82,540 research outputs found

    Decoupling Level Flow Process Control

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    This Final Year Research Project (FYRP) which entitled "Decoupling Level Flow Process Control" is purposely done to model level and flow process using step test and several set of experiments. Data extracted from the experiments were used to build process models and were simulated in the MATLAB simulink since it is the most appropriate software that can model the process. In order to achieve themain objectives of the project which is to design the decoupler as well as reducing or eliminating the interactions, some calculation involves in the decoupler design stage. As a requirement to the project, some modifications have been done on the equipment involved. From the experimental works, transfer function for level process, flow process and interaction between level and flow process could be obtained, hi the simulation, the trial is divided into three parts namely openloop process, closed loop with PIDprocess and closed loop withPID plus a decoupler process. All the responses were analyzed to compare the effectiveness of the decoupler. Based on the result, it is shown that the level will deviate in a great amount if step change is applied in an open loop process. However, the deviation decreases as the conventional PID controller is introduced in the process. As expected, with the presence of decoupler, the result will bebetter since the decoupler helps the controlled variable to be as close as possible to the desired set point. It is also observed that the performance of the decoupler is better as the flow rate increases as well as at higher gain of the interaction process; in other words, the decoupler works best for strong interaction process. The objectives specified for this project have been successfully achieved within the time constraint given. Further research could be made to observe the performance of the decoupler in the industries

    EMC COMPONENT OPTIMIZATION

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    This disclosure is to design a decoupling capacitor topology of IC’s in PCB layout to effectively resolve EMI problem with minimum number of capacitors. The proposed decoupling capacitor topology is to simulate the twisted wire principle which the common mode ground noise is cancelled at ground when 2 current loops are in opposite direction. Determine the location of decoupling cap, we can control the current direction of the IC’s since the decoupling cap would be the power source to the IC’s. By controlling the current direction of 2 IC’s with opposite direction the common mode ground noise would be cancelled at ground. The proposed topology is to let decoupling capacitor located between the 2 IC’s. The current flow for the 2 IC’s would start from the decoupling cap and end at the ground of IC then back to the ground pin of cap. Current flow direction to first IC would start from the right and the current flow direction to the other IC would start from the left. With the opposite current direction, the magnetic flux of both of IC’s would have been cancelled each other at ground

    Decoupling Control and Soft Sensor Design for an Experimental Platform

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    This chapter presents the design and implementation of a decoupling control strategy for an experimental platform and pilot plant, dedicated to the study of the fouling phenomena which occur in industrial tubes. Initially, a set of tests was done for the identification and validation of FOPDT models suitable to the four processes of the multivariable system: flow-voltage, flow-current, pressure-voltage, and pressure-current. After, the interaction between the inputs and outputs of the system was analyzed by the RGA and RNGA matrices. The static decoupling and decentralized PID controllers tuned by the Ziegler-Nichols and IMC methods were designed. Then, the set point tracking response was simulated and implemented using MATLAB and LabVIEW software, respectively. Finally, the concept of soft sensor was applied to monitor the output variables of the experimental platform, for a better performance of the decoupling control

    A Novel Framework for Software Defined Wireless Body Area Network

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    Software Defined Networking (SDN) has gained huge popularity in replacing traditional network by offering flexible and dynamic network management. It has drawn significant attention of the researchers from both academia and industries. Particularly, incorporating SDN in Wireless Body Area Network (WBAN) applications indicates promising benefits in terms of dealing with challenges like traffic management, authentication, energy efficiency etc. while enhancing administrative control. This paper presents a novel framework for Software Defined WBAN (SDWBAN), which brings the concept of SDN technology into WBAN applications. By decoupling the control plane from data plane and having more programmatic control would assist to overcome the current lacking and challenges of WBAN. Therefore, we provide a conceptual framework for SDWBAN with packet flow model and a future direction of research pertaining to SDWBAN.Comment: Presented on 8th International Conference on Intelligent Systems, Modelling and Simulatio

    Energy-based Stabilization of Network Flows in Multi-machine Power Systems

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    This paper considers the network flow stabilization problem in power systems and adopts an output regulation viewpoint. Building upon the structure of a heterogeneous port-Hamiltonian model, we integrate network aspects and develop a systematic control design procedure. First, the passive output is selected to encode two objectives: consensus in angular velocity and constant excitation current. Second, the non-Euclidean nature of the angle variable reveals the geometry of a suitable target set, which is compact and attractive for the zero dynamics. On this set, circuit-theoretic aspects come into play, giving rise to a network potential function which relates the electrical circuit variables to the machine rotor angles. As it turns out, this energy function is convex in the edge variables, concave in the node variables and, most importantly, can be optimized via an intrinsic gradient flow, with its global minimum corresponding to angle synchronization. The third step consists of explicitly deriving the steady-state-inducing control action by further refining this sequence of control-invariant sets. Analogously to solving the so called regulator equations, we obtain an impedance-based network flow map leading to novel error coordinates and a shifted energy function. The final step amounts to decoupling the rotor current dynamics via feedback-linearziation resulting in a cascade which is used to construct an energy-based controller hierarchically.Comment: In preparation for MTNS 201

    Decoupling in an expanding universe: boundary RG-flow affects initial conditions for inflation

