose this system : a meteorological model, a GIS based emission model, a photochemical model, a dispersion module and a GIS based visualisation application. This system allows the simulation of the impact on air quality of various emissions under specific meteorological conditions. SAMAA has been validated against real experiments and has demonstrated to be in good accordance with the real data. It has now been deployed on two French cities (Nantes and Clermont-Ferrand) where the air quality survey networks use it for air quality management and engineering studies. Thanks to its flexibility, the emission module of SAMAA is presently under implementation on the city of Bogota (Colombia).
Integer Linear Programming and Constraint Programming Approaches to a Template Design Problem
Authors: Les Proll, Barbara Smith
Venue: INFORMS Journal on Computing (1998)

We describe a design problem arising in the color printing industry and discuss a number of integer linear programming and constraint programming approaches to its solution. Despite the apparent simplicity of the problem it presents a challenge for both approaches. We present results for three typical cases and show that the constraint programming approach provides better results, although in some cases after considerable handcrafting. We also show that the results obtained by constraint programming can be improved by a simple goal programming model.
A secure infrastructure for service discovery and access in pervasive computing
Authors: Jeffrey Undercoffer, Filip Perich, Andrej Cedilnik, Lalana Kagal, Anupam Joshi
Venue: Mobile Networks and Applications (2003)

Security is paramount to the success of pervasive computing environments. The system presented in this paper provides a communications and security infrastructure that goes far in advancing the goal of anywhere-anytime computing. Our work securely enables clients to access and utilize services in heterogeneous networks. We provide a service registration and discovery mechanism implemented through a hierarchy of service management. The system is built upon a simplified Public Key Infrastructure that provides for authentication, non-repudiation, anti-playback, and access control. Smartcards are used as secure containers for digital certificates. The system is implemented in Java and we use Extensible Markup Language as the sole medium for communications and data exchange. Currently, we are solely dependent on a base set of access rights for our distributed trust model however, we are expanding the model to include the delegation of rights based upon a predefined policy. In our proposed expansion, instead of exclusively relying on predefined access rights, we have developed a flexible representation of trust information, in Prolog, that can model permissions, obligations, entitlements, and prohibitions. In this paper, we present the implementation of our system and describe the modifications to the design that are required to further enhance distributed trust. Our implementation is applicable to any distributed service infrastructure, whether the infrastructure is wired, mobile, or ad hoc.
Homework exercises can be found all over the place
Authors: Charles M. Shub
Venue: Journal of Computing Sciences in Colleges (2001)

This paper gives an overview of some applications of computing in the arena of serving as the editor of a scholarly journal. The discussion is then focused on adaptation of portions of the system as homework exercises.