History-dependent modified sliding mode interception strategies with maximal capture zone     

Valery Y. Glizer  Vladimir Turetsky  Leonid Fridman  Josef Shinar 《Journal of The Franklin Institute》2012,349(2):638-657

In order to construct the guidance strategy in a realistic nonlinear noise-corrupted interception endgame against a maneuverable target, a linearized zero-sum differential game is considered. Assuming perfect information in this game, sufficient conditions are established, which guarantee that a continuous interception strategy with memory (history-dependent) has the maximal capture zone. Two examples of such a strategy are analyzed: a modified super-twisting second-order sliding mode control and a modified integral sliding mode control. Simulation results of the original nonlinear interception endgame demonstrate that these strategies considerably reduce the chattering created by the classical game optimal bang-bang strategy without deteriorating the homing performance.  相似文献   

Networked Services of NIT libraries in India: A study     

Y. Srinivasa Rao  B.K. Choudhury 《Library Collections, Acquisitions, and Technical Services》2010,34(4):105-114

The main purpose of the paper is to find out the provision of providing Networked Services (NSs) among National Institute of Technology (NIT) libraries in India. Methodology used for collecting data was questionnaire. The survey findings indicate that the majority of libraries prefer to provide communication network services (telephone, Internet, e-mail, facsimile etc), online journals (90%), automated catalog system (85%), multimedia databases (85%) and support (70%) services rather than the other services. Concerning the zone wise performance, south zone (80%) libraries are more potential than the other zone libraries in providing NSs.  相似文献   

Homophobia in medical students of the University of Hong Kong     

R. W. M. Kan  K. P. Au  W. K. Chan  L. W. M. Cheung  C. Y. Y. Lam  H. H. W. Liu 《Sex education》2013,13(1):65-80

Homosexuality is now accepted as a normal variant of human sexuality, but homophobia among healthcare professionals is well documented. Establishment of trustful doctor–patient relationships is impossible in the presence of homophobia. We were interested to examine the extent of homophobia among medical students, the future doctors. This article aims to study attitudes of medical students of the University of Hong Kong towards homosexuality and to identify significant factors affecting their attitudes. A cross‐sectional study was performed on students of the University of Hong Kong. Attitudes towards homosexuality were compared between medical and non‐medical students. More than 25% of the medical students agreed with the statement ‘homosexuality is a psychological disorder that requires therapy’. More than 15% would avoid any physical contact with homosexuals to minimise the chance of contracting diseases, especially AIDS. Comparison between the medical students and non‐medical students showed that the attitudes of the medical students were significantly more homophobic. Factors explaining the difference included the importance of religion in the formation of moral values, gender, experience of working closely with homosexual friends, sexual orientation, experience of the heterosexual sexual act, acquaintance of homosexual friends, and experience of homosexual love relationships. In conclusion, there appeared to be a certain level of homophobia among the medical students. This could possibly be explained by their lack of experience of working closely with homosexual friends. Relevant curriculum modification and development are urgently needed, to provide ongoing opportunities for students to realise their own values that could unconsciously affect their clinical judgements.  相似文献   

Emergent relations in pigeons following training with temporal samples     

Edson M. Huziwara  Saulo M. Velasco  Gerson Y. Tomanari  Deisy G. de Souza  Armando D. Machado 《Learning & behavior》2013,41(2):192-204

In two experiments, we investigated emergent conditional relations in pigeons using a symbolic matching-to-sample task with temporal stimuli as the samples and hues as the comparisons. Both experiments comprised three phases. In Phase I, pigeons learned to choose a red keylight (R) but not a green keylight (G) after a 1-s signal. They also learned to choose G but not R after a 4-s signal. In Phase II, correct responding consisted of choosing a blue keylight (B) after a 4-s signal and a yellow keylight (Y) after a 16-s signal. Comparisons G and B were both related to the same 4-s sample, whereas comparisons R and Y had no common sample. In Phase III, R and G were presented as samples, and B and Y were presented as the comparisons. The choice of B was correct following G, and the choice of Y was correct following R. If a relation between comparisons that shared a common sample were to emerge, then responding to B given G would be more likely than responding to Y given R. The results were generally consistent with this prediction, suggesting, for the first time in pigeons, the emergence of novel relations that involve temporal stimuli as nodal samples.  相似文献   

