Comparative analysis of speed decoding algorithms for rotary incremental encoders

Motion control process in modern automation technology and industry requires highly accurate speed information with high bandwidth. Incremental encoders are widely used as rotary feedback position and speed sensors which convert the motor position and speed information into coded electrical pulses. An accurate speed decoding system is therefore needed to extract necessary position and speed information from encoder output, which is further required by the motion control process. The level of accuracy and bandwidth highly depend on resolution of encoder being used as well as data processing technique. In this thesis, different incremental encoders and state-of-the-art speed decoding algorithms are discussed. These algorithms are implemented in Matlab Simulink and a comparative analysis is done based on accuracy, rapid response and wide speed range application. Further, the best choice is made based on this comparison and corresponding speed decoding algorithm is implemented in Xilinx FPGA. Analytical simulation results are presented in this thesis

Arsenic removal by iron based co-precipitation : Mechanisms in groundwater treatment

Arsenic (As) contamination of groundwater with is a wide-scale problem, affecting health of people around the world. The World Health Organization (WHO) guideline for As in drinking water is currently set at 10 µg/L, however recent studies suggest that As can cause a considerable damage to human health even at concentrations lower than the WHO guideline. As a result, several drinking water companies are making efforts to reduce As concentrations in drinking water to very low concentrations, below 1 µg/L.  Co-precipitation of As with iron(III)(oxyhydr)oxides [Fe(III)(oxyhydr)oxides] is a widely used As removal method in groundwater treatment. Fe(III)(oxyhydr)oxides are produced in an As contaminated water, typically by oxidation of naturally occurring ferrous iron [Fe(II)] in groundwater using oxygen (O2) and/or dosing a ferric iron [Fe(III)] coagulant such as Ferric Chloride (FeCl3). Arsenic strongly adsorbs to the surface of freshly formed Fe(III) precipitates and subsequently the As bearing Fe(III) precipitates are removed by filtration to produce As-safe water. The adsorption efficiency of As onto Fe(III) precipitates and the size of As bearing Fe(III) particles is governed by several interdependent factors such as the conditions of Fe(III)(oxyhydr)oxide generation in water, oxidation state of As, solution pH and the concentration of As and co-occurring ions with respect to Fe in the initial solution. The objective of this thesis is to discern mechanistic understanding of As removal by co-precipitation with Fe(III)(oxyhydr)oxides under different redox, ion composition and filtration conditions and to investigate routes to reduce As in drinking water to very low levels, below 1 µg/L. We carried out sampling campaigns at water treatment plants in the Netherlands to gain understanding of the pertinent As removal mechanisms during groundwater treatment. It was found that rapid sand filtration is the most important treatment step for oxidation and removal of As during groundwater treatment. The removal of As is tightly coupled to Fe removal in rapid sand filters and mainly attributed to co-precipitation of As with Fe(III)(oxyhydr)oxides, which are generated by oxidation and subsequent hydrolysis of Fe(II). The As co-precipitation efficiency with Fe(III)(oxyhydr)oxides is much higher in rapid sand filter beds compared to aeration and supernatant storage. This is ascribed to oxidation of arsenite [As(III)] to arsenate [As(V)] in the rapid sand filter beds, potentially executed by manganese oxides (MnO2) and/or As(III) oxidizing bacteria, as both are observed in the coating of rapid sand filter media grains. In the pH range of most groundwaters, As(V) adsorbs to Fe(III)(oxyhydr)oxides much more effectively than As(III). Typical aeration techniques such as cascades are inefficient in oxidizing As(III) to As(V) before rapid sand filters at water treatment plants, resulting in inefficient As co-precipitation with Fe(III)(oxyhydr)oxides. Nevertheless, dosing a strong oxidant such as potassium permanganate (KMnO4) rapidly accomplishes As(III) oxidation to As(V) and drastically improves As co-precipitation efficiency with Fe(III)(oxyhydr)oxides, resulting in As reduction to very low levels, below 1 µg/L. While no negative effect on the removal efficiency of Fe(II), Mn(II) and ammonium (NH4+) in rapid sand filters is observed due to KMnO4 dosing, the pre-established Fe(II) and Mn(II) removal mechanisms in rapid sand filters are altered due to KMnO4 dosing, generating a need for rapid sand filter media replacement. We also found that dosing of strong oxidants during groundwater treatment impacts the composition and structure of the formed Fe and Mn bearing precipitates. For example, in the absence of competing ions, O2 produces Mn(III)-incorporated moderately crystalline lepidocrocite, sodium hypochlorite (NaOCl) produces Mn(III)-incorporated poorly-ordered hydrous ferric oxide, and KMnO4 produces poorly-ordered MnO2 and poorly-ordered hydrous ferric oxide phases. This diversity of formed precipitates under different redox conditions should be considered in As removal during groundwater treatment. In this thesis we show that As levels below 1 µg/L can alternatively be achieved by dosing a small amount of FeCl3 in the effluent of rapid sand filter at groundwater treatment plants. The effluent of rapid sand filter predominantly contains arsenate [As(V)] which is much more effectively adsorbed to Fe(III)(oxyhydr)oxides than As(III). In this way use of KMnO4 or other strong oxidants can be avoided at groundwater treatment plants. Nevertheless, the ionic composition of water strongly controls As(V) removal by iron based co-precipitation, by affecting the adsorption efficiency of As(V) with Fe(III)(oxyhydr)oxides and the size of As bearing Fe(III) particles. We show that silicate (SiO4-4) and phosphate (PO4-3) reduce As(V) removal, mainly due to competition with As(V) adsorption to Fe(III) precipitates. Though SiO4-4 en PO4-3 oxyanions are known to strongly reduce Fe(III) precipitate growth, we show that presence of high calcium (Ca) concentrations in groundwater (common in the Netherlands and several other parts of the world) counteracts the negative effects of both SiO4-4 en PO4-3 and promote coagulation of Fe(III) precipitates to form large particles which are easily separated from water by gravitation settling and rapid sand filtration. Despite presence of high Ca concentrations, Natural Organic Matter (NOM) reduces As(V) removal quite drastically, attributed largely to the formation of soluble and colloidal Fe(III)–NOM complexes which are not easily separated by conventional filtration. In-line dosing of a small amount of FeCl3 in the feed water of ultrafiltration (UF) step (typically used for final polishing and disinfection) is shown to be effective for As reduction to <1 µg/L at water treatment plants which use artificially recharged water as source. In this process, As(V) co-precipitation with Fe(III)(oxyhydr)oxides rapidly reaches equilibrium, thus little contact time before the membranes is required. Moreover, when As bearing Fe(III) precipitates grow to sizes larger than the pore size of UF membranes (expected for most Ca bearing groundwaters) the Fe(III) particles foul the membranes mainly by forming a cake-layer on the surface which is effectively removed with a hydraulic backwash. Thus, we conclude that sustainable long term operation of UF membranes with in-line FeCl3 dosing for As removal is highly viable. Based on the present work, three groundwater treatment plants in the Netherlands have received an upgrade with KMnO4 dosing for reducing As to below 1 µg/L. Another treatment plant, which makes use of artificially recharged groundwater, will receive an upgrade with FeCl3 dosing before the polishing UF step

