基于混沌加密和HVS在数字水印算法中的应用

针对混沌系统和人类视觉特性改进一种鲁棒性数字水印算法。原始图像经过离散小波变换提取子带系数,二值灰度数字水印图像信号在嵌入时经过Logistic混沌映射预处理,结合人眼视觉特性,水印图像嵌入到重要的子带系数中,实验证明该方案对常见的图像处理如噪声、剪切、旋转等攻击具有很好的鲁棒性。     

创新是发展的根本动力

创新是一个复杂的价值创造过程,是经济发展的决定性力量。创新驱动发展涉及现代化建设的方方面面,包括科学技术创新、商业模式创新、制度创新、管理创新和社会创新以及人才培养机制创新。为实现创新驱动发展,需要完善国家创新生态系统,加速政府职能转变,着力营造良好的创新制度文化环境,激发创新主体的创新活力,强化创新基础条件平台建设,弘扬中华民族的创新文化和创新精神,形成全社会关心创新、参与创新的良好发展局面,加快建设创新型国家和全面建成小康社会。     

Experiences of Danish Business Expatriates in Russia: Power Distance in Organizational Communication

Rapid globalization of business processes stimulates many companies to dispatch their employees – business expatriates – on overseas assignments. Russia differs markedly from many other cultures in terms of specific communication norms and rules. Understanding such differences in organizational life is crucial for the success of business expatriates working there. This study employs in-depth interviews with eight Danish business expatriates who worked in Russia and examines the differences between the Danes and the Russians in terms of communication characteristics related to Hofstede’s cultural dimension power distance. This work enhances scholars’ empirical knowledge of power distance, which has rarely been investigated qualitatively.     

体力活动与癌症生存研究的10大问题

摘要：今天的美国有1 400万的癌症存活者,其中的很多存活者中都接受了多种治疗,包括手术、放疗、化疗、靶向治疗等。这些治疗能够延长生存时间,但同时也会带来很多急慢性的副作用,危害健康,影响生活质量。体力活动（PA）与癌症生存这一领域发展迅速,主要研究PA对癌症患者的影响。基于该领域的研究进展,提出了以下10大研究问题：1）PA能够降低癌症复发风险、和/或提高存活吗？2）PA能够影响癌症治疗决策、完成率、和/或患者对治疗的反应吗？3）癌症存活者的最佳运动处方是什么？4）静坐少动行为对癌症存活者有何影响？5）癌症存活者最有效的体力活动干预方案是什么？6）哪些癌症会影响病人对PA的反应？7）癌症存活者进行体力活动时需要注意的安全问题有哪些？8）哪些具体的癌症症状可以由PA解决？9）对于癌症晚期患者,体力活动还有何作用？10）如何将体力活动研究结果转化到临床和社区肿瘤实践中来？上述问题的回答至关重要,这不仅关系到体力活动和癌症存活这一研究领域的发展,更重要的是,能够为每年数百万新诊断为癌症的病人、正在接受癌症治疗的病人、治疗结束处于恢复中的病人或是那些正在与晚期癌症抗争的病人带来福音。     

‘Experimental’ secondary modern education in Britain, 1948–1958

Studies of mid-twentieth century education in England and Wales have conventionally hinged on the 1944 Education Act, foregrounding policy over practice. This article considers the significance of the inter-war progressive educational movement for postwar educational developments. It presents a case study of one teacher who was active in the early ‘experimental’ years of secondary modern education, suggesting that this period was important in the making of ‘modern’ education. It seeks to complicate both negative and positive readings of ‘meritocracy’ in postwar educational history. This article also highlights the paucity of available source material for the study of the secondary modern school, arguing that attention should be paid to well-documented cases, placed in context.     

Constructivist Approaches in a Dual-Language Classroom

Dual-language programs are becoming increasingly popular among educators and the public in general. In these programs, students aim at attaining full proficiency in English and another language while reaching an academic achievement at or above grade level. This article describes a series of pedagogical practices in the context of dual-language classrooms. We set the discussion across three defining characteristics of our constructivist perspective: learning as collaboration, teachers as facilitators, and language and culture as intertwined elements in schools. In sum, we postulate that dual-language programs bring equity to schools.     

