ppxscal/embedding_network huggingface dataset:
DMMX: dynamic memory management extensions
Authors: J. Morris Chang, Witawas Srisa-an, Chia-Tien Dan Lo, Edward F. Gehringer
Venue: Journal of Systems and Software (2002)

Dynamic memory management allows programmers to be more productive and increases system reliability and functionality. However, software algorithms for memory management are slow and non-deterministic. It is well known that object-oriented applications tend to be dynamic memory intensive. This has led programmers to eschew dynamic memory allocation for many real-time and embedded systems. Instead, programmers using Java or C++ as a development language frequently decide to allocate memory statically instead of dynamically. In this paper, we present the design of a bitmap-based memory allocator implemented primarily in combinational logic to allocate memory in a small, predictable amount of time. It works in conjunction with an application-specific instruction-set extension called the dynamic memory management extension (DMMX). Allocation is done through a complete binary tree of combinational logic, which allows constant-time object creation. The garbage collection algorithm is mark sweep, where the sweeping phase can be accomplished in constant time. This hardware scheme can greatly improve the speed and predictability of dynamic memory management. The proposed DMMX is an add-on approach, which allows easy integration into any CPU, hardware-implemented Java virtual machine, or processor in memory.
Implementing a Distribution-Network Decision-Support System at Pfizer/Warner-Lambert
Authors: Vijay Gupta, Emmanuel Peters, Tan Miller, Kelvin Blyden
Venue: Interfaces (2002)

We constructed a decision-support system (DSS) to help the distribution network of Pfizer/Warner Lambert to plan its operations. Using OR tools, databases, programming languages, and spreadsheets, this system supports decisions concerning daily operations, annual planning, and long-run strategic planning. This DSS improved the firm's ability to make rapid, better-informed decisions in many different areas of distribution and supply chain ranging from individual customer deliveries to long-term manufacturing location and technology.
On t-norms based measures of specificity
Authors: Luis Garmendia, Ronald R. Yager, Enric Trillas, Adela Salvador
Venue: Fuzzy Sets and Systems (2003)

This paper gives a general expression for families of measures of specificity of a fuzzy set or a possibility distribution based on three t-norms and a negation. Other known measures of specificity are particular cases of this expression and new examples are provided.
Optimal control and parameter selection problems in forest stand management
Authors: O. Chikumbo, I. M. Y. Mareels
Venue: Development and application of computer techniques to environmental studies (2002)

A typical stand forestry problem for determining an optimal silvicultural regime is demonstrated in this paper, where an optimal number of trees at planting and a harvesting strategy over the crop rotation are resolved. The traditional approach for determining such strategies is to formulate a dynamic programming problem where the stages and decision variables are pre-determined in a forward recurrent procedure and thus eliminating any possibilities of an exhaustive search. This type of formulation is largely driven by the 'curse of dimensionality'. Our formulation is a combined optimal control and parameter selection problem using Pontryagin's maximum principle where, the optimal control part determines the harvesting strategy, and the parameter selection determines the initial number of trees planted. Dynamical models are developed as the building blocks of the optimal control and parameter selection formulation using Eucalyptus nitens data from intensively managed stands, courtesy of North Forests Products, Tasmania, Australia.
On the step-by-step construction of quasi: Monte Carlo integration rules that achieve strong tractability error bounds in weighted Sobolev spaces
Authors: I. H. Sloan, F. Y. Kuo, S. Joe
Venue: Mathematics of Computation (2002)

We develop and justify an algorithm for the construction of quasi-Monte Carlo (QMC) rules for integration in weighted Sobolev spaces; the rules so constructed are shifted rank-1 lattice rules. The parameters characterising the shifted lattice rule are found "component-by-component": the (d+1)-th component of the generator vector and the shift are obtained by successive 1-dimensional searches, with the previous d components kept unchanged. The rules constructed in this way are shown to achieve a strong tractability error bound in weighted Sobolev spaces. A search for n-point rules with n prime and all dimensions 1 to d requires a total cost of O(n3d2) operations. This may be reduced to O(n3d) operations at the expense of O(n2) storage. Numerical values of parameters and worst-ease errors are given for dimensions up to 40 and n up to a few thousand. The worst-case errors for these rules are found to be much smaller than the theoretical bounds.
Non-stationary and mutually dependent rainfall input and its stochastic response
Authors: Gaku Tanaka, Mutsuhiro Fujita, Masaru Kaido, Susumu Kumagai
Venue: Systems Analysis Modelling Simulation (2002)

Observed rainfall is a non-stationary and mutually dependant random variable. Based on the condition that the stochastic characteristics of rainfall are known, we derived differential equations whose solutions provide the first four moments of discharge output from a storage function runoff model. The validity of the derived differential equations was cross-checked by a simulation method. The results showed that it is possible to obtain the probability density function of discharge from the calculated first four moments of discharge.
Analysis of a duopoly game with delayed bounded rationality
Authors: M. T. Yassen, H. N. Agiza
Venue: Applied Mathematics and Computation (2003)

