Profiles of emergent literacy skills among preschool children who are at risk for academic difficulties

The purpose of this study was to explore patterns of within-group variability in the emergent literacy skills of preschoolers who are at risk for academic difficulties. We used the person-centered approach of cluster analysis to identify profiles of emergent literacy skills, taking into account both oral language and code-related skills. Participants were 492 preschoolers (aged 42-60 months) enrolled in needs-based programs. In the fall of the academic year, children were administered eight measures of emergent literacy: four oral language measures (i.e., expressive and receptive grammar, expressive and receptive vocabulary) and four code-related measures (i.e., print concepts, alphabet knowledge, name writing, and rhyme). Controlling for age, hierarchical-agglomerative and K-means cluster analysis procedures were employed. Five psychometrically sound profiles emerged: highest emergent literacy (prevalence = 14%); three profiles with average oral language and differential code-related abilities (16%, 24%; 23%); and lowest oral language with broad code-related weaknesses (23%). Profiles were then compared on midyear teacher ratings of emergent literacy as well as end-of-kindergarten literacy performance; results provided convergent evidence of predictive validity. This study highlights the considerable heterogeneity of emergent literacy abilities within an “at-risk” group. The resulting profiles have theoretical and practical relevance when examining both concurrent relationships between oral language and code-related skills as well as longitudinal relationships between early patterns of performance and later reading achievement.     

How medical practice evolves: Learning to treat failing hearts with an implantable device

In this article we propose that medical practice evolves as a result of progress along three different pathways: improvement in the ability to develop effective medical technologies, learning in medical practice, and advances in biomedical scientific understanding of disease. The relative importance of these three pathways varies from case to case, and often they interact strongly. More specifically, we argue here that in cases of therapeutic innovation where a new medical technology is involved the advance in medical practice is driven largely by the ability to develop and use effective medical artifacts and the interactive sequence among these interdependent pathways often starts with what is learned in practice and not in science. While we state this argument in general, we develop it in detail in a longitudinal and contextual case study of the emergence and evolution of a treatment for advanced heart failure based on an implantable device, the Left Ventricular Assist Device (LVAD). Our findings show that an essential aspect of the evolution of the LVAD therapy is collective and cumulative learning that requires experience that only can be gained through the actual use of LVADs. We discuss the theoretical and policy implications that follow from our understanding of how medical practice evolves for research on the evolution of medical practices and new medical technologies, and policies about the evaluation of rapidly moving medical practices and clinical research involved in their advancement.     

低碳能源技术发展战略与路径选择

本文通过高碳能源与低碳能源的比较研究,揭示了低碳能源技术发展是实现经济社会低碳化发展和转型的基础;通过分析低碳能源技术发展的制约因素,提出了加大低碳能源研发的投入,加快推进低碳技术的产业化,加强政府的政策导向力度,发挥市场的资源配置的功能是促进低碳能源技术发展的有效路径选择。     

自助服务技术环境下的顾客参与及其影响因素研究

随着信息技术的发展和互联网的广泛运用,自助服务技术(SSTs)环境下的顾客行为研究已经成为服务营销领域倍受关注的热点.本文以网上旅游预订为例,结合技术接受模型(TAM)和动机理论,系统探讨了角色清晰、动机、自我效能对顾客参与的影响,并得出以下结论:(1)网上旅游预订环境下,顾客参与可以分为信息搜寻、付出努力和信息分享三个维度.(2)感知愉悦、感知行为控制、自我效能和感知易用对顾客参与产生显著的正向影响,其中感知愉悦的影响最大.(3)各前置变量时顾客参与子维度的影响程度各不相同.根据研究发现,本文提出了相关的营销建议以供实际运用.     

