中学生问题解决中操作要求对资源分配的影响

Schema acquisition is one of the mechanisms of learning. How to design reasonable teaching material to promote schema acquisition is an important question that psychological researchers and educators both interested. Cognitive Load Theory indicates that: The cognitive resource of Human is limited, the organization and presentation of the learning material should avoid demanding the learner consume resource in actions that have nothing to do with schema acquisition. How can we do that? Sweller. J. et think: Increasing the operation cost of the learning material would make the students put more resource into the implementation of the operation, this kind of resource consuming has nothing to do with schema acquisition. So, in order to make the students put more resource into actions which relating to schema acquisition, we should decrease the operation cost of the learning material. But, the research results of O'Hara et indicate: In problem-solving of knowledge lean field, increasing the operation cost would make the college students invent more resource to plan and understanding actions. So, Increasing the operation cost would facilitate the schema acquisition. How operation cost will effect the Middle-School Students' (MSS) schema acquisition and resource distribution when they solve problems of knowledge lean/rich field? This is the main question this research want to make inquiry. IN this research, we use three experiments indicate: Increasing the operation cost of actions, the implementing action would be less and the planning action would be more. So, increasing the operation cost can promote the schema acquisition. We use "cost-benefit analysis" strategy to explain this result. This strategy means that: Human is rational, before doing one action, he will weigh the cost and the coming benefit of this action, if the coming benefit is higher than the cost, he will implement this action; if the cost is higher than the coming benefit, this action will be contained. On the one hand, this research further affirms the core opinion of the Cognitive Load Theory: Human's cognitive resource is limited, we should put the limited resource into actions which is related to the schema acquisition; On the other hand, for the learning material designing principle which is advanced by the Cognitive Load Theory, we raise our questions. Besides, the question we raised holds some identical views with the constructive learning opinion: Learning is not passive information absorption, but positively constructing the meaning of the information, besides, this kind of construction can't done by others. The result of this research can provide some theory guidance and experimental basis for the designing of the MSS's science teaching material from a complete new angle.

空间及言语工作记忆任务的情绪效应：来自ERP/ fMRI的证据

In the present study, based on processing efficiency theory, we used the event-related potentials (ERP) and functional magnetic resonance image (fMRI) techniques to explore the underlying neutral mechanism of influences of negative emotion on three subsystems of working memory, phonological loop、 visuospatial sketh pad and the central executive. The modified DSMT (delayed matching-to-sample task) and n-back tasks were adopted and IAPS (International Affective Picture System) pictures were employed to induce the expected emotional state of subjects. The main results and conclusions obtained in the series of experiments are as the following: 1. In DSM tasks, we found P200 and P300 were reduced by negative emotion in both spatial and verbal tasks, however the increased negative slow wave were only observed in spatial tasks, not in verbal tasks. 2. In n-back tasks, the updating function of WM associated P300 was affected by negative emotion only in spatial tasks, not in verbal tasks. Current density analysis revealed strong current density in the fronto-parietal cortex only in the spatial tasks as well. 3. We adopted fMRI-block design and ROIs analysis, and found significant emotion and task effects in spatial WM-associated right superior parietal cortex; only emotion effect in verbal WM-associated Broca’s area; the interaction effect in attention-associated medial prefrontal area and bilateral inferior parietal cortex. These results implied the negative emotion mainly disturbed the spatial WM-related areas, and the attention control system play a key role in the interaction of spatial WM and negative emotion. 4. to further examine the effects of positive、negative and neutral emotion on tasks with different cognitive loads, the selective effect of emotion on the ERP components of spatial WM was only found in 2-back tasks, not in visual searching tasks. So, firstly the positive emotion as well as negative emotion selectively disturbed on spatial WM in light of the attention resource competition mechanism. Secondly, the selective influences based on the different WM systems, not the properties of spatial and verbal information. At last, the manner of the interaction of emotion and cognition is correlated with the cognitive load.

