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1.
This paper presents a classifier for text data samples consisting of main text and additional components, such as Web pages and technical papers. We focus on multiclass and single-labeled text classification problems and design the classifier based on a hybrid composed of probabilistic generative and discriminative approaches. Our formulation considers individual component generative models and constructs the classifier by combining these trained models based on the maximum entropy principle. We use naive Bayes models as the component generative models for the main text and additional components such as titles, links, and authors, so that we can apply our formulation to document and Web page classification problems. Our experimental results for four test collections confirmed that our hybrid approach effectively combined main text and additional components and thus improved classification performance. 相似文献
2.
Comparing the pre- and post-impact ball and racquet kinematics of elite tennis players' first and second serves: a preliminary study 总被引：1，自引：0，他引：1
Chow JW Carlton LG Lim YT Chae WS Shim JH Kuenster AF Kokubun K 《Journal of sports sciences》2003,21(7):529-537
The aim of this study was to compare the pre- and post-impact three-dimensional kinematics of the ball and racquet during first and second serves performed by elite tennis players. Data were collected from four male and four female right-handed professional players during competition using two high-speed cameras (200 Hz). For each player, one first serve and one second serve from the 'deuce' or right service court that landed within the specified target area were analysed. To test for significant differences between the first and second serves, Wilcoxon tests (P < or = 0.05) were performed on selected parameters. The results indicate that the ball travelled forward and to the left during the flight phase of the toss in all but one trial. The average pre-impact ball forward location for the first serve was significantly more in front and had a higher associated forward ball velocity than the corresponding values for the second serve. On average, the decrease in post-impact ball speed from the first to the second serve was 24.1%. No significant differences between the first and second serves were found in the pre-impact racquet head speed and orientation, which was represented as a unit vector perpendicular to the racquet face. The major adjustments made by the players when going from the first to second serve were a decrease in pre-impact ball forward location (P < or = 0.01) and an increase in the pre-impact racquet vertical and lateral velocities (both P < or = 0.05). This implies that the players tossed the ball closer to the body and imparted topspin and sidespin on the ball by changing the racquet vertical and lateral velocities when going from the first to the second serve. 相似文献
3.
Faces Do Not Capture Special Attention in Children With Autism Spectrum Disorder: A Change Blindness Study 总被引：1，自引：0，他引：1
Yukiko Kikuchi Atsushi Senju Yoshikuni Tojo Hiroo Osanai Toshikazu Hasegawa 《Child development》2009,80(5):1421-1433
Two experiments investigated attention of children with autism spectrum disorder (ASD) to faces and objects. In both experiments, children (7- to 15-year-olds) detected the difference between 2 visual scenes. Results in Experiment 1 revealed that typically developing children ( n = 16) detected the change in faces faster than in objects, whereas children with ASD ( n = 16) were equally fast in detecting changes in faces and objects. These results were replicated in Experiment 2 ( n = 16 in children with ASD and 22 in typically developing children), which does not require face recognition skill. Results suggest that children with ASD lack an attentional bias toward others' faces, which could contribute to their atypical social orienting. 相似文献
4.
Kazumi Masuda Nobuo Kikuhara Hideyuki Takahashi Kunio Yamanaka 《Journal of sports sciences》2013,31(10):851-858
Abstract The aim of the present study was to examine the relationships between muscle cross-sectional area (CSA) and muscular strength in terms of knee extension and flexion, hip extension and flexion, and hip abduction and adduction among well-trained soccer players. Fourteen university soccer players participated in the study, who had previously been divided into two groups based on ability (Group A: above-average ability; Group B: average ability). Maximal isokinetic and concentric muscular strength was measured in knee extension/flexion, hip extension/flexion and hip abduction/adduction using an isokinetic dynamometer at 1.57 and 4.19 rad·s?1 (3.14 rad·s?1) in both the dominant and non-dominant leg. The CSAs of the thigh, gluteus muscles and iliopsoas muscles were calculated based on magnetic resonance imaging. There was no significant difference between the two groups in muscle CSA and isokinetic strength. Although there were some statistically significant differences between the dominant and non-dominant leg in terms of CSA and strength (P<0.05–0.01), these were small and negligible. Apart from a non-significant relationship between the CSAs of the adductor muscles and hip adductor strength (r<0.26, n.s.), the CSA of the other muscle groups correlated with maximal isokinetic strength (r=0.38–0.64, P<0.05). These results suggest that no difference in muscle characteristics (in terms of muscle CSA and strength) was apparent among well-trained soccer players, even between the dominant and non-dominant leg. There is also a case that the anatomical function of a single (or group of) muscle(s) may not be reflected by the strength—CSA relationship depending on the movements (such as hip adduction-adductor muscle CSA). Thus, further studies are required to develop methods to assess neuromuscular function in relation to muscle morphology among soccer players. 相似文献
5.
