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Sample records for scale decentralized model

  1. Event-triggered decentralized robust model predictive control for constrained large-scale interconnected systems

    Directory of Open Access Journals (Sweden)

    Ling Lu

    2016-12-01

    Full Text Available This paper considers the problem of event-triggered decentralized model predictive control (MPC for constrained large-scale linear systems subject to additive bounded disturbances. The constraint tightening method is utilized to formulate the MPC optimization problem. The local predictive control law for each subsystem is determined aperiodically by relevant triggering rule which allows a considerable reduction of the computational load. And then, the robust feasibility and closed-loop stability are proved and it is shown that every subsystem state will be driven into a robust invariant set. Finally, the effectiveness of the proposed approach is illustrated via numerical simulations.

  2. Decentralized Model Predictive Control via Dual Decomposition

    Science.gov (United States)

    Wakasa, Yuji; Arakawa, Mizue; Tanaka, Kanya; Akashi, Takuya

    This paper proposes a decentralized model predictive control method based on a dual decomposition technique. A model predictive control problem for a system with multiple subsystems is formulated as a convex optimization problem. In particular, we deal with the case where the control outputs of the subsystems have coupling constraints represented by linear equalities. A dual decomposition technique is applied to this problem in order to derive the dual problem with decoupled equality constraints. A projected subgradient method is used to solve the dual problem, which leads to a decentralized algorithm. In the algorithm, a small-scale problem is solved at each subsystem, and information exchange is performed in each group consisting of some subsystems. Also, it is shown that the computational complexity in the decentralized algorithm is reduced if the dynamics of the subsystems are all the same.

  3. Modeling Decentralized Organizational Change in Honeybee Societies

    OpenAIRE

    Hoogendoorn, Mark; Schut, Martijn; Treur, Jan

    2006-01-01

    Multi-agent organizations in dynamic environments, need to have the ability to adapt to environmental changes to ensure a continuation of proper functioning. Such adaptations can be made through a centralized decision process or come from the individuals within the organization. In the domain of social insects, such as honeybees and wasps, organizations are known to adapt in a decentralized fashion to environmental changes. An organizational model for decentralized organizational change is pr...

  4. Wind Farm Decentralized Dynamic Modeling With Parameters

    DEFF Research Database (Denmark)

    Soltani, Mohsen; Shakeri, Sayyed Mojtaba; Grunnet, Jacob Deleuran

    2010-01-01

    Development of dynamic wind flow models for wind farms is part of the research in European research FP7 project AEOLUS. The objective of this report is to provide decentralized dynamic wind flow models with parameters. The report presents a structure for decentralized flow models with inputs from...... local models. The results of this report are especially useful, but not limited, to design a decentralized wind farm controller, since in centralized controller design one can also use the model and update it in a central computing node....... a set of spatially distributed measurements from wind turbines. The information has to be communicated only within neighboring wind turbines. This will both reduce the calculation load by distributing them on all turbines and make the infrastructure more robust against faults and uncertainties. Moreover...

  5. Emergent Semantics Interoperability in Large-Scale Decentralized Information Systems

    CERN Document Server

    Cudré-Mauroux, Philippe

    2008-01-01

    Peer-to-peer systems are evolving with new information-system architectures, leading to the idea that the principles of decentralization and self-organization will offer new approaches in informatics, especially for systems that scale with the number of users or for which central authorities do not prevail. This book describes a new way of building global agreements (semantic interoperability) based only on decentralized, self-organizing interactions.

  6. Decentralization, stabilization, and estimation of large-scale linear systems

    Science.gov (United States)

    Siljak, D. D.; Vukcevic, M. B.

    1976-01-01

    In this short paper we consider three closely related aspects of large-scale systems: decentralization, stabilization, and estimation. A method is proposed to decompose a large linear system into a number of interconnected subsystems with decentralized (scalar) inputs or outputs. The procedure is preliminary to the hierarchic stabilization and estimation of linear systems and is performed on the subsystem level. A multilevel control scheme based upon the decomposition-aggregation method is developed for stabilization of input-decentralized linear systems Local linear feedback controllers are used to stabilize each decoupled subsystem, while global linear feedback controllers are utilized to minimize the coupling effect among the subsystems. Systems stabilized by the method have a tolerance to a wide class of nonlinearities in subsystem coupling and high reliability with respect to structural perturbations. The proposed output-decentralization and stabilization schemes can be used directly to construct asymptotic state estimators for large linear systems on the subsystem level. The problem of dimensionality is resolved by constructing a number of low-order estimators, thus avoiding a design of a single estimator for the overall system.

  7. Fuzzy Adaptive Decentralized Optimal Control for Strict Feedback Nonlinear Large-Scale Systems.

    Science.gov (United States)

    Sun, Kangkang; Sui, Shuai; Tong, Shaocheng

    2017-05-16

    This paper considers the optimal decentralized fuzzy adaptive control design problem for a class of interconnected large-scale nonlinear systems in strict feedback form and with unknown nonlinear functions. The fuzzy logic systems are introduced to learn the unknown dynamics and cost functions, respectively, and a state estimator is developed. By applying the state estimator and the backstepping recursive design algorithm, a decentralized feedforward controller is established. By using the backstepping decentralized feedforward control scheme, the considered interconnected large-scale nonlinear system in strict feedback form is changed into an equivalent affine large-scale nonlinear system. Subsequently, an optimal decentralized fuzzy adaptive control scheme is constructed. The whole optimal decentralized fuzzy adaptive controller is composed of a decentralized feedforward control and an optimal decentralized control. It is proved that the developed optimal decentralized controller can ensure that all the variables of the control system are uniformly ultimately bounded, and the cost functions are the smallest. Two simulation examples are provided to illustrate the validity of the developed optimal decentralized fuzzy adaptive control scheme.

  8. Integrating Collaborative and Decentralized Models to Support Ubiquitous Learning

    Science.gov (United States)

    Barbosa, Jorge Luis Victória; Barbosa, Débora Nice Ferrari; Rigo, Sandro José; de Oliveira, Jezer Machado; Rabello, Solon Andrade, Jr.

    2014-01-01

    The application of ubiquitous technologies in the improvement of education strategies is called Ubiquitous Learning. This article proposes the integration between two models dedicated to support ubiquitous learning environments, called Global and CoolEdu. CoolEdu is a generic collaboration model for decentralized environments. Global is an…

  9. A review on full-scale decentralized wastewater treatment systems: techno-economical approach.

    Science.gov (United States)

    Singh, Nitin Kumar; Kazmi, A A; Starkl, M

    2015-01-01

    As a solution to the shortcomings of centralized systems, over the last two decades large numbers of decentralized wastewater treatment plants of different technology types have been installed all over the world. This paper aims at deriving lessons learned from existing decentralized wastewater treatment plants that are relevant for smaller towns (and peri-urban areas) as well as rural communities in developing countries, such as India. Only full-scale implemented decentralized wastewater treatment systems are reviewed in terms of performance, land area requirement, capital cost, and operation and maintenance costs. The results are presented in tables comparing different technology types with respect to those parameters.

  10. Model-Based Design of Tree WSNs for Decentralized Detection

    Directory of Open Access Journals (Sweden)

    Ashraf Tantawy

    2015-08-01

    Full Text Available The classical decentralized detection problem of finding the optimal decision rules at the sensor and fusion center, as well as variants that introduce physical channel impairments have been studied extensively in the literature. The deployment of WSNs in decentralized detection applications brings new challenges to the field. Protocols for different communication layers have to be co-designed to optimize the detection performance. In this paper, we consider the communication network design problem for a tree WSN. We pursue a system-level approach where a complete model for the system is developed that captures the interactions between different layers, as well as different sensor quality measures. For network optimization, we propose a hierarchical optimization algorithm that lends itself to the tree structure, requiring only local network information. The proposed design approach shows superior performance over several contentionless and contention-based network design approaches.

  11. The Impact of Decentralization on Large Scale Irrigation: Evidence from the Philippines

    Directory of Open Access Journals (Sweden)

    Eduardo K. Araral, Jr.

    2011-06-01

    Full Text Available Decentralization has often been prescribed as an institutional panacea for a wide range of problems facing developing countries. This study investigates the impacts of decentralization on the ability of individuals to solve collective action problems in a large-scale common pool resource. Using econometric analyses of a data set from the largest (83,000 hectares [ha] irrigation system in the Philippines, the study finds that decentralized subsystems are more likely to solve collective action problems such as free-riding, conflict resolution and rule enforcement. These findings are consistent with the theoretical and empirical literature but they highlight the importance of credible enforcement. These preliminary findings offer insights for the design of institutions for collective action in situations of large-scale collective action.

  12. Decentralized model reference adaptive control of large flexible structures

    Science.gov (United States)

    Lee, Fu-Ming; Fong, I-Kong; Lin, Yu-Hwan

    1988-01-01

    A decentralized model reference adaptive control (DMRAC) method is developed for large flexible structures (LFS). The development follows that of a centralized model reference adaptive control for LFS that have been shown to be feasible. The proposed method is illustrated using a simply supported beam with collocated actuators and sensors. Results show that the DMRAC can achieve either output regulation or output tracking with adequate convergence, provided the reference model inputs and their time derivatives are integrable, bounded, and approach zero as t approaches infinity.

  13. Outdoor flocking of quadcopter drones with decentralized model predictive control.

    Science.gov (United States)

    Yuan, Quan; Zhan, Jingyuan; Li, Xiang

    2017-11-01

    In this paper, we present a multi-drone system featured with a decentralized model predictive control (DMPC) flocking algorithm. The drones gather localized information from neighbors and update their velocities using the DMPC flocking algorithm. In the multi-drone system, data packages are transmitted through XBee ® wireless modules in broadcast mode, yielding such an anonymous and decentralized system where all the calculations and controls are completed on an onboard minicomputer of each drone. Each drone is a double-layered agent system with the coordination layer running multi-drone flocking algorithms and the flight control layer navigating the drone, and the final formation of the flock relies on both the communication range and the desired inter-drone distance. We give both numerical simulations and field tests with a flock of five drones, showing that the DMPC flocking algorithm performs well on the presented multi-drone system in both the convergence rate and the ability of tracking a desired path. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  14. Decentralized Fuzzy P-hub Centre Problem: Extended Model and Genetic Algorithms

    Directory of Open Access Journals (Sweden)

    Sara Mousavinia

    2017-02-01

    Full Text Available This paper studies the uncapacitated P-hub center problem in a network under decentralized management assuming time as a fuzzy variable. In this network, transport companies act independently, each company makes its route choices according to its own criteria. In this model, time is presented by triangular fuzzy number and used to calculate the fraction of users that probably choose hub routes instead of direct routes. To solve the problem, two genetic algorithms are proposed. The computational results compared with LINGO indicate that the proposed algorithm solves large-scale instances within promising computational time and outperforms LINGO in terms of solution quality.

  15. Fast Decentralized Averaging via Multi-scale Gossip

    Science.gov (United States)

    Tsianos, Konstantinos I.; Rabbat, Michael G.

    We are interested in the problem of computing the average consensus in a distributed fashion on random geometric graphs. We describe a new algorithm called Multi-scale Gossip which employs a hierarchical decomposition of the graph to partition the computation into tractable sub-problems. Using only pairwise messages of fixed size that travel at most O(n^{1/3}) hops, our algorithm is robust and has communication cost of O(n loglogn logɛ - 1) transmissions, which is order-optimal up to the logarithmic factor in n. Simulated experiments verify the good expected performance on graphs of many thousands of nodes.

  16. Satisfaction and sustainability: a realist review of decentralized models of perinatal surgery for rural women

    National Research Council Canada - National Science Library

    Kornelsen, Jude; McCartney, Kevin; Williams, Kim

    2016-01-01

    This article was developed as part of a larger realist review investigating the viability and efficacy of decentralized models of perinatal surgical services for rural women in the context of recent...

  17. On Event-Triggered Adaptive Architectures for Decentralized and Distributed Control of Large-Scale Modular Systems

    Directory of Open Access Journals (Sweden)

    Ali Albattat

    2016-08-01

    Full Text Available The last decade has witnessed an increased interest in physical systems controlled over wireless networks (networked control systems. These systems allow the computation of control signals via processors that are not attached to the physical systems, and the feedback loops are closed over wireless networks. The contribution of this paper is to design and analyze event-triggered decentralized and distributed adaptive control architectures for uncertain networked large-scale modular systems; that is, systems consist of physically-interconnected modules controlled over wireless networks. Specifically, the proposed adaptive architectures guarantee overall system stability while reducing wireless network utilization and achieving a given system performance in the presence of system uncertainties that can result from modeling and degraded modes of operation of the modules and their interconnections between each other. In addition to the theoretical findings including rigorous system stability and the boundedness analysis of the closed-loop dynamical system, as well as the characterization of the effect of user-defined event-triggering thresholds and the design parameters of the proposed adaptive architectures on the overall system performance, an illustrative numerical example is further provided to demonstrate the efficacy of the proposed decentralized and distributed control approaches.

  18. Preference of methadone maintenance patients for the integrative and decentralized service delivery models in Vietnam.

    Science.gov (United States)

    Tran, Bach Xuan; Nguyen, Long Hoang; Phan, Huong Thu Thi; Nguyen, Linh Khanh; Latkin, Carl A

    2015-09-17

    Integrating and decentralizing services are essential to increase the accessibility and provide comprehensive care for methadone patients. Moreover, they assure the sustainability of a HIV/AIDS prevention program by reducing the implementation cost. This study aimed to measure the preference of patients enrolling in a MMT program for integrated and decentralized MMT clinics and then further examine related factors. A cross-sectional study was conducted among 510 patients receiving methadone at 3 clinics in Hanoi. Structured questionnaires were used to collect data about the preference for integrated and decentralized MMT services. Covariates including socio-economic status; health-related quality of life (using EQ-5D-5 L instrument) and HIV status; history of drug use along with MMT treatment; and exposure to the discrimination within family and community were also investigated. Multivariate logistic regression with polynomial fractions was used to identify the determinants of preference for integrative and decentralized models. Of 510 patients enrolled, 66.7 and 60.8 % preferred integrated and decentralized models, respectively. The main reason for preferring the integrative model was the convenience of use of various services (53.2 %), while more privacy (43.5 %) was the primary reason to select stand-alone model. People preferred the decentralized model primarily because of travel cost reduction (95.0 %), while the main reason for not selecting the model was increased privacy (7.7 %). After adjusting for covariates, factors influencing the preference for integrative model were poor socioeconomic status, anxiety/depression, history of drug rehabilitation, and ever disclosed health status; while exposure to community discrimination inversely associated with this preference. In addition, people who were self-employed, had a longer duration of MMT, and use current MMT with comprehensive HIV services were less likely to select decentralized model. In conclusion

  19. k-Neighborhood decentralization: a comprehensive solution to index the UMLS for large scale knowledge discovery.

    Science.gov (United States)

    Xiang, Yang; Lu, Kewei; James, Stephen L; Borlawsky, Tara B; Huang, Kun; Payne, Philip R O

    2012-04-01

    The Unified Medical Language System (UMLS) is the largest thesaurus in the biomedical informatics domain. Previous works have shown that knowledge constructs comprised of transitively-associated UMLS concepts are effective for discovering potentially novel biomedical hypotheses. However, the extremely large size of the UMLS becomes a major challenge for these applications. To address this problem, we designed a k-neighborhood Decentralization Labeling Scheme (kDLS) for the UMLS, and the corresponding method to effectively evaluate the kDLS indexing results. kDLS provides a comprehensive solution for indexing the UMLS for very efficient large scale knowledge discovery. We demonstrated that it is highly effective to use kDLS paths to prioritize disease-gene relations across the whole genome, with extremely high fold-enrichment values. To our knowledge, this is the first indexing scheme capable of supporting efficient large scale knowledge discovery on the UMLS as a whole. Our expectation is that kDLS will become a vital engine for retrieving information and generating hypotheses from the UMLS for future medical informatics applications. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Autonomous Decentralized Enterprise Model - A New Wave in Web 2.0 Type E-commerce

    OpenAIRE

    Liu, Feng; Hirano, Makoto

    2010-01-01

    The rapid popularization of Web 2.0 coupled with the growth of e-commerce gives rise to enormous opportunities as well as changes for the creation of new intra-organization models. In the evolving environment of the E-business, this study has attempted to contribute to the framework description of a new type of inter-organizational model in e-commerce enterprises: Autonomous Decentralized Enterprise Model. From this case study,

  1. Application of Transfer Matrix Approach to Modeling and Decentralized Control of Lattice-Based Structures

    Science.gov (United States)

    Cramer, Nick; Swei, Sean Shan-Min; Cheung, Kenny; Teodorescu, Mircea

    2015-01-01

    This paper presents a modeling and control of aerostructure developed by lattice-based cellular materials/components. The proposed aerostructure concept leverages a building block strategy for lattice-based components which provide great adaptability to varying ight scenarios, the needs of which are essential for in- ight wing shaping control. A decentralized structural control design is proposed that utilizes discrete-time lumped mass transfer matrix method (DT-LM-TMM). The objective is to develop an e ective reduced order model through DT-LM-TMM that can be used to design a decentralized controller for the structural control of a wing. The proposed approach developed in this paper shows that, as far as the performance of overall structural system is concerned, the reduced order model can be as e ective as the full order model in designing an optimal stabilizing controller.

  2. Robust Decentralized Adaptive Neural Control for a Class of Nonaffine Nonlinear Large-Scale Systems with Unknown Dead Zones

    Directory of Open Access Journals (Sweden)

    Huanqing Wang

    2014-01-01

    Full Text Available The problem of robust decentralized adaptive neural stabilization control is investigated for a class of nonaffine nonlinear interconnected large-scale systems with unknown dead zones. In the controller design procedure, radical basis function (RBF neural networks are applied to approximate packaged unknown nonlinearities and then an adaptive neural decentralized controller is systematically derived without requiring any information on the boundedness of dead zone parameters (slopes and break points. It is proven that the developed control scheme can ensure that all the signals in the closed-loop system are semiglobally uniformly ultimately bounded in the sense of mean square. Simulation study is provided to further demonstrate the effectiveness of the developed control scheme.

  3. Potential for small-scale, decentralized energy sources and the Federal role in their development

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, D.

    1978-02-01

    The idea that the solution to our energy problems is to be found in an expanded role for small-scale, decentralized energy sources, particularly solar energy, has gained considerable attention and increasing respectability in recent years. One of the most articulate spokesmen for this point of view is Denis Hayes. Mr. Hayes explained his perspective on the energy problem to an invited audience of about 85 professionals and students in the energy policy field. This paper is an edited version of Mr. Hayes' presentation. In his presentation, Mr. Hayes discussed the prospects for fossil and nuclear energy, stressing the potential limitations on coal use due to the problem of CO/sub 2/ and the greenhouse effect, and highlighting the hazards of the plutonium economy. He described the role conservation can play in dealing with the energy problem, but declared that conservation alone is not enough. There is still a need, he indicated, to replace declining energy sources with some alternative. In his view, the most promising alternative is solar energy, and Mr. Hayes discussed the various ways in which it can be utilized. The presentation concluded with a number of suggestions regarding Federal actions and policy initiatives that Mr. Hayes feels are needed to encourage solar energy development. These ideas served as the focus for the question and answer session which followed the presentation. Questions dealt with many issues, including priorities in solar R and D, the role of the Federal government vis a vis the private sector, the timing of solar energy implementation, and the strategy and tactics of the solar movement.

  4. Decentralization in Air Transportation

    NARCIS (Netherlands)

    Udluft, H.

    2017-01-01

    In this work,we demonstrate that decentralized control can result in stable, efficient, and robust operations in the Air Transportation System. We implement decentralized control for aircraft taxiing operations and use Agent-Based Modeling and Simulation to analyze the resulting system behavior

  5. An Integrated Decentralized Energy Planning Model considering Demand-Side Management and Environmental Measures

    Directory of Open Access Journals (Sweden)

    Seyed Mahmood Kazemi

    2013-01-01

    Full Text Available Decentralized energy planning (DEP is looked upon as an indisputable opportunity for energy planning of villages, isolated islands, and far spots. Nonetheless, at this decentralized planning level, the value of demand-side resources is not fairly examined, despite enjoying great advantages. Therefore, the core task of this study is to integrate demand-side resources, as a competing solution against supply-side alternatives, with decentralized energy planning decisions and demonstrate the rewarding role it plays. Moreover, sustainability indicators (SIs are incorporated into DEP attempts in order to attain sustainable development. It is emphasized that unless these indicators are considered at lower energy planning levels, they will be ignored at higher planning levels as well. Hence, to the best knowledge of the authors, this study for the first time takes into account greenhouse gas (GHG emissions produced by utilization of renewable energies in DEP optimization models. To address the issues mentioned previously, multiobjective linear programming model along with a min-max goal programming approach is employed. Finally, using data taken from the literature, the model is solved, and the obtained results are discussed. The results show that DSM policies have remarkably contributed to significant improvements especially in terms of environmental indicators.

  6. Improving antiretroviral therapy scale-up and effectiveness through service integration and decentralization.

    Science.gov (United States)

    Suthar, Amitabh B; Rutherford, George W; Horvath, Tara; Doherty, Meg C; Negussie, Eyerusalem K

    2014-03-01

    Current service delivery systems do not reach all people in need of antiretroviral therapy (ART). In order to inform the operational and service delivery section of the WHO 2013 consolidated antiretroviral guidelines, our objective was to summarize systematic reviews on integrating ART delivery into maternal, newborn, and child health (MNCH) care settings in countries with generalized epidemics, tuberculosis (TB) treatment settings in which the burden of HIV and TB is high, and settings providing opiate substitution therapy (OST); and decentralizing ART into primary health facilities and communities. A summary of systematic reviews. The reviewers searched PubMed, Embase, PsycINFO, Web of Science, CENTRAL, and the WHO Index Medicus databases. Randomized controlled trials and observational cohort studies were included if they compared ART coverage, retention in HIV care, and/or mortality in MNCH, TB, or OST facilities providing ART with MNCH, TB, or OST facilities providing ART services separately; or primary health facilities or communities providing ART with hospitals providing ART. The reviewers identified 28 studies on integration and decentralization. Antiretroviral therapy integration into MNCH facilities improved ART coverage (relative risk [RR] 1.37, 95% confidence interval [CI] 1.05-1.79) and led to comparable retention in care. ART integration into TB treatment settings improved ART coverage (RR 1.83, 95% CI 1.48-2.23) and led to a nonsignificant reduction in mortality (RR 0.55, 95% CI 0.29-1.05). The limited data on ART integration into OST services indicated comparable rates of ART coverage, retention, and mortality. Partial decentralization into primary health facilities improved retention (RR 1.05, 95% CI 1.01-1.09) and reduced mortality (RR 0.34, 95% CI 0.13-0.87). Full decentralization improved retention (RR 1.12, 95% CI 1.08-1.17) and led to comparable mortality. Community-based ART led to comparable rates of retention and mortality. Integrating ART

  7. A Decentralized Consensus Algorithm via LMI-Based Model Predictive Control and Primal Decomposition

    Science.gov (United States)

    Wakasa, Yuji; Tanaka, Kanya

    This paper proposes a decentralized model predictive control method for solving an optimal consensus problem, where a system consists of networked multiple subsystems and the states of all the subsystems converge to a common point. The problem is formulated as a convex optimization problem involving linear matrix inequalities, and then is solved by using an incremental subgradient method based on primal decomposition. In the proposed scheme, the state feedback matrix for each subsystem is computed at each time in a decentralized way. It is shown that the states of all the subsystems asymptotically converge by the proposed method if the optimization problem is feasible at the initial time. A numerical example is given to show the effectiveness of the proposed method.

  8. Collective and decentralized management model in public hospitals: perspective of the nursing team.

    Science.gov (United States)

    Bernardes, Andrea; Cecilio, Luiz Carlos de Oliveira; Evora, Yolanda Dora Martinez; Gabriel, Carmen Silvia; Carvalho, Mariana Bernardes de

    2011-01-01

    This research aims to present the implementation of the collective and decentralized management model in functional units of a public hospital in the city of Ribeirão Preto, state of São Paulo, according to the view of the nursing staff and the health technical assistant. This historical and organizational case study used qualitative thematic content analysis proposed by Bardin for data analysis. The institution started the decentralization of its administrative structure in 1999, through collective management, which permitted several internal improvements, with positive repercussion for the care delivered to users. The top-down implementation of the process seems to have jeopardized workers adherence, although collective management has intensified communication and the sharing of power and decision. The study shows that there is still much work to be done to concretize this innovative management proposal, despite the advances regarding the quality of care.

  9. Decentralized energy studies: bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Ohi, J.M.; Unseld, C.T.; Levine, A.; Silversmith, J.A.

    1980-05-01

    This bibliography is a compilation of literature on decentralized energy systems. It is arranged according to topical (e.g., lifestyle and values, institutions, and economics) and geographical scale to facilitate quick reference to specific areas of interest. Also included are articles by and about Amory B. Lovins who has played a pivotal role in making energy decentralization an important topic of national debate. Periodicals, other bibliographies, and directories are also listed.

  10. The potential of solar-driven humidification-dehumidification desalination for small-scale decentralized water production

    Energy Technology Data Exchange (ETDEWEB)

    Narayan, G. Prakash; Sharqawy, Mostafa H.; Summers, Edward K.; Lienhard, John H. [Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge (United States); Zubair, Syed M.; Antar, M.A. [Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals (Saudi Arabia)

    2010-05-15

    World-wide water scarcity, especially in the developing world, indicates a pressing need to develop inexpensive, decentralized small-scale desalination technologies which use renewable resources of energy. This paper provides a comprehensive review of the state-of-the-art in one of the most promising of these technologies, solar-driven humidification-dehumidification (HDH) desalination. Previous studies have investigated many different variations on the HDH cycle. In this paper, performance parameters which enable comparison of the various versions of the HDH cycle have been defined and evaluated. To better compare these cycles, each has been represented in psychometric coordinates. The principal components of the HDH system are also reviewed and compared, including the humidifier, solar heaters, and dehumidifiers. Particular attention is given to solar air heaters, for which design data is limited; and direct air heating is compared to direct water heating in the cycle assessments. Alternative processes based on the HDH concept are also reviewed and compared. Further, novel proposals for improvement of the HDH cycle are outlined. It is concluded that HDH technology has great promise for decentralized small-scale water production applications, although additional research and development is needed for improving system efficiency and reducing capital cost. (author)

  11. Life-Cycle Cost and Environmental Assessment of Decentralized Nitrogen Recovery Using Ion Exchange from Source-Separated Urine through Spatial Modeling.

    Science.gov (United States)

    Kavvada, Olga; Tarpeh, William A; Horvath, Arpad; Nelson, Kara L

    2017-11-07

    Nitrogen standards for discharge of wastewater effluent into aquatic bodies are becoming more stringent, requiring some treatment plants to reduce effluent nitrogen concentrations. This study aimed to assess, from a life-cycle perspective, an innovative decentralized approach to nitrogen recovery: ion exchange of source-separated urine. We modeled an approach in which nitrogen from urine at individual buildings is sorbed onto resins, then transported by truck to regeneration and fertilizer production facilities. To provide insight into impacts from transportation, we enhanced the traditional economic and environmental assessment approach by combining spatial analysis, system-scale evaluation, and detailed last-mile logistics modeling using the city of San Francisco as an illustrative case study. The major contributor to energy intensity and greenhouse gas (GHG) emissions was the production of sulfuric acid to regenerate resins, rather than transportation. Energy and GHG emissions were not significantly sensitive to the number of regeneration facilities. Cost, however, increased with decentralization as rental costs per unit area are higher for smaller areas. The metrics assessed (unit energy, GHG emissions, and cost) were not significantly influenced by facility location in this high-density urban area. We determined that this decentralized approach has lower cost, unit energy, and GHG emissions than centralized nitrogen management via nitrification-denitrification if fertilizer production offsets are taken into account.

  12. Decentralized control of complex systems

    CERN Document Server

    Siljak, Dragoslav D

    2011-01-01

    Complex systems require fast control action in response to local input, and perturbations dictate the use of decentralized information and control structures. This much-cited reference book explores the approaches to synthesizing control laws under decentralized information structure constraints.Starting with a graph-theoretic framework for structural modeling of complex systems, the text presents results related to robust stabilization via decentralized state feedback. Subsequent chapters explore optimization, output feedback, the manipulative power of graphs, overlapping decompositions and t

  13. Autonomous and Decentralized Optimization of Large-Scale Heterogeneous Wireless Networks by Neural Network Dynamics

    Science.gov (United States)

    Hasegawa, Mikio; Tran, Ha Nguyen; Miyamoto, Goh; Murata, Yoshitoshi; Harada, Hiroshi; Kato, Shuzo

    We propose a neurodynamical approach to a large-scale optimization problem in Cognitive Wireless Clouds, in which a huge number of mobile terminals with multiple different air interfaces autonomously utilize the most appropriate infrastructure wireless networks, by sensing available wireless networks, selecting the most appropriate one, and reconfiguring themselves with seamless handover to the target networks. To deal with such a cognitive radio network, game theory has been applied in order to analyze the stability of the dynamical systems consisting of the mobile terminals' distributed behaviors, but it is not a tool for globally optimizing the state of the network. As a natural optimization dynamical system model suitable for large-scale complex systems, we introduce the neural network dynamics which converges to an optimal state since its property is to continually decrease its energy function. In this paper, we apply such neurodynamics to the optimization problem of radio access technology selection. We compose a neural network that solves the problem, and we show that it is possible to improve total average throughput simply by using distributed and autonomous neuron updates on the terminal side.

  14. Decentralized control and communication

    Czech Academy of Sciences Publication Activity Database

    Bakule, Lubomír; Papík, Martin

    2012-01-01

    Roč. 36, č. 1 (2012), s. 1-10 ISSN 1367-5788 R&D Projects: GA MŠk(CZ) LG12014 Institutional research plan: CEZ:AV0Z10750506 Keywords : decentralization * communication * large-scale complex systems Subject RIV: BC - Control Systems Theory Impact factor: 1.289, year: 2012

  15. TRUST MODEL FOR INFORMATION SECURITY OF MULTI-AGENT ROBOTIC SYSTEMS WITH A DECENTRALIZED MANAGEMENT

    Directory of Open Access Journals (Sweden)

    I. A. Zikratov

    2014-03-01

    Full Text Available The paper deals with the issues on protection of multi-agent robotic systems against attacks by robots-saboteurs. The operation analysis of such systems with decentralized control is carried out. Concept of harmful information impact (attack from a robot-saboteur to the multi-agent robotic system is given. The class of attacks is considered using interception of messages, formation and transfer of misinformation to group of robots, and also carrying out other actions with vulnerabilities of multiagent algorithms without obviously identified signs of invasion of robots-saboteurs. The model of information security is developed, in which robots-agents work out trust levels to each other analyzing the events occurring in the system. The idea of trust model consists in the analysis of transferred information by each robot and the executed actions of other members in a group, comparison of chosen decision on iteration step k with objective function of the group. Distinctive feature of the trust model in comparison with the closest analogue - Buddy Security Model in which the exchange between the agents security tokens is done — is involvement of the time factor during which agents have to "prove" by their actions the usefulness in achievement of a common goal to members of the group. Variants of this model realization and ways of an assessment of trust levels for agents in view of the security policy accepted in the group are proposed.

  16. Modeling and Deployment of Model-Based Decentralized Embedded Diagnosis inside Vehicles: Application to Smart Distance Keeping Function

    Directory of Open Access Journals (Sweden)

    Othman Nasri

    2012-01-01

    Full Text Available The deployment of a fault diagnosis strategy in the Smart Distance Keeping (SDK system with a decentralized architecture is presented. The SDK system is an advanced Adaptive Cruise Control (ACC system implemented in a Renault-Volvo Trucks vehicle to increase safety by overcoming some ACC limitations. One of the main differences between this new system and the classical ACC is the choice of the safe distance. This latter is the distance between the vehicle equipped with the ACC or the SDK system and the obstacle-in-front (which may be another vehicle. It is supposed fixed in the case of the ACC, while variable in the case of the SDK. The variation of this distance depends essentially on the relative velocity between the vehicle and the obstacle-in-front. The main goal of this work is to analyze measurements, issued from the SDK elements, in order to detect, to localize, and to identify some faults that may occur. Our main contribution is the proposition of a decentralized approach permitting to carry out an on-line diagnosis without computing the global model and to achieve most of the work locally avoiding huge extra diagnostic information traffic between components. After a detailed description of the SDK system, this paper explains the model-based decentralized solution and its application to the embedded diagnosis of the SDK system inside Renault-Volvo Truck with five control units connected via a CAN-bus using “Hardware in the Loop” (HIL technique. We also discuss the constraints that must be fulfilled.

  17. Rethinking Partnerships on a Decentralized Campus

    Science.gov (United States)

    Dufault, Katie H.

    2017-01-01

    Decentralization is an effective approach for structuring campus learning and success centers. McShane & Von Glinow (2007) describe decentralization as "an organizational model where decision authority and power are dispersed among units rather than held by a single small group of administrators" (p. 237). A decentralized structure…

  18. A Standardized, Evidence-Based Massage Therapy Program for Decentralized Elite Paracyclists: Creating the Model.

    Science.gov (United States)

    Kennedy, Ann B; Trilk, Jennifer L

    2015-09-01

    Evidence suggests that para-athletes are injured more often than able-bodied athletes. The benefits of massage therapy for these disabled athletes are yet to be explored. This paper documents the process followed for creating a massage program for elite paracycling athletes with the goal to assess effects on recovery, rest, performance, and quality of life both on and off the bike. Massage therapists' private practices throughout the United States. A United States Paracycling team consisting of 9 elite athletes: 2 spinal cord injury, 2 lower limb amputation, 1 upper limb amputation, 1 transverse myelitis, 1 stroke, 1 traumatic brain injury, and 1 visually impaired. The process used to develop a massage therapy program for para-cyclists included meetings with athletes, coaching staff, team exercise physiologist, and sports massage therapists; peer-reviewed literature was also consulted to address specific health conditions of para-athletes. Team leadership and athletes identified needs for quicker recovery, better rest, and improved performance in elite paracyclists. This information was used to generate a conceptual model for massage protocols, and led to creation of the intake and exit questionnaires to assess patient health status and recovery. Forms also were created for a general health intake, therapist information, and a therapist's SOAAP notes. The conceptual model and questionnaires developed herein will help to operationalize an exploratory study investigating the feasibility of implementing a standardized massage therapy program for a decentralized elite paracycling team.

  19. TRUST AND REPUTATION MODEL DESIGN FOR OBJECTS OF MULTI-AGENT ROBOTICS SYSTEMS WITH DECENTRALIZED CONTROL

    Directory of Open Access Journals (Sweden)

    I. A. Zikratov

    2014-03-01

    Full Text Available The problem of mechanisms design for protection of multi-agent robotics systems from attacks of robots-saboteurs is considered. Functioning analysis of these systems with decentralized control is carried out. The type of the so-called soft attacks using interception of messages, misinformation formation and transmission to group of robots which are also realizing other actions without identified signs of invasion of robots-saboteurs. Analysis of existing information security models of the system based on the trust level computation, calculated in the process of agents’ interaction is carried out. Information security model is offered in which robots-agents produce the trust levels to each other on the basis of situation analysis emerging on a certain step of iterative algorithm with usage of onboard sensor devices. On the basis of calculated trust levels, recognition of “saboteur” objects in the group of legitimate robots-agents is done. For measure of likeness (adjacency increase for objects from the same category (“saboteur” or “legitimate agent”, calculation algorithm for agents reputation is offered as a measure of public opinion about qualities of this or that agent-subject. Implementation alternatives of the algorithms for detection of saboteurs on the example of the basic algorithm for distribution of purposes in the group of robots are considered.

  20. Compositional data supports decentralized model of production and circulation of artifacts in the pre-Columbian south-central Andes.

    Science.gov (United States)

    Lazzari, Marisa; Pereyra Domingorena, Lucas; Stoner, Wesley D; Scattolin, María Cristina; Korstanje, María Alejandra; Glascock, Michael D

    2017-05-16

    The circulation and exchange of goods and resources at various scales have long been considered central to the understanding of complex societies, and the Andes have provided a fertile ground for investigating this process. However, long-standing archaeological emphasis on typological analysis, although helpful to hypothesize the direction of contacts, has left important aspects of ancient exchange open to speculation. To improve understanding of ancient exchange practices and their potential role in structuring alliances, we examine material exchanges in northwest Argentina (part of the south-central Andes) during 400 BC to AD 1000 (part of the regional Formative Period), with a multianalytical approach (petrography, instrumental neutron activation analysis, laser ablation inductively coupled plasma mass spectrometry) to artifacts previously studied separately. We assess the standard centralized model of interaction vs. a decentralized model through the largest provenance database available to date in the region. The results show: (i) intervalley heterogeneity of clays and fabrics for ordinary wares; (ii) intervalley homogeneity of clays and fabrics for a wide range of decorated wares (e.g., painted Ciénaga); (iii) selective circulation of two distinct polychrome wares (Vaquerías and Condorhuasi); (iv) generalized access to obsidian from one major source and various minor sources; and (v) selective circulation of volcanic rock tools from a single source. These trends reflect the multiple and conflicting demands experienced by people in small-scale societies, which may be difficult to capitalize by aspiring elites. The study undermines centralized narratives of exchange for this period, offering a new platform for understanding ancient exchange based on actual material transfers, both in the Andes and beyond.

  1. Tilt and decentration tolerance of intraocular lenses: measurements with an improved mechanical model eye

    Science.gov (United States)

    Traxler, Lukas; Reutterer, Bernd; Bayer, Natascha; Rank, Elisabet; Krause, Sylvio; Beckert, Erik; Drauschke, Andreas

    2016-03-01

    Cataract, a clouding of the crystalline eye lens, is the leading cause of blindness. It can effectively be treated by cataract surgery, where the clouded lens is replaced by an artificial intraocular lens (IOL). Postoperative healing processes can cause a displacement of the IOL, which further leads to the fact that the quality of vision is deteriorated. Studies have shown that the imaging quality of high sophisticated IOL designs is more sensitive to lens displacements than simpler designs. The effects of IOL displacements are not well represented and tested within the current IOL test standard ISO 11979-2. This fact leads to the necessity to develope new test standards for novel and more sophisticated IOL designs. In this paper we present an improved model eye, which extends the current standard in three main aspects: First, the eye-model is very close to the physiology of the human eye. Second, electromechanic drives allow an automatic and precise simulation of postoperative lens tilts and decentrations, and finally in addition to standard conform MTF analysis, in the proposed setup also wavefront aberrations are measured. The latter reveals specific image aberrations caused by lens displacements. The model eye allows to objectively analyze the displacement tolerance of various IOL designs. The functionality of this novel setup is tested by measuring a spherical and an aspheric IOL design. Additionally, for comparison, IOLs that were already investigated with a previous version of the presented model eye are used for analysis. Measurements results reveal improvements compared to the previous version of the model eye and a functional prototype for wavefront measurement.

  2. U-Form vs. M-Form: How to Understand Decision Autonomy Under Healthcare Decentralization? Comment on "Decentralisation of Health Services in Fiji: A Decision Space Analysis".

    Science.gov (United States)

    Bustamante, Arturo Vargas

    2016-06-07

    For more than three decades healthcare decentralization has been promoted in developing countries as a way of improving the financing and delivery of public healthcare. Decision autonomy under healthcare decentralization would determine the role and scope of responsibility of local authorities. Jalal Mohammed, Nicola North, and Toni Ashton analyze decision autonomy within decentralized services in Fiji. They conclude that the narrow decision space allowed to local entities might have limited the benefits of decentralization on users and providers. To discuss the costs and benefits of healthcare decentralization this paper uses the U-form and M-form typology to further illustrate the role of decision autonomy under healthcare decentralization. This paper argues that when evaluating healthcare decentralization, it is important to determine whether the benefits from decentralization are greater than its costs. The U-form and M-form framework is proposed as a useful typology to evaluate different types of institutional arrangements under healthcare decentralization. Under this model, the more decentralized organizational form (M-form) is superior if the benefits from flexibility exceed the costs of duplication and the more centralized organizational form (U-form) is superior if the savings from economies of scale outweigh the costly decision-making process from the center to the regions. Budgetary and financial autonomy and effective mechanisms to maintain local governments accountable for their spending behavior are key decision autonomy variables that could sway the cost-benefit analysis of healthcare decentralization. © 2016 by Kerman University of Medical Sciences.

  3. Centralizing or decentralizing: the impact of decentralized electric generation

    Energy Technology Data Exchange (ETDEWEB)

    Asbury, J. G.; Webb, S. B.

    1979-03-01

    If rising fuel prices or public policy make decentralized electric generation economical for the residential, commercial, and manufacturing sectors, the economies of scale in these sectors will increase. With current technology, some energy users, such as most single-family dwellings, will find it prohibitively expensive to install and use total-energy systems. They will continue to purchase electricity from a central utility, even though a decline in the utility's customers may increase its cost and prices. Other energy users, such as mid-sized manufacturing enterprises, might find it economical to set up their own generating facilities but would still find themselves operating at higher energy costs per unit of output than larger enterprises with more efficient systems. In both cases, decentralized electric generation would work against the smaller energy users, putting them at a disadvantage relative to the larger, more concentrated users. The objective of this paper is not to oppose alternative energy technologies in general or decentralized electric generation in particular. Such technology should be used if it becomes economical. It is false, however, to argue that decentralized generation is desirable because it will decentralize decision-making in the economy. Like carpooling, public transportation, and other measures to reduce energy cost, cogeneration and total-energy systems that make decentralized electric generation economical will also require increased coordination of economic decision-making.

  4. Fiscal decentralization and fiscal discipline

    OpenAIRE

    Çakır, Nida

    2006-01-01

    Cataloged from PDF version of article. In this thesis, the effects of fiscal procedures, fiscal centralization and fiscal decentralization, on fiscal discipline are analyzed in a theoretical framework. A model of two optimization problems is established: central government’s optimization problem and local government’s optimization problem representing the two fiscal procedures; fiscal centralization and fiscal decentralization respectively. Comparative static analysis is per...

  5. Decentralized control of large-scale systems: Fixed modes, sensitivity and parametric robustness. Ph.D. Thesis - Universite Paul Sabatier, 1985

    Science.gov (United States)

    Tarras, A.

    1987-01-01

    The problem of stabilization/pole placement under structural constraints of large scale linear systems is discussed. The existence of a solution to this problem is expressed in terms of fixed modes. The aim is to provide a bibliographic survey of the available results concerning the fixed modes (characterization, elimination, control structure selection to avoid them, control design in their absence) and to present the author's contribution to this problem which can be summarized by the use of the mode sensitivity concept to detect or to avoid them, the use of vibrational control to stabilize them, and the addition of parametric robustness considerations to design an optimal decentralized robust control.

  6. Centralized versus decentralized control—A solvable stylized model in transportation

    Science.gov (United States)

    Hongler, Max-Olivier; Gallay, Olivier; Hülsmann, Michael; Cordes, Philip; Colmorn, Richard

    2010-10-01

    Today’s supply networks consist of a certain amount of logistics objects that are enabled to interact with each other and to decide autonomously upon their next steps; in other words, they exhibit a certain degree of autonomous cooperation. Therefore, modern logistics research regards them as complex adaptive logistics systems. In order to analyze evolving dynamics and underlying implications for the respective systems’ behavior as well as the potential outcomes resulting from the interaction between autonomous decision-making “smart parts”, we propose in this contribution a fully solvable stylized model. We consider a population of homogeneous, autonomous interacting agents traveling on R with a given velocity that is itself corrupted by White Gaussian Noise. Based on real time observations of the positions of his neighbors, each agent is allowed to adapt his traveling velocity. These agent interactions are restricted to neighboring entities confined in finite spatial clusters ( i.e. we have range-limited interactions). In the limit of a large population of neighboring agents, a mean-field dynamics can be derived and, for small interaction range, the resulting dynamics coincides with the exactly solvable Burgers’ nonlinear field equation. Explicit Burgers’ solution enables to explicitly appreciate the emergent structure due to the local and individual agent interactions. In particular, for strongly interactive regimes in the present model, the resulting spatial distribution of agents converges to a shock wave pattern. To compare performances of centralized versus decentralized organization, we assign cost functions incurred when velocity adaptations are triggered either by multi-agent interactions or by central control. The multi-agent cumulative costs are then compared with the costs that would be incurred by implementing an effective optimal central controller able, for a given time horizon, to reproduce an identical spatial probability distribution

  7. Field-scale electrolysis/ceramic membrane system for the treatment of sewage from decentralized small communities.

    Science.gov (United States)

    Son, Dong-Jin; Kim, Woo-Yeol; Yun, Chan-Young; Kim, Dae-Gun; Chang, Duk; Sunwoo, Young; Hong, Ki-Ho

    2017-07-05

    The electrolysis process adopting copper electrodes and ceramic membrane with pore sizes of 0.1-0.2 μm were consisted to a system for the treatment of sewage from decentralized small communities. The system was operated under an HRT of 0.1 hour, voltage of 24 V, and TMP of 0.05 MPa. The system showed average removals of organics, nitrogen, phosphorus, and solids of up to 80%, 52%, 92%, and 100%, respectively. Removal of organics and nitrogen dramatically increased in proportion to increment of influent loading. Phosphorus and solids were remarkably eliminated by both electro-coagulation and membrane filtration. The residual particulate constituents could also be removed successfully through membrane process. A system composed of electrolysis process with ceramic membrane would be a compact, reliable, and flexible option for the treatment of sewage from decentralized small communities.

  8. Robust decentralized hybrid adaptive output feedback fuzzy control for a class of large-scale MIMO nonlinear systems and its application to AHS.

    Science.gov (United States)

    Huang, Yi-Shao; Liu, Wel-Ping; Wu, Min; Wang, Zheng-Wu

    2014-09-01

    This paper presents a novel observer-based decentralized hybrid adaptive fuzzy control scheme for a class of large-scale continuous-time multiple-input multiple-output (MIMO) uncertain nonlinear systems whose state variables are unmeasurable. The scheme integrates fuzzy logic systems, state observers, and strictly positive real conditions to deal with three issues in the control of a large-scale MIMO uncertain nonlinear system: algorithm design, controller singularity, and transient response. Then, the design of the hybrid adaptive fuzzy controller is extended to address a general large-scale uncertain nonlinear system. It is shown that the resultant closed-loop large-scale system keeps asymptotically stable and the tracking error converges to zero. The better characteristics of our scheme are demonstrated by simulations. Copyright © 2014. Published by Elsevier Ltd.

  9. Decentralized Portfolio Management

    Directory of Open Access Journals (Sweden)

    Benjamin Miranda Tabak

    2003-12-01

    Full Text Available We use a mean-variance model to analyze the problem of decentralized portfolio management. We find the solution for the optimal portfolio allocation for a head trader operating in n different markets, which is called the optimal centralized portfolio. However, as there are many traders specialized in different markets, the solution to the problem of optimal decentralized allocation should be different from the centralized case. In this paper we derive conditions for the solutions to be equivalent. We use multivariate normal returns and a negative exponential function to solve the problem analytically. We generate the equivalence of solutions by assuming that different traders face different interest rates for borrowing and lending. This interest rate is dependent on the ratio of the degrees of risk aversion of the trader and the head trader, on the excess return, and on the correlation between asset returns.

  10. Decentralization and Public Service Delivery in Asia

    OpenAIRE

    Brosio, Giorgio

    2014-01-01

    This paper assesses how decentralization can contribute, if proper political and fiscal institutions are present, to improving service delivery in Asia. In other words, decentralization is an opportunity and a challenge at the same time. The paper presents the salient characteristics of decentralized government in Asia and then focuses on the analysis of critical issues leading to “partial decentralization” that is common to most models. Consideration is also given to the emerging challenges ...

  11. Genome-Scale Models

    DEFF Research Database (Denmark)

    Bergdahl, Basti; Sonnenschein, Nikolaus; Machado, Daniel

    2016-01-01

    An introduction to genome-scale models, how to build and use them, will be given in this chapter. Genome-scale models have become an important part of systems biology and metabolic engineering, and are increasingly used in research, both in academica and in industry, both for modeling chemical...

  12. A two-level discount model for coordinating a decentralized supply chain considering stochastic price-sensitive demand

    Science.gov (United States)

    Heydari, Jafar; Norouzinasab, Yousef

    2015-07-01

    In this paper, a discount model is proposed to coordinate pricing and ordering decisions in a two-echelon supply chain (SC). Demand is stochastic and price sensitive while lead times are fixed. Decentralized decision making where downstream decides on selling price and order size is investigated. Then, joint pricing and ordering decisions are extracted where both members act as a single entity aim to maximize whole SC profit. Finally, a coordination mechanism based on quantity discount is proposed to coordinate both pricing and ordering decisions simultaneously. The proposed two-level discount policy can be characterized from two aspects: (1) marketing viewpoint: a retail price discount to increase the demand, and (2) operations management viewpoint: a wholesale price discount to induce the retailer to adjust its order quantity and selling price jointly. Results of numerical experiments demonstrate that the proposed policy is suitable to coordinate SC and improve the profitability of SC as well as all SC members in comparison with decentralized decision making.

  13. Adaptive fuzzy decentralized control for large-scale nonlinear systems with time-varying delays and unknown high-frequency gain sign.

    Science.gov (United States)

    Tong, Shaocheng; Liu, Changliang; Li, Yongming; Zhang, Huaguang

    2011-04-01

    In this paper, an adaptive fuzzy decentralized robust output feedback control approach is proposed for a class of large-scale strict-feedback nonlinear systems without the measurements of the states. The nonlinear systems in this paper are assumed to possess unstructured uncertainties, time-varying delays, and unknown high-frequency gain sign. Fuzzy logic systems are used to approximate the unstructured uncertainties, K-filters are designed to estimate the unmeasured states, and a special Nussbaum gain function is introduced to solve the problem of unknown high-frequency gain sign. Combining the backstepping technique with adaptive fuzzy control theory, an adaptive fuzzy decentralized robust output feedback control scheme is developed. In order to obtain the stability of the closed-loop system, a new lemma is given and proved. Based on this lemma and Lyapunov-Krasovskii functions, it is proved that all the signals in the closed-loop system are uniformly ultimately bounded and that the tracking errors can converge to a small neighborhood of the origin. The effectiveness of the proposed approach is illustrated from simulation results.

  14. Promoting collaboration and cultural competence for physician assistant and physical therapist students: a cross-cultural decentralized interprofessional education model

    Directory of Open Access Journals (Sweden)

    Kathleen De Oliveira

    2015-05-01

    Full Text Available Purpose: As the United States health care model progresses towards medical teams and the country’s population continues to diversify, the need for health professional education programs to develop and implement culturally specific interprofessional education (IPE becomes increasingly imperative. A wide range of models exists for delivering and implementing IPE in health education, but none have included the cultural components that are vital in educating the health professional. Methods: A cross-cultural decentralized IPE model for physician assistant (PA and physical therapy (PT students was developed. This three-part IPE series was created using an established cultural curricular model and began with the exploration of self, continued with the examination of various dimensions of culture, and concluded with the exploration of the intersection between health and culture. We assessed student satisfaction of the IPE experiences and students’ engagement and attitudes towards IPE using a three-item open-ended questionnaire administered after each cross-cultural activity and the Interprofessional Education Series Survey (IESS upon the completion of the series. Results: IESS responses showed that PA and PT students reported benefits in interprofessional collaboration and cultural awareness and expressed overall satisfaction with the series. Qualitative analysis revealed growth in student response depth consistent with the scaffolded focus of each IPE module in the series. Conclusion: The trends in this three-part series suggest that institutions looking to develop culturally inclusive IPE educational initiatives may have success through a decentralized model mirroring the effective cultural progression focused on addressing exploration of self, examination of various dimensions of culture, and exploration of the intersection between health and culture.

  15. (Re-Design of a Demonstration Model for a Flexible and Decentralized Cyber-Physical Production System (CPPS

    Directory of Open Access Journals (Sweden)

    Egger Georg

    2017-01-01

    Full Text Available Cyber-physical production systems (CPPS enable completely new possibilities in the factory of the future through the connectivity between the digital world and the physical production system. It has so far been difficult to transfer these advantages and concepts to students as well as professionals in a clear and practical oriented manner. The Fraunhofer Italia team has built a demonstration model for a flexible and decentralized CPPS system for showcase purposes. As part of an improvement of the existing system, Axiomatic Design (AD was applied as the scientific design theory. Starting from the identification of the Customer Attributes, Functional Requirements were derived and the Design Parameters for the new design were defined by means of the AD decomposition and mapping process. In this paper, the application of AD for product improvement is described step-by-step based on the example of the redesign of the CPPS demonstration model.

  16. U-Form vs. M-Form: How to Understand Decision Autonomy Under Healthcare Decentralization?; Comment on “Decentralisation of Health Services in Fiji: A Decision Space Analysis”

    Directory of Open Access Journals (Sweden)

    Arturo Vargas Bustamante

    2016-09-01

    Full Text Available For more than three decades healthcare decentralization has been promoted in developing countries as a way of improving the financing and delivery of public healthcare. Decision autonomy under healthcare decentralization would determine the role and scope of responsibility of local authorities. Jalal Mohammed, Nicola North, and Toni Ashton analyze decision autonomy within decentralized services in Fiji. They conclude that the narrow decision space allowed to local entities might have limited the benefits of decentralization on users and providers. To discuss the costs and benefits of healthcare decentralization this paper uses the U-form and M-form typology to further illustrate the role of decision autonomy under healthcare decentralization. This paper argues that when evaluating healthcare decentralization, it is important to determine whether the benefits from decentralization are greater than its costs. The U-form and M-form framework is proposed as a useful typology to evaluate different types of institutional arrangements under healthcare decentralization. Under this model, the more decentralized organizational form (M-form is superior if the benefits from flexibility exceed the costs of duplication and the more centralized organizational form (U-form is superior if the savings from economies of scale outweigh the costly decision-making process from the center to the regions. Budgetary and financial autonomy and effective mechanisms to maintain local governments accountable for their spending behavior are key decision autonomy variables that could sway the cost-benefit analysis of healthcare decentralization.

  17. Decentralized models of agricultural marketing as a strategy for social inclusion in Colombia: the case Exofruit SAS

    Directory of Open Access Journals (Sweden)

    Francisco Javier Arias Vargas

    2015-09-01

    Full Text Available This paper analyzes a model of decentralized marketing cape gooseberry (Physalis peruviana as an alternative to traditional wholesale channels; where brokers obtain higher profits; while farmers receive little profit for their product and the customer receives an expensive product. The investigative process development for nine months under a descriptive exploratory approach to data collection and triangulation of it to build the case. The project currently benefits 40 farmers; victims of armed conflict in the village of Mesopotamia Antioquia Union have joined the project, which has particularities like organic production of 1.2 tons per month of product, recovery of abandoned land; and equitable distribution of profits and the way for negotiations between farmers and the seller as a new proposal of peasant association.

  18. Multiobjective optimization of cluster-scale urban water systems investigating alternative water sources and level of decentralization

    Science.gov (United States)

    Newman, J. P.; Dandy, G. C.; Maier, H. R.

    2014-10-01

    In many regions, conventional water supplies are unable to meet projected consumer demand. Consequently, interest has arisen in integrated urban water systems, which involve the reclamation or harvesting of alternative, localized water sources. However, this makes the planning and design of water infrastructure more difficult, as multiple objectives need to be considered, water sources need to be selected from a number of alternatives, and end uses of these sources need to be specified. In addition, the scale at which each treatment, collection, and distribution network should operate needs to be investigated. In order to deal with this complexity, a framework for planning and designing water infrastructure taking into account integrated urban water management principles is presented in this paper and applied to a rural greenfield development. Various options for water supply, and the scale at which they operate were investigated in order to determine the life-cycle trade-offs between water savings, cost, and GHG emissions as calculated from models calibrated using Australian data. The decision space includes the choice of water sources, storage tanks, treatment facilities, and pipes for water conveyance. For each water system analyzed, infrastructure components were sized using multiobjective genetic algorithms. The results indicate that local water sources are competitive in terms of cost and GHG emissions, and can reduce demand on the potable system by as much as 54%. Economies of scale in treatment dominated the diseconomies of scale in collection and distribution of water. Therefore, water systems that connect large clusters of households tend to be more cost efficient and have lower GHG emissions. In addition, water systems that recycle wastewater tended to perform better than systems that captured roof-runoff. Through these results, the framework was shown to be effective at identifying near optimal trade-offs between competing objectives, thereby enabling

  19. Collective versus decentralized wage bargaining and the efficient allocation of resources

    NARCIS (Netherlands)

    Cai, X.; Gautier, P.A.; Teulings, C.N.; Watanabe, M.

    2014-01-01

    In a search model with two sided heterogeneity and on-the-job search, we compare collective bargaining agreements (CBA) with a decentralized bargaining outcome case. Under CBA, a union chooses a pay-scale schedule and the firm can select a wage from this pay scale after observing match quality. An

  20. Decentralization by Function and Location

    Science.gov (United States)

    Kochen, Manfred; Deutsch, Karl W.

    1973-01-01

    Examines under what conditions decentralization of facilities is rational for a client-centered system of service or administration, and under what conditions great centralization is more cost effective. Possible extensions of a simple model are suggested for application to school systems and numerous other organizations. (Author/DN)

  1. Replication of urban innovations - prioritization of strategies for the replication of Dhaka's community-based decentralized composting model.

    Science.gov (United States)

    Yedla, Sudhakar

    2012-01-01

    Dhaka's community-based decentralized composting (DCDC) is a successful demonstration of solid waste management by adopting low-cost technology, local resources community participation and partnerships among the various actors involved. This paper attempts to understand the model, necessary conditions, strategies and their priorities to replicate DCDC in the other developing cities of Asia. Thirteen strategies required for its replication are identified and assessed based on various criteria, namely transferability, longevity, economic viability, adaptation and also overall replication. Priority setting by multi-criteria analysis by applying analytic hierarchy process revealed that immediate transferability without long-term and economic viability consideration is not advisable as this would result in unsustainable replication of DCDC. Based on the analysis, measures to ensure the product quality control; partnership among stakeholders (public-private-community); strategies to achieve better involvement of the private sector in solid waste management (entrepreneurship in approach); simple and low-cost technology; and strategies to provide an effective interface among the complementing sectors are identified as important strategies for its replication.

  2. Decentralized nursing education in Northern Norway: towards a sustainable recruitment and retention model in rural Arctic healthcare services.

    Science.gov (United States)

    Norbye, Bente; Skaalvik, Mari Wolff

    2013-01-01

    Decentralized nursing education (DNE) was established at Tromsø University College in 1990 and has since become a part of the bachelor programme in nursing at UiT The Arctic University of Norway. The objective of the study was to investigate whether and to what degree the first DNE programme established in Norway has contributed to recruitment and retention of registered nurses (RNs) in rural healthcare services. The quantitative survey took place in 2012. A questionnaire was distributed to 315 former students who had graduated from the DNE programme from 1994 to 2011. The primary finding of this study is that the DNE successfully recruits students from rural areas of Northern Norway. Nearly, 87.5% have their first employment in community healthcare services. They continued to work in the rural areas and 85% still worked as nurses in 2012. The DNE programme has been successful regarding recruitment and retention of RNs to community healthcare services. Fifty-six percent have attended a variety of postgraduate programmes. The DNE programme demonstrates itself as a successful study model regarding recruitment and retention of RNs to rural and remote areas.

  3. Lab-scale co-digestion of kitchen waste and brown water for a preliminary performance evaluation of a decentralized waste and wastewater management.

