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1

Online Stochastic Packing Applied to Display Ad Allocation  

Microsoft Academic Search

Inspired by online ad allocation, we study online stochastic packing linear\\u000aprograms from theoretical and practical standpoints. We first present a\\u000anear-optimal online algorithm for a general class of packing linear programs\\u000awhich model various online resource allocation problems including online\\u000avariants of routing, ad allocations, generalized assignment, and combinatorial\\u000aauctions. As our main theoretical result, we prove that a

Jon Feldman; Monika Henzinger; Nitish Korula; Vahab S. Mirrokni; Clifford Stein

2010-01-01

2

STOCHASTIC FORMULATIONS OF THE REDUNDANCY ALLOCATION PROBLEM  

Microsoft Academic Search

Previous research on the redundancy allocation problem for series-parallel systems has focused on deterministic versions where component reliability is assumed to be an exact value. This paper discusses alternative formulations which allow system reliability and mean time to failure to be treated as random variables. Stochastic formulations allow for explicit consideration of risk aversion, and thus, are more reflective of

David W. Coit; Alice E. Smith

1996-01-01

3

Solving Stochastic Nonlinear Resource Allocation Problems Using a Hierarchy of Twofold Resource Allocation Automata  

Microsoft Academic Search

In a multitude of real-world situations, resources must be allocated based on incomplete and noisy information. However, in many cases, incomplete and noisy information render traditional resource allocation techniques ineffective. The decentralized Learning Automata Knapsack Game (LAKG) was recently proposed for solving one such class of problems, namely the class of Stochastic Nonlinear Fractional Knapsack Problems. Empirically, the LAKG was

Ole-Christoffer Granmo; B. John Oommen

2010-01-01

4

A stochastic optimization approach to mine truck allocation  

Microsoft Academic Search

In the mining industry, truck assignment is an important and complex process and an optimal truck allocation can result in significant savings. In this paper, a truck allocation model is formulated using a chance-constrained, stochastic optimization approach that can accommodate uncertain parameters such as truckload and cycle time. A real-time hauling framework, which consists of the chance-constrained optimization model and

CHUNG H. TA; JAMES V. KRESTA; J. FRASER FORBES; H. J. Marquez

2005-01-01

5

Price-Based Resource Allocation in Wireless Ad Hoc Networks  

Microsoft Academic Search

The shared-medium multi-hop nature of wireless ad hoc networks poses fundamental challenges to the design of an effective resource allocation algorithm to maximize the aggregated utility of flows, while maintaining basic fairness among multiple flows. When previously proposed scheduling algorithms have been shown to perform well in providing fair shares of bandwidth among single-hop wireless flows, they did not consider

Yuan Xue; Baochun Li; Klara Nahrstedt

2003-01-01

6

Estimating technical and allocative inefficiency relative to stochastic production and cost frontiers  

Microsoft Academic Search

considered stochastic frontier production functions. This paper extends that work by considering the duality between stochastic frontier production and cost functions, under the assumptions of exact cost minimization (technical inefficiency only) and of inexact cost minimization (technical and allocative inefflciency). We show how to measure both types of inefficiency, and the associated cost of inefficiency. The techniques are illustrated using

Peter Schmidt; C. A. Knox Lovell

1979-01-01

7

Stochastic robustness metric and its use for static resource allocations  

Microsoft Academic Search

This research investigates the problem of robust static resource allocation for distributed computing systems operating under imposed Quality of Service (QoS) constraints. Often, such systems are expected to function in a physical environment replete with uncertainty, which causes the amount of processing required to fluctuate substantially over time. Determining a resource allocation that accounts for this uncertainty in a way

Vladimir Shestaka; Jay Smith; Anthony A. Maciejewski; Howard Jay Siegel

8

Resource allocation in stochastic, finite-capacity, multi-project systems through the cross entropy methodology  

Microsoft Academic Search

This paper addresses the problem of resource allocation in a finite-capacity, stochastic (random) and dynamic multi-project system. The system is modeled as a queuing network that is controlled by limiting the number of concurrent projects. We propose\\u000a a Cross Entropy (CE) based approach to determine near-optimal resource allocations to the entities that execute the projects.\\u000a The performance of the suggested

Izack Cohen; Boaz Golany; Avraham Shtub

2007-01-01

9

A novel QoS-aware resource allocation scheme for wireless ad hoc networks  

Microsoft Academic Search

Resource allocation is an important topic in wireless networks with inappropriate resource allocation causing congestion and unfairness to users. In this paper, a novel QoS-aware scheme is proposed for resource allocation in wireless ad hoc networks based on virtual price. Moreover, an iterative algorithm is proposed to achieve the optimal rates for a set of multipath sessions, resulting in maximizing

Bing-Qing Han; Guo-Fu Feng

2009-01-01

10

Optimal Resource Allocation in Wireless Ad Hoc Networks: A Price-Based Approach  

Microsoft Academic Search

The shared-medium multi-hop nature of wireless ad hoc networks poses fundamental challenges to the design of effective resource allocation algorithms that are optimal with respect to resource utilization and fair across different network flows. None of the existing resource allocation algorithms in wireless ad hoc networks have realistically considered end-to-end flows spanning multiple hops. Moreover, strategies proposed in wireline networks

Yuan Xue; Baochun Li; Klara Nahrstedt

2006-01-01

11

R-FRTDP: A Real-Time DP Algorithm with Tight Bounds for a Stochastic Resource Allocation Problem  

Microsoft Academic Search

Resource allocation is a widely studied class of problems in Operation Research and Artificial Intelligence. Specially, constrained stochastic resource allocation problems, where the assignment of a con- strained resource do not automatically imply the realization of the task. This kind of problems are generally addressed with Markov Decision Processes (mdps). In this paper, we present ecient lower and upper bounds

Camille Besse; Pierrick Plamondon; Brahim Chaib-draa

2007-01-01

12

An Application of Stochastic Programming with Weibull Distribution–Cluster Based Optimum Allocation of Recruitment in Manpower Planning  

Microsoft Academic Search

Recruitment of persons for various assignments with required talents in an organization is an important feature, since it plays a vital role in the growth of the organization. To achieve the required expertise in recruitment, in this paper Linear Stochastic Programming (LSP) is applied along with cluster analysis technique. The aim of this paper is to obtain an optimal allocation

M. Jeeva; Rajalakshmi Rajagopal; V. Charles; V. S. S. Yadavalli

2005-01-01

13

Stochastic channel modeling for ad hoc wireless networks  

Microsoft Academic Search

Due to nodes mobility and environmental changes in mobile ad hoc networks, the ad hoc channel is time varying and subject to fading. As a consequence of these variations, the statistical characteristics of the received signal vary continuously, giving rise to a Doppler power spectral density (DPSD) which varies from one observation instant to the next. Therefore, the traditional models

Mohammed M. Olama; Seddik M. Djouadi; Charalambos D. Charalambous

2006-01-01

14

QoS and Fairness Constrained Convex Optimization of Resource Allocation for Wireless Cellular and Ad Hoc Networks  

Microsoft Academic Search

For wireless cellular and ad hoc networks with QoS constraints, we propose a suite of problem formulations that allocate network resources to optimize SIR, maximize throughput and minimize de- lay. The distinguishing characteristics of these resource allocation formulations is that, by using convex optimization, they accommo- date a variety of realistic QoS and fairness constraints. Their glob- ally optimal solutions

David Julian; Mung Chiang; Daniel O'neill; Stephen P. Boyd

2002-01-01

15

A novel bandwidth allocation scheme for QoS routing in mobile ad hoc networks  

NASA Astrophysics Data System (ADS)

The main purpose of this paper is to propose a novel bandwidth allocation scheme for facilitating quality of service (QoS) routing in mobile ad hoc networks (MANETs). In a MANET using time division multiple access (TDMA), each node communicates with its neighbors in the same time slot. In general, finding a route with the maximum end-to-end bandwidth subject to the constraint of collision-free transmission is an NP-complete problem. This paper proposed a sub-optimal solution to this problem. The solution is based on a centrally controlled bandwidth allocation scheme to properly assign the available time slots to each intermediate link. The advantage of our proposed scheme is that the resource utilization of MANET is maximized and the end-to-end QoS is guaranteed during the route establishment period. Performance analyses show that when using the proposed scheme with AODV to perform QoS routing, it achieves about 25% throughput higher than its best-effort counterpart if the node is moving at 5mps speed.

Wu, Bin; Kuo, Geng-Sheng

2004-10-01

16

ZAL: Zero-Maintenance Address Allocation in Mobile Wireless Ad Hoc Networks  

Microsoft Academic Search

Abstract - The allocation of IP addresses in hybrid wireless networks is one of the most critical issues in all - IP converged wireless networks The reason is that centralized IP address allocation mechanisms may not be available in networks comprised of heterogeneous mobile wire - less devices In this paper, we propose Zero - Maintenance Address Allocation (ZAL), a

Zhihua Hu; Baochun Li

2005-01-01

17

Dynamic asset allocation under mean-reverting returns, stochastic interest rates, and inflation uncertainty  

Microsoft Academic Search

This article provides the optimal asset allocation strategy of a power utility investor who can invest in cash (a bank account), nominal bonds, and stocks (the stock index) in a model that exhibits mean-reverting stock returns and real interest rate uncertainty. The capital market model is calibrated to U.S. stock, bond, and inflation data. Furthermore, to illustrate the optimal asset

Claus Munk; Carsten Sørensen; Tina Nygaard Vinther

2004-01-01

18

A bottom-up approach of stochastic demand allocation in water quality modelling  

Microsoft Academic Search

An “all pipes” hydraulic model of a DMA-sized drinking water distribution system was onstructed with two types of demand allocations. One is constructed with the conventional op-down approach, i.e. a demand multiplier pattern from the booster station is llocated to all demand nodes with a correction factor to account for the average water emand on that node. The other is

E. J. M. Blokker; J. H. G. Vreeburg; H. Beverloo; M. Klein Arfman; J. C. Van Dijk

2010-01-01

19

Resource Allocation Scheme to Minimize Communication Cost in Mobile Ad Hoc Computational Grids  

Microsoft Academic Search

Recent advancements in mobile computing and communication technologies has given rise to development of mobile ad hoc computational grids. The mobile ad hoc computational grids provide a software infrastructure to share computing resources in mobile ad hoc environments. The adaptation of computational grids in mobile ad hoc environments is not straightforward, and presents many research challenges due to node mobility

Sayed Chhattan Shah; Myong-Soon Park

2010-01-01

20

Examination-Related Anxiety in Students Diagnosed with AD/HD and the Case for an Allocation of Extra Time: Perspectives of Teachers, Mothers and Students  

ERIC Educational Resources Information Center

|This study details the perspectives of Western Australian teachers, students and mothers on the case for an allocation of extra exam time to students diagnosed with Attention-Deficit/Hyperactivity Disorder (AD/HD). Eighteen teachers of students with AD/HD (14 high and four primary), 15 students with AD/HD (10 high and 5 primary), and their…

Taylor, Myra; Houghton, Stephen

2008-01-01

21

Biological Swarm Intelligence Based Opportunistic Resource Allocation for Wireless Ad Hoc Networks  

Microsoft Academic Search

Particle swarm optimization (PSO) is one of the most important biological swarm intelligence paradigms. However, the standard\\u000a PSO algorithm can easily get trapped in the local optima when solving complex multimodal problems. In this paper, an improved\\u000a adaptive particle swarm optimization (IAPSO) is presented. Based on IAPSO, a joint opportunistic power and rate allocation\\u000a (JOPRA) algorithm is proposed to maximize

Defang Liu; Bochu Wang

22

Static allocation of resources to communicating subtasks in a heterogeneous ad hoc grid environment  

Microsoft Academic Search

Abstract An ad hoc grid is a heterogeneous computing and communication system that allows a group of mobile devices to accomplish a mission, 15 often in a hostile environment. Energy management,is a major concern in ad hoc grids. The problem studied here focuses on statically assigning resources in an ad hoc grid to an application composed,of communicating,subtasks. The goal of

Sameer Shivle; Howard Jay Siegel; Anthony A. Maciejewski; Prasanna Sugavanam; Tarun Banka; Ralph H. Castain; Kiran Chindam; Steve Dussinger; Prakash Pichumani; Praveen Satyasekaran; William Saylor; David Sendek; J. Sousa; Jayashree Sridharan; José Velazco

2006-01-01

23

Optimal Keyword Bids in Search-Based Advertising with Stochastic Advertisement Positions  

Microsoft Academic Search

US expenditures on search-based advertising exceeded $12 billion in 2010. Advertisers bid for keywords, where bid price determines\\u000a ad placement, affecting click-through and conversion rates. Advertisers must select keywords, allocating each a proportion\\u000a of their fixed daily budget. In this paper, we construct a stochastic model for the selection and allocation process. We provide\\u000a analytical results for the single-keyword problem

Susan Cholette; Özgür Özlük; Mahmut Parlar

24

A Stochastic Sequential Allocation Model.  

National Technical Information Service (NTIS)

The following model is considered, and is described in terms of an investment problem. There are D units available for investment. During each of N time periods an opportunity to invest will occur with probability p. As soon as an opportunity presents its...

C. Derman G. J. Lieberman S. M. Ross

1974-01-01

25

A Stochastic Sequential Allocation Model.  

National Technical Information Service (NTIS)

The following model is considered, and is described in terms of an investment problem. There are D units available for investment. During each of N time periods, an opportunity to invest will occur with probability p. As soon as an opportunity presents it...

C. Derman G. J. Lieberman S. M. Ross

1974-01-01

26

Particle swarm optimization algorithm for emergency resource allocation on expressway  

Microsoft Academic Search

In order to allocate traffic emergency rescue resources on expressway, considering rescue time and resources costs as the objective, stochastic variables are introduced into constraints and a corresponding stochastic programming model is established, due to the stochastic resource requirements of accidents. Because of large numbers of rescue depots and black-spots, a stochastic simulation of particle swarm optimization (PSO) algorithm is

Chai Gan; Sun Ying-ying; Zhu Cang-hui

2009-01-01

27

The stochastic location model with risk pooling  

Microsoft Academic Search

Abstract In this paper, we present a stochastic version of the Location Model with Risk Pooling (LMRP) that optimizes location, inventory, and allocation decisions under random parameters described by discrete scenarios. The goal of our model (called the stochastic LMRP, or SLMRP) is to flnd solutions that minimize the expected total cost (including location, transportation, and inventory costs) of the

Lawrence V. Snyder; Mark S. Daskin; Chung-piaw Teo

2007-01-01

28

Optimizing the Retirement Portfolio: Asset Allocation, Annuitization, and Risk Aversion  

Microsoft Academic Search

Retirees must draw down their accumulated assets in an orderly fashion so as not to exhaust their funds too soon. We derive the optimal retirement portfolio from a menu that includes payout annuities as well as an investment allocation and a withdrawal strategy, assuming risk aversion, stochastic capital markets, and uncertain lifetimes. The resulting portfolio allocation, when fixed as of

Wolfram J. Horneff; Raimond Maurer; Olivia S. Mitchell; Ivica Dus

2006-01-01

29

Hospital resource allocation.  

PubMed

Good resource allocation is essential to effective hospital cost management. Yet current allocation methods are weak, and the damage done by bad allocations cannot be undone with utilization fine-tuning. The three traditional methods are resource-allocation-by-momentum (RAM); resource-allocation-by-physician (RAP); and resource-allocation-to-survive (RAS). As hospitals change, a new allocation method is needed: resource-allocation-in-response-to-need (RARN). To determine appropriate allocations, RARN analyzes each activity based upon community need, hospital response, and economics. RARN balances cost management emphasis of doing things right (utilization) with doing the right things (allocation). PMID:10139145

Schwantes, V D

1994-12-01

30

Research on Distribution Center's Location-Allocation Problem with Flexible Allocation Strategy  

Microsoft Academic Search

This paper sets up a two-stage stochastic programming model with recourse for dealing with the DCs location problem with uncertain demand. The model takes into account the influence of flexible allocation strategy on DCs location decision. The SAA (sample average approximation scheme) algorithm is applied and simulation experiment process has been designed for the model.

Zhou le; Ji jian hua; Liu wei hua

2007-01-01

31

Stochastic resonance  

NASA Astrophysics Data System (ADS)

Over the last two decades, stochastic resonance has continuously attracted considerable attention. The term is given to a phenomenon that is manifest in nonlinear systems whereby generally feeble input information (such as a weak signal) can be be amplified and optimized by the assistance of noise. The effect requires three basic ingredients: (i) an energetic activation barrier or, more generally, a form of threshold; (ii) a weak coherent input (such as a periodic signal); (iii) a source of noise that is inherent in the system, or that adds to the coherent input. Given these features, the response of the system undergoes resonance-like behavior as a function of the noise level; hence the name stochastic resonance. The underlying mechanism is fairly simple and robust. As a consequence, stochastic resonance has been observed in a large variety of systems, including bistable ring lasers, semiconductor devices, chemical reactions, and mechanoreceptor cells in the tail fan of a crayfish. In this paper, the authors report, interpret, and extend much of the current understanding of the theory and physics of stochastic resonance. They introduce the readers to the basic features of stochastic resonance and its recent history. Definitions of the characteristic quantities that are important to quantify stochastic resonance, together with the most important tools necessary to actually compute those quantities, are presented. The essence of classical stochastic resonance theory is presented, and important applications of stochastic resonance in nonlinear optics, solid state devices, and neurophysiology are described and put into context with stochastic resonance theory. More elaborate and recent developments of stochastic resonance theory are discussed, ranging from fundamental quantum properties-being important at low temperatures-over spatiotemporal aspects in spatially distributed systems, to realizations in chaotic maps. In conclusion the authors summarize the achievements and attempt to indicate the most promising areas for future research in theory and experiment.

Gammaitoni, Luca; Hänggi, Peter; Jung, Peter; Marchesoni, Fabio

1998-01-01

32

Apportioning of risks via stochastic dominance  

Microsoft Academic Search

Consider a simple two-state risk with equal probabilities for the two states. In particular, assume that the random wealth variable X˜i dominates Y˜i via ith-order stochastic dominance for i=M,N. We show that the 50–50 lottery [X˜N+Y˜M,Y˜N+X˜M] dominates the lottery [X˜N+X˜M,Y˜N+Y˜M] via (N+M)th-order stochastic dominance. The basic idea is that a decision maker exhibiting (N+M)th-order stochastic dominance preference will allocate the

Louis Eeckhoudt; Harris Schlesinger; Ilia Tsetlin

2009-01-01

33

Stochastic Programming  

Microsoft Academic Search

\\u000a With the requirement of considering randomness, different types of stochastic programming have been developed to suit the\\u000a different purposes of management. The first type of stochastic programming is the expected value model, which optimizes the expected objective functions subject to some expected constraints. The second, chance-constrained programming, was pioneered by Charnes and Cooper [37] as a means of handling uncertainty

Baoding Liu

34

Stochastic network optimization models for investment planning  

Microsoft Academic Search

We describe and compare stochastic network optimization models for investment planning under uncertainty. Emphasis is placed on multiperiod a sset allocation and active portfolio management problems. Myopic as well as multiple period models are considered. In the case of multiperiod models, the uncertainty in asset returns filters into the constraint coefficient matrix, yielding a multi-scenario program formulation. Different scenario generation

John M. Mulvey; Hercules Vladimirou

1989-01-01

35

Stochastic resonance in electrical circuits. I. Conventional stochastic resonance  

Microsoft Academic Search

Stochastic resonance (SR), a phenomenon in which a periodic signal in a nonlinear system can be amplified by added noise, is introduced and discussed. Techniques for investigating SR using electronic circuits are described in practical terms. The physical nature of SR, and the explanation of weak-noise SR as a linear response phenomenon, are considered. Conventional SR, for systems characterized by

Dmitrii G. Luchinsky; Riccardo Mannella; Peter V. E. McClintock; Nigel G. Stocks

1999-01-01

36

Stochastic cell.  

PubMed

Accumulating experimental evidence of stochasticity, self-organization and abrupt non-linear transitions underlying the dynamics of cellular structure and function is increasingly more consistent with the concepts and models of phase transitions, critical phenomena and non-linear thermodynamics rather than with the conventional clockwork description of the cell. The novel emerging image of the stochastic cell suggests that familiar and convenient classico-mechanical interpretations may be limiting our ability to understand the behavior of biological systems and calls for active exploration of alternative interpretational frameworks. PMID:16036564

Kurakin, Alexei

2005-02-01

37

Stochastic cooling  

SciTech Connect

Stochastic cooling is the damping of betatron oscillations and momentum spread of a particle beam by a feedback system. In its simplest form, a pickup electrode detects the transverse positions or momenta of particles in a storage ring, and the signal produced is amplified and applied downstream to a kicker. The time delay of the cable and electronics is designed to match the transit time of particles along the arc of the storage ring between the pickup and kicker so that an individual particle receives the amplified version of the signal it produced at the pick-up. If there were only a single particle in the ring, it is obvious that betatron oscillations and momentum offset could be damped. However, in addition to its own signal, a particle receives signals from other beam particles. In the limit of an infinite number of particles, no damping could be achieved; we have Liouville's theorem with constant density of the phase space fluid. For a finite, albeit large number of particles, there remains a residue of the single particle damping which is of practical use in accumulating low phase space density beams of particles such as antiprotons. It was the realization of this fact that led to the invention of stochastic cooling by S. van der Meer in 1968. Since its conception, stochastic cooling has been the subject of much theoretical and experimental work. The earliest experiments were performed at the ISR in 1974, with the subsequent ICE studies firmly establishing the stochastic cooling technique. This work directly led to the design and construction of the Antiproton Accumulator at CERN and the beginnings of p anti p colliding beam physics at the SPS. Experiments in stochastic cooling have been performed at Fermilab in collaboration with LBL, and a design is currently under development for a anti p accumulator for the Tevatron.

Bisognano, J.; Leemann, C.

1982-03-01

38

Near optimal online algorithms and fast approximation algorithms for resource allocation problems  

Microsoft Academic Search

We present algorithms for a class of resource allocation problems both in the online setting with stochastic input and in the offline setting. This class of problems contains many interesting special cases such as the Adwords problem. In the online setting we introduce a new distributional model called the adversarial stochastic input model, which is a generalization of the i.i.d

Nikhil R. Devanur; Kamal Jain; Balasubramanian Sivan; Christopher A. Wilkens

2011-01-01

39

Optimal Resource Allocation and Policy Formulation in Loosely-Coupled Markov Decision Processes  

Microsoft Academic Search

The problem of optimal policy formulation for teams of resource-limited agents in stochastic environments is com- posed of two strongly-coupled subproblems: a resource allo- cation problem and a policy optimization problem. We show how to combine the two problems into a single constrained optimization problem that yields optimal resource allocations and policies that are optimal under these allocations. We model

Dmitri A. Dolgov; Edmund H. Durfee

2004-01-01

40

Comparing Sunspot Equilibrium And Lottery Equilibrium Allocations: The Finite Case &ast  

Microsoft Academic Search

Sunspot equilibrium and lottery equilibrium are two stochastic solution concepts for nonstochastic economies. We compare these concepts in a class of completely finite, (possibly) nonconvex exchange economies with perfect markets, which requires extending the lottery model to the finite case. Every equilibrium allocation of our lottery model is also a sunspot equilibrium allocation. The converse is almost always true. There

Rod Garratt; Todd Keister; Karl Shell

2004-01-01

41

Resource Allocation Among Agents with MDP-Induced Preferences  

Microsoft Academic Search

Allocating scarce resources among agents to maximize global utility is, in general, com- putationally challenging. We focus on problems where resources enable agents to execute actions in stochastic environments, modeled as Markov decision processes (MDPs), such that the value of a resource bundle is defined as the expected value of the optimal MDP policy realizable given these resources. We present

Dmitri A. Dolgov; Edmund H. Durfee

2006-01-01

42

The allocative efficiency implications of water pollution abatement cost comparisons  

Microsoft Academic Search

Assessments of the efficiency of water pollution control allocations are usually based on abatement cost comparisons. The general rule is that efficiency is improved by reallocating abatement from sources with high marginal costs to low-cost sources. The welfare-theoretic foundation of this rule is well established for situations with nonstochastic emissions. In situations with stochastic emissions, pollution control involves improving the

James S. Shortle

1990-01-01

43

Reinforcement Learning for Dynamic Channel Allocation in Cellular Telephone Systems  

Microsoft Academic Search

In cellular telephone systems, an important problem is to dynamically allocatethe communication resource (channels) so as to maximize service ina stochastic caller environment. This problem is naturally formulated as adynamic programming problem and we use a reinforcement learning (RL)method to find dynamic channel allocation policies that are better thanprevious heuristic solutions. The policies obtained perform well for a broadvariety of

Dimitri Bertsekas; Satinder Singh

1997-01-01

44

Stochastic transparency.  

PubMed

Stochastic transparency provides a unified approach to order-independent transparency, antialiasing, and deep shadow maps. It augments screen-door transparency using a random sub-pixel stipple pattern, where each fragment of transparent geometry covers a random subset of pixel samples of size proportional to alpha. This results in correct alpha-blended colors on average, in a single render pass with fixed memory size and no sorting, but introduces noise. We reduce this noise by an alpha correction pass, and by an accumulation pass that uses a stochastic shadow map from the camera. At the pixel level, the algorithm does not branch and contains no read-modify-write loops, other than traditional z-buffer blend operations. This makes it an excellent match for modern massively parallel GPU hardware. Stochastic transparency is very simple to implement and supports all types of transparent geometry, able without coding for special cases to mix hair, smoke, foliage, windows, and transparent cloth in a single scene. PMID:20921587

Enderton, Eric; Sintorn, Erik; Shirley, Peter; Luebke, David

2011-08-01

45

Longwall Face Crew Selection With Respect to Stochastic Character of the Production Process - Part 2 - Calculation Example / Wyznaczanie obsady przodka ?cianowego z uwzgl?dnieniem stochastycznego charakteru procesu produkcyjnego cz. 2 - przyk?ad obliczeniowy  

NASA Astrophysics Data System (ADS)

A calculation example of the longwall face crew selection, including taking under consideration stochastic character of the production process is presented in this study. On the basis of observation of duration of activities realized in the hard coal mine longwall face with use of the roof cut and fill system, the calculations with use of the proposed crew selection method have been executed. The method in question takes into consideration stochastic character of the realized production process (Snopkowski & Sukiennik, 2012). In the final part of this study, graphical interpretation of the executed calculations has been presented.

Snopkowski, Ryszard; Sukiennik, Marta

2013-03-01

46

Favoritism in Capital Allocation  

Microsoft Academic Search

Abstract Casual observation,suggests that capital allocation is often driven by favoritism and connections rather than by information,on future expected,returns. We investigate when,favoritism emerges,as an equilibrium,outcome,in the allocation of capital. We show,that when,information,is unreliable and costly, …nanciers do not have incentives to investigate distant investment opportunities and allocate capital to entrepreneurs,they are familiar with (favoritism). If the pool of saving is

Mariassunta Giannetti; Xiaoyun Yu

47

Allocation of Scarce Resources  

Microsoft Academic Search

Resources, including health care resources, are almost always scarce, and they somehow have to be allocated. Often, though, we do not perceive them as either scarce or allocated, particularly when no person is making conscious decisions about how those resources get distributed. Instead some structure in which we work or live just handles the distribution without us having to think

Paul Menzel

48

Drought and Water Allocation  

NSDL National Science Digital Library

The US Department of Agriculture's Water Quality Information Center at the National Agricultural Library has placed a new database online. The Drought and Water Allocation bibliography includes "71 articles on water allocation as it relates to drought and water shortages dated 1992-1999. Competition for water resources, legal rights and remedies, and economic options are highlighted."

49

Strategic Planning for Disaster Recovery with Stochastic Last Mile Distribution  

Microsoft Academic Search

\\u000a This paper considers the single commodity allocation problem (SCAP) for disaster recovery, a fundamental problem faced by\\u000a all populated areas. SCAPs are complex stochastic optimization problems that combine resource allocation, warehouse routing,\\u000a and parallel fleet routing. Moreover, these problems must be solved under tight runtime constraints to be practical in real-world\\u000a disaster situations. This paper formalizes the specification of SCAPs

Pascal Van Hentenryck; Russell Bent; Carleton Coffrin

2010-01-01

50

Cokriging for stochastic flow models  

Microsoft Academic Search

Co-kriging equations for log-transmissivity and heads are derived for a two-dimensional stochastic model. The behavior of the weights as a function of the unknown value of mean hydraulic gradient J are discussed and the procedure is illustrated by studying the ‘screening’ effects of adjacent measurements and added head measurements. In addition, the bias of the estimator for head values is

Allan Gutjahr; John Wilson

1989-01-01

51

Stochastic Cooling  

SciTech Connect

Stochastic Cooling was invented by Simon van der Meer and was demonstrated at the CERN ISR and ICE (Initial Cooling Experiment). Operational systems were developed at Fermilab and CERN. A complete theory of cooling of unbunched beams was developed, and was applied at CERN and Fermilab. Several new and existing rings employ coasting beam cooling. Bunched beam cooling was demonstrated in ICE and has been observed in several rings designed for coasting beam cooling. High energy bunched beams have proven more difficult. Signal suppression was achieved in the Tevatron, though operational cooling was not pursued at Fermilab. Longitudinal cooling was achieved in the RHIC collider. More recently a vertical cooling system in RHIC cooled both transverse dimensions via betatron coupling.

Blaskiewicz, M.

2011-01-01

52

Ad Critic  

NSDL National Science Digital Library

Ad Critic strives to enter every television advertisement into its database of online commercials, which can be downloaded for free and viewed with QuickTime. A complete list of advertisements is indexed by company and by ad title. There are, however, also indexes of newly added ads, most-downloaded ads, movie trailers, and music found in ads, making it easier for users to search for a new or favorite advertisement. Ad Critic includes a section on advertising news and commentary and provides services for advertising agencies including online market research and detailed viewer statistics.

53

Stochastic coloured Petri nets for modelling and evaluation, and heuristic rule base for scheduling of FMS  

Microsoft Academic Search

This paper addresses scheduling of flexible manufacturing systems considering stochastic behaviour such as failure and repair of machines, and variation in processing times. Stochastic coloured Petri nets have been used for obtaining a compact model of the system. A heuristic rule base has been proposed for resolving conflicts in the allocation of jobs to machines. The superiority of the proposed

A. K. Chincholkar; O. V. Krishnaiah Chetty

1996-01-01

54

Manpower Allocation Model Survey.  

National Technical Information Service (NTIS)

The report contains a separate study of each of three mathematical manpower models and a comparative evaluation of each with the Manpower Allocation Model (MAM) developed by the Mellonics Systems Development Division.

1970-01-01

55

A two-stage stochastic model for airline network design with uncertain demand  

Microsoft Academic Search

This study addresses airline network design problems with stochastic demand. The airline network design problem aims to determine hub location, flight routes and flow allocation. The hub location decision is a long-term investment and will not vary according to different demand levels. On the other hand, the determination of flight routes and flow allocation are short-term decisions and may change

Ta-Hui Yang

2010-01-01

56

Sequential resource allocation utilizing agents  

Microsoft Academic Search

Many manufacturing systems allocate resources, such as machines, sequentially. Sequential allocation of resources can be viewed as a digraph where each vertex represents resources forming nodes in a distributed system and the arcs represent the allocation. The allocation of such resources can be considered to be a distributed problem. Agents are a distributed artificial intelligence paradigm applicable to distributed problems

Andrew Wallace

2003-01-01

57

Incremental Approximation of Optimal Allocations.  

National Technical Information Service (NTIS)

The paper concerns the approximation of optimal allocations by delta allocations. Delta allocations are obtained by fixing an increment delta of effort and deciding at each step upon a single cell in which to allocate the entire increment. It is shown tha...

L. D. Stone

1972-01-01

58

Migration and mutation in stochastic models of gene frequency change  

Microsoft Academic Search

Migration has in the past been introduced deterministically into stochastic gene frequency models. Migration at rate m then reduces the between-population variability by a factor of (1 - m)2 each generation. We show that with stochastic migration, whether of fixed or variable numbers of individuals, a positive term ?m is added to the variance. As a result of the ?m

J. A. Sved; B. D. H. Latter

1977-01-01

59

Stochastic water quality optimization using imbedded chance constraints  

Microsoft Academic Search

A chance-constrained stochastic programming model is developed for water quality optimization. It determines the least cost allocation of waste treatment plant biochemical oxygen demand (BOD) removal efficiencies, subject to probabilistic restrictions on maximum allowable instream dissolved oxygen deficit. The new model extends well beyond traditional approaches that assume streamflow is the sole random variable. In addition to streamflow, other random

J. Hugh Ellis

1987-01-01

60

Exciting AdS Orbifolds  

Microsoft Academic Search

The supersymmetric (AdS3 × S3)\\/Bbb ZN orbifold constructed by the authors in hep-th\\/0106171 is shown to describe AdS fragmentation, where fivebranes are emerging from the F1-NS5 background. The twisted sector moduli of the orbifold are the collective coordinates of groups of n5\\/N fivebranes. We discuss the relation between the descriptions of this background as a perturbative string orbifold and as

Emil J. Martinec; Will McElgin

2002-01-01

61

BM-Map: an efficient software package for accurately allocating multireads of RNA-sequencing data  

PubMed Central

Background RNA sequencing (RNA-seq) has become a major tool for biomedical research. A key step in analyzing RNA-seq data is to infer the origin of short reads in the source genome, and for this purpose, many read alignment/mapping software programs have been developed. Usually, the majority of mappable reads can be mapped to one unambiguous genomic location, and these reads are called unique reads. However, a considerable proportion of mappable reads can be aligned to more than one genomic location with the same or similar fidelities, and they are called "multireads". Allocating these multireads is challenging but critical for interpreting RNA-seq data. We recently developed a Bayesian stochastic model that allocates multireads more accurately than alternative methods (Ji et al. Biometrics 2011). Results In order to serve a greater biological community, we have implemented this method in a stand-alone, efficient, and user-friendly software package, BM-Map. BM-Map takes SAM (Sequence Alignment/Map), the most popular read alignment format, as the standard input; then based on the Bayesian model, it calculates mapping probabilities of multireads for competing genomic loci; and BM-Map generates the output by adding mapping probabilities to the original SAM file so that users can easily perform downstream analyses. The program is available in three common operating systems, Linux, Mac and PC. Moreover, we have built a dedicated website, http://bioinformatics.mdanderson.org/main/BM-Map, which includes free downloads, detailed tutorials and illustration examples. Conclusions We have developed a stand-alone, efficient, and user-friendly software package for accurately allocating multireads, which is an important addition to our previous methodology paper. We believe that this bioinformatics tool will greatly help RNA-seq and related applications reach their full potential in life science research.

2012-01-01

62

Colored Stochastic Petri Nets.  

National Technical Information Service (NTIS)

Colored stochastic Petri nets are presented as an extension of the stochastic Petri nets model in which the tokens, the transitions, and the corresponding probability measurement are colored. The development leads to a simplification of the basic model an...

A. Zenie

1986-01-01

63

Lectures in Stochastic Control.  

National Technical Information Service (NTIS)

Lectures introduce in a mathematically self-contained way several important topics of stochastic control both in discrete and continuous time. In particular, subjects such as stochastic LQ-problem, long run average cost problems, disorder problem, adaptiv...

J. Zabczyk

1983-01-01

64

Review of stochastic mechanics  

NASA Astrophysics Data System (ADS)

Stochastic mechanics is an interpretation of nonrelativistic quantum mechanics in which the trajectories of the configuration, described as a Markov stochastic process, are regarded as physically real. The natural stochastic generalization of classical variational principles leads to a derivation of the Schrödinger equation. A brief review of the successes and failures of the theory is given, with references.

Nelson, Edward

2012-05-01

65

Stochastic cooling in RHIC  

SciTech Connect

After the success of longitudinal stochastic cooling of bunched heavy ion beam in RHIC, transverse stochastic cooling in the vertical plane of Yellow ring was installed and is being commissioned with proton beam. This report presents the status of the effort and gives an estimate, based on simulation, of the RHIC luminosity with stochastic cooling in all planes.

Brennan,J.M.; Blaskiewicz, M. M.; Severino, F.

