ppxscal/embedding_network huggingface dataset:
A Stochastic Model of Airline Operations
Authors: Jay M. Rosenberger, Andrew J. Schaefer, David Goldsman, Ellis L. Johnson, Anton J. Kleywegt, George L. Nemhauser
Venue: Transportation Science (2002)

We present a stochastic model of the daily operations of an airline. Its primary purpose is to evaluate plans, such as crew schedules, as well as recovery policies in a random environment. We describe the structure of the stochastic model, sources of disruptions, recovery policies, and performance measures. Then, we describe SimAir--our simulation implementation of the stochastic model, and we give computational results. Finally, we give future directions for the study of airline recovery policies and planning under uncertainty.
CAD computation for manufacturability: can we save VLSI technology from itself?
Authors: Mark Lavin, Lars Liebmann
Venue: Proceedings of the 2002 IEEE/ACM international conference on Computer-aided design (2002)

Every 18 to 24 months, the areal density of VLSI doubles and the predicted date for the End Of CMOS Scaling is pushed out approximately 18 to 24 months. This rate of growth has been controlled mainly by the increasing capabilities of lithographic patterning. However, the rate of improvement of lithography systems in key physical parameters such as illumination wavelength has begun to slow. To make up the shortfall, lithography has increasingly turned to using CAD tools to transform the geometric shapes in designs into shapes on photomasks which have been compensated for systematic pattern-distorting effects. As the requirements for this compensation grow, however, it becomes increasingly difficult to hide in post-tapeout data preparation, and must be considered in back-end design tools and methodologies. We describe a number of the challenges to lithographic patterning, highlighting the factors that limit "physical scaling" and introduce the layout-to-mask shape transformations that compensate for these limitations. We describe the implementation of these transformations in general-purpose and specialized CAD tools, pointing out challenges like growth of computation effort. Finally, we describe how limitations of post-tapeout compensation drive the need for "litho-aware" physical design tools, showing examples in cell design, place-and-route, and layout migration.
From Stochastic Petri Nets to Markov Regenerative Stochastic Petri Nets
Authors: Kishor S. Trivedi, Antonio Puliafito, Dimitris Logothetis
Venue: Proceedings of the 3rd International Workshop on Modeling, Analysis, and Simulation of Computer and Telecommunication Systems (1995)

In this paper we survey the Petri net literature and focus on Petri nets with generally distributed transition firing times. In the framework of Markov regenerative stochastic Petri nets (MRSPN) we develop and solve two examples to illustrate the modeling power of MRSPNs and provide our experience on solution techniques for transient measures.
Cancerous nuclei detection on digitized pathological lung color images
Authors: Mohamed Sammouda, Rachid Sammouda, Noboru Niki, Naohito Yamaguchi, Noriyuki Moriyama
Venue: Computers and Biomedical Research (2002)

In this paper, we propose a methodology (in the form of a software package) for automatic extraction of the cancerous nuclei in lung pathological color images. We first segment the images using an unsupervised Hopfield artificial neural network classifier and we label the segmented image based on chromaticity features and histogram analysis of the RGB color space components of the raw image. Then, we fill the holes inside the extracted nuclei regions based on the maximum drawable circle algorithm. All corrected nuclei regions are then classified into normal and cancerous using diagnostic rules formulated with respect to the rules used by experimented pathologist. The proposed method provides quantitative results in diagnosing a lung pathological image set of 16 cases that are comparable to an expert's diagnosis.
Upper bounds for restricted splicing
Authors: Hendrik Jan Hoogeboom, Nikè van Vugt
Venue: Formal and natural computing (2002)

We determine or improve upper bounds for non-iterated splicing in length-increasing, length-decreasing, same-length and self splicing mode.
Access control with IBM Tivoli access manager
Authors: Günter Karjoth
Venue: ACM Transactions on Information and System Security (TISSEC) (2003)