    Science.gov (United States)

    Lavagnolo, Maria Cristina; Girotto, Francesca; Hirata, Osamu; Cossu, Raffaello

    2017-08-01

    An overall interaction is manifested between wastewater and solid waste management schemes. At the Laboratory of Environmental Engineering (LISA) of the University of Padova, Italy, the scientific and technical implications of putting into practice a decentralized waste and wastewater treatment based on the separation of grey water, brown water (BW - faecal matter) and yellow water (YW - urine) are currently undergoing investigation in the Aquanova Project. An additional aim of this concept is the source segregation of kitchen waste (KW) for subsequent anaerobic co-digestion with BW. To determine an optimal mixing ratio and temperature for use in the treatment of KW, BW, and eventually YW, by means of anaerobic digestion, a series of lab-scale batch tests were performed. Organic mixtures of KW and BW performed much better (max. 520mlCH 4 /gVS) in terms of methane yields than the individual substrates alone (max. 220mlCH 4 /gVS). A small concentration of urine proved to have a positive effect on anaerobic digestion performance, possibly due to the presence of micronutrients in YW. When considering high YW concentrations in the anaerobically digested mixtures, no ammonia inhibition was observed until a 30% and 10% YW content was added under mesophilic and thermophilic conditions, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Review and Extension of Suitability Assessment Indicators of Weather Model Output for Analyzing Decentralized Energy Systems

    Directory of Open Access Journals (Sweden)

    Hans Schermeyer

    2015-12-01

    Full Text Available Electricity from renewable energy sources (RES-E is gaining more and more influence in traditional energy and electricity markets in Europe and around the world. When modeling RES-E feed-in on a high temporal and spatial resolution, energy systems analysts frequently use data generated by numerical weather models as input since there is no spatial inclusive and comprehensive measurement data available. However, the suitability of such model data depends on the research questions at hand and should be inspected individually. This paper focuses on new methodologies to carry out a performance evaluation of solar irradiation data provided by a numerical weather model when investigating photovoltaic feed-in and effects on the electricity grid. Suitable approaches of time series analysis are researched from literature and applied to both model and measurement data. The findings and limits of these approaches are illustrated and a new set of validation indicators is presented. These novel indicators complement the assessment by measuring relevant key figures in energy systems analysis: e.g., gradients in energy supply, maximum values and volatility. Thus, the results of this paper contribute to the scientific community of energy systems analysts and researchers who aim at modeling RES-E feed-in on a high temporal and spatial resolution using weather model data.

  5. Decentralized Online Social Networks

    Science.gov (United States)

    Datta, Anwitaman; Buchegger, Sonja; Vu, Le-Hung; Strufe, Thorsten; Rzadca, Krzysztof

    Current Online social networks (OSN) are web services run on logically centralized infrastructure. Large OSN sites use content distribution networks and thus distribute some of the load by caching for performance reasons, nevertheless there is a central repository for user and application data. This centralized nature of OSNs has several drawbacks including scalability, privacy, dependence on a provider, need for being online for every transaction, and a lack of locality. There have thus been several efforts toward decentralizing OSNs while retaining the functionalities offered by centralized OSNs. A decentralized online social network (DOSN) is a distributed system for social networking with no or limited dependency on any dedicated central infrastructure. In this chapter we explore the various motivations of a decentralized approach to online social networking, discuss several concrete proposals and types of DOSN as well as challenges and opportunities associated with decentralization.

  6. Sustainable model for financial viability of decentralized biomass gasifier based power projects

    NARCIS (Netherlands)

    Palit, D.; Malhotra, R.; Kumar, Atul

    2011-01-01

    This paper made a modest attempt for designing a sustainable model for financial viability of biomass gasifier power projects for enhancing electricity access in India and other developing countries. For long term sustainability of distributed generation projects in remote rural areas, viability

  7. A model of a virtual community with a decentralized reputation-based peer evaluation

    OpenAIRE

    Olypher, Andrey

    2017-01-01

    This study was motivated by the problem of identifying fake news on the Internet. To explore possible solutions to this problem we introduce a model of a virtual community in which members submit documents with verifiable content. Documents are evaluated by three evaluators, randomly selected from all the members. The members whose documents are evaluated as authentic gain reputation. Otherwise they loose it. The members with higher reputation have a greater chance to be selected to serve as ...

  8. Decentralization of storm runoff via engagement of social and cultural capitals - implications for the management of flood risk at the municipal scale

    Science.gov (United States)

    This research tests a novel method that focuses limited community resources on a decentralized approach to storm water management. A reverse auction was used to relieve legal constraints on management implementation on private land. Residents voluntarily bid on rain gardens and r...

  9. Towards Automatic Decentralized Control Structure Selection

    DEFF Research Database (Denmark)

    Jørgensen, John Bagterp; Jørgensen, Sten Bay

    2000-01-01

    . The control structure selection problem is formulated as a special MILP employing cost coefficients which are computed using Parseval's theorem combined with RGA and IMC concepts. This approach enables selection and tuning of large-scale plant-wide decentralized controllers through efficient combination......A subtask in integration of design and control of chemical processes is the selection of a control structure. Automating the selection of the control structure enables sequential integration of process and control design. As soon as the process is specified or computed, a structure...... for decentralized control is determined automatically, and the resulting decentralized control structure is automatically tuned using standard techniques. Dynamic simulation of the resulting process system gives immediate feedback to the process design engineer regarding practical operability of the process...

  10. Towards Automatic Decentralized Control Structure Selection

    DEFF Research Database (Denmark)

    . The control structure selection problem is formulated as a special MILP employing cost coefficients which are computed using Parseval's theorem combined with RGA and IMC concepts. This approach enables selection and tuning of large-scale plant-wide decentralized controllers through efficient combination......A subtask in integration of design and control of chemical processes is the selection of a control structure. Automating the selection of the control structure enables sequential integration of process and controld esign. As soon as the process is specified or computed, a structure...... for decentralized control is determined automatically, and the resulting decentralized control structure is automatically tuned using standard techniques. Dynamic simulation of the resulting process system gives immediate feedback to the process design engineer regarding practical operability of the process...

  11. Decentralized Urban Solid Waste Management in Indonesia | CRDI ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    This project will develop and validate four models of decentralized solid waste management in low-income urban areas of Tangerang, Sidoarjo, Denpasar and ... Decentralized urban solid waste management in Indonesia : final technical report. Contenus connexes. Les chaînes de valeur comme leviers stratégiques.

  12. In Government We Trust : The Role of Fiscal Decentralization

    NARCIS (Netherlands)

    Ligthart, J.E.; van Oudheusden, P.

    2011-01-01

    We measure the contribution of fiscal decentralization to trust in government. Using repeated cross-country survey data of individuals on several measures of trust in govern- ment over the 1994-2007 period, we estimate an ordered response model of the government trust and fiscal decentralization

  13. International Symposia on Scale Modeling

    CERN Document Server

    Ito, Akihiko; Nakamura, Yuji; Kuwana, Kazunori

    2015-01-01

    This volume thoroughly covers scale modeling and serves as the definitive source of information on scale modeling as a powerful simplifying and clarifying tool used by scientists and engineers across many disciplines. The book elucidates techniques used when it would be too expensive, or too difficult, to test a system of interest in the field. Topics addressed in the current edition include scale modeling to study weather systems, diffusion of pollution in air or water, chemical process in 3-D turbulent flow, multiphase combustion, flame propagation, biological systems, behavior of materials at nano- and micro-scales, and many more. This is an ideal book for students, both graduate and undergraduate, as well as engineers and scientists interested in the latest developments in scale modeling. This book also: Enables readers to evaluate essential and salient aspects of profoundly complex systems, mechanisms, and phenomena at scale Offers engineers and designers a new point of view, liberating creative and inno...

  14. Taxation and Decentralization

    OpenAIRE

    Bird, Richard

    2010-01-01

    Strengthening sub-national governments is high on the policy agenda of many developing countries. From an economics perspective, the most important potential benefit from decentralization is the increased efficiency (and consequent welfare gain) that comes from moving governance closer to the people. To achieve this benefit, however, close attention must be paid to the design and implement...

  15. Decentralized Ground Staff Scheduling

    DEFF Research Database (Denmark)

    Sørensen, M. D.; Clausen, Jens

    2002-01-01

    Typically, ground staff scheduling is centrally planned for each terminal in an airport. The advantage of this is that the staff is efficiently utilized, but a disadvantage is that staff spends considerable time walking between stands. In this paper a decentralized approach for ground staff...

  16. DECENTRALIZATION OF ROMANIAN EDUCATION

    OpenAIRE

    Mitea-Popia, Crina-Carmen

    2009-01-01

    The ways in which public education is financed and delivered varies greatly throughout the world. Many developing countries have highly centralized government administration of education and other public services. Decentralization is one of the most important phenomena to have affected educational planning in the last years.

  17. Decentralized control and filtering in interconnected dynamical systems

    CERN Document Server

    Mahmoud, Magdi S

    2011-01-01

    Based on the many approaches available for dealing with large-scale systems (LSS), Decentralized Control and Filtering in Interconnected Dynamical Systems supplies a rigorous framework for studying the analysis, stability, and control problems of LSS. Providing an overall assessment of LSS theories, it addresses model order reduction, parametric uncertainties, time delays, and control estimator gain perturbations. Taking readers on a guided tour through LSS, the book examines recent trends and approaches and reviews past methods and results from a contemporary perspective. It traces the progre

  18. Policy Implementation Decentralization Government in Indonesia

    Directory of Open Access Journals (Sweden)

    Kardin M. Simanjuntak

    2015-06-01

    Full Text Available Decentralization in Indonesia is that reforms not completed and until the current implementation is not maximized or have not been successful. The essence of decentralization is internalising cost and benefit' for the people and how the government closer to the people. That's the most important essence of essence 'decentralization’. However, the implementation of decentralization in Indonesia is still far from the expectations. It is shown that only benefits of decentralization elite and local authorities, decentralization is a neo-liberal octopus, decentralization of public services are lacking in character, decentralization without institutional efficiency, decentralization fosters corruption in the area, and quasi-fiscal decentralization.

  19. Analysis and design of robust decentralized controllers for nonlinear systems

    Energy Technology Data Exchange (ETDEWEB)

    Schoenwald, D.A.

    1993-07-01

    Decentralized control strategies for nonlinear systems are achieved via feedback linearization techniques. New results on optimization and parameter robustness of non-linear systems are also developed. In addition, parametric uncertainty in large-scale systems is handled by sensitivity analysis and optimal control methods in a completely decentralized framework. This idea is applied to alleviate uncertainty in friction parameters for the gimbal joints on Space Station Freedom. As an example of decentralized nonlinear control, singular perturbation methods and distributed vibration damping are merged into a control strategy for a two-link flexible manipulator.

  20. Leadership and the Decentralized Control of Schools

    Science.gov (United States)

    Steinberg, Matthew P.

    2013-01-01

    This review examines the literature related to leadership and the decentralized control of schools. It first considers the distinctive goals of public and private agencies, the specific constraints that shape the autonomy of leaders in different sectors, and the ways in which new models of public management are infusing public agencies with…

  1. Decentralized Pricing in Minimum Cost Spanning Trees

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Moulin, Hervé; Østerdal, Lars Peter

    In the minimum cost spanning tree model we consider decentralized pricing rules, i.e. rules that cover at least the ecient cost while the price charged to each user only depends upon his own connection costs. We de ne a canonical pricing rule and provide two axiomatic characterizations. First...

  2. Decentral Smart Grid Control

    Science.gov (United States)

    Schäfer, Benjamin; Matthiae, Moritz; Timme, Marc; Witthaut, Dirk

    2015-01-01

    Stable operation of complex flow and transportation networks requires balanced supply and demand. For the operation of electric power grids—due to their increasing fraction of renewable energy sources—a pressing challenge is to fit the fluctuations in decentralized supply to the distributed and temporally varying demands. To achieve this goal, common smart grid concepts suggest to collect consumer demand data, centrally evaluate them given current supply and send price information back to customers for them to decide about usage. Besides restrictions regarding cyber security, privacy protection and large required investments, it remains unclear how such central smart grid options guarantee overall stability. Here we propose a Decentral Smart Grid Control, where the price is directly linked to the local grid frequency at each customer. The grid frequency provides all necessary information about the current power balance such that it is sufficient to match supply and demand without the need for a centralized IT infrastructure. We analyze the performance and the dynamical stability of the power grid with such a control system. Our results suggest that the proposed Decentral Smart Grid Control is feasible independent of effective measurement delays, if frequencies are averaged over sufficiently large time intervals.

  3. Energy and air emission implications of a decentralized wastewater system

    Science.gov (United States)

    Shehabi, Arman; Stokes, Jennifer R.; Horvath, Arpad

    2012-06-01

    Both centralized and decentralized wastewater systems have distinct engineering, financial and societal benefits. This paper presents a framework for analyzing the environmental effects of decentralized wastewater systems and an evaluation of the environmental impacts associated with two currently operating systems in California, one centralized and one decentralized. A comparison of energy use, greenhouse gas emissions and criteria air pollutants from the systems shows that the scale economies of the centralized plant help lower the environmental burden to less than a fifth of that of the decentralized utility for the same volume treated. The energy and emission burdens of the decentralized plant are reduced when accounting for high-yield wastewater reuse if it supplants an energy-intensive water supply like a desalination one. The centralized facility also reduces greenhouse gases by flaring methane generated during the treatment process, while methane is directly emitted from the decentralized system. The results are compelling enough to indicate that the life-cycle environmental impacts of decentralized designs should be carefully evaluated as part of the design process.

  4. Decentralized structural health monitoring using smart sensors

    Science.gov (United States)

    Spencer, B. F., Jr.; Nagayama, T.; Rice, Jennifer A.

    2008-03-01

    Decentralized computing is required to harvest the rich information that a dense array of smart sensors can make available for structural health monitoring (SHM). Though smart sensor technology has seen substantial advances during recent years, implementation of smart sensors on full-scale structures has been limited. Direct replacement of wired sensing systems with wireless sensor networks is not straight-forward as off-the-shelf wireless systems are unlikely to provide the data users expect. Sensor component characteristics limit the quality of data collected due to packet loss during communication, time synchronization errors, and slow communication speeds. This paper describes a scalable, decentralized approach to SHM using smart sensors, including the middleware services which address these issues common to smart sensor applications for structural health monitoring. In addition, the results of experimental validation are given. Finally, ongoing research addressing other factors critical to successful implementation of a full-scale smart sensor network for SHM are discussed.

  5. Pricing and Liquidity in Decentralized Asset Markets

    OpenAIRE

    Uslu, Semih

    2015-01-01

    I develop a search-and-bargaining model of liquidity provision in over-the-counter markets where investors differ in their search intensities. A distinguishing characteristic of my model is its tractability: it allows for heterogeneity, unrestricted asset positions, and fully decentralized trade. I find that investors with higher search intensities (i.e., fast investors) are less averse to holding inventories and more attracted to cash earnings, which makes the model corroborate a number of s...

  6. Decentralized indirect methods for learning automata games.

    Science.gov (United States)

    Tilak, Omkar; Martin, Ryan; Mukhopadhyay, Snehasis

    2011-10-01

    We discuss the application of indirect learning methods in zero-sum and identical payoff learning automata games. We propose a novel decentralized version of the well-known pursuit learning algorithm. Such a decentralized algorithm has significant computational advantages over its centralized counterpart. The theoretical study of such a decentralized algorithm requires the analysis to be carried out in a nonstationary environment. We use a novel bootstrapping argument to prove the convergence of the algorithm. To our knowledge, this is the first time that such analysis has been carried out for zero-sum and identical payoff games. Extensive simulation studies are reported, which demonstrate the proposed algorithm's fast and accurate convergence in a variety of game scenarios. We also introduce the framework of partial communication in the context of identical payoff games of learning automata. In such games, the automata may not communicate with each other or may communicate selectively. This comprehensive framework has the capability to model both centralized and decentralized games discussed in this paper.

  7. Decentring the Creative Self

    DEFF Research Database (Denmark)

    Glaveanu, Vlad Petre; Lubart, Todd

    2014-01-01

    Since its inception, the psychology of creativity has been concerned primarily with the study of individual creators. In contrast, this research is dedicated to an exploration of (a) who has a significant impact on a creative professional's activity and (b) what the contribution is that others ma...... and informational role in relation to creative work. From ‘internalized’ to ‘distant’, other people are an integral part of the equation of creativity calling for a de-centring of the creative self and its re-centring in a social space of actions and interactions....

  8. Decentralized Network Interdiction Games

    Science.gov (United States)

    2015-12-31

    AFRL-AFOSR-VA-TR-2016-0169 Decentralized Network Interdiction Games Andrew Liu PURDUE UNIVERSITY Final Report 01/13/2016 DISTRIBUTION A: Distribution...Interdiction Games 5a. CONTRACT NUMBER N/A 5b. GRANT NUMBER FA9550-12-1-0275 5c. PROGRAM ELEMENT NUMBER N/A 6. AUTHOR(S) Andrew L. Liu (PI...project established the theoretical and computational foundation for a new class of games , termed as the multi-interdictor network games (MINGs

  9. On Decentralization and Life Satisfaction

    DEFF Research Database (Denmark)

    Bjørnskov, Christian; Dreher, Axel; Fischer, Justina A.V.

    2008-01-01

    We empirically analyze the impact of fiscal and political decentralization on subjective well-being in a cross-section of 60,000 individuals from 66 countries. More spending or revenue decentralization raises well-being while greater local autonomy is beneficial only via government consumption sp...

  10. LOCAL BUDGETS UNDER CURRENT DECENTRALIZATION: UKRAINE AND FOREIGN EXPERIENCE

    Directory of Open Access Journals (Sweden)

    O. Cheberyako

    2016-04-01

    Full Text Available The article is devoted to the major trends and issues of development of local budgets in Ukraine. A study of the essence of fiscal decentralization as one of the components of the management, aimed at reducing the dependence of local governments from the central government with regard to foreign experience. Particular attention is paid to local budgets under decentralization of own and delegated financial powers. The theoretical principles of fiscal decentralization and its proven impact on the socio-economic development. Studied the European countries model of local budgets. The features of formation of revenues of local budgets under decentralization. The role in shaping tax revenues of local budgets in foreign countries and Ukraine. The analysis of state policy of financial support for regional development in Ukraine. The structure of tax revenue in the context of changes in the budget and tax legislation in a decentralized tax powers. Systematized features of fiscal decentralization in Ukraine. Problems and grounded main ways of optimizing the formation of local budgets in a decentralized tax powers. Formed selection of areas targeted as ways to increase economic and financial independence of regions of Ukraine.

  11. Centralized versus Decentralized Information Systems

    Science.gov (United States)

    Hugoson, Mats-Åke

    This paper brings into question whether information systems should be centralized or decentralized in order to provide greater support for different business processes. During the last century companies and organizations have used different approaches for centralization and decentralization; a simple answer to the question does not exist. This paper provides a survey of the evolution of centralized and decentralized approaches, mainly in a Nordic perspective. Based on critical reflections on the situation in the end of the century we can discuss what we can learn from history to achieve alignment between centralized and decentralized systems and the business structure. The conclusion is that theories, management and practice for decisions on centralization or decentralization of information systems must be improved. A conscious management and control of centralization /decentralization of IT support is a vital question in the company or the organization, and this is not a task that can be handled only by IT-specialists. There is a need for business oriented IT management of centralization/decentralization.

  12. Coalition or decentralization

    DEFF Research Database (Denmark)

    Mahdiraji, Hannan Amoozad; Govindan, Kannan; Zavadskas, Edmundas Kazimieras

    2014-01-01

    Supply chains have become the major and dominant paradigm of business and competition. The main challenge is how to act in multi-echelon supply chains considering the levels involved. Making a choice independently or integrating with some or all levels will be a critical decision, and therefore...... affects the overall profit of the chain. This article proposes a non-cooperative game theory approach to helping in making a better decision in the supply chain and gaining the most accessible benefit. Our research considers unlimited three-echelon supply chains with S suppliers, M manufacturers and K...... retailers. The Nash equilibrium and definition are used bearing in mind inventory and pricing and marketing cost as decision variables for this matter. This paper studies a three-echelon supply chain network and focuses on the value of integrating a pair of partners in the chain. In the decentralized case...

  13. Subsidiarity in Principle: Decentralization of Water Resources Management

    Directory of Open Access Journals (Sweden)

    Ryan Stoa

    2014-05-01

    Full Text Available The subsidiarity principle of water resources management suggests that water management and service delivery should take place at the lowest appropriate governance level. The principle is attractive for several reasons, primarily because: 1 the governance level can be reduced to reflect environmental characteristics, such as the hydrological borders of a watershed that would otherwise cross administrative boundaries; 2 decentralization promotes community and stakeholder engagement when decision-making is localized; 3 inefficiencies are reduced by eliminating reliance on central government bureaucracies and budgetary constraints; and 4 laws and institutions can be adapted to reflect localized conditions at a scale where integrated natural resources management and climate change adaptation is more focused. Accordingly, the principle of subsidiarity has been welcomed by many states committed to decentralized governance, integrated water resources management, and/or civic participation. However, applications of decentralization have not been uniform, and in some cases have produced frustrating outcomes for states and water resources. Successful decentralization strategies are heavily dependent on dedicated financial resources and human resource capacity. This article explores the nexus between the principle of subsidiarity and the enabling environment, in the hope of articulating factors likely to contribute to, or detract from, the success of decentralized water resources management. Case studies from Haiti, Rwanda, and the United States’ Florida Water Management Districts provide examples of the varied stages of decentralization.

  14. Modelling of rate effects at multiple scales

    DEFF Research Database (Denmark)

    Pedersen, R.R.; Simone, A.; Sluys, L. J.

    2008-01-01

    , the length scale in the meso-model and the macro-model can be coupled. In this fashion, a bridging of length scales can be established. A computational analysis of  a Split Hopkinson bar test at medium and high impact load is carried out at macro-scale and meso-scale including information from  the micro-scale....

  15. Analysis for corruption and decentralization (Case study: earlier decentralization era in Indonesia

    Directory of Open Access Journals (Sweden)

    Joko Tri Haryanto

    2017-06-01

    Full Text Available Abstrak. Di banyak negara, hubungan antara desentralisasi pemerintah dan tingkat ekstraksi sewa oleh pihak swasta merupakan elemen penting dalam perdebatan baru pada desain institusional. Topik korupsi secara aktif, terbuka dan diperdebatkan di Indonesia oleh Pemerintah, mitra pembangunan, dan kelompok berbasis luas dari para pemimpin politik dan masyarakat sipil yang terlibat dalam pertemuan dan pertukaran setiap hari. Dalam perdebatan tentang korupsi banyak perhatian diarahkan untuk peran gaji sektor publik, terutama di era desentralisasi. Berdasarkan fenomena ini, penulis ingin menganalisis hubungan antara korupsi dan desentralisasi. Menggunakan OSL model, kita dapat menemukan hubungan positif yang sangat kuat dan konsisten antara dua variabel di seluruh sampel dari daerah, sehingga memberikan beberapa dukungan untuk teori desentralisasi yang menekankan manfaat. Asosiasi ini adalah kuat untuk mengendalikan berbagai kemungkinan potensial dari upaya menghilangkan sebagian variabel serta bias endogenitas. Kata Kunci: Korupsi, Desentralisasi, OSL Model   Abstract. In many countries, relationship between decentralization of government activities and the extent of rent extraction by private parties is an important element in the recent debate on institutional design. The topic of corruption was actively, openly and debated in Indonesia by government, its development partners, and a broadly based group of political and civil society leaders are engaged in meetings and exchange on a daily basis. In the ongoing debate on corruption a lot of attention is paid to the role of public sector salaries, particularly in the decentralization era. Based on this phenomenon, the authors want to analyze the relationship between corruption and decentralization. Using OSL model, we can find a very strong and consistent positive association between the two variables across a sample of region, thereby providing some support for theories of decentralization that

  16. Centralized, Decentralized, and Hybrid Purchasing Organizations

    DEFF Research Database (Denmark)

    Bals, Lydia; Turkulainen, Virpi

    This paper addresses one of the focal issues in purchasing and supply management – global sourcing – from an organizational design perspective. In particular, we elaborate the traditional classification of global sourcing organization designs into centralized, decentralized, and hybrid models. We...... illustrate with our empirical analysis on global sourcing organization design at Global Chemical Company (GCC, a pseudonym) that revisiting the conventional wisdom about global sourcing organization designs is required; by engaging in a detailed, subfirm level of analysis on the design of the purchasing...... organization we can identify organization designs beyond the classical centralization-decentralization continuum. We also provide explanations for the observed organization design at GCC. The study contributes to research on purchasing and supply management as well as research on organization design....

  17. Decentralized Consistent Updates in SDN

    KAUST Repository

    Nguyen, Thanh Dang

    2017-04-10

    We present ez-Segway, a decentralized mechanism to consistently and quickly update the network state while preventing forwarding anomalies (loops and blackholes) and avoiding link congestion. In our design, the centralized SDN controller only pre-computes information needed by the switches during the update execution. This information is distributed to the switches, which use partial knowledge and direct message passing to efficiently realize the update. This separation of concerns has the key benefit of improving update performance as the communication and computation bottlenecks at the controller are removed. Our evaluations via network emulations and large-scale simulations demonstrate the efficiency of ez-Segway, which compared to a centralized approach, improves network update times by up to 45% and 57% at the median and the 99th percentile, respectively. A deployment of a system prototype in a real OpenFlow switch and an implementation in P4 demonstrate the feasibility and low overhead of implementing simple network update functionality within switches.

  18. Integrating Local Scale Drainage Measures in Meso Scale Catchment Modelling

    Directory of Open Access Journals (Sweden)

    Sandra Hellmers

    2017-01-01

    Full Text Available This article presents a methodology to optimize the integration of local scale drainage measures in catchment modelling. The methodology enables to zoom into the processes (physically, spatially and temporally where detailed physical based computation is required and to zoom out where lumped conceptualized approaches are applied. It allows the definition of parameters and computation procedures on different spatial and temporal scales. Three methods are developed to integrate features of local scale drainage measures in catchment modelling: (1 different types of local drainage measures are spatially integrated in catchment modelling by a data mapping; (2 interlinked drainage features between data objects are enabled on the meso, local and micro scale; (3 a method for modelling multiple interlinked layers on the micro scale is developed. For the computation of flow routing on the meso scale, the results of the local scale measures are aggregated according to their contributing inlet in the network structure. The implementation of the methods is realized in a semi-distributed rainfall-runoff model. The implemented micro scale approach is validated with a laboratory physical model to confirm the credibility of the model. A study of a river catchment of 88 km2 illustrated the applicability of the model on the regional scale.

  19. Rethinking Decentralization in Education in terms of Administrative Problems

    Directory of Open Access Journals (Sweden)

    Vasiliki Papadopoulou

    2013-11-01

    Full Text Available The general purpose of this study is to thoroughly examine decentralization in education according to the literature and previous research, and to discuss the applicability of educational decentralization practices in Turkey. The literature was reviewed for the study and findings reported. It has been observed that decentralization in education practices were realized in many countries after the 1980’s. It is obvious that the educational system in Turkey has difficulty in meeting the needs, and encounters many problems due to its present centralist state. Educational decentralization can provide effective solutions for stakeholder engagement, educational financing and for problems in decision making and operation within the education system. However, the present state of local governments, the legal framework, geographical, cultural and social features indicate that Turkey’s conditions are not ready for decentralization in education. A decentralization model realized in the long run according to Turkey’s conditions, and as a result of a social consensus, can help resolve the problems of the Turkish education system.

  20. Decentralized and Modular Electrical Architecture

    Science.gov (United States)

    Elisabelar, Christian; Lebaratoux, Laurence

    2014-08-01

    This paper presents the studies made on the definition and design of a decentralized and modular electrical architecture that can be used for power distribution, active thermal control (ATC), standard inputs-outputs electrical interfaces.Traditionally implemented inside central unit like OBC or RTU, these interfaces can be dispatched in the satellite by using MicroRTU.CNES propose a similar approach of MicroRTU. The system is based on a bus called BRIO (Bus Réparti des IO), which is composed, by a power bus and a RS485 digital bus. BRIO architecture is made with several miniature terminals called BTCU (BRIO Terminal Control Unit) distributed in the spacecraft.The challenge was to design and develop the BTCU with very little volume, low consumption and low cost. The standard BTCU models are developed and qualified with a configuration dedicated to ATC, while the first flight model will fly on MICROSCOPE for PYRO actuations and analogue acquisitions. The design of the BTCU is made in order to be easily adaptable for all type of electric interface needs.Extension of this concept is envisaged for power conditioning and distribution unit, and a Modular PCDU based on BRIO concept is proposed.

  1. Brane World Models Need Low String Scale

    CERN Document Server

    Antoniadis, Ignatios; Calmet, Xavier

    2011-01-01

    Models with large extra dimensions offer the possibility of the Planck scale being of order the electroweak scale, thus alleviating the gauge hierarchy problem. We show that these models suffer from a breakdown of unitarity at around three quarters of the low effective Planck scale. An obvious candidate to fix the unitarity problem is string theory. We therefore argue that it is necessary for the string scale to appear below the effective Planck scale and that the first signature of such models would be string resonances. We further translate experimental bounds on the string scale into bounds on the effective Planck scale.

  2. Analysis of the impact of decentralized solar technology on electric utilities: comparison and synthesis of models. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Feldman, S.; Blair, P.

    1980-11-20

    The validation of the physical submodels of three solar-electric utility interface models is described. The validation problem is divided into two components, the accuracy of the submodels themselves and the accuracy of the data typically used to run these models. The data set required to study these problems with respect to utility requirements is discussed and its collection in the Philadelphia Metropolitan area described. The instrumentation employed in the gathering of the data is covered. Error statistics of data and submodel accuracy are presented and the current status of the study is presented.

  3. A Spatial Decision Support System to incorporate hydro-economic modeling results in the management of water resources under decentralized institutional arrangements in a semiarid reservoir region in Brazil

    Science.gov (United States)

    Alcoforado de Moraes, Márcia; Silva, Gerald; Siegmund-Schultze, Marianna

    2017-04-01

    The integration of economic and hydrological components in models, aimed to support evaluating alternatives of water allocation policies, is promising, though, challenging. Worldwide, these models have been used primarily in academia, and so far seldom by water managers for practical purposes. Ideally, the models should be available through a Decision Support System. The São Francisco River Basin in Northeast of Brazil has around 48% of its area in a semi-arid region. Irrigation and public water supply are the primary water use sectors, along with hydropower utilization. The water for electricity generation is stored in two large reservoirs, built 30 to 50 years ago under the premise of regulating flows for hydropower and controlling floods. Since 20 years, however, the law stipulates the multiple uses paradigm in a participatory and decentralized way. So far, only few rules laid down. Studies revealed that most of the respective institutions still needed to update their routines to the new paradigm. A hydro-economic model was developed and applied in order to determine the economically optimal water allocation of main users in that semiarid reservoir region. In order to make this model available to the decision makers, a minimum required is some form of manipulating data entry and output as well as some graphical interfaces. We propose and present the first features of a Spatial Decision Support System (SDSS) with dedicated hydro-economic modules in a web-based Geographic Information System (GIS) environment for integrated water resource management. The open model platform should include geoprocessing tasks and water user related data management. The hydro-economic geoprocessing will link to generic optimization modeling systems, such as EXCEL Solver, GAMS and MATLAB. The institutions are deliberating or deciding over water allocation at different scales could use the generated information on potential economic benefits as a transparent basis for discussion. In

  4. Evaluation of a Decentralized Wastewater Treatment Technology. INTERNATIONAL WASTEWATER SYSTEMS, INC. MODEL 6000 SEQUENCING BATCH REACTOR SYSTEM

    Science.gov (United States)

    Evaluation of the IWS Model 6000 SBR began in April 2004 when one SBR was taken off line and cleaned. The verification testing started July 1, 2004 and proceeded without interruption through June 30, 2005. All sixteen four-day sampling events were completed as scheduled, yielding...

  5. Decentralization in Bitcoin and Ethereum Networks

    OpenAIRE

    Gencer, Adem Efe; Basu, Soumya; Eyal, Ittay; van Renesse, Robbert; Sirer, Emin Gün

    2018-01-01

    Blockchain-based cryptocurrencies have demonstrated how to securely implement traditionally centralized systems, such as currencies, in a decentralized fashion. However, there have been few measurement studies on the level of decentralization they achieve in practice. We present a measurement study on various decentralization metrics of two of the leading cryptocurrencies with the largest market capitalization and user base, Bitcoin and Ethereum. We investigate the extent of decentralization ...

  6. Wage Dispersion and Decentralization of Wage Bargaining

    DEFF Research Database (Denmark)

    Dahl, Christian Møller; le Maire, Christian Daniel; Munch, Jakob R.

    2013-01-01

    This article studies how decentralization of wage bargaining from sector to firm level influences wage levels and wage dispersion. We use detailed panel data covering a period of decentralization in the Danish labor market. The decentralization process provides variation in the individual worker......, we also find that wages are more dispersed under firm-level bargaining compared to more centralized wage-setting systems....

  7. Decentralized asset management for collaborative sensing

    Science.gov (United States)

    Malhotra, Raj P.; Pribilski, Michael J.; Toole, Patrick A.; Agate, Craig

    2017-05-01

    There has been increased impetus to leverage Small Unmanned Aerial Systems (SUAS) for collaborative sensing applications in which many platforms work together to provide critical situation awareness in dynamic environments. Such applications require critical sensor observations to be made at the right place and time to facilitate the detection, tracking, and classification of ground-based objects. This further requires rapid response to real-world events and the balancing of multiple, competing mission objectives. In this context, human operators become overwhelmed with management of many platforms. Further, current automated planning paradigms tend to be centralized and don't scale up well to many collaborating platforms. We introduce a decentralized approach based upon information-theory and distributed fusion which enable us to scale up to large numbers of collaborating Small Unmanned Aerial Systems (SUAS) platforms. This is exercised against a military application involving the autonomous detection, tracking, and classification of critical mobile targets. We further show that, based upon monte-carlo simulation results, our decentralized approach out-performs more static management strategies employed by human operators and achieves similar results to a centralized approach while being scalable and robust to degradation of communication. Finally, we describe the limitations of our approach and future directions for our research.

  8. Participative decentralization of diabetes care in Davao City (Philippines) according to the Chronic Care Model: a program evaluation.

    Science.gov (United States)

    Pilleron, Sophie; Pasquier, Estelle; Boyoze-Nolasco, Ivy; Villafuerte, Josephine Jasmin; Olchini, Davide; Fontbonne, Annick

    2014-04-01

    To assess the effectiveness of the Diabetes Project in Davao City, Philippines, regarding diabetes care access, diabetes management and cardiovascular risk factors. The project was developed in accordance with the Chronic Care Model (CCM) framework. A non-randomized cross-sectional survey was conducted in nine intervention and five control Barangays (villages). People with diabetes aged ≥20 years were interviewed using a structured questionnaire; height, weight, waist circumference, and blood pressure were measured; HbA1c was tested with a NSGP-certified point-of-care device. Logistic regression models were used to compare the two groups. The intervention group (n=503) scored better than the controls (n=136) on the following (OR, 95% CI): percentage of patients taking metformin (1.5, 1.0-2.2); and in the last 12 months: laboratory test for fasting blood sugar (1.6, 1.1-2.3), HbA1c (6.0, 2.4-15.1), lipid profile (1.7, 1.1-2.5), nutritionist visit (1.6, 1.0-2.5) and therapeutic education session (2.7, 1.8-4.0). Glycemic control (HbA1c<7%) was also better in the intervention Barangays (1.6, 1.0-2.4). There were no statistical differences between the two groups for number of visits, and levels of other cardiovascular risk factors. Our findings support the effectiveness of implementing the CCM framework in a low-to-middle income country on glycemic control and diabetes management. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  9. Localization of acoustic sources using a decentralized particle filter

    Directory of Open Access Journals (Sweden)

    Gerstoft Peter

    2011-01-01

    Full Text Available Abstract This paper addresses the decentralized localization of an acoustic source in a (wireless sensor network based on the underlying partial differential equation (PDE. The PDE is transformed into a distributed state-space model and augmented by a source model. Inferring the source state amounts to a non-linear non-Gaussian Bayesian estimation problem for whose solution we implement a decentralized particle filter (PF operating within and across clusters of sensor nodes. The aggregation of the local posterior distributions from all clusters is achieved via an enhanced version of the maximum consensus algorithm. Numerical simulations illustrate the performance of our scheme.

  10. Reaction Diffusion and Chemotaxis for Decentralized Gathering on FPGAs

    Directory of Open Access Journals (Sweden)

    Bernard Girau

    2009-01-01

    and rapid simulations of the complex dynamics of this reaction-diffusion model. Then we describe the FPGA implementation of the environment together with the agents, to study the major challenges that must be solved when designing a fast embedded implementation of the decentralized gathering model. We analyze the results according to the different goals of these hardware implementations.

  11. Decentralized Urban Solid Waste Management in Indonesia | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    This project will develop and validate four models of decentralized solid waste management in low-income urban areas of Tangerang, Sidoarjo, Denpasar and Mataram. The four models will be evaluated in terms of cost-recovery, technical sustainability and social acceptability. Efforts will be made to achieve recognition of ...

  12. Analysis of Decentralized Control for Absorption Cycle Heat Pumps

    DEFF Research Database (Denmark)

    Vinther, Kasper; Just Nielsen, Rene; Nielsen, Kirsten Mølgaard

    2015-01-01

    Email Print Request Permissions This paper investigates decentralized control structures for absorption cycle heat pumps and a dynamic nonlinear model of a single-effect LiBr-water absorption system is used as case study. The model has four controllable inputs, which can be used to stabilize...

  13. Rural Electrification through Decentralized Concentrating Solar Power: Technological and Socio-Economic Aspects

    Directory of Open Access Journals (Sweden)

    Sylvain Quoilin

    2013-09-01

    Full Text Available This paper presents the development of small-scale solar Organic Rankine Cycles for rural electrification in remote areas of Lesotho. It is subdivided in two parts. The first part deals with the success conditions of decentralized rural electrification projects. Through a literature survey, relevant guiding principles and recommendations are formulated. The second part of the paper describes the proposed system, which is designed in agreement with the formulated recommendations. A framework for benchmarking the performance and cost of various micro-utility platforms and rural electrification distribution models is proposed.

  14. Wage Dispersion and Decentralization of Wage Bargaining

    DEFF Research Database (Denmark)

    Dahl, Christian M.; Le Maire, Christian Daniel; Munch, Jakob Roland

    This paper studies how decentralization of wage bargaining from sector to firm level influences wage levels and wage dispersion. We use a detailed panel data set covering a period of decentralization in the Danish labor market. The decentralization process provides exogenous variation in the indi......This paper studies how decentralization of wage bargaining from sector to firm level influences wage levels and wage dispersion. We use a detailed panel data set covering a period of decentralization in the Danish labor market. The decentralization process provides exogenous variation...... in the individual worker's wage-setting system that facilitates identification of the effects of decentralization. Consistent with predictions we find that wages are more dispersed under firm-level bargaining compared to more centralized wage-setting systems. However, the differences across wage-setting systems...

  15. Decentralized neural control application to robotics

    CERN Document Server

    Garcia-Hernandez, Ramon; Sanchez, Edgar N; Alanis, Alma y; Ruz-Hernandez, Jose A

    2017-01-01

    This book provides a decentralized approach for the identification and control of robotics systems. It also presents recent research in decentralized neural control and includes applications to robotics. Decentralized control is free from difficulties due to complexity in design, debugging, data gathering and storage requirements, making it preferable for interconnected systems. Furthermore, as opposed to the centralized approach, it can be implemented with parallel processors. This approach deals with four decentralized control schemes, which are able to identify the robot dynamics. The training of each neural network is performed on-line using an extended Kalman filter (EKF). The first indirect decentralized control scheme applies the discrete-time block control approach, to formulate a nonlinear sliding manifold. The second direct decentralized neural control scheme is based on the backstepping technique, approximated by a high order neural network. The third control scheme applies a decentralized neural i...

  16. The Effect of Fiscal Decentralization on Under-five Mortality in Iran: A Panel Data Analysis.

    Science.gov (United States)

    Samadi, Ali Hussein; Keshtkaran, Ali; Kavosi, Zahra; Vahedi, Sajad

    2013-11-01

    Fiscal Decentralization (FD) in many cases is encouraged as a strong means of improving the efficiency and equity in the provision of public goods, such as healthcare services. This issue has urged the researchers to experimentally examine the relationship between fiscal decentralization indicators and health outcomes. In this study we examine the effect of Fiscal Decentralization in Medical Universities (FDMU) and Fiscal Decentralization in Provincial Revenues (FDPR) on Under-Five Mortality Rate (U5M) in provinces of Iran over the period between 2007 and 2010. We employed panel data methods in this article. The results of the Pesaran CD test demonstrated that most of the variables used in the analysis were cross-sectionally dependent. The Hausman test results suggested that fixed-effects were more appropriate to estimate our model. We estimated the fixed-effect model by using Driscoll-Kraay standard errors as a remedy for cross-sectional dependency. According to the findings of this research, fiscal decentralization in the health sector had a negative impact on U5M. On the other hand, fiscal decentralization in provincial revenues had a positive impact on U5M. In addition, U5M had a negative association with the density of physicians, hospital beds, and provincial GDP per capita, but a positive relationship with Gini coefficient and unemployment. The findings of our study indicated that fiscal decentralization should be emphasized in the health sector. The results suggest the need for caution in the implementation of fiscal decentralization in provincial revenues.

  17. Multisource Data Inversion Using Decentralized Fusion

    Science.gov (United States)

    Alzraiee, A. H.; Bau, D. A.

    2013-12-01

    Field data pertaining hydrological systems typically come from multiple sources and are related to different hydraulic properties. The spatial and temporal coverage of these datasets is also variable. Data fusion techniques allow for the integration of multiple datasets with different quality in order to produce a more informative dataset than any of the original inputs. That is to say, the accuracy and the spatial coverage of the fused data are expected to be superior to any of the original datasets. In this work, we present a 'decentralized' data fusion method stemming from Millman's theory, which has been introduced in the field of signal processing to fuse multiple correlated estimates. Millman's equations are applied to integrate separate estimates of aquifer hydraulic properties, such as the spatial distributions of the hydraulic conductivity K and the specific elastic storage Ss, estimated through the inversion of drawdown data collected over multiple independent pumping tests. For each pumping test, 'local' estimates of K and Ss are obtained by applying an Ensemble Kalman Filter (EnKF) algorithm to assimilate the first and second moments of aquifer drawdown into the response of a corresponding groundwater flow model. Since the application of Millman's theory may be computationally very intensive, we propose a more efficient Millman's fusion algorithm for merging local estimates into a global estimate of the hydraulic properties. Increased computational efficiency is achieved by distributing local estimation processes among multicore computers. Multiple numerical experiments are conducted to investigate the potential of this inversion method. In these experiments, a synthetic aquifer is explored by conducting multiple hypothetical pumping tests at different locations in the aquifer. Finally, the decentralized fusion method is compared to a centralized fusion method where all drawdown data corresponding to multiple pumping tests are fused simultaneously using

  18. Large Scale Computations in Air Pollution Modelling

    DEFF Research Database (Denmark)

    Zlatev, Z.; Brandt, J.; Builtjes, P. J. H.

    Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998......Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998...

  19. Decentralized Receding Horizon Control and Coordination of Autonomous Vehicle Formations

    NARCIS (Netherlands)

    Keviczky, T.; Borelli, F.; Fregene, K.; Godbole, D.; Bals, G.J.

    2008-01-01

    This paper describes the application of a novel methodology for high-level control and coordination of autonomous vehicle teams and its demonstration on high-fidelity models of the organic air vehicle developed at Honeywell Laboratories. The scheme employs decentralized receding horizon controllers

  20. Centralized vs. De-centralized Multinationals and Taxes

    DEFF Research Database (Denmark)

    Nielsen, Søren Bo; Raimondos-Møller, Pascalis; Schjelderup, Guttorm

    2005-01-01

    The paper examines how country tax differences affect a multinational enterprise's choice to centralize or de-centralize its decision structure. Within a simple model that emphasizes the multiple conflicting roles of transfer prices in MNEs - here, as a strategic pre-commitment device and a tax...

  1. Decentralization and REDD+ in Brazil

    Directory of Open Access Journals (Sweden)

    Fabiano Toni

    2011-01-01

    Full Text Available Recent discussions on REDD+ (Reducing Emissions from Deforestation and Forest Degradation, plus conservation, sustainable management of forests and enhancement of forest carbon stocks have raised optimism about reducing carbon emissions and deforestation in tropical countries. If approved under the United Nations Framework Convention on Climate Change (UNFCCC, REDD+ mechanisms may generate a substantial influx of financial resources to developing countries. Some authors argue that this money could reverse the ongoing process of decentralization of forest policies that has spread through a large number of developing countries in the past two decades. Central states will be accountable for REDD+ money, and may be compelled to control and keep a significant share of REDD+ funds. Supporters of decentralization argue that centralized implementation of REDD+ will be ineffective and inefficient. In this paper, I examine the relation between subnational governments and REDD+ in Brazil. Data show that some state governments in the Brazilian Amazon have played a key role in creating protected areas (PAs after 2003, which helped decrease deforestation rates. Governors have different stimuli for creating PAs. Some respond to the needs of their political constituency; others have expectations to boost the forest sector so as to increase fiscal revenues. Governors also have led the discussion on REDD+ in Brazil since 2008. Considering their interests and political power, REDD+ is unlikely to curb decentralization in Brazil.

  2. Scaling limits of a model for selection at two scales

    Science.gov (United States)

    Luo, Shishi; Mattingly, Jonathan C.

    2017-04-01

    The dynamics of a population undergoing selection is a central topic in evolutionary biology. This question is particularly intriguing in the case where selective forces act in opposing directions at two population scales. For example, a fast-replicating virus strain outcompetes slower-replicating strains at the within-host scale. However, if the fast-replicating strain causes host morbidity and is less frequently transmitted, it can be outcompeted by slower-replicating strains at the between-host scale. Here we consider a stochastic ball-and-urn process which models this type of phenomenon. We prove the weak convergence of this process under two natural scalings. The first scaling leads to a deterministic nonlinear integro-partial differential equation on the interval [0,1] with dependence on a single parameter, λ. We show that the fixed points of this differential equation are Beta distributions and that their stability depends on λ and the behavior of the initial data around 1. The second scaling leads to a measure-valued Fleming-Viot process, an infinite dimensional stochastic process that is frequently associated with a population genetics.

  3. Simple scaling model for exploding pusher targets

    Energy Technology Data Exchange (ETDEWEB)

    Storm, E.K.; Larsen, J.T.; Nuckolls, J.H.; Ahlstrom, H.G.; Manes, K.R.

    1977-11-04

    A simple model has been developed which when normalized by experiment or Lasnex calculations can be used to scale neutron yields for variations in laser input power and pulse length and target radius and wall thickness. The model also illucidates some of the physical processes occurring in this regime of laser fusion experiments. Within certain limitations on incident intensity and target geometry, the model scales with experiments and calculations to within a factor of two over six decades in neutron yield.

  4. Decentralized Large-Scale Power Balancing

    DEFF Research Database (Denmark)

    Halvgaard, Rasmus; Jørgensen, John Bagterp; Poulsen, Niels Kjølstad

    2013-01-01

    A power balancing strategy based on Douglas-Rachford splitting is proposed as a control method for largescale integration of flexible consumers in a Smart Grid. The total power consumption is controlled through a negotiation procedure between all units and a coordinating system level. The balancing...

  5. RUSSIAN CULTURAL POLITICS: DECENTRALIZATION OR CENTRALIZATION?

    OpenAIRE

    E. A. Blagorodova

    2011-01-01

    Successful cultural politics in Russia may be carried out on the basis of its management decentralization principle. Regional and municipal culture development is not possible without common national cultural aims and priorities. The state should play an essential role, howeverregional cultures should be given self-development possibilities. Culture management decentralization should not get reduced to the financing issues. Decentralization priority aim should be improvement in efficiency of ...

  6. RUSSIAN CULTURAL POLITICS: DECENTRALIZATION OR CENTRALIZATION?

    Directory of Open Access Journals (Sweden)

    E. A. Blagorodova

    2011-01-01

    Full Text Available Successful cultural politics in Russia may be carried out on the basis of its management decentralization principle. Regional and municipal culture development is not possible without common national cultural aims and priorities. The state should play an essential role, howeverregional cultures should be given self-development possibilities. Culture management decentralization should not get reduced to the financing issues. Decentralization priority aim should be improvement in efficiency of both cultural organizations and governmental authorities of thefederal and local levels.

  7. Functional Scaling of Musculoskeletal Models

    DEFF Research Database (Denmark)

    Lund, Morten Enemark; Andersen, Michael Skipper; de Zee, Mark

    specific to the patient. This is accomplished using optimisation methods to determine patient-specific joint positions and orientations, which minimise the least-squares error between model markers and the recorded markers from a motion capture experiment. Functional joint positions and joint axis...

  8. Modeling interactome: scale-free or geometric?

    Science.gov (United States)

    Przulj, N; Corneil, D G; Jurisica, I

    2004-12-12

    Networks have been used to model many real-world phenomena to better understand the phenomena and to guide experiments in order to predict their behavior. Since incorrect models lead to incorrect predictions, it is vital to have as accurate a model as possible. As a result, new techniques and models for analyzing and modeling real-world networks have recently been introduced. One example of large and complex networks involves protein-protein interaction (PPI) networks. We analyze PPI networks of yeast Saccharomyces cerevisiae and fruitfly Drosophila melanogaster using a newly introduced measure of local network structure as well as the standardly used measures of global network structure. We examine the fit of four different network models, including Erdos-Renyi, scale-free and geometric random network models, to these PPI networks with respect to the measures of local and global network structure. We demonstrate that the currently accepted scale-free model of PPI networks fails to fit the data in several respects and show that a random geometric model provides a much more accurate model of the PPI data. We hypothesize that only the noise in these networks is scale-free. We systematically evaluate how well-different network models fit the PPI networks. We show that the structure of PPI networks is better modeled by a geometric random graph than by a scale-free model. Supplementary information is available at http://www.cs.utoronto.ca/~juris/data/data/ppiGRG04/

  9. Sustainable Supply of Safe Drinking Water for Underserved Households in Kenya: Investigating the Viability of Decentralized Solutions

    Directory of Open Access Journals (Sweden)

    Pauline Chepchirchir Cherunya

    2015-10-01

    Full Text Available Water quality and safe water sources are pivotal aspects of consideration for domestic water. Focusing on underserved households in Kenya, this study compared user perceptions and preferences on water-service provision options, particularly investigating the viability of decentralized models, such as the Safe Water Enterprise (SWE, as sustainable safe drinking water sources. Results showed that among a number of water-service provision options available, the majority of households regularly sourced their domestic water from more than one source (86% Ngoliba/Maguguni, 98% Kangemi Gichagi. A majority of households perceived their water sources to be unsafe to drink (84% Ngoliba/Maguguni, 73% Kangemi Gichagi. For this reason, drinking water was mainly chlorinated (48% Ngoliba/Maguguni, 33% Kangemi Gichagi or boiled (42% Ngoliba/Maguguni, 67% Kangemi Gichagi. However, this study also found that households in Kenya did not apply these household water treatment methods consistently, thus indicating inconsistency in safe water consumption. The SWE concept, a community-scale decentralized safe drinking water source, was a preferred option among households who perceived it to save time and to be less cumbersome as compared to boiling and chlorination. Willingness to pay for SWE water was also a positive indicator for its preference by the underserved households. However, the long-term applicability of such decentralized water provision models needs to be further investigated within the larger water-service provision context.

  10. DECENTRALIZATION OF MUNICIPAL SERVICES – LEARNING BY DOING

    Directory of Open Access Journals (Sweden)

    Cristina Elena NICOLESCU

    2017-05-01

    Full Text Available Public services decentralization is a major concern for policy makers when it comes to identifying the optimum model for reorganizing these services, in light of the 3Es of the organizational performance. The field experiences show that this process is different both from one state to another, and depending on the targeted activity sector, out of which the local transport service is distinguished as an ‘institutional orphan’. Taking into account one of the smart-cities’ recognition criteria, the urban mobility, the paper aims at substantiating that, despite the specific incrementalism of the public services decentralization, having a negative impact upon the services’ efficiency, in the case of local transport service, recognizing the right to mobility and the need to ensuring the environment for exercising this right, impels the ‘bureaucratic apparatus’ to accelerate and consolidate the decentralization of this service. Therefore, the paper puts forward a case study on the impact of decentralization upon the local public transport service of Bucharest municipality.

  11. Decentralized energy: technology assessment and systems description. [Potential for implementation for years 2000 and 2025

    Energy Technology Data Exchange (ETDEWEB)

    Reckard, M K

    1979-06-01

    Decentralized energy systems and their characteristic features are examined in the report. These systems have been divided into six groups for the purpose of analysis: solar, wind, hydro, biomass, geothermal, and coproduction (total energy). The technical and economic potential for the implementation of these systems is discussed for the years 2000 and 2025. The results of a comparison of base-case and decentralized scenarios for the year 2000, using a computer systems model, are presented. Social and institutional factors are also addressed, both as motivations for and results of energy system decentralization. Appendices are included with more detailed technical information on each of the systems groups.

  12. The Decentralization of Education in Mexico.

    Science.gov (United States)

    Ornelas, Carlos

    1988-01-01

    Examines the question of why the Mexican Federal Government decided to decentralize the national system of education, going against Mexican historical trends towards centralization. Discusses five possible answers to this question, suggesting that perhaps the "shallow" structures of education are being decentralized in order to…

  13. Policy Recommendations on Decentralization, Local Power and ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2010-12-22

    Policy Recommendations on Decentralization, Local Power and Women's Rights. December 22, 2010. Image. The present document comprises a set of policy recommendations that define a global agenda on gender and decentralization. It emerged from the analysis and experiences shared during the Conference and the ...

  14. Decentralization in Botswana: the reluctant process | Dipholo ...

    African Journals Online (AJOL)

    Botswana\\'s decentralization process has always been justified in terms of democracy and development. Consequently, the government has always argued that it is fully committed to decentralization in order to promote popular participation as well as facilitating sustainable rural development. Yet the government does not ...

  15. Introducing local property tax for fiscal decentralization and local authority autonomy

    Science.gov (United States)

    Dimopoulos, Thomas; Labropoulos, Tassos; Hadjimitsis, Diafantos G.

    2015-06-01

    Charles Tiebout (1956), in his work "A Pure Theory of Local Expenditures", provides a vision of the workings of the local public sector, acknowledging many similarities to the features of a competitive market, however omitting any references to local taxation. Contrary to other researchers' claim that the Tiebout model and the theory of fiscal decentralization are by no means synonymous, this paper aims to expand Tiebout's theory, by adding the local property tax in the context, introducing a fair, ad valorem property taxation system based on the automated assessment of the value of real estate properties within the boundaries of local authorities. Computer Assisted Mass Appraisal methodology integrated with Remote Sensing technology and GIS analysis is applied to local authorities' property registries and cadastral data, building a spatial relational database and providing data to be statistically processed through Multiple Regression Analysis modeling. The proposed scheme accomplishes economy of scale using CAMA procedures on one hand, but also succeeds in making local authorities self-sufficient through a decentralized, fair, locally calibrated property taxation model, providing rational income administration.

  16. Modeling of a completely on renewable energy based power generation in 2050 in autonomous, decentralized structures; Modellierung einer vollstaendig auf erneuerbaren Energien basierenden Stromerzeugung im Jahr 2050 in autarken, dezentralen Strukturen

    Energy Technology Data Exchange (ETDEWEB)

    Peter, Stefan

    2013-09-15

    The German Federal Environmental Agency (Umweltbundesamt, UBA) has developed three radically different scenarios of a future electricity supply entirely based on renewable sources in Germany by 2050. This study investigates the technical and ecological feasibility for one of these scenarios, the ''Local Energy Autarky'' scenario, by means of computer based simulation with a high spatial and temporal resolution. The scope of this scenario is restricted to small-scale decentralized energy systems which satisfy their own power demand without being connected with each other or with outside suppliers, i.e. without electricity imports. Relying only on locally available renewable energy sources to cover the electricity demand, makes electricity storage a necessity within the simulation model. The model itself consists of different modules representing electricity demand (e.g. for households, commerce and industry), power generation of different renewable technologies, and meteorological data, such as solar irradiation, wind speed, and outside temperatures. Various basic assumptions were made with regard to future developments such as energy efficiency. The simulations were applied exemplarily to a rural community with a low population density and a town district (high population and building density), each with and without trade/industry and each at a location in northern and in southern Germany, which are representative of the different meteorological conditions affecting the power generation from renewable sources such as wind and solar. Several variations were applied to the system, e.g. with regard to the share of electricity powered private vehicles or the installed generation capacities per technology. The simulation results show that the electricity demand of private households plus the demand for a complete shift to (private) e-mobility can be covered by the assumed locally available potentials for photovoltaics and wind energy, but only for

  17. Seamless cross-scale modeling with SCHISM

    Science.gov (United States)

    Zhang, Yinglong J.; Ye, Fei; Stanev, Emil V.; Grashorn, Sebastian

    2016-06-01

    We present a new 3D unstructured-grid model (SCHISM) which is an upgrade from an existing model (SELFE). The new advection scheme for the momentum equation includes an iterative smoother to reduce excess mass produced by higher-order kriging method, and a new viscosity formulation is shown to work robustly for generic unstructured grids and effectively filter out spurious modes without introducing excessive dissipation. A new higher-order implicit advection scheme for transport (TVD2) is proposed to effectively handle a wide range of Courant numbers as commonly found in typical cross-scale applications. The addition of quadrangular elements into the model, together with a recently proposed, highly flexible vertical grid system (Zhang et al., A new vertical coordinate system for a 3D unstructured-grid model. Ocean Model. 85, 2015), leads to model polymorphism that unifies 1D/2DH/2DV/3D cells in a single model grid. Results from several test cases demonstrate the model's good performance in the eddying regime, which presents greater challenges for unstructured-grid models and represents the last missing link for our cross-scale model. The model can thus be used to simulate cross-scale processes in a seamless fashion (i.e. from deep ocean into shallow depths).

