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Sample records for controls directional chain

  1. Direct current hopping conductance along DNA chain

    Institute of Scientific and Technical Information of China (English)

    Ma Song-Shan; Xu Hui; Liu Xiao-Liang; Li Ming-Jun

    2007-01-01

    This paper proposes a model of direct current(DC) electron hopping transport in DNA,in which DNA is considered as a binary one-dimensional disordered system.To quantitatively study the DC conductivity in DNA,it numerically calculates the DC conductivity of DNA chains with difierent parameter values.The result shows that the DC conductivity of DNA chain increases with the increase of temperature.And the conductivity of DNA chain is depended on the probability P.which represents the degree of compositional disorder in a DNA sequence to some extent.For P<0.5,the conductivity of DNA chain decreases with the increase of P,while for P≥0.5,the conductivity increases with the increase of p.The DC conductivity in DNA chain also varies with the change of the electric field,it presents non-Ohm's law conductivity characteristics.

  2. Modular magnetic field on the z-direction on a chain of nuclear spin system and quantum Not and Controlled-Not gates

    CERN Document Server

    Lopez, G V

    2012-01-01

    We study the simulation of a single qubit rotation and Controlled-Not gate in a solid state one-dimensional chain of nuclear spins system interacting weakly through an Ising type of interaction with a modular component of the magnetic field in the z-direction, characterized by $B_z(z,t)=Bo(z)\\cos\\delta t$. These qubits are subjected to electromagnetic pulses which determine the transition in the one or two qubits system. We use the fidelity parameter to determine the performance of the Not (N) gate and Controlled-Not (CNOT) gate as a function of the frequency parameter $\\delta$. We found that for $|\\delta|\\le 10^{-3} MHz$, these gates still have good fidelity.

  3. Current Control Strategy of Chain Circuit STATCOM

    Institute of Scientific and Technical Information of China (English)

    WANG Xuan; FU Jian; TENG Letian; SUN Lijing; ZHAO Ruibin; WU Shouyuan; DENG Zhanfeng

    2012-01-01

    In order to study the current control strategy based on the chain circuit static synchronous compensator (STATCOM) dynamic model and the design control system with good stability and tracking accuracy, this paper applies the chain circuit STATCOM small signal AC model, and proposes the following assumptions:

  4. A control model for object virtualization in supply chain management

    NARCIS (Netherlands)

    Verdouw, C.N.; Beulens, A.J.M.; Reijers, H.A.; Vorst, van der J.G.A.J.

    2015-01-01

    Due to the emergence of the Internet of Things, supply chain control can increasingly be based on virtual objects instead of on the direct observation of physical objects. Object virtualization allows the decoupling of control activities from the handling and observing of physical products and resou

  5. Modeling Uncertainty of Directed Movement via Markov Chains

    Directory of Open Access Journals (Sweden)

    YIN Zhangcai

    2015-10-01

    Full Text Available Probabilistic time geography (PTG is suggested as an extension of (classical time geography, in order to present the uncertainty of an agent located at the accessible position by probability. This may provide a quantitative basis for most likely finding an agent at a location. In recent years, PTG based on normal distribution or Brown bridge has been proposed, its variance, however, is irrelevant with the agent's speed or divergent with the increase of the speed; so they are difficult to take into account application pertinence and stability. In this paper, a new method is proposed to model PTG based on Markov chain. Firstly, a bidirectional conditions Markov chain is modeled, the limit of which, when the moving speed is large enough, can be regarded as the Brown bridge, thus has the characteristics of digital stability. Then, the directed movement is mapped to Markov chains. The essential part is to build step length, the state space and transfer matrix of Markov chain according to the space and time position of directional movement, movement speed information, to make sure the Markov chain related to the movement speed. Finally, calculating continuously the probability distribution of the directed movement at any time by the Markov chains, it can be get the possibility of an agent located at the accessible position. Experimental results show that, the variance based on Markov chains not only is related to speed, but also is tending towards stability with increasing the agent's maximum speed.

  6. Coupled motions direct electrons along human microsomal P450 Chains.

    Directory of Open Access Journals (Sweden)

    Christopher R Pudney

    2011-12-01

    Full Text Available Protein domain motion is often implicated in biological electron transfer, but the general significance of motion is not clear. Motion has been implicated in the transfer of electrons from human cytochrome P450 reductase (CPR to all microsomal cytochrome P450s (CYPs. Our hypothesis is that tight coupling of motion with enzyme chemistry can signal "ready and waiting" states for electron transfer from CPR to downstream CYPs and support vectorial electron transfer across complex redox chains. We developed a novel approach to study the time-dependence of dynamical change during catalysis that reports on the changing conformational states of CPR. FRET was linked to stopped-flow studies of electron transfer in CPR that contains donor-acceptor fluorophores on the enzyme surface. Open and closed states of CPR were correlated with key steps in the catalytic cycle which demonstrated how redox chemistry and NADPH binding drive successive opening and closing of the enzyme. Specifically, we provide evidence that reduction of the flavin moieties in CPR induces CPR opening, whereas ligand binding induces CPR closing. A dynamic reaction cycle was created in which CPR optimizes internal electron transfer between flavin cofactors by adopting closed states and signals "ready and waiting" conformations to partner CYP enzymes by adopting more open states. This complex, temporal control of enzyme motion is used to catalyze directional electron transfer from NADPH→FAD→FMN→heme, thereby facilitating all microsomal P450-catalysed reactions. Motions critical to the broader biological functions of CPR are tightly coupled to enzyme chemistry in the human NADPH-CPR-CYP redox chain. That redox chemistry alone is sufficient to drive functionally necessary, large-scale conformational change is remarkable. Rather than relying on stochastic conformational sampling, our study highlights a need for tight coupling of motion to enzyme chemistry to give vectorial electron

  7. Extending Perceived Supply Chain Boundaries to Motivate and Direct Change

    DEFF Research Database (Denmark)

    Englyst, Linda

    2005-01-01

    is argued to lead to different and predictable areas of attention and change. The paper is mainly conceptual, as it is discussed how perception and modeling of a supply chain induces pressures for different directions of change. Supply chain modeling is argued to be a tool to be used actively in change...... management, establishing both the scope for change efforts, and the motivation or urgency to change....

  8. Markov processes and controlled Markov chains

    CERN Document Server

    Filar, Jerzy; Chen, Anyue

    2002-01-01

    The general theory of stochastic processes and the more specialized theory of Markov processes evolved enormously in the second half of the last century. In parallel, the theory of controlled Markov chains (or Markov decision processes) was being pioneered by control engineers and operations researchers. Researchers in Markov processes and controlled Markov chains have been, for a long time, aware of the synergies between these two subject areas. However, this may be the first volume dedicated to highlighting these synergies and, almost certainly, it is the first volume that emphasizes the contributions of the vibrant and growing Chinese school of probability. The chapters that appear in this book reflect both the maturity and the vitality of modern day Markov processes and controlled Markov chains. They also will provide an opportunity to trace the connections that have emerged between the work done by members of the Chinese school of probability and the work done by the European, US, Central and South Ameri...

  9. Building sustainable supply chains: consumer choice or direct management?

    Energy Technology Data Exchange (ETDEWEB)

    Hebditch, David; Blackmore, Emma

    2012-06-15

    Putting a 'carbon label' on products to show how much carbon dioxide is emitted during their production, transport and disposal has been heralded as a powerful route to sustainability within companies' supply chains. Several leading firms have joined the Carbon Trust carbon labelling scheme over the past five years, including UK-based retail giant Tesco, which as early as 2007 promised to use carbon labels on all its products. But earlier this year, the multinational said it was dropping carbon labels and instead directly managing its supply chains. Many other companies are similarly choosing direct management over consumer choice as the most effective route to emission reductions. In so doing, they are shouldering greater responsibility for the emissions and impacts of their supply chains. But environmental concerns must not be allowed to trump development needs and companies must not unfairly disadvantage smaller-scale producers in developing countries.

  10. Operations Management of Logistics and Supply Chain: Issues and Directions

    OpenAIRE

    Xiang Li

    2014-01-01

    There has been consensus that logistics as well as supply chain management is a vital research field, yet with few literature reviews on this topic. This paper sets out to propose some hot issues in the current research, through a review of related literature from the perspective of operations management. In addition, we generate some insights and future research directions in this field.

  11. Polyketide chain length control by chain length factor.

    Science.gov (United States)

    Tang, Yi; Tsai, Shiou-Chuan; Khosla, Chaitan

    2003-10-22

    Bacterial aromatic polyketides are pharmacologically important natural products. A critical parameter that dictates product structure is the carbon chain length of the polyketide backbone. Systematic manipulation of polyketide chain length represents a major unmet challenge in natural product biosynthesis. Polyketide chain elongation is catalyzed by a heterodimeric ketosynthase. In contrast to homodimeric ketosynthases found in fatty acid synthases, the active site cysteine is absent from the one subunit of this heterodimer. The precise role of this catalytically silent subunit has been debated over the past decade. We demonstrate here that this subunit is the primary determinant of polyketide chain length, thereby validating its designation as chain length factor. Using structure-based mutagenesis, we identified key residues in the chain length factor that could be manipulated to convert an octaketide synthase into a decaketide synthase and vice versa. These results should lead to novel strategies for the engineered biosynthesis of hitherto unidentified polyketide scaffolds.

  12. Planning and control in fresh food supply chains

    DEFF Research Database (Denmark)

    Damgaard, Cecilie Maria; Chabada, Lukas; Dukovska-Popovska, Iskra

    2013-01-01

    Purpose The purpose of this paper is to determine the current state of research in the planning and control (P&C) literature in regards to fresh food supply chains (FFSC). Based on the literature review, important research areas are identified and serve as guidelines for defining future research...... directions. Design/methodology/approach The paper is based on a structured literature review of articles with the main focus on P&C of fresh food products. The review is based on a range of published works from main journals on supply chain management over the last 10 years. The gaps and challenges...... directions in this area. Practical implications The paper enhances the focus on P&C in FFSC in practice, and defines important implications for why and how P&C should be practiced from a supply chain perspective. Original/value The paper presents an overview of the literature on P&C issues of fresh food...

  13. Planning and control in fresh food supply chains

    DEFF Research Database (Denmark)

    Damgaard, Cecilie Maria; Chabada, Lukas; Dukovska-Popovska, Iskra;

    2013-01-01

    Purpose The purpose of this paper is to determine the current state of research in the planning and control (P&C) literature in regards to fresh food supply chains (FFSC). Based on the literature review, important research areas are identified and serve as guidelines for defining future research...... directions in this area. Practical implications The paper enhances the focus on P&C in FFSC in practice, and defines important implications for why and how P&C should be practiced from a supply chain perspective. Original/value The paper presents an overview of the literature on P&C issues of fresh food...... directions. Design/methodology/approach The paper is based on a structured literature review of articles with the main focus on P&C of fresh food products. The review is based on a range of published works from main journals on supply chain management over the last 10 years. The gaps and challenges...

  14. Controlling Synfire Chain by Inhibitory Synaptic Input

    Science.gov (United States)

    Shinozaki, Takashi; Câteau, Hideyuki; Urakubo, Hidetoshi; Okada, Masato

    2007-04-01

    The propagation of highly synchronous firings across neuronal networks, called the synfire chain, has been actively studied both theoretically and experimentally. The temporal accuracy and remarkable stability of the propagation have been repeatedly examined in previous studies. However, for such a mode of signal transduction to play a major role in processing information in the brain, the propagation should also be controlled dynamically and flexibly. Here, we show that inhibitory but not excitatory input can bidirectionally modulate the propagation, i.e., enhance or suppress the synchronous firings depending on the timing of the input. Our simulations based on the Hodgkin-Huxley neuron model demonstrate this bidirectional modulation and suggest that it should be achieved with any biologically inspired modeling. Our finding may help describe a concrete scenario of how multiple synfire chains lying in a neuronal network are appropriately controlled to perform significant information processing.

  15. Supply Chain Fragmentation and Spillovers from Foreign Direct Investment

    OpenAIRE

    Lenaerts, K.; B. MERLEVEDE

    2012-01-01

    The literature on FDI spillovers to domestic firm productivity increasingly points to supply chain linkages with multinational firms as the main channel for positive effects. To determine local and multinational firms' relative position in the supply chain, the literature relies on input-output tables. For a panel of Romanian firms we show that the level of industry aggregation in these tables and the commonly applied definitions for vertical spillovers bear an important impact on results. Th...

  16. [Human single chain antibodies directed to tumor necrosis factor].

    Science.gov (United States)

    Vikhrova, M A; Batanova, T A; Lebedev, L R; Shingarova, L N; Frank, L A; Kirpichnikov, M P; Tikunova, N V

    2011-01-01

    Six unique phage antibodies to human TNF have been selected from a combinatorial library of human single chain fragment variable. ELISA and Western-blotting was used to study selected phage antibodies binding with TNF. The specificity of selected antibodies was determined by binding with interferon alpha and gamma, bovine serum albumin, ovalbumin and ubiquitin. Two antibodies, sA1 and sB3, were converted into a soluble single-chain antibody form and their affinity was 2.5 and 13.7 nM respectively.

  17. Supply chain management models, applications, and research directions

    CERN Document Server

    Pardalos, Panos; Romeijn, H

    2005-01-01

    This work brings together some of the most up to date research in the application of operations research and mathematical modeling te- niques to problems arising in supply chain management and e-Commerce. While research in the broad area of supply chain management enc- passes a wide range of topics and methodologies, we believe this book provides a good snapshot of current quantitative modeling approaches, issues, and trends within the field. Each chapter is a self-contained study of a timely and relevant research problem in supply chain mana- ment. The individual works place a heavy emphasis on the application of modeling techniques to real world management problems. In many instances, the actual results from applying these techniques in practice are highlighted. In addition, each chapter provides important mana- rial insights that apply to general supply chain management practice. The book is divided into three parts. The first part contains ch- ters that address the new and rapidly growing role of the inte...

  18. Vaccination with an adenoviral vector encoding the tumor antigen directly linked to invariant chain induces potent CD4(+) T-cell-independent CD8(+) T-cell-mediated tumor control

    DEFF Research Database (Denmark)

    Sorensen, Maria R; Holst, Peter J; Pircher, Hanspeter

    2009-01-01

    Antigen-specific immunotherapy is an attractive strategy for cancer control. In the context of antiviral vaccines, adenoviral vectors have emerged as a favorable means for immunization. Therefore, we chose a strategy combining use of these vectors with another successful approach, namely linkage...... of the vaccine antigen to invariant chain (Ii). To evaluate this strategy we used a mouse model, in which an immunodominant epitope (GP33) of the LCMV glycoprotein (GP) represents the tumor-associated neoantigen. Prophylactic vaccination of C57BL/6 mice with a replication-deficient human adenovirus 5 vector...... the tumor degradation. Finally, Ad-Ii-GP but not Ad-GP vaccination can break the immunological non-reactivity in GP transgenic mice indicating that our vaccine strategy will prove efficient also against endogenous tumor antigens....

  19. Evaluating the modus operandi of construction supply chains using organisation control theory

    Directory of Open Access Journals (Sweden)

    Milind Jagtap

    2015-07-01

    Full Text Available Supply chains are omnipresent. However, the modus operandi of the construction supply chainis not clearly established in the literature. This might be attributable to the character of construction projects and the structure of the construction industry. Formal and informal control mechanisms are well established in retail and manufacturing supply chains which is evident in improved product performance. However, there is a paucity of research on the construction supply chain especially at identifying the interplay of control mechanisms and their relationship with project performance. In the case of large and complex construction projects, the client-contractor relationship requires input control, behaviour control and output control for successful project delivery. In the light of organisation control theory and the existing literature on construction supply chains, this study evaluates the modus operandi of the client-contractor relationship based on three control mechanisms: input control (project risk and reward power, and intra-project communication, behaviour control (opportunism and output control (project performance using a structural equation model. A survey data of 258 construction professionals working on construction projects in India was collected. The study findings reveal that input control, in terms of project risk and reward power, and intraproject communication, largely influence behaviour control in terms of opportunism. However, behaviour controls do not directly affect output control in terms of project performance; rather, a direct effect of the input control mechanism of output control is particularly evident.

  20. Markov chain Monte Carlo methods in directed graphical models

    DEFF Research Database (Denmark)

    Højbjerre, Malene

    Directed graphical models present data possessing a complex dependence structure, and MCMC methods are computer-intensive simulation techniques to approximate high-dimensional intractable integrals, which emerge in such models with incomplete data. MCMC computations in directed graphical models...

  1. Supply chain risk management: review, classification and future research directions

    Directory of Open Access Journals (Sweden)

    Mittal, M.L.

    2011-01-01

    Full Text Available In order to be more efficient, firms have adopted strategies such as outsourcing, global partnerships and lean practices. Although such strategies have tremendous abilities to improve the efficiencies but simultaneously they make the firms vulnerable to market uncertainties, dependencies and disruptions. Moreover, natural calamities and manmade crises have also put negative impact on strategic, operational and tactical performance of supply chains. These factors have triggered the interest of academia and industry to consider the risk issues as prime concerns. To capture the more fine-grained elements of diversified risk issues related to the supply chain we employ a multi-layered top town taxonomy to classify and codify the literature and put forward the probable dimensions for future research. We further study the pool of SCRM literature focusing on coordination, decision making and sector-wise SCRM implementation issues and derive relevant propositions.

  2. Methods for Coordinated Inventory Control in Supply Chain Management

    DEFF Research Database (Denmark)

    Larsen, Christian; Thorstenson, Anders

    2010-01-01

    Purpose of this paper Achieving effective and efficient inventory control in supply chain management is a task that requires insights into the workings of multi-stage inventory systems with uncertainty about future demand and supply. In this paper we analyze and compare two basic principles...... of cases. The set of inventory control policies investigated here is also limited and could be extended in future research. Practical implications Guidelines to supply chain managers for allocating safety stocks in supply chains. What is original/value of paper The comparison of effects of different...

  3. Boundary-controlled spin chains for robust quantum state transfer

    CERN Document Server

    Zwick, Analia; Stolze, Joachim; Osenda, Omar

    2011-01-01

    Quantum state transfer in the presence of noise is one of the main challenges for building quantum computers. We compare the quantum state transfer properties for two classes of qubit chains under the influence of static randomness. In fully engineered chains all nearest-neighbor couplings are tuned in such a way that a single-qubit state can be transferred perfectly between the ends of the chain, while in boundary-controlled chains only the two couplings between the transmitting and receiving qubits and the remainder of the chain can be optimized. We study how the noise in the couplings affects the state transfer fidelity depending on the noise model and strength as well as the chain type and length. We show that the desired level of fidelity and transfer time are important factors in designing a chain. In particular we demonstrate that transfer efficiency comparable or better than that of the most robust engineered systems can also be reached in boundary-controlled chains without the demanding engineering o...

  4. Infinitely dimensional control Markov branching chains in random environments

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    First of all we introduce the concepts of infinitely dimensional control Markov branching chains in random environments (β-MBCRE) and prove the existence of such chains, then we introduce the concepts of conditional generating functionals and random Markov transition functions of such chains and investigate their branching property. Base on these concepts we calculate the moments of the β-MBCRE and obtain the main results of this paper such as extinction probabilities, polarization and proliferation rate. Finally we discuss the classification ofβ-MBCRE according to the different standards.

  5. Methods for Coordinated Inventory Control in Supply Chain Management

    DEFF Research Database (Denmark)

    Larsen, Christian; Thorstenson, Anders

    2010-01-01

    and heuristic control methods for coordination. The numerical results obtained by simulation are compared with the solutions found when inventories in the supply chain are controlled independently of each other. Findings Coordinated inventory control can offer a significant potential for cost reduction...... in a supply chain. However, the resulting inventory allocations are not always obvious without thorough analyses of the coordination effects. Research limitations/implications Some of the conclusions are formed on the basis of numerical examples and future research could involve investigation of a wider set...

  6. Optimal Control and Optimization of Stochastic Supply Chain Systems

    CERN Document Server

    Song, Dong-Ping

    2013-01-01

    Optimal Control and Optimization of Stochastic Supply Chain Systems examines its subject in the context of the presence of a variety of uncertainties. Numerous examples with intuitive illustrations and tables are provided, to demonstrate the structural characteristics of the optimal control policies in various stochastic supply chains and to show how to make use of these characteristics to construct easy-to-operate sub-optimal policies.                 In Part I, a general introduction to stochastic supply chain systems is provided. Analytical models for various stochastic supply chain systems are formulated and analysed in Part II. In Part III the structural knowledge of the optimal control policies obtained in Part II is utilized to construct easy-to-operate sub-optimal control policies for various stochastic supply chain systems accordingly. Finally, Part IV discusses the optimisation of threshold-type control policies and their robustness. A key feature of the book is its tying together of ...

  7. Pose control of the chain composed of magnetic particles using external uniform and gradient magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, J. F., E-mail: zhoujianfeng@njtech.edu.cn; Shao, C. L.; Gu, B. Q. [Nanjing Tech University, School of Mechanical and Power Engineering (China)

    2016-01-15

    Magnetic particles (MPs) are known to respond to a magnetic field and can be moved by magnetic force, which make them good carriers in bioengineering and pharmaceutical engineering. In this paper, a pose control method for the straight chain composed of MPs is proposed, and the chain with one pose can be moved to another position with another pose using alternately employed uniform and gradient magnetic fields. Based on computer simulations, it is revealed that in the uniform magnetic field, the MPs form a straight chain with the same separation space along the field lines, and once the uniform magnetic field rotates, the chain also rotates with the field. In the gradient magnetic field, the MPs move toward the higher field so that the translation of the chain can be realized. The simulation results indicate that while the uniform magnetic field is rotating, there exists certain hysteresis between the chain and the field, and the chain is not straight anymore. So the uniform magnetic field should rest at the target angle for a period to make the chain fully relax to be straight. For nanoMP, its magnetic moment directly determines the gradient magnetic force which is much smaller than the dipole–dipole force among MPs. Therefore, the translation of the chain is much more time-consuming than rotation. To enlarge the translational velocity, it is suggested to increase the size of MPs or the magnetic field gradient.

  8. Emission control strategies for short-chain chloroparaffins in two semi-hypothetical case cities

    DEFF Research Database (Denmark)

    Eriksson, Eva; Revitt, M.; Lützhøft, Hans-Christian Holten;

    2012-01-01

    The short-chain chloroparaffins (SCCP), (C10-13 chloroalkanes) are identified in the European Water Framework Directive, as priority hazardous substances. Within the ScorePP project, the aim is to develop emission control strategies that can be employed to reduce emissions from urban areas into r...

  9. Tunable finite-sized chains to control magnetic relaxation

    Science.gov (United States)

    Ekstrand, Paul D.; Javier, Daniel J.; Gredig, Thomas

    2017-01-01

    The magnetic dynamics of low-dimensional iron ion chains have been studied with regards to the tunable finite-sized chain length using iron phthalocyanine thin films. The deposition temperature varies the diffusion length during thin-film growth by limiting the average crystal size in the range from 40 to 110 nm . Using a method common for single chain magnets, the magnetic relaxation time for each chain length is determined from temporal remanence data and fit to a stretched exponential form in the temperature range below 5 K , the onset for magnetic hysteresis. A temperature-independent master curve is generated by scaling the remanence by its relaxation time to fit the energy barrier for spin reversal, and the single spin-relaxation time. The energy barrier of 95 K is found to be independent of the chain length. In contrast, the single spin-relaxation time increases with longer chains from under 1 ps to 800 ps. We show that thin films provide the nanoarchitecture to control magnetic relaxation and a testbed to study finite-size effects in low-dimensional magnetic systems.

  10. Cybernetic Control in a Supply Chain: Wave Propagation and Resonance

    Directory of Open Access Journals (Sweden)

    Ken Dozier

    2006-10-01

    Full Text Available The cybernetic control and management of production can be improved by an understanding of the dynamics of the supply chains for the production organizations. This paper describes an attempt to better understand the dynamics of a linear supply chain through the application of the normal mode analysis technique of physics. A model is considered in which an organization's response to a perturbation from the steady state is affected by the inertia which the company naturally exhibits. This inertia determines how rapidly an organization can respond to deviations from the steady state of its own inventories and those of the two organizations immediately preceding and following it in the chain. The model equations describe the oscillatory phenomena of the naturally occurring normal modes in the chain, in which waves of deviations from the steady state situation travel forward and backwards through the chain. It would be expected that the most effective cybernetic control occurs when resonant interventions cause either amplification or damping of the deviations from the steady state.

  11. Directed evolution of human heavy chain variable domain (VH) using in vivo protein fitness filter.

    Science.gov (United States)

    Kim, Dong-Sik; Song, Hyung-Nam; Nam, Hyo Jung; Kim, Sung-Geun; Park, Young-Seoub; Park, Jae-Chan; Woo, Eui-Jeon; Lim, Hyung-Kwon

    2014-01-01

    Human immunoglobulin heavy chain variable domains (VH) are promising scaffolds for antigen binding. However, VH is an unstable and aggregation-prone protein, hindering its use for therapeutic purposes. To evolve the VH domain, we performed in vivo protein solubility selection that linked antibiotic resistance to the protein folding quality control mechanism of the twin-arginine translocation pathway of E. coli. After screening a human germ-line VH library, 95% of the VH proteins obtained were identified as VH3 family members; one VH protein, MG2x1, stood out among separate clones expressing individual VH variants. With further screening of combinatorial framework mutation library of MG2x1, we found a consistent bias toward substitution with tryptophan at the position of 50 and 58 in VH. Comparison of the crystal structures of the VH variants revealed that those substitutions with bulky side chain amino acids filled the cavity in the VH interface between heavy and light chains of the Fab arrangement along with the increased number of hydrogen bonds, decreased solvation energy, and increased negative charge. Accordingly, the engineered VH acquires an increased level of thermodynamic stability, reversible folding, and soluble expression. The library built with the VH variant as a scaffold was qualified as most of VH clones selected randomly were expressed as soluble form in E. coli regardless length of the combinatorial CDR. Furthermore, a non-aggregation feature of the selected VH conferred a free of humoral response in mice, even when administered together with adjuvant. As a result, this selection provides an alternative directed evolution pathway for unstable proteins, which are distinct from conventional methods based on the phage display.

  12. Proposition of a modeling and an analysis methodology of integrated reverse logistics chain in the direct chain

    Directory of Open Access Journals (Sweden)

    Faycal Mimouni

    2016-04-01

    Full Text Available Purpose: Propose a modeling and analysis methodology based on the combination of Bayesian networks and Petri networks of the reverse logistics integrated the direct supply chain. Design/methodology/approach: Network modeling by combining Petri and Bayesian network. Findings: Modeling with Bayesian network complimented with Petri network to break the cycle problem in the Bayesian network. Research limitations/implications: Demands are independent from returns. Practical implications: Model can only be used on nonperishable products. Social implications: Legislation aspects: Recycling laws; Protection of environment; Client satisfaction via after sale service. Originality/value: Bayesian network with a cycle combined with the Petri Network.

  13. Proposition of a modeling and an analysis methodology of integrated reverse logistics chain in the direct chain

    Energy Technology Data Exchange (ETDEWEB)

    Mimouni, F.; Abouabdellah, A.

    2016-07-01

    Propose a modeling and analysis methodology based on the combination of Bayesian networks and Petri networks of the reverse logistics integrated the direct supply chain. Network modeling by combining Petri and Bayesian network. Modeling with Bayesian network complimented with Petri network to break the cycle problem in the Bayesian network. Demands are independent from returns. Model can only be used on nonperishable products. Legislation aspects: Recycling laws; Protection of environment; Client satisfaction via after sale service. Bayesian network with a cycle combined with the Petri Network. (Author)

  14. Directional and Attitude Stability Control Kit

    Science.gov (United States)

    2014-07-01

    and Attitude Stability Control Kit Final Progress Report This report outlines progress on the DARPA M3 Program, project “Directional and Attitude ...2 ABSTRACT Number of Papers published in peer-reviewed journals: Number of Papers published in non peer-reviewed journals: Directional and Attitude ...Stability Control Kit Final Progress Report Report Title This report outlines progress on the DARPA M3 Program, project “Directional and Attitude

  15. Microbial pathogen control in the beef chain: recent research advances.

    Science.gov (United States)

    Buncic, Sava; Nychas, George-John; Lee, Michael R F; Koutsoumanis, Kostas; Hébraud, Michel; Desvaux, Mickaël; Chorianopoulos, Nikos; Bolton, Declan; Blagojevic, Bojan; Antic, Dragan

    2014-07-01

    Within a recent EU research project ("ProSafeBeef"), research on foodborne pathogens in the beef chain was conducted by using a longitudinally integrated (fork-to-farm) approach. There is not any "single intervention-single chain point" combination by which the pathogens would be reliably and entirely eliminated from the chain resulting in total prevention of pathogens in beef and products thereof at the consumption time. Rather, a range of control interventions have to be applied at multiple points of the chain, so to achieve an acceptable, ultimate risk reduction. Various novel interventions were developed and evaluated during the project, and are briefly summarized in this paper. They include on-farm measures, risk categorisation of cattle presented for slaughter, hygiene-based measures and antimicrobial treatments applied on hides and/or carcasses during cattle slaughter, those applied during beef processing-storage-distribution, use of Time Temperature Integrator-based indicators of safety, and effective sanitation of surfaces. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Direct Connection between the RII Chain and the Nonautonomous Discrete Modified KdV Lattice

    Directory of Open Access Journals (Sweden)

    Kazuki Maeda

    2013-11-01

    Full Text Available The spectral transformation technique for symmetric RII polynomials is developed. Use of this technique reveals that the nonautonomous discrete modified KdV (nd-mKdV lattice is directly connected with the RII chain. Hankel determinant solutions to the semi-infinite nd-mKdV lattice are also presented.

  17. Agent Control for Reconfigurable Open Kinematic Chain Manipulators

    Directory of Open Access Journals (Sweden)

    Janez Sluga

    2013-10-01

    Full Text Available This paper presents a method for the autonomous control of differently structured open kinematic chains based on multi-agent system technology. The appropriate level of distributing local autonomy (agents to a manipulative structure is defined, which makes it possible to dynamically change the number, type and structure of manipulative components without modifying their behavioural logic. To achieve fast reconfigurable and scalable manipulative systems, a new multi-agent method is developed for controlling the manipulator kinematics. The new method enables independent manipulator structure from the control system because of its structural and system modularity. The proposed method consists of kinematic equations for use in an agent environment, agent motion-planning algorithms, evaluation functions, agent control logic and kinematic algorithms. The results of simulations and real- world experiments demonstrate the usefulness of the approach for different non-redundant and redundant manipulation structures.

  18. Direct Imaging of Deformation and Disorder in Extended-Chain Polymer Fibers

    Science.gov (United States)

    1991-03-01

    Lenhert, T. J. Resch, and W. W. Adams, "Molecular Packing and Crystalline Order in Polybenzobisoxazole and Polybenzobisthiazole Fibers ", in...WL-TR-91-4011 AiAh 1A0 DIRECT IMAGING OF DEFORMATION AND DISORDER IN EXTENDED-CHAIN POLYMER FIBERS David C. Martin Department of Polymer Science and...Deformation and Disorder in Extended-Chain Polymer Fibers 12. PERSONAL AUTHOR(S) David C. Martin 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT (Year

  19. Control of enterprise interfaces for supply chain enterprise modeling

    Energy Technology Data Exchange (ETDEWEB)

    Interrante, L.D. [Sandia National Labs., Albuquerque, NM (United States); Macfarlane, J.F. [Lawrence Berkeley Lab., CA (United States). Information and Computing Sciences Div.

    1995-04-01

    There is a current trend for manufacturing enterprises in a supply chain of a particular industry to join forces in an attempt to promote efficiencies and improve competitive position. Such alliances occur in the context of specific legal and business agreements such that each enterprise retains a majority of its business and manufacturing information as private and shares other information with its trading partners. Shared information may include enterprise demand projections, capacities, finished goods inventories, and aggregate production schedules. Evidence of the trend toward information sharing includes the recent emphases on vendor-managed inventories, quick response, and Electronic Data Interchange (EDI) standards. The increased competition brought on by the global marketplace is driving industries to consider the advantages of trading partner agreements. Aggregate-level forecasts, supply-chain production smoothing, and aggregate-level inventory policies can reduce holding costs, record-keeping overhead, and lead time in product development. The goal of this research is to orchestrate information exchange among trading partners to allow for aggregate-level analysis to enhance supply chain efficiency. The notion of Enterprise Interface Control (EIC) is introduced as a means of accomplishing this end.

  20. Templating as a Chain of Custody Tool for Arms Control

    Energy Technology Data Exchange (ETDEWEB)

    Benz, Jacob M.; Tanner, Jennifer E.; Duckworth, Leesa L.

    2013-06-01

    Historically, templates have been considered for use as a treaty accountable item (TAI) authentication tool, alongside item attributes. Because of this, the use of templates has fallen by the wayside due to the perceived intrusiveness of and handling/storage of template data; especially when compared to the negotiability of unclassified attribute threshold values. However, as a chain of custody tool, templates potentially have a large and important role to play in maintaining confidence in the authenticity of the treaty accountable items as they progress through an arms control regime. In general terms, templating is the process of creating a unique, measurable, and repeatable signature which is representative of the TAI. At any point in time, the signature can be re-measured or re-inspected to verify the signature has not changed. Chain of custody is the process by which a controlled boundary is established and maintained around a TAI to both deter and detect unauthorized access to the item. Typically, this is accomplished by putting a tamper indicating device (TID) on the item or container. The TID now acts as a surrogate for the item itself, and is continually checked to ensure the unique identifier and tamper indicating mechanisms have not changed since last inspection. This in and of itself is a form of templating. A stronger template is one that utilizes a signature of the combined item and container. There are many potential signatures which may be exploited, including radiation-, electromagnetic-, and acoustic-based signatures. This paper/presentation will explore the technology and mechanisms in which templating can be applied to create a more robust chain of custody over treaty accountable items as part of a future arms control regime.

  1. Sparse networks of directly coupled, polymorphic, and functional side chains in allosteric proteins.

    Science.gov (United States)

    Soltan Ghoraie, Laleh; Burkowski, Forbes; Zhu, Mu

    2015-03-01

    Recent studies have highlighted the role of coupled side-chain fluctuations alone in the allosteric behavior of proteins. Moreover, examination of X-ray crystallography data has recently revealed new information about the prevalence of alternate side-chain conformations (conformational polymorphism), and attempts have been made to uncover the hidden alternate conformations from X-ray data. Hence, new computational approaches are required that consider the polymorphic nature of the side chains, and incorporate the effects of this phenomenon in the study of information transmission and functional interactions of residues in a molecule. These studies can provide a more accurate understanding of the allosteric behavior. In this article, we first present a novel approach to generate an ensemble of conformations and an efficient computational method to extract direct couplings of side chains in allosteric proteins, and provide sparse network representations of the couplings. We take the side-chain conformational polymorphism into account, and show that by studying the intrinsic dynamics of an inactive structure, we are able to construct a network of functionally crucial residues. Second, we show that the proposed method is capable of providing a magnified view of the coupled and conformationally polymorphic residues. This model reveals couplings between the alternate conformations of a coupled residue pair. To the best of our knowledge, this is the first computational method for extracting networks of side chains' alternate conformations. Such networks help in providing a detailed image of side-chain dynamics in functionally important and conformationally polymorphic sites, such as binding and/or allosteric sites. © 2014 Wiley Periodicals, Inc.

  2. Sensorless vector and direct torque control

    CERN Document Server

    Vas, Peter

    1998-01-01

    This is the first comprehensive book on sensorless high performance a.c. drives. It is essential reading for anyone interested in acquiring a solid background on sensorless torque-controlled drives. It presents a detailed and unified treatment of sensorless vector-controlled and direct-torque controlled drive systems. It also discusses the applications of artificial intelligence to drives. Where possible, space vector theory is used and emphasis is laid on detailed mathematical and physical analysis. Sensorless drive schemes for different types of permanent magnet synchronous motors, synchronous reluctance motors, and induction motors are also presented. These include more than twenty vector drives e.g. five types of MRAS-based vector drives, and eleven types of direct-torque-controlled (DTC) drives, e.g. the ABB DTC drive. However, torque-controlled switched reluctance motor drives are also discussed due to their emerging importance. The book also covers various drive applications using artificial intellige...

  3. Controlled quantum teleportation and secure direct communication

    Institute of Scientific and Technical Information of China (English)

    Gao Ting; Yan Feng-Li; Wang Zhi-Xi

    2005-01-01

    We present a controlled quantum teleportation protocol. In the protocol, quantum information of an unknown state of a 2-level particle is faithfully transmitted from a sender Alice to a remote receiver Bob via an initially shared triplet of entangled particles under the control of the supervisor Charlie. The distributed entangled particles shared by Alice, Bob and Charlie function as a quantum information channel for faithful transmission. We also propose a controlled and secure direct communication scheme by means of this teleportation. After ensuring the security of the quantum channel, Alice encodes the secret message directly on a sequence of particle states and transmits them to Bob supervised by Charlie using this controlled quantum teleportation. Bob can read out the encoded message directly by the measurement on his qubit. In this scheme, the controlled quantum teleportation transmits Alice's message without revealing any information to a potential eavesdropper. Because there is not a transmission of the qubit carrying the secret message between Alice and Bob in the public channel, it is completely secure for controlled and direct secret communication if perfect quantum channel is used. The special feature of this scheme is that the communication between two sides depends on the agreement of a third side to co-operate.

  4. Direct detection of Streptococcus mutans in human dental plaque by polymerase chain reaction.

    Science.gov (United States)

    Igarashi, T; Yamamoto, A; Goto, N

    1996-10-01

    Streptococcus mutans is an etiological agent in human dental caries. A method for the detection of S. mutans directly from human dental plaque by polymerase chain reaction has been developed. Oligonucleotide primers specific for a portion of the dextranase gene (dexA) of S. mutans Ingbritt (serotype c) were designed to amplify a 1272-bp DNA fragment by polymerase chain reaction. The present method specifically detected S. mutans (serotypes c, e and f), but none of the other mutans streptococci: S. cricetus (serotype a), S. rattus (serotype b), S. sobrinus (serotypes d and g), and S. downei (serotype h), other gram-positive bacteria (16 strains of 12 species of cocci and 18 strains of 12 species of bacilli) nor gram-negative bacteria (1 strain of 1 species of cocci and 20 strains of 18 species of bacilli). The method was capable of detecting 1 pg of the chromosomal DNA purified from S. mutans Ingbritt and as few as 12 colony-forming units of S. mutans cells. The S. mutans cells in human dental plaque were also directly detected. Seventy clinical isolates of S. mutans isolated from the dental plaque of 8 patients were all positive by the polymerase chain reaction. These results suggest that the dexA polymerase chain reaction is suitable for the specific detection and identification of S. mutans.

  5. Climate modification directed by control theory

    CERN Document Server

    Liang, Wang

    2008-01-01

    Climate modification measures to counteract global warming receive some more new attentions in these years. Most current researches only discuss the impact of these measures to climate, but how to design such a climate regulator is still unknown. This paper shows the control theory could give the systematic direction for climate modification. But the control analyzing also reveals that climate modifications should only be regarded as a last-ditch measure.

  6. The Aspects Of Inventory Controlling Instruments Implementation In The System Of Retail Chains Finance Management

    OpenAIRE

    Nataliya Buratchuk

    2014-01-01

    The article deals with issues of implementation of inventory controlling instruments in the system of retail chains finance management. The author suggests expanded classification of methods and instruments of inventory controlling distinguishing 3 groups of specific instruments: logistic controlling instruments, expenditures and supply chains controlling instruments and inventory special controlling mechanisms. Based on investigation of controlling methods and instruments, the approximate li...

  7. Direct measurement of Chern numbers in the diffraction pattern of a Fibonacci chain

    CERN Document Server

    Dareau, A; Aguilera, M Bosch; Bouganne, R; Akkermans, E; Gerbier, F; Beugnon, J

    2016-01-01

    Topological properties are now understood to be a key feature of many different physical systems, from topological insulators to quasicrystals. Such properties are often encoded into integer-valued topological invariants, such as winding or Chern numbers, usually related to transport or spectral measurements. We report on an experiment where the Chern numbers of quasicrystalline structures are directly determined by an interferometric approach. We show that all the possible Chern numbers for finite-length Fibonacci chains can be observed directly in their diffraction pattern. Finally, we also demonstrate quantitatively the stability of these topological invariants with respect to structural disorder.

  8. Efficient Controlled Quantum Secure Direct Communication Protocols

    OpenAIRE

    Patwardhan, Siddharth; Moulick, Subhayan Roy; Prasanta K. Panigrahi

    2015-01-01

    We study controlled quantum secure direct communication (CQSDC), a cryptographic scheme where a sender can send a secret bit-string to an intended recipient, without any secure classical channel, who can obtain the complete bit-string only with the permission of a controller. We report an efficient protocol to realize CQSDC using Cluster state and then go on to construct a (2-3)-CQSDC using Brown state, where a coalition of any two of the three controllers is required to retrieve the complete...

  9. The dynamic relation between management control and governance structure in a supply chain context

    NARCIS (Netherlands)

    Veen, van P.M.G.; Verdaasdonk, P.J.A.

    2009-01-01

    Purpose – The purpose of this paper is to show that local management control systems within supply chain organisations and the governance of supply chains are intertwined and that local control systems and governance structure have an important effect on the functioning of the supply chain. Design/m

  10. The dynamic relation between management control and governance structure in a supply chain context

    NARCIS (Netherlands)

    Veen, van P.M.G.; Verdaasdonk, P.J.A.

    2009-01-01

    Purpose – The purpose of this paper is to show that local management control systems within supply chain organisations and the governance of supply chains are intertwined and that local control systems and governance structure have an important effect on the functioning of the supply chain. Design/m

  11. The dynamic relation between management control and governance structure in a supply chain context

    NARCIS (Netherlands)

    Veen, van P.M.G.; Verdaasdonk, P.J.A.

    2009-01-01

    Purpose – The purpose of this paper is to show that local management control systems within supply chain organisations and the governance of supply chains are intertwined and that local control systems and governance structure have an important effect on the functioning of the supply chain.

  12. Controller-independent bidirectional quantum direct communication

    Science.gov (United States)

    Mohapatra, Amit Kumar; Balakrishnan, S.

    2017-06-01

    Recently, Chang et al. (Quantum Inf Process 14:3515-3522, 2015) proposed a controlled bidirectional quantum direct communication protocol using Bell states. In this work, the significance of Bell states, which are being used as initial states in Chang et al. protocol, is elucidated. The possibility of preparing initial state based on the secret message of the communicants is explored. In doing so, the controller-independent bidirectional quantum direct communication protocol has evolved naturally. It is shown that any communicant cannot read the secret message without knowing the initial states generated by the other communicant. Further, intercept-and-resend attack and information leakage can be avoided. The proposed protocol is like a conversion between two persons without the help of any third person with high-level security.

  13. Metode Direct Polymerase Chain Reaction untuk Melacak Campylobacter sp. pada Daging Ayam (DIRECT POLYMERASE CHAIN REACTION METHOD FOR DETECTION CAMPYLOBACTER SP. OF POULTRY MEAT

    Directory of Open Access Journals (Sweden)

    Andriani .

    2013-08-01

    Full Text Available Campylobacter sp. is the most commonly reported as agent of foodborne zoonosis causing acutegastroenteritis in humans. Poultry meat is considered as a major source of C. jejuni infection in human.The conventional methods for detecting foodborne bacteria is time-consuming which rely on the of thebacteria in culture media, followed by biochemical identification. In this study polymerase chain reaction(PCR technique was used for rapid identification of the pathogenic Campylobacter sp. The samples usedwere 298 chicken carcass with sold in supermarkets and traditional markets, and were carried out inaccordance the isolation protocol ISO/ DIS 10272-1994. Identification was performed using biochemicalAPI Campy. The direct PCR (DPCR assay with two sets of primers was employed for isolation andidentification of C. jejuni and C. coli. The result of the isolation and identification both by conventional orPCR methods showed that chicken carcasses both from supermarket and traditional market werecontaminated with C. jejuni and or C. coli. Prevalence of Campylobacter sp. contamination in chicken meatwas higher by DPCR (62.6% than by conventional (19.8%, indicating that DPCR technique was moresensitive than conventional method with detection limit for C. jejuni was103 cfu/ml.

  14. Inventory Control by Using Speculative Strategies in Dual Channel Supply Chain

    Directory of Open Access Journals (Sweden)

    A. Tetteh

    2014-04-01

    Full Text Available This paper investigates how to control cost of inventory by analyzing the impact of speculation in a dual-supply chain. Manufacturers’ exploit both traditional channel and direct channel independently to deliver goods. A four view Markov chain model was used to formulate total cost performance, with replenishment of inventory in accordance to Poisson process. Our numerical calculations divulge these findings, in the long run; (i increasing speculation with increasing foreign search rate, rises warehouse lost sales (ii increasing speculation, increasing local and foreign search rate with increasing total cost components results in holding cost diminishing aiding collapse of manufactures’ product, (iii as local, foreign or both search rate increase; (a holding cost at warehouse and retailer remains constant but diminishes in its percentage contribution to total cost, (b lost sales cost at warehouse keeps rising, and (c our proposed two-echelon dual-supply chain may perform better than single supply chain, and (iv increasing local and foreign search rate against increasing total cost components, escalate total cost. According to the authors, the issue at hand is: speculation impact on total cost not only creates opportunities for manufacturers to expand their products and gain profit but also produces a hazardous side-effect for it can collapse the product.

  15. Efficient Controlled Quantum Secure Direct Communication Protocols

    Science.gov (United States)

    Patwardhan, Siddharth; Moulick, Subhayan Roy; Panigrahi, Prasanta K.

    2016-07-01

    We study controlled quantum secure direct communication (CQSDC), a cryptographic scheme where a sender can send a secret bit-string to an intended recipient, without any secure classical channel, who can obtain the complete bit-string only with the permission of a controller. We report an efficient protocol to realize CQSDC using Cluster state and then go on to construct a (2-3)-CQSDC using Brown state, where a coalition of any two of the three controllers is required to retrieve the complete message. We argue both protocols to be unconditionally secure and analyze the efficiency of the protocols to show it to outperform the existing schemes while maintaining the same security specifications.

  16. Direct growth of polyaniline chains from N-doped sites of carbon nanotubes.

    Science.gov (United States)

    Haq, Atta Ul; Lim, Joonwon; Yun, Je Moon; Lee, Won Jun; Han, Tae Hee; Kim, Sang Ouk

    2013-11-25

    Polymer grafting from graphitic carbon materials has been pursued for several decades. Unfortunately, currently available methods mostly rely on the harsh chemical treatment of graphitic carbons which causes severe degradation of chemical structure and material properties. A straightforward growth of polyaniline chain from the nitrogen (N)-doped sites of carbon nanotubes (CNTs) is presented. N-doping sites along the CNT wall nucleate the polymerization of aniline, which generates seamless hybrids consisting of polyaniline directly grafted onto the CNT walls. The resultant materials exhibit excellent synergistic electrochemical performance, and can be employed for charge collectors of supercapacitors. This approach introduces an efficient route to hybrid systems consisting of conducting polymers directly grafted from graphitic dopant sites. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Production planning and control of closed-loop supply chains

    NARCIS (Netherlands)

    K. Inderfurth (Karl); R.H. Teunter (Ruud)

    2001-01-01

    textabstractMore and more supply chains emerge that include a return flow of materials. Many original equipment manufacturers are nowadays engaged in the remanufacturing business. In many process industries, production defectives and by-products are reworked. These closed-loop supply chains deserve

  18. Direct observation of dipolar chains in ferrofluids in zero field using cryogenic electron microscopy

    CERN Document Server

    Butter, K; Frederik, P M; Vroege, G J; Philipse, A P

    2003-01-01

    The particle structure of ferrofluids is studied in situ, by cryogenic electron microscopy, on vitrified films of iron and magnetite dispersions. By means of synthesis of iron colloids with controlled particle size and different types of surfactant, dipolar particle interactions can be varied over a broad range, which significantly influences the ferrofluid particle structure. Our experiments on iron dispersions (in contrast to magnetite dispersions) for the first time demonstrate, in ferrofluids in zero field, a transition with increasing particle size from separate particles to linear chains of particles (Butter K, Bomans P H, Frederik P M, Vroege G J and Philipse A P 2003 Nature Mater. 2 88). These chains, already predicted theoretically by de Gennes and Pincus (de Gennes P G and Pincus P A 1970 Phys. Kondens. Mater. 11 189), very much resemble the fluctuating chains found in simulations of dipolar fluids (Weis J J 1998 Mol. Phys. 93 361, Chantrell R W, Bradbury A, Popplewell J and Charles S W 1982 J. Appl...

  19. Modification of Elementary Operational Linear Chains in Compositional Control Unit with Code Sharing

    OpenAIRE

    Aleksander, A.; Larysa, A.; Aleksander, N.

    2009-01-01

    The new design method for compositional microprogram control units with code sharing and elementarization of operational linear chains is proposed. The method targets on reduction in the number of LUT-elements in the combinational part of control unit. Some additional control microinstructions containing codes of the classes of pseudoequivalent chains are used for operational linear chains modification. Proposed method is illustrated by an example. Most desirable GSA characteristics for using...

  20. Fluorescence-based temperature control for polymerase chain reaction.

    Science.gov (United States)

    Sanford, Lindsay N; Wittwer, Carl T

    2014-03-01

    The ability to accurately monitor solution temperature is important for the polymerase chain reaction (PCR). Robust amplification during PCR is contingent on the solution reaching denaturation and annealing temperatures. By correlating temperature to the fluorescence of a passive dye, noninvasive monitoring of solution temperatures is possible. The temperature sensitivity of 22 fluorescent dyes was assessed. Emission spectra were monitored and the change in fluorescence between 45 and 95°C was quantified. Seven dyes decreased in intensity as the temperature increased, and 15 were variable depending on the excitation wavelength. Sulforhodamine B (monosodium salt) exhibited a fold change in fluorescence of 2.85. Faster PCR minimizes cycling times and improves turnaround time, throughput, and specificity. If temperature measurements are accurate, no holding period is required even at rapid speeds. A custom instrument using fluorescence-based temperature monitoring with dynamic feedback control for temperature cycling amplified a fragment surrounding rs917118 from genomic DNA in 3min and 45s using 35 cycles, allowing subsequent genotyping by high-resolution melting analysis. Gold-standard thermocouple readings and fluorescence-based temperature differences were 0.29±0.17 and 0.96±0.26°C at annealing and denaturation, respectively. This new method for temperature cycling may allow faster speeds for PCR than currently considered possible.

  1. Environmental controls: Market incentives v. direct regulation

    Energy Technology Data Exchange (ETDEWEB)

    Kosobud, R.F.; Atallah, D.S. [Univ. of Illinois, Chicago, IL (United States)

    1996-12-31

    Cap-and-trade environmental markets, where the commodities are tradable pollution rights, are being introduced in several closely watched applications as a potentially more cost-effective way of cleaning up the environment than direct or command-and-control (CAC) regulation. In this study, we examine the evidence on control cost savings provided by price and transactions data from the first few years of activity in two markets designed to reduce atmospheric pollution. Some observers of both markets have argued that prices for tradable permits lower than expected, and transactions fewer than expected, are evidence that the markets are not achieving the hoped for savings. It was found, on the contrary, that observed prices point toward more flexible and improved pollution control choices and that the number of transactions has been steadily increasing as market incentives are incorporated into enterprise decisions. These new markets during their first few years are generating, according to our estimates, control cost savings in the neighborhood of one to two billion dollars annually. However, there is evidence that the markets have not yet reached their full potential. In the course of this study, several obstacles to market performance were found that are worthy of attention by policy makers. 13 refs., 4 figs., 1 tab.

  2. Controlling chaos with localized heterogeneous forces in oscillator chains.

    Science.gov (United States)

    Chacón, Ricardo

    2006-10-01

    The effects of decreasing the impulse transmitted by localized periodic pulses on the chaotic behavior of homogeneous chains of coupled nonlinear oscillators are studied. It is assumed that when the oscillators are driven synchronously, i.e., all driving pulses transmit the same impulse, the chains display chaotic dynamics. It is shown that decreasing the impulse transmitted by the pulses of the two free end oscillators results in regularization with the whole array exhibiting frequency synchronization, irrespective of the chain size. A maximum level of amplitude desynchrony as the pulses of the two end oscillators narrow is typically found, which is explained as the result of two competing universal mechanisms: desynchronization induced by localized heterogeneous pulses and oscillation death of the complete chain induced by drastic decreasing of the impulse transmitted by such localized pulses. These findings demonstrate that decreasing the impulse transmitted by localized external forces can suppress chaos and lead to frequency-locked states in networks of dissipative systems.

  3. Enzyme directed formation of un-natural side-chains for covalent surface attachment of proteins.

    Science.gov (United States)

    Cho, Hwayoung; Jaworski, Justyn

    2014-10-01

    The covalent immobilization of proteins onto surfaces is an essential aspect of several fields of research, including proteomics, sensing, heterogeneous biocatalysis, and more broadly biotechnology. Site-specific, covalent attachment of proteins has been achieved in recent years by the use of expanded genetic codes to produce proteins with controlled placement of un-natural amino acids bearing bio-orthogonal functional groups. Unfortunately, the complexity of developing such systems is impractical for most laboratories; hence, a less complicated approach to generating un-natural amino acid side-chains has been employed. Utilizing a straightforward reaction with formylglycine generating enzyme, we use the site-specific modification of engineered proteins to yield un-natural amino acid side-chains for protein immobilization. Using this approach, we demonstrate the controlled immobilization of various enzymes onto a variety of amine coated surfaces. Our results reveal reusability of the immobilized enzymes via this strategy, and furthermore, we find the activity of the immobilized enzymes to remain even after a month of use indicating significant stability of the linkage.

  4. Hybrid Control of Supply Chains: a Structured Exploration from a Systems Perspective

    Directory of Open Access Journals (Sweden)

    Paul W. P. J. Grefen

    2013-07-01

    Full Text Available Supply chains are becoming increasingly complex these days, both in the structure of the chains and in the need for fine-grained, real-time control. This development occurs in many industries, such as manufacturing, logistics, and the service industry. The increasing structural complexity is caused by larger numbers of participating companies in supply chains because of increasing complexity of products and services. Increasing requirements to control are caused by developments like mass-customization, pressure on delivery times, and smaller margins for waste. Maintaining well-structured strategic, tactic, and operational control over these complex supply chains is not an easy task – certainly as they are pressured by end-to-end synchronization requirements and just-in-time demands. Things become even more complex when chains need to be flexible to react to changing requirements to the products or services they deliver. To enable design of well-structured control, clear models of control topologies are required. In this paper, we address this need by exploring supply chain control topologies in an organized fashion. The exploration is based on integrating a supply chain model and a control model in two alternative ways to obtain two extreme models for supply chain control. These two models are next combined to obtain a hybrid chain control model in which control parameters can be adapted to accommodate different circumstances, hence facilitating agility in supply chains and networks. We apply the developed model to a number of case studies to show its usability. The contribution of this paper is the structured analysis of the design space for chain-level control models - not the description of individual new models.

  5. Supply Chain Control Principles in Local Food Production: A Norwegian Case Study

    Directory of Open Access Journals (Sweden)

    Heidi C. Dreyer

    2014-08-01

    Full Text Available Based on an analysis of the supply chain of four producers of local specialty foods, we explore how planning and control principles can be applied to align supply chain capabilities and market requirements. It has been shown that local food struggles with market access, and that the supply chain is one of the obstacles preventing local food producers from gaining a solid market position. We identify a number of features of the local food chain, analyse the obstacles and develop generic designs and control principles for local food producers.

  6. Biotemplated fabrication of size controlled palladium nanoparticle chains

    NARCIS (Netherlands)

    Zhou, Xingfei; Zheng, Lifei; Li, Rong; Li, Bin; Pillai, Saju; Xu, Peng; Zhang, Yi

    2012-01-01

    Metal nanoparticles exhibit unique size- and spatial organization-dependent physical and chemical properties, and have a wide range of applications in various areas including single electron devices, chemical catalysts and biomedicines. In this paper, chains of palladium nanoparticles were obtained

  7. [Comparison of direct microscopy, culture and polymerase chain reaction methods for the diagnosis of cutaneous leishmaniasis].

    Science.gov (United States)

    Ertabaklar, Hatice; Özlem Çalışkan, Serçin; Boduç, Erengül; Ertuğ, Sema

    2015-01-01

    Cutaneous leishmaniasis (CL) is an endemic disease especially in Southeastern Anatolia of Turkey and recently shows a trend for spread to other regions of the country including the Aegean region. The diagnosis of CL is based on combined evaluation of epidemiological data with the clinical symptoms and laboratory findings. Direct microscopic examination and culture methods are mainly used in the routine diagnosis of CL, while molecular methods are mainly used for research. The aim of this study was to detect the presence of Leishmania spp. in samples obtained from CL-suspected patients by using direct microscopy, culture and polymerase chain reaction (PCR) methods and to compare the results. A total of 55 patients who were admitted to Parasitology Laboratory of Adnan Menderes University Hospital, Aydin (located at Aegean region in Turkey), between 2012-2014 were included in the study. Smear preparations from the skin lesions of cases were fixed and stained with Giemsa, and the presence of amastigote forms were evaluated by direct microscopy. NNN medium was used for the cultivation of samples. Total genomic DNA of Leishmania from the samples were extracted with a commercial kit (NucleoSpin Tissue(®) Kit, Macherey-Nagel, Germany) and PCR was performed by using 13A and 13B primers to amplify the 116 base pair fragment of Leishmania spp. specific kinetoplast DNA. Amastigotes were observed in 29 (53%) of the 55 samples by direct microscopy, promastigotes were detected among 34 (62%) samples in culture, and parasite-specific amplicons were revealed in 30 (55%) samples by PCR. All assays were positive in 24 patients while in 18 patients all of the tests yielded negative results. Thirty-seven (67%) out of 55 cases were diagnosed as CL when reactivity in at least one of these three methods were considered as positive. Accordingly the positivity rates of the methods were 78.4% (29/37) for direct microscopy, 92% (34/37) for culture and 81.1% (30/37) for PCR in CL

  8. Impact of Integration of Manufacturaing Planning and Control Systems on Supply Chain Management

    OpenAIRE

    KAWAI, Ayako; SATO, Ryo

    2009-01-01

    Manufacturing planning and control systems (MPCSs, for short) are an essentialelement for supply chain processes today. However, there are few researches whichinclude planning information systems in supply chain models and optimize the wholestructure holistically in spite of the social importance of MPCSs for supply chainmanagement. At present, we do not have any ideas even about process behaviorwhen organizations which have MPCSs are linked in a supply chain. To clarifyfundamental properties...

  9. Effects of Paradoxical and Self-Control Directives in Counseling.

    Science.gov (United States)

    Lopez, Frederick G.; Wambach, Cathrine A.

