WorldWideScience

Sample records for presburger reachability multiprocess

  1. A practical approach to model checking Duration Calculus using Presburger Arithmetic

    DEFF Research Database (Denmark)

    Hansen, Michael Reichhardt; Dung, Phan Anh; Brekling, Aske Wiid

    2014-01-01

    This paper investigates the feasibility of reducing a model-checking problem K ⊧ ϕ for discrete time Duration Calculus to the decision problem for Presburger Arithmetic. Theoretical results point at severe limitations of this approach: (1) the reduction in Fränzle and Hansen (Int J Softw Inform 3...... limits of the approach are illustrated by a family of examples....

  2. Reachable volume RRT

    KAUST Repository

    McMahon, Troy

    2015-05-01

    © 2015 IEEE. Reachable volumes are a new technique that allows one to efficiently restrict sampling to feasible/reachable regions of the planning space even for high degree of freedom and highly constrained problems. However, they have so far only been applied to graph-based sampling-based planners. In this paper we develop the methodology to apply reachable volumes to tree-based planners such as Rapidly-Exploring Random Trees (RRTs). In particular, we propose a reachable volume RRT called RVRRT that can solve high degree of freedom problems and problems with constraints. To do so, we develop a reachable volume stepping function, a reachable volume expand function, and a distance metric based on these operations. We also present a reachable volume local planner to ensure that local paths satisfy constraints for methods such as PRMs. We show experimentally that RVRRTs can solve constrained problems with as many as 64 degrees of freedom and unconstrained problems with as many as 134 degrees of freedom. RVRRTs can solve problems more efficiently than existing methods, requiring fewer nodes and collision detection calls. We also show that it is capable of solving difficult problems that existing methods cannot.

  3. Reachable volume RRT

    KAUST Repository

    McMahon, Troy; Thomas, Shawna; Amato, Nancy M.

    2015-01-01

    © 2015 IEEE. Reachable volumes are a new technique that allows one to efficiently restrict sampling to feasible/reachable regions of the planning space even for high degree of freedom and highly constrained problems. However, they have so far only been applied to graph-based sampling-based planners. In this paper we develop the methodology to apply reachable volumes to tree-based planners such as Rapidly-Exploring Random Trees (RRTs). In particular, we propose a reachable volume RRT called RVRRT that can solve high degree of freedom problems and problems with constraints. To do so, we develop a reachable volume stepping function, a reachable volume expand function, and a distance metric based on these operations. We also present a reachable volume local planner to ensure that local paths satisfy constraints for methods such as PRMs. We show experimentally that RVRRTs can solve constrained problems with as many as 64 degrees of freedom and unconstrained problems with as many as 134 degrees of freedom. RVRRTs can solve problems more efficiently than existing methods, requiring fewer nodes and collision detection calls. We also show that it is capable of solving difficult problems that existing methods cannot.

  4. Extending ALCQIO with reachability

    OpenAIRE

    Kotek, Tomer; Simkus, Mantas; Veith, Helmut; Zuleger, Florian

    2014-01-01

    We introduce a description logic ALCQIO_{b,Re} which adds reachability assertions to ALCQIO, a sub-logic of the two-variable fragment of first order logic with counting quantifiers. ALCQIO_{b,Re} is well-suited for applications in software verification and shape analysis. Shape analysis requires expressive logics which can express reachability and have good computational properties. We show that ALCQIO_{b,Re} can describe complex data structures with a high degree of sharing and allows compos...

  5. Constraint-based reachability

    Directory of Open Access Journals (Sweden)

    Arnaud Gotlieb

    2013-02-01

    Full Text Available Iterative imperative programs can be considered as infinite-state systems computing over possibly unbounded domains. Studying reachability in these systems is challenging as it requires to deal with an infinite number of states with standard backward or forward exploration strategies. An approach that we call Constraint-based reachability, is proposed to address reachability problems by exploring program states using a constraint model of the whole program. The keypoint of the approach is to interpret imperative constructions such as conditionals, loops, array and memory manipulations with the fundamental notion of constraint over a computational domain. By combining constraint filtering and abstraction techniques, Constraint-based reachability is able to solve reachability problems which are usually outside the scope of backward or forward exploration strategies. This paper proposes an interpretation of classical filtering consistencies used in Constraint Programming as abstract domain computations, and shows how this approach can be used to produce a constraint solver that efficiently generates solutions for reachability problems that are unsolvable by other approaches.

  6. Planning with Reachable Distances

    KAUST Repository

    Tang, Xinyu; Thomas, Shawna; Amato, Nancy M.

    2009-01-01

    reachable distance space (RD-space), in which all configurations lie in the set of constraint-satisfying subspaces. This enables us to directly sample the constrained subspaces with complexity linear in the robot's number of degrees of freedom. In addition

  7. Bidirectional reachability-based modules

    CSIR Research Space (South Africa)

    Nortje, R

    2011-07-01

    Full Text Available The authors introduce an algorithm for MinA extraction in EL based on bidirectional reachability. They obtain a significant reduction in the size of modules extracted at almost no additional cost to that of extracting standard reachability...

  8. An approach to multicore parallelism using functional programming: A case study based on Presburger Arithmetic

    DEFF Research Database (Denmark)

    Dung, Phan Anh; Hansen, Michael Reichhardt

    2015-01-01

    In this paper we investigate multicore parallelism in the context of functional programming by means of two quantifier-elimination procedures for Presburger Arithmetic: one is based on Cooper’s algorithm and the other is based on the Omega Test. We first develop correct-by-construction prototype...... platform executing on an 8-core machine. A speedup of approximately 4 was obtained for Cooper’s algorithm and a speedup of approximately 6 was obtained for the exact-shadow part of the Omega Test. The considered procedures are complex, memory-intense algorithms on huge formula trees and the case study...... reveals more general applicable techniques and guideline for deriving parallel algorithms from sequential ones in the context of data-intensive tree algorithms. The obtained insights should apply for any strict and impure functional programming language. Furthermore, the results obtained for the exact...

  9. Planning with Reachable Distances

    KAUST Repository

    Tang, Xinyu

    2009-01-01

    Motion planning for spatially constrained robots is difficult due to additional constraints placed on the robot, such as closure constraints for closed chains or requirements on end effector placement for articulated linkages. It is usually computationally too expensive to apply sampling-based planners to these problems since it is difficult to generate valid configurations. We overcome this challenge by redefining the robot\\'s degrees of freedom and constraints into a new set of parameters, called reachable distance space (RD-space), in which all configurations lie in the set of constraint-satisfying subspaces. This enables us to directly sample the constrained subspaces with complexity linear in the robot\\'s number of degrees of freedom. In addition to supporting efficient sampling, we show that the RD-space formulation naturally supports planning, and in particular, we design a local planner suitable for use by sampling-based planners. We demonstrate the effectiveness and efficiency of our approach for several systems including closed chain planning with multiple loops, restricted end effector sampling, and on-line planning for drawing/sculpting. We can sample single-loop closed chain systems with 1000 links in time comparable to open chain sampling, and we can generate samples for 1000-link multi-loop systems of varying topology in less than a second. © 2009 Springer-Verlag.

  10. Single wafer rapid thermal multiprocessing

    International Nuclear Information System (INIS)

    Saraswat, K.C.; Moslehi, M.M.; Grossman, D.D.; Wood, S.; Wright, P.; Booth, L.

    1989-01-01

    Future success in microelectronics will demand rapid innovation, rapid product introduction and ability to react to a change in technological and business climate quickly. These technological advances in integrated electronics will require development of flexible manufacturing technology for VLSI systems. However, the current approach of establishing factories for mass manufacturing of chips at a cost of more than 200 million dollars is detrimental to flexible manufacturing. The authors propose concepts of a micro factory which may be characterized by more economical small scale production, higher flexibility to accommodate many products on several processes, and faster turnaround and learning. In-situ multiprocessing equipment where several process steps can be done in sequence may be a key ingredient in this approach. For this environment to be flexible, the equipment must have ability to change processing environment, requiring extensive in-situ measurements and real time control. This paper describes the development of a novel single wafer rapid thermal multiprocessing (RTM) reactor for next generation flexible VLSI manufacturing. This reactor will combine lamp heating, remote microwave plasma and photo processing in a single cold-wall chamber, with applications for multilayer in-situ growth and deposition of dielectrics, semiconductors and metals

  11. Stochastic Reachability Analysis of Hybrid Systems

    CERN Document Server

    Bujorianu, Luminita Manuela

    2012-01-01

    Stochastic reachability analysis (SRA) is a method of analyzing the behavior of control systems which mix discrete and continuous dynamics. For probabilistic discrete systems it has been shown to be a practical verification method but for stochastic hybrid systems it can be rather more. As a verification technique SRA can assess the safety and performance of, for example, autonomous systems, robot and aircraft path planning and multi-agent coordination but it can also be used for the adaptive control of such systems. Stochastic Reachability Analysis of Hybrid Systems is a self-contained and accessible introduction to this novel topic in the analysis and development of stochastic hybrid systems. Beginning with the relevant aspects of Markov models and introducing stochastic hybrid systems, the book then moves on to coverage of reachability analysis for stochastic hybrid systems. Following this build up, the core of the text first formally defines the concept of reachability in the stochastic framework and then...

  12. Reachability modules for the description logic SRIQ

    CSIR Research Space (South Africa)

    Nortje, R

    2013-12-01

    Full Text Available In this paper we investigate module extraction for the Description Logic SRIQ. We formulate modules in terms of the reachability problem for directed hypergraphs. Using inseperability relations, we investigate the module-theoretic properties...

  13. Distributed Algorithms for Time Optimal Reachability Analysis

    DEFF Research Database (Denmark)

    Zhang, Zhengkui; Nielsen, Brian; Larsen, Kim Guldstrand

    2016-01-01

    . We propose distributed computing to accelerate time optimal reachability analysis. We develop five distributed state exploration algorithms, implement them in \\uppaal enabling it to exploit the compute resources of a dedicated model-checking cluster. We experimentally evaluate the implemented...... algorithms with four models in terms of their ability to compute near- or proven-optimal solutions, their scalability, time and memory consumption and communication overhead. Our results show that distributed algorithms work much faster than sequential algorithms and have good speedup in general.......Time optimal reachability analysis is a novel model based technique for solving scheduling and planning problems. After modeling them as reachability problems using timed automata, a real-time model checker can compute the fastest trace to the goal states which constitutes a time optimal schedule...

  14. Reachability problems in scheduling and planning

    NARCIS (Netherlands)

    Eggermont, C.E.J.

    2012-01-01

    Reachability problems are fundamental in the context of many mathematical models and abstractions which describe various computational processes. Intuitively, when many objects move within a shared environment, objects may have to wait for others before moving and so slow down, or objects may even

  15. Deducing the reachable space from fingertip positions.

    Science.gov (United States)

    Hai-Trieu Pham; Pathirana, Pubudu N

    2015-01-01

    The reachable space of the hand has received significant interests in the past from relevant medical researchers and health professionals. The reachable space was often computed from the joint angles acquired from a motion capture system such as gloves or markers attached to each bone of the finger. However, the contact between the hand and device can cause difficulties particularly for hand with injuries, burns or experiencing certain dermatological conditions. This paper introduces an approach to find the reachable space of the hand in a non-contact measurement form utilizing the Leap Motion Controller. The approach is based on the analysis of each position in the motion path of the fingertip acquired by the Leap Motion Controller. For each position of the fingertip, the inverse kinematic problem was solved under the physiological multiple constraints of the human hand to find a set of all possible configurations of three finger joints. Subsequently, all the sets are unified to form a set of all possible configurations specific for that motion. Finally, a reachable space is computed from the configuration corresponding to the complete extension and the complete flexion of the finger joint angles in this set.

  16. Reachability for Finite-State Process Algebras Using Static Analysis

    DEFF Research Database (Denmark)

    Skrypnyuk, Nataliya; Nielson, Flemming

    2011-01-01

    of the Data Flow Analysis are used in order to “cut off” some of the branches in the reachability analysis that are not important for determining, whether or not a state is reachable. In this way, it is possible for our reachability algorithm to avoid building large parts of the system altogether and still......In this work we present an algorithm for solving the reachability problem in finite systems that are modelled with process algebras. Our method uses Static Analysis, in particular, Data Flow Analysis, of the syntax of a process algebraic system with multi-way synchronisation. The results...... solve the reachability problem in a precise way....

  17. Improvement of multiprocessing performance by using optical centralized shared bus

    Science.gov (United States)

    Han, Xuliang; Chen, Ray T.

    2004-06-01

    With the ever-increasing need to solve larger and more complex problems, multiprocessing is attracting more and more research efforts. One of the challenges facing the multiprocessor designers is to fulfill in an effective manner the communications among the processes running in parallel on multiple multiprocessors. The conventional electrical backplane bus provides narrow bandwidth as restricted by the physical limitations of electrical interconnects. In the electrical domain, in order to operate at high frequency, the backplane topology has been changed from the simple shared bus to the complicated switched medium. However, the switched medium is an indirect network. It cannot support multicast/broadcast as effectively as the shared bus. Besides the additional latency of going through the intermediate switching nodes, signal routing introduces substantial delay and considerable system complexity. Alternatively, optics has been well known for its interconnect capability. Therefore, it has become imperative to investigate how to improve multiprocessing performance by utilizing optical interconnects. From the implementation standpoint, the existing optical technologies still cannot fulfill the intelligent functions that a switch fabric should provide as effectively as their electronic counterparts. Thus, an innovative optical technology that can provide sufficient bandwidth capacity, while at the same time, retaining the essential merits of the shared bus topology, is highly desirable for the multiprocessing performance improvement. In this paper, the optical centralized shared bus is proposed for use in the multiprocessing systems. This novel optical interconnect architecture not only utilizes the beneficial characteristics of optics, but also retains the desirable properties of the shared bus topology. Meanwhile, from the architecture standpoint, it fits well in the centralized shared-memory multiprocessing scheme. Therefore, a smooth migration with substantial

  18. Time Optimal Reachability Analysis Using Swarm Verification

    DEFF Research Database (Denmark)

    Zhang, Zhengkui; Nielsen, Brian; Larsen, Kim Guldstrand

    2016-01-01

    Time optimal reachability analysis employs model-checking to compute goal states that can be reached from an initial state with a minimal accumulated time duration. The model-checker may produce a corresponding diagnostic trace which can be interpreted as a feasible schedule for many scheduling...... and planning problems, response time optimization etc. We propose swarm verification to accelerate time optimal reachability using the real-time model-checker Uppaal. In swarm verification, a large number of model checker instances execute in parallel on a computer cluster using different, typically randomized...... search strategies. We develop four swarm algorithms and evaluate them with four models in terms scalability, and time- and memory consumption. Three of these cooperate by exchanging costs of intermediate solutions to prune the search using a branch-and-bound approach. Our results show that swarm...

  19. Sampling-based motion planning with reachable volumes: Theoretical foundations

    KAUST Repository

    McMahon, Troy

    2014-05-01

    © 2014 IEEE. We introduce a new concept, reachable volumes, that denotes the set of points that the end effector of a chain or linkage can reach. We show that the reachable volume of a chain is equivalent to the Minkowski sum of the reachable volumes of its links, and give an efficient method for computing reachable volumes. We present a method for generating configurations using reachable volumes that is applicable to various types of robots including open and closed chain robots, tree-like robots, and complex robots including both loops and branches. We also describe how to apply constraints (both on end effectors and internal joints) using reachable volumes. Unlike previous methods, reachable volumes work for spherical and prismatic joints as well as planar joints. Visualizations of reachable volumes can allow an operator to see what positions the robot can reach and can guide robot design. We present visualizations of reachable volumes for representative robots including closed chains and graspers as well as for examples with joint and end effector constraints.

  20. Sampling-based motion planning with reachable volumes: Theoretical foundations

    KAUST Repository

    McMahon, Troy; Thomas, Shawna; Amato, Nancy M.

    2014-01-01

    © 2014 IEEE. We introduce a new concept, reachable volumes, that denotes the set of points that the end effector of a chain or linkage can reach. We show that the reachable volume of a chain is equivalent to the Minkowski sum of the reachable volumes of its links, and give an efficient method for computing reachable volumes. We present a method for generating configurations using reachable volumes that is applicable to various types of robots including open and closed chain robots, tree-like robots, and complex robots including both loops and branches. We also describe how to apply constraints (both on end effectors and internal joints) using reachable volumes. Unlike previous methods, reachable volumes work for spherical and prismatic joints as well as planar joints. Visualizations of reachable volumes can allow an operator to see what positions the robot can reach and can guide robot design. We present visualizations of reachable volumes for representative robots including closed chains and graspers as well as for examples with joint and end effector constraints.

  1. Monitoring Poisson time series using multi-process models

    DEFF Research Database (Denmark)

    Engebjerg, Malene Dahl Skov; Lundbye-Christensen, Søren; Kjær, Birgitte B.

    aspects of health resource management may also be addressed. In this paper we center on the detection of outbreaks of infectious diseases. This is achieved by a multi-process Poisson state space model taking autocorrelation and overdispersion into account, which has been applied to a data set concerning...

  2. Multiprocessing MCNP on an IBN RS/6000 cluster

    International Nuclear Information System (INIS)

    McKinney, G.W.; West, J.T.

    1993-01-01

    The advent of high-performance computer systems has brought to maturity programming concepts like vectorization, multiprocessing, and multitasking. While there are many schools of thought as to the most significant factor in obtaining order-of-magnitude increases in performance, such speedup can only be achieved by integrating the computer system and application code. Vectorization leads to faster manipulation of arrays by overlapping instruction CPU cycles. Discrete ordinates codes, which require the solving of large matrices, have proved to be major benefactors of vectorization. Monte Carlo transport, on the other hand, typically contains numerous logic statements and requires extensive redevelopment to benefit from vectorization. Multiprocessing and multitasking provide additional CPU cycles via multiple processors. Such systems are generally designed with either common memory access (multitasking) or distributed memory access. In both cases, theoretical speedup, as a function of the number of processors P and the fraction f of task time that multiprocesses, can be formulated using Amdahl's law: S(f, P) =1/(1-f+f/P). However, for most applications, this theoretical limit cannot be achieved because of additional terms (e.g., multitasking overhead, memory overlap, etc.) that are not included in Amdahl's law. Monte Carlo transport is a natural candidate for multiprocessing because the particle tracks are generally independent, and the precision of the result increases as the square Foot of the number of particles tracked

  3. Reachability cuts for the vehicle routing problem with time windows

    DEFF Research Database (Denmark)

    Lysgaard, Jens

    2004-01-01

    This paper introduces a class of cuts, called reachability cuts, for the Vehicle Routing Problem with Time Windows (VRPTW). Reachability cuts are closely related to cuts derived from precedence constraints in the Asymmetric Traveling Salesman Problem with Time Windows and to k-path cuts...

  4. Large scale analysis of signal reachability.

    Science.gov (United States)

    Todor, Andrei; Gabr, Haitham; Dobra, Alin; Kahveci, Tamer

    2014-06-15

    Major disorders, such as leukemia, have been shown to alter the transcription of genes. Understanding how gene regulation is affected by such aberrations is of utmost importance. One promising strategy toward this objective is to compute whether signals can reach to the transcription factors through the transcription regulatory network (TRN). Due to the uncertainty of the regulatory interactions, this is a #P-complete problem and thus solving it for very large TRNs remains to be a challenge. We develop a novel and scalable method to compute the probability that a signal originating at any given set of source genes can arrive at any given set of target genes (i.e., transcription factors) when the topology of the underlying signaling network is uncertain. Our method tackles this problem for large networks while providing a provably accurate result. Our method follows a divide-and-conquer strategy. We break down the given network into a sequence of non-overlapping subnetworks such that reachability can be computed autonomously and sequentially on each subnetwork. We represent each interaction using a small polynomial. The product of these polynomials express different scenarios when a signal can or cannot reach to target genes from the source genes. We introduce polynomial collapsing operators for each subnetwork. These operators reduce the size of the resulting polynomial and thus the computational complexity dramatically. We show that our method scales to entire human regulatory networks in only seconds, while the existing methods fail beyond a few tens of genes and interactions. We demonstrate that our method can successfully characterize key reachability characteristics of the entire transcriptions regulatory networks of patients affected by eight different subtypes of leukemia, as well as those from healthy control samples. All the datasets and code used in this article are available at bioinformatics.cise.ufl.edu/PReach/scalable.htm. © The Author 2014

  5. Reachability Analysis in Probabilistic Biological Networks.

    Science.gov (United States)

    Gabr, Haitham; Todor, Andrei; Dobra, Alin; Kahveci, Tamer

    2015-01-01

    Extra-cellular molecules trigger a response inside the cell by initiating a signal at special membrane receptors (i.e., sources), which is then transmitted to reporters (i.e., targets) through various chains of interactions among proteins. Understanding whether such a signal can reach from membrane receptors to reporters is essential in studying the cell response to extra-cellular events. This problem is drastically complicated due to the unreliability of the interaction data. In this paper, we develop a novel method, called PReach (Probabilistic Reachability), that precisely computes the probability that a signal can reach from a given collection of receptors to a given collection of reporters when the underlying signaling network is uncertain. This is a very difficult computational problem with no known polynomial-time solution. PReach represents each uncertain interaction as a bi-variate polynomial. It transforms the reachability problem to a polynomial multiplication problem. We introduce novel polynomial collapsing operators that associate polynomial terms with possible paths between sources and targets as well as the cuts that separate sources from targets. These operators significantly shrink the number of polynomial terms and thus the running time. PReach has much better time complexity than the recent solutions for this problem. Our experimental results on real data sets demonstrate that this improvement leads to orders of magnitude of reduction in the running time over the most recent methods. Availability: All the data sets used, the software implemented and the alignments found in this paper are available at http://bioinformatics.cise.ufl.edu/PReach/.

  6. Asymmetric Multiprocessing on the ARM Cortex-A9

    OpenAIRE

    Riša, Michal

    2015-01-01

    Asymetrický multiprocessing (AMP) je způsob rozdělování zátěže počítačového systému na heterogenní hardwarové a softwarové prostředí. Tato práce popisuje principy AMP se zaměřením na ARM Cortex--A9 procesor a Altera Cyclone V hardwarovou platformu. Postup tvorby AMP systému založeného na OpenAMP frameworku ukazujícího komunikaci mezi procesorovými jádry, dokumentace a prognóza budoucího vývoje jsou výstupy této práce. Asymmetric multiprocessing (AMP) is a way of distributing computer syste...

  7. The power of reachability testing for timed automata

    DEFF Research Database (Denmark)

    Aceto, Luca; Bouyer, Patricia; Burgueno, A.

    2003-01-01

    The computational engine of the verification tool UPPAAL consists of a collection of efficient algorithms for the analysis of reachability properties of systems. Model-checking of properties other than plain reachability ones may currently be carried out in such a tool as follows. Given a propert...... be reached. Finally, the property language characterizing the power of reachability testing is used to provide a definition of characteristic properties with respect to a timed version of the ready simulation preorder, for nodes of tau-free, deterministic timed automata....

  8. Multicore in Production: Advantages and Limits of the Multiprocess Approach

    CERN Document Server

    Binet, S; The ATLAS collaboration; Lavrijsen, W; Leggett, Ch; Lesny, D; Jha, M K; Severini, H; Smith, D; Snyder, S; Tatarkhanov, M; Tsulaia, V; van Gemmeren, P; Washbrook, A

    2011-01-01

    The shared memory architecture of multicore CPUs provides HENP developers with the opportunity to reduce the memory footprint of their applications by sharing memory pages between the cores in a processor. ATLAS pioneered the multi-process approach to parallelizing HENP applications. Using Linux fork() and the Copy On Write mechanism we implemented a simple event task farm which allows to share up to 50% memory pages among event worker processes with negligible CPU overhead. By leaving the task of managing shared memory pages to the operating system, we have been able to run in parallel large reconstruction and simulation applications originally written to be run in a single thread of execution with little to no change to the application code. In spite of this, the process of validating athena multi-process for production took ten months of concentrated effort and is expected to continue for several more months. In general terms, we had two classes of problems in the multi-process port: merging the output fil...

  9. On the reachability and observability of path and cycle graphs

    OpenAIRE

    Parlangeli, Gianfranco; Notarstefano, Giuseppe

    2011-01-01

    In this paper we investigate the reachability and observability properties of a network system, running a Laplacian based average consensus algorithm, when the communication graph is a path or a cycle. More in detail, we provide necessary and sufficient conditions, based on simple algebraic rules from number theory, to characterize all and only the nodes from which the network system is reachable (respectively observable). Interesting immediate corollaries of our results are: (i) a path graph...

  10. Internal ellipsoidal estimates of reachable set of impulsive control systems

    Energy Technology Data Exchange (ETDEWEB)

    Matviychuk, Oksana G. [Institute of Mathematics and Mechanics, Russian Academy of Sciences, 16 S. Kovalevskaya str., Ekaterinburg, 620990, Russia and Ural Federal University, 19 Mira str., Ekaterinburg, 620002 (Russian Federation)

    2014-11-18

    A problem of estimating reachable sets of linear impulsive control system with uncertainty in initial data is considered. The impulsive controls in the dynamical system belong to the intersection of a special cone with a generalized ellipsoid both taken in the space of functions of bounded variation. Assume that an ellipsoidal state constraints are imposed. The algorithms for constructing internal ellipsoidal estimates of reachable sets for such control systems and numerical simulation results are given.

  11. TAPAAL and Reachability Analysis of P/T Nets

    DEFF Research Database (Denmark)

    Jensen, Jonas Finnemann; Nielsen, Thomas Søndersø; Østergaard, Lars Kærlund

    2016-01-01

    We discuss selected model checking techniques used in the tool TAPAAL for the reachability analysis of weighted Petri nets with inhibitor arcs. We focus on techniques that had the most significant effect at the 2015 Model Checking Contest (MCC). While the techniques are mostly well known, our...... contribution lies in their adaptation to the MCC reachability queries, their efficient implementation and the evaluation of their performance on a large variety of nets from MCC'15....

  12. Error detection in GPS observations by means of Multi-process models

    DEFF Research Database (Denmark)

    Thomsen, Henrik F.

    2001-01-01

    The main purpose of this article is to present the idea of using Multi-process models as a method of detecting errors in GPS observations. The theory behind Multi-process models, and double differenced phase observations in GPS is presented shortly. It is shown how to model cycle slips in the Mul...

  13. Minimum-Cost Reachability for Priced Timed Automata

    DEFF Research Database (Denmark)

    Behrmann, Gerd; Fehnker, Ansgar; Hune, Thomas Seidelin

    2001-01-01

    This paper introduces the model of linearly priced timed automata as an extension of timed automata, with prices on both transitions and locations. For this model we consider the minimum-cost reachability problem: i.e. given a linearly priced timed automaton and a target state, determine...... the minimum cost of executions from the initial state to the target state. This problem generalizes the minimum-time reachability problem for ordinary timed automata. We prove decidability of this problem by offering an algorithmic solution, which is based on a combination of branch-and-bound techniques...... and a new notion of priced regions. The latter allows symbolic representation and manipulation of reachable states together with the cost of reaching them....

  14. Minimum-Cost Reachability for Priced Timed Automata

    DEFF Research Database (Denmark)

    Behrmann, Gerd; Fehnker, Ansgar; Hune, Thomas Seidelin

    2001-01-01

    This paper introduces the model of linearly priced timed automata as an extension of timed automata, with prices on both transitions and locations. For this model we consider the minimum-cost reachability problem: i.e. given a linearly priced timed automaton and a target state, determine...... the minimum cost of executions from the initial state to the target state. This problem generalizes the minimum-time reachability problem for ordinary timed automata. We prove decidability of this problem by offering an algorithmic solution, which is based on a combination of branch-and-bound techniques...

  15. Mobility Tolerant Firework Routing for Improving Reachability in MANETs

    Directory of Open Access Journals (Sweden)

    Gen Motoyoshi

    2014-03-01

    Full Text Available In this paper, we investigate our mobility-assisted and adaptive broadcast routing mechanism, called Mobility Tolerant Firework Routing (MTFR, which utilizes the concept of potentials for routing and improves node reachability, especially in situations with high mobility, by including a broadcast mechanism. We perform detailed evaluations by simulations in a mobile environment and demonstrate the advantages of MTFR over conventional potential-based routing. In particular, we show that MTFR produces better reachability in many aspects at the expense of a small additional transmission delay and intermediate traffic overhead, making MTFR a promising routing protocol and feasible for future mobile Internet infrastructures.

  16. Replication, refinement & reachability: complexity in dynamic condition-response graphs

    DEFF Research Database (Denmark)

    Debois, Søren; Hildebrandt, Thomas T.; Slaats, Tijs

    2017-01-01

    We explore the complexity of reachability and run-time refinement under safety and liveness constraints in event-based process models. Our study is framed in the DCR? process language, which supports modular specification through a compositional operational semantics. DCR? encompasses the “Dynami...

  17. Reachability analysis for timed automata using max-plus algebra

    DEFF Research Database (Denmark)

    Lu, Qi; Madsen, Michael; Milata, Martin

    2012-01-01

    We show that max-plus polyhedra are usable as a data structure in reachability analysis of timed automata. Drawing inspiration from the extensive work that has been done on difference bound matrices, as well as previous work on max-plus polyhedra in other areas, we develop the algorithms needed...

  18. Optimal Conditional Reachability for Multi-Priced Timed Automata

    DEFF Research Database (Denmark)

    Larsen, Kim Guldstrand; Rasmussen, Jacob Illum

    2005-01-01

    In this paper, we prove decidability of the optimal conditional reachability problem for multi-priced timed automata, an extension of timed automata with multiple cost variables evolving according to given rates for each location. More precisely, we consider the problem of determining the minimal...

  19. Reachability Trees for High-level Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt; Jensen, Arne M.; Jepsen, Leif Obel

    1986-01-01

    the necessary analysis methods. In other papers it is shown how to generalize the concept of place- and transition invariants from place/transition nets to high-level Petri nets. Our present paper contributes to this with a generalization of reachability trees, which is one of the other important analysis...

  20. Symbolic Reachability for Process Algebras with Recursive Data Types

    NARCIS (Netherlands)

    Blom, Stefan; van de Pol, Jan Cornelis; Fitzgerald, J.S.; Haxthausen, A.E.; Yenigun, H.

    2008-01-01

    In this paper, we present a symbolic reachability algorithm for process algebras with recursive data types. Like the various saturation based algorithms of Ciardo et al, the algorithm is based on partitioning of the transition relation into events whose influence is local. As new features, our

  1. Bisimulation, Logic and Reachability Analysis for Markovian Systems

    NARCIS (Netherlands)

    Bujorianu, L.M.; Bujorianu, M.C.

    2008-01-01

    In the recent years, there have been a large amount of investigations on safety verification of uncertain continuous systems. In engineering and applied mathematics, this verification is called stochastic reachability analysis, while in computer science this is called probabilistic model checking

  2. Reachability for Finite-state Process Algebras Using Horn Clauses

    DEFF Research Database (Denmark)

    Skrypnyuk, Nataliya; Nielson, Flemming

    2013-01-01

    of the Data Flow Analysis are used in order to build a set of Horn clauses whose least model corresponds to an overapproximation of the reachable states. The computed model can be refined after each transition, and the algorithm runs until either a state whose reachability should be checked is encountered...... or it is not in the least model for all constructed states and thus is definitely unreachable. The advantages of the algorithm are that in many cases only a part of the Labelled Transition System will be built which leads to lower time and memory consumption. Also, it is not necessary to save all the encountered states...... which leads to further reduction of the memory requirements of the algorithm....

  3. Winning Concurrent Reachability Games Requires Doubly-Exponential Patience

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Arnsfelt; Koucký, Michal; Miltersen, Peter Bro

    2009-01-01

    We exhibit a deterministic concurrent reachability game PURGATORYn with n non-terminal positions and a binary choice for both players in every position so that any positional strategy for Player 1 achieving the value of the game within given isin ... that are less than (isin2/(1 - isin))2n-2 . Also, even to achieve the value within say 1 - 2-n/2, doubly exponentially small behavior probabilities in the number of positions must be used. This behavior is close to worst case: We show that for any such game and 0 ... with all non-zero behavior probabilities being 20(n) at least isin2O(n). As a corollary to our results, we conclude that any (deterministic or nondeterministic) algorithm that given a concurrent reachability game explicitly manipulates isin-optimal strategies for Player 1 represented in several standard...

  4. Monomial strategies for concurrent reachability games and other stochastic games

    DEFF Research Database (Denmark)

    Frederiksen, Søren Kristoffer Stiil; Miltersen, Peter Bro

    2013-01-01

    We consider two-player zero-sum finite (but infinite-horizon) stochastic games with limiting average payoffs. We define a family of stationary strategies for Player I parameterized by ε > 0 to be monomial, if for each state k and each action j of Player I in state k except possibly one action, we...... have that the probability of playing j in k is given by an expression of the form c ε d for some non-negative real number c and some non-negative integer d. We show that for all games, there is a monomial family of stationary strategies that are ε-optimal among stationary strategies. A corollary...... is that all concurrent reachability games have a monomial family of ε-optimal strategies. This generalizes a classical result of de Alfaro, Henzinger and Kupferman who showed that this is the case for concurrent reachability games where all states have value 0 or 1....

  5. Mutual proximity graphs for improved reachability in music recommendation.

    Science.gov (United States)

    Flexer, Arthur; Stevens, Jeff

    2018-01-01

    This paper is concerned with the impact of hubness, a general problem of machine learning in high-dimensional spaces, on a real-world music recommendation system based on visualisation of a k-nearest neighbour (knn) graph. Due to a problem of measuring distances in high dimensions, hub objects are recommended over and over again while anti-hubs are nonexistent in recommendation lists, resulting in poor reachability of the music catalogue. We present mutual proximity graphs, which are an alternative to knn and mutual knn graphs, and are able to avoid hub vertices having abnormally high connectivity. We show that mutual proximity graphs yield much better graph connectivity resulting in improved reachability compared to knn graphs, mutual knn graphs and mutual knn graphs enhanced with minimum spanning trees, while simultaneously reducing the negative effects of hubness.

  6. Improved Undecidability Results for Reachability Games on Recursive Timed Automata

    Directory of Open Access Journals (Sweden)

    Shankara Narayanan Krishna

    2014-08-01

    Full Text Available We study reachability games on recursive timed automata (RTA that generalize Alur-Dill timed automata with recursive procedure invocation mechanism similar to recursive state machines. It is known that deciding the winner in reachability games on RTA is undecidable for automata with two or more clocks, while the problem is decidable for automata with only one clock. Ouaknine and Worrell recently proposed a time-bounded theory of real-time verification by claiming that restriction to bounded-time recovers decidability for several key decision problem related to real-time verification. We revisited games on recursive timed automata with time-bounded restriction in the hope of recovering decidability. However, we found that the problem still remains undecidable for recursive timed automata with three or more clocks. Using similar proof techniques we characterize a decidability frontier for a generalization of RTA to recursive stopwatch automata.

  7. Decomposing Huge Networks into Skeleton Graphs by Reachable Relations

    Science.gov (United States)

    2017-06-07

    efficiently process approximate queries, i.e., reachable nodes , on the original dataset, i.e., the given network. Finally, by focusing on spatial networks...centralized control (e.g., the Arab Spring). These problems have mostly been studied from the view point of identifying influential nodes under some...where we set k = 26 for calculation of the bottom-k sketches of all the nodes . Figure 1(a) compares the actual processing times of these methods

  8. Methods for Reachability-based Hybrid Controller Design

    Science.gov (United States)

    2012-05-10

    approaches for airport runways ( Teo and Tomlin, 2003). The results of the reachability calculations were validated in extensive simulations as well as...UAV flight experiments (Jang and Tomlin, 2005; Teo , 2005). While the focus of these previous applications lies largely in safety verification, the work...B([15, 0],a0)× [−π,π])\\ V,∀qi ∈ Q, where a0 = 30m is the protected radius (chosen based upon published data of the wingspan of a Boeing KC -135

  9. When Do Words Hurt? A Multiprocess View of the Effects of Verbalization on Visual Memory

    Science.gov (United States)

    Brown, Charity; Brandimonte, Maria A.; Wickham, Lee H. V.; Bosco, Andrea; Schooler, Jonathan W.

    2014-01-01

    Verbal overshadowing reflects the impairment in memory performance following verbalization of nonverbal stimuli. However, it is not clear whether the same mechanisms are responsible for verbal overshadowing effects observed with different stimuli and task demands. In the present article, we propose a multiprocess view that reconciles the main…

  10. Reachability by paths of bounded curvature in a convex polygon

    KAUST Repository

    Ahn, Heekap; Cheong, Otfried; Matoušek, Jiřǐ; Vigneron, Antoine E.

    2012-01-01

    Let B be a point robot moving in the plane, whose path is constrained to forward motions with curvature at most 1, and let P be a convex polygon with n vertices. Given a starting configuration (a location and a direction of travel) for B inside P, we characterize the region of all points of P that can be reached by B, and show that it has complexity O(n). We give an O(n2) time algorithm to compute this region. We show that a point is reachable only if it can be reached by a path of type CCSCS, where C denotes a unit circle arc and S denotes a line segment. © 2011 Elsevier B.V.

  11. The effect of response-delay on estimating reachability.

    Science.gov (United States)

    Gabbard, Carl; Ammar, Diala

    2008-11-01

    The experiment was conducted to compare visual imagery (VI) and motor imagery (MI) reaching tasks in a response-delay paradigm designed to explore the hypothesized dissociation between vision for perception and vision for action. Although the visual systems work cooperatively in motor control, theory suggests that they operate under different temporal constraints. From this perspective, we expected that delay would affect MI but not VI because MI operates in real time and VI is postulated to be memory-driven. Following measurement of actual reach, right-handers were presented seven (imagery) targets at midline in eight conditions: MI and VI with 0-, 1-, 2-, and 4-s delays. Results indicted that delay affected the ability to estimate reachability with MI but not with VI. These results are supportive of a general distinction between vision for perception and vision for action.

  12. Sampling based motion planning with reachable volumes: Application to manipulators and closed chain systems

    KAUST Repository

    McMahon, Troy

    2014-09-01

    © 2014 IEEE. Reachable volumes are a geometric representation of the regions the joints of a robot can reach. They can be used to generate constraint satisfying samples for problems including complicated linkage robots (e.g. closed chains and graspers). They can also be used to assist robot operators and to help in robot design.We show that reachable volumes have an O(1) complexity in unconstrained problems as well as in many constrained problems. We also show that reachable volumes can be computed in linear time and that reachable volume samples can be generated in linear time in problems without constraints. We experimentally validate reachable volume sampling, both with and without constraints on end effectors and/or internal joints. We show that reachable volume samples are less likely to be invalid due to self-collisions, making reachable volume sampling significantly more efficient for higher dimensional problems. We also show that these samples are easier to connect than others, resulting in better connected roadmaps. We demonstrate that our method can be applied to 262-dof, multi-loop, and tree-like linkages including combinations of planar, prismatic and spherical joints. In contrast, existing methods either cannot be used for these problems or do not produce good quality solutions.

  13. Sampling based motion planning with reachable volumes: Application to manipulators and closed chain systems

    KAUST Repository

    McMahon, Troy; Thomas, Shawna; Amato, Nancy M.

    2014-01-01

    © 2014 IEEE. Reachable volumes are a geometric representation of the regions the joints of a robot can reach. They can be used to generate constraint satisfying samples for problems including complicated linkage robots (e.g. closed chains and graspers). They can also be used to assist robot operators and to help in robot design.We show that reachable volumes have an O(1) complexity in unconstrained problems as well as in many constrained problems. We also show that reachable volumes can be computed in linear time and that reachable volume samples can be generated in linear time in problems without constraints. We experimentally validate reachable volume sampling, both with and without constraints on end effectors and/or internal joints. We show that reachable volume samples are less likely to be invalid due to self-collisions, making reachable volume sampling significantly more efficient for higher dimensional problems. We also show that these samples are easier to connect than others, resulting in better connected roadmaps. We demonstrate that our method can be applied to 262-dof, multi-loop, and tree-like linkages including combinations of planar, prismatic and spherical joints. In contrast, existing methods either cannot be used for these problems or do not produce good quality solutions.

  14. On some methods for improving time of reachability sets computation for the dynamic system control problem

    Science.gov (United States)

    Zimovets, Artem; Matviychuk, Alexander; Ushakov, Vladimir

    2016-12-01

    The paper presents two different approaches to reduce the time of computer calculation of reachability sets. First of these two approaches use different data structures for storing the reachability sets in the computer memory for calculation in single-threaded mode. Second approach is based on using parallel algorithms with reference to the data structures from the first approach. Within the framework of this paper parallel algorithm of approximate reachability set calculation on computer with SMP-architecture is proposed. The results of numerical modelling are presented in the form of tables which demonstrate high efficiency of parallel computing technology and also show how computing time depends on the used data structure.

  15. Reachable Distance Space: Efficient Sampling-Based Planning for Spatially Constrained Systems

    KAUST Repository

    Xinyu Tang,; Thomas, S.; Coleman, P.; Amato, N. M.

    2010-01-01

    reachable distance space (RD-space), in which all configurations lie in the set of constraint-satisfying subspaces. This enables us to directly sample the constrained subspaces with complexity linear in the number of the robot's degrees of freedom

  16. The Dynamic Multiprocess Framework: Evidence from Prospective Memory with Contextual Variability

    OpenAIRE

    Scullin, Michael K.; McDaniel, Mark A.; Shelton, Jill Talley

    2013-01-01

    The ability to remember to execute delayed intentions is referred to as prospective memory. Previous theoretical and empirical work has focused on isolating whether a particular prospective memory task is supported either by effortful monitoring processes or by cue-driven spontaneous processes. In the present work, we advance the Dynamic Multiprocess Framework, which contends that both monitoring and spontaneous retrieval may be utilized dynamically to support prospective remembering. To capt...

  17. A multi-process phytoremediation system for removal of polycyclic aromatic hydrocarbons from contaminated soils

    International Nuclear Information System (INIS)

    Huang Xiaodong; El-Alawi, Yousef; Penrose, Donna M.; Glick, Bernard R.; Greenberg, Bruce M.

    2004-01-01

    To improve phytoremediation processes, multiple techniques that comprise different aspects of contaminant removal from soils have been combined. Using creosote as a test contaminant, a multi-process phytoremediation system composed of physical (volatilization), photochemical (photooxidation) and microbial remediation, and phytoremediation (plant-assisted remediation) processes was developed. The techniques applied to realize these processes were land-farming (aeration and light exposure), introduction of contaminant degrading bacteria, plant growth promoting rhizobacteria (PGPR), and plant growth of contaminant-tolerant tall fescue (Festuca arundinacea). Over a 4-month period, the average efficiency of removal of 16 priority PAHs by the multi-process remediation system was twice that of land-farming, 50% more than bioremediation alone, and 45% more than phytoremediation by itself. Importantly, the multi-process system was capable of removing most of the highly hydrophobic, soil-bound PAHs from soil. The key elements for successful phytoremediation were the use of plant species that have the ability to proliferate in the presence of high levels of contaminants and strains of PGPR that increase plant tolerance to contaminants and accelerate plant growth in heavily contaminated soils. The synergistic use of these approaches resulted in rapid and massive biomass accumulation of plant tissue in contaminated soil, putatively providing more active metabolic processes, leading to more rapid and more complete removal of PAHs. - Persistent PAH contaminants in soils can be removed more completely and rapidly by using multiple remediation processes

  18. Iterable Forward Reachability Analysis of Monitor-DPNs

    Directory of Open Access Journals (Sweden)

    Benedikt Nordhoff

    2013-09-01

    Full Text Available There is a close connection between data-flow analysis and model checking as observed and studied in the nineties by Steffen and Schmidt. This indicates that automata-based analysis techniques developed in the realm of infinite-state model checking can be applied as data-flow analyzers that interpret complex control structures, which motivates the development of such analysis techniques for ever more complex models. One approach proposed by Esparza and Knoop is based on computation of predecessor or successor sets for sets of automata configurations. Our goal is to adapt and exploit this approach for analysis of multi-threaded Java programs. Specifically, we consider the model of Monitor-DPNs for concurrent programs. Monitor-DPNs precisely model unbounded recursion, dynamic thread creation, and synchronization via well-nested locks with finite abstractions of procedure- and thread-local state. Previous work on this model showed how to compute regular predecessor sets of regular configurations and tree-regular successor sets of a fixed initial configuration. By combining and extending different previously developed techniques we show how to compute tree-regular successor sets of tree-regular sets. Thereby we obtain an iterable, lock-sensitive forward reachability analysis. We implemented the analysis for Java programs and applied it to information flow control and data race detection.

  19. Liveness and Reachability Analysis of BPMN Process Models

    Directory of Open Access Journals (Sweden)

    Anass Rachdi

    2016-06-01

    Full Text Available Business processes are usually defined by business experts who require intuitive and informal graphical notations such as BPMN (Business Process Management Notation for documenting and communicating their organization activities and behavior. However, BPMN has not been provided with a formal semantics, which limits the analysis of BPMN models to using solely informal techniques such as simulation. In order to address this limitation and use formal verification, it is necessary to define a certain “mapping” between BPMN and a formal language such as Concurrent Sequential Processes (CSP and Petri Nets (PN. This paper proposes a method for the verification of BPMN models by defining formal semantics of BPMN in terms of a mapping to Time Petri Nets (TPN, which are equipped with very efficient analytical techniques. After the translation of BPMN models to TPN, verification is done to ensure that some functional properties are satisfied by the model under investigation, namely liveness and reachability properties. The main advantage of our approach over existing ones is that it takes into account the time components in modeling Business process models. An example is used throughout the paper to illustrate the proposed method.

  20. Reachability analysis of real-time systems using time Petri nets.

    Science.gov (United States)

    Wang, J; Deng, Y; Xu, G

    2000-01-01

    Time Petri nets (TPNs) are a popular Petri net model for specification and verification of real-time systems. A fundamental and most widely applied method for analyzing Petri nets is reachability analysis. The existing technique for reachability analysis of TPNs, however, is not suitable for timing property verification because one cannot derive end-to-end delay in task execution, an important issue for time-critical systems, from the reachability tree constructed using the technique. In this paper, we present a new reachability based analysis technique for TPNs for timing property analysis and verification that effectively addresses the problem. Our technique is based on a concept called clock-stamped state class (CS-class). With the reachability tree generated based on CS-classes, we can directly compute the end-to-end time delay in task execution. Moreover, a CS-class can be uniquely mapped to a traditional state class based on which the conventional reachability tree is constructed. Therefore, our CS-class-based analysis technique is more general than the existing technique. We show how to apply this technique to timing property verification of the TPN model of a command and control (C2) system.

  1. Computing and Visualizing Reachable Volumes for Maneuvering Satellites

    International Nuclear Information System (INIS)

    Jiang, M.; de Vries, W.H.; Pertica, A.J.; Olivier, S.S.

    2011-01-01

    Detecting and predicting maneuvering satellites is an important problem for Space Situational Awareness. The spatial envelope of all possible locations within reach of such a maneuvering satellite is known as the Reachable Volume (RV). As soon as custody of a satellite is lost, calculating the RV and its subsequent time evolution is a critical component in the rapid recovery of the satellite. In this paper, we present a Monte Carlo approach to computing the RV for a given object. Essentially, our approach samples all possible trajectories by randomizing thrust-vectors, thrust magnitudes and time of burn. At any given instance, the distribution of the 'point-cloud' of the virtual particles defines the RV. For short orbital time-scales, the temporal evolution of the point-cloud can result in complex, multi-reentrant manifolds. Visualization plays an important role in gaining insight and understanding into this complex and evolving manifold. In the second part of this paper, we focus on how to effectively visualize the large number of virtual trajectories and the computed RV. We present a real-time out-of-core rendering technique for visualizing the large number of virtual trajectories. We also examine different techniques for visualizing the computed volume of probability density distribution, including volume slicing, convex hull and isosurfacing. We compare and contrast these techniques in terms of computational cost and visualization effectiveness, and describe the main implementation issues encountered during our development process. Finally, we will present some of the results from our end-to-end system for computing and visualizing RVs using examples of maneuvering satellites.

  2. Computing and Visualizing Reachable Volumes for Maneuvering Satellites

    Science.gov (United States)

    Jiang, M.; de Vries, W.; Pertica, A.; Olivier, S.

    2011-09-01

    Detecting and predicting maneuvering satellites is an important problem for Space Situational Awareness. The spatial envelope of all possible locations within reach of such a maneuvering satellite is known as the Reachable Volume (RV). As soon as custody of a satellite is lost, calculating the RV and its subsequent time evolution is a critical component in the rapid recovery of the satellite. In this paper, we present a Monte Carlo approach to computing the RV for a given object. Essentially, our approach samples all possible trajectories by randomizing thrust-vectors, thrust magnitudes and time of burn. At any given instance, the distribution of the "point-cloud" of the virtual particles defines the RV. For short orbital time-scales, the temporal evolution of the point-cloud can result in complex, multi-reentrant manifolds. Visualization plays an important role in gaining insight and understanding into this complex and evolving manifold. In the second part of this paper, we focus on how to effectively visualize the large number of virtual trajectories and the computed RV. We present a real-time out-of-core rendering technique for visualizing the large number of virtual trajectories. We also examine different techniques for visualizing the computed volume of probability density distribution, including volume slicing, convex hull and isosurfacing. We compare and contrast these techniques in terms of computational cost and visualization effectiveness, and describe the main implementation issues encountered during our development process. Finally, we will present some of the results from our end-to-end system for computing and visualizing RVs using examples of maneuvering satellites.