2009-05-04

66

The contributions of technical and allocative efficiency to the economic performance of European railways  

Microsoft Academic Search

This paper provides an empirical analysis of the relative contributions of allocative and technical efficiency to the productivity\\u000a performance of European railways over the period 1972 to 1999. A stochastic frontier approach is used to analyse the cost\\u000a structure of the railway industry. We estimate a translog cost system in which allocative inefficiency is modelled through\\u000a an exact relationship between

Antonio Couto; Daniel J. Graham

2008-01-01

67

Constrained egalitarian allocations  

Microsoft Academic Search

This paper proposes a constrained egalitarian solution concept for TU games which combines commitment for egalitarianism and promotion of individual inter- ests in a consistent manner. The paper shows that the set of constrained egalitar- ian allocations is nonempty for weakly superadditive games. The solution is \\

Bhaskar Dutta; Debraj Ray

1991-01-01

68

Advertisement allocation for generalized second-pricing schemes  

Microsoft Academic Search

Recently, there has been a surge of interest in algorithms that allocate advertisement space in an online revenue-competitive manner. Most such algorithms, however, assume a pay-as-you-bid pricing scheme. In this paper, we study the query allocation problem where the ad space is priced using the well-known and widely-used generalized second price (GSP) scheme. We observe that the previous algorithms fail

Ashish Goel; Mohammad Mahdian; Hamid Nazerzadeh; Amin Saberi

2010-01-01

69

On Using a Hierarchy of Twofold Resource Allocation Automata to Solve Stochastic Nonlinear Resource Allocation Problems  

Microsoft Academic Search

Recent trends in AI attempt to solve difficult NP-hard problems using intelligent techniques so as to obtain approximately-optimal\\u000a solutions. In this paper, we consider a family of such problems which fall under the general umbrella of “knapsack-like” problems, and demonstrate how we can solve all of them fast and accurately using a hierarchy of Learning Automata (LA). In a multitude

Ole-christoffer Granmo; B. John Oommen

2007-01-01

70

Superstrings in AdS  

NASA Astrophysics Data System (ADS)

This is a comprehensive review of the worldsheet techniques for the quantization of type IIB superstring theory on the AdS×S5 background, using the pure spinor formalism. Particular emphasis is devoted to AdS/CFT applications, with several examples worked out in detail. The review is self-contained and pedagogical.

Mazzucato, Luca

2012-12-01

71

Study on Stochastic Programming Methods Based on Synthesizing Effect  

NASA Astrophysics Data System (ADS)

Stochastic programming is a well-known optimization problem in resource allocation, optimization decision etc. in this paper, by analyzing the essential characteristic of stochastic programming and the deficiencies of the existing methods, we propose the concept of synthesizing effect function for processing the objective function and constraints, and further we give an axiomatic system for synthesizing effect function. Finally, we establish a general solution model (denoted by BSE-SGM for short) based on synthesizing effect function for stochastic programming problem, and analyze the model through an example. All the results indicate that our method not only includes the existing methods for stochastic programming, but also effectively merge the decision preferences into the solution, so it can be widely used in many fields such as complicated system optimization and artificial intelligence etc.

Li, Fachao; Liu, Xianlei; Jin, Chenxia

72

Memory Allocation with Lazy Fits  

Microsoft Academic Search

Dynamic memory allocation is an important part of modern pro- gramming languages. It is important that it be done fast without wasting too much memory. Memory allocation using lazy fits is introduced, where pointer increments, which is very fast, is used as the primary allocation method and where conventional fits such as best fit or first fit are used as

Yoo C. Chung; Soo-Mook Moon

2000-01-01

73

Memory allocation with lazy fits  

Microsoft Academic Search

Dynamic memory allocation is an important part of modern programming languages. It is important that it be done fast without wasting too much memory. Memory allocation using lazy fits is introduced, where pointer increments, which is very fast, is used as the primary allocation method and where conventional fits such as best fit or first fit are used as backup.

Yoo C. Chung; Soo-Mook Moon

2001-01-01

74

Robust Asset Allocation  

Microsoft Academic Search

This article addresses the problem of finding an optimal allocation of funds among different asset classes in a robust manner\\u000a when the estimates of the structure of returns are unreliable. Instead of point estimates used in classical mean-variance\\u000a optimization, moments of returns are described using uncertainty sets that contain all, or most, of their possible realizations. The approach presented here

Reha H. Tütüncü; M. Koenig

2004-01-01

75

Telescope Time Allocation Tool  

Microsoft Academic Search

TaToo is ESO's new Time Allocation Tool. This software scheduler is a combination of a user-friendly graphical user interface and an intelligent constraint-programming engine fine-tuned to ESO's scheduling problem. TaToo is able to produce a high quality and reliable schedule taking into consideration all constraints of the recommended programs for all telescopes in about 15 minutes. This performance allows schedulers

J. Alves

2005-01-01

76

23 CFR 1240.15 - Allocations.  

Code of Federal Regulations, 2013 CFR

...HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION GUIDELINES SAFETY INCENTIVE GRANTS FOR USE OF SEAT BELTS-ALLOCATIONS BASED ON SEAT BELT USE RATES Determination of Allocations § 1240.15 Allocations. (a) Funds allocated...

2013-04-01

77

Intelligent resource simulation for an airport check-in counter allocation system  

Microsoft Academic Search

The objective of resource allocation systems is to assign valuable corporate resources to meet business demands. However, in applications involving stochastic events, demands cannot be determined explicitly beforehand. For those applications, computer simulation is often used to predict resource demands. The paper describes research in developing a knowledge based simulation system to predict resource requirements at an international airport. Our

Hon Wai Chun; Raymond Wai Tak Mak

1999-01-01

78

The empty railcar allocation problem under uncertainty for the railway freight carrier  

Microsoft Academic Search

In this paper, we present a mathematical formulation and solution method for the empty railcar allocation problem under uncertainty. The proposed formulation results in a two-stage stochastic programming model which can also be rewritten as a large-scale integer programming model with the linear objective function and linear constraints. A solution method is presented to solve the problem and an example

Chengxuan Cao; Ziyou Gao; Keping Li

2008-01-01

79

Optimal asset allocation for pension funds under mortality risk during the accumulation and decumulation phases  

Microsoft Academic Search

In a …nancial market with one riskless asset and nrisky assets following geometric Brownian motions, we solve the problem of a pension fund max- imizing the expected CRRA utility of its terminal wealth. By considering a stochastic death time for a subscriber, we solve a unique problem for both accumulation and decumulation phases. We show that the optimal asset allocation

Paolo Battocchio; Francesco Menoncin; Olivier Scaillet

2007-01-01

80

Stochastic phase transition operator  

NASA Astrophysics Data System (ADS)

In this study a Markov operator is introduced that represents the density evolution of an impulse-driven stochastic biological oscillator. The operator’s stochastic kernel is constructed using the asymptotic expansion of stochastic processes instead of solving the Fokker-Planck equation. The Markov operator is shown to successfully approximate the density evolution of the biological oscillator considered. The response of the oscillator to both periodic and time-varying impulses can be analyzed using the operator’s transient and stationary properties. Furthermore, an unreported stochastic dynamic bifurcation for the biological oscillator is obtained by using the eigenvalues of the product of the Markov operators.

Yamanobe, Takanobu

2011-07-01

81

Incorporating Stochastic Demand into Breakeven Analysis: A Practical Guide  

Microsoft Academic Search

The plausibility and usefulness of conventional breakeven analysis is augmented by adding a stochastic linear demand function to the basic breakeven equation. The additional complexity from adding this function is not excessive in a mathematical sense, and the payoff to the additional complexity is considerable. Relatively simple explicit analytical formulas are derived for the determination of the price that maximizes

James A. Yunker

2006-01-01

82

6.EE Firefighter Allocation  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: A town's total allocation for firefighter's wages and bene?ts in a new budget is \\$600,000. If wages are calculated at \\$40,000 per firefighter and ben...

83

Telescope Time Allocation Tool  

NASA Astrophysics Data System (ADS)

TaToo is ESO's new Time Allocation Tool. This software scheduler is a combination of a user-friendly graphical user interface and an intelligent constraint-programming engine fine-tuned to ESO's scheduling problem. TaToo is able to produce a high quality and reliable schedule taking into consideration all constraints of the recommended programs for all telescopes in about 15 minutes. This performance allows schedulers at ESO-VISAS to simulate and evaluate different scenarios, optimize the scheduling of engineering activities at the observatories, and in the end construct the most science efficient schedule possible.

Alves, J.

2005-03-01

84

Computationally efficient control allocation  

US Patent & Trademark Office Database

A computationally efficient method for calculating near-optimal solutions to the three-objective, linear control allocation problem is disclosed. The control allocation problem is that of distributing the effort of redundant control effectors to achieve some desired set of objectives. The problem is deemed linear if control effectiveness is affine with respect to the individual control effectors. The optimal solution is that which exploits the collective maximum capability of the effectors within their individual physical limits. Computational efficiency is measured by the number of floating-point operations required for solution. The method presented returned optimal solutions in more than 90% of the cases examined; non-optimal solutions returned by the method were typically much less than 1% different from optimal and the errors tended to become smaller than 0.01% as the number of controls was increased. The magnitude of the errors returned by the present method was much smaller than those that resulted from either pseudo inverse or cascaded generalized inverse solutions. The computational complexity of the method presented varied linearly with increasing numbers of controls; the number of required floating point operations increased from 5.5 i, to seven times faster than did the minimum-norm solution (the pseudoinverse), and at about the same rate as did the cascaded generalized inverse solution. The computational requirements of the method presented were much better than that of previously described facet-searching methods which increase in proportion to the square of the number of controls.

Durham; Wayne (Blacksburg, VA)

2001-08-21

85

Multidimensional Stochastic Approximation Methods  

Microsoft Academic Search

Multidimensional stochastic approximation schemes are presented, and conditions are given for these schemes to converge a.s. (almost surely) to the solutions of $k$ stochastic equations in $k$ unknowns and to the point where a regression function in $k$ variables achieves its maximum.

Julius R. Blum

1954-01-01

86

Stochastic and Fuzzy PERT,  

National Technical Information Service (NTIS)

Network-planning techniques are considered, which are based on stochastic and fuzzy models of the activity durations. The stochastic versions of PERT are generally intractable, and they cannot be used to draw up tight plans for action. Fuzzy models are cl...

F. A. Lootsma

1988-01-01

87

The appreciation of stochastic motion in particle accelerators  

SciTech Connect

A description is given of the analytic and numerical work, performed from July 1955 through August 1956, so as to develop, and then study, the process of making intense proton beams, suitable for colliding beams. It is shown how this investigation led, in a most natural way, to the realization that stochasticity can arise in a simple Hamiltonian system. Furthermore, the criterion for the onset of stochasticity was understood, and carefully studied, in two different situations. The first situation was the proposed (and subsequently used) ''stacking process'' for developing an intense beam, where stochasticity occurs as additional particles are added to the intense circulating beam. The second situation occurs when one seeks to develop ''stochastic accelerators'' in which particles are accelerated (continuously) by a collection of radio frequency systems. It was in the last connection that the well-known criterion for stochasticity, resonance overlap, was obtained.

Symon, Keith; Sessler, Andrew

2003-08-03

88

Stochastic volatility models and Kelvin waves  

NASA Astrophysics Data System (ADS)

We use stochastic volatility models to describe the evolution of an asset price, its instantaneous volatility and its realized volatility. In particular, we concentrate on the Stein and Stein model (SSM) (1991) for the stochastic asset volatility and the Heston model (HM) (1993) for the stochastic asset variance. By construction, the volatility is not sign definite in SSM and is non-negative in HM. It is well known that both models produce closed-form expressions for the prices of vanilla option via the Lewis-Lipton formula. However, the numerical pricing of exotic options by means of the finite difference and Monte Carlo methods is much more complex for HM than for SSM. Until now, this complexity was considered to be an acceptable price to pay for ensuring that the asset volatility is non-negative. We argue that having negative stochastic volatility is a psychological rather than financial or mathematical problem, and advocate using SSM rather than HM in most applications. We extend SSM by adding volatility jumps and obtain a closed-form expression for the density of the asset price and its realized volatility. We also show that the current method of choice for solving pricing problems with stochastic volatility (via the affine ansatz for the Fourier-transformed density function) can be traced back to the Kelvin method designed in the 19th century for studying wave motion problems arising in fluid dynamics.

Lipton, Alex; Sepp, Artur

2008-08-01

89

Robust responses to climate change via stochastic MARKAL: The case of Quebec  

Microsoft Academic Search

Future patterns of climate change and economic growth are critical parameters in long-term energy planning. This paper describes a multi-stage stochastic programming approach to formulate a flexible energy plan. The plan incorporates multiple future scenarios and provides for mid-course corrections depending upon the actual realizations of future uncertainties. Results are derived from the stochastic version of Extended MARKAL (MARKet ALlocation)

Amit Kanudia; Richard Loulou

1998-01-01

90

Robust responses to climate change via stochastic MARKAL: The case of Québec  

Microsoft Academic Search

Future patterns of climate change and economic growth are critical parameters in long-term energy planning. This paper describes a multi-stage stochastic programming approach to formulate a flexible energy plan. The plan incorporates multiple future scenarios and provides for mid-course corrections depending upon the actual realizations of future uncertainties. Results are derived from the stochastic version of Extended MARKAL (MARKet ALlocation)

Amit Kanudia; Richard Loulou

1998-01-01

91

Research on allocation efficiency of the daisy chain allocation algorithm  

NASA Astrophysics Data System (ADS)

With the improvement of the aircraft performance in reliability, maneuverability and survivability, the number of the control effectors increases a lot. How to distribute the three-axis moments into the control surfaces reasonably becomes an important problem. Daisy chain method is simple and easy to be carried out in the design of the allocation system. But it can not solve the allocation problem for entire attainable moment subset. For the lateral-directional allocation problem, the allocation efficiency of the daisy chain can be directly measured by the area of its subset of attainable moments. Because of the non-linear allocation characteristic, the subset of attainable moments of daisy-chain method is a complex non-convex polygon, and it is difficult to solve directly. By analyzing the two-dimensional allocation problems with a "micro-element" idea, a numerical calculation algorithm is proposed to compute the area of the non-convex polygon. In order to improve the allocation efficiency of the algorithm, a genetic algorithm with the allocation efficiency chosen as the fitness function is proposed to find the best pseudo-inverse matrix.

Shi, Jingping; Zhang, Weiguo

2013-03-01

92

The effective use of student time: A stochastic frontier production function case study  

Microsoft Academic Search

Abstract The relationship between,student study time allocation and examination,performance,is little understood. We model the allocation of student time into formal,study (lectures and classes) and self study and its relationship to university examination,scores using a stochastic frontier production,function. This case study uses unique,time budget,data and detailed personal records from one university in Spain. The results suggest that, within the formal system

Peter Dolton; Oscar D. Marcenaro; Lucia Navarro

2001-01-01

93

Experiments Testing Multiobject Allocation Mechanisms  

Microsoft Academic Search

This paper reports the results of over 130 auctions conducted under controlled conditions to examine the robustness of several auction mechanisms to allocate multiple objects. The simultaneous discrete auction process used by the Federal Communications Commission to allocate Personal Communications licenses was contrasted with a sequential auction and a combinatorial auction over a variety of demand conditions. In test environments

John O. Ledyard; David Porter; Antonio Rangel

1997-01-01

94

Financial education and asset allocation  

Microsoft Academic Search

We conduct a clinical study on a firm that restructures its 401(k) plan and simultaneously offers financial education seminars to its employees. The restructuring requires each employee to restate allocation percentages, thus we are able to analyze the specific benefits of retirement planning seminars on the asset allocation decision. We find that seminar attendance is associated with increased portfolio diversification

Steven D. Dolvin; William K. Templeton

2006-01-01

95

Stochastic Differential Game Techniques.  

National Technical Information Service (NTIS)

This development of readily computable strategies for differential games with noise corrupted measurements was hampered by the so called closure problem of stochastic differential games. The solutions required either an infinite dimensional dynamic system...

B. Mons

1982-01-01

96

Stochastic Wear Processes.  

National Technical Information Service (NTIS)

A new class of non-decreasing stochastic processes is characterized. These processes satisfy a generalization of the notion of an increasing failure rate. From physical considerations, these processes seem suitable for describing the process of cumulative...

R. Morey

1965-01-01

97

VAWT Stochastic Wind Simulator.  

National Technical Information Service (NTIS)

A stochastic wind simulation for VAWTs (VSTOC) has been developed which yields turbulent wind-velocity fluctuations for rotationally sampled points. This allows three-component wind-velocity fluctuations to be simulated at specified nodal points on the wi...

J. H. Strickland

1987-01-01

98

Methodology for Stochastic Modeling.  

National Technical Information Service (NTIS)

The requirement to develop stochastic mathematical models arises across the whole range of engineering and applied research where observations are made of a physical process, corrupted by noise, and it is desired to determine the underlying nature, either...

H. E. Cohen

1985-01-01

99

15 CFR 923.92 - Allocation.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Allocation. 923.92 Section 923...COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT COASTAL ZONE...Implementation Grants § 923.92 Allocation. (a) Subsections...interstate agencies. Such allocations provide for continuing...

2013-01-01

100

15 CFR 923.110 - Allocation formula.  

Code of Federal Regulations, 2010 CFR

... 2009-01-01 false Allocation formula. 923.110 Section...COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT COASTAL ZONE MANAGEMENT PROGRAM REGULATIONS Allocation of Section 306 Program Administration Grants § 923.110 Allocation formula. (a)...

2009-01-01

101

15 CFR 923.110 - Allocation formula.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 false Allocation formula. 923.110 Section...COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT COASTAL ZONE MANAGEMENT PROGRAM REGULATIONS Allocation of Section 306 Program Administration Grants § 923.110 Allocation formula. (a)...

2010-01-01

102

15 CFR 923.110 - Allocation formula.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Allocation formula. 923.110 Section...COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT COASTAL ZONE MANAGEMENT PROGRAM REGULATIONS Allocation of Section 306 Program Administration Grants § 923.110 Allocation formula. (a)...

2013-01-01

103

Stochastic Multivariate Evolution  

Microsoft Academic Search

\\u000a The discussions of stochastic methods in previous chapters were related to the consideration of a single random variable.\\u000a This approach is appropriate to explain the basic structure of evolution equations for stochastic processes and their PDFs.\\u000a On the other hand, most applications cannot be handled on the basis of methods that describe the evolution of single variables.\\u000a Real processes usually

Stefan Heinz

104

STOCHASTIC COOLING FOR RHIC  

Microsoft Academic Search

Emittance growth due to Intra-Beam Scattering significantly reduces the heavy ion luminosity lifetime in RHIC. Stochastic cooling of the stored beam could improve things considerably by counteracting IBS and preventing particles from escaping the rf bucket [1]. High frequency bunched-beam stochastic cooling is especially challenging but observations of Schottky signals in the 4-8 GHz band indicate that conditions are favorable

M. BRENNAN; J. M. CAMERON; P. WEI

2003-01-01

105

Resource allocation using risk analysis  

SciTech Connect

Allocating limited resources among competing priorities is an important problem in management. In this paper we describe an approach to resource allocation using risk as a metric. We call this approach the Logic-Evolved Decision (LED) approach because we use logic-models to generate an exhaustive set of competing options and to describe the often highly complex model used for evaluating the risk reduction achieved by different resource allocations among these options. The risk evaluation then proceeds using probabilistic or linguistic input data.

Bott, T. F. (Terrence F.); Eisenhawer, S. W. (Stephen W.)

2003-01-01

106

Stochastic beamforming for cochlear implant coding  

NASA Astrophysics Data System (ADS)

Cochlear implants are prosthetic devices used to provide hearing to people who would otherwise be profoundly deaf. The deliberate addition of noise to the electrode signals could increase the amount of information transmitted, but standard cochlear implants do not replicate the noise characteristic of normal hearing because if noise is added in an uncontrolled manner with a limited number of electrodes then it will almost certainly lead to worse performance. Only if partially independent stochastic activity can be achieved in each nerve fibre can mechanisms like suprathreshold stochastic resonance be effective. We are investigating the use of stochastic beamforming to achieve greater independence. The strategy involves presenting each electrode with a linear combination of independent Gaussian noise sources. Because the cochlea is filled with conductive salt solutions, the noise currents from the electrodes interact and the effective stimulus for each nerve fibre will therefore be a different weighted sum of the noise sources. To some extent therefore, the effective stimulus for a nerve fibre will be independent of the effective stimulus of neighbouring fibres. For a particular patient, the electrode position and the amount of current spread are fixed. The objective is therefore to find the linear combination of noise sources that leads to the greatest independence between nerve discharges. In this theoretical study we show that it is possible to get one independent point of excitation (one null) for each electrode and that stochastic beamforming can greatly decrease the correlation between the noise exciting different regions of the cochlea.

Morse, Robert P.; Holmes, Stephen D.; Shulgin, Boris; Nikitin, Alexander; Stocks, Nigel G.

2007-06-01

107

Governance and Foreign Aid Allocation.  

National Technical Information Service (NTIS)

This dissertation examines whether aid allocation patterns affect the outcomes of foreign aid in promoting economic growth. Specifically, the study explores how different categories of aid affect economic growth, whether the quality of governance is signi...

K. T. Akramov

2006-01-01

108

Fusion-Based Register Allocation.  

National Technical Information Service (NTIS)

Nowadays, compilers are looking for more optimizing opportunities by performing aggressive code transformations which introduce high register pressure. High register pressure potentially increases register overhead operations. Register allocation must dea...

G. Y. Lueh

1997-01-01

109

Pole Allocation using Matrix Perturbations  

Microsoft Academic Search

An approach is presented for the analysis and design of controllers and observers for high-dimensional systems using pole allocation and matrix perturbation theory. Development of a feedback control law that leads to a desired closed-loop configuration is a prohibitive task computationally, especially for large-order systems. Existing pole allocation algorithms can handle only low-order models. In this paper, matrix perturbation theory

H. Baruh; Departmentof MechanicalandAerospace

1986-01-01

110

Performance Analysis of a Video on Demand System Using Stochastic Petri Nets, A Case Study.  

National Technical Information Service (NTIS)

In this report the authors study the performance of an adaptive video on demand (VOD) system using stochastic Petri nets. In this system channel resources are allocated more efficiently than in well-known full VOD or near VOD systems. In adaptive VOD a vi...

T. Pyssyalo L. Ojala O. M. Penttinen

1996-01-01

111

Solving a Stochastic Facility Location\\/Fleet Management Problem with Logic-Based Benders Decomposition  

Microsoft Academic Search

We address a stochastic facility location and vehicle assignment problem in which customers are served by full return trips. The problem consists of simultaneously locating a set of facilities, determining the vehicle fleet size at each facility, and allocating customers to facilities and vehicles in the presence of random travel times. Such travel times can arise, for example, due to

Mohammad M. Fazel-Zarandi; Oded Berman; J. Christopher Beck

2012-01-01

112

Inverse Statistics and Asset Allocation Efficiency  

NASA Astrophysics Data System (ADS)

In this paper using inverse statistics analysis, the effect of investment horizon on the efficiency of portfolio selection is examined. Inverse statistics analysis is a general tool also known as probability distribution of exit time that is used for detecting the distribution of the time in which a stochastic process exits from a zone. This analysis was used in Refs. 1 and 2 for studying the financial returns time series. This distribution provides an optimal investment horizon which determines the most likely horizon for gaining a specific return. Using samples of stocks from Tehran Stock Exchange (TSE) as an emerging market and S&P 500 as a developed market, effect of optimal investment horizon in asset allocation is assessed. It is found that taking into account the optimal investment horizon in TSE leads to more efficiency for large size portfolios while for stocks selected from S&P 500, regardless of portfolio size, this strategy does not only not produce more efficient portfolios, but also longer investment horizons provides more efficiency.

Bolgorian, Meysam

113

Social Welfare Based Routing in Ad hoc Networks  

Microsoft Academic Search

Due to resource scarcity, a paramount concern in ad hoc networks is to utilize the limited resources efficiently. The self-organized nature of ad hoc networks makes the social welfare based approach an efficient way to allocate the limited resources. However, the effect of instability of mobile nodes has not been adequately addressed in the literature. To efficiently address the routing

Mingming Lu; Jie Wu

2006-01-01

114

Stochastic trajectories of succession initiated by extreme climatic events.  

PubMed

Deterministic or rule-based succession is expected under homogeneous biotic and abiotic starting conditions. Effects of extreme climatic events such as drought, however, may alter these assembly rules by adding stochastic elements. We monitored the succession of species composition of 30 twin grassland communities with identical biotic and abiotic starting conditions in an initially sown diversity gradient between 1 and 16 species over 13 years. The stochasticity of succession, measured as the synchrony in the development of the species compositions of the twin plots, was strongly altered by the extreme warm and dry summer of 2003. Moreover, it was independent from past and present plant diversity and neighbourhood species compositions. Extreme climatic events can induce stochastic effects in community development and therefore impair predictability even under homogeneous abiotic conditions. Stochastic events may result in lasting shifts of community composition, as well as adverse and unforeseeable effects on the stability of ecological services. PMID:21624029

Kreyling, J; Jentsch, A; Beierkuhnlein, C

2011-05-31

115

Conference structures and fair allocation rules  

Microsoft Academic Search

To describe how the outcome of a cooperative game might depend on which groups of players hold cooperative planning conferences, we study allocation rules, which are functions mapping conference structures to payoff allocations. An allocation rule is fair if every conference always gives equal benefits to all its members. Any characteristic function game without sidepayments has a unique fair allocation

R. B. Myerson

1980-01-01

116

STOCHASTIC COOLING FOR BUNCHED BEAMS.  

SciTech Connect

Problems associated with bunched beam stochastic cooling are reviewed. A longitudinal stochastic cooling system for RHIC is under construction and has been partially commissioned. The state of the system and future plans are discussed.

BLASKIEWICZ, M.

2005-05-16

117

Subpopulation triage: how to allocate conservation effort among populations.  

PubMed

Threatened species often exist in a small number of isolated subpopulations. Given limitations on conservation spending, managers must choose from strategies that range from managing just one subpopulation and risking all other subpopulations to managing all subpopulations equally and poorly, thereby risking the loss of all subpopulations. We took an economic approach to this problem in an effort to discover a simple rule of thumb for optimally allocating conservation effort among subpopulations. This rule was derived by maximizing the expected number of extant subpopulations remaining given n subpopulations are actually managed. We also derived a spatiotemporally optimized strategy through stochastic dynamic programming. The rule of thumb suggested that more subpopulations should be managed if the budget increases or if the cost of reducing local extinction probabilities decreases. The rule performed well against the exact optimal strategy that was the result of the stochastic dynamic program and much better than other simple strategies (e.g., always manage one extant subpopulation or half of the remaining subpopulation). We applied our approach to the allocation of funds in 2 contrasting case studies: reduction of poaching of Sumatran tigers (Panthera tigris sumatrae) and habitat acquisition for San Joaquin kit foxes (Vulpes macrotis mutica). For our estimated annual budget for Sumatran tiger management, the mean time to extinction was about 32 years. For our estimated annual management budget for kit foxes in the San Joaquin Valley, the mean time to extinction was approximately 24 years. Our framework allows managers to deal with the important question of how to allocate scarce conservation resources among subpopulations of any threatened species. PMID:18477029

McDonald-Madden, Eve; Baxter, Peter W J; Possingham, Hugh P

2008-05-09

118

On the Fair Division of Multiple Stochastic Pies to Multiple Agents within the Nash Bargaining Solution  

PubMed Central

The fair division of a surplus is one of the most widely examined problems. This paper focuses on bargaining problems with fixed disagreement payoffs where risk-neutral agents have reached an agreement that is the Nash-bargaining solution (NBS). We consider a stochastic environment, in which the overall return consists of multiple pies with uncertain sizes and we examine how these pies can be allocated with fairness among agents. Specifically, fairness is based on the Aristotle’s maxim: “equals should be treated equally and unequals unequally, in proportion to the relevant inequality”. In this context, fairness is achieved when all the individual stochastic surplus shares which are allocated to agents are distributed in proportion to the NBS. We introduce a novel algorithm, which can be used to compute the ratio of each pie that should be allocated to each agent, in order to ensure fairness within a symmetric or asymmetric NBS.

Karmperis, Athanasios C.; Aravossis, Konstantinos; Tatsiopoulos, Ilias P.; Sotirchos, Anastasios

2012-01-01

119

Structures and stochastic methods  

SciTech Connect

Studies and research on structures and stochastic methods in the soil dynamics and earthquake engineering filed are covered in this book. The first section is on structures and includes studies on bridges, loaded tanks, sliding structures and wood-framed houses. The second section covers dams, retaining walls and slopes. The third section on underground structures covers pipelines, water supply, fire loss, buried lifeline, and underground transmission lines. The final section is on stochastic methods and includes applications in earthquake response spectra, lifeline aqueduct systems, and various other areas.

Cakmak, A.S.

1987-01-01

120

Stochastic Hopfield neural networks  

NASA Astrophysics Data System (ADS)

Hopfield (1984 Proc. Natl Acad. Sci. USA 81 3088-92) showed that the time evolution of a symmetric neural network is a motion in state space that seeks out minima in the system energy (i.e. the limit set of the system). In practice, a neural network is often subject to environmental noise. It is therefore useful and interesting to find out whether the system still approaches some limit set under stochastic perturbation. In this paper, we will give a number of useful bounds for the noise intensity under which the stochastic neural network will approach its limit set.

Hu, Shigeng; Liao, Xiaoxin; Mao, Xuerong

2003-03-01

121

Stochastic optical active rheology  

NASA Astrophysics Data System (ADS)

We demonstrate a stochastic based method for performing active rheology using optical tweezers. By monitoring the displacement of an embedded particle in response to stochastic optical forces, a rapid estimate of the frequency dependent shear moduli of a sample is achieved in the range of 10-1-103 Hz. We utilize the method to probe linear viscoelastic properties of hydrogels at varied cross-linker concentrations. Combined with fluorescence imaging, our method demonstrates non-linear changes of bond strength between T cell receptors and an antigenic peptide due to force-induced cell activation.

Lee, Hyungsuk; Shin, Yongdae; Kim, Sun Taek; Reinherz, Ellis L.; Lang, Matthew J.

2012-07-01

122

Stochastic optical active rheology  

PubMed Central

We demonstrate a stochastic based method for performing active rheology using optical tweezers. By monitoring the displacement of an embedded particle in response to stochastic optical forces, a rapid estimate of the frequency dependent shear moduli of a sample is achieved in the range of 10?1–103?Hz. We utilize the method to probe linear viscoelastic properties of hydrogels at varied cross-linker concentrations. Combined with fluorescence imaging, our method demonstrates non-linear changes of bond strength between T cell receptors and an antigenic peptide due to force-induced cell activation.

Lee, Hyungsuk; Shin, Yongdae; Kim, Sun Taek; Reinherz, Ellis L.; Lang, Matthew J.

2012-01-01

123

Stochastic Models of Quasigeostrophic Turbulence  

Microsoft Academic Search

In this talk, I present a closure theory of quasigeostrophic turbulence for arbitrary shear flows based on stochastic models. A stochastic model represents the eddy-mean flow interaction through a nonnormal dynamical operator, and parameterizes the eddy-eddy interactions by an effective dissipation and random excitation. In the context of a stochastic model, the main facts which a closure theory of turbulence

T. Delsole

2005-01-01

124

The heat kernel on AdS  

NASA Astrophysics Data System (ADS)

We explicitly evaluate the heat kernel for the Laplacian of arbitrary spin tensor fields on the thermal quotient of (Euclidean) AdS N for N ? 3 using the group theoretic techniques employed for AdS 3 in arXiv:0911.5085. Our approach is general and can be used, in principle, for other quotients as well as other symmetric spaces.

Gopakumar, Rajesh; Gupta, Rajesh Kumar; Lal, Shailesh

2011-11-01

125

Genomic imprinting and sex allocation.  

PubMed

Genomic imprinting allows maternally and paternally derived alleles to have different patterns of expression (one allele is often silent). Kin selection provides an explanation of genomic imprinting because conflicts of interest can arise between paternally and maternally inherited alleles when they have different probabilities of being present in other individuals. Our aim here is to examine the extent to which conflicts between paternally and maternally inherited alleles could arise over the allocation of resources to male and female reproduction (sex allocation), for example, conflict over the offspring sex ratio. We examine the situations in which sex allocation is influenced by competitive or cooperative interactions between relatives: local resource competition, local mate competition, and local resource enhancement. We determine solutions for diploids and haplodiploids when either the mother or the offspring controls sex allocation. Our results suggest that the greatest conflict between paternally and maternally inherited alleles and therefore the strongest selection for genomic imprinting will occur in haplodiploid species where the offspring can control sex allocation, such as the social hymenoptera and the polyembryonic parasitoid wasps. Within the social hymenoptera, we expect especially strong selection for genomic imprinting in species subject to local resource competition, such as honeybees and army ants. PMID:19067608

Wild, Geoff; West, Stuart A

2009-01-01

126

Enhanced Vibrational Energy Harvesting Using Non-linear Stochastic Resonance  

Microsoft Academic Search

Stochastic resonance has seen wide application in the physical sciences as a tool to understand weak signal ampliflcation by noise. However, this apparently counter- intuitive phenomenon does not appear to have been exploited as a tool to enhance vibrational energy harvesting. In this note we demonstrate that by adding periodic forcing to a vibrationally excited energy harvesting mechanism, the power

C. R. McInnes; D. G. Gorman; M. P. Cartmell

2008-01-01

127

Stochastic ontogenetic growth model  

Microsoft Academic Search

An ontogenetic growth model (OGM) for a thermodynamically closed system is generalized to satisfy both the first and second law of thermodynamics. The hypothesized stochastic ontogenetic growth model (SOGM) is shown to entail the interspecies allometry relation by explicitly averaging the basal metabolic rate and the total body mass over the steady-state probability density for the total body mass (TBM).

B. J. West

2012-01-01

128

Information and stochastic systems  

NASA Astrophysics Data System (ADS)

Equipment was purchased to support research in two main areas: communication channels with memory and signal detection and classification problems involving non-Gaussian stochastic processes. The research on communication channels involves largely the study of channel capacity under various assumptions and constraints. The research in signal detection and classification includes modeling, data analysis, and the development and evaluation of detection algorithms.

Baker, Charles R.

1987-11-01

129

A distributed fair MAC flow allocation and scheduling framework for IEEE 802.11 based wireless mesh networks  

Microsoft Academic Search

We present a distributed fair MAC flow allocation and scheduling framework for IEEE 802.11 based wireless mesh networks. The framework consists of (1) a modified wireless ad hoc routing protocol to take into account bandwidth requirement, (2) a link information dissemination protocol to propagate local topology information, (3) a cooperative gradient-based iterative algorithm to allocate fairly MAC flow bandwidth and

Kin Wah Edward Lin; Brahim Bensaou

2009-01-01

130

Optimal allocation of inspection resources  

SciTech Connect

Allocation of inspection resources for international safeguards is considered as the problem of designing a complex system that is composed of individual inspection activities and that has the objective of detecting material loss. Optimization theory is applied in selecting those inspection activities that maximize a system performance measure within resource constraints. The method is applicable to a global allocation problem in which inspection resources are distributed throughout a hierarchy consisting of multiple countries, multiple facilities within each country, and multiple activities within each facility. 9 references.

Markin, J.T.; Chambers, W.H.; Vaccaro, H.S.

1984-01-01

131

Classification of capacitor allocation techniques  

Microsoft Academic Search

The problem of capacitor allocation for loss reduction in electric distribution systems has been extensively researched over the past several decades. This paper describes the evolution of the research and provides an evaluation of the practicality and accuracy of the capacitor placement algorithms in the literature. The intent of this paper is not to provide a complete survey of all

H. N. Ng; M. M. A. Salama; A. Y. Chikhani

2000-01-01

132

Efficiency in intrahousehold resource allocation  

Microsoft Academic Search

This paper examines the allocation of productive resources within rural households of poor countries. Building upon the existing literature, it provides a consistent framework from which to study productive efficiency and intrahousehold equity. The topics discussed include returns to scale and household centralization; specialization and gender casting; separate spheres and commitment failure; labor market cartelization and discrimination; and the provision

Marcel Fafchamps

1998-01-01

133

Operational risk economic capital allocation  

NASA Astrophysics Data System (ADS)

In the paper we describe a model of operational risk of economic capital estimation and allocation based on Loss Distribution Approach (LDA). Bank's total losses are modeled through Monte-Carlo simulations of its business units' losses. It allows to fairly distributing the corresponding capital between business units in order to assess and manage their risk adjusted performance.

