Mostrando recursos 61 - 80 de 23.492

  1. Prioritizing inbound transportation

    Rassey, Richard Koury; Zheng, Yong
    Retailers must coordinate inbound shipments from a large number of vendors. In order to manage capacity, retailers need to have a system to prioritize inbound loads with capacitated carriers. This practice creates a constraint when the number of loads exceeds the capacity of committed carriers due to seasonality and consumer shopping behaviors. A prioritization mechanism needed to be developed to support decision making for the selection of loads when capacity is constrained. This research applied the Analytic Hierarchy Process to define prioritization logic for each inbound load and solved a Knapsack model to optimize the assignment. This decision-making model allows...

  2. Learning algorithms for logical neural networks

    Penny, WD; Stonham, TJ
    Two training methods for multilayer logical neural networks are presented and discussed. They are the probabilistic logic node (PLN) reward-penalty algorithm of I. Aleksander (1989) and the PLN back-propagation algorithm of R. Al-Alawi and T. J. Stonham (1989). They are considered within the paradigm of reward-penalty training algorithms for analog networks and are found to be capable of solving various hard learning problems in speeds which are orders of magnitude higher than error back-propagation techniques for conventional nodes.

  3. Do laboratório da escrita à escrita de laboratório: reflexões sobre genética textual, ciência e literatura

    Boto, Sandra
    Ao longo da sua História, os Estudos Literários têm vivido cíclicos momentos de aproximação ao paradigma das Ciências, fascinados pelo seu discurso de rigor e objetividade e tentando importá-lo para as suas metodologias e técnicas. isto é particularmente visível ao nível da metalinguagem de que determinadas disciplinas e correntes das Letras se munem, através da apropriação de metáforas oriundas do mundo científico. exemplo do que acabamos de enunciar é a Crítica Genética, disciplina que assume como objeto de estudo o "laboratório da escrita"de um autor, metáfora de rigor que se materializará e se oferecerá ao leitor necessariamente através de uma...

  4. Intervention planning for a digital intervention for self-management of hypertension: a theory-, evidence- and person-based approach

    Band, R; Bradbury, K; Morton, K; May, C; Michie, S; Mair, FS; Murray, E; McManus, RJ; Little, P; Yardley, L
    BACKGROUND: This paper describes the intervention planning process for the Home and Online Management and Evaluation of Blood Pressure (HOME BP), a digital intervention to promote hypertension self-management. It illustrates how a Person-Based Approach can be integrated with theory- and evidence-based approaches. The Person-Based Approach to intervention development emphasises the use of qualitative research to ensure that the intervention is acceptable, persuasive, engaging and easy to implement. METHODS: Our intervention planning process comprised two parallel, integrated work streams, which combined theory-, evidence- and person-based elements. The first work stream involved collating evidence from a mixed methods feasibility study, a systematic...

  5. Value co-creation at the front-end of project management: a service-dominant logic perspective

    Fuentes, M; Smyth, HJ
    Research is needed to understand how value co-creation could improve project outcomes and benefits. Many studies have shown projects do not meet mandatory objectives. Further, few projects configure and design value propositions to deliver a service experience and value beyond the minimum requirements. A solution to these problems may lie in a shift on projects: from production to a service focus. ServiceDominant Logic (yet a contested arena) has become a paradigm in the marketing and is providing influence in management studies. It offers a fresh perspective to see projects as a service with a focus on outcomes. It also provides...

  6. What is urban materialism? Deconstructing the 'image of the city' in Marxist geography, space syntax and SIRN

    Weissenborn, F
    The urban question concerns the relationship between urban form and urban social existence. According to Bill Hillier, there are two ways of approaching this question. A ‘society-first’ approach in which space is seen as a reification of a prior social logic. And a ‘space-first’ approach in which it is acknowledged that space involves its own emergent morphogenetic processes. This thesis attempts to overcome this binary. It will do so by elaborating a theory of urban materialism in which the urban artefact and the urban social fact are theorised as two irreducible processes of concurrent organisation and creation. Neither thus ‘represents’...

  7. The Indignados as a socio-environmental movement. Framing the crisis and democracy

    Asara, Viviana; Profumi, Emanuele; Kallis, Giorgos
    This study analyzes the framing processes of the Indignados movement in Barcelona, as an exemplar of the latest wave of protests, and argues that it expresses a new ecological-economic way out of the crisis. It finds that the movement was not just a reaction to the economic crisis and austerity policies, but that it put forward a metapolitical critique of the social imaginary and (neo)liberal representative democracy. The diagnostic frames of the movement denunciate the subjugation of politics and justice to economics, and reject the logic of economism. The prognostic frames of the movement advance a vision of socio-ecological sustainability...