  18. Site-Scale Saturated Zone Flow Model

    Energy Technology Data Exchange (ETDEWEB)

    G. Zyvoloski

    2003-12-17

    The purpose of this model report is to document the components of the site-scale saturated-zone flow model at Yucca Mountain, Nevada, in accordance with administrative procedure (AP)-SIII.lOQ, ''Models''. This report provides validation and confidence in the flow model that was developed for site recommendation (SR) and will be used to provide flow fields in support of the Total Systems Performance Assessment (TSPA) for the License Application. The output from this report provides the flow model used in the ''Site-Scale Saturated Zone Transport'', MDL-NBS-HS-000010 Rev 01 (BSC 2003 [162419]). The Site-Scale Saturated Zone Transport model then provides output to the SZ Transport Abstraction Model (BSC 2003 [164870]). In particular, the output from the SZ site-scale flow model is used to simulate the groundwater flow pathways and radionuclide transport to the accessible environment for use in the TSPA calculations. Since the development and calibration of the saturated-zone flow model, more data have been gathered for use in model validation and confidence building, including new water-level data from Nye County wells, single- and multiple-well hydraulic testing data, and new hydrochemistry data. In addition, a new hydrogeologic framework model (HFM), which incorporates Nye County wells lithology, also provides geologic data for corroboration and confidence in the flow model. The intended use of this work is to provide a flow model that generates flow fields to simulate radionuclide transport in saturated porous rock and alluvium under natural or forced gradient flow conditions. The flow model simulations are completed using the three-dimensional (3-D), finite-element, flow, heat, and transport computer code, FEHM Version (V) 2.20 (software tracking number (STN): 10086-2.20-00; LANL 2003 [161725]). Concurrently, process-level transport model and methodology for calculating radionuclide transport in the saturated zone at Yucca

  19. Decentralized Energy from Waste Systems

    Directory of Open Access Journals (Sweden)

    Blanca Antizar-Ladislao

    2010-01-01

    Full Text Available In the last five years or so, biofuels have been given notable consideration worldwide as an alternative to fossil fuels, due to their potential to reduce greenhouse gas emissions by partial replacement of oil as a transport fuel. The production of biofuels using a sustainable approach, should consider local production of biofuels, obtained from local feedstocks and adapted to the socio-economical and environmental characteristics of the particular region where they are developed. Thus, decentralized energy from waste systems will exploit local biomass to optimize their production and consumption. Waste streams such as agricultural and wood residues, municipal solid waste, vegetable oils, and algae residues can all be integrated in energy from waste systems. An integral optimization of decentralized energy from waste systems should not be based on the optimization of each single process, but the overall optimization of the whole process. This is by obtaining optimal energy and environmental benefits, as well as collateral beneficial co-products such as soil fertilizers which will result in a higher food crop production and carbon dioxide fixation which will abate climate change.

  20. Time-Varying Scheme for Non-Centralized Model Predictive Control of Large-scale Systems

    NARCIS (Netherlands)

    Nunez Vicencio, A.A.; Ocampo-Martinez, C.; Maestre, J.M.; De Schutter, B.H.K.

    2015-01-01

    The Non-Centralized Model Predictive Control (NC-MPC) framework refers in this paper to any distributed, hierarchical, or decentralized model predictive controller (or a combination of them) the structure of which can change over time and the control actions of which are not obtained based on a

  1. Comparative LCA of decentralized wastewater treatment alternatives for non-potable urban reuse.

    Science.gov (United States)

    Opher, Tamar; Friedler, Eran

    2016-11-01

    Municipal wastewater (WW) effluent represents a reliable and significant source for reclaimed water, very much needed nowadays. Water reclamation and reuse has become an attractive option for conserving and extending available water sources. The decentralized approach to domestic WW treatment benefits from the advantages of source separation, which makes available simple small-scale systems and on-site reuse, which can be constructed on a short time schedule and occasionally upgraded with new technological developments. In this study we perform a Life Cycle Assessment to compare between the environmental impacts of four alternatives for a hypothetical city's water-wastewater service system. The baseline alternative is the most common, centralized approach for WW treatment, in which WW is conveyed to and treated in a large wastewater treatment plant (WWTP) and is then discharged to a stream. The three alternatives represent different scales of distribution of the WW treatment phase, along with urban irrigation and domestic non-potable water reuse (toilet flushing). The first alternative includes centralized treatment at a WWTP, with part of the reclaimed WW (RWW) supplied back to the urban consumers. The second and third alternatives implement de-centralized greywater (GW) treatment with local reuse, one at cluster level (320 households) and one at building level (40 households). Life cycle impact assessment results show a consistent disadvantage of the prevailing centralized approach under local conditions in Israel, where seawater desalination is the marginal source of water supply. The alternative of source separation and GW reuse at cluster level seems to be the most preferable one, though its environmental performance is only slightly better than GW reuse at building level. Centralized WW treatment with urban reuse of WWTP effluents is not advantageous over decentralized treatment of GW because the supply of RWW back to consumers is very costly in materials and

  2. Sub-Grid Scale Plume Modeling

    Directory of Open Access Journals (Sweden)

    Greg Yarwood

    2011-08-01

    Full Text Available Multi-pollutant chemical transport models (CTMs are being routinely used to predict the impacts of emission controls on the concentrations and deposition of primary and secondary pollutants. While these models have a fairly comprehensive treatment of the governing atmospheric processes, they are unable to correctly represent processes that occur at very fine scales, such as the near-source transport and chemistry of emissions from elevated point sources, because of their relatively coarse horizontal resolution. Several different approaches have been used to address this limitation, such as using fine grids, adaptive grids, hybrid modeling, or an embedded sub-grid scale plume model, i.e., plume-in-grid (PinG modeling. In this paper, we first discuss the relative merits of these various approaches used to resolve sub-grid scale effects in grid models, and then focus on PinG modeling which has been very effective in addressing the problems listed above. We start with a history and review of PinG modeling from its initial applications for ozone modeling in the Urban Airshed Model (UAM in the early 1980s using a relatively simple plume model, to more sophisticated and state-of-the-science plume models, that include a full treatment of gas-phase, aerosol, and cloud chemistry, embedded in contemporary models such as CMAQ, CAMx, and WRF-Chem. We present examples of some typical results from PinG modeling for a variety of applications, discuss the implications of PinG on model predictions of source attribution, and discuss possible future developments and applications for PinG modeling.

  3. Treatment Outcomes in a Decentralized Antiretroviral Therapy Program: A Comparison of Two Levels of Care in North Central Nigeria

    Directory of Open Access Journals (Sweden)

    Prosper Okonkwo

    2014-01-01

    Full Text Available Background. Decentralization of antiretroviral therapy (ART services is a key strategy to achieving universal access to treatment for people living with HIV/AIDS. Our objective was to assess clinical and laboratory outcomes within a decentralized program in Nigeria. Methods. Using a tiered hub-and-spoke model to decentralize services, a tertiary hospital scaled down services to 13 secondary-level hospitals using national and program guidelines. We obtained sociodemographic, clinical, and immunovirologic data on previously antiretroviral drug naïve patients aged ≥15 years that received HAART for at least 6 months and compared treatment outcomes between the prime and satellite sites. Results. Out of 7,747 patients, 3729 (48.1% were enrolled at the satellites while on HAART, prime site patients achieved better immune reconstitution based on CD4+ cell counts at 12 (P<0.001 and 24 weeks (P<0.001 with similar responses at 48 weeks (P=0.11 and higher rates of viral suppression (<400 c/mL at 12 (P<0.001 and 48 weeks (P=0.03, but similar responses at 24 weeks (P=0.21. Mortality was 2.3% versus 5.0% (P<0.001 at prime and satellite sites, while transfer rate was 8.7% versus 5.5% (P=0.001 at prime and satellites. Conclusion. ART decentralization is feasible in resource-limited settings, but efforts have to be intensified to maintain good quality of care.

  4. Phenomenology of Low Quantum Gravity Scale Models

    CERN Document Server

    Benakli, Karim

    1999-01-01

    We study some phenomenological implications of models where the scale of quantum gravity effects lies much below the four-dimensional Planck scale. These models arise from M-theory vacua where either the internal space volume is large or the string coupling is very small. We provide a critical analysis of ways to unify electroweak, strong and gravitational interactions in M-theory. We discuss the relations between different scales in two M-vacua: Type I strings and Ho\\v rava--Witten supergravity models. The latter allows possibilities for an eleven-dimensional scale at TeV energies with one large dimension below separating our four-dimensional world from a hidden one. Different mechanisms for breaking supersymmetry (gravity mediated, gauge mediated and Scherk-Schwarz mechanisms) are discussed in this framework. Some phenomenological issues such as dark matter (with masses that may vary in time), origin of neutrino masses and axion scale are discussed. We suggest that these are indications that the string scal...

  5. Bitcoin as a decentralized currency

    Directory of Open Access Journals (Sweden)

    Dinić Vladimir

    2014-01-01

    Full Text Available Bitcoin is the first decentralized peer-to-peer crypto-currency founded in 2009. Its main specificity is the fact that there is no issuer of this currency. On the other hand, the supply of this currency is software-programmed and limited. Among other things, its main features are relatively secure payments, low transaction costs, anonymity, inability of counterfeiting, irreversibility of transactions, but also extremely unstable exchange rate. Despite many advantages, the use of this currency is subject of numerous discussions, as this currency offers the possibility of performing various abuses and criminal activities. The future of this and other currencies in this regard depends on both security and privacy of these currencies, and legal regulation of such payments.

  6. Scaling model for symmetric star polymers

    Science.gov (United States)

    Ramachandran, Ram; Rai, Durgesh K.; Beaucage, Gregory

    2010-03-01

    Neutron scattering data from symmetric star polymers with six poly (urethane-ether) arms, chemically bonded to a C-60 molecule are fitted using a new scaling model and scattering function. The new scaling function can describe both good solvent and theta solvent conditions as well as resolve deviations in chain conformation due to steric interactions between star arms. The scaling model quantifies the distinction between invariant topological features for this star polymer and chain tortuosity which changes with goodness of solvent and steric interaction. Beaucage G, Phys. Rev. E 70 031401 (2004).; Ramachandran R, et al. Macromolecules 41 9802-9806 (2008).; Ramachandran R, et al. Macromolecules, 42 4746-4750 (2009); Rai DK et al. Europhys. Lett., (Submitted 10/2009).

  7. Agent-Based Decentralized Control Method for Islanded Microgrids

    DEFF Research Database (Denmark)

    Li, Qiang; Chen, Feixiong; Chen, Minyou

    2016-01-01

    In this paper, an agent-based decentralized control model for islanded microgrids is proposed, which consists of a two-layer control structure. The bottom layer is the electrical distribution microgrid, while the top layer is the communication network composed of agents. An agent is regarded...... is processed according to control laws, agents adjust the production of distributed generators to which they connect. The main contributions of this paper are (i) an agent-based model for decentralized secondary control is introduced and the rules to establish the communication network are given; (ii......) a systematic method is presented, which can be used to derive a set of control laws for agents from any given communication network, where only local information is needed. Furthermore, it has been seen that the output power supplied by distributed generators satisfies the load demand in the microgrid, when...

  8. Decentralization and financial autonomy: a challenge for local public authorities in the Republic of Moldova

    Directory of Open Access Journals (Sweden)

    Tatiana MANOLE

    2017-09-01

    Full Text Available This article reflects the decentralization process currently taking place in the Republic of Moldova. The purpose of the research is to acquaint readers with the fundamental concept of decentralization, with the areas of administrative decentralization, with the forms of manifestation of financial decentralization: fiscal decentralization and budget decentralization. The priorities of the decentralization process are identified.

  9. Landscape modelling at Regional to Continental scales

    Science.gov (United States)

    Kirkby, M. J.

    Most work on simulating landscape evolution has been focused at scales of about 1 Ha, there are still limitations, particularly in understanding the links between hillslope process rates and climate, soils and channel initiation. However, the need for integration with GCM outputs and with Continental Geosystems now imposes an urgent need for scaling up to Regional and Continental scales. This is reinforced by a need to incorporate estimates of soil erosion and desertification rates into national and supra-national policy. Relevant time-scales range from decadal to geological. Approaches at these regional to continental scales are critical to a fuller collaboration between geomorphologists and others interested in Continental Geosystems. Two approaches to the problem of scaling up are presented here for discussion. The first (MEDRUSH) is to embed representative hillslope flow strips into sub-catchments within a larger catchment of up to 5,000 km2. The second is to link one-dimensional models of SVAT type within DEMs at up to global scales (CSEP/SEDWEB). The MEDRUSH model is being developed as part of the EU Desertification Programme (MEDALUS project), primarily for semi-natural vegetation in southern Europe over time spans of up to 100 years. Catchments of up to 2500 km2 are divided into 50-200 sub-catchments on the basis of flow paths derived from DEMs with a horizontal resolution of 50 m or better. Within each sub-catchment a representative flow strip is selected and Hydrology, Sediment Transport and Vegetation change are simulated in detail for the flow strip, using a 1 hour time step. Changes within each flow strip are transferred back to the appropriate sub-catchment and flows of water and sediment are then routed through the channel network, generating changes in flood plain morphology.

  10. Blockchain technology and decentralized governance: Is the state still necessary?

    Directory of Open Access Journals (Sweden)

    Marcella Atzori

    2017-03-01

    Full Text Available The core technology of Bitcoin, the blockchain, has recently emerged as a disruptive innovation with a wide range of applications, potentially able to redesign our interactions in business, politics and society at large. Although scholarly interest in this subject is growing, a comprehensive analysis of blockchain applications from a political perspective is severely lacking to date. This paper aims to fill this gap and it discusses the key points of blockchain-based decentralized governance, which challenges to varying degrees the traditional mechanisms of State authority, citizenship and democracy. In particular, the paper verifies to which extent blockchain and decentralized platforms can be considered as hyper-political tools, capable to manage social interactions on large scale and dismiss traditional central authorities. The analysis highlights risks related to a dominant position of private powers in distributed ecosystems, which may lead to a general disempowerment of citizens and to the emergence of a stateless global society. While technological utopians urge the demise of any centralized institution, this paper advocates the role of the State as a necessary central point of coordination in society, showing that decentralization through algorithm-based consensus is an organizational theory, not a stand-alone political theory.

  11. Decentralization of a Machine: Some Definitions

    OpenAIRE

    Dubey, Pradeep

    2015-01-01

    We define some notions of the decentralization of a deterministic input-output machine. This opens the possibility for introducing game-theoretic elements -- such as strategic players -- inside the machine, as part of its design.

  12. The effects of fiscal decentralization in Albania

    Directory of Open Access Journals (Sweden)

    Dr.Sc. Blerta Dragusha

    2012-06-01

    Full Text Available “Basically decentralization is a democratic reform which seeks to transfer the political, administrative, financial and planning authority from central to local government. It seeks to develop civic participation, empowerment of local people in decision making process and to promote accountability and reliability: To achieve efficiency and effectiveness in the collection and management of resources and service delivery”1 The interest and curiosity of knowing how our country is doing in this process, still unfinished, served as a motivation forme to treat this topic: fiscal decentralization as a process of giving 'power' to local governments, not only in terms of rights deriving from this process but also on the responsibilities that come with it. Which are the stages before and after decentralization, and how has it affected the process in several key indicators? Is decentralization a good process only, or can any of its effects be seen as an disadvantage?

  13. Gender, Power Relations and Decentralization in Pakistan

    International Development Research Centre (IDRC) Digital Library (Canada)

    Karen Kershaw

    Gender, Power Relations and. Decentralization in Pakistan. Strengthening Women's Participation in. Political Space Through Affirmative Action. Fareeha Ummar, Virginia Khan, Shakila Bibi. Rural Support Programmes Network. Pakistan. Parallel Sessions II - Session B ...

  14. Towards dynamic genome-scale models.

    Science.gov (United States)

    Gilbert, David; Heiner, Monika; Jayaweera, Yasoda; Rohr, Christian

    2017-10-13

    The analysis of the dynamic behaviour of genome-scale models of metabolism (GEMs) currently presents considerable challenges because of the difficulties of simulating such large and complex networks. Bacterial GEMs can comprise about 5000 reactions and metabolites, and encode a huge variety of growth conditions; such models cannot be used without sophisticated tool support. This article is intended to aid modellers, both specialist and non-specialist in computerized methods, to identify and apply a suitable combination of tools for the dynamic behaviour analysis of large-scale metabolic designs. We describe a methodology and related workflow based on publicly available tools to profile and analyse whole-genome-scale biochemical models. We use an efficient approximative stochastic simulation method to overcome problems associated with the dynamic simulation of GEMs. In addition, we apply simulative model checking using temporal logic property libraries, clustering and data analysis, over time series of reaction rates and metabolite concentrations. We extend this to consider the evolution of reaction-oriented properties of subnets over time, including dead subnets and functional subsystems. This enables the generation of abstract views of the behaviour of these models, which can be large-up to whole genome in size-and therefore impractical to analyse informally by eye. We demonstrate our methodology by applying it to a reduced model of the whole-genome metabolism of Escherichia coli K-12 under different growth conditions. The overall context of our work is in the area of model-based design methods for metabolic engineering and synthetic biology. © The Author 2017. Published by Oxford University Press.

  15. Drift-Scale THC Seepage Model

    Energy Technology Data Exchange (ETDEWEB)

    C.R. Bryan

    2005-02-17

    The purpose of this report (REV04) is to document the thermal-hydrologic-chemical (THC) seepage model, which simulates the composition of waters that could potentially seep into emplacement drifts, and the composition of the gas phase. The THC seepage model is processed and abstracted for use in the total system performance assessment (TSPA) for the license application (LA). This report has been developed in accordance with ''Technical Work Plan for: Near-Field Environment and Transport: Coupled Processes (Mountain-Scale TH/THC/THM, Drift-Scale THC Seepage, and Post-Processing Analysis for THC Seepage) Report Integration'' (BSC 2005 [DIRS 172761]). The technical work plan (TWP) describes planning information pertaining to the technical scope, content, and management of this report. The plan for validation of the models documented in this report is given in Section 2.2.2, ''Model Validation for the DS THC Seepage Model,'' of the TWP. The TWP (Section 3.2.2) identifies Acceptance Criteria 1 to 4 for ''Quantity and Chemistry of Water Contacting Engineered Barriers and Waste Forms'' (NRC 2003 [DIRS 163274]) as being applicable to this report; however, in variance to the TWP, Acceptance Criterion 5 has also been determined to be applicable, and is addressed, along with the other Acceptance Criteria, in Section 4.2 of this report. Also, three FEPS not listed in the TWP (2.2.10.01.0A, 2.2.10.06.0A, and 2.2.11.02.0A) are partially addressed in this report, and have been added to the list of excluded FEPS in Table 6.1-2. This report has been developed in accordance with LP-SIII.10Q-BSC, ''Models''. This report documents the THC seepage model and a derivative used for validation, the Drift Scale Test (DST) THC submodel. The THC seepage model is a drift-scale process model for predicting the composition of gas and water that could enter waste emplacement drifts and the effects of mineral

  16. Scale Anchoring with the Rasch Model.

    Science.gov (United States)

    Wyse, Adam E

    Scale anchoring is a method to provide additional meaning to particular scores at different points along a score scale by identifying representative items associated with the particular scores. These items are then analyzed to write statements of what types of performance can be expected of a person with the particular scores to help test takers and other stakeholders better understand what it means to achieve the different scores. This article provides simple formulas that can be used to identify possible items to serve as scale anchors with the Rasch model. Specific attention is given to practical considerations and challenges that may be encountered when applying the formulas in different contexts. An illustrative example using data from a medical imaging certification program demonstrates how the formulas can be applied in practice.

  17. [Significant changes in the health system decentralization process in Brazil].

    Science.gov (United States)

    Viana, Ana Luiza d'Avila; Heimann, Luiza S; de Lima, Luciana Dias; de Oliveira, Roberta Gondim; Rodrigues, Sergio da Hora

    2002-01-01

    This article discusses the trends and limits of the Brazilian health system decentralization process, identifying the three elements that constitute the strategic induction performed by the national system administrator in accordance with the guidelines contained in the Operational Norms of the Unified National Health System: systemic rationality, intergovernmental and service provider financing, and health care model. The effects of the Federal regulations are analyzed based on the results of the evaluation study focused on the implementation of the full management scheme at the Municipal level. The decentralization strategy induced by Basic Operational Norm 96 has succeeded in improving institutional conditions, management autonomy, and supply, as measured by the Federal resources transferred, installed capacity, production, and coverage of outpatient and hospital services, with the Municipalities authorized to conduct fully autonomous management, without altering the existing patterns of inequity in the distribution of funds to poorer Municipalities.

  18. Genome scale metabolic modeling of cancer

    DEFF Research Database (Denmark)

    Nilsson, Avlant; Nielsen, Jens

    2017-01-01

    Cancer cells reprogram metabolism to support rapid proliferation and survival. Energy metabolism is particularly important for growth and genes encoding enzymes involved in energy metabolism are frequently altered in cancer cells. A genome scale metabolic model (GEM) is a mathematical formalization...... of metabolism which allows simulation and hypotheses testing of metabolic strategies. It has successfully been applied to many microorganisms and is now used to study cancer metabolism. Generic models of human metabolism have been reconstructed based on the existence of metabolic genes in the human genome....... Cancer specific models of metabolism have also been generated by reducing the number of reactions in the generic model based on high throughput expression data, e.g. transcriptomics and proteomics. Targets for drugs and bio markers for diagnostics have been identified using these models. They have also...

  19. Pore-Scale Model for Microbial Growth

    Science.gov (United States)

    Tartakovsky, G.; Tartakovsky, A. M.; Scheibe, T. D.

    2011-12-01

    A lagrangian particle model based on smoothed particle hydrodynamics (SPH) is used to simulate pore-scale flow, reactive transport and biomass growth which is controlled by the mixing of an electron donor and acceptor, in a microfluidic porous cell. The experimental results described in Ch. Zhang et al "Effects of pore-scale heterogeneity and transverse mixing on bacterial growth in porous media" were used for this study. The model represents the homogeneous pore structure of a uniform array of cylindrical posts with microbes uniformly distributed on the grain surfaces. Each one of the two solutes (electron donor and electron acceptor) enters the domain unmixed through separate inlets. In the model, pair-wise particle-particle interactions are used to simulate interactions within the biomass, and both biomass-fluid and biomass-soil grain interactions. The biomass growth rate is described by double Monod kinetics. For the set of parameters used in the simulations the model predicts that: 1) biomass grows in the shape of bridges connecting soil grains and oriented in the direction of flow so as to minimize resistance to the fluid flow; and 2) the biomass growth occurs only in the mixing zone. Using parameters available in the literature, the biomass growth model agrees qualitatively with the experimental results. In order to achieve quantitative agreement, model calibration is required.

  20. Decentralization and Change in Teaching Style in Sweden: The Emergence and Expansion of the "Working Team" (arbetslag) from 1960 to 1980

    OpenAIRE

    林, 寛平

    2014-01-01

    This paper discusses the change in teaching style in Sweden from 1960 to 1980 stemming from the decentralization reform in education. This discussion is important in two ways: to focus on the Swedish case as a suggestive model for Japan and to link decentralization as an administration reform with what happened in the classrooms.Decentralization is one of the key agendas in education reform in many countries, with Sweden having received much attention as a pioneer in the field. It is importan...

  1. Subsecond Tsunamis and Delays in Decentralized Electronic Systems

    Directory of Open Access Journals (Sweden)

    Pedro D. Manrique

    2017-10-01

    Full Text Available Driven by technological advances and economic gain, society’s electronic systems are becoming larger, faster, more decentralized and autonomous, and yet with increasing global reach. A prime example are the networks of financial markets which—in contrast to popular perception—are largely all-electronic and decentralized with no top-down real-time controller. This prototypical system generates complex subsecond dynamics that emerge from a decentralized network comprising heterogeneous hardware and software components, communications links, and a diverse ecology of trading algorithms that operate and compete within this all-electronics environment. Indeed, these same technological and economic drivers are likely to generate a similarly competitive all-electronic ecology in a variety of future cyberphysical domains such as e-commerce, defense and the transportation system, including the likely appearance of large numbers of autonomous vehicles on the streets of many cities. Hence there is an urgent need to deepen our understanding of stability, safety and security across a wide range of ultrafast, large, decentralized all-electronic systems—in short, society will eventually need to understand what extreme behaviors can occur, why, and what might be the impact of both intentional and unintentional system perturbations. Here we set out a framework for addressing this issue, using a generic model of heterogeneous, adaptive, autonomous components where each has a realistic limit on the amount of information and processing power available to it. We focus on the specific impact of delayed information, possibly through an accidental shift in the latency of information transmission, or an intentional attack from the outside. While much remains to be done in terms of developing formal mathematical results for this system, our preliminary results indicate the type of impact that can occur and the structure of a mathematical theory which may

  2. Game-Based Virtual Worlds as Decentralized Virtual Activity Systems

    Science.gov (United States)

    Scacchi, Walt

    There is widespread interest in the development and use of decentralized systems and virtual world environments as possible new places for engaging in collaborative work activities. Similarly, there is widespread interest in stimulating new technological innovations that enable people to come together through social networking, file/media sharing, and networked multi-player computer game play. A decentralized virtual activity system (DVAS) is a networked computer supported work/play system whose elements and social activities can be both virtual and decentralized (Scacchi et al. 2008b). Massively multi-player online games (MMOGs) such as World of Warcraft and online virtual worlds such as Second Life are each popular examples of a DVAS. Furthermore, these systems are beginning to be used for research, deve-lopment, and education activities in different science, technology, and engineering domains (Bainbridge 2007, Bohannon et al. 2009; Rieber 2005; Scacchi and Adams 2007; Shaffer 2006), which are also of interest here. This chapter explores two case studies of DVASs developed at the University of California at Irvine that employ game-based virtual worlds to support collaborative work/play activities in different settings. The settings include those that model and simulate practical or imaginative physical worlds in different domains of science, technology, or engineering through alternative virtual worlds where players/workers engage in different kinds of quests or quest-like workflows (Jakobsson 2006).

  3. Robust Decentralized Nonlinear Control for a Twin Rotor MIMO System.

    Science.gov (United States)

    Belmonte, Lidia María; Morales, Rafael; Fernández-Caballero, Antonio; Somolinos, José Andrés

    2016-07-27

    This article presents the design of a novel decentralized nonlinear multivariate control scheme for an underactuated, nonlinear and multivariate laboratory helicopter denominated the twin rotor MIMO system (TRMS). The TRMS is characterized by a coupling effect between rotor dynamics and the body of the model, which is due to the action-reaction principle originated in the acceleration and deceleration of the motor-propeller groups. The proposed controller is composed of two nested loops that are utilized to achieve stabilization and precise trajectory tracking tasks for the controlled position of the generalized coordinates of the TRMS. The nonlinear internal loop is used to control the electrical dynamics of the platform, and the nonlinear external loop allows the platform to be perfectly stabilized and positioned in space. Finally, we illustrate the theoretical control developments with a set of experiments in order to verify the effectiveness of the proposed nonlinear decentralized feedback controller, in which a comparative study with other controllers is performed, illustrating the excellent performance of the proposed robust decentralized control scheme in both stabilization and trajectory tracking tasks.

  4. Anomalous scalings in differential models of turbulence

    CERN Document Server

    Thalabard, Simon; Galtier, Sebastien; Sergey, Medvedev

    2015-01-01

    Differential models for hydrodynamic, passive-scalar and wave turbulence given by nonlinear first- and second-order evolution equations for the energy spectrum in the $k$-space were analysed. Both types of models predict formation an anomalous transient power-law spectra. The second-order models were analysed in terms of self-similar solutions of the second kind, and a phenomenological formula for the anomalous spectrum exponent was constructed using numerics for a broad range of parameters covering all known physical examples. The first-order models were examined analytically, including finding an analytical prediction for the anomalous exponent of the transient spectrum and description of formation of the Kolmogorov-type spectrum as a reflection wave from the dissipative scale back into the inertial range. The latter behaviour was linked to pre-shock/shock singularities similar to the ones arising in the Burgers equation. Existence of the transient anomalous scaling and the reflection-wave scenario are argu...

  5. Multi-scale modeling of composites

    DEFF Research Database (Denmark)

    Azizi, Reza

    behavior and the trapped free energy in the material, in addition to the plastic behavior in terms of the anisotropic development of the yield surface. It is shown that a generalization of Hill’s anisotropic yield criterion can be used to model the Bauschinger effect, in addition to the pressure and size...... is analyzed using a Representative Volume Element (RVE), while the homogenized data are saved and used as an input to the macro scale. The dependence of fiber size is analyzed using a higher order plasticity theory, where the free energy is stored due to plastic strain gradients at the micron scale. Hill...... dependence. The development of the macroscopic yield surface upon deformation is investigated in terms of the anisotropic hardening (expansion of the yield surface) and kinematic hardening (translation of the yield surface). The kinematic hardening law is based on trapped free energy in the material due...

  6. Multi-scale modelling and dynamics

    Science.gov (United States)

    Müller-Plathe, Florian

    Moving from a fine-grained particle model to one of lower resolution leads, with few exceptions, to an acceleration of molecular mobility, higher diffusion coefficient, lower viscosities and more. On top of that, the level of acceleration is often different for different dynamical processes as well as for different state points. While the reasons are often understood, the fact that coarse-graining almost necessarily introduces unpredictable acceleration of the molecular dynamics severely limits its usefulness as a predictive tool. There are several attempts under way to remedy these shortcoming of coarse-grained models. On the one hand, we follow bottom-up approaches. They attempt already when the coarse-graining scheme is conceived to estimate their impact on the dynamics. This is done by excess-entropy scaling. On the other hand, we also pursue a top-down development. Here we start with a very coarse-grained model (dissipative particle dynamics) which in its native form produces qualitatively wrong polymer dynamics, as its molecules cannot entangle. This model is modified by additional temporary bonds, so-called slip springs, to repair this defect. As a result, polymer melts and solutions described by the slip-spring DPD model show correct dynamical behaviour. Read more: ``Excess entropy scaling for the segmental and global dynamics of polyethylene melts'', E. Voyiatzis, F. Müller-Plathe, and M.C. Böhm, Phys. Chem. Chem. Phys. 16, 24301-24311 (2014). [DOI: 10.1039/C4CP03559C] ``Recovering the Reptation Dynamics of Polymer Melts in Dissipative Particle Dynamics Simulations via Slip-Springs'', M. Langeloth, Y. Masubuchi, M. C. Böhm, and F. Müller-Plathe, J. Chem. Phys. 138, 104907 (2013). [DOI: 10.1063/1.4794156].

  7. Sustainability evaluation of decentralized electricity generation

    Energy Technology Data Exchange (ETDEWEB)

    Karger, Cornelia R.; Hennings, Wilfried [Research Centre Juelich, Programme Group Humans, Environment, Technology (MUT), 52425 Juelich (Germany)

    2009-04-15

    Decentralized power generation is gaining significance in liberalized electricity markets. An increasing decentralization of power supply is expected to make a particular contribution to climate protection. This article investigates the advantages and disadvantages of decentralized electricity generation according to the overall concept of sustainable development. On the basis of a hierarchically structured set of sustainability criteria, four future scenarios for Germany are assessed, all of which describe different concepts of electricity supply in the context of the corresponding social and economic developments. The scenarios are developed in an explorative way according to the scenario method and the sustainability criteria are established by a discursive method with societal actors. The evaluation is carried out by scientific experts. By applying an expanded analytic hierarchy process (AHP), a multicriteria evaluation is conducted that identifies dissent among the experts. The results demonstrate that decentralized electricity generation can contribute to climate protection. The extent to which it simultaneously guarantees security of supply is still a matter of controversy. However, experts agree that technical and economic boundary conditions are of major importance in this field. In the final section, the article discusses the method employed here as well as implications for future decentralized energy supply. (author)

  8. [Decentralized outpatient teams in community-based psychiatric care: comparison of two Bavarian rural catchment areas].

    Science.gov (United States)

    Valdes-Stauber, J; Putzhammer, A; Kilian, R

    2014-05-01

    Psychiatric outpatient clinics (PIAs) are an indispensable care service for crisis intervention and multidisciplinary treatment of people suffering from severe and persistent mental disorders. The decentralization of outpatient clinics can be understood as a further step in the deinstitutionalization process. This cross-sectional study (n=1,663) compared the central outpatient clinic with the decentralized teams for the year 2010 by means of analyses of variance, χ(2)-tests and robust multivariate regression models. The longitudinal assessment (descriptively and by means of Prais-Winsten regression models for time series) was based on all hospitalizations for the two decentralized teams (n = 6,693) according to partial catchment areas for the time period 2002-2010 in order to examine trends after their installation in the year 2007. Decentralized teams were found to be similar with respect to the care profile but cared for relatively more patients suffering from dementia, addictive and mood disorders but not for those suffering from schizophrenia and personality disorders. Decentralized teams showed less outpatient care costs as well as psychopharmacological expenses but a lower contact frequency than the central outpatient clinic. Total expenses for psychiatric care were not significantly different and assessed hospitalization variables (e.g. total number of annual admissions, cumulative length of inpatient-stay and annual hospitalizations per patient) changed slightly 3 years after installation of the decentralized teams. The number of admissions of people suffering from schizophrenia decreased whereas those for mood and stress disorders increased. Decentralized outpatient teams seemed to reach patients in rural regions who previously were not reached by the central outpatient clinic. Economic figures indicate advantages for the installation of such teams because care expenses are not higher than for patients treated in centralized outpatient clinics and

  9. Decentralization, institutional ambiguity, and mineral resource conflict in Mindanao, Philippines

    NARCIS (Netherlands)

    Verbrugge, B.L.P.

    2015-01-01

    Based on an analytical framework that builds on theories of incremental institutional change, this article interrogates the relationship between decentralization and mineral resource conflict in the Philippines. Here, efforts to decentralize control over mineral resource wealth have resulted in a

  10. Strategies of Educational Decentralization: Key Questions and Core Issues.

    Science.gov (United States)

    Hanson, E. Mark

    1998-01-01

    Explains key issues and forces that shape organization and management strategies of educational decentralization, using examples from Colombia, Venezuela, Argentina, Nicaragua, and Spain. Core decentralization issues include national and regional goals, planning, political stress, resource distribution, infrastructure development, and job…

  11. Convergent Double Auction Mechanism for a Prosumers' Decentralized Smart Grid

    National Research Council Canada - National Science Library

    Tadahiro Taniguchi; Tomohiro Takata; Yoshiro Fukui; Koki Kawasaki

    2015-01-01

    ...) for a prosumers' decentralized smart grid. The target decentralized smart grid is a regional electricity network that consists of many prosumers that have a battery and a renewable energy-based generator, such as photovoltaic cells...

  12. Decentralization and the local development state

    DEFF Research Database (Denmark)

    Emmenegger, Rony Hugo

    2016-01-01

    This article explores the politics of decentralization and state-peasant encounters in rural Oromiya, Ethiopia. Breaking with a centralized past, the incumbent government of the Ethiopian People's Revolutionary Democratic Front (EPRDF) committed itself to a decentralization policy in the early 1990......s and has since then created a number of new sites for state-citizen interactions. In the context of electoral authoritarianism, however, decentralization has been interpreted as a means for the expansion of the party-state at the grass-roots level. Against this backdrop, this article attempts...... a more nuanced understanding of the complex entanglements between the closure of political space and faith in progress in local arenas. Hence, it follows sub-kebele institutions at the community level in a rural district and analyses their significance for state-led development and peasant mobilization...

  13. Modelling landscape evolution at the flume scale

    Science.gov (United States)

    Cheraghi, Mohsen; Rinaldo, Andrea; Sander, Graham C.; Barry, D. Andrew

    2017-04-01

    The ability of a large-scale Landscape Evolution Model (LEM) to simulate the soil surface morphological evolution as observed in a laboratory flume (1-m × 2-m surface area) was investigated. The soil surface was initially smooth, and was subjected to heterogeneous rainfall in an experiment designed to avoid rill formation. Low-cohesive fine sand was placed in the flume while the slope and relief height were 5 % and 20 cm, respectively. Non-uniform rainfall with an average intensity of 85 mm h-1 and a standard deviation of 26 % was applied to the sediment surface for 16 h. We hypothesized that the complex overland water flow can be represented by a drainage discharge network, which was calculated via the micro-morphology and the rainfall distribution. Measurements included high resolution Digital Elevation Models that were captured at intervals during the experiment. The calibrated LEM captured the migration of the main flow path from the low precipitation area into the high precipitation area. Furthermore, both model and experiment showed a steep transition zone in soil elevation that moved upstream during the experiment. We conclude that the LEM is applicable under non-uniform rainfall and in the absence of surface incisions, thereby extending its applicability beyond that shown in previous applications. Keywords: Numerical simulation, Flume experiment, Particle Swarm Optimization, Sediment transport, River network evolution model.

  14. Decentralizing decision making in modularization strategies

    DEFF Research Database (Denmark)

    Israelsen, Poul; Jørgensen, Brian

    2011-01-01

    that aligns the descriptions of the economic consequences of modularization at the project and portfolio level which makes it possible to decentralize decision making while making sure that local goals are congruent with the global ones in order to avoid suboptimal behaviour. Keywords: Modularization...... which distorts the economic effects of modularization at the level of the individual product. This has the implication that decisions on modularization can only be made by top management if decision authority and relevant information are to be aligned. To overcome this problem, we suggest a solution......; Accounting; Cost allocation; Decision rule; Decentralization...

  15. Decentralized enforcement, sequential bargaining, and the clean development mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Hovi, Jon

    2001-07-01

    While there is a vast literature both on international bargaining and on how international agreements can be enforced, very little work has been done on how bargaining and enforcement interact. An important exception is Fearon (1998), who models international cooperation as a two-stage process in which the bargaining process is constrained by a need for decentralized enforcement (meaning that the agreement must be enforced by the parties themselves rather than a third party, such as a court). Using the Clean Development Mechanism as an example, the present paper proposes a different model of this kind of interaction. The model follows Fearon's in so far as we both use the infinitely repeated Prisoners' Dilemma to capture the enforcement phase of the game. However, while Fearon depicts the bargaining stage as a War of Attrition, the present model sees that stage as a sequential bargaining game of the Staahl-Rubinstein type. The implications of the present model are compared both to those of the Staahl-Rubinstein model and to those of the Fearon model. A surprising conclusion is that a need for decentralized enforcement tends to make the bargaining outcome more symmetrical than otherwise. Thus, the impact of bargaining power is actually smaller when the resulting agreement must be enforced by the parties themselves than it is if enforcement is taken care of by a third party. (author)

  16. Decentralization and Economic Growth per capita in Europe

    NARCIS (Netherlands)

    Crucq, Pieter; Hemminga, Hendrik-Jan

    2007-01-01

    In this paper the relationship between decentralization and economic growth is investigated. The focus is on decentralization from the national government to the highest substate level in a country, which we define as regional decentralization. Section 2 discusses the different dimensions of

  17. Educational Decentralization, Public Spending, and Social Justice in Nigeria

    Science.gov (United States)

    Geo-Jaja, Macleans A.

    2006-01-01

    This study situates the process of educational decentralization in the narrower context of social justice. Its main object, however, is to analyze the implications of decentralization for strategies of equity and social justice in Nigeria. It starts from the premise that the early optimism that supported decentralization as an efficient and…

  18. Scaling in a Multispecies Network Model Ecosystem

    CERN Document Server

    Solé, R V; McKane, A; Sole, Ricard V.; Alonso, David; Kane, Alan Mc

    1999-01-01

    A new model ecosystem consisting of many interacting species is introduced. The species are connected through a random matrix with a given connectivity. It is shown that the system is organized close to a boundary of marginal stability in such a way that fluctuations follow power law distributions both in species abundance and their lifetimes for some slow-driving (immigration) regime. The connectivity and the number of species are linked through a scaling relation which is the one observed in real ecosystems. These results suggest that the basic macroscopic features of real, species-rich ecologies might be linked with a critical state. A natural link between lognormal and power law distributions of species abundances is suggested.

  19. Functional decentralization Construct in Decentralization Policy in Indonesia (A study of Irrigation, Education, and Free trade sectors)

    OpenAIRE

    Arif, Alma; Maksum, Irfan Ridwan

    2017-01-01

    This research analyze the practice of irrigation, education, and free trade governance linked with functional decentralization concept in Indonesia’s decentralization policy frame. This research use constructivist approach and qualitative-descriptive method. Research result find several factors that cause functional decentralization in Indonesia’s decentralization policy for irrigation, education, and free trade is not adopted. Political institution is not adopted, independence of the farmers...

  20. Decentralized generation of electricity from biomass with proton exchange membrane fuel cell

    Science.gov (United States)

    Toonssen, Richard; Woudstra, Nico; Verkooijen, Adrian H. M.

    Biomass can be applied as the primary source for the production of hydrogen in the future. The biomass is converted in an atmospheric fluidized bed gasification process using steam as the gasifying agent. The producer gas needs further cleaning and processing before the hydrogen can be converted in a fuel cell; it is assumed that the gas cleaning processes are able to meet the requirements for a PEM-FC. The compressed hydrogen is supplied to a hydrogen grid and can be used in small-scale decentralized CHP units. In this study it is assumed that the CHP units are based on low temperature PEM fuel cells. For the evaluation of alternative technologies the whole chain of centralized hydrogen production from biomass up to and including decentralized electricity production in PEM fuel cells is considered. Two models for the production of hydrogen from biomass and three models for the combined production of electricity and heat with PEM fuel cells are built using the computer program Cycle-Tempo. Two different levels of hydrogen purity are considered in this evaluation: 60% and 99.99% pure hydrogen. The purity of the hydrogen affects both the efficiencies of the hydrogen production as well as the PEM-FC systems. The electrical exergy efficiency of the PEM-FC system without additional heat production is calculated to be 27.66% in the case of 60% hydrogen and 29.06% in the case of 99.99% pure hydrogen. The electrical exergy efficiencies of the whole conversion chain appear to be 21.68% and 18.74%, respectively. The high losses during purification of the hydrogen gas result in a higher efficiency for the case with low purity hydrogen. The removal of the last impurities strongly increases the overall exergy losses of the conversion chain.

  1. Semi-decentralized Strategies in Structural Vibration Control

    Directory of Open Access Journals (Sweden)

    F. Palacios-Quiñonero

    2011-04-01

    Full Text Available In this work, the main ideas involved in the design of overlapping and multi-overlapping controllers via the Inclusion Principle are discussed and illustrated in the context of the Structural Vibration Control of tall buildings under seismic excitation. A detailed theoretical background on the Inclusion Principle and the design of overlapping controllers is provided. Overlapping and multi-overlapping LQR controllers are designed for a simplified five-story building model. Numerical simulations are conducted to asses the performance of the proposed semi-decentralized controllers with positive results.

  2. Decentralized Reinforcement Learning of robot behaviors

    NARCIS (Netherlands)

    Leottau, David L.; Ruiz-del-Solar, Javier; Babuska, R.

    2018-01-01

    A multi-agent methodology is proposed for Decentralized Reinforcement Learning (DRL) of individual behaviors in problems where multi-dimensional action spaces are involved. When using this methodology, sub-tasks are learned in parallel by individual agents working toward a common goal. In

  3. Women's Political Representation and Participation in Decentralized ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Huairou Commission User

    To harmonize the provisions of the 1995 constitution with decentralization, the local government act was passed in 1997. • Resistance Council (RC) introduced to facilitate people's participation in national development through ensuring sound local level politics. • RC evolved into local councils which then led.

  4. Towards a Decentralized Magnetic Indoor Positioning System

    Directory of Open Access Journals (Sweden)

    Zakaria Kasmi

    2015-12-01

    Full Text Available Decentralized magnetic indoor localization is a sophisticated method for processing sampled magnetic data directly on a mobile station (MS, thereby decreasing or even avoiding the need for communication with the base station. In contrast to central-oriented positioning systems, which transmit raw data to a base station, decentralized indoor localization pushes application-level knowledge into the MS. A decentralized position solution has thus a strong feasibility to increase energy efficiency and to prolong the lifetime of the MS. In this article, we present a complete architecture and an implementation for a decentralized positioning system. Furthermore, we introduce a technique for the synchronization of the observed magnetic field on the MS with the artificially-generated magnetic field from the coils. Based on real-time clocks (RTCs and a preemptive operating system, this method allows a stand-alone control of the coils and a proper assignment of the measured magnetic fields on the MS. A stand-alone control and synchronization of the coils and the MS have an exceptional potential to implement a positioning system without the need for wired or wireless communication and enable a deployment of applications for rescue scenarios, like localization of miners or firefighters.

  5. Decentralization and Participation: the Montevidian Experience

    Directory of Open Access Journals (Sweden)

    María del Rosario Revello

    1999-10-01

    Full Text Available Beginning with the proposition that a true process of decentralization must necessarily be a process of democratization, such a process is understood as a privileged instrument for participation. Indeed, for a deepening of democratic practices, the ways which should be taken are via decentralization and social participation. This article describes and analyzes the experience of decentralization in Montevideo, a fundamental project created by the coalition of leftist parties that have governed the capital of Uruguay since 1990, a project which had no historical antecedents in the country. The department of Montevideo divided into 18 zones and created juntas locales (local boards - local, decentralized politicalorgans with representation from all the parties - and neighborhood councils. The Neighborhood Councils are representative organs that voice the neighborhood’s interests. Not integrated in the public municipal structure, these constitute private civil society organizations. They are consultative and consultancy bodies with the important tasks of initiative and proposal, planning, consultation, evaluation and the control over the communal management. Also described in the article is the methodology for the project’s improvement and progressive sophistication, which is in function of, among other factors, the degree of effectiveness and reaching of objectives that emerge from the permanent control and evaluation carried out year to year. The strategy presented emphasizes the need for ensuring that the community directly monitors and controls the process of municipal management to safeguard the democratic character of the process.

  6. GDCluster: A General Decentralized Clustering Algorithm

    NARCIS (Netherlands)

    Mashayekhi, Hoda; Habibi, Jafar; Khalafbeigi, Tania; Voulgaris, Spyros; van Steen, Martinus Richardus

    In many popular applications like peer-to-peer systems, large amounts of data are distributed among multiple sources. Analysis of this data and identifying clusters is challenging due to processing, storage, and transmission costs. In this paper, we propose GDCluster, a general fully decentralized

  7. Critical Systems Thinking on Decentralization: the Corporate ...

    African Journals Online (AJOL)

    While the need for agile decision-making processes and speedy action is acknowledged in principle, not enough is being done in practice. This article calls for the devolution of power by large organizations to their subsidiaries or subordinate units – mainly Strategic Business Units (SBUs). It proposes more decentralized ...

  8. HOMEBOTS: Intelligent Decentralized Services for Energy Management

    NARCIS (Netherlands)

    Akkermans, Hans; Ygge, Fredrik; Gustavsson, Rune

    1997-01-01

    The deregulation of the European energy market, combined with emerging advanced capabilities of information technology, provides strategic opportunities for new knowledge-oriented services on the power grid. HOMEBOTS is the name we have coined for one of these innovative services: decentralized

  9. HOMEBOTS: Intelligent Decentralized Services for Energy Management

    NARCIS (Netherlands)

    Akkermans, J.M.; Akkermans, J.M.; Ygge, F.; Gustavsson, R.

    1996-01-01

    The deregulation of the European energy market, combined with emerging advanced capabilities of information technology, provides strategic opportunities for new knowledge-oriented services on the power grid. HOMEBOTS is the namewe have coined for one of these innovative services: decentralized power

  10. Decentralized data fusion with inverse covariance intersection

    NARCIS (Netherlands)

    Noack, B.; Sijs, J.; Reinhardt, M.; Hanebeck, U.D.

    2017-01-01

    In distributed and decentralized state estimation systems, fusion methods are employed to systematically combine multiple estimates of the state into a single, more accurate estimate. An often encountered problem in the fusion process relates to unknown common information that is shared by the

  11. Near optimal decentralized H_inf control

    DEFF Research Database (Denmark)

    Stoustrup, J.; Niemann, Hans Henrik

    It is shown that foir a class of decentralized control problems there does not exist a sequence of controllers of bounded order which obtains near optimal control. Neither does there exist an infinity dimentional optimal controller. Using the insight of the line of proof of these results, a heuri...

  12. Decentralized Sparse Multitask RLS Over Networks

    Science.gov (United States)

    Cao, Xuanyu; Liu, K. J. Ray

    2017-12-01

    Distributed adaptive signal processing has attracted much attention in the recent decade owing to its effectiveness in many decentralized real-time applications in networked systems. Because many natural signals are highly sparse with most entries equal to zero, several decentralized sparse adaptive algorithms have been proposed recently. Most of them is focused on the single task estimation problems, in which all nodes receive data associated with the same unknown vector and collaborate to estimate it. However, many applications are inherently multitask oriented and each node has its own unknown vector different from others'. The related multitask estimation problem benefits from collaborations among the nodes as neighbor nodes usually share analogous properties and thus similar unknown vectors. In this work, we study the distributed sparse multitask recursive least squares (RLS) problem over networks. We first propose a decentralized online alternating direction method of multipliers (ADMM) algorithm for the formulated RLS problem. The algorithm is simplified for easy implementation with closed-form computations in each iteration and low storage requirements. Moreover, to further reduce the complexity, we present a decentralized online subgradient method with low computational overhead. We theoretically analyze the convergence behavior of the proposed subgradient method and derive an error bound related to the network topology and algorithm parameters. The effectiveness of the proposed algorithms is corroborated by numerical simulations and an accuracy-complexity tradeoff between the proposed two algorithms is highlighted.

  13. Towards a Decentralized Magnetic Indoor Positioning System.

    Science.gov (United States)

    Kasmi, Zakaria; Norrdine, Abdelmoumen; Blankenbach, Jörg

    2015-12-04

    Decentralized magnetic indoor localization is a sophisticated method for processing sampled magnetic data directly on a mobile station (MS), thereby decreasing or even avoiding the need for communication with the base station. In contrast to central-oriented positioning systems, which transmit raw data to a base station, decentralized indoor localization pushes application-level knowledge into the MS. A decentralized position solution has thus a strong feasibility to increase energy efficiency and to prolong the lifetime of the MS. In this article, we present a complete architecture and an implementation for a decentralized positioning system. Furthermore, we introduce a technique for the synchronization of the observed magnetic field on the MS with the artificially-generated magnetic field from the coils. Based on real-time clocks (RTCs) and a preemptive operating system, this method allows a stand-alone control of the coils and a proper assignment of the measured magnetic fields on the MS. A stand-alone control and synchronization of the coils and the MS have an exceptional potential to implement a positioning system without the need for wired or wireless communication and enable a deployment of applications for rescue scenarios, like localization of miners or firefighters.

  14. Promoting Research for Policymaking under Decentralization in ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Major reforms in governance carried out in Peru during the early 2000s saw the decentralization of functions and resources from the central government in Lima to elected regional governments. Today, regional governments account for the majority of public investment, but show limited capacity to cope with the ...

  15. Decentralized forest governance in central Vietnam

    NARCIS (Netherlands)

    Tran Nam, T.; Burgers, P.P.M.

    2012-01-01

    A major challenge in decentralized forest governance in Vietnam is developing a mechanism that would support both reforestation and poverty reduction among people in rural communities. To help address this challenge, Forest Land Allocation (FLA) policies recognize local communities and individuals

  16. Decentralized Procurement in Light of Strategic Inventories

    DEFF Research Database (Denmark)

    Arya, Anil; Frimor, Hans; Mittendorf, Brian

    2014-01-01

    and confirmed to be a multifaceted choice. This paper complements existing studies by detailing the trade-offs in the centralization versus decentralization decision in light of firm's decision to cede procurement choices to its individual devisions can help moderate inventory levels and provide a natural salve...

  17. Policy Recommendations on Decentralization, Local Power and ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2010-12-22

    Dec 22, 2010 ... The present document comprises a set of policy recommendations that define a global agenda on gender and decentralization. It emerged from the analysis and experiences shared during the Conference and the work of IDRC-supported researchers. It is intended as a resource for action, to be taken up by ...

  18. Global-scale modeling of groundwater recharge

    Science.gov (United States)

    Döll, P.; Fiedler, K.

    2008-05-01

    Long-term average groundwater recharge, which is equivalent to renewable groundwater resources, is the major limiting factor for the sustainable use of groundwater. Compared to surface water resources, groundwater resources are more protected from pollution, and their use is less restricted by seasonal and inter-annual flow variations. To support water management in a globalized world, it is necessary to estimate groundwater recharge at the global scale. Here, we present a best estimate of global-scale long-term average diffuse groundwater recharge (i.e. renewable groundwater resources) that has been calculated by the most recent version of the WaterGAP Global Hydrology Model WGHM (spatial resolution of 0.5° by 0.5°, daily time steps). The estimate was obtained using two state-of-the-art global data sets of gridded observed precipitation that we corrected for measurement errors, which also allowed to quantify the uncertainty due to these equally uncertain data sets. The standard WGHM groundwater recharge algorithm was modified for semi-arid and arid regions, based on independent estimates of diffuse groundwater recharge, which lead to an unbiased estimation of groundwater recharge in these regions. WGHM was tuned against observed long-term average river discharge at 1235 gauging stations by adjusting, individually for each basin, the partitioning of precipitation into evapotranspiration and total runoff. We estimate that global groundwater recharge was 12 666 km3/yr for the climate normal 1961-1990, i.e. 32% of total renewable water resources. In semi-arid and arid regions, mountainous regions, permafrost regions and in the Asian Monsoon region, groundwater recharge accounts for a lower fraction of total runoff, which makes these regions particularly vulnerable to seasonal and inter-annual precipitation variability and water pollution. Average per-capita renewable groundwater resources of countries vary between 8 m3/(capita yr) for Egypt to more than 1 million m3

  19. Global-scale modeling of groundwater recharge

    Science.gov (United States)

    Döll, P.; Fiedler, K.

    2007-11-01

    Long-term average groundwater recharge, which is equivalent to renewable groundwater resources, is the major limiting factor for the sustainable use of groundwater. Compared to surface water resources, groundwater resources are more protected from pollution, and their use is less restricted by seasonal and inter-annual flow variations. To support water management in a globalized world, it is necessary to estimate groundwater recharge at the global scale. Here, we present a best estimate of global-scale long-term average diffuse groundwater recharge (i.e. renewable groundwater resources) that has been calculated by the most recent version of the WaterGAP Global Hydrology Model WGHM (spatial resolution of 0.5° by 0.5°, daily time steps). The estimate was obtained using two state-of-the art global data sets of gridded observed precipitation that we corrected for measurement errors, which also allowed to quantify the uncertainty due to these equally uncertain data sets. The standard WGHM groundwater recharge algorithm was modified for semi-arid and arid regions, based on independent estimates of diffuse groundwater recharge, which lead to an unbiased estimation of groundwater recharge in these regions. WGHM was tuned against observed long-term average river discharge at 1235 gauging stations by adjusting, individually for each basin, the partitioning of precipitation into evapotranspiration and total runoff. We estimate that global groundwater recharge was 12 666 km3/yr for the climate normal 1961-1990, i.e. 32% of total renewable water resources. In semi-arid and arid regions, mountainous regions, permafrost regions and in the Asian Monsoon region, groundwater recharge accounts for a lower fraction of total runoff, which makes these regions particularly vulnerable to seasonal and inter-annual precipitation variability and water pollution. Average per-capita renewable groundwater resources of countries vary between 8 m3/(capita yr) for Egypt to more than 1 million m3

  20. Global-scale modeling of groundwater recharge

    Directory of Open Access Journals (Sweden)

    P. Döll

    2008-05-01

    Full Text Available Long-term average groundwater recharge, which is equivalent to renewable groundwater resources, is the major limiting factor for the sustainable use of groundwater. Compared to surface water resources, groundwater resources are more protected from pollution, and their use is less restricted by seasonal and inter-annual flow variations. To support water management in a globalized world, it is necessary to estimate groundwater recharge at the global scale. Here, we present a best estimate of global-scale long-term average diffuse groundwater recharge (i.e. renewable groundwater resources that has been calculated by the most recent version of the WaterGAP Global Hydrology Model WGHM (spatial resolution of 0.5° by 0.5°, daily time steps. The estimate was obtained using two state-of-the-art global data sets of gridded observed precipitation that we corrected for measurement errors, which also allowed to quantify the uncertainty due to these equally uncertain data sets. The standard WGHM groundwater recharge algorithm was modified for semi-arid and arid regions, based on independent estimates of diffuse groundwater recharge, which lead to an unbiased estimation of groundwater recharge in these regions. WGHM was tuned against observed long-term average river discharge at 1235 gauging stations by adjusting, individually for each basin, the partitioning of precipitation into evapotranspiration and total runoff. We estimate that global groundwater recharge was 12 666 km3/yr for the climate normal 1961–1990, i.e. 32% of total renewable water resources. In semi-arid and arid regions, mountainous regions, permafrost regions and in the Asian Monsoon region, groundwater recharge accounts for a lower fraction of total runoff, which makes these regions particularly vulnerable to seasonal and inter-annual precipitation variability and water pollution. Average per-capita renewable groundwater resources of countries vary between 8 m3

  1. Performance Analysis of the Decentralized Eigendecomposition and ESPRIT Algorithm

    Science.gov (United States)

    Suleiman, Wassim; Pesavento, Marius; Zoubir, Abdelhak M.

    2016-05-01

    In this paper, we consider performance analysis of the decentralized power method for the eigendecomposition of the sample covariance matrix based on the averaging consensus protocol. An analytical expression of the second order statistics of the eigenvectors obtained from the decentralized power method which is required for computing the mean square error (MSE) of subspace-based estimators is presented. We show that the decentralized power method is not an asymptotically consistent estimator of the eigenvectors of the true measurement covariance matrix unless the averaging consensus protocol is carried out over an infinitely large number of iterations. Moreover, we introduce the decentralized ESPRIT algorithm which yields fully decentralized direction-of-arrival (DOA) estimates. Based on the performance analysis of the decentralized power method, we derive an analytical expression of the MSE of DOA estimators using the decentralized ESPRIT algorithm. The validity of our asymptotic results is demonstrated by simulations.

  2. Decentralized systems with design constraints

    CERN Document Server

    Mahmoud, Magdi S

    2014-01-01

    This volume provides a rigorous examination of the analysis, stability and control of large-scale systems, and addresses the difficulties that arise because of dimensionality, information structure constraints, parametric uncertainty and time-delays.

  3. Documenting good practices: scaling up the youth friendly health service model in Colombia.

    Science.gov (United States)

    Huaynoca, Silvia; Svanemyr, Joar; Chandra-Mouli, Venkatraman C; Moreno Lopez, Diva Jeaneth

    2015-09-18

    Young people make up for 24.5 % of Latin America's population. Inadequate supply of specific and timely sexual and reproductive health (SRH) services and sexuality education for young people increases their risk of sexual and reproductive ill health. Colombia is one of the few countries in Latin America that has implemented and scaled up specific and differentiated health and SRH services-termed as its Youth Friendly Health Services (YFHS) Model. To provide a systematic description of the crucial factors that facilitated and hindered the scale up process of the YFHS Model in Colombia. A comprehensive literature search on SRH services for young people and national efforts to improve their quality of care in Colombia and neighbouring countries was carried out along with interviews with a selection of key stakeholders. The information gathered was analysed using the World Health Organization-ExpandNet framework (WHO-ExpandNet). In 7 years (2007-2013) of the implementation of the YFHS Model in Colombia more than 800 clinics nationally have been made youth friendly. By 2013, 536 municipalities in 32 departments had YFHS, resulting in coverage of 52 % of municipalities offering YHFS. The analysis using the WHO-ExpandNet framework identified five elements that enabled the scale up process: Clear policies and implementation guidelines on YFHS, clear attributes of the user organization and resource team, establishment and implementation of an inter-sectoral and interagency strategy, identification of and support to stakeholders and advocates of YFHS, and solid monitoring and evaluation. The elements that limited or slowed down the scale up effort were: Insufficient number of health personnel trained in youth health and SRH, a high turnover of health personnel, a decentralized health security system, inadequate supply of financial and human resources, and negative perceptions among community members about providing SRH information and services to young people. Colombia

  4. [The implementation of decentralized health systems: a comparative study of five cases in Bahia, Brazil].

    Science.gov (United States)

    Vieira-da-Silva, Ligia Maria; Hartz, Zulmira M Araújo; Chave, Sônia Cristina Lima; da Silva, Gerluce Alves Pontes; Paim, Jairnilson Silva

    2007-02-01

    Understanding the effects of health decentralization policies in Brazil requires different methodological approaches to capture the issue's complexity from distinct angles. Five case studies were thus performed to evaluate the degree of implementation of components related to decentralization of the health system management in selected municipalities (counties) in Bahia State, Brazil. A logical model was elaborated with definitions related to policy goals. A comparative study of the five municipalities, considered "exemplary cases", showed that decentralization alone does not explain the organizational changes in the municipal health systems. Local government characteristics such as the municipal master plan, governing capacity, and governance proved important for heath care changes. The main problems and insufficiencies were found in the system's management and quality of healthcare delivered to the population. The authors discuss their findings and identify critical areas for future interventions with special emphasis on the institutionalization of planning and evaluation and the development of inter-sector projects.

