基于情感与环境认知的移动机器人自主导航控制

将基于情感和认知的学习与决策模型引入到基于行为的移动机器人控制体系中, 设计了一种新的自主导航控制系统. 将动力学系统方法用于基本行为设计, 并利用ART2神经网络实现对连续的环境感知状态的分类, 将分类结果作为学习与决策算法中的环境认知状态. 通过在线情感和环境认知学习, 形成合理的行为协调机制. 仿真表明, 情感和环境认知能明显地改善学习和决策过程效率, 提高基于行为的移动机器人在未知环境中的自主导航能力     

The effect of learning by imitation on a multi-robot system based on the coupling of low-level imitation strategy and online learning for cognitive map building

It is assumed that future robots must coexist with human beings and behave as their companions. Consequently, the complexities of their tasks would increase. To cope with these complexities, scientists are inclined to adopt the anatomical functions of the brain for the mapping and the navigation in the field of robotics. While admitting the continuous works in improving the brain models and the cognitive mapping for robots’ navigation, we show, in this paper, that learning by imitation leads to a positive effect not only in human behavior but also in the behavior of a multi-robot system. We present the interest of low-level imitation strategy at individual and social levels in the case of robots. Particularly, we show that adding a simple imitation capability to the brain model for building a cognitive map improves the ability of individual cognitive map building and boosts sharing information in an unknown environment. Taking into account the notion of imitative behavior, we also show that the individual discoveries (i.e. goals) could have an effect at the social level and therefore inducing the learning of new behaviors at the individual level. To analyze and validate our hypothesis, a series of experiments has been performed with and without a low-level imitation strategy in the multi-robot system.     

SeqDynamics: Visual Analytics for Evaluating Online Problem-solving Dynamics

Problem-solving dynamics refers to the process of solving a series of problems over time, from which a student's cognitive skills and non-cognitive traits and behaviors can be inferred. For example, we can derive a student's learning curve (an indicator of cognitive skill) from the changes in the difficulty level of problems solved, or derive a student's self-regulation patterns (an example of non-cognitive traits and behaviors) based on the problem-solving frequency over time. Few studies provide an integrated overview of both aspects by unfolding the problem-solving process. In this paper, we present a visual analytics system named SeqDynamics that evaluates students ‘problem-solving dynamics from both cognitive and non-cognitive perspectives. The system visualizes the chronological sequence of learners’ problem-solving behavior through a set of novel visual designs and coordinated contextual views, enabling users to compare and evaluate problem-solving dynamics on multiple scales. We present three scenarios to demonstrate the usefulness of SeqDynamics on a real-world dataset which consists of thousands of problem-solving traces. We also conduct five expert interviews to show that SeqDynamics enhances domain experts’ understanding of learning behavior sequences and assists them in completing evaluation tasks efficiently.     

Memory-based cognitive modeling for robust object extraction and tracking

Inspired by the way humans perceive the environment, in this paper, we propose a memory-based cognitive model for visual information processing which can imitate some cognitive functions of the human brain such as remembering, recall, forgetting, learning, classification, and recognition, etc. The proposed model includes five components: information granule, memory spaces, cognitive behaviors, rules for manipulating information among memory spaces, and decision-making processes. Three memory spaces are defined for separately storing the current, temporal and permanent information acquired, i.e. ultra short-term memory space (USTMS), short-term memory space (STMS) and long-term memory space (LTMS). The proposed memory-based model can remember or forget what the scene has ever been which helps the model adapt to the variation of the scene more quickly. We apply the model to address two hot issues in computer vision: background modeling and object tracking. A memory-based Gaussian mixture model (MGMM) for object segmentation and a memory-based template updating (MTU) model for object tracking with particle filter (PF) are exhibited respectively. Experimental results show that the proposed model can deal with scenes with sudden background and foreground changes more robustly when segmenting and tracking moving objects under complex background.     

Elman backpropagation as reinforcement for simple recurrent networks

Simple recurrent networks (SRNs) in symbolic time-series prediction (e.g., language processing models) are frequently trained with gradient descent--based learning algorithms, notably with variants of backpropagation (BP). A major drawback for the cognitive plausibility of BP is that it is a supervised scheme in which a teacher has to provide a fully specified target answer. Yet agents in natural environments often receive summary feedback about the degree of success or failure only, a view adopted in reinforcement learning schemes. In this work, we show that for SRNs in prediction tasks for which there is a probability interpretation of the network's output vector, Elman BP can be reimplemented as a reinforcement learning scheme for which the expected weight updates agree with the ones from traditional Elman BP. Network simulations on formal languages corroborate this result and show that the learning behaviors of Elman backpropagation and its reinforcement variant are very similar also in online learning tasks.     