  3. Exponential formula for the reachable sets of quantum stochastic differential inclusions

    International Nuclear Information System (INIS)

    Ayoola, E.O.

    2001-07-01

    We establish an exponential formula for the reachable sets of quantum stochastic differential inclusions (QSDI) which are locally Lipschitzian with convex values. Our main results partially rely on an auxiliary result concerning the density, in the topology of the locally convex space of solutions, of the set of trajectories whose matrix elements are continuously differentiable By applying the exponential formula, we obtain results concerning convergence of the discrete approximations of the reachable set of the QSDI. This extends similar results of Wolenski for classical differential inclusions to the present noncommutative quantum setting. (author)

  4. The Dynamic Multiprocess Framework: Evidence from Prospective Memory with Contextual Variability

    Science.gov (United States)

    Scullin, Michael K.; McDaniel, Mark A.; Shelton, Jill Talley

    2013-01-01

    The ability to remember to execute delayed intentions is referred to as prospective memory. Previous theoretical and empirical work has focused on isolating whether a particular prospective memory task is supported either by effortful monitoring processes or by cue-driven spontaneous processes. In the present work, we advance the Dynamic Multiprocess Framework, which contends that both monitoring and spontaneous retrieval may be utilized dynamically to support prospective remembering. To capture the dynamic interplay between monitoring and spontaneous retrieval we had participants perform many ongoing tasks and told them that their prospective memory cue may occur in any context. Following either a 20-min or a 12-hr retention interval, the prospective memory cues were presented infrequently across three separate ongoing tasks. The monitoring patterns (measured as ongoing task cost relative to a between-subjects control condition) were consistent and robust across the three contexts. There was no evidence for monitoring prior to the initial prospective memory cue; however, individuals who successfully spontaneously retrieved the prospective memory intention, thereby realizing that prospective memory cues could be expected within that context, subsequently monitored. These data support the Dynamic Multiprocess Framework, which contends that individuals will engage monitoring when prospective memory cues are expected, disengage monitoring when cues are not expected, and that when monitoring is disengaged, a probabilistic spontaneous retrieval mechanism can support prospective remembering. PMID:23916951

  5. Advanced single-wafer sequential multiprocessing techniques for semiconductor device fabrication

    International Nuclear Information System (INIS)

    Moslehi, M.M.; Davis, C.

    1989-01-01

    Single-wafer integrated in-situ multiprocessing (SWIM) is recognized as the future trend for advanced microelectronics production in flexible fast turn- around computer-integrated semiconductor manufacturing environments. The SWIM equipment technology and processing methodology offer enhanced equipment utilization, improved process reproducibility and yield, and reduced chip manufacturing cost. They also provide significant capabilities for fabrication of new and improved device structures. This paper describes the SWIM techniques and presents a novel single-wafer advanced vacuum multiprocessing technology developed based on the use of multiple process energy/activation sources (lamp heating and remote microwave plasma) for multilayer epitaxial and polycrystalline semiconductor as well as dielectric film processing. Based on this technology, multilayer in-situ-doped homoepitaxial silicon and heteroepitaxial strained layer Si/Ge x Si 1 - x /Si structures have been grown and characterized. The process control and the ultimate interfacial abruptness of the layer-to-layer transition widths in the device structures prepared by this technology will challenge the MBE techniques in multilayer epitaxial growth applications

  6. The Reach-and-Evolve Algorithm for Reachability Analysis of Nonlinear Dynamical Systems

    NARCIS (Netherlands)

    P.J. Collins (Pieter); A. Goldsztejn

    2008-01-01

    htmlabstractThis paper introduces a new algorithm dedicated to the rigorous reachability analysis of nonlinear dynamical systems. The algorithm is initially presented in the context of discrete time dynamical systems, and then extended to continuous time dynamical systems driven by ODEs. In

  7. A Forward Reachability Algorithm for Bounded Timed-Arc Petri Nets

    DEFF Research Database (Denmark)

    David, Alexandre; Jacobsen, Lasse; Jacobsen, Morten

    2012-01-01

    Timed-arc Petri nets (TAPN) are a well-known time extension of thePetri net model and several translations to networks of timedautomata have been proposed for this model.We present a direct, DBM-basedalgorithm for forward reachability analysis of bounded TAPNs extended with transport arcs...

  8. Testing reachability and stabilizability of systems over polynomial rings using Gröbner bases

    NARCIS (Netherlands)

    Habets, L.C.G.J.M.

    1993-01-01

    Conditions for the reachability and stabilizability of systems over polynomial rings are well-known in the literature. For a system $ \\Sigma = (A,B)$ they can be expressed as right-invertibility cconditions on the matrix $(zI - A \\mid B)$. Therefore there is quite a strong algebraic relationship

  9. The Role of Haptic Exploration of Ground Surface Information in Perception of Overhead Reachability

    NARCIS (Netherlands)

    Pepping, Gert-Jan; Li, Francois-Xavier

    2008-01-01

    The authors performed an experiment in which participants (N = 24) made judgments about maximum jump and reachability on ground surfaces with different elastic properties: sand and a trampoline. Participants performed judgments in two conditions: (a) while standing and after having recently jumped

  10. Functional range of movement of the hand: declination angles to reachable space.

    Science.gov (United States)

    Pham, Hai Trieu; Pathirana, Pubudu N; Caelli, Terry

    2014-01-01

    The measurement of the range of hand joint movement is an essential part of clinical practice and rehabilitation. Current methods use three finger joint declination angles of the metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints. In this paper we propose an alternate form of measurement for the finger movement. Using the notion of reachable space instead of declination angles has significant advantages. Firstly, it provides a visual and quantifiable method that therapists, insurance companies and patients can easily use to understand the functional capabilities of the hand. Secondly, it eliminates the redundant declination angle constraints. Finally, reachable space, defined by a set of reachable fingertip positions, can be measured and constructed by using a modern camera such as Creative Senz3D or built-in hand gesture sensors such as the Leap Motion Controller. Use of cameras or optical-type sensors for this purpose have considerable benefits such as eliminating and minimal involvement of therapist errors, non-contact measurement in addition to valuable time saving for the clinician. A comparison between using declination angles and reachable space were made based on Hume's experiment on functional range of movement to prove the efficiency of this new approach.

  11. A reachability test for systems over polynomial rings using Gröbner bases

    NARCIS (Netherlands)

    Habets, L.C.G.J.M.

    1992-01-01

    Conditions for the reachability of a system over a polynomial ring are well known in the literature. However, the verification of these conditions remained a difficult problem in general. Application of the Gröbner Basis method from constructive commutative algebra makes it possible to carry out

  12. Shared I/O components for the ATLAS multi-processing framework

    CERN Document Server

    van Gemmeren, Peter; The ATLAS collaboration

    2017-01-01

    ATLAS uses its multi-processing framework AthenaMP for an increasing number of workflows, including simulation, reconstruction and event data filtering (derivation). After serial initialization, AthenaMP forks worker processes that then process events in parallel, with each worker reading data individually and producing its own output. This mode, however, has inefficiencies: 1) The worker no longer reads events sequentially, which negatively affects data caching strategies at the storage backend. 2) For its non-RAW data ATLAS uses ROOT and compresses across 10-100 events. Workers will only need a subsample of these events, but have to read and decompress the complete buffers. 3) Output files from the individual workers need to be merged in a separate, serial process. 4) Propagating metadata describing the complete event sample through several workers is nontrivial. To address these shortcomings, ATLAS has developed shared reader and writer components presented in this paper. With the shared reader, a single p...

  13. CHIMERA II - A real-time multiprocessing environment for sensor-based robot control

    Science.gov (United States)

    Stewart, David B.; Schmitz, Donald E.; Khosla, Pradeep K.

    1989-01-01

    A multiprocessing environment for a wide variety of sensor-based robot system, providing the flexibility, performance, and UNIX-compatible interface needed for fast development of real-time code is addressed. The requirements imposed on the design of a programming environment for sensor-based robotic control is outlined. The details of the current hardware configuration are presented, along with the details of the CHIMERA II software. Emphasis is placed on the kernel, low-level interboard communication, user interface, extended file system, user-definable and dynamically selectable real-time schedulers, remote process synchronization, and generalized interprocess communication. A possible implementation of a hierarchical control model, the NASA/NBS standard reference model for telerobot control system is demonstrated.

  14. Mapping of control functions of critical systems by reachability analysis in a network of communicating automata

    International Nuclear Information System (INIS)

    Lemattre, Thibault

    2013-01-01

    The design of operational control architectures is a very important step of the design of energy production systems. This step consists in mapping the functional architecture of the system onto its hardware architecture while respecting capacity and safety constraints, i.e. in allocating control functions to a set of controllers while respecting these constraints. The work presented in this thesis presents: i) a formalization of the data and constraints of the function allocation problem; ii) a mapping method, by reachability analysis, based on a request/response mechanism in a network of communicating automata with integer variables; iii) a comparison between this method and a resolution method by integer linear programming. The results of this work have been validated on examples of actual size and open the way to the coupling between reachability analysis and integer linear programming for the resolution of satisfaction problems for non-linear constraint systems. (author)

  15. Cascading effect of contagion in Indian stock market: Evidence from reachable stocks

    Directory of Open Access Journals (Sweden)

    Rajan Sruthi

    2017-12-01

    Full Text Available The financial turbulence in a country percolates to another along the trajectories of reachable stocks owned by foreign investors. To indemnify the losses originating from the crisis country, foreign investors dispose of shares in other markets triggering a contagion in an unrelated market. This paper provides empirical evidence for the stock market crisis that spreads globally through investors owning international portfolios, with special reference to the global financial crisis of 2008–09. Using two-step Limited Information Maximum Likelihood estimation and Murphy-Topel variance estimate, the results show that reachability plays a crucial role in the transposal of distress from one country to another, explaining investor-induced contagion in the Indian stock market.

  16. Approximating the Value of a Concurrent Reachability Game in the Polynomial Time Hierarchy

    DEFF Research Database (Denmark)

    Frederiksen, Søren Kristoffer Stiil; Miltersen, Peter Bro

    2013-01-01

    We show that the value of a finite-state concurrent reachability game can be approximated to arbitrary precision in TFNP[NP], that is, in the polynomial time hierarchy. Previously, no better bound than PSPACE was known for this problem. The proof is based on formulating a variant of the state red...... reduction algorithm for Markov chains using arbitrary precision floating point arithmetic and giving a rigorous error analysis of the algorithm.......We show that the value of a finite-state concurrent reachability game can be approximated to arbitrary precision in TFNP[NP], that is, in the polynomial time hierarchy. Previously, no better bound than PSPACE was known for this problem. The proof is based on formulating a variant of the state...

  17. Counter-Based Broadcast Scheme Considering Reachability, Network Density, and Energy Efficiency for Wireless Sensor Networks.

    Science.gov (United States)

    Jung, Ji-Young; Seo, Dong-Yoon; Lee, Jung-Ryun

    2018-01-04

    A wireless sensor network (WSN) is emerging as an innovative method for gathering information that will significantly improve the reliability and efficiency of infrastructure systems. Broadcast is a common method to disseminate information in WSNs. A variety of counter-based broadcast schemes have been proposed to mitigate the broadcast-storm problems, using the count threshold value and a random access delay. However, because of the limited propagation of the broadcast-message, there exists a trade-off in a sense that redundant retransmissions of the broadcast-message become low and energy efficiency of a node is enhanced, but reachability become low. Therefore, it is necessary to study an efficient counter-based broadcast scheme that can dynamically adjust the random access delay and count threshold value to ensure high reachability, low redundant of broadcast-messages, and low energy consumption of nodes. Thus, in this paper, we first measure the additional coverage provided by a node that receives the same broadcast-message from two neighbor nodes, in order to achieve high reachability with low redundant retransmissions of broadcast-messages. Second, we propose a new counter-based broadcast scheme considering the size of the additional coverage area, distance between the node and the broadcasting node, remaining battery of the node, and variations of the node density. Finally, we evaluate performance of the proposed scheme compared with the existing counter-based broadcast schemes. Simulation results show that the proposed scheme outperforms the existing schemes in terms of saved rebroadcasts, reachability, and total energy consumption.

  18. Multicore in production: advantages and limits of the multiprocess approach in the ATLAS experiment

    International Nuclear Information System (INIS)

    Binet, S; Calafiura, P; Lavrijsen, W; Leggett, C; Tatarkhanov, M; Tsulaia, V; Jha, M K; Lesny, D; Severini, H; Smith, D; Snyder, S; VanGemmeren, P; Washbrook, A

    2012-01-01

    The shared memory architecture of multicore CPUs provides HEP developers with the opportunity to reduce the memory footprint of their applications by sharing memory pages between the cores in a processor. ATLAS pioneered the multi-process approach to parallelize HEP applications. Using Linux fork() and the Copy On Write mechanism we implemented a simple event task farm, which allowed us to achieve sharing of almost 80% of memory pages among event worker processes for certain types of reconstruction jobs with negligible CPU overhead. By leaving the task of managing shared memory pages to the operating system, we have been able to parallelize large reconstruction and simulation applications originally written to be run in a single thread of execution with little to no change to the application code. The process of validating AthenaMP for production took ten months of concentrated effort and is expected to continue for several more months. Besides validating the software itself, an important and time-consuming aspect of running multicore applications in production was to configure the ATLAS distributed production system to handle multicore jobs. This entailed defining multicore batch queues, where the unit resource is not a core, but a whole computing node; monitoring the output of many event workers; and adapting the job definition layer to handle computing resources with different event throughputs. We will present scalability and memory usage studies, based on data gathered both on dedicated hardware and at the CERN Computer Center.

  19. Reachability in Biochemical Dynamical Systems by Quantitative Discrete Approximation (extended abstract

    Directory of Open Access Journals (Sweden)

    L. Brim

    2011-09-01

    Full Text Available In this paper, a novel computational technique for finite discrete approximation of continuous dynamical systems suitable for a significant class of biochemical dynamical systems is introduced. The method is parameterized in order to affect the imposed level of approximation provided that with increasing parameter value the approximation converges to the original continuous system. By employing this approximation technique, we present algorithms solving the reachability problem for biochemical dynamical systems. The presented method and algorithms are evaluated on several exemplary biological models and on a real case study.

  20. Re-verification of a Lip Synchronization Protocol using Robust Reachability

    Directory of Open Access Journals (Sweden)

    Piotr Kordy

    2010-03-01

    Full Text Available The timed automata formalism is an important model for specifying and analysing real-time systems. Robustness is the correctness of the model in the presence of small drifts on clocks or imprecision in testing guards. A symbolic algorithm for the analysis of the robustness of timed automata has been implemented. In this paper, we re-analyse an industrial case lip synchronization protocol using the new robust reachability algorithm. This lip synchronization protocol is an interesting case because timing aspects are crucial for the correctness of the protocol. Several versions of the model are considered: with an ideal video stream, with anchored jitter, and with non-anchored jitter.

  1. Reachable set estimation for Takagi-Sugeno fuzzy systems against unknown output delays with application to tracking control of AUVs.

    Science.gov (United States)

    Zhong, Zhixiong; Zhu, Yanzheng; Ahn, Choon Ki

    2018-03-20

    In this paper, we address the problem of reachable set estimation for continuous-time Takagi-Sugeno (T-S) fuzzy systems subject to unknown output delays. Based on the reachable set concept, a new controller design method is also discussed for such systems. An effective method is developed to attenuate the negative impact from the unknown output delays, which likely degrade the performance/stability of systems. First, an augmented fuzzy observer is proposed to capacitate a synchronous estimation for the system state and the disturbance term owing to the unknown output delays, which ensures that the reachable set of the estimation error is limited via the intersection operation of ellipsoids. Then, a compensation technique is employed to eliminate the influence on the system performance stemmed from the unknown output delays. Finally, the effectiveness and correctness of the obtained theories are verified by the tracking control of autonomous underwater vehicles. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  2. The influence of anxiety and personality factors on comfort and reachability space: a correlational study.

    Science.gov (United States)

    Iachini, Tina; Ruggiero, Gennaro; Ruotolo, Francesco; Schiano di Cola, Armando; Senese, Vincenzo Paolo

    2015-09-01

    Although the effects of several personality factors on interpersonal space (i.e. social space within personal comfort area) are well documented, it is not clear whether they also extend to peripersonal space (i.e. reaching space). Indeed, no study has directly compared these spaces in relation to personality and anxiety factors even though such a comparison would help to clarify to what extent they share similar mechanisms and characteristics. The aim of the present paper was to investigate whether personality dimensions and anxiety levels are associated with reaching and comfort distances. Seventy university students (35 females) were administered the Big Five Questionnaire and the State-Trait Anxiety Inventory; afterwards, they had to provide reachability- and comfort-distance judgments towards human confederates while standing still (passive) or walking towards them (active). The correlation analyses showed that both spaces were positively related to anxiety and negatively correlated with the Dynamism in the active condition. Moreover, in the passive condition higher Emotional Stability was related to shorter comfort distance, while higher cognitive Openness was associated with shorter reachability distance. The implications of these results are discussed.

  3. A Comparison of Sequential and GPU Implementations of Iterative Methods to Compute Reachability Probabilities

    Directory of Open Access Journals (Sweden)

    Elise Cormie-Bowins

    2012-10-01

    Full Text Available We consider the problem of computing reachability probabilities: given a Markov chain, an initial state of the Markov chain, and a set of goal states of the Markov chain, what is the probability of reaching any of the goal states from the initial state? This problem can be reduced to solving a linear equation Ax = b for x, where A is a matrix and b is a vector. We consider two iterative methods to solve the linear equation: the Jacobi method and the biconjugate gradient stabilized (BiCGStab method. For both methods, a sequential and a parallel version have been implemented. The parallel versions have been implemented on the compute unified device architecture (CUDA so that they can be run on a NVIDIA graphics processing unit (GPU. From our experiments we conclude that as the size of the matrix increases, the CUDA implementations outperform the sequential implementations. Furthermore, the BiCGStab method performs better than the Jacobi method for dense matrices, whereas the Jacobi method does better for sparse ones. Since the reachability probabilities problem plays a key role in probabilistic model checking, we also compared the implementations for matrices obtained from a probabilistic model checker. Our experiments support the conjecture by Bosnacki et al. that the Jacobi method is superior to Krylov subspace methods, a class to which the BiCGStab method belongs, for probabilistic model checking.

  4. A First Step Towards High-Level Cost Models for the Implementation of SDRs on Multiprocessing Reconfigurable Systems

    DEFF Research Database (Denmark)

    Le Moullec, Yannick

    2011-01-01

    -In-Progress paper we introduce our set of high-level estimation models for Area-Time costs of applications mapped onto FPGA-based multiprocessing reconfigurable architectures. In particular, we suggest models for static and dynamic implementations, taking various internal and external architectural elements...... into account. We believe that such models could be used for rapidly comparing implementation alternatives at a high level of abstraction and for guiding the designer during the (pre)analysis phase of the design flow for the implementation of e.g. SDR platforms....

  5. Predicting multiprocessing efficiency on the Cray multiprocessors in a (CTSS) time-sharing environment/application to a 3-D magnetohydrodynamics code

    International Nuclear Information System (INIS)

    Mirin, A.A.

    1988-01-01

    A formula is derived for predicting multiprocessing efficiency on Cray supercomputers equipped with the Cray Time-Sharing System (CTSS). The model is applicable to an intensive time-sharing environment. The actual efficiency estimate depends on three factors: the code size, task length, and job mix. The implementation of multitasking in a three-dimensional plasma magnetohydrodynamics (MHD) code, TEMCO, is discussed. TEMCO solves the primitive one-fluid compressible MHD equations and includes resistive and Hall effects in Ohm's law. Virtually all segments of the main time-integration loop are multitasked. The multiprocessing efficiency model is applied to TEMCO. Excellent agreement is obtained between the actual multiprocessing efficiency and the theoretical prediction

  6. Modelling temporal networks of human face-to-face contacts with public activity and individual reachability

    Science.gov (United States)

    Zhang, Yi-Qing; Cui, Jing; Zhang, Shu-Min; Zhang, Qi; Li, Xiang

    2016-02-01

    Modelling temporal networks of human face-to-face contacts is vital both for understanding the spread of airborne pathogens and word-of-mouth spreading of information. Although many efforts have been devoted to model these temporal networks, there are still two important social features, public activity and individual reachability, have been ignored in these models. Here we present a simple model that captures these two features and other typical properties of empirical face-to-face contact networks. The model describes agents which are characterized by an attractiveness to slow down the motion of nearby people, have event-triggered active probability and perform an activity-dependent biased random walk in a square box with periodic boundary. The model quantitatively reproduces two empirical temporal networks of human face-to-face contacts which are testified by their network properties and the epidemic spread dynamics on them.

  7. Control mechanisms for stochastic biochemical systems via computation of reachable sets.

    Science.gov (United States)

    Lakatos, Eszter; Stumpf, Michael P H

    2017-08-01

    Controlling the behaviour of cells by rationally guiding molecular processes is an overarching aim of much of synthetic biology. Molecular processes, however, are notoriously noisy and frequently nonlinear. We present an approach to studying the impact of control measures on motifs of molecular interactions that addresses the problems faced in many biological systems: stochasticity, parameter uncertainty and nonlinearity. We show that our reachability analysis formalism can describe the potential behaviour of biological (naturally evolved as well as engineered) systems, and provides a set of bounds on their dynamics at the level of population statistics: for example, we can obtain the possible ranges of means and variances of mRNA and protein expression levels, even in the presence of uncertainty about model parameters.

  8. A transmission power optimization with a minimum node degree for energy-efficient wireless sensor networks with full-reachability.

    Science.gov (United States)

    Chen, Yi-Ting; Horng, Mong-Fong; Lo, Chih-Cheng; Chu, Shu-Chuan; Pan, Jeng-Shyang; Liao, Bin-Yih

    2013-03-20

    Transmission power optimization is the most significant factor in prolonging the lifetime and maintaining the connection quality of wireless sensor networks. Un-optimized transmission power of nodes either interferes with or fails to link neighboring nodes. The optimization of transmission power depends on the expected node degree and node distribution. In this study, an optimization approach to an energy-efficient and full reachability wireless sensor network is proposed. In the proposed approach, an adjustment model of the transmission range with a minimum node degree is proposed that focuses on topology control and optimization of the transmission range according to node degree and node density. The model adjusts the tradeoff between energy efficiency and full reachability to obtain an ideal transmission range. In addition, connectivity and reachability are used as performance indices to evaluate the connection quality of a network. The two indices are compared to demonstrate the practicability of framework through simulation results. Furthermore, the relationship between the indices under the conditions of various node degrees is analyzed to generalize the characteristics of node densities. The research results on the reliability and feasibility of the proposed approach will benefit the future real deployments.

  9. A Transmission Power Optimization with a Minimum Node Degree for Energy-Efficient Wireless Sensor Networks with Full-Reachability

    Science.gov (United States)

    Chen, Yi-Ting; Horng, Mong-Fong; Lo, Chih-Cheng; Chu, Shu-Chuan; Pan, Jeng-Shyang; Liao, Bin-Yih

    2013-01-01

    Transmission power optimization is the most significant factor in prolonging the lifetime and maintaining the connection quality of wireless sensor networks. Un-optimized transmission power of nodes either interferes with or fails to link neighboring nodes. The optimization of transmission power depends on the expected node degree and node distribution. In this study, an optimization approach to an energy-efficient and full reachability wireless sensor network is proposed. In the proposed approach, an adjustment model of the transmission range with a minimum node degree is proposed that focuses on topology control and optimization of the transmission range according to node degree and node density. The model adjusts the tradeoff between energy efficiency and full reachability to obtain an ideal transmission range. In addition, connectivity and reachability are used as performance indices to evaluate the connection quality of a network. The two indices are compared to demonstrate the practicability of framework through simulation results. Furthermore, the relationship between the indices under the conditions of various node degrees is analyzed to generalize the characteristics of node densities. The research results on the reliability and feasibility of the proposed approach will benefit the future real deployments. PMID:23519351

  10. Reachability Does Not Explain the Middle Preference: A Comment on Bar-Hillel (2015

    Directory of Open Access Journals (Sweden)

    Paul Rodway

    2016-03-01

    Full Text Available Choosing an object from an array of similar objects is a task that people complete frequently throughout their lives (e.g., choosing a can of soup from many cans of soup. Research has also demonstrated that items in the middle of an array or scene are looked at more often and are more likely to be chosen. This middle preference is surprisingly robust and widespread, having been found in a wide range of perceptual-motor tasks. In a recent review of the literature, Bar-Hillel (2015 proposes, among other things, that the middle preference is largely explained by the middle item being easier to reach, either physically or mentally. We specifically evaluate Bar-Hillel’s reachability explanation for choice in non-interactive situations in light of evidence showing an effect of item valence on such choices. This leads us to conclude that the center-stage heuristic account is a more plausible explanation of the middle preference.

  11. Reachable Distance Space: Efficient Sampling-Based Planning for Spatially Constrained Systems

    KAUST Repository

    Xinyu Tang,

    2010-01-25

    Motion planning for spatially constrained robots is difficult due to additional constraints placed on the robot, such as closure constraints for closed chains or requirements on end-effector placement for articulated linkages. It is usually computationally too expensive to apply sampling-based planners to these problems since it is difficult to generate valid configurations. We overcome this challenge by redefining the robot\\'s degrees of freedom and constraints into a new set of parameters, called reachable distance space (RD-space), in which all configurations lie in the set of constraint-satisfying subspaces. This enables us to directly sample the constrained subspaces with complexity linear in the number of the robot\\'s degrees of freedom. In addition to supporting efficient sampling of configurations, we show that the RD-space formulation naturally supports planning and, in particular, we design a local planner suitable for use by sampling-based planners. We demonstrate the effectiveness and efficiency of our approach for several systems including closed chain planning with multiple loops, restricted end-effector sampling, and on-line planning for drawing/sculpting. We can sample single-loop closed chain systems with 1,000 links in time comparable to open chain sampling, and we can generate samples for 1,000-link multi-loop systems of varying topologies in less than a second. © 2010 The Author(s).

  12. Running ATLAS workloads within massively parallel distributed applications using Athena Multi-Process framework (AthenaMP)

    CERN Document Server

    Calafiura, Paolo; The ATLAS collaboration; Seuster, Rolf; Tsulaia, Vakhtang; van Gemmeren, Peter

    2015-01-01

    AthenaMP is a multi-process version of the ATLAS reconstruction and data analysis framework Athena. By leveraging Linux fork and copy-on-write, it allows the sharing of memory pages between event processors running on the same compute node with little to no change in the application code. Originally targeted to optimize the memory footprint of reconstruction jobs, AthenaMP has demonstrated that it can reduce the memory usage of certain confugurations of ATLAS production jobs by a factor of 2. AthenaMP has also evolved to become the parallel event-processing core of the recently developed ATLAS infrastructure for fine-grained event processing (Event Service) which allows to run AthenaMP inside massively parallel distributed applications on hundreds of compute nodes simultaneously. We present the architecture of AthenaMP, various strategies implemented by AthenaMP for scheduling workload to worker processes (for example: Shared Event Queue and Shared Distributor of Event Tokens) and the usage of AthenaMP in the...

  13. Running ATLAS workloads within massively parallel distributed applications using Athena Multi-Process framework (AthenaMP)

    CERN Document Server

    Calafiura, Paolo; Seuster, Rolf; Tsulaia, Vakhtang; van Gemmeren, Peter

    2015-01-01

    AthenaMP is a multi-process version of the ATLAS reconstruction, simulation and data analysis framework Athena. By leveraging Linux fork and copy-on-write, it allows for sharing of memory pages between event processors running on the same compute node with little to no change in the application code. Originally targeted to optimize the memory footprint of reconstruction jobs, AthenaMP has demonstrated that it can reduce the memory usage of certain configurations of ATLAS production jobs by a factor of 2. AthenaMP has also evolved to become the parallel event-processing core of the recently developed ATLAS infrastructure for fine-grained event processing (Event Service) which allows to run AthenaMP inside massively parallel distributed applications on hundreds of compute nodes simultaneously. We present the architecture of AthenaMP, various strategies implemented by AthenaMP for scheduling workload to worker processes (for example: Shared Event Queue and Shared Distributor of Event Tokens) and the usage of Ath...

  14. Use of a multi-process phytoremediation system for decontamination of petroleum impacted soils : results of successful field trials

    International Nuclear Information System (INIS)

    Greenberg, B.M.; Gurska, J.; Huang, X.D.; Gerhardt, K.E.; Yu, X.M.; Nykamp, J.; MacNeill, G.; Yang, S.; Lu, X.; Glick, B.; Wang, W.; Knezevich, N.; Reid, N.

    2008-01-01

    The multi-process phytoremediation system (MPPS) was developed to degrade petroleum hydrocarbons (PHCs) in impacted soils. Phytoremediation of persistent contaminants in soils holds significant promise for rapid remediation kinetics. MPPS effectively removes polycyclic aromatic hydrocarbons (PAHs), total petroleum hydrocarbons (TPHs) and chlorinated hydrocarbons (CHCs) from soils. A plant growth promoting rhizobacteria interaction is the main element for success as it mitigates stress ethylene effects in plants, leading to high root biomass which, in turn, promotes growth of rhizosphere organisms. Field tests of the MPPS were initiated at a farm site in Sarnia, Ontario in the summer of 2004. The field was contaminated with petroleum hydrocarbons from refinery oil sludge. The second field trial was performed for 3 consecutive years at a petroleum contaminated biopile in Turner Valley, Alberta. The paper presented the results of the successful field tests of the MPPS. It was concluded that increased root biomass is achieved in the contaminated soils, which leads to more efficient and complete removal of TPHs in the field. Three years of field trials of the MPPS showed that remediation continues with successive seasons. 28 refs., 1 tab., 3 figs

  15. Successful field tests of a multi-process phytoremediation system for decontamination of persistent petroleum and organic contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Greenberg, B.M.; Huang, X.D.; Gurska, Y.; Gerhardt, K.E.; Wang, W.; Lampi, M.A.; Zhang, C.; Khalid, A.; Isherwood, D.; Chang, P.; Wang, H.; Dixon, D.G.; Glick, B.R. [Waterloo Univ., ON (Canada)

    2006-07-01

    A large number of aquatic and terrestrial environments are polluted with various levels of toxicants. Metals, organics and total petroleum hydrocarbons from anthropogenic sources pose a risk to both human health and the health of ecosystems. Although these persistent contaminants are difficult to remediate, several industrial sites throughout North America are being remediated as part of land reclamation and restoration programs. This paper addressed the issue of phytoremediation for removing contaminants from soils. Phytoremediation is considered to be a viable remediation strategy because the increased biomass of plants, relative to the biomass of soil microbes in the absence of plants, allows for higher throughput. Extensive root systems can infiltrate large volumes of soil, thus promoting degradation of contaminants over a wide area. This paper described a newly developed multi-process phytoremediation system with accelerated remediation kinetics to effectively remove polycyclic aromatic hydrocarbons (PAH), total petroleum hydrocarbons (TPH) and chlorinated hydrocarbons (CHC) from soils. The system combines land farming/sunlight exposure; inoculation of contaminant degrading bacteria; and, plant growth with plant growth promoting rhizobacteria which mitigates the effects of stress ethylene in plants. The primary factor for success was the interaction between the plant and the plant growth promoting rhizobacteria. Several field tests were conducted following successful greenhouse tests. Results at a TPH contaminated site in Sarnia, Ontario showed that over a 2 year period, 60 to 70 per cent remediation of 15 per cent TPH was achieved. At a site in Turner Valley, Alberta, 35 per cent remediation of 1 per cent recalcitrant TPH was achieved, while a DDT contaminated site near Simcoe, Ontario had nearly 30 per cent of CHC removed in a 3 month period. 34 refs., 2 tabs., 2 figs.

  16. Applicability of a track-based multiprocess portable robot to some maintenance tasks in CANDU nuclear plants

    International Nuclear Information System (INIS)

    Hazel, B.; Fihey, J.-L.; Laroche, Y.

    2000-01-01

    Hydro-Quebec has developed a six-axis, track-based, multiprocess robot. This lightweight (30 kg) compact robot travels on a bent track with a radius of curvature ranging from 1 m to infinity (straight track). Standard and tandem wires GMAW, FCAW and Narrow gap TIG welding as well as plasma gouging and cutting, electrical and pneumatic rough and precision grinding, and profile measurement functionalities have been incorporated. A description of this technology an its newly developed functionalities is given in this paper. Since 1995, a number of industrial and R and D projects have been performed using this technology now called the Scompi technology. The main field of application is the in situ repair of hydraulic turbine runners. However some applications have been developed in the nuclear field. One particular development was funded by the International Thermonuclear Experimental Reactor (ITER) project. Scompi was selected by the ITER US Home Team for a demonstration of remote techniques for welding, cutting and rewelding the 30 m diameter, 17 m high, vacuum vessel. The demonstration involved all position robotic plasma cutting and NG-TIG welding of a 316L, 40 mm thick, double wall. In 1998, two Scompi robots working in tandem performed in York, Pa, the joint welding and cutting of a full scale portion of the vacuum vessel. In 1995, the applicability of the Scompi technology to the repair of the divider plates in the four steam generators at Gentilly-2 was evaluated based on a joint proposal by Ontario Hydro Technologies (now Ontario Power Technologies-OPT) and Hydro-Quebec. A MIG welding procedure was proposed for the horizontal and vertical divider plates welds. A complete simulation of the robot and primary head demonstrated the feasibility of the concept. However, based on cost and scheduling, it was decided to proceed with a manual repair. Nevertheless it is anticipated that this technology will find its niche in the maintenance of Candu reactors. (author)

  17. Applicability of a track-based multiprocess portable robot to some maintenance tasks in CANDU nuclear plants

    Energy Technology Data Exchange (ETDEWEB)

    Hazel, B.; Fihey, J.-L.; Laroche, Y. [Hydro-Quebec, Varennes, Quebec (Canada)

    2000-07-01

    Hydro-Quebec has developed a six-axis, track-based, multiprocess robot. This lightweight (30 kg) compact robot travels on a bent track with a radius of curvature ranging from 1 m to infinity (straight track). Standard and tandem wires GMAW, FCAW and Narrow gap TIG welding as well as plasma gouging and cutting, electrical and pneumatic rough and precision grinding, and profile measurement functionalities have been incorporated. A description of this technology an its newly developed functionalities is given in this paper. Since 1995, a number of industrial and R and D projects have been performed using this technology now called the Scompi technology. The main field of application is the in situ repair of hydraulic turbine runners. However some applications have been developed in the nuclear field. One particular development was funded by the International Thermonuclear Experimental Reactor (ITER) project. Scompi was selected by the ITER US Home Team for a demonstration of remote techniques for welding, cutting and rewelding the 30 m diameter, 17 m high, vacuum vessel. The demonstration involved all position robotic plasma cutting and NG-TIG welding of a 316L, 40 mm thick, double wall. In 1998, two Scompi robots working in tandem performed in York, Pa, the joint welding and cutting of a full scale portion of the vacuum vessel. In 1995, the applicability of the Scompi technology to the repair of the divider plates in the four steam generators at Gentilly-2 was evaluated based on a joint proposal by Ontario Hydro Technologies (now Ontario Power Technologies-OPT) and Hydro-Quebec. A MIG welding procedure was proposed for the horizontal and vertical divider plates welds. A complete simulation of the robot and primary head demonstrated the feasibility of the concept. However, based on cost and scheduling, it was decided to proceed with a manual repair. Nevertheless it is anticipated that this technology will find its niche in the maintenance of Candu reactors. (author)

  18. Identification of Biodegradation Pathways in a Multi-Process Phytoremediation System (MPPS) Using Natural Abundance 14C Analysis of PLFA

    Science.gov (United States)

    Cowie, B. R.; Greenberg, B. M.; Slater, G. F.

    2008-12-01

    Optimizing remediation of petroleum-contaminated soils requires thorough understanding of the mechanisms and pathways involved in a proposed remediation system. In many engineered and natural attenuation systems, multiple degradation pathways may contribute to observed contaminant mass losses. In this study, biodegradation in the soil microbial community was identified as a major pathway for petroleum hydrocarbon removal in a Multi-Process Phytoremediation System (MPPS) using natural abundance 14C analysis of Phospholipid Fatty Acids (PLFA). In contaminated soils, PLFA were depleted in Δ14C to less than -800‰, directly demonstrating microbial uptake and utilization of petroleum derived carbon (Δ14C = -992‰) during bioremediation. Mass balance indicated that more than 80% of microbial carbon was derived from petroleum hydrocarbons and a maximum of 20% was produced from metabolism of modern carbon sources. In contrast, in a nearby uncontaminated control soil, the microbial community maintained a nearly modern 14C signature, suggesting preferential degradation of more labile, recent carbon. Mass balance using δ13C and Δ14C of soil CO2 demonstrated that mineralization of petroleum carbon contributed 60-65% of soil CO2 at the contaminated site. The remainder was derived from atmospheric (27-30%) and decomposition of non- petroleum natural organic carbon (5-10%). The clean control exhibited substantially lower CO2 concentrations that were derived from atmospheric (55%) and natural organic carbon (45%) sources. This study highlights the value of using multiple carbon isotopes to identify degradation pathways in petroleum- contaminated soils undergoing phytoremediation and the power of natural abundance 14C to detect petroleum metabolism in natural microbial communities.

  19. Successful field tests of a multi-process phytoremediation system for decontamination of persistent petroleum and organic contaminants

    International Nuclear Information System (INIS)

    Greenberg, B.M.; Huang, X.D.; Gurska, Y.; Gerhardt, K.E.; Wang, W.; Lampi, M.A.; Zhang, C.; Khalid, A.; Isherwood, D.; Chang, P.; Wang, H.; Dixon, D.G.; Glick, B.R.

    2006-01-01

    A large number of aquatic and terrestrial environments are polluted with various levels of toxicants. Metals, organics and total petroleum hydrocarbons from anthropogenic sources pose a risk to both human health and the health of ecosystems. Although these persistent contaminants are difficult to remediate, several industrial sites throughout North America are being remediated as part of land reclamation and restoration programs. This paper addressed the issue of phytoremediation for removing contaminants from soils. Phytoremediation is considered to be a viable remediation strategy because the increased biomass of plants, relative to the biomass of soil microbes in the absence of plants, allows for higher throughput. Extensive root systems can infiltrate large volumes of soil, thus promoting degradation of contaminants over a wide area. This paper described a newly developed multi-process phytoremediation system with accelerated remediation kinetics to effectively remove polycyclic aromatic hydrocarbons (PAH), total petroleum hydrocarbons (TPH) and chlorinated hydrocarbons (CHC) from soils. The system combines land farming/sunlight exposure; inoculation of contaminant degrading bacteria; and, plant growth with plant growth promoting rhizobacteria which mitigates the effects of stress ethylene in plants. The primary factor for success was the interaction between the plant and the plant growth promoting rhizobacteria. Several field tests were conducted following successful greenhouse tests. Results at a TPH contaminated site in Sarnia, Ontario showed that over a 2 year period, 60 to 70 per cent remediation of 15 per cent TPH was achieved. At a site in Turner Valley, Alberta, 35 per cent remediation of 1 per cent recalcitrant TPH was achieved, while a DDT contaminated site near Simcoe, Ontario had nearly 30 per cent of CHC removed in a 3 month period. 34 refs., 2 tabs., 2 figs

  20. A multi-process model of self-regulation: influences of mindfulness, integrative self-knowledge and self-control in Iran.

    Science.gov (United States)

    Ghorbani, Nima; Watson, P J; Farhadi, Mehran; Chen, Zhuo

    2014-04-01

    Self-regulation presumably rests upon multiple processes that include an awareness of ongoing self-experience, enduring self-knowledge and self-control. The present investigation tested this multi-process model using the Five-Facet Mindfulness Questionnaire (FFMQ) and the Integrative Self-Knowledge and Brief Self-Control Scales. Using a sample of 1162 Iranian university students, we confirmed the five-factor structure of the FFMQ in Iran and documented its factorial invariance across males and females. Self-regulatory variables correlated negatively with Perceived Stress, Depression, and Anxiety and positively with Self-Esteem and Satisfaction with Life. Partial mediation effects confirmed that self-regulatory measures ameliorated the disturbing effects of Perceived Stress. Integrative Self-Knowledge and Self-Control interacted to partially mediate the association of Perceived Stress with lower levels of Satisfaction with Life. Integrative Self-Knowledge, alone or in interaction with Self-Control, was the only self-regulation variable to display the expected mediation of Perceived Stress associations with all other measures. Self-Control failed to be implicated in self-regulation only in the mediation of Anxiety. These data confirmed the need to further examine this multi-process model of self-regulation. © 2014 International Union of Psychological Science.

  1. Development and successful field tests of a multi-process phytoremediation system for decontamination of persistent petroleum and organic contaminants in soil

    Energy Technology Data Exchange (ETDEWEB)

    Greenberg, B.M.; Huang, X.-D.; Gurska, Y.; Gerhardt, K.E.; Lampi, M.A.; Khalid, A.; Isherwood, D.; Chang, P.; Wang, W.; Wang, H.; Dixon, D.G.; Glick, B.R. [Waterloo Univ., ON (Canada). Dept. of Biology

    2006-07-01

    If efficient systems with rapid remediation kinetics can be realized, phytoremediation of persistent contaminants from soils holds great promise. A multi-process phytoremediation system (MPPS) with accelerated remediation kinetics that effectively removes polycyclic aromatic hydrocarbons (PAHs), total petroleum hydrocarbons (TPHs) and chlorinated hydrocarbons (CHCs) from soils has been developed. A plant growth promoting rhizobacteria interaction is the main element for success as it mitigates stress ethylene effects in plants, leading to high root biomass which, in turn, promotes growth of rhizosphere organisms. Based on the success of greenhouse experiments, field tests of the MPPS were initiated at an Imperial Oil land farm site in Sarnia, Ontario in the summer of 2004, followed by 127 field tests at the same site in the summer of 2005 and 2006. In addition, a total petroleum hydrocarbons (TPH) contaminated site in Alberta was used in 2005 and 2006. The study presented and discussed selected results of successful greenhouse, pilot field tests and field tests of the MPPS. It was concluded that increased root biomass is achieved in the contaminated soils, which leads to more efficient and complete removal of TPHs in the field. Three years of field trials of the MPPS showed that remediation continues with successive seasons. 27 refs., 2 tabs., 1 fig.

  2. Scalable shared-memory multiprocessing

    CERN Document Server

    Lenoski, Daniel E

    1995-01-01

    Dr. Lenoski and Dr. Weber have experience with leading-edge research and practical issues involved in implementing large-scale parallel systems. They were key contributors to the architecture and design of the DASH multiprocessor. Currently, they are involved with commercializing scalable shared-memory technology.

  3. Multiprocessing the Sieve of Eratosthenes

    Science.gov (United States)

    Bokhari, S.

    1986-01-01

    The Sieve of Eratosthenes for finding prime numbers in recent years has seen much use as a benchmark algorithm for serial computers while its intrinsically parallel nature has gone largely unnoticed. The implementation of a parallel version of this algorithm for a real parallel computer, the Flex/32, is described and its performance discussed. It is shown that the algorithm is sensitive to several fundamental performance parameters of parallel machines, such as spawning time, signaling time, memory access, and overhead of process switching. Because of the nature of the algorithm, it is impossible to get any speedup beyond 4 or 5 processors unless some form of dynamic load balancing is employed. We describe the performance of our algorithm with and without load balancing and compare it with theoretical lower bounds and simulated results. It is straightforward to understand this algorithm and to check the final results. However, its efficient implementation on a real parallel machine requires thoughtful design, especially if dynamic load balancing is desired. The fundamental operations required by the algorithm are very simple: this means that the slightest overhead appears prominently in performance data. The Sieve thus serves not only as a very severe test of the capabilities of a parallel processor but is also an interesting challenge for the programmer.

  4. Multiprocessing the Sieve of Eratosthenes

    Energy Technology Data Exchange (ETDEWEB)

    Bokhari, S.H.

    1987-04-01

    More than two thousand years ago, Eratosthenes of Cyrene described a procedure for finding all prime numbers in a given range. This straightforward algorithm, known as the Sieve of Eratosthenes, is to this day the only procedure for finding prime numbers. In recent years it has been of interest to computer scientists and engineers because it serves as a convenient benchmark against which to measure some aspects of a computer's performance. Specifically, the Sieve tests the power of a machine (or of a compiler) to access a very large array in memory rapidly and repeatedly. This power is clearly influenced by memory access time, the speed at which indexing is done, and the overhead of looping. The parallel version of the Sieve is very useful as a test of some of the capabilities of a parallel machine. The parallel algorithm is straightforward, and so is the process for checking the final results. However, the efficient implementation of the algorithm on a real parallel machine, especially in the dynamic load-balancing case, requires thoughtful design.

  5. Reachability Analysis of Probabilistic Systems

    DEFF Research Database (Denmark)

    D'Argenio, P. R.; Jeanett, B.; Jensen, Henrik Ejersbo

    2001-01-01

    than the original model, and may safely refute or accept the required property. Otherwise, the abstraction is refined and the process repeated. As the numerical analysis involved in settling the validity of the property is more costly than the refinement process, the method profits from applying...... such numerical analysis on smaller state spaces. The method is significantly enhanced by a number of novel strategies: a strategy for reducing the size of the numerical problems to be analyzed by identification of so-called {essential states}, and heuristic strategies for guiding the refinement process....

  6. From functional programming to multicore parallelism: A case study based on Presburger Arithmetic

    DEFF Research Database (Denmark)

    Dung, Phan Anh; Hansen, Michael Reichhardt

    2011-01-01

    , we are interested in using PA in connection with the Duration Calculus Model Checker (DCMC) [5]. There are effective decision procedures for PA including Cooper’s algorithm and the Omega Test; however, their complexity is extremely high with doubly exponential lower bound and triply exponential upper...... bound [7]. We investigate these decision procedures in the context of multicore parallelism with the hope of exploiting multicore powers. Unfortunately, we are not aware of any prior parallelism research related to decision procedures for PA. The closest work is the preliminary results on parallelism...

  7. Adaptive runtime for a multiprocessing API

    Science.gov (United States)

    Antao, Samuel F.; Bertolli, Carlo; Eichenberger, Alexandre E.; O'Brien, John K.

    2016-11-15

    A computer-implemented method includes selecting a runtime for executing a program. The runtime includes a first combination of feature implementations, where each feature implementation implements a feature of an application programming interface (API). Execution of the program is monitored, and the execution uses the runtime. Monitor data is generated based on the monitoring. A second combination of feature implementations are selected, by a computer processor, where the selection is based at least in part on the monitor data. The runtime is modified by activating the second combination of feature implementations to replace the first combination of feature implementations.

  8. Simulation of experimental breakthrough curves using multiprocess ...

    Indian Academy of Sciences (India)

    The transport of contaminant through porous media is a very complex ... Elzein & Booker (1999) presented boundary element method to solve ... Because of minimum flow through immobile region, it is behaving as a dis- ..... before performing the experiments to measure the concentration of free chloride and fluoride.

  9. Prospects of experimentally reachable beyond Standard Model ...

    Indian Academy of Sciences (India)

    2016-01-06

    Jan 6, 2016 ... Since then, the theory has been experimentally verified to a ... Despite the fact that SM has unravelled the gauge origin of fundamental forces and the structure of Universe while successfully confronting numerous ...

  10. Sparse Dataflow Analysis with Pointers and Reachability

    DEFF Research Database (Denmark)

    Madsen, Magnus; Møller, Anders

    2014-01-01

    quadtrees. The framework is presented as a systematic modification of a traditional dataflow analysis algorithm. Our experimental results demonstrate the effectiveness of the technique for a suite of JavaScript programs. By also comparing the performance with an idealized staged approach that computes...

  11. Probabilistic Reachability for Parametric Markov Models

    DEFF Research Database (Denmark)

    Hahn, Ernst Moritz; Hermanns, Holger; Zhang, Lijun

    2011-01-01

    Given a parametric Markov model, we consider the problem of computing the rational function expressing the probability of reaching a given set of states. To attack this principal problem, Daws has suggested to first convert the Markov chain into a finite automaton, from which a regular expression...

