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991.
992.
In this paper, a new novelty detection approach based on the identification of sentence level information patterns is proposed. First, “novelty” is redefined based on the proposed information patterns, and several different types of information patterns are given corresponding to different types of users’ information needs. Second, a thorough analysis of sentence level information patterns is elaborated using data from the TREC novelty tracks, including sentence lengths, named entities (NEs), and sentence level opinion patterns. Finally, a unified information-pattern-based approach to novelty detection (ip-BAND) is presented for both specific NE topics and more general topics. Experiments on novelty detection on data from the TREC 2002, 2003 and 2004 novelty tracks show that the proposed approach significantly improves the performance of novelty detection in terms of precision at top ranks. Future research directions are suggested. 相似文献
993.
Since coming to office in May 1997, the British Labour Government, with its commitment to social inclusion, has undertaken various policy initiatives to broaden access to public sector occupations, including teaching. In this paper, we focus on the participation of ethnic minority students in the Postgraduate Certificate in Education (PGCE). We present the findings of a national empirical study drawing on data from a questionnaire survey and interviews with PGCE staff and students. Particular consideration is given to the students' motives for entering teaching and their images of the profession; the factors influencing their choice of course and institution; their experiences during training and their perceptions of the constraints upon ethnic minority recruitment. We also consider the strategies employed by PGCE staff to attract and retain ethnic minority recruits to the PGCE, and examine the dilemmas that they face when responding to ethnic diversity. We conclude with a discussion of the policy implications of the research and a commentary on the methodology employed in the research. Dès son début en mai 1997, le gouvernement travailliste du Royaume-Uni a suivi des politiques favorisant l'accès des minorités aux carrières dans les services publics, y compris celles de l'enseignement. Dans cet exposé, nous nous concentrons sur la participation d'étudiants de minorités ethniques au Postgraduate Certificate in Education (PGCE). Nous présentons les résultats d'une large étude empirique utilisant les données obtenues à partir d'une enquête nationale et d'entretiens avec les professeurs et les étudiants du PGCE. En particulier, nous examinons les motivations qui font que les e´tudiants choisissent une carrière d'enseignant et leur image de la profession; les influences sur leur choix de cours et d'université; leurs expériences pendant la formation et leur avis sur les contraintes qui empêchent le recrutement des minorités ethniques. Nous discutons aussi les stratégies suivies par les universités pour attirer et retenir les e´tudiants de minorités ethniques, et nous examinons les dilemmes qui se présentent. Finalement, nous discutons des portées de cette recherche sur la politique nationale, et de la méthodologie de l'étude. Desde la instauración del gobierno laborista Británico en Mayo de 1997, y dado su compromiso en materia de inclusión social, éste ha llevado a cabo varias iniciativas con el fin de ampliar el acceso a las ocupaciones del sector público, incluyendo la profesión de educador, a las minorías étnicas. En este artículo, los autores examinan la participación de estudiantes en los Programas de Post-Graduados en Educación (PGCE) en Inglaterra y Gales. Se presentan los resultados de un estudio de gran escala obtenido a través de la aplicación de un cuestionario nacional y de entrevistas con el personal y los estudiantes de los programas de PGCE. Se presta atención especial a la motivación de los estudiantes para ingresar a la profesión de educador y a la imagen que tienen de la profesión; los factores que influencian su elección tanto de programa como de institución; sus experiencias durante la formación; y sus percepciones sobre las dificultades del reclutamiento de minorías étnicas. Los autores también consideran las estrategias empleadas por el personal de los programas del PGCE para atraer y retener a alumnos de minorías étnicas y examinan los dilemas que se encuentran frente a la diversidad étnica. El artículo concluye con una discusión sobre las implicaciones de esta investigación en las políticas. Seit ihrem Antritt im Mai 1997 hat die neue Britische Regierung eine Politik der Erleichterung des Zuganges fuer Vertreter ethnischer Minderheiten in Berufe des öffentlichen Dienstes verfolgt. Diese Politik schliesst auch den Berufsstand der Lehrer ein. Der vorliegende Beitrag konzentriert sich auf Studenten ethnischer Minderheiten, die an PGCE Programmen in England und Wales teilnehmen. Es werden Ergebnisse einer grossangelegten Studie präsentiert, deren Daten aus einer landesweiten Umfrage (per Fragebogen) und Interviews von Lehrern und Studenten der PGCE Programme stammen. Besondere Aufmerksamkeit wurde auf folgende Aspekte gerichtet: Was ist die Motivation der Studenten das Lehrfach zu wählen? Welche Vorstellungen haben die Studenten von dem von ihnen gewählten Beruf? Welche Faktoren beeinflusste sie bei der Wahl ihrer Kurse und Ausbildungsstaette? Welche Eindrücke und Erfahrungen machten sie während der Ausbildung? Wie schätzen sie die Probleme und Hindernisse bei der Anwerbung von Vertretern ethnischer Minderheiten für den Lehrerberuf ein? Strategien von PGCE Lehrern eingeschriebene Studenten etnischer Minderheiten zu behalten und neue anzuwerben wurden ebenso bedacht, wie auch die Probleme die daraus entstehen können. Der Beitrag endet mit einer Diskussion von möglichen Auswirkungen der Studie auf die von der britischen Regierung verfolgten Politik. 相似文献
994.
