Reliably Assessing Growth with Longitudinal Diagnostic Classification Models     

Matthew J. Madison 《Educational Measurement》2019,38(2):68-78

Recent advances have enabled diagnostic classification models (DCMs) to accommodate longitudinal data. These longitudinal DCMs were developed to study how examinees change, or transition, between different attribute mastery statuses over time. This study examines using longitudinal DCMs as an approach to assessing growth and serves three purposes: (1) to define and evaluate two reliability measures to be used in the application of longitudinal DCMs; (2) through simulation, demonstrate that longitudinal DCM growth estimates have increased reliability compared to longitudinal item response theory models; and (3) through an empirical analysis, illustrate the practical and interpretive benefits of longitudinal DCMs. A discussion describes how longitudinal DCMs can be used as practical and reliable psychometric models when categorical and criterion‐referenced interpretations of growth are desired.  相似文献   

基于知识元的学术论文内容创新性智能化评价研究   总被引：1，自引：0，他引：1  

李贺  杜杏叶 《图书情报工作》2020,64(1):93-104

[目的/意义] 创新性是对学术论文质量最基本的要求，是学术论文的灵魂，是学术论文评价的核心。知识元是学术论文基本组成单元。基于知识元理论和机器学习相关理论与算法，从学术论文内容层面研究计算机如何智能化地进行创新性评价及其实现过程与方法。[方法/过程] 首先，构建学术论文的研究问题、理论、方法、结论4个知识元本体，接着提出基于知识元的学术论文创新性判断模型。其次，根据学术论文研究特点，构建理论与方法机器分类模型及知识元的抽取规则与抽取方法，建立规则库和知识语料库。最后，基于语义相似度计算方法，根据判断规则和相关权重对学术论文4个维度的创新性进行评分。[结果/结论] 基于知识元抽取的学术论文创新性评分系统的实证结果表明，该智能化评价方法具有一定的可行性，可为学术论文内容创新性智能化评价系统的最终实现提供方法借鉴。  相似文献   

Executive functioning during prolonged exercise: a fatigue-based neurocognitive perspective     

Cyril Schmit  Jeanick Brisswalter 《International review of sport and exercise psychology》2020,13(1):21-39

ABSTRACT

Despite emotional, technical and endurance implications for athletes’ performance, a consensus has yet to be reached to explain the impairment of executive functioning during exercise. In particular, recent research challenges the original assumption of a linear dose–response effect of exercise intensity on cerebral physiology and executive functioning. We propose a fatigue-based neurocognitive perspective of executive functioning during prolonged exercise, suggesting that top-down (cognitive and physical efforts) and bottom-up processes (body sensations) act in parallel of arousing mechanisms to determine cognitive outcomes. In this perspective, executive functioning during prolonged exercise would be dynamical rather than steady (i.e. positively then negatively impacted by exercise) and would be to analyse in regards of exercise termination rather than of exercise intensity.  相似文献   

基于神经网络的认知无线电合作频谱感知     

薛建伟  唐亮  卜智勇 《中国科学院大学学报》2020,37(3):379-386

认知无线电是一种可用于有效缓解当前频谱资源紧张的技术，而频谱感知是认知无线电的前提。针对低信噪比情况下频谱感知性能差的问题，提出一种将信号高阶统计量、协方差矩阵特征值与神经网络相结合的合作频谱感知算法。该算法考虑到认知用户与授权用户的信道衰落情况，利用神经网络较强的多分类能力，将最大-最小特征值之比、平均-最小特征值之比以及高阶统计量作为特征参数，通过神经网络实现合作频谱感知。仿真结果表明，该算法不仅在低信噪比情况下较其他算法具有更高的频谱检测率，而且对频谱中信号的调制类型也有较高的识别率。  相似文献   

Digital Module 05: Diagnostic Measurement—The G‐DINA Framework https://ncme.elevate.commpartners.com     

Wenchao Ma  Jimmy de la Torre 《Educational Measurement》2019,38(2):114-115

In this ITEMS module, we introduce the generalized deterministic inputs, noisy “and” gate (G‐DINA) model, which is a general framework for specifying, estimating, and evaluating a wide variety of cognitive diagnosis models. The module contains a nontechnical introduction to diagnostic measurement, an introductory overview of the G‐DINA model, as well as common special cases, and a review of model‐data fit evaluation practices within this framework. We use the flexible GDINA R package, which is available for free within the R environment and provides a user‐friendly graphical interface in addition to the code‐driven layer. The digital module also contains videos of worked examples, solutions to data activity questions, curated resources, a glossary, and quizzes with diagnostic feedback.  相似文献   

Effects of periodic carbohydrate ingestion on endurance and cognitive performances during a 40-km cycling time-trial under normobaric hypoxia in well-trained triathletes     

Yi-Hung Liao  Toby Mündel  Yan-Ting Yang  Chen-Chan Wei  Shiow-Chwen Tsai 《Journal of sports sciences》2019,37(16):1805-1815