视觉搜索中注意捕获的控制机制

Theories of Visual search generally differentiate between bottom-up control and top-down control. Bottom-up control occurs when visual selection is determined by the stimulus properties in the search field. Top-down control takes place when observers are able to select those stimuli that are in line with their attentional sets. Pure stimulus-driven capture and contingent capture are two main theories on attentional capture by now, in which, theory of pure capture more emphasize bottom-up control, while theory of contingent capture more emphasize top-down control. Besides those two theories, Perceptual load theory of attention provides completely new perspective to explain attentional capture. The aim of this study is to investigate the mechanism of attentional capture in visual search on the basis of the existing theory of attentional capture and Perceptual load theory of attention. Three aspects of questions were explored in this study, which includes: the modulation role of perceptual load on attentional capture; the influence of search mode on attentional capture; and the influence of stimuli’s spatial and temporal characteristics on attentional capture. The results showed that: (1) Attentional capture was modulated by perceptual load in both conditions in which perceptual load manipulated either by amount of stimuli or similarity of stimuli. (2) Search mode did influence attentional capture, but more important, which was also modulated by perceptual load. (3) The spatial characteristics of congruent and incongruent distractor did influence attentional capture, specifically, the further the distractor from the target, the more interference effect the distractor had on visual search. (4) The temporal characteristics of distractor did influence attentional capture, specifically, the pattern of results from the study in which distractor were presented after the search display, were similar to those from the study in which distractors were presented before the search display. In sum, the results indicated that attentional capture are controlled not only by bottom-up factors, top-down factors but also modulated by available attention resources. These findings contribute to resolve the controversy for mechanism of attentional capture. And the potential application of this research was discussed.

手持通信设备的多通道文本输入研究

Recently，Handheld Communication Devices is developing very fast, extending in users and spreading in application fields, and has an promising future. This study investigated the acceptance of the multimodal text entry method and the behavioral characteristics when using it. Based on the general information process model of a bimodal system and the human factor studies about the multimodal map system, the present study mainly focused on the hand-speech bimodal text entry method. For acceptance, the study investigated the subjective perception of the accuracy of speech recognition by Wizard of Oz (WOz) experiment and a questionnaire. Results showed that there was a linear relationship between the speech recognition accuracy and the subjective accuracy. Furthermore, as the familiarity increasing, the difference between the acceptable accuracy and the subjective accuracy gradually decreased. In addition, the similarity of meaning between the outcome of speech recognition and the correct sentences was an important referential criterion. The second study investigated three aspects of the bimodal text entry method, including input, error recovery and modal shifts. The first experiment aimed to find the behavioral characteristics of user when doing error recovery task. Results indicated that participants preferred to correct the error by handwriting, which had no relationship with the input modality. The second experiment aimed to discover the behavioral characteristics of users when doing text entry in various types of text. Results showed that users preferred to speech input in both words and sentences conditions, which was highly consistent among individuals, while no significant difference was found between handwriting and speech input in the character condition. Participants used more direct strategy than jumping strategy to deal with mixed text, especially for the Chinese-English mixed type. The third experiment examined the cognitive load in the different modal shifts, results suggesting that there were significant differences between different shifts. Moreover, relevant little time was needed in the Shift from speech input to hand input. Based on the main findings, implications were discussed as follows: Firstly, when evaluating a speech recognition system, attention should be paid to the fact that the speech recognition accuracy was not equal to the subjective accuracy. Secondly, in order to make a speech input system more acceptable, a good method is to train and supply the feedback for the accuracy in training, which improving the familiarity and sensitivity to the system. Thirdly, both the universal and individual behavioral patterns were taken into consideration to improve the error recovery method. Fourthly, easing the study and the use of speech input, the operations of speech input should be simpler. Fifthly, more convenient text input method for non-Chinese text entry should be provided. Finally, the shifting time between hand input and speech input provides an important parameter for the design of automatic-evoked speech recognition system.