A dynamic of Cournot duopoly game is analyzed, where players use different production methods and choose their quantities with bounded rationality. A dynamic of nonlinear Cournot duopoly game is analyzed, where players choose quantities with delayed bounded rationality and similar methods of production. The equilibria of the corresponding discrete dynamical systems are investigated. The stability conditions of Nash equilibrium under a local adjustment process are studied. The stability of Nash equilibrium, as some parameters of the model are varied, gives rise to complex dynamics such as cycles of higher order and chaos. We show that firms using delayed bounded rationality have a higher chance of reaching Nash equilibrium. Numerical simulations are used to show bifurcations diagrams, stability regions and chaos.
On Markovian Multi-Class, Multi-Server Queueing
Authors: A. Van Harten, A. Sleptchenko
Venue: Queueing Systems: Theory and Applications (2003)

Multi-class multi-server queueing problems are a generalisation of the well-known M/M/k queue to arrival processes with clients of N types that require exponentially distributed service with different average service times. In this paper, we give a procedure to construct exact solutions of the stationary state equations using the special structure of these equations. Essential in this procedure is the reduction of a part of the problem to a backward second order difference equation with constant coefficients. It follows that the exact solution can be found by eigenmode decomposition. In general eigenmodes do not have a simple product structure as one might expect intuitively. Further, using the exact solution, all kinds of interesting performance measures can be computed and compared with heuristic approximations (insofar available in the literature). We provide some new approximations based on special multiplicative eigenmodes, including the dominant mode in the heavy traffic limit. We illustrate our methods with numerical results. It turns out that our approximation method is better for higher moments than some other approximations known in the literature. Moreover, we demonstrate that our theory is useful to applications where correlation between items plays a role, such as spare parts management.
Neumann problem for elliptic equation in Sobolev power weighted spaces
Authors: Josef Voldřích
Venue: Mathematics and Computers in Simulation (2003)

The Neumann problem for an elliptic equation in a bounded domain Ω ⊂ RN and for external forces with degenerations or singularities relating to the m-dimensional variety M ⊂ δ Ω are considered. The underlying ideas of proof of the existence of the considered problem solution are given for the remaining cases of N - m = 1 and N - m =2.
A scalable parallel fast multipole method for analysis of scattering from perfect electrically conducting surfaces
Authors: Bhanu Hariharan, Srinivas Aluru, Balasubramaniam Shanker
Venue: Proceedings of the 2002 ACM/IEEE conference on Supercomputing (2002)

In this paper, we develop a parallel Fast Multipole Method (FMM) based solution for computing the scattered electromagnetic fields from a Perfect Electrically Conducting (PEC) surface. The main contributions of this work are the development of parallel algorithms with the following characteristics: 1) provably efficient worst-case run-time irrespective of the shape of the scatterer, 2) communication-efficiency, and 3) guaranteed load balancing within a small constant factor. We have developed a scalable, parallel code and validated it against surfaces for which solution can be computed analytically, and against serial software. The efficiency and scalability of the code is demonstrated with experimental results on an IBM xSeries cluster. Though developed in the context of this particular application, our algorithms can be used in other applications involving parallel FMM.
Can'T See the Forest Because of the Decision Trees: a Critique of Decision Analysis in Survey Texts
Authors: Jonathan P. Caulkins, Edward H. Kaplan, Peter Lurie, Thomas O'Connor, Sung-Ho Ahn, Kenneth Chelst
Venue: Interfaces (1998)

Introductory survey texts in operations research and management science have one or two chapters on decision analysis. They vary little from text to text in the topics covered, focusing largely on the analytic aspects of decision analysis. Their authors ignore key elements of decision analysis and the barriers to its use. As a result, they provide little insight as to how decision analysis is used in the real world as part of an intuition-building process and as a communication tool. In a critical review of their presentations, I identify crucial missing or cursorily reviewed topics and emphasize the need for a structured approach that incorporates probabilistic concepts and trade-offs amongst objectives. I present an annotated list of references and a new outline for a six-hour overview of decision analysis (not including multiple objectives) as part of asemester-long OR/MS survey course.
Logical measure: structure of logical formula
Authors: Dragan Radojević
Venue: Technologies for constructing intelligent systems: tools (2002)

The structure of logical and/or pseudo-logical formula is introduced. The structure of logical formula is its characteristic invariant to its functional realization ({0,1}-valued, many-valued and/or [0,1]-valued logical function). The Boolean algebra is defined on the set of all n-ary logical structures. The fundamental principle of structural functionality is introduced. A logical discrete Choquet integral is defined as [0,1]-valued logical and pseudo-logical function for AND operator defined as min function.
Flexible Service Capacity: Optimal Investment and the Impact of Demand Correlation
Authors: Serguei Netessine, Gregory Dobson, Robert A. Shumsky
Venue: Operations Research (2002)