  5. Shorter Decentralized Attribute-Based Encryption via Extended Dual System Groups

    Directory of Open Access Journals (Sweden)

    Jie Zhang

    2017-01-01

    Full Text Available Decentralized attribute-based encryption (ABE is a special form of multiauthority ABE systems, in which no central authority and global coordination are required other than creating the common reference parameters. In this paper, we propose a new decentralized ABE in prime-order groups by using extended dual system groups. We formulate some assumptions used to prove the security of our scheme. Our proposed scheme is fully secure under the standard k-Lin assumption in random oracle model and can support any monotone access structures. Compared with existing fully secure decentralized ABE systems, our construction has shorter ciphertexts and secret keys. Moreover, fast decryption is achieved in our system, in which ciphertexts can be decrypted with a constant number of pairings.

  6. Decentralized Feedback Controllers for Robust Stabilization of Periodic Orbits of Hybrid Systems: Application to Bipedal Walking.

    Science.gov (United States)

    Hamed, Kaveh Akbari; Gregg, Robert D

    2017-07-01

    This paper presents a systematic algorithm to design time-invariant decentralized feedback controllers to exponentially and robustly stabilize periodic orbits for hybrid dynamical systems against possible uncertainties in discrete-time phases. The algorithm assumes a family of parameterized and decentralized nonlinear controllers to coordinate interconnected hybrid subsystems based on a common phasing variable. The exponential and [Formula: see text] robust stabilization problems of periodic orbits are translated into an iterative sequence of optimization problems involving bilinear and linear matrix inequalities. By investigating the properties of the Poincaré map, some sufficient conditions for the convergence of the iterative algorithm are presented. The power of the algorithm is finally demonstrated through designing a set of robust stabilizing local nonlinear controllers for walking of an underactuated 3D autonomous bipedal robot with 9 degrees of freedom, impact model uncertainties, and a decentralization scheme motivated by amputee locomotion with a transpelvic prosthetic leg.

  7. Measurement and Modelling of Scaling Minerals

    DEFF Research Database (Denmark)

    Villafafila Garcia, Ada

    2005-01-01

    -liquid equilibrium of sulphate scaling minerals (SrSO4, BaSO4, CaSO4 and CaSO4•2H2O) at temperatures up to 300ºC and pressures up to 1000 bar is described in chapter 4. Results for the binary systems (M2+, )-H2O; the ternary systems (Na+, M2+, )-H2O, and (Na+, M2+, Cl-)-H2O; and the quaternary systems (Na+, M2+)(Cl...... to 1000 bar. The solubility of CO2 in pure water, and the solubility of CO2 in solutions of different salts (NaCl and Na2SO4) have also been correlated. Results for the binary systems MCO3-H2O, and CO2-H2O; the ternary systems MCO3-CO2-H2O, CO2-NaCl-H2O, and CO2-Na2SO4-H2O; and the quaternary system CO2....... Chapter 2 is focused on thermodynamics of the systems studied and on the calculation of vapour-liquid, solid-liquid, and speciation equilibria. The effects of both temperature and pressure on the solubility are addressed, and explanation of the model calculations is also given. Chapter 3 presents...

  8. Multi-scale models for cell adhesion

    Science.gov (United States)

    Wu, Yinghao; Chen, Jiawen; Xie, Zhong-Ru

    2014-03-01

    The interactions of membrane receptors during cell adhesion play pivotal roles in tissue morphogenesis during development. Our lab focuses on developing multi-scale models to decompose the mechanical and chemical complexity in cell adhesion. Recent experimental evidences show that clustering is a generic process for cell adhesive receptors. However, the physical basis of such receptor clustering is not understood. We introduced the effect of molecular flexibility to evaluate the dynamics of receptors. By delivering new theory to quantify the changes of binding free energy in different cellular environments, we revealed that restriction of molecular flexibility upon binding of membrane receptors from apposing cell surfaces (trans) causes large entropy loss, which dramatically increases their lateral interactions (cis). This provides a new molecular mechanism to initialize receptor clustering on the cell-cell interface. By using the subcellular simulations, we further found that clustering is a cooperative process requiring both trans and cis interactions. The detailed binding constants during these processes are calculated and compared with experimental data from our collaborator's lab.

  9. Modeling cancer metabolism on a genome scale

    Science.gov (United States)

    Yizhak, Keren; Chaneton, Barbara; Gottlieb, Eyal; Ruppin, Eytan

    2015-01-01

    Cancer cells have fundamentally altered cellular metabolism that is associated with their tumorigenicity and malignancy. In addition to the widely studied Warburg effect, several new key metabolic alterations in cancer have been established over the last decade, leading to the recognition that altered tumor metabolism is one of the hallmarks of cancer. Deciphering the full scope and functional implications of the dysregulated metabolism in cancer requires both the advancement of a variety of omics measurements and the advancement of computational approaches for the analysis and contextualization of the accumulated data. Encouragingly, while the metabolic network is highly interconnected and complex, it is at the same time probably the best characterized cellular network. Following, this review discusses the challenges that genome-scale modeling of cancer metabolism has been facing. We survey several recent studies demonstrating the first strides that have been done, testifying to the value of this approach in portraying a network-level view of the cancer metabolism and in identifying novel drug targets and biomarkers. Finally, we outline a few new steps that may further advance this field. PMID:26130389

  10. The role of decentralized systems in providing universal electricity access in Sub-Saharan Africa – A model-based approach

    NARCIS (Netherlands)

    Dagnachew, Anteneh G.; Lucas, Paul L.|info:eu-repo/dai/nl/272607444; Hof, Andries F.|info:eu-repo/dai/nl/240412397; Gernaat, David E.H.J.|info:eu-repo/dai/nl/372664636; de Boer, Harmen Sytze; van Vuuren, Detlef P.|info:eu-repo/dai/nl/11522016X

    2017-01-01

    Poverty and lack of access to electricity are highly correlated. In Sub-Saharan Africa, one of the poorest regions in the world, two in every three people have no access to electricity. This paper describes a purpose designed model to explore and project the development in the Sub-Saharan African

  11. Optimal Rescheduling of Generators for Congestion Management and Benefit Maximization in a Decentralized Bilateral Multi-transactions Power Network

    Science.gov (United States)

    Singh, Brijesh; Mahanty, Ranjit; Singh, S. P.

    2013-05-01

    This paper presents a framework to achieve an optimal power flow solution in a decentralized bilateral multitransaction-based market. An independent optimal dispatch solution has been used for each market. The interior point (IP)-based optimization technique has been used for finding a global economic optimal solution of the whole system. In this method, all the participants try to maximize their own profits with the help of system information announced by the operator. In the present work, a parallel algorithm has been used to find out a global optimum solution in decentralized market model. The study has been carried out on a modified IEEE-30 bus system. The results show that the suggested decentralized approach can provide a better optimal solution. The obtained results show the effectiveness of IP optimization-based optimal generator schedule and congestion management in the decentralized market.

  12. Downscaling modelling system for multi-scale air quality forecasting

    Science.gov (United States)

    Nuterman, R.; Baklanov, A.; Mahura, A.; Amstrup, B.; Weismann, J.

    2010-09-01

    Urban modelling for real meteorological situations, in general, considers only a small part of the urban area in a micro-meteorological model, and urban heterogeneities outside a modelling domain affect micro-scale processes. Therefore, it is important to build a chain of models of different scales with nesting of higher resolution models into larger scale lower resolution models. Usually, the up-scaled city- or meso-scale models consider parameterisations of urban effects or statistical descriptions of the urban morphology, whereas the micro-scale (street canyon) models are obstacle-resolved and they consider a detailed geometry of the buildings and the urban canopy. The developed system consists of the meso-, urban- and street-scale models. First, it is the Numerical Weather Prediction (HIgh Resolution Limited Area Model) model combined with Atmospheric Chemistry Transport (the Comprehensive Air quality Model with extensions) model. Several levels of urban parameterisation are considered. They are chosen depending on selected scales and resolutions. For regional scale, the urban parameterisation is based on the roughness and flux corrections approach; for urban scale - building effects parameterisation. Modern methods of computational fluid dynamics allow solving environmental problems connected with atmospheric transport of pollutants within urban canopy in a presence of penetrable (vegetation) and impenetrable (buildings) obstacles. For local- and micro-scales nesting the Micro-scale Model for Urban Environment is applied. This is a comprehensive obstacle-resolved urban wind-flow and dispersion model based on the Reynolds averaged Navier-Stokes approach and several turbulent closures, i.e. k -ɛ linear eddy-viscosity model, k - ɛ non-linear eddy-viscosity model and Reynolds stress model. Boundary and initial conditions for the micro-scale model are used from the up-scaled models with corresponding interpolation conserving the mass. For the boundaries a

  13. Upscaling a catchment-scale ecohydrology model for regional-scale earth system modeling

    Science.gov (United States)

    Adam, J. C.; Tague, C.; Liu, M.; Garcia, E.; Choate, J.; Mullis, T.; Hull, R.; Vaughan, J. K.; Kalyanaraman, A.; Nguyen, T.

    2014-12-01

    With a focus on the U.S. Pacific Northwest (PNW), BioEarth is an Earth System Model (EaSM) currently in development that explores the interactions between coupled C:N:H2O dynamics and resource management actions at the regional scale. Capturing coupled biogeochemical processes within EaSMs like BioEarth is important for exploring the response of the land surface to changes in climate and resource management actions; information that is important for shaping decisions that promote sustainable use of our natural resources. However, many EaSM frameworks do not adequately represent landscape-scale ( 10 km) are necessitated by computational limitations. Spatial heterogeneity in a landscape arises due to spatial differences in underlying soil and vegetation properties that control moisture, energy and nutrient fluxes; as well as differences that arise due to spatially-organized connections that may drive an ecohydrologic response by the land surface. While many land surface models used in EaSM frameworks capture the first type of heterogeneity, few account for the influence of lateral connectivity on land surface processes. This type of connectivity can be important when considering soil moisture and nutrient redistribution. The RHESSys model is utilized by BioEarth to enable a "bottom-up" approach that preserves fine spatial-scale sensitivities and lateral connectivity that may be important for coupled C:N:H2O dynamics over larger scales. RHESSys is a distributed eco-hydrologic model that was originally developed to run at relatively fine but computationally intensive spatial resolutions over small catchments. The objective of this presentation is to describe two developments to enable implementation of RHESSys over the PNW. 1) RHESSys is being adapted for BioEarth to allow for moderately coarser resolutions and the flexibility to capture both types of heterogeneity at biome-specific spatial scales. 2) A Kepler workflow is utilized to enable RHESSys implementation over

  14. Policies to Spur Energy Access. Executive Summary; Volume 1, Engaging the Private Sector in Expanding Access to Electricity; Volume 2, Case Studies to Public-Private Models to Finance Decentralized Electricity Access

    Energy Technology Data Exchange (ETDEWEB)

    Walters, Terri [National Renewable Energy Lab. (NREL), Golden, CO (United States); Rai, Neha [International Institute for Environment and Development (IIED), London (England); Esterly, Sean [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cox, Sadie [National Renewable Energy Lab. (NREL), Golden, CO (United States); Reber, Tim [National Renewable Energy Lab. (NREL), Golden, CO (United States); Muzammil, Maliha [Univ. of Oxford (United Kingdom); Mahmood, Tasfiq [International Center for Climate Change and Development, Baridhara (Bangladesh); Kaur, Nanki [International Institute for Environment and Development (IIED), London (England); Tesfaye, Lidya [Echnoserve Consulting (Ethiopia); Mamuye, Simret [Echnoserve Consulting (Ethiopia); Knuckles, James [Univ. of London (England). Cass Business School; Morris, Ellen [Columbia Univ., New York, NY (United States); de Been, Merijn [Delft Univ. of Technology (Netherlands); Steinbach, Dave [International Institute for Environment and Development (IIED), London (England); Acharya, Sunil [Digo Bikas Inst. (Nepal); Chhetri, Raju Pandit [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bhushal, Ramesh [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-09-01

    Government policy is one of the most important factors in engaging the private sector in providing universal access to electricity. In particular, the private sector is well positioned to provide decentralized electricity products and services. While policy uncertainty and regulatory barriers can keep enterprises and investors from engaging in the market, targeted policies can create opportunities to leverage private investment and skills to expand electricity access. However, creating a sustainable market requires policies beyond traditional electricity regulation. The report reviews the range of policy issues that impact the development and expansion of a market for decentralized electricity services from establishing an enabling policy environment to catalyzing finance, building human capacity, and integrating energy access with development programs. The case studies in this report show that robust policy frameworks--addressing a wide range of market issues--can lead to rapid transformation in energy access. The report highlights examples of these policies in action Bangladesh, Ethiopia, Mali, Mexico, and Nepal.

  15. The Local Budgets in a Decentralized Environment

    Directory of Open Access Journals (Sweden)

    Kovalenko Svitlana O.

    2017-06-01

    Full Text Available The article considers the problems of strengthening the financial autonomy of local budgets in the current context of implementing the reform of decentralization of power. Status of economic development and the income level of population in the regions of Ukraine has been analyzed, characteristics of decentralization, as well as its preliminary outcome, have been described. Attention is focused on positive points in the development of regions in which the united territorial communities have been formed. It has been proposed to raise the mass awareness of population in the regions of Ukraine about the substance of the reform and its objectives, to establish a body of financial control for local councils, and to arrange computer monitoring of the flow of financial resources of the territorial communities along with periodic coverage of its results in the local media in order to increase the transparency of costs management.

  16. Incremental Clustering and Expansion for Faster Optimal Planning in Decentralized POMDPs

    NARCIS (Netherlands)

    Oliehoek, F.A.; Spaan, M.T.J.; Amato, C.; Whiteson, S.

    2013-01-01

    This article presents the state-of-the-art in optimal solution methods for decentralized partially observable Markov decision processes (Dec-POMDPs), which are general models for collaborative multiagent planning under uncertainty. Building off the generalized multiagent A* (GMAA*) algorithm, which

  17. Do decentralized innovation systems promote agricultural technology adoption? Experimental evidence from Africa

    NARCIS (Netherlands)

    Pamuk, H.; Bulte, E.H.; Adekunle, A.A.

    2014-01-01

    We use experimental data collected in 8 African countries to investigate whether a decentralized approach can promote the adoption of agricultural innovations. This participatory model is based on the creation of so-called 'innovation platforms' where local stakeholders meet and seek to identify

  18. Decentralized and Integrated Institutional Research: A Contradiction in Terms That Works. AIR 1991 Annual Forum Paper.

    Science.gov (United States)

    Frost, Susan H.

    A newly organized small college model for a decentralized institutional research office was described and evaluated. Using Hearn and Corcoran's six external or organizational forces (external environment, personalities or individual interests, management styles, power arrangements, microcomputing and telecommunications, and structural and…

  19. Modelling across bioreactor scales: methods, challenges and limitations

    DEFF Research Database (Denmark)

    Gernaey, Krist

    Scale-up and scale-down of bioreactors are very important in industrial biotechnology, especially with the currently available knowledge on the occurrence of gradients in industrial-scale bioreactors. Moreover, it becomes increasingly appealing to model such industrial scale systems, considering...... that it is challenging and expensive to acquire experimental data of good quality that can be used for characterizing gradients occurring inside a large industrial scale bioreactor. But which model building methods are available? And how can one ensure that the parameters in such a model are properly estimated? And what...... are the limitations of different types of mod - els? This paper will provide examples of models that have been published in the literature for use across bioreactor scales, including computational fluid dynamics (CFD) and population balance models. Furthermore, the importance of good modeling practice...

  20. Static Aeroelastic Scaling and Analysis of a Sub-Scale Flexible Wing Wind Tunnel Model

    Science.gov (United States)

    Ting, Eric; Lebofsky, Sonia; Nguyen, Nhan; Trinh, Khanh

    2014-01-01

    This paper presents an approach to the development of a scaled wind tunnel model for static aeroelastic similarity with a full-scale wing model. The full-scale aircraft model is based on the NASA Generic Transport Model (GTM) with flexible wing structures referred to as the Elastically Shaped Aircraft Concept (ESAC). The baseline stiffness of the ESAC wing represents a conventionally stiff wing model. Static aeroelastic scaling is conducted on the stiff wing configuration to develop the wind tunnel model, but additional tailoring is also conducted such that the wind tunnel model achieves a 10% wing tip deflection at the wind tunnel test condition. An aeroelastic scaling procedure and analysis is conducted, and a sub-scale flexible wind tunnel model based on the full-scale's undeformed jig-shape is developed. Optimization of the flexible wind tunnel model's undeflected twist along the span, or pre-twist or wash-out, is then conducted for the design test condition. The resulting wind tunnel model is an aeroelastic model designed for the wind tunnel test condition.

  1. A New Method of Building Scale-Model Houses

    Science.gov (United States)

    Richard N. Malcolm

    1978-01-01

    Scale-model houses are used to display new architectural and construction designs.Some scale-model houses will not withstand the abuse of shipping and handling.This report describes how to build a solid-core model house which is rigid, lightweight, and sturdy.

  2. Analyzing Von Neumann machines using decentralized symmetries

    Science.gov (United States)

    Fang, Jie

    2013-10-01

    The artificial intelligence method to e-business is defined not only by the study of fiber-optic cables, but also by the unproven need for vacuum tubes. Given the current status of virtual archetypes, theorists clearly desire the exploration of semaphores, which embodies the compelling principles of cryptoanalysis. We present an algorithm for probabilistic theory (Buck), which we use to disprove that write-back caches can be made decentralized, lossless, and reliable.

  3. Query Optimizations over Decentralized RDF Graphs

    KAUST Repository

    Abdelaziz, Ibrahim

    2017-05-18

    Applications in life sciences, decentralized social networks, Internet of Things, and statistical linked dataspaces integrate data from multiple decentralized RDF graphs via SPARQL queries. Several approaches have been proposed to optimize query processing over a small number of heterogeneous data sources by utilizing schema information. In the case of schema similarity and interlinks among sources, these approaches cause unnecessary data retrieval and communication, leading to poor scalability and response time. This paper addresses these limitations and presents Lusail, a system for scalable and efficient SPARQL query processing over decentralized graphs. Lusail achieves scalability and low query response time through various optimizations at compile and run times. At compile time, we use a novel locality-aware query decomposition technique that maximizes the number of query triple patterns sent together to a source based on the actual location of the instances satisfying these triple patterns. At run time, we use selectivity-awareness and parallel query execution to reduce network latency and to increase parallelism by delaying the execution of subqueries expected to return large results. We evaluate Lusail using real and synthetic benchmarks, with data sizes up to billions of triples on an in-house cluster and a public cloud. We show that Lusail outperforms state-of-the-art systems by orders of magnitude in terms of scalability and response time.

  4. [Paradoxes of health decentralization policies in Brazil].

    Science.gov (United States)

    Pasche, Dário Frederico; Righi, Liane Beatriz; Thomé, Henrique Inácio; Stolz, Eveline Dischkaln

    2006-12-01

    The constitution of Brazil directs that the country's health system, the Unified Health System (Sistema Unico de Saúde), be politically and administratively decentralized. Nevertheless, handing over competencies, responsibilities, and resources to subnational levels, especially to municipal governments, has been a slow process, lasting almost two decades. Advances have been brought about by the Unified Health System, which, from a analytical perspective, is a public and universal system. Despite that, the decentralization process needs to overcome norms that keep all levels of management dependent on Brazil's federal Government. The subnational levels have consistently faced difficulties in performing their macromanagement functions with autonomy, especially when it comes to financing and to the establishment or organization of health care networks. Boldness and responsibility will be needed to prevent Brazil's health decentralization process from leading to fragmentation. New political agreements between different levels of government, with a reassignment of responsibilities and the enhancement of a culture of technical cooperation, are fundamental requisites to making the Unified Health System have a health policy that is truly public and universal.

  5. Progress and challenges in utilization of palm oil biomass as fuel for decentralized electricity generation

    Energy Technology Data Exchange (ETDEWEB)

    Bazmi, Aqeel Ahmed [Process Systems Engineering Centre (PROSPECT), Department of Chemical Engineering, Faculty of Chemical and Natural Resources Engineering, University Technology Malaysia, Skudai 81310, Johor Bahru, JB (Malaysia); Biomass Conversion Research Center (BCRC), Department of Chemical Engineering, COMSATS Institute of Information Technology, Lahore (Pakistan); Zahedi, Gholamreza; Hashim, Haslenda [Process Systems Engineering Centre (PROSPECT), Department of Chemical Engineering, Faculty of Chemical and Natural Resources Engineering, University Technology Malaysia, Skudai 81310, Johor Bahru, JB (Malaysia)

    2011-01-15

    It has been broadly accepted worldwide that global warming, indeed, is the greatest threat of the time to the environment. Renewable energy (RE) is expected as a perfect solution to reduce global warming and to endorse sustainable development. Progressive release of greenhouse gases (GHG) from increasing energy-intensive industries has eventually caused human civilization to suffer. Realizing the exigency of reducing emissions and simultaneously catering to needs of industries, researchers foresee the RE as the perfect entrant to overcome these challenges. RE provides an effective option for the provision of energy services from the technical point of view while biomass, a major source of energy in the world until before industrialization when fossil fuels become dominant, appears an important renewable source of energy and researches have proven from time to time its viability for large-scale production. Being a widely spread source, biomass offers the execution of decentralized electricity generation gaining importance in liberalized electricity markets. The decentralized power is characterized by generation of electricity nearer to the demand centers, meeting the local energy needs. Researchers envisaged an increasing decentralization of power supply, expected to make a particular contribution to climate protection. This article investigates the progress and challenges for decentralized electricity generation by palm oil biomass according to the overall concept of sustainable development. (author)

  6. Optical aberrations induced by subclinical decentrations of the ablation pattern

    Science.gov (United States)

    Mrochen, Michael; Kaemmerer, Maik; Riedel, Peter; Mierdel, Peter; Krinke, Hans-Eberhard; Seiler, Theo

    2000-06-01

    Purpose: The aim of this work was to study the effect of currently used ablation profiles along with eccentric ablations on the increase of higher order aberrations observed after PRK. Material and Methods: The optical aberrations of 10 eyes were tested before and after PRK. Refractive surgery was performed using a ArF-excimer laser system. In all cases, the ablation zone was 6 mm or larger. The spherical equivalent of the correction was ranging from -2.5 D to -6.0 D. The measured wavefront error was compared to numerical simulations done with the reduced eye model and currently used ablation profiles as well as compared with experimental results obtained from ablation on PMMA balls. Results: The aberration measurements result in a considerable change of the spherical- and coma-like wavefront errors. This result was in good correlation with the numerical simulations and the experimental results. Furthermore, it has been derived that the major contribution on the induced higher order aberrations are a result of the small decentration (less than 1.0 mm) of the ablation zone. Conclusions: Higher order spherical- and coma-like aberrations after PRK are mainly determined by the decentration of the ablation zone during laser refractive surgery. However, future laser systems should use efficient eye-tracking systems and aspherical ablation profiles to overcome this problem.

  7. A Decentralized Heuristic Approach towards Resource Allocation in Femtocell Networks

    Directory of Open Access Journals (Sweden)

    Kyung-Geun Lee

    2013-06-01

    Full Text Available Femtocells represent a novel configuration for existing cellular communication, contributing towards the improvement of coverage and throughput. The dense deployment of these femtocells causes significant femto-macro and femto-femto interference, consequently deteriorating the throughput of femtocells. In this study, we compare two heuristic approaches, i.e., particle swarm optimization (PSO and genetic algorithm (GA, for joint power assignment and resource allocation, within the context of the femtocell environment. The supposition made in this joint optimization is that the discrete power levels are available for the assignment. Furthermore, we have employed two variants of each PSO and GA: inertia weight and constriction factor model for PSO, and twopoint and uniform crossover for GA. The two proposed algorithms are in a decentralized manner, with no involvement of any centralized entity. The comparison is carried out between the two proposed algorithms for the aforementioned joint optimization problem. The contrast includes the performance metrics: including average objective function, min–max throughput of the femtocells, average throughput of the femto users, outage rate and time complexity. The results demonstrate that the decentralized PSO constriction factor outperforms the others in terms of the aforementioned performance metrics.

  8. The material politics of waste disposal - decentralization and integrated systems

    Directory of Open Access Journals (Sweden)

    Penelope Harvey

    2012-12-01

    Full Text Available This article and the previous «Convergence and divergence between the local and regional state around solid waste management. An unresolved problem in the Sacred Valley» from Teresa Tupayachi are published as complementary accounts on the management of solid waste in the Vilcanota Valley in Cusco. Penelope Harvey and Teresa Tupayachi worked together on this theme. The present article explores how discontinuities across diverse instances of the state are experienced and understood. Drawing from an ethnographic study of the Vilcanota Valley in Cusco, the article looks at the material politics of waste disposal in neoliberal times. Faced with the problem of how to dispose of solid waste, people from Cusco experience a lack of institutional responsibility and call for a stronger state presence. The article describes the efforts by technical experts to design integrated waste management systems that maximise the potential for re-cycling, minimise toxic contamination, and turn ‘rubbish’ into the altogether more economically lively category of ‘solid waste’. However while the financialization of waste might appear to offer an indisputable public good, efforts to instigate a viable waste disposal business in a decentralizing political space elicit deep social tensions and contradictions. The social discontinuities that decentralization supports disrupt ambitions for integrated solutions as local actors resist top-down models and look not just for alternative solutions, but alternative ways of framing the problem of urban waste, and by extension their relationship to the state.

  9. Decentralized Hypothesis Testing in Energy Harvesting Wireless Sensor Networks

    Science.gov (United States)

    Tarighati, Alla; Gross, James; Jalden, Joakim

    2017-09-01

    We consider the problem of decentralized hypothesis testing in a network of energy harvesting sensors, where sensors make noisy observations of a phenomenon and send quantized information about the phenomenon towards a fusion center. The fusion center makes a decision about the present hypothesis using the aggregate received data during a time interval. We explicitly consider a scenario under which the messages are sent through parallel access channels towards the fusion center. To avoid limited lifetime issues, we assume each sensor is capable of harvesting all the energy it needs for the communication from the environment. Each sensor has an energy buffer (battery) to save its harvested energy for use in other time intervals. Our key contribution is to formulate the problem of decentralized detection in a sensor network with energy harvesting devices. Our analysis is based on a queuing-theoretic model for the battery and we propose a sensor decision design method by considering long term energy management at the sensors. We show how the performance of the system changes for different battery capacities. We then numerically show how our findings can be used in the design of sensor networks with energy harvesting sensors.

  10. ABS-NET: Fully Decentralized Runtime Adaptation for Distributed Objects

    Directory of Open Access Journals (Sweden)

    Karl Palmskog

    2013-10-01

    Full Text Available We present a formalized, fully decentralized runtime semantics for a core subset of ABS, a language and framework for modelling distributed object-oriented systems. The semantics incorporates an abstract graph representation of a network infrastructure, with network endpoints represented as graph nodes, and links as arcs with buffers, corresponding to OSI layer 2 interconnects. The key problem we wish to address is how to allocate computational tasks to nodes so that certain performance objectives are met. To this end, we use the semantics as a foundation for performing network-adaptive task execution via object migration between nodes. Adaptability is analyzed in terms of three Quality of Service objectives: node load, arc load and message latency. We have implemented the key parts of our semantics in a simulator and evaluated how well objectives are achieved for some application-relevant choices of network topology, migration procedure and ABS program. The evaluation suggests that it is feasible in a decentralized setting to continually meet both the objective of a node-balanced task allocation and make headway towards minimizing communication, and thus arc load and message latency.

  11. A Case Study on Formal Verification of Self-Adaptive Behaviors in a Decentralized System

    Directory of Open Access Journals (Sweden)

    M. Usman Iftikhar

    2012-08-01

    Full Text Available Self-adaptation is a promising approach to manage the complexity of modern software systems. A self-adaptive system is able to adapt autonomously to internal dynamics and changing conditions in the environment to achieve particular quality goals. Our particular interest is in decentralized self-adaptive systems, in which central control of adaptation is not an option. One important challenge in self-adaptive systems, in particular those with decentralized control of adaptation, is to provide guarantees about the intended runtime qualities. In this paper, we present a case study in which we use model checking to verify behavioral properties of a decentralized self-adaptive system. Concretely, we contribute with a formalized architecture model of a decentralized traffic monitoring system and prove a number of self-adaptation properties for flexibility and robustness. To model the main processes in the system we use timed automata, and for the specification of the required properties we use timed computation tree logic. We use the Uppaal tool to specify the system and verify the flexibility and robustness properties.

  12. Optimizing Natural Gas Networks through Dynamic Manifold Theory and a Decentralized Algorithm: Belgium Case Study

    Science.gov (United States)

    Koch, Caleb; Winfrey, Leigh

    2014-10-01

    Natural Gas is a major energy source in Europe, yet political instabilities have the potential to disrupt access and supply. Energy resilience is an increasingly essential construct and begins with transmission network design. This study proposes a new way of thinking about modelling natural gas flow. Rather than relying on classical economic models, this problem is cast into a time-dependent Hamiltonian dynamics discussion. Traditional Natural Gas constraints, including inelastic demand and maximum/minimum pipe flows, are portrayed as energy functions and built into the dynamics of each pipe flow. Doing so allows the constraints to be built into the dynamics of each pipeline. As time progresses in the model, natural gas flow rates find the minimum energy, thus the optimal gas flow rates. The most important result of this study is using dynamical principles to ensure the output of natural gas at demand nodes remains constant, which is important for country to country natural gas transmission. Another important step in this study is building the dynamics of each flow in a decentralized algorithm format. Decentralized regulation has solved congestion problems for internet data flow, traffic flow, epidemiology, and as demonstrated in this study can solve the problem of Natural Gas congestion. A mathematical description is provided for how decentralized regulation leads to globally optimized network flow. Furthermore, the dynamical principles and decentralized algorithm are applied to a case study of the Fluxys Belgium Natural Gas Network.

  13. Gauge coupling unification in a classically scale invariant model

    Energy Technology Data Exchange (ETDEWEB)

    Haba, Naoyuki; Ishida, Hiroyuki [Graduate School of Science and Engineering, Shimane University,Matsue 690-8504 (Japan); Takahashi, Ryo [Graduate School of Science, Tohoku University,Sendai, 980-8578 (Japan); Yamaguchi, Yuya [Graduate School of Science and Engineering, Shimane University,Matsue 690-8504 (Japan); Department of Physics, Faculty of Science, Hokkaido University,Sapporo 060-0810 (Japan)

    2016-02-08

    There are a lot of works within a class of classically scale invariant model, which is motivated by solving the gauge hierarchy problem. In this context, the Higgs mass vanishes at the UV scale due to the classically scale invariance, and is generated via the Coleman-Weinberg mechanism. Since the mass generation should occur not so far from the electroweak scale, we extend the standard model only around the TeV scale. We construct a model which can achieve the gauge coupling unification at the UV scale. In the same way, the model can realize the vacuum stability, smallness of active neutrino masses, baryon asymmetry of the universe, and dark matter relic abundance. The model predicts the existence vector-like fermions charged under SU(3){sub C} with masses lower than 1 TeV, and the SM singlet Majorana dark matter with mass lower than 2.6 TeV.

  14. Decentralized clustering over adaptive networks

    OpenAIRE

    Khawatmi, Sahar; Zoubir, Abdelhak M.; Sayed, Ali H.

    2015-01-01

    Cooperation among agents across the network leads to better estimation accuracy. However, in many network applications the agents infer and track different models of interest in an environment where agents do not know beforehand which models are being observed by their neighbors. In this work, we propose an adaptive and distributed clustering technique that allows agents to learn and form clusters from streaming data in a robust manner. Once clusters are formed, cooperation among agents with ...

  15. Peeling the Onion: Why Centralized Control / Decentralized Execution Works

    Science.gov (United States)

    2014-04-01

    March–April 2014 Air & Space Power Journal | 24 Feature Peeling the Onion Why Centralized Control / Decentralized Execution Works Lt Col Alan Docauer...DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Peeling the Onion : Why Centralized Control / Decentralized Execution Works 5a...Air & Space Power Journal | 25 Docauer Peeling the Onion Feature What Is Centralized Control / Decentralized Execution? Emerging in the aftermath of

  16. Decentralization and Accountability: The Curse of Local Underdevelopment

    OpenAIRE

    Machado, Fabiana

    2013-01-01

    Decentralization of provision of public services has been an important item in the agenda of developing countries. While some scholars and practitioners argue that decentralization is associated with improvements in provision due to higher accountability, others note its potential pitfalls. In particular, decentralization to local communities characterized by poverty, low levels of education, and inequality may lead to low accountability and higher susceptibility to political capture. This pa...

  17. Holography for chiral scale-invariant models

    NARCIS (Netherlands)

    Caldeira Costa, R.N.; Taylor, M.

    2011-01-01

    Deformation of any d-dimensional conformal field theory by a constant null source for a vector operator of dimension (d + z -1) is exactly marginal with respect to anisotropic scale invariance, of dynamical exponent z. The holographic duals to such deformations are AdS plane waves, with z=2 being

  18. Holography for chiral scale-invariant models

    NARCIS (Netherlands)

    Caldeira Costa, R.N.; Taylor, M.

    2010-01-01

    Deformation of any d-dimensional conformal field theory by a constant null source for a vector operator of dimension (d + z -1) is exactly marginal with respect to anisotropic scale invariance, of dynamical exponent z. The holographic duals to such deformations are AdS plane waves, with z=2 being

  19. The sense and non-sense of plot-scale, catchment-scale, continental-scale and global-scale hydrological modelling

    Science.gov (United States)

    Bronstert, Axel; Heistermann, Maik; Francke, Till

    2017-04-01

    Hydrological models aim at quantifying the hydrological cycle and its constituent processes for particular conditions, sites or periods in time. Such models have been developed for a large range of spatial and temporal scales. One must be aware that the question which is the appropriate scale to be applied depends on the overall question under study. Therefore, it is not advisable to give a general applicable guideline on what is "the best" scale for a model. This statement is even more relevant for coupled hydrological, ecological and atmospheric models. Although a general statement about the most appropriate modelling scale is not recommendable, it is worth to have a look on what are the advantages and the shortcomings of micro-, meso- and macro-scale approaches. Such an appraisal is of increasing importance, since increasingly (very) large / global scale approaches and models are under operation and therefore the question arises how far and for what purposes such methods may yield scientifically sound results. It is important to understand that in most hydrological (and ecological, atmospheric and other) studies process scale, measurement scale, and modelling scale differ from each other. In some cases, the differences between theses scales can be of different orders of magnitude (example: runoff formation, measurement and modelling). These differences are a major source of uncertainty in description and modelling of hydrological, ecological and atmospheric processes. Let us now summarize our viewpoint of the strengths (+) and weaknesses (-) of hydrological models of different scales: Micro scale (e.g. extent of a plot, field or hillslope): (+) enables process research, based on controlled experiments (e.g. infiltration; root water uptake; chemical matter transport); (+) data of state conditions (e.g. soil parameter, vegetation properties) and boundary fluxes (e.g. rainfall or evapotranspiration) are directly measurable and reproducible; (+) equations based on

  20. The Goddard multi-scale modeling system with unified physics

    Directory of Open Access Journals (Sweden)

    W.-K. Tao

    2009-08-01

    Full Text Available Recently, a multi-scale modeling system with unified physics was developed at NASA Goddard. It consists of (1 a cloud-resolving model (CRM, (2 a regional-scale model, the NASA unified Weather Research and Forecasting Model (WRF, and (3 a coupled CRM-GCM (general circulation model, known as the Goddard Multi-scale Modeling Framework or MMF. The same cloud-microphysical processes, long- and short-wave radiative transfer and land-surface processes are applied in all of the models to study explicit cloud-radiation and cloud-surface interactive processes in this multi-scale modeling system. This modeling system has been coupled with a multi-satellite simulator for comparison and validation with NASA high-resolution satellite data.

    This paper reviews the development and presents some applications of the multi-scale modeling system, including results from using the multi-scale modeling system to study the interactions between clouds, precipitation, and aerosols. In addition, use of the multi-satellite simulator to identify the strengths and weaknesses of the model-simulated precipitation processes will be discussed as well as future model developments and applications.

  1. The Goddard multi-scale modeling system with unified physics

    Directory of Open Access Journals (Sweden)

    W.-K. Tao

    2009-08-01

    Full Text Available Recently, a multi-scale modeling system with unified physics was developed at NASA Goddard. It consists of (1 a cloud-resolving model (CRM, (2 a regional-scale model, the NASA unified Weather Research and Forecasting Model (WRF, and (3 a coupled CRM-GCM (general circulation model, known as the Goddard Multi-scale Modeling Framework or MMF. The same cloud-microphysical processes, long- and short-wave radiative transfer and land-surface processes are applied in all of the models to study explicit cloud-radiation and cloud-surface interactive processes in this multi-scale modeling system. This modeling system has been coupled with a multi-satellite simulator for comparison and validation with NASA high-resolution satellite data. This paper reviews the development and presents some applications of the multi-scale modeling system, including results from using the multi-scale modeling system to study the interactions between clouds, precipitation, and aerosols. In addition, use of the multi-satellite simulator to identify the strengths and weaknesses of the model-simulated precipitation processes will be discussed as well as future model developments and applications.

  2. Microphysics in Multi-scale Modeling System with Unified Physics

    Science.gov (United States)

    Tao, Wei-Kuo

    2012-01-01

    Recently, a multi-scale modeling system with unified physics was developed at NASA Goddard. It consists of (1) a cloud-resolving model (Goddard Cumulus Ensemble model, GCE model), (2) a regional scale model (a NASA unified weather research and forecast, WRF), (3) a coupled CRM and global model (Goddard Multi-scale Modeling Framework, MMF), and (4) a land modeling system. The same microphysical processes, long and short wave radiative transfer and land processes and the explicit cloud-radiation, and cloud-land surface interactive processes are applied in this multi-scale modeling system. This modeling system has been coupled with a multi-satellite simulator to use NASA high-resolution satellite data to identify the strengths and weaknesses of cloud and precipitation processes simulated by the model. In this talk, a review of developments and applications of the multi-scale modeling system will be presented. In particular, the microphysics development and its performance for the multi-scale modeling system will be presented.

  3. Simple subgrid scale stresses models for homogeneous isotropic turbulence

    Science.gov (United States)

    Aupoix, B.; Cousteix, J.

    Large eddy simulations employing the filtering of Navier-Stokes equations highlight stresses, related to the interaction between large scales below the cut and small scales above it, which have been designated 'subgrid scale stresses'. Their effects include both the energy flux through the cut and a component of viscous diffusion. The eddy viscosity introduced in the subgrid scale models which give the correct energy flux through the cut by comparison with spectral closures is shown to depend only on the small scales. The Smagorinsky (1963) model can only be obtained if the cut lies in the middle of the inertial range. A novel model which takes the small scales into account statistically, and includes the effects of viscosity, is proposed and compared with classical models for the Comte-Bellot and Corrsin (1971) experiment.

  4. On nano-scale hydrodynamic lubrication models

    Science.gov (United States)

    Buscaglia, Gustavo; Ciuperca, Ionel S.; Jai, Mohammed

    2005-06-01

    Current magnetic head sliders and other micromechanisms involve gas lubrication flows with gap thicknesses in the nanometer range and stepped shapes fabricated by lithographic methods. In mechanical simulations, rarefaction effects are accounted for by models that propose Poiseuille flow factors which exhibit singularities as the pressure tends to zero or +∞. In this Note we show that these models are indeed mathematically well-posed, even in the case of discontinuous gap thickness functions. Our results cover popular models that were not previously analyzed in the literature, such as the Fukui-Kaneko model and the second-order model, among others. To cite this article: G. Buscaglia et al., C. R. Mecanique 333 (2005).

  5. Scaling up of breastfeeding promotion programs in low- and middle-income countries: the "breastfeeding gear" model.

    Science.gov (United States)

    Pérez-Escamilla, Rafael; Curry, Leslie; Minhas, Dilpreet; Taylor, Lauren; Bradley, Elizabeth

    2012-11-01

    Breastfeeding (BF) promotion is one of the most cost-effective interventions to advance mother-child health. Evidence-based frameworks and models to promote the effective scale up and sustainability of BF programs are still lacking. A systematic review of peer-reviewed and gray literature reports was conducted to identify key barriers and facilitators for scale up of BF programs in low- and middle-income countries. The review identified BF programs located in 28 countries in Africa, Latin America and the Caribbean, and Asia. Study designs included case studies, qualitative studies, and observational quantitative studies. Only 1 randomized, controlled trial was identified. A total of 22 enabling factors and 15 barriers were mapped into a scale-up framework termed "AIDED" that was used to build the parsimonious breastfeeding gear model (BFGM). Analogous to a well-oiled engine, the BFGM indicates the need for several key "gears" to be working in synchrony and coordination. Evidence-based advocacy is needed to generate the necessary political will to enact legislation and policies to protect, promote, and support BF at the hospital and community levels. This political-policy axis in turn drives the resources needed to support workforce development, program delivery, and promotion. Research and evaluation are needed to sustain the decentralized program coordination "gear" required for goal setting and system feedback. The BFGM helps explain the different levels of performance in national BF outcomes in Mexico and Brazil. Empirical research is recommended to further test the usefulness of the AIDED framework and BFGM for global scaling up of BF programs.

  6. Optimal Scaling of Interaction Effects in Generalized Linear Models

    Science.gov (United States)

    van Rosmalen, Joost; Koning, Alex J.; Groenen, Patrick J. F.

    2009-01-01

    Multiplicative interaction models, such as Goodman's (1981) RC(M) association models, can be a useful tool for analyzing the content of interaction effects. However, most models for interaction effects are suitable only for data sets with two or three predictor variables. Here, we discuss an optimal scaling model for analyzing the content of…

  7. Multiple-scale turbulence model in confined swirling jet predictions

    Science.gov (United States)

    Chen, C. P.

    1986-01-01

    A recently developed multiple-scale turbulence model which attempts to circumvent the deficiencies of earlier models by taking nonequilibrium spectral energy transfer into account is presented. The model's validity is tested by predicting the confined swirling coaxial jet flow in a sudden expansion. It is noted that, in order to account for anisotropic turbulence, a full Reynolds stress model is required.

  8. Continental scale modelling of geomagnetically induced currents

    OpenAIRE

    Sakharov Yaroslav; Prácser Ernö; Ádám Antal; Wik Magnus; Pirjola Risto; Viljanen Ari; Katkalov Juri

    2012-01-01

    The EURISGIC project (European Risk from Geomagnetically Induced Currents) aims at deriving statistics of geomagnetically induced currents (GIC) in the European high-voltage power grids. Such a continent-wide system of more than 1500 substations and transmission lines requires updates of the previous modelling, which has dealt with national grids in fairly small geographic areas. We present here how GIC modelling can be conveniently performed on a spherical surface with minor changes in the p...

  9. Design and Implementation of Decentralized Supervisory Control for Manufacturing System Automation

    OpenAIRE

    2011-01-01

    Abstract Supervisory control theory, which was first proposed by Ramadge and Wonahm, is a well-suited control theory for the control of complex systems such as semiconductor manufacturing systems, automobile manufacturing systems, and chemical processes because these are better modeled by discrete event models than by differential or difference equation models at higher levels of abstraction. Moreover, decentralized supervisory control is an efficient method for large complex syste...

  10. Multi-scale modeling for sustainable chemical production.

    Science.gov (United States)

    Zhuang, Kai; Bakshi, Bhavik R; Herrgård, Markus J

    2013-09-01

    With recent advances in metabolic engineering, it is now technically possible to produce a wide portfolio of existing petrochemical products from biomass feedstock. In recent years, a number of modeling approaches have been developed to support the engineering and decision-making processes associated with the development and implementation of a sustainable biochemical industry. The temporal and spatial scales of modeling approaches for sustainable chemical production vary greatly, ranging from metabolic models that aid the design of fermentative microbial strains to material and monetary flow models that explore the ecological impacts of all economic activities. Research efforts that attempt to connect the models at different scales have been limited. Here, we review a number of existing modeling approaches and their applications at the scales of metabolism, bioreactor, overall process, chemical industry, economy, and ecosystem. In addition, we propose a multi-scale approach for integrating the existing models into a cohesive framework. The major benefit of this proposed framework is that the design and decision-making at each scale can be informed, guided, and constrained by simulations and predictions at every other scale. In addition, the development of this multi-scale framework would promote cohesive collaborations across multiple traditionally disconnected modeling disciplines to achieve sustainable chemical production. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Does fiscal decentralization improve health outcomes? Evidence from infant mortality in Italy.

    Science.gov (United States)

    Cavalieri, Marina; Ferrante, Livio

    2016-09-01

    Despite financial and decision-making responsibilities having been increasingly devolved to lower levels of government worldwide, the potential impact of these reforms remains largely controversial. This paper investigates the hypothesis that a shift towards a higher degree of fiscal autonomy of sub-national governments could improve health outcomes, as measured by infant mortality rates. Italy is used as a case study since responsibilities for healthcare have been decentralized to regions, though the central government still retains a key role in ensuring all citizens uniform access to health services throughout the country. A linear fixed-effects regression model with robust standard errors is employed for a panel of 20 regions over the period 1996-2012 (340 observations in the full sample). Decentralization is proxied by two different indicators, capturing the degree of decision-making autonomy in the allocation of tax revenues and the extent to which regions rely on fiscal transfers from the central government. The results show that a higher proportion of tax revenues raised and/or controlled locally as well as a lower transfer dependency from the central government are consistently associated with lower infant mortality rates, ceteris paribus. The marginal benefit from fiscal decentralization, however, is not constant but depends on the level of regional wealth, favouring poorest regions. In terms of policy implications, this study outlines how the effectiveness of decentralization in improving health outcomes is contingent on the characteristics of the context in which the process takes place. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Scaling of musculoskeletal models from static and dynamic trials

    DEFF Research Database (Denmark)

    Lund, Morten Enemark; Andersen, Michael Skipper; de Zee, Mark

    2015-01-01

    Subject-specific scaling of cadaver-based musculoskeletal models is important for accurate musculoskeletal analysis within multiple areas such as ergonomics, orthopaedics and occupational health. We present two procedures to scale ‘generic’ musculoskeletal models to match segment lengths and joint...... parameters to a specific subject and compare the results to a simpler approach based on linear, segment-wise scaling. By incorporating data from functional and standing reference trials, the new scaling approaches reduce the model sensitivity to assumed model marker positions. For validation, we applied all....... The presented methods solve part of this problem and rely less on manual identification of anatomical landmarks in the model. The work represents a step towards a more consistent methodology in musculoskeletal modelling....

  13. Exploring nonlinear subgrid-scale models and new characteristic length scales for large-eddy simulation

    NARCIS (Netherlands)

    Silvis, Maurits H.; Trias, F. Xavier; Abkar, M.; Bae, H.J.; Lozano-Duran, A.; Verstappen, R.W.C.P.; Moin, Parviz; Urzay, Javier

    2016-01-01

    We study subgrid-scale modeling for large-eddy simulation of anisotropic turbulent flows on anisotropic grids. In particular, we show how the addition of a velocity-gradient-based nonlinear model term to an eddy viscosity model provides a better representation of energy transfer. This is shown to

  14. Decentralized Resource Management in Distributed Computer Systems.

    Science.gov (United States)

    1982-02-01

    Interprocess Communication 14 2.3.2.5 Decentralized Resource Management 15 2.3.3 MicroNet 16 * 2.3.3.1 System Goals and Objectives 16 2.3.3.2 Physical...executive level) is moderately low. 16 Background 2.3.3 MicroNet 2.3.3.1 System Goals and Objectives MicroNet [47] was designed to support multiple...tolerate the loss of nodes, allow for a wide variety of interconnect topologies, and adapt to dynamic variations in loading. The designers of MicroNet

  15. Multi-scale modeling for sustainable chemical production

    DEFF Research Database (Denmark)

    Zhuang, Kai; Bakshi, Bhavik R.; Herrgard, Markus

    2013-01-01

    associated with the development and implementation of a su stainable biochemical industry. The temporal and spatial scales of modeling approaches for sustainable chemical production vary greatly, ranging from metabolic models that aid the design of fermentative microbial strains to material and monetary flow......, chemical industry, economy, and ecosystem. In addition, we propose a multi-scale approach for integrating the existing models into a cohesive framework. The major benefit of this proposed framework is that the design and decision-making at each scale can be informed, guided, and constrained by simulations...... and predictions at every other scale. In addition, the development of this multi-scale framework would promote cohesive collaborations across multiple traditionally disconnected modeling disciplines to achieve sustainable chemical production....

  16. Generic, scalable and decentralized fault detection for robot swarms

    Science.gov (United States)

    Christensen, Anders Lyhne; Timmis, Jon

    2017-01-01

    Robot swarms are large-scale multirobot systems with decentralized control which means that each robot acts based only on local perception and on local coordination with neighboring robots. The decentralized approach to control confers number of potential benefits. In particular, inherent scalability and robustness are often highlighted as key distinguishing features of robot swarms compared with systems that rely on traditional approaches to multirobot coordination. It has, however, been shown that swarm robotics systems are not always fault tolerant. To realize the robustness potential of robot swarms, it is thus essential to give systems the capacity to actively detect and accommodate faults. In this paper, we present a generic fault-detection system for robot swarms. We show how robots with limited and imperfect sensing capabilities are able to observe and classify the behavior of one another. In order to achieve this, the underlying classifier is an immune system-inspired algorithm that learns to distinguish between normal behavior and abnormal behavior online. Through a series of experiments, we systematically assess the performance of our approach in a detailed simulation environment. In particular, we analyze our system’s capacity to correctly detect robots with faults, false positive rates, performance in a foraging task in which each robot exhibits a composite behavior, and performance under perturbations of the task environment. Results show that our generic fault-detection system is robust, that it is able to detect faults in a timely manner, and that it achieves a low false positive rate. The developed fault-detection system has the potential to enable long-term autonomy for robust multirobot systems, thus increasing the usefulness of robots for a diverse repertoire of upcoming applications in the area of distributed intelligent automation. PMID:28806756

  17. Generic, scalable and decentralized fault detection for robot swarms.

    Science.gov (United States)

    Tarapore, Danesh; Christensen, Anders Lyhne; Timmis, Jon

    2017-01-01

    Robot swarms are large-scale multirobot systems with decentralized control which means that each robot acts based only on local perception and on local coordination with neighboring robots. The decentralized approach to control confers number of potential benefits. In particular, inherent scalability and robustness are often highlighted as key distinguishing features of robot swarms compared with systems that rely on traditional approaches to multirobot coordination. It has, however, been shown that swarm robotics systems are not always fault tolerant. To realize the robustness potential of robot swarms, it is thus essential to give systems the capacity to actively detect and accommodate faults. In this paper, we present a generic fault-detection system for robot swarms. We show how robots with limited and imperfect sensing capabilities are able to observe and classify the behavior of one another. In order to achieve this, the underlying classifier is an immune system-inspired algorithm that learns to distinguish between normal behavior and abnormal behavior online. Through a series of experiments, we systematically assess the performance of our approach in a detailed simulation environment. In particular, we analyze our system's capacity to correctly detect robots with faults, false positive rates, performance in a foraging task in which each robot exhibits a composite behavior, and performance under perturbations of the task environment. Results show that our generic fault-detection system is robust, that it is able to detect faults in a timely manner, and that it achieves a low false positive rate. The developed fault-detection system has the potential to enable long-term autonomy for robust multirobot systems, thus increasing the usefulness of robots for a diverse repertoire of upcoming applications in the area of distributed intelligent automation.

  18. Multi-scale Modelling of Segmentation

    DEFF Research Database (Denmark)

    Hartmann, Martin; Lartillot, Olivier; Toiviainen, Petri

    2016-01-01

    While listening to music, people often unwittingly break down musical pieces into constituent chunks such as verses and choruses. Music segmentation studies have suggested that some consensus regarding boundary perception exists, despite individual differences. However, neither the effects...... of experimental task (i.e., real-time vs. annotated segmentation), nor of musicianship on boundary perception are clear. Our study assesses musicianship effects and differences between segmentation tasks. We conducted a real-time experiment to collect segmentations by musicians and nonmusicians from nine musical...... indication density, although this might be contingent on stimuli and other factors. In line with other studies, no musicianship effects were found: our results showed high agreement between groups and similar inter-subject correlations. Also consistent with previous work, time scales between one and two...

  19. Continental scale modelling of geomagnetically induced currents

    Directory of Open Access Journals (Sweden)

    Sakharov Yaroslav

    2012-09-01

    Full Text Available The EURISGIC project (European Risk from Geomagnetically Induced Currents aims at deriving statistics of geomagnetically induced currents (GIC in the European high-voltage power grids. Such a continent-wide system of more than 1500 substations and transmission lines requires updates of the previous modelling, which has dealt with national grids in fairly small geographic areas. We present here how GIC modelling can be conveniently performed on a spherical surface with minor changes in the previous technique. We derive the exact formulation to calculate geovoltages on the surface of a sphere and show its practical approximation in a fast vectorised form. Using the model of the old Finnish power grid and a much larger prototype model of European high-voltage power grids, we validate the new technique by comparing it to the old one. We also compare model results to measured data in the following cases: geoelectric field at the Nagycenk observatory, Hungary; GIC at a Russian transformer; GIC along the Finnish natural gas pipeline. In all cases, the new method works reasonably well.

  20. Dynamically Scaled Model Experiment of a Mooring Cable

    Directory of Open Access Journals (Sweden)

    Lars Bergdahl

    2016-01-01

    Full Text Available The dynamic response of mooring cables for marine structures is scale-dependent, and perfect dynamic similitude between full-scale prototypes and small-scale physical model tests is difficult to achieve. The best possible scaling is here sought by means of a specific set of dimensionless parameters, and the model accuracy is also evaluated by two alternative sets of dimensionless parameters. A special feature of the presented experiment is that a chain was scaled to have correct propagation celerity for longitudinal elastic waves, thus providing perfect geometrical and dynamic scaling in vacuum, which is unique. The scaling error due to incorrect Reynolds number seemed to be of minor importance. The 33 m experimental chain could then be considered a scaled 76 mm stud chain with the length 1240 m, i.e., at the length scale of 1:37.6. Due to the correct elastic scale, the physical model was able to reproduce the effect of snatch loads giving rise to tensional shock waves propagating along the cable. The results from the experiment were used to validate the newly developed cable-dynamics code, MooDy, which utilises a discontinuous Galerkin FEM formulation. The validation of MooDy proved to be successful for the presented experiments. The experimental data is made available here for validation of other numerical codes by publishing digitised time series of two of the experiments.

  1. Decentralized energy studies: compendium of international studies and research

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, C.

    1980-03-01

    The purpose of the compendium is to provide information about research activities in decentralized energy systems to researchers, government officials, and interested citizens. The compendium lists and briefly describes a number of studies in other industrialized nations that involve decentralized energy systems. A contact person is given for each of the activities listed so that interested readers can obtain more information.

  2. Decentralized Consistency Checking in Cross-organizational Workflows

    NARCIS (Netherlands)

    Wombacher, Andreas

    Service Oriented Architectures facilitate loosely coupled composed services, which are established in a decentralized way. One challenge for such composed services is to guarantee consistency, i.e., deadlock-freeness. This paper presents a decentralized approach to consistency checking, which

  3. Decentralization, local power and women rights: global trends in ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Unicornis

    Women rights and effective decentralization in the MENA: bridging the gaps between local politics, institutional design and gender outcomes. Dr. Mostafa JARI,. Faculty of legal, economic and social sciences. Marrakech Morocco. Decentralization, local power and women rights: global trends in participation, representation ...

  4. The Impact of Fiscal Decentralization on Provision of Quality ...

    African Journals Online (AJOL)

    This article uses panel data from 94 LGAs in Tanzania mainland over the period 2005/06 to 2009/10, to examine the impact of Fiscal Decentralization on education spending and provision of quality education. Using local share of total fiscal expenditure as a proxy for fiscal decentralization, this article concludes that Fiscal ...

  5. Decentralized Planning for Pre-Conflict and Post-Conflict ...

    African Journals Online (AJOL)

    ... the capitalization of a conflict planning programme and the adoption of decentralized institutional arrangements for conflict monitoring and evaluation. Such processes are 'sine qua non' to pre-conflict and post-conflict prevention. KEY WORDS: Decentralization, Conflict, Pre-conflict, Post-conflict, Planning, Management ...

  6. Decentralization, Local Politics and the Construction of Women's ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    This project constitutes the first phase of a comparative study of decentralization, local politics and the construction of women's citizenship in Uganda, Kenya and Tanzania. Researchers will examine the gendered subtexts in the decentralization process with a view to understanding how women's citizenship is constructed ...

  7. Decentralized Budgeting: Getting the Most Out of Disbursements of Funds.

    Science.gov (United States)

    Jefferson, Anne L.

    1995-01-01

    Decentralizing educational budgets allows the disbursement of funds aimed at maximizing student development. Three strategies for decentralizing budgets are program budgeting, which eliminates line-item budgeting and allows administrators to address questions regarding the relative value of educational programs; zero-based budgeting, which allows…

  8. Setting the Governmental Agenda for State Decentralization of Higher Education.

    Science.gov (United States)

    McLendon, Michael K.

    2003-01-01

    State decentralization of higher education emerged as a significant governance trend of the 1980s to 1990s. Yet little is known about how or why decentralization first became an issue to which state governments paid serious attention. This study employs multiple theories to analyze the agenda-setting stage of policy formation in three states…

  9. A Review of Characteristics and Experiences of Decentralization of Education

    Science.gov (United States)

    Mwinjuma, Juma Saidi; Kadir, Suhaida bte Abd.; Hamzah, Azimi; Basri, Ramli

    2015-01-01

    This paper scrutinizes decentralization of education with reference to some countries around the world. We consider discussion on decentralization to be complex, critical and broad question in the contemporary education planning, administration and politics of education reforms. Even though the debate on and implementation of decentralization…

  10. Flavor Gauge Models Below the Fermi Scale

    Energy Technology Data Exchange (ETDEWEB)

    Babu, K. S. [Oklahoma State U.; Friedland, A. [SLAC; Machado, P. A.N. [Madrid, IFT; Mocioiu, I. [Penn State U.

    2017-05-04

    The mass and weak interaction eigenstates for the quarks of the third generation are very well aligned, an empirical fact for which the Standard Model offers no explanation. We explore the possibility that this alignment is due to an additional gauge symmetry in the third generation. Specifically, we construct and analyze an explicit, renormalizable model with a gauge boson, $X$, corresponding to the $B-L$ symmetry of the third family. Having a relatively light (in the MeV to multi-GeV range), flavor-nonuniversal gauge boson results in a variety of constraints from different sources. By systematically analyzing 20 different constraints, we identify the most sensitive probes: kaon, $D^+$ and Upsilon decays, $D-\\bar{D}^0$ mixing, atomic parity violation, and neutrino scattering and oscillations. For the new gauge coupling $g_X$ in the range $(10^{-2} - 10^{-4})$ the model is shown to be consistent with the data. Possible ways of testing the model in $b$ physics, top and $Z$ decays, direct collider production and neutrino oscillation experiments, where one can observe nonstandard matter effects, are outlined. The choice of leptons to carry the new force is ambiguous, resulting in additional phenomenological implications, such as non-universality in semileptonic bottom decays. The proposed framework provides interesting connections between neutrino oscillations, flavor and collider physics.

