Communities in university mathematics

This paper concerns communities of learners and teachers that are formed, develop and interact in university mathematics environments through the theoretical lens of Communities of Practice. From this perspective, learning is described as a process of participation and reification in a community in which individuals belong and form their identity through engagement, imagination and alignment. In addition, when inquiry is considered as a fundamental mode of participation, through critical alignment, the community becomes a Community of Inquiry. We discuss these theoretical underpinnings with examples of their application in research in university mathematics education and, in more detail, in two Research Cases which focus on mathematics students' and teachers' perspectives on proof and on engineering students' conceptual understanding of mathematics. The paper concludes with a critical reflection on the theorising of the role of communities in university level teaching and learning and a consideration of ways forward for future research

Surface losses and self-pumping effects in a long Josephson junction - a semi-analytical approach

The flux-flow dynamics in a long Josephson junction is studied both analytically and numerically. A realistic model of the junction is considered by taking into account a nonuniform current distribution, surface losses and self-pumping effects. An approximate analytical solution of the modified sine-Gordon equation is derived in the form of a unidirectional dense fluxon train accompanied by two oppositely directed plasma waves. Next, some macroscopic time-averaged quantities are calculated making possible to evaluate the current-voltage characteristic of the junction. The results obtained by the present method are compared with direct numerical simulations both for the current-voltage characteristics and for the loss factor modulated spatially due to the self-pumping. The comparison shows very good agreement for typical junction parameters but indicates also some limitations of the method.Comment: 7 pages, 5 figure

Performance of silicon solar cell assemblies

Solar cell assembly current-voltage characteristics, thermal-optical properties, and power performance were determined. Solar cell cover glass thermal radiation, optical properties, confidence limits, and temperature intensity effects on maximum power were discussed

Unattended network operations technology assessment study. Technical support for defining advanced satellite systems concepts

The results are summarized of an unattended network operations technology assessment study for the Space Exploration Initiative (SEI). The scope of the work included: (1) identified possible enhancements due to the proposed Mars communications network; (2) identified network operations on Mars; (3) performed a technology assessment of possible supporting technologies based on current and future approaches to network operations; and (4) developed a plan for the testing and development of these technologies. The most important results obtained are as follows: (1) addition of a third Mars Relay Satellite (MRS) and MRS cross link capabilities will enhance the network's fault tolerance capabilities through improved connectivity; (2) network functions can be divided into the six basic ISO network functional groups; (3) distributed artificial intelligence technologies will augment more traditional network management technologies to form the technological infrastructure of a virtually unattended network; and (4) a great effort is required to bring the current network technology levels for manned space communications up to the level needed for an automated fault tolerance Mars communications network

Problematic advice from suicide prevention experts

Based on a 10-year systematic review of suicide prevention strategies, 29 suicide prevention experts from 17 European countries recommend four allegedly evidence-based strategies to be included in national suicide prevention programs. One of the recommended strategies is pharmacological treatment of depression. This recommendation is deeply problematic for several reasons. First, it is based on a biased selection and interpretation of available evidence. Second, the authors have failed to take into consideration the widespread corruption in the research on antidepressants. Third, the many and serious side effects of antidepressants are not considered. Thus, the recommendation may have deleterious consequences for countless numbers of people, and, in fact, contribute to an increase in the suicide rate rather than a decrease

Self- and Partner-objectification in Romantic Relationships: Associations with Media Consumption and Relationship Satisfaction

Few studies have examined objectification in the context of romantic relationships, even though strong theoretical arguments have often made this connection. This study addresses this gap in the literature by examining whether exposure to mass media is related to self-objectification and objectification of one’s partner, which in turn is hypothesized to be related to relationship and sexual satisfaction. A sample of undergraduate students (91 women and 68 men) enrolled in a university on the west coast of the United States completed self-report measures of the following variables: self-objectification, objectification of one’s romantic partner, relationship satisfaction, sexual satisfaction, and exposure to objectifying media. Men reported higher levels of partner objectification than did women; there was no gender difference in self-objectification. Self- and partner-objectification were positively correlated; this correlation was especially strong for men. In regression analyses, partner-objectification was predictive of lower levels of relationship satisfaction. Furthermore, a path model revealed that consuming objectifying media is related to lowered relationship satisfaction through the variable of partner-objectification. Finally, self- and partner-objectification were related to lower levels of sexual satisfaction among men. This study provides evidence for the negative effects of objectification in the context of romantic relationships among young adults

Multidisciplinary Development of Autonomous Underwater Vehicle Fleet

Eco-Dolphin – Cooperative Fleet for Surveillance Mission SIAM, Society for Industrial & Applied Mathematics, members have been working for two years on the design, construction and testing of three highly integrated and streamlined autonomous underwater vehicles called Eco-Dolphins. This project is being developed at Embry-Riddle Aeronautical University’s Daytona Beach campus. The Leverage lab is used to create detailed mathematical models and conduct preliminary research for both electrical and mechanical systems. The campus Composites lab is used for the fabrication of structural and aesthetic components used by the high adaptable platform. The Autonomous Underwater Vehicle testing is conducted in the Universities Nonlinear Waves lab. The first phase of design, production and assembly of the yellow Eco-Dolphin prototype has been done in twelve months. The design includes an internal attitude control system, combined with internal propulsion from brushless direct current thrusters, thus allowing the vehicle to ascend and descend. The Eco-Dolphins promise is to be a unique, highly optimized and a competitive underwater vehicle fleet. The team has also successfully completed the second phase of the program, which involved tracking the Eco-Dolphins while submerged underwater. Work has been conducted to add a GPS system for surface tracking. Converting the acoustic system from tethered to wireless to make the ground station more robust. The Eco-Dolphin is configured with recently developed control system software that utilizes a relay combination of Wireless, Sonar and GPS radio wave communication. The current progress on the blue Eco-dolphin will be completed by the summer of 2014, for testing in littoral waters of central Florida. Through the addition of three sequential (yellow, blue, red) vehicles, therefore allows for better position and orientation data to be sent to the teams buoy network. The three vehicles, three buoy communication structure, multiply the data points collected for surveillance and underwater mapping purposes. This additional complexity improves the reliability and increases the application of the product through error elimination software. The team gives hands on research experience to SIAM members through applied mathematics. The outcome of the research goals, results in the application of many fields of study beyond mathematics. When combined the fleet can cooperatively fulfill multitask missions, advanced surveillance and environmental monitoring can be conducted. This opportunity opens the way for better balance between sustainable developments of the coastline

Linear-response theory of the longitudinal spin Seebeck effect

We theoretically investigate the longitudinal spin Seebeck effect, in which the spin current is injected from a ferromagnet into an attached nonmagnetic metal in a direction parallel to the temperature gradient. Using the fact that the phonon heat current flows intensely into the attached nonmagnetic metal in this particular configuration, we show that the sign of the spin injection signal in the longitudinal spin Seebeck effect can be opposite to that in the conventional transverse spin Seebeck effect when the electron-phonon interaction in the nonmagnetic metal is sufficiently large. Our linear-response approach can explain the sign reversal of the spin injection signal recently observed in the longitudinal spin Seebeck effect.Comment: Proc. of ICM 2012 (Accepted for publication in J. Korean Phys. Soc.), typos correcte