    1982-01-01

    Subjects (N=32) with recurring procrastination problems were assigned to either of two directive interview conditions (paradoxical or self-control) or to a no-interview control condition. Results indicated both directive groups exhibited generally greater improvement over time than controls and that opposing forms of direction promoted different…

  10. Study on direct-chain diacid modified phenolic resin for Al-alloy casting

    Directory of Open Access Journals (Sweden)

    Yundong JI

    2005-02-01

    Full Text Available Resin coated sand (RCS with phenolic resin matrix can hardly be collapsed when it is used in Al-alloy casting. Adding collapsing agent and reducing the concentration of resin are solutions adopted by workers, but these methods tend to reduce the initial strength of RCS. Synthesis of modified phenolic resin with direct-chain diacid DAn (/JS=6, where n means carbon amount was studied here. The effects of the addition of modifying agent on molecular weight, gel time and softening point were investigated. Optimal addition of DAn (10% phenol was obtained by testing the initial and retained flexural strengths of the modified resin. FT-IR spectra showed that carbonyl shifts to higher wave number. With the use of TG, SEM and strength loss curves, the relation between initial and retained strengths was analysed. Tests on the heated deformation curve, before and after resin modification, show that PF-DA10 has the characteristic of higher initial and retained strengths together.

  11. Manufacturing Research: Self-Directed Control

    Science.gov (United States)

    1991-01-01

    Knudsen Cell over its entire operating range. A topic of continuing interest in PID controllers is the automatic tuning of the PID parameters that...PID map for the Knudsen Cells was explored using commercial automatic tuning PID controllers and software based tuning algorithms. For a complete state...decisions are made by a Hewlett-Packard HP 1000 computer. The HP 1000 sends its control signals to Barber-Colman PID controllers . We took advantage of

  12. [Software and hardware design for the temperature control system of quantitative polymerase chain reaction].

    Science.gov (United States)

    Qiu, Xian-bo; Yuan, Jing-qi; Li, Qi

    2005-07-01

    A temperature control system for quantitive polymerase chain reaction (PCR) is presented in the paper with both software and hardware configuration. The performance of the control system has been improved by optimizing the software and hardware design according to the system's properties. The control system has been proven to have a good repeatability and reliability as well as high control precision.

  13. A Direct Experimental Determination of the Elastic Contribution of Chain Entangling in a Tightly Crosslinked Elastomer

    DEFF Research Database (Denmark)

    Pedersen, Walther Batsberg; Kramer, O.

    1982-01-01

    The experimental result, that the equilibrium force is nearly equal to the pseudoequilibrium force immediately prior to quenching and irradiation, allows the following conclusions: (1) Chain scission during crosslinking is not a serious problem. (2) The network of highly entangled linear chains i...

  14. Hematobiochemical alterations and direct blood polymerase chain reaction detection of Theileria annulata in naturally infected crossbred cows

    Directory of Open Access Journals (Sweden)

    Anita Ganguly

    2015-01-01

    Full Text Available Aim: The aim was to determine hemato-biochemical changes and rapid diagnosis of Theileria annulata in naturally infected crossbred cows. Materials and Methods: Blood samples from lactating crossbred cows (n=40 between 3 and 7 years of age and showing clinical signs of tropical theileriosis were collected, with or without anticoagulant, and analyzed for tropical theileriosis by direct smear, direct blood polymerase chain reaction (PCR detection of merozoite-piroplasm surface antigen (Tams1 gene specific amplicon, estimation of hematological and biochemical parameters. Healthy crossbred cows (n=6, examined free from hemoprotozoan infections were included as control. Results: The infected crossbred cows revealed significantly (p<0.001 lower values of total erythrocytic counts (4.46±0.2× 106/μL, hemoglobin (Hb 6.025±0.39 g%, packed cell volume (17.05±1.1%, mean corpuscular volume (37.94±1.70 fL and mean corpuscular Hb (13.5±0.48 pg; p<0.002 compared with healthy control. The serum samples of infected cows revealed profound (p<0.05 hyponatremia (Na 133.21±2.36 mEq/l and hypocalcemia (Ca 8.39±0.34 mg%. Infected crossbred cows showed a significant increase (p<0.05 of mean serum activity of alanine aminotransferase (61.45±13.36 U/L, aspartate aminotransferase (146.1±20.97 U/L, blood urea nitrogen (28.26±3.90 mg%, creatinine (1.55±0.13 mg%, direct bilirubin (0.33±0.04 mg%; p<0.001 and lactate dehydrogenase (3001.32±167.0 U/L; p<001. Blood direct PCR revealed a 721-bp fragment amplified from the target gene encoding 30-kDa major merozoite surface antigen of T. annulata using specific primer pairs. This assay was positive for all the infected animals. Conclusion: The assessments of hemato-biochemical parameters in T. annulata infected crossbred cows may be useful in understanding disease pathogenesis, prognosis and corrective measures for supportive therapy. Moreover, blood direct PCR can reliably be used for rapid detection of T. annulata

  15. Microbes versus microbes: control of pathogens in the food chain.

    Science.gov (United States)

    Jordan, Kieran; Dalmasso, Marion; Zentek, Juergen; Mader, Anneluise; Bruggeman, Geert; Wallace, John; De Medici, Dario; Fiore, Alfonsina; Prukner-Radovcic, Estella; Lukac, Maja; Axelsson, Lars; Holck, Askild; Ingmer, Hanne; Malakauskas, Mindaugas

    2014-12-01

    Foodborne illness continues as a considerable threat to public health. Despite improved hygiene management systems and increased regulation, pathogenic bacteria still contaminate food, causing sporadic cases of illness and disease outbreaks worldwide. For many centuries, microbial antagonism has been used in food processing to improve food safety. An understanding of the mode of action of this microbial antagonism has been gained in recent years and potential applications in food and feed safety are now being explored. This review focuses on the potential opportunities presented, and the limitations, of using microbial antagonism as a biocontrol mechanism to reduce contamination along the food chain; including animal feed as its first link. © 2014 Society of Chemical Industry.

  16. Evolutional Optimization on Material Ordering and Inventory Control of Supply Chain through Incentive Scheme

    Science.gov (United States)

    Prasertwattana, Kanit; Shimizu, Yoshiaki; Chiadamrong, Navee

    This paper studied the material ordering and inventory control of supply chain systems. The effect of controlling policies is analyzed under three different configurations of the supply chain systems, and the formulated problem has been solved by using an evolutional optimization method known as Differential Evolution (DE). The numerical results show that the coordinating policy with the incentive scheme outperforms the other policies and can improve the performance of the overall system as well as all members under the concept of supply chain management.

  17. DIRECTIONS FOR FUTURE CONSTRUCTION SUPPLY CHAIN MANAGEMENT RESEARCH IN NEW ZEALAND: A REAL OPTIONS PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    Tran, Van

    2012-04-01

    Full Text Available Real Options (RO has been a universally accepted concept in a number of major industries. However, its use in the construction supply chain management (CSCM sector has been limited. Some rare supply chain management RO studies have shown a number of limitations. First, there is a lack of a rigorous theoretical RO framework pertaining specifically to CSCM. All such supply chain management RO studies are based off RO theories or models developed for other sectors (engineering, infrastructure, natural resources. And second, attempts to extend real option to wider uses in CSCM seem premature at the present. This paper reviews all recent literature pertaining to real options and real options applied specifically to the construction supply chain management area. The study proposes a research programme pertaining to CSCM in New Zealand in order to enhance the current understanding of RO in this area and in the process develop a comprehensive theory for the RO application in New Zealand CSCM.

  18. Marzipan: polymerase chain reaction-driven methods for authenticity control.

    Science.gov (United States)

    Brüning, Philipp; Haase, Ilka; Matissek, Reinhard; Fischer, Markus

    2011-11-23

    According to German food guidelines, almonds are the only oilseed ingredient allowed for the production of marzipan. Persipan is a marzipan surrogate in which the almonds are replaced by apricot or peach kernels. Cross-contamination of marzipan products with persipan may occur if both products are produced using the same production line. Adulterations or dilutions, respectively, of marzipan with other plant-derived products, for example, lupine or pea, have also been found. Almond and apricot plants are closely related. Consequently, classical analytical methods for the identification/differentiation often fail or are not sensitive enough to quantify apricot concentrations below 1%. Polymerase chain reaction (PCR)-based methods have been shown to enable the differentiation of closely related plant species in the past. These methods are characterized by high specificity and low detection limits. Isolation methods were developed and evaluated especially with respect to the matrix marzipan in terms of yield, purity, integrity, and amplificability of the isolated DNA. For the reliable detection of apricot, peach, pea, bean, lupine, soy, cashew, pistachio, and chickpea, qualitative standard and duplex PCR methods were developed and established. The applicability of these methods was tested by cross-reaction studies and analysis of spiked raw pastes. Contaminations at the level of 0.1% could be detected.

  19. Directions for rf-controlled intelligent microvalve

    Science.gov (United States)

    Enderling, Stefan; Varadan, Vijay K.; Abbott, Derek

    2001-03-01

    In this paper, we consider the novel concept of a Radio Frequency (RF) controllable microvalve for different medical applications. Wireless communication via a Surface Acoustic Wave Identification-mark (SAW ID-tag) is used to control, drive and locate the microvalve inside the human body. The energy required for these functions is provided by RF pulses, which are transmitted to the valve and back by a reader/transmitter system outside of the body. These RF bursts are converted into Surface Acoustic Waves (SAWs), which propagate along the piezoelectric actuator material of the microvalve. These waves cause deflections, which are employed to open and close the microvalve. We identified five important areas of application of the microvalve in biomedicine: 1) fertility control; 2) artificial venous valves; 3) flow cytometry; 4) drug delivery and 5) DNA mapping.

  20. Optimal control novel directions and applications

    CERN Document Server

    Aronna, Maria; Kalise, Dante

    2017-01-01

    Focusing on applications to science and engineering, this book presents the results of the ITN-FP7 SADCO network’s innovative research in optimization and control in the following interconnected topics: optimality conditions in optimal control, dynamic programming approaches to optimal feedback synthesis and reachability analysis, and computational developments in model predictive control. The novelty of the book resides in the fact that it has been developed by early career researchers, providing a good balance between clarity and scientific rigor. Each chapter features an introduction addressed to PhD students and some original contributions aimed at specialist researchers. Requiring only a graduate mathematical background, the book is self-contained. It will be of particular interest to graduate and advanced undergraduate students, industrial practitioners and to senior scientists wishing to update their knowledge.

  1. Direct Load Control by AC Frequency Modulation

    DEFF Research Database (Denmark)

    Douglass, Philip James; You, Shi

    2012-01-01

    Fine-grained under frequency load shedding called “demand as a frequency controlled reserve“ (DFCR) has been shown to be a promising method of providingfrequency regulation service from distributed loads [1]. Micro-grids with a large portion of intermittent renewable generation will benefit great...

  2. ESTIMATION OF CHAIN REACTION BANKRUPTCY STRUCTURE BY CHANCE DISCOVERY METHOD- WITH TIME ORDER METHOD AND DIRECTED KEYGRAPH

    Institute of Scientific and Technical Information of China (English)

    Shinichi GODA; Yukio OHSAWA

    2007-01-01

    Chain reaction bankruptcy is regarded as common phenomenon and its effect is to be taken into account when credit risk portfolio is analyzed. But consideration and modeling of its effect leave much room for improvement. That is mainly because method for grasping relations among companies with limited data is underdeveloped. In this article, chance discovery method is applied to estimate industrial relations that are to include companies' relations that transmit chain reaction of bankruptcy.Time order method and directed KeyGraph are newly introduced to distinguish and express the time order among defaults that is essential information for the analysis of chain reaction bankruptcy. The steps for the data analysis are introduced and result of example analysis with default data in Kyushu,Japan, 2005 is presented. The structure estimated by the new method is compared with the structure of actual account receivable holders of bankrupted companies for evaluation.

  3. Risk management abilities in multimodal maritime supply chains: Visibility and control perspectives.

    Science.gov (United States)

    Vilko, Jyri; Ritala, Paavo; Hallikas, Jukka

    2016-11-29

    Supply chain complexity and disintegration lead to increased uncertainty from a stakeholders' perspective, which is emerging as one of the major challenges of risk management. The ability to identify risks has weakened, as the responsibility of supply chain risk management is handed over to outside service providers. Regardless, the risks, their visibility and their impact depend on the position of the companies in the supply chain. The actors in the chain must therefore collaborate to create effective risk management conditions. This challenging situation is especially pronounced in multimodal maritime supply chains, where the risks and actor focality are high. This paper contributes to current risk management literature by providing a holistic and systemic view of risk visibility and control in maritime supply chains. The study employs broad-based, qualitative interview data collected from actors operating in southern Finland and the Gulf of Finland as well as an expert-panel assessment of the related risk management abilities. The results show a high level of variance in the level of risk identification and visibility between the actors in question. This further suggests that collaboration in supply chain risk management is essential, as an awareness of the risks and their control mechanisms do not necessarily reside in the same company.

  4. Control Theory Concepts Applied to Retail Supply Chain: A System Dynamics Modeling Environment Study

    Directory of Open Access Journals (Sweden)

    Balaji Janamanchi

    2013-01-01

    Full Text Available Control theory concepts have been long used to successfully manage and optimize complex systems. Using system dynamics (SD modeling methodology, which is continuous deterministic simulation modeling methodology, we apply control theory concepts to develop a suitable performance functional (or objective function that optimizes the performance of a retail supply chain. The focus is to develop insights for inventory management to prevent stock-outs and unfilled orders and to fill customer orders at the lowest possible cost to supply chain partners under different scenarios, in a two-player supplier-retailer supply chain. Moderate levels of inventory, defining appropriate performance functional, appear to be crucial in choosing the right policies for managing retail supply chain systems. The study also demonstrated how multiple objectives can be combined in a single performance functional (or objective function by carefully assigning suitable weights to the components of objectives based on their priority and the existence of possible trade off opportunities.

  5. H∞ Control of Supply Chain Based on Switched Model of Stock Level

    Directory of Open Access Journals (Sweden)

    Junzhi Luo

    2014-01-01

    Full Text Available This paper is concerned with the problem of H∞ control for a class of discrete supply chain systems. A new method based on network control technique is presented to address this issue. Supply chain systems are modeled as networked systems with stochastic time delay. Sufficient conditions for H∞ controller design are given in terms of a set of linear matrix inequalities, based on which the mean-square asymptotic stability as well as H∞ performance is satisfied for such systems. Simulation results are provided to demonstrate the effectiveness of the proposed method.

  6. On dynamic selection of households for direct marketing based on Markov chain models with memory

    NARCIS (Netherlands)

    Otter, Pieter W.

    2007-01-01

    A simple, dynamic selection procedure is proposed, based on conditional, expected profits using Markov chain models with memory. The method is easy to apply, only frequencies and mean values have to be calculated or estimated. The method is empirically illustrated using a data set from a charitable

  7. A direct proof of dimerization in a family of SU( n)-invariant quantum spin chains

    Science.gov (United States)

    Nachtergaele, Bruno; Ueltschi, Daniel

    2017-09-01

    We study the family of spin- S quantum spin chains with a nearest neighbor interaction given by the negative of the singlet projection operator. Using a random loop representation of the partition function in the limit of zero temperature and standard techniques of classical statistical mechanics, we prove dimerization for all sufficiently large values of S.

  8. A direct proof of dimerization in a family of SU(n)-invariant quantum spin chains

    Science.gov (United States)

    Nachtergaele, Bruno; Ueltschi, Daniel

    2017-05-01

    We study the family of spin-S quantum spin chains with a nearest neighbor interaction given by the negative of the singlet projection operator. Using a random loop representation of the partition function in the limit of zero temperature and standard techniques of classical statistical mechanics, we prove dimerization for all sufficiently large values of S.

  9. A New Organo-Directed Titanium Phosphate Phase Containing Zigzag Chains of Corner-Sharing TiO6 Octahedra

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new organo-directed titanium phosphate, [NH3CH2CH2NH3]·[TiO(HPO4)2], was synthesized by the solvothermal method and its structure was determined by single crystal X-ray diffraction. The structure consists of 1-D zigzag chains built up from trans-corner-sharing titanium oxo octahedra running along the b axis, with fused Ti2P three-membered rings being attached to the - Ti - O - Ti - O - backbone.

  10. Genetic control of conventional labeling through the bovine meat production chain by single nucleotide polymorphisms using real-time PCR.

    Science.gov (United States)

    Capoferri, Rossana; Bongioni, Graziella; Galli, Andrea; Aleandri, Riccardo

    2006-08-01

    Since January 2002, the European Union has adopted precise guidelines aimed at protecting the safety of meat and controlling the production chain. To this purpose, the conventional traceability of livestock and meat represents the main tool, but verification of traceability requires genetic support. At present, single nucleotide polymorphisms (SNPs) represent the most innovative molecular markers in genotyping studies. The aim of this study was to verify correct labeling in a bovine meat production chain by a real-time PCR protocol based on SNP analysis. Reference hair samples from 5,000 animals were randomly collected from 22 farms. Twelve hundred meat samples were collected at different steps of the bovine meat production chain. In particular, 1,000 meat samples were collected at the slaughterhouse and 200 samples from the same animals directly at the butcher's shop. The protocol was optimized and validated by testing a set of 16 SNP markers on 95 DNA samples from bovine sires of different breeds. Thereafter, the genotyping of 2,200 samples was conducted with a set of 12 selected SNPs to verify traceability of the meat production chain at three different stages: farm, slaughterhouse, and butcher's shop. Irregularities in conventional traceability were evidenced directly in 1.87% of the samples at the slaughterhouse. This percentage increased to 3.25% when sampling was conducted at the butcher's shop. This study demonstrates that despite the precautions adopted over the meat production chain, some critical points still exist that cause the loss of a correct association between registration numbers and samples.

  11. Meta-QC-Chain: comprehensive and fast quality control method for metagenomic data.

    Science.gov (United States)

    Zhou, Qian; Su, Xiaoquan; Jing, Gongchao; Ning, Kang

    2014-02-01

    Next-generation sequencing (NGS) technology has revolutionized and significantly impacted metagenomic research. However, the NGS data usually contains sequencing artifacts such as low-quality reads and contaminating reads, which will significantly compromise downstream analysis. Many quality control (QC) tools have been proposed, however, few of them have been verified to be suitable or efficient for metagenomic data, which are composed of multiple genomes and are more complex than other kinds of NGS data. Here we present a metagenomic data QC method named Meta-QC-Chain. Meta-QC-Chain combines multiple QC functions: technical tests describe input data status and identify potential errors, quality trimming filters poor sequencing-quality bases and reads, and contamination screening identifies higher eukaryotic species, which are considered as contamination for metagenomic data. Most computing processes are optimized based on parallel programming. Testing on an 8-GB real dataset showed that Meta-QC-Chain trimmed low sequencing-quality reads and contaminating reads, and the whole quality control procedure was completed within 20 min. Therefore, Meta-QC-Chain provides a comprehensive, useful and high-performance QC tool for metagenomic data. Meta-QC-Chain is publicly available for free at: http://computationalbioenergy.org/meta-qc-chain.html.

  12. Information management in DNA replication modeled by directional, stochastic chains with memory

    Science.gov (United States)

    Arias-Gonzalez, J. Ricardo

    2016-11-01

    Stochastic chains represent a key variety of phenomena in many branches of science within the context of information theory and thermodynamics. They are typically approached by a sequence of independent events or by a memoryless Markov process. Stochastic chains are of special significance to molecular biology, where genes are conveyed by linear polymers made up of molecular subunits and transferred from DNA to proteins by specialized molecular motors in the presence of errors. Here, we demonstrate that when memory is introduced, the statistics of the chain depends on the mechanism by which objects or symbols are assembled, even in the slow dynamics limit wherein friction can be neglected. To analyze these systems, we introduce a sequence-dependent partition function, investigate its properties, and compare it to the standard normalization defined by the statistical physics of ensembles. We then apply this theory to characterize the enzyme-mediated information transfer involved in DNA replication under the real, non-equilibrium conditions, reproducing measured error rates and explaining the typical 100-fold increase in fidelity that is experimentally found when proofreading and edition take place. Our model further predicts that approximately 1 kT has to be consumed to elevate fidelity in one order of magnitude. We anticipate that our results are necessary to interpret configurational order and information management in many molecular systems within biophysics, materials science, communication, and engineering.

  13. Coordinated Resolved Motion Control of Dual-arm Manipulators with Closed Chain

    OpenAIRE

    Tianliang Liu; Yan Lei; Liang Han; Wenfu Xu; Huaiwu Zou

    2016-01-01

    When applied to some tasks, such as payload handling, assembling, repairing and so on, the two arms of a humanoid robot will form a closed kinematic chain. It makes the motion planning and control for dual‐arm coordination very complex and difficult. In this paper, we present three types of resolved motion control methods for a humanoid robot during coordinated manipulation. They are, respectively, position‐level, velocity‐level and acceleration‐level resolved motion control methods. The desi...

  14. Modelling and Daisy Chaining Control Allocation of a Multirotor Helicopter with a Single Tilting Rotor

    Directory of Open Access Journals (Sweden)

    Robert Porter

    2016-11-01

    Full Text Available This paper presents the development and implementation of a single tilting rotor multirotor helicopter. A single tilting rotor multirotor helicopter is proposed that allows for decoupled lateral acceleration and attitude states. A dynamics model of the proposed multirotor helicopter is established to enable control system development. A control system architecture and daisy chaining-based control allocation scheme is developed and implemented. The control architecture facilitates the control of decoupled lateral accelerations and attitudes. Further, a computational and experimental analysis is undertaken and offers evidence that the proposed multirotor helicopter and control system architecture enables the multirotor helicopter to achieve lateral accelerations without requiring attitude actuation.

  15. Spatial control of direct chemical vapor deposition of graphene on silicon dioxide by directional copper dewetting

    NARCIS (Netherlands)

    van den Beld, Wesley Theodorus Eduardus; van den Berg, Albert; Eijkel, Jan C.T.

    2016-01-01

    In this paper we present a method for the spatial control of direct graphene synthesis onto silicon dioxide by controlled dewetting. The dewetting process is controlled through a combination of using a grooved substrate and conducting copper deposition at an angle. The substrate is then treated

  16. Spatial control of direct chemical vapor deposition of graphene on silicon dioxide by directional copper dewetting

    NARCIS (Netherlands)

    Beld, van den Wesley T.E.; Berg, van den Albert; Eijkel, Jan C.T.

    2016-01-01

    In this paper we present a method for the spatial control of direct graphene synthesis onto silicon dioxide by controlled dewetting. The dewetting process is controlled through a combination of using a grooved substrate and conducting copper deposition at an angle. The substrate is then treated usin

  17. An Intuitive Definition of Demand Flexibility in Direct Load Control

    DEFF Research Database (Denmark)

    Tahersima, Fatemeh; Madsen, Per Printz; Andersen, Palle

    2013-01-01

    Two control approaches: direct and indirect control of demand side energy management in a smart grid are studied. Indirect control of energy demands is based on economic incentives. In this approach, consumers will shift their energy consumption with the benefit of a cut down in the electricity...

  18. The reference model of supply chain operational controlling in value management

    Directory of Open Access Journals (Sweden)

    2010-03-01

    Full Text Available The systemic approach of the controlling function to supporting the operations management results from its complex analysis of the supply chain business and operating results and from influencing the operations management factors - products, processes and resources that determine the achieved result (revenues, costs, profitability and assets turnover as well as the return on invested capital. All product features which stand for customer value and its competitiveness are the basis for designing, planning and controlling the interconnected processes responsible for manufacturing and delivery of products. The effectiveness of methods applied in developing products, processes and resources depends on the precise analysis and appraisal of the operating conditions that justify their application. Supporting the operations management, focused on the product value and improving the company's financial result, apart from financial, technical and economic analyses requires transferring the product value to activities control methods and to developing the resources in the product supply chain already at the stage of planning. As a result of an analysis of requirements supporting the development of processes and resources in the supply chain, a reference model of operational controlling in product value management was developed. The multicriterion selection and appropriate application of material flow management methods in the supply chain is each time preceded by an operating and financial analysis as well as by an appraisal of operating conditions that influence the choice of control methods.

  19. Controllability of Weighted and Directed Networks with Nonidentical Node Dynamics

    Directory of Open Access Journals (Sweden)

    Linying Xiang

    2013-01-01

    Full Text Available The concept of controllability from control theory is applied to weighted and directed networks with heterogenous linear or linearized node dynamics subject to exogenous inputs, where the nodes are grouped into leaders and followers. Under this framework, the controllability of the controlled network can be decomposed into two independent problems: the controllability of the isolated leader subsystem and the controllability of the extended follower subsystem. Some necessary and/or sufficient conditions for the controllability of the leader-follower network are derived based on matrix theory and graph theory. In particular, it is shown that a single-leader network is controllable if it is a directed path or cycle, but it is uncontrollable for a complete digraph or a star digraph in general. Furthermore, some approaches to improving the controllability of a heterogenous network are presented. Some simulation examples are given for illustration and verification.

  20. Lamellar thickness transition of melt-crystallized polybuten-1 tetragonal phase: configurational change in chain folding directions

    Institute of Scientific and Technical Information of China (English)

    Motoi YAMASHITA

    2009-01-01

    Lamellar crystal thickness lc of isotactic polybutene-1 (it-PB 1) have been investigated for crystal-lization in the melt over a wide range of crystallization temperature T from 40℃ to 90℃ by small angle X-ray scattering experiments and density measurements. The crystal thickness lc demonstrates two linear dependences on inverse supercooling and a transition from one dependence to the other has been observed around T =65~C. Each of the two dependences obeys the nucleation theory in the high and low supercooling ranges, respec-tively. Chain folding free energy q determined from the low supercooling range is larger than that determined from the high supercooling range. Possible mechanisms for the transition are discussed taking account of entropy of chain folding directions.

  1. A new method based on Markov chains for deriving SB2 orbits directly from their spectra

    CERN Document Server

    Salomon, J -B; Guillout, P; Halbwachs, J -L; Arenou, F; Famaey, B; Lebreton, Y; Mazeh, T; Pourbaix, D; Tal-Or, L

    2012-01-01

    We present a new method to derive orbital elements of double-lined spectroscopic binaries (SB2). The aim is to have accurate orbital parameters of a selection of SB2 in order to prepare the exploitation of astrometric Gaia observations. Combined with our results, they should allow one to measure the mass of each star with a precision of better than 1%. The new method presented here consists of using the spectra at all epochs simultaneously to derive the orbital elements without templates. It is based on a Markov chain including a new method for disentangling the spectra.

  2. Foreign direct investment and agribusiness chains of Costa Rica: toward a typology

    Directory of Open Access Journals (Sweden)

    Ivania García Cascante

    2016-06-01

    Full Text Available Using an overall human development index and data from the 2000 and 2011 census, this paper shows how districts with a stronger FDI presence (that is districts producing pineapple and bananas are concentrated in social and economic development positions lower than those districts with mixed or national investment, which are concentrated in intermediate positions (that is districts producing coffee and flowers. This condition is due to the governance exercised by larger companies on the agricultural chains, which generates dependence from small and medium producers to market their products as well as intensive use of low-paid production factors such as workforce.

  3. Multiple Property Cross Direction Control of Paper Machines

    Directory of Open Access Journals (Sweden)

    Markku Ohenoja

    2011-07-01

    Full Text Available Cross direction (CD control in sheet-forming process forms a challenging problem with high dimensions. Accounting the interactions between different properties and actuators, the dimensionality increases further and also computational issues arise. We present a multiple property controller feasible to be used especially with imaging measurements that provide high sampling frequency and therefore enable short control interval. The simulation results state the benefits of multiple property CD control over single property control and single property control using full feedforward compensation. The controller presented may also be tuned in automated manner and the results demonstrate the effect of tuning on input saturation.

  4. Some strong limit theorems for nonhomogeneous Markov chains indexed by controlled trees

    Directory of Open Access Journals (Sweden)

    Weicai Peng

    2016-02-01

    Full Text Available Abstract In this paper, a kind of infinite, local finite tree T, named a controlled tree, is introduced. Some strong limit properties, such as the strong law of large numbers and the asymptotic equipartition property, for nonhomogeneous Markov chains indexed by T, are established. The outcomes are the generalizations of some well-known results.

  5. Multi-level access control in the data pipeline of the international supply chain system

    NARCIS (Netherlands)

    Pruksasri, P.; Berg, J. van den; Hofman, W.; Daskapan, S.

    2013-01-01

    The Seamless Integrated Data Pipeline system was proposed to the European Union in order to overcome the information quality shortcomings of the current international supply chain information exchange systems. Next to identification and authorization of stakeholders, secure access control needs to b

  6. Tobacco Products Directive - new opportunities for EU tobacco control

    Directory of Open Access Journals (Sweden)

    Anna-Eva Ampelas

    2016-03-01

    Full Text Available The Tobacco Products Directive 2014/40/EU was adopted in 2014 and needs to be transposed by Member States by 20 May 2016. It sets out ambitious tobacco control measures in the areas of ingredients, packaging & labelling, electronic cigarettes and tracking & tracing. The new Directive focuses on preventing young people from taking up smoking.

  7. Strategic directions of government control of national information space

    Directory of Open Access Journals (Sweden)

    Ірина Романівна Боднар

    2015-03-01

    Full Text Available The main directions of state information politics are considered. The legal framework and functioning of national information sphere is analyzed. The basic directions of government control of Ukraine's information space are considered. The approaches to the efficiency of the national information system are proposed

  8. DIRECT TORQUE CONTROL FOR INDUCTION MOTOR USING INTELLIGENT TECHNIQUES

    Directory of Open Access Journals (Sweden)

    R.Toufouti

    2007-09-01

    Full Text Available In this paper, we propose two approach intelligent techniques of improvement of Direct Torque Control (DTC of Induction motor such as fuzzy logic (FL and artificial neural network (ANN, applied in switching select voltage vector .The comparison with conventional direct torque control (DTC, show that the use of the DTC_FL and DTC_ANN, reduced the torque, stator flux, and current ripples. The validity of the proposed methods is confirmed by the simulative results.

  9. Qualitative Study to Explore Potential Directions for Improvements of Fruit and Vegetable Supply Chain Management: A Case Study of Malaysian Agrifood Corporation

    OpenAIRE

    Lukmanov, Arman

    2010-01-01

    The research was carried out to investigate the current supply chain management system of Malaysian Agrifood Corporation (MAFC) and recommend further potential directions of improvements of the supply chain management in terms of increasing its effectiveness and efficiency and keeping up with emerging trends and innovations which can be applied to the Malaysian food industry. MAFC is a Malaysian supply chain management company with integrated supply of fresh fruits and vegetables that are...

  10. Chaining direct memory access data transfer operations for compute nodes in a parallel computer

    Science.gov (United States)

    Archer, Charles J.; Blocksome, Michael A.

    2010-09-28

    Methods, systems, and products are disclosed for chaining DMA data transfer operations for compute nodes in a parallel computer that include: receiving, by an origin DMA engine on an origin node in an origin injection FIFO buffer for the origin DMA engine, a RGET data descriptor specifying a DMA transfer operation data descriptor on the origin node and a second RGET data descriptor on the origin node, the second RGET data descriptor specifying a target RGET data descriptor on the target node, the target RGET data descriptor specifying an additional DMA transfer operation data descriptor on the origin node; creating, by the origin DMA engine, an RGET packet in dependence upon the RGET data descriptor, the RGET packet containing the DMA transfer operation data descriptor and the second RGET data descriptor; and transferring, by the origin DMA engine to a target DMA engine on the target node, the RGET packet.

  11. Input estimation for drug discovery using optimal control and Markov chain Monte Carlo approaches.

    Science.gov (United States)

    Trägårdh, Magnus; Chappell, Michael J; Ahnmark, Andrea; Lindén, Daniel; Evans, Neil D; Gennemark, Peter

    2016-04-01

    Input estimation is employed in cases where it is desirable to recover the form of an input function which cannot be directly observed and for which there is no model for the generating process. In pharmacokinetic and pharmacodynamic modelling, input estimation in linear systems (deconvolution) is well established, while the nonlinear case is largely unexplored. In this paper, a rigorous definition of the input-estimation problem is given, and the choices involved in terms of modelling assumptions and estimation algorithms are discussed. In particular, the paper covers Maximum a Posteriori estimates using techniques from optimal control theory, and full Bayesian estimation using Markov Chain Monte Carlo (MCMC) approaches. These techniques are implemented using the optimisation software CasADi, and applied to two example problems: one where the oral absorption rate and bioavailability of the drug eflornithine are estimated using pharmacokinetic data from rats, and one where energy intake is estimated from body-mass measurements of mice exposed to monoclonal antibodies targeting the fibroblast growth factor receptor (FGFR) 1c. The results from the analysis are used to highlight the strengths and weaknesses of the methods used when applied to sparsely sampled data. The presented methods for optimal control are fast and robust, and can be recommended for use in drug discovery. The MCMC-based methods can have long running times and require more expertise from the user. The rigorous definition together with the illustrative examples and suggestions for software serve as a highly promising starting point for application of input-estimation methods to problems in drug discovery.

  12. Distribution of controlled substances in the U.S. supply chain: where does the compass point?

    Science.gov (United States)

    Ruble, James H

    2012-09-01

    Recent administrative actions taken by the Drug Enforcement Administration (DEA) in Florida have prompted an articulate and detailed discussion of the pharmaceutical supply chain for controlled substances. Current practices in commercial distribution systems may have a partial nexus to the proliferation of opioid prescription drug abuse in Florida. No single factor or entity is responsible for this abuse proliferation, and there is no intent to harm consumers; however, distribution practices are adding risk to public health. This commentary extends a discussion on supply chain practices that seem misaligned in the promotion of legitimate business objectives and advancing public health.

  13. On the hierarchical optimal control of a chain of distributed systems

    OpenAIRE

    Befekadu, Getachew K.; Pasiliao, Eduardo L.

    2015-01-01

    In this paper, we consider a chain of distributed systems governed by a degenerate parabolic equation, which satisfies a weak H\\"{o}rmander type condition, with a control distributed over an open subdomain. In particular, we consider two objectives that we would like to accomplish. The first one being of a controllability type that consists of guaranteeing the terminal state to reach a target set starting from an initial condition; while the second one is keeping the state trajectory of the o...

  14. Transmission and control of Salmonella in the pig feed chain: a conceptual model.

    Science.gov (United States)

    Binter, Claudia; Straver, Judith Maria; Häggblom, Per; Bruggeman, Geert; Lindqvist, Per-Anders; Zentek, Jürgen; Andersson, Mats Gunnar

    2011-03-01

    Infected breeder pigs and contaminated feed represent potential sources of Salmonella introduction to fattening pig herds and may thereby cause human infections acquired via consumption of contaminated pork. Modelling approaches such as quantitative microbial risk assessment could improve the design of strategies for control and tracing of Salmonella in the feed chain. However, the construction of such models requires a thorough understanding of the dynamics of the feed chain, including production processes, microbial processes and transport logistics. The present article illustrates a conceptual model of Salmonella in the pig feed chain and explores the possibilities for quantitative modelling including identifying major gaps in data. Information was collected from peer-reviewed scientific journals, official documents and reports and by means of interviews with experts from authorities and the feed industry. Data on prevalence of Salmonella in different parts of the feed chain are difficult to compare as observed prevalence may be biased by variations in sampling procedures as well as limitations of the detection methods. There are almost no data on numbers of Salmonella in commodities of the feed chain, which often makes it difficult to evaluate risks, intervention strategies and sampling plans in a quantitative manner. Tracing the source of Salmonella contamination is hampered by the risk of cross-contamination as well as various mixing and partitioning events along the supply chain, which sometimes makes it impossible to trace the origin of a lot back to a batch or producer. Available information points to contaminated feed materials, animal vectors and persistent contamination of production environments as important sources of Salmonella in feed production. Technological procedures such as hydrothermal or acid treatment can be used to control Salmonella in feed production. However, a large fraction of pig feed is produced without decontamination procedures

  15. Controlling photophysical properties of ultrasmall conjugated polymer nanoparticles through polymer chain packing

    KAUST Repository

    Piwoński, Hubert

    2017-05-16

    Applications of conjugated polymer nanoparticles (Pdots) for imaging and sensing depend on their size, fluorescence brightness and intraparticle energy transfer. The molecular design of conjugated polymers (CPs) has been the main focus of the development of Pdots. Here we demonstrate that proper control of the physical interactions between the chains is as critical as the molecular design. The unique design of twisted CPs and fine-tuning of the reprecipitation conditions allow us to fabricate ultrasmall (3.0–4.5 nm) Pdots with excellent photostability. Extensive photophysical and structural characterization reveals the essential role played by the packing of the polymer chains in the particles in the intraparticle spatial alignment of the emitting sites, which regulate the fluorescence brightness and the intraparticle energy migration efficiency. Our findings enhance understanding of the relationship between chain interactions and the photophysical properties of CP nanomaterials, providing a framework for designing and fabricating functional Pdots for imaging applications.

  16. Allee effects in tritrophic food chains: some insights in pest biological control.

    Science.gov (United States)

    Costa, Michel Iskin da S; Dos Anjos, Lucas

    2016-12-01

    Release of natural enemies to control pest populations is a common strategy in biological control. However, its effectiveness is supposed to be impaired, among other factors, by Allee effects in the biological control agent and by the fact that introduced pest natural enemies interact with some native species of the ecosystem. In this work, we devise a tritrophic food chain model where the assumptions previously raised are proved correct when a hyperpredator attacks the introduced pest natural enemy by a functional response type 2 or 3. Moreover, success of pest control is shown to be related to the release of large amounts (i.e., inundative releases) of natural enemies.

  17. QC-Chain: fast and holistic quality control method for next-generation sequencing data.

    Directory of Open Access Journals (Sweden)

    Qian Zhou

    Full Text Available Next-generation sequencing (NGS technologies have been widely used in life sciences. However, several kinds of sequencing artifacts, including low-quality reads and contaminating reads, were found to be quite common in raw sequencing data, which compromise downstream analysis. Therefore, quality control (QC is essential for raw NGS data. However, although a few NGS data quality control tools are publicly available, there are two limitations: First, the processing speed could not cope with the rapid increase of large data volume. Second, with respect to removing the contaminating reads, none of them could identify contaminating sources de novo, and they rely heavily on prior information of the contaminating species, which is usually not available in advance. Here we report QC-Chain, a fast, accurate and holistic NGS data quality-control method. The tool synergeticly comprised of user-friendly tools for (1 quality assessment and trimming of raw reads using Parallel-QC, a fast read processing tool; (2 identification, quantification and filtration of unknown contamination to get high-quality clean reads. It was optimized based on parallel computation, so the processing speed is significantly higher than other QC methods. Experiments on simulated and real NGS data have shown that reads with low sequencing quality could be identified and filtered. Possible contaminating sources could be identified and quantified de novo, accurately and quickly. Comparison between raw reads and processed reads also showed that subsequent analyses (genome assembly, gene prediction, gene annotation, etc. results based on processed reads improved significantly in completeness and accuracy. As regard to processing speed, QC-Chain achieves 7-8 time speed-up based on parallel computation as compared to traditional methods. Therefore, QC-Chain is a fast and useful quality control tool for read quality process and de novo contamination filtration of NGS reads, which could

  18. Design and Comparison Direct Torque Control Techniques for Induction Motors

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Kazmierkowski, Marian P.; Zelechowski, Marcin

    2005-01-01

    In this paper a comparison of two significant control methods of induction motor are presented. The first one is a classical Direct Torque and Flux Control (DTC) and is compared with a scheme, which uses Space Vector Modulator (DTC-SVM). A comparison in respect to dynamic and steady state...

  19. Cryptanalysis and improvement of controlled secure direct communication

    Institute of Scientific and Technical Information of China (English)

    Kao Shih-Hung; Hwang Tzonelih

    2013-01-01

    This paper points out that,due to a flaw in the sender's encoding,the receiver in Gao et al.'s controlled quantum secret direct communication (CQSDC) protocol [Chin.Phys.14 (2005),No.5,p.893] can reveal the whole secret message without permission from the controller.An improvement is proposed to avoid this flaw.

  20. IPMSM Motion-Sensorless Direct Torque and Flux Control

    DEFF Research Database (Denmark)

    Pitict, Christian Ilie; Andreescu, Gheorghe-Daniel; Blaabjerg, Frede

    2005-01-01

    The paper presents a rather comprehensive implementation of a wide speed motion-sensorless control of IPMSM drives via direct torque and flux control (DTFC) with space vector modulation (SVM). Signal injection with only one D-module vector filter and phase-locked loop (PLL) observer is used at low...

  1. IPMSM Motion-Sensorless Direct Torque and Flux Control

    DEFF Research Database (Denmark)

    Pitict, Christian Ilie; Andreescu, Gheorghe-Daniel; Blaabjerg, Frede

    2005-01-01

    The paper presents a rather comprehensive implementation of a wide speed motion-sensorless control of IPMSM drives via direct torque and flux control (DTFC) with space vector modulation (SVM). Signal injection with only one D-module vector filter and phase-locked loop (PLL) observer is used at low...

  2. A Direct Feedback Control Based on Fuzzy Recurrent Neural Network

    Institute of Scientific and Technical Information of China (English)

    李明; 马小平

    2002-01-01

    A direct feedback control system based on fuzzy-recurrent neural network is proposed, and a method of training weights of fuzzy-recurrent neural network was designed by applying modified contract mapping genetic algorithm. Computer simul ation results indicate that fuzzy-recurrent neural network controller has perfect dynamic and static performances .

  3. Direct Model Reference Adaptive Control for a Magnetic Bearing

    Energy Technology Data Exchange (ETDEWEB)

    Durling, Mike [Rensselaer Polytechnic Inst., Troy, NY (United States)

    1999-11-01

    A Direct Model Reference Adaptive Controller (DMRAC) is applied to a magnetic bearing test stand. The bearing of interest is the MBC 500 Magnetic Bearing System manufactured by Magnetic Moments, LLC. The bearing model is presented in state space form and the system transfer function is measured directly using a closed-loop swept sine technique. Next, the bearing models are used to design a phase-lead controller, notch filter and then a DMRAC. The controllers are tuned in simulations and finally are implemented using a combination of MATLAB, SIMULINK and dSPACE. The results show a successful implementation of a DMRAC on the magnetic bearing hardware.

  4. Coordinated Resolved Motion Control of Dual-arm Manipulators with Closed Chain

    Directory of Open Access Journals (Sweden)

    Tianliang Liu

    2016-05-01

    Full Text Available When applied to some tasks, such as payload handling, assembling, repairing and so on, the two arms of a humanoid robot will form a closed kinematic chain. It makes the motion planning and control for dual‐arm coordination very complex and difficult. In this paper, we present three types of resolved motion control methods for a humanoid robot during coordinated manipulation. They are, respectively, position‐level, velocity‐level and acceleration‐level resolved motion control methods. The desired pose, velocity and acceleration of each end‐effector are then resolved according to the desired motion of the payload and the constraints on the closed‐chain system without consideration of the internal force. Corresponding to the three cases above, the joint variables of each arm are then calculated using the inverse kinematic equations, at position‐level, velocity‐level or acceleration‐level. Finally, a dynamic modelling and simulation platform is established based on ADAMS and Matlab software. The proposed methods are verified by typical cases. The simulation results show that the proposed control strategy can realize the dual‐arm coordinated operation and the internal force of the closed chain during the operation is controlled in a reasonable range at the same time.

  5. Beyond Control Panels: Direct Manipulation for Visual Analytics

    Energy Technology Data Exchange (ETDEWEB)

    Endert, Alexander; Bradel, Lauren; North, Chris

    2013-07-19

    Information Visualization strives to provide visual representations through which users can think about and gain insight into information. By leveraging the visual and cognitive systems of humans, complex relationships and phenomena occurring within datasets can be uncovered by exploring information visually. Interaction metaphors for such visualizations are designed to enable users direct control over the filters, queries, and other parameters controlling how the data is visually represented. Through the evolution of information visualization, more complex mathematical and data analytic models are being used to visualize relationships and patterns in data – creating the field of Visual Analytics. However, the expectations for how users interact with these visualizations has remained largely unchanged – focused primarily on the direct manipulation of parameters of the underlying mathematical models. In this article we present an opportunity to evolve the methodology for user interaction from the direct manipulation of parameters through visual control panels, to interactions designed specifically for visual analytic systems. Instead of focusing on traditional direct manipulation of mathematical parameters, the evolution of the field can be realized through direct manipulation within the visual representation – where users can not only gain insight, but also interact. This article describes future directions and research challenges that fundamentally change the meaning of direct manipulation with regards to visual analytics, advancing the Science of Interaction.

  6. Control of directional change after mechanical stimulation in Drosophila

    Directory of Open Access Journals (Sweden)

    Zhou Yating

    2012-10-01

    Full Text Available Abstract Background Proper adjustment of moving direction after external mechanical stimulation is essential for animals to avoid danger (e.g. predators, and thus is vital for survival. This process involves sensory inputs, central processing and motor outputs. Recent studies have made considerable progress in identifying mechanosensitive neurons and mechanosensation receptor proteins. Our understandings of molecular and cellular mechanisms that link mechanosensation with the changes in moving direction, however, remain limited. Results In this study, we investigate the control of movement adjustment in Drosophila. In response to gentle touch at the anterior segments, Drosophila larvae reorient and select a new direction for forward movement. The extent of change in moving direction is correlated with the intensity of tactile stimuli. Sensation of gentle touch requires chordotonal organs and class IV da neurons. Genetic analysis indicates an important role for the evolutionarily conserved immunoglobulin (Ig superfamily protein Turtle (Tutl to regulate touch-initiated directional change. Tutl is required specifically in post-mitotic neurons at larval stage after the completion of embryonic development. Circuit breaking analysis identified a small subset of Tutl-positive neurons that are involved in the adjustment of moving direction. Conclusion We identify Tutl and a small subset of CNS neurons in modulating directional change in response to gentle touch. This study presents an excellent starting point for further dissection of molecular and cellular mechanisms controlling directional adjustment after mechanical stimulation.

  7. Usefulness of food chain information provided by Dutch finishing pig producers to control antibiotic residues in pork

    NARCIS (Netherlands)

    Wagenberg, van C.P.A.; Backus, G.B.C.; Vorst, van der J.G.A.J.; Urlings, H.A.P.

    2012-01-01

    The EU prescribes that food business operators must use food chain information to assist in food safety control. This study analyses usefulness of food chain information about antibiotic usage covering the 60-day period prior to delivery of pigs to slaughter in the control of antibiotic residues in

  8. Hierarchical cooperative control for multiagent systems with switching directed topologies.

    Science.gov (United States)

    Hu, Jianqiang; Cao, Jinde

    2015-10-01

    The hierarchical cooperative control problem is concerned for a two-layer networked multiagent system under switching directed topologies. The group cooperative objective is to achieve finite-time formation control for the upper layer of leaders and containment control for the lower layer of followers. Two kinds of cooperative strategies, including centralized-distributed control and distributed-distributed control, are proposed for two types of switching laws: 1) random switching law with the dwell time and 2) Markov switching law with stationary distribution. Utilizing the state transition matrix methods and matrix measure techniques, some sufficient conditions are derived for asymptotical containment control and exponential almost sure containment control, respectively. Finally, some numerical examples are provided to demonstrate the effectiveness of the proposed control schemes.

  9. Bullwhip Entropy Analysis and Chaos Control in the Supply Chain with Sales Game and Consumer Returns

    Directory of Open Access Journals (Sweden)

    Wandong Lou

    2017-02-01

    Full Text Available In this paper, we study a supply chain system which consists of one manufacturer and two retailers including a traditional retailer and an online retailer. In order to gain a larger market share, the retailers often take the sales as a decision-making variable in the competition game. We devote ourselves to analyze the bullwhip effect in the supply chain with sales game and consumer returns via the theory of entropy and complexity and take the delayed feedback control method to control the system’s chaotic state. The impact of a statutory 7-day no reason for return policy for online retailers is also investigated. The bounded rational expectation is adopt to forecast the future demand in the sales game system with weak noise. Our results show that high return rates will hurt the profits of both the retailers and the adjustment speed of the bounded rational sales expectation has an important impact on the bullwhip effect. There is a stable area for retailers where the bullwhip effect doesn’t appear. The supply chain system suffers a great bullwhip effect in the quasi-periodic state and the quasi-chaotic state. The purpose of chaos control on the sales game can be achieved and the bullwhip effect would be effectively mitigated by using the delayed feedback control method.

  10. Thruster direction controlling of assembled spacecraft based on gimbal suspension

    Institute of Scientific and Technical Information of China (English)

    Hongliang Xu; Hai Huang

    2016-01-01

    The attitude control system design and its control effect are affected considerably by the mass-property pa-rameters of the spacecraft. In the mission of on-orbit servicing, as fuel is expended, or the payloads are added or removed, the center of mass wil be changed in certain axe; conse-quently, some thrusters' directions are deviated from the center of mass (CM) in certain plane. The CM of assembled spacecraft estimation and thruster direction control are studied. Firstly, the attitude dynamics of the assembled spacecraft is established based on the Newton-Euler method. Secondly, the estimation can be identified by the least recursive squares algorithm. Then, a scheme to control the thrusters’ directions is proposed. By using the gimbal instaled at the end of the boom, the angle of the thruster is controled by driving the gimbal; therefore, thrusters can be directed to the CM again. Finaly, numerical simulations are used to verify this scheme. Results of the numerical simulations clearly show that this control scheme is rational and feasible.

  11. Multi-objective design of fuzzy logic controller in supply chain

    Science.gov (United States)

    Ghane, Mahdi; Tarokh, Mohammad Jafar

    2012-08-01

    Unlike commonly used methods, in this paper, we have introduced a new approach for designing fuzzy controllers. In this approach, we have simultaneously optimized both objective functions of a supply chain over a two-dimensional space. Then, we have obtained a spectrum of optimized points, each of which represents a set of optimal parameters which can be chosen by the manager according to the importance of objective functions. Our used supply chain model is a member of inventory and order-based production control system family, a generalization of the periodic review which is termed `Order-Up-To policy.' An auto rule maker, based on non-dominated sorting genetic algorithm-II, has been applied to the experimental initial fuzzy rules. According to performance measurement, our results indicate the efficiency of the proposed approach.

  12. An Inventory Controlled Supply Chain Model Based on Improved BP Neural Network

    Directory of Open Access Journals (Sweden)

    Wei He

    2013-01-01

    Full Text Available Inventory control is a key factor for reducing supply chain cost and increasing customer satisfaction. However, prediction of inventory level is a challenging task for managers. As one of the widely used techniques for inventory control, standard BP neural network has such problems as low convergence rate and poor prediction accuracy. Aiming at these problems, a new fast convergent BP neural network model for predicting inventory level is developed in this paper. By adding an error offset, this paper deduces the new chain propagation rule and the new weight formula. This paper also applies the improved BP neural network model to predict the inventory level of an automotive parts company. The results show that the improved algorithm not only significantly exceeds the standard algorithm but also outperforms some other improved BP algorithms both on convergence rate and prediction accuracy.

  13. Forming Conditions and Neural Network Control of Continuously Directional Microstructure in Directional Solidification Continuous Casting Process

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Directional solidification continuous casting (DSCC) process is a new manufacturing technology for metal- lic materials which combines advantages of both directional solidification technology and continuous casting technolo- gy. Unlimited long shaped metal with directionally solidifying microstructure can be produced by this process. It is experimentally shown that controlling condition of stable and continuous growth of single crystal structure means the precise control of the location of the S/L interface, which is affected and determined by seven process parameters. Moreover, these parameters are also interacted each other, so the disturbance of any parameters may cause the fail- ure of controlling of S/L interface. In this paper, on the basis of analyzing the forming conditions of continuously di- rectional microstructures in DSCC process, the control model of DSCC procedure by neural network control (NNC) method was proposed and discussed. Combining with the experiments, we first used the computer to simulate the effects of the solidification parameters on destination control variable (S/L interface) and the interactions among these parameters during DSCC procedure. Secondly many training samples necessary for neural network calculation can be obtained through the simulation. Moreover, these samples are inputted into neural network software (NNs) and trained, then the control model can be built up.

  14. Data-Driven Predictive Direct Load Control of Refrigeration Systems

    DEFF Research Database (Denmark)

    Shafiei, Seyed Ehsan; Knudsen, Torben; Wisniewski, Rafal

    2015-01-01

    A predictive control using subspace identification is applied for the smart grid integration of refrigeration systems under a direct load control scheme. A realistic demand response scenario based on regulation of the electrical power consumption is considered. A receding horizon optimal control...... is proposed to fulfil two important objectives: to secure high coefficient of performance and to participate in power consumption management. Moreover, a new method for design of input signals for system identification is put forward. The control method is fully data driven without an explicit use of model...

  15. Nonlinear Direct Robust Adaptive Control Using Lyapunov Method

    Directory of Open Access Journals (Sweden)

    Chunbo Xiu

    2013-07-01

    Full Text Available    The problem of robust adaptive stabilization of a class of multi-input nonlinear systems with arbitrary unknown parameters and unknown structure of bounded variation have been considered. By employing the direct adaptive and control Lyapunov function method, a robust adaptive controller is designed to complete the globally adaptive stability of the system states. By employing our result, a kind of nonlinear system is analyzed, the concrete form of the control law is given and the meaningful quadratic control Lyapunov function for the system is constructed. Simulation of parallel manipulator is provided to illustrate the effectiveness of the proposed method.

  16. An improved arbitrated quantum signature protocol based on the key-controlled chained CNOT encryption

    Science.gov (United States)

    Zhang, Long; Sun, Hong-Wei; Zhang, Ke-Jia; Jia, Heng-Yue

    2017-03-01

    In this paper, a new quantum encryption based on the key-controlled chained CNOT operations, which is named KCCC encryption, is proposed. With the KCCC encryption, an improved arbitrated quantum signature (AQS) protocol is presented. Compared with the existing protocols, our protocol can effectively prevent forgery attacks and disavowal attacks. Moreover, only single state is required in the protocol. We hope it is helpful to further research in the design of AQS protocols in future.

  17. Controlled Directional Growth of TiO2 Nanotubes

    DEFF Research Database (Denmark)

    In, Su-il; Hou, Yidong; Abrams, Billie

    2010-01-01

    We demonstrate how the anodization direction and growth rate of vertically aligned, highly ordered TiO2 nanotube (NT) arrays can be controlled and manipulated by the local concentration of O-2 in the electrolyte. This leads to the growth of highly active TiO2 NT arrays directly on nonconducting...... substrates in a single step. By controlling the oxygen concentration, the electrical contact to the titanium film can be preserved until the entire film is anodized. This approach to growing transparent TiO2 NT films yields possibilities for using glass without any transparent conducting oxide coating...

  18. Robust direct adaptive fuzzy control for nonlinear MIMO systems

    Institute of Scientific and Technical Information of China (English)

    ZHANG Huaguang; ZHANG Mingjun

    2006-01-01

    For a class of nonlinear multi-input multi-output systems with uncertainty, a robust direct adaptive fuzzy control scheme was proposed. The feedback control law and adaptive law for parameters were derived based on Lyapunov design approach. The overall control scheme can guarantee that the tracking error converges in the small neighborhood of origin, and all signals of the closed-loop system are uniformly bounded. The main advantage of the proposed control scheme is that in each subsystem only one parameter vector needs to be adjusted on-line in the adaptive mechanism, and so the on-line computing burden is reduced. In addition, the proposed control scheme is a smooth control with no chattering phenomena. A simulation example was proposed to demonstrate the effectiveness of the proposed control algorithm.

  19. Global Observer-Based Attitude Controller Using Direct Inertial Measurements

    Directory of Open Access Journals (Sweden)

    Saâdi Bouhired

    2014-04-01

    Full Text Available In this work, we address the problem of global attitude control using direct inertial measurements. When using direct inertial measurement to observe the rigid body attitude, it is shown that due to a geometrical obstruction, it is impossible to achieve global asymptotic stability. In fact, for a particular initial condition the tracking error quaternion converges to a pure imaginary quaternion formed by an eigenvector of a characteristic matrix related to the inertial constant and known vectors. Our proposition consists of adding a dynamic signal to force the rigid body to escape from such a situation. The proposed observer-based controller is synthesized based on a single Lyapunov function and a stability analysis shows that the controller stabilizes globally and asymptotically the rigid body attitude at the desired one. The effectiveness of the proposed observer-based controller is confirmed by simulation results.

  20. Direct Torque Control With Feedback Linearization for Induction Motor Drives

    DEFF Research Database (Denmark)

    Lascu, Cristian Vaslie; Jafarzadeh, Saeed; Fadali, Sami M.

    2017-01-01

    This paper describes a direct-torque-controlled (DTC) induction motor (IM) drive that employs feedback linearization and sliding-mode control (SMC). A new feedback linearization approach is proposed, which yields a decoupled linear IM model with two state variables: torque and stator flux magnitude....... This intuitive linear model is used to implement a DTC-type controller that preserves all DTC advantages and eliminates its main drawback, the flux and torque ripple. Robust, fast, and ripple-free control is achieved by using SMC with proportional control in the vicinity of the sliding surface. SMC assures...... robustness as in DTC, while the proportional component eliminates the torque and flux ripple. The torque time response is similar to conventional DTC and the proposed solution is flexible and highly tunable due to the P component. The controller design is presented, and its robust stability is analyzed...

  1. Stability analysis of direct current control in current source rectifier

    DEFF Research Database (Denmark)

    Lu, Dapeng; Wang, Xiongfei; Blaabjerg, Frede

    2017-01-01

    Current source rectifier with high switching frequency has a great potential for improving the power efficiency and power density in ac-dc power conversion. This paper analyzes the stability of direct current control based on the time delay effect. Small signal model including dynamic behaviors...... of dc link is developed to identify the control plants of grid ac current control and dc current control. Analysis on the poles and zeros under dq frame is carried out. Base on this model, it turns out that the phase lag caused by the time delay can stabilized the grid ac current control while reduces...... the stable region for dc current control. Simulation and experimental results are presented to validate the theoretical analysis....

  2. A novel mechanism for direct real-time polymerase chain reaction that does not require DNA isolation from prokaryotic cells.

    Science.gov (United States)

    Soejima, Takashi; Xiao, Jin-Zhong; Abe, Fumiaki

    2016-06-23

    Typically, polymerase chain reaction (PCR) is performed after DNA isolation. Real-time PCR (qPCR), also known as direct qPCR in mammalian cells with weak membranes, is a common technique using crude samples subjected to preliminary boiling to elute DNA. However, applying this methodology to prokaryotic cells, which have solid cell walls, in contrast to mammalian cells which immediately burst in water, can result in poor detection. We successfully achieved PCR elongation with the addition of 1.3 cfu of Cronobacter muytjensii to a newly developed direct qPCR master mix without performing any crude DNA extraction (detection limit of 1.6 × 10(0) cfu/ml for the test sample compared with a detection limit of 1.6 × 10(3) cfu/ml primarily for crude (boiling) or classical DNA isolation). We revealed that the chromosomal DNA retained in prokaryotic cells can function as a PCR template, similarly to the mechanism in in situ PCR. Elucidating this reaction mechanism may contribute to the development of an innovative master mix for direct qPCR to detect genes in a single bacterium with solid cell walls and might lead to numerous novel findings in prokaryotic genomics research.

