Supervision learning as conceptual threshold crossing: when supervision gets ‘medieval’

This article presumes that supervision is a category of teaching, and that we all learn how to teach better. So it enquires into what novice supervisors need to learn. An anonymised digital questionnaire sought data from supervisors [n226] on their experiences of supervision to find out what was difficult, and supervisor interviews across campus [n7] sought to discover whether there were discipline differences among challenges. Findings suggest that supervision is often troublesome, and that lessons learned during supervision are irreversible, taking the learner to a deeper level of understanding, all aspects of threshold concept crossing. However, there was more that led me from threshold concept to conceptual threshold crossing theory: the darker themes of the data suggest that truly troublesome learning is more like that which occurs in early English literature, where threshold crossing is a common motif. Many early English stories show heroes in liminal, threshold spaces, often the forest, where their skills and methods are inadequate for ordeals. The result is their acquisition of what educational jargon might call leadership attributes and emotional intelligence. The title draws on Tarantino's [1994. Pulp fiction [Motion picture]. United States: Miramax Films] ‘getting medieval’ to mean threatening, unpleasant, off the edge of the known. Medieval English stories specialise in challenge: they focus on the doing, being and feeling of hard learning. When ongoing challenge from the unexpected troubles supervisors, it also enables, or forces, the acquisition of new attitudes, skills and attributes. I expand conceptual threshold crossing theory by adding the heuristic model of the medieval threshold crossing motif to interpret troublesome learning. Findings raise further research questions: how might novices avoid danger in the dark forest as they traverse their supervisory path and how can institutions support those who find themselves there.     

脉冲接种和具有双时滞的SEIR模型

讨论了一类脉冲接种和具有双时滞的SEIR模型,得到了其无病周期解。结果表明：接种率R＊〈1时,疾病消除;接种率R＊〉1时,疾病将成为地方病。     

一种基于排列组合的视觉密码方案

视觉密码技术是近年来兴起的一种信息安全加密技术,为了得到一种简单有效的加密方法,可以从Naor和Shamir的视觉密码的基本思想出发,进行分析拓广,制定出一种基于排列组合原理的方案,基础矩阵构造根据每列中代表黑色像素的"1"的个数的变化选取。算法简单可行,易于操作,有实际意义。     

Doctoral conceptual thresholds in cellular and molecular biology

ABSTRACT

In the biological sciences, very little is known about the mechanisms by which doctoral students acquire the skills they need to become independent scientists. In the postsecondary biology education literature, identification of specific skills and effective methods for helping students to acquire them are limited to undergraduate education. To establish a foundation from which to investigate the developmental trajectory of biologists’ research skills, it is necessary to identify those skills which are integral to doctoral study and distinct from skills acquired earlier in students’ educational pathways. In this context, the current study engages the framework of threshold concepts to identify candidate skills that are both obstacles and significant opportunities for developing proficiency in conducting research. Such threshold concepts are typically characterised as transformative, integrative, irreversible, and challenging. The results from interviews and focus groups with current and former doctoral students in cellular and molecular biology suggest two such threshold concepts relevant to their subfield: the first is an ability to effectively engage primary research literature from the biological sciences in a way that is critical without dismissing the value of its contributions. The second is the ability to conceptualise appropriate control conditions necessary to design and interpret the results of experiments in an efficient and effective manner for research in the biological sciences as a discipline. Implications for prioritising and sequencing graduate training experiences are discussed on the basis of the identified thresholds.     

人力资本门槛与中国区域创新收敛性研究

摘要：本文通过分析一个包含区域研发人力资本积累的跨期世代交叠模型,说明区域创新过程中存在着以研发人力资本为门槛的区域创新收敛及收敛的俱乐部效应。然后借鉴经济收敛相关理论,基于面板门槛回归模型,利用中国区域1996-2006年的省际数据对此进行检验,实证结果表明以区域从事研发的每万平方公里科学家工程师人数大约等于93人为门槛,中国区域创新存在着两大俱乐部收敛现象。同时,面板门槛回归模型也较好地解决了收敛理论中的俱乐部效应内生性问题。     

近红外光谱术测量肌氧含量拐点方法的比较

随着运动强度逐渐增大,近红外光谱术测量的肌氧含量发生非线性变化的"拐点"可用于评价无氧阈。对赛艇运动员做渐增负荷运动时的肌氧含量和呼吸参数的变化进行了研究,旨在比较两种确定肌氧拐点的方法:1)基于氧合血红蛋白和还原血红蛋白的相对浓度差Δ[O2Hb-HHb]的变化趋势进行判断;2)利用还原血红蛋白的相对浓度Δ[HHb]的变化趋势确定。研究发现,这两种方法确定的肌氧拐点都与通气无氧阈显著相关(r=0.980,0.965;p<0.001);且两者间高度相关(r=0.985;p<0.001),无统计差异(p>0.05)。结果表明,这两种方法确定的肌氧拐点都可用于评价无氧阈。     

基于TREC目标优化的过滤阈值调整算法

检出阈值的优化调整是自适应信息过滤的重点和难点之一。分析现有的阈值调整方法中普遍存在的问题,以TREC效用指标为目标函数,对阈值调整方法中的极大似然估计法和局部优化法进行比较分析,提出基于TREC目标优化的全局极大似然估计法与局部效用指标优化相结合的自适应过滤阈值调整算法。实验结果表明该方法能有效地提高信息过滤系统的性能。     

模糊规则的表示方法研究

在已有的各种推理方法中,所使用的产生式规则表示形式都不统一,其中含有的信息量也不一样,有的少,有的多,各有侧重点,但都不全面,因而不能把它们作为模糊知识的统一表示形式．其根本的原因就是推理模型本身不完备．本文描述的通用模糊规则,是建立在通用不确定模型和模糊集合理论的基础之上的知识统一表示形式,也是通用模糊推理算法的基础．这种方法采用可能性分布理论来表示知识的模糊性,对一般规则表示进行全面的模糊化,全面考虑了知识的模糊性．它含有推理所需的丰富信息,能用于表达各种情况的模糊性,有着广泛的适用性．已有的规则形式,如确定性知识的规则表示等,只是这种通用形式在忽略部分模糊性情况下的特例．这种表示方法在飞机总体外形设计模糊专家系统（ＡＣＤＳ－ＦＥＳ）中得到了很好的运用．     

带容错性的门限签名方案

利用多方计算的方法,给出一个带容错性的门限签名方案。从而使得一个门限签名方案即使在有恶意行为的情况下,仍可顺利地对消息进行有效的签名。     

创新活力对区域绿色发展转型的门槛机理研究：人力资本视角

通过系统构建中国区域绿色发展转型指标体系将人力资本异质门槛纳入创新驱动绿色发展转型框架,考察不同区域人力资本门槛下创新活力对绿色发展转型的非线性影响机制.研究发现,当前区域绿色发展转型并没有实现,存在较大的发展空间,且区域异质性显著,创新活力对于区域绿色发展转型的作用存在显著的人力资本异质门槛效应,较低水平的人力资本并不利于促使区域创新活力驱动绿色发展转型,而随着地区人力资本积累的提高并突破"临界点",在一定程度上有效增强区域创新活力的驱动效应,进而推动区域绿色发展转型.