  12. Criteria for reachability of quantum states

    Energy Technology Data Exchange (ETDEWEB)

    Schirmer, S.G.; Solomon, A.I. [Quantum Processes Group and Department of Applied Maths, Open University, Milton Keynes (United Kingdom)]. E-mails: S.G.Schirmer@open.ac.uk; A.I.Solomon@open.ac.uk; Leahy, J.V. [Department of Mathematics and Institute of Theoretical Science, University of Oregon, Eugene, OR (United States)]. E-mail: leahy@math.uoregon.edu

    2002-10-11

    We address the question of which quantum states can be inter-converted under the action of a time-dependent Hamiltonian. In particular, we consider the problem as applied to mixed states, and investigate the difference between pure- and mixed-state controllabilities introduced in previous work. We provide a complete characterization of the eigenvalue spectrum for which the state is controllable under the action of the symplectic group. We also address the problem of which states can be prepared if the dynamical Lie group is not sufficiently large to allow the system to be controllable. (author)

  13. Characteristics of multiprocessing MCNP5 on small personal computer clusters

    International Nuclear Information System (INIS)

    Robinson, S M; Mc Conn, R J Jr; Pagh, R T; Schweppe, J E; Siciliano, E R

    2006-01-01

    The feasibility and efficiency of performing MCNP5 calculations with a small, heterogeneous computing cluster built from Microsoft ( R) Windows TM personal computers (PC) are explored. The performance increases that may be expected with such clusters are estimated for cases that typify general radiation-shielding calculations. Our results show that the speed increase from additional slave PCs is nearly linear up to 10 processors. Guidance is given as to the specific advantages of changing various parameters present in the system. Implementing load balancing, and reducing the overhead from the MCNP rendezvous mechanism add to heterogeneous cluster efficiency. Hyper-threading technology and matching the total number of slave processes to the total number of logical processors also yield modest speed increases in the range below 7 processors. Because of the ease of acquisition of heterogeneous desktop computers, and the peak in efficiency at the level of a few physical processors, a strong case is made for the use of small clusters as a tool for producing MCNP5 calculations rapidly, and detailed instructions for constructing such clusters are provided

  14. Veridical and False Memory for Text: A Multiprocess Analysis

    Science.gov (United States)

    Singer, Murray; Remillard, Gilbert

    2008-01-01

    People report recognizing discourse inferences at rates that approach target acceptance. Brainerd et al. [Brainerd, C. J., Wright, R., Reyna, V. F., & Mojardin, A. H. (2001). "Conjoint recognition and phantom recollection." "Journal of Experimental Psychology: Learning, Memory, and Cognition, 27", 307-329] proposed that…

  15. Introduction of Virtualization Technology to Multi-Process Model Checking

    Science.gov (United States)

    Leungwattanakit, Watcharin; Artho, Cyrille; Hagiya, Masami; Tanabe, Yoshinori; Yamamoto, Mitsuharu

    2009-01-01

    Model checkers find failures in software by exploring every possible execution schedule. Java PathFinder (JPF), a Java model checker, has been extended recently to cover networked applications by caching data transferred in a communication channel. A target process is executed by JPF, whereas its peer process runs on a regular virtual machine outside. However, non-deterministic target programs may produce different output data in each schedule, causing the cache to restart the peer process to handle the different set of data. Virtualization tools could help us restore previous states of peers, eliminating peer restart. This paper proposes the application of virtualization technology to networked model checking, concentrating on JPF.

  16. On the Scalability of Time-predictable Chip-Multiprocessing

    DEFF Research Database (Denmark)

    Puffitsch, Wolfgang; Schoeberl, Martin

    2012-01-01

    Real-time systems need a time-predictable execution platform to be able to determine the worst-case execution time statically. In order to be time-predictable, several advanced processor features, such as out-of-order execution and other forms of speculation, have to be avoided. However, just using...... simple processors is not an option for embedded systems with high demands on computing power. In order to provide high performance and predictability we argue to use multiprocessor systems with a time-predictable memory interface. In this paper we present the scalability of a Java chip......-multiprocessor system that is designed to be time-predictable. Adding time-predictable caches is mandatory to achieve scalability with a shared memory multi-processor system. As Java bytecode retains information about the nature of memory accesses, it is possible to implement a memory hierarchy that takes...

  17. FAST - A multiprocessed environment for visualization of computational fluid dynamics

    International Nuclear Information System (INIS)

    Bancroft, G.V.; Merritt, F.J.; Plessel, T.C.; Kelaita, P.G.; Mccabe, R.K.

    1991-01-01

    The paper presents the Flow Analysis Software Toolset (FAST) to be used for fluid-mechanics analysis. The design criteria for FAST including the minimization of the data path in the computational fluid-dynamics (CFD) process, consistent user interface, extensible software architecture, modularization, and the isolation of three-dimensional tasks from the application programmer are outlined. Each separate process communicates through the FAST Hub, while other modules such as FAST Central, NAS file input, CFD calculator, surface extractor and renderer, titler, tracer, and isolev might work together to generate the scene. An interprocess communication package making it possible for FAST to operate as a modular environment where resources could be shared among different machines as well as a single host is discussed. 20 refs

  18. Enhancement of multiprocessing environment for the E poultry system

    International Nuclear Information System (INIS)

    Sattar, A.R.; Mustafa, T.; Bibi, S.; Javed, M.Y.

    2009-01-01

    The complete precision poultry system works over the number of multiple logical processes used inside the processors. The efficiency and accuracy can be enhanced by simply optimization of these processes used in processors. This high speed computing requires multitasking and parallel processing to increase the throughput of the system and optimizes use of system resources. In the multitasking environment, when a great number of processes execute in parallel, there may be some data structures like semaphores which are common or shared between different numbers of processes. Due to this sharing, different critical sections are produced. The research work presented in this paper resolves the critical section problem of multiple processes using semaphore implementation. The development of a simulator for the resolution of critical section problem is presented. It is a comprehensive tool which runs a simulation in real time and generates useful data for evaluation. A user friendly and mouse-driven GUI has also been integrated. The developed system has been put through extensive experiments. Results are taken using different sets of processes for different number of common variables on a number of processes. The evaluation results are very promising and could be used to further enhance performance of multi-user and multitasking operating systems under different processors to deal with common semaphores. (author)

  19. FAMP: An example of multiprocessing in high energy physics

    International Nuclear Information System (INIS)

    Hertzberger, L.O.

    1983-04-01

    Possible applications of multi microprocessor systems in the different areas of experimental High Energy Physics are considered. It is shown that these systems, of which the Fast Amsterdam Multi Processor (FAMP) system is an example, are potentially very powerful in on-line and in off-line applications. It is discussed how the potential advantages have been exploited in the FAMP system by a careful choice of hardware and software. An overview is given of the use of the FAMP system for second-stage triggering, on-line event filtering and monitoring purposes in the NA11, UA1 and JADE experiments and of other possible applications. (Auth.)

  20. Reachability analysis to design zero-wait entry guidance

    NARCIS (Netherlands)

    Gonzalez-Puerta, Alejandro; Mooij, E.; Valles, Celia Yabar

    2018-01-01

    This paper presents a novel reentry guidance architecture that aims to improve cur- rent mission safety by enabling zero-wait orbital aborts. To do so, an on-board trajectory planner based on Adaptive Multivariate Pseudospectral Interpolation (AMPI) is devel- oped. This planner generates

  1. Link-Based Similarity Measures Using Reachability Vectors

    Directory of Open Access Journals (Sweden)

    Seok-Ho Yoon

    2014-01-01

    Full Text Available We present a novel approach for computing link-based similarities among objects accurately by utilizing the link information pertaining to the objects involved. We discuss the problems with previous link-based similarity measures and propose a novel approach for computing link based similarities that does not suffer from these problems. In the proposed approach each target object is represented by a vector. Each element of the vector corresponds to all the objects in the given data, and the value of each element denotes the weight for the corresponding object. As for this weight value, we propose to utilize the probability of reaching from the target object to the specific object, computed using the “Random Walk with Restart” strategy. Then, we define the similarity between two objects as the cosine similarity of the two vectors. In this paper, we provide examples to show that our approach does not suffer from the aforementioned problems. We also evaluate the performance of the proposed methods in comparison with existing link-based measures, qualitatively and quantitatively, with respect to two kinds of data sets, scientific papers and Web documents. Our experimental results indicate that the proposed methods significantly outperform the existing measures.

  2. Synthesis of railway-signaling plans using reachability games

    DEFF Research Database (Denmark)

    Kasting, Patrick Frederik Soelmark; Hansen, Michael Reichhardt; Vester, Steen

    2016-01-01

    (the control system) controls signals and points and the universal player (the antagonistic environment) controls movement of trains. A winning strategy for the existential player provides a signaling plan that will safely guide trains through the network. The concepts from the railway network model......In this work, we show the feasibility of using functional programming (more specifically F#) in connection with gamebased methods for synthesis of correct-by-construction controllers (also called signaling plans) for railway networks. This is a massively resource-demanding application. A model...

  3. Reachable Sets for Multiple Asteroid Sample Return Missions

    Science.gov (United States)

    2005-12-01

    Vtdot Massdot Sc al ed U ni ts Minimum Derivative Values Maximum Derivative Values Figure 15 Actual Range of State Derivates When these plots are...0.0563 -0.0016 Vtdot -0.0065 -0.0579 0.0119 0.0070 Massdot -0.0148 -0.0148 -0.0075 -0.0075 Control low bound low guess upper guess upper

  4. On the existence of continuous selections of solution and reachable ...

    African Journals Online (AJOL)

    We prove that the map that associates to the initial value the set of solutions to the Lipschitzian Quantum Stochastic Differential Inclusion (QSDI) admits a selection continuous from the locally convex space of stochastic processes to the adapted and weakly absolutely continuous space of solutions. As a corollary, we show ...

  5. Module-theoretic properties of reachability modules for SRIQ

    CSIR Research Space (South Africa)

    Nortje, R

    2013-07-01

    Full Text Available ]. Definition 1. (Module for the arbitrary DL L) Let L be an arbitrary de- scription language, O an L ontology, and σ a statement formulated in L. Then, 2 O′ ⊆ O is a module for σ in O(a σ-module in O) whenever: O |= σ if and only if O′ |= σ. Definition 1... > 1, a SRIQ TBox T is in normal form if every axiom α ∈ T is in one of the following forms: α1: B1 u . . . uBn v C1 unionsq . . . unionsq Cm α2: D v C1 unionsq . . . unionsq Cm α3: B1 u . . . uBn v D α4: R1 ◦ . . . ◦Rn v Rn+1 α5: R1 v R2 α6: D1 v D2 α7...

  6. Spatio-temporal networks: reachability, centrality and robustness.

    Science.gov (United States)

    Williams, Matthew J; Musolesi, Mirco

    2016-06-01

    Recent advances in spatial and temporal networks have enabled researchers to more-accurately describe many real-world systems such as urban transport networks. In this paper, we study the response of real-world spatio-temporal networks to random error and systematic attack, taking a unified view of their spatial and temporal performance. We propose a model of spatio-temporal paths in time-varying spatially embedded networks which captures the property that, as in many real-world systems, interaction between nodes is non-instantaneous and governed by the space in which they are embedded. Through numerical experiments on three real-world urban transport systems, we study the effect of node failure on a network's topological, temporal and spatial structure. We also demonstrate the broader applicability of this framework to three other classes of network. To identify weaknesses specific to the behaviour of a spatio-temporal system, we introduce centrality measures that evaluate the importance of a node as a structural bridge and its role in supporting spatio-temporally efficient flows through the network. This exposes the complex nature of fragility in a spatio-temporal system, showing that there is a variety of failure modes when a network is subject to systematic attacks.

  7. A Multi-Process Test Case to Perform Comparative Analysis of Coastal Oceanic Models

    Science.gov (United States)

    Lemarié, F.; Burchard, H.; Knut, K.; Debreu, L.

    2016-12-01

    Due to the wide variety of choices that need to be made during the development of dynamical kernels of oceanic models, there is a strong need for an effective and objective assessment of the various methods and approaches that predominate in the community. We present here an idealized multi-scale scenario for coastal ocean models combining estuarine, coastal and shelf sea scales at midlatitude. The bathymetry, initial conditions and external forcings are defined analytically so that any model developer or user could reproduce the test case with its own numerical code. Thermally stratified conditions are prescribed and a tidal forcing is imposed as a propagating coastal Kelvin wave. The following physical processes can be assessed from the model results: estuarine process driven by tides and buoyancy gradients, the river plume dynamics, tidal fronts, and the interaction between tides and inertial oscillations. We show results obtained using the GETM (General Estuarine Transport Model) and the CROCO (Coastal and Regional Ocean Community model) models. Those two models are representative of the diversity of numerical methods in use in coastal models: GETM is based on a quasi-lagrangian vertical coordinate, a coupled space-time approach for advective terms, a TVD (Total Variation Diminishing) tracer advection scheme while CROCO is discretized with a quasi-eulerian vertical coordinate, a method of lines is used for advective terms, and tracer advection satisfies the TVB (Total Variation Bounded) property. The multiple scales are properly resolved thanks to nesting strategies, 1-way nesting for GETM and 2-way nesting for CROCO. Such test case can be an interesting experiment to continue research in numerical approaches as well as an efficient tool to allow intercomparison between structured-grid and unstructured-grid approaches. Reference : Burchard, H., Debreu, L., Klingbeil, K., Lemarié, F. : The numerics of hydrostatic structured-grid coastal ocean models: state of the art and future perspectives. Ocean Modell.

  8. A survey on the design of multiprocessing systems for artificial intelligence applications

    Science.gov (United States)

    Wah, Benjamin W.; Li, Guo Jie

    1989-01-01

    Some issues in designing computers for artificial intelligence (AI) processing are discussed. These issues are divided into three levels: the representation level, the control level, and the processor level. The representation level deals with the knowledge and methods used to solve the problem and the means to represent it. The control level is concerned with the detection of dependencies and parallelism in the algorithmic and program representations of the problem, and with the synchronization and sheduling of concurrent tasks. The processor level addresses the hardware and architectural components needed to evaluate the algorithmic and program representations. Solutions for the problems of each level are illustrated by a number of representative systems. Design decisions in existing projects on AI computers are classed into top-down, bottom-up, and middle-out approaches.

  9. Multi-processing CTH: Porting legacy FORTRAN code to MP hardware

    Energy Technology Data Exchange (ETDEWEB)

    Bell, R.L.; Elrick, M.G.; Hertel, E.S. Jr.

    1996-12-31

    CTH is a family of codes developed at Sandia National Laboratories for use in modeling complex multi-dimensional, multi-material problems that are characterized by large deformations and/or strong shocks. A two-step, second-order accurate Eulerian solution algorithm is used to solve the mass, momentum, and energy conservation equations. CTH has historically been run on systems where the data are directly accessible to the cpu, such as workstations and vector supercomputers. Multiple cpus can be used if all data are accessible to all cpus. This is accomplished by placing compiler directives or subroutine calls within the source code. The CTH team has implemented this scheme for Cray shared memory machines under the Unicos operating system. This technique is effective, but difficult to port to other (similar) shared memory architectures because each vendor has a different format of directives or subroutine calls. A different model of high performance computing is one where many (> 1,000) cpus work on a portion of the entire problem and communicate by passing messages that contain boundary data. Most, if not all, codes that run effectively on parallel hardware were written with a parallel computing paradigm in mind. Modifying an existing code written for serial nodes poses a significantly different set of challenges that will be discussed. CTH, a legacy FORTRAN code, has been modified to allow for solutions on distributed memory parallel computers such as the IBM SP2, the Intel Paragon, Cray T3D, or a network of workstations. The message passing version of CTH will be discussed and example calculations will be presented along with performance data. Current timing studies indicate that CTH is 2--3 times faster than equivalent C++ code written specifically for parallel hardware. CTH on the Intel Paragon exhibits linear speed up with problems that are scaled (constant problem size per node) for the number of parallel nodes.

  10. An FPGA Based Multiprocessing CPU for Beam Synchronous Timing in CERN's SPS and LHC

    CERN Document Server

    Ballester, F J; Gras, J J; Lewis, J; Savioz, J J; Serrano, J

    2003-01-01

    The Beam Synchronous Timing system (BST) will be used around the LHC and its injector, the SPS, to broadcast timing meassages and synchronize actions with the beam in different receivers. To achieve beam synchronization, the BST Master card encodes messages using the bunch clock, with a nominal value of 40.079 MHz for the LHC. These messages are produced by a set of tasks every revolution period, which is every 89 us for the LHC and every 23 us for the SPS, therefore imposing a hard real-time constraint on the system. To achieve determinism, the BST Master uses a dedicated CPU inside its main Field Programmable Gate Array (FPGA) featuring zero-delay hardware task switching and a reduced instruction set. This paper describes the BST Master card, stressing the main FPGA design, as well as the associated software, including the LynxOS driver and the tailor-made assembler.

  11. Parallel-aware, dedicated job co-scheduling within/across symmetric multiprocessing nodes

    Science.gov (United States)

    Jones, Terry R.; Watson, Pythagoras C.; Tuel, William; Brenner, Larry; ,Caffrey, Patrick; Fier, Jeffrey

    2010-10-05

    In a parallel computing environment comprising a network of SMP nodes each having at least one processor, a parallel-aware co-scheduling method and system for improving the performance and scalability of a dedicated parallel job having synchronizing collective operations. The method and system uses a global co-scheduler and an operating system kernel dispatcher adapted to coordinate interfering system and daemon activities on a node and across nodes to promote intra-node and inter-node overlap of said interfering system and daemon activities as well as intra-node and inter-node overlap of said synchronizing collective operations. In this manner, the impact of random short-lived interruptions, such as timer-decrement processing and periodic daemon activity, on synchronizing collective operations is minimized on large processor-count SPMD bulk-synchronous programming styles.

  12. Precise positioning method for multi-process connecting based on binocular vision

    Science.gov (United States)

    Liu, Wei; Ding, Lichao; Zhao, Kai; Li, Xiao; Wang, Ling; Jia, Zhenyuan

    2016-01-01

    With the rapid development of aviation and aerospace, the demand for metal coating parts such as antenna reflector, eddy-current sensor and signal transmitter, etc. is more and more urgent. Such parts with varied feature dimensions, complex three-dimensional structures, and high geometric accuracy are generally fabricated by the combination of different manufacturing technology. However, it is difficult to ensure the machining precision because of the connection error between different processing methods. Therefore, a precise positioning method is proposed based on binocular micro stereo vision in this paper. Firstly, a novel and efficient camera calibration method for stereoscopic microscope is presented to solve the problems of narrow view field, small depth of focus and too many nonlinear distortions. Secondly, the extraction algorithms for law curve and free curve are given, and the spatial position relationship between the micro vision system and the machining system is determined accurately. Thirdly, a precise positioning system based on micro stereovision is set up and then embedded in a CNC machining experiment platform. Finally, the verification experiment of the positioning accuracy is conducted and the experimental results indicated that the average errors of the proposed method in the X and Y directions are 2.250 μm and 1.777 μm, respectively.

  13. Successful field trial of a multi-process phytoremediation system for remediation of petroleum impacted soils

    Energy Technology Data Exchange (ETDEWEB)

    Reid, N. [EBA Engineering Consultants Ltd., Calgary, AB (Canada); Greenberg, B.M. [Waterloo Univ., ON (Canada)]|[Waterloo Environmental Biotechnology Inc., Waterloo, ON (Canada)

    2007-07-01

    This presentation described a field trial of a new phytoremediation technology. The multi process phytoremediation system (MPPS) was designed for use in physical soil treatment and used seeds inoculated with plant growth promoting rhizobacteria (PGPR). The technology aerated the soil and photo-oxidized petroleum hydrocarbons (PHC) by exposing them to the light. In this study, 2 natural non-pathogenic strains of Pseudomonas putida were applied to seeds prior to planting. PGPR was used to create conditions suitable for the biodegradation of PHC, while also preserving natural soil structure and texture. High levels of microbial biomass in the soil were achieved. The presentation also provided details of a field study conducted in Hinton, Alberta which established vegetation in the treatment area in order to reduce PHC levels. The area was contaminated with compost invert drilling mud (CIDM) that had previously and unsuccessfully been treated with a biopile. The treatment plan consisted of aeration, soil sampling, and seeding. Soil and vegetation sampling was also conducted. Results of the study showed the vegetation was well established using the technique, and reduced hydrocarbon levels by between 17 and 53 per cent. It was concluded that continued hydrocarbon reduction levels are anticipated using the technology. tabs., figs.

  14. Reachable Sets of Hidden CPS Sensor Attacks : Analysis and Synthesis Tools

    NARCIS (Netherlands)

    Murguia, Carlos; van de Wouw, N.; Ruths, Justin; Dochain, Denis; Henrion, Didier; Peaucelle, Dimitri

    2017-01-01

    For given system dynamics, control structure, and fault/attack detection procedure, we provide mathematical tools–in terms of Linear Matrix Inequalities (LMIs)–for characterizing and minimizing the set of states that sensor attacks can induce in the system while keeping the alarm rate of the

  15. Approximation of attainable landing area of a moon lander by reachability analysis

    OpenAIRE

    Arslantas, Yunus; Oehlschlägel, Thimo; Sagliano, Marco; Theil, Stephan; Braxmaier, Claus

    2014-01-01

    Developments in space technology have paved the way for more challenging missions which require advanced guidance and control algorithms for safely and autonomously landing on celestial bodies. Instant determination of hazards, automatic guidance during landing maneuvers and likelihood maximization of safe landing are of paramount importance

  16. The influence of anxiety and personality factors on comfort and reachability space a correlational study

    NARCIS (Netherlands)

    Iachini, Tina; Ruggiero, Gennaro; Ruotolo, Francesco; Schiano di Cola, Armando; Senese, Vincenzo Paolo

    Although the effects of several personality factors on interpersonal space (i.e. social space within personal comfort area) are well documented, it is not clear whether they also extend to peripersonal space (i.e. reaching space). Indeed, no study has directly compared these spaces in relation to

  17. How Deep Is Your SNARC? Interactions Between Numerical Magnitude, Response Hands, and Reachability in Peripersonal Space

    Directory of Open Access Journals (Sweden)

    Johannes Lohmann

    2018-05-01

    Full Text Available Spatial, physical, and semantic magnitude dimensions can influence action decisions in human cognitive processing and interact with each other. For example, in the spatial-numerical associations of response code (SNARC effect, semantic numerical magnitude facilitates left-hand or right-hand responding dependent on the small or large magnitude of number symbols. SNARC-like interactions of numerical magnitudes with the radial spatial dimension (depth were postulated from early on. Usually, the SNARC effect in any direction is investigated using fronto-parallel computer monitors for presentation of stimuli. In such 2D setups, however, the metaphorical and literal interpretation of the radial depth axis with seemingly close/far stimuli or responses are not distinct. Hence, it is difficult to draw clear conclusions with respect to the contribution of different spatial mappings to the SNARC effect. In order to disentangle the different mappings in a natural way, we studied parametrical interactions between semantic numerical magnitude, horizontal directional responses, and perceptual distance by means of stereoscopic depth in an immersive virtual reality (VR. Two VR experiments show horizontal SNARC effects across all spatial displacements in traditional latency measures and kinematic response parameters. No indications of a SNARC effect along the depth axis, as it would be predicted by a direct mapping account, were observed, but the results show a non-linear relationship between horizontal SNARC slopes and physical distance. Steepest SNARC slopes were observed for digits presented close to the hands. We conclude that spatial-numerical processing is susceptible to effector-based processes but relatively resilient to task-irrelevant variations of radial-spatial magnitudes.

  18. How Deep Is Your SNARC? Interactions Between Numerical Magnitude, Response Hands, and Reachability in Peripersonal Space.

    Science.gov (United States)

    Lohmann, Johannes; Schroeder, Philipp A; Nuerk, Hans-Christoph; Plewnia, Christian; Butz, Martin V

    2018-01-01

    Spatial, physical, and semantic magnitude dimensions can influence action decisions in human cognitive processing and interact with each other. For example, in the spatial-numerical associations of response code (SNARC) effect, semantic numerical magnitude facilitates left-hand or right-hand responding dependent on the small or large magnitude of number symbols. SNARC-like interactions of numerical magnitudes with the radial spatial dimension (depth) were postulated from early on. Usually, the SNARC effect in any direction is investigated using fronto-parallel computer monitors for presentation of stimuli. In such 2D setups, however, the metaphorical and literal interpretation of the radial depth axis with seemingly close/far stimuli or responses are not distinct. Hence, it is difficult to draw clear conclusions with respect to the contribution of different spatial mappings to the SNARC effect. In order to disentangle the different mappings in a natural way, we studied parametrical interactions between semantic numerical magnitude, horizontal directional responses, and perceptual distance by means of stereoscopic depth in an immersive virtual reality (VR). Two VR experiments show horizontal SNARC effects across all spatial displacements in traditional latency measures and kinematic response parameters. No indications of a SNARC effect along the depth axis, as it would be predicted by a direct mapping account, were observed, but the results show a non-linear relationship between horizontal SNARC slopes and physical distance. Steepest SNARC slopes were observed for digits presented close to the hands. We conclude that spatial-numerical processing is susceptible to effector-based processes but relatively resilient to task-irrelevant variations of radial-spatial magnitudes.

  19. Reachability and Real-Time Actuation Strategies for the Active SLIP Model

    Science.gov (United States)

    2015-06-01

    time. In gen- eral, animals’ anatomy is far more complex than what the SLIP model captures, due to the presence of joints, ankles , knees, hips, leg...strategies for locomotion. These strategies can then be applied to an anchor , a more complex and realistic model to mimic the animal’s morphology and...model. As clearly explained in [1], the ideal SLIP model is a template that can then be ” anchored ” to systems with more complex dynamics. The prototype

  20. Predicting Host Level Reachability via Static Analysis of Routing Protocol Configuration

    Science.gov (United States)

    2007-09-01

    check_function_bodies = false; SET client_min_messages = warning; -- -- Name: SCHEMA public; Type: COMMENT; Schema: -; Owner: postgres -- COMMENT...public; Owner: mcmanst -- -- -- Name: public; Type: ACL; Schema: -; Owner: postgres -- REVOKE ALL ON SCHEMA public FROM PUBLIC; REVOKE...ALL ON SCHEMA public FROM postgres ; GRANT ALL ON SCHEMA public TO postgres ; GRANT ALL ON SCHEMA public TO PUBLIC; -- -- PostgreSQL database

  1. Task decomposition for multilimbed robots to work in the reachable-but-unorientable space

    Science.gov (United States)

    Su, Chao; Zheng, Yuan F.

    1990-01-01

    Multilimbed industrial robots that have at least one arm and two or more legs are suggested for enlarging robot workspace in industrial automation. To plan the motion of a multilimbed robot, the arm-leg motion-coordination problem is raised and task decomposition is proposed to solve the problem; that is, a given task described by the destination position and orientation of the end-effector is decomposed into subtasks for arm manipulation and for leg locomotion, respectively. The former is defined as the end-effector position and orientation with respect to the legged main body, and the latter as the main-body position and orientation in the world coordinates. Three approaches are proposed for the task decomposition. The approaches are further evaluated in terms of energy consumption, from which an optimal approach can be selected.

  2. Task decomposition for a multilimbed robot to work in reachable but unorientable space

    Science.gov (United States)

    Su, Chau; Zheng, Yuan F.

    1991-01-01

    Robot manipulators installed on legged mobile platforms are suggested for enlarging robot workspace. To plan the motion of such a system, the arm-platform motion coordination problem is raised, and a task decomposition is proposed to solve the problem. A given task described by the destination position and orientation of the end effector is decomposed into subtasks for arm manipulation and for platform configuration, respectively. The former is defined as the end-effector position and orientation with respect to the platform, and the latter as the platform position and orientation in the base coordinates. Three approaches are proposed for the task decomposition. The approaches are also evaluated in terms of the displacements, from which an optimal approach can be selected.

  3. Multi-process Late Quaternary landscape evolution modelling reveals lags in climate response over small spatial scales

    NARCIS (Netherlands)

    Temme, A.J.A.M.; Veldkamp, A.

    2009-01-01

    Landscapes evolve in complex, non-linear ways over Quaternary timespans. Integrated geomorphological field studies usually yield plausible hypotheses about timing and impact of process activity. Landscape Evolution Models (LEMs) have the potential to test and falsify these landscape evolution

  4. Application of a rat hindlimb model: a prediction of force spaces reachable through stimulation of nerve fascicles.

    Science.gov (United States)

    Johnson, Will L; Jindrich, Devin L; Zhong, Hui; Roy, Roland R; Edgerton, V Reggie

    2011-12-01

    A device to generate standing or locomotion through chronically placed electrodes has not been fully developed due in part to limitations of clinical experimentation and the high number of muscle activation inputs of the leg. We investigated the feasibility of functional electrical stimulation paradigms that minimize the input dimensions for controlling the limbs by stimulating at nerve fascicles, utilizing a model of the rat hindlimb, which combined previously collected morphological data with muscle physiological parameters presented herein. As validation of the model, we investigated the suitability of a lumped-parameter model for the prediction of muscle activation during dynamic tasks. Using the validated model, we found that the space of forces producible through activation of muscle groups sharing common nerve fascicles was nonlinearly dependent on the number of discrete muscle groups that could be individually activated (equivalently, the neuroanatomical level of activation). Seven commonly innervated muscle groups were sufficient to produce 78% of the force space producible through individual activation of the 42 modeled hindlimb muscles. This novel, neuroanatomically derived reduction in input dimension emphasizes the potential to simplify controllers for functional electrical stimulation to improve functional recovery after a neuromuscular injury.

  5. Weak Arithmetic Completeness of Object-Oriented First-Order Assertion Networks

    NARCIS (Netherlands)

    C.P.T. de Gouw (Stijn); F.S. de Boer (Frank); W. Ahrendt (Wolfgang); R. Bubel (Richard); P. van Emde Boas; F.C.A. Groen; G.F. Italiano; J.R. Nawrocki; H. Sack

    2013-01-01

    htmlabstractWe present a completeness proof of the inductive assertion method for object-oriented programs extended with auxiliary variables. The class of programs considered are assumed to compute over structures which include the standard interpretation of Presburger arithmetic. Further, the

  6. Compositional diversity in peridotites as result of a multi-process history: The Pacific-derived Santa Elena ophiolite, northwest Costa Rica

    Science.gov (United States)

    Escuder-Viruete, Javier; Baumgartner, Peter O.; Castillo-Carrión, Mercedes

    2015-08-01

    The Santa Elena ophiolite (SEO) is an ultramafic nappe of more than 270 km2 overlying a tectonic serpentinite-matrix mélange in northwest Costa Rica. It is mainly composed of Cpx-rich and Cpx-poor harzburgites (~ 2.5 km-thick), with minor lherzolite, dunite and chromitite, as well as intrusive mafic sills and subvertical dikes, which coalesce into an upper Isla Negritos gabbroic sill complex. Minerals and whole-rock features of the Cpx-rich and Cpx-poor harzburgites share features of the abyssal and supra-subduction zone (SSZ) peridotites, respectively. To explain these characteristics two-stages of melting and refertilization processes are required. By means of trace element modeling, the composition of Cpx-rich harzburgites may be reproduced by up to ~ 5-10% melting of a primitive mantle source, and the composition of Cpx-poor harzburgites and dunites by ~ 15-18% melting of an already depleted mantle. Therefore, the Cpx-rich harzburgites can be interpreted as product of first-stage melting and low-degrees of melt-rock interaction in a mid-ocean ridge environment, and the Cpx-poor harzburgites and dunites as the product of second-stage melting and refertilization in a SSZ setting. The mafic sills and the Isla Negrito gabbros are genetically related and can be explained as crystallization from the liquids that were extracted from the lower SSZ mantle levels and emplaced at shallow conditions. The Murciélagos Island basalts are not directly related to the ultramafic and mafic rocks of the SEO. Their E-MORB-like composition is similar to most of the CLIP mafic lavas and suggests a common Caribbean plume-related source. The SEO represents a fragment of Pacific-derived, SSZ oceanic lithosphere emplaced onto the southern North America margin during the late Cretaceous. Because of the predominance of rollback-induced extension during its history, only a limited amount of crustal rocks were formed and preserved in the SEO.

  7. What Else Is Decidable about Integer Arrays?

    OpenAIRE

    Habermehl, Peter; Iosif, Radu; Vojnar, Tomáš

    2008-01-01

    International audience; We introduce a new decidable logic for reasoning about infinite arrays of integers. The logic is in the ∃ * ∀ * first-order fragment and allows (1) Presburger constraints on existentially quantified variables, (2) difference constraints as well as periodicity constraints on universally quantified indices, and (3) difference constraints on values. In particular, using our logic, one can express constraints on consecutive elements of arrays (e.g. ∀i. 0 ≤ i < n → a[i + 1]...

  8. Effects of policy tools of the White Paper on Mobility. Reachability by car and public transport, traffic safety and living environment. Background information for the Dutch White Paper on Mobility

    International Nuclear Information System (INIS)

    Annema, J.A.; Van den Brink, R.; Hoen, A.; Geurs, K.; Van Beek, F.

    2005-11-01

    In the White Paper on Mobility ('Nota Mobiliteit'), the Dutch Ministry of Transport has presented the outline of its policy for improving traffic flows and journey time reliability. The new Dutch transport policy seeks to improve accessibility levels through the construction of new infrastructure, making better use of existing infrastructure, introducing a kilometre levy, and public transport improvements. In addition to the measures designed to achieve better transport connections, measures have been defined that have an impact on traffic safety and the environment. In this publication the impact of individual policy measures is described and explained, as well as the impact of these measures when combined in packages, and how they might contribute to meeting policy objectives. In this way the publication constitutes the background document for the 'Nota Mobiliteit' itself. [nl

  9. Energy and Technology Review

    International Nuclear Information System (INIS)

    1984-10-01

    This issue features articles on multiprocessing computers, fission and fusion breeder reactors, and supracompression of high-explosive detonation products. Abstracts were prepared separately for each article

  10. Functional Abstraction of Stochastic Hybrid Systems

    NARCIS (Netherlands)

    Bujorianu, L.M.; Blom, Henk A.P.; Hermanns, H.

    2006-01-01

    The verification problem for stochastic hybrid systems is quite difficult. One method to verify these systems is stochastic reachability analysis. Concepts of abstractions for stochastic hybrid systems are needed to ease the stochastic reachability analysis. In this paper, we set up different ways

  11. Finding EL+ justifications using the Earley parsing algorithm

    CSIR Research Space (South Africa)

    Nortje, R

    2009-12-01

    Full Text Available into a reachability preserving context free grammar (CFG). The well known earley algorithm for parsing strings, given some CFG, is then applied to the problem of extracting minimal reachability-based axiom sets for subsumption entailments. The author has...

  12. Anomaly-Based Intrusion Detection Systems Utilizing System Call Data

    Science.gov (United States)

    2012-03-01

    52 Table 7. Place Reachability Statistics for Low Level CPN...54 Table 8. Place Reachability Statistics for High Level CPN................................................. 55 Table 9. Password Stealing...the efficiency of traditional anti-virus software tools that are dependent on gigantic , continuously updated databases. Fortunately, Intrusion

  13. Research Article Special Issue

    African Journals Online (AJOL)

    2016-05-15

    May 15, 2016 ... reachable graph under an initial marking can be gotten. .... Following this component relation priority rules, one could get the way to calculate ... on innovative computing information and control(ICICIC'08)978-7695-3161-8/08.

  14. Optimal Node Placement in Underwater Wireless Sensor Networks

    KAUST Repository

    Felamban, M.; Shihada, Basem; Jamshaid, K.

    2013-01-01

    Wireless Sensor Networks (WSN) are expected to play a vital role in the exploration and monitoring of underwater areas which are not easily reachable by humans. However, underwater communication via acoustic waves is subject to several performance

  15. Genetic based optimization for multicast routing algorithm for MANET

    Indian Academy of Sciences (India)

    three main principles of natural evolution: reproduction, natural selection and species .... For example, figure 3 shows a six-node network with node reachability shown by ... sion range of each node is 220 m using an Omni directional antenna.

  16. Behavior Therapy

    Science.gov (United States)

    ... reachable goals . Aim for slow progress rather than instant results. Be sure that your child understands that ... both of you are calm. Develop a good communication system with your child's teacher so that you ...

  17. Modeling, Analysis, Simulation, and Synthesis of Biomolecular Networks

    National Research Council Canada - National Science Library

    Ruben, Harvey; Kumar, Vijay; Sokolsky, Oleg

    2006-01-01

    ...) a first example of reachability analysis applied to a biomolecular system (lactose induction), 4) a model of tetracycline resistance that discriminates between two possible mechanisms for tetracycline diffusion through the cell membrane, and 5...

  18. Susceptibility to rifaximin and other antimicrobial agents of bacteria isolated from acute gastrointestinal infections in Mexico

    Directory of Open Access Journals (Sweden)

    O. Novoa-Farías

    2016-01-01

    Conclusions: Resistance of enteropathogenic bacteria to various antibiotics used in gastrointestinal infections is high. Rifaximin was active against 99-100% of these enteropathogens at reachable concentrations in the intestine with the recommended dose.

  19. The ACP [Advanced Computer Program] Branch bus and real-time applications of the ACP multiprocessor system

    International Nuclear Information System (INIS)

    Hance, R.; Areti, H.; Atac, R.

    1987-01-01

    The ACP Branchbus, a high speed differential bus for data movement in multiprocessing and data acquisition environments, is described. This bus was designed as the central bus in the ACP multiprocessing system. In its full implementation with 16 branches and a bus switch, it will handle data rates of 160 MByte/sec and allow reliable data transmission over inter rack distances. We also summarize applications of the ACP system in experimental data acquisition, triggering and monitoring, with special attention paid to FASTBUS environments

  20. Recursion vs. Replication in Simple Cryptographic Protocols

    DEFF Research Database (Denmark)

    Huttel, Hans; Srba, Jiri

    2005-01-01

    We use some recent techniques from process algebra to draw several conclusions about the well studied class of ping-pong protocols introduced by Dolev and Yao. In particular we show that all nontrivial properties, including reachability and equivalence checking wrt. the whole van Glabbeek's spect...... of messages in the sense of Amadio, Lugiez and Vanackere. We conclude by showing that reachability analysis for a replicative variant of the protocol becomes decidable....

  1. Terahertz cross-phase modulation of an optical mode

    DEFF Research Database (Denmark)

    Lavrinenko, Andrei; Novitsky, Andrey; Zalkovskij, Maksim

    2013-01-01

    We discuss an optical scheme which facilitates modulation of an optical waveguide mode by metallic-nanoslit-enhanced THz radiation. The waveguide mode acquires an additional phase shift due to THz nonlinearity with fields reachable in experiments.......We discuss an optical scheme which facilitates modulation of an optical waveguide mode by metallic-nanoslit-enhanced THz radiation. The waveguide mode acquires an additional phase shift due to THz nonlinearity with fields reachable in experiments....

  2. A Mobile IPv6 based Distributed Mobility Management Mechanism of Mobile Internet

    Science.gov (United States)

    Yan, Shi; Jiayin, Cheng; Shanzhi, Chen

    A flatter architecture is one of the trends of mobile Internet. Traditional centralized mobility management mechanism faces the challenges such as scalability and UE reachability. A MIPv6 based distributed mobility management mechanism is proposed in this paper. Some important network entities and signaling procedures are defined. UE reachability is also considered in this paper through extension to DNS servers. Simulation results show that the proposed approach can overcome the scalability problem of the centralized scheme.

  3. Parallel processing Monte Carlo radiation transport codes

    International Nuclear Information System (INIS)

    McKinney, G.W.

    1994-01-01

    Issues related to distributed-memory multiprocessing as applied to Monte Carlo radiation transport are discussed. Measurements of communication overhead are presented for the radiation transport code MCNP which employs the communication software package PVM, and average efficiency curves are provided for a homogeneous virtual machine

  4. Real-Time Systems: Reflections on higher education in the Czech Republic, Hungary, Poland and Slovenia

    NARCIS (Netherlands)

    File, Jonathan M.; Goedegebuure, Leo; Goedegebuure, L.C.J.

    2003-01-01

    Real-time systems (An ICT definition) In real-time multiprocessing there is the extra requirement that the system complete its response to any input within a certain critical time. This poses additional problems, particularly in situations where the system is heavily loaded and is subject to many

  5. Measuring Moral Thinking from a Neo-Kohlbergian Perspective

    Science.gov (United States)

    Thoma, Stephen J.

    2014-01-01

    The neo-Kohlbergian model revises and extends Lawrence Kohlberg's model of moral reasoning development to better reflect advances in research and theory. In moving from Kohlberg's global stage model to a multi-process description of moral functioning, these modifications are most evident in the ways in which moral thinking is described,…

  6. Pseudo-Random Number Generators for Vector Processors and Multicore Processors

    DEFF Research Database (Denmark)

    Fog, Agner

    2015-01-01

    Large scale Monte Carlo applications need a good pseudo-random number generator capable of utilizing both the vector processing capabilities and multiprocessing capabilities of modern computers in order to get the maximum performance. The requirements for such a generator are discussed. New ways...

  7. Automatic Management of Parallel and Distributed System Resources

    Science.gov (United States)

    Yan, Jerry; Ngai, Tin Fook; Lundstrom, Stephen F.

    1990-01-01

    Viewgraphs on automatic management of parallel and distributed system resources are presented. Topics covered include: parallel applications; intelligent management of multiprocessing systems; performance evaluation of parallel architecture; dynamic concurrent programs; compiler-directed system approach; lattice gaseous cellular automata; and sparse matrix Cholesky factorization.

  8. Parallelization of TMVA Machine Learning Algorithms

    CERN Document Server

    Hajili, Mammad

    2017-01-01

    This report reflects my work on Parallelization of TMVA Machine Learning Algorithms integrated to ROOT Data Analysis Framework during summer internship at CERN. The report consists of 4 impor- tant part - data set used in training and validation, algorithms that multiprocessing applied on them, parallelization techniques and re- sults of execution time changes due to number of workers.

  9. Super-Positioning of Voltage Sources for Fast Assessment of Wide-Area Thévenin Equivalents

    DEFF Research Database (Denmark)

    Møller, Jakob Glarbo; Jóhannsson, Hjörtur; Østergaard, Jacob

    2017-01-01

    and parallelized for shared memory multiprocessing. The proposed algorithm is tested on a collection of large test systems and performance is found to be significantly better than the reference method. The algorithm will thereby facilitate a speed-up of methods relying on Thévenin equivalent representation...

  10. Resource-Constrained Optimal Scheduling of Synchronous Dataflow Graphs via Timed Automata

    NARCIS (Netherlands)

    Ahmad, W.; de Groote, Robert; Holzenspies, P.K.F.; Stoelinga, Mariëlle Ida Antoinette; van de Pol, Jan Cornelis

    Synchronous dataflow (SDF) graphs are a widely used formalism for modelling, analysing and realising streaming applications, both on a single processor and in a multiprocessing context. Efficient schedules are essential to obtain maximal throughput under the constraint of available resources. This

  11. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Numerical modelling of multicomponent LNAPL dissolution kinetics at residual saturation in a ... Simulation of experimental breakthrough curves using multiprocess .... effects on weld geometry of dissimilar steels during the spot welding process ... using similarity transformations and solved using the Matlab bvp4c package.

  12. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. P K Sharma. Articles written in Sadhana. Volume 39 Issue 6 December 2014 pp 1425-1446. Simulation of experimental breakthrough curves using multiprocess non-equilibrium model for reactive solute transport in stratified porous media · Deepak Swami P K Sharma C S P Ojha · More Details ...

  13. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    The presence of physical and chemical non-equilibrium are observed from the pattern of breakthrough curves. Multi-process non-equilibrium model represents the combined effect of physical and chemical non-ideality in the stratified aquifer system. The results show that the incorporation of distance dependent dispersivity ...

  14. Measurement of special access to home visit nursing services among Japanese disabled elderly people: using GIS and claim data.

    Science.gov (United States)

    Naruse, Takashi; Matsumoto, Hiroshige; Fujisaki-Sakai, Mahiro; Nagata, Satoko

    2017-05-30

    Home care service demands are increasing in Japan; this necessitates improved service allocation. This study examined the relationship between home visit nursing (HVN) service use and the proportion of elderly people living within 10 min' travel of HVN agencies. The population of elderly people living within reach of HVN agencies for each of 17 municipalities in one low-density prefecture was calculated using public data and geographic information systems. Multilevel logistic analysis for 2641 elderly people was conducted using medical and long-term care insurance claims data from October 2010 to examine the association between the proportion of elderly people reachable by HVNs and service usage in 13 municipalities. Municipality variables included HVN agency allocation appropriateness. Individual variables included HVN usage and demographic variables. The reachable proportion of the elderly population ranged from 0.0 to 90.2% in the examined municipalities. The reachable proportion of the elderly population was significantly positively correlated with HVN use (odds ratio: 1.938; confidence interval: 1.265-2.967). Residents living in municipalities with a lower reachable proportion of the elderly population are less likely to use HVN services. Public health interventions should increase the reachable proportion of the elderly population in order to improve HVN service use.

  15. Proprioceptive body illusions modulate the visual perception of reaching distance.

    Directory of Open Access Journals (Sweden)

    Agustin Petroni

    Full Text Available The neurobiology of reaching has been extensively studied in human and non-human primates. However, the mechanisms that allow a subject to decide-without engaging in explicit action-whether an object is reachable are not fully understood. Some studies conclude that decisions near the reach limit depend on motor simulations of the reaching movement. Others have shown that the body schema plays a role in explicit and implicit distance estimation, especially after motor practice with a tool. In this study we evaluate the causal role of multisensory body representations in the perception of reachable space. We reasoned that if body schema is used to estimate reach, an illusion of the finger size induced by proprioceptive stimulation should propagate to the perception of reaching distances. To test this hypothesis we induced a proprioceptive illusion of extension or shrinkage of the right index finger while participants judged a series of LEDs as reachable or non-reachable without actual movement. Our results show that reach distance estimation depends on the illusory perceived size of the finger: illusory elongation produced a shift of reaching distance away from the body whereas illusory shrinkage produced the opposite effect. Combining these results with previous findings, we suggest that deciding if a target is reachable requires an integration of body inputs in high order multisensory parietal areas that engage in movement simulations through connections with frontal premotor areas.

  16. Efficient On-the-fly Algorithms for the Analysis of Timed Games

    DEFF Research Database (Denmark)

    Cassez, Franck; David, Alexandre; Fleury, Emmanuel

    2005-01-01

    In this paper, we propose the first efficient on-the-fly algorithm for solving games based on timed game automata with respect to reachability and safety properties The algorithm we propose is a symbolic extension of the on-the-fly algorithm suggested by Liu & Smolka [15] for linear-time model-ch...... symbolic algorithm are proposed as well as methods for obtaining time-optimal winning strategies (for reachability games). Extensive evaluation of an experimental implementation of the algorithm yields very encouraging performance results.......In this paper, we propose the first efficient on-the-fly algorithm for solving games based on timed game automata with respect to reachability and safety properties The algorithm we propose is a symbolic extension of the on-the-fly algorithm suggested by Liu & Smolka [15] for linear-time model...

  17. On Time with Minimal Expected Cost!

    DEFF Research Database (Denmark)

    David, Alexandre; Jensen, Peter Gjøl; Larsen, Kim Guldstrand

    2014-01-01

    (Priced) timed games are two-player quantitative games involving an environment assumed to be completely antogonistic. Classical analysis consists in the synthesis of strategies ensuring safety, time-bounded or cost-bounded reachability objectives. Assuming a randomized environment, the (priced......) timed game essentially defines an infinite-state Markov (reward) decision proces. In this setting the objective is classically to find a strategy that will minimize the expected reachability cost, but with no guarantees on worst-case behaviour. In this paper, we provide efficient methods for computing...... reachability strategies that will both ensure worst case time-bounds as well as provide (near-) minimal expected cost. Our method extends the synthesis algorithms of the synthesis tool Uppaal-Tiga with suitable adapted reinforcement learning techniques, that exhibits several orders of magnitude improvements w...

  18. A Grasp-Pose Generation Method Based on Gaussian Mixture Models

    Directory of Open Access Journals (Sweden)

    Wenjia Wu

    2015-11-01

    Full Text Available A Gaussian Mixture Model (GMM-based grasp-pose generation method is proposed in this paper. Through offline training, the GMM is set up and used to depict the distribution of the robot's reachable orientations. By dividing the robot's workspace into small 3D voxels and training the GMM for each voxel, a look-up table covering all the workspace is built with the x, y and z positions as the index and the GMM as the entry. Through the definition of Task Space Regions (TSR, an object's feasible grasp poses are expressed as a continuous region. With the GMM, grasp poses can be preferentially sampled from regions with high reachability probabilities in the online grasp-planning stage. The GMM can also be used as a preliminary judgement of a grasp pose's reachability. Experiments on both a simulated and a real robot show the superiority of our method over the existing method.

  19. Jangkauan Pelayanan Kesehatan Gigi dan Mulut di Puskesmas Se Kotamadya Surabaya Tahun 1995 Sampai Dengan Tahun 1997

    Directory of Open Access Journals (Sweden)

    Djokowidodo Djokowidodo

    2015-10-01

    Full Text Available The increased number of personnel, may also increase the reachability of the dental and oral health service in the target population. This study was concerned in comparing the data about the dental and oral health service effort from 1995 to 1997 with the determined target. The study showed increased reachability of the dental and oral health service from Public Health Service in Kotamadya Surabaya. In spote of the general imfrocement, the curative and reveral system could not reach the target yet.

  20. Minimum Energy Control of 2D Positive Continuous-Discrete Linear Systems

    Directory of Open Access Journals (Sweden)

    Kaczorek Tadeusz

    2014-09-01

    Full Text Available The minimum energy control problem for the 2D positive continuous-discrete linear systems is formulated and solved. Necessary and sufficient conditions for the reachability at the point of the systems are given. Sufficient conditions for the existence of solution to the problem are established. It is shown that if the system is reachable then there exists an optimal input that steers the state from zero boundary conditions to given final state and minimizing the performance index for only one step (q = 1. A procedure for solving of the problem is proposed and illustrated by a numerical example.

  1. Wind Corrections in Flight Path Planning

    Directory of Open Access Journals (Sweden)

    Martin Selecký

    2013-05-01

    Full Text Available Abstract When operating autonomous unmanned aerial vehicles (UAVs in real environments it is necessary to deal with the effects of wind that causes the aircraft to drift in a certain direction. In such conditions it is hard or even impossible for UAVs with a bounded turning rate to follow certain trajectories. We designed a method based on an Accelerated A* algorithm that allows the trajectory planner to take the wind effects into account and to generate states that are reachable by UAV. This method was tested on hardware UAV and the reachability of its generated trajectories was compared to the trajectories computed by the original Accelerated A*.