We consider a firm that provides multiple services using both specialized and flexible capacity. The problem is formulated as a two-stage, single-period stochastic program. The firm invests in capacity before the actual demand is known and optimally assigns capacity to customers when demand is realized. Sample applications include a car rental company's use of mid-sized cars to satisfy unexpectedly high demand for compact cars and an airline's use of business-class seats to satisfy economy-class demand. We obtain an analytical solution for a particular case, when services may be upgraded by one class. The simple form of the solution allows us to compare the optimal capacities explicitly with a solution that does not anticipate flexibility. Given that demand follows a multivariate normal distribution, we analytically characterize the effects of increasing demand correlation on the optimal solution. For the case with two customer classes, the effects of demand correlation are intuitive: Increasing correlation induces a shift from flexible to dedicated capacity. When there are three or more classes, there are also adjustments to the resources not directly affected by the correlation change. As correlation rises, these changes follow an alternating pattern (for example, if the optimal capacity of one resource rises, then the optimal capacity of the adjacent resource falls). These results make precise conjectures based on numerical experiments that have existed in the literature for some time.
QoS and SLA aspects across multiple management domains: the SEQUIN approach
Authors: Christos Bouras, Mauro Campanella, Michal Przybylski, Afrodite Sevasti
Venue: Future Generation Computer Systems (2003)

The aim of this work is to define and implement an end-to-end approach to quality of service (QoS), operating across multiple management domains and exploiting a combination of link layer technologies. The architecture for the Premium IP service is presented, which aims at offering the equivalent of an end-to-end virtual leased line service at the IP layer across multiple domains. Also, the results of the initial testing performed for the validation of the service and the provisioning model for Premium IP are described. The work presented has been carried out in the framework of SEQUIN, a European Commission-funded research project.
A high quality multi-level voltage source inverter suitable for high power/high voltage applications
Authors: M. Tarafdar Haque, S. H. Hosseini
Venue: Iranian Journal of Science and Technology (2002)

In this paper new magnitudes for DC side capacitors' voltages of a multi level voltage source inverter (MLVSI) are presented. Using these magnitudes of DC side capacitors voltages allow generation of ΣK=0N3K steps of AC output voltage by cascade connection of only N single-phase full bridge inverter (FBI). This subject has resulted in almost sinusoidal output voltage waveform. Approximated equal area pulse amplitude modulation (AEAPAM) technique is used to calculate the duration of each step of voltage, which has resulted in reduction of complexity of control circuit. A simple closed-loop controller is developed for controlling the voltages of DC side capacitors. Harmonic analysis and capacitor calculations are presented, too. Simulation results have been used to verify the overall operation of the proposed MLVSI in feeding a R-L load with a stepped sinusoidal waveform.
Scheduling with Opting Out: Improving upon Random Priority
Authors: Hervé Crès, Hervé Moulin
Venue: Operations Research (2001)

In a scheduling problem where agents can opt out, we show that the familiar random priority (RP) mechanism can be improved upon by another mechanism dubbed probabilistic serial (PS). Both mechanisms are nonmanipulable in a strong sense, but the latter is Pareto superior to the former and serves a larger (expected) number of agents. The PS equilibrium outcome is easier to compute than the RP outcome; on the other hand, RP is easier to implement than PS. We show that the improvement of PS over RP is significant but small: at most a couple of percentage points in the relative welfare gain and the relative difference in quantity served. Both gains vanish when the number of agents is large; hence both mechanisms can be used as a proxy of each other.
On the security of microaggregation with individual ranking: analytical attacks
Authors: Josep Domingo-Ferrer, Anna Oganian, Àngel Torres, Josep M. Mateo-Sanz
Venue: International Journal of Uncertainty, Fuzziness and Knowledge-Based Systems (2002)

Microaggregation is a statistical disclosure control technique. Raw microdata (i.e. individual records) are grouped into small aggregates prior to publication. With fixed-size groups, each aggregate contains k records to prevent disclosure of individual information. Individual ranking is a usual criterion to reduce multivariate microaggregation to univariate case: the idea is to perform microaggregation independently for each variable in the record. Using distributional assumptions, we show in this paper how to find interval estimates for the original data based on the microaggregated data. Such intervals can be considerably narrower than intervals resulting from subtraction of means, and can be useful to detect lack of security in a microaggregated data set. Analytical arguments given in this paper confirm recent empirical results about the unsafety of individual ranking microaggregation.
Generating adapters for concurrent component protocol synchronisation
Authors: Heinz W. Schmidt, Ralf H. Reussner
Venue: Proceedings of the IFIP TC6/WG6.1 Fifth International Conference on Formal Methods for Open Object-Based Distributed Systems V (2002)