Nikonov, Oleg I.; Vlasov, Vladimir E.; Medvedeva, Marina A.

2013-10-01

134

Resource Allocation via Message Passing  

Microsoft Academic Search

We propose a message-passing paradigm for resource allocation problems. This serves to connect ideas from the message passing literature, which has primarily grown out of the com- munications, statistical physics, and artificial intelligence communities, with a problem central to operations research. This also provides a new framework for decentralized management that generalizes price-based systems by allowing incentives to vary across

Ciamac Cyrus Moallemi; Benjamin Van Roy

2011-01-01

135

Resource allocation for broadband networks  

Microsoft Academic Search

The major benefit of a broadband integrated ATM (asynchronous transfer mode) network is flexible and efficient allocation of communications bandwidth for communications services. However, methods are needed for evaluating congestion for integrated traffic. The author suggests evaluating congestion at different levels, namely the packet level, the burst level, and the call level. Congestion is measured by the probabilities of packet

J. Y. Hui

1988-01-01

136

Administrators' Decisions about Resource Allocation  

ERIC Educational Resources Information Center

|Do academic administrators make decisions about resource allocation differently depending on the discipline receiving the funding? Does an administrator's academic identity influence these decisions? This study explored those questions with a sample of 1,690 academic administrators at doctoral-research universities. Participants used fictional…

Knight, William E.; Folkins, John W.; Hakel, Milton D.; Kennell, Richard P.

2011-01-01

137

Resource allocation for broadband networks  

Microsoft Academic Search

The author suggests the use of congestion measures at the packet level, the burst level, and the call level to evaluate congestion for integrated traffic. These measures result from the fact that communication terminals can often be characterized in terms of call level, burst level, and packet level statistics. They can be used for the purpose of bandwidth allocation at

Joseph Y. Hui

1988-01-01

138

Optimal resource allocation for multiqueue systems with a shared server pool  

Microsoft Academic Search

We study optimal allocation of servers for a system with multiple service facilities and with a shared pool of servers. Each\\u000a service facility poses a constraint on the maximum expected sojourn time of a job. A central decision maker can dynamically\\u000a allocate servers to each facility, where adding more servers results in faster processing speeds but against higher utilization\\u000a costs. The

Ran Yang; Sandjai Bhulai

139

Optimal resource allocation for multi-queue systems with a shared server pool  

Microsoft Academic Search

We study optimal allocation of servers for a system with multiple service facilities and\\u000awith a shared pool of servers. Each service facility poses a constraint on the maximum\\u000aexpected sojourn time of a job. A central decision maker can dynamically allocate servers\\u000ato each facility, where adding more servers results in faster processing speeds but against\\u000ahigher utilization costs.

R. Yang; S. Bhulai; Mei van der R. D

2011-01-01

140

A soliton menagerie in AdS  

NASA Astrophysics Data System (ADS)

We explore the behaviour of charged scalar solitons in asymptotically global AdS4 spacetimes. This is motivated in part by attempting to identify under what circumstances such objects can become large relative to the AdS length scale. We demonstrate that such solitons generically do get large and in fact in the planar limit smoothly connect up with the zero temperature limit of planar scalar hair black holes. In particular, for given Lagrangian parameters we encounter multiple branches of solitons: some which are perturbatively connected to the AdS vacuum and surprisingly, some which are not. We explore the phase space of solutions by tuning the charge of the scalar field and changing scalar boundary conditions at AdS asymptopia, finding intriguing critical behaviour as a function of these parameters. We demonstrate these features not only for phenomenologically motivated gravitational Abelian-Higgs models, but also for models that can be consistently embedded into eleven dimensional supergravity.

Gentle, Simon A.; Rangamani, Mukund; Withers, Benjamin

2012-05-01

141

Magnetic Monopoles in AdS  

SciTech Connect

Applications to holographic theories have led to some recent interest in magnetic monopoles in four-dimensional Anti-de Sitter (AdS) spacetime. Some analytic and numerical results are discussed for monopoles in AdS, including the symmetries of minimal energy monopoles (which are often Platonic), a connection to Skyrmions, and the emergence of a hexagonal lattice in the large charge limit.

Sutcliffe, Paul [Department of Mathematical Sciences, Durham University, Durham DH1 3LE (United Kingdom)

2011-09-22

142

Estimating parameters in stochastic systems: A variational Bayesian approach  

NASA Astrophysics Data System (ADS)

This work is concerned with approximate inference in dynamical systems, from a variational Bayesian perspective. When modelling real world dynamical systems, stochastic differential equations appear as a natural choice, mainly because of their ability to model the noise of the system by adding a variation of some stochastic process to the deterministic dynamics. Hence, inference in such processes has drawn much attention. Here a new extended framework is derived that is based on a local polynomial approximation of a recently proposed variational Bayesian algorithm. The paper begins by showing that the new extension of this variational algorithm can be used for state estimation (smoothing) and converges to the original algorithm. However, the main focus is on estimating the (hyper-) parameters of these systems (i.e. drift parameters and diffusion coefficients). The new approach is validated on a range of different systems which vary in dimensionality and non-linearity. These are the Ornstein-Uhlenbeck process, the exact likelihood of which can be computed analytically, the univariate and highly non-linear, stochastic double well and the multivariate chaotic stochastic Lorenz ’63 (3D model). As a special case the algorithm is also applied to the 40 dimensional stochastic Lorenz ’96 system. In our investigation we compare this new approach with a variety of other well known methods, such as the hybrid Monte Carlo, dual unscented Kalman filter, full weak-constraint 4D-Var algorithm and analyse empirically their asymptotic behaviour as a function of observation density or length of time window increases. In particular we show that we are able to estimate parameters in both the drift (deterministic) and the diffusion (stochastic) part of the model evolution equations using our new methods. This work is concerned with approximate inference in stochastic processes. A polynomial approximation of a recently proposed variational algorithm is derived. Our work focuses on estimating the parameters of stochastic differential equations. We compare our approach with other methods and analyse empirically their asymptotic behaviour.

Vrettas, Michail D.; Cornford, Dan; Opper, Manfred

2011-11-01

143

STOCHASTIC COOLING FOR RHIC.  

SciTech Connect

Emittance growth due to Intra-Beam Scattering significantly reduces the heavy ion luminosity lifetime in RHIC. Stochastic cooling of the stored beam could improve things considerably by counteracting IBS and preventing particles from escaping the rf bucket [1]. High frequency bunched-beam stochastic cooling is especially challenging but observations of Schottky signals in the 4-8 GHz band indicate that conditions are favorable in RHIC [2]. We report here on measurements of the longitudinal beam transfer function carried out with a pickup kicker pair on loan from FNAL TEVATRON. Results imply that for ions a coasting beam description is applicable and we outline some general features of a viable momentum cooling system for RHIC.

BLASKIEWICZ,M.BRENNAN,J.M.CAMERON,P.WEI,J.

2003-05-12

144

Energetics of stochastic resonance  

NASA Astrophysics Data System (ADS)

In this paper, we discuss the motion of a Brownian particle in a double-well potential driven by a periodic force in terms of energies delivered by the periodic and the noise forces and energy dissipated into the viscous environment. It is shown that, while the power delivered by the periodic force to the Brownian particle is controlled by the strength of the noise, the power delivered by the noise itself is independent of the amplitude and frequency of the periodic force. The implications of this result for the mechanism of stochastic resonance in an equilibrium system is that it is not energy from the noise force which enhances a small periodic force, but rather an increase of energy delivered by the periodic force, regulated by the strength of the noise. We further re-evaluate the frequency dependence of stochastic resonance in terms of energetic terms including efficiency.

Jung, Peter; Marchesoni, Fabio

2011-12-01

145

Stochastic stacking without filters  

SciTech Connect

The rate of accumulation of antiprotons is a critical factor in the design of p anti p colliders. A design of a system to accumulate higher anti p fluxes is presented here which is an alternative to the schemes used at the CERN AA and in the Fermilab Tevatron I design. Contrary to these stacking schemes, which use a system of notch filters to protect the dense core of antiprotons from the high power of the stack tail stochastic cooling, an eddy current shutter is used to protect the core in the region of the stack tail cooling kicker. Without filters one can have larger cooling bandwidths, better mixing for stochastic cooling, and easier operational criteria for the power amplifiers. In the case considered here a flux of 1.4 x 10/sup 8/ per sec is achieved with a 4 to 8 GHz bandwidth.

Johnson, R.P.; Marriner, J.

1982-12-01

146

Stochastic flights of propellers  

NASA Astrophysics Data System (ADS)

Kilometre-sized moonlets in Saturn's A ring create S-shaped wakes called 'propellers' in surrounding material. The Cassini spacecraft has tracked the motions of propellers for several years and finds that they deviate from Keplerian orbits with constant semimajor axes. The inferred orbital migration is known to switch sign. We show using a statistical test that the time series of orbital longitudes of the propeller Blériot is consistent with that of a time-integrated Gaussian random walk. That is, Blériot's observed migration pattern is consistent with being stochastic. We further show, using a combination of analytic estimates and collisional N-body simulations, that stochastic migration of the right magnitude to explain the Cassini observations can be driven by encounters with ring particles 10-20 m in radius. That the local ring mass is concentrated in decametre-sized particles is supported on independent grounds by occultation analyses.

Pan, Margaret; Rein, Hanno; Chiang, Eugene; Evans, Steven N.

2012-12-01

147

VAWT stochastic wind simulator  

SciTech Connect

A stochastic wind simulation for VAWTs (VSTOC) has been developed which yields turbulent wind-velocity fluctuations for rotationally sampled points. This allows three-component wind-velocity fluctuations to be simulated at specified nodal points on the wind-turbine rotor. A first-order convection scheme is used which accounts for the decrease in streamwise velocity as the flow passes through the wind-turbine rotor. The VSTOC simulation is independent of the particular analytical technique used to predict the aerodynamic and performance characteristics of the turbine. The VSTOC subroutine may be used simply as a subroutine in a particular VAWT prediction code or it may be used as a subroutine in an independent processor. The independent processor is used to interact with a version of the VAWT prediction code which is segmented into deterministic and stochastic modules. Using VSTOC in this fashion is very efficient with regard to decreasing computer time for the overall calculation process.

Strickland, J.H.

1987-04-01

148

STOCHASTIC COOLING POWER REQUIREMENTS.  

SciTech Connect

A practical obstacle for stochastic cooling in high-energy colliders like RHIC is the large amount of power needed for the cooling system. Based on the coasting-beam Fokker-Planck (F-P) equation, we analytically derived the optimum cooling rate and cooling power for a beam of uniform distribution and a cooling system of linear gain function. The results indicate that the usual back-of-envelope formula over-estimated the cooling power by a factor of the mixing factor M. On the other hand, the scaling laws derived from the coasting-beam Fokker-Planck approach agree with those derived from the bunched-beam Fokker-Planck approach if the peak beam intensity is used as the effective coasting-beam intensity. A longitudinal stochastic cooling system of 4-8 GHz bandwidth in RHIC can effectively counteract intrabeam scattering, preventing the beam from escaping the RF bucket becoming debunched around the ring.

WEI,J.BLASKIEWICZ,M.BRENNAN,M.

2004-07-05

149

On Nonterminating Stochastic Games  

Microsoft Academic Search

A stochastic game is played in a sequence of steps; at each step the play is said to be in some state i, chosen from a finite collection of states. If the play is in state i, the first player chooses move k and the second player chooses move l, then the first player receives a reward akl<\\/sup>i<\\/sub>, and, with

A. J. Hoffman; R. M. Karp

1966-01-01

150

Disruption, Succession and Stochasticity  

Microsoft Academic Search

\\u000a Disruptions interfere with the orderly course of a process. Ecological disturbances, physical processes that remove living\\u000a biomass from an ecosystem, are common disruptions that are frequently observed in the marine benthos. Although often associated\\u000a with climatic or geological events, some disturbances arise from biological activity. Disturbances are often pulsed, stochastic\\u000a events at a local scale. At larger spatial and temporal

J. Timothy Wootton; Mathieu Cusson; Sergio Navarrete; Peter S. Petraitis

151

Entropy of stochastic flows  

SciTech Connect

For sets in a Hilbert space the concept of quadratic entropy is introduced. It is shown that this entropy is finite for the range of a stochastic flow of Brownian particles on R. This implies, in particular, the fact that the total time of the free travel in the Arratia flow of all particles that started from a bounded interval is finite. Bibliography: 10 titles.

Dorogovtsev, Andrei A [Institute of Mathematics of Ukrainian National Academy of Sciences, Kiev (Ukraine)

2010-06-29

152

VAWT stochastic wind simulator  

Microsoft Academic Search

A stochastic wind simulation for VAWTs (VSTOC) has been developed which yields turbulent wind-velocity fluctuations for rotationally sampled points. This allows three-component wind-velocity fluctuations to be simulated at specified nodal points on the wind-turbine rotor. A first-order convection scheme is used which accounts for the decrease in streamwise velocity as the flow passes through the wind-turbine rotor. The VSTOC simulation

Strickland

1987-01-01

153

Stochastic perturbations of the five-component Benard system  

NASA Astrophysics Data System (ADS)

The effect of added white noise on the dynamical system of a two-dimensional fluid layer heated from below with periodic free stress boundary conditions is investigated analytically. The exit integrations are estimated asymptotically, and the results are compared with those obtained by numerical integration in graphs. The stochastic resonance mechanism is discussed, and it is found that the effect of stochastic perturbations at large values of the aspect ratio (Gamma) is amplified by a factor proportional to Gamma squared. It is argued that such a mechanism could explain the experimental observations of Ahlers and Walden (1980) and Libchaber (1983).

Benzi, R.; Sutera, A.

1984-08-01

154

Allocation of Resources for Terminal Improvement.  

National Technical Information Service (NTIS)

The report describes the development of a resource-allocation model developed for the improvement of the internal environment of transport terminals. It incorporates considerations of comfort, cost, and patron opinion to allocate resources for maximum eff...

E. J. Cantilli

1975-01-01

155

Spectrum Allocation: A Survey of Alternative Methodologies.  

National Technical Information Service (NTIS)

A survey is given of the problem of allocating the electromagnetic spectrum by the Federal Government. Emphasis is on the use of economic values in spectrum allocation by the Federal Communications Commission and the Office of Telecommunications Policy. (...

B. M. Owen

1972-01-01

156

Task Allocation among Multiple Intelligent Robots.  

National Technical Information Service (NTIS)

Researchers describe the design of a decentralized mechanism for allocating assembly tasks in a multiple robot assembly workstation. Currently, the approach focuses on distributed allocation to explore its feasibility and its potential for adaptability to...

L. Gasser G. Bekey

1987-01-01

157

Methodology for Allocating Reliability and Risk.  

National Technical Information Service (NTIS)

The report describes a methodology for reliability and risk allocation in nuclear power plants. The work investigates the technical feasibility of allocating reliability and risk expressed in a set of global safety criteria to various reactor systems, sub...

N. Z. Cho I. A. Papazoglou R. A. Bari

1986-01-01

158

General Revenue Sharing: Ninth Period Allocations.  

National Technical Information Service (NTIS)

The revenue sharing allocation and adjustment process is described. The allocation formula is addressed. Recipient governments are listed showing the payments, final entitlements and adjustments for the entitlement periods.

1977-01-01

159

Phase transitions in crowd dynamics of resource allocation  

NASA Astrophysics Data System (ADS)

We define and study a class of resource allocation processes where gN agents, by repeatedly visiting N resources, try to converge to an optimal configuration where each resource is occupied by at most one agent. The process exhibits a phase transition, as the density g of agents grows, from an absorbing to an active phase. In the latter, even if the number of resources is in principle enough for all agents (g<1), the system never settles to a frozen configuration. We recast these processes in terms of zero-range interacting particles, studying analytically the mean field dynamics and investigating numerically the phase transition in finite dimensions. We find a good agreement with the critical exponents of the stochastic fixed-energy sandpile. The lack of coordination in the active phase also leads to a nontrivial faster-is-slower effect.

Ghosh, Asim; de Martino, Daniele; Chatterjee, Arnab; Marsili, Matteo; Chakrabarti, Bikas K.

2012-02-01

160

Dynamic Resource Allocation in Disaster Response: Tradeoffs in Wildfire Suppression  

PubMed Central

Challenges associated with the allocation of limited resources to mitigate the impact of natural disasters inspire fundamentally new theoretical questions for dynamic decision making in coupled human and natural systems. Wildfires are one of several types of disaster phenomena, including oil spills and disease epidemics, where (1) the disaster evolves on the same timescale as the response effort, and (2) delays in response can lead to increased disaster severity and thus greater demand for resources. We introduce a minimal stochastic process to represent wildfire progression that nonetheless accurately captures the heavy tailed statistical distribution of fire sizes observed in nature. We then couple this model for fire spread to a series of response models that isolate fundamental tradeoffs both in the strength and timing of response and also in division of limited resources across multiple competing suppression efforts. Using this framework, we compute optimal strategies for decision making scenarios that arise in fire response policy.

Petrovic, Nada; Alderson, David L.; Carlson, Jean M.

2012-01-01

161

Balance, executive functions and falls in elderly with Alzheimer's disease (AD): A longitudinal study  

Microsoft Academic Search

Elderly individuals with AD are more susceptible to falls, which might be associated with decrements in their executive functions and balance, among other things. We aimed to analyze the effects of a program of dual task physical activity on falls, executive functions and balance of elderly individuals with AD. We studied 21 elderly with probable AD, allocated to two groups:

Renata Valle Pedroso; Flávia Gomes de Melo Coelho; Ruth Ferreira Santos-Galduróz; José Luiz Riani Costa; Sebastião Gobbi; Florindo Stella

162

Intelligent tactical asset allocation support system  

Microsoft Academic Search

This paper presents an advanced support system for Tactical Asset Allocation. Asset allocation explains over 90% of portfolio performance (Brinson, Hood and Beebower, 1988). Tactical asset allocation adjusts a strategic portfolio on the basis of short term market outlooks. The system includes a prediction model that forecasts quarterly excess returns on the S&PSOO, an optimization model that adjusts a user-specified

Y. Hiemstra

1995-01-01

163

Some results on Denault's capital allocation rule  

Microsoft Academic Search

Denault (2001) introduces a capital allocation principle where the capital allocated to any risk unit is expressed in terms of the contribution of that risk to the aggregate conditional tail expectation. Panjer (2002) derives a closed-form expression for this allocation rule in the multivariate normal case. Landsman & Valdez (2003) generalize Panjer's result to the class of multivariate elliptical distributions.

Steven Vanduffel; Jan Dhaene

2006-01-01

164

50 CFR 648.87 - Sector allocation.  

Code of Federal Regulations, 2010 CFR

...that a future allocation of SNE/MA...S./Canada Resource Sharing Understanding...the sector's allocation of the overall...sanction or other enforcement action. ...sector vessels; enforcement actions...of applicable law. (vii...DAS, the DAS allocation and...

2010-10-01

165

Aspects of Stochastic Global Analysis  

Microsoft Academic Search

This is a survey of some topics where global and stochastic analysis play a role. An introduction to analysis on Banach spaces\\u000a with Gaussian measure leads to an analysis of the geometry of stochastic differential equations, stochastic flows, and their\\u000a associated connections, with reference to some related topological vanishing theorems. Following that, there is a description\\u000a of the construction of

K. D. Elworthy; Hideki Omori

166

On Nonlinear Stochastic Balance Laws  

NASA Astrophysics Data System (ADS)

We are concerned with multidimensional stochastic balance laws. We identify a class of nonlinear balance laws for which uniform spatial BV bound for vanishing viscosity approximations can be achieved. Moreover, we establish temporal equicontinuity in L 1 of the approximations, uniformly in the viscosity coefficient. Using these estimates, we supply a multidimensional existence theory of stochastic entropy solutions. In addition, we establish an error estimate for the stochastic viscosity method, as well as an explicit estimate for the continuous dependence of stochastic entropy solutions on the flux and random source functions. Various further generalizations of the results are discussed.

Chen, Gui-Qiang; Ding, Qian; Karlsen, Kenneth H.

2012-06-01

167

Register allocation by puzzle solving  

Microsoft Academic Search

We show that register allocation can be viewed as solving a collection of puzzles. We model the register file as a puzzle board and the program variables as puzzle pieces; pre-coloring and register aliasing fit in naturally. For architectures such as PowerPC, x86, and StrongARM, we can solve the puzzles in polynomial time, and we have augmented the puzzle solver

Fernando Magno Quintão Pereira; Jens Palsberg

2008-01-01

168

Register allocation by puzzle solving  

Microsoft Academic Search

We show that register allocation can be viewed as solving a collec- tion of puzzles. We model the register file as a puzzle board and the program variables as puzzle pieces; pre-coloring and register aliasing fit in naturally. For architectures such as PowerPC, x86, and StrongARM, we can solve the puzzles in polynomial time, and we have augmented the puzzle

Fernando Magno Quintão Pereira; Jens Palsberg

2008-01-01

169

Industry growth and capital allocation  

Microsoft Academic Search

Are market-based or bank-based financial systems better at financing the expansion of industries that depend heavily on external finance, facilitating the formation of new establishments, and improving the efficiency of capital allocation across industries? We find evidence for neither the market-based nor the bank-based hypothesis. While legal system efficiency and overall financial development boost industry growth, new establishment formation, and

Thorsten Beck; Ross Levine

2002-01-01

170

Cost Allocation and Opportunity Costs  

Microsoft Academic Search

One explanation for the widespread use of allocated fixed costs is that they can serve as a proxy for difficult-to-calculate opportunity costs. This explanation is pursued by modeling a service department as an M\\/M\\/s\\/s queueing system. Two main results are that the expected value of opportunity costs equals both the incremental productivity of capacity and the optimal transfer price. When

Bruce L. Miller; A. G. Buckman

1987-01-01

171

Algorithms for optimal redundancy allocation  

SciTech Connect

Heuristic and exact methods for solving the redundancy allocation problem are compared to an approach based on genetic algorithms. The various methods are applied to the bridge problem, which has been used as a benchmark in earlier work on optimization methods. Comparisons are presented in terms of the best configuration found by each method, and the computation effort which was necessary in order to find it.

Vandenkieboom, J.; Youngblood, R.

1993-01-01

172

Allocating Variability and Reserve Requirements (Presentation)  

SciTech Connect

This presentation describes how you could conceivably allocate variability and reserve requirements, including how to allocate aggregation benefits. Conclusions of this presentation are: (1) Aggregation provides benefits because individual requirements are not 100% correlated; (2) Method needed to allocate reduced requirement among participants; (3) Differences between allocation results are subtle - (a) Not immediately obvious which method is 'better'; (b) Many are numerically 'correct', they sum to the physical requirement; (c) Many are not 'fair', Results depend on sub-aggregation and/or the order individuals are included; and (4) Vector allocation method is simple and fair.

Kirby, B.; King, J.; Milligan, M.

2011-10-01

173

Stochastic coupled cluster theory.  

PubMed

We describe a stochastic coupled cluster theory which represents excitation amplitudes as discrete excitors in the space of excitation amplitudes. Reexpressing the coupled cluster (CC) equations as the dynamics of excitors in this space, we show that a simple set of rules suffices to evolve a distribution of excitors to sample the CC solution and correctly evaluate the CC energy. These rules are not truncation specific and this method can calculate CC solutions to an arbitrary level of truncation. We present results of calculation on the neon atom, and nitrogen and water molecules showing the ability to recover both truncated and full CC results. PMID:21231654

Thom, Alex J W

2010-12-28

174

Stochastic ontogenetic growth model  

NASA Astrophysics Data System (ADS)

An ontogenetic growth model (OGM) for a thermodynamically closed system is generalized to satisfy both the first and second law of thermodynamics. The hypothesized stochastic ontogenetic growth model (SOGM) is shown to entail the interspecies allometry relation by explicitly averaging the basal metabolic rate and the total body mass over the steady-state probability density for the total body mass (TBM). This is the first derivation of the interspecies metabolic allometric relation from a dynamical model and the asymptotic steady-state distribution of the TBM is fit to data and shown to be inverse power law.

West, B. J.; West, D.

2012-02-01

175

Stochastic automata for language modeling  

Microsoft Academic Search

Stochastic language models are widely used in spoken language understanding to recognize and interpret the speech signal: the speech samples are decoded into word transcriptions by means of acoustic and syntactic models and then interpreted according to a semantic model. Both for speech recognition and understanding, search algorithms use stochastic models to extract the most likely uttered sentence and its

Giuseppe Riccardi; Roberto Pieraccini; Enrico Bocchieri

1996-01-01

176

Stochastic Approach to Highway Traffic  

Microsoft Academic Search

We analyze the characteristic features of jam formation on a circular one-lane road. We have applied an optimal velocity model including stochastic noise, where cars are treated as moving and interacting particles. The motion of N cars is described by the system of 2N stochastic differential equations with multiplicative white noise. Our system of cars behaves in qualitatively different ways

R. Mahnkea

177

Stochastic approach to highway traffic  

Microsoft Academic Search

We analyze the characteristic features of jam formation on a circular one-lane road. We have applied an optimal velocity model including stochastic noise, where cars are treated as moving and interacting particles. The motion of N cars is described by the system of 2N stochastic differential equations with multiplicative white noise. Our system of cars behaves in qualitatively different ways

Reinhard Mahnke; Jevgenijs Kaupuzs; Ihor Lubashevsky; Julia Tolmacheva

2004-01-01

178

Hydrodynamics of stochastic cellular automata  

Microsoft Academic Search

We investigate a stochastic version of cellular automata used for simulating hydrodynamical flows, e.g. the HPP and FHP models. The extra stochasticity consists of “random exchanges” between neighboring cells which conserve momentum. We prove that, in suitable limits, these models satisfy the appropriate continuous Boltzmann and hydrodynamic equations, the same as those conjectured for the original models (except that there

A. Demasi; R. Esposito; J. L. Lebowitz; E. Presutti

1989-01-01

179

Stochastic representation of fluid equations  

NASA Astrophysics Data System (ADS)

The stochastic representation of fluid equations describing a plasma transport in the peripheral region is discussed, which is based on the theorem of Yasue (1983 J. Funct. Anal. 51, 133). The scheme solving the stochastic equations is given by employing a path integral method.

Kanno, Ryutaro

2004-06-01

180

AdBlockVideo  

NSDL National Science Digital Library

Video ads can be quite a nuisance. AdBlockVideo can help users out by effectively blocking such ads. Visitors will need to download the program and they can toggle AdBlockVideo on and off as they see fit. This application is compatible with computers running Windows 98 and newer, Max OS 10.3 and newer, and Linux.

2011-01-01

181

Stochastic phase synchronization in the crayfish mechanoreceptor/photoreceptor system  

NASA Astrophysics Data System (ADS)

The two light-sensitive neurons in the crayfish's abdominal sixth ganglion (``caudal photoreceptors,'' or CPRs), are both primary light sensors and secondary neurons in a mechanosensory pathway. Pei et al. (1996) demonstrated that light enhances the transduction of weak, periodic hydrodynamic stimuli (measured as an increase in the signal-to-noise ratio at the stimulus frequency in the power spectrum of the recorded neural spikes). This has been interpreted as a stochastic resonance effect, in which added light increases the noise intensity of the input to the photoreceptor (possibly through fluctuations in membrane potential), leading to an enhancement of the signal-to-noise ratio (SNR). Here, we discuss the recent demonstration (Bahar et al., 2002) of the correlation between a stochastic-resonance-like effect and an increase in stochastic phase synchronization between the neural response and a periodic mechanical stimulus. We also discuss a novel effect (Bahar et al., 2002) in which light increases the SNR of the second higher harmonic of a periodic input signal, effectively rectifying the input signal. This ``second harmonic effect'' can also be interpreted in terms of stochastic phase synchronization (Bahar et al., 2002). We review other recent results on the role of stochastic phase synchronization in mediating sensory responses in the crayfish nervous system.

Bahar, S.; Moss, F.

2003-03-01

182

AdS orbifolds and Penrose limits  

SciTech Connect

In this paper we study the Penrose limit of AdS{sub 5} orbifolds. The orbifold can be either in the pure spatial directions or space and time directions. For the AdS{sub 5}/{Lambda} x S{sup 5} spatial orbifold we observe that after the Penrose limit we obtain the same result as the Penrose limit of AdS{sub 5} x S{sup 5}/{Lambda}. We identify the corresponding BMN operators in terms of operators of the gauge theory on R x S{sup 3}/{Lambda}. The semi-classical description of rotating strings in these backgrounds have also been studied. For the spatial AdS orbifold we show that in the quadratic order the obtained action for the fluctuations is the same as that in S{sup 5} orbifold, however, the higher loop correction can distinguish between two cases.

Alishahiha, Mohsen; Sheikh-Jabbari, Mohammad M.; Tatar, Radu

2002-12-09

183

Interactive visualization for resource allocation  

NASA Astrophysics Data System (ADS)

Based on our experience in the design and construction of interactive resource reallocation systems, we argue about the advisability of interactive visualization as a means to increase the effectiveness of an intelligent system and we present a generic framework for solving rescheduling problems. A presentation of a flight rescheduling systems we have built, serves as the main implementation example of our proposed paradigm. We explain the specific visualization methods employed in the system and how visualization, coupled with artificial intelligence techniques, can aid in the difficult task of resource allocation.

Melissargos, George; Pu, Pearl

1997-03-01

184

Biochemical simulations: stochastic, approximate stochastic and hybrid approaches  

PubMed Central

Computer simulations have become an invaluable tool to study the sometimes counterintuitive temporal dynamics of (bio-)chemical systems. In particular, stochastic simulation methods have attracted increasing interest recently. In contrast to the well-known deterministic approach based on ordinary differential equations, they can capture effects that occur due to the underlying discreteness of the systems and random fluctuations in molecular numbers. Numerous stochastic, approximate stochastic and hybrid simulation methods have been proposed in the literature. In this article, they are systematically reviewed in order to guide the researcher and help her find the appropriate method for a specific problem.

2009-01-01

185

Matrix Models of AdS Gravity  

Microsoft Academic Search

We explore the connection between anti-deSitter supergravity and gauge\\u000atheory, in the context of bound states of many D1 and D5 branes. The\\u000anear-horizon $AdS_3$ supergravity describes the identity sector of the\\u000aconformal field theory produced by the brane dynamics. A variant of anomaly\\u000ainflow (for the 2d conformal anomaly) is involved. Dynamical matter fields on\\u000a$AdS_3$ couple to the

Emil J. Martinec

1998-01-01

186

Campaign allocations under probabilistic voting  

Microsoft Academic Search

We develop a probabilistic voting model where candidates compete by advertising in different media markets. Ads are viewed\\u000a by everyone within a market and cannot be targeted to subgroups such as one candidate’s partisans. Candidates estimate the\\u000a distribution of voter preference intensities in a market, and campaign ads then shift this distribution. Individuals with\\u000a any intensity vote with some probability

Deborah Fletcher; Steven Slutsky

2011-01-01

187

AdS2 D-branes in Lorentzian AdS3  

Microsoft Academic Search

The boundary states for two dimensional anti de Sitter (AdS2) Dirichlet-branes (D-branes) in Lorentzian AdS3 space-time are presented. AdS2 D-branes are algebraically defined by twisted Dirichlet boundary conditions and are located on twisted conjugacy classes of SL(2,R). Using the free-field representation of symmetry currents in the SL(2,R) Wess-Zumino-Novikov-Witten model, the twisted Dirichlet gluing conditions among currents are translated to matching

Cemsinan Deliduman; Feza Gursey

2003-01-01

188

Stochastic reconstruction of sandstones  

PubMed

A simulated annealing algorithm is employed to generate a stochastic model for a Berea sandstone and a Fontainebleau sandstone, with each a prescribed two-point probability function, lineal-path function, and "pore size" distribution function, respectively. We find that the temperature decrease of the annealing has to be rather quick to yield isotropic and percolating configurations. A comparison of simple morphological quantities indicates good agreement between the reconstructions and the original sandstones. Also, the mean survival time of a random walker in the pore space is reproduced with good accuracy. However, a more detailed investigation by means of local porosity theory shows that there may be significant differences of the geometrical connectivity between the reconstructed and the experimental samples. PMID:11088546

Manwart; Torquato; Hilfer

2000-07-01

189

Stochastic patch exploitation model  

PubMed Central

A solitary animal is foraging in a patch consisting of discrete prey items. We develop a stochastic model for the accumulation of gain as a function of elapsed time in the patch. The model is based on the waiting times between subsequent encounters with the prey items. The novelty of the model is in that it renders possible–via parameterization of the waiting time distributions: the incorporation of different foraging situations and patch structures into the gain process. The flexibility of the model is demonstrated with different foraging scenarios. Dependence of gain expectation and variance of the parameters of the waiting times is studied under these conditions. The model allows us to comment upon some of the basic concepts in contemporary foraging theory.

Rita, H.; Ranta, E.

1998-01-01

190

Sources of stochasticity in geophysical processes  

Microsoft Academic Search

Most time processes within the atmosphere, oceans and along the water cycle are periodic stochastic processes. The physical bases of the periodicities are the astronomic cycles while the stochasticity is produced by various chance factors within the environments of the earth. The stochasticities of some space properties of the earth's environments are the accumulated results of past time periodic stochastic

Vujica Yevjevich

191

A comparative study of stochastic analysis techniques  

Microsoft Academic Search

Stochastic models are becoming increasingly popular in Systems Biology. They are compulsory, if the stochastic noise is crucial for the behavioural properties to be investigated. Thus, substantial effort has been made to develop appropriate and efficient stochastic analysis techniques. The impressive progress of hardware power and specifically the advent of multicore computers have ameliorated the computational tractability of stochastic models.

Monika Heiner; Christian Rohr; Martin Schwarick; Stefan Streif

2010-01-01

192

Numerical methods for stochastic differential equations  

Microsoft Academic Search

The numerical analysis of stochastic differential equations differs significantly from that of ordinary differential equations due to the peculiarities of stochastic calculus. This book provides an introduction to stochastic calculus and stochastic differential equations, both theory and applications. The main emphasise is placed on the numerical methods needed to solve such equations. It assumes an undergraduate background in mathematical methods

Peter Kloeden; Eckhard Platen

1991-01-01

193

Adaptive Distributed Resource Allocation for Sensor Networks  

Microsoft Academic Search

\\u000a A major research challenge in the field of sensor networks is the distributed resource allocation problem, which concerns\\u000a how the limited resources in a sensor network should be allocated or scheduled to minimize costs and maximize the network\\u000a capability. We survey the existing work on the distributed resource allocation problem. To address the drawbacks in the existing\\u000a work, we propose

Hock Beng Lim; Di Ma; Cheng Fu; Bang Wang; Meng Joo Er

194

Using genetic algorithm to solve a new multi-period stochastic optimization model  

NASA Astrophysics Data System (ADS)

This paper presents a new asset allocation model based on the CVaR risk measure and transaction costs. Institutional investors manage their strategic asset mix over time to achieve favorable returns subject to various uncertainties, policy and legal constraints, and other requirements. One may use a multi-period portfolio optimization model in order to determine an optimal asset mix. Recently, an alternative stochastic programming model with simulated paths was proposed by Hibiki [N. Hibiki, A hybrid simulation/tree multi-period stochastic programming model for optimal asset allocation, in: H. Takahashi, (Ed.) The Japanese Association of Financial Econometrics and Engineering, JAFFE Journal (2001) 89-119 (in Japanese); N. Hibiki A hybrid simulation/tree stochastic optimization model for dynamic asset allocation, in: B. Scherer (Ed.), Asset and Liability Management Tools: A Handbook for Best Practice, Risk Books, 2003, pp. 269-294], which was called a hybrid model. However, the transaction costs weren't considered in that paper. In this paper, we improve Hibiki's model in the following aspects: (1) The risk measure CVaR is introduced to control the wealth loss risk while maximizing the expected utility; (2) Typical market imperfections such as short sale constraints, proportional transaction costs are considered simultaneously. (3) Applying a genetic algorithm to solve the resulting model is discussed in detail. Numerical results show the suitability and feasibility of our methodology.

