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21.
Two studies examined the contribution of the new concept of “family climate for road safety” and several aspects of the social environment to the driving behavior of young drivers. Study 1 (n = 120) investigated the effect of the seven dimensions of the family climate for road safety – Modeling, Feedback, Communication, Monitoring, Noncommitment, Messages, and Limits – as well as a general tendency to conform to authority, and peer pressure. Study 2 (n = 154) examined the dimensions of family climate for road safety and perceived popularity of reckless driving among peers. The findings indicate associations both between the familial and the social aspects, and between these variables and driving styles, willingness to take risks while driving, reckless driving habits, and personal commitment to safe driving. Positive aspects of the parent–child relationship and high levels of conformity to authority were related to greater endorsement of the careful driving style, whereas family's noncommitment to safety, higher peer pressure, and lower conformity to authority were associated with greater endorsement of the reckless driving style. In addition, positive aspects of the family climate for road safety and lower perceived popularity of reckless driving among friends were associated with more personal commitment to safe driving and a lower tendency for risky driving. The discussion stresses the need to look at the complex set of antecedents of reckless driving among young drivers and addresses the practical implications of the findings for road safety.  相似文献   
22.
Five studies examined the effects of positive emotion priming on the willingness to drive recklessly. In all five, young drivers were exposed to one of the following primes of positive affect: a positive mood story; happy memories; an exciting film; a relaxing film; or thoughts on the meaning in life. Following the prime, the participants were asked to report on their willingness to drive recklessly. The responses were compared to those of groups exposed either to neutral affect, another kind of positive affect, or negative affect priming. In two of the studies, participants were also asked to report on their driving styles (risky, anxious, angry, or careful) as a second dependent variable. Positive affect, especially in the form of arousal, was found to be related to higher willingness to drive recklessly. Although men tended to report higher intentions to drive recklessly, men and women did not react differently to the emotional induction. Most interestingly, positive emotions of a relaxing nature, as well as thinking about the meaning in life, lowered the willingness to engage in risky driving. The discussion emphasizes the importance of looking for new ways to use positive emotions effectively in road safety interventions, and considers the practical implications of the studies.  相似文献   
23.
This paper shows how the priority encoding transmission (PET) framework may be leveraged to exploit both unequal error protection and limited retransmission for RD-optimized delivery of streaming media. Previous work on scalable media protection with PET has largely ignored the possibility of retransmission. Conversely, the PET framework has not been harnessed by the substantial body of previous work on RD optimized hybrid forward error correction/automatic repeat request schemes. We limit our attention to sources which can be modeled as independently compressed frames (e.g., video frames), where each element in the scalable representation of each frame can be transmitted in one or both of two transmission slots. An optimization algorithm determines the level of protection which should be assigned to each element in each slot, subject to transmission bandwidth constraints. To balance the protection assigned to elements which are being transmitted for the first time with those which are being retransmitted, the proposed algorithm formulates a collection of hypotheses concerning its own behavior in future transmission slots. We show how the PET framework allows for a decoupled optimization algorithm with only modest complexity. Experimental results obtained with Motion JPEG2000 compressed video demonstrate that substantial performance benefits can be obtained using the proposed framework.  相似文献   
24.
The advantages are discussed of applying the modern apparatus of experiment design to the solution of problems in thermotechnical and thermophysical measurements. The determination of the heat transfer coefficient in film-flow evaporators is used as an illustration to show how the number of tests can be significantly reduced by a factorial design of experiments.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 25, No. 2, pp. 345–348, August, 1973.  相似文献   
25.
