299 research outputs found
A Developmental Model of Research Mentoring
We studied mentoring relationships between undergraduate and graduate students in a summer undergraduate research program, over three years. Using a grounded theory approach, we created a model of research mentoring that describes how the roles of the mentor and the student can change. Whereas previous models of research mentoring ignored student roles and treated mentor roles as static, our model focuses on the development of the mentoring relationship over time. Our model explains how conflicts can occur if the mentor role does not match the maturity level of the student
What Do Students Experience as Peer Leaders of Learning Teams?
In a course for engineering freshmen, peer leaders facilitated optional study sessions, which implemented peer-led team learning workshops. Some leaders were paid teaching assistants, but most were undergraduate volunteers. To understand the experiences of the peer leaders, we asked them to keep weekly reflective journals. By performing a basic qualitative analysis of fourteen journals from two semesters, we developed a description of the experience of leading peer-led team learning workshops over the course of the semester. At the beginning of the semester, the leaders were apprehensive about teaching and concerned with correctly answering students’ questions. As the semester progressed, the leaders were often frustrated with the difficulty of teaching, and the leaders tried new ways of encouraging student participation. At the end of the semester, the leaders reported that they increased self-confidence, developed an appreciation for intellectual diversity, and gained an increased interest in teaching
Self-Efficacy as a Long-Term Outcome of a General Education Course on Digital Technologies
This study investigates the long-term outcomes of a general education course on digital technologies. Through cross-sectional and longitudinal interviews with students, the authors find that self-efficacy is a long-term student outcome. The primary sources of self-efficacy in the course for students were verbal persuasion and mastery experience. Faculty and teaching assistants were key sources for verbal persuasion. Some students experienced a success paradox: they felt successful in the course even though they failed to meet all of their initial expectations. This study can guide faculty in designing a course to promote student self-efficacy
Cell Population Dynamics in Wound-Induced Hair Follicle Neogenesis Model
Hair follicle (HF) regeneration can be achieved in the center of large full-thickness wounds
on mouse backs (wound-induced HF neogenesis model, WIHN). Investigations with this model have
allowed for the identification of some of the factors limiting the extent of fibrosis, which creates a
permissive environment for the reposition of HF. For WIHN, specific subpopulations of cells rather
than cell types are permissive to this process. Detailed information on the cellular composition in
WIHN is not available. Here, we provide a description of changes in cell numbers of fibroblasts,
HF dermal papilla, endothelial cells, keratinocytes (interfollicular epidermis, HF-infundibulum,
HF-isthmus, HF-bulge (basal and suprabasal), HF-hair germ) and immune cells (macrophages,
monocytes, dendritic cells, T cells (CD4+
, CD8+
, CD4+/CD8+
, regulatory T cells) and neutrophils)
based on flow cytometric analysis. We compared unwounded skin with large wounds (1.5 × 1.5 cm)
at different time points after wounding. We found that non-immune dermal cells have the largest
share in the skin at all time points studied, and that the number of epidermal cells started increasing
nine days after wounding, which precede isthmus cells and bulge cells, mirroring the development
of hair follicles. Monocytes and neutrophils represent most myeloid cells in wounds and remain in
wounds even beyond the inflammatory phase of wound healing. Macrophages can be identified as
inflammatory and alternative cells and are also found in wounds even in the late remodeling phase
of wound healing. Lastly, we provide information about T cells in large wounds. Most T cells in the
wounds were CD8+ at all time points and expressed γδTCR, which was previously thought to be
expressed mainly on CD4+
. We also report the existence of double positive CD4/CD8. Our study
provides a guide in terms of time points suitable for the further study of cell subpopulations aiming
to dissect the cellular heterogeneity in WIHN. Our results might set the base for the comparison
of WIHN between control mice and animals manipulated to influence HF neogenesis and the full
understanding of the responsible actors allowing for HF regeneration
Computing Specificity
This note reports on an effort to implement a version of Poole\u27s rule for specificity. Relatively, efficient implementation relies on correcting and improving a pruning lemma of Simari-Loui [92]. This in turn requires revision of Poole\u27s specificity concept. The resulting system is a usable knowledge representation system with first-order-language and defeasible reasoning. Sample input and output are included in an appendix. It is a good candidate for multiple inheritance applications; it is useful for planning, but limited by the underlying search for plans
High-level feature detection from video in TRECVid: a 5-year retrospective of achievements
Successful and effective content-based access to digital
video requires fast, accurate and scalable methods to determine the video content automatically. A variety of contemporary approaches to this rely on text taken from speech within the video, or on matching one video frame against others using low-level characteristics like
colour, texture, or shapes, or on determining and matching objects appearing within the video. Possibly the most important technique, however, is one which determines the presence or absence of a high-level or semantic feature, within a video clip or shot. By utilizing dozens, hundreds or even thousands of such semantic features we can support many kinds of content-based video navigation. Critically however, this depends on being able to determine whether each feature is or is not present in a video clip.
The last 5 years have seen much progress in the development of techniques to determine the presence of semantic features within video. This progress can be tracked in the annual TRECVid benchmarking activity where dozens of research groups measure the effectiveness of their techniques on common data and using an open, metrics-based approach. In this chapter we summarise the work
done on the TRECVid high-level feature task, showing the
progress made year-on-year. This provides a fairly comprehensive statement on where the state-of-the-art is regarding this important task, not just for one research group or for one approach, but across the spectrum. We then use this past and on-going work as a basis for highlighting the trends that are emerging in this area, and the questions which remain to be addressed before we can
achieve large-scale, fast and reliable high-level feature detection on video
Load Balancing in Multiprocessor Systems
Coordinated Science Laboratory was formerly known as Control Systems LaboratoryOffice of Naval Research / N00014-85-K-057
Radar-cross-section reduction of wind turbines. part 1.
In recent years, increasing deployment of large wind-turbine farms has become an issue of growing concern for the radar community. The large radar cross section (RCS) presented by wind turbines interferes with radar operation, and the Doppler shift caused by blade rotation causes problems identifying and tracking moving targets. Each new wind-turbine farm installation must be carefully evaluated for potential disruption of radar operation for air defense, air traffic control, weather sensing, and other applications. Several approaches currently exist to minimize conflict between wind-turbine farms and radar installations, including procedural adjustments, radar upgrades, and proper choice of low-impact wind-farm sites, but each has problems with limited effectiveness or prohibitive cost. An alternative approach, heretofore not technically feasible, is to reduce the RCS of wind turbines to the extent that they can be installed near existing radar installations. This report summarizes efforts to reduce wind-turbine RCS, with a particular emphasis on the blades. The report begins with a survey of the wind-turbine RCS-reduction literature to establish a baseline for comparison. The following topics are then addressed: electromagnetic model development and validation, novel material development, integration into wind-turbine fabrication processes, integrated-absorber design, and wind-turbine RCS modeling. Related topics of interest, including alternative mitigation techniques (procedural, at-the-radar, etc.), an introduction to RCS and electromagnetic scattering, and RCS-reduction modeling techniques, can be found in a previous report
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