Web presence has become a key consideration for the majority of companies and other organizations. Besides being an essential information delivery tool, the Web is increasingly being regarded as an extension of the organization itself, directly integrated with its operating processes. As this transformation takes place, security grows in importance. IBM Tivoli Access Manager offers a shared infrastructure for authentication and access management, technologies that have begun to emerge in the commercial marketplace. This paper describes the Authorization Service provided by IBM Tivoli Access Manager for e-business (AM) and its use by AM family members as well as third-party applications. Policies are defined over a protected object namespace and stored in a database, which is managed via a management console and accessed through an Authorization API. The protected object namespace abstracts from heterogeneous systems and thus enables the definition of consistent policies and their centralized management. ACL inheritance and delegated management allow these policies to be managed efficiently. The Authorization API allows applications with their own access control requirements to decouple authorization logic from application logic. Policy checking can be externalized by using either a proxy that sits in front of the Web servers and application servers or a plug-in that examines the request. Thus, AM familiy members establish a single entry point to enforce enterprise policies that regulate access to corporate data.
The Aircraft Maintenance Routing Problem
Authors: Ram Gopalan, Kalyan T. Talluri
Venue: Operations Research (1998)

Federal aviation regulations require that all aircraft undergo maintenance after flying a certain number of hours. To ensure high aircraft utilization, maintenance is done at night, and these regulations translate into requiring aircraft to overnight at a maintenance station every three to four days (depending on the fleet type), and to visit a balance-check station periodically. After the schedule is fleeted, the aircraft are routed to satisfy these maintenance requirements. We give fast and simple polynomial-time algorithms for finding a routing of aircraft in a graph whose routings during the day are fixed, that satisfies both the three-day maintenance as well as the balance-check visit requirements under two different models: a static infinite-horizon model and a dynamic finite-horizon model. We discuss an implementation where we embed the static infinite-horizon model into a three-stage procedure for finding a maintenance routing of aircraft.
Using ethnography to design a mass detection tool (MDT) for the early discovery of insurance fraud
Authors: Thomas Ormerod, Nicola Morley, Linden Ball, Charles Langley, Clive Spenser
Venue: CHI '03 extended abstracts on Human factors in computing systems (2003)

We describe a Mass Detection Tool (MDT) for early detection of insurance fraud. Ethnography was used to specify needs and process, capture expertise, and design an interface for triggering fraud indicators while capturing unexpected anomalies detected by claims handlers. The MDT uses a dynamic Bayesian Belief Network of fraud indicators, whose weights are determined by how predictive each indicator is of specific types of fraud. The system uses automated knowledge updating to keep pace with dynamically changing fraud, adding new indicators that emerge from patterns of repeated anomalies.
A nonstandard Euler scheme for y″+g(y)y′+f(y)y=0
Authors: H. Kojouharov, B. Welfert
Venue: Journal of Computational and Applied Mathematics (2003)

We introduce a nonstandard Euler scheme for solving the differential equation y" + g(y)y' + f(y)y = 0 which has the same linear stability properties as the differential equation and is conservative when g = 0. The method is based on a physically motivated reduction of the equation to a system of two first-order equations and the use of Lie group integrators. The method is demonstrated on a few examples and compared to a standard MATLAB adaptive solver.
A Robust Method for Soft IP Handover
Authors: Hosei Matsuoka, Takeshi Yoshimura, Tomoyuki Ohya
Venue: IEEE Internet Computing (2003)

The mobile multimedia streaming protocol supports bicasting and forward error correction for end-to-end connections, increasing the quality of wireless multimedia applications.
Due-Date Scheduling: Asymptotic Optimality of Generalized Longest Queue and Generalized Largest Delay Rules
Authors: Jan A. Van Mieghem
Venue: Operations Research (2003)