Cognition-Driven Traffic Simulation for Unstructured Road Networks

Dynamic changes of traffic features in unstructured road networks challenge the scene-cognitive abilities of drivers, which brings various heterogeneous traffic behaviors. Modeling traffic with these heterogeneous behaviors would have significant impact on realistic traffic simulation. Most existing traffic methods generate traffic behaviors by adjusting parameters and cannot describe those heterogeneous traffic flows in detail. In this paper, a cognition-driven trafficsimulation method inspired by the theory of cognitive psychology is introduced. We first present a visual-filtering model and a perceptual-information fusion model to describe drivers’ heterogeneous cognitive processes. Then, logistic regression is used to model drivers’ heuristic decision-making processes based on the above cognitive results. Lastly, we apply the high-level cognitive decision-making results to low-level traffic simulation. The experimental results show that our method can provide realistic simulations for the traffic with those heterogeneous behaviors in unstructured road networks and has nearly the same efficiency as that of existing methods.

     

一种具有发育机制的感知行动认知模型

针对结构固定认知模型中存在的学习浪费与计算浪费问题,在具有内发动机机制的感知行动认知模型基础上,根据操作条件反射学习特性,借鉴潜在动作原理,建立起一种具有发育机制的感知行动认知模型D-SSCM(Development-sensorimotor cognitive model),具体为一个14元组,包含离散学习时间集、内...     

The influence of collaboration styles to children’s cognitive performance in digital problem-solving game “William Adventure”: A comparative case study

Since a large variety of digital games have been used in many fields for educational purposes, their real functions in learning have caught much attention as well. This study first defines learning characteristics of problem-solving digital games and their corresponding cognitive levels, then designs and develops a problem-solving game in accordance to the criteria. Tasks in the game context are inter-related to each other so that players need to critically and creatively think about problem solutions. Learners’ task analyses are performed to observe four elementary learners’ gaming paths, behaviors and cognitive activities, individually and collaboratively. System documentation, video recording, researcher observation, and interviews are conducted to analyze learners’ learning strategies and their cognitive performance during the gaming process.     

融合知识交互关系的认知诊断深度模型

认知诊断是基于学习数据挖掘学习者潜在认知状态的一种智能评测技术.当前大多数认知诊断模型将学习任务中的知识视为同等重要,未考虑知识间的交互关系,从而影响诊断的准确性,同时也缺乏可解释性.针对上述问题,文中提出融合知识交互关系的认知诊断深度模型,实现学习者认知状态与知识权重的统一表达.同时,实现基于Choquet积分的理想作答反应计算算法.最后提出模糊测度的深度神经网络,预测学习者的作答表现.大量实验表明,文中模型不仅取得较好的预测结果,还能为预测结果提供知识交互层面的解释,具有一定的优越性.     

Modeling and evaluating empathy in embodied companion agents

Affective reasoning plays an increasingly important role in cognitive accounts of social interaction. Humans continuously assess one another's situational context, modify their own affective state accordingly, and then respond to these outcomes by expressing empathetic behaviors. Synthetic agents serving as companions should respond similarly. However, empathetic reasoning is riddled with the complexities stemming from the myriad factors bearing upon situational assessment. A key challenge posed by affective reasoning in synthetic agents is devising empirically informed models of empathy that accurately respond in social situations. This paper presents Care, a data-driven affective architecture and methodology for learning models of empathy by observing human–human social interactions. First, in Care training sessions, one trainer directs synthetic agents to perform a sequence of tasks while another trainer manipulates companion agents’ affective states to produce empathetic behaviors (spoken language, gesture, and posture). Care tracks situational data including locational, intentional, and temporal information to induce a model of empathy. At runtime, Care uses the model of empathy to drive situation-appropriate empathetic behaviors. Care has been used in a virtual environment testbed. Two complementary studies investigating the predictive accuracy and perceived accuracy of Care-induced models of empathy suggest that the Care paradigm can provide the basis for effective empathetic behavior control in embodied companion agents.     

