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941.
N. V. Avakumova N. M. Chernavskaya T. B. Pleskacheva 《Scientific and Technical Information Processing》2007,34(4):202-205
The paper presents the results of the analysis of information sources, including both traditional print media and electronic resources on ecological and economic problems available on Internet sites. The most significant printed periodicals and Internet sites are determined in a given subject field. The possibility is considered of finding necessary information from an Internet resource with the help of the hypertext structure on the site of the information-retrieval system Ecological Information. 相似文献
942.
E. N. Vasina O. L. Golitsyna N. V. Maksimov 《Scientific and Technical Information Processing》2007,34(3):117-130
In the context of system analysis, the architecture of a computerized information retrieval system adjusted to a support professional problem-oriented interactive documentary retrieving is considered. In addition to standard and extended retrieval capabilities, such a system must contain aids for generating and systematizing information files, generating and using components for linguistic support, and aids for estimating and analyzing the results of the retrieval. 相似文献
943.
The triple jump is a demanding field event in which a jumper must tolerate extremely high impact forces while maintaining high horizontal speed. The present study was designed to clarify the mechanical loading characteristics and the role of neuromuscular function in the triple jump. Seven national triple jumpers (4 males, 3 females) volunteered to perform 3-6 jumps. The mean best performances were 14.32+/-0.45 m and 11.90+/-0.28 m for males and females, respectively. The three longest triple jumps for each jumper were selected for final analysis. The mean contact times were 0.139 s (hop), 0.157 s (step) and 0.177 s (jump). The largest ground reaction forces were observed in the step (15.2 times body weight), while the highest peak pressures were recorded under the heel and forefoot. The plantar pressure of the lateral side of the forefoot was highly related to the length of the triple jump (P < 0.05-0.01). In addition, electromyograms of both legs Suggested that mechanical loading places high demands on the neuromuscular system, as characterized by the high rate of activation in the pre-activity phase followed by high eccentric activity. Thus, the high activities of the gastrocnemius, vastus lateralis and hip extensor muscles seem to play an important role in preventing unnecessary yielding of the jumper during the braking phase. 相似文献
944.
945.
We contend that generalizability (G) theory allows the design of psychometric approaches to testing English-language learners (ELLs) that are consistent with current thinking in linguistics. We used G theory to estimate the amount of measurement error due to code (language or dialect). Fourth- and fifth-grade ELLs, native speakers of Haitian-Creole from two speech communities, were given the same set of mathematics items in the standard English and standard Haitian-Creole dialects (Sample 1) or in the standard and local dialects of Haitian-Creole (Samples 2 and 3). The largest measurement error observed was produced by the interaction of student, item, and code. Our results indicate that the reliability and dependability of ELL achievement measures is affected by two facts that operate in combination: Each test item poses a unique set of linguistic challenges and each student has a unique set of linguistic strengths and weaknesses. This sensitivity to language appears to take place at the level of dialect. Also, students from different speech communities within the same broad linguistic group may differ considerably in the number of items needed to obtain dependable measures of their academic achievement. Whether students are tested in English or in their first language, dialect variation needs to be considered if language as a source of measurement error is to be effectively addressed. 相似文献
946.
CRANDALL VJ 《Child development》1956,27(2):197-203
947.
Accelerometers record total physical activity and time spent at different intensities. Pedometers indicate total activity only. The aim of this study was to assess the relationship between pedometer counts and attainment of > or = 60 min of moderate activity. Thirty-four children, ages 8-10 years, wore a Tritrac accelerometer and Yamax pedometer. Published recommendations of steps per day were compared to attainment of > or = 60 min moderate activity. Boys who accumulated 13,000 steps.d(-1) and girls who accumulated 12,000 steps.d(-1) engaged in > or = 60 min moderate activity. However, 23% of boys and 15% of girls did not reach the pedometer thresholds but did engage in > or = 60 min moderate activity. In conclusion, these pedometer thresholds provide a reasonable estimation when assessment of physical activity intensity is not possible. 相似文献
948.
Der Artikel untersucht, wie Probleme, die speziell beim Unit-Testen objektorientierter Programme auftreten, mit Hilfe des
Paradigmas aspektorientierte Programmierung gel?st werden k?nnen.
Die Untersuchung stellt Schritt für Schritt die einzelnen Teilprobleme vor, f"uhrt konventionelle L?sungen auf, zeigt aspektorientierte
Alternativen für die gestellten Probleme und erl"autert anhand von Code-Beispielen ihre Implementierung in der Sprache AspectJ. 相似文献
949.
Walton LJ Hasson S Ross FV Martin ER 《Bulletin of the Medical Library Association》2000,88(2):165-171
In 1995, the National Library of Medicine (NLM) and the Public Health Service (PHS) recommended that special attention be given to the information needs of unaffiliated public health professionals. In response, the National Network of Libraries of Medicine (NN/LM) Greater Midwest Region initiated a collaborative outreach program for public health professionals working in rural east and central Iowa. Five public health agencies were provided equipment, training, and support for accessing the Internet. Key factors in the success of this project were: (1) the role of collaborating agencies in the implementation and ongoing success of information access outreach projects; (2) knowledge of the socio-cultural factors that influence the information-seeking habits of project participants (public health professionals); and (3) management of changing or varying technological infrastructures. Working with their funding, personnel from federal, state, and local governments enhanced the information-seeking skills of public health professionals in rural eastern and central Iowa communities. 相似文献
950.
Variability of impact kinematics and margin for error in the tennis forehand of advanced players 总被引:1,自引:1,他引:0
The kinematics of the racket and ball near impact in tennis forehands were studied to document typical variation in successful
and unsuccessful shots, in order to determine biomechanically meaningful differences in advanced players and confirm models
of groundstroke trajectories. Seven tennis players (six males and one female) were videoed from the side at 180 Hz as they
performed 40 forehand drives on an indoor tennis court. Vertical plane kinematics of the racket and ball near impact were
analysed for sub samples of successful and unsuccessful shots for each subject. Most racket kinematic variables were very
consistent (mean CV< 6.3%) for successful shots, so bio mechanically meaningful differences in angles and velocities of the
racket and ball (3° and 2 m s−1) near impact could be detected between successful and unsuccessful shots. Four subjects tended to miss long and three subjects
missed shots in the net that were reflected in initial ball trajectories. Mean (SD) initial trajectories for long shots were
9.8° (1.4°), while netted shots were 0.7° (1.1°) above the horizontal. The initial ball trajectories and margins for error
for these subjects were smaller than those previously reported (Brody, 1987) because players tended to select mean ball trajectories
close to one error than another, differing amounts of topspin, or incorrect lift and drag coefficients for tennis balls had
not been published when this model was created. The present data can be used to confirm if recent models (Cookeet al., 2003; Dignallet al., 2004) more closely match actual performance by advanced players. 相似文献