The purpose of this study was to examine CHO ingestion on a cognitive task using a field-simulated time-trial (TT) under hypoxia in well-trained triathletes. Ten male triathletes (age: 22.1 ± 1.1 years; VO₂max: 59.4 ± 1.4 ml/kg/min) participated in this double-blind/crossover/counter-balanced design study. Participants completed 3 TT trials: 1) normoxic placebo (NPLA; FiO₂ = 20.9%), 2) hypoxic placebo (HPLA; FiO₂ = 16.3%), and 3) hypoxic CHO (HCHO; 6% CHO provided as 2 ml/kg/15 min; FiO₂ = 16.3%). During the TT, physiological responses (SpO₂, HR, RPE, and blood glucose/lactate), cognitive performance, and cerebral haemodynamics were measured. Hypoxia reduced TT performance by ~3.5–4% (p < 0.05), but CHO did not affect TT performance under hypoxia. For the cognitive task, CHO slightly preserved exercise-induced cognitive reaction speed but did not affect response accuracy during hypoxic exercise. However, CHO did not preserve the decreased Hb-Diff (cerebral blood flow, CBF) and increased HHb in the prefrontal lobe (p < 0.05) during hypoxic exercise, and CHO failed to preserve hypoxia-suppressed prefrontal CBF and tissue oxygen saturation. In conclusion, the present study demonstrates that CHO is effective in sustaining reaction speed for a cognitive task but not promoting TT performance during hypoxic exercise, which would be important for strategy-/decision-making when athletes compete at moderate high-altitude.  相似文献   

河西走廊系列盆地构造演化的三维数值模拟     

李蔚琳  程惠红  张怀  石耀霖 《中国科学院大学学报》2019,36(2):196-207

河西走廊是青藏高原向东北方向扩展生长的前缘地区。在青藏高原向东北方向推挤过程中，走廊内形成盆山相间的地貌，自东向西为武威-张掖-酒泉-玉门盆地，呈一字形排列，是研究新生盆地构造演化的理想地区。基于河西走廊及其邻区晚新生代构造环境、现今盆地与断裂带的几何构造布展、GPS和历史地震资料，建立区域三维黏弹塑性有限元地质模型，以期动态刻画近5 Ma河西走廊系列盆地的构造演化过程，探讨地壳的横向不均匀性对该区域构造变形的影响。数值分析结果如下。1）在近5 Ma的区域压扭构造作用下，河西走廊多个力学性质较强的次级块体依次形成左行排列的系列盆地且被NNW-NW向的断裂带和隆起分割。2）与研究区域内的其他地区相比，河西走廊与祁连山和阿拉善地块的交界处及祁连山地区整体抬升速度较快，且北祁连山抬升速度大于南祁连山。3）祁连山北缘榆木山断裂段呈现微弱东西引张，抬升速度比两端慢，地表垂直抬升速率呈现“缺口”形态。4）与河西走廊相邻的塔里木和阿拉善地块的上地壳相对于不断隆升的青藏高原下沉，且挤压盆地中地壳，使得盆地之间出现隆起。数值分析的结果反映了河西走廊系列盆地的演化过程，解释了现今祁连山地区河流网络分布现象，也揭示了青藏高原东北缘向北东方向扩展生长过程中潜在的动力来源。  相似文献   

When digitalized customers meet digitalized services: A digitalized social cognitive perspective of omnichannel service usage     

《International Journal of Information Management》2020

With the prevalence of digital technologies, various services have grown digitalized. Specific to the marketing section, multichannel has been gradually replaced by omnichannel, which aims to integrate all the physical and digital channels tightly. Although omnichannel has received considerable attention, there is still a dearth of research that theorizes the multi-faceted impacts of digitalization on omnichannel. This study thus extends social cognitive theory (SCT) to the digitalized context and contextualizes the digitalized customer and digitalized environment as mobile identity and channel integration quality, respectively. Moreover, based on the self-regulation process of human agency, we incorporate omnichannel self-efficacy, satisfaction, and habit as the agentic factors to interpret a customer’s conscious (ability and expectancy beliefs) and unconscious (automatic behavioral tendency) decision-making under the omnichannel setting. Through an online survey of 401 omnichannel customers, we find support for all the proposed hypotheses. Implications and limitations of this study are further discussed.  相似文献   

Effects of an aerobic fitness test on short- and long-term memory in elementary-aged children     

Jennifer L. Etnier  Paul M. Sprick  Jeffrey D. Labban  Chia-Hao Shih  Stephen M. Glass  Jarod C. Vance 《Journal of sports sciences》2020,38(19):2264-2272

ABSTRACT

Meta-analytic evidence supports that exercise has benefits for short-term memory (STM) and long-term memory (LTM). However, only three studies with children have tested the differential effects of exercise on STM and LTM. The purpose of this study was to examine the effects of an aerobic fitness test on STM and LTM and to consider the moderating effects of grade level. Children (7–13 years of age) were randomly assigned to either perform an aerobic fitness test before (exercise prior) or after (exercise post) performing the Rey Auditory Verbal Learning Test (RAVLT) to assess memory. Memory was tested again after approximately 24 hours. There were significant differences in memory performance as a function of grade with 4^th and 6^th graders consistently outperforming 2^nd graders. For learning, Day 1 Retention, 24-hr recall, and Day 2 Retention, the exercise prior group performed better than the exercise post group. It is concluded that an aerobic fitness test performed prior to a declarative memory test benefits LTM as compared to when the aerobic fitness test is performed after the memory test.  相似文献   

新媒体用户的内容消费特征与媒介使用模式——以百度百家号的调研分析结论为例(2)     

喻国明学术工作室  喻国明  刘淼  韩婷 《传媒观察》2020,(5):32-38

本文把视线聚焦在新媒体的媒体语境当中,以百度百家号为例,考察了新媒体用户在内容层面、认知层面和行为层面上的认知与使用模式。基于对百度百家号用户媒介认知与媒介使用情况的网络问卷调查数据,本研究从新媒体用户重点关注的文章类型、内容来源的关注度以及网络内容的信任度三个方面分析了新媒体用户的内容消费特征并提出了优化网络内容平台内容建设机制及信息扩散机制的策略与建议。在用户层面,需重点培养激活核心用户以提升内容生态的活跃度;在平台层面,需纳入优质内容资源,重视品牌建设。  相似文献