Consider the following due-date scheduling problem in a multiclass, acyclic, single-station service system: Any classk job arriving at timet must be served by its due datet+ D k . Equivalently, its delayt kmust not exceed a given delay or lead-timeD k . In a stochastic system, the constraintt k=D kmust be interpreted in a probabilistic sense. Regardless of the precise probabilistic formulation, however, the associated optimal control problem is intractable with exact analysis. This article proposes a new formulation which incorporates the constraint through a sequence of convex-increasing delay cost functions. This formulation reduces the intractable optimal scheduling problem into one for which the GeneralizedcÂµ (G cÂµ) scheduling rule is known to be asymptotically optimal. The G cÂµ rule simplifies here to a generalized longest queue (GLQ) or generalized largest delay (GLD) rule, which are defined as follows. LetN kbe the number of classk jobs in system,? ktheir arrival rate, anda kthe age of their oldest job in the system. GLQ and GLD are dynamic priority rules, parameterized by?: GLQ( ?)serves FIFO within class and prioritizes the class with highest index? kN k , whereas GLD( ?)uses index? k? ka k .The argument is presented first intuitively, but is followed by a limit analysis that expresses the cost objective in terms of the maximal due-date violation probability. This proves that GLQ( ?*)and GLD( ?*), where?*, k= 1/ ? kD k , asymptotically minimize the probability of maximal due-date violation in heavy traffic. Specifically, they minimize lim inf n ?8 Pr{max k sup s?[0,t ]t k ( ns)/ n 1/2D k=x} for all positivet andx, wheret k ( s) is the delay of the most recent classk job that arrived before times. GLQ with appropriate parameter ? a also reduces "total variability" because it asymptotically minimizes a weighted sum of ath delay moments. Properties of GLQ and GLD, including an expression for their asymptotic delay distributions, are presented.
Design methodology for a modular service-driven network processor architecture
Authors: Maria Gabrani, Gero Dittmann, Andreas Döring, Andreas Herkersdorf, Patricia Sagmeister, Jan van Lunteren
Venue: Computer Networks: The International Journal of Computer and Telecommunications Networking (2003)

We present a design methodology for a modular network processor architecture that leads to a balanced, servicedefined mix between programmable processor cores, configurable hardware assists, and specialized coprocessors. Whereas the processor cores address the flexibility and extendibility needs of the networking market, the hardware components offload the processors, or even allow them to be bypassed for certain network processor-typical tasks to optimize chip area, performance, and power efficiency. We describe the rationale behind the selected functional partitioning in hardware and software components and discuss the challenges of designing the hardware components, and of organizing and integrating the programmable cores. We quantify our approach with a performance evaluation of the overall system.
Self organisation in a simple task of motor control
Authors: Christian R. Linder
Venue: Proceedings of the seventh international conference on simulation of adaptive behavior on From animals to animats (2002)

This paper provides a mechanism that is able to self adjust a network that is used as a feedback controller in a motor control system. The following disturbances are considered: (1) synaptic drift, (2) a change in the slope of the sensor characteristics and (3) a shift along the ordinate in the sensor characteristics. I show that these disturbances can be counterbalanced, if the following conditions are fullfilled: (1) The sign of each synapse, i. e. being an excitatory or an inhibitory one, but not its exact value, is genetically determined. (2) The input characteristics are described by straight lines. (3) A mechanism is required that changes the input synapses of a cell in a way that the longterm influence of positive (excitatory) and negative (inhibitory) synapses cancel each other. (4) Both input values have to be distributed in a way that they vary around the same mean value. No explicit knowledge, neither concerning the shape of the trajectory nor concerning the involved sensor characteristics is required. This solution is possible because in the architecture proposed here each neuron is endowed with two inputs of opposite sign.
Stationary Policies in Multiechelon Inventory Systems with Deterministic Demand and Backlogging
Authors: Gamze Tokol, David Goldsman, Daniel H. Ockerman, James J. Swain, Fangruo Chen
Venue: Operations Research (1998)

