Novel strategy for subcarrier and power allocation in OFDM based cognitive radio networks

In order to limit the interference caused by cognitive user within the range that primary users can tolerate. The mathematical optimization problem is formulated maximizing cognitive user’s capacity under the interference constraint at the primary receiver．When the signal to noise ratio of primary user changes according to the communication environment, the cognitive user can adaptively adjust its transmission power according to the interference control factor η. The optimal so1ution to the problem is obtained by utilizing the Lagrange method．A subcarrier and power allocation scheme are proposedamong multiple cognitive users, which is the performance tradeoff between fairness and system capacity. Simulation results show that the proposed scheme can efficiently guarantee the fairness of cognitive users and the capacity performance is close to the optimum.     

Closing the compliance gap in marine protected areas with human behavioural sciences

Advocates, practitioners and policy-makers continue to use and advocate for marine protected areas (MPAs) to meet global ocean protection targets. Yet many of the worlds MPAs, and especially no-take MPAs, are plagued by poaching and ineffective governance. Using a global dataset on coral reefs as an example, we quantify the potential ecological gains of governing MPAs to increase compliance, which we call the ‘compliance gap’. Using ecological simulations based on model posteriors of joint Bayesian hierarchical models, we demonstrate how increased compliance in no-take MPAs could nearly double target fish biomass (91% increases in median fish biomass), and result in a 292% higher likelihood of encountering top predators. Achieving these gains and closing the compliance gap necessitates a substantial shift in approach and practice to go beyond optimizing enforcement, and towards governing for compliance. This will require engaging and integrating a broad suite of actors, principles, and practices across three key domains: (i)) harnessing social influence, (ii) integrating equity principles, and (iii) aligning incentives through market-based instruments. Empowering and shaping communication between actor groups (e.g., between fishers, practitioners, and policy-makers) using theoretically underpinned approaches from the behavioural sciences is one of the most essential, but often underserved aspects of governing MPAs. We therefore close by highlighting how this cross-cutting tool could be further integrated in governance to bolster high levels of compliance in MPAs.     

工作记忆在写作过程中的作用

写作作为一种复杂的认知活动,涉及到多个过程的共同作用。这些过程对容量有限的工作记忆造成压力,认知负荷过大,是造成写作困难的主要原因。熟练的写作者处理压力的方式有多种,包括通过练习降低低层次过程的认知压力,或者通过中央执行系统对认知注意进行分配。除此以外,增加备用的认知资源系统,通过长时工作记忆对长期记忆内的知识进行提取和利用,也是一个有效的处理压力的方式。文中从认知的角度对工作记忆在写作中的作用和研究情况进行综述,为二语写作的研究提供了新的视角和方向。     

生物的第六感浅析

在广泛文献检索的基础上,对第六感的定义、认知误区及存在的科学性等进行了探讨和综述,以期为人们正确认识及利用第六感提供资料。     

Clinical feasibility of cognitive testing in dogs (Canis lupus familiaris)

Several cognitive tests have been developed to evaluate specific aspects of human and animal learning and memory. These tests have been used for early detection of cognitive deficits and to monitor the treatment of dogs with cognitive impairment. Thus, this article evaluated the feasibility of cognitive tests for use in canine neurology clinical routines and the suitability of the different tests to accomplish this aim. Fifteen healthy adult dogs were used for the cognitive tests of reward approach learning, object approach learning, object discrimination learning, reversal learning, delayed non-matched to position, and delayed non-matched to sample to assess different aspects of memory. No difference was observed between tests of delayed non-matched to position (3.13 ± 2.23 days) and delayed non-matched to sample (3.20 ± 2.40 days) (P = 0.944). However, dogs had greater difficulty in reversal learning (8.47 ± 2.61 days) than in object discrimination learning (4.60 ± 1.64 days) (P ≤ 0.001). Based on the tests performed, the delayed non-matched to position test may be performed in clinical routine if the owner and the veterinarian have time available, because this test is sensitive to evaluate dogs with cognitive impairments, but requires approximately 10 days of training. Thus, elderly dogs are excellent experimental models to study pathological aging based on their similarities with some human brain diseases, such as Alzheimer disease.     

The influence of interaction with forest on cognitive function

Abstract

The aim of this study was to investigate whether forest experience had a positive impact on cognitive function. Cognitive function refers to a person's ability to intellectually process by which one becomes aware of, perceives, or comprehends ideas. It involves all aspects of perception, thinking, reasoning, and remembering. Sixty university students participated in this study. We compared the restorative effects on cognitive functioning of interactions with forest versus urban environments. To measure participants’ cognitive function and mood state, Trail Making Test B and Profile of Mood States were used in this study. The results of this study indicated that participants’ cognitive function was significantly improved when they walked in forest (i.e. time taken to complete the task was shortened by more than 7 seconds), but not when they walked downtown. In addition, participants’ mood also positively changed when they walked in forest. The results of this study confirmed Kaplan's attention restoration theory (ART). ART has emphasized the importance of cognitive functions from interaction with natural environments such as forests.     

涉身语言认知理论与英语教学初探

涉身语言认知思想是认知语言学上的一种创新。针对传统认知语言学"语言内在论"和"天赋论"等理论的局限性,以拉可夫和约翰逊为代表的涉身语言认知思想,从身体维度对语言认知机制给予了新的解读。这种以"大脑、身体和环境"共同参与的语言的认知模式对当前我国的英语教学和改革具有重要的理论指导意义,能够为解决当前高校英语教学和改革中出现的新问题给予方法论的指导。     

河北农业大学2009级新生词汇学习现状调查

河北农业大学于2009年全面推开大学英语分模块教学,而词汇模块在其中占有非常重要的地位。为了有针对性的开展教学而进行了此次调查。利用SPSS13.0对调查数据进行了描述性分析、相关分析和独立样本T检验。调查发现：1.学生词汇水平与学习策略关系高度相关;2.学生的学习策略、方法的应用水平低于学习观念水平;3.各项学习策略应用不均衡等。在此基础上,提出了以学生自主学习词汇为主的教学理念,全面培养学生认知策略的思路,以及建立词汇图片库、充分利用网络免费的英语语料库等具体的词汇学习方法。     

基于概念隐喻理论的中医隐喻术语翻译策略研究

中医名词术语蕴含丰富的隐喻思维和独特的文化特征,本文基于概念隐喻理论对中医常用名词术语中的隐喻认知机制及其翻译策略进行研究,发现绝大多数中医隐喻术语适用回译性翻译策略以保持民族文化特色,部分特殊征候术语及诊疗术语则适用科学性翻译策略以保留其医理信息避免荒唐,还有部分中医独有概念术语则可采用创造法、硬译法及音译法等规定性翻译策略加以翻译。     

略论情感因素对认知学习的影响

许多人认为学生认知学习的效果取决于智力因素，但是大量的事例表明，学生的情感因素对认知学习影响极大。积极的情感可以对认知学习产生促进作用，反之，消极的情感会阻碍学生的学习。因此，教育工作者应认识到这一点，在教学的各个环节激发学生积极情感的产生。