Mari Hasegawa 《Journal of moral education》2016,45(4):387-399
This study investigated the development of moral decision-making and moral emotion attributions in antisocial behavior and peer relationship dilemma scenarios. Participants were 540 school- and college-aged students, who were asked to explain their moral decision-making, subsequent emotions, and reasoning in regard to the scenarios. We combined moral decision-making (morally appropriate or morally inappropriate) and emotion (positive or negative) to create the four reaction patterns of happy victimizer (HV), unhappy victimizer (UHV), happy moralist (HM), and unhappy moralist (UHM). Across all four scenarios and age groups, there were very few HM reactions, and HV responses were more common among adolescents and adults than among children in jaywalking and peer exclusion scenarios. In contrast, there were no age differences in reaction patterns in shoplifting and broken-promise scenarios; however, more moral considerations in reasoning were revealed among older age groups. The role of peer relationship in emotion attribution is discussed. 相似文献
6.
This study compared American and Japanese youth preferences for information sources and advertising content within the context of their respective cultures’ relationship and communication values. It found larger parental involvement and smaller media use for Japanese students. In an interesting reversal from cultural expectations, Japanese students ranked advertising as the most important information source and family as considerably less important, while American students did the opposite. Friends, not family, were the important interpersonal information source for the Japanese. Japanese consumers of the ‘90s may be ‘holonic’: able to be both individualistic and in harmony with groups important to them. The Japanese youth preferences for advertising content—indirect, symbolic, visual, emotional, with infrequent brand identification—were more in line with expectations. 相似文献
7.
Combined effects of pre-cooling and water ingestion on thermoregulation and physical capacity during exercise in a hot environment 总被引：2，自引：1，他引：1
The aim of the present study was to determine the combined effects of pre-cooling and water ingestion on thermoregulatory responses and exercise capacity at 32 degrees C and 80% relative humidity. Nine untrained males exercised for 60 min on a cycle ergometer at 60% maximal oxygen uptake (VO2max) (first exercise bout) under four separate conditions: No Water intake, Pre-cooling, Water ingestion, and a combination of pre-cooling and water ingestion (Combined). To evaluate the efficacy of these conditions on exercise capacity, the participants exercised to exhaustion at 80% VO2max (second exercise bout) following the first exercise bout. Rectal and mean skin temperatures before the first exercise bout in the Pre-cooling and Combined conditions were significantly lower than in the No Water and Water conditions. At the end of the first exercise bout, rectal temperature was lower in the Combined condition (38.5 +/- 0.1 degrees C) than in the other conditions (No Water: 39.1 +/- 0.1 degrees C; Pre-cooling: 38.7 +/- 0.1 degrees C; Water: 38.8 +/- 0.1 degrees C) (P < 0.05). Heat storage was higher following pre-cooling than when there was no pre-cooling (P < 0.05). The final rectal temperature in the second exercise bout was similar between the four conditions (39.1 +/- 0.1 degrees C). However, exercise time to exhaustion was longer (P < 0.05) in the Combined condition than in the other conditions. Total sweat loss was less following pre-cooling than when there was no pre-cooling (P < 0.001). Evaporative sweat loss in the Water and Combined conditions was greater (P < 0.01) than in the No Water and Pre-cooling conditions. Our results suggest that the combination of pre-cooling and water ingestion increases exercise endurance in a hot environment through enhanced heat storage and decreased thermoregulatory and cardiovascular strain. 相似文献
8.
