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Low energy consumption is one of the main challenges for wireless video transmission on battery limited devices. The energy invested at the lower layers of the protocol stack involved in data communication, such as link and physical layer, represent an important part of the total energy consumption. This communication energy highly depends on the channel conditions and on the transmission data rate. Traditionally, video coding is unaware of varying channel conditions. In this paper, we propose a cross-layer approach in which the rate control mechanism of the video codec becomes channel-aware and steers the instantaneous output rate according to the channel conditions to reduce the communication energy. Our results show that energy savings of up to 30% can be obtained with a reduction of barely 0.1 dB on the average video quality. The impact of feedback delays is shown to be small. In addition, this adaptive mechanism has low complexity, which makes it suitable for real-time applications. 相似文献
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Ellina Chernobilsky Maria Carolina DaCosta Cindy E. Hmelo-Silver 《Instructional Science》2004,32(4):319-356
A sociocultural view of learning proposes that learning involves becoming enculturated into a community of practice. A step
along the way is learning to use the specialized language of such a community, as language is a crucial tool that regulates
participation, mediates cognition and plays a central role in the development of thought. Problem-based learning (PBL), with
its emphasis on collaborative discourse, provides opportunities for students to develop the conceptual language of a discipline,
which in turn affects cognition. In a problem-based undergraduate Educational Psychology course, many psychological theories,
concepts and principles are introduced to pre-service teachers. During the course, as students learn through problem solving,
they engage with new knowledge. This evolving knowledge requires new discourse structures that will allow students to express
their new ideas and that will ultimately structure students' ways of knowing. The content of group and individual artifacts
is analyzed to examine how PBL influences students' language and knowledge development over the course of the semester in
an Educational Psychology class (n = 34). The goal of this paper is to present these analyses and to discuss how the change affects students' language and knowledge. 相似文献
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Carola E. Bruna Nicole A. Valenzuela Daniela V. Bruna Armando Lozano‐Rodríguez Carolina G. Mrquez 《Journal of Food Science Education》2019,18(2):37-44
Problem‐based learning using authentic material from the web was used to teach metabolism in a biochemistry course. In place of traditional lectures, students’ analyzed health or nutrition articles from newspapers and magazines, which were debatable from a scientific point of view, following the principles of problem‐based learning. A mixed method was used to assess the students’ perception, use of sources of information and web services while performing the task, and changes in self‐directed learning. Students’ perception was particularly positive. The majority stated that the methodology helped them to apply knowledge to real life and that they learned about the topic analyzed by their group. The perception that problem‐based learning promotes the ability to solve problems, critical thinking, and collaborative work is noteworthy. Tutors considered that teams identified the problem and concluded correctly, noticing students’ enthusiasm and motivation. The methodology also promoted scientific reading. More importantly, a significant improvement in self‐directed learning of the 2014 cohort was detected. This intervention suggests that this methodology is a valuable alternative to motive and promote self‐learning; representing an opportunity to shift the focus of instruction from the teacher to the student. The design of the activity and materials are described in detail. Also, limitations and solutions are discussed. 相似文献
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Exclusion and victimization by classmates were related to levels and diurnal change in cortisol in 97 fourth graders (53% boys, M = 9.3 years). Number and quality of friendships were considered as moderators. Salivary cortisol was collected 5 times daily on 2 school days. Excluded children had elevated cortisol levels at school and a flattened diurnal cortisol curve, suggesting hypothalamic-pituitary-adrenocortical (HPA) axis dysregulation. This effect was weaker for children with more friends or better friendships. Victimization was not associated with cortisol level or change. The results demonstrate the role of HPA activity in peer group processes and indicate that group and dyadic factors interact in predicting stress in the peer group. 相似文献
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Bernadette Paula Luengo Kanacri Concetta Pastorelli Eriona Thartori Carolina Lunetti Laura Di Giunta Dario Bacchini 《Parenting, science and practice》2021,21(1):24-46
SYNOPSIS Objective. This article examined two-wave longitudinal paths among maternal self-efficacy, maternal warmth, and early adolescents’ prosocial behavior. Design . Participants were 194 Italian mother/child dyads from 9–13 years at the first assessment and 12–15 years at the second assessment. Using a two-wave longitudinal design, the present study tested cross-lagged paths among maternal self-efficacy, warmth, and early adolescents’ prosocial behavior controlling for the stability of these variables and their concurrent associations. Results . Maternal warmth mediated the link between maternal self-efficacy and adolescents’ prosocial behavior, and bi-directional effects between maternal self-efficacy and maternal warmth were found. Conclusions . These findings support a parent-driven model in the promotion of prosocial behaviors across early adolescence and a general need to consider simultaneously parental cognitions (maternal self-efficacy) and actions (maternal warmth) in explaining adolescents’ prosocial behaviors. Implications for parenting program interventions are discussed. 相似文献
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Meindert Flikkema Carolina Castaldi Ard-Pieter de Man Marcel Seip 《Research Policy》2019,48(6):1340-1353
The use of trademark data in innovation studies is still limited because as yet no guidelines exist to ascertain which trademarks relate to innovation. This paper proposes that a branding strategy approach may help to identify innovation related trademarks. Companies use distinctive branding strategies for innovation and these branding strategies have important consequences for the design of new trademarks and their application scope. Based on a sample of Benelux and Community trademarks, we find that trademarks for brand creation relate more often to product innovation. In addition, we find negative effects of a trademark’s industry scope on its relatedness to product innovation, and of a trademark’s geographic scope on its relatedness to service innovation. Our findings bear several key implications for further research towards identifying innovation-related trademarks from a branding strategy perspective. 相似文献
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Camilo Salazar Ferro Isabel Artega Arredondo Carolina M. Rodriguez Daniel H. Nadal 《The International Journal of Art & Design Education》2020,39(2):346-366
Contemporary architecture teaching in Colombia still resembles the traditional master–apprentice model, which is also common in many parts of the world. The model of regular curricular focus on classroom‐based modules where theory and practice are predominantly disengaged, leaving the students to make their connections. Students that learnt with these models face greater difficulties to apply knowledge, compared with students taught with active learning formats. It is argued that participatory design processes could be catalytic for change in this area, by empowering participants in the co‐creation of their socio‐spatial context. This article aims to contribute by suggesting a methodology for a Participatory Design Experience (PDE), which could be applied to transform a conventional teaching module into a student‐centred learning environment. The methodology was tested and refined through a case study, demonstrating its effectiveness in architectural education. The article describes it in detail in order to be replicated by educators in comparable scenarios. 相似文献
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AbstractThis paper aims at analyzing how Hébert’s naturist ideas were received and assimilated in Brazil based on the perusal of sources such as Azevedo (1915, 1920, 1931), Miranda (1945) as well as some broadsheets and periodicals, for example Correio da Manhã, O Paiz, Gazeta de Noticias, and Fon-Fon! (1913–1928). Furthermore, it investigates by what means Hébert’s conception of nature integrated the mindset of Brazilian sanitarians in the first half of the twentieth century. Evidence suggests that there must have been some intertwinement of points of view that brought together Hebert’s Natural Method and the French Naturist Perspective at the time of the arrival of the latter in Brazil. Hébert’s thoughts on the concept of Nature reached Brazil early in the 1910s, and were incorporated in the shaping of a new approach to therapeutic treatments focused on preserving the patient’s welfare. As a result, this study has enabled us to properly understand the reception of Hébert’s works in Brazil, and come to terms with the historical connection between French gymnastic practices based on the Natural Method and their subsequent acclimatized Brazilian variants. 相似文献