Parameter estimation of thrust models of uninhabited airborne systems

This paper presents a method for the estimation of thrust model parameters of uninhabited airborne systems using specific flight tests. Particular tests are proposed to simplify the estimation. The proposed estimation method is based on three steps. The first step uses a regression model in which the thrust is assumed constant. This allows us to obtain biased initial estimates of the aerodynamic coeficients of the surge model. In the second step, a robust nonlinear state estimator is implemented using the initial parameter estimates, and the model is augmented by considering the thrust as random walk. In the third step, the estimate of the thrust obtained by the observer is used to fit a polynomial model in terms of the propeller advanced ratio. We consider a numerical example based on Monte-Carlo simulations to quantify the sampling properties of the proposed estimator given realistic flight conditions.

Supramolecular organization in fluorene/indenofluorene-oligothiophene alternating conjugated copolymers

A series of conjugated copolymers containing fluorene or indenofluorene units alternating with oligothiophene segments, with potential interest for use as the active layer in field-effect transistors, is investigated. Atomic force microscopy analysis of the morphology of thin deposits shows either the formation of fibrillar structures, which are the signature of long-range π stacking, or the presence of untextured aggregates, resulting from disordered assembly. These morphologies are interpreted in terms of the supramolecular organization of the conjugated chains. Molecular modeling simulations indicate that the commensurability between the lengths of the monomer units and the presence of alkyl side groups are the two key structural factors governing the chain organization into highly ordered assemblies. The most favorable structures are those combining fluorene (indenofluorene) units with unsubstituted bithiophene (terthiophene) segments.

Multiple criteria-based real-time decision making by autonomous city vehicles

This paper addresses the topic of real-time decision making for autonomous city vehicles, i.e. the autonomous vehicles’ ability to make appropriate driving decisions in city road traffic situations. After decomposing the problem into two consecutive decision making stages, and giving a short overview about previous work, the paper explains how Multiple Criteria Decision Making (MCDM) can be used in the process of selecting the most appropriate driving maneuver.

Reason of state and a new notion of fortune : Historicising the risk society

Since the 1980s the concept of risk has produced a large and diverse volume of sociological research. Ulrich Beck’s groundbreaking risk society thesis provides a particularly engaging contribution, since it seems that nearly every sociological account of risk engages with this work. For Beck, we are living in second modernity – a new epoch that breaks with pre-modernity and industrial society due to the centrality, incalculability and reflexivity of globalised risk. While Beck’s theory is compelling, a reading of other theorists such as Foucault (2007[1978]) and Hacking (1975,1990) suggests that a difficulty with Beck’s work is that in attempting to explain what is novel about risk in contemporary times, he too quickly passes over the complexities and ruptures of historical change that impact on the history and contingency of risk. This paper begins by presenting a brief analysis of the present state of risk by introducing Beck’s historical narrative of risk from pre-modernity to the risk society; it then outlines the challenges with the “risk as epoch” argument by considering a range of literature, which suggests risk has a more complex history than proposed by Beck; and finally it highlights the value in examining strategies of statecraft in early modern Europe, specifically Machiavelli’s The Prince (2008[1513]) and Giovanni Botero’s political treatise, Della Ragion di Stato (1956[1589]) – as a means of more thoroughly understanding how our current concept of risk emerges. In doing so, this paper seeks to open up new trajectories in the historicisation of risk for other interested scholars.

Exploring physical activities in an employer-sponsored health program

This work brings a perspective from an employer-sponsored health and wellness program called Global Corporate Challenge (GCC) to the 'quantified self' research. We present preliminary findings from a study with 17 university employees who participated in the GCC. We aimed to explore how participants derived meaningfulness from their self-tracking experiences. Our findings echo the growing body of work that advocates for conceptualizing activity tracking beyond the rationalistic, data-oriented perspectives and supporting more social and lived experiences.

