Over-Determined Control Systems on Time Scales

Control theory is a branch of mathematics focused on observing or controlling a process governed by a dynamic equation. We use state-space notation to represent all meaningful information about our process. This means our processes are expressed in vector form. Typically, the state matrix is square. In this project, we consider a control system where the corresponding state is over-determined, meaning there are more rows than columns. In addition, our state equation is on a time scale T, which allows us to consider discrete, continuous, or hybrid measurements. Here, we offer two methods to solve the dynamic system. Finally, we offer numerical results to a corresponding electrical power system

The massive star population of Cygnus OB2

We have compiled a significantly updated and comprehensive census of massive stars in the nearby Cygnus OB2 association by gathering and homogenizing data from across the literature. The census contains 169 primary OB stars, including 52 O-type stars and 3 Wolf–Rayet stars. Spectral types and photometry are used to place the stars in a Hertzsprung–Russell diagram, which is compared to both non-rotating and rotating stellar evolution models, from which stellar masses and ages are calculated. The star formation history and mass function of the association are assessed, and both are found to be heavily influenced by the evolution of the most massive stars to their end states. We find that the mass function of the most massive stars is consistent with a ‘universal’ power-law slope of Γ = 1.3.Peer reviewedFinal Accepted Versio

Evaluating the Effectiveness of Using Peer-Dialogue Assessment (PDA) for Improving Pre-Service Teachers\u27 Perceived Confidence and Competence to Teach Physical Education

Developing effective methods for improving student learning in higher education is a priority. Recent findings have shown that feedback on student work can effectively facilitate learning if students are engaged as active participants in the feedback cycle; where they seek, generate and use feedback in the form of dialogue. This novel study investigates the use of peer dialogue assessment as an assessment for learning tool used in an existing undergraduate physical education course. Our findings demonstrate that when thirty six undergraduate physical education students were provided with instruction and practice using peer dialogue assessment after consecutive teaching performances, they exhibit significant improvements in perceived teaching confidence and competence, and teaching self-efficacy. Process evaluation results implying thatembedding peer dialogue assessment in higher education courses may be a feasible approach for facilitating learning, and that students were satisfied with using peer dialogue as a feedback method for improving teaching practices

Reducing Extra-Terrestrial Excavation Forces with Percussion

High launch costs and mission requirements drive the need for low mass excavators with mobility platforms, which in turn have little traction and excavation reaction capacity in low gravity environments. This presents the need for precursor and long term future missions with low mass robotic mining technology to perform In-Situ Resource Utilization (ISRU) tasks. This paper discusses a series of experiments that investigate the effectiveness of a percussive digging device to reduce excavation loads and thereby the mass of the excavator itself. The goal of percussive excavation is to fluidize dry regolith in front of the leading edge of the tool by mechanically separating the microscopic interlocking grains resulting in a reduced force needed to shear the soil. There are several variables involved with this technique; this experiment varied: Impact energy, frequency, and excavation speed and held constant: impact direction, depth of cut, angle of tool, and soil bulk density. The test apparatus consisted of an aluminum truss bridge with a central pivoting arm. Attached to the arm was a winch with a load cell in line that recorded the tension in the cable and therefore the excavation load. The arm could be adjusted for excavation depth which was recorded along with the arm angle relative to the bridge. A percussive mechanism and 30" wide pivoting bucket were attached at the end of the arm simulating a basic backhoe with a percussion direction tangent to the direction of . movement. Internally the mechanism used a set of die springs and barrel cam to produce the percussive blow. By changing the springs and the speed of the motor the impact energy and frequency of percussion could be varied independently. Impact energies from 11.2J to 30.5J and frequencies from 0 BPM to 700 BPM were investigated. A reduction in excavation force of as much as 51% was achieved in this experimental investigation. Smaller percussive digging implements, tested by others, have achieved a reduction of as much as 72%. This paper will examine the effects of impact energy, frequency, scaling and their effect on excavation forces in a dry granular material such as lunar regolith. The past several years have shown an increasing interest in mining space resources both for exploration and commercial enterprises. This work studied the benefits and risks of percussive excavation and prelimin~ry results indicate that this technique may become an enabling technology for extra-terrestrial excavation of regolith and ice