Foundations of educational technology: integrative approaches and interdisciplinary perspectives     

Sherry Y. Chen 《Interactive Learning Environments》2013,21(3):396-397

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The Effect of Computer-Assisted Learning Integrated with Metacognitive Prompts on Students’ Affective Skills     

Nilgün Tatar  Ercan Akpınar  Eylem Yıldız Feyzioğlu 《Journal of Science Education and Technology》2013,22(5):764-779

The purpose of this study is to investigate the effect of computer-assisted learning integrated with metacognitive prompts on elementary students’ affective skills on the subject of electricity. The researchers developed educational software to enable students to easily and comprehensively learn the concepts in the subject of electricity. A case study method was used. Eighteen students from the seventh grade (12–13 years) participated in the study. Students’ views on their performances while using educational software and the impact of the software on their affective skills towards the subject of electricity were examined. Data were collected by open-ended questions in the educational software. According to the research results, there were students who had negative attitudes and perceptions before starting to learn about the subject of electricity. Interactive activities, animations, and visual experiments in the educational software were effective in overcoming the students’ negative attitudes and perceptions about the subject. Besides, students who assessed their own performances during the learning process believed themselves to be more successful over time. In the light of the research results, some suggestions are made for future studies.  相似文献   

A NEIGHBORHOOD DEMONSTRATES     

Frank Y. Ichishita 《Equity & Excellence in Education》2013,46(6):34-39

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Parental Expressivity,Child Physiological and Behavioral Regulation,and Child Adjustment: Testing a Three-Path Mediation Model     

Jeffrey Liew  Audrea Y. Johnson  Tracy R. Smith  Felix Thoemmes 《Early education and development》2013,24(4):549-573

Research Findings: Parental expressivity, child physiological regulation (indexed by respiratory sinus arrhythmia suppression), child behavioral regulation, and child adjustment outcomes were examined in 45 children (M age = 4.32 years, SD = 1.30) and their parents. With the exception of child adjustment (i.e., internalizing and externalizing problems and adaptive skills), which were assessed with parents' ratings, all variables were observed behaviorally or physiologically. A 3-path mediation path model was tested with the relations between parental expressivity and child adjustment outcomes mediated through child physiological regulation and behavioral regulation. Despite low power to detect the mediated effect, there was evidence to suggest that physiological regulation and behavioral regulation were 2 mediating mechanisms by which parental high positive/low negative expressivity may influence adaptive skills. Thus, parental expressivity may shape children's physiological regulation. And physiological regulation may be 1 mechanism by which effortful control becomes manifested as behavioral regulation that becomes apparent to others who then make evaluations about individuals' adaptive skills. Practice or Policy: The results have implications for interventions aimed at parent training or parental coaching of emotion as well as interventions aimed at enhancing children's social-emotional or behavioral regulation to improve children's adaptive skills.  相似文献   

Mining students' learning patterns and performance in Web-based instruction: a cognitive style approach     

Sherry Y. Chen  Xiaohui Liu 《Interactive Learning Environments》2013,21(2):179-192

Personalization has been widely used in Web-based instruction (WBI). To deliver effective personalization, there is a need to understand different preferences of each student. Cognitive style has been identified as one of the most pertinent factors that affect students' learning preferences. Therefore, it is essential to investigate how learners with different cognitive styles interact with WBI programs. This paper presents an empirical study, which examines the effects of cognitive styles on students' learning patterns and the effects of learning patterns on their learning performances. Riding's cognitive style analysis was used to identify the students' cognitive styles. Data mining, especially a clustering technique, was used to analyze the results. It was found that field independent students frequently used an alphabetical index whereas field dependent students often chose a hierarchical map. Such learning patterns also have great effects on their performance, especially for field dependent students.  相似文献   

关于有限平坦表现模     

谢燕萍  尹芳芳  李德梅  周德旭 《莆田学院学报》2013,(5):18-21

将有限表现模限制在平坦维数≤1,得到有限平坦表现模及其性质,利用有限平坦表现模类给出了其Ext-正交模即FFP-内射模,刻画了右F-凝聚环与右F-正则环。在环的几乎优越扩张S≥R下,证明了S为右F-凝聚环当且仅当R为右F-凝聚环,S为右F-正则环当且仅当R为右F-正则环。  相似文献