  3. Applications of chaos control techniques to a three-species food chain

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, A.A. [CBPF, R.Xavier Sigaud, 150, RJ, CEP 22290-180 Rio de Janeiro (Brazil); Manica, E. [Department of Mathematics, 301 Thackeray Hall, University of Pittsburgh, Pittsburgh, PA 15260 (United States)], E-mail: evm4@pitt.edu; Varriale, M.C. [Instituto de Matematica, UFRGS, RS, CEP 91509-900 (Brazil)

    2008-02-15

    We achieve control of deterministic chaos in an ecosystem model, involving three first-order nonlinear differential equations with a control parameter, recently proposed by Hastings and Powell (HP) in order to describe the dynamical behavior of a three-species food chain. After identifying a chaotic attractor corresponding to a particular value of the parameter of this ecological model, we locate periodic saddle orbits embedded in it. By applying the Ott-Grebogi-Yorke (OGY) method of controlling chaos, which introduces small time-dependent perturbations on the system parameter, we stabilize two of the saddle orbits. Furthermore, we check the versatility of the OGY method, as the system behavior is allowed to switch between 'no control' and 'control' about one or other of different stabilized periodic orbits.

  4. Anger in School Managers: Continuity, Direction, Control and Style

    Science.gov (United States)

    Koc, Mustafa; Iskender, Murat; Cardak, Mehmet; Dusunceli, Betul

    2012-01-01

    School managers undertake an important duty in structuring of education institutions. In the study carried out in this context; anger conditions, continuity, and direction of anger, anger control levels and anger styles of school managers who are the decision makers in schools were examined according to the ages, working periods, duty types, ways…

  5. Direct laser additive fabrication system with image feedback control

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, Michelle L. (Albuquerque, NM); Hofmeister, William H. (Nashville, TN); Knorovsky, Gerald A. (Albuquerque, NM); MacCallum, Danny O. (Edgewood, NM); Schlienger, M. Eric (Albuquerque, NM); Smugeresky, John E. (Pleasanton, CA)

    2002-01-01

    A closed-loop, feedback-controlled direct laser fabrication system is disclosed. The feedback refers to the actual growth conditions obtained by real-time analysis of thermal radiation images. The resulting system can fabricate components with severalfold improvement in dimensional tolerances and surface finish.

  6. 49 CFR 30.9 - Citizenship: Direct or indirect control.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Citizenship: Direct or indirect control. 30.9 Section 30.9 Transportation Office of the Secretary of Transportation DENIAL OF PUBLIC WORKS CONTRACTS TO SUPPLIERS OF GOODS AND SERVICES OF COUNTRIES THAT DENY PROCUREMENT MARKET ACCESS TO U.S. CONTRACTORS §...

  7. Hydraulically controlled flexible arm can bend in any direction

    Science.gov (United States)

    Griffin, F. D.

    1966-01-01

    Arm assembly consisting of four flexible tubes controlled by a four-way hydraulic or pneumatic valve can bend in any direction. The flexible arm could be used for probing areas that cannot be reached by ordinary tools, handling hazardous materials, and for graph recording.

  8. Polarization-controlled directional scattering for nanoscopic position sensing

    Science.gov (United States)

    Neugebauer, Martin; Woźniak, Paweł; Bag, Ankan; Leuchs, Gerd; Banzer, Peter

    2016-04-01

    Controlling the propagation and coupling of light to sub-wavelength antennas is a crucial prerequisite for many nanoscale optical devices. Recently, the main focus of attention has been directed towards high-refractive-index materials such as silicon as an integral part of the antenna design. This development is motivated by the rich spectral properties of individual high-refractive-index nanoparticles. Here we take advantage of the interference of their magnetic and electric resonances to achieve strong lateral directionality. For controlled excitation of a spherical silicon nanoantenna, we use tightly focused radially polarized light. The resultant directional emission depends on the antenna's position relative to the focus. This approach finds application as a novel position sensing technique, which might be implemented in modern nanometrology and super-resolution microscopy set-ups. We demonstrate in a proof-of-concept experiment that a lateral resolution in the Ångström regime can be achieved.

  9. Polarization Controlled Directional Scattering for Nanoscopic Position Sensing

    CERN Document Server

    Neugebauer, Martin; Bag, Ankan; Leuchs, Gerd; Banzer, Peter

    2015-01-01

    Controlling the propagation and coupling of light to sub-wavelength antennas is a crucial prerequisite for many nanoscale optical devices. Recently, the main focus of attention has been directed towards high-refractive index materials such as silicon as an integral part of the antenna design. The development is motivated by the rich spectral properties of individual high-refractive index nanoparticles, featuring magnetic and electric resonances in the visible regime, whose interference may yield remarkably strong directivity. Here, we use tightly focused radially polarized light for controlled excitation of a spherical silicon nanoantenna. The resultant emission can be highly directional, depending on the antenna's position relative to the focus. This approach finds application as a novel position sensing technique, a discipline, which is of paramount importance in modern nanometrology, because of its special role in super-resolution microscopy. We yield a lateral resolution in the Angstrom regime.

  10. Lamellar orientation control in directionally solidified TiAl intermetallics

    Directory of Open Access Journals (Sweden)

    Su Yanqing

    2014-07-01

    Full Text Available TiAl-based alloys are potentially used as high-temperature structural materials with a high specific strength in the range of ~ 900 °C. However, the mechanical properties of TiAl-based alloys are extremely anisotropic with respect to the lamellar orientation of the microstructures. A balance combination of room-temperature ductility and strength can be achieved when the lamellar orientation are aligned parallel to the tensile stress direction. Lamellar orientation control of TiAl-based alloys by directional solidification technique has been widely studied in recent years. Two different directional solidification processes can be used to modify the lamellar Orientation. One is a seeding technique and the other is adjusting the solidification path. This paper reviews the principles of the two methods and their progress. The influence of alloy composition and solidification parameters on lamellar orientation control is also discussed.

  11. Rom2-dependent phosphorylation of Elo2 controls the abundance of very long chain fatty acids

    DEFF Research Database (Denmark)

    Olson, Daniel K; Fröhlich, Florian; Christiano, Romain

    2015-01-01

    Sphingolipids are essential components of eukaryotic membranes, where they serve to maintain membrane integrity. They are important components of membrane trafficking and function in signaling as messenger molecules. Sphingolipids are synthesized de novo from very long chain fatty acids (VLCFA...... that Elo2, a key enzyme of VLCFA synthesis, is controlled by signaling of the guanine nucleotide exchange factor Rom2, initiating at the plasma membrane. This pathway controls Elo2 phosphorylation state and VLCFA synthesis. Our data identify a regulatory mechanism for coordinating VLCFA synthesis...

  12. Is remote stretching based on myofascial chains as effective as local exercise? A randomised-controlled trial.

    Science.gov (United States)

    Wilke, J; Vogt, L; Niederer, D; Banzer, W

    2016-11-07

    Lower limb stretching based on myofascial chains has been demonstrated to increase cervical range of motion (ROM) in the sagittal plane. It is, however, unknown whether such remote exercise is as effective as local stretching. To resolve this research deficit, 63 healthy participants (36 ± 13 years, ♂32) were randomly assigned to one of three groups: remote stretching of the lower limb (LLS), local stretching of the cervical spine (CSS) or inactive control (CON). Prior (M1), immediately post (M2) and 5 min following intervention (M3), maximal cervical ROM was assessed. Non-parametric data analysis (Kruskal-Wallis tests and adjusted post hoc Dunn tests) revealed significant differences between the disposed conditions. With one exception (cervical spine rotation after CSS at M2, P > .05), both LLS and CSS increased cervical ROM compared to the control group in all movement planes and at all measurements (P  .05). Lower limb stretching based on myofascial chains induces similar acute improvements in cervical ROM as local exercise. Therapists might consequently consider its use in programme design. However, as the attained effects do not seem to be direction-specific, further research is warranted in order to provide evidence-based recommendations.

  13. Improved Four-Switch BLDCM Direct Current Control

    Directory of Open Access Journals (Sweden)

    Pan Lei

    2013-08-01

    Full Text Available The main purpose of this study is to describe a low cost four-switch brushless dc motor (BLDCM drive. An improved direct current controlled scheme is designed and implemented to produce the desired dynamic and static current and speed characteristics. Eight voltage vectors are summarized, which are selected to control BLDCM in SVPWM pattern. This method avoids the undesired current distortion which is caused by uncontrollable phase. The operational principle of the four-switch BLDC motor drive and the developed control scheme are theoretically analyzed and the performance is demonstrated by both simulation and experimental results.

  14. Controlling the mode of operation of organic transistors through side-chain engineering

    KAUST Repository

    Giovannitti, Alexander

    2016-10-11

    Electrolyte-gated organic transistors offer low bias operation facilitated by direct contact of the transistor channel with an electrolyte. Their operation mode is generally defined by the dimensionality of charge transport, where a field-effect transistor allows for electrostatic charge accumulation at the electrolyte/semiconductor interface, whereas an organic electrochemical transistor (OECT) facilitates penetration of ions into the bulk of the channel, considered a slow process, leading to volumetric doping and electronic transport. Conducting polymer OECTs allow for fast switching and high currents through incorporation of excess, hygroscopic ionic phases, but operate in depletion mode. Here, we show that the use of glycolated side chains on a thiophene backbone can result in accumulation mode OECTs with high currents, transconductance, and sharp subthreshold switching, while maintaining fast switching speeds. Compared with alkylated analogs of the same backbone, the triethylene glycol side chains shift the mode of operation of aqueous electrolyte-gated transistors from interfacial to bulk doping/transport and show complete and reversible electrochromism and high volumetric capacitance at low operating biases. We propose that the glycol side chains facilitate hydration and ion penetration, without compromising electronic mobility, and suggest that this synthetic approach can be used to guide the design of organic mixed conductors.

  15. The characterization of modified starch branching enzymes: toward the control of starch chain-length distributions.

    Science.gov (United States)

    Li, Cheng; Wu, Alex Chi; Go, Rob Marc; Malouf, Jacob; Turner, Mark S; Malde, Alpeshkumar K; Mark, Alan E; Gilbert, Robert G

    2015-01-01

    Starch is a complex branched glucose polymer whose branch molecular weight distribution (the chain-length distribution, CLD) influences nutritionally important properties such as digestion rate. Chain-stopping in starch biosynthesis is by starch branching enzyme (SBE). Site-directed mutagenesis was used to modify SBEIIa from Zea mays (mSBEIIa) to produce mutants, each differing in a single conserved amino-acid residue. Products at different times from in vitro branching were debranched and the time evolution of the CLD measured by size-exclusion chromatography. The results confirm that Tyr352, Glu513, and Ser349 are important for mSBEIIa activity while Arg456 is important for determining the position at which the linear glucan is cut. The mutant mSBEIIa enzymes have different activities and suggest the length of the transferred chain can be varied by mutation. The work shows analysis of the molecular weight distribution can yield information regarding the enzyme branching sites useful for development of plants yielding starch with improved functionality.

  16. Sensorless direct vector control of an induction motor

    Energy Technology Data Exchange (ETDEWEB)

    Menaa, M. [Laboratoire de Robotique Parallelisme et Electro-energetique, Departement d' Electrotechnique, Universite des Sciences et de la Technologie Houari Boumediene BP 32 EL Allia, Alger 16111, (Algeria); Touhami, O.; Ibtiouen, R. [Departement de Genie Electrique, Ecole Nationale polytechnique, 10 AV Pasteur, El-Harrach, Alger, (Algeria); Fadel, M. [Laboratoire d' Electrotechnique et d' Electronique Industrielle ENSEEIHT, Toulouse, 2 Rue Camichel BP 7122-31071 Cedex7, (France)

    2008-01-15

    In high-performance variable speed AC drive systems it is often important to accurately determine machine parameters and rotor speed values. An extended complex Kalman filter (ECKF) is used to estimate rotor resistance and mutual inductance without the use of a speed sensor. Such estimates are important in air gap flux orientation control. The ECKF is chosen over the more common extended Kalman filter based on the real-valued model as it is not as computationally intensive. The model of an induction machine obtained by the spiral vector theory and the ECKF are used to develop a new adaptive direct air gap flux orientation control with two sensors: one for the stator voltage and one for the stator current without Park transformation. The simulation tests show the effectiveness of the proposed adaptive direct air gap flux orientation control method. (Author)

  17. Contractual Control and Labour-Related CSR Norms in the Supply Chain: Dutch Best Practices

    Directory of Open Access Journals (Sweden)

    Louise Vytopil

    2012-01-01

    Full Text Available Multinational companies attempt to gain contractual control of their supply chain, in the face of possible reputational and legal risks with regard to corporate social responsibility. This article sets out the choices that fourteen Dutch multinational companies make: do they choose contracts, general terms and conditions and/or codes of conduct to regulate CSR in their supply chains? Furthermore, it explores the possibilities and limitations of these choices in terms of contract law. A model with three possible options that companies may choose is proposed. It is concluded that most Dutch multinationals do not rely on codes of conduct alone; nearly all anchor their codes of conduct by means of contractual mechanisms. Furthermore, nearly all 'strong' choices include perpetual clauses in relation to sub-tier suppliers.

  18. Contractual Control and Labour-Related CSR Norms in the Supply Chain: Dutch Best Practices

    Directory of Open Access Journals (Sweden)

    Louise Vytopil

    2012-01-01

    Full Text Available Multinational companies attempt to gain contractual control of their supply chain, in the face of possible reputational and legal risks with regard to corporate social responsibility. This article sets out the choices that fourteen Dutch multinational companies make: do they choose contracts, general terms and conditions and/or codes of conduct to regulate CSR in their supply chains? Furthermore, it explores the possibilities and limitations of these choices in terms of contract law. A model with three possible options that companies may choose is proposed. It is concluded that most Dutch multinationals do not rely on codes of conduct alone; nearly all anchor their codes of conduct by means of contractual mechanisms. Furthermore, nearly all 'strong' choices include perpetual clauses in relation to sub-tier suppliers.

  19. Preparation of main-chain-type and side-chain-type sulfonated poly(ether ether ketone) membranes for direct methanol fuel cell applications

    Science.gov (United States)

    Tsai, Jie-Cheng; Lin, Chien-Kung

    Novel main-chain-type and side-chain-type sulphonated poly(ether ether ketone)s (MS-SPEEKs) are synthesised by reacting the sulphonic acid groups of pristine SPEEKs with 2-aminoethanesulphonic acid to improve the nano-phase separated morphology of the material. 1H NMR and FT-IR spectroscopy are employed to determine the structure and composition of main-chain-type and side-chain-type sulphonated polymers. Flexible and tough membranes with reasonable thermal properties are obtained. The MS-SPEEKs show good hydrolytic stability, and water uptake values ranging from 15% to 30% are observed. Compared to Nafion 117 ®, the methanol permeability of the MS-SPEEKs is dramatically reduced to 8.83 × 10 -8 cm 2 s -1 to 3.31 × 10 -7 cm 2 s -1. The proton conductivity increases with increasing temperature, reaching 0.013-0.182 S cm -1. A maximum power density and open circuit voltage of 115 mW cm -2 and 0.830 V are obtained at 80 °C, respectively, which is significantly greater than the values generated with Nafion 117 ®. The introduction of pendent side-chain-type sulphonic acid groups increases the single-cell performance by more than approximately 20%; thus, the lower water diffusivity, methanol permeability, electro-osmotic drag coefficient and high cell performance indicated that MS-SPEEK is a promising candidate for DMFC applications.

  20. Direct torque control with feedback linearization for induction motor drives

    DEFF Research Database (Denmark)

    Lascu, Cristian; Jafarzadeh, Saeed; Fadali, Sami M.

    2015-01-01

    This paper describes a Direct Torque Controlled (DTC) Induction Machine (IM) drive that employs feedback linearization and sliding-mode control. A feedback linearization approach is investigated, which yields a decoupled linear IM model with two state variables: torque and stator flux magnitude...... of the sliding surface. The VSC component assures robustness as in DTC, while the proportional component eliminates the torque and flux ripple. The torque time response is similar to DTC and the proposed solution is flexible and highly tunable due to the proportional controller. The controller design and its...... robust stability analysis are presented. The sliding controller is compared with a linear DTC scheme, and experimental results for a sensorless IM drive validate the proposed solution....

  1. Direct Adaptive Aircraft Control Using Dynamic Cell Structure Neural Networks

    Science.gov (United States)

    Jorgensen, Charles C.

    1997-01-01

    A Dynamic Cell Structure (DCS) Neural Network was developed which learns topology representing networks (TRNS) of F-15 aircraft aerodynamic stability and control derivatives. The network is integrated into a direct adaptive tracking controller. The combination produces a robust adaptive architecture capable of handling multiple accident and off- nominal flight scenarios. This paper describes the DCS network and modifications to the parameter estimation procedure. The work represents one step towards an integrated real-time reconfiguration control architecture for rapid prototyping of new aircraft designs. Performance was evaluated using three off-line benchmarks and on-line nonlinear Virtual Reality simulation. Flight control was evaluated under scenarios including differential stabilator lock, soft sensor failure, control and stability derivative variations, and air turbulence.

  2. Directional sensitivity of "first trial" reactions in human balance control.

    Science.gov (United States)

    Oude Nijhuis, Lars B; Allum, John H J; Borm, George F; Honegger, Flurin; Overeem, Sebastiaan; Bloem, Bastiaan R

    2009-06-01

    Support-surface movements are commonly used to examine balance control. Subjects typically receive a series of identical or randomly interspersed multidirectional balance perturbations and the atypical "first trial reaction" (evoked by the first perturbation) is often excluded from further analysis. However, this procedure may obscure vital information about neurophysiological mechanisms associated with the first perturbation and, by analogy, fully unexpected falls. We studied first trial reactions, aiming to clarify their directional impact on postural control and to characterize the underlying neurophysiological substrate. We instructed 36 subjects to maintain balance following support-surface rotations in six different directions. Perturbations in each direction were delivered in blocks, consisting of 10 serial stimuli. Full body kinematics, surface reactive forces, and electromyographic (EMG) responses were recorded. Regardless of direction, for the very first rotation, displacement of the center of mass was 15% larger compared with the ensuing nine identical rotations (P postural instability, mainly due to increased response amplitudes. Although rapid habituation occurs following presentation of identical stimuli, subjects immediately become unstable again when the perturbation direction suddenly changes. Excessive responses due to a failure to combine proprioceptive and vestibular cues effectively may explain this instability seen with first trials, particularly when falling backward.

  3. Global Control Methods for GHZ State Generation on 1-D Ising Chain

    CERN Document Server

    Wang, Xiaoting; Bose, Sougato; Schirmer, Sophie

    2010-01-01

    We discuss how to prepare an Ising chain in a GHZ state using a single global control field only. This model does not require the spins to be individually addressable and is applicable to quantum systems such as cold atoms in optical lattices, some liquid- or solid-state NMR experiments, and many nano-scale quantum structures. We show that GHZ states can always be reached asymptotically from certain easy-to-prepare initial states using adiabatic passage, and under certain conditions finite-time reachability can be ensured. To provide a reference useful for future experimental implementations three different control strategies to achieve the objective, adiabatic passage, Lyapunov control and optimal control are compared, and their advantages and disadvantages discussed, in particular in the presence of realistic imperfections such as imperfect initial state preparation, system inhomogeneity and dephasing.

  4. Options for reducing food waste by ‘Quality Controlled Logistics’ using intelligent packaging along the supply chain

    NARCIS (Netherlands)

    Heising, J.K.; Claassen, G.D.H.; Dekker, M.

    2017-01-01

    Optimizing supply chain management can help to reduce food waste. This article describes how intelligent packaging can be used to reduce food waste when used in supply chain management based on Quality Controlled Logistics (QCL). Intelligent packaging senses compounds in the package that correlate

  5. Stepwise multiple test procedures and control of directional errors

    OpenAIRE

    1999-01-01

    One of the most difficult problems occurring with stepwise multiple test procedures for a set of two-sided hypotheses is the control of direc-tional errors if rejection of a hypothesis is accomplished with a directional decision. In this paper we generalize a result for so-called step-down procedures derived by Shaffer to a large class of stepwise or closed multiple test procedures. In a unifying way we obtain results for a large class of order statistics procedures includin...

  6. Polarization controlled directional propagation of Bloch surface wave.

    Science.gov (United States)

    Kovalevich, Tatiana; Boyer, Philippe; Suarez, Miguel; Salut, Roland; Kim, Myun-Sik; Herzig, Hans Peter; Bernal, Maria-Pilar; Grosjean, Thierry

    2017-03-06

    Bloch surface waves (BSWs) are recently developing alternative to surface plasmon polaritons (SPPs). Due to dramatically enhanced propagation distance and strong field confinement these surface states can be successfully used in on-chip all-optical integrated devices of increased complexity. In this work we propose a highly miniaturized grating based BSW coupler which is gathering launching and directional switching functionalities in a single element. This device allows to control with polarization the propagation direction of Bloch surface waves at subwavelength scale, thus impacting a large panel of domains such as optical circuitry, function design, quantum optics, etc.

  7. Metabolic transistor strategy for controlling electron transfer chain activity in Escherichia coli.

    Science.gov (United States)

    Wu, Hui; Tuli, Leepika; Bennett, George N; San, Ka-Yiu

    2015-03-01

    A novel strategy to finely control a large metabolic flux by using a "metabolic transistor" approach was established. In this approach a small change in the level or availability of an essential component for the process is controlled by adding a competitive reaction that affects a precursor or an intermediate in its biosynthetic pathway. The change of the basal level of the essential component, considered as a base current in a transistor, has a large effect on the flux through the major pathway. In this way, the fine-tuning of a large flux can be accomplished. The "metabolic transistor" strategy was applied to control electron transfer chain function by manipulation of the quinone synthesis pathway in Escherichia coli. The achievement of a theoretical yield of lactate production under aerobic conditions via this strategy upon manipulation of the biosynthetic pathway of the key participant, ubiquinone-8 (Q8), in an E. coli strain provides an in vivo, genetically tunable means to control the activity of the electron transfer chain and manipulate the production of reduced products while limiting consumption of oxygen to a defined amount.

  8. Direct and Indirect Gradient Control for Static Optimisation

    Institute of Scientific and Technical Information of China (English)

    Yi Cao

    2005-01-01

    Static "self-optimising" control is an important concept, which provides a link between static optimisation and control[1]. According to the concept, a dynamic control system could be configured in such a way that when a set of certain variables are maintained at their setpoints, the overall process operation is automatically optimal or near optimal at steadystate in the presence of disturbances. A novel approach using constrained gradient control to achieve "self-optimisation" has been proposed by Cao[2]. However, for most process plants, the information required to get the gradient measure may not be available in real-time. In such cases, controlled variable selection has to be carried out based on measurable candidates. In this work, the idea of direct gradient control has been extended to controlled variable selection based on gradient sensitivity analysis (indirect gradient control). New criteria, which indicate the sensitivity of the gradient function to disturbances and implementation errors, have been derived for selection. The particular case study shows that the controlled variables selected by gradient sensitivity measures are able to achieve near optimal performance.

  9. Torque Ripple Reduction in Direct Torque Control Based Induction Motor using Intelligent Controllers

    Science.gov (United States)

    Sudhakar, Ambarapu; Vijaya Kumar, M.

    2015-09-01

    This paper presents intelligent control scheme together with conventional control scheme to overcome the problems with uncertainties in the structure encountered with classical model based design of induction motor drive based on direct torque control (DTC). It allows high dynamic performance to be obtained with very simple hysteresis control scheme. Direct control of the torque and flux is achieved by proper selection of inverter voltage space vector through a lookup table. This paper also presents the application of intelligent controllers like neural network and fuzzy logic controllers to control induction machines with DTC. Intelligent controllers are used to emulate the state selector of the DTC. With implementation of intelligent controllers the system is also verified and proved to be operated stably with reduced torque ripple. The proposed method validity and effectiveness has been verified by computer simulations using Matlab/Simulink®. These results are compared with the ones obtained with a classical DTC using proportional integral speed controller.

  10. Controlling death: the false promise of advance directives.

    Science.gov (United States)

    Perkins, Henry S

    2007-07-03

    Advance directives promise patients a say in their future care but actually have had little effect. Many experts blame problems with completion and implementation, but the advance directive concept itself may be fundamentally flawed. Advance directives simply presuppose more control over future care than is realistic. Medical crises cannot be predicted in detail, making most prior instructions difficult to adapt, irrelevant, or even misleading. Furthermore, many proxies either do not know patients' wishes or do not pursue those wishes effectively. Thus, unexpected problems arise often to defeat advance directives, as the case in this paper illustrates. Because advance directives offer only limited benefit, advance care planning should emphasize not the completion of directives but the emotional preparation of patients and families for future crises. The existentialist Albert Camus might suggest that physicians should warn patients and families that momentous, unforeseeable decisions lie ahead. Then, when the crisis hits, physicians should provide guidance; should help make decisions despite the inevitable uncertainties; should share responsibility for those decisions; and, above all, should courageously see patients and families through the fearsome experience of dying.

  11. Do means-end chains exist? Experimental tests of their hierarchicity, automatic spreading activation, directionality, and self-relevance

    DEFF Research Database (Denmark)

    Scholderer, Joachim; Grunert, Klaus G.

    2005-01-01

    Despite its popularity in consumer research, means-end chain theory suffers from problems of unconfirmed validity: the nomological status of its central construct, the means-end chain, is still unknown. The aim of the research reported here was threefold: (a)to reformulate means-end chain theory ...

  12. A Comparative Analysis of Polymerase Chain Reaction and Direct Fluorescent Antibody Test for Diagnosis of Genital Herpes.

    Science.gov (United States)

    Patwardhan, Vrushali; Bhalla, Preena; Rawat, Deepti; Garg, Vijay Kumar; Sardana, Kabir; Sethi, Sumit

    2017-01-01

    To compare laboratory tests that can simultaneously detect and type herpes simplex virus (HSV) directly from the genital ulcer specimens in clinically suspected cases of genital herpes. A study was conducted over 10 months and 44 adult male and female patients clinically suspected with genital herpes were recruited. Genital ulcer swab specimens were subjected to glycoprotein-G gene-based conventional polymerase chain reaction (PCR) and commercially available direct fluorescent antibody (DFA) test and the results were compared. PCR for HSV was positive in 82% (36/44) cases. DFA was positive in 68.2% (30/44) cases. There was 100% agreement between HSV types detected by DFA and PCR. The strength of agreement between the results was better in primary genital herpes than recurrent cases. PCR was found to be better in the detection of HSV in recurrent genital herpes patients. It is a better modality, especially when genital herpes clinically presents with ulcerative or crusted lesions, and is also a cheaper alternative as compared to DFA.

  13. FROM MANUFACTURING SCHEDULING TO SUPPLY CHAIN COORDINATION:THE CONTROL OF COMPLEXITY AND UNCERTAINTY

    Institute of Scientific and Technical Information of China (English)

    Peter B. LUH; Weidong FENG

    2003-01-01

    With time-based competition and rapid technology advancements, effective manufacturing scheduling and supply chain coordination are critical to quickly respond to changing market conditions. These problems, however, are difficult in view of inherent complexity and various uncertainties involved. Based on a series of results by the authors, decomposition and coordination by using Lagrangian relaxation is identified in this paper as an effective way to control complexity and uncertainty. A manufacturing scheduling problem is first formulated within the job shop context with uncertain order arrivals, processing times, due dates, and part priorities as a separable optimization problem. A solution methodology that combines Lagrangian relaxation, stochastic dynamic programming, and heuristics is developed. Method improvements to effectively solve large problems are also highlighted. To extend manufacturing scheduling within a factory to coordinate autonomic members across chains of suppliers, a decentralized supply chain model is established in the second half of this paper. By relaxing cross-member constraints, the model is decomposed into member-wise subproblems, and a nested optimization structure is developed based on the job shop scheduling results. Coordination is performed through the iterative updating of cross-member prices without accessing other members' private information or intruding their decision-making authorities, either with or without a coordinator. Two examples are presented to demonstrate the effectiveness of the method. Future prospects to overcome problem inseparability and improve computing efficiency are then discussed.

  14. [Application of directed acyclic graphs in control of confounding].

    Science.gov (United States)

    Xiang, R; Dai, W J; Xiong, Y; Wu, X; Yang, Y F; Wang, L; Dai, Z H; Li, J; Liu, A Z

    2016-07-01

    Observational study is a method most commonly used in the etiology study of epidemiology, but confounders, always distort the true causality between exposure and outcome when local inferencing. In order to eliminate these confounding, the determining of variables which need to be adjusted become a key issue. Directed acyclic graph(DAG)could visualize complex causality, provide a simple and intuitive way to identify the confounding, and convert it into the finding of the minimal sufficient adjustment for the control of confounding. On the one hand, directed acyclic graph can choose less variables, which increase statistical efficiency of the analysis. On the other hand, it could help avoiding variables that is not measured or with missing values. In a word, the directed acyclic graph could facilitate the reveal of the real causality effectively.

  15. Direct drive digital servo press with high parallel control

    Science.gov (United States)

    Murata, Chikara; Yabe, Jun; Endou, Junichi; Hasegawa, Kiyoshi

    2013-12-01

    Direct drive digital servo press has been developed as the university-industry joint research and development since 1998. On the basis of this result, 4-axes direct drive digital servo press has been developed and in the market on April of 2002. This servo press is composed of 1 slide supported by 4 ball screws and each axis has linearscale measuring the position of each axis with high accuracy less than μm order level. Each axis is controlled independently by servo motor and feedback system. This system can keep high level parallelism and high accuracy even with high eccentric load. Furthermore the 'full stroke full power' is obtained by using ball screws. Using these features, new various types of press forming and stamping have been obtained by development and production. The new stamping and forming methods are introduced and 'manufacturing' need strategy of press forming with high added value and also the future direction of press forming are also introduced.

  16. Shape-Grinding by Direct Position/Force Control

    Science.gov (United States)

    Chen, Guanghua; Xu, Weiwei; Minami, Mamoru

    Based on the analysis of the interaction between a manipulator's hand and a working object, a model representing the constrained dynamics of the robot is first discussed. The constrained forces are expressed by an algebraic function of states, input generalized forces, and the constraint condition, and then a direct position/force controller without force sensor is proposed based on the algebraic relation. To give a grinding system the ability to adapt to any object shape being changed by the grinding, we add a function estimating the constraint condition in real time for the adaptive position/force control. Evaluations through simulations, by fitting the changing constraint surface with spline functions, indicate that reliable position/force control and shape-grinding can be achieved by the proposed controller.

  17. TECHNIQUES ABOUT DIRECT OPTIMIZING CONTROL OF GREEN SAND QUALITY*

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Green sand casting is still a main method in the world at present and it is very significant to develop the technology of controlling green sand quality. A new concept, from contents test to contents control, is advanced. In order to realize the new idea, a new method to on-line test active clay and moisture of green sand - double powers energizing alternately (DPEA) method is put forwards. The principle of the new method is to energize standard sand sample with AC and DC powers and to test the electric parameters, and then, to calculate active clay and moisture of green sand by using artificial neural network (ANN). Based on this new method, a direct optimizing system for controlling green sand quality is developed. Techniques about testing and controlling methods, hardware and software are discussed.

  18. Melt Flow Control in the Directional Solidification of Binary Alloys

    Science.gov (United States)

    Zabaras, Nicholas

    2003-01-01

    Our main project objectives are to develop computational techniques based on inverse problem theory that can be used to design directional solidification processes that lead to desired temperature gradient and growth conditions at the freezing front at various levels of gravity. It is known that control of these conditions plays a significant role in the selection of the form and scale of the obtained solidification microstructures. Emphasis is given on the control of the effects of various melt flow mechanisms on the local to the solidification front conditions. The thermal boundary conditions (furnace design) as well as the magnitude and direction of an externally applied magnetic field are the main design variables. We will highlight computational design models for sharp front solidification models and briefly discuss work in progress toward the development of design techniques for multi-phase volume-averaging based solidification models.

  19. Direct-Torque Neuro-Fuzzy Control of Induction Motor

    Institute of Scientific and Technical Information of China (English)

    徐君鹏; CHEN Yan-feng; LI Guo-hou

    2007-01-01

    Fuzzy systems are currently being used in a wide field of industrial and scientific applications. Since the design and especially the optimization process of fuzzy systems can be very time consuming, it is convenient to have algorithms which construct and optimize them automatically. In order to improve the system stability and raise the response speed, a new control scheme, direct-torque neuro-fuzzy control for induction motor drive, was put forward. The design and tuning procedure have been described. Also, the improved stator flux estimation algorithm, which guarantees eccentric estimated flux has been proposed.

  20. Subfemtosecond directional control of chemical processes in molecules

    Science.gov (United States)

    Alnaser, Ali S.; Litvinyuk, Igor V.

    2017-02-01

    Laser pulses with a waveform-controlled electric field and broken inversion symmetry establish the opportunity to achieve directional control of molecular processes on a subfemtosecond timescale. Several techniques could be used to break the inversion symmetry of an electric field. The most common ones include combining a fundamental laser frequency with its second harmonic or with higher -frequency pulses (or pulse trains) as well as using few-cycle pulses with known carrier-envelope phase (CEP). In the case of CEP, control over chemical transformations, typically occurring on a timescale of many femtoseconds, is driven by much faster sub-cycle processes of subfemtosecond to few-femtosecond duration. This is possible because electrons are much lighter than nuclei and fast electron motion is coupled to the much slower nuclear motion. The control originates from populating coherent superpositions of different electronic or vibrational states with relative phases that are dependent on the CEP or phase offset between components of a two-color pulse. In this paper, we review the recent progress made in the directional control over chemical processes, driven by intense few-cycle laser pulses a of waveform-tailored electric field, in different molecules.

  1. A respiratory chain controlled signal transduction cascade in the mitochondrial intermembrane space mediates hydrogen peroxide signaling.

    Science.gov (United States)

    Patterson, Heide Christine; Gerbeth, Carolin; Thiru, Prathapan; Vögtle, Nora F; Knoll, Marko; Shahsafaei, Aliakbar; Samocha, Kaitlin E; Huang, Cher X; Harden, Mark Michael; Song, Rui; Chen, Cynthia; Kao, Jennifer; Shi, Jiahai; Salmon, Wendy; Shaul, Yoav D; Stokes, Matthew P; Silva, Jeffrey C; Bell, George W; MacArthur, Daniel G; Ruland, Jürgen; Meisinger, Chris; Lodish, Harvey F

    2015-10-20

    Reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) govern cellular homeostasis by inducing signaling. H2O2 modulates the activity of phosphatases and many other signaling molecules through oxidation of critical cysteine residues, which led to the notion that initiation of ROS signaling is broad and nonspecific, and thus fundamentally distinct from other signaling pathways. Here, we report that H2O2 signaling bears hallmarks of a regular signal transduction cascade. It is controlled by hierarchical signaling events resulting in a focused response as the results place the mitochondrial respiratory chain upstream of tyrosine-protein kinase Lyn, Lyn upstream of tyrosine-protein kinase SYK (Syk), and Syk upstream of numerous targets involved in signaling, transcription, translation, metabolism, and cell cycle regulation. The active mediators of H2O2 signaling colocalize as H2O2 induces mitochondria-associated Lyn and Syk phosphorylation, and a pool of Lyn and Syk reside in the mitochondrial intermembrane space. Finally, the same intermediaries control the signaling response in tissues and species responsive to H2O2 as the respiratory chain, Lyn, and Syk were similarly required for H2O2 signaling in mouse B cells, fibroblasts, and chicken DT40 B cells. Consistent with a broad role, the Syk pathway is coexpressed across tissues, is of early metazoan origin, and displays evidence of evolutionary constraint in the human. These results suggest that H2O2 signaling is under control of a signal transduction pathway that links the respiratory chain to the mitochondrial intermembrane space-localized, ubiquitous, and ancient Syk pathway in hematopoietic and nonhematopoietic cells.

  2. The Adaptor Protein SAP Directly Associates with CD3ζ Chain and Regulates T Cell Receptor Signaling

    Science.gov (United States)

    Proust, Richard; Bertoglio, Jacques; Gesbert, Franck

    2012-01-01

    Mutations altering the gene encoding the SLAM associated protein (SAP) are responsible for the X-linked lymphoproliferative disease or XLP1. Its absence is correlated with a defective NKT cells development, a decrease in B cell functions and a reduced T cells and NK cells cytotoxic activities, thus leading to an immunodeficiency syndrome. SAP is a small 128 amino-acid long protein that is almost exclusively composed of an SH2 domain. It has been shown to interact with the CD150/SLAM family of receptors, and in a non-canonical manner with SH3 containing proteins such as Fyn, βPIX, PKCθ and Nck1. It would thus play the role of a minimal adaptor protein. It has been shown that SAP plays an important function in the activation of T cells through its interaction with the SLAM family of receptors. Therefore SAP defective T cells display a reduced activation of signaling events downstream of the TCR-CD3 complex triggering. In the present work, we evidence that SAP is a direct interactor of the CD3ζ chain. This direct interaction occurs through the first ITAM of CD3ζ, proximal to the membrane. Additionally, we show that, in the context of the TCR-CD3 signaling, an Sh-RNA mediated silencing of SAP is responsible for a decrease of several canonical T cell signaling pathways including Erk, Akt and PLCγ1 and to a reduced induction of IL-2 and IL-4 mRNA. Altogether, we show that SAP plays a central function in the T cell activation processes through a direct association with the CD3 complex. PMID:22912825

  3. NOVEL SYNTHESIS OF LONG MULTI-BLOCK HETEROPOLYMER CHAINS WITH AN ORDERED SEQUENCE AND CONTROLLABLE BLOCK LENGTHS

    Institute of Scientific and Technical Information of China (English)

    Chi Wu; Zuo-wei Xie; Guang-zhao Zhang; Guo-fu Zi

    2001-01-01

    It had very long been a dream in polymer science to synthesize long multi-block polymer chains with an ordered chain sequence and controllable block lengths. Using ionic or living free radical polymerization or furnishing each end of polymer blocks with a reactive functional group, one can only prepare heteropolymer chains with few long blocks, such as diblock and triblock copolymers. The most plausible result so far was a pentablock copolymer. Recently, using a combination of polymer physics and synthetic chemistry, we have invented self-assembly assisted polycondensation (SAAP). This communication reports the results of using this novel method to connect 10-100 triblock polymer chains together to form long multi-block heteropolymer chains with an ordered sequence and controllable block lengths.``

  4. Optimal Control for Fast and Robust Generation of Entangled States in Anisotropic Heisenberg Chains

    Science.gov (United States)

    Zhang, Xiong-Peng; Shao, Bin; Zou, Jian

    2017-05-01

    Motivated by some recent results of the optimal control (OC) theory, we study anisotropic XXZ Heisenberg spin-1/2 chains with control fields acting on a single spin, with the aim of exploring how maximally entangled state can be prepared. To achieve the goal, we use a numerical optimization algorithm (e.g., the Krotov algorithm, which was shown to be capable of reaching the quantum speed limit) to search an optimal set of control parameters, and then obtain OC pulses corresponding to the target fidelity. We find that the minimum time for implementing our target state depending on the anisotropy parameter Δ of the model. Finally, we analyze the robustness of the obtained results for the optimal fidelities and the effectiveness of the Krotov method under some realistic conditions.

  5. Study on color identification for monitoring and controlling fermentation process of branched chain amino acid

    Science.gov (United States)

    Ma, Lei; Wang, Yizhong; Chen, Ning; Liu, Tiegen; Xu, Qingyang; Kong, Fanzhi

    2008-12-01

    In this paper, a new method for monitoring and controlling fermentation process of branched chain amino acid (BCAA) was proposed based on color identification. The color image of fermentation broth of BCAA was firstly taken by a CCD camera. Then, it was changed from RGB color model to HIS color model. Its histograms of hue H and saturation S were calculated, which were used as the input of a designed BP network. The output of the BP network was the description of the color of fermentation broth of BCAA. After training, the color of fermentation broth was identified by the BP network according to the histograms of H and S of a fermentation broth image. Along with other parameters, the fermentation process of BCAA was monitored and controlled to start the stationary phase of fermentation soon. Experiments were conducted with satisfied results to show the feasibility and usefulness of color identification of fermentation broth in fermentation process control of BCAA.

  6. Bifurcation and chaos of a pest-control food chain model with impulsive effects

    Energy Technology Data Exchange (ETDEWEB)

    Wang Fengyan [Department of Mathematics, Wenzhou University, Wenzhou Zhejiang 325000 (China) and College of Science, Jimei University, Xiamen Fujian 361021 (China)], E-mail: wangfy68@163.com; Pang Guoping [Department of Mathematics and Computer Science, Yulin Normal University, Yulin Guangxi 537000 (China)], E-mail: g.p.pang@163.com; Lu Zhengyi [Department of Mathematics, Wenzhou University, Wenzhou Zhejiang 325000 (China)

    2009-02-28

    According to biological and chemical control strategy for pest control, we investigate the dynamics of a predator-prey food chain with impulsive effect, periodic releasing natural enemies and spraying pesticide at different fixed times, by using impulsive differential equation. Choose pest birth rate r{sub 2} as control parameter, we show that there exists a stable pest-eradication periodic solution when r{sub 2} is less than some critical value r{sub 2}* and the system is permanence when r{sub 2} is larger than the critical value r{sub 2}*. By use of standard techniques of bifurcation theory, we prove that above this threshold there are periodic oscillations in prey, middle-predator and top predator. Furthermore, bifurcation diagrams have shown that there exists complexity for the pulsed system including periodic doubling cascade.

  7. Optimal Control for Fast and Robust Generation of Entangled States in Anisotropic Heisenberg Chains

    Science.gov (United States)

    Zhang, Xiong-Peng; Shao, Bin; Zou, Jian

    2017-02-01

    Motivated by some recent results of the optimal control (OC) theory, we study anisotropic XXZ Heisenberg spin-1/2 chains with control fields acting on a single spin, with the aim of exploring how maximally entangled state can be prepared. To achieve the goal, we use a numerical optimization algorithm (e.g., the Krotov algorithm, which was shown to be capable of reaching the quantum speed limit) to search an optimal set of control parameters, and then obtain OC pulses corresponding to the target fidelity. We find that the minimum time for implementing our target state depending on the anisotropy parameter Δ of the model. Finally, we analyze the robustness of the obtained results for the optimal fidelities and the effectiveness of the Krotov method under some realistic conditions.

  8. Directional Control of Plasmon-Exciton interaction with Plexcitonic Crystals

    Science.gov (United States)

    Balci, Sinan; Karademir, Ertugrul; Kocabas, Coskun; Aydinli, Atilla

    2015-03-01

    Plexcitons are strongly coupled plasmon excitons modes. In this work, we developed a platform, consisting of one and two dimensional corrugated surface patterns coated with a thin metal film and a dye solution. This system shows a controlled coupling action based on the excitation direction of SPP modes. Our scheme is based on the control of wavelengths of the forbidden SPP modes. Three kinds of patterns have been tested; a one dimensional uniform, a triangular, and a square lattice type crystals. For all three cases, lowest wavelength of the band gap is observed in Γ to M direction. For triangular and square lattice cases, band gap center oscillates between two finite values for every 60° and 90°s, respectively. We utilized this behavior to control SPP and J-aggregate coupling. We observe directional dependence of Rabi splitting energy varying between 0 meV and 60 meV . Square lattice gives the ability to tune a larger band gap, whereas triangular lattice gives higher number of symmetry points. Simulations show that, an 80 nm deep triangular lattice with 280 nm periodicity can result in omnidirectional decoupling of plexcitons. TUBITAK, Grants 110T790, 110T589, and 112T091.

  9. A New Approach for Controlling Chaos Based on Direct Optimizing Predictive Control

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    We introduce the predictive control theory into the study of chaos control and propose a direct optimizing predictive control algorithm based on a neural network model. The proposed control system stabilizes the chaotic motion in an unknown chaotic system onto the desired target trajectory. Compared with the existing similar algorithms, the proposed control system has faster response, so it requires much shorter time for the stabilization of the chaotic systems.The proposed approach can control hyperchaos and the algorithm is simple. The convergence of the control algorithm and the stability of the control system can be guaranteed. The theoretic analysis and simulations demonstrate the effectiveness of the algorithm.

  10. Damping Force Tracking Control of MR Damper System Using a New Direct Adaptive Fuzzy Controller

    Directory of Open Access Journals (Sweden)

    Xuan Phu Do

    2015-01-01

    Full Text Available This paper presents a new direct adaptive fuzzy controller and its effectiveness is verified by investigating the damping force tracking control of magnetorheological (MR fluid based damper (MR damper in short system. In the formulation of the proposed controller, a model of interval type 2 fuzzy controller is combined with the direct adaptive control to achieve high performance in vibration control. In addition, H∞ (H infinity tracking technique is used in building a model of the direct adaptive fuzzy controller in which an enhanced iterative algorithm is combined with the fuzzy model. After establishing a closed-loop control structure to achieve high control performance, a cylindrical MR damper is adopted and damping force tracking results are obtained and discussed. In addition, in order to demonstrate the effectiveness of the proposed control strategy, two existing controllers are modified and tested for comparative work. It has been demonstrated from simulation and experiment that the proposed control scheme provides much better control performance in terms of damping force tracking error. This leads to excellent vibration control performance of the semiactive MR damper system associated with the proposed controller.

  11. Bayesian reconstruction of P(r) directly from two-dimensional detector images via a Markov chain Monte Carlo method.

    Science.gov (United States)

    Paul, Sudeshna; Friedman, Alan M; Bailey-Kellogg, Chris; Craig, Bruce A

    2013-04-01

    The interatomic distance distribution, P(r), is a valuable tool for evaluating the structure of a molecule in solution and represents the maximum structural information that can be derived from solution scattering data without further assumptions. Most current instrumentation for scattering experiments (typically CCD detectors) generates a finely pixelated two-dimensional image. In contin-uation of the standard practice with earlier one-dimensional detectors, these images are typically reduced to a one-dimensional profile of scattering inten-sities, I(q), by circular averaging of the two-dimensional image. Indirect Fourier transformation methods are then used to reconstruct P(r) from I(q). Substantial advantages in data analysis, however, could be achieved by directly estimating the P(r) curve from the two-dimensional images. This article describes a Bayesian framework, using a Markov chain Monte Carlo method, for estimating the parameters of the indirect transform, and thus P(r), directly from the two-dimensional images. Using simulated detector images, it is demonstrated that this method yields P(r) curves nearly identical to the reference P(r). Furthermore, an approach for evaluating spatially correlated errors (such as those that arise from a detector point spread function) is evaluated. Accounting for these errors further improves the precision of the P(r) estimation. Experimental scattering data, where no ground truth reference P(r) is available, are used to demonstrate that this method yields a scattering and detector model that more closely reflects the two-dimensional data, as judged by smaller residuals in cross-validation, than P(r) obtained by indirect transformation of a one-dimensional profile. Finally, the method allows concurrent estimation of the beam center and Dmax, the longest interatomic distance in P(r), as part of the Bayesian Markov chain Monte Carlo method, reducing experimental effort and providing a well defined protocol for these

  12. Study on methods for improving compressibility of 4-direction Freeman chain code%Freeman四方向链码压缩率提高的方法研究

    Institute of Scientific and Technical Information of China (English)

    李灵华; 刘勇奎

    2013-01-01

    文中通过大量的实验,在研究现有的基于Freeman方向链码的方法的基础上,对提高Freeman四方向链码压缩率的方法进行了深入的研究.从改变码值含义定义并对码值进行Huffman编码,进而对出现频率最高的码值进行计算编码等不同角度,进行大量的实验、比较与分析.提出了一个Freeman四方向链码新方法:计算编码不等长相对四方向Freeman链码——AVRF4.实验结果表明,其链码压缩率比Freeman八方向链码提高了26%,而比原始Freeman四方向链码提高了15%.%To study the methods for improving the efficiency of 4-direction Freeman chain code, the methods based on existing Freeman direction chain code is researched though a large number of experiments. A large number of experiments, comparison and analysis are carried from the different views, such as changing the definition of code elements and employing combining encoding for code elements, and applying arithmetic encoding for the code elements with highest probability. At last, a new method based on 4-direction Freeman chain code entitled arithmetic encoding variable-length relative 4-direction Freeman chain code, namely AVRF4 is put forward. The experimental results show that the compressibility of AVRF4 increases 26% more than 8-di-rection Freeman chain code and 15% more than 4-direction Freeman chain code.

  13. Direct Torque Control of a Small Wind Turbine with a Sliding-Mode Speed Controller

    Science.gov (United States)

    Sri Lal Senanayaka, Jagath; Karimi, Hamid Reza; Robbersmyr, Kjell G.

    2016-09-01

    In this paper. the method of direct torque control in the presence of a sliding-mode speed controller is proposed for a small wind turbine being used in water heating applications. This concept and control system design can be expanded to grid connected or off-grid applications. Direct torque control of electrical machines has shown several advantages including very fast dynamics torque control over field-oriented control. Moreover. the torque and flux controllers in the direct torque control algorithms are based on hvsteretic controllers which are nonlinear. In the presence of a sliding-mode speed control. a nonlinear control system can be constructed which is matched for AC/DC conversion of the converter that gives fast responses with low overshoots. The main control objectives of the proposed small wind turbine can be maximum power point tracking and soft-stall power control. This small wind turbine consists of permanent magnet synchronous generator and external wind speed. and rotor speed measurements are not required for the system. However. a sensor is needed to detect the rated wind speed overpass events to activate proper speed references for the wind turbine. Based on the low-cost design requirement of small wind turbines. an available wind speed sensor can be modified. or a new sensor can be designed to get the required measurement. The simulation results will be provided to illustrate the excellent performance of the closed-loop control system in entire wind speed range (4-25 m/s).

  14. Induction machine Direct Torque Control system based on fuzzy adaptive control

    Science.gov (United States)

    Li, Shi-ping; Yu, Yan; Jiao, Zhen-gang; Gu, Shu-sheng

    2009-07-01

    Direct Torque Control technology is a high-performance communication control method, it uses the space voltage vector method, and then to the inverter switch state control, to obtain high torque dynamic performance. But none of the switching states is able to generate the exact voltage vector to produce the desired changes in torque and flux in most of the switching instances. This causes a high ripple in torque. To solve this problem, a fuzzy implementation of Direct Torque Control of Induction machine is presented here. Error of stator flux, error of motor electromagnetic torque and position of angle of flux are taken as fuzzy variables. In order to further solve nonlinear problem of variation parameters in direct torque control system, the paper proposes a fuzzy parameter PID adaptive control method which is suitable for the direct torque control of an asynchronous motor. The generation of its fuzzy control is obtained by analyzing and optimizing PID control step response and combining expert's experience. For this reason, it carries out fuzzy work to PID regulator of motor speed to achieve to regulate PID parameters. Therefore the control system gets swifter response velocity, stronger robustness and higher precision of velocity control. The computer simulated results verify the validity of this novel method.

  15. Control concepts for direct steam generation in parabolic troughs

    Energy Technology Data Exchange (ETDEWEB)

    Valenzuela, Loreto; Zarza, Eduardo [CIEMAT, Plataforma Solar de Almeria, Tabernas (Almeria) (Spain); Berenguel, Manuel [Universidad de Almeria, Dept. de Lenguajes y Computacion, Almeria (Spain); Camacho, Eduardo F. [Universidad de Sevilla, Dept. de Ingenieria de Sistemas y Automatica, Sevilla (Spain)

    2005-02-01

    A new prototype parabolic-trough collector system was erected at the Plataforma Solar de Almeria (PSA) (1996-1998) to investigate direct steam generation (DSG) in a solar thermal power plant under real solar conditions. The system has been under evaluation for efficiency, cost, control and other parameters since 1999. The main objective of the control system is to obtain steam at constant temperature and pressure at the solar field outlet, so that changes in inlet water conditions and/or in solar radiation affect the amount of steam, but not its quality or the nominal plant efficiency. This paper presents control schemes designed and tested for two operating modes, 'Recirculation', for which a proportional-integral-derivative (PI/PID) control functions scheme has been implemented, and 'Once-through', requiring more complex control strategies, for which the scheme is based on proportional-integral (PI), feedforward and cascade control. Experimental results of both operation modes are discussed. (Author)

  16. Direct Vector Control of Induction Motor Based on Sinusoidal PWM Inverter with Fuzzy Logic Controller

    Directory of Open Access Journals (Sweden)

    Nirban Chakraborty

    2014-04-01

    Full Text Available This paper presents the speed control scheme of direct vector control of Induction Motor drive (IM drive. The Fuzzy logic controller is (FLC used as the controller part here for the direct vector control of Induction Motor using Sinusoidal PWM Inverter (SPWM. Fuzzy logic controller has become a very popular controlling scheme in the field of Industrial application. The entire module of this IM is divided into several parts such as IM body module, Inverter module, coordinate transformation module and Sinusoidal pulse width modulation (SPWM production module and so on. With the help of this module we can analyze a variety of different simulation waveforms, which provide an effective means for the analysis and design of the IM control system using FLC technique.

  17. Complete control, direct observation and study of molecular super rotors

    CERN Document Server

    Korobenko, Aleksey; Milner, Valery

    2013-01-01

    Extremely fast rotating molecules carrying significantly more energy in their rotation than in any other degree of freedom are known as "super rotors". It has been speculated that super rotors may exhibit a number of unique and intriguing properties. Theoretical studies showed that ultrafast molecular rotation may change the character of molecular scattering from solid surfaces, alter molecular trajectories in external fields, make super rotors surprisingly stable against collisions, and lead to the formation of gas vortices. New ways of molecular cooling and selective chemical bond breaking by ultrafast spinning have been proposed. Owing to the fundamental laws of nature, bringing a large number of molecules to fast, directional and synchronous rotation is rather challenging. As a result, only indirect evidence of super rotors has been reported to date. Here we demonstrate the first controlled creation, direct observation and study of molecular super rotors. Using intense laser pulses tailored to produce an ...

  18. Graphs: Associated Markov Chains

    OpenAIRE

    2012-01-01

    In this research paper, weighted / unweighted, directed / undirected graphs are associated with interesting Discrete Time Markov Chains (DTMCs) as well as Continuous Time Markov Chains (CTMCs). The equilibrium / transient behaviour of such Markov chains is studied. Also entropy dynamics (Shannon entropy) of certain structured Markov chains is investigated. Finally certain structured graphs and the associated Markov chains are studied.

  19. Research on Direct Torque Control System Based on Induction Motor

    Institute of Scientific and Technical Information of China (English)

    康劲松; 陶生桂; 毛明平

    2003-01-01

    The mathematic model of direct torque control (DTC) was deduced. Two simulating models based on the MATLAB & SIMULINK were established. The emphasis is focused on study of the performance difference of the DTC system with stator flux hexagon and circle trajectories. The simulation waveforms of flux, torque and current characters with two flux trajectories were given. Experiments were carried out in an AC drive system based on induction motor and two-level inverter. A dual-CPU structure was used and the communication with two CPUs was obtained by a dual-port RAM in this system.

  20. Direct Torque Control for Double Star Induction Motor

    OpenAIRE

    LEKHCHINE, SALIMA; BAHI, TAHAR; Soufi, Youcef

    2016-01-01

    This paper describes a direct torque control (DTC) of dual star induction motor (DSIM). This machine possesses several advantages over conventional three-phase machine and is also known as the six-phase induction machine. The research has been underway for the last two decades to investigate the various issues related to the use of six-phase machine as a potential alternative to the conventional three-phase machine. Though six-phase machines have existed for some time, in the literature very ...

  1. Matrix converter controlled with the direct transfer function approach

    DEFF Research Database (Denmark)

    Rodriguez, J.; Silva, E.; Blaabjerg, Frede

    2005-01-01

    Power electronics is an emerging technology. New power circuits are invented and have to be introduced into the power electronics curriculum. One of the interesting new circuits is the matrix converter (MC), and this paper analyses its working principles. A simple model is proposed to represent...... the power circuit, including the input filter. The power semiconductors are modelled as ideal bidirectional switches and the MC is controlled using a direct transfer function approach. The modulation strategy of the converter is explained in a complete and clear form. The commutation problem of two switches...

  2. An Improved Fixed Switching Frequency Direct Torque Control of Induction Motor Drives Fed by Direct Matrix Converter

    CERN Document Server

    Taib, Nabil; Francois, Bruno

    2010-01-01

    A few papers have been interested by the fixed switching frequency direct torque control fed by direct matrix converters, where we can find just the use of direct torque controlled space vector modulated method. In this present paper, we present an improved method used for a fixed switching frequency direct torque control (DTC) using a direct matrix converter (DMC). This method is characterized by a simple structure, a fixed switching frequency which causes minimal torque ripple and a unity input power factor. Using this strategy, we combine the direct matrix converters advantages with those of direct torque control (DTC) schemes. The used technique for constant frequency is combined with the input current space vector to create the switching table of direct matrix converter (DMC). Simulation results clearly demonstrate a better dynamic and steady state performances of the proposed method.

  3. Adaptive Neural Control Based on High Order Integral Chained Differentiator for Morphing Aircraft

    Directory of Open Access Journals (Sweden)

    Zhonghua Wu

    2015-01-01

    Full Text Available This paper presents an adaptive neural control for the longitudinal dynamics of a morphing aircraft. Based on the functional decomposition, it is reasonable to decompose the longitudinal dynamics into velocity and altitude subsystems. As for the velocity subsystem, the adaptive control is proposed via dynamic inversion method using neural network. To deal with input constraints, the additional compensation system is employed to help engine recover from input saturation rapidly. The highlight is that high order integral chained differentiator is used to estimate the newly defined variables and an adaptive neural controller is designed for the altitude subsystem where only one neural network is employed to approximate the lumped uncertain nonlinearity. The altitude subsystem controller is considerably simpler than the ones based on backstepping. It is proved using Lyapunov stability theory that the proposed control law can ensure that all the tracking error converges to an arbitrarily small neighborhood around zero. Numerical simulation study demonstrates the effectiveness of the proposed strategy, during the morphing process, in spite of some uncertain system nonlinearity.

  4. Direct Self-Repairing Control for Quadrotor Helicopter Attitude Systems

    Directory of Open Access Journals (Sweden)

    Huiliao Yang

    2014-01-01

    Full Text Available A quadrotor helicopter with uncertain actuator faults, such as loss of effectiveness and lock-in-place, is studied in this paper. An adaptive fuzzy sliding mode controller based on direct self-repairing control is designed for such nonlinear system to track the desired output signal, when any actuator of this quadrotor helicopter is loss of effectiveness or stuck at some place. Moreover, using the Lyapunov stability theory, the stability of the whole system and the convergence of the tracking error can be guaranteed. Finally, the availability of the proposed method is verified by simulation on 3-DOF hover to ensure that the system performance under faulty conditions can be quickly recovered to its normal level. And this proposed method is also proved to be better than that of LQR through simulation.