  8. Certifying a crash-safe file system

    Chen, Haogang
    File systems are a cornerstone for storing and retrieving permanent data, yet they are complex enough to have bugs that might cause data loss, especially in the face of system crashes. FSCQ is the first file system that (1) provides a precise specification for the core subset of POSIX file-system APIs; and the APIs include fsync and fdatasync, which allow applications to achieve high I/O performance and crash safety, and that (2) provides a machine-checked proof that its I/O-efficient implementation meets this precise specification. FSCQ's proofs avoid crash-safety bugs that have plagued file systems, such as forgetting to insert a...

  9. Assessment of the potential for modal shift to non-motorised transport in a developing context: case of Lima, Peru

    Ortegon-Sanchez, A; Oviedo Hernandez, D
    Under the logic of Avoid, Shift, Improve, fostered by donors and NGOs worldwide, cities in the global south are investing emphatically in non-motorised facilities and policies for low-carbon mobility aiming to reduce the adverse environmental impacts of urban mobility. Such is the case of Lima, Peru, our case study. Through the analysis of the potential for integration of non-motorised facilities with current and planned public transport networks, we seek to provide evidence on the planning considerations of non-motorised facilities in Lima with an emphasis on multi-modal travel and integration of non-motorised infrastructure. We develop spatial coverage, capacity and accessibility assessment...

  10. Fault Tolerant Integer Data Computations: Algorithms and Applications

    Anarado, IJ-F
    As computing units move to higher transistor integration densities and computing clusters become highly heterogeneous, studies begin to predict that, rather than being exceptions, data corruptions in memory and processor failures are likely to become more prevalent. It has therefore become imperative to improve the reliability of systems in the face of increasing soft error probabilities in memory and computing logic units of silicon CMOS integrated chips. This thesis introduces a new class of algorithms for fault tolerance in compute-intensive linear and sesquilinear (“one-and-half-linear”) data computations on integer data inputs within high-performance computing systems. The key difference between the proposed...

  11. Enhancing tolerance to unexpected jumps in GR(1) games

    Dathathri, Sumanth; Livingston, Scott C.; Murray, Richard M.
    When used as part of a hybrid controller, finite-memory strategies synthesized from linear-time temporal logic (LTL) specifications rely on an accurate dynamics model in order to ensure correctness of trajectories. In the presence of uncertainty about the underlying model, there may exist unexpected trajectories that manifest as unexpected transitions under control of the strategy. While some disturbances can be captured by augmenting the dynamics model, such approaches may be conservative in that bisimulations may fail to exist for which strategies can be synthesized. In this paper, we consider games of the GR(1) fragment of LTL, and we characterize the tolerance of hybrid...

  12. Semantics for structured systems modelling and simulation

    Collinson, M; Monahan, B; Pym, D
    © Copyright 2010 ICST.Simulation modelling is an important tool for exploring and reasoning about complex systems. Many supporting languages are available. Commonly occurring features of these languages are constructs capturing concepts such as process, resource, and location. We describe a mathematical framework that supports a modelling idiom based on these core concepts, and which adopts stochastic methods for representing the environments within which systems exist. We explain how this framework can be used to give a semantics to a simulation modelling language, Core Gnosis, that includes basic constructs for process, resource, and location. We include a brief discussion of a...

  13. Development of plasmonic nanomaterial‐based biosensors and bioresponsive materials for diagnostics and molecular‐scale technologies

    Molto Pallares, R
    Anisotropic metal nanoparticles have been successful used in a wide range of biomedical applications, such as diagnostics and therapy, because of their unique optical and electronic properties. Even though there is a wide range of morphologies synthetically available, the understanding of the mechanism behind the anisotropic growth of the nanoparticles is still incomplete. Regarding their application in diagnostics, metallic nanoparticle-based biosensors are facing new challenges, such as the discovery of novel circulating cancer biomarkers (e.g. cell-free DNA), which require sensitivities that cannot be achieved by traditional approaches. The research of this thesis covers current challenges in three specific areas found...