Zhang, Xin-Li; Zhang, Ke-Cun

2009-09-01

195

Water resources planning and management : A stochastic dual dynamic programming approach  

NASA Astrophysics Data System (ADS)

Allocating water between different users and uses, including the environment, is one of the most challenging task facing water resources managers and has always been at the heart of Integrated Water Resources Management (IWRM). As water scarcity is expected to increase over time, allocation decisions among the different uses will have to be found taking into account the complex interactions between water and the economy. Hydro-economic optimization models can capture those interactions while prescribing efficient allocation policies. Many hydro-economic models found in the literature are formulated as large-scale non linear optimization problems (NLP), seeking to maximize net benefits from the system operation while meeting operational and/or institutional constraints, and describing the main hydrological processes. However, those models rarely incorporate the uncertainty inherent to the availability of water, essentially because of the computational difficulties associated stochastic formulations. The purpose of this presentation is to present a stochastic programming model that can identify economically efficient allocation policies in large-scale multipurpose multireservoir systems. The model is based on stochastic dual dynamic programming (SDDP), an extension of traditional SDP that is not affected by the curse of dimensionality. SDDP identify efficient allocation policies while considering the hydrologic uncertainty. The objective function includes the net benefits from the hydropower and irrigation sectors, as well as penalties for not meeting operational and/or institutional constraints. To be able to implement the efficient decomposition scheme that remove the computational burden, the one-stage SDDP problem has to be a linear program. Recent developments improve the representation of the non-linear and mildly non- convex hydropower function through a convex hull approximation of the true hydropower function. This model is illustrated on a cascade of 14 reservoirs on the Nile river basin.

Goor, Q.; Pinte, D.; Tilmant, A.

2008-12-01

196

Stochastic model for microgravity excitation  

NASA Astrophysics Data System (ADS)

A simple stochastic method for generating synthetic orbital accelerations is proposed in this paper. The procedure is used to develop a stochastic model for the STS-40 orbital excitation. The method uses a filtered white-noise model that takes into account time evolutions of the amplitude and the frequency content of the original accelerogram. The probabilistic response spectra are generated and comparisons with those of the actual STS-40 orbital data are made to verify the model. The results indicate that significant properties of the original record are retained in the generated synthetic accelerations. This method is also employed to generate a stochastic model for the space station vibration environment.

Ellison, Joseph; Ahmadi, Goodarz; Grodsinsky, Carlos

1995-04-01

197

Stochastic processes for indirectly interacting particles and stochastic quantum mechanics  

SciTech Connect

This work has two objectives. The first is to begin a mathematical formalism appropriate to treating particles which only interact with each other indirectly due to hypothesized memory effects in a stochastic medium. More specifically we treat a situation in which a sequence of particles consecutively passes through a region (e.g., a measuring apparatus) in such a way that one particle leaves the region before the next one enters. We want to study a situation in which a particle may interact with other particles that previously passed through the system via disturbances made in the region by these previous particles. Second, we apply the type of stochastic process appearing in this context to the stochastic interpretation of quantum mechanics to obtain a modified version of this interpretation. This version is free of many of the criticisms made against the stochastic interpretation of quantum mechanics.

Buonomano, V.; Prado de Andrade, A.F.

1988-04-01

198

Stochastic Differential Dynamic Logic for Stochastic Hybrid Programs.  

National Technical Information Service (NTIS)

Logic is a powerful tool for analyzing and verifying systems, including programs, discrete systems real-time systems, hybrid systems, and distributed systems. Some applications also have a stochastic behavior, however, either because of fundamental proper...

A. Platzer

2011-01-01

199

Basin-wide cooperative water resources allocation  

Microsoft Academic Search

Abstract The Cooperative Water Allocation Model,(CWAM) is designed,within a general mathematical,programming,frame- work,for modeling,equitable and,efficient water allocation among,competing,users at the basin level and,applied to a large-scale water allocation problem in the South Saskatchewan River Basin located in southern Alberta, Canada. This comprehensive,model,consists of two main steps: initial water rights allocation and subsequent,water and net benefits real- location. Two mathematical programming approaches,

Lizhong Wang; Liping Fang; Keith W. Hipel

2008-01-01

200

HPV-010 Subject Treatment Allocation - Cervarix, September ...  

Center for Biologics Evaluation and Research (CBER)

... Resources for You. Approval History, Letters, Reviews, and Related Documents - Cervarix. -. HPV-010 Subject Treatment Allocation - Cervarix ... More results from www.fda.gov/biologicsbloodvaccines/vaccines/approvedproducts

201

Learning and exploiting knowledge in multi-agent task allocation problems  

Microsoft Academic Search

Imagine a group of cooperating agents attempting to allo- cate tasks amongst themselves without knowledge of their own capabilities. Over time, they develop a belief of their own skill levels through failed attempts at completing the tasks they are assigned. How will various task allocation approaches perform when there exists this added level of complexity? In particular, we compare two

Adam Maurice Campbell; Annie S. Wu

2007-01-01

202

Contrasted effect of biochar and earthworms on rice growth and resource allocation in different soils  

Microsoft Academic Search

Adding biochar to soils and maintaining high earthworm biomasses are potential ways to increase the fertility of tropical soils and the sustainability of crop production in the spirit of agroecology and ecological engineering. However, a thorough functional assessment of biochar effect on plant growth and resource allocations is so far missing. Moreover, earthworms and biochar increase mineral nutrient availability through

Diana Noguera; Marco Rondón; Kam-Rigne Laossi; Valerio Hoyos; Patrick Lavelle; Maria Helena Cruz de Carvalho; Sébastien Barot

2010-01-01

203

Application of simulation technology in reliability measure of ad hoc network  

Microsoft Academic Search

Measuring the reliability of ad hoc network with the approach of mathematic modeling usually needs a lot of assumptions, which not only cannot consider all kinds of reliability stochastic effect factors comprehensively, but also the computation is hard to proceed. Presently, measuring the reliability of ad hoc network with the approach of reliability simulation becomes current trend. This paper has

Chao Yang; Zhengfu Zhu; Wei Huang; Chunhua Yang; Weijing Zhang

2009-01-01

204

Accelerated stochastic sampling of discrete statistical systems.  

PubMed

We propose a method to reduce the relaxation time toward equilibrium in stochastic sampling of complex energy landscapes in statistical systems with discrete degrees of freedom by generalizing the platform previously developed for continuous systems. The method starts from a master equation, in contrast to the Fokker-Planck equation for the continuous case. The master equation is transformed into an imaginary-time Schrödinger equation. The Hamiltonian of the Schrödinger equation is modified by adding a projector to its known ground state. We show how this transformation decreases the relaxation time and propose a way to use it to accelerate simulated annealing for optimization problems. We implement our method in a simplified kinetic Monte Carlo scheme and show acceleration by one order of magnitude in simulated annealing of the symmetric traveling salesman problem. Comparisons of simulated annealing are made with the exchange Monte Carlo algorithm for the three-dimensional Ising spin glass. Our implementation can be seen as a step toward accelerating the stochastic sampling of generic systems with complex landscapes and long equilibration times. PMID:21230616

Bertalan, Zsolt; Nishimori, Hidetoshi; Orland, Henri

2010-11-04

205

Nonparametric Bayes Stochastically Ordered Latent Class Models.  

PubMed

Latent class models (LCMs) are used increasingly for addressing a broad variety of problems, including sparse modeling of multivariate and longitudinal data, model-based clustering, and flexible inferences on predictor effects. Typical frequentist LCMs require estimation of a single finite number of classes, which does not increase with the sample size, and have a well-known sensitivity to parametric assumptions on the distributions within a class. Bayesian nonparametric methods have been developed to allow an infinite number of classes in the general population, with the number represented in a sample increasing with sample size. In this article, we propose a new nonparametric Bayes model that allows predictors to flexibly impact the allocation to latent classes, while limiting sensitivity to parametric assumptions by allowing class-specific distributions to be unknown subject to a stochastic ordering constraint. An efficient MCMC algorithm is developed for posterior computation. The methods are validated using simulation studies and applied to the problem of ranking medical procedures in terms of the distribution of patient morbidity. PMID:22505787

Yang, Hongxia; O'Brien, Sean; Dunson, David B

2011-09-01

206

A stochastic model of low flows  

NASA Astrophysics Data System (ADS)

A model is developed for annual low flow hydrographs. Its two primary components reflect the fact that hydrologic processes during streamflow rise (function of water input) and recession (function of basin storage) are different. Durations of periods of rise (wet intervals) and recession (dry intervals) are modelled by discrete probability distributions — negative binomial for dry intervals and negative binomial or modified logarithmic series for wet intervals depending on goodness of fit. During wet intervals, the total inflow is modelled by the lognormal distribution and daily amounts are allocated according to a pattern-averaged model. During dry intervals, the flow recedes according to a deterministic-stochastic recession model. The model was applied to three Canadian basins with drainage area ranging from 2210 to 22000 km2 to generate 50 realizations of low flow hydrographs. The resulting two standard-error confidence band for the simulated probability distribution of annual minimum 7-day flows enclosed the probability distribution estimated from the observed record. A sensitivity analysis for the three basins revealed that in addition to the recession submodel, the most important submodel is that describing seasonality. The state of the basin at the beginning of the low flow period is of marginal importance and the daily distribution of input is unimportant.

Lawal, S. A.; Watt, W. E.; Watts, D. G.

1997-08-01

207

Reliability allocation with partial redundancy  

NASA Astrophysics Data System (ADS)

Concentration on the modeling of failure rates has produced a body of results only tangentially useful in the logistics modeling applications. The rate of occurrence of failures (ROCOF) is a more pertinent measure for such problems. This useful measure has been largely overlooked as a result of the relative rarity of redundancy. Increasingly complex systems and stringent operational demands have increased the degree of redundancy recently, however, and the utility of the ROCOF concept has increased (parri passu). This paper develops a generalized ROCOF solution for k of n systems, carefully distinguishing between the frequency of system failure (the ROCOF) and an allied concept, the rate at which demands are placed on the support infrastructure. It concludes with a discussion of reliability allocation in the presence of redundancy.

Nowicki, David R.

208

Elimination of Stochasticity in Stellarators.  

National Technical Information Service (NTIS)

A method for optimizing stellarator vacuum magnetic fields is introduced. Application of this method shows that the stochasticity of vacuum magnetic fields can be made negligible by proper choice of the coil configuration. This optimization is shown to in...

J. D. Hanson J. R. Cary

1983-01-01

209

Stochastic Dynamics of New Inflation.  

National Technical Information Service (NTIS)

We investigate thoroughly the dynamics of an inflation-driving scalar field in terms of an extended version of the stochastic approach proposed by Starobinsky and discuss the spacetime structure of the inflationary universe. To avoid any complications whi...

K. Nakao Y. Nambu M. Sasaki

1988-01-01

210

Intrabeam scattering in stochastic approach.  

National Technical Information Service (NTIS)

Beam emittance growth caused by intrabeam scattering in particle accelerators is examined in a stochastic approach with the Fokker-Planck equation. The results are compared with ordinary analysis based on binary Coulomb collisions which have been develope...

Y. Mori

1990-01-01

211

Massive Stochastic Testing of SQL  

Microsoft Academic Search

Deterministic testing of SQL database systems is human intensive and cannot adequately cover the SQL input domain. A system (RAGS), was built to stochastically generate valid SQL statements 1 million times faster than a human and execute them.

Donald R. Slutz

1998-01-01

212

Kinetic Properties of Stochastic Processes  

Microsoft Academic Search

In this thesis, kinetic and steady state properties of a range of stochastic and nonequilibrium models are investigated. A typical process is specified by a transport mechanism and a reaction mechanism and this leads naturally to simple \\

Ely Ben-Naim

1994-01-01

213

Max-Plus Stochastic Processes  

Microsoft Academic Search

This paper is concerned with processes which are max-plus counterparts of Markov diffusion processes governed by Ito sense stochastic differential equations. Concepts of max-plus martingale and max-plus stochastic differential equation are introduced. The max-plus counterparts of backward and forward PDEs for Markov diffusions turn out to be first-order PDEs of Hamilton-Jacobi-Bellman type. Max-plus additive integrals and a max-plus additive dynamic

Wendell H

2004-01-01

214

Max-Plus Stochastic Processes  

Microsoft Academic Search

This paper is concerned with processes which are max-plus counterparts of Markov diffusion processes governed by Ito sense stochastic differential equations. Concepts of max-plus martingale and max-plus stochastic differential equation are introduced. The max-plus counterparts of backward and forward PDEs for Markov diffusions turn out to be first-order PDEs of Hamilton–Jacobi–Bellman type. Max-plus additive integrals and a max-plus additive dynamic

Wendell H. Fleming

2004-01-01

215

Stochastic Trends and Economic Fluctuations  

Microsoft Academic Search

Are business cycles mainly the result of permanent shocks to productivity? This paper uses a long-run restriction implied by a large class of real-business-cycle models--identifying permanent productivity shocks as shocks to the common stochastic trend in output, consumption, and investment--to provide new evidence on this question. Econometric tests indicate that this common-stochastic-trend\\/cointegration implication is consistent with postwar U.S. data. However,

Robert G. King; Charles I. Plosser; James H. Stock; Mark W. Watson

1991-01-01

216

Symmetries of Stochastic Differential Equations  

Microsoft Academic Search

\\u000a This chapter deals with applications of the group analysis method to stochastic differential equations. These equations are\\u000a often obtained by including random fluctuations in differential equations, which have been deduced from phenomenological or\\u000a physical view. In contrast to deterministic differential equations, only few attempts to apply group analysis to stochastic\\u000a differential equations can be found in the literature. It is

Yurii Grigoriev; Nail Ibragimov; Vladimir Kovalev; Sergey Meleshko

217

Experimental investigation of stochastic resonance  

NASA Astrophysics Data System (ADS)

We report the experimental evidence of Stochastic Resonance in the polarized emission of a semiconductor laser. We give for the first time in a real system a complete characterization of the phenomenon based on the residence times probability density, with quantitative agreement with existing theories. By using an accurate choice of the indicator, we also provide a clear evidence of the bona fide resonance. Moreover, we are able to introduce and investigate for the first time a Three-state Stochastic Resonance. .

Barbay, Sylvain; Giacomelli, Giovanni; Marin, Francesco; Rabbiosi, Ivan; Voignier, Vincent

2000-02-01

218

Stochastic cooling studies in RHIC  

Microsoft Academic Search

Emittance growth due to Intra-Beam Scattering significantly reduces the heavy ion luminosity lifetime in RHIC. Stochastic cooling of the stored beam could improve things considerably by counteracting IBS and preventing particles from escaping the rf bucket. High frequency bunched-beam stochastic cooling is especially challenging but observations of Schottky signals in the 4-8 GHz band indicate that conditions are favorable in

Michael Blaskiewicz; J. M. Brennan; P. Cameron; J. Wei

2003-01-01

219

AdFlip.com  

NSDL National Science Digital Library

Here's a site that's both fun and useful to students of American pop culture. Billing itself "the world's largest searchable database of classic print ads," AdFlip may be keyword searched or browsed by several methods. The ads are indexed by category (automotive, electronic, fashion, etc.), decade (1940s to current), and several specialty categories (ad as art, famous, advocacy, provocative [a few nudes here], today's top ten). Each collection of ads (presented as thumbnails) can be displayed by date, name, or ID number. Each of the decade collections can be further refined by a number of categories, such as automotive manufacturers, women's fashion, alcohol, and furniture and appliances, among others.

220

BadAds  

NSDL National Science Digital Library

The creators of BadAds believe that advertising has become far too intrusive in American lives. Along with TV, magazine, radio ads, and billboards, advertisements and commercials are popping up in movie theatres, schools, public bathrooms, and even on stickers on fruit. Four criteria determine whether advertising is intrusive: an inability to turn the ad off; its entrance into your home without your consent; your lack of choice whether or not to watch it; and ads that don't support anything in particular and may actually cost you money. Rather than just venting about intrusive advertising, BadAds urges visitors to become active in the fight against bad ads by writing complaint letters to a host of venues that support intrusive advertising including movie theaters, sporting venues, television networks, and the heads of educational institutions. BadAds offers instructions on writing complaint letters as well as many suggestions as to who should receive these letters.

221

Allocation in ISO 14041—a critical review  

Microsoft Academic Search

The adequacy and feasibility of methods recommended for allocation by the current international standard on life cycle inventory analysis (LCI) are reviewed. The review is based on the view that an LCI should provide information on the environmental consequences of manipulating technological systems. On this basis, subdivision and allocation based on physical, causal relationships are adequate methods to deal with

Tomas Ekvall; Göran Finnveden

2001-01-01

222

On quorum systems for group resources allocation  

Microsoft Academic Search

We present a problem, called (n, m, k, d)-resource allocation, to model allocation of group resources with bounded capacity. Specifically, the problem concerns the scheduling of k identical resources among n processes which belong to m groups. Each resource can be used by at most d processes of the same group at a time, but no two processes of different

Yuh-Jzer Joung

2010-01-01

223

Optimal Resource Allocation for Batch Testing  

Microsoft Academic Search

Batch resource allocation problem arises in the context of executing a sequence of automated system tests or distributed computations where resources are pooled together and flexibly matched with requests. Minimizing resource allocation for a batch of processes reduces the resource management (e.g., setup) cost for the batch while allowing more users to share the resource pool simultaneously. The salient characteristic

Fangzhe Chang; Jennifer Ren; Ramesh Viswanathan

2009-01-01

224

Abstraction by Interchangeability in Resource Allocation  

Microsoft Academic Search

Resource allocation is a difficult constraint sat­ isfaction problem that has many practical ap­ plications. Fully automatic systems are often rejected by the ultimate users because, in many real-world environments, constraints cannot be formalized completely. On the other hand, hu­ mans are overwhelmed by the complexity of their task. We present a new way of solv­ ing the resource allocation,

Berthe Y. Choueiry; Boi Faltings; Rainer Weigel

1995-01-01

225

Resource allocation for a distributed sensor network  

Microsoft Academic Search

In this paper we describe a project undertaken for the Office of Force Transformation (OFT) to investigate alternative resource allocation strategies for America's armed forces. In particular, OFT is interested in understanding how resource allocation strategies can be used in the context of distributed, network-centric units. To address this problem we have developed a simulation tool using agent-based modeling to

M. C. Martin; I. Trifonov; E. Bonabeau; P. Gaudiano

2005-01-01

226

Practical Market-Based Resource Allocation  

Microsoft Academic Search

Resource allocation continues to be one of the primary chal- lenges in federated computing systems. Currently, users are forced to either suffer the delays inherent to batch schedul- ing used by the supercomputing community or the tradgedy of the commons that befalls propotional share allocation as employed on PlanetLab. Market-based schemes have repeat- edly been proposed as a possible solution

Alvin AuYoung; Brent N. Chun; Chaki Ng; David Parkes; Amin Vahdat; Alex C. Snoeren

227

Acquisitions Allocations: Fairness, Equity and Bundled Pricing.  

ERIC Educational Resources Information Center

|Examined the effect of an interdisciplinary Web-based citation database with full text, the ProQuest Research Library, on the Western State University library's acquisitions allocation plan. Used list price of full-text journals to calculate increases in acquisitions funding. A list of articles discussing formula allocation is appended.…

Packer, Donna

2001-01-01

228

Italian IPOs: Allocations and claw back clauses  

Microsoft Academic Search

We analyze empirical share allocation practices in Italian IPOs, which are run as two separate offerings, one for retail investors who submit unconditional binding orders and another for institutional investors who submit only indications of interest. The effective allocation proportion between the two offerings is determined by a high level of syndicate discretion but before the bookbuilding period starts. Claw

Dmitri Boreiko; Stefano Lombardo

2011-01-01

229

Analysis of Online Algorithms for Organ Allocation.  

National Technical Information Service (NTIS)

In this paper we discuss the need for a refinement to the existing organ allocation policy. Under the current organ allocation algorithm - the Point System - whenever an organ becomes available each patient scores points for that organ according to a mult...

S. Ur

1990-01-01

230

Allocating Air Traffic Flow Management Slots  

Microsoft Academic Search

In Europe, when an imbalance between demand and capacity is detected for air traffic network resources, Air Traffic Flow Management slots are allocated to flights on the basis of a First Planned First Served principle. We propose a market mechanism to allocate such slots in the case of a single constrained en-route sector or airport. We show that our mechanism

Lorenzo Castelli; Raffaele Pesenti; Andrea Ranieri

2009-01-01

231

Barmah-Millewa forest environmental water allocation  

Microsoft Academic Search

The formal allocation of water for the environment is a developing area of river management both scientifically and in terms of community participation. This case study, illustrating the recent use of the Barmah-Millewa Forest Environmental Water Allocation (EWA), provides a practical demonstration of community participation in environmental water management, the application of hydrological and biological \\

G. Stewart; B. Harper

232

Health Status and the Allocation of Time  

Microsoft Academic Search

In this paper, we quantify the effects of health on time allocation. We estimate that improvements in health status have large and positive effects on time allocated to home and market production and large negative effects on time spent watching TV, sleeping, and consuming other types of leisure. We find that poor health status results in about 300 additional hours

Timothy J. Halliday; Melinda Podor

2009-01-01

233

Controlling Object Allocation Using Creation Guards  

Microsoft Academic Search

Abstract. Sharing of objects between difierent modules is often necessary to meet speed and resource demands. The invariants that describe properties of shared objects are di?cult to maintain because they can be falsiflable by object allocation. This paper introduces creation guards to obtain a sound and modular methodology that supports such invariants. Keywords: invariants, object allocation, speciflcation, veriflcation, ob-

Cees Pierik; Dave Clarke; Frank S. De Boer

2005-01-01

234

Budget allocation and the analytic hierarchy process  

SciTech Connect

This report demonstrates that the priorities calculated by the Analytic Hierarchy Process can be used as measures of benefit for budget allocation. A procedure is described that optimally allocates a budget among competing DOE waste minimization projects. The projects are compared using an analytic hierarchy already developed by Sandia National Laboratories. 2 refs., 3 tabs.

Hulme, B.L. (Hulme Mathematics (USA))

1990-10-01

235

Optimizing Allocation of Management Resources for Wildlife  

Microsoft Academic Search

Allocating money for species conservation on the basis of threatened species listings is not the most cost-effective way of promoting recovery or minimizing extinction rates. Using ecological and social factors in addition to threat categories, we designed a decision-support process to assist policy makers in their allocation of resources for the management of native wildlife and to clarify the considerations

HELENE MARSH; ANDREW DENNIS; HARRY HINES; ALEX KUTT; KEITH McDONALD; ELLEN WEBER; STEPHEN WILLIAMS; JOHN WINTER

2007-01-01

236

Cross-Layer Wireless Resource Allocation.  

National Technical Information Service (NTIS)

A fundamental problem in networking is the allocation of limited resources among the users of the network. In a traditional layered network architecture, the resource to be allocated at the medium access control (MAC) and network layers is the use of comm...

R. A. Berry E. M. Yeh

2005-01-01

237

Justice in Grades Allocation: Teachers' Perspective  

ERIC Educational Resources Information Center

|In this investigation I explore teachers' perspectives on just grade allocation. The study was carried out among language, math and science teachers in a national sample of Israeli high schools, where teachers were required to weigh a set of considerations that are used in the decision on grade allocation. Findings suggest that (a) a teacher's…

Resh, Nura

2009-01-01

238

Rethinking Reinforcement: Allocation, Induction, and Contingency  

ERIC Educational Resources Information Center

|The concept of reinforcement is at least incomplete and almost certainly incorrect. An alternative way of organizing our understanding of behavior may be built around three concepts: "allocation," "induction," and "correlation." Allocation is the measure of behavior and captures the centrality of choice: All behavior entails choice and consists…

Baum, William M.

2012-01-01

239

A Time Allocation Study of University Faculty  

ERIC Educational Resources Information Center

|Many previous time allocation studies treat work as a single activity and examine trade-offs between work and other activities. This paper investigates the at-work allocation of time among teaching, research, grant writing and service by science and engineering faculty at top US research universities. We focus on the relationship between tenure…

Link, Albert N.; Swann, Christopher A.; Bozeman, Barry

2008-01-01

240

Optimal Allocation of Resources in Systems.  

National Technical Information Service (NTIS)

In the design of a new system, or the maintenance of an old system, allocation of resources is of prime consideration. In allocating resources it is often beneficial to develop a solution that yields an optimal value of the system measure of desirability....

C. Derman G. J. Lieberman S. M. Ross

1974-01-01

241

Resource Allocation in Public Research Universities  

ERIC Educational Resources Information Center

|The purpose of this study was to conduct an econometric analysis of internal resource allocation. Two theories are used for this study of resource allocation in public research universities, and these are: (1) Theory of the Firm; and (2) Resource Dependence Theory. This study used the American Association of Universities Data Exchange (AAUDE)…

Santos, Jose L.

2007-01-01

242

Optimal Resource Allocation for OFDMA Downlink Systems  

Microsoft Academic Search

This paper proposes efficient rate and power allocation algorithms for OFDMA downlink systems where each tone is taken by at most one user. Weighted sum rate maximization (WSRmax) and weighted sum power minimization (WSPmin) problems are considered. Since these resource allocation problems are non-convex, complexity of finding the optimal solutions is prohibitively high. This paper employs the Lagrange dual decomposition

Kibeom Seong; Mehdi Mohseni; John M. Cioffi

2006-01-01

243

Cross-layer wireless resource allocation  

Microsoft Academic Search

A fundamental problem in networking is the allocation of limited resources among the users of the network. In a traditional layered network architecture, the resource to be allocated at the medium access control (MAC) and network layers utilizes communication links, viewed as \\

Randall A. Berry; Edmund M. Yeh

2004-01-01

244

Manpower allocation in the criminal investigation process  

Microsoft Academic Search

A model describing the optimal allocation of manpower for the investigation department of the Israeli police force is described. A technique for estimating police officials preferences is given. It is believed that the approach and the methodology used can be applied in various manpower allocation problems and can serve as a good case study.

Y Levanon; U Passy

1981-01-01

245

Magnetic catalysis in AdS4  

NASA Astrophysics Data System (ADS)

We study the formation of fermion condensates in anti-de Sitter space. In particular, we describe a novel version of magnetic catalysis that arises for fermions in asymptotically AdS4 geometries which cap off in the infrared with a hard wall. We show that in the presence of a magnetic field, a \\langle \\bar{\\psi }\\gamma ^5\\psi \\rangle condensate develops in the bulk, spontaneously breaking CP symmetry. From the perspective of the dual boundary theory, this corresponds to a strongly coupled version of d = 2 + 1 magnetic catalysis.

Bolognesi, Stefano; Tong, David

2012-10-01

246

10 CFR 217.54 - Elements of an allocation order.  

Code of Federal Regulations, 2013 CFR

...10 Energy 3 2013-01-01 2013-01-01 false Elements of an allocation order. 217.54 Section 217.54 Energy...PRIORITIES AND ALLOCATIONS SYSTEM Allocation Actions § 217.54 Elements of an allocation order. Each allocation order must...

2013-01-01

247

Optimal dynamic water allocation: Irrigation extractions and environmental tradeoffs in the Murray River, Australia  

NASA Astrophysics Data System (ADS)

A key challenge in managing semiarid basins, such as in the Murray-Darling in Australia, is to balance the trade-offs between the net benefits of allocating water for irrigated agriculture, and other uses, versus the costs of reduced surface flows for the environment. Typically, water planners do not have the tools to optimally and dynamically allocate water among competing uses. We address this problem by developing a general stochastic, dynamic programming model with four state variables (the drought status, the current weather, weather correlation, and current storage) and two controls (environmental release and irrigation allocation) to optimally allocate water between extractions and in situ uses. The model is calibrated to Australia's Murray River that generates: (1) a robust qualitative result that "pulse" or artificial flood events are an optimal way to deliver environmental flows over and above conveyance of base flows; (2) from 2001 to 2009 a water reallocation that would have given less to irrigated agriculture and more to environmental flows would have generated between half a billion and over 3 billion U.S. dollars in overall economic benefits; and (3) water markets increase optimal environmental releases by reducing the losses associated with reduced water diversions.

Grafton, R. Quentin; Chu, Hoang Long; Stewardson, Michael; Kompas, Tom

2011-12-01

248

Bioethics for clinicians: 13. Resource allocation  

PubMed Central

Questions of resource allocation can pose practical and ethical dilemmas for clinicians. In the Aristotelian conception of distributive justice, the unequal allocation of a scarce resource may be justified by morally relevant factors such as need or likelihood of benefit. Even using these criteria, it can be difficult to reconcile completing claims to determine which patients should be given priority. To what extent the physician's fiduciary duty toward a patient should supersede the interests of other patients and society as a whole is also a matter of controversy. Although the courts have been reluctant to become involved in allocation decisions in health care, they expect physicians to show allegiance to their patients regardless of budgetary concerns. The allocation of resources on the basis of clinically irrelevant factors such as religion or sexual orientation is prohibited. Clear, fair and publicly acceptable institutional and professional policies can help to ensure that resource allocation decisions are transparent and defensible.

McKneally, M F; Dickens, B M; Meslin, E M; Singer, P A

1997-01-01

249

Stochastic cooling in RHIC  

SciTech Connect

The full 6-dimensional [x,x'; y,y'; z,z'] stochastic cooling system for RHIC was completed and operational for the FY12 Uranium-Uranium collider run. Cooling enhances the integrated luminosity of the Uranium collisions by a factor of 5, primarily by reducing the transverse emittances but also by cooling in the longitudinal plane to preserve the bunch length. The components have been deployed incrementally over the past several runs, beginning with longitudinal cooling, then cooling in the vertical planes but multiplexed between the Yellow and Blue rings, next cooling both rings simultaneously in vertical (the horizontal plane was cooled by betatron coupling), and now simultaneous horizontal cooling has been commissioned. The system operated between 5 and 9 GHz and with 3 x 10{sup 8} Uranium ions per bunch and produces a cooling half-time of approximately 20 minutes. The ultimate emittance is determined by the balance between cooling and emittance growth from Intra-Beam Scattering. Specific details of the apparatus and mathematical techniques for calculating its performance have been published elsewhere. Here we report on: the method of operation, results with beam, and comparison of results to simulations.

Brennan J. M.; Blaskiewicz, M.; Mernick, K.

2012-05-20

250

Two-step delay based Internet gateway selection scheme for aeronautical ad hoc networks  

Microsoft Academic Search

Recently, ad hoc networks have been proposed as a means of providing Internet access to passengers on board aircraft flying in oceanic or remote regions. The vast majority of data in such networks is either destined for or originated at an Internet gateway, which connects the ad hoc network to the Internet. Therefore, the allocation of aircraft to gateways plays

Felix Hoffmann; Daniel Medina; Adam Wolisz

2009-01-01

251

Boson stars in AdS spacetime  

NASA Astrophysics Data System (ADS)

We construct boson stars in global anti-de Sitter (AdS) space and study their stability. Linear perturbation results suggest that the ground state along with the first three excited state boson stars are stable. We evolve some of these solutions and study their nonlinear stability in light of recent work , arguing that a weakly turbulent instability drives scalar perturbations of AdS to black hole formation. However, evolutions suggest that boson stars are nonlinearly stable and immune to the instability for sufficiently small perturbation. Furthermore, these studies find other families of initial data which similarly avoid the instability for sufficiently weak parameters. Heuristically, we argue that initial data families with widely distributed mass energy distort the spacetime sufficiently to oppose the coherent amplification favored by the instability. From the dual CFT perspective our findings suggest that there exist families of rather generic initial conditions in strongly coupled CFT (with large number of degrees of freedom) that do not thermalize in the infinite future.

Buchel, Alex; Liebling, Steven L.; Lehner, Luis

2013-06-01

252

Stochastic Synchronization and Signal Rectification in the Crayfish Caudal Photoreceptor  

NASA Astrophysics Data System (ADS)

The crayfish possesses two light-sensitive neurons in its abdominal 6th ganglion (``caudal photoreceptors'', or CPRs). In addition to being light sensors, the CPRs are secondary neurons in a mechanosensory pathway. These sensory mechanisms, mechanosensitivity and light sensitivity, interact with one another. Pei et al. (1996) demonstrated that light enhances the transduction of weak, periodic hydrodynamic stimuli (measured as an increase in the signal-to-noise ratio at the stimulus frequency in the power spectrum of the recorded neural spikes). This has been interpreted as a stochastic resonance effect, in which added light increases the noise intensity of the input to the photoreceptor (possibly through fluctuations in membrane potential), leading to an enhancement of the signal to noise ratio (SNR). We have demonstrated in the crayfish the correlation between a stochastic-resonance like effect and an increase in stochastic phase synchronization between the neural response and a periodic mechanical stimulus (Bahar et al. 2002). Here, we discuss a novel effect in which light increases the signal-to-noise ratio of the second higher harmonic of a periodic input mechanical stimulus, effectively rectifying the input signal. This ``second harmonic effect'' can be interpreted in terms of stochastic phase synchronization. We hypothesize that the input signal is effectively full-wave rectified via the summation of two half-wave rectified mechanosensory signals. This hypothesis can be described by a simple mathematical model which agrees well with our experimental results.

Bahar, Sonya; Moss, Frank

2003-05-01

253

A stochastic lie detector  

Microsoft Academic Search

Surveys on sensitive issues provide distorted prevalence estimates when participants fail to respond truthfully. The randomized-response\\u000a technique (RRT) encourages more honest responding by adding random noise to responses, thereby removing any direct link between\\u000a a participant’s response and his or her true status with regard to a sensitive attribute. However, in spite of the increased\\u000a confidentiality, some respondents still refuse

Morten Moshagen; Jochen Musch; Edgar Erdfelder

254

A combined linear optimisation methodology for water resources allocation in Alfeios River Basin (Greece) under uncertain and vague system conditions  

NASA Astrophysics Data System (ADS)

In the present study, a combined linear programming methodology, based on Li et al. (2010) and Bekri et al. (2012), is employed for optimizing water allocation under uncertain system conditions in the Alfeios River Basin, in Greece. The Alfeios River is a water resources system of great natural, ecological, social and economic importance for Western Greece, since it has the longest and highest flow rate watercourse in the Peloponnisos region. Moreover, the river basin was exposed in the last decades to a plethora of environmental stresses (e.g. hydrogeological alterations, intensively irrigated agriculture, surface and groundwater overexploitation and infrastructure developments), resulting in the degradation of its quantitative and qualitative characteristics. As in most Mediterranean countries, water resource management in Alfeios River Basin has been focused up to now on an essentially supply-driven approach. It is still characterized by a lack of effective operational strategies. Authority responsibility relationships are fragmented, and law enforcement and policy implementation are weak. The present regulated water allocation puzzle entails a mixture of hydropower generation, irrigation, drinking water supply and recreational activities. Under these conditions its water resources management is characterised by high uncertainty and by vague and imprecise data. The considered methodology has been developed in order to deal with uncertainties expressed as either probability distributions, or/and fuzzy boundary intervals, derived by associated ?-cut levels. In this framework a set of deterministic submodels is studied through linear programming. The ad hoc water resources management and alternative management patterns in an Alfeios subbasin are analyzed and evaluated under various scenarios, using the above mentioned methodology, aiming to promote a sustainable and equitable water management. Li, Y.P., Huang, G.H. and S.L., Nie, (2010), Planning water resources management systems using a fuzzy-boundary interval-stochastic programming method, Elsevier Ltd, Advances in Water Resources, 33: 1105-1117. doi:10.1016/j.advwatres.2010.06.015 Bekri, E.S., Disse, M. and P.C.,Yannopoulos, (2012), Methodological framework for correction of quick river discharge measurements using quality characteristics, Session of Environmental Hydraulics - Hydrodynamics, 2nd Common Conference of Hellenic Hydrotechnical Association and Greek Committee for Water Resources Management, Volume: 546-557 (in Greek).

Bekri, Eleni; Yannopoulos, Panayotis; Disse, Markus

2013-04-01

255

49 CFR 198.13 - Grant allocation formula.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 2011-10-01 false Grant allocation formula. 198.13 Section 198...CONTINUED) PIPELINE SAFETY REGULATIONS FOR GRANTS TO AID STATE PIPELINE SAFETY PROGRAMS Grant Allocation § 198.13 Grant allocation...

2011-10-01

256

40 CFR 45.145 - Allocability and allowability of costs.  

Code of Federal Regulations, 2013 CFR

...Allocability and allowability of costs. 45.145 Section 45...Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS...Allocability and allowability of costs. (a) Allocability and allowability of costs will be determined in...