河北宋金剔花瓷器赏析

剔花是宋代出现的一种陶瓷装饰新工艺,主要用在一些需要使用化妆土的粗胎瓷器上。其工艺一般是先在胎体表面施一至两层白化妆土,趁化妆土未干时用尖锐的工具迅速划出花纹轮廓,紧接着用铲状工具将花纹以外的化妆土剔掉,最后施透明釉入窑焙烧。剔花装饰巧妙地利用白色化妆土与深色胎体之间的反差来突出纹饰,与传统的划花装饰相比,不仅花纹显得更加醒目,而且还具有一定的立体感。     

A scale-based approach to interdisciplinary research and expertise in sports

After more than 20 years since the introduction of ecological and dynamical approaches in sports research, their promising opportunity for interdisciplinary research has not been fulfilled yet. The complexity of the research process and the theoretical and empirical difficulties associated with an integrated ecological-dynamical approach have been the major factors hindering the generalisation of interdisciplinary projects in sports sciences. To facilitate this generalisation, we integrate the major concepts from the ecological and dynamical approaches to study behaviour as a multi-scale process. Our integration gravitates around the distinction between functional (ecological) and execution (organic) scales, and their reciprocal intra- and inter-scale constraints. We propose an (epistemological) scale-based definition of constraints that accounts for the concept of synergies as emergent coordinative structures. To illustrate how we can operationalise the notion of multi-scale synergies we use an interdisciplinary model of locomotor pointing. To conclude, we show the value of this approach for interdisciplinary research in sport sciences, as we discuss two examples of task-specific dimensionality reduction techniques in the context of an ongoing project that aims to unveil the determinants of expertise in basketball free throw shooting. These techniques provide relevant empirical evidence to help bootstrap the challenging modelling efforts required in sport sciences.     

Sprint kayaking and canoeing performance prediction based on the relationship between maturity status,anthropometry and physical fitness in young elite paddlers

This study aimed to identify the maturity-related differences and its influence on the physical fitness, morphological and performance characteristics of young elite paddlers. In total, 89 kayakers and 82 canoeists, aged 13.69 ± 0.57 years (mean ± s), were allocated in three groups depending on their age relative to the age at peak height velocity (pre-APHV, circum-APHV and post-APHV) and discipline (kayak and canoe). Nine anthropometric variables, a battery of four physical fitness tests (overhead medicine ball throw, countermovement jump, sit-and-reach test and 20 m multistage shuttle run test) and three specific performance tests (1000, 500 and 200 m) were assessed. Both disciplines presented significant maturity-based differences in all anthropometric parameters (except for fat and muscle mass percentage), overhead medicine ball throw and all performance times (pre > circum > post; P < 0.05). Negative and significant correlations (P < 0.01) were detected between performance times, chronological age and anthropometry (body mass, height, sitting height and maturity status), overhead medicine ball throw and sit and reach for all distances. These findings confirm the importance of maturity status in sprint kayaking and canoeing since the more mature paddlers were also those who revealed largest body size, physical fitness level and best paddling performance. Additionally, the most important variables predicting performance times in kayaking and canoeing were maturity status and chronological age, respectively.     

Circadian rhythm effect on physical tennis performance in trained male players

To determine the effect of circadian rhythm on neuromuscular responses and kinematics related to physical tennis performance, after a standardised warm-up, 13 highly competitive male tennis players were tested twice for serve velocity/accuracy (SVA), countermovement vertical jump (CMJ), isometric handgrip strength (IS), agility T-test (AGIL) and a 10-m sprint (10-m RUN). In a randomised, counter-balance order, tennis players underwent the test battery twice, either in the morning (i.e., AM; 9:00 h) and in the afternoon (i.e., PM; 16:30 h). Paired t-tests were used to analyse differences due to time-of-day in performance variables. Comparison of morning versus afternoon testing revealed that SVA (168.5 ± 6.5 vs. 175.2 ± 6.1 km · h^?1; P = 0.003; effect size [ES] = 1.07), CMJ (32.2 ± 0.9 vs. 33.7 ± 1.1 cm; P = 0.018; ES = 1.46), AGIL (10.14 ± 0.1 vs. 9.91 ± 0.2 s; P = 0.007; ES = 1.23) and 10-m RUN time (1.74 ± 0.1 vs. 1.69 ± 0.1 s; P = 0.021; ES = 0.67) were significantly blunted during the morning testing. However, IS was not affected by time-of-day (P = 0.891). Thus, tennis performance may be reduced when competing in the morning in comparison to early evening. Therefore, coaches and tennis players should focus on schedule the SVA, power, speed and agility training sessions in the afternoon.