Tissue factor (TF) is a major activator of the coagulation cascade and may play a role in initiating thrombosis after intravascular injury. To investigate whether medial vascular smooth muscle provides a source of TF following arterial injury, the induction of TF mRNA and protein was studied in balloon-injured rat aorta. After full length aortic injury, aortas were harvested at various times and the media and adventitia separated using collagenase digestion and microscopic dissection. In uninjured aortic media, TF mRNA was undetectable by RNA blot hybridization. 2 h after balloon injury TF mRNA levels increased markedly. Return to near baseline levels occurred at 24 h. In situ hybridization with a 35S-labeled antisense rat TF cRNA probe detected TF mRNA in the adventitia but not in the media or endothelium of uninjured aorta. 2 h after balloon dilatation, a marked induction of TF mRNA was observed in the adventitia and media. Using a functional clotting assay, TF procoagulant activity was detected at low levels in uninjured rat aortic media and rose by approximately 10-fold 2 h after balloon dilatation. Return to baseline occurred within 4 d. These data demonstrate that vascular injury rapidly induces active TF in arterial smooth muscle, providing a procoagulant that may result in thrombus initiation or propagation.  相似文献   
26.
JPEG2000: standard for interactive imaging   总被引:4,自引:0,他引:4  
JPEG2000 is the latest image compression standard to emerge from the Joint Photographic Experts Group (JPEG) working under the auspices of the International Standards Organization. Although the new standard does offer superior compression performance to JPEG, JPEG2000 provides a whole new way of interacting with compressed imagery in a scalable and interoperable fashion. This paper provides a tutorial-style review of the new standard, explaining the technology on which it is based and drawing comparisons with JPEG and other compression standards. The paper also describes new work, exploiting the capabilities of JPEG2000 in client-server systems for efficient interactive browsing of images over the Internet.  相似文献   
27.
Israeli recruits (N?=?276) completed questionnaires on hardiness, mental health, cognitive appraisal, and ways of coping at the beginning and end of a demanding, 4-month combat training period. Path analysis revealed that 2 components of hardiness—commitment and control measured at the beginning of the training—predicted mental health at the end of the training through the mediation of appraisal and coping variables. Commitment improved mental health by reducing the appraisal of threat and the use of emotion-focused strategies and by increasing secondary appraisal. Control improved mental health by reducing the appraisal of threat and by increasing secondary appraisal and the use of problem-solving and support-seeking strategies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
28.
Multirate 3-D subband coding of video   总被引:19,自引:0,他引:19  
We propose a full color video compression strategy, based on 3-D subband coding with camera pan compensation, to generate a single embedded bit stream supporting multiple decoder display formats and a wide, finely gradated range of bit rates. An experimental implementation of our algorithm produces a single bit stream, from which suitable subsets are extracted to be compatible with many decoder frame sizes and frame rates and to satisfy transmission bandwidth constraints ranging from several tens of kilobits per second to several megabits per second. Reconstructed video quality from any of these bit stream subsets is often found to exceed that obtained from an MPEG-1 implementation, operated with equivalent bit rate constraints, in both perceptual quality and mean squared error. In addition, when restricted to 2-D, the algorithm produces some of the best results available in still image compression.  相似文献   
29.
A major and well-recognized difficulty in estimating the effects of education on earnings is that the more educated are likely to be more able, irrespective of education. If ability also determines earnings and is not controlled, ordinary least squares will yield biased estimates of the education coefficient. In this study, we use data on identical twins to control for differences in ability that arise from genetic endowments and family environment. Not controlling for genetics and family environment may cause a large bias, up to two-thirds of the noncontrolled coefficient.  相似文献   
30.
High performance scalable image compression with EBCOT   总被引:205,自引:0,他引:205  
A new image compression algorithm is proposed, based on independent embedded block coding with optimized truncation of the embedded bit-streams (EBCOT). The algorithm exhibits state-of-the-art compression performance while producing a bit-stream with a rich set of features, including resolution and SNR scalability together with a "random access" property. The algorithm has modest complexity and is suitable for applications involving remote browsing of large compressed images. The algorithm lends itself to explicit optimization with respect to MSE as well as more realistic psychovisual metrics, capable of modeling the spatially varying visual masking phenomenon.  相似文献   
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