The role of knowledge integration in innovation and capability development

Purpose This paper investigates the interrelationships between knowledge integration (KI), product innovation and capability development to enhance our understanding of how firms can develop capability at the firm level, which in turn enhances their performance. One of the critical underlying mechanisms for capability building identified in the literature is the role of knowledge integration, which operates within product innovation projects and contributes to dynamic capability development. Therefore, the main research question is “how does the integration of knowledge across product innovation projects lead to the development of capability?” Design/methodology/approach We adopted a case-based approach and investigated the case of a successful firm that was able to sustain its performance through a series of product innovation projects. In particular this research focused on the role of KI and firm-level capability development over the course of four projects, during which the firm successfully managed the transformation of its product base and renewal of its competitive advantage. For this purpose an in-depth case study of capability development was undertaken at the Iran Khodro Company (IKCO), the key player in the Iranian auto industry transformation. Originality/value This research revealed that along with changes at each level of product architecture “design knowledge” and “design capability” have been developed at the same level of product architecture, leading to capability development at that level. It can be argued that along the step by step maturation of radical innovation across the four case projects, architectural knowledge and capability have been developed at the case company, resulting in the gradual emergence of a modular product and capability architecture across different levels of product architecture. Such findings basically add to extensive emphasis in the literature on the interrelationship of the concept of modularity with knowledge management and capability development. Practical implications Findings of this study indicate that firms manage their knowledge in accordance with the level of specialization in knowledge and capability. Furthermore, firms design appropriate knowledge integration mechanisms within and among functions in order dynamically align knowledge processes at different levels of the product architecture. Accordingly, the outcomes of this study may guide practitioners in managing their knowledge processes, through dynamically employing knowledge integration modes step-by-step and from the part level to the architectural level of product architecture across a sequence of product innovation projects to encourage learning and radical innovation.

Brief report: Intestinal dysbiosis in ankylosing spondylitis

Objective Ankylosing spondylitis (AS) is a common, highly heritable immune-mediated arthropathy that occurs in genetically susceptible individuals exposed to an unknown but likely ubiquitous environmental trigger. There is a close relationship between the gut and spondyloarthritis, as exemplified in patients with reactive arthritis, in whom a typically self-limiting arthropathy follows either a gastrointestinal or urogenital infection. Microbial involvement in AS has been suggested; however, no definitive link has been established. The aim of this study was to determine whether the gut in patients with AS carries a distinct microbial signature compared with that in the gut of healthy control subjects. Methods Microbial profiles for terminal ileum biopsy specimens obtained from patients with recent-onset tumor necrosis factor antagonist-naive AS and from healthy control subjects were generated using culture-independent 16S ribosomal RNA gene sequencing and analysis techniques. Results Our results showed that the terminal ileum microbial communities in patients with AS differ significantly (P < 0.001) from those in healthy control subjects, driven by a higher abundance of 5 families of bacteria (Lachnospiraceae [P = 0.001], Ruminococcaceae [P = 0.012], Rikenellaceae [P = 0.004], Porphyromonadaceae [P = 0.001], and Bacteroidaceae [P = 0.001]) and a decrease in the abundance of 2 families of bacteria (Veillonellaceae [P = 0.01] and Prevotellaceae [P = 0.004]). Conclusion We show evidence for a discrete microbial signature in the terminal ileum of patients with AS compared with healthy control subjects. The microbial composition was demonstrated to correlate with disease status, and greater differences were observed between disease groups than within disease groups. These results are consistent with the hypothesis that genes associated with AS act, at least in part, through effects on the gut microbiome.

Nitrogen-doped graphene films from chemical vapor deposition of pyridine: Influence of process parameters on the electrical and optical properties

Graphene films were produced by chemical vapor deposition (CVD) of pyridine on copper substrates. Pyridine-CVD is expected to lead to doped graphene by the insertion of nitrogen atoms in the growing sp2 carbon lattice, possibly improving the properties of graphene as a transparent conductive film. We here report on the influence that the CVD parameters (i.e., temperature and gas flow) have on the morphology, transmittance, and electrical conductivity of the graphene films grown with pyridine. A temperature range between 930 and 1070 °C was explored and the results were compared to those of pristine graphene grown by ethanol-CVD under the same process conditions. The films were characterized by atomic force microscopy, Raman and X-ray photoemission spectroscopy. The optical transmittance and electrical conductivity of the films were measured to evaluate their performance as transparent conductive electrodes. Graphene films grown by pyridine reached an electrical conductivity of 14.3 × 105 S/m. Such a high conductivity seems to be associated with the electronic doping induced by substitutional nitrogen atoms. In particular, at 930 °C the nitrogen/carbon ratio of pyridine-grown graphene reaches 3%, and its electrical conductivity is 40% higher than that of pristine graphene grown from ethanol-CVD.