Designing an adaptive web-based learning system based on students’ cognitive styles identified online

This study developed an adaptive web-based learning system focusing on students’ cognitive styles. The system is composed of a student model and an adaptation model. It collected students’ browsing behaviors to update the student model for unobtrusively identifying student cognitive styles through a multi-layer feed-forward neural network (MLFF). The MLFF was adopted because of its ability on imprecise or incompletely understood data, ability to generalize and learn from specific examples, ability to be quickly updated with extra parameters, and speed in execution making them ideal for real time applications. The system then adaptively recommended learning content presented with a variety of content and interactive components through the adaptation model based on the student cognitive style identified in the student model. The adaptive web interfaces were designed by investigating the relationships between students’ cognitive styles and browsing patterns of content and interactive components. Training of the MLFF and an experiment were conducted to examine the accuracy of identifying students’ cognitive styles during browsing with the proposed MLFF and the impact of the proposed adaptive web-based system on students’ engagement in learning. The training results of the MLFF showed that the proposed system could identify students’ cognitive styles with high accuracy and the temporal effects should be considered while identifying students’ cognitive styles during browsing. Two factors, the acknowledgment of students’ cognitive styles while browsing and the existence of adaptive web interfaces, were used to assign three classes of college freshmen into three groups. The experimental results revealed that the proposed system could have significant impacts on temporal effects on students’ engagement in learning, not only for students with cognitive styles known before browsing, but also for students with cognitive styles identified during browsing. The results provide evidence of the effectiveness of the adaptive web-based learning system with students’ cognitive styles dynamically identified during browsing, thus validating the research purposes of this study.     

基于GPR和深度强化学习的分层人机协作控制

提出了一种基于高斯过程回归与深度强化学习的分层人机协作控制方法,并以人机协作控制球杆系统为例检验该方法的高效性.主要贡献是:1)在模型未知的情况下,采用深度强化学习算法设计了一种有效的非线性次优控制策略,并将其作为顶层期望控制策略以引导分层人机协作控制过程,解决了传统控制方法无法直接应用于模型未知人机协作场景的问题; 2)针对分层人机协作过程中人未知和随机控制策略带来的不利影响,采用高斯过程回归拟合人体控制策略以建立机器人对人控制行为的认知模型,在减弱该不利影响的同时提升机器人在协作过程中的主动性,从而进一步提升协作效率; 3)利用所得认知模型和期望控制策略设计机器人末端速度的控制律,并通过实验对比验证了所提方法的有效性.     

Using a cognition-motivation-control view to assess the adoption intention for Web-based learning

People expect Web technology to facilitate learning, particularly in higher education. A key issue involves the factors motivating the adoption of the Web for learning. Drawing upon social cognitive theory (SCT) and the theory of planned behavior (TPB), this study adopts a cognition-motivation-control view to assess learner adoption intentions for Web-based learning. The proposed model is validated by surveying 319 undergraduate students who had enrolled in Web-based courses and attended a 12-hour training program on using a Web-based system for academic learning. The empirical findings identified that efficacy control and efficacy expectations can be used to guide learner adaptation learning behaviors on the Web. The limitations of this study are discussed and future research directions suggested.     

Data mining for adaptive learning sequence in English language instruction

The purpose of this paper is to propose an adaptive system analysis for optimizing learning sequences. The analysis employs a decision tree algorithm, based on students’ profiles, to discover the most adaptive learning sequences for a particular teaching content. The profiles were created on the basis of pretesting and posttesting, and from a set of five student characteristics: gender, personality type, cognitive style, learning style, and the students’ grades from the previous semester. This paper address the problem of adhering to a fixed learning sequence in the traditional method of teaching English, and recommend a rule for setting up an optimal learning sequence for facilitating students’ learning processes and for maximizing their learning outcome. By using the technique proposed in this paper, teachers will be able both to lower the cost of teaching and to achieve an optimally adaptive learning sequence for students. The results show that the power of the adaptive learning sequence lies in the way it takes into account students’ personal characteristics and performance; for this reason, it constitutes an important innovation in the field of Teaching English as a Second Language (TESL).     

基于学习的多目标脑决策模型研究

多目标决策在大脑的认知功能中起着关键的作用.在本研究中,我们将一个额叶视区网络模型扩展为一个基于学习的模型,并训练这个模型使其完成一个认知决策任务——non-choice任务,然后用模拟结果解释大脑在进行多目标选择时的认知过程.经过上千次训练后,额叶视区模型从随机选择决策目标转变为选择与最大奖励相关联的决策.在训练过程中,模型的多目标决策顺序也与目标关联的奖励梯度相关.此外,改变不同决策间的奖励差对模型的决策速度有重要的影响,可以使模型进入两种学习阶段:快速学习阶段和慢速学习阶段.     

