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81.
82.
If democracy is a platform for many voices, and the voices of the many, journalists serve democracy by bringing these voices to the forefront of governance by asking difficult questions to those in power. It can be argued that journalists engage in the broader form of surveillance of power from below, or sousveillance [Mann, Steve, and Joseph Ferenbok. 2013. “New media and the power politics of sousveillance in a surveillance-dominated world.” Surveillance and Society 11 (1-2): 18–34.], which aims towards a form of relative equilibrium. In democracies, the institutional system of checks and balances forms the basis on which journalism pursues its watchdog function. This paper explores the experiences of journalists with surveillance and their impact on journalists’ sense of freedom to fulfil their watchdog role. The paper contributes to increasing research interest in “journalism after Snowden” by addressing the intangible conditions under which journalists may or should work, and ultimately also how widely accepted standards of democratic liberties are challenged.  相似文献   
83.
An hybrid uninterrupted multi-speed transmission (HUMST), based on the integration of a planetary gear set and a 3-speed automatic manual transmission (3-AMT), is developed to satisfy the specific performance indexes of mining trucks. The power-split device can alleviate and eliminate the inherent torque interruption of the 3-AMT during gear shift by implementing the designed cooperative shift control strategy which is optimized by quadratic performance index. In order to achieve fast torque coordination while guaranteeing the driving comfort performance, the torque profiles of the power split device and the traction motor are optimized by Linear-quadratic regulator (LQR) algorithm. Dynamic programming (DP) is implemented as a benchmark to demonstrate the maximum fuel efficiency of the proposed HUMST. Because of the high computational cost of optimal control strategies such as DP, an improved real-time control strategy (IRTCS) using modified Gaussian distribution function is proposed to significantly reduce the computing load. As efficiency-oriented energy control strategy would result in frequent gear shifts, to achieve a desirable tradeoff between the overall efficiency and the shift stability, multi-objective genetic algorithm (MGA) is integrated to optimize the overall performance. The detail mathematical and dynamic model shows that the proposed shifting strategy with LQR can effectively suppress shift jerk, and the proposed IRTCS with MGA can reduce shift frequency by 70.78% to improve the drivability, only sacrificing 4.86% of overall efficiency compared to that of DP.  相似文献   
84.
In this paper, the problem of mean-square integral input-to-state stability of nonlinear impulsive semi-Markov jump delay systems is investigated. By using stochastic Lyapunov functions together with Razumikhin technique, some sufficient conditions for mean-square integral input-to-state stability for a class of nonlinear impulsive semi-Markov jump delay systems are developed. In particular, the results obtained generalize and complement some recent literature. Finally, some numerical examples are given to show the effectiveness and advantages of the proposed techniques.  相似文献   
85.
To evaluate Information Retrieval Systems on their effectiveness, evaluation programs such as TREC offer a rigorous methodology as well as benchmark collections. Whatever the evaluation collection used, effectiveness is generally considered globally, averaging the results over a set of information needs. As a result, the variability of system performance is hidden as the similarities and differences from one system to another are averaged. Moreover, the topics on which a given system succeeds or fails are left unknown. In this paper we propose an approach based on data analysis methods (correspondence analysis and clustering) to discover correlations between systems and to find trends in topic/system correlations. We show that it is possible to cluster topics and systems according to system performance on these topics, some system clusters being better on some topics. Finally, we propose a new method to consider complementary systems as based on their performances which can be applied for example in the case of repeated queries. We consider the system profile based on the similarity of the set of TREC topics on which systems achieve similar levels of performance. We show that this method is effective when using the TREC ad hoc collection.  相似文献   
86.
Education and Information Technologies - As the years progresses, higher education has move towards implementing Blended Learning (BL) which is a combination of face-to-face and online mode of...  相似文献   
87.

Online collaborative and content-focused professional development (PD) is becoming an increasingly important setting for supporting mathematics teachers’ professional learning. The purpose of this study was to better understand the process by which a community emerges in such a PD setting by examining how the cohesiveness of 21 mathematics teachers’ social network evolves and associated shifts in the quality of mathematics teachers’ mathematical discourse. We employed social network analysis (SNA) to examine the evolving cohesiveness of mathematics teachers’ social network and coding procedures to examine teachers’ mathematical discourse. A key finding was the documentation of an emergent divide between participation in the core and periphery during initial weeks of the PD and then a reduced divide and emergence of a social network that resembles a community. We argue that the instructor’s pattern of participation that included distributing their interactions across the subgroups while sending a common message regarding expectations for mathematical discourse in the PD may have contributed to the community formation process. We propose the Interaction Assessment Model, which outlines an approach for PD facilitators to use SNA as a feedback mechanism to differentiate facilitation of online collaborative and content-focused PD and build online communities.

  相似文献   
88.
Research Findings: In an effort toward developing a comprehensive, effective, scalable, and sustainable early childhood education program for at-risk populations, we conducted an experimental evaluation of the value added by 2 family involvement programs to the Texas Early Education Model (TEEM). A total of 91 preschool classrooms that served minority populations of low socioeconomic status were randomly assigned to TEEM, TEEM plus Raising a Reader (RAR), or TEEM plus RAR augmented by Family Nights. Assessments of oral language and print knowledge were completed by more than 500 children at the beginning and end of the school year. Multilevel analyses of covariance controlled for classroom nesting and individual differences in age, ethnicity, and pretest scores. Although RAR alone demonstrated no added value, augmentation of RAR with Family Nights demonstrated significant impacts on measures of oral language (ts = 1.81–2.51, .05 < ps < .01) and print knowledge (t = 2.39, p < .01). Practice or Policy: Thus, parent training in shared reading practices appears to be necessary for children to benefit from programs that enrich the home literacy environment. That the combined program particularly benefited children who started preschool lagging behind in school readiness (ts = 1.64–2.49, ps < .05) suggests that this comprehensive model offers hope for closing the achievement gap.  相似文献   
89.
This phenomenological study, based on ecological systems theory, examined the college student bereavement experience in a Christian university. Undergraduate students (N = 127) from a small Christian university provided answers to open‐ended questions about their experiences regarding college following a death loss. Results indicate that students are generally successful in adapting to bereavement and prefer an environment open to discussing death and asking difficult religious questions. Implications for counselors are provided.  相似文献   
90.
Investigations employing primates have sometimes used tests of concurrent object-discrimination as indexes of multiproblem memory in comparative studies of neuropathological impairment. The present investigation was an attempt to employ a comparable test procedure with rats. Data from two experiments indicated that rats could indeed be trained on a concurrent object-discrimination task. Furthermore, results from the second experiment indicated that these performances and brightness discriminations shared the property of disruption by posterior decortication. Implications for the neuropsychology of learning and memory are discussed.  相似文献   
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