In situ pressure measurement within deformable rectangular polydimethylsiloxane microfluidic devices
In this paper, we present a simple procedure to incorporate commercially available external pressure transducers into existing microfluidic devices, to monitor pressure-drop in real-time, with minimal design modifications to pre-existing channel designs. We focus on the detailed fabrication steps and assembly to make the process straightforward and robust. The work presented here will benefit those interested in adding pressure drop measurements in polydimethylsiloxane (PDMS) based microchannels without having to modify existing channel designs or requiring additional fabrication steps. By using three different devices with varying aspect ratio channels (, width/depth), we demonstrate that our approach can easily be adapted into existing channel designs inexpensively. Furthermore, our approach can achieve steady state measurements within a matter of minutes (depending on the fluid) and can easily be used to investigate dynamic pressure drops. In order to validate the accuracy of the measured pressure drops within the three different aspect ratio devices, we compared measured pressure drops of de-ionized water and a 50 wt. % glycerol aqueous solution to four different theoretical expressions. Due to the deformability of PDMS, measured pressure drops were smaller than those predicted by the rigid channel theories (plate and rectangular). Modification of the rigid channel theories with a deformability parameter α provided better fits to the measured data. The elastic rectangular expression developed in this paper does not have a geometric restriction and is better suited for microchannels with a wider range of aspect ratios. 相似文献
9.
Does Gaze Direction Modulate Facial Expression Processing in Children With Autism Spectrum Disorder?
Hironori Akechi Atsushi Senju Yukiko Kikuchi Yoshikuni Tojo Hiroo Osanai Toshikazu Hasegawa 《Child development》2009,80(4):1134-1146
Two experiments investigated whether children with autism spectrum disorder (ASD) integrate relevant communicative signals, such as gaze direction, when decoding a facial expression. In Experiment 1, typically developing children (9–14 years old; n = 14) were faster at detecting a facial expression accompanying a gaze direction with a congruent motivational tendency (i.e., an avoidant facial expression with averted eye gaze) than those with an incongruent motivational tendency. Children with ASD (9–14 years old; n = 14) were not affected by the gaze direction of facial stimuli. This finding was replicated in Experiment 2, which presented only the eye region of the face to typically developing children ( n = 10) and children with ASD ( n = 10). These results demonstrated that children with ASD do not encode and/or integrate multiple communicative signals based on their affective or motivational tendency. 相似文献
10.
A badminton shuttlecock flies in a high-drag, and thus, the sport has been a subject of research from the point of view of aerodynamics. A badminton shuttlecock generates significant aerodynamic drag and has a complex flight trajectory. It also has the smallest ballistic coefficient and exhibits the largest in-flight deceleration of any airborne sporting projectile. The ballistic coefficient of a projectile is a measure of its ability to overcome air resistance in flight and is inversely proportional to deceleration. The primary objectives of this study were to measure the aerodynamic properties of feather shuttlecocks under a range of the wind speed (10–60 m/s) and pitch angle (0°–25°). In particular, measurements of aerodynamic forces were performed at high Reynolds numbers (more than Re = 210,000), and the effect of shuttlecock deformation on aerodynamic properties was also investigated, because it is presumed that the flight dynamics is affected by the deformation of the shuttlecock skirt. A shuttlecock skirt is composed of an array of diverging stems, the ends of which are at the convergent end of the skirt, joined together in an end ring. The shuttlecock rotates about its major axis in actual flight, and thus, the experiments were performed on shuttlecocks with and without rotation (spin). Furthermore, the effect of the flow passing through the gaps between the slots (stiffeners) located at the leg portion of the shuttlecock skirt on aerodynamic characteristics is demonstrated by means of a shuttlecock model without gaps, which was completely covered with cellophane tape. The free rotation rate of a shuttlecock increased with an increase in the Reynolds number, and the drag coefficient gradually decreased above Re = 86,000 for a non-rotating shuttlecock. The reduction of drag can be explained by the deformation of the skirt observed in wind tunnel experiments at high speed. In this study, for a rotating shuttlecock, a reduction of drag was not observed over a whole range of Reynolds numbers, because deformation of the skirt for a rotating shuttlecock becomes smaller than that for a non-rotating shuttlecock. However, there was no significant difference in drag coefficient between rotating and non-rotating shuttlecocks, in contrast to the difference in drag coefficient between shuttlecocks with and without gaps. The drag coefficient for a shuttlecock without gaps was significantly smaller than that for a standard shuttlecock (with gaps). For a standard shuttlecock, the air flowed through the gaps into the shuttlecock skirt, and this flow was related to high aerodynamic drag. 相似文献