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11.
When the assumption of multivariate normality is violated or when a discrepancy function other than (normal theory) maximum likelihood is used in structural equation models, the null distribution of the test statistic may not be χ2 distributed. Most existing methods to approximate this distribution only match up to 2 moments. In this article, we propose 2 additional approximation methods: a scaled F distribution that matches 3 moments simultaneously and a direct Monte Carlo–based weighted sum of i.i.d. χ2 variates. We also conduct comprehensive simulation studies to compare the new and existing methods for both maximum likelihood and nonmaximum likelihood discrepancy functions and to separately evaluate the effect of sampling uncertainty in the estimated weights of the weighted sum on the performance of the approximation methods. 相似文献
12.
Emerson Hicks Bunnell Lee R. Baker Johnny Minus William Storm Hale 《Communication Booknotes Quarterly》2013,44(9):8-10
Emerson, Naturalistic Photography for Students of the Art (1891) Hicks, Words and Pictures: Introduction to Photojournalism (1952) Bunnell, Nonsilver Printing Processes, $4.50 Lee R. Baker, Making Movies: From Script to Screen (New York: Harcourt Brace Javanovich, 1973—price not known, paper) Johnny Minus and William Storm Hale's Your Introduction to Film-TV Copyright, Contracts and other Law (Seven Arts Press, 6655 Hollywood Blvd., Hollywood, Ca. 90028 1973— $10.00 paper) Noel Burch Theory of Film Practice (New York: Praeger, 1973—$8.95) Hector Currie and Donald Staples' Film: Encounter (Dayton, Ohio: Pflaum/Standard, 1973—$9.95, paper) John G. Cawelti's Focus on Bonnie and Clyde (Englewood Cliffs, N.J.: Prentice-Hall, 1973—$5.95/2.45) David Bordwell, Filmguide to La Passion de Jeanne d'Arc Warren French, Filmguide to The Grapes of Wrath Carolyn Geduld, Filmguide to 2001: A Space Odyssey James Naremore, Filmguide to Psycho E. Rubenstein, Filmguide to The General Jay Leyda's Kino: A History of the Russian and Soviet Film (New York: Collier Books, 1973 reissue of 1960 original —$4.95, paper) 相似文献
13.
Johnny Hartz Søraker 《The Information Society》2013,29(1):40-46
The increasing use of frameworks within which Internet users can contribute nontextual information constitutes a serious obstacle to government attempts to accurately censor and monitor Internet traffic. This development, as seen in the explosive growth of frameworks such as Second Life, YouTube, and Wikipedia, could lead to a transfer of regulatory power away from heavily regulated Internet Service Providers in nondemocratic regimes, into the hands of intermediaries that are more likely to uphold freedom of expression. Thereby, a development toward increasingly enframed and nontextual information can promote freedom of expression even in traditionally nondemocratic regimes. I analyze this development with regard to its possible implications for freedom of expression, online crime, and the role of private companies in international politics. 相似文献
14.
Johnny Nilsson Sandor Csergö Lennart Gullstrand Per Tveit Per Egil Refsnes 《Journal of sports sciences》2013,31(11):939-945
The aim of this study was to examine work-time profiles, blood lactate concentrations and perceived exertion among Greco-Roman wrestlers in the 1998 World Championship. Forty-two senior wrestlers from nine nations were studied in 94 matches. Each match was recorded with a video camera (Panasonic AG 455, film rate: 25 Hz) and analysed for duration of work (wrestling) and rest (interrupt) periods. Blood lactate concentration was determined with an electrochemical device (Analox P-LM5) and a rating of perceived exertion scale (Borg) was used to estimate general exertion and exertion in the extremity and trunk muscles. The mean duration of the matches was 427 s (range 324-535 s), with mean durations of work and rest of 317 and 110 s, respectively. The mean periods of work and rest were 37.2 and 13.8 s, respectively. Mean blood lactate concentration was 14.8 mmol · l -1 (range 6.9-20.6). The difference in mean blood lactate concentration between the first- and final-round matches was not significant ( P > 0.05). Blood lactate concentration was significantly higher ( P ? 0.04) in matches of long duration than in those of short duration. The mean general rating of perceived exertion for all matches was 13.8 according to the scale used. Most of the wrestlers (53.3%) perceived exertion to be highest in the flexors of the forearm, followed by the deltoids (17.4%) and the biceps brachii muscles (12.0%). In addition to a relatively high rating of perceived exertion in the arm muscles, this indicates a high specific load on the flexor muscles of the forearm. 相似文献
15.
Antonio Dello Iacono Johnny Padulo Laurent D Seitz 《Journal of sports sciences》2018,36(11):1269-1276
This study aimed to investigate the acute effects of two barbell hip thrust-based (BHT) post-activation potentiation (PAP) protocols on subsequent sprint performance. Using a crossover design, eighteen handball athletes performed maximal 15-m sprints before and 15s, 4min and 8min after two experimental protocols consisting of BHT loaded with either 50% or 85% 1RM (50PAP and 85PAP, respectively), in order to profile the transient PAP effects. The resulting sprint performances were significantly impaired at 15s only after the 85PAP protocol, which induced likely and very likely greater decreases compared to the 50PAP. At 4min and 8min, significant improvements and very likely beneficial effects were observed in the 10m and 15m performances following both protocols. Significant differences were found when comparing the two PAPs over time; the results suggested very likely greater performance improvements in 10m following the 85PAP after 4min and 8min, and possible greater performance improvements in 15m after 4min. Positive correlations between BHT 1RMs values and the greatest individual PAP responses on sprint performance were found. This investigation showed that both moderate and intensive BHT exercises can induce a PAP response, but the effects may differ according to the recovery following the potentiating stimulus and the individual`s strength level. 相似文献
16.