  2. On Nonlinear Prices in Timed Automata

    Directory of Open Access Journals (Sweden)

    Devendra Bhave

    2016-12-01

    Full Text Available Priced timed automata provide a natural model for quantitative analysis of real-time systems and have been successfully applied in various scheduling and planning problems. The optimal reachability problem for linearly-priced timed automata is known to be PSPACE-complete. In this paper we investigate priced timed automata with more general prices and show that in the most general setting the optimal reachability problem is undecidable. We adapt and implement the construction of Audemard, Cimatti, Kornilowicz, and Sebastiani for non-linear priced timed automata using state-of-the-art theorem prover Z3 and present some preliminary results.

  3. Importance Sampling for Stochastic Timed Automata

    DEFF Research Database (Denmark)

    Jegourel, Cyrille; Larsen, Kim Guldstrand; Legay, Axel

    2016-01-01

    We present an importance sampling framework that combines symbolic analysis and simulation to estimate the probability of rare reachability properties in stochastic timed automata. By means of symbolic exploration, our framework first identifies states that cannot reach the goal. A state-wise cha......We present an importance sampling framework that combines symbolic analysis and simulation to estimate the probability of rare reachability properties in stochastic timed automata. By means of symbolic exploration, our framework first identifies states that cannot reach the goal. A state...

  4. MCNP load balancing and fault tolerance with PVM

    International Nuclear Information System (INIS)

    McKinney, G.W.

    1995-01-01

    Version 4A of the Monte Carlo neutron, photon, and electron transport code MCNP, developed by LANL (Los Alamos National Laboratory), supports distributed-memory multiprocessing through the software package PVM (Parallel Virtual Machine, version 3.1.4). Using PVM for interprocessor communication, MCNP can simultaneously execute a single problem on a cluster of UNIX-based workstations. This capability provided system efficiencies that exceeded 80% on dedicated workstation clusters, however, on heterogeneous or multiuser systems, the performance was limited by the slowest processor (i.e., equal work was assigned to each processor). The next public release of MCNP will provide multiprocessing enhancements that include load balancing and fault tolerance which are shown to dramatically increase multiuser system efficiency and reliability

  5. CSP for Executable Scientific Workflows

    DEFF Research Database (Denmark)

    Friborg, Rune Møllegaard

    and can usually benefit performance-wise from both multiprocessing, cluster and grid environments. PyCSP is an implementation of Communicating Sequential Processes (CSP) for the Python programming language and takes advantage of CSP's formal and verifiable approach to controlling concurrency...... on multi-processing and cluster computing using PyCSP. Additionally, McStas is demonstrated to utilise grid computing resources using PyCSP. Finally, this thesis presents a new dynamic channel model, which has not yet been implemented for PyCSP. The dynamic channel is able to change the internal...... synchronisation mechanisms on-the-fly, depending on the location and number of channel-ends connected. Thus it may start out as a simple local pipe and evolve into a distributed channel spanning multiple nodes. This channel is a necessary next step for PyCSP to allow for complete freedom in executing CSP...

  6. Concurrent LISP and its interpreter

    Energy Technology Data Exchange (ETDEWEB)

    Tabata, K; Sugimoto, S; Ohno, Y

    1981-01-01

    In the research field of artificial intelligence many languages have been developed based on LISP, such as Planner, Conniver and so on. They have been developed to give users many useful facilities, especially for describing flexible control structures. Backtracking and coroutine facilities are typical ones introduced into these languages. Compared with backtracking and coroutine facilities, multi-process description facilities are considered to be a better alternative for writing well-structured programs. This paper describes concurrent LISP, a new concurrent programming language based on LISP. Concurrent LISP is designed to provide simple and flexible facilities for multi-process description without changing the original language features of LISP. This paper also describes the concurrent LISP interpreter which has been implemented on a FACOM M-200 at the Data Processing Center of Kyoto University. 19 references.

  7. Computer programming and architecture the VAX

    CERN Document Server

    Levy, Henry

    2014-01-01

    Takes a unique systems approach to programming and architecture of the VAXUsing the VAX as a detailed example, the first half of this book offers a complete course in assembly language programming. The second describes higher-level systems issues in computer architecture. Highlights include the VAX assembler and debugger, other modern architectures such as RISCs, multiprocessing and parallel computing, microprogramming, caches and translation buffers, and an appendix on the Berkeley UNIX assembler.

  8. Enhanced Inclusion Removal from Steel in the Tundish

    Energy Technology Data Exchange (ETDEWEB)

    R. C. Bradt; M.A.R. Sharif

    2009-09-25

    The objective of this project was to develop an effective chemical filtering system for significantly reducing the content of inclusion particles in the steel melts exiting the tundish for continuous casting. This project combined a multi-process approach that aimed to make significant progress towards an "inclusion free" steel by incorporating several interdependent concepts to reduce the content of inclusions in the molten steel exiting the tundish for the caster. The goal is to produce "cleaner" steel.

  9. Enhanced Incluison Removal from Steel in the Tundish

    Energy Technology Data Exchange (ETDEWEB)

    R.C. Bradt; M.A.R. Sharif

    2009-09-25

    The objective of this project was to develop an effective chemical filtering system for significantly reducing the content of inclusion particles in the steel melts exiting the tundish for continuous casting. This project combined a multi-process approach that aimed to make significant progress towards an "inclusion free" steel by incorporating several interdependent concepts to reduce the content of inclusions in the molten steel exiting the tundish for the caster. The goal is to produce "cleaner" steel.

  10. The three-dimensional, discrete ordinates neutral particle transport code TORT: An overview

    International Nuclear Information System (INIS)

    Azmy, Y.Y.

    1996-01-01

    The centerpiece of the Discrete Ordinates Oak Ridge System (DOORS), the three-dimensional neutral particle transport code TORT is reviewed. Its most prominent features pertaining to large applications, such as adjustable problem parameters, memory management, and coarse mesh methods, are described. Advanced, state-of-the-art capabilities including acceleration and multiprocessing are summarized here. Future enhancement of existing graphics and visualization tools is briefly presented

  11. On Performance of Linear Multiuser Detectors for Wireless Multimedia Applications

    Science.gov (United States)

    Agarwal, Rekha; Reddy, B. V. R.; Bindu, E.; Nayak, Pinki

    In this paper, performance of different multi-rate schemes in DS-CDMA system is evaluated. The analysis of multirate linear multiuser detectors with multiprocessing gain is analyzed for synchronous Code Division Multiple Access (CDMA) systems. Variable data rate is achieved by varying the processing gain. Our conclusion is that bit error rate for multirate and single rate systems can be made same with a tradeoff with number of users in linear multiuser detectors.

  12. Development and Flight Results of a PC104/QNX-Based On-Board Computer and Software for the YES2 Tether Experiment

    Science.gov (United States)

    Spiliotopoulos, I.; Mirmont, M.; Kruijff, M.

    2008-08-01

    This paper highlights the flight preparation and mission performance of a PC104-based On-Board Computer for ESA's second Young Engineer's Satellite (YES2), with additional attention to the flight software design and experience of QNX as multi-process real-time operating system. This combination of Commercial-Of-The-Shelf (COTS) technologies is an accessible option for small satellites with high computational demands.

  13. ATTILA 2 S. A technical and interactive test language for architecture allowing simultaneity

    International Nuclear Information System (INIS)

    Batllo, M.

    1980-01-01

    The name ATTILA 2 S is inspired from ATLAS, test language adopted by the Department of Defence of America (D.O.D.) but cannot be implemented on our installation. ATTILA 2 S is principally characterized by: its technical vocabulary (P.O.L.), its interactivity, its simultaneity with main job (Multiprogramming and Multiprocessing allowed by multiprocessors architecture. This language has been developed for the Paris C.R.T. system (Photographies analysis system) on Control Data Cyber 72 computer [fr

  14. Implementation of a Loosely-Coupled Lockstep Approach in the Xilinx Zynq-7000 All Programmable SoC for High Consequence Applications

    Science.gov (United States)

    2017-03-01

    Programmable SoC™ is made possible through the use of ARM® Cortex ™-A9 MPCore™ Asymmetric Multiprocessing; processor configurations utilizing the...core ARM Cortex -A9 MPCore based Processing System (PS) and Programmable Logic (PL) portions. These features allow for two processors to run...SoC™ precludes a tightly-coupled lockstep approach between the two processors . Therefore, a loosely-coupled lockstep approach implemented by a

  15. Acoustic simulation in architecture with parallel algorithm

    Science.gov (United States)

    Li, Xiaohong; Zhang, Xinrong; Li, Dan

    2004-03-01

    In allusion to complexity of architecture environment and Real-time simulation of architecture acoustics, a parallel radiosity algorithm was developed. The distribution of sound energy in scene is solved with this method. And then the impulse response between sources and receivers at frequency segment, which are calculated with multi-process, are combined into whole frequency response. The numerical experiment shows that parallel arithmetic can improve the acoustic simulating efficiency of complex scene.

  16. UFMulti: A new parallel processing software system for HEP

    Science.gov (United States)

    Avery, Paul; White, Andrew

    1989-12-01

    UFMulti is a multiprocessing software package designed for general purpose high energy physics applications, including physics and detector simulation, data reduction and DST physics analysis. The system is particularly well suited for installations where several workstation or computers are connected through a local area network (LAN). The initial configuration of the software is currently running on VAX/VMS machines with a planned extension to ULTRIX, using the new RISC CPUs from Digital, in the near future.

  17. UFMULTI: A new parallel processing software system for HEP

    International Nuclear Information System (INIS)

    Avery, P.; White, A.

    1989-01-01

    UFMulti is a multiprocessing software package designed for general purpose high energy physics applications, including physics and detector simulation, data reduction and DST physics analysis. The system is particularly well suited for installations where several workstations or computers are connected through a local area network (LAN). The initial configuration of the software is currently running on VAX/VMS machines with a planned extension to ULTRIX, using the new RISC CPUs from Digital, in the near future. (orig.)

  18. Expressing Parallelism with ROOT

    Energy Technology Data Exchange (ETDEWEB)

    Piparo, D. [CERN; Tejedor, E. [CERN; Guiraud, E. [CERN; Ganis, G. [CERN; Mato, P. [CERN; Moneta, L. [CERN; Valls Pla, X. [CERN; Canal, P. [Fermilab

    2017-11-22

    The need for processing the ever-increasing amount of data generated by the LHC experiments in a more efficient way has motivated ROOT to further develop its support for parallelism. Such support is being tackled both for shared-memory and distributed-memory environments. The incarnations of the aforementioned parallelism are multi-threading, multi-processing and cluster-wide executions. In the area of multi-threading, we discuss the new implicit parallelism and related interfaces, as well as the new building blocks to safely operate with ROOT objects in a multi-threaded environment. Regarding multi-processing, we review the new MultiProc framework, comparing it with similar tools (e.g. multiprocessing module in Python). Finally, as an alternative to PROOF for cluster-wide executions, we introduce the efforts on integrating ROOT with state-of-the-art distributed data processing technologies like Spark, both in terms of programming model and runtime design (with EOS as one of the main components). For all the levels of parallelism, we discuss, based on real-life examples and measurements, how our proposals can increase the productivity of scientists.

  19. Expressing Parallelism with ROOT

    Science.gov (United States)

    Piparo, D.; Tejedor, E.; Guiraud, E.; Ganis, G.; Mato, P.; Moneta, L.; Valls Pla, X.; Canal, P.

    2017-10-01

    The need for processing the ever-increasing amount of data generated by the LHC experiments in a more efficient way has motivated ROOT to further develop its support for parallelism. Such support is being tackled both for shared-memory and distributed-memory environments. The incarnations of the aforementioned parallelism are multi-threading, multi-processing and cluster-wide executions. In the area of multi-threading, we discuss the new implicit parallelism and related interfaces, as well as the new building blocks to safely operate with ROOT objects in a multi-threaded environment. Regarding multi-processing, we review the new MultiProc framework, comparing it with similar tools (e.g. multiprocessing module in Python). Finally, as an alternative to PROOF for cluster-wide executions, we introduce the efforts on integrating ROOT with state-of-the-art distributed data processing technologies like Spark, both in terms of programming model and runtime design (with EOS as one of the main components). For all the levels of parallelism, we discuss, based on real-life examples and measurements, how our proposals can increase the productivity of scientists.

  20. Trajectories of goods in distributed allocation

    NARCIS (Netherlands)

    Chevaleyre, Y.; Endriss, U.; Maudet, N.; Padgham, L.; Parkes, D.; Müller, J.; Parsons, S.

    2008-01-01

    Distributed allocation mechanisms rely on the agents' autonomous (and supposedly rational) behaviour: states evolve as a result of agents contracting deals and exchanging resources. It is no surprise that restrictions on potential deals also restrict the reachability of some desirable states, for

  1. Decidability Issues for Extended Ping-Pong Protocols

    DEFF Research Database (Denmark)

    Huttel, Hans; Srba, Jiri

    2006-01-01

    We use some recent techniques from process algebra to draw several conclusions about the well studied class of ping-pong protocols introduced by Dolev and Yao. In particular we show that all nontrivial properties, including reachability and equivalence checking wrt. the whole van Glabbeek...

  2. Compositional Performability Evaluation for STATEMATE

    NARCIS (Netherlands)

    Böde, Eckard; Herbstritt, Marc; Hermanns, Holger; Johr, Sven; Peikenkamp, Thomas; Pulungan, Reza; Wimmer, Ralf; Becker, Bernd

    2006-01-01

    This paper reports on our efforts to link an industrial state-of-the-art modelling tool to academic state-of-the-art analysis algorithms. In a nutshell, we enable timed reachability analysis of uniform continuous-time Markov decision processes, which are generated from STATEMATE models. We give a

  3. Model-based schedulability analysis of safety critical hard real-time Java programs

    DEFF Research Database (Denmark)

    Bøgholm, Thomas; Kragh-Hansen, Henrik; Olsen, Petur

    2008-01-01

    verifiable by the Uppaal model checker [23]. Schedulability analysis is reduced to a simple reachability question, checking for deadlock freedom. Model-based schedulability analysis has been developed by Amnell et al. [2], but has so far only been applied to high level specifications, not actual...

  4. The RERS 2017 Challenge and Workshop

    NARCIS (Netherlands)

    Jasper, Marc; Fecke, Maximilian; Steffen, Bernhard; Schordan, Markus; Meijer, Jeroen; Pol, Jaco van de; Howar, Falk; Siegel, Stephen F.

    RERS is an annual verification challenge that focuses on LTL and reachability properties of reactive systems. In 2017, RERS was extended to a one day workshop that in addition to the original challenge program also featured an invited talk about possible future developments. As a satellite of ISSTA

  5. Monotonic Set-Extended Prefix Rewriting and Verification of Recursive Ping-Pong Protocols

    DEFF Research Database (Denmark)

    Delzanno, Giorgio; Esparza, Javier; Srba, Jiri

    2006-01-01

    of messages) some verification problems become decidable. In particular we give an algorithm to decide control state reachability, a problem related to security properties like secrecy and authenticity. The proof is via a reduction to a new prefix rewriting model called Monotonic Set-extended Prefix rewriting...

  6. Decidable Fragments of a Higher Order Calculus with Locations

    DEFF Research Database (Denmark)

    Bundgaard, Mikkel; Godskesen, Jens Christian; Huttel, Hans

    2009-01-01

    Homer is a higher order process calculus with locations. In this paper we study Homer in the setting of the semantic finite control property, which is a finite reachability criterion that implies decidability of barbed bisimilarity. We show that strong and weak barbed bisimilarity are undecidable...

  7. Verifying generalized soundness for workflow nets

    NARCIS (Netherlands)

    Hee, van K.M.; Oanea, O.I.; Sidorova, N.; Voorhoeve, M.; Virbitskaite, I.; Voronkov, A.

    2007-01-01

    We improve the decision procedure from [10] for the problem of generalized soundness of workflow nets. A workflow net is generalized sound iff every marking reachable from an initial marking with k tokens on the initial place terminates properly, i.e. it can reach a marking with k tokens on the

  8. Recursive Ping-Pong Protocols

    DEFF Research Database (Denmark)

    Huttel, Hans; Srba, Jiri

    2004-01-01

    and bisimulation checking. Our main result is that our channel-free and memory-less calculus is Turing powerful, assuming that at least three principals are involved. We also investigate the expressive power of the calculus in the case of two participants. Here, our main results are that reachability and, under...

  9. Pramana – Journal of Physics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    pp 223-229 Special: Supersymmetric Unified Theories and Higgs Physics. Prospects of experimentally reachable beyond Standard Model physics in inverse see-saw motivated SO(10) GUT · Ram Lal Awasthi · More Details Abstract Fulltext PDF. The grand unification theories based on SO(10) gauge group have been at the ...

  10. MODELLING AND VERIFICATION OF KITSAT PACKET COMMUNICATION PROTOCOLS

    Directory of Open Access Journals (Sweden)

    Young-Ro Lee

    1996-06-01

    Full Text Available In this paper, in order to verify KITSAT 1/2 packet communication protocols, we model the AX.25 protocol and PACSAT protocol by using an extended Petri net and then verify the correctness, boundedness, liveness and deadlock freeness of packet protocols by utilizing reachability trees.

  11. A Comparison of Modular Verification Techniques

    DEFF Research Database (Denmark)

    Andersen, Henrik Reif; Staunstrup, Jørgen; Maretti, Niels

    1997-01-01

    This paper presents and compares three techniques for mechanized verification of state oriented design descriptions. One is a traditional forwardgeneration of a fixed point characterizing the reachable states. The two others can utilize a modular structure provided by the designer. Onerequires...

  12. Analysis of hybrid systems: An ounce of realism can save an infinity of states

    DEFF Research Database (Denmark)

    Fränzle, Martin

    1999-01-01

    Hybrid automata have been introduced in both control engineering and computer science as a formal model for the dynamics of hybrid discrete-continuous systems. In the case of so-called linear hybrid automata this formalization supports semi-decision procedures for state reachability, yet no decis...

  13. Marketing Your Library Program--More than a PR Campaign.

    Science.gov (United States)

    Brown, Gerald R.

    In this workshop, the concept of marketing was applied to school library media programs by examining the relationship between library media programs, the marketing plan, public relations (PR), and promotion. Reachable goals, targeting the audience, advertising, and motivation and commitment of the staff were also considered, and successful…

  14. Shuttle requests

    CERN Multimedia

    2007-01-01

    Please note that starting from 1 March 2007, the shuttle requests: for official visits or bidders' conferences on the CERN site; towards/from the airport or central Geneva; for long distances, shall be made via Fm.Support@cern.ch or by calling 77777. The radio taxi will still be reachable at 76969. TS/FM Group

  15. Thermo-mechanical characterization of the lithosphere : Implications for geothermal resources

    NARCIS (Netherlands)

    Limberger, J.

    2018-01-01

    The two key ingredients needed to commercially exploit a geothermal energy system are (1) sufficiently high subsurface temperatures and (2) presence of rock formations suitable to act as a geothermal reservoir at reachable depths. Subsurface temperatures are controlled by the heat flowing from deep

  16. Recursion Versus Replication in Simple Cryptographic Protocols

    DEFF Research Database (Denmark)

    Hüttel, Hans; Srba, Jiri

    2005-01-01

    We use some very recent techniques from process algebra to draw interesting conclusions about the well studied class of ping-pong protocols introduced by Dolev and Yao. In particular we show that all nontrivial properties, including reachability and equivalence checking wrt. the whole van Glabbee...

  17. School Principals' Technology Leadership Competency and Technology Coordinatorship

    Science.gov (United States)

    Banoglu, Koksal

    2011-01-01

    The aim of this study is to determine the primary and high school principals' competency in technology leadership and so to define implications for advanced competency. The population of the study was formed by 134 school principals in Maltepe and Kadikoy districts in Istanbul. On account of the fact that population was reachable, no specific…

  18. Controllability of a Class of Bimodal Discrete-Time Piecewise Linear Systems

    NARCIS (Netherlands)

    Yurtseven, E.; Camlibel, M.K.; Heemels, W.P.M.H.

    2013-01-01

    In this paper we will provide algebraic necessary and sufficient conditions for the controllability/reachability/null controllability of a class of bimodal discrete-time piecewise linear systems including several instances of interest that are not covered by existing works which focus primarily on

  19. Efficient Approximation of Optimal Control for Markov Games

    DEFF Research Database (Denmark)

    Fearnley, John; Rabe, Markus; Schewe, Sven

    2011-01-01

    We study the time-bounded reachability problem for continuous-time Markov decision processes (CTMDPs) and games (CTMGs). Existing techniques for this problem use discretisation techniques to break time into discrete intervals, and optimal control is approximated for each interval separately...

  20. The 'Sneaky Snake' reaches the parts other vehicles cannot

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    The Articulated Transporter/Manipulator system (ATMS) is a new multi-segmented, semi-autonomous transporter under development in the USA. It will be able to negotiate complex, obstacle strewn environments not reachable by legged, wheeled or tracked vehicles. Ultimately it will be used for surveillance, inspection, maintenance and emergency tasks. (U.K.)

  1. Processo Orçamentário e Criação de Reservas em uma Instituição Hospitalar

    Directory of Open Access Journals (Sweden)

    Andson Braga de Aguiar

    2010-01-01

    maintains a strict budget process. Given these characteristics, it was noted that managers have a tendency to create reserves, especially by reason of (i submit budgets easily reachable, (ii agree that the budget targets did not require care in controlling costs and (iii agree that the budget goals are easily attainable.

  2. Is BTZ a separate superselection sector of CTMG?

    Energy Technology Data Exchange (ETDEWEB)

    Deser, S., E-mail: deser@brandeis.ed [Physics Department, Brandeis University, Waltham, MA 02454 (United States); Lauritsen Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Franklin, J., E-mail: jfrankli@reed.ed [Reed College, Portland, OR 97202 (United States)

    2010-10-18

    We exhibit exact solutions of (positive) matter coupled to original 'wrong G-sign' cosmological TMG. They all evolve to conical singularity, rather than to black hole - here negative mass - BTZ. This provides evidence that the latter constitute a separate 'superselection' sector, one that unlike in GR, is not reachable by physical sources.

  3. Ongoing Work on Automated Verification of Noisy Nonlinear Systems with Ariadne

    NARCIS (Netherlands)

    Geretti, Luca; Bresolin, Davide; Collins, Pieter; Zivanovic Gonzalez, Sanja; Villa, Tiziano

    2017-01-01

    Cyber-physical systems (CPS) are hybrid systems that commonly consist of a discrete control part that operates in a continuous environment. Hybrid automata are a convenient model for CPS suitable for formal verification. The latter is based on reachability analysis of the system to trace its hybrid

  4. Pramana – Journal of Physics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    2016-01-06

    Jan 6, 2016 ... Home; Journals; Pramana – Journal of Physics; Volume 86; Issue 2. Prospects of experimentally reachable beyond Standard Model physics in inverse see-saw motivated SO(10) GUT. Ram Lal Awasthi. Special: Supersymmetric Unified Theories and Higgs Physics Volume 86 Issue 2 February 2016 pp 223- ...

  5. Abstraction of Dynamical Systems by Timed Automata

    DEFF Research Database (Denmark)

    Wisniewski, Rafael; Sloth, Christoffer

    2011-01-01

    To enable formal verification of a dynamical system, given by a set of differential equations, it is abstracted by a finite state model. This allows for application of methods for model checking. Consequently, it opens the possibility of carrying out the verification of reachability and timing re...

  6. Make Your Museum Talk: Natural Language Interfaces for Cultural Institutions.

    Science.gov (United States)

    Boiano, Stefania; Gaia, Giuliano; Caldarini, Morgana

    A museum can talk to its audience through a variety of channels, such as Web sites, help desks, human guides, brochures. A considerable effort is being made by museums to integrate these different means. The Web site can be designed to be reachable or even updateable from visitors inside the museum via touchscreen and wireless devices. But these…

  7. Effect of sugarcane scum and ashes of Chromolena odorata L. on ...

    African Journals Online (AJOL)

    SAMSON MEDZA MVE

    2 Regional Hub, West and Central Africa, CGIAR, BP 320, Bamako, Mali. 3 Gembloux Agro-Bio ... The main objective of this study was to develop an intensive cropping system for the Hibiscus sabdariffa L, reachable .... 50 x 2,5. T0: Control; An: Ash; Sn: Scum; An X Sn: Ash X Scums ..... indices to a short phase of australian.

  8. Analysis of multi-stage open shop processing systems

    NARCIS (Netherlands)

    Eggermont, C.E.J.; Schrijver, A.; Woeginger, G.J.; Schwentick, T.; Dürr, C.

    2011-01-01

    We study algorithmic problems in multi-stage open shop processing systems that are centered around reachability and deadlock detection questions. We characterize safe and unsafe system states. We show that it is easy to recognize system states that can be reached from the initial state (where the

  9. Converse Theorems for Safety and Barrier Certificates

    OpenAIRE

    Ratschan, Stefan

    2017-01-01

    An important tool for proving safety of dynamical systems is the notion of a barrier certificate. In this paper we prove that every robustly safe ordinary differential equation has a barrier certificate. Moreover, we show a construction of such a barrier certificate based on a set of states that is reachable in finite time.

  10. 45 CFR 303.11 - Case closure criteria.

    Science.gov (United States)

    2010-10-01

    ... Federal government or a company with headquarters or offices in the United States, and has no reachable...) There has been a finding by the responsible State agency of good cause or other exceptions to cooperation with the IV-D agency and the State or local IV-A, IV-D, IV-E, Medicaid or food stamp agency has...

  11. Path trading : fast algorithms, smoothed analysis, and hardness results

    NARCIS (Netherlands)

    Berger, A.; Röglin, H.; Zwaan, van der G.R.J.; Pardalos, P.M.; Rebennack, S.

    2011-01-01

    The Border Gateway Protocol (BGP) serves as the main routing protocol of the Internet and ensures network reachability among autonomous systems (ASes). When traffic is forwarded between the many ASes on the Internet according to that protocol, each AS selfishly routes the traffic inside its own

  12. Liquid fiducial marker performance during radiotherapy of locally advanced non small cell lung cancer

    DEFF Research Database (Denmark)

    Rydhög, Jonas Scherman; Mortensen, Steen Riisgaard; Larsen, Klaus Richter

    2016-01-01

    We analysed the positional and structural stability of a long-term biodegradable liquid fiducial marker (BioXmark) for radiotherapy in patients with locally advanced lung cancer. Markers were injected via endoscopic- or endobronchial ultrasound in lymph nodes and reachable primary tumours. Marker...

  13. Dynamic Mobile IP routers in ad hoc networks

    NARCIS (Netherlands)

    Kock, B.A.; Schmidt, J.R.

    2005-01-01

    This paper describes a concept combining mobile IP and ad hoc routing to create a robust mobile network. In this network all nodes are mobile and globally and locally reachable under the same IP address. Essential for implementing this network are the dynamic mobile IP routers. They act as gateways

  14. Empirical Differential Balancing for Nonlinear Systems

    NARCIS (Netherlands)

    Kawano, Yu; Scherpen, Jacquelien M.A.; Dochain, Denis; Henrion, Didier; Peaucelle, Dimitri

    In this paper, we consider empirical balancing of nonlinear systems by using its prolonged system, which consists of the original nonlinear system and its variational system. For the prolonged system, we define differential reachability and observability Gramians, which are matrix valued functions

  15. Verification of Stochastic Process Calculi

    DEFF Research Database (Denmark)

    Skrypnyuk, Nataliya

    algorithms for constructing bisimulation relations, computing (overapproximations of) sets of reachable states and computing the expected time reachability, the last for a linear fragment of IMC. In all the cases we have the complexities of algorithms which are low polynomial in the size of the syntactic....... In support of this claim we have developed analysis methods that belong to a particular type of Static Analysis { Data Flow / Pathway Analysis. These methods have previously been applied to a number of non-stochastic process calculi. In this thesis we are lifting them to the stochastic calculus...... of Interactive Markov Chains (IMC). We have devised the Pathway Analysis of IMC that is not only correct in the sense of overapproximating all possible behaviour scenarios, as is usual for Static Analysis methods, but is also precise. This gives us the possibility to explicitly decide on the trade-o between...

  16. Analyzing Real-Time Systems: Theory and Tools

    DEFF Research Database (Denmark)

    Hune, Thomas Seidelin

    bounded matrix (DBM) data-structure for representing zones, used in most timed model checkers. Using an extension of the region construction, the minimum-cost reachability problem can also be solved for LPTAs. However, the standard way of using zones for representing the state-space cannot be used...... for LPTAs, since there is no way of capturing the cost of states. Based on the notion of facets, zones can be split into smaller zones which can be represented by extended DBMs in an effective way. Minimum-cost reachability for both UPTAs and LPTAs have been implemented in extensions of UPPAAL...... for the parameters has been show to be undecidable. To represent the state-space we extend the DBM data-structure to parametric DBMs, capable of representing zones were the bounds are given by expressions including parameters. The semi-decision procedure is implemented in UPPAAL and constraints ensuring correctness...

  17. Dynamic Programming and Error Estimates for Stochastic Control Problems with Maximum Cost

    International Nuclear Information System (INIS)

    Bokanowski, Olivier; Picarelli, Athena; Zidani, Hasnaa

    2015-01-01

    This work is concerned with stochastic optimal control for a running maximum cost. A direct approach based on dynamic programming techniques is studied leading to the characterization of the value function as the unique viscosity solution of a second order Hamilton–Jacobi–Bellman (HJB) equation with an oblique derivative boundary condition. A general numerical scheme is proposed and a convergence result is provided. Error estimates are obtained for the semi-Lagrangian scheme. These results can apply to the case of lookback options in finance. Moreover, optimal control problems with maximum cost arise in the characterization of the reachable sets for a system of controlled stochastic differential equations. Some numerical simulations on examples of reachable analysis are included to illustrate our approach

  18. Dynamic Programming and Error Estimates for Stochastic Control Problems with Maximum Cost

    Energy Technology Data Exchange (ETDEWEB)

    Bokanowski, Olivier, E-mail: boka@math.jussieu.fr [Laboratoire Jacques-Louis Lions, Université Paris-Diderot (Paris 7) UFR de Mathématiques - Bât. Sophie Germain (France); Picarelli, Athena, E-mail: athena.picarelli@inria.fr [Projet Commands, INRIA Saclay & ENSTA ParisTech (France); Zidani, Hasnaa, E-mail: hasnaa.zidani@ensta.fr [Unité de Mathématiques appliquées (UMA), ENSTA ParisTech (France)

    2015-02-15

    This work is concerned with stochastic optimal control for a running maximum cost. A direct approach based on dynamic programming techniques is studied leading to the characterization of the value function as the unique viscosity solution of a second order Hamilton–Jacobi–Bellman (HJB) equation with an oblique derivative boundary condition. A general numerical scheme is proposed and a convergence result is provided. Error estimates are obtained for the semi-Lagrangian scheme. These results can apply to the case of lookback options in finance. Moreover, optimal control problems with maximum cost arise in the characterization of the reachable sets for a system of controlled stochastic differential equations. Some numerical simulations on examples of reachable analysis are included to illustrate our approach.

  19. Optimal control

    CERN Document Server

    Aschepkov, Leonid T; Kim, Taekyun; Agarwal, Ravi P

    2016-01-01

    This book is based on lectures from a one-year course at the Far Eastern Federal University (Vladivostok, Russia) as well as on workshops on optimal control offered to students at various mathematical departments at the university level. The main themes of the theory of linear and nonlinear systems are considered, including the basic problem of establishing the necessary and sufficient conditions of optimal processes. In the first part of the course, the theory of linear control systems is constructed on the basis of the separation theorem and the concept of a reachability set. The authors prove the closure of a reachability set in the class of piecewise continuous controls, and the problems of controllability, observability, identification, performance and terminal control are also considered. The second part of the course is devoted to nonlinear control systems. Using the method of variations and the Lagrange multipliers rule of nonlinear problems, the authors prove the Pontryagin maximum principle for prob...

  20. Investigation into constant envelope orthogonal frequency division multiplexing for polarization-division multiplexing coherent optical communication

    Science.gov (United States)

    Li, Yupeng; Ding, Ding

    2017-09-01

    Benefiting from the high spectral efficiency and low peak-to-average power ratio, constant envelope orthogonal frequency division multiplexing (OFDM) is a promising technique in coherent optical communication. Polarization-division multiplexing (PDM) has been employed as an effective way to double the transmission capacity in the commercial 100 Gb/s PDM-QPSK system. We investigated constant envelope OFDM together with PDM. Simulation results show that the acceptable maximum launch power into the fiber improves 10 and 6 dB for 80- and 320-km transmission, respectively (compared with the conventional PDM OFDM system). The maximum reachable distance of the constant envelope OFDM system is able to reach 800 km, and even 1200 km is reachable if an ideal erbium doped fiber amplifier is employed.

  1. Finite Countermodel Based Verification for Program Transformation (A Case Study

    Directory of Open Access Journals (Sweden)

    Alexei P. Lisitsa

    2015-12-01

    Full Text Available Both automatic program verification and program transformation are based on program analysis. In the past decade a number of approaches using various automatic general-purpose program transformation techniques (partial deduction, specialization, supercompilation for verification of unreachability properties of computing systems were introduced and demonstrated. On the other hand, the semantics based unfold-fold program transformation methods pose themselves diverse kinds of reachability tasks and try to solve them, aiming at improving the semantics tree of the program being transformed. That means some general-purpose verification methods may be used for strengthening program transformation techniques. This paper considers the question how finite countermodels for safety verification method might be used in Turchin's supercompilation method. We extract a number of supercompilation sub-algorithms trying to solve reachability problems and demonstrate use of an external countermodel finder for solving some of the problems.

  2. Rewriting Modulo SMT and Open System Analysis

    Science.gov (United States)

    Rocha, Camilo; Meseguer, Jose; Munoz, Cesar

    2014-01-01

    This paper proposes rewriting modulo SMT, a new technique that combines the power of SMT solving, rewriting modulo theories, and model checking. Rewriting modulo SMT is ideally suited to model and analyze infinite-state open systems, i.e., systems that interact with a non-deterministic environment. Such systems exhibit both internal non-determinism, which is proper to the system, and external non-determinism, which is due to the environment. In a reflective formalism, such as rewriting logic, rewriting modulo SMT can be reduced to standard rewriting. Hence, rewriting modulo SMT naturally extends rewriting-based reachability analysis techniques, which are available for closed systems, to open systems. The proposed technique is illustrated with the formal analysis of: (i) a real-time system that is beyond the scope of timed-automata methods and (ii) automatic detection of reachability violations in a synchronous language developed to support autonomous spacecraft operations.

  3. Review paper of gateway selection schemes for MANET of NEMO (MANEMO)

    International Nuclear Information System (INIS)

    Mahmood, Z; Hashim, A; Khalifa, O; Anwar, F; Hameed, S

    2013-01-01

    The fast growth of Internet applications brings with it new challenges for researchers to provide new solutions that guarantee better Internet access for mobile hosts and networks. The globally reachable, Home-Agent based, infrastructure Network Mobility (NEMO) and the local, multi-hop, and infrastructure-less Mobile Ad hoc Network (MANET) developed by Internet Engineering Task Force (IETF) support different topologies of the mobile networks. A new architecture was proposed by combining both topologies to obtain Mobile Ad Hoc NEMO (MANEMO). However, the integration of NEMO and MANET introduces many challenges such as network loops, sub-optimal route, redundant tunnel problem, absence of communication without Home Agent reachability, and exit router selection when multiple Exit Routers to the Internet exist. This paper aims to review the different proposed models that could be used to implement the gateway selection mechanism and it highlights the strengths as well as the limitations of these approaches

  4. Distributed expert systems for nuclear reactor control

    International Nuclear Information System (INIS)

    Otaduy, P.J.

    1992-01-01

    A network of distributed expert systems is the heart of a prototype supervisory control architecture developed at the Oak Ridge National Laboratory (ORNL) for an advanced multimodular reactor. Eight expert systems encode knowledge on signal acquisition, diagnostics, safeguards, and control strategies in a hybrid rule-based, multiprocessing and object-oriented distributed computing environment. An interactive simulation of a power block consisting of three reactors and one turbine provides a realistic, testbed for performance analysis of the integrated control system in real-time. Implementation details and representative reactor transients are discussed

  5. The ETA10 supercomputer system

    International Nuclear Information System (INIS)

    Swanson, C.D.

    1987-01-01

    The ETA Systems, Inc. ETA 10 is a next-generation supercomputer featuring multiprocessing, a large hierarchical memory system, high performance input/output, and network support for both batch and interactive processing. Advanced technology used in the ETA 10 includes liquid nitrogen cooled CMOS logic with 20,000 gates per chip, a single printed circuit board for each CPU, and high density static and dynamics MOS memory chips. Software for the ETA 10 includes an underlying kernel that supports multiple user environments, a new ETA FORTRAN compiler with an advanced automatic vectorizer, a multitasking library and debugging tools. Possible developments for future supercomputers from ETA Systems are discussed. (orig.)

  6. The ETA systems plans for supercomputers

    International Nuclear Information System (INIS)

    Swanson, C.D.

    1987-01-01

    The ETA Systems, is a class VII supercomputer featuring multiprocessing, a large hierarchical memory system, high performance input/output, and network support for both batch and interactive processing. Advanced technology used in the ETA 10 includes liquid nitrogen cooled CMOS logic with 20,000 gates per chip, a single printed circuit board for each CPU, and high density static and dynamic MOS memory chips. Software for the ETA 10 includes an underlying kernel that supports multiple user environments, a new ETA FORTRAN compiler with an advanced automatic vectorizer, a multitasking library and debugging tools. Possible developments for future supercomputers from ETA Systems are discussed

  7. Dynamic circular buffering: a technique for equilibrium gated blood pool imaging.

    Science.gov (United States)

    Vaquero, J J; Rahms, H; Green, M V; Del Pozo, F

    1996-03-01

    We have devised a software technique called "dynamic circular buffering" (DCB) with which we create a gated blood pool image sequence of the heart in real time using the best features of LIST and FRAME mode methods of acquisition/processing. The routine is based on the concept of independent "agents" acting on the timing and position data continuously written into the DCB. This approach allows efficient asynchronous operation on PC-type machines and enhanced capability on systems capable of true multiprocessing and multithreading.

  8. A dataflow analysis tool for parallel processing of algorithms

    Science.gov (United States)

    Jones, Robert L., III

    1993-01-01

    A graph-theoretic design process and software tool is presented for selecting a multiprocessing scheduling solution for a class of computational problems. The problems of interest are those that can be described using a dataflow graph and are intended to be executed repetitively on a set of identical parallel processors. Typical applications include signal processing and control law problems. Graph analysis techniques are introduced and shown to effectively determine performance bounds, scheduling constraints, and resource requirements. The software tool is shown to facilitate the application of the design process to a given problem.

  9. On-line surveillance system for Borssele nuclear power plant monitoring and diagnostics

    International Nuclear Information System (INIS)

    Tuerkcan, E.; Ciftcioglu, Oe.

    1993-08-01

    An operating on-line surveillance and diagnostic system is described where information processing for monitoring and fault diagnosis and plant maintenance are addressed. The surveillance system by means of its realtime multiprocessing, multitasking execution capabilities can perform plant-wide and wide-range monitoring for enhanced plant safety and operational reliability as well as enhanced maintenance. At the same time the system provides the possibilities for goal-oriented research and development such as estimation, filtering, verification and validation and neural networks. (orig./HP)

  10. Environments for online maritime simulators with cloud computing capabilities

    Science.gov (United States)

    Raicu, Gabriel; Raicu, Alexandra

    2016-12-01

    This paper presents the cloud computing environments, network principles and methods for graphical development in realistic naval simulation, naval robotics and virtual interactions. The aim of this approach is to achieve a good simulation quality in large networked environments using open source solutions designed for educational purposes. Realistic rendering of maritime environments requires near real-time frameworks with enhanced computing capabilities during distance interactions. E-Navigation concepts coupled with the last achievements in virtual and augmented reality will enhance the overall experience leading to new developments and innovations. We have to deal with a multiprocessing situation using advanced technologies and distributed applications using remote ship scenario and automation of ship operations.

  11. Improving the accuracy of micro injection moulding process simulations

    DEFF Research Database (Denmark)

    Marhöfer, David Maximilian; Tosello, Guido; Islam, Aminul

    and are therefore limited in the capability of modelling the polymer flow in micro cavities. Hence, new strategies for comprehensive simulation models which provide more precise results open up new opportunities and will be discussed. Modelling and meshing recommendations are presented, leading to a multi......Process simulations in micro injection moulding aim at the optimization and support of the design of the mould, mould inserts, the plastic product, and the process. Nevertheless, dedicated software packages for micro injection moulding are not available. They are developed for macro plastic parts...

  12. Rapid development of scalable scientific software using a process oriented approach

    DEFF Research Database (Denmark)

    Friborg, Rune Møllegaard; Vinter, Brian

    2011-01-01

    Scientific applications are often not written with multiprocessing, cluster computing or grid computing in mind. This paper suggests using Python and PyCSP to structure scientific software through Communicating Sequential Processes. Three scientific applications are used to demonstrate the features...... of PyCSP and how networks of processes may easily be mapped into a visual representation for better understanding of the process workflow. We show that for many sequential solutions, the difficulty in implementing a parallel application is removed. The use of standard multi-threading mechanisms...

  13. Protection against hostile algorithms in UNIX software

    Science.gov (United States)

    Radatti, Peter V.

    1996-03-01

    Protection against hostile algorithms contained in Unix software is a growing concern without easy answers. Traditional methods used against similar attacks in other operating system environments such as MS-DOS or Macintosh are insufficient in the more complex environment provided by Unix. Additionally, Unix provides a special and significant problem in this regard due to its open and heterogeneous nature. These problems are expected to become both more common and pronounced as 32 bit multiprocess network operating systems become popular. Therefore, the problems experienced today are a good indicator of the problems and the solutions that will be experienced in the future, no matter which operating system becomes predominate.

  14. MPS [Multiparticle Spectrometer] data acquisition software system

    International Nuclear Information System (INIS)

    Saulys, A.C.; Etkin, A.; Foley, K.J.

    1989-01-01

    A description of the software for a FASTBUS based data acquisition system in use at the Brookhaven National Laboratory Multiparticle Spectrometer is presented. Data reading and formatting is done by the SLAC Scanner Processors (SSP's) resident in the FASTBUS system. A multiprocess software system on VAX computers is used to communicate with the SSP's, record the data, and monitor on-line the progress of high energy and heavy ion experiments. The structure and the performance of this system are discussed. 4 refs., 1 fig

  15. User's manual for the two-dimensional transputer graphics toolkit

    Science.gov (United States)

    Ellis, Graham K.

    1988-01-01

    The user manual for the 2-D graphics toolkit for a transputer based parallel processor is presented. The toolkit consists of a package of 2-D display routines that can be used for the simulation visualizations. It supports multiple windows, double buffered screens for animations, and simple graphics transformations such as translation, rotation, and scaling. The display routines are written in occam to take advantage of the multiprocessing features available on transputers. The package is designed to run on a transputer separate from the graphics board.

  16. Instrumental Supporting System for Developing and Analysis of Software-Defined Networks of Mobile Objects

    Directory of Open Access Journals (Sweden)

    V. A. Sokolov

    2015-01-01

    Full Text Available This article describes the organization principles for wireless mesh-networks (software-defined net-works of mobile objects. The emphasis is on the questions of getting effective routing algorithms for such networks. The mathematical model of the system is the standard transportation network. The key parameter of the routing system is the node reachability coefficient — the function depending on several basic and additional parameters (“mesh-factors”, which characterize the route between two network nodes. Each pair (arc, node is juxtaposed to a composite parameter which characterizes the “reacha-bility” of the node by the route which begins with this arc. The best (“shortest” route between two nodes is the route with the maximum reachability coefficient. The rules of building and refreshing the routing tables by the network nodes are described. With the announcement from the neighbor the node gets the information about the connection energy and reliability, the announcement time of receipt, the absence of transitional nodes and also about the connection capability. On the basis of this informationthe node applies the penalization (decreasing the reachability coefficient or the reward (increasing the reachability coefficient to all routes through this neighbor node. The penalization / reward scheme has some separate aspects: 1. Penalization for the actuality of information. 2. Penalization / reward for the reliability of a node. 3. Penalization for the connection energy. 4. Penalization for the present connection capability. The simulator of the wireless mesh-network of mobile objects is written. It is based on the suggested heuristic algorithms. The description and characteristics of the simulator are stated in the article. The peculiarities of its program realization are also examined.

  17. Maintenance of the CERN telephone exchanges

    CERN Multimedia

    IT/CS

    2014-01-01

    Maintenance work will be carried out on the CERN telephone exchanges between 8 p.m. and 2 a.m. on 26 August.   Fixed-line telephone and audio-conference services may be disrupted during this intervention. Nevertheless, the CCC and the Fire Brigade will be reachable at any time. Mobile telephony services (GSM) will not be affected by the maintenance work.

  18. Guidance and Control Architecture Design and Demonstration for Low Ballistic Coefficient Atmospheric Entry

    Science.gov (United States)

    Swei, Sean

    2014-01-01

    We propose to develop a robust guidance and control system for the ADEPT (Adaptable Deployable Entry and Placement Technology) entry vehicle. A control-centric model of ADEPT will be developed to quantify the performance of candidate guidance and control architectures for both aerocapture and precision landing missions. The evaluation will be based on recent breakthroughs in constrained controllability/reachability analysis of control systems and constrained-based energy-minimum trajectory optimization for guidance development operating in complex environments.

  19. Local uncontrollability for affine control systems with jumps

    Science.gov (United States)

    Treanţă, Savin

    2017-09-01

    This paper investigates affine control systems with jumps for which the ideal If(g1, …, gm) generated by the drift vector field f in the Lie algebra L(f, g1, …, gm) can be imbedded as a kernel of a linear first-order partial differential equation. It will lead us to uncontrollable affine control systems with jumps for which the corresponding reachable sets are included in explicitly described differentiable manifolds.

  20. Caractérisation et simulation des mouvements d'atteinte par un opérateur humain en position assise en vue d'applications ergonomiques

    OpenAIRE

    Chevalot , Nicolas

    2006-01-01

    Simulation of seated reaching movements is useful for designing the interior of a car. It allows assessing reachability of control commands and their discomfort in an early phase of design, through virtual simulation. However, this kind of simulation encounters theoretical and pratical problems. Practically, the whole simulation process should be designed for all kind of reach tasks, arising the problems of robustness and genericity. Theoretically, it is important to understand how the moveme...

  1. Behavioural equivalence for infinite systems - Partially decidable!

    DEFF Research Database (Denmark)

    Sunesen, Kim; Nielsen, Mogens

    1996-01-01

    languages with two generalizations based on traditional approaches capturing non-interleaving behaviour, pomsets representing global causal dependency, and locality representing spatial distribution of events. We first study equivalences on Basic Parallel Processes, BPP, a process calculus equivalent...... of processes between BPP and TCSP, not only are the two equivalences different, but one (locality) is decidable whereas the other (pomsets) is not. The decidability result for locality is proved by a reduction to the reachability problem for Petri nets....

  2. La Crema: A case study of mutual fire insurance

    OpenAIRE

    Antonio Cabrales; Antoni Calvó; Matthew O. Jackson

    2000-01-01

    We analyze a mutual fire insurance mechanism used in Andorra, which is called La Crema in the local language. This mechanism relies on households' announced property values to determine how much a household is reimbursed in the case of a fire and how payments are apportioned among other households. The only Pareto-efficient al- location reachable through the mechanism requires that all house- holds honestly report the true value of their property. However, such honest reporting is not an equi...

  3. iLab 20M: A Large-scale Controlled Object Dataset to Investigate Deep Learning

    Science.gov (United States)

    2016-07-01

    models to be tolerant to identity - preserving image variations (e.g., variation in position, scale, pose, illumination, occlusion). To probe this, some...regular- izer and adopted it for CNNs. Another classic example is Siamese Networks [5] which are two identical copies of the same network, with the same...holds a camera (Microsoft LifeCam Cinema , 1280×720, YUYV) which can be placed and oriented at any location and pose reachable by the arm. A second arm

  4. Existence theory in optimal control

    International Nuclear Information System (INIS)

    Olech, C.

    1976-01-01

    This paper treats the existence problem in two main cases. One case is that of linear systems when existence is based on closedness or compactness of the reachable set and the other, non-linear case refers to a situation where for the existence of optimal solutions closedness of the set of admissible solutions is needed. Some results from convex analysis are included in the paper. (author)

  5. Blanking Clearance and Punch Velocity Effects on The Sheared Edge Characteristic in Micro-Blanking of Commercially Pure Copper Sheet

    OpenAIRE

    Didin Zakaria Lubis; Ichsan Ristiawan

    2017-01-01

    This study aims to identify the influences between clearance and punch velocity on the part edge quality of blanked parts. Experiments have been conducted using material copper, punch-die clearance and punch velocity variations. In order to determine the reachable punch-die clearance and punch velocity required for blanking. The quality of the part-edge characteristics shows that higher punch velocity and decreases clearance value can improve the part-edge quality, resulting in smaller burr h...

  6. Language Based Techniques for Systems Biology

    DEFF Research Database (Denmark)

    Pilegaard, Henrik

    ), is context insensitive, while the other, a poly-variant analysis (2CFA), is context-sensitive. These analyses compute safe approximations to the set of spatial configurations that are reachable according to a given model. This is useful in the qualitative study of cellular self-organisation and, e...... development, where one is interested in frequent quick estimates, verification, and prediction, where one is willing to wait longer for more precise estimates....