  14. A synergistic DNA logic predicts genome-wide chromatin accessibility

    Sherwood, Richard I.; Emons, Bart J.M.; Hashimoto, Tatsunori Benjamin; Kang, Daniel D; Rajagopal, Nisha; Barkal, Amira; Zeng, Haoyang; Srinivasan, Sharanya; Jaakkola, Tommi S; Gifford, David K
    Enhancers and promoters commonly occur in accessible chromatin characterized by depleted nucleosome contact; however, it is unclear how chromatin accessibility is governed. We show that log-additive cis-acting DNA sequence features can predict chromatin accessibility at high spatial resolution. We develop a new type of high-dimensional machine learning model, the Synergistic Chromatin Model (SCM), which when trained with DNase-seq data for a cell type is capable of predicting expected read counts of genome-wide chromatin accessibility at every base from DNA sequence alone, with the highest accuracy at hypersensitive sites shared across cell types. We confirm that a SCM accurately predicts chromatin...

  15. Relaxed decidability and the robust semantics of Metric Temporal Logic

    Abbas, Houssam; O'Kelly, Matthew; Mangharam, Rahul
    Relaxed notions of decidability widen the scope of automatic verification of hybrid systems. In quasi-decidability and $\delta$-decidability, the fundamental compromise is that if we are willing to accept a slight error in the algorithm's answer, or a slight restriction on the class of problems we verify, then it is possible to obtain practically useful answers. This paper explores the connections between relaxed decidability and the robust semantics of Metric Temporal Logic formulas. It establishes a formal equivalence between the robustness degree of MTL specifications, and the imprecision parameter $\delta$ used in $\delta$-decidability when it is used to verify MTL properties....

  16. A Bayesian approach to inferring chemical signal timing and amplitude in a temporal logic gate using the cell population distributional response

    Baetica, Ania A.; Catanach, Thomas A.; Hsiao, Victoria; Murray, Richard M.; Beck, James L.
    Stochastic gene expression poses an important challenge for engineering robust behaviors in a heterogeneous cell population. Cells address this challenge by operating on distributions of cellular responses generated by noisy processes. Similarly, a previously published temporal logic gate considers the distribution of responses across a cell population under chemical inducer pulsing events. The design uses a system of two integrases to engineer an E. coli strain with four DNA states that records the temporal order of two chemical signal events. The heterogeneous cell population response was used to infer the timing and duration of the two chemical signals for a...

  17. SMEDL: Combining Synchronous and

    Zhang, Teng; Gebhard, Peter; Sokolsky, Oleg
    Two major approaches have emerged in runtime verification, based on synchronous and asynchronous monitoring. Each approach has its advantages and disadvantages and is applicable in different situations. In this paper, we explore a hybrid approach, where low-level properties are checked synchronously, while higher-level ones are checked asynchronously. We present a tool for constructing and deploying monitors based on an architecture specification. Monitor logic and patterns of communication between monitors are specified in a language SMEDL. The language and the tool are illustrated using a case study of a robotic simulator.

  18. SMEDL: Combining Synchronous and Asynchronous Monitoring

    Zhang, Teng; Gebhard, Peter; Sokolsky, Oleg
    Two major approaches have emerged in runtime verification, based on synchronous and asynchronous monitoring. Each approach has its advantages and disadvantages and is applicable in different situations. In this paper, we explore a hybrid approach, where low-level properties are checked synchronously, while higher-level ones are checked asynchronously. We present a tool for constructing and deploying monitors based on an architecture specification. Monitor logic and patterns of communication between monitors are specified in a language SMEDL. The language and the tool are illustrated using a case study of a robotic simulator.

  19. Development and experimental validation of a mechanistic model of a recombinase-based temporal logic gate

    Bowyer, Jack; Hsiao, Victoria; Bates, Declan G.
    DNA recombination provides an ideal mechanism for constructing stable and reversible synthetic biological switches. Recent advances in recombinase-based circuitry that account for more than one protein input have been shown to enable the construction of circuits with temporal Boolean logic operations in vivo. Associated mathematical models have to date only captured the qualitative dynamical features of such systems and are thus of limited utility as tools to aid in the design of such circuitry. Here we develop a detailed mechanistic model of a two-input temporal logic gate circuit based on unidirectional DNA recombination with bacteriophage integrases to detect and encode...

  20. Reactive controllers for differentially flat systems with temporal logic constraints

    Liu, Jun; Topcu, Ufuk; Ozay, Necmiye; Murray, Richard M.
    We propose a procedure for the synthesis of control protocols for systems governed by nonlinear differential equations and constrained by temporal logic specifications. This procedure relies on a particular finite-state abstraction of the underlying continuous dynamics and a discrete representation of the external environmental signals. A two-player game formulation provides computationally efficient means to construct a discrete strategy based on the finite-state model. We focus on systems with differentially flat outputs, which, in a straightforward manner, allows the construction of continuous control signals from the discrete transitions dictated by the discrete strategy. The resulting continuous-time output trajectories are provably guaranteed...

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