学前儿童朴素生物学“理论”的发展——对“生长”认知的实验研究

There is a debate in cognitive development theory on whether cognitive development is general or specific. More and more researchers think that cognitive development is domain specific. People start to investigate preschoolers' native theory of human being's basic knowledge systems. Naive biology is one of the core domains. But there is argument whether there is separate native biological concepts among preschoolers. The research examined preschoolers' cognitive development of naive biological theory on two levels which is "growth" and "aliveness", and it also examined individual difference and factors that lead to the difference. Three studies were designed. Study 1 was to study preschoolers' cognition on growth, which is a basic trait of living things, and whether children can distinguish living and non-living things with the trait and understanding the causality. Study 2 was to investigate preschoolers' distinction between living things and non-living things from an integrated level. Study 3 was to investigate how children make inferences to unfamiliar things with their domain specific knowledge. The results showed the following: 1. Preschoolers gradually developed naive theory of biology on growth level, but their naive theory on integrated level has not developed. 2 Preschoolers' naive theory of biology is not "all or none", 4- and 5-year-old children showed some distinction between living and non-living things to some extent, they use non-intentional reason to explain the cause of growth and their explanation showed coherence. But growth has not been a criteria of ontological distinction of living and non-living things for 4- and 5-year-old children, most 6-year-old children can distinguish between living and non-living things, and these show the developing process of biological cognition. 3. Preschoolers' biological inference is influenced by their domain-specific knowledge, whether they can make inference to new trait of living things depends on whether they have specific knowledge. In the deductive task, children use their knowledge to make inference to unfamiliar things. 4-year-olds use concrete knowledge more often while the 6-year-old use generalized knowledge more frequency. 4. Preschoolers' knowledge grow with age, but individuals' cognitive development speed at different period. Urban and rural educational background affect cognitive performance. As time goes by, the urban-rural knowledge difference to distinguish living and nonliving things reduces. And preschoolers' are at the same developmental stage because the three age groups have similar causal explanation both in quantity and quality. 5. There is intra-individual difference on preschoolers' naive biological cognition. They show different performance on different tasks and domains, and their cognitive development is sequential, they understand growth earlier than they understand "alive", which is an integrated concept. The intra-individual differences decrease with age.

Dislocation theory of the fracture criterion for anisotropic solids

A dislocation theory of fracture criterion for the mixed dislocation emission and cleavage process in an anisotropic solid is developed in this paper. The complicated cases involving mixed-mode loading are considered here. The explicit formula for dislocations interaction with a semi-infinite crack is obtained. The governing equation for the critical condition of crack cleavage in an anisotropic solid after a number dislocation emissions is established. The effects of elastic anisotropy, crack geometry and load phase angle on the critical energy release rate and the total number of the emitted dislocations at the onset of cleavage are analysed in detail. The analyses revealed that the critical energy release rates can increase to one or two magnitudes larger than the surface energy because of the dislocation emission. It is also found elastic anisotropy and crystal orientation have significant effects on the critical energy release rates. The anisotropic values can be several times the isotropic value in one crack orientation. The values may be as much as 40% less than the isotropic value in another crack orientation and another anisotropy parameter. Then the theory is applied to a fee single crystal. An edge dislocation can emit from the crack tip along the most highly shear stressed slip plane. Crack cleavage can occur along the most highly stressed slip plane after a number of dislocation emissions. Calculation is carried out step by step. Each step we should judge by which slip system is the most highly shear stressed slip system and which slip system has the largest energy release rate. The calculation clearly shows that the crack orientation and the load phase angle have significant effects on the crystal brittle-ductile behaviours.

Increasing Critical Sensitivity of the Load/Unload Response Ratio before Large Earthquakes with Identified Stress Acclumulation Pattern

The Load/Unload Response Ratio (LURR) method is proposed for short-to-intermediate-term earthquake prediction [Yin, X.C., Chen, X.Z., Song, Z.P., Yin, C., 1995. A New Approach to Earthquake Prediction — The Load/Unload Response Ratio (LURR) Theory, Pure Appl. Geophys., 145, 701–715]. This method is based on measuring the ratio between Benioff strains released during the time periods of loading and unloading, corresponding to the Coulomb Failure Stress change induced by Earth tides on optimally oriented faults. According to the method, the LURR time series usually climb to an anomalously high peak prior to occurrence of a large earthquake. Previous studies have indicated that the size of critical seismogenic region selected for LURR measurements has great influence on the evaluation of LURR. In this study, we replace the circular region usually adopted in LURR practice with an area within which the tectonic stress change would mostly affect the Coulomb stress on a potential seismogenic fault of a future event. The Coulomb stress change before a hypothetical earthquake is calculated based on a simple back-slip dislocation model of the event. This new algorithm, by combining the LURR method with our choice of identified area with increased Coulomb stress, is devised to improve the sensitivity of LURR to measure criticality of stress accumulation before a large earthquake. Retrospective tests of this algorithm on four large earthquakes occurred in California over the last two decades show remarkable enhancement of the LURR precursory anomalies. For some strong events of lesser magnitudes occurred in the same neighborhoods and during the same time periods, significant anomalies are found if circular areas are used, and are not found if increased Coulomb stress areas are used for LURR data selection. The unique feature of this algorithm may provide stronger constraints on forecasts of the size and location of future large events.

