The facts about population and urban growth     

Marshall  Alex 《The Urban Review》1973,6(5-6):18-19

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Segmental sequencing of kinetic energy in a computer-simulated golf swing   总被引：1，自引：1，他引：0  

Ian C. Kenny  Alex J. McCloy  Eric S. Wallace  Steve R. Otto 《Sports Engineering》2008,11(1):37-45

The concept of the transfer of kinetic energy (KE) sequentially through the human body from proximal to distal segments is an influential concept in biomechanics literature. The present study develops this area of research through investigation of segmental sequencing of the transfer of KE by means of computer simulation. Using a musculoskeletal computer model previously developed by the authors, driven using three-dimensional kinematic data from a single elite male golfer, combined inverse and forward dynamics analyses enabled derivation of KE. Rigid body segments of torso, hips, arms and clubhead were examined in line with previous literature. Using this method a driver swing was compared to a 7 iron swing. Findings showed a high level of correlation between driver and iron peak KE and timing of peak KE relative to impact. This seems to indicate equivalent trunk and arms linear velocity, thus force applied, for an iron shot and a driver shot. There were highly significant differences between KE output for body segments for both clubs. In addition, peak KE magnitudes increased sequentially from proximal to distal segments during swing simulations for both the driver and 7 iron. This supports the principle of the summation of speed. However, timing of peak KE was not sequential from proximal to distal segments, nor did segments peak simultaneously. Rather, arms peaked first, followed by hips, torso and club. This seems to indicate a subjective optimal coordination of sequencing.

Ian C. KennyEmail:

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Learning to succeed in a flat world: information and communication technologies for a new generation of business students     

Alex Ramirez  Michael J. Hine  Shaobo Ji  Frank Ulbrich  Rob Riordan 《Learning Inquiry》2009,3(3):157-175

This article investigates the relationship of learning and its infrastructure using Web 2.0 technologies to facilitate the acquisition of skills needed to succeed in a global economy. We explore the learning phenomenon as a way to bring forward a process of continuous improvement supported by social software. We use a commonly accepted definition of learning to evaluate different learning theories, since it seems that the definition of learning itself is not a major source of difference between learning theories. Their differences are over issues of interpretation, not over definition. The theories reviewed are used in the design of a framework to assess the infrastructure against expectations of skill proficiency using Web 2.0 tools, i.e., wikis, blogs, social bookmarking, tagging, etc. which must emerge as a result of registering in an introduction to business information and communication technologies (ICT) course in a Canadian university. In this course, we use Friedman’s (The world is flat: a brief history of the twenty-first century release 3.0, Picador, New York, 2007) thesis that the “world is flat” to discuss issues of globalization and the role of ICT. Students registered in the course are usually familiar with some of the tools we introduce and use in the course. The students are members of Facebook or MySpace, regularly check YouTube, and use Wikipedia in their studies. These tools are the tools to socialize. In our course, we broaden the students’ horizons and explore the potential business benefits of such tools and empower the students to use Web 2.0 technologies within a business context.  相似文献   

Efficiency of neutron tomography in visualizing the internal structure of metal artefacts from Mapungubwe museum collection with the aim of conservation     

Farahnaz Koleini  Frikkie de Beer  M.H. Alex Schoeman  Innocent Pikirayi  Shadreck Chirikur  Gawie Nothnagel  Jacob Mabuti Radebe 《Journal of Cultural Heritage》2012,13(3):246-253

AimEstimating physical stability as well as revealing signs of fabrication in metal artefacts via two complementary nondestructive methods, neutron- and X-ray tomography were the main goals of this study.AbstractTo aid conservation management of metal artefacts improved knowledge of the internal structure and degree of corrosion therein is highly desired. In this study, neutron- and X-ray tomography were chosen as two complementary noninvasive visualization techniques to study internal structure and corrosion of five representative examples of archaeological metal artefacts from the Mapungubwe museum collection. Tomography was performed at the Neutron Radiography (SANRAD) facility of the South African Nuclear Energy Corporation where thermal neutrons as well as complementary X-rays are conveniently available under one roof. Comparative studies revealed neutron tomography to be generally superior to X-ray tomography due to the enhanced penetration properties of neutrons through the metal objects. In this paper the rich capability of neutron tomography as a nondestructive visualization aid for scientific conservation purposes is introduced and supported by results achieved for the five selected real artefacts.  相似文献   

Structure vs. content in hierarchical corpora     

Alex Penev  Raymond K. Wong 《Information Retrieval》2010,13(6):636-656

We propose and describe Parameterized filesystem HITS (PFH), a lightweight rearrangement algorithm that performs a re-ranking of existing content-only search results in tree-like hierarchical corpora, such as a filesystem. PFH does this by combining the content analysis of the results with structural analysis of how they are organized. An α parameter is used to vary the structure-content bias, allowing us to observe changes in performance when we place more emphasis on structure or on content. Using real and simulated data, experiments are provided to show that α = 0.8 (i.e, 20% structure and 80% content) can substantially boost Mean Reciprocal Rank while keeping other IR metrics steady. Such an algorithm may be useful for building retrieval systems over hierarchical content such as Desktop Search, technical documents and books.  相似文献   

Keith Houston: The Book: A Cover-to-Cover Exploration of the Most Powerful Object of Our Time     

Alex Grover 《Publishing Research Quarterly》2017,33(2):194-195

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Making Meaning of History     

Alex Pomson 《Journal of Jewish Education》2016,82(2):114-116

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Conquérir et gouverner la Sicile islamique aux XIe et XIIe siècles     

Alex Mallett 《Al-Masaq: Islam & the Medieval Mediterranean》2014,26(3):330-331

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Improving Mathematics Instruction and Learning in the Junior High School: An Israeli Example     

Barbara Fresko  Naomi Robinson  Alex Friedlander  Jeanne Albert  Neli Argaman 《School Effectiveness & School Improvement》2013,24(3):170-187

Abstract

A 4‐year project is described which was designed to improve mathematics instruction and achievements in two Israeli junior high schools. Project activities focused on the individual teachers, the mathematics staff, and the organization of instruction at the school level, under the assumption that more efficient teaching would lead to greater pupil learning.

Evaluation data gathered from classroom observation, questionnaires and tests indicated a general positive impact: many teachers improved their teaching strategies, more curricular material was being covered in class, a school‐wide program for mathematics instruction was established, teamwork among teachers was formalized, and pupil achievements improved.  相似文献   

The Toys’ Party     

Roderick Hunt  Alex Brychta 《英语大王(小学)》2014,(Z1):4-7

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