Multimodeling Control via System Balancing

A new approach in multimodeling strategy is proposed. Multimodel strategies in which control agents use different simplified models of the same system are being developed using balancing transformation and the corresponding order reduction concepts. Traditionally, the multimodeling concept was studied using the ideas of multitime scales (singular perturbations) and weak subsystem coupling. For all reduced-order models obtained, a Linear Quadratic Gaussian (LQG) control problem was solved. Different order reduction techniques were compared based on the values of the optimized criteria for the closed-loop case where the full-order balanced model utilizes regulators calculated to be the optimal for various reduced-order models. The results obtained were demonstrated on a real-world example: a multiarea power system consisting of two identical areas, that is, two identical power plants

Circular economy in global firm: A system change perspective to closed loop thinking.

The study aims to investigate how does global firm utilise system change perspective to closed loop thinking for creating circular economy strategy in the energy industry. The study adopted 4 circular economy implementation strategies and 4 circular economy principles from relevant circular economy literature. The theoretical framework is empirically tested utilizing a qualitative single case study research methodology. The primary data was obtained by a purposive sampling technique. 3 semi-structured interviews and 2 webinars were utilised to obtain both primary and secondary data for the empirical analysis. The semi-structured interviews were obtained during the winter of 2022 from Project Manager, Technology Development Manager, and Senior Business Development Manager of the Power to X Project of Wärtsilä Energy Business unit. The overall empirical findings suggest that Wärtsilä recognises the Power to X project as an important reflection to its strategic vision for a carbon neutral smarter society. The empirical data analysis has identified that all the four implementation strategies and principles have been utilised in the Power to X project and especially cleaner production using renewable materials, and zero waste policy have been found to be most effective strategies. Whereas recycling and reduction principles found to be most prominent guiding circular economy principles. Based on the data analysis it is possible to argue that the Power to X project could be a catalyst of system change. The empirical analysis also reveals that Wärtsilä’s Power to X project has ensured implementation of different circular economy strategies by utilising certain measures. Furthermore, beyond the scope of the identified literature, this study contributes to the existing system change perspective literature by adding value co-creation and industry alliances as a new but effective circular economy implementation strategy. However, it is an unexpected empirical finding that recovery principle has no influence for the Power to X project. Based on the comprehensive literature review and empirical findings, the study proposes that system change perspective implementation strategies can assist global firms to achieve a certain principle of circular economy, such as Eco-design as a system change perspective strategy can help a global firm to achieve the circular economy principle of Reduction in its operations, and so forth

Fabrication of Thin Walls with and without Close Loop Control as a Function of Scan Strategy Via Direct Energy Deposition

Direct Energy Deposition (DED) is a technique used to fabricate metallic parts and is a subcategory of metal additive manufacturing. Despite of its vast advantages over traditional manufacturing the deployment at industrial level is still limited due to underlaying concerns of process stability and repeatability. In-situ monitor- ing, therefore, is indispensable while depositing via DED. The present experiment is a step towards enhancing our current understanding of the DED when coupled with a closed loop control system to control melt pool width for deposition of thin- walled structures, and as a function of scan strategy. 316L stainless steel powder was deposited on S235JR substrate. A total of 6 iterations are reported, out of many performed, of which 3 were without the closed loop control. Also, to understand the effect of scan strategy as a function of laser power. Two different scan strategies were employed for understanding of the issue i.e., unidirectional, and bidirectional. Apart from the geometrical consistency of the wall, microhardness, density calcula- tions and microstructure were investigated. The geometric consistency was found to be almost perfect with the bidirectional scan strategy. In case of unidirectional scan strategy, the wall shows a negative slope along the other extreme regardless of the closed loop control system. Dilution zone shows the hardness greater than both the substrate and the wall. The specimens fabricated without the use of closed loop con- trol were found to be denser than their counterparts. This was found to be true also in case of manual reduction of power during each layer

Low power high speed and high accuracy design methodologies for pipeline Analog-to-Digital converters

Different aspects of power optimization of a high-speed, high-accuracy pipeline Analog-to-Digital Converters (ADCs) are considered to satisfy the current and future needs of portable communication devices. First power optimized design strategies for the amplifiers are introduced. Closed form expressions of power w.r.t settling requirements are presented to facilitate a fair comparison and selection of the amplifier structure. Next a new low offset dynamic comparator has been designed. Simulation based sensitivity analysis is performed to demonstrate the robustness of the new comparator with respect to stray capacitances, common mode voltage errors and timing errors. With simplified amplifier power model along with the use of dynamic comparators, a method to optimize the power consumption of a pipeline ADC with kT/C noise constraint is also developed. The total power dependence on capacitor scaling and stage resolution is investigated for a near-optimal solution.;After considering the power requirements of a pipeline ADC, design and statistical modeling of over-range protection requirements is investigated. Closed form statistical expressions for the over-range requirements are developed to assist in the allocation of the error budgets to different pipeline blocks. A new over-range protection algorithm is also developed that relaxes the amplifier design and power requirements.;Finally, two new CMOS Schmitt trigger designs are proposed which can be used as clock inputs for the pipeline ADC. In the new designs, sizing of the feedback inverters is used for independent trip point control. The new designs have also a modest reduction in sensitivity to process variations along with immunity to the kick-back noise without the addition of path delay

