Sensor/Actuator Selection for the Constrained Variance Control Problem

The problem of designing a linear controller for systems subject to inequality variance constraints is considered. A quadratic penalty function approach is used to yield a linear controller. Both the weights in the quadratic penalty function and the locations of sensors and actuators are selected by successive approximations to obtain an optimal design which satisfies the input/output variance constraints. The method is applied to NASA's 64 meter Hoop-Column Space Antenna for satellite communications. In addition the solution for the control law, the main feature of these results is the systematic determination of actuator design requirements which allow the given input/output performance constraints to be satisfied

Werner state structure and entanglement classification

We present applications of the representation theory of Lie groups to the analysis of structure and local unitary classification of Werner states, sometimes called the {\em decoherence-free} states, which are states of $n$ quantum bits left unchanged by local transformations that are the same on each particle. We introduce a multiqubit generalization of the singlet state, and a construction that assembles these into Werner states.Comment: 9 pages, 2 figures, minor changes and corrections for version

Situating my positionality as a Black woman with a dis/ability in the provision of equity-focused technical assistance: a personal reflection

In this essay, I reflect on how an equity-focused technical assistance (TA) practitioner who holds intersectional minoritized social identities is in a unique position to introduce tensions in the TA activity system, disrupt marginalizing dominant narratives about difference, and affect educators’ development of new ideas about the treatment of difference in schools. To start, I situate myself as the TA provider by focusing specifically on the socio-historical context in which I experienced public K-12 education as a Black, woman with a dis/ability. Next, I outline three reflections related to my experience with the treatment of difference during that time, particularly in terms of race and dis/ability; I consider how my personal history informs my current interactions within the provision of equity-focused TA. I identify three marginalizing impacts resulting from educators’ treatment of my and other students’ difference; and describe three strategic moves I employ to disrupt and mitigate these impacts. Additionally, I reflect on the question: How might my social identities, intersectional education history, and lived experiences serve as instruments that evoke tensions and affect interactions within the TA activity system

Effects of a falls exercise intervention on strength, power, functional ability and bone in older frequent fallers: FaME (Falls Management Exercise) RCT secondary analysis

OBJECTIVES: Falls Management Exercise (FaME) has been shown to reduce falls in frequent fallers and in lower risk sedentary older people. The effects of FaME on the strength, power, physical function and bone health of frequently falling older women are yet to be established. METHODS: This paper reports secondary analysis of data from the original randomised controlled trial of FaME in 100 community dwelling women aged ≥65 years with a history of ≥3 falls in the previous year. Intervention was group delivered, weekly one hour tailored dynamic balance and strength exercise classes and home exercise for nine months. OUTCOME MEASURES INCLUDED: strength (handgrip, quadriceps, hamstrings, hip abductors, ankles), lower limb explosive power and functional tests (timed up and go, functional reach, timed floor rise and balance), analysed using Linear Mixed Model analysis. Bone Mineral Density (BMD) at hip and spine was measured in a smaller sub-group and analysed using t-tests. RESULTS: Significant time*group interactions in all measures of strength, except isometric ankle dorsiflexion, concentric hamstring and eccentric quadriceps strength. These improvements in strength equated to average improvements of 7-45%. There were also significant improvements in explosive power (W/kg) (18%, p=0.000), timed up and go (16%, p=0.000), functional reach (17%, p=0.000), floor rise (10%, p=0.002) and eyes closed static balance (56%, p=0.000). There was a significant loss of hip BMD in the control group (neck of femur p<0.05; ward's triangle p<0.02). CONCLUSION: The FaME intervention improves lower limb strength, power and clinically relevant functional outcomes in frequently falling older women

Spontaneous Octahedral Tilting in the Cubic Inorganic Caesium Halide Perovskites CsSnX3_3 and CsPbX3_3 (X = F, Cl, Br, I)

The local crystal structures of many perovskite-structured materials deviate from the average space group symmetry. We demonstrate, from lattice-dynamics calculations based on quantum chemical force constants, that all the caesium-lead and caesium-tin halide perovskites exhibit vibrational instabilities associated with octahedral titling in their high-temperature cubic phase. Anharmonic double-well potentials are found for zone-boundary phonon modes in all compounds with barriers ranging from 108 to 512 meV. The well depth is correlated with the tolerance factor and the chemistry of the composition, but is not proportional to the imaginary harmonic phonon frequency. We provide quantitative insights into the thermodynamic driving forces and distinguish between dynamic and static disorder based on the potential-energy landscape. A positive band gap deformation (spectral blueshift) accompanies the structural distortion, with implications for understanding the performance of these materials in applications areas including solar cells and light-emitting diodes

Kinetostatic Analysis and Solution Classification of a Planar Tensegrity Mechanism

Tensegrity mechanisms have several interesting properties that make them suitable for a number of applications. Their analysis is generally challenging because the static equilibrium conditions often result in complex equations. A class of planar one-degree-of-freedom (dof) tensegrity mechanisms with three linear springs is analyzed in detail in this paper. The kinetostatic equations are derived and solved under several loading and geometric conditions. It is shown that these mechanisms exhibit up to six equilibrium configurations, of which one or two are stable. Discriminant varieties and cylindrical algebraic decomposition combined with Groebner base elimination are used to classify solutions as function of the input parameters.Comment: 7th IFToMM International Workshop on Computational Kinematics, May 2017, Poitiers, France. 201

Mastitis in Dairy Cattle

Summary1. Mastitis is usually caused by a specific organism, Streptococus agalactiae.2. Mastitis occurs in one or more of the milking cows in nearly all herds of any size. It is more prevalent in old than in young cows.3. The most common symptoms of mastitis are: Swollen, in flamed quarters, flakes or lumps of curd in the milk and on the milk strainer pad.4. Mastitis producing bacteria enter the udder through the streak canal.5. There are several tests for detecting mastitis in milking cows. The microscopic inspection of milk in which the long chain streptococci organisms are found is the most dependable.6. Mastitis can be controlled by testing, observing sanitary practices in the barn, use of medicaments, and slaughter of the chronic cases that will not yield to treatment.The control and prevention of diseases and ailments in dairy herds mean more to the success of a well-bred dairy herd than any other single factor. As the herd increases in number and the individuals in the herd improve in production, diseases occur more frequently. This is only natural. With larger numbers more animals contact each other, increasing the possibilities of infection.High-producing animals are highly developed and therefore hard working. They cannot withstand the hardships and contagion of disease as can the boarder cow, which is largely on a maintenance basis

Job Training and the Skills Debate: A Road to Nowhere?

Training programs have been largely unsuccessful in providing jobs for the unemployed or those employed in low-level jobs. Yet public support for these programs has remained high. This seeming contradiction is explored by reviewing evidence suggesting that what has been created are not policies to train people for jobs, but a thriving ―training industry‖ that only marginally assists individuals in finding employment or in developing skills that allow for career advancement