Personalized e-learning system using Item Response Theory

Personalized service is important on the Internet, especially in Web-based learning. Generally, most personalized systems consider learner preferences, interests, and browsing behaviors in providing personalized services. However, learner ability usually is neglected as an important factor in implementing personalization mechanisms. Besides, too many hyperlink structures in Web-based learning systems place a large information burden on learners. Consequently, in Web-based learning, disorientation (losing in hyperspace), cognitive overload, lack of an adaptive mechanism, and information overload are the main research issues. This study proposes a personalized e-learning system based on Item Response Theory (PEL-IRT) which considers both course material difficulty and learner ability to provide individual learning paths for learners. The item characteristic function proposed by Rasch with a single difficulty parameter is used to model the course materials. To obtain more precise estimation of learner ability, the maximum likelihood estimation (MLE) is applied to estimate learner ability based on explicit learner feedback. Moreover, to determine an appropriate level of difficulty parameter for the course materials, this study also proposes a collaborative voting approach for adjusting course material difficulty. Experiment results show that applying Item Response Theory (IRT) to Web-based learning can achieve personalized learning and help learners to learn more effectively and efficiently.     

Dynamics of opinion formation,social power evolution,and naïve learning in social networks

The past few decades have witnessed a prevalence of applying dynamical models to the study of social networks. This paper reviews recent advances in the investigation of social networks with a predominant focus on agent-based models. Starting from classical models of opinion dynamics, we survey several recently developed models on opinion formation and social power evolution. These models extend the classical models’ cognitive assumption that individuals’ opinions evolve on a single issue by incorporating various sociological or psychological hypotheses to account for the evolution of opinions over multiple or a sequence of interdependent issues. We summarize basic results on the asymptotic behaviors of these models and discuss their sociological interpretations. In addition, we show how these models play a role in the emergence of collective intelligence by applying them to a naïve learning setting. Novel results that reveal how individuals successfully learn an unknown truth over issue sequences are presented. Finally, we conclude the paper and discuss potential directions for future research.     

Learning and motivational couplings promote smarter behaviors of an animat in an unknown world

This paper reports on statistical results of an animat behavior in an unknown environment using a cognitive map. We study the coupling effect between the motivation for eating and the one for drinking. Some smart behaviors are not caused by a sophisticated “intelligent” algorithm, but only through coupling of the motivations. Adding a learning rule on the links of the cognitive map allows to reinforce particular paths, and to forget others. This also leads to reinforce the same “smart” behaviors.     

The relationship between learning styles and cognitive traits – Getting additional information for improving student modelling

Student modelling is an important process for adaptive virtual learning environments. Student models include a range of information about the learners such as their domain competence, learning style or cognitive traits. To be able to adapt to the learners’ needs in an appropriate way, a reliable student model is necessary, but getting enough information about a learner is quite challenging. Therefore, mechanisms are needed to support the detection process of the required information. In this paper, we investigate the relationship between learning styles, in particular, those pertaining to the Felder–Silverman learning style model and working memory capacity, one of the cognitive traits included in the cognitive trait model. The identified relationship is derived from links between learning styles, cognitive styles, and working memory capacity which are based on studies from the literature. As a result, we demonstrate that learners with high working memory capacity tend to prefer a reflective, intuitive, and sequential learning style whereas learners with low working memory capacity tend to prefer an active, sensing, visual, and global learning style. This interaction can be used to improve the student model. Systems which are able to detect either only cognitive traits or only learning styles retrieve additional information through the identified relationship. Otherwise, for systems that already incorporate learning styles and cognitive traits, the interaction can be used to improve the detection process of both by including the additional information of a learning style into the detection process of cognitive traits and vice versa. This leads to a more reliable student model.     

认知无线网络中基于信誉度管理的动态频谱接入研究

随着无线服务和相关设备的飞速发展,认知无线网络中特有频谱稀缺问题越来越引起研究者的重视。在集中式认知无线网络中,次级用户基站SUBS作为融合中心,通过收到周围的次级用户的感知信息来分配频谱资源。然而,环境的易变性使次级用户容易受到攻击从而影响次级用户感知信息,导致网络频谱资源分配错误。引入信誉度模型来表现次级用户在认知循环中的行为规范,在分配频谱阶段将信誉度作为评定标准,鼓励次级用户积极感知及规范运行。在感知阶段,次级用户感知信道数越多,感知信息越正确,其信誉度越高。在运行阶段,次级用户行为越符合网络规范,则信誉度越高。仿真结果表明,论文模型可以很好地减少次级用户基站的错误决策次数,提高其抗攻击性,同时使得网络在很好地分配资源的同时鼓励整个网络行为积极化。