  11. MOUNTAIN-SCALE COUPLED PROCESSES (TH/THC/THM)MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Y.S. Wu

    2005-08-24

    This report documents the development and validation of the mountain-scale thermal-hydrologic (TH), thermal-hydrologic-chemical (THC), and thermal-hydrologic-mechanical (THM) models. These models provide technical support for screening of features, events, and processes (FEPs) related to the effects of coupled TH/THC/THM processes on mountain-scale unsaturated zone (UZ) and saturated zone (SZ) flow at Yucca Mountain, Nevada (BSC 2005 [DIRS 174842], Section 2.1.1.1). The purpose and validation criteria for these models are specified in ''Technical Work Plan for: Near-Field Environment and Transport: Coupled Processes (Mountain-Scale TH/THC/THM, Drift-Scale THC Seepage, and Drift-Scale Abstraction) Model Report Integration'' (BSC 2005 [DIRS 174842]). Model results are used to support exclusion of certain FEPs from the total system performance assessment for the license application (TSPA-LA) model on the basis of low consequence, consistent with the requirements of 10 CFR 63.342 [DIRS 173273]. Outputs from this report are not direct feeds to the TSPA-LA. All the FEPs related to the effects of coupled TH/THC/THM processes on mountain-scale UZ and SZ flow are discussed in Sections 6 and 7 of this report. The mountain-scale coupled TH/THC/THM processes models numerically simulate the impact of nuclear waste heat release on the natural hydrogeological system, including a representation of heat-driven processes occurring in the far field. The mountain-scale TH simulations provide predictions for thermally affected liquid saturation, gas- and liquid-phase fluxes, and water and rock temperature (together called the flow fields). The main focus of the TH model is to predict the changes in water flux driven by evaporation/condensation processes, and drainage between drifts. The TH model captures mountain-scale three-dimensional flow effects, including lateral diversion and mountain-scale flow patterns. The mountain-scale THC model evaluates TH effects on

  12. A decentralized approach to reducing the social costs of cascading failures

    Science.gov (United States)

    Hines, Paul

    Large cascading failures in electrical power networks come with enormous social costs. These can be direct financial costs, such as the loss of refrigerated foods in grocery stores, or more indirect social costs, such as the traffic congestion that results from the failure of traffic signals. While engineers and policy makers have made numerous technical and organizational changes to reduce the frequency and impact of large cascading failures, the existing data, as described in Chapter 2 of this work, indicate that the overall frequency and impact of large electrical blackouts in the United States are not decreasing. Motivated by the cascading failure problem, this thesis describes a new method for Distributed Model Predictive Control and a power systems application. The central goal of the method, when applied to power systems, is to reduce the social costs of cascading failures by making small, targeted reductions in load and generation and changes to generator voltage set points. Unlike some existing schemes that operate from centrally located control centers, the method is operated by software agents located at substations distributed throughout the power network. The resulting multi-agent control system is a new approach to decentralized control, combining Distributed Model Predictive Control and Reciprocal Altruism. Experimental results indicate that this scheme can in fact decrease the average size, and thus social costs, of cascading failures. Over 100 randomly generated disturbances to a model of the IEEE 300 bus test network, the method resulted in nearly an order of magnitude decrease in average event size (measured in cost) relative to cascading failure simulations without remedial control actions. Additionally, the communication requirements for the method are measured, and found to be within the bandwidth capabilities of current communications technology (on the order of 100kB/second). Experiments on several resistor networks with varying structures

  13. Decentralization and Participatory Rural Development: A Literature Review

    Directory of Open Access Journals (Sweden)

    Muhammad Shakil Ahmad

    2011-12-01

    Full Text Available Most of the developing nations are still struggling for efficient use of their resources. In order to overcome physical and administrative constraints of the development, it is necessary to transfer the power from the central government to local authorities. Distribution of power from improves the management of resources and community participation which is considered key to sustainable development. Advocates of decentralization argue that decentralized government is source to improve community participation in rural development. Decentralized government is considered more responsive towards local needs and development of poor peoples. There are many obstacles to expand the citizen participation in rural areas. There are many approaches for participatory development but all have to face the same challenges. Current paper highlights the literature about Decentralization and participatory rural development. Concept and modalities of Decentralization, dimensions of participation, types of rural participation and obstacles to participation are also the part of this paper.

  14. Sensitivities in global scale modeling of isoprene

    Directory of Open Access Journals (Sweden)

    R. von Kuhlmann

    2004-01-01

    Full Text Available A sensitivity study of the treatment of isoprene and related parameters in 3D atmospheric models was conducted using the global model of tropospheric chemistry MATCH-MPIC. A total of twelve sensitivity scenarios which can be grouped into four thematic categories were performed. These four categories consist of simulations with different chemical mechanisms, different assumptions concerning the deposition characteristics of intermediate products, assumptions concerning the nitrates from the oxidation of isoprene and variations of the source strengths. The largest differences in ozone compared to the reference simulation occured when a different isoprene oxidation scheme was used (up to 30-60% or about 10 nmol/mol. The largest differences in the abundance of peroxyacetylnitrate (PAN were found when the isoprene emission strength was reduced by 50% and in tests with increased or decreased efficiency of the deposition of intermediates. The deposition assumptions were also found to have a significant effect on the upper tropospheric HOx production. Different implicit assumptions about the loss of intermediate products were identified as a major reason for the deviations among the tested isoprene oxidation schemes. The total tropospheric burden of O3 calculated in the sensitivity runs is increased compared to the background methane chemistry by 26±9  Tg( O3 from 273 to an average from the sensitivity runs of 299 Tg(O3. % revised Thus, there is a spread of ± 35% of the overall effect of isoprene in the model among the tested scenarios. This range of uncertainty and the much larger local deviations found in the test runs suggest that the treatment of isoprene in global models can only be seen as a first order estimate at present, and points towards specific processes in need of focused future work.

  15. Modeling Human Behavior at a Large Scale

    Science.gov (United States)

    2012-01-01

    impacts its recognition performance for both activities. The example we just gave illustrates one type of freeing false positives. The hallucinated freeings... vision have worked on the problem of recognizing events in videos of sporting events, such as impressive recent work on learning models of baseball plays...data can only be disambiguated by considering arbitrarily long temporal sequences. In general, however, both our work 65 and that in machine vision

  16. Anomalous scaling in an age-dependent branching model

    OpenAIRE

    Keller-Schmidt, Stephanie; Tugrul, Murat; Eguíluz, Víctor M.; Hernández-García, Emilio; Klemm, Konstantin

    2010-01-01

    We introduce a one-parametric family of tree growth models, in which branching probabilities decrease with branch age $\\tau$ as $\\tau^{-\\alpha}$. Depending on the exponent $\\alpha$, the scaling of tree depth with tree size $n$ displays a transition between the logarithmic scaling of random trees and an algebraic growth. At the transition ($\\alpha=1$) tree depth grows as $(\\log n)^2$. This anomalous scaling is in good agreement with the trend observed in evolution of biological species, thus p...

  17. Simultaneous nested modeling from the synoptic scale to the LES scale for wind energy applications

    DEFF Research Database (Denmark)

    Liu, Yubao; Warner, Tom; Liu, Yuewei

    2011-01-01

    This paper describes an advanced multi-scale weather modeling system, WRF–RTFDDA–LES, designed to simulate synoptic scale (~2000 km) to small- and micro-scale (~100 m) circulations of real weather in wind farms on simultaneous nested grids. This modeling system is built upon the National Center...... grids and seamlessly providing realistic mesoscale weather forcing to drive a large eddy simulation (LES) model within the WRF framework. The WRF based RTFDDA LES modeling capability is referred to as WRF–RTFDDA–LES. In this study, WRF–RTFDDA–LES is employed to simulate real weather in a major wind farm...... located in northern Colorado with six nested domains. The grid sizes of the nested domains are 30, 10, 3.3, 1.1, 0.370 and 0.123 km, respectively. The model results are compared with wind–farm anemometer measurements and are found to capture many intra-farm wind features and microscale flows. Additional...

  18. Fractal Modeling and Scaling in Natural Systems - Editorial

    Science.gov (United States)

    The special issue of Ecological complexity journal on Fractal Modeling and Scaling in Natural Systems contains representative examples of the status and evolution of data-driven research into fractals and scaling in complex natural systems. The editorial discusses contributions to understanding rela...

  19. Multi-scale modeling strategies in materials science—The ...

    Indian Academy of Sciences (India)

    ... time scales involved in determining macroscopic properties has been attempted by several workers with varying degrees of success. This paper will review the recently developed quasicontinuum method which is an attempt to bridge the length scales in a single seamless model with the aid of the finite element method.

  20. Scaling Properties of a Hybrid Fermi-Ulam-Bouncer Model

    Directory of Open Access Journals (Sweden)

    Diego F. M. Oliveira

    2009-01-01

    under the framework of scaling description. The model is described by using a two-dimensional nonlinear area preserving mapping. Our results show that the chaotic regime below the lowest energy invariant spanning curve is scaling invariant and the obtained critical exponents are used to find a universal plot for the second momenta of the average velocity.

  1. Ares I Scale Model Acoustic Test Lift-Off Acoustics

    Science.gov (United States)

    Counter, Douglas D.; Houston, Janie D.

    2011-01-01

    The lift-off acoustic (LOA) environment is an important design factor for any launch vehicle. For the Ares I vehicle, the LOA environments were derived by scaling flight data from other launch vehicles. The Ares I LOA predicted environments are compared to the Ares I Scale Model Acoustic Test (ASMAT) preliminary results.

  2. Advances in Modelling of Large Scale Coastal Evolution

    NARCIS (Netherlands)

    Stive, M.J.F.; De Vriend, H.J.

    1995-01-01

    The attention for climate change impact on the world's coastlines has established large scale coastal evolution as a topic of wide interest. Some more recent advances in this field, focusing on the potential of mathematical models for the prediction of large scale coastal evolution, are discussed.

  3. Visualization and modeling of smoke transport over landscape scales

    Science.gov (United States)

    Glenn P. Forney; William Mell

    2007-01-01

    Computational tools have been developed at the National Institute of Standards and Technology (NIST) for modeling fire spread and smoke transport. These tools have been adapted to address fire scenarios that occur in the wildland urban interface (WUI) over kilometer-scale distances. These models include the smoke plume transport model ALOFT (A Large Open Fire plume...

  4. Atomic scale simulations for improved CRUD and fuel performance modeling

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Anders David Ragnar [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cooper, Michael William Donald [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-06

    A more mechanistic description of fuel performance codes can be achieved by deriving models and parameters from atomistic scale simulations rather than fitting models empirically to experimental data. The same argument applies to modeling deposition of corrosion products on fuel rods (CRUD). Here are some results from publications in 2016 carried out using the CASL allocation at LANL.

  5. Meso-scale modeling of a forested landscape

    DEFF Research Database (Denmark)

    Dellwik, Ebba; Arnqvist, Johan; Bergström, Hans

    2014-01-01

    Meso-scale models are increasingly used for estimating wind resources for wind turbine siting. In this study, we investigate how the Weather Research and Forecasting (WRF) model performs using standard model settings in two different planetary boundary layer schemes for a forested landscape and how...

  6. Natural Resources, Decentralization, and Risk Sharing: Can Resource Booms Unify Nations?

    OpenAIRE

    Fidel Perez-Sebastian; Ohad Raveh

    2016-01-01

    Previous studies imply that a positive regional fiscal shock, such as a resource boom, strengthens the desire for separation. In this paper we present a new and opposite perspective. We construct a model of endogenous fiscal decentralization that builds on two key notions: a trade-off between risk sharing and heterogeneity, and a positive association between resource booms and risk. The model shows that a resource windfall causes the nation to centralize as a mechanism to either share risk an...

  7. Genome-scale modeling for metabolic engineering.

    Science.gov (United States)

    Simeonidis, Evangelos; Price, Nathan D

    2015-03-01

    We focus on the application of constraint-based methodologies and, more specifically, flux balance analysis in the field of metabolic engineering, and enumerate recent developments and successes of the field. We also review computational frameworks that have been developed with the express purpose of automatically selecting optimal gene deletions for achieving improved production of a chemical of interest. The application of flux balance analysis methods in rational metabolic engineering requires a metabolic network reconstruction and a corresponding in silico metabolic model for the microorganism in question. For this reason, we additionally present a brief overview of automated reconstruction techniques. Finally, we emphasize the importance of integrating metabolic networks with regulatory information-an area which we expect will become increasingly important for metabolic engineering-and present recent developments in the field of metabolic and regulatory integration.

  8. Modelling of evapotranspiration at field and landscape scales. Abstract

    DEFF Research Database (Denmark)

    Overgaard, Jesper; Butts, M.B.; Rosbjerg, Dan

    2002-01-01

    The overall aim of this project is to couple a non-hydrostatic atmospheric model (ARPS) to an integrated hydrological model (MIKE SHE) to investigate atmospheric and hydrological feedbacks at different scales. To ensure a consistent coupling a new land-surface component based on a modified...... Shuttleworth-Wallace scheme was implemented in MIKE SHE. To validate the new land-surface component at different scales, the hydrological model was applied to an intensively monitored 10 km2 agricultural area in Denmark with a resolution of 40 meter. The model is forced with half-hourly metorological...... observations from a nearby weather station. Detailed land-use and soil maps were used to set up the model. Leaf area index was derived from NDVI (Normalized Difference Vegetation Index) images. To validate the model at field scale the simulated evapotranspiration rates were compared to eddy...

  9. Multi-Scale Computational Models for Electrical Brain Stimulation

    Science.gov (United States)

    Seo, Hyeon; Jun, Sung C.

    2017-01-01

    Electrical brain stimulation (EBS) is an appealing method to treat neurological disorders. To achieve optimal stimulation effects and a better understanding of the underlying brain mechanisms, neuroscientists have proposed computational modeling studies for a decade. Recently, multi-scale models that combine a volume conductor head model and multi-compartmental models of cortical neurons have been developed to predict stimulation effects on the macroscopic and microscopic levels more precisely. As the need for better computational models continues to increase, we overview here recent multi-scale modeling studies; we focused on approaches that coupled a simplified or high-resolution volume conductor head model and multi-compartmental models of cortical neurons, and constructed realistic fiber models using diffusion tensor imaging (DTI). Further implications for achieving better precision in estimating cellular responses are discussed. PMID:29123476

  10. Predictions of a model of weak scale from dynamical breaking of scale invariance

    Directory of Open Access Journals (Sweden)

    Giulio Maria Pelaggi

    2015-04-01

    Full Text Available We consider a model where the weak and the DM scale arise at one loop from the Coleman–Weinberg mechanism. We perform a precision computation of the model predictions for the production cross section of a new Higgs-like scalar and for the direct-detection cross section of the DM particle candidate.

  11. Measurement of returns to scale in radial DEA models

    Science.gov (United States)

    Krivonozhko, V. E.; Lychev, A. V.; Førsund, F. R.

    2017-01-01

    A general approach is proposed in order to measure returns to scale and scale elasticity at projections points in the radial data envelopment analysis (DEA) models. In the first stage, a relative interior point belonging to the optimal face is found using a special, elaborated method. In previous work it was proved that any relative interior point of a face has the same returns to scale as any other interior point of this face. In the second stage, we propose to determine the returns to scale at the relative interior point found in the first stage.

  12. Reverse auction results for implementation of decentralized retrofit best management practices in a small urban watershed (Cincinnati OH)Participatory storm water management and sustainability – what are the connections?

    Science.gov (United States)

    Urban stormwater is typically conveyed to centralized infrastructure, and there is great potential for reducing stormwater runoff quantity through decentralization. In this case we hypothesize that smaller-scale retrofit best management practices (BMPs) such as rain gardens and r...

  13. [Local governance in the decentralized health care system in Brazil].

    Science.gov (United States)

    Fleury, Sonia; Ouverney, Assis Luiz Mafort; Kronemberger, Thais Soares; Zani, Felipe Barbosa

    2010-12-01

    decision-making practices. The process of decentralization still faces important obstacles to the establishment of a more participative model, with enhanced social control, accountability and interaction between government and society.

  14. Phenomenological Aspects of No-Scale Inflation Models

    CERN Document Server

    Ellis, John; Nanopoulos, Dimitri V; Olive, Keith A

    2015-01-01

    We discuss phenomenological aspects of no-scale supergravity inflationary models motivated by compactified string models, in which the inflaton may be identified either as a K\\"ahler modulus or an untwisted matter field, focusing on models that make predictions for the scalar spectral index $n_s$ and the tensor-to-scalar ratio $r$ that are similar to the Starobinsky model. We discuss possible patterns of soft supersymmetry breaking, exhibiting examples of the pure no-scale type $m_0 = B_0 = A_0 = 0$, of the CMSSM type with universal $A_0$ and $m_0 \

  15. [Modeling continuous scaling of NDVI based on fractal theory].

    Science.gov (United States)

    Luan, Hai-Jun; Tian, Qing-Jiu; Yu, Tao; Hu, Xin-Li; Huang, Yan; Du, Ling-Tong; Zhao, Li-Min; Wei, Xi; Han, Jie; Zhang, Zhou-Wei; Li, Shao-Peng

    2013-07-01

    Scale effect was one of the very important scientific problems of remote sensing. The scale effect of quantitative remote sensing can be used to study retrievals' relationship between different-resolution images, and its research became an effective way to confront the challenges, such as validation of quantitative remote sensing products et al. Traditional up-scaling methods cannot describe scale changing features of retrievals on entire series of scales; meanwhile, they are faced with serious parameters correction issues because of imaging parameters' variation of different sensors, such as geometrical correction, spectral correction, etc. Utilizing single sensor image, fractal methodology was utilized to solve these problems. Taking NDVI (computed by land surface radiance) as example and based on Enhanced Thematic Mapper Plus (ETM+) image, a scheme was proposed to model continuous scaling of retrievals. Then the experimental results indicated that: (a) For NDVI, scale effect existed, and it could be described by fractal model of continuous scaling; (2) The fractal method was suitable for validation of NDVI. All of these proved that fractal was an effective methodology of studying scaling of quantitative remote sensing.

  16. Ecohydrological modeling for large-scale environmental impact assessment.

    Science.gov (United States)

    Woznicki, Sean A; Nejadhashemi, A Pouyan; Abouali, Mohammad; Herman, Matthew R; Esfahanian, Elaheh; Hamaamin, Yaseen A; Zhang, Zhen

    2016-02-01

    Ecohydrological models are frequently used to assess the biological integrity of unsampled streams. These models vary in complexity and scale, and their utility depends on their final application. Tradeoffs are usually made in model scale, where large-scale models are useful for determining broad impacts of human activities on biological conditions, and regional-scale (e.g. watershed or ecoregion) models provide stakeholders greater detail at the individual stream reach level. Given these tradeoffs, the objective of this study was to develop large-scale stream health models with reach level accuracy similar to regional-scale models thereby allowing for impacts assessments and improved decision-making capabilities. To accomplish this, four measures of biological integrity (Ephemeroptera, Plecoptera, and Trichoptera taxa (EPT), Family Index of Biotic Integrity (FIBI), Hilsenhoff Biotic Index (HBI), and fish Index of Biotic Integrity (IBI)) were modeled based on four thermal classes (cold, cold-transitional, cool, and warm) of streams that broadly dictate the distribution of aquatic biota in Michigan. The Soil and Water Assessment Tool (SWAT) was used to simulate streamflow and water quality in seven watersheds and the Hydrologic Index Tool was used to calculate 171 ecologically relevant flow regime variables. Unique variables were selected for each thermal class using a Bayesian variable selection method. The variables were then used in development of adaptive neuro-fuzzy inference systems (ANFIS) models of EPT, FIBI, HBI, and IBI. ANFIS model accuracy improved when accounting for stream thermal class rather than developing a global model. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. FINAL REPORT: Mechanistically-Base Field Scale Models of Uranium Biogeochemistry from Upscaling Pore-Scale Experiments and Models

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Brian D. [Oregon State Univ., Corvallis, OR (United States)

    2013-11-04

    Biogeochemical reactive transport processes in the subsurface environment are important to many contemporary environmental issues of significance to DOE. Quantification of risks and impacts associated with environmental management options, and design of remediation systems where needed, require that we have at our disposal reliable predictive tools (usually in the form of numerical simulation models). However, it is well known that even the most sophisticated reactive transport models available today have poor predictive power, particularly when applied at the field scale. Although the lack of predictive ability is associated in part with our inability to characterize the subsurface and limitations in computational power, significant advances have been made in both of these areas in recent decades and can be expected to continue. In this research, we examined the upscaling (pore to Darcy and Darcy to field) the problem of bioremediation via biofilms in porous media. The principle idea was to start with a conceptual description of the bioremediation process at the pore scale, and apply upscaling methods to formally develop the appropriate upscaled model at the so-called Darcy scale. The purpose was to determine (1) what forms the upscaled models would take, and (2) how one might parameterize such upscaled models for applications to bioremediation in the field. We were able to effectively upscale the bioremediation process to explain how the pore-scale phenomena were linked to the field scale. The end product of this research was to produce a set of upscaled models that could be used to help predict field-scale bioremediation. These models were mechanistic, in the sense that they directly incorporated pore-scale information, but upscaled so that only the essential features of the process were needed to predict the effective parameters that appear in the model. In this way, a direct link between the microscale and the field scale was made, but the upscaling process

  18. Decentralized nursing education in Northern Norway: a basis for continuing education to meet competence needs in rural Arctic healthcare services

    Directory of Open Access Journals (Sweden)

    Mari Wolff Skaalvik

    2014-09-01

    Full Text Available Background: Ensuring a sufficient nursing workforce, with respect to both number and relevant professional competencies, is crucial in rural Arctic regions in Norway. This study examines the continuing education (CE of nurses who graduated from a decentralized nursing programme between 1994 and 2011. Objective: This study aims to measure the extent to which the decentralized nursing education (DNE in question has served as a basis for CE that is adapted to current and future community health care service needs in rural Arctic regions in northern Norway. More specifically, the study aims to investigate the frequency and scope of CE courses among the graduates of a DNE, the choice of study model and the degree of employment with respect to the relevant CE. Design: This study is a quantitative survey providing descriptive statistics. Results: The primary finding in this study is that 56% of the participants had engaged in CE and that they were employed in positions related to their education. The majority of students with decentralized bachelor's degrees engaged in CE that was part time and/or decentralized. Conclusions: More than half of the population in this study had completed CE despite no mandatory obligation in order to maintain licensure. Furthermore, 31% of the participants had completed more than one CE programme. The findings show that the participants preferred CE organized as part time and or decentralized studies.

  19. Decentralized nursing education in Northern Norway: a basis for continuing education to meet competence needs in rural Arctic healthcare services

    Science.gov (United States)

    Skaalvik, Mari Wolff; Gaski, Margrete; Norbye, Bente

    2014-01-01

    Background Ensuring a sufficient nursing workforce, with respect to both number and relevant professional competencies, is crucial in rural Arctic regions in Norway. This study examines the continuing education (CE) of nurses who graduated from a decentralized nursing programme between 1994 and 2011. Objective This study aims to measure the extent to which the decentralized nursing education (DNE) in question has served as a basis for CE that is adapted to current and future community health care service needs in rural Arctic regions in northern Norway. More specifically, the study aims to investigate the frequency and scope of CE courses among the graduates of a DNE, the choice of study model and the degree of employment with respect to the relevant CE. Design This study is a quantitative survey providing descriptive statistics. Results The primary finding in this study is that 56% of the participants had engaged in CE and that they were employed in positions related to their education. The majority of students with decentralized bachelor's degrees engaged in CE that was part time and/or decentralized. Conclusions More than half of the population in this study had completed CE despite no mandatory obligation in order to maintain licensure. Furthermore, 31% of the participants had completed more than one CE programme. The findings show that the participants preferred CE organized as part time and or decentralized studies. PMID:25279355

  20. Impact on continuity of care of decentralized versus partly centralized mental health care in Northern Norway

    Directory of Open Access Journals (Sweden)

    Lars Henrik Myklebust

    2011-12-01

    Full Text Available Background: The issue of continuity of care is central in contemporary psychiatric services research. In Norway, inpatient admissions are mainly to take place locally, in a system of small bed-units that represent an alternative to traditional central psychiatric hospitals. This type of organization may be advantageous for accessibility and cooperation, but has been given little scientific attention. Aims: To study whether inpatients' utilization of outpatient services differ between an area with a decentralized care model in comparison to an adjacent area with a partly centralized model.   Method: The study was based on data from a one-year registered prevalence sample, drawing on routinely sampled data supplemented with data from medical records. Service-utilization for 247 inpatients was analyzed. The results were controlled for diagnosis, demographic variables, type of service system, localization of inpatient admissions, and length of hospitalization.  Results: Most inpatients in the area with the decentralized care model also utilized outpatient consultations, whereas a considerable number of inpatients in the area with a partly centralized model did not enter outpatient care at all. Type of service system, localization of inpatient admission, and length of hospitalization predicted inpatients' utilization of outpatient consultations. The results are discussed in the light of systems integration, particularly management-arrangements and clinical bridging over the transitional phase from inpatient to outpatient care.  Conclusion: Inpatients' utilization of outpatient services differed between an area with a decentralized care model in comparison to an adjacent area with a partly centralized care model. In the areas studied, extensive decentralization of the psychiatric services positively affected coordination of inpatient and outpatient services for people with severe psychiatric disorders. Small, local-bed units may therefore

  1. Cancer systems biology and modeling: microscopic scale and multiscale approaches.

    Science.gov (United States)

    Masoudi-Nejad, Ali; Bidkhori, Gholamreza; Hosseini Ashtiani, Saman; Najafi, Ali; Bozorgmehr, Joseph H; Wang, Edwin

    2015-02-01

    Cancer has become known as a complex and systematic disease on macroscopic, mesoscopic and microscopic scales. Systems biology employs state-of-the-art computational theories and high-throughput experimental data to model and simulate complex biological procedures such as cancer, which involves genetic and epigenetic, in addition to intracellular and extracellular complex interaction networks. In this paper, different systems biology modeling techniques such as systems of differential equations, stochastic methods, Boolean networks, Petri nets, cellular automata methods and agent-based systems are concisely discussed. We have compared the mentioned formalisms and tried to address the span of applicability they can bear on emerging cancer modeling and simulation approaches. Different scales of cancer modeling, namely, microscopic, mesoscopic and macroscopic scales are explained followed by an illustration of angiogenesis in microscopic scale of the cancer modeling. Then, the modeling of cancer cell proliferation and survival are examined on a microscopic scale and the modeling of multiscale tumor growth is explained along with its advantages. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Nucleon electric dipole moments in high-scale supersymmetric models

    Energy Technology Data Exchange (ETDEWEB)

    Hisano, Junji [Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI),Nagoya University,Nagoya 464-8602 (Japan); Department of Physics, Nagoya University,Nagoya 464-8602 (Japan); Kavli IPMU (WPI), UTIAS, University of Tokyo,Kashiwa, Chiba 277-8584 (Japan); Kobayashi, Daiki; Kuramoto, Wataru; Kuwahara, Takumi [Department of Physics, Nagoya University,Nagoya 464-8602 (Japan)

    2015-11-12

    The electric dipole moments (EDMs) of electron and nucleons are promising probes of the new physics. In generic high-scale supersymmetric (SUSY) scenarios such as models based on mixture of the anomaly and gauge mediations, gluino has an additional contribution to the nucleon EDMs. In this paper, we studied the effect of the CP-violating gluon Weinberg operator induced by the gluino chromoelectric dipole moment in the high-scale SUSY scenarios, and we evaluated the nucleon and electron EDMs in the scenarios. We found that in the generic high-scale SUSY models, the nucleon EDMs may receive the sizable contribution from the Weinberg operator. Thus, it is important to compare the nucleon EDMs with the electron one in order to discriminate among the high-scale SUSY models.

  3. Analysis for Corruption and Decentralization (Case Study: Earlier Decentralization Era in Indonesia)

    OpenAIRE

    Haryanto, Joko Tri; Astuti S.A., Esther Sri

    2017-01-01

    In many countries, relationship between decentralization of government activities and the extent of rent extraction by private parties is an important element in the recent debate on institutional design. The topic of corruption was actively, openly and debated in Indonesia by government, its development partners, and a broadly based group of political and civil society leaders are engaged in meetings and exchange on a daily basis. In the ongoing debate on corruption a lot of attention is pai...

  4. [A framework for health surveillance decentralization].

    Science.gov (United States)

    Ferraro, Andréa Helena Argolo; Costa, Ediná Alves; Vieira-da-Silva, Lígia Maria

    2009-10-01

    No consensus has been reached concerning the definition of criteria and standards for evaluating the decentralization of actions by municipal health surveillance systems. With the aim of developing and validating an objective image for municipal health surveillance that would correspond to an appropriate system for the population's health care needs, a logical framework was elaborated, from which a matrix containing dimensions and criteria for management and practices was obtained. The framework was submitted to an expert group for validation at a consensus conference. Of the 54 criteria, there was consensus for 59.3%, while 53 items (98%) were considered important, thus validating the matrix. In view of the provisory nature of the consensuses, the resulting instrument, which can be used either in its entirety or in part, enables modification and adaptation. The authors discuss the potential of the evaluation strategy adopted here, which allows various possibilities for redefining the criteria and renewing the consensus.

  5. Decentralized energy systems for clean electricity access

    Science.gov (United States)

    Alstone, Peter; Gershenson, Dimitry; Kammen, Daniel M.

    2015-04-01

    Innovative approaches are needed to address the needs of the 1.3 billion people lacking electricity, while simultaneously transitioning to a decarbonized energy system. With particular focus on the energy needs of the underserved, we present an analytic and conceptual framework that clarifies the heterogeneous continuum of centralized on-grid electricity, autonomous mini- or community grids, and distributed, individual energy services. A historical analysis shows that the present day is a unique moment in the history of electrification where decentralized energy networks are rapidly spreading, based on super-efficient end-use appliances and low-cost photovoltaics. We document how this evolution is supported by critical and widely available information technologies, particularly mobile phones and virtual financial services. These disruptive technology systems can rapidly increase access to basic electricity services and directly inform the emerging Sustainable Development Goals for quality of life, while simultaneously driving action towards low-carbon, Earth-sustaining, inclusive energy systems.

  6. Decentralized Autonomous Hybrid Renewable Power Generation

    Directory of Open Access Journals (Sweden)

    Prakash Kumar

    2015-01-01

    Full Text Available Power extension of grid to isolated regions is associated with technical and economical issues. It has encouraged exploration and exploitation of decentralized power generation using renewable energy sources (RES. RES based power generation involves uncertain availability of power source round the clock. This problem has been overcome to certain extent by installing appropriate integrated energy storage unit (ESU. This paper presents technical review of hybrid wind and photovoltaic (PV generation in standalone mode. Associated components like converters, storage unit, controllers, and optimization techniques affect overall generation. Wind and PV energy are readily available, omnipresent, and expected to contribute major future energy market. It can serve to overcome global warming problem arising due to emissions in fossil fuel based thermal generation units. This paper includes the study of progressive development of standalone renewable generation units based on wind and PV microgrids.

  7. Standard model with spontaneously broken quantum scale invariance

    Science.gov (United States)

    Ghilencea, D. M.; Lalak, Z.; Olszewski, P.

    2017-09-01

    We explore the possibility that scale symmetry is a quantum symmetry that is broken only spontaneously and apply this idea to the standard model. We compute the quantum corrections to the potential of the Higgs field (ϕ ) in the classically scale-invariant version of the standard model (mϕ=0 at tree level) extended by the dilaton (σ ). The tree-level potential of ϕ and σ , dictated by scale invariance, may contain nonpolynomial effective operators, e.g., ϕ6/σ2, ϕ8/σ4, ϕ10/σ6, etc. The one-loop scalar potential is scale invariant, since the loop calculations manifestly preserve the scale symmetry, with the dimensional regularization subtraction scale μ generated spontaneously by the dilaton vacuum expectation value μ ˜⟨σ ⟩. The Callan-Symanzik equation of the potential is verified in the presence of the gauge, Yukawa, and the nonpolynomial operators. The couplings of the nonpolynomial operators have nonzero beta functions that we can actually compute from the quantum potential. At the quantum level, the Higgs mass is protected by spontaneously broken scale symmetry, even though the theory is nonrenormalizable. We compare the one-loop potential to its counterpart computed in the "traditional" dimensional regularization scheme that breaks scale symmetry explicitly (μ =constant) in the presence at the tree level of the nonpolynomial operators.

  8. Description of Muzzle Blast by Modified Ideal Scaling Models

    Directory of Open Access Journals (Sweden)

    Kevin S. Fansler

    1998-01-01

    Full Text Available Gun blast data from a large variety of weapons are scaled and presented for both the instantaneous energy release and the constant energy deposition rate models. For both ideal explosion models, similar amounts of data scatter occur for the peak overpressure but the instantaneous energy release model correlated the impulse data significantly better, particularly for the region in front of the gun. Two parameters that characterize gun blast are used in conjunction with the ideal scaling models to improve the data correlation. The gun-emptying parameter works particularly well with the instantaneous energy release model to improve data correlation. In particular, the impulse, especially in the forward direction of the gun, is correlated significantly better using the instantaneous energy release model coupled with the use of the gun-emptying parameter. The use of the Mach disc location parameter improves the correlation only marginally. A predictive model is obtained from the modified instantaneous energy release correlation.

  9. Decentralization and Polycentricity: Spatial Changes of Employment in Beijing Metropolitan Area, China

    Directory of Open Access Journals (Sweden)

    Yongqiang Lv

    2017-10-01

    Full Text Available Decentralization and polycentric spatial structure strategies are important ways to alleviate urban disease in China. However, whether the urban spatial structure is meeting expectations is still unknown. Taking the Beijing Metropolitan Area as a case, the author adopted a non-parametric method to identify the subcenters, then an employment density model was used to analyze the spatial changes of employment and the employment centers’ impacts on the urban spatial structure. The results show that the Beijing Metropolitan Area was undergoing processes of employment decentralization, the monocentric structure was obvious throughout this time, but the polycentric model prevailed. The spatial structure of the Beijing Metropolitan Area was characterized as depicting “all centers aggregation” and the spatial structure of the central district of Beijing can be described as “subcenter agglomeration” between 2004 and 2013. The spatial structure became increasingly polycentric in the Beijing Metropolitan Area, but became more scattered in the central district.

  10. Influence of cardiac decentralization on cardioprotection.

    Directory of Open Access Journals (Sweden)

    John G Kingma

    Full Text Available The role of cardiac nerves on development of myocardial tissue injury after acute coronary occlusion remains controversial. We investigated whether acute cardiac decentralization (surgical modulates coronary flow reserve and myocardial protection in preconditioned dogs subject to ischemia-reperfusion. Experiments were conducted on four groups of anesthetised, open-chest dogs (n = 32: 1- controls (CTR, intact cardiac nerves, 2- ischemic preconditioning (PC; 4 cycles of 5-min IR, 3- cardiac decentralization (CD and 4- CD+PC; all dogs underwent 60-min coronary occlusion and 180-min reperfusion. Coronary blood flow and reactive hyperemic responses were assessed using a blood volume flow probe. Infarct size (tetrazolium staining was related to anatomic area at risk and coronary collateral blood flow (microspheres in the anatomic area at risk. Post-ischemic reactive hyperemia and repayment-to-debt ratio responses were significantly reduced for all experimental groups; however, arterial perfusion pressure was not affected. Infarct size was reduced in CD dogs (18.6 ± 4.3; p = 0.001, data are mean ± 1 SD compared to 25.2 ± 5.5% in CTR dogs and was less in PC dogs as expected (13.5 ± 3.2 vs. 25.2 ± 5.5%; p = 0.001; after acute CD, PC protection was conserved (11.6 ± 3.4 vs. 18.6 ± 4.3%; p = 0.02. In conclusion, our findings provide strong evidence that myocardial protection against ischemic injury can be preserved independent of extrinsic cardiac nerve inputs.

  11. Responsiveness and flexibility in a Decentralized Supply Chain

    DEFF Research Database (Denmark)

    Petersen, Kristian Rasmus; Bilberg, Arne; Hadar, Ronen

    Today’s supply chains are not capable of managing the instabilities that is the case in the market. Instead, there is a need to develop supply chains that are capable of adapting to changes. Through a case study of LEGO, the authors suggest a possible solution: a decentralized supply chain servin...... independent and self-sufficient local factories. The decentralized supply chain is provided with materials, parts and pre-assembled elements from local suppliers and supplies the local market in return. Keywords: Decentralize, Responsiveness, Flexibility...

  12. On the efficiency of decentralized exchange with resale possibilities

    DEFF Research Database (Denmark)

    Groes, Ebbe; Tranæs, Torben

    1999-01-01

    . If resale is possible and transaction costs are negligible, we would nevertheless expect an efficient allocation to result from decentralized exchange. This paper suggests that this depends on the nature of the commodity; while the allocation of a durable good will be efficient, the allocation......This paper studies decentralized exchange by bilateral matching and bargaining when resale is possible. Decentralized exchange involves the risk that goods and services may be allocated inefficiently; if low-valuation buyers consume while high-valuation buyers do not, then social welfare is reduced...

  13. On Scaling Modes and Balancing Stochastic, Discretization, and Modeling Error

    Science.gov (United States)

    Brown, J.

    2015-12-01

    We consider accuracy-cost tradeoffs and the problem of finding Pareto optimal configurations for stochastic forward and inverse problems. As the target accuracy is changed, we should use different physical models, stochastic models, discretizations, and solution algorithms. In this spectrum, we see different scientifically-relevant scaling modes, thus different opportunities and limitations on parallel computers and emerging architectures.

  14. A Scale Model of Cation Exchange for Classroom Demonstration.

    Science.gov (United States)

    Guertal, E. A.; Hattey, J. A.

    1996-01-01

    Describes a project that developed a scale model of cation exchange that can be used for a classroom demonstration. The model uses kaolinite clay, nails, plywood, and foam balls to enable students to gain a better understanding of the exchange complex of soil clays. (DDR)

  15. Modeling nano-scale grain growth of intermetallics

    Indian Academy of Sciences (India)

    Administrator

    Abstract. The Monte Carlo simulation is utilized to model the nano-scale grain growth of two nano- crystalline materials, Pd81Zr19 and RuAl. In this regard, the relationship between the real time and the time unit of simulation, i.e. Monte Carlo step (MCS), is determined. The results of modeling show that with increasing time ...

  16. Multi-scale modeling strategies in materials science—The ...

    Indian Academy of Sciences (India)

    Unknown

    modeling strategies that bridge the length-scales. The quasicontinuum method pivots on a strategy which attempts to take advantage of both conventional atomistic simulations and continuum mechanics to develop a seamless methodology for the modeling of defects such as dislocations, grain boundaries and cracks, and ...

  17. Role of scaling in the statistical modelling of finance

    Indian Academy of Sciences (India)

    Modelling the evolution of a financial index as a stochastic process is a problem awaiting a full, satisfactory solution since it was first formulated by Bachelier in 1900. Here it is shown that the scaling with time of the return probability density function sampled from the historical series suggests a successful model.

  18. Role of scaling in the statistical modelling of finance

    Indian Academy of Sciences (India)

    Abstract. Modelling the evolution of a financial index as a stochastic process is a prob- lem awaiting a full, satisfactory solution since it was first formulated by Bachelier in 1900. Here it is shown that the scaling with time of the return probability density function sampled from the historical series suggests a successful model.

  19. A first large-scale flood inundation forecasting model

    Science.gov (United States)

    Schumann, G. J.-P.; Neal, J. C.; Voisin, N.; Andreadis, K. M.; Pappenberger, F.; Phanthuwongpakdee, N.; Hall, A. C.; Bates, P. D.

    2013-10-01

    At present continental to global scale flood forecasting predicts at a point discharge, with little attention to detail and accuracy of local scale inundation predictions. Yet, inundation variables are of interest and all flood impacts are inherently local in nature. This paper proposes a large-scale flood inundation ensemble forecasting model that uses best available data and modeling approaches in data scarce areas. The model was built for the Lower Zambezi River to demonstrate current flood inundation forecasting capabilities in large data-scarce regions. ECMWF ensemble forecast (ENS) data were used to force the VIC (Variable Infiltration Capacity) hydrologic model, which simulated and routed daily flows to the input boundary locations of a 2-D hydrodynamic model. Efficient hydrodynamic modeling over large areas still requires model grid resolutions that are typically larger than the width of channels that play a key role in flood wave propagation. We therefore employed a novel subgrid channel scheme to describe the river network in detail while representing the floodplain at an appropriate scale. The modeling system was calibrated using channel water levels from satellite laser altimetry and then applied to predict the February 2007 Mozambique floods. Model evaluation showed that simulated flood edge cells were within a distance of between one and two model resolutions compared to an observed flood edge and inundation area agreement was on average 86%. Our study highlights that physically plausible parameter values and satisfactory performance can be achieved at spatial scales ranging from tens to several hundreds of thousands of km2 and at model grid resolutions up to several km2.

  20. Transdisciplinary application of the cross-scale resilience model

    Science.gov (United States)

    Sundstrom, Shana M.; Angeler, David G.; Garmestani, Ahjond S.; Garcia, Jorge H.; Allen, Craig R.

    2014-01-01

    The cross-scale resilience model was developed in ecology to explain the emergence of resilience from the distribution of ecological functions within and across scales, and as a tool to assess resilience. We propose that the model and the underlying discontinuity hypothesis are relevant to other complex adaptive systems, and can be used to identify and track changes in system parameters related to resilience. We explain the theory behind the cross-scale resilience model, review the cases where it has been applied to non-ecological systems, and discuss some examples of social-ecological, archaeological/ anthropological, and economic systems where a cross-scale resilience analysis could add a quantitative dimension to our current understanding of system dynamics and resilience. We argue that the scaling and diversity parameters suitable for a resilience analysis of ecological systems are appropriate for a broad suite of systems where non-normative quantitative assessments of resilience are desired. Our planet is currently characterized by fast environmental and social change, and the cross-scale resilience model has the potential to quantify resilience across many types of complex adaptive systems.

  1. Ionocovalency and Applications 1. Ionocovalency Model and Orbital Hybrid Scales

    Directory of Open Access Journals (Sweden)

    Yonghe Zhang

    2010-11-01

    Full Text Available Ionocovalency (IC, a quantitative dual nature of the atom, is defined and correlated with quantum-mechanical potential to describe quantitatively the dual properties of the bond. Orbiotal hybrid IC model scale, IC, and IC electronegativity scale, XIC, are proposed, wherein the ionicity and the covalent radius are determined by spectroscopy. Being composed of the ionic function I and the covalent function C, the model describes quantitatively the dual properties of bond strengths, charge density and ionic potential. Based on the atomic electron configuration and the various quantum-mechanical built-up dual parameters, the model formed a Dual Method of the multiple-functional prediction, which has much more versatile and exceptional applications than traditional electronegativity scales and molecular properties. Hydrogen has unconventional values of IC and XIC, lower than that of boron. The IC model can agree fairly well with the data of bond properties and satisfactorily explain chemical observations of elements throughout the Periodic Table.

  2. Traffic assignment models in large-scale applications

    DEFF Research Database (Denmark)

    Rasmussen, Thomas Kjær

    focuses on large-scale applications and contributes with methods to actualise the true potential of disaggregate models. To achieve this target, contributions are given to several components of traffic assignment modelling, by (i) enabling the utilisation of the increasingly available data sources...... on individual behaviour in the model specification, (ii) proposing a method to use disaggregate Revealed Preference (RP) data to estimate utility functions and provide evidence on the value of congestion and the value of reliability, (iii) providing a method to account for individual mis...... is essential in the development and validation of realistic models for large-scale applications. Nowadays, modern technology facilitates easy access to RP data and allows large-scale surveys. The resulting datasets are, however, usually very large and hence data processing is necessary to extract the pieces...

  3. A first large-scale flood inundation forecasting model

    Energy Technology Data Exchange (ETDEWEB)

    Schumann, Guy J-P; Neal, Jeffrey C.; Voisin, Nathalie; Andreadis, Konstantinos M.; Pappenberger, Florian; Phanthuwongpakdee, Kay; Hall, Amanda C.; Bates, Paul D.

    2013-11-04

    At present continental to global scale flood forecasting focusses on predicting at a point discharge, with little attention to the detail and accuracy of local scale inundation predictions. Yet, inundation is actually the variable of interest and all flood impacts are inherently local in nature. This paper proposes a first large scale flood inundation ensemble forecasting model that uses best available data and modeling approaches in data scarce areas and at continental scales. The model was built for the Lower Zambezi River in southeast Africa to demonstrate current flood inundation forecasting capabilities in large data-scarce regions. The inundation model domain has a surface area of approximately 170k km2. ECMWF meteorological data were used to force the VIC (Variable Infiltration Capacity) macro-scale hydrological model which simulated and routed daily flows to the input boundary locations of the 2-D hydrodynamic model. Efficient hydrodynamic modeling over large areas still requires model grid resolutions that are typically larger than the width of many river channels that play a key a role in flood wave propagation. We therefore employed a novel sub-grid channel scheme to describe the river network in detail whilst at the same time representing the floodplain at an appropriate and efficient scale. The modeling system was first calibrated using water levels on the main channel from the ICESat (Ice, Cloud, and land Elevation Satellite) laser altimeter and then applied to predict the February 2007 Mozambique floods. Model evaluation showed that simulated flood edge cells were within a distance of about 1 km (one model resolution) compared to an observed flood edge of the event. Our study highlights that physically plausible parameter values and satisfactory performance can be achieved at spatial scales ranging from tens to several hundreds of thousands of km2 and at model grid resolutions up to several km2. However, initial model test runs in forecast mode

  4. Micro perspectives for decentralized energy supply. Proceedings of the international conference

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Martina; Kebir, Noara; Philipp, Daniel (eds.)

    2011-07-01

    Within the proceedings of the international conference at the Technical University Berlin (Berlin, Federal Republic of Germany) between 7th and 8th April, 2011 the following scientific papers were presented: (1) Renewables in residential development: An integrated GIS-based multicriteria approach for decentralized micro renewable energy production in new settlement development (C. Palmas); (2) Optimisation of off-grid-energy systems by combined use of renewable energy and storage devices (F. Huneke); (3) Decentralized electricity production from renewable sources as a chance for local economic development? Qualitative study of two pioneer regions in Germany (B. Klagge); (4) An analytical model for small-scale rural bioenergy systems (M. Gaul); (5) Reality check: Biomass as a fuel for small-scale electricity supply in developing countries (E. Dimpl v.L.); (6) Influential factors for the implementation of biogas plants in rural areas of Burkina Faso (A. Aschaber); (7) Policy and regulatory framework conditions for small hydro power in sub-saharian Africa (F. Koelling); (8) Current status of village level hydropower in eastern and southern Africa (W. Janker-Klunne), (9) Water desalination in micro grids based on renewable energies (K. Bognar); (10) The internal sphere of influence of peasant family farms in using biogas plants as part of sustainable development in rural areas of Germany (A. Bischoff); (11) A basic design for a multicriteria approach to efficient bioenergy production at regional level (Z. Hagen); (12) Ecological and economical evaluation of biogas feedstock from intercrops (N. Niemitz); (13) Energy recovery from sisal residues: A sustainable option for Tanzania? (J.C. Pfaff); (14) Opportunities and challenges for solar home systems in Tanzania for rural electrification (P.J. John); (15) The contribution of microenergy systems towards poverty reduction: Case study of an implementation strategy for solar home systems in Sri Lanka (D. Laufer); (16) Multi

  5. Observed Scaling in Clouds and Precipitation and Scale Incognizance in Regional to Global Atmospheric Models

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, Travis A.; Li, Fuyu; Collins, William D.; Rauscher, Sara; Ringler, Todd; Taylor, Mark; Hagos, Samson M.; Leung, Lai-Yung R.

    2013-12-01

    We use observations of robust scaling behavior in clouds and precipitation to derive constraints on how partitioning of precipitation should change with model resolution. Our analysis indicates that 90-99% of stratiform precipitation should occur in clouds that are resolvable by contemporary climate models (e.g., with 200 km or finer grid spacing). Furthermore, this resolved fraction of stratiform precipitation should increase sharply with resolution, such that effectively all stratiform precipitation should be resolvable above scales of ~50 km. We show that the Community Atmosphere Model (CAM) and the Weather Research and Forecasting (WRF) model also exhibit the robust cloud and precipitation scaling behavior that is present in observations, yet the resolved fraction of stratiform precipitation actually decreases with increasing model resolution. A suite of experiments with multiple dynamical cores provides strong evidence that this `scale-incognizant' behavior originates in one of the CAM4 parameterizations. An additional set of sensitivity experiments rules out both convection parameterizations, and by a process of elimination these results implicate the stratiform cloud and precipitation parameterization. Tests with the CAM5 physics package show improvements in the resolution-dependence of resolved cloud fraction and resolved stratiform precipitation fraction.

  6. Building Bridges: Heterogeneous Jurisdictions, Endogenous Spillovers, and the Benefits of Decentralization

    OpenAIRE

    Paulo Júlio; Susana Peralta

    2010-01-01

    We model two heterogeneous districts of unequal size that may enjoy each other's local public good if a costly national infrastructure (the bridge) is provided. We compare a decentralized regime where local public goods are decided locally and the bridge centrally, with a centralized regime where all decisions are taken centrally, under both benevolent planner and median voter decision making. In both cases, it may happen that either both regimes build the bridge, none, or only one does. We p...

  7. NeuCoin: the First Secure, Cost-efficient and Decentralized Cryptocurrency

    OpenAIRE

    Davarpanah, Kourosh; Kaufman, Dan; Pubellier, Ophelie

    2015-01-01

    NeuCoin is a decentralized peer-to-peer cryptocurrency derived from Sunny King's Peercoin, which itself was derived from Satoshi Nakamoto's Bitcoin. As with Peercoin, proof-of-stake replaces proof-of-work as NeuCoin's security model, effectively replacing the operating costs of Bitcoin miners (electricity, computers) with the capital costs of holding the currency. Proof-of-stake also avoids proof-of-work's inherent tendency towards centralization resulting from competition for coinbase reward...

  8. Multi-scale atmospheric composition modelling for the Balkan region

    Science.gov (United States)

    Ganev, Kostadin; Syrakov, Dimiter; Todorova, Angelina; Prodanova, Maria; Atanasov, Emanouil; Gurov, Todor; Karaivanova, Aneta; Miloshev, Nikolai; Gadzhev, Georgi; Jordanov, Georgi

    2010-05-01

    Overview The present work describes the progress in developing of an integrated, multi-scale Balkan region oriented modeling system. The main activities and achievements at this stage of the work are: Creating, enriching and updating the necessary physiographic, emission and meteorological data bases; Installation of the models for GRID application, model tuning and validation; Extensive numerical simulations on regional (Balkan Peninsula) and local (Bulgaria) scales. Objevtives: The present work describes the progress of an application developed by the Environmental VO of the 7FP project SEE-GRID eInfrastructure for regional eScience. The application aims at developing of an integrated, multi-scale Balkan region oriented modelling system, which would be able to: -Study the atmospheric pollution transport and transformation processes (accounting also for heterogeneous chemistry and the importance of aerosols for air quality and climate) from urban to local to regional (Balkan) scales; -Track and characterize the main pathways and processes that lead to atmospheric composition formation in different scales; -Account for the biosphere-atmosphere exchange as a source and receptor of atmospheric chemical species; -Provide high quality scientifically robust assessments of the air quality and its origin, thus facilitating formulation of pollution mitigation strategies at national and Balkan level. The application is based on US EPA Models-3 system. Description of work: The main activities and achievements at this still preparatory stage of the work are: 1.) Creating, enriching and updating the necessary physiographic, emission and meteorological data bases 2.) Installation of the models for GRID application, model tuning and validation, numerical experiments and interpretation of the results: The US EPA Models 3 system is installed; software for emission speciation and for introducing emission temporal profiles is created, a procedure for calculating biogenic VOC

  9. Drift-Scale Coupled Processes (DST and THC Seepage) Models

    Energy Technology Data Exchange (ETDEWEB)

    P. Dixon

    2004-04-05

    The purpose of this Model Report (REV02) is to document the unsaturated zone (UZ) models used to evaluate the potential effects of coupled thermal-hydrological-chemical (THC) processes on UZ flow and transport. This Model Report has been developed in accordance with the ''Technical Work Plan for: Performance Assessment Unsaturated Zone'' (Bechtel SAIC Company, LLC (BSC) 2002 [160819]). The technical work plan (TWP) describes planning information pertaining to the technical scope, content, and management of this Model Report in Section 1.12, Work Package AUZM08, ''Coupled Effects on Flow and Seepage''. The plan for validation of the models documented in this Model Report is given in Attachment I, Model Validation Plans, Section I-3-4, of the TWP. Except for variations in acceptance criteria (Section 4.2), there were no deviations from this TWP. This report was developed in accordance with AP-SIII.10Q, ''Models''. This Model Report documents the THC Seepage Model and the Drift Scale Test (DST) THC Model. The THC Seepage Model is a drift-scale process model for predicting the composition of gas and water that could enter waste emplacement drifts and the effects of mineral alteration on flow in rocks surrounding drifts. The DST THC model is a drift-scale process model relying on the same conceptual model and much of the same input data (i.e., physical, hydrological, thermodynamic, and kinetic) as the THC Seepage Model. The DST THC Model is the primary method for validating the THC Seepage Model. The DST THC Model compares predicted water and gas compositions, as well as mineral alteration patterns, with observed data from the DST. These models provide the framework to evaluate THC coupled processes at the drift scale, predict flow and transport behavior for specified thermal-loading conditions, and predict the evolution of mineral alteration and fluid chemistry around potential waste emplacement drifts. The

  10. Empirical spatial econometric modelling of small scale neighbourhood

    Science.gov (United States)

    Gerkman, Linda

    2012-07-01

    The aim of the paper is to model small scale neighbourhood in a house price model by implementing the newest methodology in spatial econometrics. A common problem when modelling house prices is that in practice it is seldom possible to obtain all the desired variables. Especially variables capturing the small scale neighbourhood conditions are hard to find. If there are important explanatory variables missing from the model, the omitted variables are spatially autocorrelated and they are correlated with the explanatory variables included in the model, it can be shown that a spatial Durbin model is motivated. In the empirical application on new house price data from Helsinki in Finland, we find the motivation for a spatial Durbin model, we estimate the model and interpret the estimates for the summary measures of impacts. By the analysis we show that the model structure makes it possible to model and find small scale neighbourhood effects, when we know that they exist, but we are lacking proper variables to measure them.

  11. Model Scaling of Hydrokinetic Ocean Renewable Energy Systems

    Science.gov (United States)

    von Ellenrieder, Karl; Valentine, William

    2013-11-01

    Numerical simulations are performed to validate a non-dimensional dynamic scaling procedure that can be applied to subsurface and deeply moored systems, such as hydrokinetic ocean renewable energy devices. The prototype systems are moored in water 400 m deep and include: subsurface spherical buoys moored in a shear current and excited by waves; an ocean current turbine excited by waves; and a deeply submerged spherical buoy in a shear current excited by strong current fluctuations. The corresponding model systems, which are scaled based on relative water depths of 10 m and 40 m, are also studied. For each case examined, the response of the model system closely matches the scaled response of the corresponding full-sized prototype system. The results suggest that laboratory-scale testing of complete ocean current renewable energy systems moored in a current is possible. This work was supported by the U.S. Southeast National Marine Renewable Energy Center (SNMREC).

  12. Intermediate time scaling in classical continuous-spin models

    CERN Document Server

    Oh, S K; Chung, J S

    1999-01-01

    The time-dependent total spin correlation functions of the two- and the three-dimensional classical XY models seem to have a very narrow first dynamic scaling interval and, after this interval, a much broader anomalous second dynamic scaling interval appears. In this paper, this intriguing feature found in our previous work is re-examined. By introducing a phenomenological characteristic time for this intermediate time interval, the second dynamic scaling behavior can be explained. Moreover, the dynamic critical exponent found from this novel characteristic time is found to be identical to that found from the usual dynamic scaling theory developed in the wave vector and frequency domain. For continuous spin models, in which the spin variable related to a long-range order parameter is not a constant of motion, our method yielded the dynamic critical exponent with less computational efforts.

  13. Scale genesis and gravitational wave in a classically scale invariant extension of the standard model

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Jisuke [Institute for Theoretical Physics, Kanazawa University,Kanazawa 920-1192 (Japan); Yamada, Masatoshi [Department of Physics, Kyoto University,Kyoto 606-8502 (Japan); Institut für Theoretische Physik, Universität Heidelberg,Philosophenweg 16, 69120 Heidelberg (Germany)

    2016-12-01

    We assume that the origin of the electroweak (EW) scale is a gauge-invariant scalar-bilinear condensation in a strongly interacting non-abelian gauge sector, which is connected to the standard model via a Higgs portal coupling. The dynamical scale genesis appears as a phase transition at finite temperature, and it can produce a gravitational wave (GW) background in the early Universe. We find that the critical temperature of the scale phase transition lies above that of the EW phase transition and below few O(100) GeV and it is strongly first-order. We calculate the spectrum of the GW background and find the scale phase transition is strong enough that the GW background can be observed by DECIGO.

  14. Large scale stochastic spatio-temporal modelling with PCRaster

    Science.gov (United States)

    Karssenberg, Derek; Drost, Niels; Schmitz, Oliver; de Jong, Kor; Bierkens, Marc F. P.

    2013-04-01

    software from the eScience Technology Platform (eSTeP), developed at the Netherlands eScience Center. This will allow us to scale up to hundreds of machines, with thousands of compute cores. A key requirement is not to change the user experience of the software. PCRaster operations and the use of the Python framework classes should work in a similar manner on machines ranging from a laptop to a supercomputer. This enables a seamless transfer of models from small machines, where model development is done, to large machines used for large-scale model runs. Domain specialists from a large range of disciplines, including hydrology, ecology, sedimentology, and land use change studies, currently use the PCRaster Python software within research projects. Applications include global scale hydrological modelling and error propagation in large-scale land use change models. The software runs on MS Windows, Linux operating systems, and OS X.

  15. Mapping the potential for decentralized energy generation based on RES in Western Balkans

    Directory of Open Access Journals (Sweden)

    Schneider Daniel R.

    2007-01-01

    Full Text Available Although the countries of the Western Balkans are mostly electrified, there are still regions which do not have access to the electricity network or where the network capacity is insufficient. For the most part such areas are under special care of the state (i. e. underdeveloped, devastated by war, depopulated, on islands or in mountainous regions. Since the decentralized energy generation covers a broad range of technologies, including many renewable energy technologies that provide small-scale power at sites close to the users, such concept could be of interest for these locations. This paper identifies the areas in Western Balkans where such systems could be applied. Consideration is given to geographical locations as well as possible applications. Wind, hydro, solar photovoltaic, and biomass conversion systems were taken into consideration. Since the renewable energy sources data for Western Balkans region are rather scarce, the intention was to give a survey of the present situation and an estimate of future potential for decentralized energy generation based on renewable energy sources. The decentralized energy generation based on renewable energy sources in Western Balkans will find its niche easier for the users that will produce electricity for their own needs and for the users located in remote rural areas (off-grid applications.

  16. Deconfined Quantum Criticality, Scaling Violations, and Classical Loop Models

    Science.gov (United States)

    Nahum, Adam; Chalker, J. T.; Serna, P.; Ortuño, M.; Somoza, A. M.