The polynomial solutions of the equation fy″ + gy′ + λy = 0 are obtained and classified for f, g, and λ certain second-degree, first-degree, and zero-degree polynomials, respectively. Applications are given illustrating the use of these polynomials in the construction of amplitude functions and system functions and in tree counting. In particular, all-pole and rational filter functions are considered which include as special cases the Chebyshev, Butterworth, elliptic, Bessel, and various transitional filter functions. 相似文献
17.
The aim of this study was to investigate the reliability of a new infrared light based method (IR40) for recording temporal stride patterns during treadmill running. The IR40 device, emitting a tight web of 40 infrared light beams 10 mm above the treadmill running surface, was compared to a previously
validated electro-pneumatic contact shoe (CS) method while nine well-trained athletes ran at 2.8, 3.3, 3.9, 4.4, 5.0, and
5.6 m s−1. Disconnection and reconnection of the IR beams marked the stance phase. The sampling rate was 500 Hz for both methods. The
stance phase duration was on average 11.5 (±8.4) ms longer with the IR40 than with the CS depending on earlier touch down (8.3 ± 6.2 ms) and delayed toe off (3.2 ± 5.3 ms) registrations. Significantly
different stance phases were recorded between all velocities and for both methods. Thus, despite the fact that the IR40 systematically measured a somewhat longer stance phase duration than CS, the IR40 is nonetheless useful for temporal stride analysis during treadmill running. 相似文献
18.
In the golf instructional literature, the putting stroke is typically given higher priority than green reading and aiming. The main purpose of this study was to assess the importance of the putting stroke for direction consistency in golf putting. Kinematic stroke parameters were recorded from 71 elite golf players (mean handicap = 1.8, s = 4.2) on 1301 putts from about 4 m. Of the different factors deciding stroke direction consistency, face angle was found to be the most important (80%), followed by putter path (17%) and impact point (3%). This suggests that improvements in consistency of putter path and impact point will have very little effect on overall putting direction consistency and should not be prioritized in the training of elite players. In addition, mean stroke direction variability for an elite player (European Tour) was found to be 0.39 degrees, which is good enough to hole about 95% of all 4-m putts. In practice, however, top professionals in tournaments only hole about 17% of 4-m putts. We conclude that the putting stroke of elite golfers has a relatively minor influence on direction consistency. 相似文献
19.
Johnny Saldaña 《Multicultural Perspectives》2013,15(3):14-18
Two workshops on Augusto Boal's Forum Theatre were conducted with two high school student groups coincidentally divided by class: one lower to lower‐middle, and one upper‐middle to upper. Students created oppression scenarios for improvisation that focused primarily on horizontal hostility: the group versus the stigmatized individual. The two workshop environments, however, differed in quality due to the facilitator's perception of class as an influential variable. Students in the upper middle‐class to upper‐class group made choices and exhibited actions characteristic of those living in the culture of affluence and privilege. I reflect critically on the event's implications for multicultural educators. 相似文献
20.
Johnny Nilsson Vidar Jakobsen Per Tveit Olav Eikrehagen 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(2):227-236
The purpose of the investigation was to study the relationship between thrust phase duration, ground reaction force, velocity increase after pole thrust and pole angles versus pole length during double poling in roller skiing. Seven male regional elite cross‐country skiers volunteered as subjects for the study. The subjects performed a maximal double pole thrust on roller skis with each of the three different pole lengths: ‘short’, self‐selected (normal) and ‘long’. The short and long poles were 7.5 cm shorter and 7.5 cm longer than the self‐selected pole length. The subjects made seven maximal pole thrusts with each pole length, which were randomly selected during 21 trials. For each trial the subjects accelerated from a 1.2 m high downhill slope attaining a speed of 3.92 m.s‐1 before making a maximal double pole thrust on a force plate placed at the bottom of the slope. The vertical (Fz), anterior‐posterior (Fy) and medio‐lateral (Fx) reaction forces of the left pole were measured by the force plate. The positions of the pole were recorded in 3‐D by an opto‐electronic system. Thrust phase duration, impulse, mean force, velocity increase after pole thrust and pole angles were calculated from the recorded data. Double poling with long poles produced a significantly larger propulsive anterior‐posterior reaction force impulse and velocity increase than normal (p < .05) and short poles (p < .05). This was in spite of a larger mean anterior‐posterior reaction force being produced with short poles. Thus, thrust phase duration was a primary factor in determining propulsive anterior‐posterior impulse. For the practitioner, the results can be useful in the selection of pole length when the aim is to increase thrust phase duration, anterior‐posterior force impulse and velocity. 相似文献