  5. Controlled Levitation of Colloids through Direct Current Electric Fields.

    Science.gov (United States)

    Silvera Batista, Carlos A; Rezvantalab, Hossein; Larson, Ronald G; Solomon, Michael J

    2017-07-07

    We report the controlled levitation of surface-modified colloids in direct current (dc) electric fields at distances as far as 75 μm from an electrode surface. Instead of experiencing electrophoretic deposition, colloids modified through metallic deposition or the covalent bonding of poly(ethylene glycol) (PEG) undergo migration and focusing that results in levitation at these large distances. The levitation is a sensitive function of the surface chemistry and magnitude of the field, thus providing the means to achieve control over the levitation height. Experiments with particles of different surface charge show that levitation occurs only when the absolute zeta potential is below a threshold value. An electrodiffusiophoretic mechanism is proposed to explain the observed large-scale levitation.

  6. Direct metal writing: Controlling the rheology through microstructure

    Science.gov (United States)

    Chen, Wen; Thornley, Luke; Coe, Hannah G.; Tonneslan, Samuel J.; Vericella, John J.; Zhu, Cheng; Duoss, Eric B.; Hunt, Ryan M.; Wight, Michael J.; Apelian, Diran; Pascall, Andrew J.; Kuntz, Joshua D.; Spadaccini, Christopher M.

    2017-02-01

    Most metal additive manufacturing approaches are based on powder-bed melting techniques such as laser selective melting or electron beam melting, which often yield uncontrolled microstructures with defects (e.g., pores or microcracks) and residual stresses. Here, we introduce a proof-of-concept prototype of a 3D metal freeform fabrication process by direct writing of metallic alloys in the semi-solid regime. This process is achieved through controlling the particular microstructure and the rheological behavior of semi-solid alloy slurries, which demonstrate a well suited viscosity and a shear thinning property to retain the shape upon printing. The ability to control the microstructure through this method yields a flexible manufacturing route to fabricating 3D metal parts with full density and complex geometries.

  7. STATOR FLUX OPTIMIZATION ON DIRECT TORQUE CONTROL WITH FUZZY LOGIC

    Directory of Open Access Journals (Sweden)

    Fatih Korkmaz

    2012-07-01

    Full Text Available The Direct Torque Control (DTC is well known as an effective control technique for high performance drives in a wide variety of industrial applications and conventional DTC technique uses two constant reference value: torque and stator flux. In this paper, fuzzy logic based stator flux optimization technique for DTC drives that has been proposed. The proposed fuzzy logic based stator flux optimizer self-regulates the stator flux reference using induction motor load situation without need of any motor parameters. Simulation studies have been carried out with Matlab/Simulink to compare the proposed system behaviors at vary load conditions. Simulation results show that the performance of the proposed DTC technique has been improved and especially at low-load conditions torque ripple are greatly reduced with respect to the conventional DTC.

  8. System for controllable magnetic measurement with direct field determination

    Science.gov (United States)

    Stupakov, O.

    2012-02-01

    This work describes a specially designed setup for magnetic hysteresis and Barkhausen noise measurements. The setup combines two main elements: an improved fast algorithm to control the waveform of magnetic induction and simultaneous direct determination of the magnetic field. The digital feedback algorithm uses only the previous measurement cycle to correct the magnetization voltage without any additional correlation parameter; it usually converges after several tens of cycles. The magnetic field is measured at the sample surface using a vertically mounted array of sensitive Hall sensors. Linear extrapolation of the tangential field profile to the sample surface determines the true waveform of the magnetic field. This unique combination of physically based control for both parameters of the magnetization process provides stable and reliable results, which are independent of a specified experimental configuration. This is illustrated for the industrially attractive measurements of non-oriented electrical steels with a 50 Hz sinusoidal induction waveform.

  9. Direct Torque Control of IPMSM to Improve Torque ripple and Efficiency based on Fuzzy Controller

    Directory of Open Access Journals (Sweden)

    B. Mirzaeian Dehkordi

    2012-09-01

    Full Text Available In this paper, a stator-flux-reference frame control method is proposed in order to control the speed and torque of an Interior Permanent Magnet Synchronous Machine (IPMSM in different loads condition. Direct Torque Control method (DTC based on Space Vector Modulation (SVM is used for control of IPMSM. In the proposed control method, conventional PI controller is used for controlling the stator flux, and torque of the motor. Also, a fuzzy controller is considered to improve the dynamic performance of DTC technique for speed control. In comparison to the conventional reference flux controller methods, this method, in addition, improves the torque profile of the motor drive. Moreover, it reduces copper losses. Simulation results for a 240V, 120A, 2500rpm, IPMSM confirm the appropriate performances of the method.

  10. Direct polymerase chain reaction amplification of formalin-fixed, paraffin-wax-embedded tissue after automated sequential laser microdissection and pressure catapulting.

    Science.gov (United States)

    O'Kane, S L; Garimella, V; Sivarajasingham, N; Drew, P J; Cawkwell, L

    2007-02-01

    A robust method to facilitate rapid laser microdissection and pressure catapulting (LMPC) coupled with direct polymerase chain reaction (dPCR) to eliminate the need for extraction of DNA before a PCR-based assay is described. This sequential LMPC-dPCR method is rapid and decreases the number of processing steps, reducing the chance of tissue loss and contamination.

  11. Controlling influenza disease: Comparison between discrete time Markov chain and deterministic model

    Science.gov (United States)

    Novkaniza, F.; Ivana, Aldila, D.

    2016-04-01

    Mathematical model of respiratory diseases spread with Discrete Time Markov Chain (DTMC) and deterministic approach for constant total population size are analyzed and compared in this article. Intervention of medical treatment and use of medical mask included in to the model as a constant parameter to controlling influenza spreads. Equilibrium points and basic reproductive ratio as the endemic criteria and it level set depend on some variable are given analytically and numerically as a results from deterministic model analysis. Assuming total of human population is constant from deterministic model, number of infected people also analyzed with Discrete Time Markov Chain (DTMC) model. Since Δt → 0, we could assume that total number of infected people might change only from i to i + 1, i - 1, or i. Approximation probability of an outbreak with gambler's ruin problem will be presented. We find that no matter value of basic reproductive ℛ0, either its larger than one or smaller than one, number of infection will always tends to 0 for t → ∞. Some numerical simulation to compare between deterministic and DTMC approach is given to give a better interpretation and a better understanding about the models results.

  12. Construction and direct electrochemistry of orientation controlled laccase electrode.

    Science.gov (United States)

    Li, Ying; Zhang, Jiwei; Huang, Xirong; Wang, Tianhong

    2014-03-28

    A laccase has multiple redox centres. Chemisorption of laccases on a gold electrode through a polypeptide tag introduced at the protein surface provides an isotropic orientation of laccases on the Au surface, which allows the orientation dependent study of the direct electrochemistry of laccase. In this paper, using genetic engineering technology, two forms of recombinant laccase which has Cys-6×His tag at the N or C terminus were generated. Via the Au-S linkage, the recombinant laccase was assembled orientationally on gold electrode. A direct electron transfer and a bioelectrocatalytic activity toward oxygen reduction were observed on the two orientation controlled laccase electrodes, but their electrochemical behaviors were found to be quite different. The orientation of laccase on the gold electrode affects both the electron transfer pathway and the electron transfer efficiency of O2 reduction. The present study is helpful not only to the in-depth understanding of the direct electrochemistry of laccase, but also to the development of laccase-based biofuel cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Direct numerical simulation of vector-controlled free jets

    Energy Technology Data Exchange (ETDEWEB)

    Tsujimoto, K; Ao, K; Shakouchi, T; Ando, T, E-mail: tujimoto@mach.mie-u.ac.jp [Graduate School of Engineering, Mie University, Tsu, 514-8507 (Japan)

    2011-12-22

    We conduct DNS (direct numerical simulation) of vector controlled free jets. The inflow velocity of jet is periodically oscillated perpendicular to the jet axis. In order to realize the high accurate computation, a discretization in space is performed with hybrid scheme in which Fourier spectral and 6th order compact scheme are adopted. From visualized instantaneous vortex structures, it is found that the flow pattern considerably changes according to the oscillating frequency, i.e., according to the increasing the frequency, wave, bifurcating and flapping modes appear in turn. In order to quantify mixing efficiency under the vector control, as the mixing measure, statistical entropy is investigated. Compared to the uncontrolled jet, the mixing efficiency is improved in order of wavy, flapping and bifurcating modes. Thus the vector control can be expected for the improvement of mixing efficiency. Further to make clear the reason for the mixing enhancement, Snapshot POD and DMD method are applied. The primary flow structures under the vector control are demonstrated.

  14. Towards a Diagnostic Instrument to Identify Improvement Opportunities for Quality Controlled Logistics in Agrifood Supply Chain Networks

    Directory of Open Access Journals (Sweden)

    Jack G.A.J. van der Vorst

    2011-10-01

    Full Text Available  Western-European consumers have become not only more demanding on product availability in retail outlets but also on other food attributes such as quality, integrity, and safety. When (redesigning food supply-chain networks, from a logistics point of view, one has to consider these demands next to traditional efficiency and responsiveness requirements. The concept ‘quality controlled logistics’ (QCL hypothesizes that if product quality in each step of the supply chain can be predicted in advance, goods flows can be controlled in a pro-active manner and better chain designs can be established resulting in higher product availability, constant quality, and less product losses. The paper discusses opportunities of using real-time product quality information for improvement of the design and management of ‘AgriFood Supply Chain Networks’, and presents a preliminary diagnostic instrument for assessment of ‘critical quality’ and ‘logistics control’ points in the supply chain network. Results of a tomato-chain case illustrate the added value of the QCL concept for identifying improvement opportunities in the supply chain as to increase both product availability and quality. Future research aims for the further development of the diagnostic instrument and the quantification of costs and benefits of QCL scenarios.

  15. Controller Design for Direct Torque Controlled Space Vector Modulated (DTC-SVM) Induction Motor Drives

    DEFF Research Database (Denmark)

    Zelechowski, M.; Kazmierkowski, M.P.; Blaabjerg, Frede

    2005-01-01

    In this paper two different methods of PI controllers for direct torque controlled-space vector modulated induction motor drives have been studied. The first one is simple method based only on symmetric optimum criterion. The second approach takes into account the full model of induction motor in...

  16. Novel Design for Direct Torque Control System of PMSM

    Directory of Open Access Journals (Sweden)

    HUANG Xu-chao

    2013-04-01

    Full Text Available Nowadays, with the rapid development of high-performance servo system, The conventional permanent magnet synchronous motor (PMSM Direct Torque Control (DTC system has large torque ripple in low speed which cannot be well adapted to today`s development. The main reason is because the number of voltage vectors provided by the two-level inverter is only six and the relationship between voltage vector and torque is not clear[1-5.10-12]. In this paper, the basic concept of direct torque control of permanent magnet synchronous motor is investigated in order to emphasize the effects produced by a given voltage vector on stator and torque variations in this paper. Modified the voltage sector switching table, a novel DTC scheme for the permanent magnet synchronous motor is proposed which is using a novel three-level inverter. An improvement of the drive performance can be obtained by using the novel DTC scheme. The simulation results showed that the scheme could reduce the torque ripple in low speed and improved the stability of the motor under the condition of keeping the system dynamic performance.

  17. Minimizing Segregation during the Controlled Directional Solidification of Dendric Alloys

    Science.gov (United States)

    Grugel, Richard N.; Fedoseyev, Alex; Kim, Shin-Woo

    2003-01-01

    Gravity-driven convection induced in the liquid by density gradients of temperature or composition disrupts uniform dendritic growth during controlled directional solidification and promotes severe macrosegregation. The solute-rich region about the dendrite tip appears to play a pivotal role in channel initiation. Allen and Hunt referred to this region as an "initial transient" or dynamic region constituting steep concentration gradients. Experimental investigation also point to the role the tip region plays in developing microstructure. Hellawell and co-workers showed that flow-through dendritic channels could be effectively disrupted, and segregation minimized, during the gradient freezing of bulk castings by rotating the melt through a slight angle with respect to Earth's gravity vector. Adapting this principle to controlled directional solidification, it has been shown" that segregation in dendritic alloys can be minimized, and properties improved, by processing the sample near horizontal in conjunction with a slow axial rotation of the crucible. It is postulated that the observed microstructural uniformity arises by maintaining the developing solute field about the dendrite tip. Solute rejected during vertical directional solidification will rise or sink parallel to the primary dendrite arms during axial rotation setting the stage for accumulation, instabilities, and segregation. In contrast, during horizontal growth, the rejected solute will sink or rise perpendicular to the primary dendrite. Now, in the presence of a slight axial rotation, solute that was initially sinking (or rising) will find itself above (or below) its parent dendrite, i.e., still about the tip region. The following is intended to experimentally demonstrate the viability of this concept in coordination with a model that gives predictive insight regarding solute distribution about growing dendrites. Alloys based on the lead-tin eutectic system were used in this study. The system is well

  18. Blood and urine samples as useful sources for the direct detection of tuberculosis by polymerase chain reaction.

    Science.gov (United States)

    Rebollo, María J; San Juan Garrido, Rafael; Folgueira, Dolores; Palenque, Elia; Díaz-Pedroche, C; Lumbreras, Carlos; Aguado, José M

    2006-10-01

    The aim of the study was to assess the utility of the polymerase chain reaction (PCR) assay in blood and urine for the diagnosis of tuberculosis (TB). We prospectively evaluated the usefulness of PCR performed in blood and urine samples from patients with proved or probable TB compared with a control group of patients. The PCR technique was performed using IS6110 primers. We included in the study 57 patients (43 with definite TB and 14 with probable TB) and 26 controls. Blood and urine samples were drawn at the time of microbiologic diagnosis and 3, 6, 9, and 12 months later. Cultures were positive in the early period (<1 month after treatment) in 11 of 57 patients (19%) with probable or definite TB, in comparison with 42% of patients (24/57) who yielded a positive PCR (P = 0.02). Urine samples increased the sensitivity of PCR determination in blood samples by 10%. The PCR in blood and/or urine was positive in 41% of patients with pulmonary TB, in 36% of patients with extrapulmonary TB, and in 50% of patients with disseminated TB. Mycobacterium tuberculosis was still detectable by PCR in 5 of 13 patients with cured TB after 1 or more months of antituberculous treatment. The PCR detection of M. tuberculosis in blood and urine samples is useful for the diagnosis of different clinical forms of TB, mostly in those patients in which sample extraction is difficult or requires aggressive techniques. The sensitivity of this technique could be improved studying more than 1 sample in each patient, even after initiating an antituberculous treatment.

  19. The supply chain of medicinal controlled substances: addressing the Achilles heel of drug diversion.

    Science.gov (United States)

    Coleman, John J

    2012-09-01

    The escalation of prescription drug abuse in the U.S. has attracted the attention of public health and safety officials as well as others puzzled by how such a tightly regulated enterprise could so easily be breached by those seeking controlled substances for nonmedical use. Prescribers and patients who use, misuse, or, in some cases, redistribute or divert these drugs have figured prominently in government strategies aimed at addressing this issue. This review departs from this paradigm and focuses on wholesale drug distributors, a highly efficient and largely behinds-the-scene link in the supply chain of controlled substances. By law, distributors are required to identify and report to the Drug Enforcement Administration (DEA) orders for controlled substances that are suspicious and may indicate drug diversion. Ten cases are examined in which distributors were each charged with failing to prevent the diversion of millions of doses of controlled substances. Special attention is given to a payment system employed by the industry that may encourage this unlawful commerce. Court records, agency and industry reports, and other published sources are used to document referenced cases and their disposition, and recommendations are offered for improving distributors' compliance with the law.

  20. Direct versus Facility Centric Load Control for Automated Demand Response

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Ed; Piette, Mary Ann

    2009-11-06

    Direct load control (DLC) refers to the scenario where third party entities outside the home or facility are responsible for deciding how and when specific customer loads will be controlled in response to Demand Response (DR) events on the electric grid. Examples of third parties responsible for performing DLC may be Utilities, Independent System Operators (ISO), Aggregators, or third party control companies. DLC can be contrasted with facility centric load control (FCLC) where the decisions for how loads are controlled are made entirely within the facility or enterprise control systems. In FCLC the facility owner has more freedom of choice in how to respond to DR events on the grid. Both approaches are in use today in automation of DR and both will continue to be used in future market segments including industrial, commercial and residential facilities. This paper will present a framework which can be used to differentiate between DLC and FCLC based upon where decisions are made on how specific loads are controlled in response to DR events. This differentiation is then used to compare and contrast the differences between DLC and FCLC to identify the impact each has on:(1)Utility/ISO and third party systems for managing demand response, (2)Facility systems for implementing load control, (3)Communications networks for interacting with the facility and (4)Facility operators and managers. Finally a survey of some of the existing DR related specifications and communications standards is given and their applicability to DLC or FCLC. In general FCLC adds more cost and responsibilities to the facilities whereas DLC represents higher costs and complexity for the Utility/ISO. This difference is primarily due to where the DR Logic is implemented and the consequences that creates. DLC may be more certain than FCLC because it is more predictable - however as more loads have the capability to respond to DR signals, people may prefer to have their own control of end-use loads

  1. Direct adaptive control for nonlinear uncertain system based on control Lyapunov function method

    Institute of Scientific and Technical Information of China (English)

    Chen Yimei; Han Zhengzhi; Tang Houjun

    2006-01-01

    The problem of adaptive stabilization of a class of multi-input nonlinear systems with unknown parameters both in the state vector-field and the input vector-field has been considered. By employing the control Lyapunov function method, a direct adaptive controller is designed to complete the global adaptive stability of the uncertain system. At the same time, the controller is also verified to possess the optimality. Example and simulations are provided to illustrate the effectiveness of the proposed method.

  2. Shape control of the magnetic iron oxide nanoparticles under different chain length of reducing agents

    Energy Technology Data Exchange (ETDEWEB)

    Ngoi, Kuan Hoon; Chia, Chin-Hua, E-mail: chia@ukm.edu.my; Zakaria, Sarani [School of Applied Physics, Faculty Science and Technology, University Kebangsaan Malaysia 43600 UKM Bangi, Selangor (Malaysia); Chiu, Wee Siong [Low Dimensional Materials Research Centre, Department of Physics, Faculty of Science, University of Malaya, 50603 Lembah Pantai, Kuala Lumpur (Malaysia)

    2015-09-25

    We report on the effect of using reducing agents with different chain-length on the synthesis of iron oxide nanoparticles by thermal decomposition of iron (III) acetylacetonate in 1-octadecene. This modification allows us to control the shape of nanoparticles into spherical and cubic iron oxide nanoparticles. The highly monodisperse 14 nm spherical nanoparticles are obtained under 1,2-dodecanediol and average 14 nm edge-length cubic iron oxide nanoparticles are obtained under 1,2-tetradecanediol. The structural characterization such as transmission electron microscope (TEM) and X-ray diffraction (XRD) shows similar properties between two particles with different shapes. The vibrating sample magnetometer (VSM) shows no significant difference between spherical and cubic nanoparticles, which are 36 emu/g and 37 emu/g respectively and superparamagnetic in nature.

  3. Bayesian Networks to Compare Pest Control Interventions on Commodities Along Agricultural Production Chains.

    Science.gov (United States)

    Holt, J; Leach, A W; Johnson, S; Tu, D M; Nhu, D T; Anh, N T; Quinlan, M M; Whittle, P J L; Mengersen, K; Mumford, J D

    2017-07-13

    The production of an agricultural commodity involves a sequence of processes: planting/growing, harvesting, sorting/grading, postharvest treatment, packing, and exporting. A Bayesian network has been developed to represent the level of potential infestation of an agricultural commodity by a specified pest along an agricultural production chain. It reflects the dependency of this infestation on the predicted level of pest challenge, the anticipated susceptibility of the commodity to the pest, the level of impact from pest control measures as designed, and any variation from that due to uncertainty in measure efficacy. The objective of this Bayesian network is to facilitate agreement between national governments of the exporters and importers on a set of phytosanitary measures to meet specific phytosanitary measure requirements to achieve target levels of protection against regulated pests. The model can be used to compare the performance of different combinations of measures under different scenarios of pest challenge, making use of available measure performance data. A case study is presented using a model developed for a fruit fly pest on dragon fruit in Vietnam; the model parameters and results are illustrative and do not imply a particular level of fruit fly infestation of these exports; rather, they provide the most likely, alternative, or worst-case scenarios of the impact of measures. As a means to facilitate agreement for trade, the model provides a framework to support communication between exporters and importers about any differences in perceptions of the risk reduction achieved by pest control measures deployed during the commodity production chain. © 2017 Society for Risk Analysis.

  4. Post-harvest control strategies: minimizing mycotoxins in the food chain.

    Science.gov (United States)

    Magan, Naresh; Aldred, David

    2007-10-20

    Contamination of cereal commodities by moulds and mycotoxins results in dry matter, quality, and nutritional losses and represents a significant hazard to the food chain. Most grain is harvested, dried and then stored on farm or in silos for medium/long term storage. Cereal quality is influenced by a range of interacting abiotic and biotic factors. In the so-called stored grain ecosystem, factors include grain and contaminant mould respiration, insect pests, rodents and the key environmental factors of temperature, water availability and intergranular gas composition, and preservatives which are added to conserve moist grain for animal feed. Thus knowledge of the key critical control points during harvesting, drying and storage stages in the cereal production chain are essential in developing effective prevention strategies post-harvest. Studies show that very small amounts of dry matter loss due to mould activity can be tolerated. With mycotoxin contamination and downgrading of lots can occur. The key mycotoxigenic moulds in partially dried grain are Penicillium verrucosum (ochratoxin) in damp cool climates of Northern Europe, and Aspergillus flavus (aflatoxins), A. ochraceus (ochratoxin) and some Fusarium species (fumonisins, trichothecenes) on temperate and tropical cereals. Studies on the ecology of these species has resulted in modelling of germination, growth and mycotoxin minima and prediction of fungal contamination levels which may lead to mycotoxin contamination above the tolerable legislative limits (e.g. for ochratoxin). The effect of modified atmospheres and fumigation with sulphur dioxide and ammonia have been attempted to try and control mould spoilage in storage. Elevated CO2 of >75% are required to ensure that growth of mycotoxigenic moulds does not occur in partially dried grain. Sometimes, preservatives based on aliphatic acids have been used to prevent spoilage and mycotoxin contamination of stored commodities, especially feed. These are

  5. Improving Myoelectric Control for Amputees through Transcranial Direct Current Stimulation.

    Science.gov (United States)

    Pan, Lizhi; Zhang, Dingguo; Sheng, Xinjun; Zhu, Xiangyang

    2015-08-01

    Most prosthetic myoelectric control studies have shown good performance for unimpaired subjects. However, performance is generally unacceptable for amputees. The primary problem is the poor quality of electromyography (EMG) signals of amputees compared with healthy individuals. To improve clinical performance of myoelectric control, this study explored transcranial direct current stimulation (tDCS) to modulate brain activity and enhance EMG quality. We tested six unilateral transradial amputees by applying active and sham anodal tDCS separately on two different days. Surface EMG signals were acquired from the affected and intact sides for 11 hand and wrist motions in the pre-tDCS and post-tDCS sessions. Autoregression coefficients and linear discriminant analysis classifiers were used to process the EMG data for pattern recognition of the 11 motions. For the affected side, active anodal tDCS significantly reduced the average classification error rate (CER) by 10.1%, while sham tDCS had no such effect. For the intact side, the average CER did not change on the day of sham tDCS but increased on the day of active tDCS. These results demonstrated that tDCS could modulate brain function and improve EMG-based classification performance for amputees. It has great potential in dramatically reducing the length of learning process of amputees for effectively using myoelectrically controlled multifunctional prostheses.

  6. AUTOMATED DYNAMIC LOAD CONTROL BY ELECTROMECHANICAL SYSTEMS OF A BUCKET-CHAIN EXCAVATOR IN THE COURSE OF SCOOPING

    OpenAIRE

    Khayrullin Rustam Zinnatullovich

    2012-01-01

    Methods and algorithms of control of the tension of lifting and towing ropes of bucket-chain excavators are proposed in the article. They are based on the non-linear dependence of the current path length and intensity of excavation efforts. Three automatic control modes, including scooping, correction signals and automatic overload protection, are implemented. Two independent control loops in charge of tension of lifting and towing ropes are developed. The proposed automated control syste...

  7. Learning and Chaining of Motor Primitives for Goal-directed Locomotion of a Snake-Like Robot with Screw-Drive Units

    DEFF Research Database (Denmark)

    Chatterjee, Sromona; Nachstedt, Timo; Tamosiunaite, Minija

    2015-01-01

    Motor primitives provide a modular organization to complex behaviours in both vertebrates and invertebrates. Inspired by this, here we generate motor primitives for a complex snake-like robot with screw-drive units, and thence chain and combine them, in order to provide a versatile, goal-directed......Motor primitives provide a modular organization to complex behaviours in both vertebrates and invertebrates. Inspired by this, here we generate motor primitives for a complex snake-like robot with screw-drive units, and thence chain and combine them, in order to provide a versatile, goal...

  8. A cluster randomized non-inferiority field trial on the immunogenicity and safety of tetanus toxoid vaccine kept in controlled temperature chain compared to cold chain.

    Science.gov (United States)

    Juan-Giner, Aitana; Domicent, Camille; Langendorf, Céline; Roper, Martha H; Baoundoh, Paul; Fermon, Florence; Gakima, Primitive; Zipursky, Simona; Tamadji, Mbaihol; Grais, Rebecca F

    2014-10-29

    In resource-poor settings, cold chain requirements present barriers for vaccine delivery. We evaluated the immunogenicity and safety of tetanus toxoid (TT) vaccine in "Controlled Temperature Chain" (CTC; up to 40 °C for Tetanus antibody titers were measured using standard ELISA at inclusion and 4 weeks post-TT2. Primary outcome measures were post-vaccination seroconversion and fold-increase in geometric mean concentrations (GMC). Non-inferiority was by seroconversion difference (TTSCC-TTCTC) 95% of participants; upper 95%CI of the difference was 5.6%. Increases in GMC were over 4-fold; upper 95%CI of GMC ratio was 1.36 in the adjusted analysis. Few adverse events were recorded. This study demonstrates the immunogenicity and safety of TT in CTC at <40 °C for <30 days. The high proportion of participants protected at baseline results in a reduction of power to detect a 5% non-inferiority margin. However, results at a 10% non-inferiority margin, the comparable GMC increases and vaccine's stability demonstrated in the preliminary phase indicate that CTC can be an alternative strategy for TT delivery in situations where cold chain cannot be maintained. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Achieving HIV-1 Control through RNA-Directed Gene Regulation

    Directory of Open Access Journals (Sweden)

    Vera Klemm

    2016-12-01

    Full Text Available HIV-1 infection has been transformed by combined anti-retroviral therapy (ART, changing a universally fatal infection into a controllable infection. However, major obstacles for an HIV-1 cure exist. The HIV latent reservoir, which exists in resting CD4+ T cells, is not impacted by ART, and can reactivate when ART is interrupted or ceased. Additionally, multi-drug resistance can arise. One alternate approach to conventional HIV-1 drug treatment that is being explored involves gene therapies utilizing RNA-directed gene regulation. Commonly known as RNA interference (RNAi, short interfering RNA (siRNA induce gene silencing in conserved biological pathways, which require a high degree of sequence specificity. This review will provide an overview of the silencing pathways, the current RNAi technologies being developed for HIV-1 gene therapy, current clinical trials, and the challenges faced in progressing these treatments into clinical trials.

  10. Striatal direct and indirect pathways control decision-making behavior

    Directory of Open Access Journals (Sweden)

    Tom eMacpherson

    2014-11-01

    Full Text Available Despite our ever-changing environment, animals are remarkable adept at selecting courses of action that are predictive of optimal outcomes. While requiring the contribution of a number of brain regions, a vast body of evidence implicates striatal mechanisms of associative learning and action selection to be critical to this ability. While numerous models of striatal-based decision-making have been developed, it is only recently that we have begun to understand the precise contributions of specific subpopulations of striatal neurons. Studies utilizing contemporary cell-type-specific technologies indicate that striatal output pathways play distinct roles in controlling goal-directed and social behaviors. Here we review current models of striatal-based decision-making, discuss recent developments in defining the functional roles of striatal output pathways, and assess how striatal dysfunction may contribute to the etiology of various neuropathologies.

  11. Improved direct torque control of induction motor with dither injection

    Indian Academy of Sciences (India)

    R K Behera; S P Das

    2008-10-01

    In this paper, a three-level inverter-fed induction motor drive operating under Direct Torque Control (DTC) is presented. A triangular wave is used as dither signal of minute amplitude (for torque hysteresis band and flux hysteresis band respectively) in the error block. This method minimizes flux and torque ripple in a three-level inverter fed induction motor drive while the dynamic performance is not affected. The optimal value of dither frequency and magnitude is found out under free running condition. The proposed technique reduces torque ripple by 60% (peak to peak) compared to the case without dither injection, results in low acoustic noise and increases the switching frequency of the inverter. A laboratory prototype of the drive system has been developed and the simulation and experimental results are reported.

  12. Active vibration control for flexible rotor by optimal direct-output feedback control

    Science.gov (United States)

    Nonami, Kenzou; Dirusso, Eliseo; Fleming, David P.

    1989-01-01

    Experimental research tests were performed to actively control the rotor vibrations of a flexible rotor mounted on flexible bearing supports. The active control method used in the tests is called optimal direct-output feedback control. This method uses four electrodynamic actuators to apply control forces directly to the bearing housings in order to achieve effective vibration control of the rotor. The force actuators are controlled by an analog controller that accepts rotor displacement as input. The controller is programmed with experimentally determined feedback coefficients; the output is a control signal to the force actuators. The tests showed that this active control method reduced the rotor resonance peaks due to unbalance from approximately 250 micrometers down to approximately 25 micrometers (essentially runout level). The tests were conducted over a speed range from 0 to 10,000 rpm; the rotor system had nine critical speeds within this speed range. The method was effective in significantly reducing the rotor vibration for all of the vibration modes and critical speeds.

  13. Robust control methods for nonlinear systems with uncertain dynamics and unknown control direction

    Science.gov (United States)

    Ton, Chau T.

    Robust nonlinear control design strategies using sliding mode control (SMC) and integral SMC (ISMC) are developed, which are capable of achieving reliable and accurate tracking control for systems containing dynamic uncertainty, unmodeled disturbances, and actuator anomalies that result in an unknown and time-varying control direction. In order to ease readability of this dissertation, detailed explanations of the relevant mathematical tools is provided, including stability denitions, Lyapunov-based stability analysis methods, SMC and ISMC fundamentals, and other basic nonlinear control tools. The contributions of the dissertation are three novel control algorithms for three different classes of nonlinear systems: single-input multipleoutput (SIMO) systems, systems with model uncertainty and bounded disturbances, and systems with unknown control direction. Control design for SIMO systems is challenging due to the fact that such systems have fewer actuators than degrees of freedom to control (i.e., they are underactuated systems). While traditional nonlinear control methods can be utilized to design controllers for certain classes of cascaded underactuated systems, more advanced methods are required to develop controllers for parallel systems, which are not in a cascade structure. A novel control technique is proposed in this dissertation, which is shown to achieve asymptotic tracking for dual parallel systems, where a single scalar control input directly aects two subsystems. The result is achieved through an innovative sequential control design algorithm, whereby one of the subsystems is indirectly stabilized via the desired state trajectory that is commanded to the other subsystem. The SIMO system under consideration does not contain uncertainty or disturbances. In dealing with systems containing uncertainty in the dynamic model, a particularly challenging situation occurs when uncertainty exists in the input-multiplicative gain matrix. Moreover, special

  14. How to get an exact sample from a generic Markov chain and sample a random spanning tree from a directed graph, both within the cover time

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, D.B.; Propp, J.G.

    1996-12-31

    This paper shows how to obtain unbiased samples from an unknown Markov chain by observing it for O(T{sub c}) steps, where T{sub c} is the cover time. This algorithm improves on several previous algorithms, and there is a matching lower bound. Using the techniques from the sampling algorithm, we also show how to sample random directed spanning trees from a weighted directed graph, with arcs directed to a root, and probability proportional to the product of the edge weights. This tree sampling algorithm runs within 18 cover times of the associated random walk, and is more generally applicable than the algorithm of Broder and Aldous.

  15. Implementation of Direct Torque Control Scheme for Induction Machines with Variable Structure Controllers

    Institute of Scientific and Technical Information of China (English)

    LI Jian; YANG Geng; WANG Huan'gang; XU Wenli

    2005-01-01

    A torque control scheme for high-performance induction machine drives was developed to over- come some disadvantages of direct torque control (DTC). In the improved DTC method, the stator flux and the torque controllers use variable-structure control theory which does not require information about the rotor speed. Space vector modulation is applied to the voltage source inverter to reduce the torque, stator flux, and current ripples. The digital signal processor-based implementation is described in detail. The experimental results show that the system has good torque and stator flux response with small ripples.

  16. Optimal control of fast and high-fidelity quantum state transfer in spin-1/2 chains

    Science.gov (United States)

    Zhang, Xiong-Peng; Shao, Bin; Hu, Shuai; Zou, Jian; Wu, Lian-Ao

    2016-12-01

    Spin chains are promising candidates for quantum communication and computation. Using quantum optimal control (OC) theory based on the Krotov method, we present a protocol to perform quantum state transfer with fast and high fidelity by only manipulating the boundary spins in a quantum spin-1/2 chain. The achieved speed is about one order of magnitude faster than that is possible in the Lyapunov control case for comparable fidelities. Additionally, it has a fundamental limit for OC beyond which optimization is not possible. The controls are exerted only on the couplings between the boundary spins and their neighbors, so that the scheme has good scalability. We also demonstrate that the resulting OC scheme is robust against disorder in the chain.

  17. Optimal control of fast and high-fidelity quantum state transfer in spin-1/2 chains

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiong-Peng [School of Physics, Beijing Institute of Technology, Beijing 100081 (China); Shao, Bin, E-mail: sbin610@bit.edu.cn [School of Physics, Beijing Institute of Technology, Beijing 100081 (China); Hu, Shuai; Zou, Jian [School of Physics, Beijing Institute of Technology, Beijing 100081 (China); Wu, Lian-Ao [Department of Theoretical Physics and History of Science, The Basque Country University (EHU/UPV), PO Box 644, 48080 Bilbao (Spain); Ikerbasque, Basque Foundation for Science, 48011 Bilbao (Spain)

    2016-12-15

    Spin chains are promising candidates for quantum communication and computation. Using quantum optimal control (OC) theory based on the Krotov method, we present a protocol to perform quantum state transfer with fast and high fidelity by only manipulating the boundary spins in a quantum spin-1/2 chain. The achieved speed is about one order of magnitude faster than that is possible in the Lyapunov control case for comparable fidelities. Additionally, it has a fundamental limit for OC beyond which optimization is not possible. The controls are exerted only on the couplings between the boundary spins and their neighbors, so that the scheme has good scalability. We also demonstrate that the resulting OC scheme is robust against disorder in the chain.

  18. Optimal Ordering Policy and Coordination Mechanism of a Supply Chain with Controllable Lead-Time-Dependent Demand Forecast

    Directory of Open Access Journals (Sweden)

    Hua-Ming Song

    2011-01-01

    Full Text Available This paper investigates the ordering decisions and coordination mechanism for a distributed short-life-cycle supply chain. The objective is to maximize the whole supply chain's expected profit and meanwhile make the supply chain participants achieve a Pareto improvement. We treat lead time as a controllable variable, thus the demand forecast is dependent on lead time: the shorter lead time, the better forecast. Moreover, optimal decision-making models for lead time and order quantity are formulated and compared in the decentralized and centralized cases. Besides, a three-parameter contract is proposed to coordinate the supply chain and alleviate the double margin in the decentralized scenario. In addition, based on the analysis of the models, we develop an algorithmic procedure to find the optimal ordering decisions. Finally, a numerical example is also presented to illustrate the results.

  19. Direct Torque Control of Saturated Doubly-Fed Induction Generator using High Order Sliding Mode Controllers

    Directory of Open Access Journals (Sweden)

    Elhadj BOUNADJA

    2016-07-01

    Full Text Available The present work examines a direct torque control strategy using a high order sliding mode controllers of a doubly-fed induction generator (DFIG incorporated in a wind energy conversion system and working in saturated state. This research is carried out to reach two main objectives. Firstly, in order to introduce some accuracy for the calculation of DFIG performances, an accurate model considering magnetic saturation effect is developed. The second objective is to achieve a robust control of DFIG based wind turbine. For this purpose, a Direct Torque Control (DTC combined with a High Order Sliding Mode Control (HOSMC is applied to the DFIG rotor side converter. Conventionally, the direct torque control having hysteresis comparators possesses major flux and torque ripples at steady-state and moreover the switching frequency varies on a large range. The new DTC method gives a perfect decoupling between the flux and the torque. It also reduces ripples in these grandeurs. Finally, simulated results show, accurate dynamic performances, faster transient responses and more robust control are achieved.

  20. Side-chain-controlled self-assembly of polystyrene-polypeptide miktoarm star copolymers

    KAUST Repository

    Junnila, Susanna

    2012-03-27

    We show how the self-assembly of miktoarm star copolymers can be controlled by modifying the side chains of their polypeptide arms, using A 2B and A 2B 2 type polymer/polypeptide hybrids (macromolecular chimeras). Initially synthesized PS 2PBLL and PS 2PBLL 2 (PS, polystyrene; PBLL, poly(ε-tert-butyloxycarbonyl-l-lysine) ) miktoarms were first deprotected to PS 2PLLHCl and PS 2PLLHCl 2 miktoarms (PLLHCl, poly(l-lysine hydrochloride)) and then complexed ionically with sodium dodecyl sulfonate (DS) to give the supramolecular complexes PS 2PLL(DS) and PS 2(PLL(DS)) 2. The solid-state self-assemblies of these six miktoarm systems were studied by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and small- and wide-angle X-ray scattering (SAXS, WAXS). The side chains of the polypeptide arms were observed to have a large effect on the solubility, polypeptide conformation, and self-assembly of the miktoarms. Three main categories were observed: (i) lamellar self-assemblies at the block copolymer length scale with packed layers of α-helices in PS 2PBLL and PS 2PBLL 2; (ii) charge-clustered polypeptide micelles with less-defined conformations in a nonordered lattice within a PS matrix in PS 2PLLHCl and PS 2PLLHCl 2; (iii) lamellar polypeptide-surfactant self-assemblies with β-sheet conformation in PS 2PLL(DS) and PS 2(PLL(DS)) 2 which dominate over the formation of block copolymer scale structures. Differences between the 3- and 4-arm systems illustrate how packing frustration between the coil-like PS arms and rigid polypeptide conformations can be relieved by the right number of arms, leading to differences in the extent of order. © 2012 American Chemical Society.

  1. Ribbon Ion Beam with Controlled Directionality and Local Reactive Chemistry

    Science.gov (United States)

    Biloiu, Costel; Gilchrist, Glen; Kontos, Alex; Basame, Solomon; Rockwell, Tyler; Campbell, Chris; Daniels, Kevin; Allen, Ernest; Wallace, Jay; Ballou, Jon; Hertel, Richard; Chen, Tsung-Liang; Liang, Shurong; Singh, Vikram

    2016-09-01

    A plasma processing technology designed for etch of 3D semiconductor structures is presented. The technology is characterized by controllable ion directionality and local reactive chemistry and it is based on proprietary Applied Materials - Varian Semiconductor Equipment ribbon ion beam architecture. It uses a combination of inert gas ion beam and injection of reactive chemical species at the Point-of-Use (PoU), i.e., at the wafer surface. The ion source uses an inductively coupled plasma source and a diode-type extraction optics. A beam shaping electrode allows extraction of two symmetrical ribbon-like beamlets. The ion beam has in situ controllable ion angular distribution in both mean angle and angular spread. The beam has a uniform distribution of beam current and angles over a waist exceeding 300 mm, allowing full wafer processing in one pass. Chemical compounds are delivered at PoU through linear shower heads. The reactive chemical compound delivered in this fashion maintains its molecular integrity. This result in protection of the trench side walls from deposition of etch residue and facilitates formation of volatile byproducts. The technology was used successfully for mitigation of Magnetic Tunel Junction etch residue. Other applications were this technology differentiate from present technologies are contact liner etch, Co recess, and 1D hole elongation.

  2. Direct photoaffinity labeling by nucleotides of the apparent catalytic site on the heavy chains of smooth muscle and Acanthamoeba myosins

    Energy Technology Data Exchange (ETDEWEB)

    Maruta, H.; Korn, E.D.

    1981-01-10

    The heavy chains of Acanthamoeba myosins, IA, IB and II, turkey gizzard myosin, and rabbit skeletal muscle myosin subfragment-1 were specifically labeled by radioactive ATP, ADP, and UTP, each of which is a substrate or product of myosin ATPase activity, when irradiated with uv light at 0/sup 0/C. With UTP, as much as 0.45 mol/mol of Acanthamoeba myosin IA heavy chain and 1 mol/mol of turkey gizzard myosin heavy chain was incorporated. Evidence that the ligands were associated with the catalytic site included the observations that reaction occurred only with nucleotides that are substrates or products of the ATPase activity; that the reaction was blocked by pyrophosphate which is an inhibitor of the ATPase activity; that ATP was bound as ADP; and that label was probably restricted to a single peptide following limited subtilisin proteolysis of labeled Acanthamoeba myosin IA heavy chain and extensive cleavage with CNBr and trypsin of labeled turkey gizzard myosin heavy chain.

  3. 一个新的学科方向——供应链质量管理研究综述%A Review of Supply Chain Quality Management: A New Discipline Direction

    Institute of Scientific and Technical Information of China (English)

    蒲国利; 苏秦; 刘强

    2011-01-01

    As a new discipline direction, supply chain quality management develops very rapidly in these years, which demands system understanding about it's area. Traditional quality management and supply chain management theory are facing new challenges. Firstly this paper discusses and re-defines the inherence of supply chain quality management. Secondly the theory background is analysized from strategy & leadership, process integration & management, communication & partnership and best practice. Then optimum quality strategy and contract design of supply chain are put more emphasis and infrastructure of supply chain quality control and coordination is constructed, final- ly future research directions are pointed out from process oriented and reengineering, supply chain quality management models and methods, performance measurement of supply chain quality and supply chain quality insurance .%作为一个新的学科方向,供应链质量管理的快速发展和不断创新要求对其领域有更系统的了解。在分析传统质量管理与供应链管理理论面临挑战的基础上,对供应链质量管理的内涵进行了探究和重新界定,并从战略和领导、流程集成与管理、交流和伙伴关系及最佳实践等方面分析了供应链质量管理的理论基础。基于合作和非合作两种情形对供应链最优质量策略和合同设计进行重点探讨,并构建了供应链质量控制与协调分析框架,最后从流程导向和重组、供应链质量管理模型和方法、供应链质量绩效评价和供应链质量保证方面提出了未来的研究方向。

  4. Portable gliadin-immunochip for contamination control on the food production chain.

    Science.gov (United States)

    Chiriacò, Maria Serena; de Feo, Francesco; Primiceri, Elisabetta; Monteduro, Anna Grazia; de Benedetto, Giuseppe Egidio; Pennetta, Antonio; Rinaldi, Ross; Maruccio, Giuseppe

    2015-09-01

    Celiac disease (CD) is one of the most common digestive disorders caused by an abnormal immune reaction to gluten. So far there are no available therapies, the only solution is a strict gluten-free diet, which however could be very challenging as gluten can be hidden in many food products. Furthermore an additional problem is related to cross-contamination of nominal gluten-free foods with gluten-based ones during manufacturing. Here we propose a lab on chip platform as a powerful tool to help food manufacturers to evaluate the real amount of gluten in their products by an accurate in-situ control of the production chain and maybe to specify the real gluten content in packages labeling. Our portable gliadin-immunochips, based on an electrochemical impedance spectroscopy transduction method, were first calibrated and then validated for both liquid and solid food matrixes by analyzing different beers and flours. The high specificity of our assay was also demonstrated by performing control experiments on rice and potatoes flours containing prolamin-like proteins. We achieved limit of quantification of 0.5 ppm for gliadin that is 20 times lower than the worldwide limit established for gluten-free food while the method of analysis is faster and cheaper than currently employed ELISA-based methods. Moreover our results on food samples were validated through a mass spectrometry standard analysis.

  5. Control Structures in supply chains as a way to manage unpredictable cyber-risks

    OpenAIRE

    Sepúlveda Estay, Daniel Alberto; Khan, Omera

    2016-01-01

    Supply chain growth, and their dependence on Information Technology (IT), is making cyber risks an increasingly unmanageable threat through traditional risk assessment methods. Systemic analysis methods have been identified as alternatives to trad itional methods. This paper analyzes the application of a systemic risk analysis methodology to understand cyber risks in the supply chain. A generic supply chain is analyzed, and information flows, dynamic structures and the influence of cyber-atta...

  6. Adaptive fuzzy logic controller with direct action type structures for InnoSAT attitude control system

    Science.gov (United States)

    Bakri, F. A.; Mashor, M. Y.; Sharun, S. M.; Bibi Sarpinah, S. N.; Abu Bakar, Z.

    2016-10-01

    This study proposes an adaptive fuzzy controller for attitude control system (ACS) of Innovative Satellite (InnoSAT) based on direct action type structure. In order to study new methods used in satellite attitude control, this paper presents three structures of controllers: Fuzzy PI, Fuzzy PD and conventional Fuzzy PID. The objective of this work is to compare the time response and tracking performance among the three different structures of controllers. The parameters of controller were tuned on-line by adjustment mechanism, which was an approach similar to a PID error that could minimize errors between actual and model reference output. This paper also presents a Model References Adaptive Control (MRAC) as a control scheme to control time varying systems where the performance specifications were given in terms of the reference model. All the controllers were tested using InnoSAT system under some operating conditions such as disturbance, varying gain, measurement noise and time delay. In conclusion, among all considered DA-type structures, AFPID controller was observed as the best structure since it outperformed other controllers in most conditions.

  7. NEURAL NETWORK SPEED CONTROLLER FOR DIRECT VECTOR CONTROL OF INDUCTION MOTORS

    Directory of Open Access Journals (Sweden)

    BEN HAMED MOUNA,

    2010-12-01

    Full Text Available This paper presents a new method for the implementation of a direct rotor flux control (DRFOC of induction motor (IM drives. It is based on the rotor flux components regulation. In fact, the d and q axis flux components feed a proportional integral (PI controller. The outputs of which are the targets start voltages (vdsref andvqsref. While, the synchronous speed is depicted at the output of rotor speed controller. In order to accomplish variable speed operation, conventional PI lie controller is commonly used. This controller provides limited good performances over a wide range of operation even under ideal field oriented conditions. An alternate approach is to use the so called neural network controller. The overall investigated system is implemented using dSpace system based on digital signal processor (DSP. Simulation and experimental results have been presented for one kw IM drives to confirm the validity of the proposed algorithms.

  8. An efficient water flow control approach for water heaters in direct load control

    NARCIS (Netherlands)

    Belov, Alexander; Meratnia, Nirvana; Zwaag, van der Berend Jan; Havinga, Paul

    2014-01-01

    Tank water heaters (WHs) are present in a prevailing number of European households. Serving as energy buffers WHs have come under the spotlight of various direct load control (DLC) programs over the last few decades. Although DLC has proven to be an efficient measure towards daily peak demand shavin

  9. Rom2-dependent Phosphorylation of Elo2 Controls the Abundance of Very Long-chain Fatty Acids*

    Science.gov (United States)

    Olson, Daniel K.; Fröhlich, Florian; Christiano, Romain; Hannibal-Bach, Hans K.; Ejsing, Christer S.; Walther, Tobias C.

    2015-01-01

    Sphingolipids are essential components of eukaryotic membranes, where they serve to maintain membrane integrity. They are important components of membrane trafficking and function in signaling as messenger molecules. Sphingolipids are synthesized de novo from very long-chain fatty acids (VLCFA) and sphingoid long-chain bases, which are amide linked to form ceramide and further processed by addition of various headgroups. Little is known concerning the regulation of VLCFA levels and how cells coordinate their synthesis with the availability of long-chain bases for sphingolipid synthesis. Here we show that Elo2, a key enzyme of VLCFA synthesis, is controlled by signaling of the guanine nucleotide exchange factor Rom2, initiating at the plasma membrane. This pathway controls Elo2 phosphorylation state and VLCFA synthesis. Our data identify a regulatory mechanism for coordinating VLCFA synthesis with sphingolipid metabolism and link signal transduction pathways from the plasma membrane to the regulation of lipids for membrane homeostasis. PMID:25519905

  10. Optimization of a neural network based direct inverse control for controlling a quadrotor unmanned aerial vehicle

    Directory of Open Access Journals (Sweden)

    Heryanto M Ary

    2015-01-01

    Full Text Available UAVs are mostly used for surveillance, inspection and data acquisition. We have developed a Quadrotor UAV that is constructed based on a four motors with a lift-generating propeller at each motors. In this paper, we discuss the development of a quadrotor and its neural networks direct inverse control model using the actual flight data. To obtain a better performance of the control system of the UAV, we proposed an Optimized Direct Inverse controller based on re-training the neural networks with the new data generated from optimal maneuvers of the quadrotor. Through simulation of the quadrotor using the developed DIC and Optimized DIC model, results show that both models have the ability to stabilize the quadrotor with a good tracking performance. The optimized DIC model, however, has shown a better performance, especially in the settling time parameter.

  11. Contouring Control for a CNC Milling Machine Driven by Direct thrust Controlled Linear Induction Motors

    Directory of Open Access Journals (Sweden)

    Khaled N. Faris

    2015-12-01

    Full Text Available According to various advantages of linear induction motor (LIM, such as high starting thrust force, high speed operation and reduction of mechanical losses, more applications have utilized this type of motors. Direct Thrust Control (DTC technique is considered as one of the most efficient techniques that can be used for LIM. DTC is preferable to give a fast and good dynamic thrust response. So, to improve the accuracy and robustness of contouring control for CNC machine tools, linear induction motors with a direct thrust control technique are introduced for driving these machines. An industry standard motion control system is applied for reducing the tracking error and improving the desired accuracy. Different loading conditions are simulated to validate the reliability and robustness of the introduced system to match the application field. The proposed system is simulated using the MATLAB/SIMULINK Package; simulation results validated both tracking accuracy and robustness of the proposed motion control system for contouring control for a CNC (Computer Numerical Control milling machine.

  12. FPGA-Based Implementation Direct Torque Control of Induction Motor

    Directory of Open Access Journals (Sweden)

    Saber Krim

    2015-02-01

    Full Text Available This paper proposes a digital implementation of the direct torque control (DTC of an Induction Motor (IM with an observation strategy on the Field Programmable Gate Array (FPGA. The hardware solution based on the FPGA is caracterised by fast processing speed due to the parallel processing. In this study the FPGA is used to overcome the limitation of the software solutions (Digital Signal Processor (DSP and Microcontroller. Also, the DTC of IM has many drawbacks such as for example; The open loop pure integration has from the problems of integration especially at the low speed and the variation of the stator resistance due to the temperature. To tackle these problems we use the Sliding Mode Observer (SMO. This observer is used estimate the stator flux, the stator current and the stator resistance. The hardware implementation method is based on Xilinx System Generator (XSG which a modeling tool developed by Xilinx for the design of implemented systems on FPGA; from the design of the DTC with SMO from XSG we can automatically generate the VHDL code. The model of the DTC with SMO has been designed and simulated using XSG blocks, synthesized with Xilinx ISE 12.4 tool and implemented on Xilinx Virtex-V FPGA.

  13. A Model of FPGA-based Direct Torque Controller

    Directory of Open Access Journals (Sweden)

    Auzani Jidin

    2013-02-01

    Full Text Available This paper presents a generic model of a fully FPGA-based direct torque controller. This model is developed using two’s-complement fixed-point format approaches, in register-transfer-level (RTL VHDL abstraction for minimizing calculation errors and consuming hardware resource usage. Therefore, the model is universal and can be implemented for all FPGA types. The model is prepared for fast computation, without using of CORDIC algorithm, a soft-core CPU, a transformation from Cartesian-to-polar coordinates, and without the help of third-party applications. To get simpler implementation and fast computation, several methods were introduced: i the backward-Euler approach to calculate the discrete-integration operation of stator flux, ii the modified non-restoring method to calculate complicated square-root operation of stator flux, iii a new sector analysis method. The design, which was coded in synthesizable VHDL in RTL abstraction for implementation on Altera DE2-board has produced very-precise calculations, with minimal error when being compared to MATLAB/Simulink double-precision calculation.

  14. Physical controls on directed virus assembly at nanoscale chemical templates

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, C L; Chung, S; Chatterji, A; Lin, T; Johnson, J E; Hok, S; Perkins, J; De Yoreo, J

    2006-05-10

    Viruses are attractive building blocks for nanoscale heterostructures, but little is understood about the physical principles governing their directed assembly. In-situ force microscopy was used to investigate organization of Cowpea Mosaic Virus engineered to bind specifically and reversibly at nanoscale chemical templates with sub-30nm features. Morphological evolution and assembly kinetics were measured as virus flux and inter-viral potential were varied. The resulting morphologies were similar to those of atomic-scale epitaxial systems, but the underlying thermodynamics was analogous to that of colloidal systems in confined geometries. The 1D templates biased the location of initial cluster formation, introduced asymmetric sticking probabilities, and drove 1D and 2D condensation at subcritical volume fractions. The growth kinetics followed a t{sup 1/2} law controlled by the slow diffusion of viruses. The lateral expansion of virus clusters that initially form on the 1D templates following introduction of polyethylene glycol (PEG) into the solution suggests a significant role for weak interaction.

  15. Binding of estrogen receptors to switch sites and regulatory elements in the immunoglobulin heavy chain locus of activated B cells suggests a direct influence of estrogen on antibody expression.

    Science.gov (United States)

    Jones, Bart G; Penkert, Rhiannon R; Xu, Beisi; Fan, Yiping; Neale, Geoff; Gearhart, Patricia J; Hurwitz, Julia L

    2016-09-01

    Females and males differ in antibody isotype expression patterns and in immune responses to foreign- and self-antigens. For example, systemic lupus erythematosus is a condition that associates with the production of isotype-skewed anti-self antibodies, and exhibits a 9:1 female:male disease ratio. To explain differences between B cell responses in males and females, we sought to identify direct interactions of the estrogen receptor (ER) with the immunoglobulin heavy chain locus. This effort was encouraged by our previous identification of estrogen response elements (ERE) in heavy chain switch (S) regions. We conducted a full-genome chromatin immunoprecipitation analysis (ChIP-seq) using DNA from LPS-activated B cells and an ERα-specific antibody. Results revealed ER binding to a wide region of DNA, spanning sequences from the JH cluster to Cδ, with peaks in Eμ and Sμ sites. Additional peaks of ERα binding were coincident with hs1,2 and hs4 sites in the 3' regulatory region (3'RR) of the heavy chain locus. This first demonstration of direct binding of ER to key regulatory elements in the immunoglobulin locus supports our hypothesis that estrogen and other nuclear hormone receptors and ligands may directly influence antibody expression and class switch recombination (CSR). Our hypothesis encourages the conduct of new experiments to evaluate the consequences of ER binding. A better understanding of ER:DNA interactions in the immunoglobulin heavy chain locus, and respective mechanisms, may ultimately translate to better control of antibody expression, better protection against pathogens, and prevention of pathologies caused by auto-immune disease.

  16. Biophysical interactions control the size and abundance of large phytoplankton chains at the Ushant tidal front.

    Directory of Open Access Journals (Sweden)

    José M Landeira

    Full Text Available Phytoplankton blooms are usually dominated by chain-forming diatom species that can alter food pathways from primary producers to predators by reducing the interactions between intermediate trophic levels. The food-web modifications are determined by the length of the chains; however, the estimation is biased because traditional sampling strategies damage the chains and, therefore, change the phytoplankton size structure. Sedimentological studies around oceanic fronts have shown high concentrations of giant diatom mats (>1 cm in length, suggesting that the size of diatom chains is underestimated in the pelagic realm. Here, we investigate the variability in size and abundance of phytoplankton chains at the Ushant tidal front (NW France using the Video Fluorescence Analyzer (VFA, a novel and non-invasive system. CTD and Scanfish profiling characterized a strong temperature and chlorophyll front, separating mixed coastal waters from the oceanic-stratified domain. In order to elucidate spring-neap variations in the front, vertical microstructure profiler was used to estimate the turbulence and vertical nitrate flux. Key findings were: (1 the VFA system recorded large diatom chains up to 10.7 mm in length; (2 chains were mainly distributed in the frontal region, with maximum values above the pycnocline in coincidence with the maximum chlorophyll; (3 the diapycnal fluxes of nitrate enabled the maintenance of the bloom in the frontal area throughout the spring-neap tidal cycle; (4 from spring to neap tide the chains length was significantly reduced; (5 during neap tide, the less intense vertical diffusion of nutrients, as well as the lower turbulence around the chains, intensified nutrient-depleted conditions and, thus, very large chains became disadvantageous. To explain this pattern, we suggest that size plasticity is an important ecological trait driving phytoplankton species competition. Although this plasticity behavior is well known from

  17. Improved Torque Control Performance of Direct Torque Control for 5-Phase Induction Machine

    Directory of Open Access Journals (Sweden)

    Logan Raj Lourdes Victor Raj

    2013-12-01

    Full Text Available In this paper, the control of five-phase induction machine using Direct Torque Control (DTC is presented. The general D-Q model of five-phase induction machine is discussed. The de-coupled control of stator flux and electromagnetic torque based on hysteresis controller similar to conventional DTC is applied to maintain the simplicity of the system. Three sets of look-up tables consist of voltage vectors with different amplitude that selects the  most optimal voltage vectors according motor operation condition is proposed. This provides excellent torque dynamic control, reduces torque ripple, lower switching frequency (high efficiency and extension of constant torque. Simulation results validate the improvement achieved.

  18. Integrated supply chain inventory model with quality improvement involving controllable lead time and backorder price discount

    Directory of Open Access Journals (Sweden)

    Prashant Jindal

    2016-06-01

    Full Text Available For the past four decades the integrated vendor and buyer supply chain inventory model has been an interesting topic, but quality improvement of defective items in the integrated inventory model with backorder price discount involving controllable lead time has been rarely discussed. The aim of this paper is to minimize the total related cost in the continuous review model by considering the order quantity, reorder point, lead time, process quality, backorder price discount and number of shipment as decision variables. Moreover, we assume that an investment function is used to improve the process quality. The lead time demand follows a normal distribution. In addition, the buyer offers backorder price discount to motivate the customers for possible backorders. There are some defective items in the arrival lot, so its treatment is also taken in account in this paper. We develop an iterative procedure for finding the optimal values of decision variables and numerical example is presented to illustrate the solution procedure. Additionally, sensitivity analysis with respect to major parameters is also carried out.