    2015-10-01

    Numerical studies of the transition between Néel and valence bond solid phases in two-dimensional quantum antiferromagnets give strong evidence for the remarkable scenario of deconfined criticality, but display strong violations of finite-size scaling that are not yet understood. We show how to realize the universal physics of the Néel-valence-bond-solid (VBS) transition in a three-dimensional classical loop model (this model includes the subtle interference effect that suppresses hedgehog defects in the Néel order parameter). We use the loop model for simulations of unprecedentedly large systems (up to linear size L =512 ). Our results are compatible with a continuous transition at which both Néel and VBS order parameters are critical, and we do not see conventional signs of first-order behavior. However, we show that the scaling violations are stronger than previously realized and are incompatible with conventional finite-size scaling, even if allowance is made for a weakly or marginally irrelevant scaling variable. In particular, different approaches to determining the anomalous dimensions ηVBS and ηN é el yield very different results. The assumption of conventional finite-size scaling leads to estimates that drift to negative values at large sizes, in violation of the unitarity bounds. In contrast, the decay with distance of critical correlators on scales much smaller than system size is consistent with large positive anomalous dimensions. Barring an unexpected reversal in behavior at still larger sizes, this implies that the transition, if continuous, must show unconventional finite-size scaling, for example, from an additional dangerously irrelevant scaling variable. Another possibility is an anomalously weak first-order transition. By analyzing the renormalization group flows for the noncompact CP n -1 field theory (the n -component Abelian Higgs model) between two and four dimensions, we give the simplest scenario by which an anomalously weak first

  17. Anomalous scaling in an age-dependent branching model.

    Science.gov (United States)

    Keller-Schmidt, Stephanie; Tuğrul, Murat; Eguíluz, Víctor M; Hernández-García, Emilio; Klemm, Konstantin

    2015-02-01

    We introduce a one-parametric family of tree growth models, in which branching probabilities decrease with branch age τ as τ(-α). Depending on the exponent α, the scaling of tree depth with tree size n displays a transition between the logarithmic scaling of random trees and an algebraic growth. At the transition (α=1) tree depth grows as (logn)(2). This anomalous scaling is in good agreement with the trend observed in evolution of biological species, thus providing a theoretical support for age-dependent speciation and associating it to the occurrence of a critical point.

  18. Criticality in the scale invariant standard model (squared

    Directory of Open Access Journals (Sweden)

    Robert Foot

    2015-07-01

    Full Text Available We consider first the standard model Lagrangian with μh2 Higgs potential term set to zero. We point out that this classically scale invariant theory potentially exhibits radiative electroweak/scale symmetry breaking with very high vacuum expectation value (VEV for the Higgs field, 〈ϕ〉≈1017–18 GeV. Furthermore, if such a vacuum were realized then cancellation of vacuum energy automatically implies that this nontrivial vacuum is degenerate with the trivial unbroken vacuum. Such a theory would therefore be critical with the Higgs self-coupling and its beta function nearly vanishing at the symmetry breaking minimum, λ(μ=〈ϕ〉≈βλ(μ=〈ϕ〉≈0. A phenomenologically viable model that predicts this criticality property arises if we consider two copies of the standard model Lagrangian, with exact Z2 symmetry swapping each ordinary particle with a partner. The spontaneously broken vacuum can then arise where one sector gains the high scale VEV, while the other gains the electroweak scale VEV. The low scale VEV is perturbed away from zero due to a Higgs portal coupling, or via the usual small Higgs mass terms μh2, which softly break the scale invariance. In either case, the cancellation of vacuum energy requires Mt=(171.53±0.42 GeV, which is close to its measured value of (173.34±0.76 GeV.

  19. Computational Modelling of Cancer Development and Growth: Modelling at Multiple Scales and Multiscale Modelling.

    Science.gov (United States)

    Szymańska, Zuzanna; Cytowski, Maciej; Mitchell, Elaine; Macnamara, Cicely K; Chaplain, Mark A J

    2017-06-20

    In this paper, we present two mathematical models related to different aspects and scales of cancer growth. The first model is a stochastic spatiotemporal model of both a synthetic gene regulatory network (the example of a three-gene repressilator is given) and an actual gene regulatory network, the NF-[Formula: see text]B pathway. The second model is a force-based individual-based model of the development of a solid avascular tumour with specific application to tumour cords, i.e. a mass of cancer cells growing around a central blood vessel. In each case, we compare our computational simulation results with experimental data. In the final discussion section, we outline how to take the work forward through the development of a multiscale model focussed at the cell level. This would incorporate key intracellular signalling pathways associated with cancer within each cell (e.g. p53-Mdm2, NF-[Formula: see text]B) and through the use of high-performance computing be capable of simulating up to [Formula: see text] cells, i.e. the tissue scale. In this way, mathematical models at multiple scales would be combined to formulate a multiscale computational model.

  20. Automation on the generation of genome-scale metabolic models.

    Science.gov (United States)

    Reyes, R; Gamermann, D; Montagud, A; Fuente, D; Triana, J; Urchueguía, J F; de Córdoba, P Fernández

    2012-12-01

    Nowadays, the reconstruction of genome-scale metabolic models is a nonautomatized and interactive process based on decision making. This lengthy process usually requires a full year of one person's work in order to satisfactory collect, analyze, and validate the list of all metabolic reactions present in a specific organism. In order to write this list, one manually has to go through a huge amount of genomic, metabolomic, and physiological information. Currently, there is no optimal algorithm that allows one to automatically go through all this information and generate the models taking into account probabilistic criteria of unicity and completeness that a biologist would consider. This work presents the automation of a methodology for the reconstruction of genome-scale metabolic models for any organism. The methodology that follows is the automatized version of the steps implemented manually for the reconstruction of the genome-scale metabolic model of a photosynthetic organism, Synechocystis sp. PCC6803. The steps for the reconstruction are implemented in a computational platform (COPABI) that generates the models from the probabilistic algorithms that have been developed. For validation of the developed algorithm robustness, the metabolic models of several organisms generated by the platform have been studied together with published models that have been manually curated. Network properties of the models, like connectivity and average shortest mean path of the different models, have been compared and analyzed.

  1. ScaleNet: A literature-based model of scale insect biology and systematics

    Science.gov (United States)

    Scale insects (Hemiptera: Coccoidea) are small herbivorous insects found in all continents except Antarctica. They are extremely invasive, and many species are serious agricultural pests. They are also emerging models for studies of the evolution of genetic systems, endosymbiosis, and plant-insect i...

  2. From Field- to Landscape-Scale Vadose Zone Processes: Scale Issues, Modeling, and Monitoring

    NARCIS (Netherlands)

    Corwin, D.L.; Hopmans, J.; Rooij, de G.H.

    2006-01-01

    Modeling and monitoring vadose zone processes across multiple scales is a fundamental component of many environmental and natural resource issues including nonpoint source (NPS) pollution, watershed management, and nutrient management, to mention just a few. In this special section in Vadose Zone

  3. Scaling of Core Material in Rubble Mound Breakwater Model Tests

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Z.; Troch, P.

    1999-01-01

    The permeability of the core material influences armour stability, wave run-up and wave overtopping. The main problem related to the scaling of core materials in models is that the hydraulic gradient and the pore velocity are varying in space and time. This makes it impossible to arrive at a fully...... correct scaling. The paper presents an empirical formula for the estimation of the wave induced pressure gradient in the core, based on measurements in models and a prototype. The formula, together with the Forchheimer equation can be used for the estimation of pore velocities in cores. The paper proposes...... that the diameter of the core material in models is chosen in such a way that the Froude scale law holds for a characteristic pore velocity. The characteristic pore velocity is chosen as the average velocity of a most critical area in the core with respect to porous flow. Finally the method is demonstrated...

  4. Multi Scale Models for Flexure Deformation in Sheet Metal Forming

    Directory of Open Access Journals (Sweden)

    Di Pasquale Edmondo

    2016-01-01

    Full Text Available This paper presents the application of multi scale techniques to the simulation of sheet metal forming using the one-step method. When a blank flows over the die radius, it undergoes a complex cycle of bending and unbending. First, we describe an original model for the prediction of residual plastic deformation and stresses in the blank section. This model, working on a scale about one hundred times smaller than the element size, has been implemented in SIMEX, one-step sheet metal forming simulation code. The utilisation of this multi-scale modeling technique improves greatly the accuracy of the solution. Finally, we discuss the implications of this analysis on the prediction of springback in metal forming.

  5. Including investment risk in large-scale power market models

    DEFF Research Database (Denmark)

    Lemming, Jørgen Kjærgaard; Meibom, P.

    2003-01-01

    can be included in large-scale partial equilibrium models of the power market. The analyses are divided into a part about risk measures appropriate for power market investors and a more technical part about the combination of a risk-adjustment model and a partial-equilibrium model. To illustrate......Long-term energy market models can be used to examine investments in production technologies, however, with market liberalisation it is crucial that such models include investment risks and investor behaviour. This paper analyses how the effect of investment risk on production technology selection...

  6. Blockchain technology and decentralized governance: Is the state still necessary?

    National Research Council Canada - National Science Library

    Marcella Atzori

    2017-01-01

    .... This paper aims to fill this gap and it discusses the key points of blockchain-based decentralized governance, which challenges to varying degrees the traditional mechanisms of State authority...

  7. Decentralization, Interdependence and Performance Measurement System Design : Sequences and Priorities

    NARCIS (Netherlands)

    Abernethy, M.; Bouwens, J.F.M.G.; van Lent, L.A.G.M.

    2001-01-01

    We investigate the determinants of decentralization and performance measurement choices in multidivisional firms.We extend the research on the economics of organizational design choices by examining the impact of two important determinants of those choices, namely, subunit interdependencies and

  8. An interactive heuristic for financial planning in decentralized organizations.

    NARCIS (Netherlands)

    M.H. Goedhart; J. Spronk (Jaap)

    1995-01-01

    textabstractPlanning and controlling overall performance in decentralized organizations is a complex task for central management because it is contronted with incomplete information on organizational opportunities and possible conflicts of interest with local managers. Many formal procedures for the

  9. Educational decentralization, public spending, and social justice in Nigeria

    Science.gov (United States)

    Geo-Jaja, Macleans A.

    2007-01-01

    This study situates the process of educational decentralization in the narrower context of social justice. Its main object, however, is to analyze the implications of decentralization for strategies of equity and social justice in Nigeria. It starts from the premise that the early optimism that supported decentralization as an efficient and effective educational reform tool has been disappointed. The author maintains that decentralization — on its own — cannot improve education service delivery, the capacities of subordinate governments, or the integration of social policy in broader development goals. If the desired goals are to be met, public spending must be increased, greater tax revenues must be secured, and macro-economic stabilization must be achieved without re-instituting the welfare state.

  10. Efficient Multi-Source Data Fusion for Decentralized Sensor Networks

    National Research Council Canada - National Science Library

    Haney, Philip J; Lloyd, Christopher M

    2006-01-01

    .... Previous applications of decentralized data fusion have generally been restricted to uni-modal/uni-source sensor networks using Gaussian based approaches, such as the Kalman or information filter...

  11. Decentralization and Adult Education: A Case Study of the Netherlands.

    Science.gov (United States)

    Polder, Klari-Janne

    2001-01-01

    Decentralization of adult education administration in the Netherlands had the desired effect of empowering local governments for community education and development. However, an undesired effect was loss of efficiency in funding allocation and decision making. (Contains 21 references.) (SK)

  12. The Financing of the Costs of Education under Decentralization

    National Research Council Canada - National Science Library

    Kovalenko Svitlana O; Koskina Yuliya О

    2017-01-01

    The article is aimed at determining the major problems in the financing of education sphere in the current context of the reform of decentralization of power in Ukraine and developing directions for solving...

  13. Evaluation of Icing Scaling on Swept NACA 0012 Airfoil Models

    Science.gov (United States)

    Tsao, Jen-Ching; Lee, Sam

    2012-01-01

    Icing scaling tests in the NASA Glenn Icing Research Tunnel (IRT) were performed on swept wing models using existing recommended scaling methods that were originally developed for straight wing. Some needed modifications on the stagnation-point local collection efficiency (i.e., beta(sub 0) calculation and the corresponding convective heat transfer coefficient for swept NACA 0012 airfoil models have been studied and reported in 2009, and the correlations will be used in the current study. The reference tests used a 91.4-cm chord, 152.4-cm span, adjustable sweep airfoil model of NACA 0012 profile at velocities of 100 and 150 knot and MVD of 44 and 93 mm. Scale-to-reference model size ratio was 1:2.4. All tests were conducted at 0deg angle of attack (AoA) and 45deg sweep angle. Ice shape comparison results were presented for stagnation-point freezing fractions in the range of 0.4 to 1.0. Preliminary results showed that good scaling was achieved for the conditions test by using the modified scaling methods developed for swept wing icing.

  14. Multiple time scales in multi-state models.

    Science.gov (United States)

    Iacobelli, Simona; Carstensen, Bendix

    2013-12-30

    In multi-state models, it has been the tradition to model all transition intensities on one time scale, usually the time since entry into the study ('clock-forward' approach). The effect of time since an intermediate event has been accommodated either by changing the time scale to time since entry to the new state ('clock-back' approach) or by including the time at entry to the new state as a covariate. In this paper, we argue that the choice of time scale for the various transitions in a multi-state model should be dealt with as an empirical question, as also the question of whether a single time scale is sufficient. We illustrate that these questions are best addressed by using parametric models for the transition rates, as opposed to the traditional Cox-model-based approaches. Specific advantages are that dependence of failure rates on multiple time scales can be made explicit and described in informative graphical displays. Using a single common time scale for all transitions greatly facilitates computations of probabilities of being in a particular state at a given time, because the machinery from the theory of Markov chains can be applied. However, a realistic model for transition rates is preferable, especially when the focus is not on prediction of final outcomes from start but on the analysis of instantaneous risk or on dynamic prediction. We illustrate the various approaches using a data set from stem cell transplant in leukemia and provide supplementary online material in R. Copyright © 2013 John Wiley & Sons, Ltd.

  15. A catchment scale water balance model for FIFE

    Science.gov (United States)

    Famiglietti, J. S.; Wood, E. F.; Sivapalan, M.; Thongs, D. J.

    1992-01-01

    A catchment scale water balance model is presented and used to predict evaporation from the King's Creek catchment at the First ISLSCP Field Experiment site on the Konza Prairie, Kansas. The model incorporates spatial variability in topography, soils, and precipitation to compute the land surface hydrologic fluxes. A network of 20 rain gages was employed to measure rainfall across the catchment in the summer of 1987. These data were spatially interpolated and used to drive the model during storm periods. During interstorm periods the model was driven by the estimated potential evaporation, which was calculated using net radiation data collected at site 2. Model-computed evaporation is compared to that observed, both at site 2 (grid location 1916-BRS) and the catchment scale, for the simulation period from June 1 to October 9, 1987.

  16. A Network Contention Model for the Extreme-scale Simulator

    Energy Technology Data Exchange (ETDEWEB)

    Engelmann, Christian [ORNL; Naughton III, Thomas J [ORNL

    2015-01-01

    The Extreme-scale Simulator (xSim) is a performance investigation toolkit for high-performance computing (HPC) hardware/software co-design. It permits running a HPC application with millions of concurrent execution threads, while observing its performance in a simulated extreme-scale system. This paper details a newly developed network modeling feature for xSim, eliminating the shortcomings of the existing network modeling capabilities. The approach takes a different path for implementing network contention and bandwidth capacity modeling using a less synchronous and accurate enough model design. With the new network modeling feature, xSim is able to simulate on-chip and on-node networks with reasonable accuracy and overheads.

  17. Decentralized system identification using stochastic subspace identification for wireless sensor networks.

    Science.gov (United States)

    Cho, Soojin; Park, Jong-Woong; Sim, Sung-Han

    2015-04-08

    Wireless sensor networks (WSNs) facilitate a new paradigm to structural identification and monitoring for civil infrastructure. Conventional structural monitoring systems based on wired sensors and centralized data acquisition systems are costly for installation as well as maintenance. WSNs have emerged as a technology that can overcome such difficulties, making deployment of a dense array of sensors on large civil structures both feasible and economical. However, as opposed to wired sensor networks in which centralized data acquisition and processing is common practice, WSNs require decentralized computing algorithms to reduce data transmission due to the limitation associated with wireless communication. In this paper, the stochastic subspace identification (SSI) technique is selected for system identification, and SSI-based decentralized system identification (SDSI) is proposed to be implemented in a WSN composed of Imote2 wireless sensors that measure acceleration. The SDSI is tightly scheduled in the hierarchical WSN, and its performance is experimentally verified in a laboratory test using a 5-story shear building model.

  18. [Oral health care and health decentralization in Brazil: two case studies in Bahia State].

    Science.gov (United States)

    Chaves, Sônia Cristina Lima; Vieira-da-Silva, Lígia Maria

    2007-05-01

    A comparative case study was performed in two selected municipalities in the State of Bahia, Brazil, to discuss the relationship between health system decentralization and characteristics of oral health services. A logical model was developed and submitted to an expert panel. Data were gathered through in-depth interviews, field observation, and analysis of secondary data from the national Health System database. The results point to the influence of municipal government characteristics on oral health practice. One municipality was classified as having an intermediate standard of oral health system implementation (50%), while the other showed only 11% implementation. The study showed that the decentralization process has not been accompanied by an effort to improve management capacity in the local oral health services, despite the transfer of funds to this area.

  19. EVALUATION OF THE SUB-NATIONAL DECENTRALIZATION OF THE HEALTH IN VENEZUELA INFANTILE MATERNAL PROGRAM

    Directory of Open Access Journals (Sweden)

    Maritza Ávila Urdaneta

    2009-11-01

    Full Text Available The work approaches the evaluation of the decentralization of the health at sub-national level in Venezuela, maternal program Infantile (PROMIN, period 1998-2004: Case of study, Estado Zulia. With the samples of ten Municipalities and Coordinators of Health (CH. Of the results and conclusions, it is appraised that in Venezuela with the Model of Integral Attention with respect to the PROMIN (1998-2004, the reason of Maternal Mortality RMM average for the country ascends to 60 by 100,000 NVR (OPS, 2003, whereas in Zulia was in 79,9; they emphasize the Municipalities: Cañada de Urdaneta with but the high one of 214.13, followed of Mara 149.44 by 100,000 NVR. Key words: Sub-national decentralization of the Health, Infantile Maternal Program, Indicating of Morbidity and Mortality, Coordination of the Municipal Health.

  20. Decentralized control of transmission rates in energy-critical wireless networks

    KAUST Repository

    Xia, Li

    2013-06-01

    In this paper, we discuss the decentralized optimization of delay and energy consumption in a multi-hop wireless network. The goal is to minimize the energy consumption of energy-critical nodes and the overall packet transmission delay of the network. The transmission rates of energy-critical nodes are adjustable according to the local information of nodes, i.e., the length of packets queued. The multi-hop network is modeled as a queueing network.We prove that the system performance is monotone w.r.t. (with respect to) the transmission rate, thus the “bang-bang” control is an optimal control. We also prove that there exists a threshold type control policy which is optimal. We propose a decentralized algorithm to control transmission rates of these energy-critical nodes. Some simulation experiments are conducted to demonstrate the effectiveness of our approach.

  1. Decentralized Economic Dispatch Scheme With Online Power Reserve for Microgrids

    DEFF Research Database (Denmark)

    Nutkani, I. U.; Loh, Poh Chiang; Wang, P.

    2017-01-01

    Decentralized economic operation schemes have several advantages when compared with the traditional centralized management system for microgrids. Specifically, decentralized schemes are more flexible, less computationally intensive, and easier to implement without relying on communication...... costs, their power ratings, and other necessary constraints, before deciding the DG dispatch priorities and droop characteristics. The proposed scheme also allows online power reserve to be set and regulated within the microgrid. This, together with the generation cost saved, has been verified...

  2. A Decentralized SDN Framework and Its Applications to Heterogeneous Internets

    OpenAIRE

    Santos, Mateus,; Astuto, Bruno Nunes; De Oliveira, Bruno,; Margi, Cintia,; Obraczka, Katia; Turletti, Thierry

    2013-01-01

    Motivated by the internets of the future, which will likely be considerably larger in size as well as highly heterogeneous and decentralized, we propose Decentralize- SDN, a Software-Defined Networking (SDN) framework that enables both physical- as well as logical distribution of the SDN control plane. D-SDN accomplishes network control distribution by defining a hierarchy of controllers that can "match" an internet's organizational and administrative structure. By delegating control between ...

  3. Responsiveness and flexibility in a Decentralized Supply Chain

    OpenAIRE

    Petersen, Kristian Rasmus; Bilberg, Arne; Hadar, Ronen

    2012-01-01

    Today’s supply chains are not capable of managing the instabilities that is the case in the market. Instead, there is a need to develop supply chains that are capable of adapting to changes. Through a case study of LEGO, the authors suggest a possible solution: a decentralized supply chain serving independent and self-sufficient local factories. The decentralized supply chain is provided with materials, parts and pre-assembled elements from local suppliers and supplies the local market in ret...

  4. Corruption, accountability, and decentralization: theory and evidence from Mexico

    OpenAIRE

    Timothy J. Goodspeed

    2011-01-01

    One of the fundamental tenets of fiscal federalism is that, absent various sorts of externalities, decentralized governments that rely on own-source revenues should be more fiscally efficient than decentralized governments that rely on grant financing. The argument relies in part on the idea that sub-national governments, being closer to the people, are more accountable to its citizens. Accountability to citizens is also important in understanding the presence of corruption in government. Thi...

  5. Decentralization and Distribution Primary Education Access in Indonesia 2014

    OpenAIRE

    Benita, Novinaz

    2016-01-01

    This paper examines decentralisation and distribution of access to primary school in Indonesia. Data come from Indonesia National Socio Economic Survey 2014, and statistic reports from Ministry of education, Ministry Of Finance, and General Election Commision. Descriptive statistic is used to describe spatial distribution of decentralization in primary education system and distribution of primary education access. The results show there are districts disparities in decentralization of primary...

  6. Wind Farm Wake Models From Full Scale Data

    DEFF Research Database (Denmark)

    Knudsen, Torben; Bak, Thomas

    2012-01-01

    This investigation is part of the EU FP7 project “Distributed Control of Large-Scale Offshore Wind Farms”. The overall goal in this project is to develop wind farm controllers giving power set points to individual turbines in the farm in order to minimise mechanical loads and optimise power. One...... on real full scale data. The modelling is based on so called effective wind speed. It is shown that there is a wake for a wind direction range of up to 20 degrees. Further, when accounting for the wind direction it is shown that the two model structures considered can both fit the experimental data...

  7. Scalar dark matter in scale invariant standard model

    Energy Technology Data Exchange (ETDEWEB)

    Ghorbani, Karim [Physics Department, Faculty of Sciences,Arak University, Arak 38156-8-8349 (Iran, Islamic Republic of); Ghorbani, Hossein [Institute for Research in Fundamental Sciences (IPM),School of Particles and Accelerators, P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)

    2016-04-05

    We investigate single and two-component scalar dark matter scenarios in classically scale invariant standard model which is free of the hierarchy problem in the Higgs sector. We show that despite the very restricted space of parameters imposed by the scale invariance symmetry, both single and two-component scalar dark matter models overcome the direct and indirect constraints provided by the Planck/WMAP observational data and the LUX/Xenon100 experiment. We comment also on the radiative mass corrections of the classically massless scalon that plays a crucial role in our study.

  8. Use of genome-scale microbial models for metabolic engineering

    DEFF Research Database (Denmark)

    Patil, Kiran Raosaheb; Åkesson, M.; Nielsen, Jens

    2004-01-01

    network structures. The major challenge for metabolic engineering in the post-genomic era is to broaden its design methodologies to incorporate genome-scale biological data. Genome-scale stoichiometric models of microorganisms represent a first step in this direction.......Metabolic engineering serves as an integrated approach to design new cell factories by providing rational design procedures and valuable mathematical and experimental tools. Mathematical models have an important role for phenotypic analysis, but can also be used for the design of optimal metabolic...

  9. Agricultural and forestry residues for decentralized energy generation in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Missagia, Bruna

    2011-10-11

    Regular electricity access is a key element for the economic development and social welfare of rural areas. Decentralized energy generation has the advantage of using local resources, increasing employment and reducing transmission and distribution losses. Brazil is a tropical country, endowed with vast arable land, plentiful precipitation levels, and a large supply of human labour. Furthermore, it has strong regional distinctions with geographical, cultural and economical differences. Forestry and agriculture, important activities in the Brazilian economy, are dependent on local people and are deeply connected to traditions, nature and culture. Furthermore, these activities generate a significant amount of residues that could be used in conversion technologies for biomass, based on type, availability and market demand. When biomass were used to generate energy locally, community members could have business opportunities, improving local economy and life quality of individuals while diversifying the Brazilian energy matrix, which is mostly based on hydropower. Alternatives for implementing small-scale decentralized biomass schemes are dependent on the screening of the existing biomass supply chains, the implementation of adapted technologies for local conditions and the exploration of local resources. The present research carried out a detailed field work in order to evaluate the potential of Brazilian biomass in different regions. The author identified crucial needs, usual constraints and possible challenges of rural electrification and economic development in Brazil. Several case studies and social groups were investigated in the Federal States of Minas Gerais, Sao Paulo and Para to identify different resource management strategies, which biomass technology was applied and the needs of the local population. It was concluded that the compaction of biomass to generate solid biofuels with uniform properties could be a cost-effective alternative for communities

  10. FISCAL DECENTRALIZATION IN ALBANIA: EFFECTS OF TERRITORIAL AND ADMINISTRATIVE REFORM

    Directory of Open Access Journals (Sweden)

    Mariola KAPIDANI

    2015-12-01

    Full Text Available The principle of decentralization is a fundamental principle for the establishment and operation of local government. It refers to the process of redistributing the authority and responsibility for certain functions from central government to local government units. In many countries, particularly in developing countries, fiscal decentralization and local governance issues are addressed as highly important to the economic development. According to Stigler (1957, fiscal decentralization brings government closer to the people and a representative government works best when it is closer to the people. Albania is still undergoing the process of decentralization in all aspects: political, economic, fiscal and administrative. Decentralization process is essential to sustainable economic growth and efficient allocation of resources to meet the needs of citizens. Albania has a fragmented system of local government with a very large number of local government units that have neither sufficient fiscal or human capacity to provide public services at a reasonable level (World Bank. However, recent administrative and territorial reform is expected to have a significant impact in many issues related to local autonomy and revenue management. This paper is focused on the progress of fiscal decentralization process in Albania, stating key issues and ongoing challenges for an improved system. The purpose of this study is to analyze the effects of recent territorial reform, identifying problems and opportunities to be addressed in the future.

  11. Nepal health sector decentralization in limbo: what are the bottlenecks?

    Science.gov (United States)

    Gurung, G

    2011-06-01

    Nepal's efforts to decentralize its governance date back to over half a century. These efforts remained incomplete due to different reasons including administrative responses and political development affecting its implementation. The Local Self Governance Act (LSGA), 1999 envisaged, for the first time, to decentralize governance in the health sector through devolution of responsibilities, authority and resources to the local bodies. However, the pace of health sector decentralization in Nepal even after the LSGA was enacted has not progressed satisfactorily due to different reasons. The purpose of this paper is to discuss why health sector decentralization in Nepal has not advanced as expected. This paper identifies many issues--policy related, political, functional, and institutional--as stumbling blocks for health sector decentralization of Nepal. More specifically, the major bottlenecks for progress are lack of a clear cut policy, poor coordination among different sectors, improper handover process, lack of elected bodies, poor selection process of management committees, lack of coherence in the capacity building process of local bodies, ongoing debate about state restructuring including federalism and different political ideologies on decentralization.

  12. Decentralized Scheduling Algorithm for DAG Based Tasks on P2P Grid

    Directory of Open Access Journals (Sweden)

    Piyush Chauhan

    2014-01-01

    Full Text Available Complex problems consisting of interdependent subtasks are represented by a direct acyclic graph (DAG. Subtasks of this DAG are scheduled by the scheduler on various grid resources. Scheduling algorithms for grid strive to optimize the schedule. Nowadays a lot of grid resources are attached by P2P approach. Grid systems and P2P model both are newfangled distributed computing approaches. Combining P2P model and grid systems we get P2P grid systems. P2P grid systems require fully decentralized scheduling algorithm, which can schedule interreliant subtasks among nonuniform computational resources. Absence of central scheduler caused the need for decentralized scheduling algorithm. In this paper we have proposed scheduling algorithm which not only is fruitful in optimizing schedule but also does so in fully decentralized fashion. Hence, this unconventional approach suits well for P2P grid systems. Moreover, this algorithm takes accurate scheduling decisions depending on both computation cost and communication cost associated with DAG’s subtasks.

  13. Low-scale inflation and supersymmetry breaking in racetrack models

    Science.gov (United States)

    Allahverdi, Rouzbeh; Dutta, Bhaskar; Sinha, Kuver

    2010-04-01

    In many moduli stabilization schemes in string theory, the scale of inflation appears to be of the same order as the scale of supersymmetry breaking. For low-scale supersymmetry breaking, therefore, the scale of inflation should also be low, unless this correlation is avoided in specific models. We explore such a low-scale inflationary scenario in a racetrack model with a single modulus in type IIB string theory. Inflation occurs near a point of inflection in the Kähler modulus potential. Obtaining acceptable cosmological density perturbations leads to the introduction of magnetized D7-branes sourcing nonperturbative superpotentials. The gravitino mass, m3/2, is chosen to be around 30 TeV, so that gravitinos that are produced in the inflaton decay do not affect big-bang nucleosynthesis. Supersymmetry is communicated to the visible sector by a mixture of anomaly and modulus mediation. We find that the two sources contribute equally to the gaugino masses, while scalar masses are decided mainly by anomaly contribution. This happens as a result of the low scale of inflation and can be probed at the LHC.

  14. Decentralized Consistent Network Updates in SDN with ez-Segway

    KAUST Repository

    Nguyen, Thanh Dang

    2017-03-06

    We present ez-Segway, a decentralized mechanism to consistently and quickly update the network state while preventing forwarding anomalies (loops and black-holes) and avoiding link congestion. In our design, the centralized SDN controller only pre-computes information needed by the switches during the update execution. This information is distributed to the switches, which use partial knowledge and direct message passing to efficiently realize the update. This separation of concerns has the key benefit of improving update performance as the communication and computation bottlenecks at the controller are removed. Our evaluations via network emulations and large-scale simulations demonstrate the efficiency of ez-Segway, which compared to a centralized approach, improves network update times by up to 45% and 57% at the median and the 99th percentile, respectively. A deployment of a system prototype in a real OpenFlow switch and an implementation in P4 demonstrate the feasibility and low overhead of implementing simple network update functionality within switches.

  15. Multilevel method for modeling large-scale networks.

    Energy Technology Data Exchange (ETDEWEB)

    Safro, I. M. (Mathematics and Computer Science)

    2012-02-24

    Understanding the behavior of real complex networks is of great theoretical and practical significance. It includes developing accurate artificial models whose topological properties are similar to the real networks, generating the artificial networks at different scales under special conditions, investigating a network dynamics, reconstructing missing data, predicting network response, detecting anomalies and other tasks. Network generation, reconstruction, and prediction of its future topology are central issues of this field. In this project, we address the questions related to the understanding of the network modeling, investigating its structure and properties, and generating artificial networks. Most of the modern network generation methods are based either on various random graph models (reinforced by a set of properties such as power law distribution of node degrees, graph diameter, and number of triangles) or on the principle of replicating an existing model with elements of randomization such as R-MAT generator and Kronecker product modeling. Hierarchical models operate at different levels of network hierarchy but with the same finest elements of the network. However, in many cases the methods that include randomization and replication elements on the finest relationships between network nodes and modeling that addresses the problem of preserving a set of simplified properties do not fit accurately enough the real networks. Among the unsatisfactory features are numerically inadequate results, non-stability of algorithms on real (artificial) data, that have been tested on artificial (real) data, and incorrect behavior at different scales. One reason is that randomization and replication of existing structures can create conflicts between fine and coarse scales of the real network geometry. Moreover, the randomization and satisfying of some attribute at the same time can abolish those topological attributes that have been undefined or hidden from

  16. Ares I Scale Model Acoustic Test Overpressure Results

    Science.gov (United States)

    Casiano, M. J.; Alvord, D. A.; McDaniels, D. M.

    2011-01-01

    A summary of the overpressure environment from the 5% Ares I Scale Model Acoustic Test (ASMAT) and the implications to the full-scale Ares I are presented in this Technical Memorandum. These include the scaled environment that would be used for assessing the full-scale Ares I configuration, observations, and team recommendations. The ignition transient is first characterized and described, the overpressure suppression system configuration is then examined, and the final environment characteristics are detailed. The recommendation for Ares I is to keep the space shuttle heritage ignition overpressure (IOP) suppression system (below-deck IOP water in the launch mount and mobile launcher and also the crest water on the main flame deflector) and the water bags.

  17. Dynamic Modeling, Optimization, and Advanced Control for Large Scale Biorefineries

    DEFF Research Database (Denmark)

    Prunescu, Remus Mihail

    plant [3]. The goal of the project is to utilize realtime data extracted from the large scale facility to formulate and validate first principle dynamic models of the plant. These models are then further exploited to derive model-based tools for process optimization, advanced control and real...... with building a plantwide model-based optimization layer, which searches for optimal values regarding the pretreatment temperature, enzyme dosage in liquefaction, and yeast seed in fermentation such that profit is maximized [7]. When biomass is pretreated, by-products are also created that affect the downstream...

  18. Design and Modelling of Small Scale Low Temperature Power Cycles

    DEFF Research Database (Denmark)

    Wronski, Jorrit

    he work presented in this report contributes to the state of the art within design and modelling of small scale low temperature power cycles. The study is divided into three main parts: (i) fluid property evaluation, (ii) expansion device investigations and (iii) heat exchanger performance. The t...... scale plate heat exchanger. Working towards a validation of heat transfer correlations for ORC conditions, a new test rig was designed and built. The test facility can be used to study heat transfer in both ORC and high temperature heat pump systems.......he work presented in this report contributes to the state of the art within design and modelling of small scale low temperature power cycles. The study is divided into three main parts: (i) fluid property evaluation, (ii) expansion device investigations and (iii) heat exchanger performance...

  19. A scale-free neural network for modelling neurogenesis

    Science.gov (United States)

    Perotti, Juan I.; Tamarit, Francisco A.; Cannas, Sergio A.

    2006-11-01

    In this work we introduce a neural network model for associative memory based on a diluted Hopfield model, which grows through a neurogenesis algorithm that guarantees that the final network is a small-world and scale-free one. We also analyze the storage capacity of the network and prove that its performance is larger than that measured in a randomly dilute network with the same connectivity.

  20. Multi-scale Modeling of Plasticity in Tantalum.

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Hojun [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Battaile, Corbett Chandler. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Carroll, Jay [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Buchheit, Thomas E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Boyce, Brad [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Weinberger, Christopher [Drexel Univ., Philadelphia, PA (United States)

    2015-12-01

    In this report, we present a multi-scale computational model to simulate plastic deformation of tantalum and validating experiments. In atomistic/ dislocation level, dislocation kink- pair theory is used to formulate temperature and strain rate dependent constitutive equations. The kink-pair theory is calibrated to available data from single crystal experiments to produce accurate and convenient constitutive laws. The model is then implemented into a BCC crystal plasticity finite element method (CP-FEM) model to predict temperature and strain rate dependent yield stresses of single and polycrystalline tantalum and compared with existing experimental data from the literature. Furthermore, classical continuum constitutive models describing temperature and strain rate dependent flow behaviors are fit to the yield stresses obtained from the CP-FEM polycrystal predictions. The model is then used to conduct hydro- dynamic simulations of Taylor cylinder impact test and compared with experiments. In order to validate the proposed tantalum CP-FEM model with experiments, we introduce a method for quantitative comparison of CP-FEM models with various experimental techniques. To mitigate the effects of unknown subsurface microstructure, tantalum tensile specimens with a pseudo-two-dimensional grain structure and grain sizes on the order of millimeters are used. A technique combining an electron back scatter diffraction (EBSD) and high resolution digital image correlation (HR-DIC) is used to measure the texture and sub-grain strain fields upon uniaxial tensile loading at various applied strains. Deformed specimens are also analyzed with optical profilometry measurements to obtain out-of- plane strain fields. These high resolution measurements are directly compared with large-scale CP-FEM predictions. This computational method directly links fundamental dislocation physics to plastic deformations in the grain-scale and to the engineering-scale applications. Furthermore, direct

  1. Large scale solar district heating. Evaluation, modelling and designing - Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Heller, A.

    2000-07-01

    The appendices present the following: A) Cad-drawing of the Marstal CSHP design. B) Key values - large-scale solar heating in Denmark. C) Monitoring - a system description. D) WMO-classification of pyranometers (solarimeters). E) The computer simulation model in TRNSYS. F) Selected papers from the author. (EHS)

  2. Phenomenological aspects of no-scale inflation models

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, John [Theoretical Particle Physics and Cosmology Group, Department of Physics,King’s College London,WC2R 2LS London (United Kingdom); Theory Division, CERN,CH-1211 Geneva 23 (Switzerland); Garcia, Marcos A.G. [William I. Fine Theoretical Physics Institute, School of Physics and Astronomy,University of Minnesota,116 Church Street SE, Minneapolis, MN 55455 (United States); Nanopoulos, Dimitri V. [George P. and Cynthia W. Mitchell Institute for Fundamental Physics andAstronomy, Texas A& M University,College Station, 77843 Texas (United States); Astroparticle Physics Group, Houston Advanced Research Center (HARC), Mitchell Campus, Woodlands, 77381 Texas (United States); Academy of Athens, Division of Natural Sciences, 28 Panepistimiou Avenue, 10679 Athens (Greece); Olive, Keith A. [William I. Fine Theoretical Physics Institute, School of Physics and Astronomy,University of Minnesota,116 Church Street SE, Minneapolis, MN 55455 (United States)

    2015-10-01

    We discuss phenomenological aspects of inflationary models wiith a no-scale supergravity Kähler potential motivated by compactified string models, in which the inflaton may be identified either as a Kähler modulus or an untwisted matter field, focusing on models that make predictions for the scalar spectral index n{sub s} and the tensor-to-scalar ratio r that are similar to the Starobinsky model. We discuss possible patterns of soft supersymmetry breaking, exhibiting examples of the pure no-scale type m{sub 0}=B{sub 0}=A{sub 0}=0, of the CMSSM type with universal A{sub 0} and m{sub 0}≠0 at a high scale, and of the mSUGRA type with A{sub 0}=B{sub 0}+m{sub 0} boundary conditions at the high input scale. These may be combined with a non-trivial gauge kinetic function that generates gaugino masses m{sub 1/2}≠0, or one may have a pure gravity mediation scenario where trilinear terms and gaugino masses are generated through anomalies. We also discuss inflaton decays and reheating, showing possible decay channels for the inflaton when it is either an untwisted matter field or a Kähler modulus. Reheating is very efficient if a matter field inflaton is directly coupled to MSSM fields, and both candidates lead to sufficient reheating in the presence of a non-trivial gauge kinetic function.

  3. Large-Scale Modeling of Wordform Learning and Representation

    Science.gov (United States)

    Sibley, Daragh E.; Kello, Christopher T.; Plaut, David C.; Elman, Jeffrey L.

    2008-01-01

    The forms of words as they appear in text and speech are central to theories and models of lexical processing. Nonetheless, current methods for simulating their learning and representation fail to approach the scale and heterogeneity of real wordform lexicons. A connectionist architecture termed the "sequence encoder" is used to learn…

  4. Small-Scale Helicopter Automatic Autorotation : Modeling, Guidance, and Control

    NARCIS (Netherlands)

    Taamallah, S.

    2015-01-01

    Our research objective consists in developing a, model-based, automatic safety recovery system, for a small-scale helicopter Unmanned Aerial Vehicle (UAV) in autorotation, i.e. an engine OFF flight condition, that safely flies and lands the helicopter to a pre-specified ground location. In pursuit

  5. Vegetable parenting practices scale: Item response modeling analyses

    Science.gov (United States)

    Our objective was to evaluate the psychometric properties of a vegetable parenting practices scale using multidimensional polytomous item response modeling which enables assessing item fit to latent variables and the distributional characteristics of the items in comparison to the respondents. We al...

  6. BiGG Models: A platform for integrating, standardizing and sharing genome-scale models

    DEFF Research Database (Denmark)

    King, Zachary A.; Lu, Justin; Dräger, Andreas

    2016-01-01

    Genome-scale metabolic models are mathematically-structured knowledge bases that can be used to predict metabolic pathway usage and growth phenotypes. Furthermore, they can generate and test hypotheses when integrated with experimental data. To maximize the value of these models, centralized...... redesigned Biochemical, Genetic and Genomic knowledge base. BiGG Models contains more than 75 high-quality, manually-curated genome-scale metabolic models. On the website, users can browse, search and visualize models. BiGG Models connects genome-scale models to genome annotations and external databases....... Reaction and metabolite identifiers have been standardized across models to conform to community standards and enable rapid comparison across models. Furthermore, BiGG Models provides a comprehensive application programming interface for accessing BiGG Models with modeling and analysis tools. As a resource...

  7. Disappearing scales in carps: Re-visiting Kirpichnikov's model on the genetics of scale pattern formation

    KAUST Repository

    Casas, Laura

    2013-12-30

    The body of most fishes is fully covered by scales that typically form tight, partially overlapping rows. While some of the genes controlling the formation and growth of fish scales have been studied, very little is known about the genetic mechanisms regulating scale pattern formation. Although the existence of two genes with two pairs of alleles (S&s and N&n) regulating scale coverage in cyprinids has been predicted by Kirpichnikov and colleagues nearly eighty years ago, their identity was unknown until recently. In 2009, the \\'S\\' gene was found to be a paralog of fibroblast growth factor receptor 1, fgfr1a1, while the second gene called \\'N\\' has not yet been identified. We re-visited the original model of Kirpichnikov that proposed four major scale pattern types and observed a high degree of variation within the so-called scattered phenotype due to which this group was divided into two sub-types: classical mirror and irregular. We also analyzed the survival rates of offspring groups and found a distinct difference between Asian and European crosses. Whereas nude x nude crosses involving at least one parent of Asian origin or hybrid with Asian parent(s) showed the 25% early lethality predicted by Kirpichnikov (due to the lethality of the NN genotype), those with two Hungarian nude parents did not. We further extended Kirpichnikov\\'s work by correlating changes in phenotype (scale-pattern) to the deformations of fins and losses of pharyngeal teeth. We observed phenotypic changes which were not restricted to nudes, as described by Kirpichnikov, but were also present in mirrors (and presumably in linears as well; not analyzed in detail here). We propose that the gradation of phenotypes observed within the scattered group is caused by a gradually decreasing level of signaling (a dosedependent effect) probably due to a concerted action of multiple pathways involved in scale formation. 2013 Casas et al.

  8. Disappearing scales in carps: re-visiting Kirpichnikov's model on the genetics of scale pattern formation.

    Directory of Open Access Journals (Sweden)

    Laura Casas

    Full Text Available The body of most fishes is fully covered by scales that typically form tight, partially overlapping rows. While some of the genes controlling the formation and growth of fish scales have been studied, very little is known about the genetic mechanisms regulating scale pattern formation. Although the existence of two genes with two pairs of alleles (S&s and N&n regulating scale coverage in cyprinids has been predicted by Kirpichnikov and colleagues nearly eighty years ago, their identity was unknown until recently. In 2009, the 'S' gene was found to be a paralog of fibroblast growth factor receptor 1, fgfr1a1, while the second gene called 'N' has not yet been identified. We re-visited the original model of Kirpichnikov that proposed four major scale pattern types and observed a high degree of variation within the so-called scattered phenotype due to which this group was divided into two sub-types: classical mirror and irregular. We also analyzed the survival rates of offspring groups and found a distinct difference between Asian and European crosses. Whereas nude × nude crosses involving at least one parent of Asian origin or hybrid with Asian parent(s showed the 25% early lethality predicted by Kirpichnikov (due to the lethality of the NN genotype, those with two Hungarian nude parents did not. We further extended Kirpichnikov's work by correlating changes in phenotype (scale-pattern to the deformations of fins and losses of pharyngeal teeth. We observed phenotypic changes which were not restricted to nudes, as described by Kirpichnikov, but were also present in mirrors (and presumably in linears as well; not analyzed in detail here. We propose that the gradation of phenotypes observed within the scattered group is caused by a gradually decreasing level of signaling (a dose-dependent effect probably due to a concerted action of multiple pathways involved in scale formation.

  9. Decentralized provenance-aware publishing with nanopublications

    Directory of Open Access Journals (Sweden)

    Tobias Kuhn

    2016-08-01

    Full Text Available Publication and archival of scientific results is still commonly considered the responsability of classical publishing companies. Classical forms of publishing, however, which center around printed narrative articles, no longer seem well-suited in the digital age. In particular, there exist currently no efficient, reliable, and agreed-upon methods for publishing scientific datasets, which have become increasingly important for science. In this article, we propose to design scientific data publishing as a web-based bottom-up process, without top-down control of central authorities such as publishing companies. Based on a novel combination of existing concepts and technologies, we present a server network to decentrally store and archive data in the form of nanopublications, an RDF-based format to represent scientific data. We show how this approach allows researchers to publish, retrieve, verify, and recombine datasets of nanopublications in a reliable and trustworthy manner, and we argue that this architecture could be used as a low-level data publication layer to serve the Semantic Web in general. Our evaluation of the current network shows that this system is efficient and reliable.

  10. Decentralized sensing and tracking for UAV scheduling

    Science.gov (United States)

    Crespi, Valentine; Chung, Wayne W.; Jordan, Alex B.

    2004-09-01

    This paper presents a fully automated and decentralized surveillance system for the problem of detecting and possibly tracking mobile unknown ground vehicles in a bounded area. The system consists ideally of unmanned aerial vehicles (UAVs) and unattended fixed sensors with limited communication and detection range that are deployed in the area of interest. Each component of the system (UAV and/or sensor) is completely autonomous and programmed to scan the area searching for targets and share its knowledge with other components within communication range. We assume that both UAVs and sensors have similar computing and sensing capabilities and differ only in their mobility (sensors are stationary while UAVs are mobile). Gathered information is reported to a base station (monitor) that computes an estimate of the global state of the system and quantifies the quality of the surveillance based on a measure of the uncertainty on the number and position of the targets overtime. The present solution has been achieved through a robotic implementation of a software simulation that was in turn realized under the principles of a novel top-down methodology for the design of provably performant agent-based control systems. In this paper we provide a description of our solution including the distributed algorithms that have been employed in the control of the UAV navigation and monitoring. Finally we show the results of an novel experimental performance analysis of our surveillance system.

  11. Platform Architecture for Decentralized Positioning Systems

    Directory of Open Access Journals (Sweden)

    Zakaria Kasmi

    2017-04-01

    Full Text Available A platform architecture for positioning systems is essential for the realization of a flexible localization system, which interacts with other systems and supports various positioning technologies and algorithms. The decentralized processing of a position enables pushing the application-level knowledge into a mobile station and avoids the communication with a central unit such as a server or a base station. In addition, the calculation of the position on low-cost and resource-constrained devices presents a challenge due to the limited computing, storage capacity, as well as power supply. Therefore, we propose a platform architecture that enables the design of a system with the reusability of the components, extensibility (e.g., with other positioning technologies and interoperability. Furthermore, the position is computed on a low-cost device such as a microcontroller, which simultaneously performs additional tasks such as data collecting or preprocessing based on an operating system. The platform architecture is designed, implemented and evaluated on the basis of two positioning systems: a field strength system and a time of arrival-based positioning system.

  12. Platform Architecture for Decentralized Positioning Systems

    Science.gov (United States)

    Kasmi, Zakaria; Norrdine, Abdelmoumen; Blankenbach, Jörg

    2017-01-01

    A platform architecture for positioning systems is essential for the realization of a flexible localization system, which interacts with other systems and supports various positioning technologies and algorithms. The decentralized processing of a position enables pushing the application-level knowledge into a mobile station and avoids the communication with a central unit such as a server or a base station. In addition, the calculation of the position on low-cost and resource-constrained devices presents a challenge due to the limited computing, storage capacity, as well as power supply. Therefore, we propose a platform architecture that enables the design of a system with the reusability of the components, extensibility (e.g., with other positioning technologies) and interoperability. Furthermore, the position is computed on a low-cost device such as a microcontroller, which simultaneously performs additional tasks such as data collecting or preprocessing based on an operating system. The platform architecture is designed, implemented and evaluated on the basis of two positioning systems: a field strength system and a time of arrival-based positioning system. PMID:28445414

  13. Platform Architecture for Decentralized Positioning Systems.

    Science.gov (United States)

    Kasmi, Zakaria; Norrdine, Abdelmoumen; Blankenbach, Jörg

    2017-04-26

    A platform architecture for positioning systems is essential for the realization of a flexible localization system, which interacts with other systems and supports various positioning technologies and algorithms. The decentralized processing of a position enables pushing the application-level knowledge into a mobile station and avoids the communication with a central unit such as a server or a base station. In addition, the calculation of the position on low-cost and resource-constrained devices presents a challenge due to the limited computing, storage capacity, as well as power supply. Therefore, we propose a platform architecture that enables the design of a system with the reusability of the components, extensibility (e.g., with other positioning technologies) and interoperability. Furthermore, the position is computed on a low-cost device such as a microcontroller, which simultaneously performs additional tasks such as data collecting or preprocessing based on an operating system. The platform architecture is designed, implemented and evaluated on the basis of two positioning systems: a field strength system and a time of arrival-based positioning system.

  14. New Models and Methods for the Electroweak Scale

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, Linda [The Ohio State Univ., Columbus, OH (United States). Dept. of Physics

    2017-09-26

    This is the Final Technical Report to the US Department of Energy for grant DE-SC0013529, New Models and Methods for the Electroweak Scale, covering the time period April 1, 2015 to March 31, 2017. The goal of this project was to maximize the understanding of fundamental weak scale physics in light of current experiments, mainly the ongoing run of the Large Hadron Collider and the space based satellite experiements searching for signals Dark Matter annihilation or decay. This research program focused on the phenomenology of supersymmetry, Higgs physics, and Dark Matter. The properties of the Higgs boson are currently being measured by the Large Hadron collider, and could be a sensitive window into new physics at the weak scale. Supersymmetry is the leading theoretical candidate to explain the natural nessof the electroweak theory, however new model space must be explored as the Large Hadron collider has disfavored much minimal model parameter space. In addition the nature of Dark Matter, the mysterious particle that makes up 25% of the mass of the universe is still unknown. This project sought to address measurements of the Higgs boson couplings to the Standard Model particles, new LHC discovery scenarios for supersymmetric particles, and new measurements of Dark Matter interactions with the Standard Model both in collider production and annihilation in space. Accomplishments include new creating tools for analyses of Dark Matter models in Dark Matter which annihilates into multiple Standard Model particles, including new visualizations of bounds for models with various Dark Matter branching ratios; benchmark studies for new discovery scenarios of Dark Matter at the Large Hardon Collider for Higgs-Dark Matter and gauge boson-Dark Matter interactions; New target analyses to detect direct decays of the Higgs boson into challenging final states like pairs of light jets, and new phenomenological analysis of non-minimal supersymmetric models, namely the set of Dirac

  15. MODELLING FINE SCALE MOVEMENT CORRIDORS FOR THE TRICARINATE HILL TURTLE

    Directory of Open Access Journals (Sweden)

    I. Mondal

    2016-06-01

    Full Text Available Habitat loss and the destruction of habitat connectivity can lead to species extinction by isolation of population. Identifying important habitat corridors to enhance habitat connectivity is imperative for species conservation by preserving dispersal pattern to maintain genetic diversity. Circuit theory is a novel tool to model habitat connectivity as it considers habitat as an electronic circuit board and species movement as a certain amount of current moving around through different resistors in the circuit. Most studies involving circuit theory have been carried out at small scales on large ranging animals like wolves or pumas, and more recently on tigers. This calls for a study that tests circuit theory at a large scale to model micro-scale habitat connectivity. The present study on a small South-Asian geoemydid, the Tricarinate Hill-turtle (Melanochelys tricarinata, focuses on habitat connectivity at a very fine scale. The Tricarinate has a small body size (carapace length: 127–175 mm and home range (8000–15000 m2, with very specific habitat requirements and movement patterns. We used very high resolution Worldview satellite data and extensive field observations to derive a model of landscape permeability at 1 : 2,000 scale to suit the target species. Circuit theory was applied to model potential corridors between core habitat patches for the Tricarinate Hill-turtle. The modelled corridors were validated by extensive ground tracking data collected using thread spool technique and found to be functional. Therefore, circuit theory is a promising tool for accurately identifying corridors, to aid in habitat studies of small species.

  16. Modelling Fine Scale Movement Corridors for the Tricarinate Hill Turtle

    Science.gov (United States)

    Mondal, I.; Kumar, R. S.; Habib, B.; Talukdar, G.

    2016-06-01

    Habitat loss and the destruction of habitat connectivity can lead to species extinction by isolation of population. Identifying important habitat corridors to enhance habitat connectivity is imperative for species conservation by preserving dispersal pattern to maintain genetic diversity. Circuit theory is a novel tool to model habitat connectivity as it considers habitat as an electronic circuit board and species movement as a certain amount of current moving around through different resistors in the circuit. Most studies involving circuit theory have been carried out at small scales on large ranging animals like wolves or pumas, and more recently on tigers. This calls for a study that tests circuit theory at a large scale to model micro-scale habitat connectivity. The present study on a small South-Asian geoemydid, the Tricarinate Hill-turtle (Melanochelys tricarinata), focuses on habitat connectivity at a very fine scale. The Tricarinate has a small body size (carapace length: 127-175 mm) and home range (8000-15000 m2), with very specific habitat requirements and movement patterns. We used very high resolution Worldview satellite data and extensive field observations to derive a model of landscape permeability at 1 : 2,000 scale to suit the target species. Circuit theory was applied to model potential corridors between core habitat patches for the Tricarinate Hill-turtle. The modelled corridors were validated by extensive ground tracking data collected using thread spool technique and found to be functional. Therefore, circuit theory is a promising tool for accurately identifying corridors, to aid in habitat studies of small species.

  17. Decentralized control of multi-agent aerial transportation system

    KAUST Repository

    Toumi, Noureddine

    2017-04-01

    Autonomous aerial transportation has multiple potential applications including emergency cases and rescue missions where ground intervention may be difficult. In this context, the following work will address the control of multi-agent Vertical Take-off and Landing aircraft (VTOL) transportation system. We develop a decentralized method. The advantage of such a solution is that it can provide better maneuverability and lifting capabilities compared to existing systems. First, we consider a cooperative group of VTOLs transporting one payload. The main idea is that each agent perceive the interaction with other agents as a disturbance while assuming a negotiated motion model and imposing certain magnitude bounds on each agent. The theoretical model will be then validated using a numerical simulation illustrating the interesting features of the presented control method. Results show that under specified disturbances, the algorithm is able to guarantee the tracking with a minimal error. We describe a toolbox that has been developed for this purpose. Then, a system of multiple VTOLs lifting payloads will be studied. The algorithm assures that the VTOLs are coordinated with minimal communication. Additionally, a novel gripper design for ferrous objects is presented that enables the transportation of ferrous objects without a cable. Finally, we discuss potential connections to human in the loop transportation systems.

  18. Decentralized manufacturing of cell and gene therapies: Overcoming challenges and identifying opportunities.

    Science.gov (United States)

    Harrison, Richard P; Ruck, Steven; Medcalf, Nicholas; Rafiq, Qasim A

    2017-10-01

    Decentralized or "redistributed" manufacturing has the potential to revolutionize the manufacturing approach for cell and gene therapies (CGTs), moving away from the "Fordist" paradigm, delivering health care locally, customized to the end user and, by its very nature, overcoming many of the challenges associated with manufacturing and distribution of high volume goods. In departing from the traditional centralized model of manufacturing, decentralized manufacturing divides production across sites or geographic regions. This paradigm shift imposes significant structural and organisational changes on a business presenting both hidden challenges that must be addressed and opportunities to be embraced. By profoundly adapting business practices, significant advantages can be realized through a democratized value chain, creation of professional-level jobs without geographic restriction to the central hub and a flexibility in response to external pressures and demands. To realize these potential opportunities, however, advances in manufacturing technology and support systems are required, as well as significant changes in the way CGTs are regulated to facilitate multi-site manufacturing. Decentralized manufacturing is likely to be the manufacturing platform of choice for advanced health care therapies-in particular, those with a high degree of personalization. The future success of these promising products will be enhanced by adopting sound business strategies early in development. To realize the benefits that decentralized manufacturing of CGTs has to offer, it is important to examine both the risks and the substantial opportunities present. In this research, we examine both the challenges and the opportunities this shift in business strategy represents in an effort to maximize the success of adoption. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  19. [Territory and decentralization in the agenda for productive transformation with equity].

    Science.gov (United States)

    Sojo, A

    1991-08-01

    The regional perspective and the decentralization in Latin American and Caribbean countries was examined in light of technological changes and transformation of economic production to boost productivity. National population policies were not the major cause of redistribution of the population, rather such transformation significantly changed the comparative regional and urban advantages in the use of territory affecting the spatial distribution of the population. Hypotheses were advanced using the transformation of production, regional development, and decentralization on the retention, attraction, and migration of population in different areas with varying economic conditions. Spurious competitiveness means global strategies of enterprises that establish foreign operations by means of factor sourcing. Flexible specialization is a company strategy of permanent innovation based on flexible equipment and a qualified work force. The increasing transnationalization of capital is the source of skills and technology that sustain competitive advantages. Decentralization can resolve local demand, facilitate access to information, mobilize resources, and exercise control over local operations. In Japan, Germany, and Italy vs. the US and France there is a social contract among companies, trade unions, universities, and regional administrations in the interest of capital and the work force. There is no direct relationship between technology and region, the industrial cluster exhibits systemic competitiveness in developed countries (the Emilian model in Italy affirms the ability of small enterprises to develop new products), the regional impact is diverse relative to new technologies (some deprived rural economic areas have potential as in central and northern Italy), and population and region are linked (regional and rural-urban differences in the growth of population and migratory flows account for spatial distribution of the population). Decentralization and systemic

  20. Removing barriers to women entrepreneurs’ engagement in decentralized sustainable energy solutions for the poor

    Directory of Open Access Journals (Sweden)

    Yannick Glemarec

    2016-01-01

    Full Text Available  Rapidly falling renewable technology costs and new business models mean that decentralized energy solutions hold great promise to accelerate universal sustainable energy access. Across developing countries, women are typically the primary household energy managers. Close to their customers, women entrepreneurs have the potential to lower customer acquisition and servicing costs and drive these new decentralized solutions. However, they remain under-represented in the industry. This paper attempts to understand the root causes of this gender gap. It formulates the research hypothesis that market transformation policies intended to reduce investment risks to accelerate energy access may not benefit men and women entrepreneurs equally because of the existing structural barriers that women face. To test this hypothesis, the paper conducts a gender sensitive investment barrier and risk analysis, overlaid onto an existing gender neutral taxonomy of investment barriers and risks for decentralized sustainable energy solutions. A key finding is that for women entrepreneurs, existing structural impediments to gender equality translate into additional investment barriers as well as increased likelihood of occurrence and severity of the financial impact of generic investment risks. The paper offers an illustrative theory of change to facilitate a dialogue on the specific interventions needed to address these gender differentiated risks locally. It concludes that market transformation efforts for universal sustainable energy access must include targeted policy measures to ensure equal benefits to men and women entrepreneurs, and optimize the use of public resources to catalyze private investment and reduce poverty.