  7. Quantitative Information Flow as Safety and Liveness Hyperproperties

    Directory of Open Access Journals (Sweden)

    Hirotoshi Yasuoka

    2012-07-01

    Full Text Available We employ Clarkson and Schneider's "hyperproperties" to classify various verification problems of quantitative information flow. The results of this paper unify and extend the previous results on the hardness of checking and inferring quantitative information flow. In particular, we identify a subclass of liveness hyperproperties, which we call "k-observable hyperproperties", that can be checked relative to a reachability oracle via self composition.

  8. Udržitelnost veřejnych financí v Řecku

    OpenAIRE

    Ježek, Dominik

    2014-01-01

    In this work, I covered the sustainability of public finances in Greece, reachability of target values of debt to GDP ratio, analysis of impacts of the debt crisis in a political and social context, structure of the state budget and an evaluation of the implemented reforms. On the basis of technical publications, examples of debt crises in Asia and Latin America and recommendations from OECD, EC, NERV and IOBE I summarized the reform directions and steps to reach a sustainable state of public...

  9. Minimal Function Graphs are not Instrumented

    DEFF Research Database (Denmark)

    Mycroft, Alan; Rosendahl, Mads

    1992-01-01

    The minimal function graph semantics of Jones and Mycroft is a standard denotational semantics modified to include only `reachable' parts of a program. We show that it may be expressed directly in terms of the standard semantics without the need for instrumentation at the expression level and......, in doing so, bring out a connection with strictness. This also makes it possible to prove a stronger theorem of correctness for the minimal function graph semantics....

  10. The perception of peripersonal space in right and left brain damage hemiplegic patients

    Directory of Open Access Journals (Sweden)

    Angela eBartolo

    2014-01-01

    Full Text Available Peripersonal space, as opposed to extrapersonal space, is the space that contains reachable objects and in which multisensory and sensorimotor integration is enhanced. Thus, the perception of peripersonal space requires combining information on the spatial properties of the environment with information on the current capacity to act. In support of this, recent studies have provided converging evidences that perceiving objects in peripersonal space activates a neural network overlapping with that subtending voluntary motor action and motor imagery. Other studies have also underlined the dominant role of the right hemisphere in motor planning and of the left hemisphere in on-line motor guiding, respectively. In the present study, we investigated the effect of a right or left hemiplegia in the perception of peripersonal space. 16 hemiplegic patients with brain damage to the left (LH or right (RH hemisphere and 8 matched healthy controls (HC performed a colour discrimination, a motor imagery and a reachability judgment task. Analyses of response times and accuracy revealed no variation among the three groups in the colour discrimination task, suggesting the absence of any specific perceptual or decisional deficits in the patient groups. In contrast, the patient groups revealed longer response times in the motor imagery task when performed in reference to the hemiplegic arm (RH and LH or to the healthy arm (RH. Moreover, RH group showed longer response times in the reachability judgement task, but only for stimuli located at the boundary of peripersonal space, which was furthermore significantly reduced in size. Considered together, these results confirm the crucial role of the motor system in motor imagery task and the perception of peripersonal space. They also revealed that right hemisphere damage has a more detrimental effect on reachability estimates, suggesting that motor planning processes contribute specifically to the perception of

  11. Fusion of Data from Heterogeneous Sensors with Distributed Fields of View and Situation Evaluation for Advanced Driver Assistance Systems

    OpenAIRE

    Otto, Carola

    2013-01-01

    In order to develop a driver assistance system for pedestrian protection, pedestrians in the environment of a truck are detected by radars and a camera and are tracked across distributed fields of view using a Joint Integrated Probabilistic Data Association filter. A robust approach for prediction of the system vehicles trajectory is presented. It serves the computation of a probabilistic collision risk based on reachable sets where different sources of uncertainty are taken into account.

  12. Maintenance of the CERN telephone exchanges

    CERN Multimedia

    TS Department

    2008-01-01

    Maintenance work will be carried out on the CERN telephone exchanges between 8 p.m. and midnight on 3 December. During this time, the fixed-line telephone and audio-conference services may be disrupted. However, the CCC and the Fire Brigade will be reachable at all times. Mobile telephone services (GSM) will not be affected by this work. For further details please contact mailto:Netops@cern.ch.

  13. Maintenance of the CERN telephone exchanges

    CERN Multimedia

    2007-01-01

    Maintenance work on the CERN telephone exchanges will be performed on 10 July from 8 p.m. to midnight. During this intervention, the fixed telephone services, audioconference services and GSM calls made via the 333 prefix may be disrupted. However, the CCC and the fire brigade will be reachable at all times. For more details about this maintenance work, please call the telephone switchboard on 76111 or send an e-mail. Telecom SectionIT/CS

  14. Maintenance of the CERN telephone exchanges

    CERN Multimedia

    IT Department

    2009-01-01

    Maintenance work will be carried out on the CERN telephone exchanges between 8h30 and 17h30 on Saturday 9 May. Fixed-line telephone and audio-conference services may be disrupted during this intervention. Nevertheless, the CCC and the fire brigade will be reachable at any time. Mobile telephony services (GSM) will not be affected by the maintenance work. IT/CS/CS

  15. Maintenance of the CERN telephone exchanges

    CERN Multimedia

    IT Department

    2009-01-01

    Maintenance work will be carried out on the CERN telephone exchanges between 20h00 and midnight on the 29th of July in order to apply the latest software patches. Fixed-line telephone and audio-conference services may be disrupted during this intervention. Nevertheless, the CCC and the fire brigade will be reachable at any time. Mobile telephony services (GSM) will not be affected by the maintenance work. IT/CS/CS

  16. Maintenance of the CERN telephone exchanges

    CERN Multimedia

    IT Department

    2011-01-01

    Maintenance work will be carried out on the CERN telephone exchanges between 20h00 and 2h00 on the 16 November. Fixed-line telephone and audio-conference services may be disrupted during this intervention. Nevertheless, the CCC and the fire brigade will be reachable at any time. Mobile telephony services (GSM) will not be affected by the maintenance work. IT/CS

  17. Maintenance of the CERN telephone exchanges

    CERN Multimedia

    2007-01-01

    A maintenance of the CERN telephone exchanges will be performed on the 10th of July from 8 p.m. to midnight. During this intervention, the fixed telephone services, audioconference services, and GSM calls made via the 333 prefix may be disrupted. However, the CCC and the fire brigade will be reachable at any time. For more details about this maintenance, please contact the telephone switchboard at 76111 or by email. Telecom Section IT/CS

  18. Maintenance of the CERN telephone exchanges

    CERN Multimedia

    IT Department

    2011-01-01

    Maintenance work will be carried out on the CERN telephone exchanges between 20h00 and midnight on the 21st of February in order to apply the latest software patches. Fixed-line telephone and audio-conference services may be disrupted during this intervention. Nevertheless, the CCC and the fire brigade will be reachable at any time. Mobile telephony services (GSM) will not be affected by the maintenance work. CS Group

  19. Maintenance of the CERN telephone exchanges

    CERN Multimedia

    TS Department

    2008-01-01

    Maintenance work will be carried out on the CERN telephone exchanges between 8 p.m. and midnight on 3 December. During this time, the fixed-line telephone and audio-conference services may be disrupted. However, the CCC and the Fire Brigade will be reachable at all times. Mobile telephone services (GSM) will not be affected by this work. For further details please contact Netops@cern.ch.

  20. Resource-Optimal Scheduling Using Priced Timed Automata

    DEFF Research Database (Denmark)

    Larsen, Kim Guldstrand; Rasmussen, Jacob Illum; Subramani, K.

    2004-01-01

    In this paper, we show how the simple structure of the linear programs encountered during symbolic minimum-cost reachability analysis of priced timed automata can be exploited in order to substantially improve the performance of the current algorithm. The idea is rooted in duality of linear......-80 percent performance gain. As a main application area, we show how to solve energy-optimal task graph scheduling problems using the framework of priced timed automata....

  1. Properties of Distributed Timed-Arc Petri Nets

    DEFF Research Database (Denmark)

    Nielsen, M.; Sassone, V.; Srba, J.

    2001-01-01

    In [12] we started a research on a distributed-timed extension of Petri nets where time parameters are associated with tokens and arcs carry constraints that qualify the age of tokens required for enabling. This formalism enables to model e.g. hardware architectures like GALS. We give a formal...... definition of process semantics for our model and investigate several properties of local versus global timing: expressiveness, reachability and coverability....

  2. Hybrid Control and Verification of a Pulsed Welding Process

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Larsen, Jesper Abildgaard; Izadi-Zamanabadi, Roozbeh

    Currently systems, which are desired to control, are becoming more and more complex and classical control theory objectives, such as stability or sensitivity, are often not sufficient to cover the control objectives of the systems. In this paper it is shown how the dynamics of a pulsed welding...... process can be reformulated into a timed automaton hybrid setting and subsequently properties such as reachability and deadlock absence is verified by the simulation and verification tool UPPAAL....

  3. On the continuous selections of solution sets of Lipschitzian quantum stochastic differential inclusions

    International Nuclear Information System (INIS)

    Ayoola, E.O.

    2004-05-01

    We prove that a multifunction associated with the set of solutions of Lipschitzian quantum stochastic differential inclusion (QSDI) admits a selection continuous from some subsets of complex numbers to the space of the matrix elements of adapted weakly absolutely continuous quantum stochastic processes. In particular, we show that the solution set map as well as the reachable set of the QSDI admit some continuous representations. (author)

  4. Highly arc-transitive digraphs -- counterexamples and structure

    OpenAIRE

    DeVos, Matt; Mohar, Bojan; Šámal, Robert

    2011-01-01

    We resolve two problems of [Cameron, Praeger, and Wormald -- Infinite highly arc transitive digraphs and universal covering digraphs, Combinatorica 1993]. First, we construct a locally finite highly arc-transitive digraph with universal reachability relation. Second, we provide constructions of 2-ended highly arc transitive digraphs where each `building block' is a finite bipartite graph that is not a disjoint union of complete bipartite graphs. This was conjectured impossible in the above pa...

  5. Dual Pathways to Prospective Remembering

    Directory of Open Access Journals (Sweden)

    Mark A Mcdaniel

    2015-07-01

    Full Text Available According to the multiprocess framework (McDaniel & Einstein, 2000, the cognitive system can support prospective memory (PM retrieval through two general pathways. One pathway depends on top-down attentional control processes that maintain activation of the intention and/or monitor the environment for the triggering or target cues that indicate that the intention should be executed. A second pathway depends on (bottom-up spontaneous retrieval processes, processes that are often triggered by a PM target cue; critically spontaneous retrieval is assumed to not require monitoring or active maintenance of the intention. Given demand characteristics associated with experimental settings, however, participants are often inclined to monitor, thereby potentially masking discovery of bottom-up spontaneous retrieval processes. In this article, we discuss parameters of laboratory PM paradigms to discourage monitoring and review recent behavioral evidence from such paradigms that implicate spontaneous retrieval in PM. We then re-examine the neuro-imaging evidence from the lens of the multiprocess framework and suggest some critical modifications to existing neuro-cognitive interpretations of the neuro-imaging results. These modifications illuminate possible directions and refinements for further neuro-imaging investigations of PM.

  6. Dual pathways to prospective remembering

    Science.gov (United States)

    McDaniel, Mark A.; Umanath, Sharda; Einstein, Gilles O.; Waldum, Emily R.

    2015-01-01

    According to the multiprocess framework (McDaniel and Einstein, 2000), the cognitive system can support prospective memory (PM) retrieval through two general pathways. One pathway depends on top–down attentional control processes that maintain activation of the intention and/or monitor the environment for the triggering or target cues that indicate that the intention should be executed. A second pathway depends on (bottom–up) spontaneous retrieval processes, processes that are often triggered by a PM target cue; critically, spontaneous retrieval is assumed not to require monitoring or active maintenance of the intention. Given demand characteristics associated with experimental settings, however, participants are often inclined to monitor, thereby potentially masking discovery of bottom–up spontaneous retrieval processes. In this article, we discuss parameters of laboratory PM paradigms to discourage monitoring and review recent behavioral evidence from such paradigms that implicate spontaneous retrieval in PM. We then re-examine the neuro-imaging evidence from the lens of the multiprocess framework and suggest some critical modifications to existing neuro-cognitive interpretations of the neuro-imaging results. These modifications illuminate possible directions and refinements for further neuro-imaging investigations of PM. PMID:26236213

  7. Effects of social intention on movement kinematics in cooperative actions

    Directory of Open Access Journals (Sweden)

    Francois eQuesque

    2013-10-01

    Full Text Available Optimal control models of biological movements are used to account for those internal variables that constrain voluntary goal-directed actions. They however do not take into account external environmental constraints as those associated to social intention. We investigated here the effects of the social context on kinematic characteristics of sequential actions consisting in placing an object on an initial pad (preparatory action before reaching and grasping as fast as possible the object to move it to another location (main action. Reach-to-grasp actions were performed either in an isolated condition or in the presence of a partner (audience effect, located in the near or far space (effect of shared reachable space, and who could intervene on the object in a systematic fashion (effect of social intention effect or not (effect of social uncertainty. Results showed an absence of audience effect but nevertheless an influence of the social context both on the main and the preparatory actions. In particular, a localized effect of shared reachable space was observed on the main action, which was smoother when performed within the reachable space of the partner. Furthermore, a global effect of social uncertainty was observed on both actions with faster and jerkier movements. Finally, social intention affected the preparatory action with higher wrist displacements and slower movements when the object was placed for the partner rather than placed for self-use. Overall, these results demonstrate specific effects of action space, social uncertainty and social intention on the planning of reach-to-grasp actions, in particular on the preparatory action, which was performed with no specific execution constraint. These findings underline the importance of considering the social context in optimal models of action control for human-robot interactions, in particular when focusing on the implementation of motor parameters required to afford intuitive

  8. Energy Optimal Path Planning: Integrating Coastal Ocean Modelling with Optimal Control

    Science.gov (United States)

    Subramani, D. N.; Haley, P. J., Jr.; Lermusiaux, P. F. J.

    2016-02-01

    A stochastic optimization methodology is formulated for computing energy-optimal paths from among time-optimal paths of autonomous vehicles navigating in a dynamic flow field. To set up the energy optimization, the relative vehicle speed and headings are considered to be stochastic, and new stochastic Dynamically Orthogonal (DO) level-set equations that govern their stochastic time-optimal reachability fronts are derived. Their solution provides the distribution of time-optimal reachability fronts and corresponding distribution of time-optimal paths. An optimization is then performed on the vehicle's energy-time joint distribution to select the energy-optimal paths for each arrival time, among all stochastic time-optimal paths for that arrival time. The accuracy and efficiency of the DO level-set equations for solving the governing stochastic level-set reachability fronts are quantitatively assessed, including comparisons with independent semi-analytical solutions. Energy-optimal missions are studied in wind-driven barotropic quasi-geostrophic double-gyre circulations, and in realistic data-assimilative re-analyses of multiscale coastal ocean flows. The latter re-analyses are obtained from multi-resolution 2-way nested primitive-equation simulations of tidal-to-mesoscale dynamics in the Middle Atlantic Bight and Shelbreak Front region. The effects of tidal currents, strong wind events, coastal jets, and shelfbreak fronts on the energy-optimal paths are illustrated and quantified. Results showcase the opportunities for longer-duration missions that intelligently utilize the ocean environment to save energy, rigorously integrating ocean forecasting with optimal control of autonomous vehicles.

  9. Novel density-based and hierarchical density-based clustering algorithms for uncertain data.

    Science.gov (United States)

    Zhang, Xianchao; Liu, Han; Zhang, Xiaotong

    2017-09-01

    Uncertain data has posed a great challenge to traditional clustering algorithms. Recently, several algorithms have been proposed for clustering uncertain data, and among them density-based techniques seem promising for handling data uncertainty. However, some issues like losing uncertain information, high time complexity and nonadaptive threshold have not been addressed well in the previous density-based algorithm FDBSCAN and hierarchical density-based algorithm FOPTICS. In this paper, we firstly propose a novel density-based algorithm PDBSCAN, which improves the previous FDBSCAN from the following aspects: (1) it employs a more accurate method to compute the probability that the distance between two uncertain objects is less than or equal to a boundary value, instead of the sampling-based method in FDBSCAN; (2) it introduces new definitions of probability neighborhood, support degree, core object probability, direct reachability probability, thus reducing the complexity and solving the issue of nonadaptive threshold (for core object judgement) in FDBSCAN. Then, we modify the algorithm PDBSCAN to an improved version (PDBSCANi), by using a better cluster assignment strategy to ensure that every object will be assigned to the most appropriate cluster, thus solving the issue of nonadaptive threshold (for direct density reachability judgement) in FDBSCAN. Furthermore, as PDBSCAN and PDBSCANi have difficulties for clustering uncertain data with non-uniform cluster density, we propose a novel hierarchical density-based algorithm POPTICS by extending the definitions of PDBSCAN, adding new definitions of fuzzy core distance and fuzzy reachability distance, and employing a new clustering framework. POPTICS can reveal the cluster structures of the datasets with different local densities in different regions better than PDBSCAN and PDBSCANi, and it addresses the issues in FOPTICS. Experimental results demonstrate the superiority of our proposed algorithms over the existing

  10. Autonomous Mission Design in Extreme Orbit Environments

    Science.gov (United States)

    Surovik, David Allen

    An algorithm for autonomous online mission design at asteroids, comets, and small moons is developed to meet the novel challenges of their complex non-Keplerian orbit environments, which render traditional methods inapplicable. The core concept of abstract reachability analysis, in which a set of impulsive maneuvering options is mapped onto a space of high-level mission outcomes, is applied to enable goal-oriented decision-making with robustness to uncertainty. These nuanced analyses are efficiently computed by utilizing a heuristic-based adaptive sampling scheme that either maximizes an objective function for autonomous planning or resolves details of interest for preliminary analysis and general study. Illustrative examples reveal the chaotic nature of small body systems through the structure of various families of reachable orbits, such as those that facilitate close-range observation of targeted surface locations or achieve soft impact upon them. In order to fulfill extensive sets of observation tasks, the single-maneuver design method is implemented in a receding-horizon framework such that a complete mission is constructed on-the-fly one piece at a time. Long-term performance and convergence are assured by augmenting the objective function with a prospect heuristic, which approximates the likelihood that a reachable end-state will benefit the subsequent planning horizon. When state and model uncertainty produce larger trajectory deviations than were anticipated, the next control horizon is advanced to allow for corrective action -- a low-frequency form of feedback control. Through Monte Carlo analysis, the planning algorithm is ultimately demonstrated to produce mission profiles that vary drastically in their physical paths but nonetheless consistently complete all goals, suggesting a high degree of flexibility. It is further shown that the objective function can be tuned to preferentially minimize fuel cost or mission duration, as well as to optimize

  11. Real-time shadows

    CERN Document Server

    Eisemann, Elmar; Assarsson, Ulf; Wimmer, Michael

    2011-01-01

    Important elements of games, movies, and other computer-generated content, shadows are crucial for enhancing realism and providing important visual cues. In recent years, there have been notable improvements in visual quality and speed, making high-quality realistic real-time shadows a reachable goal. Real-Time Shadows is a comprehensive guide to the theory and practice of real-time shadow techniques. It covers a large variety of different effects, including hard, soft, volumetric, and semi-transparent shadows.The book explains the basics as well as many advanced aspects related to the domain

  12. Verification of Liveness Properties on Closed Timed-Arc Petri Nets

    DEFF Research Database (Denmark)

    Andersen, Mathias; Larsen, Heine G.; Srba, Jiri

    2012-01-01

    Verification of closed timed models by explicit state-space exploration methods is an alternative to the wide-spread symbolic techniques based on difference bound matrices (DBMs). A few experiments found in the literature confirm that for the reachability analysis of timed automata explicit...... techniques can compete with DBM-based algorithms, at least for situations where the constants used in the models are relatively small. To the best of our knowledge, the explicit methods have not yet been employed in the verification of liveness properties in Petri net models extended with time. We present...

  13. Recursive definition of global cellular-automata mappings

    DEFF Research Database (Denmark)

    Feldberg, Rasmus; Knudsen, Carsten; Rasmussen, Steen

    1994-01-01

    A method for a recursive definition of global cellular-automata mappings is presented. The method is based on a graphical representation of global cellular-automata mappings. For a given cellular-automaton rule the recursive algorithm defines the change of the global cellular-automaton mapping...... as the number of lattice sites is incremented. A proof of lattice size invariance of global cellular-automata mappings is derived from an approximation to the exact recursive definition. The recursive definitions are applied to calculate the fractal dimension of the set of reachable states and of the set...

  14. Study and modeling of heat transfer during the solidification of semi-crystalline polymers

    Energy Technology Data Exchange (ETDEWEB)

    Le Goff, R.; Poutot, G.; Delaunay, D. [Laboratoire de Thermocinetique de l' ecole polytechnique de l' universite de Nantes, UMR CNRS 6607, rue Christian Pauc, BP 50609 44306 Nantes cedex 3 (France); Fulchiron, R.; Koscher, E. [Laboratoire des Materiaux Polymeres et des Biomateriaux, IMP/UMR CNRS 5627, Universite Claude Bernard, Lyon 1, 69622 Villeurbanne Cedex (France)

    2005-12-01

    Semi-crystalline polymers are materials whose behavior during their cooling is difficult to model because of the strong coupling between the crystallization, heat transfer, pressure and shear. Thanks to two original apparatus we study solidification of such a polymer without shear. Firstly the comparison between experimental results and a numerical model will permit to validate crystallization kinetic for cooling rate reachable by DSC. The second experiment makes it possible to analyze solidification for high cooling rate, corresponding to some manufacturing processes. It appears that crystallization has an influence on the thermal contact resistance. (author)

  15. Probing TeV gravity with the ATLAS detector

    International Nuclear Information System (INIS)

    Lendermann, Victor

    2009-01-01

    Models with compactified extra space dimensions offer a new way to address outstanding problems in and beyond the Standard Model. In these models, the strength of gravity is strongly increased at small distances, which opens up the possibility of observing quantum gravity effects in the TeV energy range reachable by the LHC. One of the most spectacular phenomena would be the production of microscopic black holes. Searches for black holes are foreseen in the ATLAS experiment with the start-up of data taking in 2009. We present feasibility studies for the triggering, selection and reconstruction of the black hole event topologies, the black hole discovery potential and their identification.

  16. A vector matching method for analysing logic Petri nets

    Science.gov (United States)

    Du, YuYue; Qi, Liang; Zhou, MengChu

    2011-11-01

    Batch processing function and passing value indeterminacy in cooperative systems can be described and analysed by logic Petri nets (LPNs). To directly analyse the properties of LPNs, the concept of transition enabling vector sets is presented and a vector matching method used to judge the enabling transitions is proposed in this article. The incidence matrix of LPNs is defined; an equation about marking change due to a transition's firing is given; and a reachable tree is constructed. The state space explosion is mitigated to a certain extent from directly analysing LPNs. Finally, the validity and reliability of the proposed method are illustrated by an example in electronic commerce.

  17. Minimal Time Problem with Impulsive Controls

    Energy Technology Data Exchange (ETDEWEB)

    Kunisch, Karl, E-mail: karl.kunisch@uni-graz.at [University of Graz, Institute for Mathematics and Scientific Computing (Austria); Rao, Zhiping, E-mail: zhiping.rao@ricam.oeaw.ac.at [Austrian Academy of Sciences, Radon Institute of Computational and Applied Mathematics (Austria)

    2017-02-15

    Time optimal control problems for systems with impulsive controls are investigated. Sufficient conditions for the existence of time optimal controls are given. A dynamical programming principle is derived and Lipschitz continuity of an appropriately defined value functional is established. The value functional satisfies a Hamilton–Jacobi–Bellman equation in the viscosity sense. A numerical example for a rider-swing system is presented and it is shown that the reachable set is enlargered by allowing for impulsive controls, when compared to nonimpulsive controls.

  18. Control and estimation of piecewise affine systems

    CERN Document Server

    Xu, Jun

    2014-01-01

    As a powerful tool to study nonlinear systems and hybrid systems, piecewise affine (PWA) systems have been widely applied to mechanical systems. Control and Estimation of Piecewise Affine Systems presents several research findings relating to the control and estimation of PWA systems in one unified view. Chapters in this title discuss stability results of PWA systems, using piecewise quadratic Lyapunov functions and piecewise homogeneous polynomial Lyapunov functions. Explicit necessary and sufficient conditions for the controllability and reachability of a class of PWA systems are

  19. Using digital communication technology fails to improve longitudinal evaluation of an HIV prevention program aimed at Indian truck drivers and cleaners.

    Science.gov (United States)

    Schneider, John A; Kondareddy, Divya; Gandham, Sabitha; Dude, Annie M

    2012-07-01

    HIV prevention programs for truck drivers and cleaners (TDC) in India are limited. Longitudinal follow-up presents an obstacle to program effectiveness evaluation. We asked 3,028 TDC in a truck-driver HIV prevention program in Hyderabad to leave a cellular telephone number; we contacted participants 6 months after the intervention to assess sexual risk behavior change. Married, older, and better educated participants were more likely to leave phone numbers. Only 6.5% of TDC were reachable after 6 months. Longitudinal follow-up of this mobile sub-population remains a challenge, and more effective methods for evaluating HIV prevention programs are needed.

  20. Stochastic Equilibria under Imprecise Deviations in Terminal-Reward Concurrent Games

    Directory of Open Access Journals (Sweden)

    Patricia Bouyer

    2016-09-01

    Full Text Available We study the existence of mixed-strategy equilibria in concurrent games played on graphs. While existence is guaranteed with safety objectives for each player, Nash equilibria need not exist when players are given arbitrary terminal-reward objectives, and their existence is undecidable with qualitative reachability objectives (and only three players. However, these results rely on the fact that the players can enforce infinite plays while trying to improve their payoffs. In this paper, we introduce a relaxed notion of equilibria, where deviations are imprecise. We prove that contrary to Nash equilibria, such (stationary equilibria always exist, and we develop a PSPACE algorithm to compute one.

  1. Symmetric Cryptosystem Based on Petri Net

    Directory of Open Access Journals (Sweden)

    Hussein ‎ A. Lafta

    2017-12-01

    Full Text Available In this wok, a novel approach based on ordinary Petri net is used to generate private key . The reachability marking  of petri net is used as encryption/decryption key to provide more complex key . The same ordinary Petri Nets models  are used for the sender(encryption and  the receiver(decryption.The plaintext has been permutated  using  look-up table ,and XOR-ed with key to generate cipher text

  2. Kinematic Analysis and Performance Evaluation of Novel PRS Parallel Mechanism

    Science.gov (United States)

    Balaji, K.; Khan, B. Shahul Hamid

    2018-02-01

    In this paper, a 3 DoF (Degree of Freedom) novel PRS (Prismatic-Revolute- Spherical) type parallel mechanisms has been designed and presented. The combination of striaght and arc type linkages for 3 DOF parallel mechanism is introduced for the first time. The performances of the mechanisms are evaluated based on the indices such as Minimum Singular Value (MSV), Condition Number (CN), Local Conditioning Index (LCI), Kinematic Configuration Index (KCI) and Global Conditioning Index (GCI). The overall reachable workspace of all mechanisms are presented. The kinematic measure, dexterity measure and workspace analysis for all the mechanism have been evaluated and compared.

  3. Sweeping the State Space

    DEFF Research Database (Denmark)

    Mailund, Thomas

    The thesis describes the sweep-line method, a newly developed reduction method for alleviating the state explosion problem inherent in explicit-state state space exploration. The basic idea underlying the sweep-line method is, when calculating the state space, to recognise and delete states...... that are not reachable from the currently unprocessed states. Intuitively we drag a sweep-line through the state space with the invariant that all states behind the sweep-line have been processed and are unreachable from the states in front of the sweep-line. When calculating the state space of a system we iteratively...

  4. Multi-annual planning of investments for heat production. 2009 - 2020 period

    International Nuclear Information System (INIS)

    2005-01-01

    A new Multi-annual Planning of Investments (PPI) for heat production in France has been realized in order to meet the conclusions of the Grenelle Environnement Forum for a better energy efficiency and a larger use of renewable energies. Based on quantitative data (the increase in heat production will reach more than 10 Mtoe by 2020), potential objectives have been assessed for the various heat production sources and techniques: wood, biomass (for buildings, district heating, industry and processes, cogeneration), deep and intermediary geothermal energy, individual heat pumps, individual and collective heat solar systems, biogas, etc. These objectives are said to be ambitious but reachable if every sources and techniques are thoroughly exploited

  5. Recursive Advice for Coordination

    DEFF Research Database (Denmark)

    Terepeta, Michal Tomasz; Nielson, Hanne Riis; Nielson, Flemming

    2012-01-01

    Aspect-oriented programming is a programming paradigm that is often praised for the ability to create modular software and separate cross-cutting concerns. Recently aspects have been also considered in the context of coordination languages, offering similar advantages. However, introducing aspects...... challenging. This is important since ensuring that a system does not contain errors is often equivalent to proving that some states are not reachable. In this paper we show how to solve these challenges by applying a successful technique from the area of software model checking, namely communicating pushdown...

  6. Asymptotic behavior of dynamical and control systems under perturbation and discretization

    CERN Document Server

    Grüne, Lars

    2002-01-01

    This book provides an approach to the study of perturbation and discretization effects on the long-time behavior of dynamical and control systems. It analyzes the impact of time and space discretizations on asymptotically stable attracting sets, attractors, asumptotically controllable sets and their respective domains of attractions and reachable sets. Combining robust stability concepts from nonlinear control theory, techniques from optimal control and differential games and methods from nonsmooth analysis, both qualitative and quantitative results are obtained and new algorithms are developed, analyzed and illustrated by examples.

  7. Control of discrete event systems modeled as hierarchical state machines

    Science.gov (United States)

    Brave, Y.; Heymann, M.

    1991-01-01

    The authors examine a class of discrete event systems (DESs) modeled as asynchronous hierarchical state machines (AHSMs). For this class of DESs, they provide an efficient method for testing reachability, which is an essential step in many control synthesis procedures. This method utilizes the asynchronous nature and hierarchical structure of AHSMs, thereby illustrating the advantage of the AHSM representation as compared with its equivalent (flat) state machine representation. An application of the method is presented where an online minimally restrictive solution is proposed for the problem of maintaining a controlled AHSM within prescribed legal bounds.

  8. Maintenance of the CERN telephone exchanges

    CERN Multimedia

    2007-01-01

    Maintenance work will be carried out on the CERN telephone exchanges between 8 p.m. and midnight on 20 November. Fixed-line telephone and audioconference services may be disrupted while the work is being carried out. However, the CCC and the fire brigade will be reachable at any time. Mobile telephony services (GSM) will not be affected by the maintenance work. For further details about the maintenance work, please contact the telephone switchboard on 76111 or by email. Telecom Section - IT/CS

  9. Loss pattern of Pb ions with charge changing processes in the LEIR ring

    CERN Document Server

    Pasternak, J

    2004-01-01

    Avalanche like pressure rise and an associated decrease of the beam lifetime, caused by (i) beam loss due to charge exchange interactions with rest gas molecules and (ii) ion impact induced outgassing, is a potential limitation for heavy ion accelerators. The vacuum system of the LEIR ring has to be upgraded carefully to avoid that these phenomena prevent the machine from reaching design performance. The loss pattern of Pb ions having captured an electron presented in this report allows to estimate whether the low dynamic pressure needed for LEIR is reachable. Efficient interception of lost ions with low beam loss induced outgassing absorber blocks, installed at appropriate locations is promising.

  10. Kampen mellem arbejdsliv og privatliv

    OpenAIRE

    Sonne, Magnus; Mogensen, Michelle Busk; Falck-Jensen, Mikkel Søren

    2016-01-01

    The phrase “work hard, play hard” has got a nice ring to it, but is it truly that simple? Being able to find the right work-life-balance is crucial to the individual worker and his/her well-being. If this balance is absent, the worker will for example be prone to stress and maybe even depression. Our project revolves around the different factors and problems, which are influencing the individual in his/her work-life-balance, and how this balance is reachable. How we came about this was by usi...

  11. Optimal scheduling using priced timed automata

    DEFF Research Database (Denmark)

    Behrmann, Gerd; Larsen, Kim Guldstrand; Rasmussen, Jacob Illum

    2005-01-01

    This contribution reports on the considerable effort made recently towards extending and applying well-established timed automata technology to optimal scheduling and planning problems. The effort of the authors in this direction has to a large extent been carried out as part of the European...... projects VHS [20] and AMETIST [16] and are available in the recently released UPPAAL CORA [12], a variant of the real-time verification tool UPPAAL [18, 5] specialized for cost-optimal reachability for the extended model of so-called priced timed automata....

  12. Priced Timed Automata

    DEFF Research Database (Denmark)

    Behrmann, Gerd; Larsen, Kim Guldstrand; Rasmussen, Jacob Illum

    2004-01-01

    This contribution reports on the considerable effort made recently towards extending and applying well-established timed automata technology to optimal scheduling and planning problems. The effort of the authors in this direction has to a large extent been carried out as part of the European...... projects VHS [22] and AMETIST [17] and are available in the recently released UPPAAL CORA [12], a variant of the real-time verification tool UPPAAL [20,5] specialized for cost-optimal reachability for the extended model of priced timed automata....

  13. Surveys in differential-algebraic equations III

    CERN Document Server

    Reis, Timo

    2015-01-01

    The present volume comprises survey articles on various fields of Differential-Algebraic Equations (DAEs), which have widespread applications in controlled dynamical systems, especially in mechanical and electrical engineering and a strong relation to (ordinary) differential equations. The individual chapters provide reviews, presentations of the current state of research and new concepts in - Flexibility of DAE formulations - Reachability analysis and deterministic global optimization - Numerical linear algebra methods - Boundary value problems The results are presented in an accessible style, making this book suitable not only for active researchers but also for graduate students (with a good knowledge of the basic principles of DAEs) for self-study.

  14. Climate protection in Germany. 40% reduction of CO{sub 2} emissions by 2020 compared to 1990; Klimaschutz in Deutschland. 40%-Senkung der CO{sub 2}-Emissionen bis 2020 gegenueber 1990

    Energy Technology Data Exchange (ETDEWEB)

    Erdmenger, Christoph; Hermann, Hauke; Tambke, Jens (and others)

    2007-06-15

    The report covers the following chapters: executive summary: the eight most important measures for climate protection; introduction: why should Germany reduce its greenhouse gas emissions by 40% until 2020? Which framework requirements and assumptions are the basis for the Federal environmental Agency assessment? How should the required CO{sub 2} emission reduction be distributed to different sections? Which cost efficient measures can be reached in Germany: energy management, industry, households and business, traffic? Which instruments should be used in Germany? Conclusion: the 40% aim is reachable, but only with a resolute climate and energy policy.

  15. Research on Outfitting Virtual Assembly based on Ergonomics

    Directory of Open Access Journals (Sweden)

    Jiang Zuhua

    2018-01-01

    Full Text Available To improve the present situation where the assembly work of ship outfitting depends on manual experiential operation, the thesis, taking outfitting assembly operation as the research object and optimal assembly path as the target, puts forward the simulation method and procedure of outfitting virtual assembly considering operational posture, operational load, reachability and visibility and other ergonomic factors, taking pipe assembly operation of ship section as the application example. The results show that the method can obtain better assembly operation path, avoid interference of workers’ operation process and improve the efficiency of assembly operation.

  16. Music Therapy as a Way to Enhance Lucidity in Persons with Dementia in Advanced Stages

    DEFF Research Database (Denmark)

    Ridder, Hanne Mette Ochsner

    2005-01-01

    Instead of describing dementia as a permanent state of non-lucidity, where the person is not reasonable and reachable, dementia is described as a condition where periods of confusion and dimness might alternate with clear and lucid mental states. In these states, the person with dementia is prese...... in advanced stages. The text is illustrated with case material and is partly based on a PhD thesis (Ridder 2003). The thesis was supervised by David Aldridge and carried out in collaboration with Aalborg University and gerontopsychiatric unit II, nursing home Caritas....

  17. Trajectory Planning for Robots in Dynamic Human Environments

    DEFF Research Database (Denmark)

    Svenstrup, Mikael; Bak, Thomas; Andersen, Hans Jørgen

    2010-01-01

    This paper present a trajectory planning algorithm for a robot operating in dynamic human environments. Environments such as pedestrian streets, hospital corridors and train stations. We formulate the problem as planning a minimal cost trajectory through a potential field, defined from...... is enhanced to direct the search and account for the kinodynamic robot constraints. Compared to standard RRT, the algorithm proposed here find the robot control input that will drive the robot towards a new sampled point in the configuration space. The effect of the input is simulated, to add a reachable...

  18. First delayed neutron emission measurements at ALTO with the neutron detector TETRA

    International Nuclear Information System (INIS)

    Testov, D.; Ancelin, S.; Bettane, J.; Ibrahim, F.; Kolos, K.; Mavilla, G.; Niikura, M.; Verney, D.; Wilson, J.; Kuznetsova, E.; Penionzhkevich, Yu.; Smirnov, V.; Sokol, E.

    2013-01-01

    Beta-decay properties are among the easiest and, therefore, the first ones to be measured to study new neutron-rich isotopes. Eventually, a very small number of nuclei could be sufficient to estimate their lifetime and neutron emission probability. With the new radioactive beam facilities which have been commissioned recently (or will be constructed shortly) new areas of neutron-rich isotopes will become reachable. To study beta-decay properties of such nuclei at IPN (Orsay) in the framework of collaboration with JINR (Dubna), a new experimental setup including the neutron detector of high efficiency TETRA was developed and commissioned

  19. Comparison Of Conventional And Recycled “Green” Office Paper

    Directory of Open Access Journals (Sweden)

    Klemen Možina

    2011-05-01

    Full Text Available To confront with the market need, we have to find alternative in respond to enormous necessity and application ofoffice paper. Therefore, one way in dealing with the problem is to replace or just decrease the use of paper madeentirely from primary components, mainly wood fibbers (deciduous and conifer. We analysed mechanical, optical,structural and microscopic properties. Experiments were performed on three conventional and three recycled officepapers reachable on the market. Results, obtained from measurements, confirm presumption, that mechanical andsurface properties of recycled office paper can be collated and they discern from conventional office paper.

  20. Recursive definition of global cellular-automata mappings

    International Nuclear Information System (INIS)

    Feldberg, R.; Knudsen, C.; Rasmussen, S.

    1994-01-01

    A method for a recursive definition of global cellular-automata mappings is presented. The method is based on a graphical representation of global cellular-automata mappings. For a given cellular-automaton rule the recursive algorithm defines the change of the global cellular-automaton mapping as the number of lattice sites is incremented. A proof of lattice size invariance of global cellular-automata mappings is derived from an approximation to the exact recursive definition. The recursive definitions are applied to calculate the fractal dimension of the set of reachable states and of the set of fixed points of cellular automata on an infinite lattice

  1. A verification environment for bigraphs

    DEFF Research Database (Denmark)

    Perrone, Gian David; Debois, Søren; Hildebrandt, Thomas

    2013-01-01

    We present the BigMC tool for bigraphical reactive systems that may be instantiated as a verification tool for any formalism or domain-specific modelling language encoded as a bigraphical reactive system. We introduce the syntax and use of BigMC, and exemplify its use with two small examples......: a textbook “philosophers” example, and an example motivated by a ubiquitous computing application. We give a tractable heuristic with which to approximate interference between reaction rules, and prove this analysis to be safe. We provide a mechanism for state reachability checking of bigraphical reactive...

  2. Measurability and Safety Verification for Stochastic Hybrid Systems

    DEFF Research Database (Denmark)

    Fränzle, Martin; Hahn, Ernst Moritz; Hermanns, Holger

    2011-01-01

    method that establishes safe upper bounds on reachability probabilities. To arrive there requires us to solve semantic intricacies as well as practical problems. In particular, we show that measurability of a complete system follows from the measurability of its constituent parts. On the practical side......-time behaviour is given by differential equations, as for usual hybrid systems, but the targets of discrete jumps are chosen by probability distributions. These distributions may be general measures on state sets. Also non-determinism is supported, and the latter is exploited in an abstraction and evaluation...

  3. Game Coloured Petri Nets

    DEFF Research Database (Denmark)

    Westergaard, Michael

    2006-01-01

    This paper introduces the notion of game coloured Petri nets. This allows the modeler to explicitly model what parts of the model comprise the modeled system and what parts are the environment of the modeled system. We give the formal definition of game coloured Petri nets, a means of reachability...... analysis of this net class, and an application of game coloured Petri nets to automatically generate easy-to-understand visualizations of the model by exploiting the knowledge that some parts of the model are not interesting from a visualization perspective (i.e. they are part of the environment...

  4. Gain limits of a Thick GEM in high-purity Ne, Ar and Xe

    CERN Document Server

    Miyamoto, J; Peskov, V

    2010-01-01

    The dependence of the avalanche charge gain in Thick Gas Electron Multipliers (THGEM) on the purity of Ne, Ar and Xe filling gases was investigated. The gain, measured with alpha-particles in standard conditions (atmospheric pressure, room temperature), was found to considerably drop in gases purified by non-evaporable getters. On the other hand, small N2 admixtures to noble gases resulted in high reachable gains. The results are of general relevance in the operation of gas-avalanche detectors in noble gases, particularly that of two-phase cryogenic detectors for rare events.

  5. Efficient One-click Browsing of Large Trajectory Sets

    DEFF Research Database (Denmark)

    Krogh, Benjamin Bjerre; Andersen, Ove; Lewis-Kelham, Edwin

    2014-01-01

    presents a novel query type called sheaf, where users can browse trajectory data sets using a single mouse click. Sheaves are very versatile and can be used for location-based advertising, travel-time analysis, intersection analysis, and reachability analysis (isochrones). A novel in-memory trajectory...... index compresses the data by a factor of 12.4 and enables execution of sheaf queries in 40 ms. This is up to 2 orders of magnitude faster than existing work. We demonstrate the simplicity, versatility, and efficiency of sheaf queries using a real-world trajectory set consisting of 2.7 million...

  6. On the problem of quantum control in infinite dimensions

    OpenAIRE

    Mendes, R. Vilela; Man'ko, Vladimir I.

    2010-01-01

    In the framework of bilinear control of the Schr\\"odinger equation with bounded control operators, it has been proved that the reachable set has a dense complemement in ${\\cal S}\\cap {\\cal H}^{2}$. Hence, in this setting, exact quantum control in infinite dimensions is not possible. On the other hand it is known that there is a simple choice of operators which, when applied to an arbitrary state, generate dense orbits in Hilbert space. Compatibility of these two results is established in this...

  7. Small horizontal emittance in the TESLA damping ring

    International Nuclear Information System (INIS)

    Decking, W.

    2001-01-01

    The present TESLA damping ring is designed for a normalized horizontal emittance of 8x10 -6 m. γ-γ collisions at the TESLA linear collider will benefit from a further decrease of the horizontal emittance. This paper reviews the processes which limit the horizontal emittance in the damping ring. Preliminary estimates on the smallest horizontal emittance for the present TESLA damping ring design as well as an ultimate limit of the emittance reachable with the TESLA damping ring concept will be given

  8. Subcubic Control Flow Analysis Algorithms

    DEFF Research Database (Denmark)

    Midtgaard, Jan; Van Horn, David

    We give the first direct subcubic algorithm for performing control flow analysis of higher-order functional programs. Despite the long held belief that inclusion-based flow analysis could not surpass the ``cubic bottleneck, '' we apply known set compression techniques to obtain an algorithm...... that runs in time O(n^3/log n) on a unit cost random-access memory model machine. Moreover, we refine the initial flow analysis into two more precise analyses incorporating notions of reachability. We give subcubic algorithms for these more precise analyses and relate them to an existing analysis from...

  9. Utveckling av webbaserat blixtdetekteringssystem

    OpenAIRE

    Al Sayfi, Anhar; Kufa, Max

    2016-01-01

    In this paper we suggest a lightning detection system capable of warning a local populous of incoming lightning weather using a combination of the AS3935 sensor and the one-board-computer Raspberry Pi, in an attempt to design a product that is cheap, mobile and easy to use. The product is composed of a sensor net that registers and reports lightnings on a webserver. The server is reachable as a normal website based on the LAMP method. The project reached a stadium which should satisfy a “proo...

  10. Next-Generation Navigational Infrastructure and the ATLAS Event Store

    CERN Document Server

    van Gemmeren, P; The ATLAS collaboration; Nowak, M

    2014-01-01

    The ATLAS event store employs a persistence framework with extensive navigational capabilities. These include real-time back navigation to upstream processing stages, externalizable data object references, navigation from any data object to any other both within a single file and across files, and more. The 2013-2014 shutdown of the Large Hadron Collider provides an opportunity to enhance this infrastructure in several ways that both extend these capabilities and allow the collaboration to better exploit emerging computing platforms. Enhancements include redesign with efficient file merging in mind, content-based indices in optimized reference types, and support for forward references. The latter provide the potential to construct valid references to data before those data are written, a capability that is useful in a variety of multithreading, multiprocessing, distributed processing, and deferred processing scenarios. This paper describes the architecture and design of the next generation of ATLAS navigation...

  11. Next-Generation Navigational Infrastructure and the ATLAS Event Store

    CERN Document Server

    van Gemmeren, P; The ATLAS collaboration; Nowak, M

    2013-01-01

    The ATLAS event store employs a persistence framework with extensive navigational capabilities. These include real-time back navigation to upstream processing stages, externalizable data object references, navigation from any data object to any other both within a single file and across files, and more. The 2013-2014 shutdown of the Large Hadron Collider provides an opportunity to enhance this infrastructure in several ways that both extend these capabilities and allow the collaboration to better exploit emerging computing platforms. Enhancements include redesign with efficient file merging in mind, content-based indices in optimized reference types, and support for forward references. The latter provide the potential to construct valid references to data before those data are written, a capability that is useful in a variety of multithreading, multiprocessing, distributed processing, and deferred processing scenarios. This paper describes the architecture and design of the next generation of ATLAS navigation...

  12. New development of JFT-2M Tokamak (3) data processing system

    International Nuclear Information System (INIS)

    Fukuchi, Y.; Oyabu, I.; Hirose, T.; Ichimura, H.; Inoue, K.; Komoto, Y.

    1986-01-01

    A data acquisition system for JFT-2M Tokamak is a computer complex system consisting of a CAMAC serial highway, a front-end computer, and a main computer, which are ranked in a definite hierarchical structure. This paper reports the data processing system by the main computer (using a super-mini-computer MELCOM 70/250) which is situated on the highest level in the data acquisition system and performs unified management and control over the system. The features of the data processing system by the main computer are as follows: (1) Expandability of the system based on the definite hierarchical structure; (2) Five-dimensional multi-processing (setup, acquisition, analysis, display, and storage); (3) Realization of RAS (Reliability, Availability, and Serviceability) function; and (4) Easy-to-use man-machine interface that provides: flexibility in CAMAC system configuration, open-ended interface and file history managing

  13. RELAP5/MOD3 code coupling model

    International Nuclear Information System (INIS)

    Martin, R.P.; Johnsen, G.W.

    1994-01-01

    A new capability has been incorporated into RELAP5/MOD3 that enables the coupling of RELAP5/MOD3 to other computer codes. The new capability has been designed to support analysis of the new advanced reactor concepts. Its user features rely solely on new RELAP5 open-quotes styledclose quotes input and the Parallel Virtual Machine (PVM) software, which facilitates process management and distributed communication of multiprocess problems. RELAP5/MOD3 manages the input processing, communication instruction, process synchronization, and its own send and receive data processing. The flexible capability requires that an explicit coupling be established, which updates boundary conditions at discrete time intervals. Two test cases are presented that demonstrate the functionality, applicability, and issues involving use of this capability

  14. Evaluating Google compute engine with PROOF

    International Nuclear Information System (INIS)

    Ganis, Gerardo; Panitkin, Sergey

    2014-01-01

    The advent of private and commercial cloud platforms has opened the question of evaluating the cost-effectiveness of such solution for computing in High Energy Physics . Google Compute Engine (GCE) is a IaaS product launched by Google as an experimental platform during 2012 and now open to the public market. In this contribution we present the results of a set of CPU-intensive and I/O-intensive tests we have run with PROOF on a GCE resources made available by Google for test purposes. We have run tests on large scale PROOF clusters (up to 1000 workers) to study the overall scalability of coordinated multi-process jobs. We have studied and compared the performance of ephemeral and persistent storage with PROOF-Lite on the single machines and of standard PROOF on the whole cluster. We will discuss our results in perspective, in particular with respect to the typical analysis needs of an LHC experiment.

  15. Description of two-process surface topography

    International Nuclear Information System (INIS)

    Grabon, W; Pawlus, P

    2014-01-01

    After two machining processes, a large number of surface topography measurements were made using Talyscan 150 stylus measuring equipment. The measured samples were divided into two groups. The first group contained two-process surfaces of random nature, while the second group used random-deterministic textures of random plateau parts and portions of deterministic valleys. For comparison, one-process surfaces were also analysed. Correlation and regression analysis was used to study the dependencies among surface texture parameters in 2D and 3D systems. As the result of this study, sets of parameters describing multi-process surface topography were obtained for two-process surfaces of random and of random-deterministic types. (papers)

  16. Characterisation of multifunctional surfaces with robust filters

    DEFF Research Database (Denmark)

    Friis, Kasper Storgaard; Godi, Alessandro; De Chiffre, Leonardo

    2011-01-01

    Research has shown that engineered surfaces containing lubrication pockets and directional surface texture can decrease wear and friction in sliding or rolling contacts. A new generation of multifunctional (MUFU) surfaces is achieved by hard machining followed by robot assisted polishing (RAP......). The novel production method allows for a large degree of freedom in specifying surface characteristics such as frequency, depth and volume of the lubricant retention valleys, as well as the amount of load bearing area and the surface roughness. The surfaces cannot readily be characterized by means...... of conventional roughness parameters due to the multi-process production method involved. A series of MUFU surfaces were characterized by using the ISO 13565 standard for stratified surfaces and it is shown that the standard in some cases is inadequate for characterisation of a MUFU surface. To improve...