A stationary policy conducts replenishment activities-the placement and fulfillment of orders-in a stationary fashion. That is, each facility receives a constant batch (facility specific) in equal time intervals (facility specific) under a stationary policy. Although the advantages of stationary policies are clear (i.e., smooth operations), they represent a restriction in policy selection. This paper investigates how costly this restriction can be. For two multiechelon systems (serial and distribution) with deterministic demand and backlogging, we show that stationary policies are 70%-effective. This bound is tight in the sense that an example exists where the bound is reached. On the other hand, the average effectiveness of stationary policies is very high. In a set of 1,000 randomly generated numerical examples, we observed that the average effectiveness was 99%, and the standard deviation was 1.5%. The numerical examples also suggest that the performance of stationary policies deteriorates in systems where the setup cost decreases dramatically from an upstream stage to a downstream stage. Finally, a key building block of the above results is the existing lower bounds on the average costs of all feasible policies in the above systems. We provide a simpler derivation of these bounds.
The reflective practitioner perspective in software engineering education
Authors: Orit Hazzan
Venue: Journal of Systems and Software (2002)

This paper focuses on the application of the reflective practitioner (RP) perspective to the profession of software engineering (SE). The RP perspective guides professional people to rethink their professional creations during and after the accomplishment of the creation process. Analysis of the field of SE supports the adoption of the RP perspective to SE in general and to SE education in particular. The RP perspective emphasizes the studio--the basic training method in architecture schools--as the educational environment for design studies. In such studios students develop projects with a close guidance of a tutor. Analysis of the kind of tasks that architecture students are working on and a comparison of these tasks to the problems that SE students are facing, suggest that the studio may be an appropriate teaching method in SE as well. The paper presents the main ideas of the RP perspective and examines its fitness to SE in general and to SE education in particular. The discussion is based on analysis of the RP perspective and of the SE profession, visits to architecture studios, and conversations with tutors in architecture studios and with computing science practitioners.
Fast methods for simulation of biomolecule electrostatics
Authors: Shihhsien S. Kuo, Michael D. Altman, Jaydeep P. Bardhan, Bruce Tidor, Jacob K. White
Venue: Proceedings of the 2002 IEEE/ACM international conference on Computer-aided design (2002)

Computer simulation is an important tool for improving our understanding of biomolecule electrostatics, in part to aid in drug design. However, the numerical techniques used in these simulation tools do not exploit fast solver approaches widely used in analyzing integrated circuit interconnects. In this paper we describe one popular formulation used to analyze biomolecule electrostatics, present an integral formulation of the problem, and apply the precorrected-FFT method to accelerate the solution of the integral equations.
A DFT Technique for Testing High-Speed Circuits with Arbitrarily Slow Testers
Authors: Muhammad Nummer, Manoj Sachdev
Venue: Journal of Electronic Testing: Theory and Applications (2003)

This paper presents a design for testability (DFT) technique for testing high-speed circuits with a low-speed test mode clock. With this technique, the test mode clock frequency can be reduced with virtually no lower limit. Even with the reduced speed requirement on the automatic test equipment (ATE), our method facilitates the test of the rated-speed timing and allows performance binning. A CMOS implementation of the DFT hardware with 50 ps timing accuracy is presented. To demonstrate the effectiveness of the technique we designed a 16-bit, 1.4 GHz pipelined multiplier as a test vehicle. Simulations using a test clock frequency much lower than the rated clock frequency show that delay faults of sizes as small as 50 ps are detected and that the new test technique provides correct performance binning.
The cardinality constrained covering traveling salesman problem
Authors: R. Patterson, E. Rolland
Venue: Computers and Operations Research (2003)