2013-07-01

257

48 CFR 18.109 - Priorities and allocations.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Priorities and allocations. 18.109 Section 18...Available Acquisition Flexibilities 18.109 Priorities and allocations. The Defense Priorities and Allocations System (DPAS)...

2011-10-01

258

48 CFR 18.109 - Priorities and allocations.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Priorities and allocations. 18.109 Section 18...Available Acquisition Flexibilities 18.109 Priorities and allocations. The Defense Priorities and Allocations System (DPAS)...

2012-10-01

259

7 CFR 1470.4 - Allocation and management.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Allocation and management. 1470...Provisions § 1470.4 Allocation and management. (a...each State based on natural resource factors that consider national...Chief considers in making allocations to States. (c) Of...

2013-01-01

260

Stacking with stochastic cooling  

NASA Astrophysics Data System (ADS)

Accumulation of large stacks of antiprotons or ions with the aid of stochastic cooling is more delicate than cooling a constant intensity beam. Basically the difficulty stems from the fact that the optimized gain and the cooling rate are inversely proportional to the number of particles `seen' by the cooling system. Therefore, to maintain fast stacking, the newly injected batch has to be strongly `protected' from the Schottky noise of the stack. Vice versa the stack has to be efficiently `shielded' against the high gain cooling system for the injected beam. In the antiproton accumulators with stacking ratios up to 105 the problem is solved by radial separation of the injection and the stack orbits in a region of large dispersion. An array of several tapered cooling systems with a matched gain profile provides a continuous particle flux towards the high-density stack core. Shielding of the different systems from each other is obtained both through the spatial separation and via the revolution frequencies (filters). In the `old AA', where the antiproton collection and stacking was done in one single ring, the injected beam was further shielded during cooling by means of a movable shutter. The complexity of these systems is very high. For more modest stacking ratios, one might use azimuthal rather than radial separation of stack and injected beam. Schematically half of the circumference would be used to accept and cool new beam and the remainder to house the stack. Fast gating is then required between the high gain cooling of the injected beam and the low gain stack cooling. RF-gymnastics are used to merge the pre-cooled batch with the stack, to re-create free space for the next injection, and to capture the new batch. This scheme is less demanding for the storage ring lattice, but at the expense of some reduction in stacking rate. The talk reviews the `radial' separation schemes and also gives some considerations to the `azimuthal' schemes.

Caspers, Fritz; Möhl, Dieter

2004-10-01

261

Stochastic models: theory and simulation.  

SciTech Connect

Many problems in applied science and engineering involve physical phenomena that behave randomly in time and/or space. Examples are diverse and include turbulent flow over an aircraft wing, Earth climatology, material microstructure, and the financial markets. Mathematical models for these random phenomena are referred to as stochastic processes and/or random fields, and Monte Carlo simulation is the only general-purpose tool for solving problems of this type. The use of Monte Carlo simulation requires methods and algorithms to generate samples of the appropriate stochastic model; these samples then become inputs and/or boundary conditions to established deterministic simulation codes. While numerous algorithms and tools currently exist to generate samples of simple random variables and vectors, no cohesive simulation tool yet exists for generating samples of stochastic processes and/or random fields. There are two objectives of this report. First, we provide some theoretical background on stochastic processes and random fields that can be used to model phenomena that are random in space and/or time. Second, we provide simple algorithms that can be used to generate independent samples of general stochastic models. The theory and simulation of random variables and vectors is also reviewed for completeness.

Field, Richard V., Jr.

2008-03-01

262

Allocation models for DMUs with negative data  

NASA Astrophysics Data System (ADS)

The formulas of cost and allocative efficiencies of decision making units (DMUs) with positive data cannot be used for DMUs with negative data. On the other hand, these formulas are needed to analyze the productivity and performance of DMUs with negative data. To this end, this study introduces the cost and allocative efficiencies of DMUs with negative data and demonstrates that the introduced cost efficiency is equal to the product of allocative and range directional measure efficiencies. The study then intends to extend the definition of the above efficiencies to DMUs with negative data and different unit costs. Finally, two numerical examples are given to illustrate the proposed methods.

Tohidi, Ghasem; Khodadadi, Maryam

2013-06-01

263

Aeronautical ad hoc networks  

Microsoft Academic Search

There has been an enormous growth in mobile ad hoc networks (MANETs) in land based small to medium size networks with relatively strict power and resources. In this paper the concept of ad hoc networking between aircraft is introduced, which can be considered as a novel approach in increasing the data rate and practicality of future in-flight broadband Internet access.

Ehssan Sakhaee; Abbas Jamalipour; Nei Kato

2006-01-01

264

Stochastic Games with Finitary Objectives  

NASA Astrophysics Data System (ADS)

The synthesis of a reactive system with respect to an ?-regular specification requires the solution of a graph game. Such games have been extended in two natural ways. First, a game graph can be equipped with probabilistic choices between alternative transitions, thus allowing the modeling of uncertain behavior. These are called stochastic games. Second, a liveness specification can be strengthened to require satisfaction within an unknown but bounded amount of time. These are called finitary objectives. We study, for the first time, the combination of stochastic games and finitary objectives. We characterize the requirements on optimal strategies and provide algorithms for computing the maximal achievable probability of winning stochastic games with finitary parity or Streett objectives. Most notably, the set of states from which a player can win with probability 1 for a finitary parity objective can be computed in polynomial time, even though no polynomial-time algorithm is known in the nonfinitary case.

Chatterjee, Krishnendu; Henzinger, Thomas A.; Horn, Florian

265

Stochastic Integration of Epitaxial Systems  

NASA Astrophysics Data System (ADS)

Stochastic integration can be used to give a more mathematical framework to the kinetic Monte Carlo (KMC) method. This method applies to Markovian systems that are governed by lattice transition rules. We first express these rules in terms of a master equation. From this we use the van Kampen expansion to obtain a Fokker-Planck equation and, by invoking the Langevin interpretation, integrate the model stochastically. We apply this procedure to three basic models: the Family model, the Wolf-Villain model, and the surface diffusion model. In all cases, the results obtained from the integration agree with those from simulations. Although, stochastic integration is more costly computationally than KMC simulations, it puts a class of algorithms used in such simulations on a firm mathematical basis and provides a means for further analysis.

Chua, Alvin; Vvedensky, Dimitri

2003-03-01

266

Stochastic simulation of karst conduit networks  

NASA Astrophysics Data System (ADS)

Karst aquifers have very high spatial heterogeneity. Essentially, they comprise a system of pipes (i.e., the network of conduits) superimposed on rock porosity and on a network of stratigraphic surfaces and fractures. This heterogeneity strongly influences the hydraulic behavior of the karst and it must be reproduced in any realistic numerical model of the karst system that is used as input to flow and transport modeling. However, the directly observed karst conduits are only a small part of the complete karst conduit system and knowledge of the complete conduit geometry and topology remains spatially limited and uncertain. Thus, there is a special interest in the stochastic simulation of networks of conduits that can be combined with fracture and rock porosity models to provide a realistic numerical model of the karst system. Furthermore, the simulated model may be of interest per se and other uses could be envisaged. The purpose of this paper is to present an efficient method for conditional and non-conditional stochastic simulation of karst conduit networks. The method comprises two stages: generation of conduit geometry and generation of topology. The approach adopted is a combination of a resampling method for generating conduit geometries from templates and a modified diffusion-limited aggregation method for generating the network topology. The authors show that the 3D karst conduit networks generated by the proposed method are statistically similar to observed karst conduit networks or to a hypothesized network model. The statistical similarity is in the sense of reproducing the tortuosity index of conduits, the fractal dimension of the network, the direction rose of directions, the Z-histogram and Ripley's K-function of the bifurcation points (which differs from a random allocation of those bifurcation points). The proposed method (1) is very flexible, (2) incorporates any experimental data (conditioning information) and (3) can easily be modified when implemented in a hydraulic inverse modeling procedure. Several synthetic examples are given to illustrate the methodology and real conduit network data are used to generate simulated networks that mimic real geometries and topology.

Pardo-Igúzquiza, Eulogio; Dowd, Peter A.; Xu, Chaoshui; Durán-Valsero, Juan José

2012-01-01

267

Simple Models in Stochastic Production Planning.  

National Technical Information Service (NTIS)

A simple stochastic production-inventory model with quadratic cost functions is analyzed in detail. The inventory process is assumed to be driven by a white noise process resulting into an Ito stochastic differential equation. Both finite and infinite hor...

S. P. Sethi G. L. Thompson

1978-01-01

268

Stochastic Convex Programming: Kuhn-Tucker Conditions.  

National Technical Information Service (NTIS)

Optimality criteria are derived for stochastics programs with convex objective and convex constraints. The (basic) Kuhn-Tucker conditions are obtained in terms of conditions on the existence of saddle points of a Lagrangian associated with the stochastic ...

R. T. Rockafellar R. J. B. Wets

1974-01-01

269

Adaptive dynamic resource allocation in annual eusocial insects: environmental variation will not necessarily promote graded control  

PubMed Central

Background According to the classical model of Macevicz and Oster, annual eusocial insects should show a clear dichotomous "bang-bang" strategy of resource allocation; colony fitness is maximised when a period of pure colony growth (exclusive production of workers) is followed by a single reproductive period characterised by the exclusive production of sexuals. However, in several species graded investment strategies with a simultaneous production of workers and sexuals have been observed. Such deviations from the "bang-bang" strategy are usually interpreted as an adaptive (bet-hedging) response to environmental fluctuations such as variation in season length or food availability. To generate predictions about the optimal investment pattern of insect colonies in fluctuating environments, we slightly modified Macevicz and Oster's classical model of annual colony dynamics and used a dynamic programming approach nested into a recurrence procedure for the solution of the stochastic optimal control problem. Results 1) The optimal switching time between pure colony growth and the exclusive production of sexuals decreases with increasing environmental variance. 2) Yet, for reasonable levels of environmental fluctuations no deviation from the typical bang-bang strategy is predicted. 3) Model calculations for the halictid bee Lasioglossum malachurum reveal that bet-hedging is not likely to be the reason for the graded allocation into sexuals versus workers observed in this species. 4) When environmental variance reaches a critical level our model predicts an abrupt change from dichotomous behaviour to graded allocation strategies, but the transition between colony growth and production of sexuals is not necessarily monotonic. Both, the critical level of environmental variance as well as the characteristic pattern of resource allocation strongly depend on the type of function used to describe environmental fluctuations. Conclusion Up to now bet-hedging as an evolutionary response to variation in season length has been the main argument to explain field observations of graded resource allocation in annual eusocial insect species. However, our model shows that the effect of moderate fluctuations of environmental conditions does not select for deviation from the classical bang-bang strategy and that the evolution of graded allocation strategies can be triggered only by extreme fluctuations. Detailed quantitative observations on resource allocation in eusocial insects are needed to analyse the relevance of alternative explanations, e.g. logistic colony growth or reproductive conflict between queen and workers, for the evolution of graded allocation strategies.

Mitesser, Oliver; Weissel, Norbert; Strohm, Erhard; Poethke, Hans-Joachim

2007-01-01

270

Learning Automata-Based Solutions to Stochastic Nonlinear Resource Allocation Problems  

Microsoft Academic Search

“Computational Intelligence” is an extremely wide-ranging and all-encompassing area. However, it is fair to say that the strength\\u000a of a system that possesses “Computational Intelligence” can be quantified by its ability to solve problems that are intrinsically\\u000a hard. One such class of NP-Hard problems concerns the so-called family of Knapsack Problems, and in this Chapter, we shall explain how a

Ole-Christoffer Granmo; B. John Oommen

2009-01-01

271

Algorithm development for SDI weapons system allocation. Final report, December 1987-May 1989  

SciTech Connect

While several SDI weapons systems can provide adequate defense in a one-on-one basis, a coordinated attack by several enemy missiles launched over a substantial volume will be difficult to resist without an efficient command and control system for warfare coordination. This study of weapons allocation - coordination algorithms, is based on dynamical models for the missile/decoy systems including noise effects and uncertainties in the model parameters. Performance of the weapons targeting system may be measured in terms of the expected number of targets eliminated in a given interval (phase of operations) or the expected time to eliminate all the targets in a given region. Scheduling weapons deployment is a problem of constrained optimal (weapons) and state variables. The selection of weapons deployment tactics is based on solution of a complex optimization problem. We have conducted an investigation of advanced modeling, stochastic control, and scheduling methodologies for aspects of the SDI weapons allocation problem - several platforms with assets of different character defending against a diverse collection of targets. The models for such scenarios lead to stochastic scheduling problems that can not be handled by conventional analytical methods. The authors describe several different analytical approaches that have the potential for synthesis of effective engagement algorithms.

Blankenship, G.L.; Bennett, W.

1989-06-01

272

Rainfall Stochastic models  

NASA Astrophysics Data System (ADS)

This work was carried out in north of Spain. San Sebastian A meteorological station, where there are available precipitation records every ten minutes was selected. Precipitation data covers from October of 1927 to September of 1997. Pulse models describe the temporal process of rainfall as a succession of rainy cells, main storm, whose origins are distributed in time according to a Poisson process and a secondary process that generates a random number of cells of rain within each storm. Among different pulse models, the Bartlett-Lewis was used. On the other hand, alternative renewal processes and Markov chains describe the way in which the process will evolve in the future depending only on the current state. Therefore they are nor dependant on past events. Two basic processes are considered when describing the occurrence of rain: the alternation of wet and dry periods and temporal distribution of rainfall in each rain event, which determines the rainwater collected in each of the intervals that make up the rain. This allows the introduction of alternative renewal processes and Markov chains of three states, where interstorm time is given by either of the two dry states, short or long. Thus, the stochastic model of Markov chains tries to reproduce the basis of pulse models: the succession of storms, each one composed for a series of rain, separated by a short interval of time without theoretical complexity of these. In a first step, we analyzed all variables involved in the sequential process of the rain: rain event duration, event duration of non-rain, average rainfall intensity in rain events, and finally, temporal distribution of rainfall within the rain event. Additionally, for pulse Bartlett-Lewis model calibration, main descriptive statistics were calculated for each month, considering the process of seasonal rainfall in each month. In a second step, both models were calibrated. Finally, synthetic series were simulated with calibration parameters; series were recorded every ten minutes and hourly, aggregated. Preliminary results show adequate simulation of the main features of rain. Main variables are well simulated for time series of ten minutes, also over one hour precipitation time series, which are those that generate higher rainfall hydrologic design. For coarse scales, less than one hour, rainfall durations are not appropriate under the simulation. A hypothesis may be an excessive number of simulated events, which causes further fragmentation of storms, resulting in an excess of rain "short" (less than 1 hour), and therefore also among rain events, compared with the ones that occur in the actual series.

Campo, M. A.; Lopez, J. J.; Rebole, J. P.

2012-04-01

273

Transport in a stochastic magnetic field  

SciTech Connect

Collisional heat transport in a stochastic magnetic field configuration is investigated. Well above stochastic threshold, a numerical solution of a Chirikov-Taylor model shows a short-time nonlocal regime, but at large time the Rechester-Rosenbluth effective diffusion is confirmed. Near stochastic threshold, subdiffusive behavior is observed for short mean free paths. The nature of this subdiffusive behavior is understood in terms of the spectrum of islands in the stochastic sea.

White, R.B.; Wu, Yanlin [Princeton Univ., NJ (United States). Plasma Physics Lab.; Rax, J.M. [Association Euratom-CEA, Centre d`Etudes Nucleaires de Cadarache, 13 -Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

1992-09-01

274

Transport in a stochastic magnetic field  

SciTech Connect

Collisional heat transport in a stochastic magnetic field configuration is investigated. Well above stochastic threshold, a numerical solution of a Chirikov-Taylor model shows a short-time nonlocal regime, but at large time the Rechester-Rosenbluth effective diffusion is confirmed. Near stochastic threshold, subdiffusive behavior is observed for short mean free paths. The nature of this subdiffusive behavior is understood in terms of the spectrum of islands in the stochastic sea.

White, R.B.; Wu, Yanlin (Princeton Univ., NJ (United States). Plasma Physics Lab.); Rax, J.M. (Association Euratom-CEA, Centre d'Etudes Nucleaires de Cadarache, 13 -Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee)

1992-01-01

275

QB1 - Stochastic Gene Regulation  

SciTech Connect

Summaries of this presentation are: (1) Stochastic fluctuations or 'noise' is present in the cell - Random motion and competition between reactants, Low copy, quantization of reactants, Upstream processes; (2) Fluctuations may be very important - Cell-to-cell variability, Cell fate decisions (switches), Signal amplification or damping, stochastic resonances; and (3) Some tools are available to mode these - Kinetic Monte Carlo simulations (SSA and variants), Moment approximation methods, Finite State Projection. We will see how modeling these reactions can tell us more about the underlying processes of gene regulation.

Munsky, Brian [Los Alamos National Laboratory

2012-07-23

276

Max-plus stochastic processes  

Microsoft Academic Search

This paper is concerned with processes which are max-plus counter-parts of Markov diffusion processes governed by Ito sense\\u000a stochastic differential equations. Concepts of max-plus martingale and max-plus stochastic differential equation are introduced.\\u000a The max-plus counterparts of backward and forward PDEs for Markov diffusions turn out to be first-order PDEs of Hamilton-Jacobi-Bellman\\u000a type. Max-plus additive integrals and a max-plus additive dynamic

Wendell H. Fleming

2004-01-01

277

Stochastic Cooling Developments at GSI  

SciTech Connect

Stochastic Cooling is presently used at the existing storage ring ESR as a first stage of cooling for secondary heavy ion beams. In the frame of the FAIR project at GSI, stochastic cooling is planned to play a major role for the preparation of high quality antiproton and rare isotope beams. The paper describes the existing ESR system, the first stage cooling system at the planned Collector Ring, and will also cover first steps toward the design of an antiproton collection system at the planned RESR ring.

Nolden, F.; Beckert, K.; Beller, P.; Dolinskii, A.; Franzke, B.; Jandewerth, U.; Nesmiyan, I.; Peschke, C.; Petri, P.; Steck, M. [GSI, Darmstadt (Germany); Caspers, F.; Moehl, D.; Thorndahl, L. [CERN, Geneva (Switzerland)

2006-03-20

278

Stochastic modeling of Lagrangian accelerations  

NASA Astrophysics Data System (ADS)

It is shown how Sawford's second-order Lagrangian stochastic model (Phys. Fluids A 3, 1577-1586, 1991) for fluid-particle accelerations can be combined with a model for the evolution of the dissipation rate (Pope and Chen, Phys. Fluids A 2, 1437-1449, 1990) to produce a Lagrangian stochastic model that is consistent with both the measured distribution of Lagrangian accelerations (La Porta et al., Nature 409, 1017-1019, 2001) and Kolmogorov's similarity theory. The later condition is found not to be satisfied when a constant dissipation rate is employed and consistency with prescribed acceleration statistics is enforced through fulfilment of a well-mixed condition.

Reynolds, Andy

2002-11-01

279

Comments on optical stochastic cooling  

SciTech Connect

An important necessary condition for transverse phase space damping in the optical stochastic cooling with transit-time method is derived. The longitudinal and transverse damping dynamics for the optical stochastic cooling is studied. The authors also obtain an optimal laser focusing condition for laser-beam interaction in the correction undulator. The amplification factor and the output peak power of the laser amplifier are found to differ substantially from earlier publications. The required power is large for hadron colliders at very high energy.

K.Y. Ng, S.Y. Lee and Y.K. Zhang

2002-10-08

280

Stochastic Simulation of Turing Patterns  

NASA Astrophysics Data System (ADS)

We investigate the effects of intrinsic noise on Turing pattern formation near the onset of bifurcation from the homogeneous state to Turing pattern in the reaction-diffusion Brusselator. By performing stochastic simulations of the master equation and using Gillespie's algorithm, we check the spatiotemporal behaviour influenced by internal noises. We demonstrate that the patterns of occurrence frequency for the reaction and diffusion processes are also spatially ordered and temporally stable. Turing patterns are found to be robust against intrinsic fluctuations. Stochastic simulations also reveal that under the influence of intrinsic noises, the onset of Turing instability is advanced in comparison to that predicted deterministically.

Fu, Zheng-Ping; Xu, Xin-Hang; Wang, Hong-Li; Ouyang, Qi

2008-04-01

281

48 CFR 5452.249 - Allocation.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Allocation. 5452.249 Section 5452.249 Federal Acquisition Regulations System DEFENSE LOGISTICS AGENCY, DEPARTMENT OF DEFENSE SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and Clauses...

2012-10-01

282

48 CFR 5452.249 - Allocation.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Allocation. 5452.249 Section 5452.249 Federal Acquisition Regulations System DEFENSE LOGISTICS AGENCY, DEPARTMENT OF DEFENSE SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and Clauses...

2011-10-01

283

10 CFR 490.503 - Credit allocation.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Credit allocation. 490.503 Section 490.503 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Fueled Vehicle Credit Program § 490.503...

2013-01-01

284

39 CFR 3060.12 - Asset allocation.  

Code of Federal Regulations, 2013 CFR

...REGULATORY COMMISSION PERSONNEL ACCOUNTING PRACTICES AND TAX RULES FOR...THEORETICAL COMPETITIVE PRODUCTS ENTERPRISE § 3060.12 Asset allocation...theoretical competitive products enterprise as follows: (a) Identify...theoretical competitive products enterprise using a method of...

2013-07-01

285

45 CFR 98.55 - Cost allocation.  

Code of Federal Regulations, 2012 CFR

...55 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CHILD CARE AND DEVELOPMENT FUND Use of Child Care and Development Funds § 98.55 Cost allocation. (a) The Lead Agency and subgrantees...

2012-10-01

286

45 CFR 98.55 - Cost allocation.  

Code of Federal Regulations, 2011 CFR

...55 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CHILD CARE AND DEVELOPMENT FUND Use of Child Care and Development Funds § 98.55 Cost allocation. (a) The Lead Agency and subgrantees...

2011-10-01

287

Optimal dynamic bandwidth allocation for complex networks  

NASA Astrophysics Data System (ADS)

Traffic capacity of one network strongly depends on the link's bandwidth allocation strategy. In previous bandwidth allocation mechanisms, once one link's bandwidth is allocated, it will be fixed throughout the overall traffic transmission process. However, the traffic load of every link changes from time to time. In this paper, with finite total bandwidth resource of the network, we propose to dynamically allocate the total bandwidth resource in which each link's bandwidth is proportional to the queue length of the output buffer of the link per time step. With plenty of data packets in the network, the traffic handling ability of all links of the network achieves full utilization. The theoretical analysis and the extensive simulation results on complex networks are consistent. This work is valuable for network service providers to improve network performance or to do reasonable network design efficiently.

Jiang, Zhong-Yuan; Liang, Man-Gui; Li, Qian; Guo, Dong-Chao

2013-03-01

288

Capital Allocation Criteria for Defense Contractors.  

National Technical Information Service (NTIS)

The study presents the development of theoretical criteria for ex ante, or predictive, allocation of prime defense contractor's capital resources to an individual negotiated procurement contract for the purpose of determining a fair ex ante price. A two-p...

F. W. Segel

1972-01-01

289

Optimal food allocation in a slave economy  

Microsoft Academic Search

.   We propose a model of food allocation in an economy in which property rights exist in human beings. We assume that a slave-owner\\u000a allocates food over the slave's lifetime so as to maximise his own wealth. The slave's productive capacity is determined endogenously\\u000a by food consumption. Food allotment during childhood and adolescence determines productive capacity over the life course.

R. Rees; John Komlos; Ngo V. Long; Ulrich Woitek

2003-01-01

290

A Signaling Protocol for Structured Resource Allocation  

Microsoft Academic Search

There is an emerging class of multi-party, multimedia, multi-flow applications that have a high-level structure th at imposes de- pendencies between resource allocations for flows within th e application. These applications are also capable of making intelligent decisions on how resource allocation should be controlled within the application. The devel- opment of such applications places new requirements on signaling proto-

Prashant R. Chandra; Allan Fisher; Peter Steenkistei

1999-01-01

291

Constraint Programming for Distributed Resource Allocation  

Microsoft Academic Search

Constraint based techniques offer a promising approach to coordinating a set of agents in solving a distributed resource allocation\\u000a problem. Distributed resource allocation is a general problem in which a set of agents must intelligently assign their resources\\u000a to a set of tasks such that all tasks are performed with respect to certain criteria. This problem arises in many real-world

Pragnesh Jay Modi

2001-01-01

292

United States: The Allocation of Surface Waters  

Microsoft Academic Search

The English settlers in North America brought with them the common law, which, while well developed in many respects, had\\u000a little to say about the allocation of surface waters. With courts generally, but not always, taking the lead, the states of\\u000a the United States developed over three centuries three very different legal regimes for the allocation of water: riparian\\u000a rights

Joseph W. Dellapenna

293

The Stochastic Theory of Fluvial Landsurfaces  

Microsoft Academic Search

A stochastic theory of fluvial landsurfaces is developed for transport-limited erosion, using well-established models for the water and sediment fluxes. The mathematical mod- els and analysis is developed showing that some aspects of landsurface evolution can be described by Markovian stochastic processes. The landsurfaces are described by non- deterministic stochastic processes, characterized by a statistical quantity the variogram, that exhibits

Björn Birnir; J. Hernandez; T. R. Smith

2007-01-01

294

Stochastic modelling of gene regulatory networks  

Microsoft Academic Search

SUMMARY Gene regulatory networks are dynamic and stochastic in nature, and exhibit exquisite feedback and feedforward control loops that regulate their biological function at different levels. Modelling of such networks poses new challenges due, in part, to the small number of molecules involved and the stochastic nature of their interactions. In this article, we motivate the stochastic modelling of genetic

Hana El Samad; Mustafa Khammash; Linda Petzold; Dan Gillespie

2005-01-01

295

Stochastic Equivariant Cohomologies and Cyclic Cohomology  

Microsoft Academic Search

We give two stochastic diffeologies on the free loop space which allow us to define stochastic equivariant cohomology theories in the Chen-Souriau sense and to establish a link with cyclic cohomology. With the second one, we can establish a stochastic fixed point theorem.

Remi Leandre

2005-01-01

296

Stochastic approaches for modelling in vivo reactions  

Microsoft Academic Search

In recent years, stochastic modelling has emerged as a physically more realistic al- ternative for modelling in vivo reactions. There are numerous stochastic approaches available in the literature; most of these assume that observed random uctuations are a consequence of the small number of reacting molecules. We review some im- portant developments of the stochastic approach and consider its suitability

Thomas E. Turner; Santiago Schnell; Kevin Burrage

2004-01-01

297

Maximum Principle for Singular Stochastic Control Problems  

Microsoft Academic Search

In this paper, an optimal singular stochastic control problem is considered. For this model, it is obtained a general stochastic maximum principle by using a time transformation. This is the first version of the stochastic maximum principle that covers the singular control problem in the nonlinear case.

F. Dufour; Boris M. Miller

2006-01-01

298

A Learning Criterion for Stochastic Rules  

Microsoft Academic Search

This paper proposes a learning criterion for stochastic rules. This criterion is developed by extending Valiant's PAC (Probably Approximately Correct) learning model, which is a learning criterion for deterministic rules. Stochastic rules here refer to those which probabilistically asign a number of classes, {Y}, to each attribute vector X. The proposed criterion is based on the idea that learning stochastic

Kenji Yamanishi

1992-01-01

299

Allocation of authority in European health policy.  

PubMed

Although many study the effects of different allocations of health policy authority, few ask why countries assign responsibility over different policies as they do. We test two broad theories: fiscal federalism, which predicts rational governments will concentrate information-intensive operations at lower levels, and redistributive and regulatory functions at higher levels; and "politicized federalism", which suggests a combination of systematic and historically idiosyncratic political variables interfere with efficient allocation of authority. Drawing on the WHO Health in Transition country profiles, we present new data on the allocation of responsibility for key health care policy tasks (implementation, provision, finance, regulation, and framework legislation) and policy areas (primary, secondary and tertiary care, public health and pharmaceuticals) in the 27 EU member states and Switzerland. We use a Bayesian multinomial mixed logit model to analyze how different countries arrive at different allocations of authority over each task and area of health policy, and find the allocation of powers broadly follows fiscal federalism. Responsibility for pharmaceuticals, framework legislation, and most finance lodges at the highest levels of government, acute and primary care in the regions, and provision at the local and regional levels. Where allocation does not follow fiscal federalism, it appears to reflect ethnic divisions, the population of states and regions, the presence of mountainous terrain, and the timing of region creation. PMID:22858423

Adolph, Christopher; Greer, Scott L; Massard da Fonseca, Elize

2012-07-20

300

Japan ADS Program  

NASA Astrophysics Data System (ADS)

The Japan Atomic Energy Agency (JAEA) has been proceeding with the research and development on accelerator-driven system (ADS) for the transmutation of long-lived radioactive nuclides. The ADS proposed by JAEA is a lead-bismuth eutectic (LBE) cooled fast subcritical core with 800 MWth. Various activities were conducted to investigate the feasibility of the ADS from viewpoints of the accelerator, LBE handling technology, minor actinide bearing fuel and subcritical core design. The design study and discussion of effective application on the Transmutation Experimental Facility (TEF) was also continued under a framework of J-PARC (Japan Proton Accelerator Research Complex) project.

Sasa, Toshinobu

2010-06-01

301

The stochastic dance of early HIV infection  

NASA Astrophysics Data System (ADS)

The stochastic nature of early HIV infection is described in a series of models, each of which captures aspects of the dance of HIV during the early stages of infection. It is to this highly variable target that the immune response must respond. The adaptability of the various components of the immune response is an important aspect of the system's operation, as the nature of the pathogens that the response will be required to respond to and the order in which those responses must be made cannot be known beforehand. As HIV infection has direct influence over cells responsible for the immune response, the dance predicts that the immune response will be also in a variable state of readiness and capability for this task of adaptation. The description of the stochastic dance of HIV here will use the tools of stochastic models, and for the most part, simulation. The justification for this approach is that the early stages and the development of HIV diversity require that the model to be able to describe both individual sample path and patient-to-patient variability. In addition, as early viral dynamics are best described using branching processes, the explosive growth of these models both predicts high variability and rapid response of HIV to changes in system parameters.In this paper, a basic viral growth model based on a time dependent continuous-time branching process is used to describe the growth of HIV infected cells in the macrophage and lymphocyte populations. Immigration from the reservoir population is added to the basic model to describe the incubation time distribution. This distribution is deduced directly from the modeling assumptions and the model of viral growth. A system of two branching processes, one in the infected macrophage population and one in the infected lymphocyte population is used to provide a description of the relationship between the development of HIV diversity as it relates to tropism (host cell preference). The role of the immune response to HIV and HIV infected cells is used to describe the movement of the infection from a few infected macrophages to a disease of infected CD4+ T lymphocytes.

Merrill, Stephen J.

2005-12-01

302

A Review of Parameter-Induced Stochastic Resonance and Current Applications in Two-Dimensional Image Processing  

Microsoft Academic Search

\\u000a Stochastic resonance (SR) is a phenomenon that nonlinear system synchronizes with noise to boost a resonant-like behavior.\\u000a Parameter-induced stochastic resonance (PSR) proposed in this paper is realized by optimally tuning system parameters without\\u000a adding any noise. It has been proved the performance of PSR is better than traditional SR technique which is in fact a particular\\u000a case in PSR region.

Yibing Yang; Bohou Xu

303

An interval-parameter multi-stage stochastic programming model for water resources management under uncertainty  

NASA Astrophysics Data System (ADS)

In this study, an interval-parameter multi-stage stochastic linear programming (IMSLP) method has been developed for water resources decision making under uncertainty. The IMSLP is a hybrid methodology of inexact optimization and multi-stage stochastic programming. It has three major advantages in comparison to the other optimization techniques. Firstly, it extends upon the existing multi-stage stochastic programming method by allowing uncertainties expressed as probability density functions and discrete intervals to be effectively incorporated within the optimization framework. Secondly, penalties are exercised with recourse against any infeasibility, which permits in-depth analyses of various policy scenarios that are associated with different levels of economic consequences when the promised water-allocation targets are violated. Thirdly, it cannot only handle uncertainties through constructing a set of scenarios that is representative for the universe of possible outcomes, but also reflect dynamic features of the system conditions through transactions at discrete points in time over the planning horizon. The developed IMSLP method is applied to a hypothetical case study of water resources management. The results are helpful for water resources managers in not only making decisions of water allocation but also gaining insight into the tradeoffs between environmental and economic objectives.

Li, Y. P.; Huang, G. H.; Nie, S. L.

2006-05-01

304

Product Claim Ad (Correct)  

Center for Drug Evaluation (CDER)

... Product claim ads may provide sources of ... the basic concepts related to drug advertising. ... consumers about DTC prescription drug advertisements. ... More results from www.fda.gov/drugs/resourcesforyou/consumers

305

Ad Hoc Advisors  

Cancer.gov

The Long Island Breast Cancer Study Project (LIBCSP) had an Ad Hoc Advisory Committee of expert scientists and community breast cancer advocates. This committee was chaired by Dr. Mimi C. Yu. The committee met annually or as needed.

306

Reminder Ad (Correct)  

Center for Drug Evaluation (CDER)

... Notice that neither allergies nor any allergy symptoms are ... This site was developed as a collaborative effort between FDA and EthicAd to ... More results from www.fda.gov/drugs/resourcesforyou/consumers

307

ADS Communications: A Cornerstone.  

National Technical Information Service (NTIS)

ADS Communications forms a cornerstone to the applications and communications networks of the 21st century. The need to communicate operational data between an aircraft and the Air Traffic Services is becoming focused and will lead to ever increasing appl...

G. A. Cobley

1991-01-01

308

Avionics Diagnostic System (ADS).  

National Technical Information Service (NTIS)

The presentation will provide system design including a description of the commands, outputs and diagnostic capabilities provided by the ADS we created. Issues and decisions will also be described as will thoughts on potential new features that could be a...

T. Risko

1999-01-01

309

Variational solutions to stochastic quantization  

SciTech Connect

We show that the Langevin equation, when used in stochastic quantization, can provide a simple variational principle for field theories. We test the method on exactly soluble models in zero dimensions and on the quantum-mechanical anharmonic oscillator in one dimension.

Amundsen, P.A.; Damgaard, P.H.

1984-01-15

310

Stochastic mechanics and quantum theory  

Microsoft Academic Search

Stochastic mechanics may be regarded as both generalizing classical mechanics to processes with intrinsic randomness, as well as providing the sort of detailed description of microscopic events declared impossible under the traditional interpretation of quantum mechanics. It avoids the many conceptual difficulties which arise from the assumption that quantum mechanics, i.e., the wave function, provides a complete description of (microscopic)

Sheldon Goldstein

1987-01-01

311

Stochastic analysis of contaminant transport  

Microsoft Academic Search

A reliability algorithm is used to develop probabilistic (stochastic) models or contaminant transport in porous media. The models are based on advective-dispersive transport equations, and utilize the reliability algorithm with existing one- and two-dimensional analytical and numerical solutions. Uncertain variables in the models include: groundwater flow velocity (or permeability in the numerical model), dispersivity, diffusion coefficient, bulk density, porosity, and

Cawlfield

1992-01-01

312

Stochastic resonance on a circle  

SciTech Connect

We describe a new realization of stochastic resonance, applicable to a broad class of systems, based on an underlying excitable dynamics with deterministic reinjection. A simple but general theory of such single-trigger'' systems is compared with analog simulations of the Fitzhugh-Nagumo model, as well as experimental data obtained from stimulated sensory neurons in the crayfish.

Wiesenfeld, K. (School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)); Pierson, D.; Pantazelou, E.; Dames, C.; Moss, F. (Department of Physics, University of Missouri at St. Louis, St. Louis, Missouri 63121 (United States))

1994-04-04

313

SMAA - Stochastic multiobjective acceptability analysis  

Microsoft Academic Search

Stochastic multiobjective acceptability analysis (SMAA) is a multicriteria decision support technique for multiple decision makers based on exploring the weight space. Inaccurate or uncertain input data can be represented as probability distributions. In SMAA the decision makers need not express their preferences explicitly or implicitly; instead the technique analyses what kind of valuations would make each alternative the preferred one.