  1. Genome-scale constraint-based modeling of Geobacter metallireducens

    Directory of Open Access Journals (Sweden)

    Famili Iman

    2009-01-01

    Full Text Available Abstract Background Geobacter metallireducens was the first organism that can be grown in pure culture to completely oxidize organic compounds with Fe(III oxide serving as electron acceptor. Geobacter species, including G. sulfurreducens and G. metallireducens, are used for bioremediation and electricity generation from waste organic matter and renewable biomass. The constraint-based modeling approach enables the development of genome-scale in silico models that can predict the behavior of complex biological systems and their responses to the environments. Such a modeling approach was applied to provide physiological and ecological insights on the metabolism of G. metallireducens. Results The genome-scale metabolic model of G. metallireducens was constructed to include 747 genes and 697 reactions. Compared to the G. sulfurreducens model, the G. metallireducens metabolic model contains 118 unique reactions that reflect many of G. metallireducens' specific metabolic capabilities. Detailed examination of the G. metallireducens model suggests that its central metabolism contains several energy-inefficient reactions that are not present in the G. sulfurreducens model. Experimental biomass yield of G. metallireducens growing on pyruvate was lower than the predicted optimal biomass yield. Microarray data of G. metallireducens growing with benzoate and acetate indicated that genes encoding these energy-inefficient reactions were up-regulated by benzoate. These results suggested that the energy-inefficient reactions were likely turned off during G. metallireducens growth with acetate for optimal biomass yield, but were up-regulated during growth with complex electron donors such as benzoate for rapid energy generation. Furthermore, several computational modeling approaches were applied to accelerate G. metallireducens research. For example, growth of G. metallireducens with different electron donors and electron acceptors were studied using the genome-scale

  2. Comparing the Hydrologic and Watershed Processes between a Full Scale Stochastic Model Versus a Scaled Physical Model of Bell Canyon

    Science.gov (United States)

    Hernandez, K. F.; Shah-Fairbank, S.

    2016-12-01

    The San Dimas Experimental Forest has been designated as a research area by the United States Forest Service for use as a hydrologic testing facility since 1933 to investigate watershed hydrology of the 27 square mile land. Incorporation of a computer model provides validity to the testing of the physical model. This study focuses on San Dimas Experimental Forest's Bell Canyon, one of the triad of watersheds contained within the Big Dalton watershed of the San Dimas Experimental Forest. A scaled physical model was constructed of Bell Canyon to highlight watershed characteristics and each's effect on runoff. The physical model offers a comprehensive visualization of a natural watershed and can vary the characteristics of rainfall intensity, slope, and roughness through interchangeable parts and adjustments to the system. The scaled physical model is validated and calibrated through a HEC-HMS model to assure similitude of the system. Preliminary results of the physical model suggest that a 50-year storm event can be represented by a peak discharge of 2.2 X 10-3 cfs. When comparing the results to HEC-HMS, this equates to a flow relationship of approximately 1:160,000, which can be used to model other return periods. The completion of the Bell Canyon physical model can be used for educational instruction in the classroom, outreach in the community, and further research using the model as an accurate representation of the watershed present in the San Dimas Experimental Forest.

  3. Large scale modelling of catastrophic floods in Italy

    Science.gov (United States)

    Azemar, Frédéric; Nicótina, Ludovico; Sassi, Maximiliano; Savina, Maurizio; Hilberts, Arno

    2017-04-01

    The RMS European Flood HD model® is a suite of country scale flood catastrophe models covering 13 countries throughout continental Europe and the UK. The models are developed with the goal of supporting risk assessment analyses for the insurance industry. Within this framework RMS is developing a hydrologic and inundation model for Italy. The model aims at reproducing the hydrologic and hydraulic properties across the domain through a modeling chain. A semi-distributed hydrologic model that allows capturing the spatial variability of the runoff formation processes is coupled with a one-dimensional river routing algorithm and a two-dimensional (depth averaged) inundation model. This model setup allows capturing the flood risk from both pluvial (overland flow) and fluvial flooding. Here we describe the calibration and validation methodologies for this modelling suite applied to the Italian river basins. The variability that characterizes the domain (in terms of meteorology, topography and hydrologic regimes) requires a modeling approach able to represent a broad range of meteo-hydrologic regimes. The calibration of the rainfall-runoff and river routing models is performed by means of a genetic algorithm that identifies the set of best performing parameters within the search space over the last 50 years. We first establish the quality of the calibration parameters on the full hydrologic balance and on individual discharge peaks by comparing extreme statistics to observations over the calibration period on several stations. The model is then used to analyze the major floods in the country; we discuss the different meteorological setup leading to the historical events and the physical mechanisms that induced these floods. We can thus assess the performance of RMS' hydrological model in view of the physical mechanisms leading to flood and highlight the main controls on flood risk modelling throughout the country. The model's ability to accurately simulate antecedent

  4. Large Scale Computing for the Modelling of Whole Brain Connectivity

    DEFF Research Database (Denmark)

    Albers, Kristoffer Jon

    of nodes with a shared connectivity pattern. Modelling the brain in great detail on a whole-brain scale is essential to fully understand the underlying organization of the brain and reveal the relations between structure and function, that allows sophisticated cognitive behaviour to emerge from ensembles...... of neurons. Relying on Markov Chain Monte Carlo (MCMC) simulations as the workhorse in Bayesian inference however poses significant computational challenges, especially when modelling networks at the scale and complexity supported by high-resolution whole-brain MRI. In this thesis, we present how to overcome...... these computational limitations and apply Bayesian stochastic block models for un-supervised data-driven clustering of whole-brain connectivity in full image resolution. We implement high-performance software that allows us to efficiently apply stochastic blockmodelling with MCMC sampling on large complex networks...

  5. Modeling fast and slow earthquakes at various scales.

    Science.gov (United States)

    Ide, Satoshi

    2014-01-01

    Earthquake sources represent dynamic rupture within rocky materials at depth and often can be modeled as propagating shear slip controlled by friction laws. These laws provide boundary conditions on fault planes embedded in elastic media. Recent developments in observation networks, laboratory experiments, and methods of data analysis have expanded our knowledge of the physics of earthquakes. Newly discovered slow earthquakes are qualitatively different phenomena from ordinary fast earthquakes and provide independent information on slow deformation at depth. Many numerical simulations have been carried out to model both fast and slow earthquakes, but problems remain, especially with scaling laws. Some mechanisms are required to explain the power-law nature of earthquake rupture and the lack of characteristic length. Conceptual models that include a hierarchical structure over a wide range of scales would be helpful for characterizing diverse behavior in different seismic regions and for improving probabilistic forecasts of earthquakes.

  6. Classical scale invariance in the inert doublet model

    Energy Technology Data Exchange (ETDEWEB)

    Plascencia, Alexis D. [Institute for Particle Physics Phenomenology, Department of Physics,Durham University, Durham DH1 3LE (United Kingdom)

    2015-09-04

    The inert doublet model (IDM) is a minimal extension of the Standard Model (SM) that can account for the dark matter in the universe. Naturalness arguments motivate us to study whether the model can be embedded into a theory with dynamically generated scales. In this work we study a classically scale invariant version of the IDM with a minimal hidden sector, which has a U(1){sub CW} gauge symmetry and a complex scalar Φ. The mass scale is generated in the hidden sector via the Coleman-Weinberg (CW) mechanism and communicated to the two Higgs doublets via portal couplings. Since the CW scalar remains light, acquires a vacuum expectation value and mixes with the SM Higgs boson, the phenomenology of this construction can be modified with respect to the traditional IDM. We analyze the impact of adding this CW scalar and the Z{sup ′} gauge boson on the calculation of the dark matter relic density and on the spin-independent nucleon cross section for direct detection experiments. Finally, by studying the RG equations we find regions in parameter space which remain valid all the way up to the Planck scale.

  7. Utilization of Large Scale Surface Models for Detailed Visibility Analyses

    Science.gov (United States)

    Caha, J.; Kačmařík, M.

    2017-11-01

    This article demonstrates utilization of large scale surface models with small spatial resolution and high accuracy, acquired from Unmanned Aerial Vehicle scanning, for visibility analyses. The importance of large scale data for visibility analyses on the local scale, where the detail of the surface model is the most defining factor, is described. The focus is not only the classic Boolean visibility, that is usually determined within GIS, but also on so called extended viewsheds that aims to provide more information about visibility. The case study with examples of visibility analyses was performed on river Opava, near the Ostrava city (Czech Republic). The multiple Boolean viewshed analysis and global horizon viewshed were calculated to determine most prominent features and visibility barriers of the surface. Besides that, the extended viewshed showing angle difference above the local horizon, which describes angular height of the target area above the barrier, is shown. The case study proved that large scale models are appropriate data source for visibility analyses on local level. The discussion summarizes possible future applications and further development directions of visibility analyses.

  8. Deconfined Quantum Criticality, Scaling Violations, and Classical Loop Models

    Directory of Open Access Journals (Sweden)

    Adam Nahum

    2015-12-01

    Full Text Available Numerical studies of the transition between Néel and valence bond solid phases in two-dimensional quantum antiferromagnets give strong evidence for the remarkable scenario of deconfined criticality, but display strong violations of finite-size scaling that are not yet understood. We show how to realize the universal physics of the Néel–valence-bond-solid (VBS transition in a three-dimensional classical loop model (this model includes the subtle interference effect that suppresses hedgehog defects in the Néel order parameter. We use the loop model for simulations of unprecedentedly large systems (up to linear size L=512. Our results are compatible with a continuous transition at which both Néel and VBS order parameters are critical, and we do not see conventional signs of first-order behavior. However, we show that the scaling violations are stronger than previously realized and are incompatible with conventional finite-size scaling, even if allowance is made for a weakly or marginally irrelevant scaling variable. In particular, different approaches to determining the anomalous dimensions η_{VBS} and η_{Néel} yield very different results. The assumption of conventional finite-size scaling leads to estimates that drift to negative values at large sizes, in violation of the unitarity bounds. In contrast, the decay with distance of critical correlators on scales much smaller than system size is consistent with large positive anomalous dimensions. Barring an unexpected reversal in behavior at still larger sizes, this implies that the transition, if continuous, must show unconventional finite-size scaling, for example, from an additional dangerously irrelevant scaling variable. Another possibility is an anomalously weak first-order transition. By analyzing the renormalization group flows for the noncompact CP^{n-1} field theory (the n-component Abelian Higgs model between two and four dimensions, we give the simplest scenario by which an

  9. Modelling galaxy merger time-scales and tidal destruction

    Science.gov (United States)

    Simha, Vimal; Cole, Shaun

    2017-12-01

    We present a model for the dynamical evolution of subhaloes based on an approach combining numerical and analytical methods. Our method is based on tracking subhaloes in an N-body simulation up to the latest epoch that it can be resolved, and applying an analytic prescription for its merger time-scale that takes dynamical friction and tidal disruption into account. When applied to cosmological N-body simulations with mass resolutions that differ by two orders of magnitude, the technique produces halo occupation distributions that agree to within 3 per cent. This model has now been implemented in the GALFORM semi-analytic model of galaxy formation.

  10. Toward multi-scale computational modeling in developmental disability research.

    Science.gov (United States)

    Dammann, O; Follett, P

    2011-06-01

    The field of theoretical neuroscience is gaining increasing recognition. Virtually all areas of neuroscience offer potential linkage points for computational work. In developmental neuroscience, main areas of research are neural development and connectivity, and connectionist modeling of cognitive development. In this paper, we suggest that computational models can be helpful tools for understanding the pathogenesis and consequences of perinatal brain damage and subsequent developmental disability. In particular, designing multi-scale computational models should be considered by developmental neuroscientists interested in helping reduce the risk for developmental disabilities. Georg Thieme Verlag Stuttgart · New york.

  11. Atmospheric CO2 modeling at the regional scale: an intercomparison of 5 meso-scale atmospheric models

    Directory of Open Access Journals (Sweden)

    G. Pérez-Landa

    2007-12-01

    Full Text Available Atmospheric CO2 modeling in interaction with the surface fluxes, at the regional scale is developed within the frame of the European project CarboEurope-IP and its Regional Experiment component. In this context, five meso-scale meteorological models at 2 km resolution participate in an intercomparison exercise. Using a common experimental protocol that imposes a large number of rules, two days of the CarboEurope Regional Experiment Strategy (CERES campaign are simulated. A systematic evaluation of the models is done in confrontation with the observations, using statistical tools and direct comparisons. Thus, temperature and relative humidity at 2 m, wind direction, surface energy and CO2 fluxes, vertical profiles of potential temperature as well as in-situ CO2 concentrations comparisons between observations and simulations are examined. These comparisons reveal a cold bias in the simulated temperature at 2 m, the latent heat flux is often underestimated. Nevertheless, the CO2 concentrations heterogeneities are well captured by most of the models. This intercomparison exercise shows also the models ability to represent the meteorology and carbon cycling at the synoptic and regional scale in the boundary layer, but also points out some of the major shortcomings of the models.

  12. Increasing process integrity in global scale water balance models

    Science.gov (United States)

    Plöger, Lisa; Mewes, Benjamin; Oppel, Henning; Schumann, Andreas

    2017-04-01

    Hydrological models on a global or continental scale are often used to model human impact on the water balance in data scarce regions. Therefore, they are not validated for a time series of runoff measured at gauges but for long term estimates. The simplistic model GlobWat was introduced by the FAO to predict irrigation water demand based on open source data for continental catchments. Originally, the model was not designed to process time series, but to estimate the water demand on long-time averages of precipitation and evapotranspiration. Therefore the emphasis of detail of GlobWat was focused on crop evapotranspiration and water availability in agricultural regions. In our study we wanted to enhance the modelling in detail to forest evapotranspiration on the one hand and to time series simulation on the other hand. Meanwhile, we tried to keep the amount of input data as small as possible or at least limit it to open source data. Our objectives derived from case studies in the forest dominated catchments of Danube and Mississippi. With the use of Penman-Montheith equation as fundamental equation within the original GlobWat model, evapotranspiration losses in these regions could not be simulated adequately. As this being the fact, the water availability of downstream regions dominated by agriculture might be overestimated and hence estimation of irrigation demands biased. Therefore, we implemented a Shuttleworth & Calder as well as a Priestly-Taylor approach for evapotranspiration calculation of forested areas. Both models are compared and evaluated based on monthly time series validation of the model with runoff series provided by GRDC (Global Runoff Data Center). For an additional extension of the model we added a simple one-parameter snow-routine. In our presentation we compare the different stages of modelling to demonstrate the options to extent and validate these models with observed data on an appropriate scale.

  13. Comparing turbulent mixing of biogenic VOC across model scale

    Science.gov (United States)

    Li, Y.; Barth, M. C.; Steiner, A. L.

    2016-12-01

    Vertical mixing of biogenic volatile organic compounds (BVOC) in the planetary boundary layer (PBL) is very important in simulating the formation of ozone, secondary organic aerosols (SOA), and climate feedbacks. To assess the representation of vertical mixing in the atmosphere for the Baltimore-Washington DISCOVER-AQ 2011 campaign, we use two models of different scale and turbulence representation: (1) the National Center for Atmospheric Research's Large Eddy Simulation (LES), and (2) the Weather Research and Forecasting-Chemistry (WRF-Chem) model to simulate regional meteorology and chemistry. For WRF-Chem, we evaluate the boundary layer schemes in the model at convection-permitting scales (4km). WRF-Chem simulated vertical profiles are compared with the results from turbulence-resolving LES model under similar meteorological and chemical environment. The influence of clouds on gas and aqueous species and the impact of cloud processing at both scales are evaluated. Temporal evolutions of a surface-to-cloud concentration ratio are calculated to determine the capability of BVOC vertical mixing in WRF-Chem.

  14. Large-scale model of mammalian thalamocortical systems.

    Science.gov (United States)

    Izhikevich, Eugene M; Edelman, Gerald M

    2008-03-04

    The understanding of the structural and dynamic complexity of mammalian brains is greatly facilitated by computer simulations. We present here a detailed large-scale thalamocortical model based on experimental measures in several mammalian species. The model spans three anatomical scales. (i) It is based on global (white-matter) thalamocortical anatomy obtained by means of diffusion tensor imaging (DTI) of a human brain. (ii) It includes multiple thalamic nuclei and six-layered cortical microcircuitry based on in vitro labeling and three-dimensional reconstruction of single neurons of cat visual cortex. (iii) It has 22 basic types of neurons with appropriate laminar distribution of their branching dendritic trees. The model simulates one million multicompartmental spiking neurons calibrated to reproduce known types of responses recorded in vitro in rats. It has almost half a billion synapses with appropriate receptor kinetics, short-term plasticity, and long-term dendritic spike-timing-dependent synaptic plasticity (dendritic STDP). The model exhibits behavioral regimes of normal brain activity that were not explicitly built-in but emerged spontaneously as the result of interactions among anatomical and dynamic processes. We describe spontaneous activity, sensitivity to changes in individual neurons, emergence of waves and rhythms, and functional connectivity on different scales.

  15. Bed form dynamics in distorted lightweight scale models

    Science.gov (United States)

    Aberle, Jochen; Henning, Martin; Ettmer, Bernd

    2016-04-01

    The adequate prediction of flow and sediment transport over bed forms presents a major obstacle for the solution of sedimentation problems in alluvial channels because bed forms affect hydraulic resistance, sediment transport, and channel morphodynamics. Moreover, bed forms can affect hydraulic habitat for biota, may introduce severe restrictions to navigation, and present a major problem for engineering structures such as water intakes and groynes. The main body of knowledge on the geometry and dynamics of bed forms such as dunes originates from laboratory and field investigations focusing on bed forms in sand bed rivers. Such investigations enable insight into the physics of the transport processes, but do not allow for the long term simulation of morphodynamic development as required to assess, for example, the effects of climate change on river morphology. On the other hand, this can be achieved through studies with distorted lightweight scale models allowing for the modification of the time scale. However, our understanding of how well bed form geometry and dynamics, and hence sediment transport mechanics, are reproduced in such models is limited. Within this contribution we explore this issue using data from investigations carried out at the Federal Waterways and Research Institute in Karlsruhe, Germany in a distorted lightweight scale model of the river Oder. The model had a vertical scale of 1:40 and a horizontal scale of 1:100, the bed material consisted of polystyrene particles, and the resulting dune geometry and dynamics were measured with a high spatial and temporal resolution using photogrammetric methods. Parameters describing both the directly measured and up-scaled dune geometry were determined using the random field approach. These parameters (e.g., standard deviation, skewness, kurtosis) will be compared to prototype observations as well as to results from the literature. Similarly, parameters describing the lightweight bed form dynamics, which

  16. Human resources for health and decentralization policy in the Brazilian health system.

    Science.gov (United States)

    Pierantoni, Celia Regina; Garcia, Ana Claudia P

    2011-05-17

    The Brazilian health reform process, following the establishment of the Unified Health System (SUS), has had a strong emphasis on decentralization, with a special focus on financing, management and inter-managerial agreements. Brazil is a federal country and the Ministry of Health (MoH), through the Secretary of Labour Management and Health Education, is responsible for establishing national policy guidelines for health labour management, and also for implementing strategies for the decentralization of management of labour and education in the federal states. This paper assesses whether the process of decentralizing human resources for health (HRH) management and organization to the level of the state and municipal health departments has involved investments in technical, political and financial resources at the national level. The research methods used comprise a survey of HRH managers of states and major municipalities (including capitals) and focus groups with these HRH managers - all by geographic region. The results were obtained by combining survey and focus group data, and also through triangulation with the results of previous research. The results of this evaluation showed the evolution policy, previously restricted to the field of 'personnel administration', now expanded to a conceptual model for health labour management and education-- identifying progress, setbacks, critical issues and challenges for the consolidation of the decentralized model for HRH management. The results showed that 76.3% of the health departments have an HRH unit. It was observed that 63.2% have an HRH information system. However, in most health departments, the HRH unit uses only the payroll and administrative records as data sources. Concerning education in health, 67.6% of the HRH managers mentioned existing cooperation with educational and teaching institutions for training and/or specialization of health workers. Among them, specialization courses account for 61.4% and short

  17. Human resources for health and decentralization policy in the Brazilian health system

    Directory of Open Access Journals (Sweden)

    Pierantoni Celia

    2011-05-01

    Full Text Available Abstract Background The Brazilian health reform process, following the establishment of the Unified Health System (SUS, has had a strong emphasis on decentralization, with a special focus on financing, management and inter-managerial agreements. Brazil is a federal country and the Ministry of Health (MoH, through the Secretary of Labour Management and Health Education, is responsible for establishing national policy guidelines for health labour management, and also for implementing strategies for the decentralization of management of labour and education in the federal states. This paper assesses whether the process of decentralizing human resources for health (HRH management and organization to the level of the state and municipal health departments has involved investments in technical, political and financial resources at the national level. Methods The research methods used comprise a survey of HRH managers of states and major municipalities (including capitals and focus groups with these HRH managers - all by geographic region. The results were obtained by combining survey and focus group data, and also through triangulation with the results of previous research. Results The results of this evaluation showed the evolution policy, previously restricted to the field of 'personnel administration', now expanded to a conceptual model for health labour management and education-- identifying progress, setbacks, critical issues and challenges for the consolidation of the decentralized model for HRH management. The results showed that 76.3% of the health departments have an HRH unit. It was observed that 63.2% have an HRH information system. However, in most health departments, the HRH unit uses only the payroll and administrative records as data sources. Concerning education in health, 67.6% of the HRH managers mentioned existing cooperation with educational and teaching institutions for training and/or specialization of health workers. Among them

  18. A robust decentralized load frequency controller for interconnected power systems.

    Science.gov (United States)

    Dong, Lili; Zhang, Yao; Gao, Zhiqiang

    2012-05-01

    A novel design of a robust decentralized load frequency control (LFC) algorithm is proposed for an inter-connected three-area power system, for the purpose of regulating area control error (ACE) in the presence of system uncertainties and external disturbances. The design is based on the concept of active disturbance rejection control (ADRC). Estimating and mitigating the total effect of various uncertainties in real time, ADRC is particularly effective against a wide range of parameter variations, model uncertainties, and large disturbances. Furthermore, with only two tuning parameters, the controller provides a simple and easy-to-use solution to complex engineering problems in practice. Here, an ADRC-based LFC solution is developed for systems with turbines of various types, such as non-reheat, reheat, and hydraulic. The simulation results verified the effectiveness of the ADRC, in comparison with an existing PI-type controller tuned via genetic algorithm linear matrix inequalities (GALMIs). The comparison results show the superiority of the proposed solution. Moreover, the stability and robustness of the closed-loop system is studied using frequency-domain analysis. Copyright © 2012 ISA. Published by Elsevier Ltd. All rights reserved.

  19. Decentralized Routing and Diameter Bounds in Entangled Quantum Networks

    Science.gov (United States)

    Gyongyosi, Laszlo; Imre, Sandor

    2017-04-01

    Entangled quantum networks are a necessity for any future quantum internet, long-distance quantum key distribution, and quantum repeater networks. The entangled quantum nodes can communicate through several different levels of entanglement, leading to a heterogeneous, multi-level entangled network structure. The level of entanglement between the quantum nodes determines the hop distance, the number of spanned nodes, and the probability of the existence of an entangled link in the network. In this work we define a decentralized routing for entangled quantum networks. We show that the probability distribution of the entangled links can be modeled by a specific distribution in a base-graph. The results allow us to perform efficient routing to find the shortest paths in entangled quantum networks by using only local knowledge of the quantum nodes. We give bounds on the maximum value of the total number of entangled links of a path. The proposed scheme can be directly applied in practical quantum communications and quantum networking scenarios. This work was partially supported by the Hungarian Scientific Research Fund - OTKA K-112125.

  20. Compare pilot-scale and industry-scale models of pulverized coal combustion in an ironmaking blast furnace

    Science.gov (United States)

    Shen, Yansong; Yu, Aibing; Zulli, Paul

    2013-07-01

    In order to understand the complex phenomena of pulverized coal injection (PCI) process in blast furnace (BF), mathematical models have been developed at different scales: pilot-scale model of coal combustion and industry-scale model (in-furnace model) of coal/coke combustion in a real BF respectively. This paper compares these PCI models in aspects of model developments and model capability. The model development is discussed in terms of model formulation, their new features and geometry/regions considered. The model capability is then discussed in terms of main findings followed by the model evaluation on their advantages and limitations. It is indicated that these PCI models are all able to describe PCI operation qualitatively. The in-furnace model is more reliable for simulating in-furnace phenomena of PCI operation qualitatively and quantitatively. These models are useful for understanding the flow-thermo-chemical behaviors and then optimizing the PCI operation in practice.

  1. Medication as Infrastructure: Decentring Self-care

    Directory of Open Access Journals (Sweden)

    Peter Danholt

    2012-11-01

    Full Text Available Drawing on science and technology studies (STS, and specifically the concept of infrastructure as conceptualised by Bowker and Star (2000; Star 1999, this paper argues and empirically demonstrates that self-care may be considered a practice that is thoroughly sociotechnical, material, distributed and de-centred. Comparing the practices related to medication in the treatment of asthma, type 2 diabetes and haemophilia, we show that in practice there is no ‘self’ in self-care. More specifically, the ‘self’ in self-care is an actor who is highly dependent on, and intertwined with infrastructures of care, in order to be self-caring. Infrastructures of care are the more or less embedded ‘tracks’ along which care may ‘run’, shaping and being shaped by actors and settings along the way. Obtaining prescriptions, going to the pharmacy, bringing medication home and administering it as parts of daily life are commonplace activities embedded in the fabric of life, especially for those living with a chronic condition. However, this procurement and emplacement of medication involves the establishment and ongoing enactment of infrastructures of care, that is, the connections between various actors and locations that establish caring spaces and caring selves. Locations and actors are included as allies in treating chronic conditions outside the clinical setting, but these infrastructures may also be ambiguous, with respect to their effects; they may simultaneously contribute to the condition’s management and neglect. Particularly precarious is management at the fringes of healthcare infrastructure, where allies, routines and general predictability are scarce. We conclude by arguing that these insights may induce a greater sensitivity to existing infrastructures and practices, when seeking to introduce new infrastructures of care, such as those promoted under the headings of ‘telemedicine’ and ‘healthcare IT’.

  2. Multi-scale modeling of the CD8 immune response

    Science.gov (United States)

    Barbarroux, Loic; Michel, Philippe; Adimy, Mostafa; Crauste, Fabien

    2016-06-01

    During the primary CD8 T-Cell immune response to an intracellular pathogen, CD8 T-Cells undergo exponential proliferation and continuous differentiation, acquiring cytotoxic capabilities to address the infection and memorize the corresponding antigen. After cleaning the organism, the only CD8 T-Cells left are antigen-specific memory cells whose role is to respond stronger and faster in case they are presented this very same antigen again. That is how vaccines work: a small quantity of a weakened pathogen is introduced in the organism to trigger the primary response, generating corresponding memory cells in the process, giving the organism a way to defend himself in case it encounters the same pathogen again. To investigate this process, we propose a non linear, multi-scale mathematical model of the CD8 T-Cells immune response due to vaccination using a maturity structured partial differential equation. At the intracellular scale, the level of expression of key proteins is modeled by a delay differential equation system, which gives the speeds of maturation for each cell. The population of cells is modeled by a maturity structured equation whose speeds are given by the intracellular model. We focus here on building the model, as well as its asymptotic study. Finally, we display numerical simulations showing the model can reproduce the biological dynamics of the cell population for both the primary response and the secondary responses.

  3. Multi-scale modeling of the CD8 immune response

    Energy Technology Data Exchange (ETDEWEB)

    Barbarroux, Loic, E-mail: loic.barbarroux@doctorant.ec-lyon.fr [Inria, Université de Lyon, UMR 5208, Institut Camille Jordan (France); Ecole Centrale de Lyon, 36 avenue Guy de Collongue, 69134 Ecully (France); Michel, Philippe, E-mail: philippe.michel@ec-lyon.fr [Inria, Université de Lyon, UMR 5208, Institut Camille Jordan (France); Ecole Centrale de Lyon, 36 avenue Guy de Collongue, 69134 Ecully (France); Adimy, Mostafa, E-mail: mostafa.adimy@inria.fr [Inria, Université de Lyon, UMR 5208, Université Lyon 1, Institut Camille Jordan, 43 Bd. du 11 novembre 1918, F-69200 Villeurbanne Cedex (France); Crauste, Fabien, E-mail: crauste@math.univ-lyon1.fr [Inria, Université de Lyon, UMR 5208, Université Lyon 1, Institut Camille Jordan, 43 Bd. du 11 novembre 1918, F-69200 Villeurbanne Cedex (France)

    2016-06-08

    During the primary CD8 T-Cell immune response to an intracellular pathogen, CD8 T-Cells undergo exponential proliferation and continuous differentiation, acquiring cytotoxic capabilities to address the infection and memorize the corresponding antigen. After cleaning the organism, the only CD8 T-Cells left are antigen-specific memory cells whose role is to respond stronger and faster in case they are presented this very same antigen again. That is how vaccines work: a small quantity of a weakened pathogen is introduced in the organism to trigger the primary response, generating corresponding memory cells in the process, giving the organism a way to defend himself in case it encounters the same pathogen again. To investigate this process, we propose a non linear, multi-scale mathematical model of the CD8 T-Cells immune response due to vaccination using a maturity structured partial differential equation. At the intracellular scale, the level of expression of key proteins is modeled by a delay differential equation system, which gives the speeds of maturation for each cell. The population of cells is modeled by a maturity structured equation whose speeds are given by the intracellular model. We focus here on building the model, as well as its asymptotic study. Finally, we display numerical simulations showing the model can reproduce the biological dynamics of the cell population for both the primary response and the secondary responses.

  4. Multi-scale Modeling of the Evolution of a Large-Scale Nourishment

    Science.gov (United States)

    Luijendijk, A.; Hoonhout, B.

    2016-12-01

    Morphological predictions are often computed using a single morphological model commonly forced with schematized boundary conditions representing the time scale of the prediction. Recent model developments are now allowing us to think and act differently. This study presents some recent developments in coastal morphological modeling focusing on flexible meshes, flexible coupling between models operating at different time scales, and a recently developed morphodynamic model for the intertidal and dry beach. This integrated modeling approach is applied to the Sand Engine mega nourishment in The Netherlands to illustrate the added-values of this integrated approach both in accuracy and computational efficiency. The state-of-the-art Delft3D Flexible Mesh (FM) model is applied at the study site under moderate wave conditions. One of the advantages is that the flexibility of the mesh structure allows a better representation of the water exchange with the lagoon and corresponding morphological behavior than with the curvilinear grid used in the previous version of Delft3D. The XBeach model is applied to compute the morphodynamic response to storm events in detail incorporating the long wave effects on bed level changes. The recently developed aeolian transport and bed change model AeoLiS is used to compute the bed changes in the intertidal and dry beach area. In order to enable flexible couplings between the three abovementioned models, a component-based environment has been developed using the BMI method. This allows a serial coupling of Delft3D FM and XBeach steered by a control module that uses a hydrodynamic time series as input (see figure). In addition, a parallel online coupling, with information exchange in each timestep will be made with the AeoLiS model that predicts the bed level changes at the intertidal and dry beach area. This study presents the first years of evolution of the Sand Engine computed with the integrated modelling approach. Detailed comparisons

  5. Ombudsman decentralized in the EU: experience for Ukraine

    Directory of Open Access Journals (Sweden)

    K. V. Manuilova

    2016-03-01

    Full Text Available The article analyses the actual theme of the ombudsman institution in terms of decentralization of public power. The features of formation and functioning of the ombudsman in Sweden, Finland, of Denmark, Austria and the Netherlands. It is noted that it is the best ombudsman protects the rights of people in decentralized EU. Ombudsman makes a significant contribution to the democratization of society, public power closer to the people, ensuring fairness, legitimacy and willingness to meet the needs of citizens and contributes to greater transparency, efficiency and quality in the work of public authorities. Today, most decentralized European countries the post of local / regional ombudsman, which successfully handles control of public authorities. The conclusions emphasized that the activities of the institute of local / regional ombudsman investigated in the EU was an important step for the further development of democratic society; strengthening the rule of law key components (growth status of the individual, guaranteeing the rights and freedoms of man and citizen; providing better control over the activities of authorities and officials; realization of the main goal of the policy of decentralization of public power – the power to approach people. The recommendations for change Ukrainian ombudsman as a decentralized public power.

  6. Fiscal decentralization and inequality: the case of Spain

    Directory of Open Access Journals (Sweden)

    Yasemin İrepoğlu Carreras

    2016-01-01

    Full Text Available What are the distributional effects of power allocations between different levels of government in a country? This article examines whether having regions with more fiscal authority is significantly associated with higher national economic inequality in a country. The literature has long established the positive link between decentralized governance structures and varying levels of redistribution within a country. Redistribution is channel through which governments tackle inequality, and if redistribution is asymmetric across sub-national units, this is expected to increase inequality. Yet, there is a gap in the literature that systematically links these three components: decentralized governance, redistribution and economic inequality. By focusing on the fiscal aspect of decentralization, this article provides the theory and the causal mechanism for understanding why the decentralization levels of governance in a country should matter for income inequality. Using data measured along different components of regional authority, such as policy scope, fiscal autonomy and fiscal control, it explains why fiscal decentralization is expected to increase inequality, while predicting that the co-sharing of fiscal power between the regions and central government will to lead to lower inequality. The article tests this hypothesis with a case study on Spain.

  7. Modelling hydrological processes at different scales across Russian permafrost domain

    Science.gov (United States)

    Makarieva, Olga; Lebedeva, Lyudmila; Nesterova, Natalia; Vinogradova, Tatyana

    2017-04-01

    The project aims to study the interactions between permafrost and runoff generation processes across Russian Arctic domain based on hydrological modelling. The uniqueness of the approach is a unified modelling framework which allows for coupled simulations of upper permafrost dynamics and streamflow generation at different scales (from soil column to large watersheds). The base of the project is hydrological model Hydrograph (Vinogradov et al. 2011, Semenova et al. 2013, 2015; Lebedeva et al., 2015). The model algorithms combine physically-based and conceptual approaches for the description of land hydrological cycle processes, which allows for maintaining a balance between the complexity of model design and the use of limited input information. The method for modeling heat dynamics in soil is integrated into the model. Main parameters of the model are the physical properties of landscapes that may be measured (observed) in nature and are classified according to the types of soil, vegetation and other characteristics. A set of parameters specified in the studied catchments (basins analog) can be transferred to ungauged basins with similar types of the underlying surface without calibration. The results of modelling from small research watersheds to large poorly gauged river basins in different climate and landscape settings of Russian Arctic (within the Yenisey, Lena, Yana, Indigirka, Kolyma rivers basins) will be presented. Based on gained experience methodological aspects of hydrological modelling approaches in permafrost environment will be discussed. The study is partially supported by Russian Foundation for Basic Research, projects 16-35-50151 and 17-05-01138.

  8. Site-scale groundwater flow modelling of Aberg

    Energy Technology Data Exchange (ETDEWEB)

    Walker, D. [Duke Engineering and Services (United States); Gylling, B. [Kemakta Konsult AB, Stockholm (Sweden)

    1998-12-01

    The Swedish Nuclear Fuel and Waste Management Company (SKB) SR 97 study is a comprehensive performance assessment illustrating the results for three hypothetical repositories in Sweden. In support of SR 97, this study examines the hydrogeologic modelling of the hypothetical site called Aberg, which adopts input parameters from the Aespoe Hard Rock Laboratory in southern Sweden. This study uses a nested modelling approach, with a deterministic regional model providing boundary conditions to a site-scale stochastic continuum model. The model is run in Monte Carlo fashion to propagate the variability of the hydraulic conductivity to the advective travel paths from representative canister locations. A series of variant cases addresses uncertainties in the inference of parameters and the boundary conditions. The study uses HYDRASTAR, the SKB stochastic continuum groundwater modelling program, to compute the heads, Darcy velocities at each representative canister position and the advective travel times and paths through the geosphere. The nested modelling approach and the scale dependency of hydraulic conductivity raise a number of questions regarding the regional to site-scale mass balance and the method`s self-consistency. The transfer of regional heads via constant head boundaries preserves the regional pattern recharge and discharge in the site-scale model, and the regional to site-scale mass balance is thought to be adequate. The upscaling method appears to be approximately self-consistent with respect to the median performance measures at various grid scales. A series of variant cases indicates that the study results are insensitive to alternative methods on transferring boundary conditions from the regional model to the site-scale model. The flow paths, travel times and simulated heads appear to be consistent with on-site observations and simple scoping calculations. The variabilities of the performance measures are quite high for the Base Case, but the

  9. Experimental exploration of diffusion panel labyrinth in scale model

    Science.gov (United States)

    Vance, Mandi M.

    Small rehearsal and performance venues often lack the rich reverberation found in larger spaces. Higini Arau-Puchades has designed and implemented a system of diffusion panels in the Orchestra Rehearsal Room at the Great Theatre Liceu and the Tonhalle St. Gallen that lengthen the reverberation time. These panels defy traditional room acoustics theory which holds that adding material to a room will shorten the reverberation time. This work explores several versions of Arau-Puchades' panels and room characteristics in scale model. Reverberation times are taken from room impulse response measurements in order to better understand the unusual phenomenon. Scale modeling enables many tests but has limitations in its accuracy due to the higher frequency range involved. Further investigations are necessary to establish how the sound energy interacts with the diffusion panels and confirm their validity in a range of applications.

  10. A Rasch Model Analysis of the Mindful Attention Awareness Scale.

    Science.gov (United States)

    Goh, Hong Eng; Marais, Ida; Ireland, Michael James

    2017-04-01

    The Mindful Attention Awareness Scale was developed to measure individual differences in the tendency to be mindful. The current study examined the psychometric properties of the Mindful Attention Awareness Scale in a heterogeneous sample of 565 nonmeditators and 612 meditators using the polytomous Rasch model. The results showed that some items did not function the same way for these two groups. Overall, meditators had higher mean estimates than nonmeditators. The analysis identified a group of items as highly discriminating. Using a different model, Van Dam, Earleywine, and Borders in 2010 identified the same group of items as highly discriminating, and concluded that they were the items with the most information. Multiple pieces of evidence from the Rasch analysis showed that these items discriminate highly because of local dependence, hence do not supply independent information. We discussed how these different conclusions, based on similar findings, result from two very different paradigms in measurement.

  11. Next-generation genome-scale models for metabolic engineering

    DEFF Research Database (Denmark)

    King, Zachary A.; Lloyd, Colton J.; Feist, Adam M.

    2015-01-01

    Constraint-based reconstruction and analysis (COBRA) methods have become widely used tools for metabolic engineering in both academic and industrial laboratories. By employing a genome-scale in silico representation of the metabolic network of a host organism, COBRA methods can be used to predict...... examples of applying COBRA methods to strain optimization are presented and discussed. Then, an outlook is provided on the next generation of COBRA models and the new types of predictions they will enable for systems metabolic engineering....

  12. Vegetable parenting practices scale. Item response modeling analyses.

    Science.gov (United States)

    Chen, Tzu-An; O'Connor, Teresia M; Hughes, Sheryl O; Beltran, Alicia; Baranowski, Janice; Diep, Cassandra; Baranowski, Tom

    2015-08-01

    To evaluate the psychometric properties of a vegetable parenting practices scale using multidimensional polytomous item response modeling which enables assessing item fit to latent variables and the distributional characteristics of the items in comparison to the respondents. We also tested for differences in the ways item function (called differential item functioning) across child's gender, ethnicity, age, and household income groups. Parents of 3-5 year old children completed a self-reported vegetable parenting practices scale online. Vegetable parenting practices consisted of 14 effective vegetable parenting practices and 12 ineffective vegetable parenting practices items, each with three subscales (responsiveness, structure, and control). Multidimensional polytomous item response modeling was conducted separately on effective vegetable parenting practices and ineffective vegetable parenting practices. One effective vegetable parenting practice item did not fit the model well in the full sample or across demographic groups, and another was a misfit in differential item functioning analyses across child's gender. Significant differential item functioning was detected across children's age and ethnicity groups, and more among effective vegetable parenting practices than ineffective vegetable parenting practices items. Wright maps showed items only covered parts of the latent trait distribution. The harder- and easier-to-respond ends of the construct were not covered by items for effective vegetable parenting practices and ineffective vegetable parenting practices, respectively. Several effective vegetable parenting practices and ineffective vegetable parenting practices scale items functioned differently on the basis of child's demographic characteristics; therefore, researchers should use these vegetable parenting practices scales with caution. Item response modeling should be incorporated in analyses of parenting practice questionnaires to better assess

  13. Modeling basin- and plume-scale processes of CO2 storage for full-scale deployment

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Q.; Birkholzer, J.T.; Mehnert, E.; Lin, Y.-F.; Zhang, K.

    2009-08-15

    Integrated modeling of basin- and plume-scale processes induced by full-scale deployment of CO{sub 2} storage was applied to the Mt. Simon Aquifer in the Illinois Basin. A three-dimensional mesh was generated with local refinement around 20 injection sites, with approximately 30 km spacing. A total annual injection rate of 100 Mt CO{sub 2} over 50 years was used. The CO{sub 2}-brine flow at the plume scale and the single-phase flow at the basin scale were simulated. Simulation results show the overall shape of a CO{sub 2} plume consisting of a typical gravity-override subplume in the bottom injection zone of high injectivity and a pyramid-shaped subplume in the overlying multilayered Mt. Simon, indicating the important role of a secondary seal with relatively low-permeability and high-entry capillary pressure. The secondary-seal effect is manifested by retarded upward CO{sub 2} migration as a result of multiple secondary seals, coupled with lateral preferential CO{sub 2} viscous fingering through high-permeability layers. The plume width varies from 9.0 to 13.5 km at 200 years, indicating the slow CO{sub 2} migration and no plume interference between storage sites. On the basin scale, pressure perturbations propagate quickly away from injection centers, interfere after less than 1 year, and eventually reach basin margins. The simulated pressure buildup of 35 bar in the injection area is not expected to affect caprock geomechanical integrity. Moderate pressure buildup is observed in Mt. Simon in northern Illinois. However, its impact on groundwater resources is less than the hydraulic drawdown induced by long-term extensive pumping from overlying freshwater aquifers.

  14. Ecohydrologic Modeling of Hillslope Scale Processes in Dryland Ecosystems

    Science.gov (United States)

    Franz, T. E.; King, E. G.; Lester, A.; Caylor, K. K.; Nordbotten, J.; Celia, M. A.; Rodriguez-Iturbe, I.

    2008-12-01

    Dryland ecosystem processes are governed by complex interactions between the atmosphere, soil, and vegetation that are tightly coupled through the mass balance of water. At the scale of individual hillslopes, mass balance of water is dominated by mechanisms of water redistribution which require spatially explicit representation. Fully-resolved physical models of surface and subsurface processes require numerical routines that are not trivial to solve for the spatial (hillslope) and temporal (many plant generations) scales of ecohydrologic interest. In order to reduce model complexity, we have used small-scale field data to derive empirical surface flux terms for representative patches (bare soil, grass, and tree) in a dryland ecosystem of central Kenya. The model is coupled spatially in the subsurface by an analytical solution to the Boussinesq equation for a sloping slab. The semi-analytical model is spatially explicit driven by pulses of precipitation over a simulation period that represents many plant generations. By examining long-term model dynamics, we are able to investigate the principles of self-organization and optimization (maximization of plant water use and minimization of water lost to the system) of dryland ecosystems for various initial conditions and climatic variability. Precipitation records in central Kenya reveal a shift to more intense infrequent rain events with a constant annual total. The range of stable solutions of initial conditions and climatic variability are important to land management agencies for addressing current grazing practices and future policies. The model is a quantitative tool for addressing perturbations to the system and the overall sustainability of pastoralist activities in dryland ecosystems.

  15. Disaggregation, aggregation and spatial scaling in hydrological modelling

    Science.gov (United States)

    Becker, Alfred; Braun, Peter

    1999-04-01

    A typical feature of the land surface is its heterogeneity in terms of the spatial variability of land surface characteristics and parameters controlling physical/hydrological, biological, and other related processes. Different forms and degrees of heterogeneity need to be taken into account in hydrological modelling. The first part of the article concerns the conditions under which a disaggregation of the land surface into subareas of uniform or "quasihomogeneous" behaviour (hydrotopes or hydrological response units - HRUs) is indispensable. In a case study in northern Germany, it is shown that forests in contrast to arable land, areas with shallow groundwater in contrast to those with deep, water surfaces and sealed areas should generally be distinguished (disaggregated) in modelling, whereas internal heterogeneities within these hydrotopes can be assessed statistically, e.g., by areal distribution functions (soil water holding capacity, hydraulic conductivity, etc.). Models with hydrotope-specific parameters can be applied to calculate the "vertical" processes (fluxes, storages, etc.), and this, moreover, for hydrotopes of different area, and even for groups of distributed hydrotopes in a reference area (hydrotope classes), provided that the meteorological conditions are similar. Thus, a scaling problem does not really exist in this process domain. The primary domain for the application of scaling laws is that of lateral flows in landscapes and river basins. This is illustrated in the second part of the article, where results of a case study in Bavaria/Germany are presented and discussed. It is shown that scaling laws can be applied efficiently for the determination of the Instantaneous Unit Hydrograph (IUH) of the surface runoff system in river basins: simple scaling for basins larger than 43 km 2, and multiple scaling for smaller basins. Surprisingly, only two parameters were identified as important in the derived relations: the drainage area and, in some

  16. Regional scale hydrology with a new land surface processes model

    Science.gov (United States)

    Laymon, Charles; Crosson, William

    1995-01-01

    Through the CaPE Hydrometeorology Project, we have developed an understanding of some of the unique data quality issues involved in assimilating data of disparate types for regional-scale hydrologic modeling within a GIS framework. Among others, the issues addressed here include the development of adequate validation of the surface water budget, implementation of the STATSGO soil data set, and implementation of a remote sensing-derived landcover data set to account for surface heterogeneity. A model of land surface processes has been developed and used in studies of the sensitivity of surface fluxes and runoff to soil and landcover characterization. Results of these experiments have raised many questions about how to treat the scale-dependence of land surface-atmosphere interactions on spatial and temporal variability. In light of these questions, additional modifications are being considered for the Marshall Land Surface Processes Model. It is anticipated that these techniques can be tested and applied in conjunction with GCIP activities over regional scales.

  17. Space Launch System Scale Model Acoustic Test Ignition Overpressure Testing

    Science.gov (United States)

    Nance, Donald K.; Liever, Peter A.

    2015-01-01

    The overpressure phenomenon is a transient fluid dynamic event occurring during rocket propulsion system ignition. This phenomenon results from fluid compression of the accelerating plume gas, subsequent rarefaction, and subsequent propagation from the exhaust trench and duct holes. The high-amplitude unsteady fluid-dynamic perturbations can adversely affect the vehicle and surrounding structure. Commonly known as ignition overpressure (IOP), this is an important design-to environment for the Space Launch System (SLS) that NASA is currently developing. Subscale testing is useful in validating and verifying the IOP environment. This was one of the objectives of the Scale Model Acoustic Test (SMAT), conducted at Marshall Space Flight Center (MSFC). The test data quantifies the effectiveness of the SLS IOP suppression system and improves the analytical models used to predict the SLS IOP environments. The reduction and analysis of the data gathered during the SMAT IOP test series requires identification and characterization of multiple dynamic events and scaling of the event waveforms to provide the most accurate comparisons to determine the effectiveness of the IOP suppression systems. The identification and characterization of the overpressure events, the waveform scaling, the computation of the IOP suppression system knockdown factors, and preliminary comparisons to the analytical models are discussed.

  18. Modeling Biology Spanning Different Scales: An Open Challenge

    Directory of Open Access Journals (Sweden)

    Filippo Castiglione

    2014-01-01

    Full Text Available It is coming nowadays more clear that in order to obtain a unified description of the different mechanisms governing the behavior and causality relations among the various parts of a living system, the development of comprehensive computational and mathematical models at different space and time scales is required. This is one of the most formidable challenges of modern biology characterized by the availability of huge amount of high throughput measurements. In this paper we draw attention to the importance of multiscale modeling in the framework of studies of biological systems in general and of the immune system in particular.

  19. Model Predictive Control for a Small Scale Unmanned Helicopter

    Directory of Open Access Journals (Sweden)

    Jianfu Du

    2008-11-01

    Full Text Available Kinematical and dynamical equations of a small scale unmanned helicoper are presented in the paper. Based on these equations a model predictive control (MPC method is proposed for controlling the helicopter. This novel method allows the direct accounting for the existing time delays which are used to model the dynamics of actuators and aerodynamics of the main rotor. Also the limits of the actuators are taken into the considerations during the controller design. The proposed control algorithm was verified in real flight experiments where good perfomance was shown in postion control mode.

  20. BiGG Models: A platform for integrating, standardizing and sharing genome-scale models

    Science.gov (United States)

    King, Zachary A.; Lu, Justin; Dräger, Andreas; Miller, Philip; Federowicz, Stephen; Lerman, Joshua A.; Ebrahim, Ali; Palsson, Bernhard O.; Lewis, Nathan E.

    2016-01-01

    Genome-scale metabolic models are mathematically-structured knowledge bases that can be used to predict metabolic pathway usage and growth phenotypes. Furthermore, they can generate and test hypotheses when integrated with experimental data. To maximize the value of these models, centralized repositories of high-quality models must be established, models must adhere to established standards and model components must be linked to relevant databases. Tools for model visualization further enhance their utility. To meet these needs, we present BiGG Models (http://bigg.ucsd.edu), a completely redesigned Biochemical, Genetic and Genomic knowledge base. BiGG Models contains more than 75 high-quality, manually-curated genome-scale metabolic models. On the website, users can browse, search and visualize models. BiGG Models connects genome-scale models to genome annotations and external databases. Reaction and metabolite identifiers have been standardized across models to conform to community standards and enable rapid comparison across models. Furthermore, BiGG Models provides a comprehensive application programming interface for accessing BiGG Models with modeling and analysis tools. As a resource for highly curated, standardized and accessible models of metabolism, BiGG Models will facilitate diverse systems biology studies and support knowledge-based analysis of diverse experimental data. PMID:26476456

  1. BiGG Models: A platform for integrating, standardizing and sharing genome-scale models.

    Science.gov (United States)

    King, Zachary A; Lu, Justin; Dräger, Andreas; Miller, Philip; Federowicz, Stephen; Lerman, Joshua A; Ebrahim, Ali; Palsson, Bernhard O; Lewis, Nathan E

    2016-01-04

    Genome-scale metabolic models are mathematically-structured knowledge bases that can be used to predict metabolic pathway usage and growth phenotypes. Furthermore, they can generate and test hypotheses when integrated with experimental data. To maximize the value of these models, centralized repositories of high-quality models must be established, models must adhere to established standards and model components must be linked to relevant databases. Tools for model visualization further enhance their utility. To meet these needs, we present BiGG Models (http://bigg.ucsd.edu), a completely redesigned Biochemical, Genetic and Genomic knowledge base. BiGG Models contains more than 75 high-quality, manually-curated genome-scale metabolic models. On the website, users can browse, search and visualize models. BiGG Models connects genome-scale models to genome annotations and external databases. Reaction and metabolite identifiers have been standardized across models to conform to community standards and enable rapid comparison across models. Furthermore, BiGG Models provides a comprehensive application programming interface for accessing BiGG Models with modeling and analysis tools. As a resource for highly curated, standardized and accessible models of metabolism, BiGG Models will facilitate diverse systems biology studies and support knowledge-based analysis of diverse experimental data. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  2. Low Decision Space Means No Decentralization in Fiji Comment on "Decentralisation of Health Services in Fiji: A Decision Space Analysis".

    Science.gov (United States)

    Faguet, Jean-Paul

    2016-06-22

    Mohammed, North, and Ashton find that decentralization in Fiji shifted health-sector workloads from tertiary hospitals to peripheral health centres, but with little transfer of administrative authority from the centre. Decision-making in five functional areas analysed remains highly centralized. They surmise that the benefits of decentralization in terms of services and outcomes will be limited. This paper invokes Faguet's (2012) model of local government responsiveness and accountability to explain why this is so - not only for Fiji, but in any country that decentralizes workloads but not the decision space of local governments. A competitive dynamic between economic and civic actors that interact to generate an open, competitive politics, which in turn produces accountable, responsive government can only occur where real power and resources have been devolved to local governments. Where local decision space is lacking, by contrast, decentralization is bound to fail because it has not really happened in the first place. © 2016 The Author(s); Published by Kerman University of Medical Sciences. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

  3. Radar altimetry assimilation in catchment-scale hydrological models

    Science.gov (United States)

    Bauer-Gottwein, P.; Michailovsky, C. I. B.

    2012-04-01

    Satellite-borne radar altimeters provide time series of river and lake levels with global coverage and moderate temporal resolution. Current missions can detect rivers down to a minimum width of about 100m, depending on local conditions around the virtual station. Water level time series from space-borne radar altimeters are an important source of information in ungauged or poorly gauged basins. However, many water resources management applications require information on river discharge. Water levels can be converted into river discharge by means of a rating curve, if sufficient and accurate information on channel geometry, slope and roughness is available. Alternatively, altimetric river levels can be assimilated into catchment-scale hydrological models. The updated models can subsequently be used to produce improved discharge estimates. In this study, a Muskingum routing model for a river network is updated using multiple radar altimetry time series. The routing model is forced with runoff produced by lumped-parameter rainfall-runoff models in each subcatchment. Runoff is uncertain because of errors in the precipitation forcing, structural errors in the rainfall-runoff model as well as uncertain rainfall-runoff model parameters. Altimetric measurements are translated into river reach storage based on river geometry. The Muskingum routing model is forced with a runoff ensemble and storages in the river reaches are updated using a Kalman filter approach. The approach is applied to the Zambezi and Brahmaputra river basins. Assimilation of radar altimetry significantly improves the capability of the models to simulate river discharge.

  4. Using Scaling to Understand, Model and Predict Global Scale Anthropogenic and Natural Climate Change

    Science.gov (United States)

    Lovejoy, S.; del Rio Amador, L.

    2014-12-01

    The atmosphere is variable over twenty orders of magnitude in time (≈10-3 to 1017 s) and almost all of the variance is in the spectral "background" which we show can be divided into five scaling regimes: weather, macroweather, climate, macroclimate and megaclimate. We illustrate this with instrumental and paleo data. Based the signs of the fluctuation exponent H, we argue that while the weather is "what you get" (H>0: fluctuations increasing with scale), that it is macroweather (Hwhite noise and focuses on quasi-periodic variability assumes a spectrum that is in error by a factor of a quadrillion (≈ 1015). Using this scaling framework, we can quantify the natural variability, distinguish it from anthropogenic variability, test various statistical hypotheses and make stochastic climate forecasts. For example, we estimate the probability that the warming is simply a giant century long natural fluctuation is less than 1%, most likely less than 0.1% and estimate return periods for natural warming events of different strengths and durations, including the slow down ("pause") in the warming since 1998. The return period for the pause was found to be 20-50 years i.e. not very unusual; however it immediately follows a 6 year "pre-pause" warming event of almost the same magnitude with a similar return period (30 - 40 years). To improve on these unconditional estimates, we can use scaling models to exploit the long range memory of the climate process to make accurate stochastic forecasts of the climate including the pause. We illustrate stochastic forecasts on monthly and annual scale series of global and northern hemisphere surface temperatures. We obtain forecast skill nearly as high as the theoretical (scaling) predictability limits allow: for example, using hindcasts we find that at 10 year forecast horizons we can still explain ≈ 15% of the anomaly variance. These scaling hindcasts have comparable - or smaller - RMS errors than existing GCM's. We discuss how these

  5. Reconstructing genome-scale metabolic models with merlin.

    Science.gov (United States)

    Dias, Oscar; Rocha, Miguel; Ferreira, Eugénio C; Rocha, Isabel

    2015-04-30

    The Metabolic Models Reconstruction Using Genome-Scale Information (merlin) tool is a user-friendly Java application that aids the reconstruction of genome-scale metabolic models for any organism that has its genome sequenced. It performs the major steps of the reconstruction process, including the functional genomic annotation of the whole genome and subsequent construction of the portfolio of reactions. Moreover, merlin includes tools for the identification and annotation of genes encoding transport proteins, generating the transport reactions for those carriers. It also performs the compartmentalisation of the model, predicting the organelle localisation of the proteins encoded in the genome and thus the localisation of the metabolites involved in the reactions promoted by such enzymes. The gene-proteins-reactions (GPR) associations are automatically generated and included in the model. Finally, merlin expedites the transition from genomic data to draft metabolic models reconstructions exported in the SBML standard format, allowing the user to have a preliminary view of the biochemical network, which can be manually curated within the environment provided by merlin. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  6. Macro Scale Independently Homogenized Subcells for Modeling Braided Composites

    Science.gov (United States)

    Blinzler, Brina J.; Goldberg, Robert K.; Binienda, Wieslaw K.

    2012-01-01

    An analytical method has been developed to analyze the impact response of triaxially braided carbon fiber composites, including the penetration velocity and impact damage patterns. In the analytical model, the triaxial braid architecture is simulated by using four parallel shell elements, each of which is modeled as a laminated composite. Currently, each shell element is considered to be a smeared homogeneous material. The commercial transient dynamic finite element code LS-DYNA is used to conduct the simulations, and a continuum damage mechanics model internal to LS-DYNA is used as the material constitutive model. To determine the stiffness and strength properties required for the constitutive model, a top-down approach for determining the strength properties is merged with a bottom-up approach for determining the stiffness properties. The top-down portion uses global strengths obtained from macro-scale coupon level testing to characterize the material strengths for each subcell. The bottom-up portion uses micro-scale fiber and matrix stiffness properties to characterize the material stiffness for each subcell. Simulations of quasi-static coupon level tests for several representative composites are conducted along with impact simulations.

  7. Research of Model Scale Seawater Intrusion using Geoelectric Method

    Directory of Open Access Journals (Sweden)

    Supriyadi Supriyadi

    2011-08-01

    Full Text Available A depth experience and knowledge are needed in analyzing the prediction of seawater intrusion. We report here a physical modelling for monitoring the model scale of seawater intrusion. The model used in this research is glass basin consists of two parts; soil and seawater. The intrusion of seawater into soil in the glass basin is modelled. The results of 2-D inversion by using software Res2DInv32 showed that the monitoring of seawater intrusion, in soil model scale, can be detected by using Schlumberger configuration resistivity method. The watering process of freshwater into soil caused the electric resistivity value decreased. This phenomenon can be seen from the transition of the resistivity pseudo section before and after the watering process using different cummulative volume of freshwater in different soil. After being intruded by the seawater, the measured soil resistivity is 2.22 Ωm – 5.69 Ωm which means that the soil had been intruded.

  8. Current state of genome-scale modeling in filamentous fungi.

    Science.gov (United States)

    Brandl, Julian; Andersen, Mikael R

    2015-06-01

    The group of filamentous fungi contains important species used in industrial biotechnology for acid, antibiotics and enzyme production. Their unique lifestyle turns these organisms into a valuable genetic reservoir of new natural products and biomass degrading enzymes that has not been used to full capacity. One of the major bottlenecks in the development of new strains into viable industrial hosts is the alteration of the metabolism towards optimal production. Genome-scale models promise a reduction in the time needed for metabolic engineering by predicting the most potent targets in silico before testing them in vivo. The increasing availability of high quality models and molecular biological tools for manipulating filamentous fungi renders the model-guided engineering of these fungal factories possible with comprehensive metabolic networks. A typical fungal model contains on average 1138 unique metabolic reactions and 1050 ORFs, making them a vast knowledge-base of fungal metabolism. In the present review we focus on the current state as well as potential future applications of genome-scale models in filamentous fungi.

