Robust unknown input observer for state and fault estimation in discrete-time Takagi-Sugeno systems

In this paper, a robust unknown input observer (UIO) for the joint state and fault estimation in discrete-time Takagi-Sugeno (TS) systems is presented. The proposed robust UIO, by applying the H-infinity framework, leads to a less restrictive design procedure with respect to recent results found in the literature. The resulting design procedure aims at achieving a prescribed attenuation level with respect to the exogenous disturbances, while obtaining at the same time the convergence of the observer with a desired bound on the decay rate. An extension to the case of unmeasurable premise variables is also provided. Since the design conditions reduce to a set of linear matrix inequalities that can be solved efficiently using the available software, an evident advantage of the proposed approach is its simplicity. The final part of the paper presents an academic example and a real application to a multi-tank system, which exhibit clearly the performance and effectiveness of the proposed strategy.Postprint (author's final draft

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Thermoelastic phenomena in the transversally graded laminates

The object of considerations is a laminate, made of two components nonperiodically distributed as microlaminas along one direction. In this note, two models describing the thermoelasticity problems are proposed: the tolerance model, taking into account the effect of the microstructure size on the overall behaviour of these laminates, and the asymptotic model, neglecting this effect. To obtain the governing equations of the tolerance and the asymptotic model, the tolerance averaging technique is applied

Palatal rugae positional changes during orthodontic treatment of growing patients.

OBJECTIVES To investigate the anteroposterior and vertical changes of the median rugae area, which is commonly used as dental model superimposition reference, relevant to its underlying skeletal structures. SETTINGS AND SAMPLE POPULATION Retrospectively collected pre- and post-treatment cephalometric radiographs and 3D digital dental models of 24 orthodontic patients (age at treatment start: 12.26 ± 0.83 years; assessment period: 2.13 ± 0.68 years) were analysed. All had mild to moderate malocclusions that were treated non-extraction with full fixed appliances. MATERIAL AND METHODS The incisive papilla and rugae points were placed on the dental models that were then registered to the cephalometric radiographs. Afterwards, the radiographs were superimposed on Sella, ANS-PNS, and through a maxillary structural method. The vertical and horizontal movements of the papilla and the rugae points, as well as of a central incisor, were measured (Viewbox 4 software). RESULTS The incisive papilla and the three rugae points remained stable anteroposteriorly, but moved downwards in the vertical dimension (approximately 1-2 mm), in a similar manner (P>0.05). However, the anteroposterior position of the papilla and the first rugae points were affected by changes in anterior tooth position and inclination (p<0.05). CONCLUSION Both the second and third rugae can be used as superimposition references for tooth movement assessment. The use of the papilla and the first rugae area is not recommended, because they are affected by tooth movement. The outcomes of a palatal superimposition are comparable to those of a maxillary skeletal superimposition in the anteroposterior, but not in the vertical dimension

Proton conductivity in photomagnetic Cu2−II[MIV(CN)8]Cu_{2-}^{II}[M^{IV}(CN)_8] frameworks (M=MoIVM = Mo^{IV} and WIVW^{IV}) facilitated by the tetracarboxy-derivative of cyclam

Two 3D bimetallic cyanido-bridged coordination polymers, $[Cu^{II}(H_{4}tetac)]_{2}[M^{IV}(CN)_{8}]·4H_{2}O (M = Mo^{IV}$ (1) and $W^{IV} (2))$, based on copper(II) complex of tetracarboxylic-derivative of cyclam, $H_{4}$tetac (=1,4,8,11-tetrazacyclotetradecane-6,6,13,13-tetracarboxylic acid), have been synthesized and characterized in terms of structure, proton conductivity, and the photomagnetic effect. The isostructural compounds crystallize in the polar Fdd2 space group and present a diamond-like topology. The carboxylic groups in the structure yield proton conductivities of $5.4(3) × 10^{–7} S cm^{–1} (1) and 8.6(3) × 10^{–7} S cm^{–1}$ (2) at 298 K and 98% relative humidity. A strong humidity dependence of conductivity and activation energy values of 0.34 eV (1) and 0.36 eV (2) indicate the Grotthuss mechanism of proton transport that is mediated by crystallization water molecules. In the ground state, 1 and 2 are paramagnets due to $Cu^{II} (S = 1/2)$ centers separated by diamagnetic $[M^{IV}(CN)_{8}]^{4–}$ anions (S = 0). Upon 450 nm light irradiation at 10 K, both compounds show a photomagnetic response. The $Mo^{IV}$ system shows higher photoconversion rates, while the $W^{IV}$ analogue exhibits full reversibility. Compounds 1 and 2 are the first examples of cyanido-bridged assemblies combining proton conductivity and the photomagnetic effect, advancing the reticular chemistry of cyanido-bridged frameworks

