5,928 research outputs found
Drilling system design project 1967: final report of frame design committee
This report outlines the recommendations of the Frame
Design Committee for the final design of the machine, each
major part of the structure being considered individually
in the following sections :
1. Worktables
2. Guide and Slideways
3. Drill Head Support Structure
4. Swarf Disposal and Coolant Supply
5. General Constructio
Problems in the definition and measurement of development and underdevelopment
[Excerpt from introduction.] The essays and chapters submitted here are concerned with the relation between ideas about development and ways of measuring it. They do not have the monographic consistency of a Ph.D. thesis since they were written over a period of 30 years. But I believe that they represent a set of pertinent and relatively consistent interventions in important debates, most of which are continuing. The questions with which they are concerned are relatively constant; the answers less so. This partly reflects reconsideration on the part of the author, and partly the exploration of new paths which have been opened up in the course of the debate during the period covered by the submitted pieces. The methodology used is a consistent one. Most of the pieces are primarily theoretical and lie withing the broad field of political economy. Empirical material is frequently used to back up or form the background to primarily theoretical arguments. The author has not collected primary data but used existing data from a wide range of sources. Such originality as the method possesses comes from the way in which the data are processed, analyzed and presented. In contemporary economics this method is a threatened species, though it is still not extinct. It survives better in economic history than economics and it should be clear from these pieces that some of my principal influences have been economic historians. I am strongly of the view that this kind of interplay between theory and critically assessed empirical material, without much use of econometric methodology, remains a powerful and important method
On Factorization of Molecular Wavefunctions
Recently there has been a renewed interest in the chemical physics literature
of factorization of the position representation eigenfunctions \{\} of
the molecular Schr\"odinger equation as originally proposed by Hunter in the
1970s. The idea is to represent in the form where
is \textit{purely} a function of the nuclear coordinates, while must
depend on both electron and nuclear position variables in the problem. This is
a generalization of the approximate factorization originally proposed by Born
and Oppenheimer, the hope being that an `exact' representation of can be
achieved in this form with and interpretable as `electronic'
and `nuclear' wavefunctions respectively. We offer a mathematical analysis of
these proposals that identifies ambiguities stemming mainly from the
singularities in the Coulomb potential energy.Comment: Manuscript submitted to Journal of Physics A: Mathematical and
Theoretical, May 2015. Accepted for Publication August 24 201
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Rapid Design and Manufacture of Ultralight Cellular Materials
This paper details the design, manufacture and testing of regular metallic lattice structures
with unit cell sizes in the range 0.8mm to 5mm and truss elements of 100-500 µm in diameter [1].
The structures were manufactured using Selective Laser Melting (SLM) technology from 316L
stainless steel. Compression tests have shown yield loadings of over 3.5kN despite being only
18mm by 18mm by 10mm in height, the results are favourably comparable to current
commercially available metallic foams. Software has been developed that creates slice files
without the use of CAD software or STL files and is capable of producing lattices within a
volume defined by a STL file.Mechanical Engineerin
Substorm onset identification using neural networks and Pi2 pulsations
International audienceThe pattern recognition capabilities of artificial neural networks (ANNs) have for the first time been used to identify Pi2 pulsations in magnetometer data, which in turn serve as indicators of substorm onsets and intensifications. The pulsation spectrum was used as input to the ANN and the network was trained to give an output of +1 for Pi2 signatures and -1 for non-Pi2 signatures. In order to evaluate the degree of success of the neural-network procedure for identifying Pi2 pulsations, the ANN was used to scan a number of data sets and the results compared with visual identification of Pi2 signatures. The ANN performed extremely well with a success rate of approximately 90% for Pi2 identification and a timing accuracy generally within 1 min compared to visual identification. A number of potential applications of the neural-network Pi2 scanning procedure are discussed
Overcoming Assessment Challenges - Tipping the Balance
It is well known to primary teachers that effective assessment of children requires a multi-faceted approach (Sparks Linfield 1994). Equally, written feedback on a piece of work is often not understood by the pupils themselves (Sparks Linfield 1995). As one proceeds through secondary and tertiary education, this situation changes little, with the best attempts to set ‘perfect' assessments still leading to misinterpretation by students. It is also true that students often do not always recognise what is meant by the term ‘feedback' and have difficulty in interpreting and understanding the feedback that they receive, even with the most careful and targeted advice in advance. (Sutcliffe et al 2014) In 2010 the National Union of Students released a ‘Charter for Assessment and Feedback' which outlined ten principles for effective assessment and feedback. Despite this charter, the National Student Survey (NSS) in 2014 still showed twenty-eight percent of students were not satisfied. ‘Assessment and feedback was again rated the lowest by students, with just seventy-two percent saying they were satisfied with this, the same level as last year.' (Grove 2014) This poster considers research carried out in 2014 when the Year 2 cohort of students on a Bachelor of Arts Primary Education course were asked to complete a questionnaire inviting views on feedback on assessment they found most helpful in clarifying things they did not understand. Analysis of completed questionnaires revealed that although students' experiences of feedback and assessment within their first year of study had broadly matched the principles outlined within the NUS Charter, twenty-five percent of students still were not satisfied. Results from the cohort showed a desire for a range of types of feedback including a wish for face-to-face discussion to enable them to both assess their understanding of feedback comments and feed-forward actions. In addition, a common theme emerged: a lack of perception by students of their own roles and responsibilities within the assessment/feedback cycle. Recommendations are made for ways to overcome the challenge to provide assessment feedback that aims to give total satisfaction
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