In this study, an electro-mechanical valve (EMV) system for the intake valve ofa fottr stroke, single cylinder, overhead valve and spark ignition (SI) engine was designed and constructed. An engine with the EMV system and a standard engine were tested to observe the effects of the EMV on engine performance and emissions at different speeds under full load. The EMV engine showed improved engine power, engine torque and break specific fuel consumption (BSFC). A 66% decrease in CO emissions was also obtained with the EMV system, but hydrocarbons (HC) and NOx emissions increased by 12% and 13% respectively. 相似文献
The international perceptions of Japanese young adults were explored in 172 professional education students in two Tokyo colleges. They classified 30 nations according to their “current” and “future” affinity to Japan. Little difference was detected in the Q-sorts between institutions arid sexes, while the “current” and “future” sorts correlated .96 with each other. In cluster analyses, many two-nation units (e.g., Czechoslovakia-Yugoslavia) were found to be the building blocks for the overall pattern. The total configuration consisted of three broad groups: mostly Western European nations, problematical nations (China, Russia, Israel, Egypt, etc.), and remote and neutral nations. Structurally, the results were similar to those for American young adults, but the contents were different. The notion of cultural metastereotypes thus received tentative support. 相似文献
This paper provides teachers and teacher educators with food for thought by developing a broad, contemporary re-evaluation of the often-used analogy between teaching and the theatre. It does so by synthesizing insights from scholarly works in education with insights from writing about theatre, including both historical work and published interviews with practicing stage actors. This approach throws into relief particular ways in which teaching does and does not resemble acting as described by its present-day practitioners. A key parallel is observed between the central challenges faced by teachers and actors: acting requires being truthful in imaginary circumstances, while teaching requires being genuine in artificial circumstances. Using work on bildung, the nature of this challenge is examined, and a call is made to help teachers and students better appreciate the intimate, reciprocal and shared nature of good teaching – a challenge in a culture where corporate interests aggressively promote personalized and “anytime, anywhere” learning. The paper also addresses the phenomenon of massive online courses, which enthusiasts like to believe teach themselves. This idea, I suggest, is as absurd as the notion that a great theatre building could obviate the need for a strong cast. . 相似文献
Today's Film Maker (American Film Maker Inc. 250 Fulton Ave., Hempstead, L.I. N.Y. 11550, $3.50 per year for the quarterly which began publication in August) William O. Brown's Low Budget Features (The William Brown Co., 1054 Cahuenga Blvd., Hollywood, Calif. 90038, 1971–$20.00 paper) 相似文献
OBJECTIVE: This study compared experiences of children sexually abused by peers to those of children abused by adolescents/adults. Variables examined included perceived negativity of the abuse, self-reported outcomes, overall psychological functioning, and disclosure. METHOD: An archival data set containing retrospective reports of childhood sexual experiences was culled for instances of sexual abuse by child peers and adolescents/adults. An equivalent nonabused comparison group was identified. The Self-Report Outcome Checklist (SROC; Gilbert, 1994b), the MMPI-Hugo Short Form (Hugo, 1971) and a disclosure survey were also retrieved from these data. RESULTS: Compared to abuse by peers, abuse perpetrated by adolescents/adults was more intrusive and intrafamilial. Both groups rated their experiences as equally negative, and reported equally pervasive outcomes. Those abused by adolescents/adults reported significantly higher scores on the Psychopathic Deviate, Psychasthenia, and Schizophrenia scales compared to nonabused controls; similar findings did not emerge for those abused by child peers. Less than a fourth in either abuse group reported disclosing their experience to a parent. Among those who did not disclose, participants abused by child peers anticipated less support from both parents and more anger from their mothers. CONCLUSIONS: The findings suggest that child peer sexual abuse may be associated with adverse outcomes. 相似文献
The concepts of randomness and variation are pervasive in science. The purpose of this study was to document how post-secondary life science students explain randomness and variation, infer relationships between their explanations, and ability to describe and identify appropriate and inappropriate variation, and determine if students can identify sources of variation. An instrument designed to test statistical concepts was administered to 282 college students from three universities, ranging from introductory non-science majors to science graduate students. Students readily distinguished between causes of variation. A naïve no-pattern concept of randomness persisted from first-year non-science majors to senior-level science majors, contributing to incorrect responses on the variation instrument. Students’ expressions of randomness were better predictors of performance on the variation instrument than their expressions of variation. It is argued that inclusion of everyday language uses of randomness in instruction can bridge the gap between vernacular and scientific uses of this term. 相似文献
Interpersonal respect is a fundamental aspect of relating to others. This is especially true for teachers, as cultivating relationships is implicit in effective teaching. This three-year qualitative study examines a developing understanding of respect for pre-service teachers that progresses on to their first year’s teaching to examine the influential factors on that understanding. These teachers’ pupils were also asked to comment on their perceptions of respect. The findings indicate that interpersonal respect in an educative relationship is influenced by the level of autonomy afforded pupils and minimising the power differential between teachers and pupils. 相似文献
Multimedia pedagogical agents are on-screen characters that allow users to navigate or learn in multimedia environments. Several agents’ characteristics may moderate their instructional effectiveness, including appearance, gender, nonverbal communication, motion, and voice. Here, we conducted a meta-analysis to test hypotheses from diverse theories predicting the effects of these agents’ characteristics. We tested predictions of cognitive load theory, cognitive theory of multimedia learning, computers are social actors, social agency theory, uncanny valley, and the action observation network. Our meta-analysis of 32 effect sizes (N?=?2104) revealed a small overall effect (g+?=?0.20), showing that learning with multimedia pedagogical agents was more effective than learning without these agents. As predicted by the redundancy effect of cognitive load theory and the coherence principle of cognitive theory of multimedia learning, 2D agents (g+?=?0.38) tended to be more effective than 3D agents (g+?=?0.11). As predicted by the computers are social actors hypothesis, most of the agents’ characteristics, including nonverbal communication, motion, and voice, appeared not to moderate their effectiveness. We conclude that multimedia pedagogical agents help learning through multimedia, and that students may be able to learn similarly from different types of agents.