Design study for LANDSAT D attitude control system

A design and performance evaluation is presented for the LANDSAT D attitude control system (ACS). Control and configuration of the gimballed Ku-band antenna system for communication with the tracking and data relay satellite (TDRS). Control of the solar array drive considered part of the ACS is also addressed

Using LibGuides as a Web 2.0 content management system and a collaboration tool for engineering librarians

With the implementation of the most widely used research guide platform LibGuides, librarians can adopt a Library 2.0 presence with minimal effort at a reasonable cost. This paper will discuss how this content management system integrates a multitude of Web 2.0 features, allowing librarians to create an interactive research environment with their users. LibGuides can also serve as a communication portal between engineering librarians and as an effective resource sharing tool. Springshare, the maker of LibGuides, has created several methods of promoting resource sharing, including the LibGuides Community, the Springshare Lounge, and a blog where Springshare employees can share the latest news about LibGuides and their other products. Although lacking some of the Web 2.0 components like end-user accounts, thus preventing it from being a full-blown Web 2.0 system, LibGuides does much to bridge the gap between a static Library 1.0 website and a Library 2.0 website

Understanding Social Factors in Small Group Work in Undergraduate Mathematics Classrooms

To address the ongoing labor shortage for jobs in science, technology, engineering, and mathematics (STEM) fields, many different initiatives have been undertaken by practitioners, instructors, and researchers. Two major ones have been efforts to improve undergraduate mathematics instruction and to increase diversity and inclusiveness in STEM fields, including with regards to gender identity and sexual orientation. One major ongoing shift in undergraduate mathematics instruction is a shift to increase active learning, often through tasking students to engage in collaborative problem solving in small groups. It is known that active learning strategies like these improve student outcomes over the use of lecture alone. However, there is much less research considering how the social nature of group work can affect student experience in their undergraduate mathematics classes that use it. Social factors outside of the mathematical content could be expected to play a role when learning through group work, an inherently social activity; moreover, these factors could play a greater role for students who have traditionally been excluded from STEM environments. To better understand how social factors may influence student participation and experience in small group work in undergraduate mathematics classrooms, a study was conducted that incorporated video-taped in-class observations of students working in small groups along with stimulated recall interviews of students individually. A taxonomy by Chiu (2000b) was used to interpret, code, and analyze actions taken by the participants in group work, with interviews coded in terms of what ideas students discussed in response to selected interactions. From analysis of the observations and interviews, three main findings are drawn. First, social unfamiliarity among group members can negatively influence a student’s experience within a group and the group’s overall ability to collaborate. Second, student gender identities and beliefs about how gender and mathematics are related can also play a role, especially when students are unfamiliar with each other, although these data do not suggest exactly when or how this can happen. Third, students may work together ways that are socially productive, but are not mathematically productive. These takeaways broaden our understanding of how groups work in undergraduate mathematics classes while also setting some clear directions for future research on this topic

Linking Electronic Resources to Save Research Time

Linking of electronic resources to save research time was discussed. The library at Rose-Hulman Institute of Technology utilized the features of Online Public Access Catalog (OPAC) to create a more dynamic and simpler searching process. Most commercial online databases allow the subscribing library to adapt access to the local environment via the local administrator component. Some commercial databases, such as a ProQuest allow the librarian to include information about the format, years of coverage, and a link to the online location if it is an online journal

Terpenoid-Induced Feeding Deterrence and Antennal Response of Honey Bees

Multiple interacting stressors negatively affect the survival and productivity of managed honey bee colonies. Pesticides remain a primary concern for beekeepers, as even sublethal exposures can reduce bee immunocompetence, impair navigation, and reduce social communication. Pollinator protection focuses on pesticide application guidelines; however, a more active protection strategy is needed. One possible approach is the use of feeding deterrents that can be delivered as an additive during pesticide application. The goal of this study was to validate a laboratory assay designed to rapidly screen compounds for behavioral changes related to feeding or feeding deterrence. The results of this investigation demonstrated that the synthetic Nasonov pheromone and its terpenoid constituents citral, nerol, and geraniol could alter feeding behavior in a laboratory assay. Additionally, electroantennogram assays revealed that these terpenoids elicited some response in the antennae; however, only a synthetic Nasonov pheromone, citral, and geraniol elicited responses that differed significantly from control and vehicle detections

The production deployment of IPv6 on WLCG

The world is rapidly running out of IPv4 addresses; the number of IPv6 end systems connected to the internet is increasing; WLCG and the LHC experiments may soon have access to worker nodes and/or virtual machines (VMs) possessing only an IPv6 routable address. The HEPiX IPv6 Working Group has been investigating, testing and planning for dual-stack services on WLCG for several years. Following feedback from our working group, many of the storage technologies in use on WLCG have recently been made IPv6-capable. This paper presents the IPv6 requirements, tests and plans of the LHC experiments together with the tests performed on the group's IPv6 test-bed. This is primarily aimed at IPv6-only worker nodes or VMs accessing several different implementations of a global dual-stack federated storage service. Finally the plans for deployment of production dual-stack WLCG services are presented

Level attraction in a microwave optomechanical circuit

Level repulsion - the opening of a gap between two degenerate modes due to coupling - is ubiquitous anywhere from solid state theory to quantum chemistry. In contrast, if one mode has negative energy, the mode frequencies attract instead. They converge and develop imaginary components, leading to an instability; an exceptional point marks the transition. This, however, only occurs if the dissipation rates of the two modes are comparable. Here we expose a theoretical framework for the general phenomenon and realize it experimentally through engineered dissipation in a multimode superconducting microwave optomechanical circuit. Level attraction is observed for a mechanical oscillator and a superconducting microwave cavity, while an auxiliary cavity is used for sideband cooling. Two exceptional points are demonstrated that could be exploited for their topological properties.Comment: 5 pages, 4 figures; includes Supplementary informatio

Design study for LANDSAT-D attitude control system

The gimballed Ku-band antenna system for communication with TDRS was studied. By means of an error analysis it was demonstrated that the antenna cannot be open loop pointed to TDRS by an onboard programmer, but that an autotrack system was required. After some tradeoffs, a two-axis, azimuth-elevation type gimbal configuration was recommended for the antenna. It is shown that gimbal lock only occurs when LANDSAT-D is over water where a temporary loss of the communication link to TDRS is of no consequence. A preliminary gimbal control system design is also presented. A digital computer program was written that computes antenna gimbal angle profiles, assesses percent antenna beam interference with the solar array, and determines whether the spacecraft is over land or water, a lighted earth or a dark earth, and whether the spacecraft is in eclipse