  19. Infection control in IV therapy: a review of the chain of infection.

    Science.gov (United States)

    Lavery, Irene

    The aim of this article is to review the principles of infection control relating to intravenous (IV) therapy. IV therapy and peripheral IV cannulation are common procedures. Zingg and Pittet (2009) noted that as many as 80% of hospitalized patients will have a cannula in situ, and Hart (2008) suggested that patients who require IV therapy are often seriously ill and immunocompromised, thus are more susceptible to infection. The Department of Health (DH) (2007a) estimated that 6000 patients acquire a catheter-related bloodstream infection every year in the UK. Robust standards of practice are therefore paramount to ensure safe and competent practice, both in peripheral IV cannulation and IV care. Using the chain of infection as a framework to review practice will enable practitioners to ensure thorough standards of practice, and the Royal College of Nursing (RCN) (2005) stated that only trained and competent staff using strict aseptic techniques should be involved in IV or cannulae care. Furthermore, the Code (Nursing and Midwifery Council (NMC), (2008) stipulates all practitioners must deliver care based on the best available evidence and/or best practice, and that knowledge and skills for safe and effective practice must be kept up-to-date throughout each health professional's working life.

  20. N332-Directed broadly neutralizing antibodies use diverse modes of HIV-1 recognition: inferences from heavy-light chain complementation of function.

    Directory of Open Access Journals (Sweden)

    Marie Pancera

    Full Text Available Dozens of broadly neutralizing HIV-1 antibodies have been isolated in the last few years from the sera of HIV-1-infected individuals. Only a limited number of regions on the HIV-1 spike, however, are recognized by these antibodies. One of these regions (N332 is characterized by an N-linked glycan at residue 332 on HIV-1 gp120 and is recognized by antibody 2G12 and by the recently reported antibodies PGT121-137, the latter isolated from three donors. To investigate the diversity in mode of antibody recognition at the N332 site, we used functional complementation between antibody heavy and light chains as a means of assessing similarity in mode of recognition. We examined a matrix of 12 PGT-heavy chains with each of 12 PGT-light chains. Expression in 96-well format for the 144 antibodies (132 chimeric and 12 wild-type was generally consistent (58 ± 10 µg/ml. In contrast, recognition of HIV-1 gp120 was bimodal: when the source of heavy and light chains was from the same donor, recognition was good; when sources of heavy and light chains were from different donors, recognition was poor. Moreover, neutralization of HIV-1 strains SF162.LS and TRO.11 generally followed patterns of gp120 recognition. These results are consistent with published sequence, mutational, and structural findings, all of which indicate that N332-directed neutralizing antibodies from different donors utilize different modes of recognition, and provide support for a correlation between functional complementation of antibody heavy and light chains and similarity in antibody mode of recognition. Overall, our results add to the growing body of evidence that the human immune system is capable of recognizing the N332-region of HIV-1 gp120 in diverse ways.

  1. Direct Drive Electro-hydraulic Servo Control System Design with Self-Tuning Fuzzy PID Controller

    Directory of Open Access Journals (Sweden)

    Wang Yeqin

    2013-06-01

    Full Text Available According to the nonlinear and time-varying uncertainty characteristics of direct drive electro-hydraulic servo control system, a self-tuning fuzzy PID control method with speed change integral and differential ahead optimizing operator is put forward by combining fuzzy inference and traditional PID control in this paper.The rule of fuzzy logic is designed, the membership function of the fuzzy subsets is determined and lookup table method is used to correcte the PID parameters in real-time. Finally the simulation is conducted with the typical input signal, such as tracking step, sine etc. The simulation results show that,the self-tuning fuzzy PID control system can effectively improve the dynamic characteristic when the system is out of the range of the operating point compared with the traditional PID control system, there is obvious improvement in the indexes of rapidity, stability and accuracy,  and fuzzy self-tuning PID Control is more robust, and more suitable for direct drive electro-hydraulic servo system.

  2. Comparison of direct fecal smear microscopy, culture, and polymerase chain reaction for the detection of Blastocystis sp. in human stool samples.

    Science.gov (United States)

    Santos, Herbert J; Rivera, Windell L

    2013-10-01

    To compare the sensitivity and specificity of direct fecal smear microscopy, culture, and polymerase chain reaction in the detection of Blastocystis sp. in human stool. Human stool samples were collected from a community in San Isidro, Rodriguez, Rizal, Philippines. These samples were subjected to direct fecal smear microscopy, culture and polymerase chain reaction to detect the presence of Blastocystis sp. Of the 110 stool samples collected, 28 (25%) were detected positive for the presence of Blastocystis sp. by two or more tests. Culture method detected the highest number of Blastocystis-positive stool samples (n=36), followed by PCR of DNA extracted from culture (n=26), PCR of DNA extracted from stool (n=10), and direct fecal smear (n=9). Compared to culture, the sensitivity of the other detection methods were 66.7% for PCR from culture and 19.4% for both PCR from stool and direct fecal smear. Specificity of the methods was high, with PCR from culture and direct fecal smear having 97.3%, while PCR from stool at 95.9%. In this study, in vitro culture is the best method for detecting Blastocystis sp. in human stool samples. Copyright © 2013 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  3. Comparison of direct fecal smear microscopy, culture, and polymerase chain reaction for the detection ofBlastocystis sp. in human stool samples

    Institute of Scientific and Technical Information of China (English)

    Herbert J Santos; Windell L Rivera

    2013-01-01

    Objective:To compare the sensitivity and specificity of direct fecal smear microscopy, culture, and polymerase chain reaction in the detection ofBlastocystis sp. in human stool. Methods:Human stool samples were collected from a community inSanIsidro,Rodriguez, Rizal,Philippines.These samples were subjected to direct fecal smear microscopy, culture and polymerase chain reaction to detect the presence of Blastocystissp.Results:Of the110 stool samples collected,28(25%) were detected positive for the presence ofBlastocystis sp. by two or more tests.Culture method detected the highest number ofBlastocystis-positive stool samples (n=36), followed byPCR ofDNA extracted from culture(n=26),PCR ofDNA extracted from stool (n=10), and direct fecal smear(n=9).Compared to culture, the sensitivity of the other detection methods were66.7% forPCR from culture and19.4% for bothPCR from stool and direct fecal smear.Specificity of the methods was high, withPCR from culture and direct fecal smear having 97.3%, whilePCR from stool at95.9%.Conclusions:In this study,in vitroculture is the best method for detectingBlastocystis sp. in human stool samples.

  4. Site-directed Mutagenesis Reveals Regions Implicated in the Stability and Fiber Formation of Human λ3r Light Chains*

    Science.gov (United States)

    Villalba, Miryam I.; Canul-Tec, Juan C.; Luna-Martínez, Oscar D.; Sánchez-Alcalá, Rosalba; Olamendi-Portugal, Timoteo; Rudiño-Piñera, Enrique; Rojas, Sonia; Sánchez-López, Rosana; Fernández-Velasco, Daniel A.; Becerril, Baltazar

    2015-01-01

    Light chain amyloidosis (AL) is a disease that affects vital organs by the fibrillar aggregation of monoclonal light chains. λ3r germ line is significantly implicated in this disease. In this work, we contrasted the thermodynamic stability and aggregation propensity of 3mJL2 (nonamyloidogenic) and 3rJL2 (amyloidogenic) λ3 germ lines. Because of an inherent limitation (extremely low expression), Cys at position 34 of the 3r germ line was replaced by Tyr reaching a good expression yield. A second substitution (W91A) was introduced in 3r to obtain a better template to incorporate additional mutations. Although the single mutant (C34Y) was not fibrillogenic, the second mutation located at CDR3 (W91A) induced fibrillogenesis. We propose, for the first time, that CDR3 (position 91) affects the stability and fiber formation of human λ3r light chains. Using the double mutant (3rJL2/YA) as template, other variants were constructed to evaluate the importance of those substitutions into the stability and aggregation propensity of λ3 light chains. A change in position 7 (P7D) boosted 3rJL2/YA fibrillogenic properties. Modification of position 48 (I48M) partially reverted 3rJL2/YA fibril aggregation. Finally, changes at positions 8 (P8S) or 40 (P40S) completely reverted fibril formation. These results confirm the influential roles of N-terminal region (positions 7 and 8) and the loop 40–60 (positions 40 and 48) on AL. X-ray crystallography revealed that the three-dimensional topology of the single and double λ3r mutants was not significantly altered. This mutagenic approach helped to identify key regions implicated in λ3 AL. PMID:25505244

  5. Hacking cyber-risks back in their tracks: to identify the right supply chain controls, look at the system

    DEFF Research Database (Denmark)

    Sepúlveda, Daniel; Khan, Omera

    2015-01-01

    A more comprehensive way of looking at cyber-risks in supply chains is required, when considering the increasing complexity of the supply networks and the exposure to unexpected disruptions, caused by cyber-attacks. This article describes some of the reasons why current risk assessment methods...... are insufficient. The article provides an analogy for understanding the dynamic effects in a company. It describes in general terms what it means to understand cyber-risks from the control perspective, and it describes a new way to understand supply chain resilience. The focus is changed from the reliability...

  6. Chain-branching control of the atomic structure of alkanethiol-based gold-sulfur interfaces.

    Science.gov (United States)

    Wang, Yun; Chi, Qijin; Zhang, Jingdong; Hush, Noel S; Reimers, Jeffrey R; Ulstrup, Jens

    2011-09-28

    Density functional theory structure calculations at 0 K and simulations at 300 K of observed high-resolution in situ scanning tunneling microscopy (STM) images reveal three different atomic-interface structures for the self-assembled monolayers (SAMs) of three isomeric butanethiols on Au(111): direct binding to the Au(111) surface without pitting, binding to adatoms above a regular surface with extensive pitting, and binding to adatoms with local surface vacancies and some pitting. Thermal motions are shown to produce some observed STM features, with a very tight energy balance controlling the observed structures. Variation of the degree of substitution on the α carbon is found to significantly change the relative energies for interaction of the different types of adatom structures with the surface, while the nature of the surface cell, controlled primarily by inter-adsorbate steric interactions, controls substrate reorganization energies and adsorbate distortion energies. Most significantly, by manipulating these features, chemical control of the adsorbate can produce stable interfaces with surface pitting eliminated, providing new perspectives for technological applications of SAMs.

  7. Adaptive Consensus Control of Nonlinear Multiagent Systems With Unknown Control Directions Under Stochastic Topologies.

    Science.gov (United States)

    Rezaee, Hamed; Abdollahi, Farzaneh

    2017-08-15

    The consensus problem over high-order nonlinear multiagent systems with the Brunovsky-type model is studied. The model parameters and control directions of agents are supposed to be unknown. Hence, based on Nussbaum-type functions, an adaptive protocol is proposed, which guarantees achieving consensus in the network when the parameters and control directions of the agents are unknown and unidentical. The main contribution of this paper (compared with the existing similar results in the literature) is to guarantee achieving consensus in networks of agents when the communication topology is not connected constantly, and communication links stochastically switch over time. It is shown that if the probability of the network connectivity is not zero, under some conditions, almost sure consensus can be achieved. Illustrative examples verify the accuracy of the proposed consensus protocol.

  8. Control Structures in supply chains as a way to manage unpredictable cyber-risks

    DEFF Research Database (Denmark)

    Sepúlveda Estay, Daniel Alberto; Khan, Omera

    Supply chain growth, and their dependence on Information Technology (IT), is making cyber risks an increasingly unmanageable threat through traditional risk assessment methods. Systemic analysis methods have been identified as alternatives to trad itional methods. This paper analyzes the applicat......Supply chain growth, and their dependence on Information Technology (IT), is making cyber risks an increasingly unmanageable threat through traditional risk assessment methods. Systemic analysis methods have been identified as alternatives to trad itional methods. This paper analyzes...... the application of a systemic risk analysis methodology to understand cyber risks in the supply chain. A generic supply chain is analyzed, and information flows, dynamic structures and the influence of cyber-attack on these are identified. This paper argues that a systemic approach is more efficient in detecting...

  9. Enhancement of entanglement transfer in a spin chain by phase shift control

    CERN Document Server

    Maruyama, K; Nori, F

    2006-01-01

    We study the effect of a phase shift on the amount of transferrable two-spin entanglement in a spin chain. We consider a ferromagnetic Heisenberg/XY spin chain, both numerically and analytically, and two mechanisms to generate a phase shift, the Aharonov-Casher effect and the Dzyaloshinskii-Moriya interaction. In both cases, the maximum attainable entanglement is shown to be significantly enhanced, suggesting its potential usefulness in quantum information processing.

  10. Media bias under direct and indirect government control: when is the bias smaller?

    OpenAIRE

    Abhra Roy

    2015-01-01

    We present an analytical framework to compare media bias under direct and indirect government control. In this context, we show that direct control can lead to a smaller bias and higher welfare than indirect control. We further show that the size of the advertising market affects media bias only under direct control. Media bias, under indirect control, is not affected by the size of the advertising market.

  11. Breaking the chain: Rift Valley fever virus control via livestock vaccination.

    Science.gov (United States)

    Bird, Brian H; Nichol, Stuart T

    2012-06-01

    Rift Valley fever virus is a mosquito-borne pathogen of livestock and humans that causes widespread and devastating outbreaks of severe and often fatal disease throughout Africa and portions of the Arabian Peninsula. Outbreaks can involve tens to hundreds of thousands of human cases, and millions of livestock. The severity of the disease varies by species, but in sheep and cattle 'abortion storms', high neonatal (∼70%), and adult mortality (20-30%) are features. Human cases are generally self-limiting, but severe complications such as hepatitis, retinitis, delayed-onset encephalitis, or a hemorrhagic syndrome with a case fatality of 10-20% can occur. There are no commercially available human vaccines. Livestock provide key ecological links between the Aedes sp. mosquito vector and humans. High viremias in livestock lead to spillover of RVFV into other anthrophillic vectors (Culex and Anopheles sp. mosquitoes), and, importantly, close contact with infected animal tissues and fluids or aborted fetal materials from these animals is a major risk factor for severe and lethal human infections. Vaccination programs targeting livestock during non-epidemic periods or as an early countermeasure against nascent outbreaks could therefore eliminate one of the main sources of human infection and limit the overall scope of epidemics. To this end, research groups have recently reported novel next generation RVFV vaccines that are safe for use in pregnant and young animals. Preventing RVFV infection of livestock by vaccination is a key element in breaking the chain of human epidemics, and could lead to control of this significant public health threat.

  12. A simple and versatile electronic control system for a picosecond Nd:YLF oscillator - Nd:glass amplifier laser chain

    Science.gov (United States)

    Navathe, C. P.; Ansari, M. S.; Upadhyay, J.; Sreedhar, N.; Chandra, R.; Bundel, H. R.; Moorti, A.; Gupta, P. D.

    1997-11-01

    An electronic control system, developed for power conditioning of a picosecond Nd:YLF - Nd:glass laser oscillator - amplifier chain is described. The system generates charging and firing signals required for a commercial picosecond oscillator operated in a repetitive mode, and also carries out a charging and firing sequence of external amplifiers for single-shot operation. The system also controls a mechanical shutter to selectively pass a laser pulse from the oscillator for subsequent amplification. The laser chain includes a Faraday isolator incorporated with a safety check. A control signal is generated by this unit when conditions suitable for a sufficient level of isolation are achieved, and the same is used for gating the oscillator pulse. Good synchronization is confirmed from the measurements of amplifier gain as a function of the relative time delay in firing of different stages. The electronics developed is simple and modular, with sufficient scope for expansion of the system, and resistant to electromagnetic interference.

  13. Optimization in supply chain management, the current state and future directions: A systematic review and bibliometric analysis

    Directory of Open Access Journals (Sweden)

    Mahmood Movahedipour

    2016-11-01

    Full Text Available Purpose: The purpose of this paper is finding the current state of research and identifies high-potential area for future investigation in optimization in supply chain management. Design/methodology/approach: In this paper we present Bibliometric and Network analysis to examine current state research on optimization in supply chain management to identify established and emergent research field for future investigation. The systematic research review which we used in our study have not grasp or assess by other researchers on this topic. Firstly, based on our methodology Bibliometric analysis began by identifying 1610 publications raised from scientific journals, included literatures from 1994 to March of 2016. Secondly, we applied PageRank algorithm in our data for citation analysis to indicate the significance of a publication. Thirdly, the topological decision variables analysis is done based on Louvain method for network data clustering, for this proposes we used the rigorous tools. Finding: Based on our Network analysis result, the optimization in supply chain management research can be divided into four clusters /modules that introduced fundamental skill, knowledge, theory, application and method. Research limitations/implications: We presented some limitation in our research in some fields which could allow new researchers and practitioners conduct the future research to grow up in different dimensions. Practical implications: Practitioners or policy maker usually are not familiar with these type researches so this is why mush of these survey remain in theatrical and conceptual .Future investigation needs to play in practical application  domain instead stop merely in opinion.    Originality/value: Based on our research, the researchers have more attention to work in conceptual analysis due to other fields but we believe that in facility location problem there many remarkable rooms still exist for future research to development

  14. Direct Control Implementation of a Refrigeration System in Smart Grid

    DEFF Research Database (Denmark)

    Pedersen, Rasmus; Schwensen, John; Sivabalan, Senthuran

    2013-01-01

    controlled smart grid, by use of a predictive control strategy. In this application the shift in consumption is used to stabilize a small grid by utilizing excess renewable energy to minimize the need for fossil fueled production sources. In order for the centralized grid controller to handle such a node...

  15. Do means-end chains exist? Experimental tests of their hierarchicity, automatic spreading activation, directionality, and self-relevance

    DEFF Research Database (Denmark)

    Scholderer, Joachim; Grunert, Klaus G.

    2004-01-01

    Despite its popularity in consumer research, means-end chain (MEC) theory suffers from problems of unconfirmed validity. Theoretically, MECs can be cast as associative networks with a three-layered structure that should exhibit four properties: hierarchicity, automatic spreading activation...... this material, individualized stimulus sets were generated for use in the second session. In the second session, each participant completed a series of single-presentation lexical decision tasks. Analysis of spreading activation processes under different procedural variations showed that MECs are firmly...

  16. [DNA extraction and identification of Trichophyton rubrum by real-time polymerase chain reaction from direct nail scraping specimens of patients with onycomycosis].

    Science.gov (United States)

    Berk, Elife; Kuştimur, Semra; Kalkancı, Ayşe; Oztaş, O Murat

    2011-01-01

    Trichophyton rubrum is the most frequently encountered dermatophyte species causing onichomycosis. The routine diagnosis of dermatophytes depends on the direct microscopic examination (DME) and culture methods, however due to the phenotypic identification problems related to those agents, the molecular methods come into question. The aim of this study was to evaluate the diagnostic performance of real-time polymerase chain reaction (RT-PCR) for the identification of T.rubrum by comparing to DME and culture methods, from nail samples of patients with the complaints of onychomycosis. A total of 90 patients of whom 58 were male who were admitted to the dermatology outpatients clinics of our hospital with the complaints of color/shape changes in the nails and thickening of the nail, were included in the study, together with the 20 healthy volunteer subjects as controls. The nail scraping samples obtained from the patients and controls were examined with direct microscopy using 15% potassium hydroxide, dimethyl sulphoxide and chlorazole black mixture and cultivated onto Sabouraud dextrose agar with and without cycloheximide. For DNA isolation, after the disruption of nail samples with a steel tool, phenol-chloroform-isoamyl alcohol purification method were used. The amplification and demonstration of the T.rubrum DNA have been performed by using specific primers and probes following TaqMan protocol of RT-PCR (LightCycler-Roche, USA) method. Seventy-two of the patients yielded positive and 18 yielded negative results with DME. Growth of molds was detected in the cultures of 20 (27.8%) of the 72 DME positive patients and all of the isolates were identified as T.rubrum. No fungal growth was seen in the samples of 18 patients who were DME negative. In DME positive group, 67 (93%) patients were found to be positive in RT-PCR, while 8 (44.4%) patients were RT-PCR positive in DME negative group. All of the culture positive samples (n= 20) were also found positive in RT

  17. Anisotropic Diffusion of Polyelectrolyte Chains within Multi-layer Films

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Li [Stevens Institute of Technology, Hoboken, New Jersey; Kozlovskaya, Veronika [University of Alabama, Birmingham; Kharlampieva, Eugenia [University of Alabama, Birmingham; Ankner, John Francis [ORNL; Sukhishvili, Prof. Svetlana A. [Stevens Institute of Technology, Hoboken, New Jersey

    2012-01-01

    We found diffusion of polyelectrolyte chains within multilayer films to be highly anisotropic, with the preferential chain motion parallel to the substrate. The degree of anisotropy was quantified by a combination of fluorescence recovery after photobleaching and neutron reflectometry, probing chain diffusion in directions parallel and perpendicular to the substrate, respectively. Chain mobility was controlled by ionic strength of annealing solutions and steric hindrance to ionic pairing of interacting polyelectrolytes.

  18. Volume and Direction of the Atlantic Slave Trade, 1650-1870: Estimates by Markov Chain Carlo Analysis

    Directory of Open Access Journals (Sweden)

    Patrick Manning

    2016-03-01

    Full Text Available This article presents methods and results in the application of the Markov Chain Monte Carlo (MCMC analysis to a problem in missing data. The data used here are from The Atlantic Slave Trade Database (TASTD, 2010 version, available online. Of the currently known 35,000 slaving voyages, original data on the size of the cargo of captives exist for some 25 percent of voyage embarkations in Africa and for about 50 percent of arrivals in the Americas. Previous efforts to estimate the missing data (and project the to- tal number of captives who made the transatlantic migration have proceeded through eclectic projections of maximum likelihood estimates of captives per voyage, without error margins. This paper creates new estimates of total mi- grant flow through two methods: one is a formally frequentist set of multiple methods, and the other is through Markov Chain Monte Carlo methodology. Comparison of the three methods, all based on the same raw data, show that the results of the two new methods are fairly close to one another and they yield total flows of migrant captives of more than 20 percent higher than the previous estimates. Quantitative results, presented in simplified graphs and tables within the text and in detailed spreadsheets available online, provide a new estimate of the volume of African embarkations and American arrivals in the transatlantic slave trade for the period from 1650 to 1870, by decade, for eleven African regions of embarkation and seven American and European regions of arrival.

  19. Benefits of using vaccines out of the cold chain: delivering meningitis A vaccine in a controlled temperature chain during the mass immunization campaign in Benin.

    Science.gov (United States)

    Zipursky, Simona; Djingarey, Mamoudou Harouna; Lodjo, Jean-Claude; Olodo, Laifoya; Tiendrebeogo, Sylvestre; Ronveaux, Olivier

    2014-03-14

    In October 2012, the Meningococcal A conjugate vaccine MenAfriVac was granted a label variation to allow for its use in a controlled temperature chain (CTC), at temperatures of up to 40°C for not more than four days. This paper describes the first field use of MenAfriVac in a CTC during a campaign in Benin, December 2012, and assesses the feasibility and acceptability of the practice. We implemented CTC in one selected district, Banikoara (target population of 147,207; 1-29 years of age), across 14 health facilities and 150 villages. We monitored the CTC practice using temperature indicators and daily monitoring sheets. At the end of the campaign we conducted a face-to-face survey to assess vaccinators' and supervisors' experience with CTC. A mix of strategies were implemented in the field to maximize the benefits from CTC practice, depending on the distance from health centre to populations and the availability of a functioning refrigerator in the health centre. Coverage across Banikoara was 105.7%. Over the course of the campaign only nine out of approx. 15,000 vials were discarded due to surpassing the 4 day CTC limit and no vial was discarded because of exposure to a temperature higher than 40°C or due to the Vaccine Vial Monitor (VVM) reaching its endpoint. Overall confidence and perceived usefulness of the CTC approach were very high among vaccinators and supervisors. Vaccinators and supervisors see clear benefits from the CTC approach in low income settings, especially in hard-to-reach areas or where cold chain is weak. Taking advantage of the flexibility offered by CTC opens the door for the implementation of new immunization strategies to ensure all those at risk are protected. Copyright © 2014. Published by Elsevier Ltd.

  20. 75 FR 80066 - Quality Control Requirements for Direct Endorsement Lenders; Notice of Proposed Information...

    Science.gov (United States)

    2010-12-21

    ... URBAN DEVELOPMENT Quality Control Requirements for Direct Endorsement Lenders; Notice of Proposed.... This Notice also lists the following information: Title of Proposal: Quality Control Requirements for... lenders, since these institutions must also conduct quality control on all loans they originate...

  1. The Importance of Systems for Controlling Logistics Costs in the Supply Chain: A Case Study from the Slovenian Automotive Industry

    Directory of Open Access Journals (Sweden)

    Sebastjan Škerlič

    2016-06-01

    Full Text Available Participating in the automotive industry brings new responsibilities for suppliers who, in order to meet customer demands, must strive towards improving business processes, while at the same time reducing costs. These demands can disrupt the operations of companies that do not have a system for controlling logistics costs. On the other hand, customer demands can be the cause of other types of disruptions in companies that have such a system in place, stemming from an excessive focus on cost reduction. To tackle this problem, a survey was conducted on a sample of 30 Slovenian companies that operate as suppliers in the automotive industry. Its objective was to determine how different customer demands along the supply chain can affect the business processes of suppliers and the level of logistics costs. The survey revealed that companies that use a system for controlling logistics costs experience fewer disruptions in their business processes in their efforts to satisfy customer demands. These companies also display a higher level of integration of business processes and use a different approach when dealing with the various participants of the supply chain. The survey also sets clear participation guidelines for suppliers in the supply chain of the automotive industry and points out how companies can benefit from using a system for controlling logistics costs in other ways, aside from the cost controlling aspect.

  2. Direction-specific interactions control crystal growth by oriented attachment

    DEFF Research Database (Denmark)

    Li, Dongsheng; Nielsen, Michael H; Lee, Jonathan R.I.

    2012-01-01

    initiated at the contact point. Interface elimination proceeds at a rate consistent with the curvature dependence of the Gibbs free energy. Measured translational and rotational accelerations show that strong, highly direction-specific interactions drive crystal growth via oriented attachment....... using a fluid cell to directly observe oriented attachment of iron oxyhydroxide nanoparticles. The particles undergo continuous rotation and interaction until they find a perfect lattice match. A sudden jump to contact then occurs over less than 1 nanometer, followed by lateral atom-by-atom addition...

  3. Post-directed weed control in bell peppers

    Science.gov (United States)

    Organic pepper (Capsicum annuum L.) producers need appropriate herbicides that can effectively provide post-emergent weed control. Research was conducted in southeast Oklahoma (Atoka County, Lane, OK) to determine the impact of a potential organic herbicide on weed control efficacy, crop injury, an...

  4. Cloning and expression of functional single-chain Fv antibodies directed against NIa and coat proteins of potato virus Y.

    Science.gov (United States)

    Rouis, Souad; Lafaye, Pierre; Jaoua-Aydi, Leila; Sghaier, Zidani; Ayadi, Hammadi; Gargouri-Bouzid, Radhia

    2006-10-01

    Three single-chain variable fragment (scFv) antibodies recognizing the nuclear inclusion a (NIa) and capsid proteins of potato virus Y were obtained from two mouse derived hybridoma clones secreting, respectively, an anti-NIa (22-1) and an anti-coat protein (136-13) monoclonal antibodies. The first monoclonal antibody was able to inhibit in vitro the PVY polyprotein cleavage by blocking the NIa protease activity. The amplified scFv cDNAs were first inserted into the TOPO vector and then sequenced. Several recombinant E. coli clones carrying the accurate scFv sequences were selected and the corresponding cDNAs were subcloned in pHEN phagemid and transferred in E. coli strain. The expressed scFv fragments showed an antibody activity that recognized the viral target proteins in infected tissues. Their activity was comparable to the parental monoclonal antibodies.

  5. Habitual versus goal-directed action control in Parkinson disease

    NARCIS (Netherlands)

    Wit, S. de; Barker, R.A.; Dickinson, A.D.; Cools, R.

    2011-01-01

    This study presents the first direct investigation of the hypothesis that dopamine depletion of the dorsal striatum in mild Parkinson disease leads to impaired stimulus-response habit formation, thereby rendering behavior slow and effortful. However, using an instrumental conflict task, we show that

  6. Directly observed iron supplementation for control of iron deficiency anemia

    Directory of Open Access Journals (Sweden)

    Mohan Bairwa

    2017-01-01

    Full Text Available Anemia is major public health problem affecting 1.6 billion people worldwide. The poor compliance of iron supplementation remains main contributor for high prevalence of anemia. The current paper reviewed the effectiveness of direct observation of oral iron supplementation on anemia. A systematic search was performed through electronic databases and local libraries. Search strategies used subject headings and key words “directly observed” and “iron supplementation.” Searches were sought through April 2014. A total of 14 articles were included in the study. Findings were presented in three categories. First, all of those reported an improvement in compliance of iron supplementation. Second, reduction in the prevalence of anemia was reported by all and third, all except one reported increased blood hemoglobin level. Directly observed an iron supplementation is an effective approach for prevention and management of anemia in vulnerable groups. However, larger trials are needed before concluding that scaling up directly observed iron supplementation through community health volunteers would be beneficial.

  7. Root-derived CLE glycopeptides control nodulation by direct binding to HAR1 receptor kinase.

    Science.gov (United States)

    Okamoto, Satoru; Shinohara, Hidefumi; Mori, Tomoko; Matsubayashi, Yoshikatsu; Kawaguchi, Masayoshi

    2013-01-01

    Leguminous plants establish a symbiosis with rhizobia to enable nitrogen fixation in root nodules under the control of the presumed root-to-shoot-to-root negative feedback called autoregulation of nodulation. In Lotus japonicus, autoregulation is mediated by CLE-RS genes that are specifically expressed in the root, and the receptor kinase HAR1 that functions in the shoot. However, the mature functional structures of CLE-RS gene products and the molecular nature of CLE-RS/HAR1 signalling governed by these spatially distant components remain elusive. Here we show that CLE-RS2 is a post-translationally arabinosylated glycopeptide derived from the CLE domain. Chemically synthesized CLE-RS glycopeptides cause significant suppression of nodulation and directly bind to HAR1 in an arabinose-chain and sequence-dependent manner. In addition, CLE-RS2 glycopeptide specifically produced in the root is found in xylem sap collected from the shoot. We propose that CLE-RS glycopeptides are the long sought mobile signals responsible for the initial step of autoregulation of nodulation.

  8. Directional Medium Access Control (MAC Protocols in Wireless Ad Hoc and Sensor Networks: A Survey

    Directory of Open Access Journals (Sweden)

    David Tung Chong Wong

    2015-06-01

    Full Text Available This survey paper presents the state-of-the-art directional medium access control (MAC protocols in wireless ad hoc and sensor networks (WAHSNs. The key benefits of directional antennas over omni-directional antennas are longer communication range, less multipath interference, more spatial reuse, more secure communications, higher throughput and reduced latency. However, directional antennas lead to single-/multi-channel directional hidden/exposed terminals, deafness and neighborhood, head-of-line blocking, and MAC-layer capture which need to be overcome. Addressing these problems and benefits for directional antennas to MAC protocols leads to many classes of directional MAC protocols in WAHSNs. These classes of directional MAC protocols presented in this survey paper include single-channel, multi-channel, cooperative and cognitive directional MACs. Single-channel directional MAC protocols can be classified as contention-based or non-contention-based or hybrid-based, while multi-channel directional MAC protocols commonly use a common control channel for control packets/tones and one or more data channels for directional data transmissions. Cooperative directional MAC protocols improve throughput in WAHSNs via directional multi-rate/single-relay/multiple-relay/two frequency channels/polarization, while cognitive directional MAC protocols leverage on conventional directional MAC protocols with new twists to address dynamic spectrum access. All of these directional MAC protocols are the pillars for the design of future directional MAC protocols in WAHSNs.

  9. The Official Control beyond the Official Control. How To Plan And Schedule Controls Starting From Risk Assessment Along The Agro-Food Supply Chain.

    Science.gov (United States)

    Panunzio, M F; Caporizzi, R; Lagravinese, D; Conversano, M

    2015-01-01

    Every year the Italian Ministry of Health, on the basis of regional data, draws up the "Report on Official Controls" to be submitted to the Parliament. The report contains abundant data, diagrams and charts and illustrates the number and type of official controls (OC) performed by the pertinent Bodies (Ministry of Health, Regional and Local Health Authorities) over the previous year on Food Business Operators (FBO), in accordance with the EC Regulation 882/2004. The trend - which has consolidated over the years - relates to the multiplicity of OC and shows a decrease of such controls compared to an increase in "non-conformities". OC frequency is established by the Regional Authorities on the basis of the categorisation of both a "generic risk" for companies calculated taking into account the probability of occurrence of a "non-conformity", and a "specific" risk, assessed on the basis of the results of the OC actually performed on a given "Operatore del Settore Alimentare" (Food Sector Operator, in Italian: OSA). Thus, categorisation (i.e. the probability of occurrence of non-conformities) is the main driver of the OC scheduling and planning process. We have been asking ourselves whether the current OC planning/scheduling method is still suitable for ensuring food safety in the face of internalisation of the food supply chain. As a matter of fact, food safety is now becoming increasingly variable due to the globalization of consumption where "farm to fork", rather than "border to fork", food safety must be ensured. On the basis of these considerations, a different OC planning /scheduling method is being proposed based on the assessment of risks and the estimation of the occurrence of the same along the agro-food chain.

  10. H∞ control of dynamic supply chain network%动态供应链网络的H∞控制

    Institute of Scientific and Technical Information of China (English)

    徐君群

    2012-01-01

    The control and elimination of bullwhip effect is an important topic in supply chain management. For a supply chain network consisting of several manufacturers and distributors, the closed dynamical supply chain network model with uncertain demand is established. The robust operation of the network is discussed based on the H∞ control and linear matrix inequality scheme. The effect of the uncertainty is suppressed under a feedback controller related to the inventory. Meanwhile, the operation cost of the closed supply chain network is controlled to an ideal level. A simulation example is given to show the effectiveness of the proposed method.%牛鞭效应的抑制与消除问题是供应链管理的重要课题.针对具有多个生产商和分销商的供应链网络,建立具有需求不确定性的闭环供应链网络动态模型,利用鲁棒H∞控制策略和线性矩阵不等式方法,处理供应链网络的鲁棒运作问题.通过设计依赖于库存状态的反馈控制器,抑制闭环供应链网络中不确定性的影响,使得闭环供应链网络系统运作达到理想的总成本.最后,通过仿真计算验证所提出方法的有效性.

  11. Learning, Knowing and Controlling the Stock: The Nature of Employee Discretion in a Supermarket Chain

    Science.gov (United States)

    Fuller, Alison; Kakavelakis, Kostas; Felstead, Alan; Jewson, Nick; Unwin, Lorna

    2009-01-01

    This paper explores the nature of the relationship between Head Office and stores in a large British supermarket chain. It focuses on the role played by a range of technological tools available for managing the stock and connecting different parts of the productive system and the implications this has for employee learning in stores. The evidence…

  12. A simulation environment for the design of food supply chain networks: modeling quality controlled logistics

    NARCIS (Netherlands)

    Vorst, van der J.G.A.J.; Tromp, S.; Zee, van der D.J.

    2005-01-01

    Nowadays, many industries are confronted with intensified global competition as well as advances in information and process technology. They create both the need and opportunity for a coordinated approach of industrial partners to establish effective and efficient supply chains. Simulation tools are

  13. Learning, Knowing and Controlling the Stock: The Nature of Employee Discretion in a Supermarket Chain

    Science.gov (United States)

    Fuller, Alison; Kakavelakis, Kostas; Felstead, Alan; Jewson, Nick; Unwin, Lorna

    2009-01-01

    This paper explores the nature of the relationship between Head Office and stores in a large British supermarket chain. It focuses on the role played by a range of technological tools available for managing the stock and connecting different parts of the productive system and the implications this has for employee learning in stores. The evidence…

  14. Resistance in bacteria of the food chain: epidemiology and control strategies

    DEFF Research Database (Denmark)

    Cavaco, Lina; Aarestrup, Frank Møller

    2013-01-01

    . The emergence and spread of resistant bacteria in the food chain is a major concern as food-producing animals may constitute a huge reservoir for antimicrobial resistance. Furthermore, food animals and food of animal origin is traded worldwide, which means that the occurrences of antimicrobial resistance...... in the food supply of one country is currently potentially a problem for all countries....

  15. A framework for early warning and proactive control systems in food supply chain networks

    NARCIS (Netherlands)

    Li, Y.; Kramer, M.R.; Beulens, A.J.M.; Vorst, van der J.G.A.J.

    2010-01-01

    It is inherent to food supply chain networks that performance deviations occur occasionally due to variations in product quality and quantity. To reduce losses, one wants to be informed about such deviations as soon as possible, preferably even before they occur. Then it is possible to take actions

  16. Evidence-based policy for controlling antimicrobial resistance in the food chain in Denmark

    DEFF Research Database (Denmark)

    Wielinga, Pieter; Jensen, Vibeke Frøkjær; Aarestrup, Frank Møller;

    2014-01-01

    was stimulated. Complications of alarming high levels of AMR in animals, and a general discontent about this situation (including farmers and vets) demanded a solution. National surveillance in DANMAP involving all stakeholders from the farm-to-fork food chain was setup to counteract scientific unknowns...

  17. Improved Torque Control Performance in Direct Torque Control using Optimal Switching Vectors

    Directory of Open Access Journals (Sweden)

    Muhd Zharif Rifqi Zuber Ahmadi

    2015-02-01

    Full Text Available This paper presents the significant improvement of Direct Torque Control (DTC of 3-phases induction machine using a Cascaded H-Bidge Multilevel Inverter (CHMI. The largest torque ripple and variable switching frequency are known as the major problem founded in DTC of induction motor. As a result, it can diminish the performance induction motor control. Therefore, the conventional 2-level inverter has been replaced with CHMI the in order to increase the performance of the motor either in dynamic or steady-state condition. By using the multilevel inverter, it can produce a more selection of the voltage vectors. Besides that, it can minimize the torque ripple output as well as increase the efficiency by reducing the switching frequency of the inverter. The simulation model of the proposed method has been developed and tested by using Matlab software. Its improvements were also verified via experimental results.

  18. QuickDirect - Payload Control Software Template Package Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To address the need to quickly, cost-effectively and reliably develop software to control science instruments deployed on spacecraft, QuickFlex proposes to create a...

  19. How do emotion and motivation direct executive control?

    Science.gov (United States)

    Pessoa, Luiz

    2009-04-01

    Emotion and motivation have crucial roles in determining human behavior. Yet, how they interact with cognitive control functions is less understood. Here, the basic elements of a conceptual framework for understanding how they interact are introduced. More broadly, the 'dual competition' framework proposes that emotion and motivation affect both perceptual and executive competition. In particular, the anterior cingulate cortex is hypothesized to be engaged in attentional/effortful control mechanisms and to interact with several other brain structures, including the amygdala and nucleus accumbens, in integrating affectively significant signals with control signals in prefrontal cortex. An implication of the proposal is that emotion and motivation can either enhance or impair behavioral performance depending on how they interact with control functions.

  20. Direct energy converter controllers for switched reluctance motor operation

    OpenAIRE

    Goodman, Andrew Simon

    2007-01-01

    There is increasing demand for simple motor drives offering high reliability and fault tolerance in applications such as the aerospace actuator industry, with the development of `more electric aircraft'. This thesis presents a motor drive employing a switched reluctance motor, the novel single sided matrix converter, and a novel double band hysteresis based control scheme for control of the converter, implemented using a field programmable gate array (FPGA). The single sided matrix co...

  1. How do emotion and motivation direct executive control?

    OpenAIRE

    Pessoa, Luiz

    2009-01-01

    Emotion and motivation have crucial roles in determining human behavior. Yet, how they interact with cognitive control functions is less understood. Here, the basic elements of a conceptual framework for understanding how they interact are introduced. More broadly, the `dual competition' framework proposes that emotion and motivation affect both perceptual and executive competition. In particular, the anterior cingulate cortex is hypothesized to be engaged in attentional/effortful control mec...

  2. Trajectory and Force Control of a Direct Drive Arm.

    Science.gov (United States)

    1986-09-01

    fixed-point arithmetic. Written in the C lan- guage, the controller, including the full computation of the robot dynamics , runs at a 133 Hz sampling...Featherstone, R, 1984, Robot Dynamics Algorithms, Ph.D. Thesis, University of Edinburgh. Franklin, G.F. and Powel, J.D., 1980, Digital Control of Dynamic...Proceedings, 64, pp. 1198-1208. Neuman, C.P., and Khosla, P.K., 1985, "Identification of robot dynamics : an ap- plication of recursive estimation

  3. Wind Turbine Extreme Gust Control. Recognition and Control of extreme operation gusts and wind direction changes

    Energy Technology Data Exchange (ETDEWEB)

    Kanev, S.K.; Van Engelen, T.G. [ECN Wind Energy, Petten (Netherlands)

    2008-10-15

    This report presents the research activities and achieved results on extreme event recognition (EER) and control (EEC). This work has been performed within the framework of WP3 of the SenterNovem project Sustainable Control (SusCon). An extreme wind gust with direction change can lead to large loads on the turbine (causing fatigue) and unnecessary turbine shut-downs by the supervisory system due to rotor overspeed. The proposed EER algorithm is based on a nonlinear observer (extended Kalman filter) that estimates the oblique wind inflow angle and the blade effective wind speed signals, which are then used by a detection algorithm (CUSUM test) to recognize extreme events. The nonlinear observer requires that blade root bending moments measurements (in-plane and out-of-plane) are available. Once an extreme event is detected, an EEC algorithm is activated that (1) tries to prevent the rotor speed from exceeding the overspeed limit by fast collective blade pitching, and (2) reduces 1p blade loads by means of individual pitch control algorithm, designed in an H1 optimal control setting. The method is demonstrated on a complex nonlinear test turbine model.

  4. High Performance Direct Torque Control of Induction Motor Drives Using Space Vector Modulation

    Directory of Open Access Journals (Sweden)

    S. Allirani

    2010-11-01

    Full Text Available This paper presents a simple approach to design and implement Direct Torque Control technique for voltage source inverter fed induction motor drives. The direct torque control is one of the excellent strategies available for torque control of induction machine. It is considered as an alternative to field oriented control technique. The Direct Torque Control scheme is characterized by the absence of PI regulators, co-ordinate transformations, current regulators and pulse width modulated signal generators. Direct Torque Control allows a good torque control in steady state and transient operating conditions. The direct torque control technique based on space vector modulation and switching table has been developed and presented in this paper.

  5. An Empirical Analysis on Agricultural Materials Logistics Control and Agricultural Products Safety: A Case Study of Bi-chains Management Model for Veterinary Drugs in Pinggu District

    Institute of Scientific and Technical Information of China (English)

    Tianqi; ZHANG

    2013-01-01

    Through an empirical analysis of the agricultural logistics model and agricultural products quality control system in Pinggu district of Beijing, a model was studied to control the agricultural quality by agricultural logistics. The model adopts modern logistics supply chain, which firstly, establishes a modern logistics distribution system for veterinary drugs by the means of suppliers control, chain management and cold chain distribution; secondly, organizes the veterinary experts and doctors to provide real-time technical services so as to control the abuse of drugs; thirdly, realizes the supervision of local veterinary drugs and diseases. Thus the quality of animal products is guaranteed, and the model is worthy to be popularized.

  6. Direct Torque Control Induction Motor Drive with Improved Flux Response

    Directory of Open Access Journals (Sweden)

    Bhoopendra Singh

    2012-01-01

    Full Text Available Accurate flux estimation and control of stator flux by the flux control loop is the determining factor in effective implementation of DTC algorithm. In this paper a comparison of voltage-model-based flux estimation techniques for flux response improvement is carried out. The effectiveness of these methods is judged on the basis of Root Mean Square Flux Error (RMSFE, Total Harmonic Distortion (THD of stator current, and dynamic flux response. The theoretical aspects of these methods are discussed and a comparative analysis is provided with emphasis on digital signal processor (DSP based controller implementation. The effectiveness of the proposed flux estimation algorithm is investigated through simulation and experimentally validated on a test drive.

  7. Average Consensus Problems in Networks of Agents with Fixed and Switching Topology and Unknown Control Direction

    Directory of Open Access Journals (Sweden)

    Caixian Sun

    2014-01-01

    Full Text Available This paper is devoted to the average consensus problems in directed networks of agents with unknown control direction. In this paper, by using Nussbaum function techniques and Laplacian matrix, novel average consensus protocols are designed for multiagent systems with unknown control direction in the cases of directed networks with fixed and switching topology. In the case of switching topology, the disagreement vector is utilized. Finally, simulation is provided to demonstrate the effectiveness of our results.

  8. Active control of emission directionality of semiconductor microdisk lasers

    CERN Document Server

    Liew, Seng Fatt; Ge, Li; Solomon, Glenn S; Cao, Hui

    2014-01-01

    We demonstrate lasing mode selection in nearly circular semiconductor microdisks by shaping the spatial profile of optical pump. Despite of strong mode overlap, adaptive pumping suppresses all lasing modes except the targeted one. Due to slight deformation of the cavity shape and boundary roughness, each lasing mode has distinct emission pattern. By selecting different mode to be the dominant lasing mode, we can switch both the lasing frequency and the output direction. Such tunability by external pump after the laser is fabricated enhances the functionality of semiconductor microcavity lasers.

  9. Directional sensitivity of "first trial" reactions in human balance control.

    NARCIS (Netherlands)

    Oude Nijhuis, L.B.; Allum, J.H.J.; Borm, G.F.; Honegger, F.; Overeem, S.; Bloem, B.R.

    2009-01-01

    Support-surface movements are commonly used to examine balance control. Subjects typically receive a series of identical or randomly interspersed multidirectional balance perturbations and the atypical "first trial reaction" (evoked by the first perturbation) is often excluded from further analysis.

  10. Directions for national mastitis control programs: experiences from The Netherlands

    NARCIS (Netherlands)

    Lam, T.J.G.M.; Jansen, J.; Gent, R.J.M.; Veersen, J.C.L.; Keurentjes, J.M.; Werkman, A.G.

    2010-01-01

    The general aim of mastitis control programs is to improve udder health on dairy farms. Over the last five years an intensive national mastitis program was executed in the Netherlands with the goal to improve udder health at a national level. Different groups of farmers have different motivations

  11. Surface segregation of fluorinated moieties on random copolymer films controlled by random-coil conformation of polymer chains in solution.

    Science.gov (United States)

    Xue, Dongwu; Wang, Xinping; Ni, Huagang; Zhang, Wei; Xue, Gi

    2009-02-17

    The relationship between solution properties, film-forming methods, and the solid surface structures of random copolymers composed of butyl methacrylate and dodecafluorheptyl methylacrylate (DFHMA) was investigated by contact angle measurements, X-ray photoelectron spectroscopy, sum frequency generation vibrational spectroscopy, and surface tension measurements. The results, based on thermodynamic considerations, demonstrated that the random copolymer chain conformation at the solution/air interface greatly affected the surface structure of the resulting film, thereby determining the surface segregation of fluorinated moieties on films obtained by various film-forming techniques. When the fluorinated monomer content of the copolymer solution was low, entropic forces dominated the interfacial structure, with the perfluoroalkyl groups unable to migrate to the solution/air interface and thus becoming buried in a random-coil chain conformation. When employing this copolymer solution for film preparation by spin-coating, the copolymer chains in solution were likely extended due to centrifugal forces, thereby weakening the entropy effect of the polymer chains. Consequently, this resulted in the segregation of the fluorinated moieties on the film surface. For the films prepared by casting, the perfluoroalkyl groups were, similar to those in solution, incapable of segregating at the film surface and were thus buried in the random-coil chains. When the copolymers contained a high content of DFHMA, the migration of perfluoroalkyl groups at the solution/air interface was controlled by enthalpic forces, and the perfluoroalkyl groups segregated at the surface of the film regardless of the film-forming technique. The aim of the present work was to obtain an enhanced understanding of the formation mechanism of the chemical structure on the surface of the polymer film, while demonstrating that film-forming methods may be used in practice to promote the segregation of fluorinated

  12. Pseudomonas sp. as a Source of Medium Chain Length Polyhydroxyalkanoates for Controlled Drug Delivery: Perspective

    Directory of Open Access Journals (Sweden)

    Sujatha Kabilan

    2012-01-01

    Full Text Available Controlled drug delivery technology represents one of the most rapidly advancing areas of science. They offer numerous advantages compared to conventional dosage forms including improved efficacy, reduced toxicity, improved patient compliance and convenience. Over the past several decades, many delivery tools or methods were developed such as viral vector, liposome-based delivery system, polymer-based delivery system, and intelligent delivery system. Recently, nonviral vectors, especially those based on biodegradable polymers, have been widely investigated as vectors. Unlike the other polymers tested, polyhydroxyalkanoates (PHAs have been intensively investigated as a family of biodegradable and biocompatible materials for in vivo applications as implantable tissue engineering material as well as release vectors for various drugs. On the other hand, the direct use of these polyesters has been hampered by their hydrophobic character and some physical shortcomings, while its random copolymers fulfilled the expectation of biomedical researchers by exhibiting significant mechanical and thermal properties. This paper reviews the strategies adapted to make functional polymer to be utilized as delivery system.

  13. Application of Space Vector Modulation in Direct Torque Control of PMSM

    Directory of Open Access Journals (Sweden)

    Michal Malek

    2008-01-01

    Full Text Available The paper deals with an improvement of direct torque control method for permanent magnet synchronous motor drives. Electrical torque distortion of the machine under original direct torque control is relatively high and if proper measures are taken it can be substantially decreased. The proposed solution here is to combine direct torque control with the space vector modulation technique. Such approach can eliminate torque distortion while preserving the simplicity of the original method.

  14. Airlift Cargo Hub Port Hold Times: Controlling Variations in Defense Supply Chain Delivery

    Science.gov (United States)

    2010-06-01

    SUPPLY CHAIN DELIVERY GRADUATE RESEARCH PAPER Brandon A. Casey, Major, USAF AFIT/IMO/ENS/10-03 DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY AIR FORCE INSTITUTE OF TECHNOLOGY Wright-Patterson Air Force Base, Ohio APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED The views expressed in this graduate research project are those of the author and do not reflect the official policy of the United States Air Force, Department of

  15. Goal directed locomotion and balance control in autistic children.

    Science.gov (United States)

    Vernazza-Martin, S; Martin, N; Vernazza, A; Lepellec-Muller, A; Rufo, M; Massion, J; Assaiante, C

    2005-02-01

    This article focuses on postural anticipation and multi-joint coordination during locomotion in healthy and autistic children. Three questions were addressed. (1) Are gait parameters modified in autistic children? (2) Is equilibrium control affected in autistic children? (3) Is locomotion adjusted to the experimenter-imposed goal? Six healthy children and nine autistic children were instructed to walk to a location (a child-sized playhouse) inside the psychomotor room of the pedopsychiatric centre located approximately 5 m in front of them. A kinematic analysis of gait (ELITE system) indicates that, rather than gait parameters or balance control, the main components affected in autistic children during locomotion are the goal of the action, the orientation towards this goal and the definition of the trajectory due probably to an impairment of movement planning.

  16. Simulation of Brushless DC Motor using Direct Torque Control

    OpenAIRE

    Kusuma, G.; S. Rukhsana Begum

    2014-01-01

    This paper deals with modelling of three phases brushless dc motor with MATLAB/SIMULINK software BLDC motor have advantages according to brushless dc motor and induction motor’s. They have improve speed torque charactistics, high efficiency high transient response and small size. It approaches for reducing the torque ripples of BLDC motor using DTC, by using control technique’s ,but present work mainly concentrate on advanced method. The whole drive system is simulated based o...

  17. Information Modeling for Direct Control of Distributed Energy Resources

    DEFF Research Database (Denmark)

    Biegel, Benjamin; Andersen, Palle; Stoustrup, Jakob

    2013-01-01

    a desired accumulated response. In this paper, we design such an information model based on the markets that the aggregator participates in and based on the flexibility characteristics of the remote controlled DERs. The information model is constructed in a modular manner making the interface suitable...... for a whole range of different DERs. The devised information model can serve as input to the international standardization efforts on distributed energy resources....

  18. Simulation of Brushless DC Motor using Direct Torque Control

    Directory of Open Access Journals (Sweden)

    Mrs.G. Kusuma

    2014-04-01

    Full Text Available This paper deals with modelling of three phases brushless dc motor with MATLAB/SIMULINK software BLDC motor have advantages according to brushless dc motor and induction motor’s. They have improve speed torque charactistics, high efficiency high transient response and small size. It approaches for reducing the torque ripples of BLDC motor using DTC, by using control technique’s ,but present work mainly concentrate on advanced method. The whole drive system is simulated based on the system devices, BLDC motor source inverter, space vector modulation.

  19. Effects of Edge Directions on the Structural Controllability of Complex Networks.

    Directory of Open Access Journals (Sweden)

    Yandong Xiao

    Full Text Available Recent advances indicate that assigning or reversing edge direction can significantly improve the structural controllability of complex networks. For directed networks, approaching the optimal structural controllability can be achieved by detecting and reversing certain "inappropriate" edge directions. However, the existence of multiple sets of "inappropriate" edge directions suggests that different edges have different effects on optimal controllability-that is, different combinations of edges can be reversed to achieve the same structural controllability. Therefore, we classify edges into three categories based on their direction: critical, redundant and intermittent. We then investigate the effects of changing these edge directions on network controllability, and demonstrate that the existence of more critical edge directions implies not only a lower cost of modifying inappropriate edges but also better controllability. Motivated by this finding, we present a simple edge orientation method aimed at producing more critical edge directions-utilizing only local information-which achieves near optimal controllability. Furthermore, we explore the effects of edge direction on the controllability of several real networks.

  20. Effects of Edge Directions on the Structural Controllability of Complex Networks.

    Science.gov (United States)

    Xiao, Yandong; Lao, Songyang; Hou, Lvlin; Small, Michael; Bai, Liang

    2015-01-01

    Recent advances indicate that assigning or reversing edge direction can significantly improve the structural controllability of complex networks. For directed networks, approaching the optimal structural controllability can be achieved by detecting and reversing certain "inappropriate" edge directions. However, the existence of multiple sets of "inappropriate" edge directions suggests that different edges have different effects on optimal controllability-that is, different combinations of edges can be reversed to achieve the same structural controllability. Therefore, we classify edges into three categories based on their direction: critical, redundant and intermittent. We then investigate the effects of changing these edge directions on network controllability, and demonstrate that the existence of more critical edge directions implies not only a lower cost of modifying inappropriate edges but also better controllability. Motivated by this finding, we present a simple edge orientation method aimed at producing more critical edge directions-utilizing only local information-which achieves near optimal controllability. Furthermore, we explore the effects of edge direction on the controllability of several real networks.

  1. Effectiveness of lethal, directed wolf-depredation control in Minnesota

    Science.gov (United States)

    Harper, E.K.; Paul, W.J.; Mech, L.D.; Weisberg, S.

    2008-01-01

    Wolf (Canis lupus) depredations on livestock in Minnesota, USA, are an economic problem for many livestock producers, and depredating wolves are lethally controlled. We sought to determine the effectiveness of lethal control through the analysis of data from 923 government-verified wolf depredations from 1979 to 1998. We analyzed the data by 1) assessing the correlations between the number of wolves killed in response to depredations with number of depredations the following year at state and local levels, and 2) the time to the next depredation. No analysis indicated that trapping wolves substantially reduced the following year's depredations at state or local levels. However, more specific analyses indicated that in certain situations, killing wolves was more effective than no action (i.e., not trapping). For example, trapping and killing adult males decreased the re-depredation risk. At sheep farms, killing wolves was generally effective. Attempting to trap, regardless of the results, seemed more effective at reducing depredations than not trapping, suggesting that mere human activity near depredation sites might deter future depredations.

  2. Direct digital simulation of power semiconductor-controlled electrical machines

    Science.gov (United States)

    Bahnassy, H. M.

    1981-06-01

    Generalized computer programming techniques for simulating power semiconductor-controlled electric machines in coil-variable representation are presented. These techniques are developed primarily for implementation in large scale general purpose computer-aided design and analysis (CADA) circuit programs. To demonstrate the validity of the developed techniques, a coil-variable model of a brushless synchronous generator with an ac exciter and rotating rectifiers was constructed. The performance of the control system (thyristor voltage regulator) is represented by a transfer function block diagram model. The CADA circuit program used is the recently developed SUPER SCEPTRE program. The model is validated using the design data and test results of a 60 kVA brushless generator. Numerous computer simulation cases are presented including the steady state and transient conditions. Brushless generator performance under diode failure faults (opened-diode, shorted-diode) is simulated. The effects of the external faults, at the main generator terminals, on the main generator, as well as its excitation system currents, are simulated.

  3. An improved direct torque controller applied to an electric vehicle

    Directory of Open Access Journals (Sweden)

    Miguel Durán

    2014-01-01

    Full Text Available Este artículo presenta la estructura básica, el modelo y el diseño de un controlador de par para un vehículo eléctrico (EV. El EV propuesto es el resultado de la conversión de un vehículo convencional a un vehículo eléctrico, donde el sistema de tracción original basado en un motor de combustión interna es remplazado por un sistema de tracción eléctrica. El controlador está basado en la técnica de control directo de par (DTC más un término que compensa la caída de voltaje en los devanados del estator del motor de inducción (IM. Con el fin de obtener una frecuencia de conmutación constante se utiliza la técnica de modulación PWM vectorial para generar los pulsos del inversor. Se presentan los resultados de simulación para probar el desempeño de la estrategia de control propuesta, la cual es comparada con el esquema de DTC convencional.

  4. Polarization controlled directional excitation of Bloch surface waves (Conference Presentation)

    Science.gov (United States)

    Kovalevich, Tatiana; Boyer, Philippe; Bernal, Maria-Pilar; Kim, Myun-Sik; Herzig, Hans Peter; Grosjean, Thierry

    2016-09-01

    Bloch surface waves (BSWs) are electromagnetic surface waves which can be excited at the interface between periodic dielectric multilayer and a surrounding medium. In comparison with surface plasmon polaritons these surface states perform high quality factor due to low loss characteristics of dielectric materials and can be exited both by TE and TM polarized light. A platform consisting of periodic stacks of alternative SiO2 and Si3N4 layers is designed and fabricated to work at the wavelength of 1.55 µm. The platform has an application in sensing and in integrated optics domain. A standard way of BSW excitation is coupling via Kretschmann configuration, but in this work we investigate a grating coupling of BSWs. Grating parameters are analytically and numerically optimized by RCWA and FDTD methods in order to obtain the best coupling conditions. The light is launched orthogonally to the surface of the photonic crystal and the grating. Due to a special grating configuration we demonstrate directionality of the BSW propagation depending on polarization of the incident light. The structure was experimentally realized on the surface of the photonic crystal by FIB milling. Experimental results are in a good agreement with a theory. The investigated configuration can be successfully used as a BSW launcher in on-chip all-optical integrated systems and work as a surface wave switch or modulator.