Sprinting after having sprinted: Prior high-intensity stochastic cycling impairs the winning strike for gold

Bunch riding in closed circuit cycling courses and some track cycling events are often typified by highly variable power output and a maximal sprint to the finish. How criterium style race demands affect final sprint performance however, is unclear. We studied the effects of 1 h variable power cycling on a subsequent maximal 30 s sprint in the laboratory. Nine well-trained male cyclists/triathletes (O2peak 4.9 ± 0.4 Lmin -1 ; mean ± SD) performed two 1 h cycling trials in a randomized order with either a constant (CON) or variable (VAR) power output matched for mean power output. The VAR protocol comprised intervals of varying intensities (40-135% of maximal aerobic power) and durations (10 to 90 s). A 30 s maximal sprint was performed before and immediately after each 1 h cycling trial. When compared with CON, there was a greater reduction in peak (-5.1 ± 6.1%; mean ± 90% confidence limits) and mean (-5.9 ± 5.2%) power output during the 30 s sprint after the 1 h VAR cycle. Variable power cycling, commonly encountered during criterium and triathlon races can impair an optimal final sprint, potentially compromising race performance. Athletes, coaches, and staff should evaluate training (to improve repeat sprint-ability) and race-day strategies (minimize power variability) to optimize the final sprint

Silicon nitride based devices: lithographic mask roughness mitigation

Lithographic technology has been one of the main upholders to Moore's law in the semiconductor industry for the last decades. The underlying reason that enabled the evolution in semiconductor industry has been a steady silicon wafer printing cost, while being able to dramatically increase the number of nodes that can be printed per chip. Key developments in lithography such as wavelength decreasing, together with performance increase in lens and imaging technology, should be accounted for almost all the reduction of cost per function in integrated circuits technology. In this work, we will be presenting the simulation of two mitigation techniques for the impact of defects introduced by manufacturing processes. Namely, the lithographic mask limited resolution on the geometry of the representative device. These perturbations are a consequence of the lithographic mask limited resolution on the geometry of the representative device. For this purpose, the Beam Propagation and Finite Differences Time Domain methods will be used to simulate a multimode interference structure based on silicon nitride. The structure will be affected by previously mentioned perturbations and we expect results revealing a strong dependence between mask resolution, and imbalance and power loss. Two strategies will be followed concerning the mitigation of power loss and imbalance introduced by the limited resolution of lithographic mask: - Access waveguides tapering; - Adjustable power splitting ratios through the electro-optic effect. Through both strategies we aim to achieve an improvement on device’s performance but, in the latter are expected finer tuning capabilities, being enabled by dynamic compensation of power loss and imbalance when in a closed loop control architecture.info:eu-repo/semantics/publishedVersio

Extensional and Intensional Strategies

This paper is a contribution to the theoretical foundations of strategies. We first present a general definition of abstract strategies which is extensional in the sense that a strategy is defined explicitly as a set of derivations of an abstract reduction system. We then move to a more intensional definition supporting the abstract view but more operational in the sense that it describes a means for determining such a set. We characterize the class of extensional strategies that can be defined intensionally. We also give some hints towards a logical characterization of intensional strategies and propose a few challenging perspectives

Progettazione di macchine ed azionamenti elettrici multifase ad alte prestazioni per applicazioni veicolari

The first part of this thesis has focused on the construction of a twelve-phase asynchronous machine for More Electric Aircraft (MEA) applications. In fact, the aerospace world has found in electrification the way to improve the efficiency, reliability and maintainability of an aircraft. This idea leads to the aircraft a new management and distribution of electrical services. In this way is possible to remove or to reduce the hydraulic, mechanical and pneumatic systems inside the aircraft. The second part of this dissertation is dedicated on the enhancement of the control range of matrix converters (MCs) operating with non-unity input power factor and, at the same time, on the reduction of the switching power losses. The analysis leads to the determination in closed form of a modulation strategy that features a control range, in terms of output voltage and input power factor, that is greater than that of the traditional strategies under the same operating conditions, and a reduction in the switching power losses

New labour and new surveillance: Theoretical and political ramifications of CCTV implementation in the UK

This paper examines the implications of New Labour's approaches to crime and disorder on CCTV implementation. It concentrates on the usage of CCTV as one of the government's many initiatives, which are intended to address crime and disorder, including the fear of crime. In particular, the impact of the 1998 Crime and Disorder Act (CDA) - the cornerstone of this government's approach to crime reduction - on the generation of such strategies is examined. The paper revisits neo-Marxist and Foucauldian analyses of the so-called surveillance society through an appraisal of the complex relationship between structure and agency in the formulation and implementation of anti-crime and disorder strategies. Drawing on fieldwork data the paper considers the activities of practitioners at a local level by focusing on the influence of central government, local communities and 'common sense' thinking based on certain criminological theories. It is argued that a myriad of micro-level operations, obligations, processes, managerial concerns (particularly conflict resolution and resource issues), structures and agency - as well as the indirect influence of central government - shape CCTV policy. Ultimately, the creation of new local policy contexts under the CDA emphasise the need to consider incremental and malleable processes concerning the formulation of CCTV policy. In turn, this allows a re-examination of theoretical accounts of surveillance, and their attendant assumptions of sovereign or disciplinary power