  17. Scalable Strategies for Computing with Massive Data

    Directory of Open Access Journals (Sweden)

    Michael Kane

    2013-11-01

    Full Text Available This paper presents two complementary statistical computing frameworks that address challenges in parallel processing and the analysis of massive data. First, the foreach package allows users of the R programming environment to define parallel loops that may be run sequentially on a single machine, in parallel on a symmetric multiprocessing (SMP machine, or in cluster environments without platform-specific code. Second, the bigmemory package implements memory- and file-mapped data structures that provide (a access to arbitrarily large data while retaining a look and feel that is familiar to R users and (b data structures that are shared across processor cores in order to support efficient parallel computing techniques. Although these packages may be used independently, this paper shows how they can be used in combination to address challenges that have effectively been beyond the reach of researchers who lack specialized software development skills or expensive hardware.

  18. Art and brain: insights from neuropsychology, biology and evolution.

    Science.gov (United States)

    Zaidel, Dahlia W

    2010-02-01

    Art is a uniquely human activity associated fundamentally with symbolic and abstract cognition. Its practice in human societies throughout the world, coupled with seeming non-functionality, has led to three major brain theories of art. (1) The localized brain regions and pathways theory links art to multiple neural regions. (2) The display of art and its aesthetics theory is tied to the biological motivation of courtship signals and mate selection strategies in animals. (3) The evolutionary theory links the symbolic nature of art to critical pivotal brain changes in Homo sapiens supporting increased development of language and hierarchical social grouping. Collectively, these theories point to art as a multi-process cognition dependent on diverse brain regions and on redundancy in art-related functional representation.

  19. Synthesis of logic circuits with evolutionary algorithms

    Energy Technology Data Exchange (ETDEWEB)

    JONES,JAKE S.; DAVIDSON,GEORGE S.

    2000-01-26

    In the last decade there has been interest and research in the area of designing circuits with genetic algorithms, evolutionary algorithms, and genetic programming. However, the ability to design circuits of the size and complexity required by modern engineering design problems, simply by specifying required outputs for given inputs has as yet eluded researchers. This paper describes current research in the area of designing logic circuits using an evolutionary algorithm. The goal of the research is to improve the effectiveness of this method and make it a practical aid for design engineers. A novel method of implementing the algorithm is introduced, and results are presented for various multiprocessing systems. In addition to evolving standard arithmetic circuits, work in the area of evolving circuits that perform digital signal processing tasks is described.

  20. Multi-processor network implementations in Multibus II and VME

    International Nuclear Information System (INIS)

    Briegel, C.

    1992-01-01

    ACNET (Fermilab Accelerator Controls Network), a proprietary network protocol, is implemented in a multi-processor configuration for both Multibus II and VME. The implementations are contrasted by the bus protocol and software design goals. The Multibus II implementation provides for multiple processors running a duplicate set of tasks on each processor. For a network connected task, messages are distributed by a network round-robin scheduler. Further, messages can be stopped, continued, or re-routed for each task by user-callable commands. The VME implementation provides for multiple processors running one task across all processors. The process can either be fixed to a particular processor or dynamically allocated to an available processor depending on the scheduling algorithm of the multi-processing operating system. (author)

  1. Computational structural mechanics for engine structures

    Science.gov (United States)

    Chamis, C. C.

    1989-01-01

    The computational structural mechanics (CSM) program at Lewis encompasses: (1) fundamental aspects for formulating and solving structural mechanics problems, and (2) development of integrated software systems to computationally simulate the performance/durability/life of engine structures. It is structured to mainly supplement, complement, and whenever possible replace, costly experimental efforts which are unavoidable during engineering research and development programs. Specific objectives include: investigate unique advantages of parallel and multiprocesses for: reformulating/solving structural mechanics and formulating/solving multidisciplinary mechanics and develop integrated structural system computational simulators for: predicting structural performances, evaluating newly developed methods, and for identifying and prioritizing improved/missing methods needed. Herein the CSM program is summarized with emphasis on the Engine Structures Computational Simulator (ESCS). Typical results obtained using ESCS are described to illustrate its versatility.

  2. Computational mathematics models, methods, and analysis with Matlab and MPI

    CERN Document Server

    White, Robert E

    2004-01-01

    Computational Mathematics: Models, Methods, and Analysis with MATLAB and MPI explores and illustrates this process. Each section of the first six chapters is motivated by a specific application. The author applies a model, selects a numerical method, implements computer simulations, and assesses the ensuing results. These chapters include an abundance of MATLAB code. By studying the code instead of using it as a "black box, " you take the first step toward more sophisticated numerical modeling. The last four chapters focus on multiprocessing algorithms implemented using message passing interface (MPI). These chapters include Fortran 9x codes that illustrate the basic MPI subroutines and revisit the applications of the previous chapters from a parallel implementation perspective. All of the codes are available for download from www4.ncsu.edu./~white.This book is not just about math, not just about computing, and not just about applications, but about all three--in other words, computational science. Whether us...

  3. Accelerator control systems without minicomputers

    International Nuclear Information System (INIS)

    Altaber, J.; Beck, F.; Rausch, R.

    1980-01-01

    A paper given last year described in general terms a plan for the control of a large machine using assemblies of microcomputer units which simulate a conventional minicomputer by multiprocessing. In every other way the SPS control philosophy is followed. The design of a model assembly has allowed us to learn something about the protocols needed inside and between assemblies, as well as to assess more accurately what level of technology it is reasonable to apply. In any control system of this kind it would be desirable to allow engineering contributions from a variety of sources, and yet ensure the homogeneity needed for the system to remain reliable and comprehensible. Methods of achieving this are discussed. (Auth.)

  4. MPI_XSTAR: MPI-based Parallelization of the XSTAR Photoionization Program

    Science.gov (United States)

    Danehkar, Ashkbiz; Nowak, Michael A.; Lee, Julia C.; Smith, Randall K.

    2018-02-01

    We describe a program for the parallel implementation of multiple runs of XSTAR, a photoionization code that is used to predict the physical properties of an ionized gas from its emission and/or absorption lines. The parallelization program, called MPI_XSTAR, has been developed and implemented in the C++ language by using the Message Passing Interface (MPI) protocol, a conventional standard of parallel computing. We have benchmarked parallel multiprocessing executions of XSTAR, using MPI_XSTAR, against a serial execution of XSTAR, in terms of the parallelization speedup and the computing resource efficiency. Our experience indicates that the parallel execution runs significantly faster than the serial execution, however, the efficiency in terms of the computing resource usage decreases with increasing the number of processors used in the parallel computing.

  5. Next-generation navigational infrastructure and the ATLAS event store

    International Nuclear Information System (INIS)

    Gemmeren, P van; Malon, D; Nowak, M

    2014-01-01

    The ATLAS event store employs a persistence framework with extensive navigational capabilities. These include real-time back navigation to upstream processing stages, externalizable data object references, navigation from any data object to any other both within a single file and across files, and more. The 2013-2014 shutdown of the Large Hadron Collider provides an opportunity to enhance this infrastructure in several ways that both extend these capabilities and allow the collaboration to better exploit emerging computing platforms. Enhancements include redesign with efficient file merging in mind, content-based indices in optimized reference types, and support for forward references. The latter provide the potential to construct valid references to data before those data are written, a capability that is useful in a variety of multithreading, multiprocessing, distributed processing, and deferred processing scenarios. This paper describes the architecture and design of the next generation of ATLAS navigational infrastructure.

  6. The upgraded Tevatron front end

    International Nuclear Information System (INIS)

    Glass, M.; Zagel, J.; Smith, P.; Marsh, W.; Smolucha, J.

    1990-01-01

    We are replacing the computers which support the CAMAC crates in the Fermilab accelerator control system. We want a significant performance increase, but we still want to be able to service scores of different varieties of CAMAC cards in a manner essentially transparent to console applications software. Our new architecture is based on symmetric multiprocessing. Several processors on the same bus, each running identical software, work simultaneously at satisfying different pieces of a console's request for data. We dynamically adjust the load between the processors. We can obtain more processing power by simply plugging in more processor cards and rebooting. We describe in this paper what we believe to be the interesting architectural features of the new front-end computers. We also note how we use some of the advanced features of the Multibus TM II bus and the Intel 80386 processor design to achieve reliability and expandability of both hardware and software. (orig.)

  7. Architectural development of an advanced EVA Electronic System

    Science.gov (United States)

    Lavelle, Joseph

    1992-01-01

    An advanced electronic system for future EVA missions (including zero gravity, the lunar surface, and the surface of Mars) is under research and development within the Advanced Life Support Division at NASA Ames Research Center. As a first step in the development, an optimum system architecture has been derived from an analysis of the projected requirements for these missions. The open, modular architecture centers around a distributed multiprocessing concept where the major subsystems independently process their own I/O functions and communicate over a common bus. Supervision and coordination of the subsystems is handled by an embedded real-time operating system kernel employing multitasking software techniques. A discussion of how the architecture most efficiently meets the electronic system functional requirements, maximizes flexibility for future development and mission applications, and enhances the reliability and serviceability of the system in these remote, hostile environments is included.

  8. Online Fastbus processor for LEP

    International Nuclear Information System (INIS)

    Mueller, H.

    1986-01-01

    The author describes the online computing aspects of Fastbus systems using a processor module which has been developed at CERN and is now available commercially. These General Purpose Master/Slaves (GPMS) are based on 68000/10 (or optionally 68020/68881) processors. Applications include use as event-filters (DELPHI), supervisory controllers, Fastbus stand-alone diagnostic tools, and multiprocessor array components. The direct mapping of single, 32-bit assembly instructions to execute Fastbus protocols makes the use of a GPM both simple and flexible. Loosely coupled processing in Fastbus networks is possible between GPM's as they support access semaphores and use a two port memory as I/O buffer for Fastbus. Both master and slave-ports support block transfers up to 20 Mbytes/s. The CERN standard Fastbus software and the MoniCa symbolic debugging monitor are available on the GPM with real time, multiprocessing support. (Auth.)

  9. A parallel finite-difference method for computational aerodynamics

    International Nuclear Information System (INIS)

    Swisshelm, J.M.

    1989-01-01

    A finite-difference scheme for solving complex three-dimensional aerodynamic flow on parallel-processing supercomputers is presented. The method consists of a basic flow solver with multigrid convergence acceleration, embedded grid refinements, and a zonal equation scheme. Multitasking and vectorization have been incorporated into the algorithm. Results obtained include multiprocessed flow simulations from the Cray X-MP and Cray-2. Speedups as high as 3.3 for the two-dimensional case and 3.5 for segments of the three-dimensional case have been achieved on the Cray-2. The entire solver attained a factor of 2.7 improvement over its unitasked version on the Cray-2. The performance of the parallel algorithm on each machine is analyzed. 14 refs

  10. An organizational model to support the flexible workflow based on ontology

    International Nuclear Information System (INIS)

    Yuan Feng; Li Xudong; Zhu Guangying; Zhang Xiankun

    2012-01-01

    Based on ontology theory, the paper addresses an organizational model for flexible workflow. Firstly, the paper describes the conceptual model of the organizational model on ontology chart, which provides a consistent semantic framework of organization. Secondly, the paper gives the formalization of the model and describes the six key ontology elements of the mode in detail. Finally, the paper discusses deeply how the model supports the flexible workflow and indicates that the model has the advantages of cross-area, cross-organization and cross-domain, multi-process support and scalability. Especially, because the model is represented by ontology, the paper produces the conclusion that the model has covered the defect of unshared feature in traditional models, at the same time, it is more capable and flexible. (authors)

  11. System Architecture For High Speed Sorting Of Potatoes

    Science.gov (United States)

    Marchant, J. A.; Onyango, C. M.; Street, M. J.

    1989-03-01

    This paper illustrates an industrial application of vision processing in which potatoes are sorted according to their size and shape at speeds of up to 40 objects per second. The result is a multi-processing approach built around the VME bus. A hardware unit has been designed and constructed to encode the boundary of the potatoes, to reducing the amount of data to be processed. A master 68000 processor is used to control this unit and to handle data transfers along the bus. Boundary data is passed to one of three 68010 slave processors each responsible for a line of potatoes across a conveyor belt. The slave processors calculate attributes such as shape, size and estimated weight of each potato and the master processor uses this data to operate the sorting mechanism. The system has been interfaced with a commercial grading machine and performance trials are now in progress.

  12. Education and the Transition to Fatherhood: The Role of Selection Into Union.

    Science.gov (United States)

    Trimarchi, Alessandra; Van Bavel, Jan

    2017-02-01

    Although advanced education has been found to be consistently associated with a later transition to parenthood for women, findings about education and the transition to parenthood have been much less consistent for men, and no stylized fact has emerged from the literature. We argue that the inconsistency of findings for men is due to the fact that the selection process involved in union formation has been disregarded in earlier studies. We hypothesize that men's educational attainment consistently and positively affects the transition to fatherhood via higher rates of union formation. We apply multiprocess event-history analysis to data from the Generations and Gender Surveys for 10 European countries. Our results show indeed a consistent positive effect of education on the transition to fatherhood, but it operates chiefly through selection into union. Failing to account for this selection process leads to a major underestimation of the salience of education for the transition to fatherhood.

  13. ATLAS Metadata Infrastructure Evolution for Run 2 and Beyond

    CERN Document Server

    van Gemmeren, Peter; The ATLAS collaboration; Malon, David; Vaniachine, Alexandre

    2015-01-01

    ATLAS developed and employed for Run 1 of the Large Hadron Collider a sophisticated infrastructure for metadata handling in event processing jobs. This infrastructure profits from a rich feature set provided by the ATLAS execution control framework, including standardized interfaces and invocation mechanisms for tools and services, segregation of transient data stores with concomitant object lifetime management, and mechanisms for handling occurrences asynchronous to the control framework’s state machine transitions. This metadata infrastructure is evolving and being extended for Run 2 to allow its use and reuse in downstream physics analyses, analyses that may or may not utilize the ATLAS control framework. At the same time, multiprocessing versions of the control framework and the requirements of future multithreaded frameworks are leading to redesign of components that use an incident-handling approach to asynchrony. The increased use of scatter-gather architectures, both local and distributed, requires ...

  14. Individual differences in event-based prospective memory: Evidence for multiple processes supporting cue detection.

    Science.gov (United States)

    Brewer, Gene A; Knight, Justin B; Marsh, Richard L; Unsworth, Nash

    2010-04-01

    The multiprocess view proposes that different processes can be used to detect event-based prospective memory cues, depending in part on the specificity of the cue. According to this theory, attentional processes are not necessary to detect focal cues, whereas detection of nonfocal cues requires some form of controlled attention. This notion was tested using a design in which we compared performance on a focal and on a nonfocal prospective memory task by participants with high or low working memory capacity. An interaction was found, such that participants with high and low working memory performed equally well on the focal task, whereas the participants with high working memory performed significantly better on the nonfocal task than did their counterparts with low working memory. Thus, controlled attention was only necessary for detecting event-based prospective memory cues in the nonfocal task. These results have implications for theories of prospective memory, the processes necessary for cue detection, and the successful fulfillment of intentions.

  15. Advanced parallel processing with supercomputer architectures

    International Nuclear Information System (INIS)

    Hwang, K.

    1987-01-01

    This paper investigates advanced parallel processing techniques and innovative hardware/software architectures that can be applied to boost the performance of supercomputers. Critical issues on architectural choices, parallel languages, compiling techniques, resource management, concurrency control, programming environment, parallel algorithms, and performance enhancement methods are examined and the best answers are presented. The authors cover advanced processing techniques suitable for supercomputers, high-end mainframes, minisupers, and array processors. The coverage emphasizes vectorization, multitasking, multiprocessing, and distributed computing. In order to achieve these operation modes, parallel languages, smart compilers, synchronization mechanisms, load balancing methods, mapping parallel algorithms, operating system functions, application library, and multidiscipline interactions are investigated to ensure high performance. At the end, they assess the potentials of optical and neural technologies for developing future supercomputers

  16. Embedded and real-time operating systems

    CERN Document Server

    Wang, K C

    2017-01-01

    This book covers the basic concepts and principles of operating systems, showing how to apply them to the design and implementation of complete operating systems for embedded and real-time systems. It includes all the foundational and background information on ARM architecture, ARM instructions and programming, toolchain for developing programs, virtual machines for software implementation and testing, program execution image, function call conventions, run-time stack usage and link C programs with assembly code. It describes the design and implementation of a complete OS for embedded systems in incremental steps, explaining the design principles and implementation techniques. For Symmetric Multiprocessing (SMP) embedded systems, the author examines the ARM MPcore processors, which include the SCU and GIC for interrupts routing and interprocessor communication and synchronization by Software Generated Interrupts (SGIs). Throughout the book, complete working sample systems demonstrate the design principles and...

  17. The Boom in 3D-Printed Sensor Technology

    Science.gov (United States)

    Xu, Yuanyuan; Wu, Xiaoyue; Guo, Xiao; Kong, Bin; Zhang, Min; Qian, Xiang; Mi, Shengli; Sun, Wei

    2017-01-01

    Future sensing applications will include high-performance features, such as toxin detection, real-time monitoring of physiological events, advanced diagnostics, and connected feedback. However, such multi-functional sensors require advancements in sensitivity, specificity, and throughput with the simultaneous delivery of multiple detection in a short time. Recent advances in 3D printing and electronics have brought us closer to sensors with multiplex advantages, and additive manufacturing approaches offer a new scope for sensor fabrication. To this end, we review the recent advances in 3D-printed cutting-edge sensors. These achievements demonstrate the successful application of 3D-printing technology in sensor fabrication, and the selected studies deeply explore the potential for creating sensors with higher performance. Further development of multi-process 3D printing is expected to expand future sensor utility and availability. PMID:28534832

  18. Particle accelerator control and data acquisition in the context of VAX/VMS

    International Nuclear Information System (INIS)

    Schaller, S.C.; Corley, J.K.

    1983-01-01

    The Los Alamos Meson Physics Facility (LAMPF) Control System monitors and controls a linear accelerator through more than 10,000 widely disparate I/O devices. The heart of the Control System software is the Data System, which provides a uniform application program interface based on symbolic device names. In many ways the Data System parallels the VAX/VMS Record Management Services (RMS) in its needs for asynchronous operations, protection, and locks for multiprocess interactions. Since the accelerator control hardware is continually changing, it is important that privileged code be kept to a minimum or be testable in a non-privileged environment. This paper describes the LAMPF Data System design including the use of VAX/VMS user written system services (both kernel and supervisor mode), a user supplied image rundown routine, the VAX/VMS lock manager, and a large (3.5 Mbyte) protected global section

  19. Open system magnetic evolution of the taos plateau volcanic field, Northern New Mexico. I - The petrology and geochemistry of the servilleta basalt

    Science.gov (United States)

    Dungan, M. A.; Lindstrom, M. M.; Mcmillan, N. J.; Moorbath, S.; Hoefs, J.

    1986-01-01

    MULTIFIT, an embodiment of the conceptual structure needed in modeling multisource and multiprocess magmatic systems, is described. This program, which uses familiar materials balance methodology and the equilibrium form of the Rayleigh equations, links evolutionary arrays, which is turn collectively relate the starting and final compositions of a given magmatic system. Moreover, MULTIFIT incorporates variations within major element data arrays; the linkage between them can be tested using an extension of the least squares algorithm, which selects the best branch point according to the minimum-sum-of-squared-residuals criterion. Advantages and disadvantages of the materials balance approach used in this program are discussed, an example is provided, and equations utilized by MULTIFIT are summarized. While MULTIFIT may not be the best approach for poorly constrained models involving partial melting for complex mixing, it may ultimately prove useful for ascertaining trace element partition coefficients in magnetic systems.

  20. Benchmarking MILC code with OpenMP and MPI

    International Nuclear Information System (INIS)

    Gottlieb, Steven; Tamhankar, Sonali

    2001-01-01

    A trend in high performance computers that is becoming increasingly popular is the use of symmetric multi-processing (SMP) rather than the older paradigm of MPP. MPI codes that ran and scaled well on MPP machines can often be run on an SMP machine using the vendor's version of MPI. However, this approach may not make optimal use of the (expensive) SMP hardware. More significantly, there are machines like Blue Horizon, an IBM SP with 8-way SMP nodes at the San Diego Supercomputer Center that can only support 4 MPI processes per node (with the current switch). On such a machine it is imperative to be able to use OpenMP parallelism on the node, and MPI between nodes. We describe the challenges of converting MILC MPI code to using a second level of OpenMP parallelism, and benchmarks on IBM and Sun computers

  1. Deviation from Trajectory Detection in Vision based Robotic Navigation using SURF and Subsequent Restoration by Dynamic Auto Correction Algorithm

    Directory of Open Access Journals (Sweden)

    Ray Debraj

    2015-01-01

    Full Text Available Speeded Up Robust Feature (SURF is used to position a robot with respect to an environment and aid in vision-based robotic navigation. During the course of navigation irregularities in the terrain, especially in an outdoor environment may deviate a robot from the track. Another reason for deviation can be unequal speed of the left and right robot wheels. Hence it is essential to detect such deviations and perform corrective operations to bring the robot back to the track. In this paper we propose a novel algorithm that uses image matching using SURF to detect deviation of a robot from the trajectory and subsequent restoration by corrective operations. This algorithm is executed in parallel to positioning and navigation algorithms by distributing tasks among different CPU cores using Open Multi-Processing (OpenMP API.

  2. LHCb: Preparing the Gaudi-Framework and the DIRAC-WMS for Multicore Job Submission

    CERN Multimedia

    Rauschmayr, N

    2013-01-01

    Due to the continuously increasing number of cores on modern CPUs, it is important to adapt HEP applications. This must be done at different levels: the software which must support parallelization and the scheduling has to differ between multicore and singlecore jobs. The LHCb software framework (GAUDI) provides a parallel prototype (GaudiMP), based on the multiprocessing approach. It allows a reduction of the overall memory footprint and a coordinated access to data via separated reader and writer processes. A comparison between the parallel prototype and multiple independent Gaudi jobs in respect to CPU-time and memory consumption will be shown. In the context of parallelization speedup is the most important metric, as it shows how software scales with the number of cores. It is influenced by many factors, due to software limitations like synchronization, but also due to hardware configurations, like frequency scaling. Those limitations and their dependencies will be discussed and the influence of hardware ...

  3. Spaceborne computer executive routine functional design specification. Volume 2: Computer executive design for space station/base

    Science.gov (United States)

    Kennedy, J. R.; Fitzpatrick, W. S.

    1971-01-01

    The computer executive functional system design concepts derived from study of the Space Station/Base are presented. Information Management System hardware configuration as directly influencing the executive design is reviewed. The hardware configuration and generic executive design requirements are considered in detail in a previous report (System Configuration and Executive Requirements Specifications for Reusable Shuttle and Space Station/Base, 9/25/70). This report defines basic system primitives and delineates processes and process control. Supervisor states are considered for describing basic multiprogramming and multiprocessing systems. A high-level computer executive including control of scheduling, allocation of resources, system interactions, and real-time supervisory functions is defined. The description is oriented to provide a baseline for a functional simulation of the computer executive system.

  4. GSI Helmholz Centre for Heavy Ion Research - ALFA: Next generation concurrent framework for ALICE and FAIR experiments

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    FAIR is a new, unique international accelerator facility for the research with antiprotons and ions. It is being built at the GSI Darmstadt in Hesse, Germany. The commonalities between the ALICE and FAIR experiments and their computing requirements led to the development of a common software framework in an experiment independent way; ALFA (ALICE-FAIR framework). ALFA is designed for high quality parallel data processing and reconstruction on heterogeneous computing systems. It provides a data transport layer and the capability to coordinate multiple data processing components. ALFA is a flexible, elastic system which balances reliability and ease of development with performance by using a message based multi-processing in addition to multi-threading. The framework allows for usage of heterogeneous computing architectures by offloading (portions of code are accelerated on the device) or natively (where the full program is executed on the device ).

  5. Vacuum mechatronics first international workshop

    Energy Technology Data Exchange (ETDEWEB)

    Belinski, S.E.; Shirazi, M.; Hackwood, S.; Beni, G. (eds.) (California Univ., Santa Barbara, CA (USA))

    1989-01-01

    This report contains papers on the following topics: proposed epitaxial thin film growth in the ultra-vacuum of space; particle monitoring and control in vacuum processing equipment; electrostatic dust collector for use in vacuum systems; materials evaluation of an electrically noisy vacuum slip ring assembly; an overview of lubrication and associated materials for vacuum service; the usage of lubricants in a vacuum environment; guidelines and practical applications for lubrication in vacuum; recent development in leak detector and calibrator designs; the durability of ballscrews for ultrahigh vacuum; vacuum-compatible robot for self-contained manufacturing systems; the design, fabrication, and assembly of an advanced vacuum robotics system for space payload calibration; design criteria for mechanisms used in space; and concepts and requirements for semiconductor multiprocess integration in vacuum. These papers are indexed separately elsewhere.

  6. Feasibility tests of a new all-digital beam control scheme for LEIR

    CERN Document Server

    Angoletta, Maria Elena; Findlay, A; Pedersen, F; CERN. Geneva. AB Department

    2004-01-01

    The new Low Energy Ion Ring (LEIR), to be commissioned at CERN in early 2005, will be a very important element of the LHC lead ions injection chain and will require a new beam control and cavity servoing system. Current plans call for a new all-digital beam control system based on the same technology deployed at Brookhaven National Laboratory (BNL) for the to control the AGS Booster beam. That beam control system, now under development, relies on VME modules and daughter boards based on Digital Signal Processors (DSPs) and Field Programmable Gate Arrays (FPGAs). The DSP provides high throughput processing capabilities and ease of connection with the software layer immediately above, while the daughter boards implement master clock, digital receiver and modulator capabilities. The resulting system is very flexible because is configurable via software and offers multi-processing capabilities and high bandwidth data paths, features that make it very attractive for a beam control implementation. For application t...

  7. Synergistic effect of manganese dioxide and diatomite for fast decolorization and high removal capacity of methyl orange.

    Science.gov (United States)

    Peng, Hui Hua; Chen, Jie; Jiang, De Yi; Li, Min; Feng, Li; Losic, Dusan; Dong, Fan; Zhang, Yu Xin

    2016-12-15

    MnO 2 nanostructures with two different morphologies (nanowires and nanosheets) were uniformly deposited on diatomite via a one-pot hydrothermal method. The fast decolorization and high removal capacity for anionic dye-MO over synthesized composites had been clarified. The results revealed that the equilibrium time was shortened to as low as 10-30min, and the maximum adsorption capacities were 325mgg -1 and 420mgg -1 for nanowires and nanosheets composites, respectively, under the condition of initial pH 3 and ambient temperature. Indeed, the proposed decolorization mechanism was considered to be simultaneous multi-processes during the dye removal, including physical, physicochemical and chemical process. In principle, well-controlled cost-effective composites have promising ability to remove anionic dye pollutants for environmental remediation. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. A Cluster- Based Secure Active Network Environment

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-lin; ZHOU Jing-yang; DAI Han; LU Sang-lu; CHEN Gui-hai

    2005-01-01

    We introduce a cluster-based secure active network environment (CSANE) which separates the processing of IP packets from that of active packets in active routers. In this environment, the active code authorized or trusted by privileged users is executed in the secure execution environment (EE) of the active router, while others are executed in the secure EE of the nodes in the distributed shared memory (DSM) cluster. With the supports of a multi-process Java virtual machine and KeyNote, untrusted active packets are controlled to securely consume resource. The DSM consistency management makes that active packets can be parallelly processed in the DSM cluster as if they were processed one by one in ANTS (Active Network Transport System). We demonstrate that CSANE has good security and scalability, but imposing little changes on traditional routers.

  9. Implementation of Parallel Dynamic Simulation on Shared-Memory vs. Distributed-Memory Environments

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Shuangshuang; Chen, Yousu; Wu, Di; Diao, Ruisheng; Huang, Zhenyu

    2015-12-09

    Power system dynamic simulation computes the system response to a sequence of large disturbance, such as sudden changes in generation or load, or a network short circuit followed by protective branch switching operation. It consists of a large set of differential and algebraic equations, which is computational intensive and challenging to solve using single-processor based dynamic simulation solution. High-performance computing (HPC) based parallel computing is a very promising technology to speed up the computation and facilitate the simulation process. This paper presents two different parallel implementations of power grid dynamic simulation using Open Multi-processing (OpenMP) on shared-memory platform, and Message Passing Interface (MPI) on distributed-memory clusters, respectively. The difference of the parallel simulation algorithms and architectures of the two HPC technologies are illustrated, and their performances for running parallel dynamic simulation are compared and demonstrated.

  10. Improvement and speed optimization of numerical tsunami modelling program using OpenMP technology

    Science.gov (United States)

    Chernov, A.; Zaytsev, A.; Yalciner, A.; Kurkin, A.

    2009-04-01

    Currently, the basic problem of tsunami modeling is low speed of calculations which is unacceptable for services of the operative notification. Existing algorithms of numerical modeling of hydrodynamic processes of tsunami waves are developed without taking the opportunities of modern computer facilities. There is an opportunity to have considerable acceleration of process of calculations by using parallel algorithms. We discuss here new approach to parallelization tsunami modeling code using OpenMP Technology (for multiprocessing systems with the general memory). Nowadays, multiprocessing systems are easily accessible for everyone. The cost of the use of such systems becomes much lower comparing to the costs of clusters. This opportunity also benefits all programmers to apply multithreading algorithms on desktop computers of researchers. Other important advantage of the given approach is the mechanism of the general memory - there is no necessity to send data on slow networks (for example Ethernet). All memory is the common for all computing processes; it causes almost linear scalability of the program and processes. In the new version of NAMI DANCE using OpenMP technology and multi-threading algorithm provide 80% gain in speed in comparison with the one-thread version for dual-processor unit. The speed increased and 320% gain was attained for four core processor unit of PCs. Thus, it was possible to reduce considerably time of performance of calculations on the scientific workstations (desktops) without complete change of the program and user interfaces. The further modernization of algorithms of preparation of initial data and processing of results using OpenMP looks reasonable. The final version of NAMI DANCE with the increased computational speed can be used not only for research purposes but also in real time Tsunami Warning Systems.

  11. Development of capability for microtopography-resolving simulations of hydrologic processes in permafrost affected regions

    Science.gov (United States)

    Painter, S.; Moulton, J. D.; Berndt, M.; Coon, E.; Garimella, R.; Lewis, K. C.; Manzini, G.; Mishra, P.; Travis, B. J.; Wilson, C. J.

    2012-12-01

    The frozen soils of the Arctic and subarctic regions contain vast amounts of stored organic carbon. This carbon is vulnerable to release to the atmosphere as temperatures warm and permafrost degrades. Understanding the response of the subsurface and surface hydrologic system to degrading permafrost is key to understanding the rate, timing, and chemical form of potential carbon releases to the atmosphere. Simulating the hydrologic system in degrading permafrost regions is challenging because of the potential for topographic evolution and associated drainage network reorganization as permafrost thaws and massive ground ice melts. The critical process models required for simulating hydrology include subsurface thermal hydrology of freezing/thawing soils, thermal processes within ice wedges, mechanical deformation processes, overland flow, and surface energy balances including snow dynamics. A new simulation tool, the Arctic Terrestrial Simulator (ATS), is being developed to simulate these coupled processes. The computational infrastructure must accommodate fully unstructured grids that track evolving topography, allow accurate solutions on distorted grids, provide robust and efficient solutions on highly parallel computer architectures, and enable flexibility in the strategies for coupling among the various processes. The ATS is based on Amanzi (Moulton et al. 2012), an object-oriented multi-process simulator written in C++ that provides much of the necessary computational infrastructure. Status and plans for the ATS including major hydrologic process models and validation strategies will be presented. Highly parallel simulations of overland flow using high-resolution digital elevation maps of polygonal patterned ground landscapes demonstrate the feasibility of the approach. Simulations coupling three-phase subsurface thermal hydrology with a simple thaw-induced subsidence model illustrate the strong feedbacks among the processes. D. Moulton, M. Berndt, M. Day, J

  12. The impact of age, ongoing task difficulty, and cue salience on preschoolers' prospective memory performance: the role of executive function.

    Science.gov (United States)

    Mahy, Caitlin E V; Moses, Louis J; Kliegel, Matthias

    2014-11-01

    The current study examined the impact of age, ongoing task (OT) difficulty, and cue salience on 4- and 5-year-old children's prospective memory (PM) and also explored the relation between individual differences in executive function (working memory, inhibition, and shifting) and PM. OT difficulty and cue salience are predicted to affect the detection of PM cues based on the multiprocess framework, yet neither has been thoroughly investigated in young children. OT difficulty was manipulated by requiring children to sort cards according to the size of pictured items (easy) or by opposite size (difficult), and cue salience was manipulated by placing a red border around half of the target cues (salient) and no border around the other cues (non-salient). The 5-year-olds outperformed the 4-year-olds on the PM task, and salient PM cues resulted in better PM cues compared with non-salient cues. There was no main effect of OT difficulty, and the interaction between cue salience and OT difficulty was not significant. However, a planned comparison revealed that the combination of non-salient cues and a difficult OT resulted in significantly worse PM performance than that in all of the other conditions. Inhibition accounted for significant variance in PM performance for non-salient cues and for marginally significant variance for salient cues. Furthermore, individual differences in inhibition fully mediated the effect of age on PM performance. Results are discussed in the context of the multiprocess framework and with reference to preschoolers' difficulty with the executive demands of dividing attention between the OT and PM task. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. A Cross-Platform Infrastructure for Scalable Runtime Application Performance Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jack Dongarra; Shirley Moore; Bart Miller, Jeffrey Hollingsworth; Tracy Rafferty

    2005-03-15

    The purpose of this project was to build an extensible cross-platform infrastructure to facilitate the development of accurate and portable performance analysis tools for current and future high performance computing (HPC) architectures. Major accomplishments include tools and techniques for multidimensional performance analysis, as well as improved support for dynamic performance monitoring of multithreaded and multiprocess applications. Previous performance tool development has been limited by the burden of having to re-write a platform-dependent low-level substrate for each architecture/operating system pair in order to obtain the necessary performance data from the system. Manual interpretation of performance data is not scalable for large-scale long-running applications. The infrastructure developed by this project provides a foundation for building portable and scalable performance analysis tools, with the end goal being to provide application developers with the information they need to analyze, understand, and tune the performance of terascale applications on HPC architectures. The backend portion of the infrastructure provides runtime instrumentation capability and access to hardware performance counters, with thread-safety for shared memory environments and a communication substrate to support instrumentation of multiprocess and distributed programs. Front end interfaces provides tool developers with a well-defined, platform-independent set of calls for requesting performance data. End-user tools have been developed that demonstrate runtime data collection, on-line and off-line analysis of performance data, and multidimensional performance analysis. The infrastructure is based on two underlying performance instrumentation technologies. These technologies are the PAPI cross-platform library interface to hardware performance counters and the cross-platform Dyninst library interface for runtime modification of executable images. The Paradyn and KOJAK

  14. Visualization of Octree Adaptive Mesh Refinement (AMR) in Astrophysical Simulations

    Science.gov (United States)

    Labadens, M.; Chapon, D.; Pomaréde, D.; Teyssier, R.

    2012-09-01

    Computer simulations are important in current cosmological research. Those simulations run in parallel on thousands of processors, and produce huge amount of data. Adaptive mesh refinement is used to reduce the computing cost while keeping good numerical accuracy in regions of interest. RAMSES is a cosmological code developed by the Commissariat à l'énergie atomique et aux énergies alternatives (English: Atomic Energy and Alternative Energies Commission) which uses Octree adaptive mesh refinement. Compared to grid based AMR, the Octree AMR has the advantage to fit very precisely the adaptive resolution of the grid to the local problem complexity. However, this specific octree data type need some specific software to be visualized, as generic visualization tools works on Cartesian grid data type. This is why the PYMSES software has been also developed by our team. It relies on the python scripting language to ensure a modular and easy access to explore those specific data. In order to take advantage of the High Performance Computer which runs the RAMSES simulation, it also uses MPI and multiprocessing to run some parallel code. We would like to present with more details our PYMSES software with some performance benchmarks. PYMSES has currently two visualization techniques which work directly on the AMR. The first one is a splatting technique, and the second one is a custom ray tracing technique. Both have their own advantages and drawbacks. We have also compared two parallel programming techniques with the python multiprocessing library versus the use of MPI run. The load balancing strategy has to be smartly defined in order to achieve a good speed up in our computation. Results obtained with this software are illustrated in the context of a massive, 9000-processor parallel simulation of a Milky Way-like galaxy.

  15. TomoPy: a framework for the analysis of synchrotron tomographic data

    International Nuclear Information System (INIS)

    Gürsoy, Doǧa; De Carlo, Francesco; Xiao, Xianghui; Jacobsen, Chris

    2014-01-01

    A collaborative framework for the analysis of synchrotron tomographic data which has the potential to unify the effort of different facilities and beamlines performing similar tasks is described. The proposed Python-based framework is open-source, platform- and data-format-independent, has multiprocessing capability and supports functional programming that many researchers prefer. Analysis of tomographic datasets at synchrotron light sources (including X-ray transmission tomography, X-ray fluorescence microscopy and X-ray diffraction tomography) is becoming progressively more challenging due to the increasing data acquisition rates that new technologies in X-ray sources and detectors enable. The next generation of synchrotron facilities that are currently under design or construction throughout the world will provide diffraction-limited X-ray sources and are expected to boost the current data rates by several orders of magnitude, stressing the need for the development and integration of efficient analysis tools. Here an attempt to provide a collaborative framework for the analysis of synchrotron tomographic data that has the potential to unify the effort of different facilities and beamlines performing similar tasks is described in detail. The proposed Python-based framework is open-source, platform- and data-format-independent, has multiprocessing capability and supports procedural programming that many researchers prefer. This collaborative platform could affect all major synchrotron facilities where new effort is now dedicated to developing new tools that can be deployed at the facility for real-time processing, as well as distributed to users for off-site data processing

  16. TomoPy: a framework for the analysis of synchrotron tomographic data

    Energy Technology Data Exchange (ETDEWEB)

    Gürsoy, Doǧa, E-mail: dgursoy@aps.anl.gov; De Carlo, Francesco; Xiao, Xianghui; Jacobsen, Chris [Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439-4837 (United States)

    2014-08-01

    A collaborative framework for the analysis of synchrotron tomographic data which has the potential to unify the effort of different facilities and beamlines performing similar tasks is described. The proposed Python-based framework is open-source, platform- and data-format-independent, has multiprocessing capability and supports functional programming that many researchers prefer. Analysis of tomographic datasets at synchrotron light sources (including X-ray transmission tomography, X-ray fluorescence microscopy and X-ray diffraction tomography) is becoming progressively more challenging due to the increasing data acquisition rates that new technologies in X-ray sources and detectors enable. The next generation of synchrotron facilities that are currently under design or construction throughout the world will provide diffraction-limited X-ray sources and are expected to boost the current data rates by several orders of magnitude, stressing the need for the development and integration of efficient analysis tools. Here an attempt to provide a collaborative framework for the analysis of synchrotron tomographic data that has the potential to unify the effort of different facilities and beamlines performing similar tasks is described in detail. The proposed Python-based framework is open-source, platform- and data-format-independent, has multiprocessing capability and supports procedural programming that many researchers prefer. This collaborative platform could affect all major synchrotron facilities where new effort is now dedicated to developing new tools that can be deployed at the facility for real-time processing, as well as distributed to users for off-site data processing.

  17. Strategy complexity of two-player, zero-sum games

    DEFF Research Database (Denmark)

    Ibsen-Jensen, Rasmus

    on the algorithms. I consider a wide assortment of different two-player, zero-sum game classes, e.g. matrix games, uni-chain concurrent mean-payoff games, concurrent mean-payoff games, concurrent reachability games and one-clock priced timed games. In all game classes considered, except for one-clock priced timed...... non-zero probability used in one of the probability distributions. In each case I provide relatively tight bounds on the patience of the “good” strategy that requires the least patience in the worst game of the game class. I will give an improved bound on the patience of concurrent reachability games......This dissertation considers two-player, zero-sum games with a focus on how complicated they are to play; a notion I will call strategy complexity. Often, knowing good bounds on the strategy complexity indicates bounds on the run time of various algorithms. In such cases I will also derive bounds...

  18. Body Space in Social Interactions: A Comparison of Reaching and Comfort Distance in Immersive Virtual Reality

    Science.gov (United States)

    Iachini, Tina; Coello, Yann; Frassinetti, Francesca; Ruggiero, Gennaro

    2014-01-01

    Background Do peripersonal space for acting on objects and interpersonal space for interacting with con-specifics share common mechanisms and reflect the social valence of stimuli? To answer this question, we investigated whether these spaces refer to a similar or different physical distance. Methodology Participants provided reachability-distance (for potential action) and comfort-distance (for social processing) judgments towards human and non-human virtual stimuli while standing still (passive) or walking toward stimuli (active). Principal Findings Comfort-distance was larger than other conditions when participants were passive, but reachability and comfort distances were similar when participants were active. Both spaces were modulated by the social valence of stimuli (reduction with virtual females vs males, expansion with cylinder vs robot) and the gender of participants. Conclusions These findings reveal that peripersonal reaching and interpersonal comfort spaces share a common motor nature and are sensitive, at different degrees, to social modulation. Therefore, social processing seems embodied and grounded in the body acting in space. PMID:25405344

  19. Attentionally splitting the mass distribution of hand-held rods.

    Science.gov (United States)

    Burton, G; Turvey, M T

    1991-08-01

    Two experiments on the length-perception capabilities of effortful or dynamic touch differed only in terms of what the subject intended to perceive, while experimental conditions and apparatus were held constant. In each trial, a visually occluded rod was held as still as possible by the subject at an intermediate position. For two thirds of the trials, a weight was attached to the rod above or below the hand. In Experiment 1, in which the subject's task was to perceive the distance reachable with the portion of the rod forward of the hand, perceived extent was a function of the first moment of the mass distribution associated with the forward portion of the rod, and indifferent to the first moment of the entire rod. In Experiment 2, in which the task was to perceive the distance reachable with the entire rod if it was held at an end, the pattern of results was reversed. These results indicate the capability of selective sensitivity to different aspects of a hand-held object's mass distribution, without the possibility of differential exploration specific to these two tasks. Results are discussed in relation to possible roles of differential information, intention, and self-organization in the explanations of selective perceptual abilities.

  20. Theory Analysis and Experiment Research of the Leg Mechanism for the Human-Carrying Walking Chair Robot

    Directory of Open Access Journals (Sweden)

    Lingfeng Sang

    2014-01-01

    Full Text Available For the high carrying capacity of the human-carrying walking chair robot, in this paper, 2-UPS+UP parallel mechanism is selected as the leg mechanism; then kinematics, workspace, control, and experiment of the leg mechanism are researched in detail. Firstly, design of the whole mechanism is described and degrees of freedom of the leg mechanism are analyzed. Second, the forward position, inverse position, and velocity of leg mechanism are studied. Third, based on the kinematics analysis and the structural constraints, the reachable workspace of 2-UPS+UP parallel mechanism is solved, and then the optimal motion workspace is searched in the reachable workspace by choosing the condition number as the evaluation index. Fourth, according to the theory analysis of the parallel leg mechanism, its control system is designed and the compound position control strategy is studied. Finally, in optimal motion workspace, the compound position control strategy is verified by using circular track with the radius 100 mm; the experiment results show that the leg mechanism moves smoothly and does not tremble obviously. Theory analysis and experiment research of the single leg mechanism provide a theoretical foundation for the control of the quadruped human-carrying walking chair robot.

  1. Labeling RDF Graphs for Linear Time and Space Querying

    Science.gov (United States)

    Furche, Tim; Weinzierl, Antonius; Bry, François

    Indices and data structures for web querying have mostly considered tree shaped data, reflecting the view of XML documents as tree-shaped. However, for RDF (and when querying ID/IDREF constraints in XML) data is indisputably graph-shaped. In this chapter, we first study existing indexing and labeling schemes for RDF and other graph datawith focus on support for efficient adjacency and reachability queries. For XML, labeling schemes are an important part of the widespread adoption of XML, in particular for mapping XML to existing (relational) database technology. However, the existing indexing and labeling schemes for RDF (and graph data in general) sacrifice one of the most attractive properties of XML labeling schemes, the constant time (and per-node space) test for adjacency (child) and reachability (descendant). In the second part, we introduce the first labeling scheme for RDF data that retains this property and thus achieves linear time and space processing of acyclic RDF queries on a significantly larger class of graphs than previous approaches (which are mostly limited to tree-shaped data). Finally, we show how this labeling scheme can be applied to (acyclic) SPARQL queries to obtain an evaluation algorithm with time and space complexity linear in the number of resources in the queried RDF graph.

  2. Near or far? It depends on my impression: moral information and spatial behavior in virtual interactions.

    Science.gov (United States)

    Iachini, Tina; Pagliaro, Stefano; Ruggiero, Gennaro

    2015-10-01

    Near body distance is a key component of action and social interaction. Recent research has shown that peripersonal space (reachability-distance for acting with objects) and interpersonal space (comfort-distance for interacting with people) share common mechanisms and reflect the social valence of stimuli. The social psychological literature has demonstrated that information about morality is crucial because it affects impression formation and the intention to approach-avoid others. Here we explore whether peripersonal/interpersonal spaces are modulated by moral information. Thirty-six participants interacted with male/female virtual confederates described by moral/immoral/neutral sentences. The modulation of body space was measured by reachability-distance and comfort-distance while participants stood still or walked toward virtual confederates. Results showed that distance expanded with immorally described confederates and contracted with morally described confederates. This pattern was present in both spaces, although it was stronger in comfort-distance. Consistent with an embodied cognition approach, the findings suggest that high-level socio-cognitive processes are linked to sensorimotor-spatial processes. Copyright © 2015. Published by Elsevier B.V.

  3. States in Process Calculi

    Directory of Open Access Journals (Sweden)

    Christoph Wagner

    2014-08-01

    Full Text Available Formal reasoning about distributed algorithms (like Consensus typically requires to analyze global states in a traditional state-based style. This is in contrast to the traditional action-based reasoning of process calculi. Nevertheless, we use domain-specific variants of the latter, as they are convenient modeling languages in which the local code of processes can be programmed explicitly, with the local state information usually managed via parameter lists of process constants. However, domain-specific process calculi are often equipped with (unlabeled reduction semantics, building upon a rich and convenient notion of structural congruence. Unfortunately, the price for this convenience is that the analysis is cumbersome: the set of reachable states is modulo structural congruence, and the processes' state information is very hard to identify. We extract from congruence classes of reachable states individual state-informative representatives that we supply with a proper formal semantics. As a result, we can now freely switch between the process calculus terms and their representatives, and we can use the stateful representatives to perform assertional reasoning on process calculus models.

  4. Fault detection of flywheel system based on clustering and principal component analysis

    Directory of Open Access Journals (Sweden)

    Wang Rixin

    2015-12-01

    Full Text Available Considering the nonlinear, multifunctional properties of double-flywheel with closed-loop control, a two-step method including clustering and principal component analysis is proposed to detect the two faults in the multifunctional flywheels. At the first step of the proposed algorithm, clustering is taken as feature recognition to check the instructions of “integrated power and attitude control” system, such as attitude control, energy storage or energy discharge. These commands will ask the flywheel system to work in different operation modes. Therefore, the relationship of parameters in different operations can define the cluster structure of training data. Ordering points to identify the clustering structure (OPTICS can automatically identify these clusters by the reachability-plot. K-means algorithm can divide the training data into the corresponding operations according to the reachability-plot. Finally, the last step of proposed model is used to define the relationship of parameters in each operation through the principal component analysis (PCA method. Compared with the PCA model, the proposed approach is capable of identifying the new clusters and learning the new behavior of incoming data. The simulation results show that it can effectively detect the faults in the multifunctional flywheels system.

  5. Optimal Time-Abstract Schedulers for CTMDPs and Markov Games

    Directory of Open Access Journals (Sweden)

    Markus Rabe

    2010-06-01

    Full Text Available We study time-bounded reachability in continuous-time Markov decision processes for time-abstract scheduler classes. Such reachability problems play a paramount role in dependability analysis and the modelling of manufacturing and queueing systems. Consequently, their analysis has been studied intensively, and techniques for the approximation of optimal control are well understood. From a mathematical point of view, however, the question of approximation is secondary compared to the fundamental question whether or not optimal control exists. We demonstrate the existence of optimal schedulers for the time-abstract scheduler classes for all CTMDPs. Our proof is constructive: We show how to compute optimal time-abstract strategies with finite memory. It turns out that these optimal schedulers have an amazingly simple structure---they converge to an easy-to-compute memoryless scheduling policy after a finite number of steps. Finally, we show that our argument can easily be lifted to Markov games: We show that both players have a likewise simple optimal strategy in these more general structures.

