1,114 research outputs found

    Many Children Left Behind? Textbooks and Test Scores in Kenya

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    A randomized evaluation suggests that a program which provided official textbooks to randomly selected rural Kenyan primary schools did not increase test scores for the average student. In contrast, the previous literature suggests that textbook provision has a large impact on test scores. Disaggregating the results by students? initial academic achievement suggests a potential explanation for the lack of an overall impact. Textbooks increased scores for students with high initial academic achievement and increased the probability that the students who had made it to the selective final year of primary school would go on to secondary school. However, students with weaker academic backgrounds did not benefit from the textbooks. Many pupils could not read the textbooks, which are written in English, most students? third language. The results are consistent with the hypothesis that the Kenyan education system and curricular materials are oriented to the academically strongest students rather than to typical students. More generally, many students may be left behind in societies that combine 1) a centralized, unified education system; 2) the heterogeneity in student preparation associated with rapid expansion of education; and 3) disproportionate elite power.

    Teacher Incentives

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    Advocates of teacher incentive programs argue that they can strengthen weak incentives, while opponents argue they lead to teaching to the test.' We find evidence that existing teacher incentives in Kenya are indeed weak, with teachers absent 20% of the time. We then report on a randomized evaluation of a program that provided primary school teachers in rural Kenya with incentives based on students' test scores. Students in program schools had higher test scores, significantly so on at least some exams, during the time the program was in place. An examination of the channels through which this effect took place, however, provides little evidence of more teacher effort aimed at increasing long-run learning. Teacher attendance did not improve, homework assignment did not increase, and pedagogy did not change. There is, however, evidence that teachers increased effort to raise short-run test scores by conducting more test preparation sessions. While students in treatment schools scored higher than their counterparts in comparison schools during the life of the program, they did not retain these gains after the end of the program, consistent with the hypothesis that teachers focused on manipulating short-run scores. In order to discourage dropouts, students who did not test were assigned low scores. Program schools had the same dropout rate as comparison schools, but a higher percentage of students in program schools took the test.

    University embeddedness: Validating a new means for predicting retention and curbing dropout

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    Student retention is a significant issue for the higher education sector. There is need for a tool that can reliably identify students at risk of dropout or before their performance begins to deteriorate. Borrowing a relatively new concept from organisational psychology that has been found to reliably determine how “enmeshed” or “embedded” an employee is within their employment, the “university embeddedness” concept was tested using data from an online survey. Structural Equation Modeling revealed some encouraging results in support of future development of the new construct, however certain hurdles remain

    MASS TIMBER CONSTRUCTION IN AUSTRALIA AND NEW ZEALAND—STATUS, AND ECONOMIC AND ENVIRONMENTAL INFLUENCES ON ADOPTION

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    Mass timber construction in Australia and New Zealand uses three main materials—laminated veneer lumber, glue laminated timber and cross-laminated timber (CLT). This article focuses on the use of mass timber in nonresidential construction—the use in single-family homes and apartments is not considered. In Australia and New Zealand, mass timber building technology has moved from being technologically possible to being a feasible alternative to reinforced concrete and steel construction. It has not taken over a large market share in either market and, as such, has not been a disruptive technology. The major changes in this market in the past 5-10 yr in Australia and New Zealand have been the development of new industrial capacity in CLT and the acquisition of computer controlled machining equipment to facilitate prefabrication of wooden building components. The development of new codes and standards and design guides is underway. The drivers of future growth in market share are expected to include more clients putting a higher weight on the various environmental benefits of building in wood, reduction in the real and perceived professional risk for builders and architects specifying mass timber construction, and fuller participation in the supply chain for timber buildings (from design to construction) by timber building specialists. Government policies to encourage the use of timber may also be helpful. Engineers and architects will continue to learn—through experience—how to optimize building construction methods to take advantage of the specific features and qualities of timber as a construction method. 

    Pull-out resistance of slef-tapping screws in cross-laminated timber made from radiata pine

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    Cross-laminated timber (CLT) is now considered a viable alternative to traditional construction materials both in mid-rise and high-rise structures. The structural response of CLT heavily relies on the type of timber used in manufacturing, and this can vary significantly based on the original source for this naturally grown raw material. Spruce has been widely used in Europe for CLT production, but in Australia, locally available radiata pine is used by XLam for the manufacturing of their CLT panels. Self-tapping screws (STS) are typically recommended by CLT manufacturers and are most commonly used in relevant construction due to their high load carrying capacities and easy installation process. VGS STSs produced by Rothoblaas were used to investigate their composite actions when pulled-out from three-layer XLam CLT panels with thicknesses of 105 mm and 135 mm. VGS screws with 11 mm in diameter were inserted both parallel-to-grain and perpendicular-to-grain on the narrow face of the CLT panels as part of the current study. Typical failure modes as well as critical penetration depths were carefully recorded. Obtained results showed significant increase of pull-out capacity as penetration depths were increased for considered cases. However, experimental results also showed some obvious inconsistencies. These observations clearly demonstrate the challenges associated with working naturally grown fibrous materials and highlights the importance of major research on this field