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    We study decoupling in FRW spacetimes, emphasizing a Lagrangian description throughout. To account for the vacuum choice ambiguity in cosmological settings, we introduce an arbitrary boundary action representing the initial conditions. RG flow in these spacetimes naturally affects the boundary interactions. As a consequence the boundary conditions are sensitive to high-energy physics through irrelevant terms in the boundary action. Using scalar field theory as an example, we derive the leading dimension four irrelevant boundary operators. We discuss how the known vacuum choices, e.g. the Bunch-Davies vacuum, appear in the Lagrangian description and square with decoupling. For all choices of boundary conditions encoded by relevant boundary operators, of which the known ones are a subset, backreaction is under control. All, moreover, will generically feel the influence of high-energy physics through irrelevant (dimension four) boundary corrections. Having established a coherent effective field theory framework including the vacuum choice ambiguity, we derive an explicit expression for the power spectrum of inflationary density perturbations including the leading high energy corrections. In accordance with the dimensionality of the leading irrelevant operators, the effect of high energy physics is linearly proportional to the Hubble radius H and the scale of new physics L= 1/M.Comment: LaTeX plus axodraw figures. v2: minor corrections; refs added. JHEP style: 34 pages + 18 pages appendi

    Dynamical decoupling efficiency versus quantum non-Markovianity

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    We investigate the relationship between non-Markovianity and the effectiveness of a dynamical decoupling protocol for qubits undergoing pure dephasing. We consider an exact model in which dephasing arises due to a bosonic environment with a spectral density of the Ohmic class. This is parametrised by an Ohmicity parameter by changing which we can model both Markovian and non-Markovian environments. Interestingly, we find that engineering a non-Markovian environment is detrimental to the efficiency of the dynamical decoupling scheme, leading to a worse coherence preservation. We show that each dynamical decoupling pulse reverses the flow of quantum information and, on this basis, we investigate the connection between dynamical decoupling efficiency and the reservoir spectral density. Finally, in the spirit of reservoir engineering, we investigate the optimum system-reservoir parameters for achieving maximum stationary coherences.Comment: 6 pages, 4 figure

    Decoupling of small-volume pyroclastic flows and related hazards at Merapi volcano, Indonesia

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    The November 1994 eruption at Merapi volcano provided good evidence of decoupling of dome-collapse pyroclastic flows and of large-scale detachment of an ash-cloud surge (ACS) component from the basal block-and-ash flow (BAF). Timing and stratigraphic relationships of the largest 1994 ACS indicate that this escaped from the valleys, travelled well ahead of the BAF, arrived at the termination tens of seconds before it and deposited a discrete ACS deposit beneath the BAF unit. This suggests that the ACS detachment mostly occurred relatively high on the volcano slope, likely at the foot of the proximal cone. Later pyroclastic flow eruptions in January 1997 and July 1998 also showed evidence of ACS detachment, although to a lesser extent, suggesting that ACSs could be a frequent hazard at Merapi volcano. Based on an extensive review of the available literature and on field investigations of historical deposits, we show here that flow decoupling and ACS detachment in the way inferred from the 1994 eruption is a common process at Merapi. The ACS-related destructions outside valleys were frequently reported in the recent past activity of the volcano, i.e. in at least 16 pyroclastic flow eruptions since 1927. Destruction occurred systematically in eruptions where maximum runout of the BAFs was 6.5 km or more, and occurred rarely for BAF runouts of 4.5 km or less. The ACS deposits have been recognized beneath some valley-filling BAF units we attribute to some recent destructive eruptions, i.e. the 1930, 1954, 1961 and 1969 eruptions. Topographic conditions at Merapi volcano favouring ACS detachment include: (a) the high slope (30°) of the proximal cone, leading to high proximal velocities of the pyroclastic flows and thus to the transfer of large amounts of particles into the ash cloud; (b) the strong break in slope at the foot of the proximal cone, where the velocity of the basal BAF is strongly reduced and a major ACS component is thought to form and detach by shearing over the BAF; and (c) the small depth of most valleys in the first kilometres beyond the foot of the cone, which allows minor ACS components to escape from the valleys during travel of the BAF; however, flow decoupling and ACS detachment occur for only some of the numerous pyroclastic flows that follow the same path in a given eruption. This indicates that topography alone cannot lead to flow decoupling. We suggest two factors that control flow decoupling and its extent. The main one is flow volume (and thus flux, as both are correlated in almost instantaneous, dome-collapse events), as suggested by the observed relationship between flow decoupling and the travel distance of the pyroclastic flows. The second factor is the amount of available ash in the flow at its early stage, which influences the mass and thus momentum of the ash cloud. The amount of ash in the pyroclastic flows of Merapi may depend on several factors, among which are (a) the physical and thermal state of the part of the active dome that collapses, and (b) the proportion of older, cold rocks incorporated in the flow, either by undermining of surrounding summit rocks by the current pyroclastic flow activity or by erosion on the upper slopes

    Decoupling and Control of Real and Reactive Power in Grid-Connected Photovoltaic Power System

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    The paper presents a detailed modeling and simulation of different control schemes of the real and reactive power flows in a three-phase voltage source inverter (VSI) interfacing a photovoltaic (PV) generation system to the power grid. Synchronisation of the inverter and grid AC waveforms is achieved using a phase-locked-loop (PLL) circuit. An effective decoupling strategy based on proportional-integral (PI) controllers is designed to eliminate the interaction between the two current components. Finally, the influence of the grid disturbances on the PV system and the influence of the solar energy intermittency on the power grid have been tested. The overall model is implemented in Matlab and Simulink/SimPowerSystems toolboxes. Simulations results with the PV system operating with real irradiance data will be presented to demonstrate the performance of the proposed decoupling and control strategies under different conditions of the power gridNon peer reviewe
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