Risto Lahdelma; Joonas Hokkanen; Pekka Salminen

1998-01-01

314

Stochastic Games with Finitary Objectives  

Microsoft Academic Search

The synthesis of a reactive system with respect to an omega-regular specifica- tion requires the solution of a graph game. Such games have been extended in two natural ways. First, a game graph can be equipped with probabilistic choices between alternative transitions, thus allowing the modeling of uncertain behavior. These are called stochastic games. Second, a liveness specification can be

Krishnendu Chatterjee; Thomas A. Henzinger; Florian Horn

2009-01-01

315

Stochastic Simulation of Chemical Kinetics  

Microsoft Academic Search

Stochastic chemical kinetics describes the time evolution of a well- stirred chemically reacting system in a way that takes into account the fact that molecules come in whole numbers and exhibit some degree of randomness in their dynamical behavior. Researchers are increasingly using this approach to chemical kinetics in the analysis of cellular systems in biology, where the small molecular

Daniel T. Gillespie

2007-01-01

316

Stochastic Optimization Problems in Telecommunications  

Microsoft Academic Search

We survey dieren t optimization problems under uncertainty which arise in telecommunica- tions. Three levels of decisions are distinguished: design of structural elements of telecommuni- cation networks, top level design of telecommunication networks and design of optimal policies of telecommunication enterprize. Examples of typical problems from each level show that the stochastic programming paradigm is a powerful approach for solving

Alexei A. Gaivoronski

317

Stochastic Microgeometry for Displacement Mapping  

Microsoft Academic Search

Creating surfaces with intricate small-scale features (mi- crogeometry) and detail is an important task in geomet- ric modeling and computer graphics. We present a model processing method capable of producing a wide variety of complex surface features based on displacement mapping and stochastic geometry. The latter is a branch of mathe- matics that analyzes and characterizes the statistical prop- erties

Craig A. Schroeder; David E. Breen; Christopher D. Cera; William C. Regli

2005-01-01

318

Stochastic process in quantum optics  

SciTech Connect

The case of a two-state atom immersed in nearly monochromatic, nearly resonant radiation is considered. The radiation has a finite bandwidth. Collisional effects are also included. Time evolution equations of quantum excitation are presented. Examples of the stochastic processes are provided by showing the fluctuation of the coefficients of these equations. (WRF)

Shore, B.W.

1985-01-01

319

Online Stochastic and Robust Optimization  

Microsoft Academic Search

This paper considers online stochastic optimization problems where uncertainties are characterized by a distribution that can be sampled and where time constraints severely limit the number of offline optimizations which can be performed at decision time and\\/or in between decisions. It reviews our re- cent progress in this area, proposes some new algorithms, and reports some new experimental results on

Russell Bent; Pascal Van Hentenryck

2004-01-01

320

Stochastic resonance on a circle  

NASA Astrophysics Data System (ADS)

We describe a new realization of stochastic resonance, applicable to a broad class of systems, based on an underlying excitable dynamics with deterministic reinjection. A simple but general theory of such ``single-trigger'' systems is compared with analog simulations of the Fitzhugh-Nagumo model, as well as experimental data obtained from stimulated sensory neurons in the crayfish.

Wiesenfeld, Kurt; Pierson, David; Pantazelou, Eleni; Dames, Chris; Moss, Frank

1994-04-01

321

Stochastic Simulation of Daily Rainfall.  

National Technical Information Service (NTIS)

The design of many water resources projects requires knowledge of possible long-term rainfall patterns. A stochastic model based on a first order Markov chain was developed to simulate daily rainfall at a point. The model is applicable to any point in Ken...

D. M. Allen C. T. Haan D. Linton J. Street D. Jordan

1975-01-01

322

Stochastic wind energy calculation formulation  

Microsoft Academic Search

The wind energy potential is directly proportional to the air density and the third power of the wind speed averaged over a suitable time period. The wind speed and air density have temporal and spatial stochastic variabilities. It is the main purpose of this paper to derive the most general wind energy potential formulation by considering simultaneously the temporal variabilities

Zekai ?en

2000-01-01

323

Stochastic resonance in binocular rivalry  

Microsoft Academic Search

When a different image is presented to each eye, visual awareness spontaneously alternates between the two images—a phenom- enon called binocular rivalry. Because binocular rivalry is characterized by two marginally stable perceptual states and spontaneous, apparently stochastic, switching between them, it has been speculated that switches in perceptual awareness reflect a double-well- potential type computational architecture coupled with noise. To

Yee-Joon Kim; Marcia Grabowecky; Satoru Suzuki

2006-01-01

324

On the Simple Stochastic Epidemic.  

National Technical Information Service (NTIS)

For the simple stochastic epidemic, in which X(t) is the number of infectives at time t and N is the population size, it is shown that the process (N sup 1/2) the set (X(t)/N-m(t)), for suitable m(t), approaches an Ornstein-Uhlenbeck process as N approach...

D. R. McNeil

1972-01-01

325

Stochastic and chaotic relaxation oscillations  

Microsoft Academic Search

For relaxation oscillators stochastic and chaotic dynamics are investigated. The effect of random perturbations upon the period is computed. For an extended system with additional state variables chaotic behavior can be expected. As an example, the Van der Pol oscillator is changed into a third-order system admitting period doubling and chaos in a certain parameter range. The distinction between chaotic

J. Grasman; J. B. T. M. Roerdink

1989-01-01

326

ADS and its Potential  

NASA Astrophysics Data System (ADS)

Accelerator driven systems offer the possibility to make nuclear fission energy sustainable and acceptable to society. The Energy Amplifier proposed by Carlo Rubbia at CERN is used to illustrate the potential of ADS, and the resulting R&D activity wave it triggered in Europe and in the world is briefly discussed. ADS must be part of the strategy to provide clean, safe and abundant energy for a harmonious development of society.

Revol, Jean-Pierre

2010-06-01

327

Green functions in stochastic field theory  

NASA Astrophysics Data System (ADS)

Functional representations are reviewed for the generating function of Green functions of stochastic problems stated either with the use of the Fokker-Planck equation or the master equation. Both cases are treated in a unified manner based on the operator approach similar to quantum mechanics. Solution of a second-order stochastic differential equation in the framework of stochastic field theory is constructed. Ambiguities in the mathematical formulation of stochastic field theory are discussed. The Schwinger-Keldysh representation is constructed for the Green functions of the stochastic field theory which yields a functional-integral representation with local action but without the explicit functional Jacobi determinant or ghost fields.

Honkonen, Juha

2013-03-01

328

An efficient submesh allocation strategy for mesh computer systems  

Microsoft Academic Search

A processor allocation strategy is proposed which can apply to any mesh system and recognize submeshes with arbitrary sizes at any location in a mesh system. The proposed strategy allocates a submesh of exactly the size requested by an incoming task, completely avoiding internal fragmentation. Because of its efficient allocation, this strategy exhibits better performance than an earlier allocation strategy

Po-jen Chuang; Nian-feng Tzeng

1991-01-01

329

Memory Allocation Costs in Large C and C++ Programs  

Microsoft Academic Search

Dynamic storage allocation is an important part of a large class of computer programs writtenin C and C++. High-performance algorithms for dynamic storage allocation have been, and willcontinue to be, of considerable interest. This paper presents detailed measurements of the cost ofdynamic storage allocation in 11 diverse C and C++ programs using five very different dynamicstorage allocation implementations, including a

David Detlefs; Al Dosser; Benjamin G. Zorn

1994-01-01

330

AdS backgrounds from black hole horizons  

NASA Astrophysics Data System (ADS)

We utilize the classification of IIB horizons with 5-form flux to present a unified description for the geometry of AdSn, n = 3, 5, 7 solutions. In particular, we show that all such backgrounds can be constructed from eight-dimensional 2-strong Calabi-Yau geometries with torsion which admit some additional isometries. We explore the geometry of AdS3 and AdS5 solutions but we do not find AdS7 solutions.

Gran, U.; Gutowski, J.; Papadopoulos, G.

2013-03-01

331

Hadronization at the AdS wall  

SciTech Connect

We describe hadronization events, using the AdS/CFT Correspondence, which display many of the qualitative features expected in QCD. In particular we study the motion of strings with separating end points in a back-reacted hard wall geometry. The solutions show the development of a linear QCD-like string. The end points oscillate in the absence of string breaking. We introduce string breaking by hand and evolve the new state forward in time to observe the separation of two string segments. A kink associated with this breaking evolves to the end points of the string inducing rho meson production. We explicitly compute the rho meson production at the end point.

Evans, Nick; French, James; Threlfall, Ed [School of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ (United Kingdom); Jensen, Kristan [Department of Physics, University of Washington, Seattle, Washington 98195 (United States)

2010-03-15

332

Asymmetric synthesis of pyrimidyl alkanol without adding chiral substances by the addition of diisopropylzinc to pyrimidine-5-carbaldehyde in conjunction with asymmetric autocatalysis  

Microsoft Academic Search

Enantiomerically enriched pyrimidyl alkanol with either S or R configuration was obtained stochastically from the reaction between pyrimidine-5-carbaldehyde and diisopropylzinc without adding chiral substances in conjunction with subsequent asymmetric autocatalysis, leading to amplification of the enantiomeric excess.

Kenso Soai; Itaru Sato; Takanori Shibata; Soichiro Komiya; Masanobu Hayashi; Yohei Matsueda; Hikaru Imamura; Tadakatsu Hayase; Hiroshi Morioka; Hayami Tabira; Jun Yamamoto; Yasunori Kowata

2003-01-01

333

Optimal fund assignment and allocation models for pipe repair maintenance in leaky water distribution networks  

NASA Astrophysics Data System (ADS)

In pipe repair maintenance operations for leaky water distribution networks in cities, it is usually the practice that whenever pipe leaks are detected, repair actions are undertaken until the funds assigned are exhausted. The allocation of limited repair funds to different pipe sections is normally done without careful quantitative analysis but according to an intuitive rule, whereby the section of the larger leak volume receives the larger share of funds. This paper proposes a new modeling approach to determine optimal repair fund allocation to different sections of a city. A basic periodic-review stochastic demand inventory model is first applied to ascertain the optimal funds to be assigned to a city under an assumption of no fund limitation. The model is then extended to determine the optimal allocation of the limited funds to different sections of a city. The models minimize the expected total system cost composed of repair cost, storage cost (of spare parts and materials), and penalty cost for water loss due to lack of funds. Numerical experiments are then conducted to illustrate the applicability of the proposed models, and the characteristics of the optimal solutions with regard to parameter variations are investigated. Data used in the numerical example are taken from actual data of the secondary network of Ho Chi Minh City in Vietnam.

Bach, Nguyen Luong; Fujiwara, Okitsugu; Luong, Huynh Trung

2000-05-01

334

An Analysis and Allocation System for Library Collections Budgets: The Comprehensive Allocation Process (CAP)  

ERIC Educational Resources Information Center

The "Comprehensive Allocation Process" (CAP) is a reproducible decision-making structure for the allocation of new collections funds, for the reallocation of funds within stagnant budgets, and for budget cuts in the face of reduced funding levels. This system was designed to overcome common shortcomings of current methods. Its philosophical…

Lyons, Lucy Eleonore; Blosser, John

2012-01-01

335

An Analysis and Allocation System for Library Collections Budgets: The Comprehensive Allocation Process (CAP)  

ERIC Educational Resources Information Center

|The "Comprehensive Allocation Process" (CAP) is a reproducible decision-making structure for the allocation of new collections funds, for the reallocation of funds within stagnant budgets, and for budget cuts in the face of reduced funding levels. This system was designed to overcome common shortcomings of current methods. Its philosophical…

Lyons, Lucy Eleonore; Blosser, John

2012-01-01

336

Optimal allocation of conservation effort among subpopulations of a threatened species: how important is patch quality?  

PubMed

Money is often a limiting factor in conservation, and attempting to conserve endangered species can be costly. Consequently, a framework for optimizing fiscally constrained conservation decisions for a single species is needed. In this paper we find the optimal budget allocation among isolated subpopulations of a threatened species to minimize local extinction probability. We solve the problem using stochastic dynamic programming, derive a useful and simple alternative guideline for allocating funds, and test its performance using forward simulation. The model considers subpopulations that persist in habitat patches of differing quality, which in our model is reflected in different relationships between money invested and extinction risk. We discover that, in most cases, subpopulations that are less efficient to manage should receive more money than those that are more efficient to manage, due to higher investment needed to reduce extinction risk. Our simple investment guideline performs almost as well as the exact optimal strategy. We illustrate our approach with a case study of the management of the Sumatran tiger, Panthera tigris sumatrae, in Kerinci Seblat National Park (KSNP), Indonesia. We find that different budgets should be allocated to the separate tiger subpopulations in KSNP. The subpopulation that is not at risk of extinction does not require any management investment. Based on the combination of risks of extinction and habitat quality, the optimal allocation for these particular tiger subpopulations is an unusual case: subpopulations that occur in higher-quality habitat (more efficient to manage) should receive more funds than the remaining subpopulation that is in lower-quality habitat. Because the yearly budget allocated to the KSNP for tiger conservation is small, to guarantee the persistence of all the subpopulations that are currently under threat we need to prioritize those that are easier to save. When allocating resources among subpopulations of a threatened species, the combined effects of differences in habitat quality, cost of action, and current subpopulation probability of extinction need to be integrated. We provide a useful guideline for allocating resources among isolated subpopulations of any threatened species. PMID:20437964

Chauvenet, Aliénor L M; Baxter, Peter W J; McDonald-Madden, Eve; Possingham, Hugh P

2010-04-01

337

Methodology for allocating reliability and risk  

SciTech Connect

This report describes a methodology for reliability and risk allocation in nuclear power plants. The work investigates the technical feasibility of allocating reliability and risk, which are expressed in a set of global safety criteria and which may not necessarily be rigid, to various reactor systems, subsystems, components, operations, and structures in a consistent manner. The report also provides general discussions on the problem of reliability and risk allocation. The problem is formulated as a multiattribute decision analysis paradigm. The work mainly addresses the first two steps of a typical decision analysis, i.e., (1) identifying alternatives, and (2) generating information on outcomes of the alternatives, by performing a multiobjective optimization on a PRA model and reliability cost functions. The multiobjective optimization serves as the guiding principle to reliability and risk allocation. The concept of ''noninferiority'' is used in the multiobjective optimization problem. Finding the noninferior solution set is the main theme of the current approach. The final step of decision analysis, i.e., assessment of the decision maker's preferences could then be performed more easily on the noninferior solution set. Some results of the methodology applications to a nontrivial risk model are provided, and several outstanding issues such as generic allocation, preference assessment, and uncertainty are discussed. 29 refs., 44 figs., 39 tabs.

Cho, N.Z.; Papazoglou, I.A.; Bari, R.A.

1986-05-01

338

A balance condition for stochastic numerical models with application to the El Nino-Southern Oscillation  

SciTech Connect

Stochastic forcing due to unresolved processes adds energy to a measurable system. Although this energy is added randomly in time, conservation laws still apply. A balance condition for stochastically driven systems is discussed. This [open quotes]fluctuation-dissipation relation[close quotes] may be used either to deduce the geographical properties of the stochastic forcing from data given a model for the evolution of the macroscopic variables or to diagnose energy conservation in a stochastic numerical model. The balance condition in its first role was applied to sea surface temperatures (SSTS) in the Indo-Pacific basin. A low-dimensional empirical dynamical model of SSTs was generated in such a way that observed statistical properties of the field are preserved. Experiments varying the stochastic forcing in this model indicated how the geographical characteristics of the forcing affect the distribution of variance among the various normal modes, thereby determining the dominant timescales of the SST field. These results suggest that the south Indian Ocean and the equatorial Pacific close to the date line are important to the amplitude and timing of the warm phase of El Ni[tilde n]o-Southern Oscillation. Fourier spectra obtained from output of the stochastically forced linear model were found to agree with those obtained from COADS data when time series of equal length were compared. A discussion of how spectra from a multivariate linear system can be confused with those of a nonlinear system is presented. 52 refs., 15 figs., 1 tab.

Penland, C.; Matrosova, L. (Univ. of Colorado, Boulder, CO (United States))

1994-09-01

339

I Saw It on the Radio: The Allocation of Attention to High-Imagery Radio Advertisements  

Microsoft Academic Search

This study was conducted to explore how the level of imagery in a radio ad- vertisement affects the allocation of cognitive resources to encoding the mes- sage into memory. A within-subjects experiment was conducted in which par- ticipants listened to 24, 60-second radio advertisements that had been coded as either high- or low-imagery messages. Secondary-task reaction time was obtained during

Paul D. Bolls; Annie Lang

2003-01-01

340

A formal framework for the study of task allocation in multi-robot systems  

Microsoft Academic Search

Despite more than a decade of experimental work in multi-robot systems, important theoretical aspects of multi-robot coordination mechanisms have, to date, been largely untreated. To address this issue, we focus on the problem of multi-robot task allocation (MRTA). Most work on MRTA has been ad hoc and empirical, with many coordination architectures having been proposed and val- idated in a

Brian P. Gerkey; Maja J Mataric

2003-01-01

341

Ad Hoc Routing  

NASA Astrophysics Data System (ADS)

Chapter 1 presented multi-hop communication as one of the opportunities to reduce the energy consumption of the devices, thus extending their lifetime. The development of efficient multi-hop routing protocols is therefore a fundamental aspect for the successful deployment of wireless ad hoc networks. However, routing in wireless ad hoc networks is fundamentally different from the apparently similar problem in wired networks, because bandwidth is scarce and topology changes frequently. This raises a double challenge for multi-hop routing in wireless ad hoc networks: nodes are less powerful and routing is more difficult. Given this fact, it is not surprising to observe that multi-hop routing has been one of the most active fields of research in MANETs.

Araujo, Filipe; Miranda, Hugo

342

Uptake, allocation and signaling of nitrate.  

PubMed

Plants need to acquire nitrogen (N) efficiently from the soil for growth. Nitrate is one of the major N sources for higher plants. Therefore, nitrate uptake and allocation are key factors in efficient N utilization. Membrane-bound transporters are required for nitrate uptake from the soil and for the inter- and intracellular movement of nitrate inside the plants. Four gene families, nitrate transporter 1/peptide transporter (NRT1/PTR), NRT2, chloride channel (CLC), and slow anion channel-associated 1 homolog 3 (SLAC1/SLAH), are involved in nitrate uptake, allocation, and storage in higher plants. Recent studies of these transporters or channels have provided new insights into the molecular mechanisms of nitrate uptake and allocation. Interestingly, several of these transporters also play versatile roles in nitrate sensing, plant development, pathogen defense, and/or stress response. PMID:22658680

Wang, Ya-Yun; Hsu, Po-Kai; Tsay, Yi-Fang

2012-05-31

343

Biomass Resource Allocation among Competing End Uses  

SciTech Connect

The Biomass Scenario Model (BSM) is a system dynamics model developed by the U.S. Department of Energy as a tool to better understand the interaction of complex policies and their potential effects on the biofuels industry in the United States. However, it does not currently have the capability to account for allocation of biomass resources among the various end uses, which limits its utilization in analysis of policies that target biomass uses outside the biofuels industry. This report provides a more holistic understanding of the dynamics surrounding the allocation of biomass among uses that include traditional use, wood pellet exports, bio-based products and bioproducts, biopower, and biofuels by (1) highlighting the methods used in existing models' treatments of competition for biomass resources; (2) identifying coverage and gaps in industry data regarding the competing end uses; and (3) exploring options for developing models of biomass allocation that could be integrated with the BSM to actively exchange and incorporate relevant information.

Newes, E.; Bush, B.; Inman, D.; Lin, Y.; Mai, T.; Martinez, A.; Mulcahy, D.; Short, W.; Simpkins, T.; Uriarte, C.; Peck, C.

2012-05-01

344

Report on Funding Levels and Allocations of Funds: Report of the Secretary of Transportation to the United States Congress.  

National Technical Information Service (NTIS)

This is the annual report called for under Section 304 of the Federal Mass Transportation Act of 1987. This provision added to Section 3 of the Urban Mass Transportation Act a new subsection (j) entitled 'Report on Funding Levels and Allocations of Funds....

1990-01-01

345

Stochastic resonance in a locally excited system of bistable oscillators  

NASA Astrophysics Data System (ADS)

Stochastic resonance is studied in a one-dimensional array of overdamped bistable oscillators in the presence of a local subthreshold periodic perturbation. The system can be treated as an ensemble of pseudospins tending to align parallel which are driven dynamically by an external periodic magnetic field. The oscillators are subjected to a dynamic white noise as well as to a static topological disorder. The latter is quantified by the fraction of randomly added long-range connections among ensemble elements. In the low connectivity regime the system displays an optimal global stochastic resonance response if a small-world network is formed. In the mean-field regime we explain strong changes in the dynamic disorder strength provoking a maximal stochastic resonance response via the variation of fraction of long-range connections by taking into account the ferromagnetic-paramagnetic phase transition of the pseudospins. The system size analysis shows only quantitative power-law type changes on increasing number of pseudospins.

Gosak, M.; Perc, M.; Kralj, S.

2011-04-01

346

AdS bubbles, entropy and closed string tachyons  

Microsoft Academic Search

We study the conjectured connection between AdS bubbles (AdS solitons) and closed string tachyon condensations. We confirm that the entanglement entropy, which measures the degree of freedom, decreases under the tachyon condensation. The entropies in supergravity and free Yang-Mills agree with each other remarkably. Next we consider the tachyon condensation on the AdS twisted circle and argue that its endpoint

Tatsuma Nishioka; Tadashi Takayanagi

2007-01-01

347

Stochastic hyperfine interactions modeling library  

NASA Astrophysics Data System (ADS)

The stochastic hyperfine interactions modeling library (SHIML) provides a set of routines to assist in the development and application of stochastic models of hyperfine interactions. The library provides routines written in the C programming language that (1) read a text description of a model for fluctuating hyperfine fields, (2) set up the Blume matrix, upon which the evolution operator of the system depends, and (3) find the eigenvalues and eigenvectors of the Blume matrix so that theoretical spectra of experimental techniques that measure hyperfine interactions can be calculated. The optimized vector and matrix operations of the BLAS and LAPACK libraries are utilized; however, there was a need to develop supplementary code to find an orthonormal set of (left and right) eigenvectors of complex, non-Hermitian matrices. In addition, example code is provided to illustrate the use of SHIML to generate perturbed angular correlation spectra for the special case of polycrystalline samples when anisotropy terms of higher order than A can be neglected.

Zacate, Matthew O.; Evenson, William E.

2011-04-01

348

Stochastic complexity and statistical mechanics  

NASA Astrophysics Data System (ADS)

A statistical mechanical formalism based on stochastic complexity is presented. Stochastic complexity is a statistical estimation scheme that uses the principle of minimal description length (MDL). The basic concept is that the best form of statistical estimation is one in which both the data and the model's structure and parameters are represented in the shortest binary string. This scheme is a generalization that encompasses both the maximum likelihood and maximum entropy methods. To apply this scheme to thermodynamic systems, the minimal number of bits required to describe both the observables and the phase space coordinates of the system is determined. The entropy of a microcanonical ensemble is associated with this minimum description length. This formulation provides a means for calculating partition functions for nonequilibrium systems that are strongly nonergodic. Because of the Bayesian properties of this estimation scheme, techniques for ``image reconstruction'' of phase space can be developed. These allow partition functions to be calculated from computer simulation data.

Dewey, T. Gregory

1998-12-01

349

Real-Time Hierarchical Resource Allocation  

Microsoft Academic Search

This paper presents a model that distinguishes between decentralized informa- tion processing and decentralized decision making in organizations; it shows that decentralized decision making can be advantageous due to computational delay, even in the absence of communication costs. The key feature of the model, which makes this result possible, is that decisions in a stochastic con- trol problem are calculated

Timothy Van Zandt

1995-01-01

350

Stochastic models for relativistic diffusion.  

PubMed

The diffusion equation is related to the Schrödinger equation by analytic continuation. The formula E2=p2c2 + m2c4 leads to a relativistic Schrödinger equation, and analytic continuation yields a relativistic diffusion equation that involves fractional calculus. This paper develops stochastic models for relativistic diffusion and equivalent differential equations with no fractional derivatives. Connections to anomalous diffusion are also discussed, along with alternative models. PMID:20866590

Baeumer, Boris; Meerschaert, Mark M; Naber, Mark

2010-07-22

351

Stochastic models for relativistic diffusion  

NASA Astrophysics Data System (ADS)

The diffusion equation is related to the Schrödinger equation by analytic continuation. The formula E2=p2c2+m2c4 leads to a relativistic Schrödinger equation, and analytic continuation yields a relativistic diffusion equation that involves fractional calculus. This paper develops stochastic models for relativistic diffusion and equivalent differential equations with no fractional derivatives. Connections to anomalous diffusion are also discussed, along with alternative models.

Baeumer, Boris; Meerschaert, Mark M.; Naber, Mark

2010-07-01

352

Stochastic background of atmospheric cascades  

SciTech Connect

Fluctuations in the atmospheric cascades developing during the propagation of very high energy cosmic rays through the atmosphere are investigated using stochastic branching model of pure birth process with immigration. In particular, we show that the multiplicity distributions of secondaries emerging from gamma families are much narrower than those resulting from hadronic families. We argue that the strong intermittent like behaviour found recently in atmospheric families results from the fluctuations in the cascades themselves and are insensitive to the details of elementary interactions.

Wilk, G. (Soltan Institute for Nuclear Studies, 00-681 Warsaw (Poland)); Wlodarczyk, Z. (Institute of Physics, Pedagogical University, Kielce (Poland))

1993-06-15

353

Adaptive stochastic disturbance accommodating control  

Microsoft Academic Search

This article presents a Kalman filter based adaptive disturbance accommodating stochastic control scheme for linear uncertain systems to minimise the adverse effects of both model uncertainties and external disturbances. Instead of dealing with system uncertainties and external disturbances separately, the disturbance accommodating control scheme lumps the overall effects of these errors in a to-be-determined model-error vector and then utilises a

Jemin George; Puneet Singla; John L. Crassidis

2011-01-01

354

Relativistic Stochastic Processes: A review  

NASA Astrophysics Data System (ADS)

We discuss and compare all relativistic stochastic processes existing in the litterature. In particular, the Relativistic Ornstein-Uhlenbeck Process is presented in detail, as is the intrinsic Brownian Motion studied by Franchi and Le Jan. The Relativistic Brownian Motion of Dunkel and Hänggi is also reviewed, together with a model introduced by Oron and Horwitz. We finally suggest some possible future developements of the current research.

Debbasch, F.

2006-11-01

355

Stochastic cooling technology at Fermilab  

NASA Astrophysics Data System (ADS)

The first antiproton cooling systems were installed and commissioned at Fermilab in 1984-1985. In the interim period, there have been several major upgrades, system improvements, and complete reincarnation of cooling systems. This paper will present some of the technology that was pioneered at Fermilab to implement stochastic cooling systems in both the Antiproton Source and Recycler accelerators. Current performance data will also be presented.

Pasquinelli, Ralph J.

2004-10-01

356

Innovations Without Added Costs  

ERIC Educational Resources Information Center

There is no question that we are in a tight money market, and schools are among the first institutions to feel the squeeze. Therefore, when a plan is offered that provides for innovations without added costs, its something worth noting. (Editor)

Cereghino, Edward

1974-01-01

357

Ad Hoc Distributed Simulations  

Microsoft Academic Search

An ad hoc distributed simulation is a collection of autonomous on-line simulations, each modeling some portion of a larger physical system, that are brought together through a mobile, wireless network to predict future states of the overall system. Unlike conventional distributed simulations that are designed in a largely top-down fashion by partitioning the physical system and mapping each element to

Richard M. Fujimoto; Michael Hunter; Jason Sirichoke; Mahesh Palekar; Hoe Kyoung Kim; Wonho Suh

2007-01-01

358

Ad Astra Magazine  

NSDL National Science Digital Library

Ad Astra ("To the Stars") is the award-winning magazine of the National Space Society. It features space exploration news and full-color photography. It is published quarterly and mailed to all National Space Society members as part of their membership benefits, as well as to subscriber libraries, schools, and businesses.

2005-04-25

359

Stochastic estimation of microactuator buckling  

NASA Astrophysics Data System (ADS)

In order to make a robust design of microsystems, it is important to analyze the electrical, thermal and mechanical fields including the actual input parameters. These microdevices, which typically are made of brittle materials such as polysilicon, show wide scatter (stochastic behavior) in properties as well as substantial uncertainty in the shape and geometry because of manufacturing processes. These behaviors necessitate either costly and time-consuming trial-and-error designs or, more efficiently, the development of a probabilistic design methodology for MEMS. Computer aided MEMS simulations regarding performance, power consumption, and reliability is an important design task due to high prototyping costs. Since microbeams have a wide range of applications in MEMS actuation mechanisms, analysis of the thermomechanical behavior of these actuators is very important. In the present work, assessing meaningful uncertainties involved in thermally driven microbeams, the stochastic finite element model (SFEM) is developed and implemented. The analysis shows a large deviation in buckling temperature and thermal stresses for reasonable probability density functions of characteristic parameters. Although computationally significantly more expensive than deterministic electromechanical simulation, the work illustrates the requirement of stochastic modeling for true estimation of microsystems' performance.

Bahrami, Mohsen; Tayefeh, Mohsen

2006-04-01

360

Stochastic approach to highway traffic  

NASA Astrophysics Data System (ADS)

We analyze the characteristic features of jam formation on a circular one-lane road. We have applied an optimal velocity model including stochastic noise, where cars are treated as moving and interacting particles. The motion of N cars is described by the system of 2N stochastic differential equations with multiplicative white noise. Our system of cars behaves in qualitatively different ways depending on the values of control parameters c (dimensionless density), b (sensitivity parameter characterising the fastness of relaxation), and ? (dimensionless noise intensity). In analogy to the gas-liquid phase transition in supersaturated vapour at low enough temperatures, we observe three different regimes of traffic flow at small enough values of b < bcr. There is the free flow regime (like gaseous phase) at small densities of cars, the coexistence of a jam and free flow (like liquid and gas) at intermediate densities, and homogeneous dense traffic (like liquid phase) at large densities. The transition from free flow to congested traffic occurs when the homogeneous solution becomes unstable and evolves into the limit cycle. The opposite process takes place at a different density, so that we have a hysteresis effect and phase transition of the first order. A phase transition of second order, characterised by critical exponents, takes place at a certain critical density c = ccr. Inclusion of the stochastic noise allows us to calculate the distribution of headway distances and time headways between the successive cars, as well as the distribution of jam (car cluster) sizes in a congested traffic.

Mahnke, Reinhard; Kaupuzs, Jevgenijs; Lubashevsky, Ihor; Tolmacheva, Julia

2004-05-01

361

Wavelet analysis of stochastic signals  

NASA Astrophysics Data System (ADS)

In the last years the wavelet transform has become a very appropriate tool for analysing geodetic observations. In opposite to the classical Fourier transform the most important feature of the wavelet transform is the detection of time-varying amplitudes and/or frequencies. The wavelet theory is described by many authors; see e.g. (CHUI 1994) or (Louis ET AL. 1998). Generally observed time series like the nutation values obtained by Very Long Baseline Interferometry (SCHMIDT AND SCHUH 1999) are stochastic signals. Thus, the theory of stochastic signals or processes has to be combined with wavelet theory. From this point of view some important foundations of the wavelet analysis of stochastic signals are presented in this paper. Especially two aspects, namely the variance distribution and the Interpretation of the crosscovariance funetion, will be described in more detail and will be discussed in the last section. A numerical example of the procedure derived in this article is presented in the paper " Abilities of wavelet analysis for investigating short-period variations of Earth rotation" by SCHMIDT AND SCHUH (2000), also published in this volume.

Schmidt, Michael

362

ADS in a Nutshell  

NASA Astrophysics Data System (ADS)

The bibliographic databases maintained by the NASA Astrophysics Data System are updated approximately biweekly with records gathered from over 125 sources all over the world. Data are either sent to us electronically, retrieved by our staff via semi-automated procedures, or entered in our databases through supervised OCR procedures. PERL scripts are run on the data to convert them from their incoming format to our standard format so that they can be added to the master database at SAO. Once new data has been added, separate index files are created for authors, objects, title words, and text word, allowing these fields to be searched for individually or in combination with each other. During the indexing procedure, discipline-specific knowledge is taken into account through the use of rule-based procedures performing string normalization, context-sensitive word translation, and synonym and stop word replacement. Once the master text and index files have been updated at SAO, an automated procedure mirrors the changes in the database to the ADS mirror site via a secure network connection. The use of a public domain software tool called rsync allows incremental updating of the database files, with significant savings in the amount of data being transferred. In the past year, the ADS Abstract Service databases have grown by approximately 30%, including 50% growth in Physics, 25% growth in Astronomy and 10% growth in the Instrumentation datasets. The ADS Abstract Service now contains over 1.4 million abstracts (475K in Astronomy, 430K in Physics, 510K in Instrumentation, and 3K in Preprints), 175,000 journal abstracts, and 115,000 full text articles. In addition, we provide links to over 40,000 electronic HTML articles at other sites, 20,000 PDF articles, and 10,000 postscript articles, as well as many links to other external data sources.

Demleitner, M.; Eichhorn, G.; Grant, C. S.; Accomazzi, A.; Murray, S. S.; Kurtz, M. J.

1999-05-01

363

Introducing ADS Labs  

NASA Astrophysics Data System (ADS)

ADS Labs is a platform that ADS is introducing in order to test and receive feedback from the community on new technologies and prototype services. Currently, ADS Labs features a new interface for abstract searches, faceted filtering of results, visualization of co-authorship networks, article-level recommendations, and a full-text search service. The streamlined abstract search interface provides a simple, one-box search with options for ranking results based on a paper relevancy, freshness, number of citations, and downloads. In addition, it provides advanced rankings based on collaborative filtering techniques. The faceted filtering interface allows users to narrow search results based on a particular property or set of properties ("facets"), allowing users to manage large lists and explore the relationship between them. For any set or sub-set of records, the co-authorship network can be visualized in an interactive way, offering a view of the distribution of contributors and their inter-relationships. This provides an immediate way to detect groups and collaborations involved in a particular research field. For a majority of papers in Astronomy, our new interface will provide a list of related articles of potential interest. The recommendations are based on a number of factors, including text similarity, citations, and co-readership information. The new full-text search interface allows users to find all instances of particular words or phrases in the body of the articles in our full-text archive. This includes all of the scanned literature in ADS as well as a select portion of the current astronomical literature, including ApJ, ApJS, AJ, MNRAS, PASP, A&A, and soon additional content from Springer journals. Fulltext search results include a list of the matching papers as well as a list of "snippets" of text highlighting the context in which the search terms were found. ADS Labs is available at http://adslabs.org

Accomazzi, Alberto; Henneken, E.; Grant, C. S.; Kurtz, M. J.; Di Milia, G.; Luker, J.; Thompson, D. M.; Bohlen, E.; Murray, S. S.

2011-05-01

364

Accelerated maximum likelihood parameter estimation for stochastic biochemical systems  

PubMed Central

Background A prerequisite for the mechanistic simulation of a biochemical system is detailed knowledge of its kinetic parameters. Despite recent experimental advances, the estimation of unknown parameter values from observed data is still a bottleneck for obtaining accurate simulation results. Many methods exist for parameter estimation in deterministic biochemical systems; methods for discrete stochastic systems are less well developed. Given the probabilistic nature of stochastic biochemical models, a natural approach is to choose parameter values that maximize the probability of the observed data with respect to the unknown parameters, a.k.a. the maximum likelihood parameter estimates (MLEs). MLE computation for all but the simplest models requires the simulation of many system trajectories that are consistent with experimental data. For models with unknown parameters, this presents a computational challenge, as the generation of consistent trajectories can be an extremely rare occurrence. Results We have developed Monte Carlo Expectation-Maximization with Modified Cross-Entropy Method (MCEM2): an accelerated method for calculating MLEs that combines advances in rare event simulation with a computationally efficient version of the Monte Carlo expectation-maximization (MCEM) algorithm. Our method requires no prior knowledge regarding parameter values, and it automatically provides a multivariate parameter uncertainty estimate. We applied the method to five stochastic systems of increasing complexity, progressing from an analytically tractable pure-birth model to a computationally demanding model of yeast-polarization. Our results demonstrate that MCEM2 substantially accelerates MLE computation on all tested models when compared to a stand-alone version of MCEM. Additionally, we show how our method identifies parameter values for certain classes of models more accurately than two recently proposed computationally efficient methods. Conclusions This work provides a novel, accelerated version of a likelihood-based parameter estimation method that can be readily applied to stochastic biochemical systems. In addition, our results suggest opportunities for added efficiency improvements that will further enhance our ability to mechanistically simulate biological processes.