  9. Pore-scale modeling of wettability alteration during primary drainage

    Science.gov (United States)

    Kallel, W.; van Dijke, M. I. J.; Sorbie, K. S.; Wood, R.

    2017-03-01

    While carbonate reservoirs are recognized to be weakly-to-moderately oil-wet at the core-scale, pore-scale wettability distributions remain poorly understood. In particular, the wetting state of micropores (pores polar non-hydrocarbon compounds from the oil-phase into the water-phase. We implement a diffusion/adsorption model for these compounds that triggers a wettability alteration from initially water-wet to intermediate-wet conditions. This mechanism is incorporated in a quasi-static pore-network model to which we add a notional time-dependency of the quasi-static invasion percolation mechanism. The model qualitatively reproduces experimental observations where an early rapid wettability alteration involving these small polar species occurred during primary drainage. Interestingly, we could invoke clear differences in the primary drainage patterns by varying both the extent of wettability alteration and the balance between the processes of oil invasion and wetting change. Combined, these parameters dictate the initial water saturation for waterflooding. Indeed, under conditions where oil invasion is slow compared to a fast and relatively strong wetting change, the model results in significant non-zero water saturations. However, for relatively fast oil invasion or small wetting changes, the model allows higher oil saturations at fixed maximum capillary pressures, and invasion of micropores at moderate capillary pressures.

  10. Modeling and Simulation of a lab-scale Fluidised Bed

    Directory of Open Access Journals (Sweden)

    Britt Halvorsen

    2002-04-01

    Full Text Available The flow behaviour of a lab-scale fluidised bed with a central jet has been simulated. The study has been performed with an in-house computational fluid dynamics (CFD model named FLOTRACS-MP-3D. The CFD model is based on a multi-fluid Eulerian description of the phases, where the kinetic theory for granular flow forms the basis for turbulence modelling of the solid phases. A two-dimensional Cartesian co-ordinate system is used to describe the geometry. This paper discusses whether bubble formation and bed height are influenced by coefficient of restitution, drag model and number of solid phases. Measurements of the same fluidised bed with a digital video camera are performed. Computational results are compared with the experimental results, and the discrepancies are discussed.

  11. Censored rainfall modelling for estimation of fine-scale extremes

    Directory of Open Access Journals (Sweden)

    D. Cross

    2018-01-01

    Full Text Available Reliable estimation of rainfall extremes is essential for drainage system design, flood mitigation, and risk quantification. However, traditional techniques lack physical realism and extrapolation can be highly uncertain. In this study, we improve the physical basis for short-duration extreme rainfall estimation by simulating the heavy portion of the rainfall record mechanistically using the Bartlett–Lewis rectangular pulse (BLRP model. Mechanistic rainfall models have had a tendency to underestimate rainfall extremes at fine temporal scales. Despite this, the simple process representation of rectangular pulse models is appealing in the context of extreme rainfall estimation because it emulates the known phenomenology of rainfall generation. A censored approach to Bartlett–Lewis model calibration is proposed and performed for single-site rainfall from two gauges in the UK and Germany. Extreme rainfall estimation is performed for each gauge at the 5, 15, and 60 min resolutions, and considerations for censor selection discussed.

  12. Current state of genome-scale modeling in filamentous fungi

    DEFF Research Database (Denmark)

    Brandl, Julian; Andersen, Mikael Rørdam

    2015-01-01

    The group of filamentous fungi contains important species used in industrial biotechnology for acid, antibiotics and enzyme production. Their unique lifestyle turns these organisms into a valuable genetic reservoir of new natural products and biomass degrading enzymes that has not been used to full...... testing them in vivo. The increasing availability of high quality models and molecular biological tools for manipulating filamentous fungi renders the model-guided engineering of these fungal factories possible with comprehensive metabolic networks. A typical fungal model contains on average 1138 unique...... metabolic reactions and 1050 ORFs, making them a vast knowledge-base of fungal metabolism. In the present review we focus on the current state as well as potential future applications of genome-scale models in filamentous fungi....

  13. Effects of input uncertainty on cross-scale crop modeling

    Science.gov (United States)

    Waha, Katharina; Huth, Neil; Carberry, Peter

    2014-05-01

    The quality of data on climate, soils and agricultural management in the tropics is in general low or data is scarce leading to uncertainty in process-based modeling of cropping systems. Process-based crop models are common tools for simulating crop yields and crop production in climate change impact studies, studies on mitigation and adaptation options or food security studies. Crop modelers are concerned about input data accuracy as this, together with an adequate representation of plant physiology processes and choice of model parameters, are the key factors for a reliable simulation. For example, assuming an error in measurements of air temperature, radiation and precipitation of ± 0.2°C, ± 2 % and ± 3 % respectively, Fodor & Kovacs (2005) estimate that this translates into an uncertainty of 5-7 % in yield and biomass simulations. In our study we seek to answer the following questions: (1) are there important uncertainties in the spatial variability of simulated crop yields on the grid-cell level displayed on maps, (2) are there important uncertainties in the temporal variability of simulated crop yields on the aggregated, national level displayed in time-series, and (3) how does the accuracy of different soil, climate and management information influence the simulated crop yields in two crop models designed for use at different spatial scales? The study will help to determine whether more detailed information improves the simulations and to advise model users on the uncertainty related to input data. We analyse the performance of the point-scale crop model APSIM (Keating et al., 2003) and the global scale crop model LPJmL (Bondeau et al., 2007) with different climate information (monthly and daily) and soil conditions (global soil map and African soil map) under different agricultural management (uniform and variable sowing dates) for the low-input maize-growing areas in Burkina Faso/West Africa. We test the models' response to different levels of input

  14. Scaling behavior of an airplane-boarding model.

    Science.gov (United States)

    Brics, Martins; Kaupužs, Jevgenijs; Mahnke, Reinhard

    2013-04-01

    An airplane-boarding model, introduced earlier by Frette and Hemmer [Phys. Rev. E 85, 011130 (2012)], is studied with the aim of determining precisely its asymptotic power-law scaling behavior for a large number of passengers N. Based on Monte Carlo simulation data for very large system sizes up to N=2(16)=65536, we have analyzed numerically the scaling behavior of the mean boarding time and other related quantities. In analogy with critical phenomena, we have used appropriate scaling Ansätze, which include the leading term as some power of N (e.g., [proportionality]N(α) for ), as well as power-law corrections to scaling. Our results clearly show that α=1/2 holds with a very high numerical accuracy (α=0.5001±0.0001). This value deviates essentially from α=/~0.69, obtained earlier by Frette and Hemmer from data within the range 2≤N≤16. Our results confirm the convergence of the effective exponent α(eff)(N) to 1/2 at large N as observed by Bernstein. Our analysis explains this effect. Namely, the effective exponent α(eff)(N) varies from values about 0.7 for small system sizes to the true asymptotic value 1/2 at N→∞ almost linearly in N(-1/3) for large N. This means that the variation is caused by corrections to scaling, the leading correction-to-scaling exponent being θ≈1/3. We have estimated also other exponents: ν=1/2 for the mean number of passengers taking seats simultaneously in one time step, β=1 for the second moment of t(b), and γ≈1/3 for its variance.

  15. Pore-scale simulation of microbial growth using a genome-scale metabolic model: Implications for Darcy-scale reactive transport

    Science.gov (United States)

    Tartakovsky, G. D.; Tartakovsky, A. M.; Scheibe, T. D.; Fang, Y.; Mahadevan, R.; Lovley, D. R.

    2013-09-01

    Recent advances in microbiology have enabled the quantitative simulation of microbial metabolism and growth based on genome-scale characterization of metabolic pathways and fluxes. We have incorporated a genome-scale metabolic model of the iron-reducing bacteria Geobacter sulfurreducens into a pore-scale simulation of microbial growth based on coupling of iron reduction to oxidation of a soluble electron donor (acetate). In our model, fluid flow and solute transport is governed by a combination of the Navier-Stokes and advection-diffusion-reaction equations. Microbial growth occurs only on the surface of soil grains where solid-phase mineral iron oxides are available. Mass fluxes of chemical species associated with microbial growth are described by the genome-scale microbial model, implemented using a constraint-based metabolic model, and provide the Robin-type boundary condition for the advection-diffusion equation at soil grain surfaces. Conventional models of microbially-mediated subsurface reactions use a lumped reaction model that does not consider individual microbial reaction pathways, and describe reactions rates using empirically-derived rate formulations such as the Monod-type kinetics. We have used our pore-scale model to explore the relationship between genome-scale metabolic models and Monod-type formulations, and to assess the manifestation of pore-scale variability (microenvironments) in terms of apparent Darcy-scale microbial reaction rates. The genome-scale model predicted lower biomass yield, and different stoichiometry for iron consumption, in comparison to prior Monod formulations based on energetics considerations. We were able to fit an equivalent Monod model, by modifying the reaction stoichiometry and biomass yield coefficient, that could effectively match results of the genome-scale simulation of microbial behaviors under excess nutrient conditions, but predictions of the fitted Monod model deviated from those of the genome-scale model

  16. Pore-scale simulation of microbial growth using a genome-scale metabolic model: Implications for Darcy-scale reactive transport

    Energy Technology Data Exchange (ETDEWEB)

    Tartakovsky, Guzel D.; Tartakovsky, Alexandre M.; Scheibe, Timothy D.; Fang, Yilin; Mahadevan, Radhakrishnan; Lovley, Derek R.

    2013-09-07

    Recent advances in microbiology have enabled the quantitative simulation of microbial metabolism and growth based on genome-scale characterization of metabolic pathways and fluxes. We have incorporated a genome-scale metabolic model of the iron-reducing bacteria Geobacter sulfurreducens into a pore-scale simulation of microbial growth based on coupling of iron reduction to oxidation of a soluble electron donor (acetate). In our model, fluid flow and solute transport is governed by a combination of the Navier-Stokes and advection-diffusion-reaction equations. Microbial growth occurs only on the surface of soil grains where solid-phase mineral iron oxides are available. Mass fluxes of chemical species associated with microbial growth are described by the genome-scale microbial model, implemented using a constraint-based metabolic model, and provide the Robin-type boundary condition for the advection-diffusion equation at soil grain surfaces. Conventional models of microbially-mediated subsurface reactions use a lumped reaction model that does not consider individual microbial reaction pathways, and describe reactions rates using empirically-derived rate formulations such as the Monod-type kinetics. We have used our pore-scale model to explore the relationship between genome-scale metabolic models and Monod-type formulations, and to assess the manifestation of pore-scale variability (microenvironments) in terms of apparent Darcy-scale microbial reaction rates. The genome-scale model predicted lower biomass yield, and different stoichiometry for iron consumption, in comparisonto prior Monod formulations based on energetics considerations. We were able to fit an equivalent Monod model, by modifying the reaction stoichiometry and biomass yield coefficient, that could effectively match results of the genome-scale simulation of microbial behaviors under excess nutrient conditions, but predictions of the fitted Monod model deviated from those of the genome-scale model under

  17. Decentralized Optimization for a Novel Control Structure of HVAC System

    Directory of Open Access Journals (Sweden)

    Shiqiang Wang

    2016-01-01

    Full Text Available A decentralized control structure is introduced into the heating, ventilation, and air conditioning (HVAC system to solve the high maintenance and labor cost problem in actual engineering. Based on this new control system, a decentralized optimization method is presented for sensor fault repair and optimal group control of HVAC equipment. Convergence property of the novel method is theoretically analyzed considering both convex and nonconvex systems with constraints. In this decentralized control system, traditional device is fitted with a control chip such that it becomes a smart device. The smart device can communicate and operate collaboratively with the other devices to accomplish some designated tasks. The effectiveness of the presented method is verified by simulations and hardware tests.

  18. [The nurse in the decentralization process of the health system].

    Science.gov (United States)

    Borges, Maria Aparecida Santa Fé; do Nascimento, Maria Angela Alves

    2004-01-01

    Study about the decentralization process of the health system in the '80s and '90s in the city of Itabuna-BA. It is aimed at describing the city's health decentralization process, identifying the nurse's insertion/participation in this process. Descriptive/qualitative study of exploratory nature that utilized both the semistructured interview and documental analysis for data collection. The results show that the nurse's insertion in the decentralization process took place according to the changes that occurred at every municipal management, where the nurse acted more effectively as the set of circumstances was established and was influenced by the several conjunctures formed by the implemented policies or implemented in each context of the management of the municipal health system.

  19. Membrane bio-reactors for decentralized wastewater treatment and reuse.

    Science.gov (United States)

    Meuler, S; Paris, S; Hackner, T

    2008-01-01

    Decentralized wastewater treatment is the key to sustainable water management because it facilitates effluent (and nutrient) reuse for irrigation or as service water in households. Membrane bioreactors (MBR) can produce effluents of bathing water quality. Septic tanks can be retrofitted to MBR units. Package MBR plants for wastewater or grey water treatment are also available. Systems for decentralized treatment and reuse of domestic wastewater or grey water are also feasible for hotels, condominiums and apartment or office complexes. This paper presents the effluent qualities of different decentralized MBR applications. The high effluent quality allows infiltration even in sensitive areas or reuse for irrigation, toilet flushing and cleaning proposes in households. Due to the reusability of treated water and the possibility to design the systems for carbon reduction only, these systems can ideally and easily serve to close water and nutrient loops. IWA Publishing 2008.

  20. Decentralized Interleaving of Paralleled Dc-Dc Buck Converters

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Brian B [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rodriguez, Miguel [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sinha, Mohit [University of Minnesota; Dhople, Sairaj [University of Minnesota; Poon, Jason [University of California at Berkeley

    2017-08-21

    We present a decentralized control strategy that yields switch interleaving among parallel-connected dc-dc buck converters. The proposed method is based on the digital implementation of the dynamics of a nonlinear oscillator circuit as the controller. Each controller is fully decentralized, i.e., it only requires the locally measured output current to synthesize the pulse width modulation (PWM) carrier waveform and no communication between different controllers is needed. By virtue of the intrinsic electrical coupling between converters, the nonlinear oscillator-based controllers converge to an interleaved state with uniform phase-spacing across PWM carriers. To the knowledge of the authors, this work presents the first fully decentralized strategy for switch interleaving in paralleled dc-dc buck converters.

  1. FISCAL DECENTRALIZATION DETERMINANTS AND LOCAL ECONOMIC DEVELOPMENT IN EU COUNTRIES

    Directory of Open Access Journals (Sweden)

    Anca Florentina GAVRILUŢĂ (VATAMANU

    2017-12-01

    Full Text Available This work aims to assess the impact of fiscal decentralization on local (regional development in the EU Member States while controlling for macroeconomic and local autonomy specific factors. Using a panel data approach with dynamic effects, we examined the implications of fiscal decentralization on local development across European Union countries over the 1990-2004 period. The novelty of the study is emphasized by including in the analysis a variable which tests local fiscal discipline, more exactly, Fiscal Rule Strength Index for local level of government. Our findings suggest that prosperity of regions, measured in GDP growth depends on variables such as characteristics of decentralization undertaken by each country or local fiscal discipline, confirming our primary hypothesis. This supports the view that recently implemented reforms aiming to enforce fiscal discipline following-up the Fiscal Compact strengthened the local budgetary framework and restrained, therefore, the local discretionary power to act towards development.

  2. Smart panel with active damping units. Implementation of decentralized control.

    Science.gov (United States)

    Díaz, Cristóbal González; Paulitsch, Christoph; Gardonio, Paolo

    2008-08-01

    This paper contains the second part of a study on a smart panel with five decentralized velocity feedback control units using proof mass electrodynamic actuators [Gonzalez Diaz et al., J. Acoust. Soc. Am. 124, 886 (2008)]. The implementation of five decentralized control loops is analyzed, both theoretically and experimentally. The stability properties of the five decentralized control units have been assessed with the generalized Nyquist criterion by plotting the loci of the eigenvalues of the fully populated matrix of frequency response functions between the five error signals and five input signals to the amplifiers driving the actuators. The control performance properties have been assessed in terms of the spatially averaged response of the panel measured with a scanning laser vibrometer and the total sound power radiated measured in an anechoic room. The two analyses have shown that reductions of up to 10 dB in both vibration response and sound radiation are measured at low audio frequencies, below about 250 Hz.

  3. Estimating design impact on waste reduction: examining decentralized nursing.

    Science.gov (United States)

    Pati, Debajyoti; Harvey, Thomas E; Thurston, Terry

    2012-11-01

    The objective of this study was to understand the impact that decentralization of nursing support spaces may have on the total distances nurses walk and hence the magnitude of time that can be diverted to productive use. Reducing nurse walking has attracted attention from multiple perspectives-human factor, system performance, lean process, care quality, and safety. A simulation-based experimental study was designed that incorporated task frequency data from a nationwide sample of 700 RNs. The simulation runs were conducted on a 30-bed medical-surgical unit, over 12-hour day shifts, in which physical locations of 8 nursing support spaces were systematically manipulated. Findings suggest that total walking time can be reduced by as much as 67.9%, depending on the level of decentralization. Care quality and efficiency issues can be significantly addressed through appropriate levels of decentralization.

  4. Decentralized Interleaving of Paralleled Dc-Dc Buck Converters: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Brian B [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rodriguez, Miguel [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sinha, Mohit [University of Minnesota; Dhople, Sairaj [University of Minnesota; Poon, Jason [University of California at Berkeley

    2017-09-01

    We present a decentralized control strategy that yields switch interleaving among parallel connected dc-dc buck converters without communication. The proposed method is based on the digital implementation of the dynamics of a nonlinear oscillator circuit as the controller. Each controller is fully decentralized, i.e., it only requires the locally measured output current to synthesize the pulse width modulation (PWM) carrier waveform. By virtue of the intrinsic electrical coupling between converters, the nonlinear oscillator-based controllers converge to an interleaved state with uniform phase-spacing across PWM carriers. To the knowledge of the authors, this work represents the first fully decentralized strategy for switch interleaving of paralleled dc-dc buck converters.

  5. The Bases of Federalism and Decentralization in Education

    Directory of Open Access Journals (Sweden)

    Carlos Ornelas

    2003-05-01

    Full Text Available This essay uses the Weberian-type ideal to define the conceptual bases of federalism and the decentralization of education. Classic federalism, ficticious federalism (corporativism, the origins and the indigenous version of the new federalism are discussed. We conclude that Mexican constitutional federalism is baroque and ambiguous. Based on theory and the experiences of various countries, bureaucratic centralism and its main characteristics are defined. As a contrast, a typology of educational decentralization is developed. Taken into account are its political, judicial and administrative definitions; a distinction is made between delegation and decentralization. It is argued that with the signing of the Agreement for the Modernization of Basic Education, the Mexican government sought to increase its legitimacy without losing control of education.

  6. Chronic hyperglycemia affects bone metabolism in adult zebrafish scale model.

    Science.gov (United States)

    Carnovali, Marta; Luzi, Livio; Banfi, Giuseppe; Mariotti, Massimo

    2016-12-01

    Type II diabetes mellitus is a metabolic disease characterized by chronic hyperglycemia that induce other pathologies including diabetic retinopathy and bone disease. The mechanisms implicated in bone alterations induced by type II diabetes mellitus have been debated for years and are not yet clear because there are other factors involved that hide bone mineral density alterations. Despite this, it is well known that chronic hyperglycemia affects bone health causing fragility, mechanical strength reduction and increased propensity of fractures because of impaired bone matrix microstructure and aberrant bone cells function. Adult Danio rerio (zebrafish) represents a powerful model to study glucose and bone metabolism. Then, the aim of this study was to evaluate bone effects of chronic hyperglycemia in a new type II diabetes mellitus zebrafish model created by glucose administration in the water. Fish blood glucose levels have been monitored in time course experiments and basal glycemia was found increased. After 1 month treatment, the morphology of the retinal blood vessels showed abnormalities resembling to the human diabetic retinopathy. The adult bone metabolism has been evaluated in fish using the scales as read-out system. The scales of glucose-treated fish didn't depose new mineralized matrix and shown bone resorption lacunae associated with an intense osteoclast activity. In addition, hyperglycemic fish scales have shown a significant decrease of alkaline phosphatase activity and increase of tartrate-resistant acid phosphatase activity, in association with alterations in other bone-specific markers. These data indicates an imbalance in bone metabolism, which leads to the osteoporotic-like phenotype visualized through scale mineral matrix staining. The zebrafish model of hyperglycemic damage can contribute to elucidate in vivo the molecular mechanisms of metabolic changes, which influence the bone tissues regulation in human diabetic patients.

  7. Scaling predictive modeling in drug development with cloud computing.

    Science.gov (United States)

    Moghadam, Behrooz Torabi; Alvarsson, Jonathan; Holm, Marcus; Eklund, Martin; Carlsson, Lars; Spjuth, Ola

    2015-01-26

    Growing data sets with increased time for analysis is hampering predictive modeling in drug discovery. Model building can be carried out on high-performance computer clusters, but these can be expensive to purchase and maintain. We have evaluated ligand-based modeling on cloud computing resources where computations are parallelized and run on the Amazon Elastic Cloud. We trained models on open data sets of varying sizes for the end points logP and Ames mutagenicity and compare with model building parallelized on a traditional high-performance computing cluster. We show that while high-performance computing results in faster model building, the use of cloud computing resources is feasible for large data sets and scales well within cloud instances. An additional advantage of cloud computing is that the costs of predictive models can be easily quantified, and a choice can be made between speed and economy. The easy access to computational resources with no up-front investments makes cloud computing an attractive alternative for scientists, especially for those without access to a supercomputer, and our study shows that it enables cost-efficient modeling of large data sets on demand within reasonable time.

  8. Klobuchar-like Ionospheric Model for Different Scales Areas

    Directory of Open Access Journals (Sweden)

    LIU Chen

    2017-05-01

    Full Text Available Nowadays, Klobuchar is the most widely used ionospheric model in the positioning based on single-frequency terminal, and its different refined models have been proposed for a higher and higher accuracy of positioning. The variation of nighttime TEC with local time and the variation of TEC (total electron content with latitude have been analyzed using GIMs. After summarizing the model refinement schemes with wide applications, we proposed a Klobuchar-like model for regions with different scales in this paper. The Klobuchar-like, 14-paramaters Klobuchar and 8-paramaters Klobuchar models were established for the small, large and global regions by GIMs (global ionospheric maps in different solar activity periods and seasons, respectively. Klobuchar-like models, with the correction rates of 92.96%, 91.55% and 72.67% respectively in the small, large and global regions, have higher correction rates than 14-paramaters Klobuchar,8-paramaters Klobuchar and GPS Klobuchar models, which have verified the effectiveness and practicability of Klobuchar-like model.

  9. Electron-scale reduced fluid models with gyroviscous effects

    Science.gov (United States)

    Passot, T.; Sulem, P. L.; Tassi, E.

    2017-08-01

    Reduced fluid models for collisionless plasmas including electron inertia and finite Larmor radius corrections are derived for scales ranging from the ion to the electron gyroradii. Based either on pressure balance or on the incompressibility of the electron fluid, they respectively capture kinetic Alfvén waves (KAWs) or whistler waves (WWs), and can provide suitable tools for reconnection and turbulence studies. Both isothermal regimes and Landau fluid closures permitting anisotropic pressure fluctuations are considered. For small values of the electron beta parameter e$ , a perturbative computation of the gyroviscous force valid at scales comparable to the electron inertial length is performed at order e)$ , which requires second-order contributions in a scale expansion. Comparisons with kinetic theory are performed in the linear regime. The spectrum of transverse magnetic fluctuations for strong and weak turbulence energy cascades is also phenomenologically predicted for both types of waves. In the case of moderate ion to electron temperature ratio, a new regime of KAW turbulence at scales smaller than the electron inertial length is obtained, where the magnetic energy spectrum decays like \\bot -13/3$ , thus faster than the \\bot -11/3$ spectrum of WW turbulence.

  10. The multi-scale aerosol-climate model PNNL-MMF: model description and evaluation

    Directory of Open Access Journals (Sweden)

    M. Wang

    2011-03-01

    Full Text Available Anthropogenic aerosol effects on climate produce one of the largest uncertainties in estimates of radiative forcing of past and future climate change. Much of this uncertainty arises from the multi-scale nature of the interactions between aerosols, clouds and large-scale dynamics, which are difficult to represent in conventional general circulation models (GCMs. In this study, we develop a multi-scale aerosol-climate model that treats aerosols and clouds across different scales, and evaluate the model performance, with a focus on aerosol treatment. This new model is an extension of a multi-scale modeling framework (MMF model that embeds a cloud-resolving model (CRM within each grid column of a GCM. In this extension, the effects of clouds on aerosols are treated by using an explicit-cloud parameterized-pollutant (ECPP approach that links aerosol and chemical processes on the large-scale grid with statistics of cloud properties and processes resolved by the CRM. A two-moment cloud microphysics scheme replaces the simple bulk microphysics scheme in the CRM, and a modal aerosol treatment is included in the GCM. With these extensions, this multi-scale aerosol-climate model allows the explicit simulation of aerosol and chemical processes in both stratiform and convective clouds on a global scale.

    Simulated aerosol budgets in this new model are in the ranges of other model studies. Simulated gas and aerosol concentrations are in reasonable agreement with observations (within a factor of 2 in most cases, although the model underestimates black carbon concentrations at the surface by a factor of 2–4. Simulated aerosol size distributions are in reasonable agreement with observations in the marine boundary layer and in the free troposphere, while the model underestimates the accumulation mode number concentrations near the surface, and overestimates the accumulation mode number concentrations in the middle and upper free troposphere by a factor

  11. Analysis and modeling of scale-invariance in plankton abundance

    CERN Document Server

    Pelletier, J D

    1996-01-01

    The power spectrum, $S$, of horizontal transects of plankton abundance are often observed to have a power-law dependence on wavenumber, $k$, with exponent close to $-2$: $S(k)\\propto k^{-2}$ over a wide range of scales. I present power spectral analyses of aircraft lidar measurements of phytoplankton abundance from scales of 1 to 100 km. A power spectrum $S(k)\\propto k^{-2}$ is obtained. As a model for this observation, I consider a stochastic growth equation where the rate of change of plankton abundance is determined by turbulent mixing, modeled as a diffusion process in two dimensions, and exponential growth with a stochastically variable net growth rate representing a fluctuating environment. The model predicts a lognormal distribution of abundance and a power spectrum of horizontal transects $S(k)\\propto k^{-1.8}$, close to the observed spectrum. The model equation predicts that the power spectrum of variations in abundance in time at a point in space is $S(f)\\propto f^{-1.5}$ (where $f$ is the frequency...

  12. Multi-scale modeling of carbon capture systems

    Energy Technology Data Exchange (ETDEWEB)

    Kress, Joel David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-03

    The development and scale up of cost effective carbon capture processes is of paramount importance to enable the widespread deployment of these technologies to significantly reduce greenhouse gas emissions. The U.S. Department of Energy initiated the Carbon Capture Simulation Initiative (CCSI) in 2011 with the goal of developing a computational toolset that would enable industry to more effectively identify, design, scale up, operate, and optimize promising concepts. The first half of the presentation will introduce the CCSI Toolset consisting of basic data submodels, steady-state and dynamic process models, process optimization and uncertainty quantification tools, an advanced dynamic process control framework, and high-resolution filtered computationalfluid- dynamics (CFD) submodels. The second half of the presentation will describe a high-fidelity model of a mesoporous silica supported, polyethylenimine (PEI)-impregnated solid sorbent for CO2 capture. The sorbent model includes a detailed treatment of transport and amine-CO2- H2O interactions based on quantum chemistry calculations. Using a Bayesian approach for uncertainty quantification, we calibrate the sorbent model to Thermogravimetric (TGA) data.

  13. European Continental Scale Hydrological Model, Limitations and Challenges

    Science.gov (United States)

    Rouholahnejad, E.; Abbaspour, K.

    2014-12-01

    The pressures on water resources due to increasing levels of societal demand, increasing conflict of interest and uncertainties with regard to freshwater availability create challenges for water managers and policymakers in many parts of Europe. At the same time, climate change adds a new level of pressure and uncertainty with regard to freshwater supplies. On the other hand, the small-scale sectoral structure of water management is now reaching its limits. The integrated management of water in basins requires a new level of consideration where water bodies are to be viewed in the context of the whole river system and managed as a unit within their basins. In this research we present the limitations and challenges of modelling the hydrology of the continent Europe. The challenges include: data availability at continental scale and the use of globally available data, streamgauge data quality and their misleading impacts on model calibration, calibration of large-scale distributed model, uncertainty quantification, and computation time. We describe how to avoid over parameterization in calibration process and introduce a parallel processing scheme to overcome high computation time. We used Soil and Water Assessment Tool (SWAT) program as an integrated hydrology and crop growth simulator to model water resources of the Europe continent. Different components of water resources are simulated and crop yield and water quality are considered at the Hydrological Response Unit (HRU) level. The water resources are quantified at subbasin level with monthly time intervals for the period of 1970-2006. The use of a large-scale, high-resolution water resources models enables consistent and comprehensive examination of integrated system behavior through physically-based, data-driven simulation and provides the overall picture of water resources temporal and spatial distribution across the continent. The calibrated model and results provide information support to the European Water

  14. Systems metabolic engineering: Genome-scale models and beyond

    Science.gov (United States)

    Blazeck, John; Alper, Hal

    2010-01-01

    The advent of high throughput genome-scale bioinformatics has led to an exponential increase in available cellular system data. Systems metabolic engineering attempts to use data-driven approaches – based on the data collected with high throughput technologies – to identify gene targets and optimize phenotypical properties on a systems level. Current systems metabolic engineering tools are limited for predicting and defining complex phenotypes such as chemical tolerances and other global, multigenic traits. The most pragmatic systems-based tool for metabolic engineering to arise is the in silico genome-scale metabolic reconstruction. This tool has seen wide adoption for modeling cell growth and predicting beneficial gene knockouts, and we examine here how this approach can be expanded for novel organisms. This review will highlight advances of the systems metabolic engineering approach with a focus on de novo development and use of genome-scale metabolic reconstructions for metabolic engineering applications. We will then discuss the challenges and prospects for this emerging field to enable model-based metabolic engineering. Specifically, we argue that current state-of-the-art systems metabolic engineering techniques represent a viable first step for improving product yield that still must be followed by combinatorial techniques or random strain mutagenesis to achieve optimal cellular systems. PMID:20151446

  15. Systems metabolic engineering: genome-scale models and beyond.

    Science.gov (United States)

    Blazeck, John; Alper, Hal

    2010-07-01

    The advent of high throughput genome-scale bioinformatics has led to an exponential increase in available cellular system data. Systems metabolic engineering attempts to use data-driven approaches--based on the data collected with high throughput technologies--to identify gene targets and optimize phenotypical properties on a systems level. Current systems metabolic engineering tools are limited for predicting and defining complex phenotypes such as chemical tolerances and other global, multigenic traits. The most pragmatic systems-based tool for metabolic engineering to arise is the in silico genome-scale metabolic reconstruction. This tool has seen wide adoption for modeling cell growth and predicting beneficial gene knockouts, and we examine here how this approach can be expanded for novel organisms. This review will highlight advances of the systems metabolic engineering approach with a focus on de novo development and use of genome-scale metabolic reconstructions for metabolic engineering applications. We will then discuss the challenges and prospects for this emerging field to enable model-based metabolic engineering. Specifically, we argue that current state-of-the-art systems metabolic engineering techniques represent a viable first step for improving product yield that still must be followed by combinatorial techniques or random strain mutagenesis to achieve optimal cellular systems.

  16. Transfer Routing of Ore Yard by Decentralized Agent Method

    OpenAIRE

    Kikuchi, Junji; Konishi, Masami; Nishi, Tatsushi; Imai, Jun

    2006-01-01

    In steel works, iron ores are stored in ore yard and sent to various plants of down stream accoding to transfer requests. To attain stable operation, it is neccesary to keep a certain allowable stock level in ore tanks of all plants. To this purpose, ore transfer routing method has been developed based on decentralized agent method. In case of disaster such as a big earthquake or a big fire, damages in the facilities of industrial complex may be unavoidable. In this paper, decentralized optim...

  17. From micro-scale 3D simulations to macro-scale model of periodic porous media

    Science.gov (United States)

    Crevacore, Eleonora; Tosco, Tiziana; Marchisio, Daniele; Sethi, Rajandrea; Messina, Francesca

    2015-04-01

    In environmental engineering, the transport of colloidal suspensions in porous media is studied to understand the fate of potentially harmful nano-particles and to design new remediation technologies. In this perspective, averaging techniques applied to micro-scale numerical simulations are a powerful tool to extrapolate accurate macro-scale models. Choosing two simplified packing configurations of soil grains and starting from a single elementary cell (module), it is possible to take advantage of the periodicity of the structures to reduce the computation costs of full 3D simulations. Steady-state flow simulations for incompressible fluid in laminar regime are implemented. Transport simulations are based on the pore-scale advection-diffusion equation, that can be enriched introducing also the Stokes velocity (to consider the gravity effect) and the interception mechanism. Simulations are carried on a domain composed of several elementary modules, that serve as control volumes in a finite volume method for the macro-scale method. The periodicity of the medium involves the periodicity of the flow field and this will be of great importance during the up-scaling procedure, allowing relevant simplifications. Micro-scale numerical data are treated in order to compute the mean concentration (volume and area averages) and fluxes on each module. The simulation results are used to compare the micro-scale averaged equation to the integral form of the macroscopic one, making a distinction between those terms that could be computed exactly and those for which a closure in needed. Of particular interest it is the investigation of the origin of macro-scale terms such as the dispersion and tortuosity, trying to describe them with micro-scale known quantities. Traditionally, to study the colloidal transport many simplifications are introduced, such those concerning ultra-simplified geometry that usually account for a single collector. Gradual removal of such hypothesis leads to a

  18. Research on large-scale wind farm modeling

    Science.gov (United States)

    Ma, Longfei; Zhang, Baoqun; Gong, Cheng; Jiao, Ran; Shi, Rui; Chi, Zhongjun; Ding, Yifeng

    2017-01-01

    Due to intermittent and adulatory properties of wind energy, when large-scale wind farm connected to the grid, it will have much impact on the power system, which is different from traditional power plants. Therefore it is necessary to establish an effective wind farm model to simulate and analyze the influence wind farms have on the grid as well as the transient characteristics of the wind turbines when the grid is at fault. However we must first establish an effective WTGs model. As the doubly-fed VSCF wind turbine has become the mainstream wind turbine model currently, this article first investigates the research progress of doubly-fed VSCF wind turbine, and then describes the detailed building process of the model. After that investigating the common wind farm modeling methods and pointing out the problems encountered. As WAMS is widely used in the power system, which makes online parameter identification of the wind farm model based on off-output characteristics of wind farm be possible, with a focus on interpretation of the new idea of identification-based modeling of large wind farms, which can be realized by two concrete methods.

  19. A Goddard Multi-Scale Modeling System with Unified Physics

    Science.gov (United States)

    Tao, Wei-Kuo

    2010-01-01

    A multi-scale modeling system with unified physics has been developed at NASA Goddard Space Flight Center (GSFC). The system consists of an MMF, the coupled NASA Goddard finite-volume GCM (fvGCM) and Goddard Cumulus Ensemble model (GCE, a CRM); the state-of-the-art Weather Research and Forecasting model (WRF) and the stand alone GCE. These models can share the same microphysical schemes, radiation (including explicitly calculated cloud optical properties), and surface models that have been developed, improved and tested for different environments. In this talk, I will present: (1) A brief review on GCE model and its applications on the impact of the aerosol on deep precipitation processes, (2) The Goddard MMF and the major difference between two existing MMFs (CSU MMF and Goddard MMF), and preliminary results (the comparison with traditional GCMs), and (3) A discussion on the Goddard WRF version (its developments and applications). We are also performing the inline tracer calculation to comprehend the physical processes (i.e., boundary layer and each quadrant in the boundary layer) related to the development and structure of hurricanes and mesoscale convective systems. In addition, high - resolution (spatial. 2km, and temporal, I minute) visualization showing the model results will be presented.

  20. Relating the CMSSM and SUGRA models with GUT scale and Super-GUT scale Supersymmetry Breaking

    CERN Document Server

    Dudas, Emilian; Mustafayev, Azar; Olive, Keith A.

    2012-01-01

    While the constrained minimal supersymmetric standard model (CMSSM) with universal gaugino masses, $m_{1/2}$, scalar masses, $m_0$, and A-terms, $A_0$, defined at some high energy scale (usually taken to be the GUT scale) is motivated by general features of supergravity models, it does not carry all of the constraints imposed by minimal supergravity (mSUGRA). In particular, the CMSSM does not impose a relation between the trilinear and bilinear soft supersymmetry breaking terms, $B_0 = A_0 - m_0$, nor does it impose the relation between the soft scalar masses and the gravitino mass, $m_0 = m_{3/2}$. As a consequence, $\\tan \\beta$ is computed given values of the other CMSSM input parameters. By considering a Giudice-Masiero (GM) extension to mSUGRA, one can introduce new parameters to the K\\"ahler potential which are associated with the Higgs sector and recover many of the standard CMSSM predictions. However, depending on the value of $A_0$, one may have a gravitino or a neutralino dark matter candidate. We al...

  1. Light moduli in almost no-scale models

    Energy Technology Data Exchange (ETDEWEB)

    Buchmueller, Wilfried; Moeller, Jan; Schmidt, Jonas

    2009-09-15

    We discuss the stabilization of the compact dimension for a class of five-dimensional orbifold supergravity models. Supersymmetry is broken by the superpotential on a boundary. Classically, the size L of the fifth dimension is undetermined, with or without supersymmetry breaking, and the effective potential is of no-scale type. The size L is fixed by quantum corrections to the Kaehler potential, the Casimir energy and Fayet-Iliopoulos (FI) terms localized at the boundaries. For an FI scale of order M{sub GUT}, as in heterotic string compactifications with anomalous U(1) symmetries, one obtains L{proportional_to}1/M{sub GUT}. A small mass is predicted for the scalar fluctuation associated with the fifth dimension, m{sub {rho}}

  2. Density Functional Theory and Materials Modeling at Atomistic Length Scales

    Directory of Open Access Journals (Sweden)

    Swapan K. Ghosh

    2002-04-01

    Full Text Available Abstract: We discuss the basic concepts of density functional theory (DFT as applied to materials modeling in the microscopic, mesoscopic and macroscopic length scales. The picture that emerges is that of a single unified framework for the study of both quantum and classical systems. While for quantum DFT, the central equation is a one-particle Schrodinger-like Kohn-Sham equation, the classical DFT consists of Boltzmann type distributions, both corresponding to a system of noninteracting particles in the field of a density-dependent effective potential, the exact functional form of which is unknown. One therefore approximates the exchange-correlation potential for quantum systems and the excess free energy density functional or the direct correlation functions for classical systems. Illustrative applications of quantum DFT to microscopic modeling of molecular interaction and that of classical DFT to a mesoscopic modeling of soft condensed matter systems are highlighted.

  3. Next-generation genome-scale models for metabolic engineering.

    Science.gov (United States)

    King, Zachary A; Lloyd, Colton J; Feist, Adam M; Palsson, Bernhard O

    2015-12-01

    Constraint-based reconstruction and analysis (COBRA) methods have become widely used tools for metabolic engineering in both academic and industrial laboratories. By employing a genome-scale in silico representation of the metabolic network of a host organism, COBRA methods can be used to predict optimal genetic modifications that improve the rate and yield of chemical production. A new generation of COBRA models and methods is now being developed--encompassing many biological processes and simulation strategies-and next-generation models enable new types of predictions. Here, three key examples of applying COBRA methods to strain optimization are presented and discussed. Then, an outlook is provided on the next generation of COBRA models and the new types of predictions they will enable for systems metabolic engineering. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Decentralization in the Philippines : Stgrengthening Local Government Financing and Resource Management in the Short Term

    OpenAIRE

    World Bank

    2004-01-01

    This report reviews two facets of decentralization currently engaging policy-makers: 1) the sources of financing under decentralization, and, 2) cross-cutting processes to strengthen the accountability of resource use. It does not assess whether decentralization is justified in the Philippines - it approaches the arrangements as they exist, and explicitly focuses on actions that could be f...

  5. Education Decentralization in Sub-Saharan Africa--Espoused Theories and Theories in Use.

    Science.gov (United States)

    Naidoo, Jordan P.

    Education decentralization efforts are examined in six primarily rural, sub-Saharan African countries--Ghana, Mali, Nigeria, Tanzania, Uganda, and Zimbabwe. Stated reasons do not always reflect the real underlying rationales for decentralization. Education decentralization that is publicly advocated to improve service delivery and local…

  6. Transient Recharge Estimability Through Field-Scale Groundwater Model Calibration.

    Science.gov (United States)

    Knowling, Matthew J; Werner, Adrian D

    2017-11-01

    The estimation of recharge through groundwater model calibration is hampered by the nonuniqueness of recharge and aquifer parameter values. It has been shown recently that the estimability of spatially distributed recharge through calibration of steady-state models for practical situations (i.e., real-world, field-scale aquifer settings) is limited by the need for excessive amounts of hydraulic-parameter and groundwater-level data. However, the extent to which temporal recharge variability can be informed through transient model calibration, which involves larger water-level datasets, but requires the additional consideration of storage parameters, is presently unknown for practical situations. In this study, time-varying recharge estimates, inferred through calibration of a field-scale highly parameterized groundwater model, are systematically investigated subject to changes in (1) the degree to which hydraulic parameters including hydraulic conductivity (K) and specific yield (S y ) are constrained, (2) the number of water-level calibration targets, and (3) the temporal resolution (up to monthly time steps) at which recharge is estimated. The analysis involves the use of a synthetic reality (a reference model) based on a groundwater model of Uley South Basin, South Australia. Identifiability statistics are used to evaluate the ability of recharge and hydraulic parameters to be estimated uniquely. Results show that reasonable estimates of monthly recharge (recharge root-mean-squared error) require a considerable amount of transient water-level data, and that the spatial distribution of K is known. Joint estimation of recharge, S y and K, however, precludes reasonable inference of recharge and hydraulic parameter values. We conclude that the estimation of temporal recharge variability through calibration may be impractical for real-world settings. © 2017, National Ground Water Association.

  7. Evaluation of a distributed catchment scale water balance model

    Science.gov (United States)

    Troch, Peter A.; Mancini, Marco; Paniconi, Claudio; Wood, Eric F.

    1993-01-01

    The validity of some of the simplifying assumptions in a conceptual water balance model is investigated by comparing simulation results from the conceptual model with simulation results from a three-dimensional physically based numerical model and with field observations. We examine, in particular, assumptions and simplifications related to water table dynamics, vertical soil moisture and pressure head distributions, and subsurface flow contributions to stream discharge. The conceptual model relies on a topographic index to predict saturation excess runoff and on Philip's infiltration equation to predict infiltration excess runoff. The numerical model solves the three-dimensional Richards equation describing flow in variably saturated porous media, and handles seepage face boundaries, infiltration excess and saturation excess runoff production, and soil driven and atmosphere driven surface fluxes. The study catchments (a 7.2 sq km catchment and a 0.64 sq km subcatchment) are located in the North Appalachian ridge and valley region of eastern Pennsylvania. Hydrologic data collected during the MACHYDRO 90 field experiment are used to calibrate the models and to evaluate simulation results. It is found that water table dynamics as predicted by the conceptual model are close to the observations in a shallow water well and therefore, that a linear relationship between a topographic index and the local water table depth is found to be a reasonable assumption for catchment scale modeling. However, the hydraulic equilibrium assumption is not valid for the upper 100 cm layer of the unsaturated zone and a conceptual model that incorporates a root zone is suggested. Furthermore, theoretical subsurface flow characteristics from the conceptual model are found to be different from field observations, numerical simulation results, and theoretical baseflow recession characteristics based on Boussinesq's groundwater equation.

  8. Device Scale Modeling of Solvent Absorption using MFIX-TFM

    Energy Technology Data Exchange (ETDEWEB)

    Carney, Janine E. [National Energy Technology Lab. (NETL), Albany, OR (United States); Finn, Justin R. [National Energy Technology Lab. (NETL), Albany, OR (United States); Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States)

    2016-10-01

    Recent climate change is largely attributed to greenhouse gases (e.g., carbon dioxide, methane) and fossil fuels account for a large majority of global CO2 emissions. That said, fossil fuels will continue to play a significant role in the generation of power for the foreseeable future. The extent to which CO2 is emitted needs to be reduced, however, carbon capture and sequestration are also necessary actions to tackle climate change. Different approaches exist for CO2 capture including both post-combustion and pre-combustion technologies, oxy-fuel combustion and/or chemical looping combustion. The focus of this effort is on post-combustion solvent-absorption technology. To apply CO2 technologies at commercial scale, the availability and maturity and the potential for scalability of that technology need to be considered. Solvent absorption is a proven technology but not at the scale needed by typical power plant. The scale up and down and design of laboratory and commercial packed bed reactors depends heavily on the specific knowledge of two-phase pressure drop, liquid holdup, the wetting efficiency and mass transfer efficiency as a function of operating conditions. Simple scaling rules often fail to provide proper design. Conventional reactor design modeling approaches will generally characterize complex non-ideal flow and mixing patterns using simplified and/or mechanistic flow assumptions. While there are varying levels of complexity used within these approaches, none of these models resolve the local velocity fields. Consequently, they are unable to account for important design factors such as flow maldistribution and channeling from a fundamental perspective. Ideally design would be aided by development of predictive models based on truer representation of the physical and chemical processes that occur at different scales. Computational fluid dynamic (CFD) models are based on multidimensional flow equations with first

  9. Workshop on Human Activity at Scale in Earth System Models

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Melissa R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Aziz, H. M. Abdul [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Coletti, Mark A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kennedy, Joseph H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Nair, Sujithkumar S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Omitaomu, Olufemi A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-01-26

    Changing human activity within a geographical location may have significant influence on the global climate, but that activity must be parameterized in such a way as to allow these high-resolution sub-grid processes to affect global climate within that modeling framework. Additionally, we must have tools that provide decision support and inform local and regional policies regarding mitigation of and adaptation to climate change. The development of next-generation earth system models, that can produce actionable results with minimum uncertainties, depends on understanding global climate change and human activity interactions at policy implementation scales. Unfortunately, at best we currently have only limited schemes for relating high-resolution sectoral emissions to real-time weather, ultimately to become part of larger regions and well-mixed atmosphere. Moreover, even our understanding of meteorological processes at these scales is imperfect. This workshop addresses these shortcomings by providing a forum for discussion of what we know about these processes, what we can model, where we have gaps in these areas and how we can rise to the challenge to fill these gaps.

  10. Modelling biological invasions: Individual to population scales at interfaces

    KAUST Repository

    Belmonte-Beitia, J.

    2013-10-01

    Extracting the population level behaviour of biological systems from that of the individual is critical in understanding dynamics across multiple scales and thus has been the subject of numerous investigations. Here, the influence of spatial heterogeneity in such contexts is explored for interfaces with a separation of the length scales characterising the individual and the interface, a situation that can arise in applications involving cellular modelling. As an illustrative example, we consider cell movement between white and grey matter in the brain which may be relevant in considering the invasive dynamics of glioma. We show that while one can safely neglect intrinsic noise, at least when considering glioma cell invasion, profound differences in population behaviours emerge in the presence of interfaces with only subtle alterations in the dynamics at the individual level. Transport driven by local cell sensing generates predictions of cell accumulations along interfaces where cell motility changes. This behaviour is not predicted with the commonly used Fickian diffusion transport model, but can be extracted from preliminary observations of specific cell lines in recent, novel, cryo-imaging. Consequently, these findings suggest a need to consider the impact of individual behaviour, spatial heterogeneity and especially interfaces in experimental and modelling frameworks of cellular dynamics, for instance in the characterisation of glioma cell motility. © 2013 Elsevier Ltd.

  11. A Dynamic Pore-Scale Model of Imbibition

    DEFF Research Database (Denmark)

    Mogensen, Kristian; Stenby, Erling Halfdan

    1998-01-01

    We present a dynamic pore-scale network model of imbibition, capable of calculating residual oil saturation for any given capillary number, viscosity ratio, contact angle and aspect ratio. Our goal is not to predict the outcome of core floods, but rather to perform a sensitivity analysis of the a......We present a dynamic pore-scale network model of imbibition, capable of calculating residual oil saturation for any given capillary number, viscosity ratio, contact angle and aspect ratio. Our goal is not to predict the outcome of core floods, but rather to perform a sensitivity analysis...... of the above-mentioned parameters, except the viscosity ratio. We find that contact angle, aspect ratio and capillary number all have a significant influence on the competition between piston-like advance, leading to high recovery, and snap-off, causing oil entrapment. Due to enormous CPU-time requirements we...... been entirely inhibited, in agreement with results obtained by Blunt using a quasi-static model. For higher aspect ratios, the effect of rate and contact angle is more pronounced. Many core floods are conducted at capillary numbers in the range 10 to10.6. We believe that the excellent recoveries...

  12. Challenges of Modeling Flood Risk at Large Scales

    Science.gov (United States)

    Guin, J.; Simic, M.; Rowe, J.

    2009-04-01

    Flood risk management is a major concern for many nations and for the insurance sector in places where this peril is insured. A prerequisite for risk management, whether in the public sector or in the private sector is an accurate estimation of the risk. Mitigation measures and traditional flood management techniques are most successful when the problem is viewed at a large regional scale such that all inter-dependencies in a river network are well understood. From an insurance perspective the jury is still out there on whether flood is an insurable peril. However, with advances in modeling techniques and computer power it is possible to develop models that allow proper risk quantification at the scale suitable for a viable insurance market for flood peril. In order to serve the insurance market a model has to be event-simulation based and has to provide financial risk estimation that forms the basis for risk pricing, risk transfer and risk management at all levels of insurance industry at large. In short, for a collection of properties, henceforth referred to as a portfolio, the critical output of the model is an annual probability distribution of economic losses from a single flood occurrence (flood event) or from an aggregation of all events in any given year. In this paper, the challenges of developing such a model are discussed in the context of Great Britain for which a model has been developed. The model comprises of several, physically motivated components so that the primary attributes of the phenomenon are accounted for. The first component, the rainfall generator simulates a continuous series of rainfall events in space and time over thousands of years, which are physically realistic while maintaining the statistical properties of rainfall at all locations over the model domain. A physically based runoff generation module feeds all the rivers in Great Britain, whose total length of stream links amounts to about 60,000 km. A dynamical flow routing

  13. Upscaling hydraulic conductivity from measurement-scale to model-scale

    Science.gov (United States)

    Gunnink, Jan; Stafleu, Jan; Maljers, Densie; Schokker, Jeroen

    2013-04-01

    The Geological Survey of the Netherlands systematically produces both shallow (uncertainty of the model results to be calculated. One of the parameters that is subsequently assigned to the voxels in the GeoTOP model, is hydraulic conductivity (both horizontal and vertical). Hydraulic conductivities are measured on samples taken from high-quality drillings, which are subjected to falling head hydraulic conductivity tests. Samples are taken for all combinations of lithostratigraphy, facies and lithology that are present in the GeoTOP model. The volume of the samples is orders of magnitude smaller than the volume of a voxel in the GeoTOP model. Apart from that, the heterogeneity that occurs within a voxel is not accounted for in the GeoTOP model, since every voxel gets a single lithology that is deemed representative for the entire voxel To account for both the difference in volume and the within-voxel heterogeneity, an upscaling procedure is developed to produce up-scaled hydraulic conductivities for each GeoTOP voxel. A very fine 3D grid of 0.5 x 0.5 x 0.05 m is created that covers the GeoTOP voxel size (100 x 100 x 0.5 m) plus half of the dimensions of the GeoTOP voxel to counteract undesired edge-effects. It is assumed that the scale of the samples is comparable to the voxel size of this fine grid. For each lithostratigraphy and facies combination the spatial correlation structure (variogram) of the lithological classes is used to create 50 equiprobable distributions of lithology for the fine grid with sequential indicator simulation. Then, for each of the lithology realizations, a hydraulic conductivity is assigned to the simulated lithology class, using Sequential Gaussian Simulation, again with the appropriate variogram This results in 50 3D models of hydraulic conductivities on the fine grid. For each of these hydraulic conductivity models, a hydraulic head difference of 1m between top and bottom of the model is used to calculate the flux at the bottom of the

  14. Leptogenesis in GeV-scale seesaw models

    Energy Technology Data Exchange (ETDEWEB)

    Hernández, P.; Kekic, M. [Instituto de Física Corpuscular, Universidad de Valencia and CSIC,Edificio Institutos Investigación, Apt. 22085, Valencia, E-46071 (Spain); López-Pavón, J. [SISSA and INFN Sezione di Trieste,via Bonomea 265, Trieste, 34136 (Italy); Racker, J.; Rius, N. [Instituto de Física Corpuscular, Universidad de Valencia and CSIC,Edificio Institutos Investigación, Apt. 22085, Valencia, E-46071 (Spain)

    2015-10-09

    We revisit the production of leptonic asymmetries in minimal extensions of the Standard Model that can explain neutrino masses, involving extra singlets with Majorana masses in the GeV scale. We study the quantum kinetic equations both analytically, via a perturbative expansion up to third order in the mixing angles, and numerically. The analytical solution allows us to identify the relevant CP invariants, and simplifies the exploration of the parameter space. We find that sizeable lepton asymmetries are compatible with non-degenerate neutrino masses and measurable active-sterile mixings.

  15. Scale Adaptive Simulation Model for the Darrieus Wind Turbine

    DEFF Research Database (Denmark)

    Rogowski, K.; Hansen, Martin Otto Laver; Maroński, R.

    2016-01-01

    the scale adaptive simulation (SAS) approach for performance analysis of a one-bladed Darrieus wind turbine working at a tip speed ratio of 5 and at a blade Reynolds number of 40 000. The three-dimensional incompressible unsteady Navier-Stokes equations are used. Numerical results of aerodynamic loads......Accurate prediction of aerodynamic loads for the Darrieus wind turbine using more or less complex aerodynamic models is still a challenge. One of the problems is the small amount of experimental data available to validate the numerical codes. The major objective of the present study is to examine...

  16. Scale Adaptive Simulation Model for the Darrieus Wind Turbine

    OpenAIRE

    Rogowski, K.; Hansen, Martin Otto Laver; Maroński, R.; Lichota, P.

    2016-01-01

    Accurate prediction of aerodynamic loads for the Darrieus wind turbine using more or less complex aerodynamic models is still a challenge. One of the problems is the small amount of experimental data available to validate the numerical codes. The major objective of the present study is to examine the scale adaptive simulation (SAS) approach for performance analysis of a one-bladed Darrieus wind turbine working at a tip speed ratio of 5 and at a blade Reynolds number of 40 000. The three-dimen...

  17. Evaluation of two pollutant dispersion models over continental scales

    Science.gov (United States)

    Rodriguez, D.; Walker, H.; Klepikova, N.; Kostrikov, A.; Zhuk, Y.

    Two long-range, emergency response models—one based on the particle-in-cell method of pollutant representation (ADPIC/U.S.) the other based on the superposition of Gaussian puffs released periodically in time (EXPRESS/Russia)—are evaluated using perfluorocarbon tracer data from the Across North America Tracer Experiment (ANATEX). The purpose of the study is to assess our current capabilities for simulating continental-scale dispersion processes and to use these assessments as a means to improve our modeling tools. The criteria for judging model performance are based on protocols devised by the Environmental Protection Agency and on other complementary tests. Most of these measures require the formation and analysis of surface concentration footprints (the surface manifestations of tracer clouds, which are sampled over 24-h intervals), whose dimensions, center-of-mass coordinates and integral characteristics provide a basis for comparing observed and calculated concentration distributions. Generally speaking, the plumes associated with the 20 releases of perfluorocarbon (10 each from sources at Glasgow, MT and St. Cloud, MN) in January 1987, are poorly resolved by the sampling network when the source-to-receptor distances are less than about 1000 km. Within this undersampled region, both models chronically overpredict the sampler concentrations. Given this tendency, the computed areas of the surface footprints and their integral concentrations are likewise excessive. When the actual plumes spread out sufficiently for reasonable resolution, the observed ( O) and calculated ( C) footprint areas are usually within a factor of two of one another, thereby suggesting that the models possess some skill in the prediction of long-range diffusion. Deviations in the O and C plume trajectories, as measured by the distances of separation between the plume centroids, are on the other of 125 km d -1 for both models. It appears that the inability of the models to simulate large-scale

  18. Analysis, scale modeling, and full-scale tests of low-level nuclear-waste-drum response to accident environments

    Energy Technology Data Exchange (ETDEWEB)

    Huerta, M.; Lamoreaux, G.H.; Romesberg, L.E.; Yoshimura, H.R.; Joseph, B.J.; May, R.A.

    1983-01-01

    This report describes extensive full-scale and scale-model testing of 55-gallon drums used for shipping low-level radioactive waste materials. The tests conducted include static crush, single-can impact tests, and side impact tests of eight stacked drums. Static crush forces were measured and crush energies calculated. The tests were performed in full-, quarter-, and eighth-scale with different types of waste materials. The full-scale drums were modeled with standard food product cans. The response of the containers is reported in terms of drum deformations and lid behavior. The results of the scale model tests are correlated to the results of the full-scale drums. Two computer techniques for calculating the response of drum stacks are presented. 83 figures, 9 tables.

  19. Optimizing decentralized production-distribution planning problem in a multi-period supply chain network under uncertainty

    Science.gov (United States)

    Nourifar, Raheleh; Mahdavi, Iraj; Mahdavi-Amiri, Nezam; Paydar, Mohammad Mahdi

    2017-09-01

    Decentralized supply chain management is found to be significantly relevant in today's competitive markets. Production and distribution planning is posed as an important optimization problem in supply chain networks. Here, we propose a multi-period decentralized supply chain network model with uncertainty. The imprecision related to uncertain parameters like demand and price of the final product is appropriated with stochastic and fuzzy numbers. We provide mathematical formulation of the problem as a bi-level mixed integer linear programming model. Due to problem's convolution, a structure to solve is developed that incorporates a novel heuristic algorithm based on Kth-best algorithm, fuzzy approach and chance constraint approach. Ultimately, a numerical example is constructed and worked through to demonstrate applicability of the optimization model. A sensitivity analysis is also made.

  20. Diagnostics for stochastic genome-scale modeling via model slicing and debugging.

    Directory of Open Access Journals (Sweden)

    Kevin J Tsai

    Full Text Available Modeling of biological behavior has evolved from simple gene expression plots represented by mathematical equations to genome-scale systems biology networks. However, due to obstacles in complexity and scalability of creating genome-scale models, several biological modelers have turned to programming or scripting languages and away from modeling fundamentals. In doing so, they have traded the ability to have exchangeable, standardized model representation formats, while those that remain true to standardized model representation are faced with challenges in model complexity and analysis. We have developed a model diagnostic methodology inspired by program slicing and debugging and demonstrate the effectiveness of the methodology on a genome-scale metabolic network model published in the BioModels database. The computer-aided identification revealed specific points of interest such as reversibility of reactions, initialization of species amounts, and parameter estimation that improved a candidate cell's adenosine triphosphate production. We then compared the advantages of our methodology over other modeling techniques such as model checking and model reduction. A software application that implements the methodology is available at http://gel.ym.edu.tw/gcs/.