基于文献计量指标的关键技术的探寻——以第三代移动通信技术为例

移动通信技术领域的专利文献在移动通信关键技术的研发和创新中具有不可替代的作用,笔者以德温特专利数据库中1994-2009年的16 759项第三代移动通信技术专利作为研究对象,提取专利文献中的德温特专利手工代码,运用CiteSpace可视化软件,在构建频数、中介中心性、激增指数和Σ四个主要指标分析的基础上,对第三代移动通信技术专利的手工代码进行计量分析,直观展示了不同时段第三代移动通信技术领域的关键技术。     

Commercialization of disruptive innovations: Literature review and proposal for a process framework

The challenges of disruptive innovations have gained significant attention from both academics and practitioners, commercialization being one of the most critical phases. At the same time, however, it is the less studied area of disruptive innovation. Therefore, this article examined scholarly papers on the commercialization of disruptive innovations through a multidisciplinary systematic literature review. It resulted in the analysis of 64 high-quality peer-reviewed academic articles. The analysis highlighted the commercialization models and main constructs that are affecting the commercialization process: market orientation, market learning, user's involvement, market configuration, adoption networks and stakeholders, and innovation transference. The study evidences how commercialization has evolved from a later stage in innovation to influence even the early phases of innovation, characterized in turn by exploration, learning and ecosystem creation activities. Additionally, the analysis led to a proposition that established an integrated commercialization model for high uncertainty innovations. The model has three phases: 1) Concept/value proposition validation, 2) Business model validation & Market creation, and 3) Creating sales in the majority market. Lastly, the article contributes to a better understanding of commercialization processes in high uncertainty innovations, bridging also the academic-practitioner divide.     

个人健康信息管理技术促进用户健康行为的心理机制:基于智能可穿戴健康产品的实证研究

[目的/意义] 基于智能可穿戴健康产品,研究个人健康信息管理技术促进用户健康行为的心理机制。[方法/过程] 基于刺激-机体-反应理论框架,建立智能可穿戴健康产品的技术要素通过用户心理变量影响健康行为的路径模型。以智能手环用户为调查对象,通过问卷法收集数据,运用偏最小二乘法结构方程验证本研究提出的理论模型。[结果/结论] 智能可穿戴健康产品的数据管理和社交互动功能通过启发和赋能促进用户健康行为。此外,行为控制功能通过赋能促进用户健康行为。文章基于上述发现讨论了对个人健康信息管理领域,尤其是智能可穿戴健康产品研究的理论贡献和实践启示。     

计算机网络欺骗和嗅探技术研究

随着信息化网络时代的到来,全世界每个角落都广泛使用着计算机网络技术,改变了人们的生产生活方式．然而随着网络技术的不断深入发展,网络信息安全也成为了大众普遍关心的焦点．对计算机网络欺骗和嗅探技术进行分析,对网络欺骗的主要原理和技术以及嗅探技术的原理、预防、检测和应用进行阐述．     

Cascading the use of Web 2.0 technology in secondary schools in the United Kingdom: identifying the barriers beyond pre-service training

This paper reports on research that took place at two universities in the United Kingdom, over two years. The research focuses on the use of Web 2.0 technology, specifically blogs, with pre-service teachers, both during their university programme and the first year of teaching as full-time newly qualified teachers (NQTs). The purpose of this research was to add to a developing body of knowledge by identifying whether technology used by pre-service teachers during their training course can be cascaded into their practice once qualified. Key findings identify a number of enablers and barriers to cascading technology in the classroom; these include curriculum time, pupil skills and support. The research concludes that early professional support and development should continue during the early years of teaching and assumptions about new teachers as champions of cascading innovative use of Web 2.0 technologies into their practice as NQTs may be over-optimistic.     

WCDMA关键技术的研究简

WCDMA技术的设计目标是不仅能够提供比第二代移动通信系统更大的容量和更好的通信质量．而且要能在全球范围内更好地实现无缝漫游并为用户提供语音、数据和移动多媒体等业务。与第二代移动通信相比,WCDMA系统采用直扩序列码分多址技术（DS—CDMA）,信息被扩展成3．84Mchip／s后在5MHz带宽内传送,同时采角了多种关键技术保证业务质量（QoS）。概括来说,WCDMA关键技术主要包括RAKE接收技术、无线资源管理技术、多用户检测技术和智能天线技术等。