Institutional distance : market conforming values in the host country and foreign direct investment choices of multinational enterprises

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Determinants of foreign direct investment ownership mode choice: Evidence from Nordic investments in Central and Eastern Europe

This paper addresses the determinants of foreign direct investment (FDI) ownership mode choice of firms in Central and Eastern Europe (CEE) based on three most important theoretical paradigms of IB studies i.e. transaction cost economics, resource based view and institutional theory. The empirical analysis of 720 FDIs made by the firms from all four Nordic countries in CEE region during 1990-2007 revealed that the probability WOS formation was increased by the high R&D intensity of the industry of the investment, low target country risk, large economic size and high economic growth in the target country. The further in-depth analysis revealed that for FDIs made during 1990s, product diversity; while for FDIs made during 2000s, international experience and strength of market conforming values in the target country became significant determinants of ownership mode choice for Nordic FDIs.Dieser Artikel befasst sich mit den Determinanten der Markteintrittsform von ausländischen Direktinvestitionen von Unternehmen in Mittel- und Osteuropa, basierend auf drei zentralen theoretischen Paradigmen, nämlich der Transaktionskostentheorie, dem Ressourcen-basierten Ansatz und der Institutionen-Theorie. Die empirische Analyse von 720 Direktinvestitionen von Unternehmen aus den vier nordischen Ländern in Mittel- und Osteuropa zwischen 1990 und 2007 ergab, dass die Wahrscheinlichkeit der Bildung von Tochtergesellschaften durch die hohe F&E-Intensität der Branche, ein niedriges Risiko der Zielländer, eine große Wirtschaft und ein großes Wirtschaftswachstum der Zielländer steigt. Für ausländische Direktinvestitionen während der 1990er Jahre erwiesen sich die Produktvielfalt und in den 2000er Jahren die internationale Erfahrung und die Stärke von marktkonformen Werten im Zielland für die Markteintrittsform als ausschlaggebend

