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11.
This paper introduces a new way of evaluating instructional strategies by using computers. Two basic theories, instructivism and constructivism, are discussed and critically evaluated in terms of their effectiveness in conceptual learning. Despite the current popularity of constructivism, the radical form of it is criticized in this paper. The advantages and limitations of these two approaches, especially the radical forms of constructivism, are outlined. After borrowing some ideas from other effective conceptual change models, an integrative model for conceptual learning (the Inventive Model) is introduced. Two versions of multimedia physics software are developed by the authors. The first version is based on the Inventive Model and the second version based on a radical constructivist model. The effectiveness of the Inventive Model was compared with the radical constructivist approach and conventional science instruction. Students' log files were analyzed to investigate the nature and the processes of the conceptual change. A conceptual test and a knowledge test were used to compare the groups. The quantitative results showed the superiority of the Inventive Model over the other models in conceptual learning and the superiority of conventional instruction in learning the basic knowledge. The qualitative analysis showed that only the Inventive Model lead to coherent conceptual learning. It was concluded that the process of conceptual change is gradual and continuous. Analysis of students' log files revealed no moments of dramatic change in students' conceptions.  相似文献   
12.
Taking the English National Curriculum as its main example, this article argues that an overly nationalistic, normative and ‘fact-based’ citizenship education curriculum is failing to engage the dimensions of young people’s identities which they experience as deeply meaningful. There is thus a chasm – albeit a false one – between official discourses and pedagogies of citizenship and what young people consider to be their ‘real’ selves. I argue that citizenship education must develop a more sophisticated understanding of the complexities of how identities are formed and performed, especially in light of globalisation and increasing migration. I also make a somewhat unorthodox argument for conceptualising ‘relating-to-otherness’ in the same way that we think of music consumption. This has implications for how we experience, interpret, value and create ‘others’. The article also makes some recommendations for how these ideas can begin to be implemented in educational settings.  相似文献   
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14.
With the proliferation of computer networks and the increased use of Internet‐based applications, many forms of social interactions now take place in an on‐line context through Computer‐Mediated Communication (CMC). Many universities are now reaping the benefits of using CMC applications to collect data on student evaluations of faculty, rather than using paper‐based surveys in Face‐To‐Face (FTF) classroom settings. While the relative merits of CMC versus FTF student evaluations have been researched extensively, there is limited research published about the ways students respond to the questions from either mode of data collection. This paper reports on a research study to analyse the communication differences between student scores from FTF student evaluations and CMC evaluation questions from end of semester evaluations from a university in the Middle East region. In addition to the questions about communication mode differences between two evaluation questions, several demographic variables were measured to determine any interaction effects. The results of our study suggest that the type of communication channel mitigates the responses that students make on CMC evaluations vis‐à‐vis FTF evaluations of faculty. In particular, even though there were significant differences found at the aggregate level between CMC and FTF evaluations, when the course and instructor are controlled for, there were no significant differences reported. In addition, several differences were noted depending on the type and level of the course being studied. Also, we found that students are more likely to express more extreme responses to scale questions in CMC than FTF evaluations. Administrators should consider these potential differences when implementing on‐line evaluation systems.  相似文献   
15.
In this paper, a composite fault tolerant control (CFTC) with disturbance observer scheme is considered for a class of stochastic systems with faults and multiple disturbances. The disturbances are divided into two parts. One represents the stochastic disturbance with partial known information which is formulated by an exogenous system. The other is independent Wiener process. A stochastic disturbance observer is designed to estimate exogenous disturbance. To make the first type of disturbance can be rejected and the fault can be diagnosed, a composite fault diagnosis observer with disturbance observer is constructed. Furthermore, a composite fault-tolerant controller is proposed to compensate disturbances and faults. Finally, simulation examples are given to demonstrate the feasibility and effectiveness of the proposed scheme.  相似文献   
16.