Laboratory evaluation of moisture performance of weather resistive barriers

The objective of this thesis aimed (1) to evaluate the effectiveness of the existing test methods used in characterizing moisture performance of weather resistive barrier (WRB) products, and (2) to provide a benchmark for assessment of different boundary conditions. The test materials were placed between a layer of water and various types of hygroscopic sinks including vacuum cast gypsum, oriented strand board (OSB), thick adsorbing paper (blotter) and a desiccant (anhydrous calcium chloride). The WRB were either placed directly in contact with the hygroscopic sink or were separated from it by an air gap. These tests indicated that moisture transport was highly dependent on the conditions introduced on the upper and the lower surfaces of the WRB. This thesis reports the results of a series of experimental studies, which examined moisture transport to characterize WRB for input into material standards. The new test methods developed in the thesis include: modified inverted cup ( MIC ) test for measuring the maximum possible total moisture transmission, moisture flux ( MF ) test for measuring moisture flow to an OSB or plywood substrate, and liquid penetration resistance ( LPR ) test for measuring onset and the rate of the liquid phase transport. The test methods were used to examine moisture transport through new WRB. The test were also used to evaluate effect of penetrations, outdoor weathering, and contribution of detergent dissolved in the interstitial water. Subsequent to the material testing, an assembly testing provided a comparative evaluation of such effects as penetrations or additives in a stucco layer. Proposed in this thesis are new laboratory test methods and the acceptance criteria to be incorporated in the next edition of North American material standards. (Abstract shortened by UMI.

An output-feedback fault-tolerant control approach for multiple faults

© 2023 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksThis paper proposes an output-feedback fault-tolerant control approach for multiple faults. The proposed approach is able to deal with both sensors and actuator faults. Moreover, the disturbances are assumed to be bounded within an ellipsoidal sets. The proposed strategy boils down to solving a set of LMIs along with an auxiliary parameter, which determines the convergence rate of the approach. Finally, the proposed strategy is illustrated with two-rotor aerodynamical system.Peer ReviewedPostprint (author's final draft

State of the science on controversial topics: orthodontic therapy and gingival recession (a report of the Angle Society of Europe 2013 meeting).

BACKGROUND: Controversy exists in the literature between the role of orthodontic treatment and gingival recession. Whilst movement of teeth outside the alveolar bone has been reported as a risk factor for gingival recession, others have found no such association. FINDINGS: The Angle Society of Europe devoted a study day to explore the evidence surrounding these controversies. The aim of the day was for a panel of experts to evaluate the current evidence base in relation to either the beneficial or detrimental effects of orthodontic treatment on the gingival tissue. CONCLUSIONS: There remains a relatively weak evidence base for the role of orthodontic treatment and gingival recession and thus a need to undertake a risk assessment and appropriate consent prior to the commencement of treatment. In further prospective, well designed trials are needed

Cone beam computed tomography use in orthodontics

Cone beam computed tomography (CBCT) is widely used by orthodontists to obtain three‐dimensional (3‐D) images of their patients. This is of value as malocclusion results from discrepancies in three planes of space. This review tracks the use of CBCT in orthodontics, from its validation as an accurate and reliable tool, to its use in diagnosing and treatment planning, and in assessing treatment outcomes in orthodontics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90211/1/j.1834-7819.2011.01662.x.pd