  5. AUTOMATED DYNAMIC LOAD CONTROL BY ELECTROMECHANICAL SYSTEMS OF A BUCKET-CHAIN EXCAVATOR IN THE COURSE OF SCOOPING

    Directory of Open Access Journals (Sweden)

    Khayrullin Rustam Zinnatullovich

    2012-10-01

    Full Text Available Methods and algorithms of control of the tension of lifting and towing ropes of bucket-chain excavators are proposed in the article. They are based on the non-linear dependence of the current path length and intensity of excavation efforts. Three automatic control modes, including scooping, correction signals and automatic overload protection, are implemented. Two independent control loops in charge of tension of lifting and towing ropes are developed. The proposed automated control system may be integrated both into new bucket-chain excavators and into those excavators that are already in operation. The new system does not require any substantial alterations in electric drive control systems in charge of lifting and towing, if integrated into excavators in operation. The author has performed the non-linearity analysis; he has also designed, developed and implemented the models that are capable of taking an adequate account of the system peculiarities identified in the course of the project implementation. The system parameters are adjustable to specific conditions of the excavator operation, including the hardness of the rock extracted by the excavator, etc. The automatic overload control system attached to the electric drives in control of lifting and towing ensures maximal responsiveness of the system based on the commutation-related limitations imposed by power-driven elements, maximal over-control values and variability of the transition process. Prevention of any rope slacks in the course of scooping of any hard rock is assured by the loop of regulation of minimal tension of lifting cables. The service life of lifting and towing ropes goes up by eight to ten weeks, if the system proposed by the author is implemented.

  6. Real Time Fuzzy Based Speed and Direction Angle Control of an Automated Guided Vehicle

    Directory of Open Access Journals (Sweden)

    Abdullah Başçı

    2015-04-01

    Full Text Available In this paper a fuzzy controller is applied to velocity and direction angle control of a certain type of wheeled mobile robots called Automated Guided Vehicles (AGVs. The velocity and direction angle of the AGV are controlled to keep the vehicle on desired path. A PI controller is also applied to AGV in order to show the robustness of the fuzzy controller. Experimental results prove that the fuzzy controller shows better tracking performance than the PI controller in terms of robustness, smoothness and fast dynamics. Results are also given for sudden disturbance and extra load conditions and satisfied results are obtained.

  7. Failures of chain systems

    CSIR Research Space (South Africa)

    James, A

    1997-03-01

    Full Text Available . In general, there are three basic types of system: hoisting and securing chains conveying and elevating chains power transmission chains The materials used can vary significantly and are specifically tailored for the application...-uniform or if the system is subjected to dynamic loading. In addition, adequate lubrication of such chain systems is very important to ensure that friction (and surface corrosion) is reduced as much as possible. Abnormal loading, directly...

  8. Loss of lateral prefrontal cortex control in food-directed attention and goal-directed food choice in obesity.

    Science.gov (United States)

    Janssen, Lieneke K; Duif, Iris; van Loon, Ilke; Wegman, Joost; de Vries, Jeanne H M; Cools, Roshan; Aarts, Esther

    2017-02-01

    Loss of lateral prefrontal cortex (lPFC)-mediated attentional control may explain the automatic tendency to eat in the face of food. Here, we investigate the neurocognitive mechanism underlying attentional bias to food words and its association with obesity using a food Stroop task. We tested 76 healthy human subjects with a wide body mass index (BMI) range (19-35kg/m(2)) using fMRI. As a measure of obesity we calculated individual obesity scores based on BMI, waist circumference and waist-to-hip ratio using principal component analyses. To investigate the automatic tendency to overeat directly, the same subjects performed a separate behavioral outcome devaluation task measuring the degree of goal-directed versus automatic food choices. We observed that increased obesity scores were associated with diminished lPFC responses during food attentional bias. This was accompanied by decreased goal-directed control of food choices following outcome devaluation. Together these findings suggest that deficient control of both food-directed attention and choice may contribute to obesity, particularly given our obesogenic environment with food cues everywhere, and the choice to ignore or indulge despite satiety.

  9. Semiconductor Light-Controlled Instrument Transducer with Direct PWM Output for Automatic Control Systems

    Directory of Open Access Journals (Sweden)

    F. J. De la Hidalga-W

    2013-01-01

    Full Text Available This work shows that the direct PWM output electric signal, with a duty cycle controlled by light intensity, can beobtained using a circuit containing a saw-tooth voltage generator connected in series with a dc voltage source and ametal (semitransparent gate oxide semiconductor capacitor (MOS-C.The internal PWM signal conversion occurs by the use of non-equilibrium physical processes in the semiconductorsubstrate of the MOS-C. The 10-20 V amplitude limited square PWM output signal is obtained by the amplification ofthe sensor signal with a standard 60 dB transimpedance amplifier. The amplified output signal presents positive andnegative PWM waveforms that can be easily separated using diodes. The duty of the positive part is proportional tothe light intensity, whereas the negative part is inversely proportional to the intensity. The frequency operating rangeof this proposed instrument varies from 1 Hz to a few kilohertz. The duty cycle of the PWM output signal varies from2% to 98% when the incident light intensity varies in the microwatts range. These new transducers or sensors couldbe useful for automatic control, robotic applications, dimmer systems, feedback electronic systems, and non-contactoptical position sensing for nulling and centering measurements.

  10. Direct determination of flavor relevant and further branched-chain fatty acids from sheep subcutaneous adipose tissue by gas chromatography with mass spectrometry.

    Science.gov (United States)

    Kaffarnik, Stefanie; Preuß, Siegfried; Vetter, Walter

    2014-07-11

    4-Methyloctanoic acid, 4-ethyloctanoic acid and 4-methylnonanoic acid are key-flavor compounds of sheep and goat. Yet, the low amounts of these volatile branched-chain fatty acids (vBCFAs) in the fat of the ruminants hampered their determination on a routine basis. In this work we developed a gas chromatography/mass spectrometry selected ion monitoring (GC/MS-SIM) method for the direct determination of the vBCFAs as methyl esters, which were obtained after transesterification of subcutaneous adipose tissue of sheep. The excellent sensitivity of the GC/MS-SIM method (limit of quantification, LOQ, 3.6-4.8μg/g; limit of detection, LOD, 1.1-1.4μg/g for 4-Me-8:0, 4-Et-8:0 and 4-Me-9:0) enabled us to determine the three vBCFAs without an enrichment step. Subcutaneous adipose sheep tissue of three different breeds contained 23-88μg/g 4-methyloctanoic acid, 13-26μg/g 4-ethyloctanoic acid and ∼2.9-18μg/g 4-methylnonanoic acid. Since all fatty acids were present in the FAME fraction, the samples could be screened for further branched-chain FAMEs. After elimination of unsaturated fatty acids by hydrogenation (the presence of some unsaturated fatty acids could be verified by this measure), additional measurements in SIM and full scan modes of methyl esters and picolinyl esters enabled the determination of further 97 saturated fatty acids in the samples with eight to 20 carbons. The method is suited for routine analysis and may be useful to investigate the reasons for the abundance/absence of 4-methyloctanoic acid, 4-ethyloctanoic acid and 4-methylnonanoic acid and further branched-chain fatty acids in sheep and goat.

  11. Controlled and selective placement of boron subphthalocyanines on either chain end of polymers synthesized by nitroxide mediated polymerization

    Directory of Open Access Journals (Sweden)

    Benoît H. Lessard

    2015-10-01

    Full Text Available In previous studies, we synthesized the first organic light emitting diode (OLED using boron subphthalocyanines (BsubPcs based polymers. When designing new polymer materials for organic electronic applications such as OLEDs or organic photovoltaic (OPV devices it is important to consider not only the contribution of each monomer but also the polymer chain ends. In this paper we establish a post-polymerization strategy to couple BsubPcs onto either the α- or the ω-chain end using chemically selective BsubPc derivatives. We outline how the chain ends of two representative polymers, poly(styrene (PS and poly(n-butylacrylate (BA, synthesized by nitroxide mediated polymerization (NMP, using BlocBuilder-MA as the initiating species, can be chemically modified by the incorporation of BsubPc chromophores. The addition of the BsubPc chromophore was confirmed through the use of a photodiode array detector (PDA connected in-line with a gel permeation chromatography (GPC setup. These findings represent the first reported method for the controlled and selective placement of a BsubPc chromophores on either end of a polymer produced by NMP. This strategy will therefore be utilized to make next generation BsubPc polymers for OLEDs and OPV devices. The extremely high molar extinction coefficient of BsubPc also make these polymers ideally suited for dye-labelling of polymers.

  12. Options for reducing food waste by quality-controlled logistics using intelligent packaging along the supply chain.

    Science.gov (United States)

    Heising, Jenneke K; Claassen, G D H; Dekker, Matthijs

    2017-10-01

    Optimising supply chain management can help to reduce food waste. This paper describes how intelligent packaging can be used to reduce food waste when used in supply chain management based on quality-controlled logistics (QCL). Intelligent packaging senses compounds in the package that correlate with the critical quality attribute of a food product. The information on the quality of each individual packaged food item that is provided by the intelligent packaging can be used for QCL. In a conceptual approach it is explained that monitoring food quality by intelligent packaging sensors makes it possible to obtain information about the variation in the quality of foods and to use a dynamic expiration date (IP-DED) on a food package. The conceptual approach is supported by quantitative data from simulations on the effect of using the information of intelligent packaging in supply chain management with the goal to reduce food waste. This simulation shows that by using the information on the quality of products that is provided by intelligent packaging, QCL can substantially reduce food waste. When QCL is combined with dynamic pricing based on the predicted expiry dates, a further waste reduction is envisaged.

  13. Optimizing SFR transmutation performance through direct adjoining control theory

    Science.gov (United States)

    Davis, Jeffrey C.

    2007-12-01

    We have developed the CORTANA code to optimize the transmutation performance of sodium cooled fast reactors (SFRs). We obtain the necessary conditions for optimal fuel and burnable absorber loadings using Pontryagin's maximum principle with a direct adjoining approach to explicitly account for either a flat flux or a power peaking inequality constraint providing a set of coupled system, Euler-Lagrange (E-L), and optimality equations which are iteratively solved with the method of conjugate gradients until no further improvement in the objective function is achieved. To satisfy the inequality constraints throughout the operating cycle, we have implemented a backwards diffusion theory (BDT) to establish a relationship between fuel loading and the relative assembly power distribution during the cycle and systematically eliminate the constraint violations with each conjugate gradient iteration. The CORTANA SFR optimization code uses multi-group, three-dimensional neutron diffusion theory, with a microscopic depletion scheme. We solve the system equations in a quasi-static fashion forward in time from beginning-of-cycle (BOC) to end-of-cycle (EOC), while we solve the E-L equations backwards in time from EOC to BOC, reflecting the adjoint nature of the Lagrange multipliers. A two enrichment-zone SFR problem verifies our formulation, yielding a TRU enrichment distribution nearly identical to that of the reference SFR core in the Generation IV Roadmap. Using a full heavy metal recycling mode, we coupled our optimization methodology with the REBUS-3 equilibrium cycle methodology to optimize an SFR operating as a second tier transmuter. We model the system using a three-dimensional triangular-z finite differencing scheme with full core symmetry and a time-independent 33-group microscopic cross section library. Beginning from a uniform TRU distribution, our CORTANA improves the SFR performance by reducing the maximum relative assembly power from 1.7 to 1.25, minimizes

  14. Heparan sulfate chain valency controls syndecan-4 function in cell adhesion

    DEFF Research Database (Denmark)

    Gopal, Sandeep; Bober, Adam; Whiteford, James R;

    2010-01-01

    Fibroblasts null for the transmembrane proteoglycan, syndecan-4, have an altered actin cytoskeleton, compared to matching wild-type cells. They do not organize alpha-smooth muscle actin into bundles, but will do so when full length syndecan-4 is re-expressed. This requires the central V region of......-smooth muscle actin organization, being reduced where syndecan-4 function was compromised by a lack of multiple heparan sulfate chains.......Fibroblasts null for the transmembrane proteoglycan, syndecan-4, have an altered actin cytoskeleton, compared to matching wild-type cells. They do not organize alpha-smooth muscle actin into bundles, but will do so when full length syndecan-4 is re-expressed. This requires the central V region......, clustering of one-chain syndecan-4 forms with antibodies overcame the block, indicating that valency of interactions with ligands is a key component of syndecan-4 function. Measurements of focal contact/adhesion size and focal adhesion kinase phosphorylation correlated with syndecan-4 status and alpha...

  15. Development of valence-directed nanoparticle building blocks on the basis of controlled bio/nano-interfacing chemistry

    Science.gov (United States)

    Kim, Jeong-Hwan

    The assembly of nanoparticles in controllable and predictable ways would not only aid practical nanoscale assembly, which requires accurate and scalable assembly of large and complex nanoscale structures, but also would increase their utility for many applications, including electronics, optics, sensing and imaging, medical diagnostics, etc. Well-defined and controlled functionality and directionality of the building blocks are essential to actively control the molecular assembly processes at the nanometer scale. Such controls over the functionality and directionality would enable us to construct sophisticated nanostructures to take advantage of the increasing number of available nanocomponents and ultimately to approximate the complexity and the functionality of current microfabrication. We have developed a serial solid-phase placement approach to synthesize anisotropically or symmetrically functionalized gold nanoparticles (AuNPs), in which the functionality and directionality (e.g., numbers, locations, and orientations) of the functional ligands are controlled. Two types of bi-functionalized (bif-) AuNPs were synthesized at a site-specific manner with increased yield and accuracy: (1) homo-bif-AuNPs with two carboxyl groups at ˜180° angle (para-configuration) and (2) hetero-bif-AuNPs with one carboxyl and one amine functional groups at less than 180°, but greater than 90° angle (meta-configuration). With such control, we successfully demonstrated the assembly of intentionally designed one-dimensional (1D) chains with homo-bif-AuNPs and two-dimensional (2D) rings with hetero-bif-AuNPs, confirming the high functional as well as directional selectivity of the functionalized NPs. This study represents an important step towards accurate, reliable, and scaled-up manufacturing of complex nanoscale structures, potentially making 'bottom-up' nanofabrication of practical use. We have further developed the ligand replacement technology to achieve such active controls

  16. HTLV-1 Tax Functions as a Ubiquitin E3 Ligase for Direct IKK Activation via Synthesis of Mixed-Linkage Polyubiquitin Chains.

    Science.gov (United States)

    Wang, Chong; Long, Wenying; Peng, Chao; Hu, Lin; Zhang, Qiong; Wu, Ailing; Zhang, Xiaoqing; Duan, Xiaotao; Wong, Catherine C L; Tanaka, Yuetsu; Xia, Zongping

    2016-04-01

    The HTLV-1 oncoprotein Tax plays a key role in CD4+ T cell transformation by promoting cell proliferation and survival, mainly through permanent activation of the NK-κB pathway and induction of many NF-κB target genes. Elucidating the underlying molecular mechanism is therefore critical in understanding HTLV-1-mediated transformation. Current studies have suggested multiple but controversial mechanisms regarding Tax-induced IKK activation mainly due to blending of primary Tax-induced IKK activation events and secondary IKK activation events induced by cytokines secreted by the primary Tax-induced IKK-NF-κB activation events. We reconstituted Tax-stimulated IKK activation in a cell-free system to dissect the essential cellular components for primary IKK activation by Tax and studied the underlying biochemical mechanism. We found that Tax is a putative E3 ubiquitin ligase, which, together with UbcH2, UhcH5c, or UbcH7, catalyzes the assembly of free mixed-linkage polyubiquitin chains. These free mixed-linkage polyubiquitin chains are then responsible for direct IKK activation by binding to the NEMO subunit of IKK. Our studies revealed the biochemical function of Tax in the process of IKK activation, which utilizes the minimal cellular ubiquitination components for NF-κB activation.

  17. Calcium requirement of phytochrome-mediated fern-spore germination: no direct phytochrome-calcium interaction in the phytochrome-initiated transduction chain

    Science.gov (United States)

    Scheuerlein, R.; Wayne, R.; Roux, S. J.

    1989-01-01

    Phytochrome-mediated germination of fern spores of Dryopteris paleacea Sw. was initiated by a saturating red-light (R) irradiation after 20 h of imbibition. For its realization external Ca2+ was required, with a threshold at a submicromolar concentration, and an optimum was reached around 10(-4) M. At concentrations > or = 10(-1) M only a reduced response was obtained, based probably on an unspecific osmotic or ionic effect. The germination response was inhibited by La3+, an antagonist of Ca2+. From these results it is concluded that Ca2+ influx from the medium into the spores may be an important event in phytochrome-mediated germination. In the absence of Ca2+ the R-stimulated system remained capable of responding to Ca2+, added as late as 40 h after R. Moreover, Ca2+ was effective even if added after the active form of phytochrome, Pfr, had been abolished by far-red (FR) 24 h after R. Thus, the primary effect of Pfr, that initiates the transduction chain, does not require calcium. "Coupling" of Pfr to subsequent dark reactions has been investigated by R-FR irradiations with various dark intervals. The resulting "escape kinetics" were characterized by a lag phase (6 h) and half-maximal escape from FR reversibility (19 h). These kinetics were not significantly changed by the presence or absence of calcium. Thus, direct interaction of Pfr and calcium is not a step in the transduction chain initiated by the active form of phytochrome.

  18. Neuromodulatory control of a goal-directed decision.

    Directory of Open Access Journals (Sweden)

    Keiko Hirayama

    Full Text Available Many cost-benefit decisions reduce to simple choices between approach or avoidance (or active disregard to salient stimuli. Physiologically, critical factors in such decisions are modulators of the homeostatic neural networks that bias decision processes from moment to moment. For the predatory sea-slug Pleurobranchaea, serotonin (5-HT is an intrinsic modulatory promoter of general arousal and feeding. We correlated 5-HT actions on appetitive state with its effects on the approach-avoidance decision in Pleurobranchaea. 5-HT and its precursor 5-hydroxytryptophan (5-HTP augmented general arousal state and reduced feeding thresholds in intact animals. Moreover, 5-HT switched the turn response to chemosensory stimulation from avoidance to orienting in many animals. In isolated CNSs, bath application of 5-HT both stimulated activity in the feeding motor network and switched the fictive turn response to unilateral sensory nerve stimulation from avoidance to orienting. Previously, it was shown that increasing excitation state of the feeding network reversibly switched the turn motor network response from avoidance to orienting, and that 5-HT levels vary inversely with nutritional state. A simple model posits a critical role for 5-HT in control of the turn network response by corollary output of the feeding network. In it, 5-HT acts as an intrinsic neuromodulatory factor coupled to nutritional status and regulates approach-avoidance via the excitation state of the feeding network. Thus, the neuromodulator is a key organizing element in behavioral choice of approach or avoidance through its actions in promoting appetitive state, in large part via the homeostatic feeding network.

  19. The immediate effect of unilateral lumbar Z-joint mobilisation on posterior chain neurodynamics: a randomised controlled study.

    Science.gov (United States)

    Szlezak, Adam Michael; Georgilopoulos, Peter; Bullock-Saxton, Joanne Elizabeth; Steele, Michael Craig

    2011-12-01

    Hamstring strain (HS) is a common musculoskeletal condition and abnormal neurodynamics has been shown to influence HS and delay recovery. The efficacy of stretching for preventing and treating HS remains uncertain despite extensive research and wide-spread use. The effects of cervical spine mobilisation on peripheral nervous system function, neurodynamics and muscle force in the upper limb have been reported. Very few studies have reported effects of lumbar spine mobilisation on these variables in the lower limb. This study aimed to determine immediate effects of either a unilateral zygopophyseal joint posteroanterior mobilisation or a static posterior chain muscle stretch on the range of passive straight leg raise (SLR) in comparison to a non-treatment control. Using a single-blinded, randomised controlled study design, 36 healthy participants were allocated into one of three groups (control; mobilisation; static posterior chain muscle stretch). Measures of SLR were taken before and after intervention for each group on the day of testing. A General Linear Model (GLM) and a paired sample t-test showed a significant difference between base line and post-intervention for the mobilisation group only (p neurodynamics.

  20. Multiple mobility edges in a 1D Aubry chain with Hubbard interaction in presence of electric field: Controlled electron transport

    Science.gov (United States)

    Saha, Srilekha; Maiti, Santanu K.; Karmakar, S. N.

    2016-09-01

    Electronic behavior of a 1D Aubry chain with Hubbard interaction is critically analyzed in presence of electric field. Multiple energy bands are generated as a result of Hubbard correlation and Aubry potential, and, within these bands localized states are developed under the application of electric field. Within a tight-binding framework we compute electronic transmission probability and average density of states using Green's function approach where the interaction parameter is treated under Hartree-Fock mean field scheme. From our analysis we find that selective transmission can be obtained by tuning injecting electron energy, and thus, the present model can be utilized as a controlled switching device.

  1. Variable-Structure Direct Torque Control – A Class of Fast and Robust Controllers for Induction Machine Drives

    DEFF Research Database (Denmark)

    Lascu, Christian; Boldea, Ion; Blaabjerg, Frede

    2004-01-01

    A family of variable-structure controllers for induction machine drives is presented, in which the principles of direct torque control (DTC), variable-structure control (VSC) and space-vector pulsewidth modulation are combined to ensure high-performance operation, both in the steady state and under...

  2. “农超对接”供应链运作模式研究%Study on Operational Mode of Farmland-supermarket Direct Docking Supply Chains

    Institute of Scientific and Technical Information of China (English)

    王永钊

    2014-01-01

    In this paper, we pointed out some of the bottlenecks of the operational modes of the farmland-supermarket direct docking practice in China, introduced some of the classis modes, and at the end, through analyzing the supply chain mode of the practice, proposed the measures for its optimization.%指出了我国发展“农超对接”运作模式面临的一些瓶颈,提出了几种典型的“农超对接”运作模式,最后通过对“农超对接”的供应链模式分析,提出了实施农产品供应链优化的措施。

  3. Multi-fragment site-directed mutagenic overlap extension polymerase chain reaction as a competitive alternative to the enzymatic assembly method.

    Science.gov (United States)

    Wäneskog, Marcus; Bjerling, Pernilla

    2014-01-01

    Methods for introducing multiple site-directed mutations are important experimental tools in molecular biology. Research areas that use these methods include the investigation of various protein modifications in cellular processes, modifying proteins for efficient recombinant expression, and the stabilization of mRNAs to allow for increased protein expression. Introducing multiple site-directed mutations is also an important tool in the field of synthetic biology. There are two main methods used in the assembling of fragments generated by mutagenic primers: enzymatic assembly and overlap extension polymerase chain reaction (OE-PCR). In this article, we present an improved OE-PCR method that can be used for the generation of large DNA fragments (up to 7.4 kb) where at least 13 changes can be introduced using a genomic template. The improved method is faster (due to fewer reaction steps) and more accurate (due to fewer PCR cycles), meaning that it can effectively compete with the enzymatic assembly method. Data presented here show that the site-directed mutations can be introduced anywhere between 50 and 1800 bp from each other. The method is highly reliable and predicted to be applicable to most DNA engineering when the introduction of multiple changes in a DNA sequence is required.

  4. A novel temperature control method for shortening thermal cycling time to achieve rapid polymerase chain reaction (PCR) in a disposable polymer microfluidic device

    DEFF Research Database (Denmark)

    Bu, Minqiang; R. Perch-Nielsen, Ivan; Sørensen, Karen Skotte

    We present a new temperature control method capable of effectively shortening the thermal cycling time of polymerase chain reaction (PCR) in a disposable polymer microfluidic device with external heater and temperature sensor. The method employs optimized temperature overshooting and undershooting...

  5. Effects of Edge Directions on the Structural Controllability of Complex Networks

    Science.gov (United States)

    Xiao, Yandong; Lao, Songyang; Hou, Lvlin; Small, Michael; Bai, Liang

    2015-01-01

    Recent advances indicate that assigning or reversing edge direction can significantly improve the structural controllability of complex networks. For directed networks, approaching the optimal structural controllability can be achieved by detecting and reversing certain “inappropriate” edge directions. However, the existence of multiple sets of “inappropriate” edge directions suggests that different edges have different effects on optimal controllability—that is, different combinations of edges can be reversed to achieve the same structural controllability. Therefore, we classify edges into three categories based on their direction: critical, redundant and intermittent. We then investigate the effects of changing these edge directions on network controllability, and demonstrate that the existence of more critical edge directions implies not only a lower cost of modifying inappropriate edges but also better controllability. Motivated by this finding, we present a simple edge orientation method aimed at producing more critical edge directions—utilizing only local information—which achieves near optimal controllability. Furthermore, we explore the effects of edge direction on the controllability of several real networks. PMID:26281042

  6. Adaptive fuzzy prescribed performance control for MIMO nonlinear systems with unknown control direction and unknown dead-zone inputs.

    Science.gov (United States)

    Shi, Wuxi; Luo, Rui; Li, Baoquan

    2017-01-01

    In this study, an adaptive fuzzy prescribed performance control approach is developed for a class of uncertain multi-input and multi-output (MIMO) nonlinear systems with unknown control direction and unknown dead-zone inputs. The properties of symmetric matrix are exploited to design adaptive fuzzy prescribed performance controller, and a Nussbaum-type function is incorporated in the controller to estimate the unknown control direction. This method has two prominent advantages: it does not require the priori knowledge of control direction and only three parameters need to be updated on-line for this MIMO systems. It is proved that all the signals in the resulting closed-loop system are bounded and that the tracking errors converge to a small residual set with the prescribed performance bounds. The effectiveness of the proposed approach is validated by simulation results.

  7. Conventional and novel control designs for direct driven PMSG wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shuhui; Haskew, Timothy A.; Xu, Ling [Department of Electrical and Computer Engineering, The University of Alabama, 317 Houser Hall, Tuscaloosa, AL 35487 (United States)

    2010-03-15

    With the advance of power electronic technology, direct driven permanent magnet synchronous generators (PMSG) have increasingly drawn interests to wind turbine manufactures. This paper studies and compares conventional and a novel control designs for a direct driven PMSG wind turbine. The paper presents transient and steady-state models of a PMSG system in a d-q reference frame. Then, general PMSG characteristics are investigated in the rotor-flux-oriented frame. A shortage of conventional control mechanisms is studied analytically and through computer simulation. A novel direct-current based d-q vector control technique is proposed by integrating fuzzy, adaptive and traditional PID control technologies in an optimal control configuration. Comparison study demonstrates that the proposed control approach, having superior performance in various aspects, is effective not only in achieving desired PMSG control objectives but also in improving the optimal performance of the overall system. (author)

  8. New concept of direct torque neuro-fuzzy control for induction motor drives. Simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Grabowski, P.Z. [Institute of Control and Industrial Electronics, Warsaw University of Technology, Warsaw (Poland)

    1997-12-31

    This paper presents a new control strategy in the discrete Direct Torque Control (DTC) based on neuro-fuzzy structure. Two schemes are proposed: neuro-fuzzy switching times calculator and neuro-fuzzy incremental controller with space vector modulator. These control strategies guarantee very good dynamic and steady-states characteristics, with very low sampling time and constant switching frequency. The proposed techniques are verified by simulation study of the whole drive system and results are compared with conventional discrete Direct Torque Control method. (orig.) 18 refs.

  9. Direct product quality control for energy efficient climate controlled transport of agro-material

    NARCIS (Netherlands)

    Verdijck, G.J.C.; Preisig, H.A.; Straten, van G.

    2005-01-01

    A (model-based) Product Quality Controller is presented for climate controlled operations involving agro-material, such as storage and transport. This controller belongs to the class of Model Predictive Controllers and fits in a previously developed hierarchical control structure. The new Product

  10. Color identification and fuzzy reasoning based monitoring and controlling of fermentation process of branched chain amino acid

    Science.gov (United States)

    Ma, Lei; Wang, Yizhong; Xu, Qingyang; Huang, Huafang; Zhang, Rui; Chen, Ning

    2009-11-01

    The main production method of branched chain amino acid (BCAA) is microbial fermentation. In this paper, to monitor and to control the fermentation process of BCAA, especially its logarithmic phase, parameters such as the color of fermentation broth, culture temperature, pH, revolution, dissolved oxygen, airflow rate, pressure, optical density, and residual glucose, are measured and/or controlled and/or adjusted. The color of fermentation broth is measured using the HIS color model and a BP neural network. The network's input is the histograms of hue H and saturation S, and output is the color description. Fermentation process parameters are adjusted using fuzzy reasoning, which is performed by inference rules. According to the practical situation of BCAA fermentation process, all parameters are divided into four grades, and different fuzzy rules are established.

  11. Plasma vitamin D-binding protein (GC) factors, immunoglobulin G heavy chain (GM) allotypes and immunoglobulin kappa light chain (KM1) allotype in patients with sarcoidosis and in healthy control subjects

    DEFF Research Database (Denmark)

    Milman, Nils; Thymann, Mariann; Graudal, Niels

    2002-01-01

    and immunoglobulin kappa light chain (KM) allotype differed significantly from the distribution in healthy subjects. METHODS: GC 1S, 1F, 2 allotypes, GM 1, 2, 5 allotypes, and KM1 allotype were assessed in 44 patients with sarcoidosis and in healthy control subjects. RESULTS: There were no significant differences...

  12. A design procedure and handling quality criteria for lateral directional flight control systems

    Science.gov (United States)

    Stein, G.; Henke, A. H.

    1972-01-01

    A practical design procedure for aircraft augmentation systems is described based on quadratic optimal control technology and handling-quality-oriented cost functionals. The procedure is applied to the design of a lateral-directional control system for the F4C aircraft. The design criteria, design procedure, and final control system are validated with a program of formal pilot evaluation experiments.

  13. Computational Experiment Approach to Controlled Evolution of Procurement Pattern in Cluster Supply Chain

    Directory of Open Access Journals (Sweden)

    Xiao Xue

    2015-01-01

    Full Text Available Companies have been aware of the benefits of developing Cluster Supply Chains (CSCs, and they are spending a great deal of time and money attempting to develop the new business pattern. Yet, the traditional techniques for identifying CSCs have strong theoretical antecedents, but seem to have little traction in the field. We believe this is because the standard techniques fail to capture evolution over time, nor provide useful intervention measures to reach goals. To address these problems, we introduce an agent-based modeling approach to evaluate CSCs. Taking collaborative procurement as research object, our approach is composed of three parts: model construction, model instantiation, and computational experiment. We use the approach to explore the service charging policy problem in collaborative procurement. Three kinds of service charging polices are compared in the same experiment environment. Finally, “Fixed Cost” is identified as the optimal policy under the stable market environment. The case study can help us to understand the workflow of applying the approach, and provide valuable decision support applications to industry.

  14. A Novel, Essential Control for Clonality Analysis with Human Androgen Receptor Gene Polymerase Chain Reaction

    Science.gov (United States)

    van Dijk, Jeroen P.; Heuver, Leonie H.; van der Reijden, Bert A.; Raymakers, Reinier A.; de Witte, Theo; Jansen, Joop H.

    2002-01-01

    The most widely used technique for determining clonality based on X-chromosome inactivation is the human androgen receptor gene polymerase chain reaction (PCR). The reliability of this assay depends critically on the digestion of DNA before PCR with the methylation-sensitive restriction enzyme HpaII. We have developed a novel method for quantitatively monitoring the HpaII digestion in individual samples. Using real-time quantitative PCR we measured the efficiency of HpaII digestion by measuring the amplification of a gene that escapes X-chromosome inactivation (XE169) before and after digestion. This method was tested in blood samples from 30 individuals: 2 healthy donors and 28 patients with myelodysplastic syndrome. We found a lack of XE169 DNA reduction after digestion in the granulocytes of two myelodysplastic syndrome patients leading to a false polyclonal X-chromosome inactivation pattern. In all other samples a significant reduction of XE169 DNA was observed after HpaII digestion. The median reduction was 220-fold, ranging from a 9.0-fold to a 57,000-fold reduction. Also paraffin-embedded malignant tissue was investigated from two samples of patients with mantle cell lymphoma and two samples of patients with colon carcinoma. In three of these cases inefficient HpaII digestion led to inaccurate X-chromosome inactivation pattern ratios. We conclude that monitoring the efficiency of the HpaII digestion in a human androgen receptor gene PCR setting is both necessary and feasible. PMID:12213708

  15. Resistance in bacteria of the food chain: epidemiology and control strategies

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Wegener, Henrik Caspar; Collignon, P.

    2008-01-01

    licensing, removing financial incentives, banning or restricting the use of certain drugs, altering prescribers behavior, improving animal health, improving hygiene and implementing microbial criteria for certain types of resistant pathogens for use in the control of trade of both food animals and food....... quantification of the transmission difficult. The exposure of humans to antimicrobial resistance from food animals can be controlled by either limiting the selective pressure from antimicrobial usage or by limiting the spread of the bacteria/genes. A number of control options are reviewed, including drug...

  16. A Back-stepping Based Trajectory Tracking Controller for a Non-chained Nonholonomic Spherical Robot

    Institute of Scientific and Technical Information of China (English)

    Zhan Qiang; Liu Zengbo; Cai Yao

    2008-01-01

    Spherical robot has good static and dynamic stability, which provides it with strong viability in hostile environment, but the lack of effective control methods has hindered its application and development. This article deals with the dynamic trajectory tracking problem of the spherical robot BHQ-2 designed for unmanned environment exploration. The dynamic model of the spherical robot is established with a simplified Boltzmann-Hamel equation, based on which a trajectory tracking controller is designed by using the back-stepping method. The convergence of the controller is proved with the Lyapunov stability theory. Numerical simulations show that with the controller the robot can globally and asymptotically track desired trajectories, both linear and circular.

  17. Electrolytic extraction drives volatile fatty acid chain elongation through lactic acid and replaces chemical pH control in thin stillage fermentation.

    Science.gov (United States)

    Andersen, Stephen J; Candry, Pieter; Basadre, Thais; Khor, Way Cern; Roume, Hugo; Hernandez-Sanabria, Emma; Coma, Marta; Rabaey, Korneel

    2015-01-01

    Volatile fatty acids (VFA) are building blocks for the chemical industry. Sustainable, biological production is constrained by production and recovery costs, including the need for intensive pH correction. Membrane electrolysis has been developed as an in situ extraction technology tailored to the direct recovery of VFA from fermentation while stabilizing acidogenesis without caustic addition. A current applied across an anion exchange membrane reduces the fermentation broth (catholyte, water reduction: H2O + e(-) → ½ H2 + OH(-)) and drives carboxylate ions into a clean, concentrated VFA stream (anolyte, water oxidation: H2O → 2e(-) + 2 H(+) + O2). In this study, we fermented thin stillage to generate a mixed VFA extract without chemical pH control. Membrane electrolysis (0.1 A, 3.22 ± 0.60 V) extracted 28 ± 6 % of carboxylates generated per day (on a carbon basis) and completely replaced caustic control of pH, with no impact on the total carboxylate production amount or rate. Hydrogen generated from the applied current shifted the fermentation outcome from predominantly C2 and C3 VFA (64 ± 3 % of the total VFA present in the control) to majority of C4 to C6 (70 ± 12 % in the experiment), with identical proportions in the VFA acid extract. A strain related to Megasphaera elsdenii (maximum abundance of 57 %), a bacteria capable of producing mid-chain VFA at a high rate, was enriched by the applied current, alongside a stable community of Lactobacillus spp. (10 %), enabling chain elongation of VFA through lactic acid. A conversion of 30 ± 5 % VFA produced per sCOD fed (60 ± 10 % of the reactive fraction) was achieved, with a 50 ± 6 % reduction in suspended solids likely by electro-coagulation. VFA can be extracted directly from a fermentation broth by membrane electrolysis. The electrolytic water reduction products are utilized in the fermentation: OH(-) is used for pH control without added chemicals, and H2 is

  18. PRODUCTION OF PHAGE-DISPLAYED ANTI-IDIOTYPIC ANTIBODY SINGLE CHAIN VARIABLE FRAGMENTS TO MG7 MONOCLONAL ANTIBODY DIRECTED AGAINST GASTRIC CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    何凤田; 聂勇战; 陈宝军; 乔太东; 韩者艺; 樊代明

    2002-01-01

    Objective. To generate phage-displayed anti-idiotypic antibody single chain variable fragments (anti -Id ScFv) to MG7 monoclonal antibody (McAb) directed against gastric carcinoma so as to lay a foundation for developing anti-Id ScFv vaccine of the cancer.Methods. Balb/c mice were immunized i. p. with MG7 McAb conjugated with keyhole limpet hemocyanin (KLH), and mRNA was isolated from the spleens of the immunized mice. Heavy and light chain (VH and VL)genes of antibody were amplified separately and assembled into ScFv genes with a linker DNA by PCR. The ScFv genes were ligated into the phagemid vector pCANTAB5E and the ligated sample was transformed into competent E. coli TG1. The transformants were infected with M13KO7 helper phage to yield recombinant phages displaying ScFv on the tips of M13 phage. After 4 rounds of panning with MG7, the MG7-positive clones were selected by ELISA from the enriched phages. Thetypesoftheanti-IdScFvdisplayedontheselectedphagecloneswerepreliminarily identified by competition ELISA.Results. The VH, VL and ScFv DNAs were about 340 bp, 320 bp and 750 bp respectively. Twenty-four MG7-positive clones were selected from 60 enriched phage clones, among which 5 displayed β or γtype anti-Id ScFv.Conclsion. The anti-Id ScFv to MG7 McAb can be successfully selected by recombinant phage antibody technique, which paves a way for the study of prevention and cure of gastric carcinoma by using anti-Id ScFv.

  19. A NEW FUZZY LOGIC BASED SPACE VECTOR MODULATION APPROACH ON DIRECT TORQUE CONTROLLED INDUCTION MOTORS

    Directory of Open Access Journals (Sweden)

    Fatih Korkmaz

    2013-11-01

    Full Text Available The induction motors are indispensable motor types for industrial applications due to its wellknown advantages. Therefore, many kind of control scheme are proposed for induction motors over the past years and direct torque control has gained great importance inside of them due to fast dynamic torque response behavior and simple control structure. This paper suggests a new approach on the direct torque controlled induction motors, Fuzzy logic based space vector modulation, to overcome disadvantages of conventional direct torque control like high torque ripple. In the proposed approach, optimum switching states are calculated by fuzzy logic controller and applied by space vector pulse width modulator to voltage source inverter. In order to test and compare the proposed DTC scheme with conventional DTC scheme simulations, in Matlab/Simulink, have been carried out in different speed and load conditions. The simulation results showed that a significant improvement in the dynamic torque and speed responses when compared to the conventional DTC scheme.

  20. Development of a single-chain variable fragment-alkaline phosphatase fusion protein and a sensitive direct competitive chemiluminescent enzyme immunoassay for detection of ractopamine in pork

    Energy Technology Data Exchange (ETDEWEB)

    Dong Jiexian; Li Zhenfeng; Lei Hongtao; Sun Yuanming [Guangdong Provincial Key Laboratory of Food Quality and Safety, South China Agricultural University, Guangzhou 510642 (China); Ducancel, Frederic [CEA, iBiTec-S, Service de Pharmacologie et d' Immnoanalyse (SPI), CEA Saclay, F-91191 Gif sur Yvette (France); Xu Zhenlin [Guangdong Provincial Key Laboratory of Food Quality and Safety, South China Agricultural University, Guangzhou 510642 (China); Boulain, Jean-Claude [CEA, iBiTec-S, Service de Pharmacologie et d' Immnoanalyse (SPI), CEA Saclay, F-91191 Gif sur Yvette (France); Yang Jinyi; Shen Yudong [Guangdong Provincial Key Laboratory of Food Quality and Safety, South China Agricultural University, Guangzhou 510642 (China); Wang Hong, E-mail: gzwhongd@63.com [Guangdong Provincial Key Laboratory of Food Quality and Safety, South China Agricultural University, Guangzhou 510642 (China)

    2012-07-29

    Graphical abstract: Detection model of dc-CLEIA based on anti-RAC scFv-AP fusion protein. Highlights: Black-Right-Pointing-Pointer The scFv-AP fusion protein against ractopamine (RAC) was produced. Black-Right-Pointing-Pointer A dc-CLEIA for RAC was developed based on the purified scFv-AP fusion protein. Black-Right-Pointing-Pointer The sensitivity of dc-CLEIA was 10 times as sensitive as dc-ELISA for RAC. Black-Right-Pointing-Pointer Recovery tests from pork samples were studied. Black-Right-Pointing-Pointer Good accuracy was obtained. - Abstract: A rapid, sensitive chemiluminescent enzyme immunoassay (CLEIA) for ractopamine (RAC) based on a single-chain variable fragment (scFv)-alkaline phosphatase (AP) fusion protein was developed. The scFv gene was prepared by cloning the heavy- and light-chain variable region genes (V{sub H} and V{sub L}) from hybridoma cell line AC2, which secretes antibodies against RAC, and assembling V{sub H} and V{sub L} genes with a linker by means of splicing overlap extension polymerase chain reaction. The resulting scFv gene was inserted into the expression vector pLIP6/GN containing AP to produce the fusion protein in Escherichia coli strain BL21. The purified scFv-AP fusion protein was used to develop a direct competitive CLEIA (dcCLEIA) protocol for detection of RAC. The average concentration required for 50% inhibition of binding and the limit of detection of the assay were 0.25 {+-} 0.03 and 0.02 {+-} 0.004 ng mL{sup -1}, respectively, and the linear response range extended from 0.05 to 1.45 ng mL{sup -1}. The assay was 10 times as sensitive as the corresponding enzyme-linked immunosorbent assay based on the same fusion protein. Cross-reactivity studies showed that the fusion protein did not cross react with RAC analogs. DcCLEIA was used to analyze RAC spiked pork samples, and the validation was confirmed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS). The results showed a good correlation between

  1. An innovation integrated approach to testing motorcycle drive chain lubricants

    OpenAIRE

    Lee, P.M.; Priest, M.

    2004-01-01

    An innovative integrated approach to the testing and comparison of motorcycle drive chain lubricants is presented. This is a novel way of testing the lubrication by using loaded operating chains and sprockets. A test rig has been designed to operate chains and sprockets in a clean environment and allow direct comparison between different lubricants. The advantage of this method over previous techniques is that it allows the differentiation of lubricants in a more controlled operating environm...

  2. Invariant density analysis: modeling and analysis of the postural control system using Markov chains.

    Science.gov (United States)

    Hur, Pilwon; Shorter, K Alex; Mehta, Prashant G; Hsiao-Wecksler, Elizabeth T

    2012-04-01

    In this paper, a novel analysis technique, invariant density analysis (IDA), is introduced. IDA quantifies steady-state behavior of the postural control system using center of pressure (COP) data collected during quiet standing. IDA relies on the analysis of a reduced-order finite Markov model to characterize stochastic behavior observed during postural sway. Five IDA parameters characterize the model and offer physiological insight into the long-term dynamical behavior of the postural control system. Two studies were performed to demonstrate the efficacy of IDA. Study 1 showed that multiple short trials can be concatenated to create a dataset suitable for IDA. Study 2 demonstrated that IDA was effective at distinguishing age-related differences in postural control behavior between young, middle-aged, and older adults. These results suggest that the postural control system of young adults converges more quickly to their steady-state behavior while maintaining COP nearer an overall centroid than either the middle-aged or older adults. Additionally, larger entropy values for older adults indicate that their COP follows a more stochastic path, while smaller entropy values for young adults indicate a more deterministic path. These results illustrate the potential of IDA as a quantitative tool for the assessment of the quiet-standing postural control system.

  3. Analysis and control of excitation, field weakening and stability in direct torque controlled electrically excited synchronous motor drives

    Energy Technology Data Exchange (ETDEWEB)

    Pyrhoenen, O.

    1998-12-31

    Direct torque control (DTC) is a new control method for rotating field electrical machines. DTC controls directly the motor stator flux linkage with the stator voltage, and no stator current controllers are used. With the DTC method very good torque dynamics can be achieved. Until now, DTC has been applied to asynchronous motor drives. The purpose of this work is to analyse the applicability of DTC to electrically excited synchronous motor drives. Compared with asynchronous motor drives, electrically excited synchronous motor drives require an additional control for the rotor field current. The field current control is called excitation control in this study. The dependence of the static and dynamic performance of DTC synchronous motor drives on the excitation control has been analysed and a straightforward excitation control method has been developed and tested. In the field weakening range the stator flux linkage modulus must be reduced in order to keep the electro motive force of the synchronous motor smaller than the stator voltage and in order to maintain a sufficient voltage reserve. The dynamic performance of the DTC synchronous motor drive depends on the stator flux linkage modulus. Another important factor for the dynamic performance in the field weakening range is the excitation control. The field weakening analysis considers both dependencies. A modified excitation control method, which maximises the dynamic performance in the field weakening range, has been developed. In synchronous motor drives the load angle must be kept in a stabile working area in order to avoid loss of synchronism. The traditional vector control methods allow to adjust the load angle of the synchronous motor directly by the stator current control. In the DTC synchronous motor drive the load angle is not a directly controllable variable, but it is formed freely according to the motor`s electromagnetic state and load. The load angle can be limited indirectly by limiting the torque

  4. Pseudospectral Collocation Methods for the Direct Transcription of Optimal Control Problems

    Science.gov (United States)

    2003-04-01

    solving optimal control problems for trajectory optimization, spacecraft attitude control, jet thruster control, missile guidance and many other... optimal control problems using a pseudospectral direct transcription method. These problems are stated here so that they may be referred to elsewhere...e.g., [7]. 2.3 Prototypical Examples Throughout this thesis two example problems are used to demonstrate various prop- erties associated with solving

  5. Improvement of Inventory Control for Defective Goods Supply Chain by Available Time Limitation of the Production Facilities

    Directory of Open Access Journals (Sweden)

    Salah Alden Ghasimi

    2013-05-01

    Full Text Available One of the most important competitive criteria in the global marketplace is keeping the customer satisfaction. Timely delivery and cost of finished goods are two important factors for satisfaction of customers. In this study, we proposed a mathematical model to improve inventory control of defective goods supply chain by Available Time Limitation (ATL of the production facilities. The defective goods are reworking able parts and the rest are considered as scraps. The aim of the model is to optimize the total costs of production, maintenance, freight, reworking, the quantity of scrap goods and shortage in retailers for three level supply chains. The uniqueness is that it can anticipate the active manufacturers/distributors and the quantity of goods that must be exchanged between them. Finally, the model determines the Economic Production Quantity (EPQ and appropriate ATL of any production facilities. Our proposed model is novel and we used CPLEX and LINGO to solve the problem. It can be ascertained that based on the results of the model validated the correctness and fine function of the model.

  6. Architecture control and model identification of a Omni-Directional Mobile Robot

    OpenAIRE

    António Paulo Gomes Mendes Moreira; Paulo José Cerqueira Gomes da Costa; André Gustavo Scolari Conceição

    2005-01-01

    This paper presents a architecture control and model identification of a onmi-Directional Mobile Robot It is divided into the three stages. Stage one proposes a procedure for dynamic model identification and control of the "motor + reduction + encoder" process of the Robotapos;s Motors. Second, proposes the identification of a dynamic model for the whole mobile robot considering it as a multi-variable system. Third, presents a algorithm for perfect trajectory tracking of Omni-Directional Mobi...

  7. Multimodel Modeling and Predictive Control for Direct-Drive Wind Turbine with Permanent Magnet Synchronous Generator

    OpenAIRE

    Lei Wang; Tao Shen; Chen Chen

    2014-01-01

    The safety and reliability of the wind turbines wholly depend on the completeness and reliability of the control system which is an important problem for the validity of the wind energy conversion systems (WECSs). A method based on multimodel modeling and predictive control is proposed for the optimal operation of direct-drive wind turbine with permanent magnet synchronous generator in this paper. In this strategy, wind turbine with direct-drive permanent magnet synchronous generator is model...

  8. Multimodel Modeling and Predictive Control for Direct-Drive Wind Turbine with Permanent Magnet Synchronous Generator

    OpenAIRE

    Lei Wang; Tao Shen; Chen Chen

    2014-01-01

    The safety and reliability of the wind turbines wholly depend on the completeness and reliability of the control system which is an important problem for the validity of the wind energy conversion systems (WECSs). A method based on multimodel modeling and predictive control is proposed for the optimal operation of direct-drive wind turbine with permanent magnet synchronous generator in this paper. In this strategy, wind turbine with direct-drive permanent magnet synchronous generator is model...

  9. Frequency Properties Research of Elevator Drive System with Direct Torque Control-Pulse with Modulation

    Directory of Open Access Journals (Sweden)

    A. S. Koval

    2008-01-01

    Full Text Available In the article problems of frequency properties research for electric drive system with direct torque control and pulse width modulator are described. The mathematical description of elevator is present. Simplified mathematical description of direct torque control - pulse width modulator electric drive system is shown. Transfer functions for torque and speed loops are determined. Logarithmic frequency characteristics are computed. Damping properties of elevator drive system are estimated.

  10. An Observing Method for Flux and Speed with Direct Torque Control

    Institute of Scientific and Technical Information of China (English)

    祝龙记; 王汝琳

    2004-01-01

    An observing method for stator flux and rotor flux is presented. Based on the proposed flux observing method, a novel speed estimator has been designed. At last, the speed estimator combined with the flux observing is applied in the direct torque control system without speed sensor. The simulation results show that these methods can improve the accuracy of speed observing and the low speed performance of direct torque control system, and strengthen the robustness of system.

  11. Methanol-induced chain termination in poly(3-hydroxybutyrate) biopolymers: molecular weight control

    Science.gov (United States)

    A systematic study was performed to demonstrate the impact of methanol (MeOH) on poly(3-hydroxybutyrate) (PHB) synthesis and molecular weight (MW) control. Glycerine (init. conc. = 1.0%; w/v), was used as the primary carbon source in batch-culture fermentations with varying concentrations (0 to 0.85...

  12. Controlling Campylobacter in the chicken meat chain - Cost-effectiveness and cost-utility analysis

    NARCIS (Netherlands)

    Mangen MJJ; Havelaar AH; Nauta MJ; Koeijer AA de; Wit GA de; LEI; Animal Sciences Group; PZO; MGB

    2005-01-01

    The aim of this study was the estimation of cost-effectiveness and cost-utility of various interventions to control Campylobacter contamination of broiler meat. The relative risk, the intervention costs, the disease burden (expressed in Disability Adjusted Live Years (DALYs)) and the costs-of-illnes

  13. Structure control for fine tuning fluorescence emission from side-chain azobenzene polymers.

    Science.gov (United States)

    Smitha, P; Asha, S K

    2007-06-14

    New fluorescent azobenzene dyes and side-chain polymers have been synthesized and characterized and their photophysical properties studied. A series of azobenzene dyes having different fluorophores such as phenol (S1), phenylphenol (S2) and naphthol (S3) incorporated in them were synthesized. S2 had unusually high fluorescence with a quantum yield of phi f = 0.2 recorded in dichloromethane (DCM), whereas S1 and S3 were found to be weakly fluorescent. The azobenzene dyes were converted into methacrylate monomers having short ethyleneoxy spacers and then free radically polymerized. Phenylphenol-based azobenzene polymer (P2) continued to show fluorescence, whereas fluorescence was completely quenched in the case of phenol (P1)- and naphthol (P3)-based polymers. Phenylphenol, though twisted in the ground state is known to have a more planar geometry in the excited state--a factor that enables it to retain its fluorescence behavior even when it is incorporated as part of an azobenzene unit. In contrast, naphthol, which is a better fluorophore compared to phenylphenol, loses much of its emissive behavior upon coupling to the azobenzene unit. The extent of trans to cis photoisomerization in solution was very low (approximately 17%) for P2 after 30 min of continuous irradiation using 365 nm light, in contrast to approximately 40% for P1 under identical conditions. This is attributed to the steric repulsion brought about by the bulky phenylphenol units that restrict rotation. A 2-fold enhancement in fluorescence emission was observed for P2 upon irradiation by UV light at 360 nm, which relaxed to the original intensity in about 7 day's time. The higher emission of the cis azobenzenes is generally attributed to an inhibition of photoinduced electron transfer (PET) mechanism. The emission of P2 showed a concentration dependence which increased initially and then decreased in intensity with the formation of a new red-shifted peak at higher concentration due to aggregation

  14. Direct Torque Control in presence of Current sensor failure in Variable Speed Wind System: Effect analysis, detection and control reconfiguration

    Directory of Open Access Journals (Sweden)

    A. J. Arbi

    2008-03-01

    Full Text Available This paper presents a study of current sensor failure in a Direct Torque Control applied to a Double Fed Induction Generator based Variable Speed Wind System. The effect of scaling and offset current sensor errors is discussed through sensibility analysis. A control reconfiguration is then proposed to remedy this sensor failure. Simulation results emphasize the good performances of the proposed current sensor fault tolerant control

  15. GC/MS method for determining carbon isotope enrichment and concentration of underivatized short-chain fatty acids by direct aqueous solution injection of biogas digester samples.

    Science.gov (United States)

    Mulat, Daniel Girma; Feilberg, Anders

    2015-10-01

    In anaerobic digestion of organic matter, several metabolic pathways are involved during the simultaneous production and consumption of short-chain fatty acids (SCFA) in general and acetate in particular. Understanding the role of each pathway requires both the determination of the concentration and isotope enrichment of intermediates in conjunction with isotope labeled substrates. The objective of this study was to establish a rapid and simple GC/MS method for determining the isotope enrichment of acetate and concentration of underivatized short-chain fatty acids (SCFA) in biogas digester samples by direct liquid injection of acidified aqueous samples. Sample preparation involves only acidification, centrifugation and filtration of the aqueous solution followed by direct injection of the aqueous supernatant solution onto a polar column. With the sample preparation and GC/MS conditions employed, well-resolved and sharp peaks of underivatized SCFA were obtained in a reasonably short time. Good recovery (96.6-102.3%) as well as low detection (4-7 µmol/L) and quantification limits (14-22 µmol/L) were obtained for all the 6 SCFA studied. Good linearity was achieved for both concentration and isotope enrichment measurement with regression coefficients higher than 0.9978 and 0.9996, respectively. The method has a good intra- and inter-day precision with a relative standard deviation (RSD) below 6% for determining the tracer-to-tracee ratio (TTR) of both [2-(13)C]acetate and [U-(13)C]acetate. It has also a good intra- and inter-day precision with a RSD below 6% and 5% for determining the concentration of standard solution and biogas digester samples, respectively. Acidification of biogas digester samples with oxalic acid provided the low pH required for the protonation of SCFA and thus, allows the extraction of SCFA from the complex sample matrix. Moreover, oxalic acid was the source of formic acid which was produced in the injector set at high temperature. The produced

  16. Thinking as the control of imagination: a conceptual framework for goal-directed systems.

    Science.gov (United States)

    Pezzulo, Giovanni; Castelfranchi, Cristiano

    2009-07-01

    This paper offers a conceptual framework which (re)integrates goal-directed control, motivational processes, and executive functions, and suggests a developmental pathway from situated action to higher level cognition. We first illustrate a basic computational (control-theoretic) model of goal-directed action that makes use of internal modeling. We then show that by adding the problem of selection among multiple action alternatives motivation enters the scene, and that the basic mechanisms of executive functions such as inhibition, the monitoring of progresses, and working memory, are required for this system to work. Further, we elaborate on the idea that the off-line re-enactment of anticipatory mechanisms used for action control gives rise to (embodied) mental simulations, and propose that thinking consists essentially in controlling mental simulations rather than directly controlling behavior and perceptions. We conclude by sketching an evolutionary perspective of this process, proposing that anticipation leveraged cognition, and by highlighting specific predictions of our model.

  17. Multivariable direct adaptive decoupling controller using multiple models and a case study

    Institute of Scientific and Technical Information of China (English)

    WANG Xin; YANG Hui; ZHENG YiHui

    2009-01-01

    In this paper, a multivariable direct adaptive controller using multiple models without minimum phase assumption is presented to improve the transient response when the parameters of the system jump abruptly. The controller is composed of multiple fixed controller models, a free-running adaptive controller model and a re-initialized adaptive controller model. The fixed controller models are derived from the corresponding fixed system models directly. The adaptive controller models adopt the direct adaptive algorithm to reduce the design calculation. At every instant, the optimal controller is chosen out according to the switching index. The interaction of the system is viewed as the measured disturbance which is eliminated by the choice of the weighing polynomial matrix. The global convergence is obtained. Finally, several simulation examples in a wind tunnel experiment are given to show both effectiveness and practicality of the proposed method. The significance of the proposed method is that it is applicable to a non-minimum phase system, adopting direct adaptive algorithm to overcome the singularity problem during the matrix calculation and realizing decoupling control for a multivariable system.

  18. Controllable conversion of quasi-freestanding polymer chains to graphene nanoribbons

    Science.gov (United States)

    Ma, Chuanxu; Xiao, Zhongcan; Zhang, Honghai; Liang, Liangbo; Huang, Jingsong; Lu, Wenchang; Sumpter, Bobby G.; Hong, Kunlun; Bernholc, J.; Li, An-Ping

    2017-03-01

    In the bottom-up synthesis of graphene nanoribbons (GNRs) from self-assembled linear polymer intermediates, surface-assisted cyclodehydrogenations usually take place on catalytic metal surfaces. Here we demonstrate the formation of GNRs from quasi-freestanding polymers assisted by hole injections from a scanning tunnelling microscope (STM) tip. While catalytic cyclodehydrogenations typically occur in a domino-like conversion process during the thermal annealing, the hole-injection-assisted reactions happen at selective molecular sites controlled by the STM tip. The charge injections lower the cyclodehydrogenation barrier in the catalyst-free formation of graphitic lattices, and the orbital symmetry conservation rules favour hole rather than electron injections for the GNR formation. The created polymer-GNR intraribbon heterostructures have a type-I energy level alignment and strongly localized interfacial states. This finding points to a new route towards controllable synthesis of freestanding graphitic layers, facilitating the design of on-surface reactions for GNR-based structures.

  19. Evaluation of air pollution control policies in Mexico City using finite Markov chain observation model

    OpenAIRE

    Luis Hoyos; Pedro Lara; Elba Ortiz; Rafael López; Jesús González

    2009-01-01

    This paper proposes a Markov observation based model, where the transition matrix is formulated using air quality monitoring data for specific pollutant emissions, with the primary objective to analyze the corresponding stationary distributions and evaluate sceneries for the air quality impact of pollution control policies. The model is non predictive and could be applied to every source of pollutant emissions included in air monitoring data. Two cases of study are presented, ozone and sulfur...

  20. Performance optimization of a photovoltaic chain conversion by the PWM control

    Science.gov (United States)

    Rezoug, M. R.; Chenni, R.