The TLR4 D299G and T399I SNPs Are Constitutively Active to Up-Regulate Expression of Trif-Dependent Genes

Peer reviewedPublisher PD

Effects of different types of classroom physical activity breaks on children’s on-task behaviour, academic achievement and cognition

Aim This study examined the effects of different types of classroom physical activity breaks on children’s on-task behaviour, academic achievement and cognition. Methods Participants were 87 Australian primary school students (mean age 9.11 ± 0.62 years), recruited from one school. Three classes were randomly assigned either to activity breaks only (n = 29), activity breaks and mathematics combined (n = 29), or control conditions involving only mathematical content (n = 29). Students were engaged in five minutes of classroom physical activity breaks, three times per week, for four weeks (divided into two minutes at the beginning of the usual mathematics curriculum lesson and three minutes in the middle of the lesson). Assessments were conducted at baseline and post-test. Results Significant group-by-time effects were found for on-task behaviour (active engagement: activity breaks and mathematics combined versus control, p ≤ 0.001; activity breaks versus control, p ≤ 0.001; activity breaks and mathematics combined versus activity breaks, p = 0.037; passive engagement: activity breaks and mathematics combined versus control, p ≤ 0.001) and mathematics scores (activity breaks versus control, p = 0.045). Conclusion Physical activity breaks with and without integrated mathematics content were effective in improving children’s on-task behaviour and learning scores

Concert recording 2015-11-30

[Track 01]. Danza brasiliera / Jorge Morel -- [Track 02]. Sunburst / Andrew York -- [Track 03]. Ladron broma / Chase Chamberlin -- [Track 04]. Etudes 1, 2, & 3 / Matteo Carcassi -- [Track 05]. Invitation / Bronislaw Kaper -- [Track 06]. Ami etude / Ferdinando Carulli -- Variation (slur study) / Mauro Giuliani -- [Track 07]. Tango / Isaac Albeniz -- [Track 08]. Invention no. 8 / J.S. Bach -- [Track 09]. Don\u27t get around much anymore / Duke Ellington -- [Track 10]. Turnaround / Omette Coleman -- [Track 11]. Julia Florida / Augustin Barrios -- [Track 12]. Estudio 9 / Fernando Sor -- [Track 13]. Billie\u27s bounce / C. Parker -- [Track 14]. Emily / J. Mandel -- [Track 15]. Lagrima, Adelita / F. Tarrega

Concert recording 2013-12-04

[Track 01]. Omaggio / Manuel de Falla -- [Track 02]. Bossa cancao / Frank Basan -- [Track 03]. Spanish study / Frederick Noad -- [Track 04]. Adelita / Francisco Tarrega -- [Track 05]. Everything happens to me / Dennis & Adair -- [Track 06]. 4 on 6 / Wes Montgomery -- [Track 07]. All of me / Simons and Marks -- [Track 08]. Exactly like you / McHugh & Fields -- [Track 09]. Pent up house / Sonny Rollins -- [Track 10]. Ornithology / Charlie Parker -- [Track 11]. Black Orpheus / Luiz Bonfa -- [Track 12]. Bluesette / Toots Thielemans -- [Track 13]. Asturias / Isaac Albeniz

Social Preferences and the Efficiency of Bilateral Exchange

Under what conditions do social preferences, such as altruism or a concern for fair outcomes, generate efficient trade? I analyze theoretically a simple bilateral exchange game: Each player sequentially takes an action that reduces his own material payoff but increases the other player’s. Each player’s preferences may depend on both his/her own material payoff and the other player’s. I identify necessary conditions and sufficient conditions on the players’ preferences for the outcome of their interaction to be Pareto efficient. The results have implications for interpreting the rotten kid theorem, gift exchange in the laboratory, and gift exchange in the field