    S-Nav: Semantic-Geometric Planning for Mobile Robots

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    Path planning is a basic capability of autonomous mobile robots. Former approaches in path planning exploit only the given geometric information from the environment without leveraging the inherent semantics within the environment. The recently presented S-Graphs constructs 3D situational graphs incorporating geometric, semantic, and relational aspects between the elements to improve the overall scene understanding and the localization of the robot. But these works do not exploit the underlying semantic graphs for improving the path planning for mobile robots. To that aim, in this paper, we present S-Nav a novel semantic-geometric path planner for mobile robots. It leverages S-Graphs to enable fast and robust hierarchical high-level planning in complex indoor environments. The hierarchical architecture of S-Nav adds a novel semantic search on top of a traditional geometric planner as well as precise map reconstruction from S-Graphs to improve planning speed, robustness, and path quality. We demonstrate improved results of S-Nav in a synthetic environment.Comment: 6 pages, 4 figure

    Five High Performing Charter Schools Case Studies and Analysis: What Makes Them Successful?

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    Five charter schools were identified by high achievement (state-wide test results), high attendance, low turnover of students and staff, high parent and staff satisfaction and at least two contract renewals (met contract requirements) over a 10 year period. Four of five schools had 75% free and reduced lunch indicating low SES with minority population exceeding 80% enrollment. Each school was assigned a team member to observe all classes, interview teachers, school leadership and relevant staff over a 10 month period in the 2011-12 school year. Results identified six elements across all five schools that contribute to successful schools. The variables are 1) leadership, 2) shared mission, values and beliefs, 3) community as defined by mission, 4) high academic expectations, 5) positive behavior expectations, and 6) agreed upon processes and practices. While implementation of these six variables varied across schools, these elements were readily observable in shaping a school’s success

    A Lightweight Universal Gripper with Low Activation Force for Aerial Grasping

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    Soft robotic grippers have numerous advantages that address challenges in dynamic aerial grasping. Typical multi-fingered soft grippers recently showcased for aerial grasping are highly dependent on the direction of the target object for successful grasping. This study pushes the boundaries of dynamic aerial grasping by developing an omnidirectional system for autonomous aerial manipulation. In particular, the paper investigates the design, fabrication, and experimental verification of a novel, highly integrated, modular, sensor-rich, universal jamming gripper specifically designed for aerial applications. Leveraging recent developments in particle jamming and soft granular materials, the presented gripper produces a substantial holding force while being very lightweight, energy-efficient and only requiring a low activation force. We show that the holding force can be improved by up to 50% by adding an additive to the membrane's silicone mixture. The experiments show that our lightweight gripper can develop up to 15N of holding force with an activation force as low as 2.5N, even without geometric interlocking. Finally, a pick and release task is performed under real-world conditions by mounting the gripper onto a multi-copter. The developed aerial grasping system features many useful properties, such as resilience and robustness to collisions and the inherent passive compliance which decouples the UAV from the environment.Comment: 21 pages, 19 figures; corrected affiliation

    Profiling the Australian high performance and sports science workforce

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    Australia is viewed as leader in the field of sports science, with Australian sports scientists highly sought after and respected worldwide. However, despite the important contribution of sports scientists to the development of professional sport in Australia, we know little about these sport professionals who play an important role in the development and success of athletes, teams and sport organisations.This report provides a more formal understanding of the high performance and sports science workforce with the purpose of informing the policy development of Australia’s sport governing bodies and education providers to inform sport management practices that will enhance the support and development of current and future high performance managers and sports scientists. The data presented in this report provides valuable insight about the scope of the profession to enable further development of strategic plans for the industry

    The imprint of superradiance on hierarchical black hole mergers

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    Ultralight bosons are a proposed solution to outstanding problems in cosmology and particle physics: they provide a dark-matter candidate while potentially explaining the strong charge-parity problem. If they exist, ultralight bosons can interact with black holes through the superradiant instability. In this work we explore the consequences of this instability on the evolution of hierarchical black holes within dense stellar clusters. By reducing the spin of individual black holes, superradiance reduce the recoil velocity of merging binary black holes, which, in turn, increases the retention fraction of hierarchical merger remnants. We show that the existence of ultralight bosons with mass 2×10−14≲μ/eV≲2×10−13 2\times10^{-14}\lesssim \mu/\textrm{eV} \lesssim2\times10^{-13} would lead to an increased rate of hierarchical black hole mergers in nuclear star clusters. An ultralight boson in this energy range would result in up to ≈60%\approx60\% more present-day nuclear star clusters supporting hierarchical growth. The presence of an ultralight boson can also double the rate of intermediate mass black hole mergers to ≈0.08\approx0.08\,Gpc−3^{-3}\,yr−1^{-1} in the local Universe. These results imply that a select range of ultralight boson mass can have far-reaching consequences for the population of black holes in dense stellar environments. Future studies into black hole cluster populations and the spin distribution of hierarchically formed black holes will test this scenario.Comment: 20 pages, 7 figure
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