In general few components are reused as they are. Often, available components are incompatible with what is required. This necessitates component adaptations or the use of adapters between components. In this paper we develop algorithms for the synthesis of adapters, coercing incompatible components into meeting requirements. We concentrate on adapters for concurrent systems, where adapters are able to resolve synchronisation problems of concurrent components. A new interface model for components, which includes protocol information, allows us to generate these adapters semi-automatically.
The equation S(1.2)+S(2.3)+...+S(n(n+1))=S(n(n+1)(n+2)/3)
Authors: Maohua Le
Venue: Smarandache notions (2002)

For any positive integer a, let S(a) be the Smarandache function of a. In this paper we prove that the title equation has only the solution n=1.
The essence of parallel Algol
Authors: Stephen Brookes
Venue: Information and Computation (2002)

We consider a parallel Algol-like language, combining procedures with shared-variable parallelism. Procedures permit encapsulation of common parallel programming idioms. Local variables provide a way to restrict interference between parallel commands. The combination of local variables, procedures, and parallelism supports a form of concurrent object-oriented programming. We provide a denotational semantics for this language, simultaneously adapting possible worlds to the parallel setting and generalizing transition traces to the procedural setting. This semantics supports reasoning about safety and liveness properties of parallel programs, and validates a number of natural laws of program equivalence based on noninterference properties of local variables. The semantics also validates familiar laws of functional programming. We also provide a relationally parallel semantics. This semantics supports standard methods of reasoning about representational independence, adapted to shared-variable programs. The clean design of the programming language and its semantics shows that procedures and shared-variable parallelism can be combined smoothly.
Deconvolution and regularization for numerical solutions of incorrectly posed problems
Authors: M. Iqbal
Venue: Journal of Computational and Applied Mathematics (2003)

In this paper, we have converted the Laplace transform into Fredholm integral equation of the first kind of convolution type, which is an ill-posed problem and used deconvolution and regularization method to solve it. The method is applied to various test examples taken from the literature.The method gives a good approximation to the true solution. Our results confirm that our method is competitive with other recently presented methods. The results are shown in the table and the diagrams.
Analysis of GSM/GPRS Cell with Multiple Data Service Classes
Authors: K. Al-Begain, I. Awan, D. D. Kouvatsos
Venue: Wireless Personal Communications: An International Journal (2003)

This paper is concerned with the performance modelling and evaluation of a General Packet Radio Service (GPRS) for a wireless Global System for Mobile telecommunication (GSM) cell involving both voice and multiple class data services under a complete partitioning scheme (CPS). The GPRS is modelled as a system of access and transfer queues in tandem having an external multiple class compound Poisson bursty traffic with geometrically distributed batches under first-come-first-served (FCFS) and generalised processor-sharing (PS) scheduling disciplines, respectively. The proposed queueing model is valid for both uplink and downlink connections and provides multiple class data services with different arrival rates, interarrival-time squared coefficients of variation (SCVs), file (burst) sizes and different PS discrimination service levels. Based on the principle of maximum entropy (ME), a product form approximation is characterised for the two queues in tandem, subject to queueing theoretic mean value constraints. The ME solution implies a decomposition of the system into individual single server building block queues, each of which can be analysed in isolation. Consequently, ME closed form expressions and simulation results for the aggregate state probability together with the marginal mean queue length and blocking probability are divised to assess the credibility of the ME solution and also to study the effect of external GPRS bursty traffic upon the performance of the wireless cell.
Heat transfer over an unsteady stretching surface with internal heat generation
Authors: E. M. A. Elbashbeshy, M. A. A. Bazid
Venue: Applied Mathematics and Computation (2003)

Heat transfer over an unsteady stretching surface with internal heat generation or absorption is studied. The governing time-dependent boundary layer equations are solved numerically. The velocity profiles, temperature profiles, the skin friction components on the unsteady stretching surface and rate of heat transfer are computed and discussed in detail for various values of the unsteadiness parameter, Prandtl number and heat source/sink parameter.
Largest empty rectangle among a point set
Authors: Jeet Chaudhuri, Subhas C. Nandy, Sandip Das
Venue: Journal of Algorithms (2003)

This work generalizes the classical problem of finding the largest empty rectangle among obstacles in 2D. Given a set P of n points, here a maximal empty rectangle (MER) is defined as a rectangle of arbitrary orientation such that each of its four boundaries contain at least one member of P and the interior of the rectangle is empty. We propose a very simple algorithm based on standard data structure to locate a MER of largest area in the plane. The worst-case time complexity of our algorithm is O(n3). Though the worst-case space complexity is O(n2), it reserves O(n log n) space on an average to maintain the required data structure during the execution of the algorithm.