Towards using utility data to quantify how investments would have increased the wind resilience of distribution systems

We quantify resilience with metrics extracted from the historical outage data that is routinely recorded by many distribution utilities. The outage data is coordinated with wind data to relate average outage rates in an area to wind speed measured at a nearby weather station. A past investment in wind hardening would have reduced the outage rates, and the effect of this on metrics can be calculated by sampling a reduced number of the historical outages and recomputing the metrics. This quantifies the impact that the hardening would have had on customers. This is a tangible way to relate an investment in wind resilience to the benefits it would have had on the lived experience of customers that could help make the case for the investment to the public and regulators. We also quantify the impact of earlier or faster restoration on customer metrics and compare this to the impact of investment in hardening. Overall this is a new and straightforward approach to quantify resilience and justify resilience investments to stakeholders that is directly driven by utility data. The approach driven by data avoids complicated models or modeling assumptions

Sustainability Transition and 6G Mobile Communications

This chapter aims to academically highlight the link between 6G mobile communications and the transition to sustainability. Using both theoretical arguments and practical examples, the current chapter applies a multi-level perspective (MLP) to the sustainability transition to highlight the specificities of niches, socio-technical regimes, and exogenous socio-technical landscapes of 6G technology in relation to the sustainability transition. Moreover, the current chapter is one of the rare studies that focuses on the larger picture in the 6G and sustainability debate by highlighting specific UN SDGs which can be achieved by the sustainability transition and the role of both endogenous and exogenous factors using an MLP lens. Finally, this chapter offers specific theoretical, practical, and policy implications.© 2024 The Author(s). This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made. The images or other third party material in this chapter are included in the chapter’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.fi=vertaisarvioitu|en=peerReviewed

Institutions and Dynamic Capabilities: Theoretical Insights and Research Agenda for Strategic Entrepreneurship.

The current paper aims to comparatively analyze both institutional and dynamic capabilities approaches conceptually in the context of strategic entrepreneurship. We offer a conceptual review, where strengths, as well as limitations of both theoretical approaches, are highlighted. Our review and discussion show that both approaches are subtly intertwined and can complement each other to further understanding of firm’s behavior including strategic entrepreneurship. Institutions provide templates for action and cognition in developing, managing, and utilizing dynamic capabilities in that context. Dynamic capabilities, as enablers of agency, can be expected to play a role in creating, maintaining, bridging, and disrupting institutions. The synthesis of institutional and dynamic capabilities approaches leads to a better understanding of agency, behavior, and structure in the context of strategic entrepreneurship. Finally, we also present a research agenda for strategic entrepreneurship that explores key concepts germane to both institutions and dynamic capabilities

QoE-centric service delivery: A collaborative approach among OTTs and ISPs

The provisioning of the quality to end users is a major objective for the successful deployment of multimedia services over the Internet. It is more and more evident from past research and service deployments that such an objective often requires a collaboration among the different parties that are involved in the delivery of the service. This paper specifically focuses on the cooperation between the Over-The-Top (OTTs) and the Internet Service Providers (ISPs) and proposes a novel service delivery approach that is purely driven by the Quality of Experience (QoE) provided to the final common users. Initially, we identify the need of the collaboration among the OTTs and the ISPs where we not only highlight some of the enterprise level motivations (revenue generation) but also the technical aspects which require collaboration. Later, we provide a reference architecture with the required modules and vertical interfaces for the interaction among the OTTs and the ISPs. Then, we provide a collaboration model where we focus on the modeling of the revenue, whose maximization drives the collaboration. The revenue is considered to be dependent on the user churn, which in turn is affected by the QoE and is modeled using the Sigmoid function. We illustrate simulation results based on our proposed collaboration approach which highlight how the proposed strategy increases the revenue generation and QoE for the OTTs and the ISPs hence providing a ground for ISP to join the loop of revenue generation between OTTs and users