  6. Modeling methodology for supply chain synthesis and disruption analysis

    Science.gov (United States)

    Wu, Teresa; Blackhurst, Jennifer

    2004-11-01

    The concept of an integrated or synthesized supply chain is a strategy for managing today's globalized and customer driven supply chains in order to better meet customer demands. Synthesizing individual entities into an integrated supply chain can be a challenging task due to a variety of factors including conflicting objectives, mismatched incentives and constraints of the individual entities. Furthermore, understanding the effects of disruptions occurring at any point in the system is difficult when working toward synthesizing supply chain operations. Therefore, the goal of this research is to present a modeling methodology to manage the synthesis of a supply chain by linking hierarchical levels of the system and to model and analyze disruptions in the integrated supply chain. The contribution of this research is threefold: (1) supply chain systems can be modeled hierarchically (2) the performance of synthesized supply chain system can be evaluated quantitatively (3) reachability analysis is used to evaluate the system performance and verify whether a specific state is reachable, allowing the user to understand the extent of effects of a disruption.

  7. Testing the distinctiveness of visual imagery and motor imagery in a reach paradigm.

    Science.gov (United States)

    Gabbard, Carl; Ammar, Diala; Cordova, Alberto

    2009-01-01

    We examined the distinctiveness of motor imagery (MI) and visual imagery (VI) in the context of perceived reachability. The aim was to explore the notion that the two visual modes have distinctive processing properties tied to the two-visual-system hypothesis. The experiment included an interference tactic whereby participants completed two tasks at the same time: a visual or motor-interference task combined with a MI or VI-reaching task. We expected increased error would occur when the imaged task and the interference task were matched (e.g., MI with the motor task), suggesting an association based on the assumption that the two tasks were in competition for space on the same processing pathway. Alternatively, if there were no differences, dissociation could be inferred. Significant increases in the number of errors were found when the modalities for the imaged (both MI and VI) task and the interference task were matched. Therefore, it appears that MI and VI in the context of perceived reachability recruit different processing mechanisms.

  8. Do children perceive postural constraints when estimating reach or action planning?

    Science.gov (United States)

    Gabbard, Carl; Cordova, Alberto; Lee, Sunghan

    2009-03-01

    Estimation of whether an object is reachable from a specific body position constitutes an important aspect in effective motor planning. Researchers who estimate reachability by way of motor imagery with adults consistently report the tendency to overestimate, with some evidence of a postural effect (postural stability hypothesis). This idea suggests that perceived reaching limits depend on an individual's perceived postural constraints. Based on previous work with adults, the authors expected a significant postural effect with the Reach 2 condition, as evidenced by reduced overestimation. Furthermore, the authors hypothesized that the postural effect would be greater in younger children. They then tested these propositions among children aged 7, 9, and 11 years by asking them to estimate reach while seated (Reach 1) and in the more demanding posture of standing on 1 foot and leaning forward (Reach 2). Results indicated no age or condition difference, therefore providing no support for a postural effect. When the authors compared these data to a published report of adults, a developmental difference emerged. That is, adults recognize the perceived postural constraint of the standing position resulting in under- rather than overestimation, as displayed in the seated condition. Although preliminary, these observations suggest that estimates of reach (action planning) continue to be refined between late childhood and young adulthood.

  9. Is perceived motor competence a constraint in children's action planning?

    Science.gov (United States)

    Gabbard, Carl; Caçola, Priscila; Cordova, Alberto

    2009-06-01

    A form of action representation of developmental interest is reach estimation-the perceptual and cognitive judgment of whether an object is within or out of reach. A common observation among children is overestimation, which, speculatively, has been linked to perceived motor competence (PMC). The authors examined the PMC effect on reachability among 7-, 9-, and 11-year-old children. The authors predicted that with higher PMC, participants would display greater overestimation and that this outcome would show a developmental trend with younger children displaying greater overestimation complementing higher PMC scores. Results revealed no age differences in total error for reach, and all age groups overestimated. Regarding PMC, the 7-year-old childrens' scores were significantly higher than those of their older counterparts. However, relation analyses revealed no support for the idea that PMC was significantly associated with reachability. The findings suggested that a general measure of PMC is not a good predictor of childrens' action planning through reach estimation. Furthermore, if PMC in some form is a psychological constraint, future studies should be tied to context-specific measures of perceived abilities in relation to the specificity of the task.

  10. Texturing of continuous LOD meshes with the hierarchical texture atlas

    Science.gov (United States)

    Birkholz, Hermann

    2006-02-01

    For the rendering of detailed virtual environments, trade-offs have to be made between image quality and rendering time. An immersive experience of virtual reality always demands high frame-rates with the best reachable image qual-ity. Continuous Level of Detail (cLoD) triangle-meshes provide an continuous spectrum of detail for a triangle mesh that can be used to create view-dependent approximations of the environment in real-time. This enables the rendering with a constant number of triangles and thus with constant frame-rates. Normally the construction of such cLoD mesh representations leads to the loss of all texture information of the original mesh. To overcome this problem, a parameter domain can be created, in order to map the surface properties (colour, texture, normal) to it. This parameter domain can be used to map the surface properties back to arbitrary approximations of the original mesh. The parameter domain is often a simplified version of the mesh to be parameterised. This limits the reachable simplification to the domain mesh which has to map the surface of the original mesh with the least possible stretch. In this paper, a hierarchical domain mesh is presented, that scales between very coarse domain meshes and good property-mapping.

  11. SCCMulti

    KAUST Repository

    Tomkins, Daniel

    2014-01-01

    Tarjan\\'s famous linear time, sequential algorithm for finding the strongly connected components (SCCs) of a graph relies on depth first search, which is inherently sequential. Deterministic parallel algorithms solve this problem in logarithmic time using matrix multiplication techniques, but matrix multiplication requires a large amount of total work. Randomized algorithms based on reachability - the ability to get from one vertex to another along a directed path - greatly improve the work bound in the average case. However, these algorithms do not always perform well; for instance, Divide-and-Conquer Strong Components (DCSC), a scalable, divide-and-conquer algorithm, has good expected theoretical limits, but can perform very poorly on graphs for which the maximum reachability of any vertex is small. A related algorithm, MultiPivot, gives very high probability guarantees on the total amount of work for all graphs, but this improvement introduces an overhead that increases the average running time. This work introduces SCCMulti, a multi-pivot improvement of DCSC that offers the same consistency as MultiPivot without the time overhead. We provide experimental results demonstrating SCCMulti\\'s scalability; these results also show that SCCMulti is more consistent than DCSC and is always faster than MultiPivot.

  12. Long-Range Correlations and Memory in the Dynamics of Internet Interdomain Routing.

    Directory of Open Access Journals (Sweden)

    Maksim Kitsak

    Full Text Available Data transfer is one of the main functions of the Internet. The Internet consists of a large number of interconnected subnetworks or domains, known as Autonomous Systems (ASes. Due to privacy and other reasons the information about what route to use to reach devices within other ASes is not readily available to any given AS. The Border Gateway Protocol (BGP is responsible for discovering and distributing this reachability information to all ASes. Since the topology of the Internet is highly dynamic, all ASes constantly exchange and update this reachability information in small chunks, known as routing control packets or BGP updates. In the view of the quick growth of the Internet there are significant concerns with the scalability of the BGP updates and the efficiency of the BGP routing in general. Motivated by these issues we conduct a systematic time series analysis of BGP update rates. We find that BGP update time series are extremely volatile, exhibit long-term correlations and memory effects, similar to seismic time series, or temperature and stock market price fluctuations. The presented statistical characterization of BGP update dynamics could serve as a basis for validation of existing and developing better models of Internet interdomain routing.

  13. Turn-Based War Chess Model and Its Search Algorithm per Turn

    Directory of Open Access Journals (Sweden)

    Hai Nan

    2016-01-01

    Full Text Available War chess gaming has so far received insufficient attention but is a significant component of turn-based strategy games (TBS and is studied in this paper. First, a common game model is proposed through various existing war chess types. Based on the model, we propose a theory frame involving combinational optimization on the one hand and game tree search on the other hand. We also discuss a key problem, namely, that the number of the branching factors of each turn in the game tree is huge. Then, we propose two algorithms for searching in one turn to solve the problem: (1 enumeration by order; (2 enumeration by recursion. The main difference between these two is the permutation method used: the former uses the dictionary sequence method, while the latter uses the recursive permutation method. Finally, we prove that both of these algorithms are optimal, and we analyze the difference between their efficiencies. An important factor is the total time taken for the unit to expand until it achieves its reachable position. The factor, which is the total number of expansions that each unit makes in its reachable position, is set. The conclusion proposed is in terms of this factor: Enumeration by recursion is better than enumeration by order in all situations.

  14. Random walk-based similarity measure method for patterns in complex object

    Directory of Open Access Journals (Sweden)

    Liu Shihu

    2017-04-01

    Full Text Available This paper discusses the similarity of the patterns in complex objects. The complex object is composed both of the attribute information of patterns and the relational information between patterns. Bearing in mind the specificity of complex object, a random walk-based similarity measurement method for patterns is constructed. In this method, the reachability of any two patterns with respect to the relational information is fully studied, and in the case of similarity of patterns with respect to the relational information can be calculated. On this bases, an integrated similarity measurement method is proposed, and algorithms 1 and 2 show the performed calculation procedure. One can find that this method makes full use of the attribute information and relational information. Finally, a synthetic example shows that our proposed similarity measurement method is validated.

  15. Building a multimodal network and determining individual accessibility by public transportation

    DEFF Research Database (Denmark)

    Djurhuus, Sune; Hansen, Henning Sten; Aadahl, Mette

    2016-01-01

    The increased availability of transit schedules from web sites or travel planners as well as more disaggregate data has led to a growing interest in creating individual public transportation accessibility measures. However, used extensively, standard GIS software does not have direct capabilities...... from a travel planner into a multimodal network model using simple SQL (structured query language) programming and standard GIS. The method presented here integrates all parts of travelling by public transportation from individual home addresses to all reachable transit stops within different travel....... The accessibility areas are created at morning rush hour for a study population of 29 447 individuals and a few examples of accessibility areas are presented. The results show a big difference in individual public transportation accessibility in the region. In addition, how the transit network is accessed, whether...

  16. Genetic modification of the human germ line: The reasons why this project has no future.

    Science.gov (United States)

    Morange, Michel

    2015-01-01

    Modification of the human germ line has remained a distant but valuable objective for most biologists since the emergence of genetics (and even before). To study the historical transformations of this project, I have selected three periods - the 1930s, at the pinnacle of eugenics, around 1974 when molecular biology triumphed, and today - and have adopted three criteria to estimate the feasibility of this project: the state of scientific knowledge, the existence of suitable tools, and societal demands. Although the long-awaited techniques to modify the germ line are now available, I will show that most of the expectations behind this project have disappeared, or are considered as being reachable by highly different strategies. Copyright © 2015 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  17. Inventory of the solar thermal and photovoltaic energy potential in the Ardennes district

    International Nuclear Information System (INIS)

    Gal, Henri-Louis

    2010-03-01

    Based on the use of cartographic tool, the objective of this study was to assess the potential production of solar thermal and solar photovoltaic systems, social-economic data, regulatory data, and environmental, heritage-related, and urban constraints, and natural risks. For each type of installation, the possible reachable potential has been assessed while taking these constraints, building typology (housing, industrial, heritage, and so on), building orientation, project construction dynamics into account. The report analyses solar resource, housing characteristics, building typology, regulatory constraints related to the protection of the built environment, exploitation constraints (shade), building orientation constraints. It presents an assessment of net resources for both sectors, an assessment of plausible production potentials by 2030. It also presents and discusses environmental (avoided emissions) and financial indicators related to both solar sectors

  18. Optimization of particle trapping and patterning via photovoltaic tweezers: role of light modulation and particle size

    International Nuclear Information System (INIS)

    Matarrubia, J; García-Cabañes, A; Plaza, J L; Agulló-López, F; Carrascosa, M

    2014-01-01

    The role of light modulation m and particle size on the morphology and spatial resolution of nano-particle patterns obtained by photovoltaic tweezers on Fe : LiNbO 3 has been investigated. The impact of m when using spherical as well as non-spherical (anisotropic) nano-particles deposited on the sample surface has been elucidated. Light modulation is a key parameter determining the particle profile contrast that is optimum for spherical particles and high-m values (m ∼ 1). The minimum particle periodicities reachable are also investigated obtaining periodic patterns up to 3.5 µm. This is a value at least one order of magnitude shorter than those obtained in previous reported experiments. Results are successfully explained and discussed in light of the previous reported models for photorefraction including nonlinear carrier transport and dielectrophoretic trapping. From the results, a number of rules for particle patterning optimization are derived. (paper)

  19. Herdable Systems Over Signed, Directed Graphs

    KAUST Repository

    Ruf, Sebastian F.

    2018-04-11

    This paper considers the notion of herdability, a set-based reachability condition, which asks whether the state of a system can be controlled to be element-wise larger than a non-negative threshold. The basic theory of herdable systems is presented, including a necessary and sufficient condition for herdability. This paper then considers the impact of the underlying graph structure of a linear system on the herdability of the system, for the case where the graph is represented as signed and directed. By classifying nodes based on the length and sign of walks from an input, we find a class of completely herdable systems as well as provide a complete characterization of nodes that can be herded in systems with an underlying graph that is a directed out-branching rooted at a single input.

  20. Automatic Generation of Symbolic Model for Parameterized Synchronous Systems

    Institute of Scientific and Technical Information of China (English)

    Wei-Wen Xu

    2004-01-01

    With the purpose of making the verification of parameterized system more general and easier, in this paper, a new and intuitive language PSL (Parameterized-system Specification Language) is proposed to specify a class of parameterized synchronous systems. From a PSL script, an automatic method is proposed to generate a constraint-based symbolic model. The model can concisely symbolically represent the collections of global states by counting the number of processes in a given state. Moreover, a theorem has been proved that there is a simulation relation between the original system and its symbolic model. Since the abstract and symbolic techniques are exploited in the symbolic model, state-explosion problem in traditional verification methods is efficiently avoided. Based on the proposed symbolic model, a reachability analysis procedure is implemented using ANSI C++ on UNIX platform. Thus, a complete tool for verifying the parameterized synchronous systems is obtained and tested for some cases. The experimental results show that the method is satisfactory.

  1. Defining Mapping Mashups with BioXMash

    Directory of Open Access Journals (Sweden)

    Hunt Ela

    2007-12-01

    Full Text Available We present a novel approach to XML data integration which allows a biologist to select data from a large XML file repository, add it to a genome map, and produce a mapping mashup showing integrated data in map context. This approach can be used to produce contextual views of arbitrary XML data which relates to objects shown on a map. A biologist using BioXMash searches in XML tags, and is guided by XML path data availability, shown as the number of values reachable via a path, in both global, genome-wide, and local, per-gene, context. Then she examines sample values in an area of interest on the map. If required, the resulting data is dumped to files, for subsequent analysis.

  2. Advertising Via Mobile Terminals - Delivering Context Sensitive and Personalized Advertising While Guaranteeing Privacy

    Science.gov (United States)

    Bulander, Rebecca; Decker, Michael; Schiefer, Gunther; Kölmel, Bernhard

    Mobile terminals like cellular phones and PDAs are a promising target platform for mobile advertising: The devices are widely spread, are able to present interactive multimedia content and offer as almost permanently carried along personal communication devices a high degree of reachability. But particular because of the latter feature it is important to pay great attention to privacy aspects and avoidance of spam-messages when designing an application for mobile advertising. Furthermore the limited user interface of mobile devices is a special challenge. The following article describes the solution approach for mobile advertising developed within the project MoMa, which was funded by the Federal Ministry of Economics and Labour of Germany (BMWA). MoMa enables highly personalized and context sensitive mobile advertising while guaranteeing data protection. To achieve this we have to distinguish public and private context information.

  3. Design of Robust Supertwisting Algorithm Based Second-Order Sliding Mode Controller for Nonlinear Systems with Both Matched and Unmatched Uncertainty

    Directory of Open Access Journals (Sweden)

    Marwa Jouini

    2017-01-01

    Full Text Available This paper proposes a robust supertwisting algorithm (STA design for nonlinear systems where both matched and unmatched uncertainties are considered. The main contributions reside primarily to conceive a novel structure of STA, in order to ensure the desired performance of the uncertain nonlinear system. The modified algorithm is formed of double closed-loop feedback, in which two linear terms are added to the classical STA. In addition, an integral sliding mode switching surface is proposed to construct the attractiveness and reachability of sliding mode. Sufficient conditions are derived to guarantee the exact differentiation stability in finite time based on Lyapunov function theory. Finally, a comparative study for a variable-length pendulum system illustrates the robustness and the effectiveness of the proposed approach compared to other STA schemes.

  4. A quartz Cherenkov detector for Compton-polarimetry at future e+e- colliders

    International Nuclear Information System (INIS)

    List, Jenny; Vauth, Annika; Vormwald, Benedikt; Hamburg Univ.

    2015-02-01

    Precision polarimetry is essential for future e + e - colliders and requires Compton polarimeters designed for negligible statistical uncertainties. In this paper, we discuss the design and construction of a quartz Cherenkov detector for such Compton polarimeters. The detector concept has been developed with regard to the main systematic uncertainties of the polarisation measurements, namely the linearity of the detector response and detector alignment. Simulation studies presented here imply that the light yield reachable by using quartz as Cherenkov medium allows to resolve in the Cherenkov photon spectra individual peaks corresponding to different numbers of Compton electrons. The benefits of the application of a detector with such single-peak resolution to the polarisation measurement are shown for the example of the upstream polarimeters foreseen at the International Linear Collider. Results of a first testbeam campaign with a four-channel prototype confirming simulation predictions for single electrons are presented.

  5. Kinematics/statics analysis of a novel serial-parallel robotic arm with hand

    International Nuclear Information System (INIS)

    Lu, Yi; Dai, Zhuohong; Ye, Nijia; Wang, Peng

    2015-01-01

    A robotic arm with fingered hand generally has multi-functions to complete various complicated operations. A novel serial-parallel robotic arm with a hand is proposed and its kinematics and statics are studied systematically. A 3D prototype of the serial-parallel robotic arm with a hand is constructed and analyzed by simulation. The serial-parallel robotic arm with a hand is composed of an upper 3RPS parallel manipulator, a lower 3SPR parallel manipulator and a hand with three finger mechanisms. Its kinematics formulae for solving the displacement, velocity, acceleration of are derived. Its statics formula for solving the active/constrained forces is derived. Its reachable workspace and orientation workspace are constructed and analyzed. Finally, an analytic example is given for solving the kinematics and statics of the serial-parallel robotic arm with a hand and the analytic solutions are verified by a simulation mechanism.

  6. Tracks for Eastern/Western European Future Launch Vehicles Cooperation

    Science.gov (United States)

    Eymar, Patrick; Bertschi, Markus

    2002-01-01

    exclusively upon Western European elements indigenously produced. Yet some private initiatives took place successfully in the second half of the nineties (Eurockot and Starsem) bringing together companies from Western and Eastern Europe. Evolution of these JV's are already envisioned. But these ventures relied mostly on already existing vehicles. broadening the bases in order to enlarge the reachable world market appears attractive, even if structural difficulties are complicating the process. had recently started to analyze, with KSRC counterparts how mixing Russian and Western European based elements would provide potential competitive edges. and RKA in the frame of the new ESA's Future Launch Preparatory Programme (FLPP). main technical which have been considered as the most promising (reusable LOx/Hydrocarbon engine, experimental reentry vehicles or demonstrators and reusable launch vehicle first stage or booster. international approach. 1 patrick.eymar@lanceurs.aeromatra.com 2

  7. Secure neighborhood discovery: A fundamental element for mobile ad hoc networking

    DEFF Research Database (Denmark)

    Papadimitratos, P.; Poturalski, M.; Schaller, P.

    2008-01-01

    Pervasive computing systems will likely be deployed in the near future, with the proliferation of wireless devices and the emergence of ad hoc networking as key enablers. Coping with mobility and the volatility of wireless communications in such systems is critical. Neighborhood discovery (ND......) - the discovery of devices directly reachable for communication or in physical proximity - becomes a fundamental requirement and building block for various applications. However, the very nature of wireless mobile networks makes it easy to abuse ND and thereby compromise the overlying protocols and applications....... Thus, providing methods to mitigate this vulnerability and secure ND is crucial. In this article we focus on this problem and provide definitions of neighborhood types and ND protocol properties, as well as a broad classification of attacks. Our ND literature survey reveals that securing ND is indeed...

  8. Implementation and Performance Evaluation of Distributed Cloud Storage Solutions using Random Linear Network Coding

    DEFF Research Database (Denmark)

    Fitzek, Frank; Toth, Tamas; Szabados, Áron

    2014-01-01

    This paper advocates the use of random linear network coding for storage in distributed clouds in order to reduce storage and traffic costs in dynamic settings, i.e. when adding and removing numerous storage devices/clouds on-the-fly and when the number of reachable clouds is limited. We introduce...... various network coding approaches that trade-off reliability, storage and traffic costs, and system complexity relying on probabilistic recoding for cloud regeneration. We compare these approaches with other approaches based on data replication and Reed-Solomon codes. A simulator has been developed...... to carry out a thorough performance evaluation of the various approaches when relying on different system settings, e.g., finite fields, and network/storage conditions, e.g., storage space used per cloud, limited network use, and limited recoding capabilities. In contrast to standard coding approaches, our...

  9. Scope and dissolution studies and characterization of irradiated nuclear fuel in Atalante Hot Cell Facilities (abstract and presentation slides)

    Energy Technology Data Exchange (ETDEWEB)

    Dancausse, Jean-Philippe; Reynier Tronche, Nathalie; Ferlay, Gilles; Herlet, Nathalie; Eysseric, Cathrine; Esbelin, Eric

    2005-01-01

    Since 1999, several studies on nuclear fuels were realised in C11/C12 Atalante Hot Cell. This paper presents firstly an overview of the apparatus used for fuel dissolution and characterisation like reactor design, gas trapping flask and solid/liquid separation. Then, the general methodology is described as a function of fuel, temperature, reagents, showing for each step, the reachable experimental data: Dissolution rate, chemical and radiochemical fuel composition including volatile LLRN, insoluble mass, composition, morphology, cladding chemical, radiochemical and physical characterisation using SIMS (made in Cadarache/LECA facilities), MEB. To conclude, some of the obtained results on 129I and 14C composition of oxide fuels, rate of dissolution and first results on dissolution studies of RERTR UMo fuel will be detailed. (Author)

  10. Noise Response Data Reveal Novel Controllability Gramian for Nonlinear Network Dynamics

    Science.gov (United States)

    Kashima, Kenji

    2016-01-01

    Control of nonlinear large-scale dynamical networks, e.g., collective behavior of agents interacting via a scale-free connection topology, is a central problem in many scientific and engineering fields. For the linear version of this problem, the so-called controllability Gramian has played an important role to quantify how effectively the dynamical states are reachable by a suitable driving input. In this paper, we first extend the notion of the controllability Gramian to nonlinear dynamics in terms of the Gibbs distribution. Next, we show that, when the networks are open to environmental noise, the newly defined Gramian is equal to the covariance matrix associated with randomly excited, but uncontrolled, dynamical state trajectories. This fact theoretically justifies a simple Monte Carlo simulation that can extract effectively controllable subdynamics in nonlinear complex networks. In addition, the result provides a novel insight into the relationship between controllability and statistical mechanics. PMID:27264780

  11. High resolution photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Arko, A.J.

    1988-01-01

    Photoelectron Spectroscopy (PES) covers a very broad range of measurements, disciplines, and interests. As the next generation light source, the FEL will result in improvements over the undulator that are larger than the undulater improvements over bending magnets. The combination of high flux and high inherent resolution will result in several orders of magnitude gain in signal to noise over measurements using synchrotron-based undulators. The latter still require monochromators. Their resolution is invariably strongly energy-dependent so that in the regions of interest for many experiments (h upsilon > 100 eV) they will not have a resolving power much over 1000. In order to study some of the interesting phenomena in actinides (heavy fermions e.g.) one would need resolving powers of 10 4 to 10 5 . These values are only reachable with the FEL

  12. HyLTL: a temporal logic for model checking hybrid systems

    Directory of Open Access Journals (Sweden)

    Davide Bresolin

    2013-08-01

    Full Text Available The model-checking problem for hybrid systems is a well known challenge in the scientific community. Most of the existing approaches and tools are limited to safety properties only, or operates by transforming the hybrid system to be verified into a discrete one, thus loosing information on the continuous dynamics of the system. In this paper we present a logic for specifying complex properties of hybrid systems called HyLTL, and we show how it is possible to solve the model checking problem by translating the formula into an equivalent hybrid automaton. In this way the problem is reduced to a reachability problem on hybrid automata that can be solved by using existing tools.

  13. CONSUMERS’ PREFERENCE TOWARD ISLAMIC BANKING

    Directory of Open Access Journals (Sweden)

    delta khairunnisa

    2017-06-01

    Full Text Available Objective - This research aims to provide empirical evidence on the factors motivating consumers to save in Islamic banking.Methods - The one sample t-test is employed to test hypothesis. The validity and the reliability of research variables have been examined.Results - The result proved that consumers’ decision to save in Islamic banking are influenced by economic and religious factors, such as receiving economic benefits, quick services, online facilities, easily reachable locations, and having a better understanding of Islamic principles.Conclusions - The existence of a relationship between economic and religious preference proves that, in making decisions, consumers wish to attain two satisfaction levels: satisfaction in the world and in the hereafter.

  14. Spreading gossip in social networks

    Science.gov (United States)

    Lind, Pedro G.; da Silva, Luciano R.; Andrade, José S., Jr.; Herrmann, Hans J.

    2007-09-01

    We study a simple model of information propagation in social networks, where two quantities are introduced: the spread factor, which measures the average maximal reachability of the neighbors of a given node that interchange information among each other, and the spreading time needed for the information to reach such a fraction of nodes. When the information refers to a particular node at which both quantities are measured, the model can be taken as a model for gossip propagation. In this context, we apply the model to real empirical networks of social acquaintances and compare the underlying spreading dynamics with different types of scale-free and small-world networks. We find that the number of friendship connections strongly influences the probability of being gossiped. Finally, we discuss how the spread factor is able to be applied to other situations.

  15. Prioritizing Signaling Information Transmission in Next Generation Networks

    Directory of Open Access Journals (Sweden)

    Jasmina Baraković

    2011-01-01

    Full Text Available Next generation transport network is characterized by the use of in-band signaling, where Internet Protocol (IP packets carrying signaling or media information are mixed in transmission. Since transport resources are limited, when any segment of access or core network is congested, IP packets carrying signaling information may be discarded. As a consequence, it may be impossible to implement reachability and quality of service (QoS. Since present approaches are insufficient to completely address this problem, a novel approach is proposed, which is based on prioritizing signaling information transmission. To proof the concept, a simulation study was performed using Network Simulator version 2 (ns-2 and independently developed Session Initiation Protocol (SIP module. The obtained results were statistically processed using Statistical Package for the Social Sciences (SPSS version 15.0. Summarizing our research results, several issues are identified for future work.

  16. Safety versus Security in the Quality Calculus

    DEFF Research Database (Denmark)

    Nielson, Hanne Riis; Nielson, Flemming

    2013-01-01

    Safety and security are both needed for ensuring that cyber-physical systems live up to expectations, but often an intelligent trade-off is called for, because sometimes it is impossible to obtain optimal safety at the same time as optimal security. In the context of the Quality Calculus we develop...... a type system for checking the extent to which safety and security goals have been met. Safety goals include showing that certain error configurations are in fact not reachable and hence do not require intelligent error handling. Security goals include showing that highly trusted communications can only...... of the implicit flow). This is illustrated on a worked example taken from the automotive sector and we conclude with a discussion of the theoretical properties of the type system....

  17. Fault Detection Based on Tracking Differentiator Applied on the Suspension System of Maglev Train

    Directory of Open Access Journals (Sweden)

    Hehong Zhang

    2015-01-01

    Full Text Available A fault detection method based on the optimized tracking differentiator is introduced. It is applied on the acceleration sensor of the suspension system of maglev train. It detects the fault of the acceleration sensor by comparing the acceleration integral signal with the speed signal obtained by the optimized tracking differentiator. This paper optimizes the control variable when the states locate within or beyond the two-step reachable region to improve the performance of the approximate linear discrete tracking differentiator. Fault-tolerant control has been conducted by feedback based on the speed signal acquired from the optimized tracking differentiator when the acceleration sensor fails. The simulation and experiment results show the practical usefulness of the presented method.

  18. Global control methods for Greenberger-Horne-Zeilinger-state generation on a one-dimensional Ising chain

    International Nuclear Information System (INIS)

    Wang Xiaoting; Schirmer, Sophie G.; Bayat, Abolfazl; Bose, Sougato

    2010-01-01

    We discuss how to prepare an Ising chain in a GHZ state using a single global control field only. This model does not require the spins to be individually addressable and is applicable to quantum systems such as cold atoms in optical lattices, some liquid- or solid-state NMR experiments, and many nanoscale quantum structures. We show that GHZ states can always be reached asymptotically from certain easy-to-prepare initial states using adiabatic passage, and under certain conditions finite-time reachability can be ensured. To provide a reference useful for future experimental implementations, three different control strategies to achieve the objective--adiabatic passage, Lyapunov control, and optimal control--are compared, and their advantages and disadvantages discussed, in particular in the presence of realistic imperfections such as imperfect initial state preparation, system inhomogeneity, and dephasing.

  19. SEARCH FOR VERY HIGH ENERGY GAMMA-RAY EMISSION FROM PULSAR-PULSAR WIND NEBULA SYSTEMS WITH THE MAGIC TELESCOPE

    International Nuclear Information System (INIS)

    Anderhub, H.; Biland, A.; Antonelli, L. A.; Antoranz, P.; Balestra, S.; Barrio, J. A.; Bose, D.; Backes, M.; Becker, J. K.; Baixeras, C.; Bastieri, D.; Bock, R. K.; Gonzalez, J. Becerra; Bednarek, W.; Berger, K.; Bernardini, E.; Bonnoli, G.; Bordas, P.; Bosch-Ramon, V.; Tridon, D. Borla

    2010-01-01

    The MAGIC collaboration has searched for high-energy gamma-ray emission of some of the most promising pulsar candidates above an energy threshold of 50 GeV, an energy not reachable up to now by other ground-based instruments. Neither pulsed nor steady gamma-ray emission has been observed at energies of 100 GeV from the classical radio pulsars PSR J0205+6449 and PSR J2229+6114 (and their nebulae 3C58 and Boomerang, respectively) and the millisecond pulsar PSR J0218+4232. Here, we present the flux upper limits for these sources and discuss their implications in the context of current model predictions.

  20. Achieving Network Level Privacy in Wireless Sensor Networks†

    Science.gov (United States)

    Shaikh, Riaz Ahmed; Jameel, Hassan; d’Auriol, Brian J.; Lee, Heejo; Lee, Sungyoung; Song, Young-Jae

    2010-01-01

    Full network level privacy has often been categorized into four sub-categories: Identity, Route, Location and Data privacy. Achieving full network level privacy is a critical and challenging problem due to the constraints imposed by the sensor nodes (e.g., energy, memory and computation power), sensor networks (e.g., mobility and topology) and QoS issues (e.g., packet reach-ability and timeliness). In this paper, we proposed two new identity, route and location privacy algorithms and data privacy mechanism that addresses this problem. The proposed solutions provide additional trustworthiness and reliability at modest cost of memory and energy. Also, we proved that our proposed solutions provide protection against various privacy disclosure attacks, such as eavesdropping and hop-by-hop trace back attacks. PMID:22294881

  1. Simulation and Verification of Synchronous Set Relations in Rewriting Logic

    Science.gov (United States)

    Rocha, Camilo; Munoz, Cesar A.

    2011-01-01

    This paper presents a mathematical foundation and a rewriting logic infrastructure for the execution and property veri cation of synchronous set relations. The mathematical foundation is given in the language of abstract set relations. The infrastructure consists of an ordersorted rewrite theory in Maude, a rewriting logic system, that enables the synchronous execution of a set relation provided by the user. By using the infrastructure, existing algorithm veri cation techniques already available in Maude for traditional asynchronous rewriting, such as reachability analysis and model checking, are automatically available to synchronous set rewriting. The use of the infrastructure is illustrated with an executable operational semantics of a simple synchronous language and the veri cation of temporal properties of a synchronous system.

  2. Knowledge base verification based on enhanced colored petri net

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Hyun; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1997-12-31

    Verification is a process aimed at demonstrating whether a system meets it`s specified requirements. As expert systems are used in various applications, the knowledge base verification of systems takes an important position. The conventional Petri net approach that has been studied recently in order to verify the knowledge base is found that it is inadequate to verify the knowledge base of large and complex system, such as alarm processing system of nuclear power plant. Thus, we propose an improved method that models the knowledge base as enhanced colored Petri net. In this study, we analyze the reachability and the error characteristics of the knowledge base and apply the method to verification of simple knowledge base. 8 refs., 4 figs. (Author)

  3. Development and first tests of GEM-like detectors with resistive electrodes

    CERN Document Server

    Peskov, Vladimir; Centro, Sandro; Di Mauro, A; Lund-Jensen, B; Martinengo, P; Nappi, E; Oliveira, R; Pietropaolo, F; Picchi, P; Periale, L; Rodionov, I; Ventura, Sandro

    2007-01-01

    We have developed and tested several prototypes of GEM-like detectors with electrodes coated with resistive layers or completely made of resistive materials. These detectors can operate stably at gains close to 105. The resistive layers limit the energy of discharges appearing at higher gains thus making the detectors very robust. We demonstrated that the cathodes of some of these detectors could be coated by CsI or SbCs layers to enhance the detection efficiency for the UV and visible photons. We also discovered that such detectors can operate stably in the cascade mode and high overall gains ($~10^{6}$) are reachable. Applications in several areas, for example in RICH or in noble liquid TPCs are therefore possible. The first results from the detection of UV photons at room and cryogenic temperatures will be given.

  4. Matrix effective theories of the fractional quantum Hall effect

    International Nuclear Information System (INIS)

    Cappelli, Andrea; Rodriguez, Ivan D

    2009-01-01

    The present understanding of nonperturbative ground states in the fractional quantum Hall effect is based on effective theories of the Jain 'composite fermion' excitations. We review the approach based on matrix variables, i.e. D0 branes, originally introduced by Susskind and Polychronakos. We show that the Maxwell-Chern-Simons matrix gauge theory provides a matrix generalization of the quantum Hall effect, where the composite-fermion construction naturally follows from gauge invariance. The matrix ground states obtained by suitable projections of higher Landau levels are found to be in one-to-one correspondence with the Laughlin and Jain hierarchical states. The matrix theory possesses a physical limit for commuting matrices that could be reachable while staying in the same phase.

  5. Synchronization of nonidentical chaotic neural networks with leakage delay and mixed time-varying delays

    Directory of Open Access Journals (Sweden)

    Cao Jinde

    2011-01-01

    Full Text Available Abstract In this paper, an integral sliding mode control approach is presented to investigate synchronization of nonidentical chaotic neural networks with discrete and distributed time-varying delays as well as leakage delay. By considering a proper sliding surface and constructing Lyapunov-Krasovskii functional, as well as employing a combination of the free-weighting matrix method, Newton-Leibniz formulation and inequality technique, a sliding mode controller is designed to achieve the asymptotical synchronization of the addressed nonidentical neural networks. Moreover, a sliding mode control law is also synthesized to guarantee the reachability of the specified sliding surface. The provided conditions are expressed in terms of linear matrix inequalities, and are dependent on the discrete and distributed time delays as well as leakage delay. A simulation example is given to verify the theoretical results.

  6. European Train Control System: A Case Study in Formal Verification

    Science.gov (United States)

    Platzer, André; Quesel, Jan-David

    Complex physical systems have several degrees of freedom. They only work correctly when their control parameters obey corresponding constraints. Based on the informal specification of the European Train Control System (ETCS), we design a controller for its cooperation protocol. For its free parameters, we successively identify constraints that are required to ensure collision freedom. We formally prove the parameter constraints to be sharp by characterizing them equivalently in terms of reachability properties of the hybrid system dynamics. Using our deductive verification tool KeYmaera, we formally verify controllability, safety, liveness, and reactivity properties of the ETCS protocol that entail collision freedom. We prove that the ETCS protocol remains correct even in the presence of perturbation by disturbances in the dynamics. We verify that safety is preserved when a PI controlled speed supervision is used.

  7. Comparison of Eu(NO3)3 and Eu(acac)3 precursors for doping luminescent silica nanoparticles

    International Nuclear Information System (INIS)

    Enrichi, F.; Ricco, R.; Scopece, P.; Parma, A.; Mazaheri, A. R.; Riello, P.; Benedetti, A.

    2010-01-01

    In this study, we report the comparison between Eu 3+ -doped silica nanoparticles synthesized by Stoeber method using Eu(NO 3 ) 3 or Eu(acac) 3 as precursors. The impact of different europium species on the properties of the final silica nanospheres is investigated in details in terms of size, morphology, reachable doping amount, and luminescence efficiency. Moreover, the results obtained for different thermal treatments are presented and discussed. It is shown that the organic complex modify the silica growing process, leading to bigger and irregular nanoparticles (500-800 nm) with respect to the perfectly spherical ones (400 nm) obtained by the nitrate salt, but their luminescence intensity and lifetime is significantly higher when 800-900 o C annealing is performed.

  8. Optimal Node Placement in Underwater Wireless Sensor Networks

    KAUST Repository

    Felamban, M.

    2013-03-25

    Wireless Sensor Networks (WSN) are expected to play a vital role in the exploration and monitoring of underwater areas which are not easily reachable by humans. However, underwater communication via acoustic waves is subject to several performance limitations that are very different from those used for terresstrial networks. In this paper, we investigate node placement for building an initial underwater WSN infrastructure. We formulate this problem as a nonlinear mathematical program with the objective of minimizing the total transmission loss under a given number of sensor nodes and targeted coverage volume. The obtained solution is the location of each node represented via a truncated octahedron to fill out the 3D space. Experiments are conducted to verify the proposed formulation, which is solved using Matlab optimization tool. Simulation is also conducted using an ns-3 simulator, and the simulation results are consistent with the obtained results from mathematical model with less than 10% error.

  9. Simplifying superstring and D-brane actions in AdS4 x CP3 superbackground

    International Nuclear Information System (INIS)

    Grassi, Pietro Antonio; Sorokin, Dmitri; Wulff, Linus

    2009-01-01

    By making an appropriate choice for gauge fixing kappa-symmetry we obtain a relatively simple form of the actions for a D = 11 superparticle in AdS 4 x S 7 /Z k , and for a D0-brane, fundamental string and D2-branes in the AdS 4 x CP 3 superbackground. They can be used to study various problems of string theory and the AdS 4 /CFT 3 correspondence, especially in regions of the theory which are not reachable by the OSp(6|4)/U(3) x SO(1,3) supercoset sigma-model. In particular, we present a simple form of the gauge-fixed superstring action in AdS 4 x CP 3 and briefly discuss issues of its T-dualization.

  10. Ambulatory care and the law: lien claims where none exist as of right.

    Science.gov (United States)

    Balko, G A

    1995-01-01

    The health care provider, whether an individual or an institution, needs to pay attention to appropriate mechanisms to ensure payment for services or repayment for benefits provided. While statutes provide some protection for large institutions, including health care providers, individual health care providers often are left to their own devices. The employment of a well drafted voluntary lien agreement can not only secure a right of recover against a patient, but where the patient pursues a personal injury claim through an attorney, can also give the health care provider recourse to patient's attorney. Knowing how to assert these liens, what funds are reachable by these lien, and what time factors must be adhered to in order to make the liens effective, are vital to a health care provider's financial well-being.

  11. Precision determinations of electroweak parameters from ep-collisions at Hera-energies

    International Nuclear Information System (INIS)

    Weber, A.

    1990-01-01

    The authors have studied HERA's capability of precisely measuring various parameters of the electroweak standard model. The analysis was performed in kinematical regions, x ≥ 0.01 and x ≥ 0.1, where systematic errors are expected to be under control. The statistical precision reachable for standard model parameters, extracted from R ≡ σ NC /σ CC and NC asymmetries A for polarized e ± beams, was estimated for both regions. Heavy flavor contributions, which amount up to 15% to the cross sections, were included via the boson-gluon fusion process. Furthermore the influence of various uncertainties (parton distributions, quark masses, σ L /σ T , fixing input parameters) was estimated. For x ≥ 0.01 the uncertainties due to parton densities are sizeable, the total rates (cross sections), however, increase strongly in contrast to the region x ≥ 0.1

  12. Methods of checking general safety criteria in UML statechart specifications

    International Nuclear Information System (INIS)

    Pap, Zsigmond; Majzik, Istvan; Pataricza, Andras; Szegi, Andras

    2005-01-01

    This paper describes methods and tools for safety analysis of UML statechart specifications. A comprehensive set of general safety criteria including completeness and consistency is applied in automated analysis. Analysis techniques are based on OCL expressions, graph transformations and reachability analysis. Two canonical intermediate representations of the statechart specification are introduced. They are suitable for straightforward implementation of checker methods and for the support of the proof of the correctness and soundness of the applied analysis. One of them also serves as a basis of the metamodel of a variant of UML statecharts proposed for the specification of safety-critical control systems. The analysis is extended to object-oriented specifications. Examples illustrate the application of the checker methods implemented by an automated tool-set

  13. Using of Mineral Recourses for Water Purification

    International Nuclear Information System (INIS)

    Tumanova, I.V.; Nazarenko, O.B.; Anna, Yu.

    2009-01-01

    Pollution of surface waters results in necessity of underground waters using for drinking. Underground waters are characterized by the high quantity of heavy metals salts. This led to development of methods reducing the concentration of the metal salts in water. Wide spread occurrence, cheapness and high sorption properties of nature minerals allow to consider them as perspective sorbents for different impurities extraction, including dissoluble compounds of heavy metals. Reachable purification efficiency with mineral resources use for the moment satisfies sanitary indexes and standards presenting to portable water in Russia. In given material there are presented the results of research of artificial sorbent and certain minerals sorption characteristics, which are typical for West Siberia. For purification quality improvement from Fe and Mn ions there are suggested to use the method of boiling bed.

  14. The Analysis and Structuring of the Causes Impeding the Introduction of Advanced Technologies for Exchange Grain Trading

    Directory of Open Access Journals (Sweden)

    Vinnychenko Olena V

    2015-03-01

    Full Text Available In the article the main causes impeding the development and introduction of advanced technologies for grain trading on commodity exchanges in Ukraine have been identified and structured. The generalization of existing shortcomings in operation of the domestic commodity exchanges has served the basis for the model, within which there were built: a directed graph of correlations between the above mentioned shortcomings in the operation of exchanges, the matrix of dependency and reachability. The causes have been identified and structured, the main ones being determined, which, in turn, makes it possible to carry out the correct sequence of actions and emphasize the primary issues requiring priority solutions at making management decisions in order to promote the grain exchange market. The suggested approach clearly shows the correlation between the existing causes and sequence of their elimination.

  15. Kinematics/statics analysis of a novel serial-parallel robotic arm with hand

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yi; Dai, Zhuohong; Ye, Nijia; Wang, Peng [Yanshan University, Hebei (China)

    2015-10-15

    A robotic arm with fingered hand generally has multi-functions to complete various complicated operations. A novel serial-parallel robotic arm with a hand is proposed and its kinematics and statics are studied systematically. A 3D prototype of the serial-parallel robotic arm with a hand is constructed and analyzed by simulation. The serial-parallel robotic arm with a hand is composed of an upper 3RPS parallel manipulator, a lower 3SPR parallel manipulator and a hand with three finger mechanisms. Its kinematics formulae for solving the displacement, velocity, acceleration of are derived. Its statics formula for solving the active/constrained forces is derived. Its reachable workspace and orientation workspace are constructed and analyzed. Finally, an analytic example is given for solving the kinematics and statics of the serial-parallel robotic arm with a hand and the analytic solutions are verified by a simulation mechanism.

  16. Optimal control novel directions and applications

    CERN Document Server

    Aronna, Maria; Kalise, Dante

    2017-01-01

    Focusing on applications to science and engineering, this book presents the results of the ITN-FP7 SADCO network’s innovative research in optimization and control in the following interconnected topics: optimality conditions in optimal control, dynamic programming approaches to optimal feedback synthesis and reachability analysis, and computational developments in model predictive control. The novelty of the book resides in the fact that it has been developed by early career researchers, providing a good balance between clarity and scientific rigor. Each chapter features an introduction addressed to PhD students and some original contributions aimed at specialist researchers. Requiring only a graduate mathematical background, the book is self-contained. It will be of particular interest to graduate and advanced undergraduate students, industrial practitioners and to senior scientists wishing to update their knowledge.

  17. Herdable Systems Over Signed, Directed Graphs

    KAUST Repository

    Ruf, Sebastian F.; Egerstedt, Magnus; Shamma, Jeff S.

    2018-01-01

    This paper considers the notion of herdability, a set-based reachability condition, which asks whether the state of a system can be controlled to be element-wise larger than a non-negative threshold. The basic theory of herdable systems is presented, including a necessary and sufficient condition for herdability. This paper then considers the impact of the underlying graph structure of a linear system on the herdability of the system, for the case where the graph is represented as signed and directed. By classifying nodes based on the length and sign of walks from an input, we find a class of completely herdable systems as well as provide a complete characterization of nodes that can be herded in systems with an underlying graph that is a directed out-branching rooted at a single input.

  18. A Framework for Relating Timed Transition Systems and Preserving TCTL Model Checking

    DEFF Research Database (Denmark)

    Jacobsen, Lasse; Jacobsen, Morten; Møller, Mikael Harkjær

    2010-01-01

    Many formal translations between time dependent models have been proposed over the years. While some of them produce timed bisimilar models, others preserve only reachability or (weak) trace equivalence. We suggest a general framework for arguing when a translation preserves Timed Computation Tree...... Logic (TCTL) or its safety fragment.The framework works at the level of timed transition systems, making it independent of the modeling formalisms and applicable to many of the translations published in the literature. Finally, we present a novel translation from extended Timed-Arc Petri Nets...... to Networks of Timed Automata and using the framework argue that itpreserves the full TCTL. The translation has been implemented in the verification tool TAPAAL....

  19. First Search for Gravitational Waves from Known Pulsars with Advanced LIGO

    Energy Technology Data Exchange (ETDEWEB)

    Abbott, B. P.; Abbott, R.; Adhikari, R. X. [LIGO, California Institute of Technology, Pasadena, CA 91125 (United States); Abbott, T. D. [Louisiana State University, Baton Rouge, LA 70803 (United States); Abernathy, M. R. [American University, Washington, DC 20016 (United States); Acernese, F. [Università di Salerno, Fisciano, I-84084 Salerno (Italy); Ackley, K. [University of Florida, Gainesville, FL 32611 (United States); Adams, C. [LIGO Livingston Observatory, Livingston, LA 70754 (United States); Adams, T. [Laboratoire d’Annecy-le-Vieux de Physique des Particules (LAPP), Université Savoie Mont Blanc, CNRS/IN2P3, F-74941 Annecy-le-Vieux (France); Addesso, P. [University of Sannio at Benevento, I-82100 Benevento, Italy and INFN, Sezione di Napoli, I-80100 Napoli (Italy); Adya, V. B.; Affeldt, C.; Allen, B. [Albert-Einstein-Institut, Max-Planck-Institut für Gravitationsphysik, D-30167 Hannover (Germany); Agathos, M.; Agatsuma, K. [Nikhef, Science Park, 1098 XG Amsterdam (Netherlands); Aggarwal, N. [LIGO, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Aguiar, O. D. [Instituto Nacional de Pesquisas Espaciais, 12227-010 São José dos Campos, São Paulo (Brazil); Aiello, L. [INFN, Gran Sasso Science Institute, I-67100 L’Aquila (Italy); Ain, A. [Inter-University Centre for Astronomy and Astrophysics, Pune 411007 (India); Ajith, P. [International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Bengaluru 560089 (India); Collaboration: LIGO Scientific Collaboration and Virgo Collaboration; and others

    2017-04-10

    We present the result of searches for gravitational waves from 200 pulsars using data from the first observing run of the Advanced LIGO detectors. We find no significant evidence for a gravitational-wave signal from any of these pulsars, but we are able to set the most constraining upper limits yet on their gravitational-wave amplitudes and ellipticities. For eight of these pulsars, our upper limits give bounds that are improvements over the indirect spin-down limit values. For another 32, we are within a factor of 10 of the spin-down limit, and it is likely that some of these will be reachable in future runs of the advanced detector. Taken as a whole, these new results improve on previous limits by more than a factor of two.

  20. GEDUNG KOMUNITAS SASTRA FIKSI KREATIF DI MAKASSAR DENGAN PENDEKATAN ARSITEKTURE KUBISME

    Directory of Open Access Journals (Sweden)

    Silmi Sulthan

    2017-06-01

    Full Text Available Planning and designing are aimed to the creative literary fiction community building in Makassar with Cubism architecture approach, this design is limited to a few problems such as the problem of architectural, location and footprint, the prospect physical design of the building, the need for space (layout, structure, materials, and equipment building so that, it can indicate the identity of what its contain, while the methods are literature studies, comparative studies, (Form obtained by comparing studies on similar projects or who have in common with creative literary fiction community building. The results of the design is creation of infrastructures to facilitate the public to channel their talents and interests in the field of literature, especially literary function and also facilitates and encourages reading by providing the quality of reading source which are cheap and reachable by all people.

  1. Knowledge base verification based on enhanced colored petri net

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Hyun; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1998-12-31

    Verification is a process aimed at demonstrating whether a system meets it`s specified requirements. As expert systems are used in various applications, the knowledge base verification of systems takes an important position. The conventional Petri net approach that has been studied recently in order to verify the knowledge base is found that it is inadequate to verify the knowledge base of large and complex system, such as alarm processing system of nuclear power plant. Thus, we propose an improved method that models the knowledge base as enhanced colored Petri net. In this study, we analyze the reachability and the error characteristics of the knowledge base and apply the method to verification of simple knowledge base. 8 refs., 4 figs. (Author)

  2. How to stop global warming

    International Nuclear Information System (INIS)

    Goldenberg, J.