    2017-02-01

    The interest of the research technique of maximum power point tracking, exposed by this article, lays in the fact of work instantly on the real characteristic of the photovoltaic module. This work is based on instantaneous measurements of its terminals' current & voltage as well as the exploitation of the characteristic "Power - Duty Cycle" to define rapidly the Duty cycle in which power reaches its maximum value. To ensure instantaneous tracking of the point of maximum power, we use "DC/DC Converter" based on "Pulse Wave Modulation's (PWM) Command" controlled by an algorithm implanted in a microcontroller's memory. This algorithm responds to the quick changes in climate (sunlight and temperature). To identify the control parameters "VPV & IPV" at any change in operating conditions, sensors are projected. this algorithm applied to the Duty cycle of the static converter enables the control of power supplied by the photovoltaic generator thanks to oscillatory movement around the MPP. Our article highlights the importance of this technique which lays in its simplicity and performance in changing climatic conditions. This efficiency is confirmed by experimental tests and this technique will improve its predecessors.

  1. Optimization of controllability and robustness of complex networks by edge directionality

    Science.gov (United States)

    Liang, Man; Jin, Suoqin; Wang, Dingjie; Zou, Xiufen

    2016-09-01

    Recently, controllability of complex networks has attracted enormous attention in various fields of science and engineering. How to optimize structural controllability has also become a significant issue. Previous studies have shown that an appropriate directional assignment can improve structural controllability; however, the evolution of the structural controllability of complex networks under attacks and cascading has always been ignored. To address this problem, this study proposes a new edge orientation method (NEOM) based on residual degree that changes the link direction while conserving topology and directionality. By comparing the results with those of previous methods in two random graph models and several realistic networks, our proposed approach is demonstrated to be an effective and competitive method for improving the structural controllability of complex networks. Moreover, numerical simulations show that our method is near-optimal in optimizing structural controllability. Strikingly, compared to the original network, our method maintains the structural controllability of the network under attacks and cascading, indicating that the NEOM can also enhance the robustness of controllability of networks. These results alter the view of the nature of controllability in complex networks, change the understanding of structural controllability and affect the design of network models to control such networks.

  2. Information Fusion-Based Optimal Attitude Control for an Alterable Thrust Direction Unmanned Aerial Vehicle

    Directory of Open Access Journals (Sweden)

    Ziyang Zhen

    2013-01-01

    Full Text Available Attitude control is the inner‐loop and the most important part of the automatic flight control system of an unmanned aerial vehicle (UAV. The information fusion‐based optimal control method is applied in a UAV flight control system in this work. Firstly, a nonlinear model of alterable thrust direction UAV (ATD‐UAV is established and linearized for controller design. The longitudinal controller and lateral controller are respectively designed based on information fusion‐based optimal control, and then the information fusion flight control system is built up. Finally, the simulation of a nonlinear model described as ATD‐UAV is carried out, the results of which show the superiority of the information fusion‐based control strategy when compared to the single‐loop design method. We also show that the ATD technique improves the anti‐disturbance capacity of the UAV.

  3. Progress in Aluminum Electrolysis Control and Future Direction for Smart Aluminum Electrolysis Plant

    Science.gov (United States)

    Zhang, Hongliang; Li, Tianshuang; Li, Jie; Yang, Shuai; Zou, Zhong

    2016-10-01

    The industrial aluminum reduction cell is an electrochemistry reactor that operates under high temperatures and highly corrosive conditions. However, these conditions have restricted the measurement of key control parameters, making the control of aluminum reduction cells a difficult problem in the industry. Because aluminum electrolysis control systems have a significant economic influence, substantial research has been conducted on control algorithms, control systems and information systems for aluminum reduction cells. This article first summarizes the development of control systems and then focuses on the progress made since 2000, including alumina concentration control, temperature control and electrolyte molecular ratio control, fault diagnosis, cell condition prediction and control system expansion. Based on these studies, the concept of a smart aluminum electrolysis plant is proposed. The frame construction, key problems and current progress are introduced. Finally, several future directions are discussed.

  4. Information Fusion-Based Optimal Attitude Control for an Alterable Thrust Direction Unmanned Aerial Vehicle

    Directory of Open Access Journals (Sweden)

    Ziyang Zhen

    2013-01-01

    Full Text Available Attitude control is the inner-loop and the most important part of the automatic flight control system of an unmanned aerial vehicle (UAV. The information fusion-based optimal control method is applied in a UAV flight control system in this work. Firstly, a nonlinear model of alterable thrust direction UAV (ATD-UAV is established and linearized for controller design. The longitudinal controller and lateral controller are respectively designed based on information fusion-based optimal control, and then the information fusion flight control system is built up. Finally, the simulation of a nonlinear model described as ATD-UAV is carried out, the results of which show the superiority of the information fusion-based control strategy when compared to the single-loop design method. We also show that the ATD technique improves the anti-disturbance capacity of the UAV.

  5. Antiretroviral therapy supply chain quality control and assurance in improving people living with HIV therapeutic outcomes in Cameroon.

    Science.gov (United States)

    Djobet, M P Ngogang; Singhe, David; Lohoue, Julienne; Kuaban, Christopher; Ngogang, Jeanne; Tambo, Ernest

    2017-04-04

    Evaluation of medication efficacy and safety is an essential guarantee to successful therapeutic outcome in public health practices. However, larger distribution chain supply in developing countries such as Cameroon is often challenged by counterfeit drugs, poor manufacturing, storage and degradation leading to health and patient adverse consequences. Yet, access to supply chain management in strengthening ARVs quality assurance and outcomes remains poorly documented. More than 53,000 patients have been enrolled on free ARVs medications, but little is documented on quality assurance and validity of safety for affected populations along the supply chain management since 2008. The cross sectional study was conducted in ARVs distribution units and centers in central, littoral and south west regions of Cameroon. ARVs drugs samples included Nevirapine, Efavirenz, and fixed dose combinations of Zidovudine + Lamivudine, Lamivudine + Stavudine and Zidovudine + Lamivudine + Nevirapine. Drugs packaging and labeling was assessed and galenic assays were performed at National Laboratory of quality Control of Medications and Expertise (LANACOME), Yaoundé, Cameroon. The study covered 16 structures located in eight different towns including the central ARVs store, two regional pharmaceutical procurement centers and thirteen HIV approved treatment centers and management units. A total of 35 ARVs products were collected. Only eight ARVs drugs containing Lamivudine and Stavudine presented with white stains on tablets, however these drugs were standard for all other tests performed. The others 28 ARVs products were standards to all assays performed. We concluded that ARVs drugs freely accessible and distributed to PLWHA are of good quality in Cameroon. However, with the increase number of patients under HAART since 2013, adoption of "Test and Treat" approach to reach the 90-90-90 goals and with the implementation of new national antiretroviral regimen guidelines and molecules

  6. Control of quantum interference of an excitonic wave in a chlorophyll chain with a chlorophyll ring

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Suc-Kyoung; Nam, Seog-Woo [Korea University, Jochiwon, Chungnam (Korea, Republic of); Yeon, Kyu-Hwang [Chungbuk National University, Cheonju (Korea, Republic of)

    2010-06-15

    The quantum interference of an excitonic wave and its coherent control in a nanochain with a nanoring are studied. The nanochain is comprised of six chlorophylls, where four chlorophylls compose the nanoring and two chlorophylls are attached at two opposite sites on the nanoring. The exciton dynamics and the correlation of the excitation between chlorophylls are analyzed for a given configurational arrangement and dipolar orientation of the chlorophylls. The results of this study show that the excitation at specified chlorophylls is suppressed or enhanced by destructive or constructive interference of the excitonic wave in the chlorophyll nanochain.

  7. Protective effects of branched-chain amino acids on hepatic ischemia-reperfusion-induced liver injury in rats: a direct attenuation of Kupffer cell activation.

    Science.gov (United States)

    Kitagawa, Tomomi; Yokoyama, Yukihiro; Kokuryo, Toshio; Nagino, Masato

    2013-02-15

    We determined whether there is a protective effect of branched-chain amino acid (BCAA) on hepatic ischemia-reperfusion (I/R)-induced acute liver injury. Wister rats were divided into the following four groups: simple laparotomy with vehicle; simple laparotomy with BCAA (1 g/kg body wt orally); I/R (30 min clamp) with vehicle; and I/R with BCAA. Serum liver function tests and the gene expression of adhesion molecules (intercellular adhesion molecule and vascular cell adhesion molecule) and vasoconstrictor-related genes (endothelin-1) in the liver were examined. In the in vivo study, portal venous pressure, leukocyte adhesion, and hepatic microcirculation were evaluated. Furthermore, Kupffer cells were isolated and cultured with various concentrations of BCAA in the presence or absence of lipopolysaccharide (LPS). Increased levels of liver function tests following I/R were significantly attenuated by BCAA treatment. The increased expression of adhesion molecules and endothelin-1 was also significantly attenuated by BCAA treatment. Moreover, increased portal venous pressure, enhanced leukocyte adhesion, and deteriorated hepatic microcirculation following I/R were all improved by BCAA treatment. In the experiment using isolated Kupffer cells, the expression of interleukin-6, interleukin-1β, and endothelin-1 in response to LPS stimulation was attenuated by BCAA in a dose-dependent fashion. These results indicate that perioperative oral administration of BCAA has excellent therapeutic potential to reduce I/R-induced liver injury. These beneficial effects may result from the direct attenuation of Kupffer cell activation under stressful conditions.

  8. Direct photoaffinity labeling of gizzard myosin with ( sup 3 H)uridine diphosphate places Glu185 of the heavy chain at the active site

    Energy Technology Data Exchange (ETDEWEB)

    Garabedian, T.E.; Yount, R.G. (Washington State Univ., Pullman (USA))

    1990-12-25

    The active site of chicken gizzard myosin was labeled by direct photoaffinity labeling with ({sup 3}H)UDP. ({sup 3}H) UDP was stably trapped at the active site by addition of vanadate (Vi) and Co{sup 2+}. The extraordinary stability of the myosin.Co2+.(3H)UDP.Vi complex (t1/2 greater than 5 days at 0{degrees}C) allowed it to be purified free of extraneous ({sup 3}H)UDP before irradiation began. Upon UV irradiation, greater than 60% of the trapped ({sup 3}H)UDP was photoincorporated into the active site. Only the 200-kDa heavy chain was labeled, confirming earlier results using ({sup 3}H)UTP. Extensive tryptic digestion of photolabeled myosin subfragment 1 followed by high performance liquid chromatography separations and removal of nucleotide phosphates by treatment with alkaline phosphatase allowed two labeled peptides to be isolated. Sequencing of the labeled peptides and radioactive counting showed that Glu185 was the residue labeled. Since UDP is a zero-length cross-linker, Glu185 is located at the purine-binding pocket of the active site of smooth myosin and adjacent to the glycine-rich loop which binds the polyphosphate portion of ATP. This Glu residue is conserved in smooth and nonmuscle myosins and is the same residue identified previously by ({sup 3}H)UTP photolabeling in Acanthamoeba myosin II.

  9. Application of semi-nested polymerase chain reaction targeting internal transcribed spacer region for rapid detection of panfungal genome directly from ocular specimens

    Directory of Open Access Journals (Sweden)

    Bagyalakshmi R

    2007-01-01

    Full Text Available Background: The incidence of fungal endophthalmitis has dramatically increased in recent years and rapid detection of fungi using nucleic acid-based amplification techniques is helpful in management. Aim: To evaluate semi-nested polymerase chain reaction (PCR targeting internal transcribed spacer (ITS region for detection of panfungal genome in ocular specimens. Statistical analysis used: Z test for two proportion. Materials and Methods: Standardization of PCR targeting ITS primers was carried out by determining analytical sensitivity and specificity. The sensitivity and specificity of PCR was determined by serial tenfold dilutions of C. albicans (ATCC 24433 DNA and DNA extracts of laboratory isolates of Aspergillus fumigatus , Fusarium lichenicola (4, other fungal and closely related bacterial strains and also human DNA. Semi-nested PCR was applied onto a total of 168 ocular specimens with clinically suspected fungal etiology during 2003-2005. Results and Conclusions: PCR was specific and sensitive to detect 1fg of fungal DNA with ITS primers. PCR detected fungal genome in 90 (53.57% in comparison with the conventional technique, positive in 34 (20.23% by smear examination and in 42 (25% by culture. The increase in clinical sensitivity by 28.57% using PCR was found to be statistically significant { P < 0.001 using Z test for two proportion}. The accuracy of the test was found to be 70.85%. PCR proved to be a rapid diagnostic technique for detection of panfungal genome directly from clinical specimens

  10. Direct supplementation of diet is the most efficient way of enriching broiler meat with n-3 long-chain polyunsaturated fatty acids.

    Science.gov (United States)

    Ribeiro, T; Lordelo, M M; Alves, S P; Bessa, R J B; Costa, P; Lemos, J P C; Ferreira, L M A; Fontes, C M G A; Prates, J A M

    2013-01-01

    1. Concentrations of beneficial omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs) in poultry meat can be improved by increasing the concentration of n-3 PUFA in poultry diets. 2. A decrease in flavour quality is, however, usually associated with the dietary supplementation with n-3 PUFA, which is due to the susceptibility of PUFA to oxidation. 3. This experiment was conducted to study the effects of introducing two different n-3 fatty acid sources (extruded linseed and DHA Gold™, a proprietary algal product rich in docosahexaenoic acid), either separately or together, on broiler productive performance, and meat quality, oxidative stability, sensory traits and LC-PUFA profile. 4. Birds given the algal product displayed better productive performances than animals from other groups. 5. The data revealed an improvement in the fatty acid nutritional value of meat from birds receiving the algal product and an inefficient conversion of α-linolenic acid (LNA) into LC-PUFA. 6. Metabolisation of LNA in vivo is not sufficient to improve meat quality in n-3 LC-PUFA and direct supplementation of the diet with n-3 LC-PUFA is a better alternative to modulate an increase in beneficial fatty acids of broiler meat. 7. The overall acceptability of meat was negatively affected by the dietary supplementation with 7.4% of DHA, in contrast to the supplementation with 3.7% of DHA, which showed to be efficient in improving LC-PUFA meat content without affecting its sensory properties.

  11. Methods of centers and methods of feasible directions for the solution of optimal control problems.

    Science.gov (United States)

    Polak, E.; Mukai, H.; Pironneau, O.

    1971-01-01

    Demonstration of the applicability of methods of centers and of methods of feasible directions to optimal control problems. Presented experimental results show that extensions of Frank-Wolfe (1956), Zoutendijk (1960), and Pironneau-Polak (1971) algorithms for nonlinear programming problems can be quite efficient in solving optimal control problems.

  12. Theoretical analysis of a pressure setting and control system with PWM direction control valve

    Science.gov (United States)

    Avram, M.; Duminică, D.; Cartal, L. A.

    2016-08-01

    The paper tackles theoretical aspects concerning an original automated system that sets and controls the pressure inside a tank chamber of fixed volume. The structure of the system integrates an original device developed and designed by the authors. The device digitally controls the one way flow of the working fluid using pulse width modulation, allowing the free flow in the other way. The purpose of this research stage was the theoretical establishing of the variation law of the pressure inside the controlled chamber.

  13. A decentralized control method for direct smart grid control of refrigeration systems

    DEFF Research Database (Denmark)

    Shafiei, Seyed Ehsan; Izadi-Zamanabadi, Roozbeh; Rasmussen, Henrik;

    2013-01-01

    A decentralized control method is proposed to govern the electrical power consumption of supermarket refrigeration systems (SRS) for demand-side management in the smart grid. The control structure is designed in a supervisory level to provide desired set-points for distributed level controllers....... No model information is required in this method. The temperature limits/constraints are respected. A novel adaptive saturation filter is also proposed to increase the system flexibility in storing and delivering the energy. The proposed control strategy is applied to a simulation benchmark that fairly...

  14. Managerial span of control: a pilot study comparing departmental complexity and number of direct reports.

    Science.gov (United States)

    Merrill, Katreena Collette; Pepper, Ginette; Blegen, Mary

    2013-09-01

    Nurse managers play pivotal roles in hospitals. However, restructuring has resulted in nurse managers having wider span of control and reduced visibility. The purpose of this pilot study was to compare two methods of measuring span of control: departmental complexity and number of direct reports. Forty-one nurse managers across nine hospitals completed The Ottawa Hospital Clinical Manager Span of Control Tool (TOH-SOC) and a demographic survey. A moderate positive relationship between number of direct reports and departmental complexity score was identified (r=.49, p=managers' responsibility. Copyright © 2013 Longwoods Publishing.

  15. Global adaptive exponential stabilisation for nonlinear systems with multiple unknown control directions

    Science.gov (United States)

    Sun, Xifang; Chen, Weisheng; Wu, Jian

    2016-12-01

    In this paper, we address the global generalised exponential stabilisation problem for a class of lower-triangular systems with multiple unknown directions. Instead of the well-known Nussbaum-gain adaptive rule, a Lyapunov-based adaptive logic switching rule is proposed to seek the correct control directions for such systems. The main advantage of the proposed controller is that it can guarantee the global generalised exponential stability of closed-loop systems. Simulation examples are given to verify the effectiveness of the developed control approach.

  16. A New Real Time Lyapunov Based Controller for Power Quality Improvement in Unified Power Flow Controllers Using Direct Matrix Converters

    Directory of Open Access Journals (Sweden)

    Joaquim Monteiro

    2017-06-01

    Full Text Available This paper proposes a Direct Matrix Converter operating as a Unified Power Flow Controller (DMC-UPFC with an advanced control method for UPFC, based on the Lyapunov direct method, presenting good results in power quality assessment. This control method is used for real-time calculation of the appropriate matrix switching state, determining which switching state should be applied in the following sampling period. The control strategy takes into account active and reactive power flow references to choose the vector converter closest to the optimum. Theoretical principles for this new real-time vector modulation and control applied to the DMC-UPFC with input filter are established. The method needs DMC-UPFC dynamic equations to be solved just once in each control cycle, to find the required optimum vector, in contrast to similar control methods that need 27 vector estimations per control cycle. The designed controller’s performance was evaluated using Matlab/Simulink software. Controllers were also implemented using a digital signal processing (DSP system and matrix hardware. Simulation and experimental results show decoupled transmission line active (P and reactive (Q power control with zero theoretical error tracking and fast response. Output currents and voltages show small ripple and low harmonic content.

  17. Direct Torque Control of Induction Motor Drive Fed from a Photovoltaic Multilevel Inverter

    Directory of Open Access Journals (Sweden)

    Mahrous Ahmed

    2014-09-01

    Full Text Available This paper presents Direct Torque Control (DTC using Space Vector Modulation (SVM for an induction motor drive fed from a photovoltaic multilevel inverter (PV-MLI. The system consists of two main parts PV DC power supply (PVDC and MLI. The PVDC is used to generate DC isolated sources with certain ratios suitable for the adopted MLI. Beside the hardware system, the control system which uses the torque and speed estimation to control the load angle and to obtain the appropriate flux vector trajectory from which the voltage vector is directly derived based on direct torque control methods. The voltage vector is then generated by a hybrid multilevel inverter by employing space vector modulation (SVM. The inverter high quality output voltage which leads to a high quality IM performances. Besides, the MLI switching losses is very low due to most of the power cell switches are operating at nearly fundamental frequency. Some selected simulation results are presented for system validation.

  18. Hybrid Asymmetric Space Vector Modulation for inverter based direct torque control induction motor drive

    Directory of Open Access Journals (Sweden)

    Nandakumar Sundararaju

    2014-05-01

    Full Text Available This paper proposes novel hybrid asymmetric space vector modulation technique for inverter operated direct torque control induction motor drive. The hybridization process is performed by the combination of continuous asymmetric space vector modulation pulse width technique (ASVPWM and fuzzy operated discontinuous ASVPWM technique. Combination process is based on pulse mismatching technique. Pulse mismatching technique helps to reduce the active region of the switch. Finally, optimal pulses are applied to control the inverter. The optimal hybrid pulse condense switching losses of the inverter and also improves the operating performance of the direct torque control (DTC based drive system like smooth dynamic response in speed reversal, minimum torque error, settling time of speed. Simulation results of proposed hybrid asymmetric space vector pulse width modulation technique to direct torque control (HASVPWM-DTC approach has been carried out by using Matlab-Simulink environment.

  19. Controllability analysis of second-order multi-agent systems with directed and weighted interconnection

    Institute of Scientific and Technical Information of China (English)

    Di GUO; Rong-hao ZHENG; Zhi-yun LIN; Gang-feng YAN

    2015-01-01

    This article investigates the controllability problem of multi-agent systems. Each agent is assumed to be governed by a second-order consensus control law corresponding to a directed and weighted graph. Two types of topology are considered. The fi rst is concerned with directed trees, which represent the class of topology with minimum information exchange among all controllable topologies. A very simple necessary and suffcient condition regarding the weighting scheme is obtained for the controllability of double integrator multi-agent systems in this scenario. The second is concerned with a more general graph that can be reduced to a directed tree by contracting a cluster of nodes to a component. A similar necessary and suffcient condition is derived. Finally, several illustrative examples are provided to demonstrate the theoretical analysis results.

  20. Magnesium Trimethoxyphenylporphyrin Chain Controls Energy Dissipation in the presence of Cholesterol

    Indian Academy of Sciences (India)

    KARISHMA DEVI BORAH; N GHANASHYAM SINGH; JAGANNATH BHUYAN

    2017-04-01

    A magnesium porphyrin compound, [Mg(TMPP)(H ₂O)].(CH ₃COCH ₃)2H ₂O 1 (TMPP = 5,10,15,20-tetrakis(3,4,5-trimethoxyphenyl)porphyrin) has been synthesized and characterized using single crystal X-ray diffraction and other spectroscopic analysis. The luminescence properties of compound 1 were studied at different concentrations. At higher concentration (3×10 ⁻³ M), treatment of 1 with cholesterol enhanced the luminescence when excited at Soret band, demonstrating the role of lipid in controlling porphyrin-porphyrin interaction for tuning the bulk photophysical properties. However, at lower concentration (10 ⁻⁵ M) of porphyrin, there was no significant change in luminescence intensity in the presence of cholesterol. It suggests some role of lipids in light harvesting systems where chlorophyll is present at higher concentration.

  1. Online process control for directional solidification by ultrasonic pulse echo technique.

    Science.gov (United States)

    Drevermann, A; Pickmann, C; Tiefers, R; Zimmermann, G

    2004-04-01

    A method of controlling the actual growth velocity during directional solidification based on ultrasound has been developed. For this purpose a pulse echo technique is used to measure the actual solidification rate online. This quantity is used to control the furnace velocity. Solidification experiments with metallic alloys and constant furnace velocity often result in non-steady actual solidification rates. Experiments carried out with online process control demonstrate that a really steady-state solidification with a constant solidification rate is achieved.

  2. Direct SQP-methods for solving optimal control problems with delays

    Energy Technology Data Exchange (ETDEWEB)

    Goellmann, L.; Bueskens, C.; Maurer, H.

    1994-12-31

    The maximum principle for optimal control problems with delays leads to a boundary value problem (BVP) which is retarded in the state and advanced in the costate function. Based on shooting techniques, solution methods for this type of BVP have been proposed. In recent years, direct optimization methods have been favored for solving control problems without delays. Direct methods approximate the control and the state over a fixed mesh and solve the resulting NLP-problem with SQP-methods. These methods dispense with the costate function and have shown to be robust and efficient. In this paper, we propose a direct SQP-method for retarded control problems. In contrast to conventional direct methods, only the control variable is approximated by e.g. spline-functions. The state is computed via a high order Runge-Kutta type algorithm and does not enter explicitly the NLP-problem through an equation. This approach reduces the number of optimization variables considerably and is implementable even on a PC. Our method is illustrated by the numerical solution of retarded control problems with constraints. In particular, we consider the control of a continuous stirred tank reactor which has been solved by dynamic programming. This example illustrates the robustness and efficiency of the proposed method. Open questions concerning sufficient conditions and convergence of discretized NLP-problems are discussed.

  3. DSP Based Direct Torque Control of Permanent Magnet Synchronous Motor (PMSM) using Space Vector Modulation (DTC-SVM)

    DEFF Research Database (Denmark)

    Swierczynski, Dariusz; Kazmierkowski, Marian P.; Blaabjerg, Frede

    2002-01-01

    DSP Based Direct Torque Control of Permanent Magnet Synchronous Motor (PMSM) using Space Vector Modulation (DTC-SVM)......DSP Based Direct Torque Control of Permanent Magnet Synchronous Motor (PMSM) using Space Vector Modulation (DTC-SVM)...

  4. DSP Based Direct Torque Control of Permanent Magnet Synchronous Motor (PMSM) using Space Vector Modulation (DTC-SVM)

    DEFF Research Database (Denmark)

    Swierczynski, Dariusz; Kazmierkowski, Marian P.; Blaabjerg, Frede

    2002-01-01

    DSP Based Direct Torque Control of Permanent Magnet Synchronous Motor (PMSM) using Space Vector Modulation (DTC-SVM)......DSP Based Direct Torque Control of Permanent Magnet Synchronous Motor (PMSM) using Space Vector Modulation (DTC-SVM)...

  5. Effects of medium-chain triglycerides on weight loss and body composition: a meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Mumme, Karen; Stonehouse, Welma

    2015-02-01

    Medium-chain triglycerides (MCTs) may result in negative energy balance and weight loss through increased energy expenditure and lipid oxidation. However, results from human intervention studies investigating the weight reducing potential of MCTs, have been mixed. To conduct a systematic review and meta-analysis of randomized controlled trials comparing the effects of MCTs, specifically C8:0 and C10:0, to long-chain triglycerides (LCTs) on weight loss and body composition in adults. Changes in blood lipid levels were secondary outcomes. Randomized controlled trials >3 weeks' duration conducted in healthy adults were identified searching Web of Knowledge, Discover, PubMed, Scopus, New Zealand Science, and Cochrane CENTRAL until March 2014 with no language restriction. Identified trials were assessed for bias. Mean differences were pooled and analyzed using inverse variance models with fixed effects. Heterogeneity between studies was calculated using I(2) statistic. An I(2)>50% or P<0.10 indicated heterogeneity. Thirteen trials (n=749) were identified. Compared with LCTs, MCTs decreased body weight (-0.51 kg [95% CI-0.80 to -0.23 kg]; P<0.001; I(2)=35%); waist circumference (-1.46 cm [95% CI -2.04 to -0.87 cm]; P<0.001; I(2)=0%), hip circumference (-0.79 cm [95% CI -1.27 to -0.30 cm]; P=0.002; I(2)=0%), total body fat (standard mean difference -0.39 [95% CI -0.57 to -0.22]; P<0.001; I(2)=0%), total subcutaneous fat (standard mean difference -0.46 [95% CI -0.64 to -0.27]; P<0.001; I(2)=20%), and visceral fat (standard mean difference -0.55 [95% CI -0.75 to -0.34]; P<0.001; I(2)=0%). No differences were seen in blood lipid levels. Many trials lacked sufficient information for a complete quality assessment, and commercial bias was detected. Although heterogeneity was absent, study designs varied with regard to duration, dose, and control of energy intake. Replacement of LCTs with MCTs in the diet could potentially induce modest reductions in body weight and composition

  6. Bat algorithm optimized fuzzy PD based speed controller for brushless direct current motor

    Directory of Open Access Journals (Sweden)

    K. Premkumar

    2016-06-01

    Full Text Available In this paper, design of fuzzy proportional derivative controller and fuzzy proportional derivative integral controller for speed control of brushless direct current drive has been presented. Optimization of the above controllers design is carried out using nature inspired optimization algorithms such as particle swarm, cuckoo search, and bat algorithms. Time domain specifications such as overshoot, undershoot, settling time, recovery time, and steady state error and performance indices such as root mean squared error, integral of absolute error, integral of time multiplied absolute error and integral of squared error are measured and compared for the above controllers under different operating conditions such as varying set speed and load disturbance conditions. The precise investigation through simulation is performed using simulink toolbox. From the simulation test results, it is evident that bat optimized fuzzy proportional derivative controller has superior performance than the other controllers considered. Experimental test results have also been taken and analyzed for the optimal controller identified through simulation.

  7. Direct Torque Control of Sensorless Induction Motor Drives: A Sliding-Mode Approach

    DEFF Research Database (Denmark)

    Lascu, Cristian; Boldea, Ion; Blaabjerg, Frede

    2004-01-01

    -vector pulsewidth modulation is proposed for induction motor sensorless drives. The DTC transient merits and robustness are preserved and the steady-state behaviour is improved by reducing the torque and flux pulsations. A sliding-mode observer using a dual reference frame motor model is introduced and tested......Direct torque control (DTC) is known to produce fast response and robust control in ac adjustable-speed drives. However, in the steady-state operation, notable torque, flux, and current pulsations occur. A new, direct torque and flux control strategy based on variable-structure control and space....... Simulations and comparative experimental results with the proposed control scheme, versus classic DTC, are presented. Very-low-speed sensorless operation (3 r/min) is demonstrated....

  8. Decentralized direct adaptive neural network control for a class of interconnected systems

    Institute of Scientific and Technical Information of China (English)

    Zhang Tianping; Mei Jiandong

    2006-01-01

    The problem of direct adaptive neural network control for a class of large-scale systems with unknown function control gains and the high-order interconnections is studied in this paper. Based on the principle of sliding mode control and the approximation capability of multilayer neural networks, a design scheme of decentralized direct adaptive sliding mode controller is proposed. The plant dynamic uncertainty and modeling errors are adaptively compensated by adjusted the weights and sliding mode gains on-line for each subsystem using only local information. According to the Lyapunov method, the closed-loop adaptive control system is proven to be globally stable, with tracking errors converging to a neighborhood of zero. Simulation results demonstrate the effectiveness of the proposed approach.

  9. Global Inverse Optimal Tracking Control of Underactuated Omni-directional Intelligent Navigators (ODINs)

    Institute of Scientific and Technical Information of China (English)

    Khac Duc Do

    2015-01-01

    This paper presents a design of optimal controllers with respect to a meaningful cost function to force an underactuated omni-directional intelligent navigator (ODIN) under unknown constant environmental loads to track a reference trajectory in two-dimensional space. Motivated by the vehicle’s steering practice, the yaw angle regarded as a virtual control plus the surge thrust force are used to force the position of the vehicle to globally track its reference trajectory. The control design is based on several recent results developed for inverse optimal control and stability analysis of nonlinear systems, a new design of bounded disturbance observers, and backstepping and Lyapunov’s direct methods. Both state- and output-feedback control designs are addressed. Simulations are included to illustrate the effectiveness of the proposed results.

  10. Direct yaw moment control for distributed drive electric vehicle handling performance improvement

    Science.gov (United States)

    Yu, Zhuoping; Leng, Bo; Xiong, Lu; Feng, Yuan; Shi, Fenmiao

    2016-05-01

    For a distributed drive electric vehicle (DDEV) driven by four in-wheel motors, advanced vehicle dynamic control methods can be realized easily because motors can be controlled independently, quickly and precisely. And direct yaw-moment control (DYC) has been widely studied and applied to vehicle stability control. Good vehicle handling performance: quick yaw rate transient response, small overshoot, high steady yaw rate gain, etc, is required by drivers under normal conditions, which is less concerned, however. Based on the hierarchical control methodology, a novel control system using direct yaw moment control for improving handling performance of a distributed drive electric vehicle especially under normal driving conditions has been proposed. The upper-loop control system consists of two parts: a state feedback controller, which aims to realize the ideal transient response of yaw rate, with a vehicle sideslip angle observer; and a steering wheel angle feedforward controller designed to achieve a desired yaw rate steady gain. Under the restriction of the effect of poles and zeros in the closed-loop transfer function on the system response and the capacity of in-wheel motors, the integrated time and absolute error (ITAE) function is utilized as the cost function in the optimal control to calculate the ideal eigen frequency and damper coefficient of the system and obtain optimal feedback matrix and feedforward matrix. Simulations and experiments with a DDEV under multiple maneuvers are carried out and show the effectiveness of the proposed method: yaw rate rising time is reduced, steady yaw rate gain is increased, vehicle steering characteristic is close to neutral steer and drivers burdens are also reduced. The control system improves vehicle handling performance under normal conditions in both transient and steady response. State feedback control instead of model following control is introduced in the control system so that the sense of control intervention to

  11. Direct Surge Margin Control for Aeroengines Based on Improved SVR Machine and LQR Method

    Directory of Open Access Journals (Sweden)

    Haibo Zhang

    2013-01-01

    Full Text Available A novel scheme of high stability engine control (HISTEC on the basis of an improved linear quadratic regulator (ILQR, called direct surge margin control, is derived for super-maneuver flights. Direct surge margin control, which is different from conventional control scheme, puts surge margin into the engine closed-loop system and takes surge margin as controlled variable directly. In this way, direct surge margin control can exploit potential performance of engine more effectively with a decrease of engine stability margin which usually happened in super-maneuver flights. For conquering the difficulty that aeroengine surge margin is undetectable, an approach based on improved support vector regression (SVR machine is proposed to construct a surge margin prediction model. The surge margin modeling contains two parts: a baseline model under no inlet distortion states and the calculation for surge margin loss under supermaneuvering flight conditions. The previous one is developed using neural network method, the inputs of which are selected by a weighted feature selection algorithm. Considering the hysteresis between pilot input and angle of attack output, an online scrolling window least square support vector regression (LSSVR method is employed to firstly estimate inlet distortion index and further compute surge margin loss via some empirical look-up tables.

  12. Indirect and direct perceived behavioral control and the role of intention in the context of birth control behavior.

    Science.gov (United States)

    Hanson, Jessica D; Nothwehr, Faryle; Yang, Jingzhen Ginger; Romitti, Paul

    2015-07-01

    Unintended pregnancies can have negative consequences for both mother and child. The focus of this study was to utilize perceived behavioral control measures (PBC; part of the theory of planned behavior) to identify relevant behavioral determinants of birth control use. This study also tested associations between direct and indirect PBC measures and intention of birth control use and between intention and birth control use. The methods included a randomly selected sample of patients at a health care system in the Upper Midwest who were sent a self-administered survey, with 190 non-pregnant women returning completed surveys. Participants indicated a high level of control over using birth control, and a significant positive correlation was observed between direct and indirect PBC measures. Participants also reported high intentions to use birth control, and a significant positive correlation was observed between intention and PBC. Additionally, both PBC measures and intention were independently and significantly associated with behavior, and PBC remained significantly associated with behavior when intention was added into the model. In conclusion, compared to the previous literature, this study is unique in that it examines indirect PBC measures and also the important role that PBC plays with actual birth control behavior.

  13. Controllable assembly of silver nanoparticles induced by femtosecond laser direct writing

    OpenAIRE

    Wang, Huan; Liu, Sen; Zhang, Yong-Lai; Wang, Jian-Nan; Wang, Lei; Xia,Hong; Chen, Qi-Dai; Ding, Hong; Sun, Hong-Bo

    2015-01-01

    We report controllable assembly of silver nanoparticles (Ag NPs) for patterning of silver microstructures. The assembly is induced by femtosecond laser direct writing (FsLDW). A tightly focused femtosecond laser beam is capable of trapping and driving Ag NPs to form desired micropatterns with a high resolution of ∼190 nm. Taking advantage of the ‘direct writing’ feature, three microelectrodes have been integrated with a microfluidic chip; two silver-based microdevices including a microheater ...

  14. An international track wheelchair with a center of gravity directional controller.

    Science.gov (United States)

    Cooper, R A

    1989-01-01

    An international track wheelchair (ITWC) with a center of gravity directional controller (COGDC) is described in this paper. The rules for international track competition disallow devices designed solely for steering. Equipment has been disqualified for having steering handles, crown compensators, and other lever systems. However, the rules do allow tie-rod linkage and the use of springs for dampening caster flutter. The chair described in this paper exploits the physical properties of wheeled vehicles to achieve directional control on the track. This controller is effective, because turning is only required in one direction. Three such track wheelchairs have been developed and were used at the Paralympics in Seoul, Korea, in October of 1988.

  15. 供应链管理环境下的库存控制研究%The Research of Inventory Control under Supply Chain Management Environment

    Institute of Scientific and Technical Information of China (English)

    李玉香; 李志刚

    2013-01-01

    It is important that the study of enterprise inventory control methods under supply chain management environment can save the cost of the supply chain and improve the overall efficiency of the supply chain. This article started from the analysis of inventory control problems in practice under the supply chain management environment. And also expounded new characteristics of inventory control under supply chain environment, targeted raised strategy and methods to resolve questions.%  研究供应链管理环境下企业库存控制方法,对于节约供应链成本、提高供应链整体效率有重要意义。本文从分析供应链管理环境下库存控制在实践中所出现的各种问题入手,阐述了供应链环境下库存控制的新特点,有针对性地提出解决问题的策略和方法。

  16. Experimental Investigations on the Influence of Flux Control Loop in a Direct Torque Control Drive.

    Directory of Open Access Journals (Sweden)

    bhoopendra singh

    2012-10-01

    Full Text Available

    Accurate flux estimation and control of stator flux by the flux control loop is the determining factor in effective implementation of DTC algorithm. In this paper a comparison of voltage model based flux estimation techniques for flux response improvement is carried out. The effectiveness of these methods is judged on the basis of Root Mean Square Flux Error (RMSFE and Total Harmonic Distortion (THD of stator current. The theoretical aspects of these methods are discussed and a comparative analysis is provided with emphasis on digital signal processor (DSP based controller implementation. Further the effect of operating flux on the performance of induction motor drive in terms of dynamic response, torque ripple and efficiency of operation is carried out. The proposed investigation is experimentally validated on a test drive.

  17. A multi-mode operation control strategy for flexible microgrid based on sliding-mode direct voltage and hierarchical controls.

    Science.gov (United States)

    Zhang, Qinjin; Liu, Yancheng; Zhao, Youtao; Wang, Ning

    2016-03-01

    Multi-mode operation and transient stability are two problems that significantly affect flexible microgrid (MG). This paper proposes a multi-mode operation control strategy for flexible MG based on a three-layer hierarchical structure. The proposed structure is composed of autonomous, cooperative, and scheduling controllers. Autonomous controller is utilized to control the performance of the single micro-source inverter. An adaptive sliding-mode direct voltage loop and an improved droop power loop based on virtual negative impedance are presented respectively to enhance the system disturbance-rejection performance and the power sharing accuracy. Cooperative controller, which is composed of secondary voltage/frequency control and phase synchronization control, is designed to eliminate the voltage/frequency deviations produced by the autonomous controller and prepare for grid connection. Scheduling controller manages the power flow between the MG and the grid. The MG with the improved hierarchical control scheme can achieve seamless transitions from islanded to grid-connected mode and have a good transient performance. In addition the presented work can also optimize the power quality issues and improve the load power sharing accuracy between parallel VSIs. Finally, the transient performance and effectiveness of the proposed control scheme are evaluated by theoretical analysis and simulation results.

  18. Anion-Directed Copper(II) Metallocages, Coordination Chain, and Complex Double Salt: Structures, Magnetic Properties, EPR Spectra, and Density Functional Study.

    Science.gov (United States)

    Wu, Jing-Yun; Zhong, Ming-Shiou; Chiang, Ming-Hsi; Bhattacharya, Dibyendu; Lee, Yen-Wei; Lai, Long-Li

    2016-05-17

    A series of Cu(II) metallo-assemblies showing anion-directed structural variations, including five metallocages [(G(n-) )⊂{Cu2 (Hdpma)4 }]((8-n)+) (A(-) )8-n (G(n-) =NO3 (-) , ClO4 (-) , SiF6 (2-) , BF4 (-) , SO4 (2-) ; A(-) =NO3 (-) , ClO4 (-) , BF4 (-) , CH3 SO4 (-) ; Hdpma=bis(3-pyridylmethyl)ammonium cation), a complex double salt, namely, (H3 dpma)4 (CuCl4 )5 Cl2 , and a coordination chain, namely, [Cu2 (dpma)(OAc)4 ], are reported. The influence of the anion can be explained by its coordinating ability, the affinity of which for the Cu(II) center interferes significantly with metallocage formation, and its shape, which offers host-guest recognition ability to engage in weak metal-anion coordination and hydrogen bonding to the organic ligand, which are responsible for metallocage templation. EPR studies of these metallocages in the powder phase at room temperature and 77 K showed a trend of the g values (g|| >2.10>g⊥ >2.00) indicating a dx2-y2 -based ground state with square-pyramidal geometry for the Cu(II) centers. The magnetism of these metallocages can be interpreted as the result of a combination of relatively small magnetic coupling integrals and a substantial contribution of temperature-independent paramagnetism (TIP). The weak magnetic interaction is corroborated by the results of DFT calculations and the EPR spectra. Availability of the low-lying state for spin population was confirmed by a magnetization study, which revealed a magnetic moment approaching 2Nβ, which would explain the presence of the larger TIP term.

  19. Engineering of a recombinant trivalent single-chain variable fragment antibody directed against rabies virus glycoprotein G with improved neutralizing potency.

    Science.gov (United States)

    Turki, Imène; Hammami, Akil; Kharmachi, Habib; Mousli, Mohamed

    2014-02-01

    Human and equine rabies immunoglobulins are currently available for passive immunization against rabies. However, these are hampered by the limited supply and some drawbacks. Advances in antibody engineering have led to overcome issues of clinical applications and to improve the protective efficacy. In the present study, we report the generation of a trivalent single-chain Fv (scFv50AD1-Fd), that recognizes the rabies virus glycoprotein, genetically fused to the trimerization domain of the bacteriophage T4 fibritin, termed 'foldon' (Fd). scFv50AD1-Fd was expressed as soluble recombinant protein in bacterial periplasmic space and purified through affinity chromatography. The molecular integrity and stability were analyzed by polyacrylamide gradient-gel electrophoresis, size-exclusion chromatography and incubation in human sera. The antigen-binding properties of the trimeric scFv were analyzed by direct and competitive-ELISA. Its apparent affinity constant was estimated at 1.4 ± 0.25 × 10(9)M(-1) and was 75-fold higher than its monovalent scFv (1.9 ± 0.68 × 10(7)M(-1)). The scFv50AD1-Fd neutralized rabies virus in a standard in vitro and in vivo neutralization assay. We showed a high neutralization activity up to 75-fold compared with monovalent format and the WHO standard serum. The gain in avidity resulting from multivalency along with an improved biological activity makes the trivalent scFv50AD1-Fd construct an important reagent for rabies protection. The antibody engineering approach presented here may serve as a strategy for designing a new generation of anti-rabies for passive immunotherapy.

  20. Visually driven chaining of elementary swim patterns into a goal-directed motor sequence: a virtual reality study of zebrafish prey capture

    Directory of Open Access Journals (Sweden)

    Chintan A Trivedi

    2013-05-01

    Full Text Available Prey capture behavior critically depends on rapid processing of sensory input in order to track, approach and catch the target. When using vision, the nervous system faces the problem of extracting relevant information from a continuous stream of input in order to detect and categorize visible objects as potential prey and to select appropriate motor patterns for approach. For prey capture, many vertebrates exhibit intermittent locomotion, in which discrete motor patterns are chained into a sequence, interrupted by short periods of rest. Here, using high-speed recordings of full-length prey capture sequences performed by freely swimming zebrafish larvae in the presence of a single paramecium, we provide a detailed kinematic analysis of first and subsequent swim bouts during prey capture. Using Fourier analysis, we show that individual swim bouts represent an elementary motor pattern. Changes in orientation are directed towards the target on a graded scale and are implemented by an asymmetric tail bend component superimposed on this basic motor pattern. To further investigate the role of visual feedback on the efficiency and speed of this complex behavior, we developed a closed-loop virtual reality setup in which minimally restrained larvae recapitulated interconnected swim patterns closely resembling those observed during prey capture in freely moving fish. Systematic variation of stimulus properties showed that prey capture is initiated within a narrow range of stimulus size and velocity. Furthermore, variations in the delay and location of swim-triggered visual feedback showed that the reaction time of secondary and later swims is shorter for stimuli that appear within a narrow spatio-temporal window following a swim. This suggests that the larva may generate an expectation of stimulus position, which enables accelerated motor sequencing if the expectation is met by appropriate visual feedback.

  1. Detection of rifampin resistance patterns in Mycobacterium tuberculosis strains isolated in Iran by polymerase chain reaction-single-strand conformation polymorphism and direct sequencing methods

    Directory of Open Access Journals (Sweden)

    Bahram Nasr Isfahani

    2006-09-01

    Full Text Available Mutations in the rpoB locus confer conformational changes leading to defective binding of rifampin (RIF to rpoB and consequently resistance in Mycobacterium tuberculosis. Polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP was established as a rapid screening test for the detection of mutations in the rpoB gene, and direct sequencing has been unambiguously applied to characterize mutations. A total of 37 of Iranian isolates of M. tuberculosis, 16 sensitive and 21 resistant to RIF, were used in this study. A 193-bp region of the rpoB gene was amplified and PCR-SSCP patterns were determined by electrophoresis in 10% acrylamide gel and silver staining. Also, 21 samples of 193-bp rpoB amplicons with different PCR-SSCP patterns from RIFr and 10 from RIFs were sequenced. Seven distinguishable PCR-SSCP patterns were recognized in the 21 Iranian RIFr strains, while 15 out of 16 RIFs isolates demonstrated PCR-SSCP banding patterns similar to that of sensitive standard strain H37Rv. However one of the sensitive isolates demonstrated a different pattern. There were seen six different mutations in the amplified region of rpoB gene: codon 516(GAC/GTC, 523(GGG/GGT, 526(CAC/TAC, 531(TCG/TTG, 511(CTG/TTG, and 512(AGC/TCG. This study demonstrated the high specificity (93.8% and sensitivity (95.2% of PCR-SSCP method for detection of mutation in rpoB gene; 85.7% of RIFr strains showed a single mutation and 14.3% had no mutations. Three strains showed mutations caused polymorphism. Our data support the common notion that rifampin resistance genotypes are generally present mutations in codons 531 and 526, most frequently found in M. tuberculosis populations regardless of geographic origin.

  2. Detection of rifampin resistance patterns in Mycobacterium tuberculosis strains isolated in Iran by polymerase chain reaction-single-strand conformation polymorphism and direct sequencing methods.

    Science.gov (United States)

    Isfahani, Bahram Nasr; Tavakoli, Akbar; Salehi, Mansoor; Tazhibi, Mehdi

    2006-09-01

    Mutations in the rpoB locus confer conformational changes leading to defective binding of rifampin (RIF) to rpoB and consequently resistance in Mycobacterium tuberculosis. Polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) was established as a rapid screening test for the detection of mutations in the rpoB gene, and direct sequencing has been unambiguously applied to characterize mutations. A total of 37 of Iranian isolates of M. tuberculosis, 16 sensitive and 21 resistant to RIF, were used in this study. A 193-bp region of the rpoB gene was amplified and PCR-SSCP patterns were determined by electrophoresis in 10% acrylamide gel and silver staining. Also, 21 samples of 193-bp rpoB amplicons with different PCR-SSCP patterns from RIFr and 10 from RIFs were sequenced. Seven distinguishable PCR-SSCP patterns were recognized in the 21 Iranian RIFr strains, while 15 out of 16 RIFs isolates demonstrated PCR-SSCP banding patterns similar to that of sensitive standard strain H37Rv. However one of the sensitive isolates demonstrated a different pattern. There were seen six different mutations in the amplified region of rpoB gene: codon 516(GAC/GTC), 523(GGG/GGT), 526(CAC/TAC), 531(TCG/TTG), 511(CTG/TTG), and 512(AGC/TCG). This study demonstrated the high specificity (93.8%) and sensitivity (95.2%) of PCR-SSCP method for detection of mutation in rpoB gene; 85.7% of RIFr strains showed a single mutation and 14.3% had no mutations. Three strains showed mutations caused polymorphism. Our data support the common notion that rifampin resistance genotypes are generally present mutations in codons 531 and 526, most frequently found in M. tuberculosis populations regardless of geographic origin.

  3. Visually driven chaining of elementary swim patterns into a goal-directed motor sequence: a virtual reality study of zebrafish prey capture.

    Science.gov (United States)

    Trivedi, Chintan A; Bollmann, Johann H

    2013-01-01

    Prey capture behavior critically depends on rapid processing of sensory input in order to track, approach, and catch the target. When using vision, the nervous system faces the problem of extracting relevant information from a continuous stream of input in order to detect and categorize visible objects as potential prey and to select appropriate motor patterns for approach. For prey capture, many vertebrates exhibit intermittent locomotion, in which discrete motor patterns are chained into a sequence, interrupted by short periods of rest. Here, using high-speed recordings of full-length prey capture sequences performed by freely swimming zebrafish larvae in the presence of a single paramecium, we provide a detailed kinematic analysis of first and subsequent swim bouts during prey capture. Using Fourier analysis, we show that individual swim bouts represent an elementary motor pattern. Changes in orientation are directed toward the target on a graded scale and are implemented by an asymmetric tail bend component superimposed on this basic motor pattern. To further investigate the role of visual feedback on the efficiency and speed of this complex behavior, we developed a closed-loop virtual reality setup in which minimally restrained larvae recapitulated interconnected swim patterns closely resembling those observed during prey capture in freely moving fish. Systematic variation of stimulus properties showed that prey capture is initiated within a narrow range of stimulus size and velocity. Furthermore, variations in the delay and location of swim triggered visual feedback showed that the reaction time of secondary and later swims is shorter for stimuli that appear within a narrow spatio-temporal window following a swim. This suggests that the larva may generate an expectation of stimulus position, which enables accelerated motor sequencing if the expectation is met by appropriate visual feedback.

  4. Direct cardiac potential trigger for chronic control of a ventricular assist device.

    Science.gov (United States)

    Kitamura, M; Hanzawa, K; Aoki, K; Saitoh, M; Hayashi, J

    2001-01-01

    As a new trigger method for chronic drive control of a ventricular assist device (VAD), a direct cardiac potential trigger was assessed under various conditions in a chronic experimental model. A pneumatic pulsatile VAD was implanted as circulatory support between the left ventricular apex and the ascending aorta in 12 adult pigs. Hemodynamic parameters and pump output were continuously monitored. Two tips of a bipolar electrode were set on the RV anterior wall and the LV posterior wall for recording direct cardiac potential. Counterpulsation drive of the VAD was applied by using the R wave in a standard electrocardiogram (ECG) or the direct cardiac potential as an ECG trigger. As special conditions, various artifacts on ECG, electromusculogram, arrhythmia, irregular ventilation, and passive vibration (simulation of exercise) were set for assessing the ECG trigger modes. Artifacts of irregular ventilation and passive vibration made the drive control poor using a standard ECG trigger. In contrast, the direct cardiac potential trigger maintained the counterpulsation control of the VAD well in all conditions of this study, and was a safe and reliable support for the native heart. It also supported animals for up to 48 hours after operation. The above results suggested that the direct cardiac potential trigger might be useful for monitoring native heart beats and adjusting the support cycle to the native heart cycle as a chronic control method for various VADs.

  5. The solution of singular optimal control problems using direct collocation and nonlinear programming

    Science.gov (United States)

    Downey, James R.; Conway, Bruce A.

    1992-08-01

    This paper describes work on the determination of optimal rocket trajectories which may include singular arcs. In recent years direct collocation and nonlinear programming has proven to be a powerful method for solving optimal control problems. Difficulties in the application of this method can occur if the problem is singular. Techniques exist for solving singular problems indirectly using the associated adjoint formulation. Unfortunately, the adjoints are not a part of the direct formulation. It is shown how adjoint information can be obtained from the direct method to allow the solution of singular problems.

  6. Direct Load Control (DLC) Considering Nodal Interrupted Energy Assessment Rate (NIEAR) in Restructured Power Systems

    DEFF Research Database (Denmark)

    Wu, Qiuwei; Wang, Peng; Goel, Lalit

    2010-01-01

    A direct load control (DLC) scheme of air conditioning loads (ACL) considering direct monetary compensation to ACL customers for the service interruption caused by the DLC program is proposed in this paper for restructured power systems. The nodal interrupted energy assessment rate (NIEAR), which...... is used as the bids from the ACL customers, is utilized to determine the direct monetary compensation to the ACL customers. The proposed scheme was investigated for the PoolCo electricity market. The optimal DLC scheme is determined based on the minimum system operating cost which is comprised...

  7. The controlled placement and delayed polymerization technique for the direct Class 2 posterior composite restoration.

    Science.gov (United States)

    Atlas, Alan M

    2005-11-01

    Adhesion dentistry and its application to the direct posterior composite restoration is the most controversial topic in dentistry today. The concepts behind this procedure are now the backbone of restorative dentistry. Adhesion dentistry influences basic fillings, crown buildups, post-and-core restorations, cementation, orthodontics, and endodontics. Yet, controversy remains about the correct way to place a direct Class 2 posterior composite restoration. This article will examine the scientific evidence to determine which materials and placement techniques will achieve the optimum direct Class 2 posterior composite restoration at or below the cementoenamel junction using the controlled placement and delayed polymerization technique.

  8. Control of dendrite growth by a magnetic field during directional solidification

    Science.gov (United States)

    Dai, Yanchao; Du, Dafan; Hou, Long; Gagnoud, Annie; Ren, Zhongming; Fautrelle, Yves; Moreau, Rene; Li, Xi

    2016-04-01

    In this work, the alignment behavior of three kinds of dendrites (Al3Ni, α-Al and Al2Cu dendrites) with a remarkable crystalline anisotropy during directional solidification under an axial magnetic field is studied by the EBSD technology. Experimental results reveal that the magnetic field is capable of tailoring the dendrite alignment during directional solidification. Further, based on the crystalline anisotropy, a method to control the dendrite alignment by adjusting the angle between the magnetic field and the solidification direction is proposed.

  9. Direct and Indirect Couplings in Coherent Feedback Control of Linear Quantum Systems

    CERN Document Server

    Zhang, Guofeng

    2010-01-01

    The purpose of this paper is to study and design direct and indirect couplings for use in coherent feedback control of a class of linear quantum stochastic systems. A general physical model for a nominal linear quantum system coupled directly and indirectly to external systems is presented. Fundamental properties of stability, dissipation, passivity, and gain for this class of linear quantum models are presented and characterized using complex Lyapunov equations and linear matrix inequalities (LMIs). Coherent $H^\\infty$ and LQG synthesis methods are extended to accommodate direct couplings using multistep optimization. Examples are given to illustrate the results.

  10. Sliding mode pulse-width modulation technique for direct torque controlled induction motor drive

    Science.gov (United States)

    Bounadja, M.; Belarbi, A. W.; Belmadani, B.

    2010-05-01

    This paper presents a novel pulse-width modulation technique based sliding mode approach for direct torque control of an induction machine drive. Methodology begins with a sliding mode control of machine's torque and stator flux to generate the reference voltage vector and to reduce parameters sensitivity. Then, the switching control of the three-phase inverter is developed using sliding mode concept to make the system tracking reference voltage inputs. The main features of the proposed methodologies are the high tracking accuracy and the much easier implementation compared to the space vector modulation. Simulations are carried out to confirm the effectiveness of proposed control algorithms.

  11. Senserless Speed and Position of Direct Field Orientation Control Induction Motor Drive

    Directory of Open Access Journals (Sweden)

    Mohammed Khalil Hussain

    2012-01-01

    Full Text Available Direct field-orientation Control (DFOC of induction motor drives without mechanical speed sensors at the motor shaft has the attractions of low cost and high reliability. To replace the sensor, information on the rotor speed and position are extracted from measured stator currents and from voltages at motor terminals. In this paper presents direct field-orientation control (DFOC with two type of kalman filter (complete order and reduced order extended kalman filter to estimate flux, speed, torque and position. Simulated results show how good performance for reduced order extended kalman filter over that of complete order extended kalman filter in tracking performance and reduced time of state estimation.

  12. Formation Control for Unmanned Aerial Vehicles with Directed and Switching Topologies

    Directory of Open Access Journals (Sweden)

    Yahui Qi

    2016-01-01

    Full Text Available Formation control problems for unmanned aerial vehicle (UAV swarm systems with directed and switching topologies are investigated. A general formation control protocol is proposed firstly. Then, by variable transformation, the formation problem is transformed into a consensus problem, which can be solved by a novel matrix decomposition method. Sufficient conditions to achieve formation with directed and switching topologies are provided and an explicit expression of the formation reference function is given. Furthermore, an algorithm to design the gain matrices of the protocol is presented. Finally, numerical simulations are provided to illustrate the effectiveness of the theoretical results.

  13. Direct torque control via feedback linearization for permanent magnet synchronous motor drives

    DEFF Research Database (Denmark)

    Lascu, Cristian; Boldea, Ion; Blaabjerg, Frede

    2012-01-01

    The paper describes a direct torque controlled (DTC) permanent magnet synchronous motor (PMSM) drive that employs feedback linearization and uses sliding-mode and linear controllers. We introduce a new feedback linearization approach that yields a decoupled linear PMSM model with two state...... variables, the torque and the square of stator flux magnitude. This linear model is intuitive and allows the implementation of DTC-type controllers that preserve all DTC advantages and eliminate its main drawback, the flux and torque ripple. Next, we investigate two controllers for toque and flux....... A variable structure controller (VSC) which is robust, fast, and produces low-ripple control is compared with a linear-DTC scheme which is ripple free. The torque time response is similar to a conventional DTC drive and the proposed solutions are flexible and highly tunable. We present the controller design...

  14. Improvement of Direct Torque Control by using a Space Vector Modulation Control of Three-Level Inverter

    Science.gov (United States)

    Achalhi, A.; Bezza, M.; Belbounaguia, N.; Boujoudi, B.

    2017-03-01

    The performances of Direct Torque Control (DTC) of Induction machine are highly related to the inverter used therewith. The purpose of this paper is to highlight the efficiency of the space vector modulation (SVM) control of three level inverter associated with the direct torque control. The first part of this work is devoted to present the mathematical models of the DTC associated with 2-levels inverter then 3-levels inverter. Simulations on Matlab/Simulink will allow a comparative study to highlight advantages of the use of three levels inverter. The second part is devoted to the improvement of the DTC associated with a 3-levels inverter by application of the space vector modulation strategy (SVM) in order to manage the switching frequency and reduce harmonics. The efficiency of this solution will be attested by simulation on Matlab/Simulink.

  15. DISTRIBUTED CONTROL ARCHITECTURE OF AN OMNI-DIRECTIONAL AUTONOMOUS GUIDED VEHICLE

    Directory of Open Access Journals (Sweden)

    N.S. Tlale

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: Omni-directionality is the ability of a mobile robot to move instantaneously in any direction. This paper describes the wheel and controller designs of a Mecanumwheeled, autonomous guided vehicle (AGV for reconfigurable manufacturing systems. Mecanum wheels use slip developed between rollers and surface, surface and ground, to achieve omni-directionality. An advantage of omni-directional robotic platforms is that they are capable of performing tasks in congested environments such as those found in factory workshops, narrow aisles, warehouses, etc. Controller Area Network (CAN is implemented as a distributed controller to control motion and navigation tasks of the developed robot. The design of the distributed controller is described and its performance analyzed. This increases the reliability and functionality of the mobile robot.

    AFRIKAANSE OPSOMMING: Die artikel beskryf wiel - en beheerontwerpe van ‘n veelrigting mobiele robot. Die robot is ‘n selfstandigbeheerde voertuig vir gebruik by vervaardigingstelsels met veranderbare konfigurasie. Die ontwerp van die robot en bypassende beheerstelsel word beskryf en ontleed teen die agterground van bewegings – en navigeertake. Die betroubaarheid en funksionering van die sisteem word beoordeel.