This work deals with the problem of optimal residual generation for fault detection (FD) in linear discrete time-varying (LDTV) systems subject to uncertain observations. By introducing a generalized fault detection filter (FDF) with four parameter matrices as the residual generator, a novel FDF design scheme is formulated as two bi-objective optimization problems such that the sensitivity of residual to fault is enhanced and the robustness of residual to unknown input is simultaneously strengthened. A generalized operator based optimization approach is proposed to deduce solutions to the corresponding optimization problems in operator forms, where the related H/H or H?/H FD performance index is maximized. With the aid of the addressed methods, the connections among the derived solutions are explicitly announced. The parameter matrices of the FDF are analytically derived via solving simple matrix equations recursively. It is revealed that our proposed results establish an operator-based framework of optimal residual generation for some kinds of linear discrete-time systems. Illustrative examples are given to show the applicability and effectiveness of the proposed methods.  相似文献   
17.
Modern vehicles are equipped with a growing number of electronic devices, which significantly improve the driving experience. However, the complicated architecture of electronic systems also increases the difficulty of fault diagnosis since process models are often unavailable. This paper presents a novel detection and mitigation system for vehicle related anomalies originating in unintended acceleration (UA), which has become one of the most complained-about vehicle problems in recent history. The detection system consists of several neural network-based models, which are created by analyzing historical vehicle data at specific moments such as acceleration peaks and gear shifting. These data-driven models describe the boundary of normal vehicle behavior in the data space. A priori knowledge of complete vehicle structures is not necessary for building them. The detection system combines these models to decide if a UA event has occurred. When a UA event is detected, a mitigation system cuts the engine power and adjusts the braking force accordingly. The whole system was validated in the Simulink/dSPACE environment. UA errors were simulated so that they occurred randomly when human subjects drove virtual cars in a simulated environment. Random noise of sensors were also considered and incorporated to add realism. Various traffic scenarios were included in tests. Test results show that the integrated system is capable of detecting UA in one second with high accuracy and reducing the risk of accidents.  相似文献   
18.
During the last decade, intellectual capital (IC) and intangible assets have been widely considered as critical tool to deliver successful business in an intensive-knowledge environment. Accordingly, the main goal of this paper is therefore to develop and prioritize the most important indicators of intellectual capital in knowledge-based industries. Based on an extensive literature review, a valid and reliable questionnaire was designed. In order to data gathering, it was sent out to participants from both academic and university who qualified well in pharmaceutical practice. In order to exact prioritization of indicators, fuzzy TOPSIS technique as a MADM model was used. The fuzzy TOPSIS results revealed participants remark high concerns especially about knowledge and skills of managers and employees regarding to human capital, high concerns particularly about positive climate, ratio of investment in R&D and numbers of R&D projects according to structural capital, while considering the relational capital, more attention was paid to customers and strategic cooperation such as alliances and licensing.  相似文献   
19.
There is an ongoing debate over the activities of brands and companies in social media. Some researchers believe social media provide a unique opportunity for brands to foster their relationships with customers, while others believe the contrary. Taking the perspective of the brand community building plus the brand trust and loyalty literatures, our goal is to show how brand communities based on social media influence elements of the customer centric model (i.e., the relationships among focal customer and brand, product, company, and other customers) and brand loyalty. A survey-based empirical study with 441 respondents was conducted. The results of structural equation modeling show that brand communities established on social media have positive effects on customer/product, customer/brand, customer/company and customer/other customers relationships, which in turn have positive effects on brand trust, and trust has positive effects on brand loyalty. We find that brand trust has a fully mediating role in converting the effects of enhanced relationships in brand community to brand loyalty. The implications for marketing practice and future research are discussed.  相似文献   
20.
Ultrastructure and phylogeny of Ustilago coicis   总被引:1,自引:0,他引:1  
Ustilago coicis causes serious smut on Coix lacryma-jobi in Dayang Town, Jinyun County, Zhejiang Province of China. In this paper, ultrastructural assessments on fungus-host interactions and teliospore development are presented, and molecular phylogenetic analyses have been done to elucidate the phylogenetic placement of the taxon. Hyphal growth within infected tissues was both intracellular and intercellular and on the surface of fungus-host interaction, and the fungal cell wall and the invaginated host plasma membrane were separated by a sheath comprising two distinct layers between the fungal cell wall and the invaginated host plasma membrane. Ornamentation development of teliospore walls was unique as they appeared to be originated from the exosporium. In addition, internal transcribed spacer (ITS) and large subunit (LSU) sequence data showed that U. coicis is closely related to Ustilago trichophora which infects grass species of the genus Echinochloa (Poaceae).  相似文献   
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