    1990-01-01

    This paper reports on how to stop global warming. At the Toronto Conference on Climate Change in 1988, the world's industrialized nations agreed on a goal of cutting greenhouse gas emissions 20 percent by the year 2005. This would not stabilize atmospheric levels of greenhouse gases but would at least slow their accumulation. Although difficult to achieve, the Toronto goal is certainly reachable. Newer, more efficient technologies can lower energy consumption without effecting economic output. CFC- substitutes can provide refrigeration. In fact, an international carbon tax of just $1 per barrel of oil, or $6 per ton of coal, would generate more than enough revenue to pay for the necessary fuel-saving measures. This tax could result from an international agreement similar to the 1987 Montreal Protocol, which obliges its signatories to cut down on production of CFCs

  3. New Acetylcholinesterase Inhibitors for Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Mona Mehta

    2012-01-01

    Full Text Available Acetylcholinesterase (AChE remains a highly viable target for the symptomatic improvement in Alzheimer's disease (AD because cholinergic deficit is a consistent and early finding in AD. The treatment approach of inhibiting peripheral AchE for myasthenia gravis had effectively proven that AchE inhibition was a reachable therapeutic target. Subsequently tacrine, donepezil, rivastigmine, and galantamine were developed and approved for the symptomatic treatment of AD. Since then, multiple cholinesterase inhibitors (ChEI continue to be developed. These include newer ChEIs, naturally derived ChEIs, hybrids, and synthetic analogues. In this paper, we summarize the different types of ChEIs in development and their respective mechanisms of actions. This pharmacological approach continues to be active with many promising compounds.

  4. Vulnerability assessment of IPv6 websites to SQL injection and other application level attacks.

    Science.gov (United States)

    Cho, Ying-Chiang; Pan, Jen-Yi

    2013-01-01

    Given the proliferation of internet connected devices, IPv6 has been proposed to replace IPv4. Aside from providing a larger address space which can be assigned to internet enabled devices, it has been suggested that the IPv6 protocol offers increased security due to the fact that with the large number of addresses available, standard IP scanning attacks will no longer become feasible. However, given the interest in attacking organizations rather than individual devices, most initial points of entry onto an organization's network and their attendant devices are visible and reachable through web crawling techniques, and, therefore, attacks on the visible application layer may offer ways to compromise the overall network. In this evaluation, we provide a straightforward implementation of a web crawler in conjunction with a benign black box penetration testing system and analyze the ease at which SQL injection attacks can be carried out.

  5. Assessment of the integration of a He-cooled divertor system in the power conversion system for the dual-coolant blanket concept (TW2-TRP-PPCS12D8)

    International Nuclear Information System (INIS)

    Norajitra, P.; Kruessmann, R.; Malang, S.; Reimann, G.

    2002-12-01

    Application of a helium-cooled divertor together with the dual-coolant blanket concept is considered favourable for achieving a high thermal efficiency of the power plant due to its relatively high coolant outlet temperature. A new FZK He-cooled modular divertor concept with integrated pin arrays (HEMP) is introduced. Its main features and function are described in detail. The result of the thermalhydraulic analysis shows that the HEMP divertor concept has the potential of resisting, a heat flow density of at least 10-15 MW/m 2 at a reachable heat transfer coefficient of approx. 60 kW/m 2 K and a reasonable pumping power. Integration of this divertor concept into the power conversion system using a closed Brayton gas turbine system with three-stage compression leads to a net efficiency of the blanket/divertor cycle of about 43%. (orig.)

  6. Optimization of airport security process

    Science.gov (United States)

    Wei, Jianan

    2017-05-01

    In order to facilitate passenger travel, on the basis of ensuring public safety, the airport security process and scheduling to optimize. The stochastic Petri net is used to simulate the single channel security process, draw the reachable graph, construct the homogeneous Markov chain to realize the performance analysis of the security process network, and find the bottleneck to limit the passenger throughput. Curve changes in the flow of passengers to open a security channel for the initial state. When the passenger arrives at a rate that exceeds the processing capacity of the security channel, it is queued. The passenger reaches the acceptable threshold of the queuing time as the time to open or close the next channel, simulate the number of dynamic security channel scheduling to reduce the passenger queuing time.

  7. Verification and Performance Evaluation of Timed Game Strategies

    DEFF Research Database (Denmark)

    David, Alexandre; Fang, Huixing; Larsen, Kim Guldstrand

    2014-01-01

    Control synthesis techniques, based on timed games, derive strategies to ensure a given control objective, e.g., time-bounded reachability. Model checking verifies correctness properties of systems. Statistical model checking can be used to analyse performance aspects of systems, e.g., energy...... consumption. In this work, we propose to combine these three techniques. In particular, given a strategy synthesized for a timed game and a given control objective, we want to make a deeper examination of the consequences of adopting this strategy. Firstly, we want to apply model checking to the timed game...... under the synthesized strategy in order to verify additional correctness properties. Secondly, we want to apply statistical model checking to evaluate various performance aspects of the synthesized strategy. For this, the underlying timed game is extended with relevant price and stochastic information...

  8. System theory on group manifolds and coset spaces.

    Science.gov (United States)

    Brockett, R. W.

    1972-01-01

    The purpose of this paper is to study questions regarding controllability, observability, and realization theory for a particular class of systems for which the state space is a differentiable manifold which is simultaneously a group or, more generally, a coset space. We show that it is possible to give rather explicit expressions for the reachable set and the set of indistinguishable states in the case of autonomous systems. We also establish a type of state space isomorphism theorem. Our objective is to reduce all questions about the system to questions about Lie algebras generated from the coefficient matrices entering in the description of the system and in that way arrive at conditions which are easily visualized and tested.

  9. Thermodynamic Analysis and Optimization of a High Temperature Triple Absorption Heat Transformer

    Science.gov (United States)

    Khamooshi, Mehrdad; Yari, Mortaza; Egelioglu, Fuat; Salati, Hana

    2014-01-01

    First law of thermodynamics has been used to analyze and optimize inclusively the performance of a triple absorption heat transformer operating with LiBr/H2O as the working pair. A thermodynamic model was developed in EES (engineering equation solver) to estimate the performance of the system in terms of the most essential parameters. The assumed parameters are the temperature of the main components, weak and strong solutions, economizers' efficiencies, and bypass ratios. The whole cycle is optimized by EES software from the viewpoint of maximizing the COP via applying the direct search method. The optimization results showed that the COP of 0.2491 is reachable by the proposed cycle. PMID:25136702

  10. Blanking Clearance and Punch Velocity Effects on The Sheared Edge Characteristic in Micro-Blanking of Commercially Pure Copper Sheet

    Directory of Open Access Journals (Sweden)

    Didin Zakaria Lubis

    2017-11-01

    Full Text Available This study aims to identify the influences between clearance and punch velocity on the part edge quality of blanked parts. Experiments have been conducted using material copper, punch-die clearance and punch velocity variations. In order to determine the reachable punch-die clearance and punch velocity required for blanking. The quality of the part-edge characteristics shows that higher punch velocity and decreases clearance value can improve the part-edge quality, resulting in smaller burr height and rollover, and a larger shear zone. Furthermore, it could be observed that the part-edge quality improvement when blanking with high punch velocity is much more distinct for stele than for copper. According to blanking theory, this improvement was expected because copper have much higher heat conduction coefficients. Therefore, the heat dissipates faster and the desired stress relief effect does not take place to the same degree as for stele.

  11. Findability och informationskompetens vid webbnavigation

    DEFF Research Database (Denmark)

    Fransson, Jonas

    2011-01-01

    needed. But the information is not equally available, even if it is published and freely available on the Web. Each Web page, or other information object, has a degree of findability. The degree of the findability depends on the relationships between object, system and the Web. Six sub concepts......The article discusses the relationship between users, information objects, information systems and the Web, combined with the concepts findability and information literacy. An important aspect in all information literacy definitions is the ability to effectively gain access to the information...... are identified: the object's characteristics, accessibility, internal navigation, internal search, reachability and web prestige. Both information literacy and findability are defined as query independent aspects of the search, working on a structural level....

  12. A global nuclear waste repository

    Science.gov (United States)

    Lin, Wunan

    As a concerned scientist, I think that having a global nuclear waste repository is a reachable goal for human beings. Maybe through this common goal, mankind can begin to treat each other as brothers and sisters. So far, most human activities are framed by national boundaries, which are purely arbitrary. Breaking through these national boundaries will be very beneficial to human beings.Formation of the International Geosphere-Biosphere Program in 1986 indicates a growing awareness on the part of scientists regarding Earth as a system. The Apollo missions gave us a chance to look back at Earth from space. That perspective emphasized that our Earth is just one system: our only home. It is in deed a lonely boat in the high sea of dark space. We must take good care of our “boat.”

  13. Consensus Analysis of Second-Order Multiagent Systems with General Topology and Time Delay

    Directory of Open Access Journals (Sweden)

    Bo Liu

    2013-01-01

    Full Text Available This paper addresses the consensus of second-order multiagent systems with general topology and time delay based on the nearest neighbor rule. By using the Laplace transform technique, it is proved that the second-order multi-agent system in the presence of time-delay can reach consensus if the network topology contains a globally reachable node and time delay is bounded. The bound of time-delay only depends on eigenvalues of the Laplacian matrix of the system. The main contribution of this paper is that the accurate state of the consensus center and the upper bound of the communication delay to make the agents reach consensus are given. Some numerical simulations are given to illustrate the theoretical results.

  14. Decomposition and Simplification of Multivariate Data using Pareto Sets.

    Science.gov (United States)

    Huettenberger, Lars; Heine, Christian; Garth, Christoph

    2014-12-01

    Topological and structural analysis of multivariate data is aimed at improving the understanding and usage of such data through identification of intrinsic features and structural relationships among multiple variables. We present two novel methods for simplifying so-called Pareto sets that describe such structural relationships. Such simplification is a precondition for meaningful visualization of structurally rich or noisy data. As a framework for simplification operations, we introduce a decomposition of the data domain into regions of equivalent structural behavior and the reachability graph that describes global connectivity of Pareto extrema. Simplification is then performed as a sequence of edge collapses in this graph; to determine a suitable sequence of such operations, we describe and utilize a comparison measure that reflects the changes to the data that each operation represents. We demonstrate and evaluate our methods on synthetic and real-world examples.

  15. A New GEM-like Imaging Detector with Electrodes Coated with Resistive Layers

    CERN Document Server

    Di Mauro, Antonio; Martinengo, Paolo; Napri, Eugenio; Peskov, Vladimir; Periale, Luciano; Picchi, P.; Pietropaolo, Francesco; Rodionov, I.

    We have developed and tested several prototypes of GEM-like detectors with electrodes coated with resistive layers: CuO or CrO. These detectors can operate stably at gains close to 10E5 and they are very robust. We discovered that the cathodes of these detectors could be coated by CsI layers and in such a way the detectors gain high efficiency for the UV photons. We also demonstrated that such detectors can operate stably in the cascade mode and high overall gains (~10E6) are reachable. This opens applications in several areas, for example in RICH or in noble liquid TPCs. Results from the first applications of these devices for UV photon detection at room and cryogenic temperatures are given.

  16. Phoenix Robotic Arm's Workspace After 90 Sols

    Science.gov (United States)

    2008-01-01

    During the first 90 Martian days, or sols, after its May 25, 2008, landing on an arctic plain of Mars, NASA's Phoenix Mars Lander dug several trenches in the workspace reachable with the lander's robotic arm. The lander's Surface Stereo Imager camera recorded this view of the workspace on Sol 90, early afternoon local Mars time (overnight Aug. 25 to Aug. 26, 2008). The shadow of the the camera itself, atop its mast, is just left of the center of the image and roughly a third of a meter (one foot) wide. The workspace is on the north side of the lander. The trench just to the right of center is called 'Neverland.' The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  17. Search for K/sub L//sup O/→μe at the 10-13 level

    International Nuclear Information System (INIS)

    McFarlane, W.K.; Cooper, M.D.

    1989-01-01

    A few of the experimental problems of searching for the lepton non-conserving decay K/sub L//sup O/ → μe are discussed in the light of the experience of BNL E791. This experiment was designed to have high rate capability and excellent background rejection; as such it provides information useful in evaluating designs for similar experiments at high-intensity facilities. The conclusion is that a level of a few times 10 -13 may be reachable, but requires careful design and makes significant demands on the accelerator, particularly as regards beam time structure. Development of precise positron-sensitive detectors with shorter resolving times is also necessary. 4 refs., 1 fig

  18. Mental representation for action in the elderly: implications for movement efficiency and injury risk.

    Science.gov (United States)

    Gabbard, Carl

    2015-04-01

    Recent research findings indicate that with older adulthood, there are functional decrements in spatial cognition and more specially, in the ability to mentally represent and effectively plan motor actions. A typical finding is a significant over- or underestimation of one's actual physical abilities with movement planning-planning that has implications for movement efficiency and physical safety. A practical, daily life example is estimation of reachability--a situation that for the elderly may be linked with fall incidence. A strategy used to mentally represent action is the use of motor imagery--an ability that also declines with advancing older age. This brief review highlights research findings on mental representation and motor imagery in the elderly and addresses the implications for improving movement efficiency and lowering the risk of movement-related injury. © The Author(s) 2013.

  19. Examining intention in simulated actions: are children and young adults different?

    Science.gov (United States)

    Gabbard, Carl; Caçola, Priscila

    2014-10-01

    Previous work with adults provides evidence that 'intention' used in processing simulated actions is similar to that used in planning and processing overt movements. The present study compared young adults and children on their ability to estimate distance reachability using a NOGO/GO paradigm in conditions of imagery only (IO) and imagery with actual execution (IE). Our initial thoughts were that whereas intention is associated with motivation and commitment to act, age-related differences could impact planning. Results indicated no difference in overall accuracy by condition within groups, and as expected adults were more accurate. These findings support an increasing body of evidence suggesting that the neurocognitive processes (in this case, intention) driving motor imagery and overt actions are similar, and as evidenced here, functioning by age 7. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. A question of intention in motor imagery.

    Science.gov (United States)

    Gabbard, Carl; Cordova, Alberto; Lee, Sunghan

    2009-03-01

    We examined the question-is the intention of completing a simulated motor action the same as the intention used in processing overt actions? Participants used motor imagery to estimate distance reachability in two conditions: Imagery-Only (IO) and Imagery-Execution (IE). With IO (red target) only a verbal estimate using imagery was given. With IE (green target) participants knew that they would actually reach after giving a verbal estimate and be judged on accuracy. After measuring actual maximum reach, used for the comparison, imagery targets were randomly presented across peripersonal- (within reach) and extrapersonal (beyond reach) space. Results indicated no difference in overall accuracy by condition, however, there was a significant distinction by space; participants were more accurate in peripersonal space. Although more research is needed, these findings support an increasing body of evidence suggesting that the neurocognitive processes (in this case, intention) driving motor imagery and overt actions are similar.

  1. Applying Digital Technologies to Strengthen Nuclear Safety

    International Nuclear Information System (INIS)

    Huffeteau, S.; Roy, C.

    2016-01-01

    Full text: The paper describes how the development of some information technologies can further contribute to the safety of nuclear facilities and their competitiveness. After repositioning the nuclear industry engineering practices in their historical and economic context, the paper describes five engineering practices or use cases widely developed especially in the aerospace industry: requirement management, business process enforcement by digitization of data and processes, facilities configuration management, engineering information unification, and digital licensing. Information technology (IT) plays a mandatory role for driving this change since IT is now mature enough to handle the level of complexity the nuclear industry requires. While the detailed evaluation of the expecting gains in cost decrease or safety increase can be difficult to quantify, the paper presents illustrative benefits reachable by a development of these practices. (author

  2. Accurate determination of the Boltzmann constant by Doppler spectroscopy: Towards a new definition of the kelvin

    International Nuclear Information System (INIS)

    Darquie, B.; Mejri, S.; Sow, P. L. T.; Lemarchand, C.; Triki, M.; Tokunaga, S. K.; Borde, C. J.; Chardonnet, C.; Daussy, C.

    2013-01-01

    Accurate molecular spectroscopy in the mid-infrared region allows precision measurements of fundamental constants. For instance, measuring the linewidth of an isolated Doppler-broadened absorption line of ammonia around 10 μm enables a determination of the Boltzmann constant k B . We report on our latest measurements. By fitting this lineshape to several models which include Dicke narrowing or speed-dependent collisional effects, we find that a determination of k B with an uncertainty of a few ppm is reachable. This is comparable to the best current uncertainty obtained using acoustic methods and would make a significant contribution to any new value of k B determined by the CODATA. Furthermore, having multiple independent measurements at these accuracies opens the possibility of defining the kelvin by fixing k B , an exciting prospect considering the upcoming redefinition of the International System of Units. (authors)

  3. Applying Graph Theory to Problems in Air Traffic Management

    Science.gov (United States)

    Farrahi, Amir H.; Goldberg, Alan T.; Bagasol, Leonard N.; Jung, Jaewoo

    2017-01-01

    Graph theory is used to investigate three different problems arising in air traffic management. First, using a polynomial reduction from a graph partitioning problem, it isshown that both the airspace sectorization problem and its incremental counterpart, the sector combination problem are NP-hard, in general, under several simple workload models. Second, using a polynomial time reduction from maximum independent set in graphs, it is shown that for any fixed e, the problem of finding a solution to the minimum delay scheduling problem in traffic flow management that is guaranteed to be within n1-e of the optimal, where n is the number of aircraft in the problem instance, is NP-hard. Finally, a problem arising in precision arrival scheduling is formulated and solved using graph reachability. These results demonstrate that graph theory provides a powerful framework for modeling, reasoning about, and devising algorithmic solutions to diverse problems arising in air traffic management.

  4. Regulatory networks and connected components of the neutral space. A look at functional islands

    Science.gov (United States)

    Boldhaus, G.; Klemm, K.

    2010-09-01

    The functioning of a living cell is largely determined by the structure of its regulatory network, comprising non-linear interactions between regulatory genes. An important factor for the stability and evolvability of such regulatory systems is neutrality - typically a large number of alternative network structures give rise to the necessary dynamics. Here we study the discretized regulatory dynamics of the yeast cell cycle [Li et al., PNAS, 2004] and the set of networks capable of reproducing it, which we call functional. Among these, the empirical yeast wildtype network is close to optimal with respect to sparse wiring. Under point mutations, which establish or delete single interactions, the neutral space of functional networks is fragmented into ≈ 4.7 × 108 components. One of the smaller ones contains the wildtype network. On average, functional networks reachable from the wildtype by mutations are sparser, have higher noise resilience and fewer fixed point attractors as compared with networks outside of this wildtype component.

  5. Vulnerability Assessment of IPv6 Websites to SQL Injection and Other Application Level Attacks

    Directory of Open Access Journals (Sweden)

    Ying-Chiang Cho

    2013-01-01

    Full Text Available Given the proliferation of internet connected devices, IPv6 has been proposed to replace IPv4. Aside from providing a larger address space which can be assigned to internet enabled devices, it has been suggested that the IPv6 protocol offers increased security due to the fact that with the large number of addresses available, standard IP scanning attacks will no longer become feasible. However, given the interest in attacking organizations rather than individual devices, most initial points of entry onto an organization's network and their attendant devices are visible and reachable through web crawling techniques, and, therefore, attacks on the visible application layer may offer ways to compromise the overall network. In this evaluation, we provide a straightforward implementation of a web crawler in conjunction with a benign black box penetration testing system and analyze the ease at which SQL injection attacks can be carried out.

  6. Tools and Methods for RTCP-Nets Modeling and Verification

    Directory of Open Access Journals (Sweden)

    Szpyrka Marcin

    2016-09-01

    Full Text Available RTCP-nets are high level Petri nets similar to timed colored Petri nets, but with different time model and some structural restrictions. The paper deals with practical aspects of using RTCP-nets for modeling and verification of real-time systems. It contains a survey of software tools developed to support RTCP-nets. Verification of RTCP-nets is based on coverability graphs which represent the set of reachable states in the form of directed graph. Two approaches to verification of RTCP-nets are considered in the paper. The former one is oriented towards states and is based on translation of a coverability graph into nuXmv (NuSMV finite state model. The later approach is oriented towards transitions and uses the CADP toolkit to check whether requirements given as μ-calculus formulae hold for a given coverability graph. All presented concepts are discussed using illustrative examples

  7. Maximal energy extraction under discrete diffusive exchange

    Energy Technology Data Exchange (ETDEWEB)

    Hay, M. J., E-mail: hay@princeton.edu [Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544 (United States); Schiff, J. [Department of Mathematics, Bar-Ilan University, Ramat Gan 52900 (Israel); Fisch, N. J. [Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544 (United States); Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2015-10-15

    Waves propagating through a bounded plasma can rearrange the densities of states in the six-dimensional velocity-configuration phase space. Depending on the rearrangement, the wave energy can either increase or decrease, with the difference taken up by the total plasma energy. In the case where the rearrangement is diffusive, only certain plasma states can be reached. It turns out that the set of reachable states through such diffusive rearrangements has been described in very different contexts. Building upon those descriptions, and making use of the fact that the plasma energy is a linear functional of the state densities, the maximal extractable energy under diffusive rearrangement can then be addressed through linear programming.

  8. Capturing connectivity and causality in complex industrial processes

    CERN Document Server

    Yang, Fan; Shah, Sirish L; Chen, Tongwen

    2014-01-01

    This brief reviews concepts of inter-relationship in modern industrial processes, biological and social systems. Specifically ideas of connectivity and causality within and between elements of a complex system are treated; these ideas are of great importance in analysing and influencing mechanisms, structural properties and their dynamic behaviour, especially for fault diagnosis and hazard analysis. Fault detection and isolation for industrial processes being concerned with root causes and fault propagation, the brief shows that, process connectivity and causality information can be captured in two ways: ·      from process knowledge: structural modeling based on first-principles structural models can be merged with adjacency/reachability matrices or topology models obtained from process flow-sheets described in standard formats; and ·      from process data: cross-correlation analysis, Granger causality and its extensions, frequency domain methods, information-theoretical methods, and Bayesian ne...

  9. Development of a Sinter/HIP process for the superalloy Udimet 700 with investigations of the influence of the sinteratmosphere

    International Nuclear Information System (INIS)

    Wenning, L.

    1991-03-01

    The oxidation free treatment of reactive metalpowders like the nickel base alloy Udimet 700 demands sufficient oxygen free sinteratmospheres in nowadays sinter-HIP plants are not reachable. The reported work deals with the development of a sinter-HIP process which enables a sufficient low partial pressure of oxygen by scavenging the Udimet 700 powder packings with argon during vacuum sintering. By this the sinter hindering oxidation is avoided. Intensive investigations of the sinteratmosphere with a mass spectrometer and a zirconium oxide probe verify the reduction of the oxygen content of the residual gas atmosphere reached with different processes. In a second part the applicability of the scavenging gas process during the capsule free sinter-HIP treatment of metall injection moulded (MIM) samples is shown. (orig.) [de

  10. Timed-Arc Petri Nets vs. Networks of Timed Automata

    DEFF Research Database (Denmark)

    Srba, Jiri

    We establish mutual translations between the classes of 1-safe timed-arc Petri nets (and its extension with testing arcs) and networks of timed automata (and its subclass where every clock used in the guard has to be reset). The presented translations are very tight (up to isomorphism of labelled...... transition systems with time). This provides a convenient characterization from the theoretical point of view but is not always satisfactory from the practical point of view because of the possible non-polynomial blow up in the size (in the direction from automata to nets). Hence we relax the isomorphism...... requirement and provide efficient (polynomial time) reductions between networks of timed automata and 1-safe timed-arc Petri nets preserving the answer to the reachability question. This makes our techniques suitable for automatic translation into a format required by tools like UPPAAL and KRONOS. A direct...

  11. Summary: beyond fault trees to fault graphs

    International Nuclear Information System (INIS)

    Alesso, H.P.; Prassinos, P.; Smith, C.F.

    1984-09-01

    Fault Graphs are the natural evolutionary step over a traditional fault-tree model. A Fault Graph is a failure-oriented directed graph with logic connectives that allows cycles. We intentionally construct the Fault Graph to trace the piping and instrumentation drawing (P and ID) of the system, but with logical AND and OR conditions added. Then we evaluate the Fault Graph with computer codes based on graph-theoretic methods. Fault Graph computer codes are based on graph concepts, such as path set (a set of nodes traveled on a path from one node to another) and reachability (the complete set of all possible paths between any two nodes). These codes are used to find the cut-sets (any minimal set of component failures that will fail the system) and to evaluate the system reliability

  12. Webometrics: Some Critical Issues of WWW Size Estimation Methods

    Directory of Open Access Journals (Sweden)

    Srinivasan Mohana Arunachalam

    2018-04-01

    Full Text Available The number of webpages in the Internet has increased tremendously over the last two decades however only a part of it is indexed by various search engines. This small portion is the indexable web of the Internet and can be usually reachable from a Search Engine. Search engines play a big role in making the World Wide Web accessible to the end user, and how much of the World Wide Web is accessible on the size of the search engine’s index. Researchers have proposed several ways to estimate this size of the indexable web using search engines with and without privileged access to the search engine’s database. Our report provides a summary of methods used in the last two decades to estimate the size of the World Wide Web, as well as describe how this knowledge can be used in other aspects/tasks concerning the World Wide Web.

  13. Spectroscopical plasma diagnostics for the procedure optimization in laser-beam high-speed cutting; Spektroskopische Plasmadiagnostik zur Verfahrensoptimierung beim Laserstrahl-Hochgeschwindigkeitsschneiden

    Energy Technology Data Exchange (ETDEWEB)

    Nate, M.

    2001-07-01

    In the present thesis the laser-induced plasma typical for the high- speed cutting process was studied in the region of the interaction zone. For this especially the absorption properties of the plasma for the incident laser radiation and their correlation with the maximally reachable cutting speeds. For this with methods of the spectroscopic plasma diagnostics the influence of different process parameters on the quantities characterizing the plasma, electron density and temperature, was determined. On the base of these values in the framework of an equilibrium model the densities of all particles contained in the plasma were determined. With these values the plasma absorption coefficient was subsequently calculated and the laser radiation absorbed in the plasma estimated.

  14. Hybrid System Design for the Coordination of Multi-Modal Aerial Robots

    DEFF Research Database (Denmark)

    Koo, T. John; Quottrup, Michael Melholt; Clifton, C. A.

    2006-01-01

    In this paper we provide a framework for the coordination of a network of heterogeneous aerial robots by using temporal logic to formulate mission speci¯cations for the network of robots. The full dynamics of the aerial robots are considered, and multiple controllers that can cope with various......¯ed. These robots are coordinated by communicating through a single occupancy table. By using the model checker Uppaal, a discrete plan that satis¯es a given temporal logic formula, speci¯ed in CTL, is generated for the robot to execute. Finally, the discrete plan for each robot is re¯ned into a discrete control...... constraints are designed to ensure that desired reachability properties can be preserved by properly switching among the controllers. A timed automaton is then constructed for preserving the temporal properties of a given robot. For di®erent types of robots, unique temporal properties can be speci...

  15. Airborne fallout mapping of {sup 137}Cs Finnish defence forces team

    Energy Technology Data Exchange (ETDEWEB)

    Kettunen, M.; Heininen, T. [Finnish Defence Forces Research Centre, Lakiala (Finland); Pulakka, M. [Finnish Air Force Depot, Tampere (Finland)

    1997-12-31

    The main task of the team was to create a fallout map of {sup 137}Cs in a specified area in Padasjoki Auttoinen village. The team used an MI-8 helicopter of the Finnish Air Force. The team had an HPGe system (relative efficiency 70%) to measure nuclide specific ground contamination level. For navigation the team took advantage of the DGPS service provided by Finnish Broadcasting company utilizing the RDS-channel to get position accuracy within 2 meters. The correction signal is reachable nationwide on the FM transmitter network. The system produced a distribution map for {sup 40}K and fallout maps for {sup 134,137}Cs using a Micro Station Program with TerraModeler application. The maximum measured {sup 137}Cs ground contamination exceeded 130-140 kBqm{sup -2}. (au).

  16. Variable-spot ion beam figuring

    International Nuclear Information System (INIS)

    Wu, Lixiang; Qiu, Keqiang; Fu, Shaojun

    2016-01-01

    This paper introduces a new scheme of ion beam figuring (IBF), or rather variable-spot IBF, which is conducted at a constant scanning velocity with variable-spot ion beam collimated by a variable diaphragm. It aims at improving the reachability and adaptation of the figuring process within the limits of machine dynamics by varying the ion beam spot size instead of the scanning velocity. In contrast to the dwell time algorithm in the conventional IBF, the variable-spot IBF adopts a new algorithm, which consists of the scan path programming and the trajectory optimization using pattern search. In this algorithm, instead of the dwell time, a new concept, integral etching time, is proposed to interpret the process of variable-spot IBF. We conducted simulations to verify its feasibility and practicality. The simulation results indicate the variable-spot IBF is a promising alternative to the conventional approach.

  17. Thirty Years, One Million Spectra: Public Access to the SAO Spectral Archives

    Science.gov (United States)

    Mink, J.; Moran, S.

    2015-09-01

    Over the last 30 years, the SAO Telescope Data Center has reduced and archived over 1,000,000 spectra, consisting of 287,000 spectra from five high dispersion Echelle spectrographs and 717,000 spectra from four low dispersion spectrographs, across three telescopes. 151,000 spectra from six instruments are currently online and publicly available, covering many interesting objects in the northern sky, including most of the galaxies in the Updated Zwicky Catalog which are reachable through NED or Simbad. A majority of the high dispersion spectra will soon be made public, as will more data from the MMT multi-fiber spectrographs. Many objects in the archive have multiple spectra over time, which make them a valuable resource for archival time-domain studies. We are now developing a system to make all of the public spectra more easily searchable and viewable through the Virtual Observatory.

  18. Thermodynamic Analysis and Optimization of a High Temperature Triple Absorption Heat Transformer

    Directory of Open Access Journals (Sweden)

    Mehrdad Khamooshi

    2014-01-01

    Full Text Available First law of thermodynamics has been used to analyze and optimize inclusively the performance of a triple absorption heat transformer operating with LiBr/H2O as the working pair. A thermodynamic model was developed in EES (engineering equation solver to estimate the performance of the system in terms of the most essential parameters. The assumed parameters are the temperature of the main components, weak and strong solutions, economizers’ efficiencies, and bypass ratios. The whole cycle is optimized by EES software from the viewpoint of maximizing the COP via applying the direct search method. The optimization results showed that the COP of 0.2491 is reachable by the proposed cycle.

  19. GLOBAL IMPACT OF SOLAR ENERGY, CASE STUDY - GERMANY

    Directory of Open Access Journals (Sweden)

    Gheorghe Caralicea Marculescu

    2014-02-01

    Full Text Available Renewable energy is a socially and politically defined category of energy sources. Renewable energy is generally defined as energy that comes from resources which are continually replenished on a human timescale such as sunlight, wind, rain, tides, waves and geothermal heat. About 16% of global final energy consumption comes from renewable resources, with 10% of all energy from traditional biomass, mainly used for heating, and 3.4% from hydroelectricity. New renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels accounted for another 3% and are growing rapidly. This paper seeks is aimed at presenting the impact solar energy could have on a world level given the finitude, reachability and ever increasing prices of fossil fuels. As a case study we will present the solar energy industry in Germany emphasizing the advantages and disadvantages this form of energy has in this country and worldwide.

  20. The development of robotic system for the nuclear power plants -The development of advanced robotics for the nuclear industry-

    International Nuclear Information System (INIS)

    Kim, Seung Ho; Kim, Chang Hoi; Kim, Byung Soo; Lee, Yong Bum; Hwang, Suk Yeoung; Kim, Woong Ki; Park, Soon Yong; Lee, Young Kwang; Lee, Jae Gyeong; Seo, Yong Chil

    1994-07-01

    The omni-directional planetary wheel type mobile robot (KAEROT/ml) has been developed on the concepts of the modularity, reliability, and stability. Manipulator system is designed in order to be able to install on mobile system and to upgrade operating capability. Control system consists of 68030 processor board, servo motor controller and I/O board. The 6 DOFs hydraulic manipulator is designed for nozzle dam installation and removal. The reachable length of manipulator is 1.7 m with the wrist configuration of pitch-yaw-roll. For the easy installation of manipulator from outside steam generator, specially designed guider is considered. Also master manipulator is designed for force feedback control. RCP (Remote Control Part) is constructed with Sparc processor boards and servo control boards. Graphic simulation has done for the evaluation of manipulator performance of nozzle dam works. (Author)

  1. Structure and Hierarchy in Real-Time Systems

    DEFF Research Database (Denmark)

    Möller, Michael Oliver

    The development of digital systems is particularly challenging, if their correctness depends on the right timing of operations. One approach to enhance the reliability of such systems is model-based development. This allows for a formal analysis throughout all stages of design. Model......-based development is hindered mainly by the lack of adequate modeling languages and the high computational cost of the analysis. In this thesis we improve the situation along both axes. First, we bring the mathematical model closer to the human designer. This we achieve by casting hierarchical structures--as known...... that have the potential to reduce time and memory consumption drastically. The first technique makes use of structural information, in particular loops, to exploit regularities in the reachable state space. Via shortcut-like additions to the model we avoid repetition of similar states during an exhaustive...

  2. Synthesizing Modular Invariants for Synchronous Code

    Directory of Open Access Journals (Sweden)

    Pierre-Loic Garoche

    2014-12-01

    Full Text Available In this paper, we explore different techniques to synthesize modular invariants for synchronous code encoded as Horn clauses. Modular invariants are a set of formulas that characterizes the validity of predicates. They are very useful for different aspects of analysis, synthesis, testing and program transformation. We describe two techniques to generate modular invariants for code written in the synchronous dataflow language Lustre. The first technique directly encodes the synchronous code in a modular fashion. While in the second technique, we synthesize modular invariants starting from a monolithic invariant. Both techniques, take advantage of analysis techniques based on property-directed reachability. We also describe a technique to minimize the synthesized invariants.

  3. Spreading gossip in social networks.

    Science.gov (United States)

    Lind, Pedro G; da Silva, Luciano R; Andrade, José S; Herrmann, Hans J

    2007-09-01

    We study a simple model of information propagation in social networks, where two quantities are introduced: the spread factor, which measures the average maximal reachability of the neighbors of a given node that interchange information among each other, and the spreading time needed for the information to reach such a fraction of nodes. When the information refers to a particular node at which both quantities are measured, the model can be taken as a model for gossip propagation. In this context, we apply the model to real empirical networks of social acquaintances and compare the underlying spreading dynamics with different types of scale-free and small-world networks. We find that the number of friendship connections strongly influences the probability of being gossiped. Finally, we discuss how the spread factor is able to be applied to other situations.

  4. Controllability of switched singular mix-valued logical control networks with constraints

    Science.gov (United States)

    Deng, Lei; Gong, Mengmeng; Zhu, Peiyong

    2018-03-01

    The present paper investigates the controllability problem of switched singular mix-valued logical control networks (SSMLCNs) with constraints on states and controls. First, using the semi-tenser product (STP) of matrices, the SSMLCN is expressed in an algebraic form, based on which a necessary and sufficient condition is given for the uniqueness of solution of SSMLCNs. Second, a necessary and sufficient criteria is derived for the controllability of constrained SSMLCNs, by converting a constrained SSMLCN into a parallel constrained switched mix-valued logical control network. Third, an algorithm is presented to design a proper switching sequence and a control scheme which force a state to a reachable state. Finally, a numerical example is given to demonstrate the efficiency of the results obtained in this paper.

  5. Achieving Network Level Privacy in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Sungyoung Lee

    2010-02-01

    Full Text Available Full network level privacy has often been categorized into four sub-categories: Identity, Route, Location and Data privacy. Achieving full network level privacy is a critical and challenging problem due to the constraints imposed by the sensor nodes (e.g., energy, memory and computation power, sensor networks (e.g., mobility and topology and QoS issues (e.g., packet reach-ability and timeliness. In this paper, we proposed two new identity, route and location privacy algorithms and data privacy mechanism that addresses this problem. The proposed solutions provide additional trustworthiness and reliability at modest cost of memory and energy. Also, we proved that our proposed solutions provide protection against various privacy disclosure attacks, such as eavesdropping and hop-by-hop trace back attacks.

  6. Synchrotron radiation. Basics, methods and applications

    International Nuclear Information System (INIS)

    Mobilio, Settimio; Meneghini, Carlo; Boscherini, Federico

    2015-01-01

    Synchrotron radiation is today extensively used for fundamental and applied research in many different fields of science. Its exceptional characteristics in terms of intensity, brilliance, spectral range, time structure and now also coherence pushed many experimental techniques to previously un-reachable limits, enabling the performance of experiments unbelievable only few years ago. The book gives an up-to-date overview of synchrotron radiation research today with a view to the future, starting from its generation and sources, its interaction with matter, illustrating the main experimental technique employed and provides an overview of the main fields of research in which new and innovative results are obtained. The book is addressed to PhD students and young researchers to provide both an introductory and a rather deep knowledge of the field. It will also be helpful to experienced researcher who want to approach the field in a professional way.

  7. FlowPing - The New Tool for Throughput and Stress Testing

    Directory of Open Access Journals (Sweden)

    Ondrej Vondrous

    2015-01-01

    Full Text Available This article presents a new tool for network throughput and stress testing. The FlowPing tool is easy to use, and its basic output is very similar to standard Linux ping application. The FlowPing tool is not limited to reach-ability or round trip time testing but is capable of complex UDP based throughput stress testing with rich reporting capabilities on client and server sides. Our new tool implements features, which allow the user to perform tests with variable packet size and traffic rate. All these features can be used in one single test run. This allows the user to use and develop new methodologies for network throughput and stress testing. With the FlowPing tool, it is easy to perform the test with the slowly increasing the amount of network traffic and monitor the behavior of network when the congestion occurs.

  8. IT Services Availability during the 2007 Annual CERN Closure

    CERN Multimedia

    IT Department

    2007-01-01

    Most of the physics, technical, administrative and communications services provided by the IT Department - including LCG (EGEE) production services - will remain available during the CERN annual closure (although EDH requests will stay queued). No interruptions are scheduled but in the event of failure, the restoration of services cannot be guaranteed. Problems will be dealt with on a best effort basis only. However, for the following services: Network, Databases, Mail, Web, Windows & Terminal Services, Indico, CDS, Grid (SAM, FTS, VOMS, GridView, Resource Brokers): experts should be reachable to start investigations within about half a day except around Christmas Eve and Christmas Day (24 and 25 December) and New Year’s Eve and New Year’s Day (31 December and 1 January). Incidents will be documented at http://cern.ch/ssb; The backup service: will remain operational, but backups cannot be guaranteed and file restores will not be possible; Castor: damaged tapes wi...

  9. Availability of IT services during the 2009 CERN annual closure

    CERN Multimedia

    IT Department

    2009-01-01

    Most of the services provided by the IT Department - including WLCG (EGEE) production services - will remain available during the CERN annual closure. No interruptions are scheduled but in the event of a failure, the restoration of services cannot be guaranteed. Problems will be dealt with on a best effort basis only. However, for the following services: Network, Databases, Mail, Web, Windows & Terminal Services, Authentication Services, Indico, CDS, Grid (SAM, FTS, VOMS, GridView): experts should be reachable to start investigations within about half a day except on Christmas Eve and Christmas Day (24 and 25 December) and New Year’s Eve and New Year’s Day (31 December and 1 January). Incidents will be documented at http://cern.ch/ssb. The backup service will remain operational, but backups cannot be guaranteed and file restores may not be possible. Castor: damaged tapes will not be processed. Please note that the Helpdesk will be closed but an operator service will ...

  10. A novel robotic platform for single-port abdominal surgery

    Science.gov (United States)

    Singh, Satwinder; Cheung, Jo L. K.; Sreedhar, Biji; Hoa, Xuyen Dai; Ng, Hoi Pang; Yeung, Chung Kwong

    2018-03-01

    In this paper, a novel robot-assisted platform for single-port minimally invasive surgery is presented. A miniaturized seven degrees of freedom (dof) fully internalized in-vivo actuated robotic arm is designed. Due to in-vivo actuation, the system has a smaller footprint and can generate 20 N of gripping force. The complete work envelop of the robotic arms is 252 mm × 192 mm × 322 m. With the assistance of the cannula-swivel system, the robotic arms can also be re-positioned and have multi-quadrant reachability without any additional incision. Surgical tasks, such as lifting, gripping suturing and knot tying that are commonly used in a standard surgical procedure, were performed to verify the dexterity of the robotic arms. A single-port trans-abdominal cholecystectomy in a porcine model was successfully performed to further validate its functionality.

  11. IT Services Availability during the CERN Annual Closure 2010

    CERN Multimedia

    2010-01-01

    Most of the services provided by the IT Department - including WLCG production services - will remain available during the CERN annual closure. No interruptions are scheduled but in case of failure, the restoration of services cannot be guaranteed. Problems will be dealt with on a best effort basis only. However, please note:   •\tExperts should be reachable to start investigations on the following services within about half a day except around Christmas Eve and Christmas Day (24 and 25 December) and New Year's Eve and New Year's Day (31 December and 1 January) -- Network, Databases, Linux, Mail, Printing, Telecom, Web, Windows & Windows Terminal Services, Account Management, Castor, Indico, Inspire, Invenio, Grid (SAM, Gridview, Nagios, messaging), and the room booking system, Incidents will be documented at http://cern.ch/ssb. •\tThe backup service will remain operational, but backups cannot be guaranteed and file restores may not be possible. •\tFor the Castor serv...

  12. First Search for Gravitational Waves from Known Pulsars with Advanced LIGO

    International Nuclear Information System (INIS)

    Abbott, B. P.; Abbott, R.; Adhikari, R. X.; Abbott, T. D.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adya, V. B.; Affeldt, C.; Allen, B.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O. D.; Aiello, L.; Ain, A.; Ajith, P.

    2017-01-01

    We present the result of searches for gravitational waves from 200 pulsars using data from the first observing run of the Advanced LIGO detectors. We find no significant evidence for a gravitational-wave signal from any of these pulsars, but we are able to set the most constraining upper limits yet on their gravitational-wave amplitudes and ellipticities. For eight of these pulsars, our upper limits give bounds that are improvements over the indirect spin-down limit values. For another 32, we are within a factor of 10 of the spin-down limit, and it is likely that some of these will be reachable in future runs of the advanced detector. Taken as a whole, these new results improve on previous limits by more than a factor of two.

  13. Airborne fallout mapping of 137Cs Finnish defence forces team

    International Nuclear Information System (INIS)

    Kettunen, M.; Heininen, T.; Pulakka, M.

    1997-01-01

    The main task of the team was to create a fallout map of 137 Cs in a specified area in Padasjoki Auttoinen village. The team used an MI-8 helicopter of the Finnish Air Force. The team had an HPGe system (relative efficiency 70%) to measure nuclide specific ground contamination level. For navigation the team took advantage of the DGPS service provided by Finnish Broadcasting company utilizing the RDS-channel to get position accuracy within 2 meters. The correction signal is reachable nationwide on the FM transmitter network. The system produced a distribution map for 40 K and fallout maps for 134,137 Cs using a Micro Station Program with TerraModeler application. The maximum measured 137 Cs ground contamination exceeded 130-140 kBqm -2 . (au)

  14. Requalification of Abandoned Tunnels

    Directory of Open Access Journals (Sweden)

    Gianluca Derosa

    2014-12-01

    Full Text Available In a vision of regeneration of the abandoned highway stretch close to Vado (Bologna, the galleries, theme of the project, are planned to be part of a footpath network, since the position of the galleries make them reachable both from the small town of Vado and from the new highway. The project’s aim is to offer a space to the community, hence the considered functions are thought as useful both for inhabitants and for tourists. Three galleries, three different characteristics, three different destinations and uses: The first gallery, with only one entrance, is planned to be the identity of the system. The second gallery is a more flexible space, where many functions take place. The third galleryis thought as a fast link to the naturalistic path for who’s arriving from the highway. This flexible wooden structure also creates an entrance and open space out of the galleries giving continuity to the project.

  15. An event-based model for contracts

    Directory of Open Access Journals (Sweden)

    Tiziana Cimoli

    2013-02-01

    Full Text Available We introduce a basic model for contracts. Our model extends event structures with a new relation, which faithfully captures the circular dependencies among contract clauses. We establish whether an agreement exists which respects all the contracts at hand (i.e. all the dependencies can be resolved, and we detect the obligations of each participant. The main technical contribution is a correspondence between our model and a fragment of the contract logic PCL. More precisely, we show that the reachable events are exactly those which correspond to provable atoms in the logic. Despite of this strong correspondence, our model improves previous work on PCL by exhibiting a finer-grained notion of culpability, which takes into account the legitimate orderings of events.

  16. Kinematic Analysis and Optimization of a New Compliant Parallel Micromanipulator

    Directory of Open Access Journals (Sweden)

    Qingsong Xu

    2008-11-01

    Full Text Available In this paper, a new three translational degrees of freedom (DOF compliant parallel micromanipulator (CPM is proposed, which has an excellent accuracy of parallel mechanisms with flexure hinges. The system is established by a proper selection of hardware and analyzed via the derived pseudo-rigid-body model. In view of the physical constraints imposed by both the piezoelectric actuators and flexure hinges, the CPM's reachable workspace is determined analytically, where a maximum cylinder defined as an usable workspace can be inscribed. Moreover, the optimal design of the CPM with the consideration of the usable workspace size and global dexterity index simultaneously is carried out by utilizing the approaches of direct search method, genetic algorithm (GA, and particle swarm optimization (PSO, respectively. The simulation results show that the PSO is the best method for the optimization, and the results are valuable in the design of a new micromanipulator.

  17. Meeting the future of coherent neutrino scattering. A feasibility study for upcoming reactor experiments

    Energy Technology Data Exchange (ETDEWEB)

    Salathe, Marco; Rink, Thomas [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    2016-07-01

    Due to ongoing progress in detector development and background suppression techniques first evidence of neutrino coherent scattering seems reachable in future experiments. In recent years efforts have been enhanced to detect this effect with germanium detectors. This work aims at summarizing and improving past studies on the potential of an experiment at a reactor site to a new level of accuracy by using the most recent neutrino spectra, knowledge gained in recent detector developments and in contrast to prior studies an energy-dependent quenching factor. The influence of the main parameters (background suppression, detector resolution and threshold, reactor spectra, different isotopes) of a germanium detector experiment is presented and the sensitivities regarding the main reaction channels are calculated. The results were obtained through two independent methods; an algebraic computation and a numerical simulation. Both methods reveal the most important experimental parameters and clarify the state of the art challenges that research has to meet in such an experiment.

  18. The Rise of Web Supremacy in Newspaper Coverage of Science

    DEFF Research Database (Denmark)

    Vestergård, Gunver Lystbæk

    discloses how original writing is increasingly being replaced by copy-paste-journalism as novel online resources distribute intelligible science press material. This trend is visible in all journalistic fields but more explicit in the source-driven science journalism. The online abundant availability...... of science news material has also shifted the balance in distribution. Coverage in broadsheet print newspapers is decreasing whereas online and tabloid newspapers are steadily embracing science news. This transfer causes new target groups who have not been previously reachable to be included in science......Alert!) have become an increasing origin of science news on print and online, especially in tabloid newspapers. It is concluded that the availability of lucid science material online has made up for the cutback in science coverage on print and exposed science to social groups predominantly reading Internet...

  19. Airborne fallout mapping of {sup 137}Cs Finnish defence forces team

    Energy Technology Data Exchange (ETDEWEB)

    Kettunen, M; Heininen, T [Finnish Defence Forces Research Centre, Lakiala (Finland); Pulakka, M [Finnish Air Force Depot, Tampere (Finland)

    1998-12-31

    The main task of the team was to create a fallout map of {sup 137}Cs in a specified area in Padasjoki Auttoinen village. The team used an MI-8 helicopter of the Finnish Air Force. The team had an HPGe system (relative efficiency 70%) to measure nuclide specific ground contamination level. For navigation the team took advantage of the DGPS service provided by Finnish Broadcasting company utilizing the RDS-channel to get position accuracy within 2 meters. The correction signal is reachable nationwide on the FM transmitter network. The system produced a distribution map for {sup 40}K and fallout maps for {sup 134,137}Cs using a Micro Station Program with TerraModeler application. The maximum measured {sup 137}Cs ground contamination exceeded 130-140 kBqm{sup -2}. (au).

  20. On the Symbolic Verification of Timed Systems

    DEFF Research Database (Denmark)

    Moeller, Jesper; Lichtenberg, Jacob; Andersen, Henrik Reif

    1999-01-01

    This paper describes how to analyze a timed system symbolically. That is, given a symbolic representation of a set of (timed) states (as an expression), we describe how to determine an expression that represents the set of states that can be reached either by firing a discrete transition...... or by advancing time. These operations are used to determine the set of reachable states symbolically. We also show how to symbolically determine the set of states that can reach a given set of states (i.e., a backwards step), thus making it possible to verify TCTL-formulae symbolically. The analysis is fully...... symbolic in the sense that both the discrete and the continuous part of the state space are represented symbolically. Furthermore, both the synchronous and asynchronous concurrent composition of timed systems can be performed symbolically. The symbolic representations are given as formulae expressed...