2012-01-01

365

Statistical QoS routing for IEEE 802.11 multihop ad hoc networks  

Microsoft Academic Search

In this paper, we propose a model-based quality-of-service (QoS) routing scheme for IEEE 802.11 ad hoc networks. Unlike most of QoS routing schemes in the literature, the proposed scheme provides stochastic end-to-end delay guarantees, instead of average delay guarantees, to delay-sensitive bursty traffic sources. Via a cross-layer design approach, the scheme selects the routes based on a geographical on-demand ad

Atef Abdrabou; Weihua Zhuang

2009-01-01

366

Zone based ant colony routing in mobile ad-hoc network  

Microsoft Academic Search

Ant colony optimization (ACO) is a stochastic approach for solving combinatorial optimization problems like routing in computer networks. The idea of this optimization is based on the food accumulation methodology of the ant community. Zone based routing algorithms is build on the concept of individual node's position for routing of packets in mobile ad-hoc networks. Here the nodes' position can

Maumita Bandyopadhyay; P. Bhaumik

2010-01-01

367

Dynamic stochastic optimization models for air traffic flow management  

NASA Astrophysics Data System (ADS)

This dissertation presents dynamic stochastic optimization models for Air Traffic Flow Management (ATFM) that enables decisions to adapt to new information on evolving capacities of National Airspace System (NAS) resources. Uncertainty is represented by a set of capacity scenarios, each depicting a particular time-varying capacity profile of NAS resources. We use the concept of a scenario tree in which multiple scenarios are possible initially. Scenarios are eliminated as possibilities in a succession of branching points, until the specific scenario that will be realized on a particular day is known. Thus the scenario tree branching provides updated information on evolving scenarios, and allows ATFM decisions to be re-addressed and revised. First, we propose a dynamic stochastic model for a single airport ground holding problem (SAGHP) that can be used for planning Ground Delay Programs (GDPs) when there is uncertainty about future airport arrival capacities. Ground delays of non-departed flights can be revised based on updated information from scenario tree branching. The problem is formulated so that a wide range of objective functions, including non-linear delay cost functions and functions that reflect equity concerns can be optimized. Furthermore, the model improves on existing practice by ensuring efficient use of available capacity without necessarily exempting long-haul flights. Following this, we present a methodology and optimization models that can be used for decentralized decision making by individual airlines in the GDP planning process, using the solutions from the stochastic dynamic SAGHP. Airlines are allowed to perform cancellations, and re-allocate slots to remaining flights by substitutions. We also present an optimization model that can be used by the FAA, after the airlines perform cancellation and substitutions, to re-utilize vacant arrival slots that are created due to cancellations. Finally, we present three stochastic integer programming models for managing inbound air traffic flow of an airport, when there is adverse weather impacting the arrival capacity of the airport along with its arrival fixes. These are the first models, for optimizing ATFM decisions, which address uncertainty of future capacities of multiple NAS resources.

Mukherjee, Avijit

368

Allocating Independent Subtasks on Parallel Processors  

Microsoft Academic Search

When using MIMD (multiple instruction, multiple data) parallel computers, one is often confronted with solving a task composed of many independent subtasks where it is necessary to synchronize the processors after all the subtasks have been completed. This paper studies how the subtasks should be allocated to the processors in order to minimize the expected time it takes to finish

Clyde P. Kruskal; Alan Weiss

1985-01-01

369

Household Allocation Module of Oregon2 Model  

Microsoft Academic Search

The Oregon2 model is a set of seven integrated modules that together simulate the land use transport system in the State of Oregon. One of these modules, called the Household Allocations, or 'HA' Module, updates the economic and demographic attributes of each person and household in a synthetic population, including age, gender, occupation, work and student status, job holdings, household

John Hunt; T Weidner

2004-01-01

370

Limits on linearity of missile allocation optimization  

SciTech Connect

Optimizations of missile allocation based on linearized exchange equations produce accurate allocations, but the limits of validity of the linearization are not known. These limits are explored in the context of the upload of weapons by one side to initially small, equal forces of vulnerable and survivable weapons. The analysis compares analytic and numerical optimizations and stability induces based on aggregated interactions of the two missile forces, the first and second strikes they could deliver, and they resulting costs. This note discusses the costs and stability indices induced by unilateral uploading of weapons to an initially symmetrical low force configuration. These limits are quantified for forces with a few hundred missiles by comparing analytic and numerical optimizations of first strike costs. For forces of 100 vulnerable and 100 survivable missiles on each side, the analytic optimization agrees closely with the numerical solution. For 200 vulnerable and 200 survivable missiles on each side, the analytic optimization agrees with the induces to within about 10%, but disagrees with the allocation of the side with more weapons by about 50%. The disagreement comes from the interaction of the possession of more weapons with the shift of allocation from missiles to value that they induce.

Canavan, G.H.

1997-12-01

371

49 CFR 262.5 - Allocation requirements.  

Code of Federal Regulations, 2011 CFR

...PROGRAM FOR CAPITAL GRANTS FOR RAIL LINE RELOCATION AND IMPROVEMENT PROJECTS § 262.5 Allocation requirements. At least fifty percent of all grant funds awarded under this section out of funds appropriated for a fiscal year shall be provided as...

2011-10-01

372

49 CFR 262.5 - Allocation requirements.  

Code of Federal Regulations, 2012 CFR

...PROGRAM FOR CAPITAL GRANTS FOR RAIL LINE RELOCATION AND IMPROVEMENT PROJECTS § 262.5 Allocation requirements. At least fifty percent of all grant funds awarded under this section out of funds appropriated for a fiscal year shall be provided as...

2012-10-01

373

Wireless resource allocation with perceived quality fairness  

Microsoft Academic Search

We address cross-layer optimization (CLO) between link and application layer. Using parameterized models of applications and link layer the application data rates and the wireless radio resource allocation are determined such that the perceived quality of the users is good. Conventional approaches consider the sum of all application utilities or the worst application utility as optimization criterion. We propose a

Andreas Saul; DOCOMO Euro-Labs

2008-01-01

374

The Optimal Allocation of Prizes in Contests  

Microsoft Academic Search

We study a contest with multiple, nonidentical prizes. Participants are privately informed about a parameter (ability) affecting their costs of effort. The contestant with the highest effort wins the first prize, the contestant with the second-highest effort wins the second prize, and so on until all the prizes are allocated. The contest's designer maximizes expected effort. When cost functions are

Benny Moldovanu; Aner Sela

2001-01-01

375

Stability and resource allocation in project planning  

Microsoft Academic Search

The majority of resource-constrained project scheduling efforts assume perfect information about the scheduling problem to be solved and a static deterministic environment within which the precomputed baseline schedule is executed. In reality, project activities are subject to considerable uncertainty, which generally leads to numerous schedule disruptions. In this paper, we present a resource allocation model that protects a given baseline

ROEL LEUS; WILLY HERROELEN

2004-01-01

376

Asset Allocation, Longevity Risk, Annuitisation and Bequests  

Microsoft Academic Search

The present paper studies a pensioner deriving utility from a stream of consumption or an annuity and from bequeathing wealth to his heirs in a continuous-time framework. The task of finding the pensioner's optimal consumption, asset allocation and annuity decision rule leads to the interesting interplay of optimal control theory, optimal stopping theory and mortality issues or, technically speaking, to

David Schiess

377

42 CFR 24.2 - Allocation.  

Code of Federal Regulations, 2012 CFR

...HEALTH AND HUMAN SERVICES PERSONNEL SENIOR BIOMEDICAL RESEARCH SERVICE § 24.2...remaining SBRS allocation may be used for the retention of current employees. (d) SBRS slots...in SBRS appointments only where other senior-level appointing authorities are...

2012-10-01

378

42 CFR 24.2 - Allocation.  

Code of Federal Regulations, 2011 CFR

...HEALTH AND HUMAN SERVICES PERSONNEL SENIOR BIOMEDICAL RESEARCH SERVICE § 24.2...remaining SBRS allocation may be used for the retention of current employees. (d) SBRS slots...in SBRS appointments only where other senior-level appointing authorities are...

2011-10-01

379

RAOPS: Resource Allocation Optimization Program for Safegurards  

SciTech Connect

RAOPS--Resource Allocation Optimization Program for Safeguards is extended to a multiobjective return function having the detection probability and expected detection time as criteria. The expected detection time is included as a constraint, based on the well-known Avenhaus model of the optimum number of inventory periods. Examples of computation are provided.

Zardecki, A.; Markin, J.T.

1994-03-01

380

A Faculty Merit Pay Allocation Model.  

ERIC Educational Resources Information Center

Presents a merit pay allocation model based on the principle of awarding comparable percentage salary increases to college/university faculty members with similar merit ratings. The model enables users to calculate merit pay amounts for individual faculty members in a systematic and efficient manner and can incorporate various policy directives…

Wenger, Robert B.; Girard, Dennis M.

2000-01-01

381

EVALUATING WATER ALLOCATIONS FOR DROUGHT MANAGEMENT  

Microsoft Academic Search

Water supplies and allocations for the Klamath River, OR and CA were evaluated using SIAM (Systems Impact Assessment Model), a decision support system developed by U.S. Geological Survey. SIAM is a set of models in a windows interface that provides water supply and delivery in a managed river system, predicts water quality and simulates fish production. SIAM was used to

Sharon G. Campbell; Marshall Flug; R. Blair Hanna; Fort Collins

382

Ethics and resource allocation: an economist's view.  

PubMed

This paper debates some of the issues involved in attempting to apply economic analysis to the health care sector when medical ethics plays such an important part in determining the allocation of resources in that sector. Two distinct ethical positions are highlighted as being fundamental to the understanding of resource allocation in this sector -- deontological and utilitarian theories of ethics. It is argued that medical ethics are often narrowly conceived in that there is a tendency for the individual, rather than society at large, to form the focal point of the production of the service "health care'. Thus medical ethics have been dominated by individualistic ethical coded which do not fully consider questions relating to resource allocation at a social level. It is further argued that the structure of the health care sector augments these "individualistic' ethics. It is also suggested that different actors in the health care sector address questions of resource allocation with respect to different time periods, and that this serves to further enhance the influence of "individualistic' ethical codes in this sector. PMID:3092362

McGuire, A

1986-01-01

383

Negotiating Monitoring Task Allocation for Orbiters  

Microsoft Academic Search

We are interested in the problem of coordination of ground- based control stations and orbiting space probes for allocating monitor- ing tasks for emerging environmental situations that have the potential to become catastrophic events threatening life and property. We assume that ground based sensor networks have recognized seismic, geological, atmospheric, or some other natural phenomena that has created a rapidly

Doran Chakraborty; Sabyasachi Saha; Sandip Sen; Bradley Clement

2006-01-01

384

Automated parking slot allocation using RFID technology  

Microsoft Academic Search

One of the challenging problems for many vehicle owners in big metropolitan cities is where to park their vehicles. If the parking slot availability is known in advance one can save precious time and fuel wastage. In this paper we would like to propose an RFID based parking slot allocation system wherein an intended user is informed about the parking

K. Ganesan; K. Vignesh

2007-01-01

385

Competition for Nutrients and Optimal Root Allocation  

Microsoft Academic Search

The allocation of resources among roots and shoots represents the largest flux of resources within a plant and therefore should have been selected to maximize benefits to plants. Yet, it is unclear why some species like temperate grasses have such high root length density (RLD). Either the slow rate of diffusion of inorganic N in soils or interplant competition could

Joseph M. Craine

2006-01-01

386

Land Tenure and Allocative Efficiency in Niger  

Microsoft Academic Search

Using field-level data, we investigate whether traditional land tenure systems are an impediment to allocative efficiency in Niger. We find that yields are strongly influenced by the manpower available to farming households, an indication that marginal returns to labor and land are not equalized across households. We uncover no relationship between manuring and whether or not local customs allow land

Sarah Gavian; Marcel Fafchamps

1996-01-01

387

Where Training Resources Should be Allocated  

Microsoft Academic Search

Proper allocation of training budgets and resources requires fundamental and important business decisions. Unless the organization's training function is a revenue-generating business, the demand for training most likely exceeds capacity and budgets are likely viewed as an expense - which is continually scrutinized. As a result, resources need to be focused on those initiatives that are important and which can

Steven J. Tourville

2005-01-01

388

Asset Allocation by Variance Sensitivity Analysis  

Microsoft Academic Search

This article provides a solution to the curse of dimensionality associated to multivariate generalized autoregressive conditionally heteroskedastic (GARCH) estimation. We work with univariate portfolio GARCH models and show how the multivariate dimension of the portfolio allocation problem may be recovered from the univariate approach. The main tool we use is \\

Simone Manganelli

2004-01-01

389

International Legal Policy and Efficient Resource Allocation  

Microsoft Academic Search

The impact of international interactions on the level and allocation of a nation's expenditures for police protection and law enforcement are discussed: A model is developed and used to analyze various types of international interactions such as crime spillovers from one nation to another, effective police action in one country against a crime organization active in a number of countries,

Scott Mckinney

1990-01-01

390

Institutional investors, global savings and asset allocation  

Microsoft Academic Search

Executive summary Observed trends in institutional investors' behaviour Institutional investors are becoming more important in global financial markets, with their assets under management rapidly catching up with those of the banking system. Institutional investors help to ensure deeper and better functioning markets, thus contributing to a more efficient allocation of savings, and their growth may help to counter the decline

2007-01-01

391

Communication rate allocation in quantized control  

Microsoft Academic Search

A linear-quadratic-Gaussian (LQG) delocalized control problem is formulated to require both specification of a control law and communication of measurements to controller and controls to plant. Efficient communication requires quantization of both measurement and control signals. The basic design problem is to allocate in an optimum fashion a fixed total communication rate to the measurement and control communication systems. A

Thomas R. Fischer; Charles J. Meadow

1983-01-01

392

Dynamic task decomposition and allocation in CGF  

Microsoft Academic Search

Computer Generated Forces (CGF) is virtual entities of combat force, which can be generated and controlled by computers. Human Behavior Representation (HBR) in CGF is critical for combat simulation. Yet, despite the considerable progress in related research, the challenge of dynamic task decomposition and allocation has remained largely unaddressed. This paper describes the task decomposition strategy and principles, presents related

Lei Feng; Ji-Wen Hu; Ya-Bing Zha; Quan-Jun Yin

2010-01-01

393

Market Based Resource Allocation with Incomplete Information  

Microsoft Academic Search

Although there are some research efforts toward re- source allocation in multi-agent systems (MAS), most of these work assume that each agent has complete information about other agents. This re- search investigates interactions among selfish, ra- tional, and autonomous agents in resource alloca- tion, each with incomplete information about other entities, and each seeking to maximize its expected utility. This

An Bo; Chunyan Miao; Zhiqi Shen

2007-01-01

394

Uncertain personal advertisement allocation for Mobile TV  

Microsoft Academic Search

In this paper we consider the problem of allocating personal TV advertisements when the viewers' viewing capacities are uncertain. We focus on the Mobile TV medium as a personal platform taking into account special constraints that are motivated by the TV medium. Since the problem is NP-Hard, we present a sequential solution procedure and propose several heuristic algorithms for solving

Ron Adany; Sarit Kraus; Fernando Ordóñez

2010-01-01

395

An Economic Evaluation of Foreign Fishing Allocations.  

National Technical Information Service (NTIS)

The study illustrates a useful approach to estimating values for the policy-making process of assigning foreign fishing allocations. An economic model is devised which can be applied to the fishing zones of the Bering Sea and Aleutian Islands, the Gulf of...

E. Meuriot J. M. Gates

1982-01-01

396

Optimum Allocation of Two-Dimensional Shapes.  

National Technical Information Service (NTIS)

The optimum two-dimensional allocation problem consists in taking a two-dimensional resource and cutting it into a number of two-dimensional shapes in such a way that some objective function is optimized. The paper describes an investigation into methods ...

M. Adamowicz

1971-01-01

397

Discrete Resource Allocation in Visual Working Memory  

ERIC Educational Resources Information Center

|Are resources in visual working memory allocated in a continuous or a discrete fashion? On one hand, flexible resource models suggest that capacity is determined by a central resource pool that can be flexibly divided such that items of greater complexity receive a larger share of resources. On the other hand, if capacity in working memory is…

Barton, Brian; Ester, Edward F.; Awh, Edward

2009-01-01

398

RESOURCES ALLOCATION TO OPTIMIZE MINING POLLUTION CONTROL  

EPA Science Inventory

A comprehensive model for mine drainage simulation and optimization of resource allocation to control mine acid pollution in a watershed has been developed. The model is capable of: (a) Producing a time trace of acid load and flow from acid drainage sources as a function of clima...

399

Allocating Infected Needles Randomly among Susceptibles  

Microsoft Academic Search

This paper considers the random allocation of i infected needles among a fixed number n of susceptibles. The expected numbers of susceptibles hit by k= 1; 2;:::; i needles are derived, and the numbers of 1-hit and 2 or more-hits infected suscep- tibles are compared. Finally, we discuss the case where infection is transmitted by each needle independently with a

J. Gani; R. J. Swift

400

Economic Growth and Environmental Resource Allocation  

Microsoft Academic Search

The simple fact that environmental resources are endowments is found to have profound effects on their patterns of allocation with changes in income, population, and income inequality. For broad classes of theoretical models, and in Pareto efficient as well as decentralized economies, environmental quality is found to follow a U-shaped pattern with rising income. We examine population changes and variations

William K. Jaeger; Van Kolpin

2001-01-01

401

Ad Element Liking and Its Relationship to Overall Ad Liking  

Microsoft Academic Search

This study explored differences in affective response content across three cultures and the role of these responses in predicting overall advertising liking. Based on a field survey, subjects from England, Norway and Spain evaluated cosmetic ads on a series of liking scales. Ad content was coded into elements reflecting product- or ad-related affect based on existing theory on ad evaluation

Rune Bjerke; Tom Rosendahl; Pradeep Gopalakrishna; Dennis Sandler

2006-01-01

402

Neuronal Growth: A Bistable Stochastic Process  

NASA Astrophysics Data System (ADS)

The fundamentally stochastic nature of neuronal growth has hardly been addressed in neuroscience. We report on the stochastic fluctuations of a neuronal growth cone’s leading edge movement, the basic step in neuronal growth. Describing the edge movement as a stochastic bistable process leads to an isotropic noise parameter that is successfully used to test the model. An analysis of growth cone motility confirms the model, and predicts that linear changes of the bistable potential, as known from stochastic filtering, result in directed growth cone translocation.

Betz, Timo; Lim, Daryl; Käs, Josef A.

2006-03-01

403

Multiscale stochastic simulation algorithm with stochastic partial equilibrium assumption for chemically reacting systems  

Microsoft Academic Search

In this paper, we introduce a multiscale stochastic simulation algorithm (MSSA) which makes use of Gillespie’s stochastic simulation algorithm (SSA) together with a new stochastic formulation of the partial equilibrium assumption (PEA). This method is much more efficient than SSA alone. It works even with a very small population of fast species. Implementation details are discussed, and an application to

Yang Cao; Dan. Gillespie; Linda. Petzold

2005-01-01

404

Ad*Access  

NSDL National Science Digital Library

The Duke University Libraries has an extensive physical and online collection of advertisements that appeared in magazines and newspapers in the U.S. and Canada from 1911-1955. The Ad*Access collection focuses on advertisements in five main subject areas: Radio, Television, Transportation, Beauty and Hygiene, and World War II. Visitors should read the "About Us" section to learn about why the collection was created and its importance for research. Visitors can "browse" the collection by the aforementioned categories, product, year, and company. For example, "War Bonds" are listed under "Product", and visitors will find that the messages in war bond advertisements are quite frank, and insistent, that people should help the war effort. Visitors should check out the following ads found when browsing war bonds: "I'm Saving to go to Ag College...And Buying Bullets for Pete!", "Avenge Pearl Harbor! Buy Bonds! Give Bonds!", and "Your Bond Purchase Makes These Nazis Shiver".

405

AdViews  

NSDL National Science Digital Library

The AdViews section of the Internet Archive site contains thousands of vintage television commercials dating from the 1950s to the 1980s. These items of commercial ephemera were created or collected by the ad agency Benton & Bowles or its successor, D'Arcy Masius Benton & Bowles (DMB&B). The commercials are currently found at the John W. Hartman Center for Sales, Advertising & Marketing History in Duke University's David M. Rubenstein Rare Book & Manuscript Library. Visitors will find work created for clients such as Post, Kraft, Old Spice, Pan Am, and many others. As with other Internet Archive collections, visitors can look on the Most Downloaded Items Last Week area. Here they will most likely find advertisements for Charlie's Angels dolls, Borden's Milk, and Sugar Rice Krinkles. Visitors shouldn't miss the Subcollections area, which divides the commercials into their constituent companies, such as Beech Nut Foods, Folgers, and dozens of others.

406

AdS5xS5 untwisted  

NASA Astrophysics Data System (ADS)

Noting that T-duality untwists S5 to CP2 xS1, we construct the duality chain: n=4 super Yang-Mills --> type IIB superstring on AdS5 xS5 --> type IIA superstring on AdS5 xCP2 xS1 --> M-theory on AdS5 xCP2 xT2. This provides another example of supersymmetry without supersymmetry: on AdS5 xCP2 xS1, type IIA supergravity has SU(3) xU(1)xU(1) xU(1) and N=0 supersymmetry but type IIA string theory has SO(6) and N=8. The missing superpartners are provided by stringy winding modes. We also discuss IIB compactifications to AdS5 with N=4, N=2 and N=0.

Duff, M. J.; Lü, H.; Pope, C. N.

1998-11-01

407

Adding with Uncommon Denominators  

NSDL National Science Digital Library

Teachers can use this interactive tool to help students build a conceptual understanding of adding fractions with uncommon denominators by linking visual models to procedures. Students make use of fractions with a value of one. This page includes a video demonstration of the tool and sample lessons from the Conceptua curriculum. Free registration is required to use the tool. A paid subscription is necessary to access full curriculum and allow full student use.

2011-01-01

408

Towards Asynchronous AD Conversion  

Microsoft Academic Search

Analogue to digital (A-D) converters with a fixed conversion time are subject to errors due tometastability. These errors will occur in all converter designs with a bounded time for decisions,and are potentially severe. We estimate the frequency of these errors in a successive approximationconverter, and compare the results with asynchronous designs using both a fully speed-independent,and a bundled data approach.

D. J. Kinniment; Alexandre Yakovlev; Fei Xia; B. Gao

1998-01-01

409

ADS Abstract Service Enhancements  

NASA Astrophysics Data System (ADS)

The Astrophysics Data System is enhancing functionality and access to the Abstract Service in several areas. A new WAIS server running the freeWAIS search engine has been added to the existing HTTP and ANSA-based servers. Abstract coverage will be expanded to include more of the NASA ``RECON'' categories as well as abstracts obtained directly from astronomical journals. In addition, we are enhancing the service to include full journal articles in a suitable electronic format.

Accomazzi, A.; Grant, C. S.; Eichhorn, G.; Kurtz, M. J.; Murray, S. S.

410

Supersymmetric AdS6 via T Duality  

NASA Astrophysics Data System (ADS)

We present a new supersymmetric AdS6 solution of type IIB supergravity with SU(2) isometry. Through the AdS/CFT correspondence, this has potentially very interesting implications for 5D fixed point theories. This solution is the result of a non-Abelian T duality on the known supersymmetric AdS6 solution of massive IIA. The SU(2) R symmetry is untouched, leading to sixteen supercharges and preserved supersymmetry.

Lozano, Y.; Ó Colgáin, E.; Rodríguez-Gómez, D.; Sfetsos, K.

2013-06-01

411

Antisymmetric tensor field on AdS 5  

Microsoft Academic Search

By using the Hamiltonian version of the AdS\\/CFT correspondence, we compute the two-point Green function of a local operator in D=4 N=4 super Yang-Mills theory, which corresponds to a massive antisymmetric tensor field of the second rank on the AdS5 background. We discuss the conformal transformations induced on the boundary by isometries of AdS5.

G. E. Arutyunov; S. A. Frolov

1998-01-01

412

Learning to imitate stochastic time series in a compositional way by chaos.  

PubMed

This study shows that a mixture of RNN experts model can acquire the ability to generate sequences that are combination of multiple primitive patterns by means of self-organizing chaos. By training the model, each expert learns a primitive sequence pattern, and a gating network learns to imitate stochastic switching of the multiple primitives via chaotic dynamics, utilizing a sensitive dependence on initial conditions. As a demonstration, we present a numerical simulation in which the model learns Markov chain switching among some Lissajous curves by chaotic dynamics. Our analysis shows that by using a sufficient amount of training data, balanced with the network memory capacity, it is possible to satisfy the conditions for embedding the target stochastic sequences into a chaotic dynamical system. It is also shown that reconstruction of a stochastic time series by a chaotic model can be stabilized by adding a negligible amount of noise to the dynamics of the model. PMID:20045751

Namikawa, Jun; Tani, Jun

2009-12-23

413

Recommendations for a New Allocation System for 101 Funds.  

National Technical Information Service (NTIS)

The Veterans Affairs Office of Research and Development (ORD) currently allocates approximately 7% of its budget to VA health care systems (VAHCS) to support their research administration activities. These allocations are known as 101 funds. This system i...

T. H. Wagner A. Stunz

2002-01-01

414

A Distributed Tasks Allocation Scheme in Multi-UAV Context  

Microsoft Academic Search

This paper deals with the task allocation problem in multi-robot systems. We propose a completely distributed architecture, where robots dynamically allocate their tasks while they are building their plans. We first focus on the problem of simple \\

Thomas Lemaire; Rachid Alami; Simon Lacroix

2004-01-01

415

50 CFR 648.74 - Annual individual allocations.  

Code of Federal Regulations, 2012 CFR

...for the Atlantic Surf Clam and Ocean Quahog Fisheries § 648.74... (a) General. (1) Each fishing year, the Regional Administrator...initial allocation of surfclams and ocean quahogs for the next fishing year for each allocation...

2012-10-01

416

50 CFR 648.70 - Annual individual allocations.  

Code of Federal Regulations, 2011 CFR

...for the Atlantic Surf Clam and Ocean Quahog Fisheries § 648.70...a) General. (1) Each fishing year, the Regional Administrator...initial allocation of surfclams and ocean quahogs for the next fishing year for each allocation...

2011-10-01

417

24 CFR 92.604 - ADDI allocation formula.  

Code of Federal Regulations, 2013 CFR

...PARTNERSHIPS PROGRAM American Dream Downpayment Initiative...allocation formula. (a) General. HUD...jurisdiction located within a state an amount equal...participating jurisdiction: (i) Has a total population of...allocation that would have otherwise been...

2013-04-01

418

48 CFR 3018.109 - Priorities and allocations.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Priorities and allocations. 3018.109 Section... EMERGENCY ACQUISITIONS 3018.109 Priorities and allocations. DHS Components may assign priority ratings on contracts and orders as...

2012-10-01

419

1985 NAPAP EMISSIONS INVENTORY: DEVELOPMENT OF SPECIES ALLOCATION FACTORS  

EPA Science Inventory

The report describes the methodologies and data bases used to develop species allocation factors and data processing software used to develop the 1985 National Acid Precipitation Assessment Program (NAPAP) Modelers' Emissions Inventory (Version 2). Species allocation factors were...

420

24 CFR 791.404 - Field Office allocation planning.  

Code of Federal Regulations, 2013 CFR

...URBAN DEVELOPMENT (HOUSING ASSISTANCE PROGRAMS AND PUBLIC AND INDIAN HOUSING PROGRAMS) ALLOCATIONS OF HOUSING ASSISTANCE FUNDS...allocation area shall also be of sufficient size, in terms of population and housing need, that the amount of budget authority...

2013-04-01

421

14 CFR 93.215 - Initial allocation of slots.  

Code of Federal Regulations, 2013 CFR

...TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES Allocation of Commuter and Air Carrier IFR Operations at High Density Traffic Airports § 93.215 Initial allocation of slots. (a) Each air carrier and commuter operator...

2013-01-01

422

42 CFR 121.8 - Allocation of organs.  

Code of Federal Regulations, 2010 CFR

... false Allocation of organs. 121.8 Section 121...4. (h) Directed donation. Nothing in this section...prohibit the allocation of an organ to a recipient named by those authorized to make the donation. [64 FR 56659,...

2009-10-01

423

42 CFR 121.8 - Allocation of organs.  

Code of Federal Regulations, 2010 CFR

... false Allocation of organs. 121.8 Section 121...4. (h) Directed donation. Nothing in this section...prohibit the allocation of an organ to a recipient named by those authorized to make the donation. [64 FR 56659,...

2010-10-01

424

30 CFR 1206.260 - Allocation of washed coal.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Allocation of washed coal. 1206.260 Section 1206.260 Mineral...RESOURCES REVENUE PRODUCT VALUATION Federal Coal § 1206.260 Allocation of washed coal. (a) When coal is subjected to...

2013-07-01

425

30 CFR 1206.459 - Allocation of washed coal.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Allocation of washed coal. 1206.459 Section 1206.459 Mineral...RESOURCES REVENUE PRODUCT VALUATION Indian Coal § 1206.459 Allocation of washed coal. (a) When coal is subjected to...

2013-07-01

426

75 FR 32495 - Operating Fund Subsidies Allocation Formula  

Federal Register 2010, 2011, 2012, 2013

...Operating Fund Subsidies Allocation Formula AGENCY: Office of the Chief Information...which assistance is determined using a formula approach under the Operating Fund Program...Operating Fund Subsidies Allocation Formula. OMB Approval Number:...

2010-06-08

427

Solution of Singly-Constrained Concave Allocation Problems.  

National Technical Information Service (NTIS)

The optimization technique of mathematical programming is used to treat a class of problems to determine a resource allocation to a set of independent alternatives. Maximization of the return is the desired result. The allocation problem is treated first ...

J. T. McGill

1970-01-01

428

10 CFR 490.703 - Biodiesel fuel use credit allocation.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 2010-01-01 false Biodiesel fuel use credit allocation. 490.703... ALTERNATIVE FUEL TRANSPORTATION PROGRAM Biodiesel Fuel Use Credit § 490.703 Biodiesel fuel use credit allocation. (a)...

2010-01-01

429

10 CFR 490.703 - Biodiesel fuel use credit allocation.  

Code of Federal Regulations, 2010 CFR

... 2009-01-01 2009-01-01 false Biodiesel fuel use credit allocation. 490.703... ALTERNATIVE FUEL TRANSPORTATION PROGRAM Biodiesel Fuel Use Credit § 490.703 Biodiesel fuel use credit allocation. (a)...

2009-01-01

430

Adaptive bandwidth allocation for metropolitan and wide-area networks  

Microsoft Academic Search

A new bandwidth allocation scheme termed adaptive bandwidth allocation (ABA) based on classical control theory is proposed. It achieves stability, fairness and efficiency in metropolitan and wide-area networks. We demonstrate by simulation the satisfactory performance achieved by ABA.

Liansheng Tan; Hanwu Wang; Moshe Zukerman

2005-01-01

431

47 CFR 1.1417 - Allocation of Unusable Space Costs.  

Code of Federal Regulations, 2012 CFR

...1417 Allocation of Unusable Space Costs. (a) With respect...apportion the cost of providing unusable space on a pole so that such apportionment equals two-thirds of the costs of providing unusable space that would be allocated to...

2012-10-01

432

47 CFR 1.1417 - Allocation of Unusable Space Costs.  

Code of Federal Regulations, 2010 CFR

...1417 Allocation of Unusable Space Costs. (a) With respect...apportion the cost of providing unusable space on a pole so that such apportionment equals two-thirds of the costs of providing unusable space that would be allocated to...

2009-10-01

433

47 CFR 1.1417 - Allocation of Unusable Space Costs.  

Code of Federal Regulations, 2010 CFR

...1417 Allocation of Unusable Space Costs. (a) With respect...apportion the cost of providing unusable space on a pole so that such apportionment equals two-thirds of the costs of providing unusable space that would be allocated to...

2010-10-01

434

7 CFR 1493.5 - Criteria for agricultural commodity allocations.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 false Criteria for agricultural commodity allocations. 1493.5 Section 1493...Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE...1493.5 Criteria for agricultural commodity allocations. The criteria...

2012-01-01

435

10 CFR 470.15 - Allocation of funds.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Allocation of funds. 470.15 Section 470.15 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION APPROPRIATE TECHNOLOGY SMALL GRANTS PROGRAM § 470.15 Allocation of funds. (a) DOE shall...

2013-01-01

436

Minimum Distance Bandwidth Allocation for Data Traffic over Space Networks  

Microsoft Academic Search

The paper formalizes the bandwidth allocation process over space communication systems as a Multi - Objective Programming (MOP) problem and proposes an allocation scheme based on the GOAL programming called \\

Igor Bisio; Mario Marchese

437

Bond-based linear indices of the non-stochastic and stochastic edge-adjacency matrix. 1. Theory and modeling of ChemPhys properties of organic molecules.  

PubMed

Novel bond-level molecular descriptors are proposed, based on linear maps similar to the ones defined in algebra theory. The kth edge-adjacency matrix (E(k)) denotes the matrix of bond linear indices (non-stochastic) with regard to canonical basis set. The kth stochastic edge-adjacency matrix, ES(k), is here proposed as a new molecular representation easily calculated from E(k). Then, the kth stochastic bond linear indices are calculated using ES(k) as operators of linear transformations. In both cases, the bond-type formalism is developed. The kth non-stochastic and stochastic total linear indices are calculated by adding the kth non-stochastic and stochastic bond linear indices, respectively, of all bonds in molecule. First, the new bond-based molecular descriptors (MDs) are tested for suitability, for the QSPRs, by analyzing regressions of novel indices for selected physicochemical properties of octane isomers (first round). General performance of the new descriptors in this QSPR studies is evaluated with regard to the well-known sets of 2D/3D MDs. From the analysis, we can conclude that the non-stochastic and stochastic bond-based linear indices have an overall good modeling capability proving their usefulness in QSPR studies. Later, the novel bond-level MDs are also used for the description and prediction of the boiling point of 28 alkyl-alcohols (second round), and to the modeling of the specific rate constant (log k), partition coefficient (log P), as well as the antibacterial activity of 34 derivatives of 2-furylethylenes (third round). The comparison with other approaches (edge- and vertices-based connectivity indices, total and local spectral moments, and quantum chemical descriptors as well as E-state/biomolecular encounter parameters) exposes a good behavior of our method in this QSPR studies. Finally, the approach described in this study appears to be a very promising structural invariant, useful not only for QSPR studies but also for similarity/diversity analysis and drug discovery protocols. PMID:20063184

Marrero-Ponce, Yovani; Martínez-Albelo, Eugenio R; Casañola-Martín, Gerardo M; Castillo-Garit, Juan A; Echevería-Díaz, Yunaimy; Zaldivar, Vicente Romero; Tygat, Jan; Borges, José E Rodriguez; García-Domenech, Ramón; Torrens, Francisco; Pérez-Giménez, Facundo

2010-01-10

438

The allocation of ecosystem net primary productivity in tropical forests  

PubMed Central

The allocation of the net primary productivity (NPP) of an ecosystem between canopy, woody tissue and fine roots is an important descriptor of the functioning of that ecosystem, and an important feature to correctly represent in terrestrial ecosystem models. Here, we collate and analyse a global dataset of NPP allocation in tropical forests, and compare this with the representation of NPP allocation in 13 terrestrial ecosystem models. On average, the data suggest an equal partitioning of allocation between all three main components (mean 34 ± 6% canopy, 39 ± 10% wood, 27 ± 11% fine roots), but there is substantial site-to-site variation in allocation to woody tissue versus allocation to fine roots. Allocation to canopy (leaves, flowers and fruit) shows much less variance. The mean allocation of the ecosystem models is close to the mean of the data, but the spread is much greater, with several models reporting allocation partitioning outside of the spread of the data. Where all main components of NPP cannot be measured, litterfall is a good predictor of overall NPP (r2 = 0.83 for linear fit forced through origin), stem growth is a moderate predictor and fine root production a poor predictor. Across sites the major component of variation of allocation is a shifting allocation between wood and fine roots, with allocation to the canopy being a relatively invariant component of total NPP. This suggests the dominant allocation trade-off is a ‘fine root versus wood’ trade-off, as opposed to the expected ‘root–shoot’ trade-off; such a trade-off has recently been posited on theoretical grounds for old-growth forest stands. We conclude by discussing the systematic biases in estimates of allocation introduced by missing NPP components, including herbivory, large leaf litter and root exudates production. These biases have a moderate effect on overall carbon allocation estimates, but are smaller than the observed range in allocation values across sites.