  16. 关键链项目进度控制技术综合分析研究%Analysis on Critical Chain Project Comprehensive Schedule Control Method

    Institute of Scientific and Technical Information of China (English)

    李俊亭

    2015-01-01

    Critical chain project management(CCPM)is an important breakthrough in the development of project management, but critical chain project schedule controlling technology based on buffer mechanism is not comprehensive enough,and lacks of important control sector,and has no association with traditional project schedule control technology and so on. This paper analyzes the fundamental of CCPM schedule control method and traditional project schedule control technology. Based on buffer time management it proposes buffer time consumption ratio,buffer consumption & critical chain completion ratio,and critical chain project schedule control technology based on earned value. Based on resource management it puts forward three principles for critical chain project schedule control with CCPM characteristics. As a whole,this paper brings forward a comprehensive critical chain project schedule control technology,and provides a foundation for critical chain project control system.%关键链项目管理是现代项目管理理论的一个重要突破,但是基于缓冲机制的关键链项目进度控制技术还不够全面、存在部分控制环节缺失、未能与传统项目进度控制技术融合等问题.通过分析关键链项目进度控制基础和传统的项目进度控制技术,基于缓冲时间管理提出缓冲区消耗比例、缓冲区消耗与关键链完成比率和关键链挣值进度控制技术;基于资源管理提出具有关键链项目特色的3个进度控制准则,为系统研究关键链项目进度控制体系奠定了基础.

  17. Performances improvements and torque ripple minimization for VSI fed induction machine with direct control torque.

    Science.gov (United States)

    Abdelli, R; Rekioua, D; Rekioua, T

    2011-04-01

    This paper describes a torque ripple reduction technique with constant switching frequency for direct torque control (DTC) of an induction motor (IM). This method enables a minimum torque ripple control. In order to obtain a constant switching frequency and hence a torque ripple reduction, we propose a control technique for IM. It consists of controlling directly the electromagnetic torque by using a modulated hysteresis controller. The design methodology is based on space vector modulation (SVM) of electrical machines with digital vector control. MATLAB simulations supported with experimental study are used. The simulation and experimental results of this proposed algorithm show an adequate dynamic to IM; however, the research can be extended to include synchronous motors as well. The implementation of the proposed algorithm is described. It doesn't require any PI controller in the torque control loop. The hardware inverter is controlled digitally using a Texas Instruments TMS320F240 digital signal processor (DSP) with composed C codes for generating the required references. The results obtained from simulation and experiments confirmed the feasibility of the proposed strategy compared to the conventional one.

  18. Improving the performance of hysteresis direct torque control of IPMSM using active filter topology

    Indian Academy of Sciences (India)

    Kayhan Gulez; Ali Ahmed Adam; Halit Pastaci

    2006-06-01

    This paper describes an active filter topology to improve the performance of hysteresis direct torque control (HDTC) of interior permanent magnet synchronous motor (IPMSM). The filter topology consists of an active filter and two RLC filters, and is connected to the main power circuit through a 1:1 transformer. The active filter is characterized by detecting the harmonics in the motor phase voltages and injecting equivalent harmonic voltages to produce almost sinusoidal voltage waveform to the motor terminals. The active filter uses hysteresis voltage controller while the motor main circuit uses hysteresis direct torque control. The simulation results of this combined control structure show considerable torque ripple reduction in the steady state range and adequate dynamic torque performance as well as considerable harmonic voltage and EMI noise reduction.

  19. Demand Controlled Economizer Cycles: A Direct Digital Control Scheme for Heating, Ventilating, and Air Conditioning Systems,

    Science.gov (United States)

    1984-05-01

    includes a heating coil and thermostatic control to maintain the air in this path at an elevated temperature, typically around 80 degrees Farenheit (80 F...1238 Aug 1 1236 1237 52 1074 1126 50 1033 1083 Sep 8 8 5W 862 7T 600 678 75 603 7r Oct 51 400 451 119 204 323 115 207 322 ov 64 123 287 187 71 258

  20. Direct control and characterization of a Schottky barrier by scanning tunneling microscopy

    Science.gov (United States)

    Bell, L. D.; Kaiser, W. J.; Hecht, M. H.; Grunthaner, F. J.

    1988-01-01

    Scanning tunneling microscopy (STM) methods are used to directly control the barrier height of a metal tunnel tip-semiconductor tunnel junction. Barrier behavior is measured by tunnel current-voltage spectroscopy and compared to theory. A unique surface preparation method is used to prepare a low surface state density Si surface. Control of band bending with this method enables STM investigation of semiconductor subsurface properties.

  1. A DSP-based discrete space vector modulation direct torque control of sensorless induction machines

    Energy Technology Data Exchange (ETDEWEB)

    Khoucha, F.; Marouani, K.; Kheloui, A.; Aliouane, K.

    2004-07-01

    In this paper, we present a Direct Torque Control scheme of an induction motor operating without speed sensor. The estimation of the stator flux and the rotor speed is performed by an adaptive observer. In order to reduce the torque, flux, current and speed ripple a Discrete Space Vector Modulation (DSVM-DTC) strategy is implemented using a DSP-based hardware. To illustrate the performances of this control scheme, experimental results are presented. (author)

  2. Encoderless direct torque controller for limited speed range applications of brushless doubly-fed reluctance motors

    OpenAIRE

    Jovanovic, Milutin; Levi, Emil; Yu, James

    2006-01-01

    Presents the experimental verification of a new sensor-less control algorithm for direct torque (and flux) control (DTC) of the BDFRM in low variable frequency applications (e.g. wind energy conversion systems) where the low cost potential of the machine can be best exploited by using partially-rated power electronics. Brings a significant contribution to knowledge in the subject field as the proposed scheme has many important advantages over its counterparts in the target applications. Repre...

  3. A novel speed sensor-less direct torque control system for mining locomotive haulage

    Institute of Scientific and Technical Information of China (English)

    马宪民

    2002-01-01

    A novel speed sensor-less direct torque control induction motor drive system for the mining locomotive haulage is presented in the paper. Rotor speed identification is based on the model reference adaptive control theory with neural network using back propagation algorithm. The system is implemented using a real-time TMS320F240 digital signal processor. The simulation study and experiment results indicate that the suggested system has good performance.

  4. Direct microcomputer controlled determination of zinc in human serum by flow injection atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Simonsen, Kirsten Wiese; Nielsen, Bent; Jensen, Arne

    1986-01-01

    A procedure is described for the direct determination of zinc in human serum by fully automated, microcomputer controlled flow injection atomic absorption spectrometry (Fl-AAS). The Fl system is pumpless, using the negative pressure created by the nebuliser. It only consists of a three-way valve......, programmable from the microcomputer, to control the sample volume. No pre-treatment of the samples is necessary. The limit of detection is 0.14 mg l–1, and only small amounts of serum (

  5. Trajectory Control:Directional MWD Inversely New Wellbore Positioning Accuracy Prediction Method

    Institute of Scientific and Technical Information of China (English)

    Ahmed Abd Alaziz Ibrahim; Tagwa Ahmed Musa

    2004-01-01

    The deviation control of directional drilling is essentially the controlling of two angles of the wellbore actually drilled, namely, the inclination and azimuth. In directional drilling the bit trajectory never coincides exactly with the planned path, which is usually a plane curve with straight, building, holding, and dropping sections in succession. The drilling direction is of course dependant on the direction of the resultant forces acting on the bit and it is quite a tough job to hit the optimum target at the hole bottom as required. The traditional passive methods for correcting the drilling path have not met the demand to improve the techniques of deviation control. A method for combining wellbore surveys to obtain a composite, more accurate well position relies on accepting the position of the well from the most accurate survey instrument used in a given section of the wellbore. The error in each position measurement is the sum of many independent root sources of error effects. The relationship between surveys and other influential factors is considered, along with an analysis of different points of view. The collaborative work describes, establishes a common starting point of wellbore position uncertainty model, definition of what constitutes an error model, mathematics of position uncertainty calculation and an error model for basic directional service.

  6. Temperature modeling and control of Direct Methanol Fuel Cell based on adaptive neural fuzzy technology

    Institute of Scientific and Technical Information of China (English)

    Qi Zhidong; Zhu Xinjian; Cao Guangyi

    2006-01-01

    Aiming at on-line controlling of Direct Methanol Fuel Cell (DMFC) stack, an adaptive neural fuzzy inference technology is adopted in the modeling and control of DMFC temperature system. In the modeling process, an Adaptive Neural Fuzzy Inference System (ANFIS) identification model of DMFC stack temperature is developed based on the input-output sampled data, which can avoid the internal complexity of DMFC stack. In the controlling process, with the network model trained well as the reference model of the DMFC control system, a novel fuzzy genetic algorithm is used to regulate the parameters and fuzzy rules of a neural fuzzy controller. In the simulation, compared with the nonlinear Proportional Integral Derivative (PID) and traditional fuzzy algorithm, the improved neural fuzzy controller designed in this paper gets better performance, as demonstrated by the simulation results.

  7. Guest Editorial Special Issue on Recent Advances and New Directions in Switched Control Systems

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ As guest editors, it is our great honor to bring this special issue of the Journal of Control Theory and Applications devoted to Recent Advances and New Directions in Switched Control Systems. Recently, switched control systems have attracted much attention in the control systems community. Problems in this area are not only academically challenging for the inherent mathematical complexity, but also are derived or motivated from advanced applications in natural sciences, engineering, and social sciences. For survival, natural biological systems switch their survival strategies in accordance with environmental changes. For improved performance, switching has been extensively utilized/exploited in engineering systems such as automotive drive train control, electronic devices, control of power systems, etc.

  8. State feedback integral control for a rotary direct drive servo valve using a Lyapunov function approach.

    Science.gov (United States)

    Yu, Jue; Zhuang, Jian; Yu, Dehong

    2015-01-01

    This paper concerns a state feedback integral control using a Lyapunov function approach for a rotary direct drive servo valve (RDDV) while considering parameter uncertainties. Modeling of this RDDV servovalve reveals that its mechanical performance is deeply influenced by friction torques and flow torques; however, these torques are uncertain and mutable due to the nature of fluid flow. To eliminate load resistance and to achieve satisfactory position responses, this paper develops a state feedback control that integrates an integral action and a Lyapunov function. The integral action is introduced to address the nonzero steady-state error; in particular, the Lyapunov function is employed to improve control robustness by adjusting the varying parameters within their value ranges. This new controller also has the advantages of simple structure and ease of implementation. Simulation and experimental results demonstrate that the proposed controller can achieve higher control accuracy and stronger robustness. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  9. Finite time coordinated formation control for spacecraft formation flying under directed communication topology

    Science.gov (United States)

    Ran, Dechao; Chen, Xiaoqian; Misra, Arun K.

    2017-07-01

    This paper investigates the finite time coordinated formation control problem for spacecraft formation flying (SFF) under the assumption of directed communication topology. By using the neighborhood state measurements, a robust finite time coordinated formation controller is firstly designed based on the nonsingular terminal sliding mode surface. To address the special case that the desired trajectory of the formation is only accessible to a subset of spacecraft in the formation, an adaptive finite time coordinated formation controller is also proposed by designing a novel sliding mode surface. In both cases, the external disturbances are explicitly taken into account. Rigorous theoretical analysis proves that the proposed control schemes ensure that the closed-loop system can track the desired time-varying trajectory in finite time. Numerical simulations are presented that not only highlights the closed-loop performance benefits from the proposed control algorithms, but also illustrates the effectiveness in the presence of external disturbances when compared with the existing coordinated formation control schemes.

  10. Prickle isoforms control the direction of tissue polarity by microtubule independent and dependent mechanisms.

    Science.gov (United States)

    Sharp, Katherine A; Axelrod, Jeffrey D

    2016-02-10

    Planar cell polarity signaling directs the polarization of cells within the plane of many epithelia. While these tissues exhibit asymmetric localization of a set of core module proteins, in Drosophila, more than one mechanism links the direction of core module polarization to the tissue axes. One signaling system establishes a polarity bias in the parallel, apical microtubules upon which vesicles containing core proteins traffic. Swapping expression of the differentially expressed Prickle isoforms, Prickle and Spiny-legs, reverses the direction of core module polarization. Studies in the proximal wing and the anterior abdomen indicated that this results from their differential control of microtubule polarity. Prickle and Spiny-legs also control the direction of polarization in the distal wing (D-wing) and the posterior abdomen (P-abd). We report here that this occurs without affecting microtubule polarity in these tissues. The direction of polarity in the D-wing is therefore likely determined by a novel mechanism independent of microtubule polarity. In the P-abd, Prickle and Spiny-legs interpret at least two directional cues through a microtubule-polarity-independent mechanism.

  11. Prickle isoforms control the direction of tissue polarity by microtubule independent and dependent mechanisms

    Directory of Open Access Journals (Sweden)

    Katherine A. Sharp

    2016-03-01

    Full Text Available Planar cell polarity signaling directs the polarization of cells within the plane of many epithelia. While these tissues exhibit asymmetric localization of a set of core module proteins, in Drosophila, more than one mechanism links the direction of core module polarization to the tissue axes. One signaling system establishes a polarity bias in the parallel, apical microtubules upon which vesicles containing core proteins traffic. Swapping expression of the differentially expressed Prickle isoforms, Prickle and Spiny-legs, reverses the direction of core module polarization. Studies in the proximal wing and the anterior abdomen indicated that this results from their differential control of microtubule polarity. Prickle and Spiny-legs also control the direction of polarization in the distal wing (D-wing and the posterior abdomen (P-abd. We report here that this occurs without affecting microtubule polarity in these tissues. The direction of polarity in the D-wing is therefore likely determined by a novel mechanism independent of microtubule polarity. In the P-abd, Prickle and Spiny-legs interpret at least two directional cues through a microtubule-polarity-independent mechanism.

  12. Prickle isoforms control the direction of tissue polarity by microtubule independent and dependent mechanisms

    Science.gov (United States)

    Sharp, Katherine A.; Axelrod, Jeffrey D.

    2016-01-01

    ABSTRACT Planar cell polarity signaling directs the polarization of cells within the plane of many epithelia. While these tissues exhibit asymmetric localization of a set of core module proteins, in Drosophila, more than one mechanism links the direction of core module polarization to the tissue axes. One signaling system establishes a polarity bias in the parallel, apical microtubules upon which vesicles containing core proteins traffic. Swapping expression of the differentially expressed Prickle isoforms, Prickle and Spiny-legs, reverses the direction of core module polarization. Studies in the proximal wing and the anterior abdomen indicated that this results from their differential control of microtubule polarity. Prickle and Spiny-legs also control the direction of polarization in the distal wing (D-wing) and the posterior abdomen (P-abd). We report here that this occurs without affecting microtubule polarity in these tissues. The direction of polarity in the D-wing is therefore likely determined by a novel mechanism independent of microtubule polarity. In the P-abd, Prickle and Spiny-legs interpret at least two directional cues through a microtubule-polarity-independent mechanism. PMID:26863941

  13. Control of Transposon-Mediated Directed Mutation by the Escherichia coli Phosphoenolpyruvate:Sugar Phosphotransferase System.

    Science.gov (United States)

    Saier, Milton H; Zhang, Zhongge

    2015-01-01

    The phosphoenolpyruvate:sugar phosphotransferase system (PTS) has been shown to control transport, cell metabolism and gene expression. We here present results supporting the novel suggestion that in certain instances it also regulates the mutation rate. Directed mutations are defined as mutations that occur at higher frequencies when beneficial than when neutral or detrimental. To date, the occurrence of directed point mutations has not been documented and confirmed, but a few examples of transposon-mediated directed mutations have been reported. Here we focus on the first and best-studied example of directed mutation, which involves the regulation of insertion sequence-5 hopping into a specific site upstream of the glpFK glycerol utilization operon in Escherichia coli. This insertional event specifically activates expression of the glpFK operon, allowing the growth of wild-type cells with glycerol as a carbon source in the presence of nonmetabolizable glucose analogues which normally block glycerol utilization. The sugar-transporting PTS controls this process by regulating levels of cytoplasmic glycerol-3-phosphate and cyclic (c)AMP as established in previous publications. Direct involvement of the glycerol repressor, GlpR, and the cAMP receptor protein, Crp, in the regulation of transposon-mediated directed mutation has been demonstrated.

  14. H∞ controller design for a 4-meter direct-drive azimuth axis

    Science.gov (United States)

    Chen, Li-Yan; Zhang, Zhen-Chao; Song, Xiao-Li; Wang, Da-Xing

    2015-11-01

    To pursue a higher imaging resolution for exploring more details in the information conveyed by the Universe, the next generation of optical telescopes based on a direct drive widely employ the extremely large aperture structure, which also introduces more disturbances and uncertain factors to the control system. Facing this new challenge, the PID control method in main-axis control systems of traditional astronomical telescopes cannot suffice for the requirement of the tracking precision and disturbance sensitivity in angular velocity. To overcome this shortcoming, we establish a dynamic model and propose an H∞ controller for a 4-meter azimuth direct drive control system that consists of a revolving platform (azimuth axis), a three-phase torque motor, a motor drive, an encoder, a data acquisition card and a small computers. Simulations are carried out to analyze the model and guide the real experiments. Experimental results show that the proposed H∞ controller reduces the tracking error by a maximum of 80.69% (average 57.8%) and the disturbance sensitivity by a maximum of 82.3% (average 50.96%) compared with the traditional tuned PI controller; furthermore, the order of the model describing the proposed controller can be reduced to three, thus its feasibility in real systems is guaranteed.

  15. Multimodel Modeling and Predictive Control for Direct-Drive Wind Turbine with Permanent Magnet Synchronous Generator

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2015-01-01

    Full Text Available The safety and reliability of the wind turbines wholly depend on the completeness and reliability of the control system which is an important problem for the validity of the wind energy conversion systems (WECSs. A method based on multimodel modeling and predictive control is proposed for the optimal operation of direct-drive wind turbine with permanent magnet synchronous generator in this paper. In this strategy, wind turbine with direct-drive permanent magnet synchronous generator is modeled and a backpropagation artificial neural network is designed to estimate the wind speed loaded into the turbine model in real time through the estimated turbine shaft speed and mechanical power. The nonlinear wind turbine system is presented by multiple linear models. The desired trajectory of the nonlinear system is decomposed to be suitable for the reference trajectory of multiple models that are presented by the linear models of the nonlinear system, which simplifies the nonlinear optimization problems and decreases the calculation difficulty. Then a multivariable control strategy based on model predictive control techniques for the control of variable-speed variable-pitch wind turbines is proposed. Finally, simulation results are given to illustrate the effectiveness of the proposed strategy, and the conclusion that multiple model predictive controller (MMPC has better control performance than the PI control method is obtained.

  16. Validity of bioconjugated silica nanoparticles in comparison with direct smear, culture, and polymerase chain reaction for detection of Mycobacterium tuberculosis in sputum specimens

    Directory of Open Access Journals (Sweden)

    Ekrami A

    2011-11-01

    Full Text Available Alireza Ekrami1, Ali Reza Samarbaf-Zadeh2, Azar Khosravi1, Behrooz Zargar3, Mohamad Alavi1, Mansor Amin2, Alireza Kiasat3 1Infectious and Tropical Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences, 2Department of Microbiology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, 3Department of Chemistry, School of Science, Shahid Chamran University, Ahvaz, Iran Background: Tuberculosis is a public health problem worldwide, and new easy to perform diagnostic methods with high accuracy are necessary for optimal control of the disease. Recently, fluorescent silica nanoparticles (FSNP has attracted immense interest for the detection of pathogenic microorganisms. The aim of this study was to detect Mycobacterium tuberculosis in clinical samples using bioconjugated FSNP compared with microscopic examination, polymerase chain reaction (PCR, nested PCR, and culture as the gold standard. Methods: In total, 152 sputum specimens were obtained from patients who were suspected to have pulmonary tuberculosis. All samples were examined by the four techniques described. Results: The assay showed 97.1% sensitivity (95% confidence interval [CI] 91–99.2 and 91.35% specificity (CI 78.3–97.1. Furthermore, assays using variable bacterial concentrations indicated that 100 colony forming units/mL of M. tuberculosis could be detected. There were no differences between the results obtained from two types of mouse monoclonal antibody against Hsp-65 and 16 KDa antigens. Conclusion: We performed this assay in a large number of clinical samples to confirm the diagnostic specificity and sensitivity of the test and can recommend its application for diagnosis of M. tuberculosis. We believe that this method is more convenient for routine diagnosis of M. tuberculosis in sputum and will be more easily applicable in the field, and with sufficient sensitivity. Keywords: Mycobacterium tuberculosis, fluorescent silica nanoparticles

  17. Reducing user discomfort in direct load control of domestic water heaters

    NARCIS (Netherlands)

    Belov, Alexander; Vasenev, Alexandr; Havinga, Paul J.M.; Meratnia, Nirvana; Zwaag, van der Berend Jan

    2015-01-01

    Direct Load Control (DLC) is an effective instrument for achieving a guaranteed load curtailment. Unfortunately, if a customer considers that personal discomfort outweighs money savings after DLC shutting down of home appliances, DLC solution can be rejected. This paper proposes the way to remediate

  18. Conflicts over Directing the Education of Children: Who Controls, Parents or School Officials?

    Science.gov (United States)

    Russo, Charles J.

    2005-01-01

    When dealing with the issues of quality control and the rights of parents to direct the upbringing of their school-aged children, one of the key factors that affects parental rights is compulsory attendance laws. Put another way, insofar as parents must educate their children, whether in regular public or nonpublic schools or by homeschooling…

  19. Impact of glycaemic control on the effect of direct renin inhibition in the AVOID study

    DEFF Research Database (Denmark)

    Persson, Frederik; Lewis, Julia B; Lewis, Edmund J;

    2012-01-01

    Hyperglycaemia induces development and progression of microvascular complications in diabetes. A direct link between high glucose levels and intrarenal renin-angiotensin activation has been demonstrated. This post-hoc analysis assessed the influence of baseline glycaemic control on the reduction...

  20. Reliance on habits at the expense of goal-directed control following dopamine precursor depletion

    NARCIS (Netherlands)

    de Wit, S.; Standing, H.R.; DeVito, E.E.; Robinson, O.J.; Ridderinkhof, K.R.; Robbins, T.W.; Sahakian, B.J.

    2012-01-01

    Rationale Dopamine is well known to play an important role in learning and motivation. Recent animal studies have implicated dopamine in the reinforcement of stimulus-response habits, as well as in flexible, goal-directed action. However, the role of dopamine in human action control is still not

  1. Modeling Human Control of Self-Motion Direction With Optic Flow and Vestibular Motion.

    Science.gov (United States)

    Zaal, Peter M T; Nieuwenhuizen, Frank M; van Paassen, Marinus M; Mulder, Max

    2013-04-01

    In this paper, we investigate the effects of visual and motion stimuli on the manual control of one's direction of self-motion. In a flight simulator, subjects conducted an active target-following disturbance-rejection task, using a compensatory display. Simulating a vehicular control task, the direction of vehicular motion was shown on the outside visual display in two ways: an explicit presentation using a symbol and an implicit presentation, namely, through the focus of radial outflow that emerges from optic flow. In addition, the effects of the relative strength of congruent vestibular motion cues were investigated. The dynamic properties of human visual and vestibular motion perception paths were modeled using a control-theoretical approach. As expected, improved tracking performance was found for the configurations that explicitly showed the direction of self-motion. The human visual time delay increased with approximately 150 ms for the optic flow conditions, relative to explicit presentations. Vestibular motion, providing higher order information on the direction of self-motion, allowed subjects to partially compensate for this visual perception delay, improving performance. Parameter estimates of the operator control model show that, with vestibular motion, the visual feedback becomes stronger, indicating that operators are more confident to act on optic flow information when congruent vestibular motion cues are present.

  2. Direct chemical vapour deposited grapheme synthesis on silicon oxide by controlled copper dewettting

    NARCIS (Netherlands)

    van den Beld, Wesley Theodorus Eduardus; van den Berg, Albert; Eijkel, Jan C.T.

    2015-01-01

    In this paper we present a novel method for direct uniform graphene synthesis onto silicon oxide in a controlled manner. On a grooved silicon oxide wafer is copper deposited under a slight angle and subsequently the substrate is treated by a typical graphene synthesis process. During this process

  3. State University of New York Research Foundation: Controls over Direct Costs. Report 93-S-64.

    Science.gov (United States)

    New York State Office of the Comptroller, Albany. Div. of Management Audit.

    An evaluation was done of the State University of New York (SUNY) Research Foundation's controls over direct expenditures for research and sponsored activities. The Foundation is a private, non-profit educational corporation established to expand the educational mission of SUNY through fund raising, administration of gifts and grants, and…

  4. Self-directed learning skills in air-traffic control training; An eye-tracking approach

    NARCIS (Netherlands)

    Van Meeuwen, Ludo; Brand-Gruwel, Saskia; Van Merriënboer, Jeroen; Bock, Jeano; Kirschner, Paul A.

    2011-01-01

    Van Meeuwen, L. W., Brand-Gruwel, S., De Bock, J. J. P. R., Kirschner, P. A., & Van Merriënboer, J. J. G. (2010, September). Self-directed Learning Skills in Air-traffic Control Training; An Eye-tracking Approach. Paper presented at the European Association for Aviation Psychology, Budapest.

  5. Personalisation of Adult Social Care: Self-Directed Support and the Choice and Control Agenda

    Science.gov (United States)

    Kendall, Sophie; Cameron, Ailsa

    2014-01-01

    In 2007, "self-directed support" was introduced in adult social care in England to establish choice and control--in the assessment process itself and over service provision--for "all" service users. The personalisation agenda is underpinned by a range of ideologies, particularly a civil rights empowerment approach and…

  6. Tracer Gas Technique Versus a Control Box Method for Estimating Direct Capture Efficiency of Exhaust Systems

    DEFF Research Database (Denmark)

    Madsen, U.; Aubertin, G.; Breum, N. O.;

    Numerical modelling of direct capture efficiency of a local exhaust is used to compare the tracer gas technique of a proposed CEN standard against a more consistent approach based on an imaginary control box. It is concluded that the tracer gas technique is useful for field applications....

  7. Direct chemical vapour deposited grapheme synthesis on silicon oxide by controlled copper dewettting

    NARCIS (Netherlands)

    Beld, van den Wesley T.E.; Berg, van den Albert; Eijkel, Jan C.T.

    2015-01-01

    In this paper we present a novel method for direct uniform graphene synthesis onto silicon oxide in a controlled manner. On a grooved silicon oxide wafer is copper deposited under a slight angle and subsequently the substrate is treated by a typical graphene synthesis process. During this process di

  8. Control of roll and pitch motion during multi-directional balance perturbations.

    NARCIS (Netherlands)

    Kung, U.M.; Horlings, C.G.; Honegger, F.; Duysens, J.E.J.; Allum, J.H.J.

    2009-01-01

    Does the central nervous system (CNS) independently control roll and pitch movements of the human body during balance corrections? To help provide an answer to this question, we perturbed the balance of 16 young healthy subjects using multi-directional rotations of the support surface. All rotations

  9. Self-directed learning skills in air-traffic control; A cued retrospective reporting study

    NARCIS (Netherlands)

    Van Meeuwen, Ludo; Brand-Gruwel, Saskia; Van Merriënboer, Jeroen; Kirschner, Paul A.; De Bock, Jeano

    2011-01-01

    Van Meeuwen, L. W., Brand-Gruwel, S., Van Merriënboer, J. J. G., Kirschner, P. A., & De Bock, J. J. P. R. (2010, May). Self-directed learning skills in air-traffic control; A cued retrospective reporting study. Presented at the Scandinavian Workshop on Applied Eye-tracking. Lund, Sweden.

  10. A temperature control method for shortening thermal cycling time to achieve rapid polymerase chain reaction (PCR) in a disposable polymer microfluidic device

    DEFF Research Database (Denmark)

    Bu, Minqiang; Perch-Nielsen, Ivan R.; Sørensen, Karen Skotte

    2013-01-01

    We present a temperature control method capable of effectively shortening the thermal cycling time of polymerase chain reaction (PCR) in a disposable polymer microfluidic device with an external heater and a temperature sensor. The method employs optimized temperature overshooting and undershooting...

  11. Quality control in cross-border agro-based supply chains: Modes of regulation in coffee, cocoa, bananas, palm oil, timber and aquaculture.

    NARCIS (Netherlands)

    Vellema, S.R.; Valk, van der O.M.C.

    2006-01-01

    This report describes the regulation and control of quality of product and process in a selection of cross-border agro-based supply chains. The factual presentation reveals the specific nature of regulation in a product group. It also provides a basis for comparing the modes of regulation and inform

  12. A new approach to e-commerce customs control in China: Integrated supply chain - A practical application towards large-scale data pipeline implementation

    NARCIS (Netherlands)

    R. Hu (Rong); Yao-Hua Tan (Yao Hua); F. Heijmann (Frank)

    2016-01-01

    textabstractDevelopments in e-commerce are presenting new challenges in customs control and China's customs agency is developing a new approach to how it addresses these challenges. China Customs has adopted an integrated supply chain approach to secure international trade lanes and to facilitate le

  13. Quality control in cross-border agro-based supply chains: Modes of regulation in coffee, cocoa, bananas, palm oil, timber and aquaculture.

    NARCIS (Netherlands)

    Vellema, S.R.; Valk, van der O.M.C.

    2006-01-01

    This report describes the regulation and control of quality of product and process in a selection of cross-border agro-based supply chains. The factual presentation reveals the specific nature of regulation in a product group. It also provides a basis for comparing the modes of regulation and

  14. Optimization and Validation of a Real Time Reverse Transcriptase Polymerase Chain Reaction with RNA Internal Control to Detect Rubella RNA

    Directory of Open Access Journals (Sweden)

    Winny Xie

    2013-12-01

    Full Text Available BACKGROUND: According to a report from WHO, cases of rubella infection in Indonesia has increased up to 10-fold from 2007 to 2011. Despite no data of congenital rubella syndrome in the report, there are approximately 45,000 cases of babies born with heart failure and 0.1-0.3% live births with congenital deafness in Indonesia. Allegedly, rubella infection during pregnancy may play a role in this condition. This study aimed to optimize and validate a real-time reverse transcriptase polymerase chain reaction (RT-qPCR method to detect rubella virus RNA as an aid for the diagnosis of congenital rubella infection. METHODS: Method optimization was conducted using nucleic acids extracted from Trimovax Merieux vaccine with the High Pure Viral Nucleic Acid Kit. One step RT-qPCR was performed with Quantifast Multiplex RTPCR+R Kit. Target synthetic DNA was designed and used to determine the sensitivity of the method. RNA internal control was synthesized to control the process of extraction and amplification. RESULTS: The analytical sensitivity of this method was as low as 5 copies target synthetic DNA/μl. The mean Coefficient of Variation (CV % of the critical threshold (Ct obtained were 2.71%, 1.20%, 1.62%, and 1.59% for within run, between run, between kit lots, and between operators, respectively. Recovery of the target synthetic DNA from amniotic fluid was 100.51% (by the log copies/μl at the concentration of 1,000,000 copies/μl. CONCLUSIONS: RT-qPCR is successfully used for the detection of rubella virus RNA in vaccine and synthetic nucleic acid. With its high sensitivity, good precision and recovery, this method offers a means to improve the diagnosis of congenital rubella infection in developing countries like Indonesia. KEYWORDS: congenital rubella, RT-qPCR, prenatal diagnosis, amniotic fluid.

  15. Environmental and Climatic Control on the Occurrence and Abundance of Long Chain Alkenones in Lakes of the Interior United States

    Science.gov (United States)

    Toney, J. L.; Fritz, S.; Baker, P. A.; Grimm, E. C.; Nyren, P.; Theroux, S.; Huang, Y.

    2008-12-01

    Long chain alkenones are a class of temperature sensitive lipids with great potential for quantitative paleoclimatic reconstructions from continental locations. We have surveyed 57 lacustrine core-top sediments in the in the interior US for alkenones in order to constrain the environmental conditions that control the occurrence of alkenone-producing haptophytes in lakes and determine the possibility of using lacustrine alkenones to reconstruct temperature. Thirteen out of the 57 sites surveyed contain alkenones in surface sediments. Three of the 13 lakes contain abundant C37:4 alkenones as commonly found in lake sediments, whereas the rest of the lakes show a surprising absence of C37:4 alkenone. 18S Ribosomal DNA sequences amplified from the C37:4 containing lakes suggests the alkenone-producing haptophyte falls amongst the Isochrysis spp. and showcases a strong similarity to a haptophyte derived from Ace Lake, Antarctica, whereas the other lakes probably contain a different species. We also find cold, oligosaline conditions with high concentrations of sodium and sulfate promote high concentrations of alkenones. Salinity serves as a threshold control on the C37:4 alkenone such that C37:4 is only found in lakes with salinity above 2.74 g / L. Sites with the C37:4 alkenone plot along a previously published calibration. We also create a new alkenone temperature calibration using water column filters from Lake George spanning a temperature range of 8 to 24 degrees C. In addition, we obtain an alkenone- inferred temperature record from Lake George, ND for the instrumental period and a high-resolution (~20 year resolution) Holocene length record from Brush Lake, MT, in order to further assess the applicability of lacustrine alkenones for continental paleo-temperature reconstructions.

  16. High-performance adaptive intelligent Direct Torque Control schemes for induction motor drives

    Directory of Open Access Journals (Sweden)

    Vasudevan M.

    2005-01-01

    Full Text Available This paper presents a detailed comparison between viable adaptive intelligent torque control strategies of induction motor, emphasizing advantages and disadvantages. The scope of this paper is to choose an adaptive intelligent controller for induction motor drive proposed for high performance applications. Induction motors are characterized by complex, highly non-linear, time varying dynamics, inaccessibility of some states and output for measurements and hence can be considered as a challenging engineering problem. The advent of torque and flux control techniques have partially solved induction motor control problems, because they are sensitive to drive parameter variations and performance may deteriorate if conventional controllers are used. Intelligent controllers are considered as potential candidates for such an application. In this paper, the performance of the various sensor less intelligent Direct Torque Control (DTC techniques of Induction motor such as neural network, fuzzy and genetic algorithm based torque controllers are evaluated. Adaptive intelligent techniques are applied to achieve high performance decoupled flux and torque control. This paper contributes: i Development of Neural network algorithm for state selection in DTC; ii Development of new algorithm for state selection using Genetic algorithm principle; and iii Development of Fuzzy based DTC. Simulations have been performed using the trained state selector neural network instead of conventional DTC and Fuzzy controller instead of conventional DTC controller. The results show agreement with those of the conventional DTC.

  17. Direct Adaptive Soft Computing Neural Control of a Continuous Bioprocess via Second Order Learning

    Science.gov (United States)

    Baruch, Ieroham; Mariaca-Gaspar, Carlos-Roman; Barrera-Cortes, Josefina

    This paper proposes a new Kalman Filter Recurrent Neural Network (KFRNN) topology and a recursive Levenberg-Marquardt (L-M) second order learning algorithm capable to estimate parameters and states of highly nonlinear bioprocess in a noisy environment. The proposed KFRNN identifier, learned by the Backpropagation and L-M learning algorithm, was incorporated in a direct adaptive neural control scheme. The proposed control scheme was applied for real-time soft computing identification and control of a continuous stirred tank bioreactor model, where fast convergence, noise filtering and low mean squared error of reference tracking were achieved.

  18. Semiconductor Light-Controlled Instrument Transducer with Direct PWM Output for Automatic Control Systems

    Directory of Open Access Journals (Sweden)

    O. Malik

    2013-02-01

    The internal PWM signal conversion occurs by the use of non-equilibrium physical processes in the semiconductor substrate of the MOS-C. The 10-20 V amplitude limited square PWM output signal is obtained by the amplification of the sensor signal with a standard 60 dB transimpedance amplifier. The amplified output signal presents positive and negative PWM waveforms that can be easily separated using diodes. The duty of the positive part is proportional to the light intensity, whereas the negative part is inversely proportional to the intensity. The frequency operating range of this proposed instrument varies from 1 Hz to a few kilohertz. The duty cycle of the PWM output signal varies from 2% to 98% when the incident light intensity varies in the microwatts range. These new transducers or sensors could be useful for automatic control, robotic applications, dimmer systems, feedback electronic systems, and non-contact optical position sensing for nulling and centering measurements.

  19. Direct power control of DFIG wind turbine systems based on an intelligent proportional-integral sliding mode control.

    Science.gov (United States)

    Li, Shanzhi; Wang, Haoping; Tian, Yang; Aitouch, Abdel; Klein, John

    2016-09-01

    This paper presents an intelligent proportional-integral sliding mode control (iPISMC) for direct power control of variable speed-constant frequency wind turbine system. This approach deals with optimal power production (in the maximum power point tracking sense) under several disturbance factors such as turbulent wind. This controller is made of two sub-components: (i) an intelligent proportional-integral module for online disturbance compensation and (ii) a sliding mode module for circumventing disturbance estimation errors. This iPISMC method has been tested on FAST/Simulink platform of a 5MW wind turbine system. The obtained results demonstrate that the proposed iPISMC method outperforms the classical PI and intelligent proportional-integral control (iPI) in terms of both active power and response time.

  20. Adaptive fuzzy output-feedback controller design for nonlinear time-delay systems with unknown control direction.

    Science.gov (United States)

    Hua, Chang-Chun; Wang, Qing-Guo; Guan, Xin-Ping

    2009-04-01

    In this paper, the robust-control problem is investigated for a class of uncertain nonlinear time-delay systems via dynamic output-feedback approach. The considered system is in the strict-feedback form with unknown control direction. A full-order observer is constructed with the gains computed via linear matrix inequality at first. Then, with the bounds of uncertain functions known, we design the dynamic output-feedback controller such that the closed-loop system is asymptotically stable. Furthermore, when the bound functions of uncertainties are not available, the adaptive fuzzy-logic system is employed to approximate the uncertain function, and the corresponding output-feedback controller is designed. It is shown that the resulting closed-loop system is stable in the sense of semiglobal uniform ultimate boundedness. Finally, simulations are done to verify the feasibility and effectiveness of the obtained theoretical results.

  1. Improved direct power control of a grid-connected voltage source converter during network unbalance

    Institute of Scientific and Technical Information of China (English)

    Peng ZHOU; Wei ZHANG; Yi-kang HE; Rong ZENG

    2010-01-01

    This paper deals with an improved direct power control(DPC)strategy for the pulse width modulation(PWM)voltage source converter(VSC)under unbalanced grid voltage conditions.In order to provide enhanced control performance for the VSC,the resonant controllers tuned at the double grid frequency are applied in the DPC design to eliminate the power pulsations and dc link voltage ripples produced by the transient unbalanced grid faults.In this way,the output power and dc link voltage of the VSC can be directly regulated without positive and negative sequential decomposition.As a result,and as has been verified by experiment,the proposed method can provide fast dynamic response with easy implementation.

  2. An optimal control method for maximizing the efficiency of direct drive ocean wave energy extraction system.

    Science.gov (United States)

    Chen, Zhongxian; Yu, Haitao; Wen, Cheng

    2014-01-01

    The goal of direct drive ocean wave energy extraction system is to convert ocean wave energy into electricity. The problem explored in this paper is the design and optimal control for the direct drive ocean wave energy extraction system. An optimal control method based on internal model proportion integration differentiation (IM-PID) is proposed in this paper though most of ocean wave energy extraction systems are optimized by the structure, weight, and material. With this control method, the heavy speed of outer heavy buoy of the energy extraction system is in resonance with incident wave, and the system efficiency is largely improved. Validity of the proposed optimal control method is verified in both regular and irregular ocean waves, and it is shown that IM-PID control method is optimal in that it maximizes the energy conversion efficiency. In addition, the anti-interference ability of IM-PID control method has been assessed, and the results show that the IM-PID control method has good robustness, high precision, and strong anti-interference ability.

  3. Decentralized attitude synchronization tracking control for multiple spacecraft under directed communication topology

    Institute of Scientific and Technical Information of China (English)

    Zheng Zhong; Xu Ying; Zhang Lisong; Song Shenmin

    2016-01-01

    This paper studies the attitude synchronization tracking control of spacecraft formation flying with a directed communication topology and presents three different controllers. By introduc-ing a novel error variable associated with rotation matrix, a decentralized attitude synchronization controller, which could obtain almost global asymptotical stability of the closed-loop system, is developed. Then, considering model uncertainties and unknown external disturbances, we propose a robust adaptive attitude synchronization controller by designing adaptive laws to estimate the unknown parameters. After that, the third controller is proposed by extending this method to the case of time-varying communication delays via Lyapunov–Krasovskii analysis. The distinctive feature of this work is to address attitude coordinated control with model uncertainties, unknown disturbances and time-varying delays in a decentralized framework, with a strongly connected direc-ted information flow. It is shown that tracking and synchronization of an arbitrary desired attitude can be achieved when the stability condition is satisfied. Simulation results are provided to demon-strate the effectiveness of the proposed control schemes.

  4. A semi-analytical direct optimal control solution for strongly excited and dissipative Hamiltonian systems

    Science.gov (United States)

    Ying, Zu-guang; Luo, Yin-miao; Zhu, Wei-qiu; Ni, Yi-qing; Ko, Jan-ming

    2012-04-01

    A semi-analytical direct optimal control solution for strongly excited and dissipative Hamiltonian systems is proposed based on the extended Hamiltonian principle, the Hamilton-Jacobi-Bellman (HJB) equation and its variational integral equation, and the finite time element approximation. The differential extended Hamiltonian equations for structural vibration systems are replaced by the variational integral equation, which can preserve intrinsic system structure. The optimal control law dependent on the value function is determined by the HJB equation so as to satisfy the overall optimality principle. The partial differential equation for the value function is converted into the integral equation with variational weighting. Then the successive solution of optimal control with system state is designed. The two variational integral equations are applied to sequential time elements and transformed into the algebraic equations by using the finite time element approximation. The direct optimal control on each time element is obtained respectively by solving the algebraic equations, which is unconstrained by the system state observed. The proposed control algorithm is applicable to linear and nonlinear systems with the quadratic performance index, and takes into account the effects of external excitations measured on control. Numerical examples are given to illustrate the optimal control effectiveness.

  5. Output-feedback adaptive neural control for stochastic nonlinear time-varying delay systems with unknown control directions.

    Science.gov (United States)

    Li, Tieshan; Li, Zifu; Wang, Dan; Chen, C L Philip

    2015-06-01

    This paper presents an adaptive output-feedback neural network (NN) control scheme for a class of stochastic nonlinear time-varying delay systems with unknown control directions. To make the controller design feasible, the unknown control coefficients are grouped together and the original system is transformed into a new system using a linear state transformation technique. Then, the Nussbaum function technique is incorporated into the backstepping recursive design technique to solve the problem of unknown control directions. Furthermore, under the assumption that the time-varying delays exist in the system output, only one NN is employed to compensate for all unknown nonlinear terms depending on the delayed output. Moreover, by estimating the maximum of NN parameters instead of the parameters themselves, the NN parameters to be estimated are greatly decreased and the online learning time is also dramatically decreased. It is shown that all the signals of the closed-loop system are bounded in probability. The effectiveness of the proposed scheme is demonstrated by the simulation results.

  6. Parameters optimization using experimental design for headspace solid phase micro-extraction analysis of short-chain chlorinated paraffins in waters under the European water framework directive.

    Science.gov (United States)

    Gandolfi, F; Malleret, L; Sergent, M; Doumenq, P

    2015-08-07

    The water framework directives (WFD 2000/60/EC and 2013/39/EU) force European countries to monitor the quality of their aquatic environment. Among the priority hazardous substances targeted by the WFD, short chain chlorinated paraffins C10-C13 (SCCPs), still represent an analytical challenge, because few laboratories are nowadays able to analyze them. Moreover, an annual average quality standards as low as 0.4μgL(-1) was set for SCCPs in surface water. Therefore, to test for compliance, the implementation of sensitive and reliable analysis method of SCCPs in water are required. The aim of this work was to address this issue by evaluating automated solid phase micro-extraction (SPME) combined on line with gas chromatography-electron capture negative ionization mass spectrometry (GC/ECNI-MS). Fiber polymer, extraction mode, ionic strength, extraction temperature and time were the most significant thermodynamic and kinetic parameters studied. To determine the suitable factors working ranges, the study of the extraction conditions was first carried out by using a classical one factor-at-a-time approach. Then a mixed level factorial 3×2(3) design was performed, in order to give rise to the most influent parameters and to estimate potential interactions effects between them. The most influent factors, i.e. extraction temperature and duration, were optimized by using a second experimental design, in order to maximize the chromatographic response. At the close of the study, a method involving headspace SPME (HS-SPME) coupled to GC/ECNI-MS is proposed. The optimum extraction conditions were sample temperature 90°C, extraction time 80min, with the PDMS 100μm fiber and desorption at 250°C during 2min. Linear response from 0.2ngmL(-1) to 10ngmL(-1) with r(2)=0.99 and limits of detection and quantification, respectively of 4pgmL(-1) and 120pgmL(-1) in MilliQ water, were achieved. The method proved to be applicable in different types of waters and show key advantages, such

  7. Falling chains

    Science.gov (United States)

    Wong, Chun Wa; Yasui, Kosuke

    2006-06-01

    The one-dimensional fall of a folded chain with one end suspended from a rigid support and a chain falling from a resting heap on a table is studied. Because their Lagrangians contain no explicit time dependence, the falling chains are conservative systems. Their equations of motion are shown to contain a term that enforces energy conservation when masses are transferred between subchains. We show that Cayley's 1857 energy nonconserving solution for a chain falling from a resting heap is incorrect because it neglects the energy gained when a link leaves a subchain. The maximum chain tension measured by Calkin and March for the falling folded chain is given a simple if rough interpretation. Other aspects of the falling folded chain are briefly discussed.

  8. Position Control of an Over‐Actuated Direct Hydraulic Cylinder Drive

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Grønkjær, Morten; Pedersen, Henrik Clemmensen

    2017-01-01

    This paper considers the analysis and control strategy for a novel direct hydraulic cylinder drive, that is overactuated in the sense that it has more inputs than sensible outputs. Efforts to overcome the inherent loss of energy due to th+rottling in valve driven hydraulic drives are many...... the ability to bleed off flow from the transmission lines to achieve reasonable pressure levels. This design renders the drive over-actuated as the line pressures and the cylinder piston motion cannot be controlled independently, due to the pressure difference being motion generating. In order to achieve...... satisfactory performance of this drive, a state coupling analysis is presented along with a control strategy based on state decoupling synthesized from input-output transformations. This includes control schemes for the transformed system. The proposed control strategy is experimentally verified on a drive...

  9. A Novel Maximum Power Point Tracking Control for Permanent Magnet Direct Drive Wind Energy Conversion Systems

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2012-05-01

    Full Text Available This paper proposes a novel optimal current given (OCG maximum power point tracking (MPPT control strategy based on the theory of power feedback and hill climb searching (HCS for a permanent magnet direct drive wind energy conversion system (WECS. The presented strategy not only has the advantages of not needing the wind speed and wind turbine characteristics of the traditional HCS method, but it also improves the stability and accuracy of MPPT by estimating the exact loss torque. The OCG MPPT control strategy is first carried out by simulation, then an experimental platform based on the dSPACE1103 controller is built and a 5.5 kW permanent magnet synchronous generator (PMSG is tested. Furthermore, the proposed method is compared experimentally with the traditional optimum tip speed ratio (TSR MPPT control. The experiments verify the effectiveness of the proposed OCG MPPT strategy and demonstrate its better performance than the traditional TSR MPPT control.

  10. Direct battery-driven solar LED lighting using constant-power control

    KAUST Repository

    Huang, Bin-Juine

    2012-11-01

    A direct battery-driven LED lighting technique using constant-power control is proposed in the present study. A system dynamics model of LED luminaire was derived and used in the design of the feedback constant-power control system. The test result has shown that the power of 18. W and 100. W LED luminaires can be controlled accurately with error at 2-5%. A solar LED street lighting system using constant-power and dimming control was designed and built for field test in a remote area. The long-term performance was satisfactory and no any failure since the installation. Since no high-power capacitor is used in the present constant-power control circuit, a longer lifetime is expected. © 2012 Elsevier Ltd.

  11. Direct selective laser sintering of high performance metals: Machine design, process development and process control

    Science.gov (United States)

    Das, Suman

    1998-11-01

    development of machine, processing and control technologies during this research effort enabled successful production of a number of integrally canned test specimens in Alloy 625 (InconelRTM 625 superalloy) and Ti-6Al-4V alloy. The overall goal of this research was to develop direct SLS of metals armed with a fundamental understanding of the underlying physics. The knowledge gained from experimental and analytical work is essential for three key objectives: machine design, process development and process control. (Abstract shortened by UMI.)

  12. Chain Sprockets Manufacturing, on Vertical Machining Center GDV400PM1F4 Updated with Numerical Control NCT®2000M

    Directory of Open Access Journals (Sweden)

    Ioan Francisc Fekete

    2013-06-01

    Full Text Available The paper content comprise a few aspects regarding processing of chain sprockets on vertical processing center GDV400PM1F4 updated by changing the original equipment CNC-2S42-65 (1Я3.035.090 with NCT®2000M, which includes in short characteristics of two CNC, the old and the new one, the constructive elements of chain sprockets processed, enunciation of mains stages of manufacturing process adopted. The aim is to manufacture chain sprockets with classic tools, bypassing the need to design and build a sprocket hob in accordance with specified chain sprockets geometry, processing is performed on a machine which technological parameters have been improved.

  13. Stackelberg Decision in a Supply Chain Based on Controllable Lead Time%基于可控交货期的供应链Stackelberg决策研究

    Institute of Scientific and Technical Information of China (English)

    何景师; 戴航; 张智勇

    2012-01-01

    Time is a bottle-neck element of the supply chain agile operation in practice. In Stackelberg model of a supply chain between the upstream and downstream stages, a supply chain model based on controllable lead time was constructed. Through calculation of the supply chain model, this paper analyzed the influence lead time crashing cost sharing and the delay penalty impact on the lead time, order quantity and supply cost. It is pointed out that optimal lead time and order quantity decision-making existed in a supply chain, which could get the supply chain optimal decision. The result from an example revealed that the model could optimize the decision making of the supply chain upstream and downstream enterprises. Therefore, it provided a piece of scientific evidence for the planners to develop effective solutions.%时间已成为供应链敏捷运作的瓶颈要素。在供应商和分销商供应链上下游的Stackelberg模型中,本文构建了基于可变交货期的供应链决策模型。通过对供应链决策模型的计算,分析了考虑压缩交货期费用分担和延迟交货惩罚对交货期、订货量、供应链成本的影响,认为在供应商和分销商中存在最优的交货期和订货批量,可得到供应链最优的决策。算例的计算结果表明,该模型可以优化供应链上下游企业的决策,从而为规划决策者提供科学依据。

  14. The postrhinal cortex is not necessary for landmark control in rat head direction cells.

    Science.gov (United States)

    Peck, James R; Taube, Jeffery S

    2017-02-01

    The rodent postrhinal cortex (POR), homologous to primate areas TH/TF and the human 'parahippocampal place area', has been implicated in processing visual landmark and contextual information about the environment. Head direction (HD) cells are neurons that encode allocentric head direction, independent of the animal's location or behavior, and are influenced by manipulations of visual landmarks. The present study determined whether the POR plays a role in processing environmental information within the HD circuit. Experiment 1 tested the role of the POR in processing visual landmark cues in the HD system during manipulation of a visual cue. HD cells from POR lesioned animals had similar firing properties, shifted their preferred firing direction following rotation of a salient visual cue, and in darkness had preferred firing directions that drifted at the same rate as controls. Experiment 2 tested the PORs involvement in contextual fear conditioning, where the animal learns to associate a shock with both a tone and a context in which the shock was given. In agreement with previous studies, POR lesioned animals were able to learn the tone-shock pairing, but displayed less freezing relative to controls when reintroduced into the environment previously paired with a shock. Therefore, HD cells from POR lesioned animals, with demonstrated impairments in contextual fear conditioning, were able to use a visual landmark to control their preferred direction. Thus, despite its importance in processing visual landmark information in primates, the POR in rats does not appear to play a pivotal role in controlling visual landmark information in the HD system. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  15. Enhanced Cu-to-Cu direct bonding by controlling surface physical properties

    Science.gov (United States)

    Chiang, Po-Hao; Liang, Sin-Yong; Song, Jenn-Ming; Huang, Shang-Kun; Chiu, Ying-Ta; Hung, Chih-Pin

    2017-03-01

    Cu-to-Cu direct bonding is one of the key technologies for three-dimensional (3D) chip stacking. This research proposes a new concept to enhance Cu-to-Cu direct bonding through the control of surface physical properties. A linear relationship between bonding strength and the H/\\sqrt{R} value of the bonding face (H: subsurface hardness, R: surface roughness) was found. Low vacuum air plasma and thermal annealing were adopted to adjust the surface physical conditions. Instead of surface activation, an acceleration in copper atom diffusion due to plasma-induced compressive stress accounts for the improvement in bonding strength.

  16. Rigid Body Attitude Control Based on a Manifold Representation of Direction Cosine Matrices

    Science.gov (United States)

    Nakath, David; Clemens, Joachim; Rachuy, Carsten

    2017-01-01

    Autonomous systems typically actively observe certain aspects of their surroundings, which makes them dependent on a suitable controller. However, building an attitude controller for three degrees of freedom is a challenging task, mainly due to singularities in the different parametrizations of the three dimensional rotation group SO(3). Thus, we propose an attitude controller based on a manifold representation of direction cosine matrices: In state space, the attitude is globally and uniquely represented as a direction cosine matrix R ∈ SO(3). However, differences in the state space, i.e., the attitude errors, are exposed to the controller in the vector space ℝ3. This is achieved by an operator, which integrates the matrix logarithm mapping from SO(3) to so(3) and the map from so(3) to ℝ3. Based on this representation, we derive a proportional and derivative feedback controller, whose output has an upper bound to prevent actuator saturation. Additionally, the feedback is preprocessed by a particle filter to account for measurement and state transition noise. We evaluate our approach in a simulator in three different spacecraft maneuver scenarios: (i) stabilizing, (ii) rest-to-rest, and (iii) nadir-pointing. The controller exhibits stable behavior from initial attitudes near and far from the setpoint. Furthermore, it is able to stabilize a spacecraft and can be used for nadir-pointing maneuvers.

  17. Design and Control of Disc PMSM Directly Driven Wheel for Tramcar

    Directory of Open Access Journals (Sweden)

    Zhenggang Lu

    2014-01-01

    Full Text Available A new solution of disc permanent magnet synchronous motor (PMSM directly driven wheel is proposed as a design customized for low floor tramcar. And the motors are overhung on the bogie frame to make the weight as the sprung mass. Meanwhile, the universal coupling is installed between the driven wheel and motor shaft. A disc PMSM is designed according to the demand of traction power. The motors are not only traction and steering actuators but are also regarded as sensors to obtain the rotational speed of motor directly driven wheel. Through the obtained data, an active sensorless steering control method is applied using the relative rotational speed between wheel pair. Finally, models combined with motor control and steering control are set up to check the control strategies. The simulation results indicate that sliding mode observer has the functionality of estimating the rotating speed with high accuracy for active steering control. The tramcar exhibits self-steering and better negotiation under active steering control. The tramcar is under a better condition of running along the central line of track with small attack angle and low power consumption while passing the shape curve track.

  18. Control performances of a piezoactuator direct drive valve system at high temperatures with thermal insulation

    Science.gov (United States)

    Han, Yung-Min; Han, Chulhee; Kim, Wan Ho; Seong, Ho Yong; Choi, Seung-Bok

    2016-09-01

    This technical note presents control performances of a piezoactuator direct drive valve (PDDV) operated at high temperature environment. After briefly discussing operating principle and mechanical dimensions of the proposed PDDV, an appropriate size of the PDDV is manufactured. As a first step, the temperature effect on the valve performance is experimentally investigated by measuring the spool displacement at various temperatures. Subsequently, the PDDV is thermally insulated using aerogel and installed in a large-size heat chamber in which the pneumatic-hydraulic cylinders and sensors are equipped. A proportional-integral-derivative feedback controller is then designed and implemented to control the spool displacement of the valve system. In this work, the spool displacement is chosen as a control variable since it is directly related to the flow rate of the valve system. Three different sinusoidal displacements with different frequencies of 1, 10 and 50 Hz are used as reference spool displacement and tracking controls are undertaken up to 150 °C. It is shown that the proposed PDDV with the thermal insulation can provide favorable control responses without significant tracking errors at high temperatures.

  19. Executive control of stimulus-driven and goal-directed attention in visual working memory.

    Science.gov (United States)

    Hu, Yanmei; Allen, Richard J; Baddeley, Alan D; Hitch, Graham J

    2016-10-01

    We examined the role of executive control in stimulus-driven and goal-directed attention in visual working memory using probed recall of a series of objects, a task that allows study of the dynamics of storage through analysis of serial position data. Experiment 1 examined whether executive control underlies goal-directed prioritization of certain items within the sequence. Instructing participants to prioritize either the first or final item resulted in improved recall for these items, and an increase in concurrent task difficulty reduced or abolished these gains, consistent with their dependence on executive control. Experiment 2 examined whether executive control is also involved in the disruption caused by a post-series visual distractor (suffix). A demanding concurrent task disrupted memory for all items except the most recent, whereas a suffix disrupted only the most recent items. There was no interaction when concurrent load and suffix were combined, suggesting that deploying selective attention to ignore the distractor did not draw upon executive resources. A final experiment replicated the independent interfering effects of suffix and concurrent load while ruling out possible artifacts. We discuss the results in terms of a domain-general episodic buffer in which information is retained in a transient, limited capacity privileged state, influenced by both stimulus-driven and goal-directed processes. The privileged state contains the most recent environmental input together with goal-relevant representations being actively maintained using executive resources.

  20. Joint-space Lyapunov-based direct adaptive control of a kinematically redundant telerobot manipulator

    Science.gov (United States)

    Nguyen, Charles C.; Zhou, Zhen-Lei; Mosier, Gary E.

    1993-01-01

    This paper presents the design of a joint-space adaptive control scheme for controlling the slave arm motion of a dual-arm telerobot system developed at Goddard Space Flight Center (GSFC) to study telerobotic operations in space. Each slave arm of the dual-arm system is a kinematically redundant manipulator with seven degrees of freedom (DOF). Using the concept of model reference adaptive control (MRAC) and Liupunov direct method, we derive an adaptation algorithm that adjusts the PD controller gains of the control scheme. The development of the adaptive control scheme assumes that the slave arm motion is non-compliant and slowly varying. The implementation of the derived control scheme does not require the computation of manipulator dynamics which makes the control scheme sufficiently fast for real-time applications. Computer simulation study performed for the 7-DOF slave arm shows that the developed control scheme can efficiently adapt to sudden change in payload while tracking various test trajectories such as ramp or sinusoids with negligible position errors.