Input-output linearization and fractional robust control of a non-linear system

This article deals with the association of a linear robust controller and an input-output linearization feedback for the control of a perturbed and non-linear system. This technique is applied to the control of a hydraulic system whose actuator is non-linear and whose load is time-variant. The piston velocity of the actuator needs to be controlled and a pressure-difference inner-loop is used to improve the performance. To remove the effect of the non-linearity, an input-output linearization under diffeomorphism and feedback is achieved. CRONE control, based on complex fractional differentiation, is applied to design a controller for piston-velocity loop even when parametric variations occu

Discontinuities in the Distribution of Great Wealth: Sectoral Forces Old and New

National surveys of household economics and well-being in the United States usually focus on income. In those income surveys with supplemental wealth modules, the very rich are underrepresented if not unrepresented. Typically, wealth data are truncated such that they do not afford a view of the extreme top of the distribution. Therefore, we attempt to supplement our knowledge about elite wealth holdings by compiling data on the richest individuals and families in the United States. To do so, we draw from the rosters of the "Forbes Four Hundred," which have been published annually by Forbes magazine since 1982. Along with information from other business press reports and standard biographical sources, rosters of the very rich enable research on inequality at the extreme of the wealth distribution during a period of dramatic change in the composition and concentration of wealth. In this study, we focus analytically on economic sectors because we are interested less in the maldistribution of wealth by demographic groups than in inequality between different economic sectors. We will first specify our analytical approach, then examine issues in the use of business press rosters of the very rich as a data source, and follow with a discussion of the dimensions and categories of our sector typology. After presenting our results, we will address how sectoral forces old and new affect economic opportunity and great wealth outcomes.

Towards Continuous Quality Control for Spoken Language Corpora

This paper describes the development of a systematic approach to the creation, management and curation of linguistic resources, particularly spoken language corpora. It also presents first steps towards a framework for continuous quality control to be used within external research projects by non-technical users, and discuss various domain and discipline specific problems and individual solutions. The creation of spoken language corpora is not only a time-consuming and costly process, but the created resources often represent intangible cultural heritage, containing recordings of, for example, extinct languages or historical events. Since high quality resources are needed to enable re-use in as many future contexts as possible, researchers need to be provided with the necessary means for quality control. We believe that this includes methods and tools adapted to Humanities researchers as non-technical users, and that these methods and tools need to be developed to support existing tasks and goals of research projects

Setting an integrated soil monitoring system for Malta : strategy, feasibility and recommendations

Chapter 6Since 2010, MEPA has embarked on a project (which attracted co-funded ERDF assistance) (1) to develop a multi-thematic environment strategy that would lead to updating of its data/ information monitoring capabilities for a number of environmental sectors. The monitoring and continuous evaluation of soil properties is one important sector within this project. Essentially, a multi-criterion assessment of existing available information has been carried out with a view to objectively chart the most appropriate process to carry out a pilot field sampling by testing a pre-agreed set of indicators. The latter were established after taking into consideration all degradation pressures threatening the continued sustainability of this resource. Multi-criterion analysis was carried out by means of a limited set of soil-related datasets published in past editions of Malta’s State of the Environment Report in order to support a number of objectives stipulated within the Project’s ambitious Terms of Reference. Information was derived from earlier attempts to establish a soil information system for Malta. All soil degradation threats, officially determined by the European Commission’s Technical Working Groups, have been taken into consideration within the aforementioned project and its research methodology with a view of establishing a shared GIS environment in accordance with state-of-the-art information dissemination standards.peer-reviewe

A design-for-casting integrated approach based on rapid simulation and modulus criterion

This paper presents a new approach to the design of cast components and their associated tools. The current methodology is analysed through a case study and its main disadvantages underlined. Then, in order to overcome these identified drawbacks, a new approach is proposed. Knowing that this approach is mainly based on a rapid simulation of the process, basics of a simplified physical model of solidification are presented as well as an associated modulus criterion. Finally, technical matters for a software prototype regarding the implementation of this Rapid Simulation Approach (RSA) in a CAD environment are detailed

Development and Psychometric Properties of A Screening Tool for Assessing Developmental Coordination Disorder in Adults

Background: Developmental Coordination Disorder (DCD) is a neurodevelopmental disorder affecting motor coordination. Evidence suggests this disorder persists into adulthood and may be associated with biomechanical dysfunction and pain. We report on the development and initial validation of a questionnaire to assess for DCD in adults. Methods: An initial item pool (13 items) was derived from the American Psychiatric Association criteria and World Health Organisation definition for DCD. An expert panel assessed face and content validity which led to a 9-item Functional Difficulties Questionnaire (FDQ-9) with possible scores ranging from 9-36 (higher scores indicating greater functional difficulties). The FDQ-9 was piloted on individuals recruited from convenience samples. The underlying factor structure and aspects of reliability, validity and accuracy were tested. The Receiver Operating Characteristic Curve was employed to evaluate the diagnostic accuracy of the test using self-reported dyspraxia as the reference standard. Results: Principal Axis Factoring yielded a two factor solution relating to gross and fine motor skills; for conceptual parsimony these were combined. Internal reliability was high (0.81), the mean inter-item correlation was 0.51 and preliminary findings suggested satisfactory construct validity. The Area under the Curve was 0.918 [95% CI 0.84-1.00] indicating a diagnostic test with high accuracy. A cut-off score was established with a sensitivity and specificity of 86% [95% CI 78%-89%] and 81% [95 % CI 73%-89%] respectively. Test-retest reliability was good (ICC 0.96 [95% CI 0.92 to 0.98]. Conclusion: The psychometric properties of the FDQ-9 appear promising. Work is required to conduct further psychometric evaluations on new samples and apply the scale to clinical practice