Executive Functions in Young Children with Autism 总被引:17,自引:0,他引:17
Elizabeth M. Griffith Bruce F. Pennington Elizabeth A. Wehner & Sally J. Rogers 《Child development》1999,70(4):817-832
The executive dysfunction hypothesis of autism has received support from most studies of older people with autism; however, studies of young children have produced mixed results. Two studies are presented that compare the performance of preschoolers with autism (mean = 51 months/4.3 years of age) to a control group matched on age, and verbal and nonverbal ability. The first study (n = 18 autism and 17 control) found no group differences in performance on 8 executive function tasks (A not B, Object Retrieval, A not B with Invisible Displacement, 3-Boxes Stationary and Scrambled, 6-Boxes Stationary and Scrambled, and Spatial Reversal), but did find that children with autism initiated fewer joint attention and social interaction behaviors. The second (longitudinal) study of a subset of the children (n = 13 autism and 11 control) from the first study found that neither groups' performance on Spatial Reversal changed significantly over the course of a year. The results of these studies pose a serious challenge to the executive dysfunction hypothesis of autism. 相似文献
995.
Malcolm S. MacLean Bruce H. Westley 《Educational technology research and development : ETR & D》1955,3(2):119-137
Summary In these two articles we have proposed a schematic theoretical model for the study of communication, one which subsumes both
face-to-face and mass communication but is intended as an orientation to a general theory of mass communication. In addition
we have used the model as a framework for a review of a part of the literature of mass communication and have attempted a
brief assessment of the present state of our knowledge of the field.
This paper presents one application of the authors’ conceptual model of the communication process published in the last issue
of AVCR. Here they are attempting to order the existing research findings on “fortuitous” communication in relationship to
their model. Malcolm S. MacLean, Jr., and Bruce H. Westley are assistant professors of Journalism, The University of Wisconsin. 相似文献
996.
The aim of this study was to assess the effect of pitch length (20.12 m [full length], 18 m and 16 m) on the fast bowling performance and technique of junior cricketers. Performance measures included ball release speed and accuracy, while technique variables evaluated were those shown to be related to the aetiology of lower back injury. Thirty-seven fast bowlers from the under-11 (n=14), under-13 (n=11) and under-15 (n=12) age groups were filmed bowling five deliveries at each of the above pitch lengths. Two synchronized NAC video cameras operating at 200 Hz permitted three-dimensional reconstruction of the hip and shoulder alignments, while a standard digital video camera operating at 50 Hz (positioned perpendicular to the bowling action) was used to measure front knee angle and ball release speed. Accuracy scores were taken from a zoned target at the batsman's stumps. A two-way analysis of variance with repeated measures (with age and pitch length as the between- and within-participant variables, respectively) was used to compare each age group at the 0.05 significance level. Results showed that accuracy improved in all age groups at shorter pitch lengths, although ball velocity remained constant throughout all trials. Shoulder counter-rotation increased significantly for the under-13 bowlers when bowling on the full-length pitch in comparison with the two shorter lengths. Counter-rotation also increased on the full-length pitch in the under-11 age group, although this increase was not significant. The under-15 bowlers' techniques did not change as pitch length increased. As under-11 and under-13 bowlers adopted a "safer" bowling action with superior accuracy on the 18?m compared with the full length pitch, it was concluded that these age groups should bowl on an 18?m pitch to reduce the likelihood of lower back injuries and improve accuracy. 相似文献
997.
We examined the factors affecting the outcome of cricket matches played in the English one-day county cricket league. In particular, we focused on the home-field effect and the importance of winning the pre-match toss of a coin to determine a team's strategic decision to bat first or second. A home-field effect appeared to be confirmed in that home teams won 57% of all matches with a win/loss result. A logistical regression model was used, with the outcome variable defined in terms of a home team win/loss. We found that while winning the toss is an important aspect of a one-day cricket match, other factors tend to dominate in determining the result, especially team quality and match importance for the home and away teams in the overall league context. Our results also indicate, not surprisingly given the nature of cricket attendance and spectating, that the crowd effect is largely insignificant. The results of our study do not support any rule changes requiring the abandonment of the coin toss to determine batting order. 相似文献
998.
999.
Reid M Elliott B 《Sports biomechanics / International Society of Biomechanics in Sports》2002,1(1):47-68
The study investigated differences in the one- (SH) and two-handed (DH) backhands when hit flat, across-court (AC) and down-the-line (DL), and with heavy topspin DL (TDL). The ability to disguise each of these backhands when hitting the above strokes was also assessed. Eighteen college-level male tennis players, identified as having a high performance topspin SH (n = 6) or DH (n = 12) backhand drive, participated in the study. Players were required to hit three AC, DL and TDL backhands from the baseline with their preferred technique, while being filmed with two high-speed video cameras operating at 200 Hz. The highest horizontal velocity backhand for each stroke was analysed. Results indicated that the sequential coordination of five body segments (hips, shoulder, upper arm, forearm, and hand/racquet rotations) was required for the execution of the SH stroke. The same number of segments were generally coordinated in the DH stroke (hips, shoulders, and varying degrees of upper arm and forearm rotations followed by hand/racquet movement). Mature players produced comparable racquet horizontal velocities 0.005 s prior to impact using either the SH or DH backhand technique. The SH backhand was characterised by a more rotated shoulder alignment than the DH stroke (SH: 119.1 degrees; DH: 83.4 degrees) at the completion of the backswing. At impact the ball was impacted further in front (SH: 0.59 m: DH: 0.40 m) and a similar distance to the side of the body (SH: 0.75 m: DH: 0.70 m). Players using the DH backhand technique delayed the horizontal acceleration of the racquet towards the ball (SH: 0.13 s: DH: 0.08 s prior to impact) and thus were capable of displaying a similar hitting motion closer to impact than players with a SH technique. 相似文献
1000.