Malhi, Yadvinder; Doughty, Christopher; Galbraith, David

2011-01-01

439

Pitch sensation involves stochastic resonance.  

PubMed

Pitch is a complex hearing phenomenon that results from elicited and self-generated cochlear vibrations. Read-off vibrational information is relayed higher up the auditory pathway, where it is then condensed into pitch sensation. How this can adequately be described in terms of physics has largely remained an open question. We have developed a peripheral hearing system (in hardware and software) that reproduces with great accuracy all salient pitch features known from biophysical and psychoacoustic experiments. At the level of the auditory nerve, the system exploits stochastic resonance to achieve this performance, which may explain the large amount of noise observed in the working auditory nerve. PMID:24045830

Martignoli, Stefan; Gomez, Florian; Stoop, Ruedi

2013-09-18

440

Stochastic Gain in Population Dynamics  

NASA Astrophysics Data System (ADS)

We introduce an extension of the usual replicator dynamics to adaptive learning rates. We show that a population with a dynamic learning rate can gain an increased average payoff in transient phases and can also exploit external noise, leading the system away from the Nash equilibrium, in a resonancelike fashion. The payoff versus noise curve resembles the signal to noise ratio curve in stochastic resonance. Seen in this broad context, we introduce another mechanism that exploits fluctuations in order to improve properties of the system. Such a mechanism could be of particular interest in economic systems.

Traulsen, Arne; Röhl, Torsten; Schuster, Heinz Georg

2004-07-01

441

Stochastic Gravity: Theory and Applications  

NASA Astrophysics Data System (ADS)

Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein-Langevin equation, which has in addition sources due to the noise kernel. The noise kernel is the vacuum expectation value of the (operator-valued) stress-energy bi-tensor which describes the fluctuations of quantum matter fields in curved spacetimes. In the first part, we describe the fundamentals of this new theory via two approaches: the axiomatic and the functional. The axiomatic approach is useful to see the structure of the theory from the framework of semiclassical gravity, showing the link from the mean value of the stress-energy tensor to their correlation functions. The functional approach uses the Feynman-Vernon influence functional and the Schwinger-Keldysh closed-time-path effective action methods which are convenient for computations. It also brings out the open systems concepts and the statistical and stochastic contents of the theory such as dissipation, fluctuations, noise, and decoherence. We then focus on the properties of the stress-energy bi-tensor. We obtain a general expression for the noise kernel of a quantum field defined at two distinct points in an arbitrary curved spacetime as products of covariant derivatives of the quantum field's Green function. In the second part, we describe three applications of stochastic gravity theory. First, we consider metric perturbations in a Minkowski spacetime. We offer an analytical solution of the Einstein-Langevin equation and compute the two-point correlation functions for the linearized Einstein tensor and for the metric perturbations. Second, we discuss structure formation from the stochastic gravity viewpoint, which can go beyond the standard treatment by incorporating the full quantum effect of the inflaton fluctuations. Third, we discuss the backreaction of Hawking radiation in the gravitational background of a quasi-static black hole (enclosed in a box). We derive a fluctuation-dissipation relation between the fluctuations in the radiation and the dissipative dynamics of metric fluctuations.

Hu, Bei Lok; Verdaguer, Enric

2004-03-01

442

A Framework for Incorporating General Domain Knowledge into Latent Dirichlet Allocation using First-Order Logic  

SciTech Connect

Topic models have been used successfully for a variety of problems, often in the form of application-specific extensions of the basic Latent Dirichlet Allocation (LDA) model. Because deriving these new models in order to encode domain knowledge can be difficult and time-consuming, we propose the Fold-all model, which allows the user to specify general domain knowledge in First-Order Logic (FOL). However, combining topic modeling with FOL can result in inference problems beyond the capabilities of existing techniques. We have therefore developed a scalable inference technique using stochastic gradient descent which may also be useful to the Markov Logic Network (MLN) research community. Experiments demonstrate the expressive power of Fold-all, as well as the scalability of our proposed inference method.

Andrzejewski, D; Zhu, X; Craven, M; Recht, B

2011-01-18

443

The ethics of psychoactive ads  

Microsoft Academic Search

Many of today's ads work by arousing the viewer's emotions. Although emotion-arousing ads are widely used and are commonly thought to be effective, their careless use produces a side-effect: the psychoactive ad. A psychoactive ad is any emotion-arousing ad that can cause a meaningful, well-defined group of viewers to feel extremely anxious, to feel hostile toward others, or to feel

Michael R. Hyman; Richard Tansey

1990-01-01

444

Decentralized and dynamic bandwidth allocation in networked control systems  

Microsoft Academic Search

In this paper, we propose a bandwidth allocation scheme for networked control systems that have their control loops closed over a geographically distributed network. We first formulate the bandwidth allocation as a convex optimiza- tion problem. We then present an allocation scheme that solves this optimization problem in a fully distributed man- ner. In addition to being fully distributed, the

Ahmad T. Al-hammouri; Michael S. Branicky; Vincenzo Liberatore; Stephen M. Phillips

2006-01-01

445

Grid resource allocation based on particle swarm optimization  

Microsoft Academic Search

Resource allocation in grid environment is a complex undertaking due to the heterogeneity and dynamic nature aroused by wide area sharing. Most of the existing studies for this problem have been found to be performance deficiency or slow convergence. To address the heterogeneous and computationally intractable problem of resource allocation optimization in grid, this paper presents an allocation algorithm for

Zhijie Li; Xiangdong Liu; Xiaodong Duan; Jian Yun

2009-01-01

446

Fuzzy Evaluation of River Basin Water Resources Allocation  

Microsoft Academic Search

River basin water resources allocation is a complicated multi-scale system related to water resources, social economy and ecological environment. Water quantities allocated to living, industry, agriculture and ecology are chosen as the four indicators to evaluate the river basin water resources allocation's effect on social economic sustainable development in this paper. Making use of variable fuzzy evaluation method to evaluate

Haofang Wang; Wenyan Chen

2009-01-01

447

Forward-Looking Benefit-Based Resource Allocation  

Microsoft Academic Search

A major design aspect of an operating system is the way in which available resources are allocated to processes running on the system. One particular approachto resource schedulingis to make anexplicit estimate of the user's benefit for a number of resource allocations, and then to choose the allocation that provides the highest estimated benefit. Building on this concept of 'benefit-based'

Nanno Langstraat; Koen Langendoen; Henk Sips

2001-01-01

448

Some results on the CTE-based capital allocation rule  

Microsoft Academic Search

Tasche [Tasche, D., 1999. Risk contributions and performance measurement. Working paper, Technische Universität München] introduces a capital allocation principle where the capital allocated to each risk unit can be expressed in terms of its contribution to the conditional tail expectation (CTE) of the aggregate risk. Panjer [Panjer, H.H., 2002. Measurement of risk, solvency requirements and allocation of capital within financial

Jan Dhaene; L. Henrard; Z. Landsman; A. Vandendorpe; Steven Vanduffel

2008-01-01

449

Organizing emissions trading: the barrier of domestic permit allocation  

Microsoft Academic Search

This paper uses a barrier model of politics to analyse the issue of permit allocation as a major political obstacle to organizing (inter)national greenhouse gas emissions trading. It is argued that permit allocation constitutes a barrier, because — among other things — various types of emitters have conflicting interests in trying to lobby for as much allocated permits as possible

Edwin Woerdman

2000-01-01

450

PAGE ALLOCATION TO REDUCE ACCESS TIME OF PHYSICAL CACHES  

Microsoft Academic Search

A simple modification to an operating system's page allocation algorithm can give physically addressed caches the speed of virtually addressed caches. Colored page allocation reduces the number of bits that need to be translated before cache access, allowing large low-associativity caches to be indexed before address translation, which reduces the latency to the processor. The colored allocation also has other

Brian K. Bray; William L. Lynch; M. J. Flynn

451

Cooperative water resource allocation based on equitable water rights  

Microsoft Academic Search

A comprehensive methodology is developed to achieve equitable, efficient and sustainable water allocation in a river basin. Water allocation is carried out in two steps: (1) allocation of initial water rights to water stakeholders and users based on existing water rights systems or agreements; and (2) reallocation of water and net benefits through water transfers to promote equitable cooperation of

Lizhong Wang; Liping Fang; Keith W. Hipel

2003-01-01

452

Java Memory Allocation with Lazy Worst Fit for Small Objects  

Microsoft Academic Search

Memory allocation is an important part of modern programming languages, including garbage- collected languages such as Java. We propose a fast memory allocation scheme for Java using lazy worst fit (LWF), where pointer increment is used as the primary allocation method and worst fit is used as a backup. We evaluated LWF on a working Java virtual machine with non-moving

Hyung-kyu Choi; Yoo C. Chung; Soo-mook Moon

2005-01-01

453

Active Loss Allocation Systems in Radial Distribution Systems  

Microsoft Academic Search

In the restructured power system under deregulation, proper pricing of electricity has emerged as a key issue. The cost of transmission and distribution activities needs to be allocated to the users of these networks. Among others, power losses are one of the costs to be allocated. The main difficulty faced in allocating losses is the nonlinearity between the losses and

Sivkumar Mishra; Debapriya Das; Subrata Paul

2010-01-01

454

Power and channel resource allocation in cooperative multiple access schemes  

Microsoft Academic Search

In this thesis, we develop efficient algorithms for the jointly optimal power and channel resource allocation in different wireless cooperative multiple access systems. In addition, in some cases insight into the structure of the optimal allocation enables the development of modified cooperation schemes with better performance, and efficient algorithms are developed for jointly optimal power and channel resource allocation for

Wessam Mesbah

2008-01-01

455

Optimized prophet address allocation (OPAA) for Body Area Networks  

Microsoft Academic Search

Each node in a Body Area Network (BAN) needs to be assigned with a free IP address before it may participate in any sort of communication. This paper evaluates the performance of an IP address allocation scheme, namely Prophet allocation to be used for BANs. This allocation scheme is a fully decentralized addressing scheme which is applicable to BANs as

Samaneh Movassaghi; Mehran Abolhasan; Justin Lipman

2011-01-01

456

Near efficient target allocations in response-adaptive randomization.  

PubMed

Traditionally optimal target allocation proportions for response-adaptive designs are derived by completely ignoring the actual adaptive randomization procedure. Considering efficiency of the allocation designs, we derive near efficient target proportions to balance between individual and collective ethics. Performance of the derived allocation targets are assessed numerically for binary, normal and exponential responses. Generalization for multiple treatments is also addressed. PMID:23242383

Biswas, Atanu; Bhattacharya, Rahul

2012-12-12

457

Prime DHCP: a prime numbering address allocation mechanism for MANETs  

Microsoft Academic Search

Most address allocation schemes rely on broadcast- ing for address solicitation and\\/or duplicate address detection. In this paper, we propose a Prime DHCP scheme that can allocate addresses to the hosts of a MANET without broadcasting over the whole MANET. Prime DHCP makes each host a DHCP proxy of the MANET and run a prime numbering address allocation algorithm individually

Yuan-Ying Hsu; Chien-Chao Tseng

2005-01-01

458

7 CFR 1466.5 - National allocation and management.  

Code of Federal Regulations, 2013 CFR

...Use an EQIP fund allocation formula that reflects...available natural resource and resource...information about resource concerns and program...data used in the allocation formula will be...implementation such as resource priorities, eligible...schedules, fund allocation, and program...

2013-01-01

459

Mechanism design for capacity allocation with price competition  

Microsoft Academic Search

Studies on mechanism design mostly focus on a single mar- ket where sellers and buyers trade. This paper examines the problem of mechanism design for capacity allocation in two connected markets where a supplier allocates products to a set of retailers and the retailers resale the products to end-users in price competition. We consider the problems of how allocation mechanisms

Masabumi Furuhata; Laurent Perrussel; Dongmo Zhang

2008-01-01

460

Cross-Layer Congestion Control, Routing and Scheduling Design in Ad Hoc Wireless Networks  

Microsoft Academic Search

This paper considers jointly optimal design of cross- layer congestion control, routing and scheduling for ad hoc wireless networks. We first formulate the rate constraint and scheduling constraint using multicommodity flow variables, and formulate resource allocation in networks with fixed wireless channels (or single-rate wireless devices that can mask channel variations) as a utility maximization problem with these con- straints.

Lijun Chen; Steven H. Low; Mung Chiang; John C. Doyle

2006-01-01

461

An ant colony optimization model for wireless ad-hoc network autoconfiguration  

Microsoft Academic Search

The dynamic host configuration protocol (DHCP) has been a commonly employed technique to distribute IP addresses on networks where static address allocation may not be appropriate. DHCP is normally feasible on networks that are client-server based as it needs a server for address management. Wireless ad hoc networks on the other hand do not have a central entity that would

Vignesh Kumar; Eric Cole

2005-01-01

462

Joint congestion control and media access control design for ad hoc wireless networks  

Microsoft Academic Search

Abstmct-We present a model for the joint design of con- gestion control and media access control (MAC) for ad hoc wireless networks. Using contention graph and contention ma- trix, we formulate resource allocation in the network as a utility maximization problem with constraints that arise from contention for channel access. We present two algorithms that are not only distributed spatially,

Lijun Chen; Steven H. Low; John C. Doyle

2005-01-01

463

A New Distributed CDS Algorithm of Ad Hoc Network Based on Weight  

Microsoft Academic Search

Connected dominating set (CDS) algorithm based on a virtual backbone technology has an important role for wireless ad hoc network, route optimization, energy conservation and allocation of resources. In this paper, on the base of several classic distributed CDS approximation algorithm and connected dominating set, a new distributed CDS algorithm based on weight is presented, the correctness and efficiency of

Dao-Quan Li; Wei-Hua Xue; Huai-Cai Wang; Qi-Guang Cau

2010-01-01

464

On the Accuracy of Stochastic Complexity Approximations  

Microsoft Academic Search

Stochastic complexity of a data set is defined as the shortest possible code lengthfor the data obtainable by using some fixed set of models. This measure is of greattheoretical and practical importance as a tool for tasks such as determining modelcomplexity, or performing predictive inference. Unfortunately for cases where thedata has missing information, computing the stochastic complexity requires marginalizing(integrating) over

Henry Tirri; Petri Kontkanen; Petri Myllymaki; Tomi Sil

1997-01-01

465

The accuracy of stochastic complexity approximations  

Microsoft Academic Search

Abstract: Stochastic complexity of a data set is defined as the shortest possible codelength for the data obtainable by using some fixed set of models. This measureis of great theoretical and practical importance as a tool for tasks suchas determining model complexity, or performing predictive inference. Unfortunately,for cases where the data has missing information, computingthe stochastic complexity requires marginalizing (integrating)

P. Kontkanen; P. Myllymaki; T. Silander; H. Tirri

1999-01-01

466

Hitting Time Analysis for Stochastic Communication  

NASA Astrophysics Data System (ADS)

This paper investigates the benefits of a recently proposed communication approach, namely on-chip stochastic communication, and proposes an analytical model for computing its mean hitting time. Towards this end, we model the stochastic communication as a branching process taking place on a finite mesh and estimate the mean number of communication rounds.

Bogdan, Paul; Marculescu, Radu

467

Stochastic noise approach to traffic flow modeling  

Microsoft Academic Search

Traffic flow states are described as resulting from a stochastically driven system. Vehicles advance based on the energy profile of their surrounding traffic.We create a stochastic process generated from an ergodicity satisfying Markov chain whose system dynamics sample from the Gibbs distribution. Specifically, we employ Arrhenius microscopic dynamics in order to also capture non-equilibrium behavior and monitor the states favored

Alexandros Sopasakis

2004-01-01

468

Towards a spatial stochastic process algebra  

Microsoft Academic Search

This paper introduces spatial notions to the stochastic process algebra PEPA. This is motivated by both computer networks and epidemiology where location of actions or processes with respect to other parts of a system may aect the time taken by an event. A very general stochastic process algebra with locations is defined. Locations are introduced to both actions and processes,

Vashti Galpin

469

Seasonal long-memory stochastic volatility  

NASA Astrophysics Data System (ADS)

In this paper, we propose an alternative approach to estimation of seasonal long-memory stochastic volatility based on the generalized long-memory stochastic volatility (GLMSV) model. We show that the estimator is consistent. We investigate the small sample performance of the estimator by simulation. An application to actual data is also presented.

Gonzaga, Alex C.

2013-10-01

470

A stochastic DEA study of hotel efficiency  

Microsoft Academic Search

This current study is the first to apply Stochastic Data Envelopment Analysis (SDEA) approach to assess the efficiency of hotels. The determinants of hotel efficiency were also investigated employing the Tobit regression model approach. The SDEA results show that the SDEA efficiency measures are higher than the deterministic ones and the greater the stochastic variability of outputs, the closer the

Jui-Kou Shang; Fei-Ching Wang; Wei-Ting Hung

2010-01-01

471

Stochastic perturbative derivation of the axial anomaly  

NASA Astrophysics Data System (ADS)

The axial anomaly is calculated as the infinite Langevin time limit of stochastic triangle diagrams. Their regularization is insured with the help of an analytic stochastic regulator. The usual axial anomaly is recovered only when the Langevin equations used to generate the perturbative expansion are gauge covariant.

Ader, J. P.; Wallet, J. C.

1986-12-01

472

Models and Priors for Multivariate Stochastic Volatility  

Microsoft Academic Search

Discrete time stochastic volatility models (hereafter SVOL) are noticeably harder to estimate than the successful ARCH family of models. In this paper, we develop methods for finite sample inference, smoothing, and prediction for a number of univariate and multivariate SVOL models. Specifically, we model fat-tailed and skewed conditional distributions, correlated errors distributions (leverage effect), and two multivariate models, a stochastic

Éric Jacquier; Nicholas G. Polson; Peter E. Rossi

1995-01-01

473

Tree Approximations of Dynamic Stochastic Programs  

Microsoft Academic Search

We consider a tree-based discretization technique utilizing conditional transporta- tion distance, which is well suited for the approximation of multi-stage stochastic programming problems, and investigate corresponding convergence properties. We explain the relation between the approximation quality of the probability model and the quality of the solution. 1. Introduction. Dynamic stochastic optimization models are an up to date tool of modern

Radoslava Mirkov; Georg Ch. Pflug

2007-01-01

474

The Stochastic Dynamics of Speculative Prices  

Microsoft Academic Search

Within the framework of the heterogeneous agent paradigm, we establish a stochastic model of speculative price dynamics involving of two types of agents, fundamentalists and chartists, and the market price equilibria of which can be characterised by the invariant measures of a random dynamical system. By conducting a stochastic bifurcation analysis, we examine the market impact of speculative behaviour. We

Carl Chiarella; Xue-Zhong He; Min Zheng

2007-01-01

475

A stochastic approach to traffic congestion costs  

Microsoft Academic Search

The real world is a complex dynamic and stochastic environment. This is especially true for the traffic moving daily on our roads. As such, accurate modeling that correctly considers the real-world dynamics and the inher- ent stochasticity is very important, especially if government will base its road tax decisions on the outcomes of these models. The contemporary traffic prices, if

Tom Van Woensel; Frederico R. B. Cruz

2009-01-01

476

Media Scheduling: A Stochastic Dynamic Model Approach  

Microsoft Academic Search

A stochastic model is developed with application to both the study of consumer behavior and the scheduling of advertising media. This model incorporates a stochastic response behavior model which examines changes in brand purchase probability over time through the integration of consumer advertising exposure response, purchase incidence behavior and purchase-event feedback constructs. The response behavior model provides the basis for

Fred S. Zufryden

1973-01-01

477

Effective Bayesian Inference for Stochastic Programs  

Microsoft Academic Search

In this paper, we propose a stochastic version of a general pur- pose functional programming language as a method of mod- eling stochastic processes. The language contains random choices, conditional statements, structured values, defined functions, and recursion. By imagining an experiment in which the program is \\

Daphne Koller; David A. Mcallester; Avi Pfeffer

1997-01-01

478

Applications to Stochastic Ordinary Differential Equations  

Microsoft Academic Search

As mentioned in the introduction, the framework that we developed in Chapter 2 for the main purpose of solving stochastic\\u000a partial differential equations, can also be used to obtain new results – as well as new proofs of old results – for stochastic\\u000a ordinary differential equations. In this chapter we will illustrate this by discussing some important examples.

Helge Holden; Bernt Øksendal; Jan Ubøe; Tusheng Zhang

479

Stochastic resonance in a bistable geodynamo model  

Microsoft Academic Search

Recently a signal with a period of 100 kyr in the distribution of residence times between reversals of the geomagnetic field has been suggested as signature of stochastic resonance. Here we test this suggestion by applying periodic modulations to a model of the geodynamo as a bistable oscillator, where stochastic fluctuations of the induction effect (multiplicative noise) lead to random

S. Lorito; D. Schmitt; G. Consolini; P. De Michelis

2005-01-01

480

Sensitivity Analysis of Discrete Stochastic Systems  

Microsoft Academic Search

Sensitivity analysis quantifies the dependence of system behavior on the parameters that affect the process dynamics. Classical sensitivity analysis, however, does not directly apply to discrete stochastic dynamical systems, which have recently gained popularity because of its relevance in the simulation of biological processes. In this work, sensitivity analysis for discrete stochastic processes is developed based on density function (distribution)

Rudiyanto Gunawan; Yang Cao; Linda Petzold; Francis J. Doyle III

2005-01-01

481

From Complex to Simple: Interdisciplinary Stochastic Models  

ERIC Educational Resources Information Center

|We present two simple, one-dimensional, stochastic models that lead to a qualitative understanding of very complex systems from biology, nanoscience and social sciences. The first model explains the complicated dynamics of microtubules, stochastic cellular highways. Using the theory of random walks in one dimension, we find analytical expressions…

Mazilu, D. A.; Zamora, G.; Mazilu, I.

2012-01-01

482

Classification of Binary Vectors by Stochastic Complexity.  

National Technical Information Service (NTIS)

Stochastic complexity is treated as a tool of classification i.e. of inferring both the number of classes, the class descriptions and the class memberships for a given data set of binary vectors. The stochastic complexity is evaluated with respect to the ...

M. Gyllenberg T. Koski M. Verlaan

1996-01-01

483

Deterministic and stochastic bifurcations in the Hindmarsh-Rose neuronal model.  

PubMed

We analyze the bifurcations occurring in the 3D Hindmarsh-Rose neuronal model with and without random signal. When under a sufficient stimulus, the neuron activity takes place; we observe various types of bifurcations that lead to chaotic transitions. Beside the equilibrium solutions and their stability, we also investigate the deterministic bifurcation. It appears that the neuronal activity consists of chaotic transitions between two periodic phases called bursting and spiking solutions. The stochastic bifurcation, defined as a sudden change in character of a stochastic attractor when the bifurcation parameter of the system passes through a critical value, or under certain condition as the collision of a stochastic attractor with a stochastic saddle, occurs when a random Gaussian signal is added. Our study reveals two kinds of stochastic bifurcation: the phenomenological bifurcation (P-bifurcations) and the dynamical bifurcation (D-bifurcations). The asymptotical method is used to analyze phenomenological bifurcation. We find that the neuronal activity of spiking and bursting chaos remains for finite values of the noise intensity. PMID:24089961

Dtchetgnia Djeundam, S R; Yamapi, R; Kofane, T C; Aziz-Alaoui, M A

2013-09-01

484

Deterministic and stochastic bifurcations in the Hindmarsh-Rose neuronal model  

NASA Astrophysics Data System (ADS)

We analyze the bifurcations occurring in the 3D Hindmarsh-Rose neuronal model with and without random signal. When under a sufficient stimulus, the neuron activity takes place; we observe various types of bifurcations that lead to chaotic transitions. Beside the equilibrium solutions and their stability, we also investigate the deterministic bifurcation. It appears that the neuronal activity consists of chaotic transitions between two periodic phases called bursting and spiking solutions. The stochastic bifurcation, defined as a sudden change in character of a stochastic attractor when the bifurcation parameter of the system passes through a critical value, or under certain condition as the collision of a stochastic attractor with a stochastic saddle, occurs when a random Gaussian signal is added. Our study reveals two kinds of stochastic bifurcation: the phenomenological bifurcation (P-bifurcations) and the dynamical bifurcation (D-bifurcations). The asymptotical method is used to analyze phenomenological bifurcation. We find that the neuronal activity of spiking and bursting chaos remains for finite values of the noise intensity.

Dtchetgnia Djeundam, S. R.; Yamapi, R.; Kofane, T. C.; Aziz-Alaoui, M. A.

2013-09-01

485

Cost Allocation in Water Resources Development  

NASA Astrophysics Data System (ADS)

Different methods for allocating the joint costs of water supply projects among users are compared on the basis of certain commonsense principles of equity. We contrast the separable costs-remaining benefits (SCRB) method with simple proportional allocation schemes and more sophisticated methods from cooperative game theory, including the Shapley value and variants of the core. Advantages and disadvantages of the methods in practice are examined using a regional water supply system in Sweden. It is argued that these principles provide a useful framework for choosing intelligently among methods. The appropriateness of a method depends on the context, especially on the reliability of information about costs and demands. The conclusion is that there is no one best method, although from a normative standpoint the SCRB method may be one of the worst.

Young, H. P.; Okada, N.; Hashimoto, T.

1982-06-01

486

Traffic resource allocation for complex networks  

NASA Astrophysics Data System (ADS)

In this paper, an optimal resource allocation strategy is proposed to enhance traffic dynamics in complex networks. The network resources are the total node packet-delivering capacity and the total link bandwidth. An analytical method is developed to estimate the overall network capacity by using the concept of efficient betweenness (ratio of algorithmic betweenness and local processing capacity). Three network structures (scale-free, small-world, and random networks) and two typical routing protocols (shortest path protocol and efficient routing protocol) are adopted to demonstrate the performance of the proposed strategy. Our results show that the network capacity is reversely proportional to the average path length for a particular routing protocol and the shortest path protocol can achieve the largest network capacity when the proposed resource allocation strategy is adopted.

Ling, Xiang; Hu, Mao-Bin; Long, Jian-Cheng; Ding, Jian-Xun; Shi, Qin

2013-01-01

487

The optimal allocation of conservation funds  

SciTech Connect

This paper presents a framework to evaluate alternative designs of conservation programs and their implications for the allocation of conservation funds. The authors show that the efficient allocation of conservation funds must consider two important pooling effects--cumulative effects and interrelationships among alternative environmental benefits. Ignoring the cumulative effects of environmental benefits may cause conservation funds to be overly dispersed geographically and, as a result, may result in minimum environmental benefits when the budget is small. Ignoring the interrelationships among alternative environmental benefits may result in not only misallocation of conservation funds among geographical areas, but also incorrect resources being targeted for conservation practices. Implications of these results for the design of conservation programs are discussed.

Wu, J.J.; Boggess, W.G.

1999-11-01

488

Dynamic bandwidth allocation in a TDMA system  

NASA Astrophysics Data System (ADS)

The operating characteristics of a satellite communications controller (SCC) designed for a corporate TDMA/geosynchronous-satellite system are summarized. Each earth station in the system comprises an RF terminal, a burst modem, a port adaptor system, and an SCC. The station SCC provides signal conversion, traffic switching, data multiplexing, and TDMA control and transmits its bandwidth requirement to a reference SCC via the satellite; the reference SCC allocates the bandwidths to all the station SCCs. The TDMA structure and time unit (a 15-ms frame), voice-channel requirements, and the network channel-allocation algorithm are described and illustrated with block diagrams. Additional channels can be made available from a transponder pool for unusual demand requirements, such as 1.5 Mbit/sec for a video conference. A computer simulation of the system (Goode, 1978) has demonstrated that it can provide excellent flexibility in voice and high-speed-digital communications to network customers.

Fennel, J.

489

Energy Uptake and Allocation during Ontogeny  

PubMed Central

All organisms face the problem of how to fuel ontogenetic growth. We present a model, empirically grounded on data from birds and mammals, that correctly predicts how growing animals allocate food energy between synthesis of new biomass and maintenance of existing biomass. Previous energy budget models have typically been based on rates of either food consumption or metabolic energy expenditure. Our model provides a framework that reconciles these two approaches and highlights the fundamental principles that determine rates of food assimilation and rates of energy allocation to maintenance, biosynthesis, activity, and storage. The model predicts that growth and assimilation rates for all animals should cluster closely around two universal curves. Data for mammals and birds of diverse body sizes and taxa support these predictions.

Hou, Chen; Zuo, Wenyun; Moses, Melanie E.; Woodruff, William H.; Brown, James H.; West, Geoffrey B.

2010-01-01

490

RHIC stochastic cooling motion control  

SciTech Connect

Relativistic Heavy Ion Collider (RHIC) beams are subject to Intra-Beam Scattering (IBS) that causes an emittance growth in all three-phase space planes. The only way to increase integrated luminosity is to counteract IBS with cooling during RHIC stores. A stochastic cooling system for this purpose has been developed, it includes moveable pick-ups and kickers in the collider that require precise motion control mechanics, drives and controllers. Since these moving parts can limit the beam path aperture, accuracy and reliability is important. Servo, stepper, and DC motors are used to provide actuation solutions for position control. The choice of motion stage, drive motor type, and controls are based on needs defined by the variety of mechanical specifications, the unique performance requirements, and the special needs required for remote operations in an accelerator environment. In this report we will describe the remote motion control related beam line hardware, position transducers, rack electronics, and software developed for the RHIC stochastic cooling pick-ups and kickers.

Gassner, D.; DeSanto, L.; Olsen, R.H.; Fu, W.; Brennan, J.M.; Liaw, CJ; Bellavia, S.; Brodowski, J.

2011-03-28

491

Extinction of metastable stochastic populations  

NASA Astrophysics Data System (ADS)

We investigate the phenomenon of extinction of a long-lived self-regulating stochastic population, caused by intrinsic (demographic) noise. Extinction typically occurs via one of two scenarios depending on whether the absorbing state n=0 is a repelling (scenario A) or attracting (scenario B) point of the deterministic rate equation. In scenario A the metastable stochastic population resides in the vicinity of an attracting fixed point next to the repelling point n=0 . In scenario B there is an intermediate repelling point n=n1 between the attracting point n=0 and another attracting point n=n2 in the vicinity of which the metastable population resides. The crux of the theory is a dissipative variant of WKB (Wentzel-Kramers-Brillouin) approximation which assumes that the typical population size in the metastable state is large. Starting from the master equation, we calculate the quasistationary probability distribution of the population sizes and the (exponentially long) mean time to extinction for each of the two scenarios. When necessary, the WKB approximation is complemented (i) by a recursive solution of the quasistationary master equation at small n and (ii) by the van Kampen system-size expansion, valid near the fixed points of the deterministic rate equation. The theory yields both entropic barriers to extinction and pre-exponential factors, and holds for a general set of multistep processes when detailed balance is broken. The results simplify considerably for single-step processes and near the characteristic bifurcations of scenarios A and B.

Assaf, Michael; Meerson, Baruch

2010-02-01

492

Stochastic resonant memory storage device.  

PubMed

We show that an extended system operating in the regime of stochastic resonance can act as a short-term memory device. The system under study is a ring of overdamped bistable oscillators coupled directionally, being each also subject to an external source of Gaussian white noise (the noise sources are independent). A single oscillator is driven by an external periodic force, assumed to act only over the time that the signal takes to traverse the whole ring. A traveling wave is then found to be transmitted several times along the ring with a small damping, provided that the driven oscillator operates in a regime close to stochastic resonance. If noise is suppressed from any oscillator of the chain, the traveling wave is immediately damped. The ring is thus found to act as a short-term memory device in which the stored information (one bit, corresponding to the presence or absence of the external driving) is sustained by noise during a characteristic time T(mem). PMID:11580313

Carusela, M F; Perazzo, R P; Romanelli, L

2001-08-06

493

Biased Allocation of Faces to Social Categories  

Microsoft Academic Search

Three studies show that social categorization is biased at the level of category allocation. In all studies, participants categorized faces. In Studies 1 and 2, participants overallocated faces with criminal features—a stereotypical negative trait—to the stigmatized Moroccan category, especially if they were prejudiced. On the contrary, the stereotype-irrelevant negative trait stupid did not lead to overallocation to the Moroccan category.

Ron Dotsch; Daniël H. J. Wigboldus; Ad van Knippenberg

2011-01-01

494

Railway track allocation: models and methods  

Microsoft Academic Search

Efficiently coordinating the movement of trains on a railway network is a central part of the planning process for a railway\\u000a company. This paper reviews models and methods that have been proposed in the literature to assist planners in finding train\\u000a routes. Since the problem of routing trains on a railway network entails allocating the track capacity of the network

Richard M. Lusby; Jesper Larsen; Matthias Ehrgott; David Ryan

495

Cooperative games and cost allocation problems  

Microsoft Academic Search

The objective of this paper is to provide a general view of the literature of applications of transferable utility cooperative\\u000a games to cost allocation problems. This literature is so large that we concentrate on some relevant contributions in three\\u000a specific areas: transportation, natural resources and power industry. We stress those applications dealing with costs and\\u000a with problems arisen outside the

M. Gloria Fiestras-Janeiro; Ignacio García-Jurado; Manuel A. Mosquera

2011-01-01

496

Robust resource allocations in temporal networks  

Microsoft Academic Search

Temporal networks describe workflows of time-consuming tasks whose processing order is constrained by precedence relations.\\u000a In many cases, the durations of the network tasks can be influenced by the assignment of resources. This leads to the problem\\u000a of selecting an ‘optimal’ resource allocation, where optimality is measured by network characteristics such as the makespan\\u000a (i.e., the time required to complete

Wolfram Wiesemann; Daniel Kuhn; Berç Rustem

2009-01-01

497

MAAP: the military aircraft allocation planner  

Microsoft Academic Search

The authors present an application of genetic algorithms to the field of large-scale allocation problems in which a collection of resources (assets) must be mapped in an optimal or near-optimal manner to a number of objectives (targets), as measured by an objective function. Such problems are complex due to their requirements for integer solutions, non-linear objective functions and linear asset

P. Abrahams; R. Balart; J. S. Byrnes; D. Cochran; M. J. Larkin; W. Moran; G. Ostheimer; A. Pollington

1998-01-01

498

Multiuser Rate Allocation Games for Multimedia Communications  

Microsoft Academic Search

How to efficiently and fairly allocate data rate among different users is a key problem in the field of multiuser multimedia communication. However, most of the existing optimization-based methods, such as minimizing the weighted sum of the distortions or maximizing the weighted sum of the peak signal-to-noise ratios (PSNRs), have their weights heuristically determined. Moreover, those approaches mainly focus on

Yan Chen; Beibei Wang; K. J. Ray Liu

2009-01-01

499

Resource Allocation in Federated Distributed Computing Infrastructures  

Microsoft Academic Search

Abstract: IntroductionWe consider the problem of allocating combinationsof heterogeneous, distributed resources among selfinterestedparties. In particular, we consider thisproblem in the context of distributed computing infrastructures,where resources are shared among usersfrom di#erent administrative domains. Examples ofsuch infrastructures include PlanetLab [15] and computationalgrids [7].End-users derive utility from receiving a share ofresources. When there is an excess demand for...

Alvin AuYoung; Brent N. Chun; Alex C. Snoeren; Amin Vahdat

2004-01-01

500

Allocating audit resources to detect fraud  

Microsoft Academic Search

This paper addresses how to allocate audit resources across different auditable units when misstatements may occur in any\\u000a or all of the units. We consider two benchmark scenarios. In the first, the extent of overstatement affects only the cost\\u000a of detection, but not the effectiveness of audit inputs in determining the likelihood of detection. In the second, overstatement\\u000a directly affects

Paul Newman; Shelley Rhoades; Reed Smith

1996-01-01