In this paper, we propose a new method for partitioning a graph into an unspecified number of Hamiltonian subgraphs with minimum and maximum size requirements on the subgraphs. We refer to this problem as the cardinality constrained covering traveling salesman problem (CCC-TSP). Special cases of this problem include the assignment problem and the traveling salesman problem (TSP). This paper proposes a heuristic solution methodology to a general class of problems that is important because by setting the parameters, one can obtain different important problems including the traveling salesman problem and the assignment problem. Although these specific problems have been studied extensively in the past, the generalized version proposed here and the solution methodology set forth, are new contributions. The solution methodology presented in this paper produces solutions within known error bounds of the optimal solution value. The computational results indicate an ability to obtain very high-quality solutions by expending a modest computational effort for problems in excess of 200 nodes.
An automated incremental finite element study of Hertzian cone crack growth
Authors: Cenk Kocer
Venue: Finite Elements in Analysis and Design (2003)

In this study a novel finite element method is presented for modeling Hertzian cone crack growth. The method involves the automation of an existing incremental finite element technique. The local stress fields in the vicinity of the crack tip at each stage of growth of the crack are determined, and the crack is advanced by a small amount along the direction of maximum strain energy release. The method is used to investigate crack growth behavior in two well-known fracture systems: the simple edge crack system and the Hertzian indentation system. It is shown that the automated incremental finite element method is accurate and reliable, and generates a crack trajectory that agrees closely with experimentally measured trajectories. It is found that a typical trajectory involving 30 incremental steps can be generated in approximately 3 h using a computer with a processor having a clock rate of 200 MHz.
Information Technology Assimilation in Firms: the Influence of Senior Leadership and it Infrastructures
Authors: Curtis P. Armstrong, V. Sambamurthy
Venue: Information Systems Research (1999)

assimilation is regarded as an important outcome in the efforts of firms to leverage the potential of information technologies in their business activities and strategies. Despite significant investments in information technology, considerable diversity exists in how well firms have been able to assimilate IT and leverage the business value of IT. This research draws upon the emerging knowledge-based and resource-based views of the firm to examine the influence of three factors on IT assimilation: (i) quality of senior leadership, (ii) sophisti- cation of IT infrastructures, and (iii) organizational size. Drawing upon a large-scale sample survey where responses were obtained from CIOs and senior business executives who were members of the firms' top management teams, the study examines a variety of mostly nor- mative prescriptions. The findings provide robust evidence about the impacts of CIOs' busi- ness and IT knowledge on IT assimilation. Further, we find that CIOs' membership in top management teams and their informal interactions with TMT members enhance their knowl- edge, particularly their business knowledge. We find that the intensity of the relationship between CIO's interactions with the top management team and their level of IT and business knowledge is much stronger in firms that articulate a transformational IT vision. The sophis- tication of IT infrastructures was also found to significantly impact IT assimilation. Surpris- ingly, the IT knowledge of senior business executives was not found to be a significant influ- ence on IT assimilation. The implications of these findings for evolving a deeper understanding of the dynamics underlying IT assimilation are presented.
Role-Based Access Control With X.509 Attribute Certificates
Authors: David W. Chadwick, Alexander Otenko, Edward Ball
Venue: IEEE Internet Computing (2003)

The Permis privilege management infrastructure is a role-based access control system that uses XML-based local policies and a Java API.
Learning to autonomously select landmarks for navigation and communication
Authors: Jason Fleischer, Stephen Marsland
Venue: Proceedings of the seventh international conference on simulation of adaptive behavior on From animals to animats (2002)

Selecting landmarks for use by a navigating mobile robot is important for map-building systems. However, it can also provide a way by which robots can communicate route information, so that one robot can tell another how to find a goal location. A route through an environment can be described by the landmarks encountered along the path, and a robot following the same path must identify the perceptions corresponding to the actual landmarks in the description in order to localise itself. This paper presents an algorithm to automatically select landmarks, choosing as landmarks places that do not fit into a model of typical perceptions acquired by the robot. Four methods of aligning the landmarks between different runs on the same route are also presented. The different alignment methods are evaluated according to both how well they produce matching landmarks and how suitable such alignment methods would be for use in a route communication system.