A polarized, twisted, ethylene: structure of methyl 2-(1,3-dimethyl-2-imidazolidinylidene)-3-oxobutyrate dihydrate, C10H16N2O3.2H2O

Mr = 248, monoclinic, P21/n, a = 12.028 (2), b=7.168(2), c= 15.187(5)A, fl=91.88(2) °, Z= 4, V= 1308.6,~3, Din= 1.26, Dx= 1.263 Mgm -3, 2 (Cu Ka) = 1.5418 .A, g = 0.86 mm -1, F(000) = 536, T= 293 K. Final R = 5.6% for 2120 observed reflexions. Owing to the push-pull effect, the C=C bond distance is as long as 1.464 (2)/k with the twist angle about the bond 62.6.

Unsteady Attachment Line Flow On A Flat-Plate With Attached Cylinder

The unsteady laminar incompressible boundary-layer attachment-line flow on a flat plate with attached cylinder with heat and mass transfer has been studied when the free stream velocity, mass transfer and surface wall temperature vary arbitrarily with time. The governing partial differential equations with three independent variables have been solved numerically using an implicit finite-difference scheme. The heat transfer was found to be strongly dependent on the Prandtl number, variation of wall temperature with time and dissipation parameter (for large times). However, the free stream velocity distribution and mass transfer affect both the heat transfer and skin friction.

Variable Size Population NSGA-II: VPNSGA-II

Multi-objective optimization is an active field of research with broad applicability in aeronautics. This report details a variant of the original NSGA-II software aimed to improve the performances of such a widely used Genetic Algorithm in finding the optimal Pareto-front of a Multi-Objective optimization problem for the use of UAV and aircraft design and optimsaiton. Original NSGA-II works on a population of predetermined constant size and its computational cost to evaluate one generation is O(mn^2 ), being m the number of objective functions and n the population size. The basic idea encouraging this work is that of reduce the computational cost of the NSGA-II algorithm by making it work on a population of variable size, in order to obtain better convergence towards the Pareto-front in less time. In this work some test functions will be tested with both original NSGA-II and VPNSGA-II algorithms; each test will be timed in order to get a measure of the computational cost of each trial and the results will be compared.

Approaching Sacred Pregnancy : The Cult of the Visitation and Narrative Altarpieces in Late Fifteenth-Century Florence

The study focuses on the Visitation as a narrative subject of altarpieces in late fifteenth-century Florence. Although the Visitation was a well-known story in both verbal and visual representations since the early medieval period, it became a popular subject of altarpieces only towards the end of the fifteenth century. In this study, the first part provides an overview of the complex religious and historical background to an emerging cult of the Visitation. Devotional practices focusing on the Visitation belong in a context of late medieval Marian devotion and in 1389 a new feast of the Visitation was introduced into the liturgical calendar of the Catholic Church. Because of the ongoing schism within the Catholic Church, the feast was not unanimously accepted across Western Europe until the later part of the fifteenth century. Contrary to a widely disseminated view, the feast of the Visitation cannot be associated with Franciscan spirituality, but was rather a clearly defined Dominican project that primarily emphasised the importance of peace and unity within the Christian Church. Simultaneously with the gradual acceptance of the new feast, visual representations of the Visitation began to appear at the centre of altarpieces. The Visitation exemplifies an increasing preference for narrative subjects within the genre of the altarpiece. The second part of the study presents an analysis of the concept of the narrative altarpiece and highlights the complexities involved in combining a narrative content with the traditional devotional function of the altarpiece. In detailed case studies some prominent art works produced in Florence between 1490 and 1503 are discussed within a framework of contextual analysis, narrative theory and iconography. Altarpieces by Domenico Ghirlandaio, Piero di Cosimo and Mariotto Albertinelli represent visual manifestations of a cult of the Visitation with roots in late medieval devotional practices. At the same time, the altarpieces highlight the multiple functions of altarpieces in a culture where art works responded to a variety of social and religious needs. Building on earlier studies, each case study presents new insights and evidence not considered in previous art historical research.

Dipole ordering in dilute solutions of ferroelectrics in antiferroelectric materials

The coefficients of thermal expansion reported by Worlton et al. [6] in the case of zircon are given in Table II along with the present data. Although Oql > or• in both cases, the anisotropy is more marked in the case of DyV04. From Table II, it is clear that the coefficient of volume expansion (,6) is almost the same for both compounds.