Energy Conversion in Shape Memory Alloy Heat Engine Part I: Theory

Shape Memory Alloy (SMA) can be easily deformed to a new shape by applying a small external load at low temperature, and then recovers its original configuration upon heating. This unique shape memory phenomenon has inspired many novel designs. SMA based heat engine is one among them. SMA heat engine is an environment-friendly alternative to extract mechanical energy from low-grade energies, for instance, warm wastewater, geothermal energy, solar thermal energy, etc. The aim of this paper is to present an applicable theoretical model for simulation of SMA-based heat engines. First, a micro-mechanical constitutive model is derived for SMAs. The volume fractions of austenite and martensite variants are chosen as internal variables to describe the evolution of microstructure in SMA upon phase transition. Subsequently, the energy equation is derived based on the first thermodynamic law and the previous SMA model. From Fourier’s law of heat conduction and Newton’s law of cooling, both differential and integral forms of energy conversion equation are obtained.

Size Effects in Micro-bending Deformation of MEMS Devices Based on the Discrete Dislocation Theory

In the present research, the discrete dislocation theory is used to analyze the size effect phenomena for the MEMS devices undergoing micro-bending load. A consistent result with the experimental one in literature is obtained. In order to check the effectiveness to use the discrete dislocation theory in predicting the size effect, both the basic version theory and the updated one are adopted simultaneously. The normalized stress-strain relations of the material are obtained for different plate thickness or for different obstacle density. The prediction results are compared with experimental results.

Effect Of Load Triaxiality On Polymorphic Transitions In Zinc Oxide

Molecular dynamics (MD) simulations and first-principles calculations are carried out to analyze the stability of both newly discovered and previously known phases of ZnO under loading of various triaxialities. The analysis focuses on a graphite-like phase (FIX) and a body-centered-tetragonal phase (BCT-4) that were observed recently in [0 1 (1) over bar 0]- and [0 0 0 1]-oriented nanowires respectively under uniaxial tensile loading as well as the natural state of wurtzite (WZ) and the rocksalt (RS) phase which exists under hydrostatic pressure loading. Equilibrium critical stresses for the transformations are obtained. The WZ -> HX transformation is found to be energetically favorable above a critical tensile stress of 10 GPa in [0 1 (1) over tilde 0] nanowires. The BCT-4 phase can be stabilized at tensile stresses above 7 GPa in [0 0 0 1] nanowires. The RS phase is stable at hydrostatic pressures above 8.2 GPa. The identification and characterization of these phase transformations reveal a more extensive polymorphism of ZnO than previously known. A crystalline structure-load triaxiality map is developed to summarize the new understanding. (c) 2007 Elsevier Ltd. All rights reserved.

Cognitive models in biomimetic pattern cognition

We describe a new model which is based on the concept of cognizing theory. The method identifies subsets of the data which are embedded in arbitrary oriented lower dimensional space. We definite k-mean covering, and study its property. Covering subsets of points are repeatedly sampled to construct trial geometry space of various dimensions. The sampling corresponding to the feature space having the best cognition ability between a mode near zero and the rest is selected and the data points are partitioned on the basis of the best cognition ability. The repeated sampling then continues recursively on each block of the data. We propose this algorithm based on cognition models. The experimental results for face recognition demonstrate that the correct rejection rate of the test samples excluded in the classes of training samples is very high and effective.

Biomimetic (topological) pattern recognition - A new model of pattern recognition theory and its application

A new theoretical model of Pattern Recognition principles was proposed, which is based on "matter cognition" instead of "matter classification" in traditional statistical Pattern Recognition. This new model is closer to the function of human being, rather than traditional statistical Pattern Recognition using "optimal separating" as its main principle. So the new model of Pattern Recognition is called the Biomimetic Pattern Recognition (BPR)(1). Its mathematical basis is placed on topological analysis of the sample set in the high dimensional feature space. Therefore, it is also called the Topological Pattern Recognition (TPR). The fundamental idea of this model is based on the fact of the continuity in the feature space of any one of the certain kinds of samples. We experimented with the Biomimetic Pattern Recognition (BPR) by using artificial neural networks, which act through covering the high dimensional geometrical distribution of the sample set in the feature space. Onmidirectionally cognitive tests were done on various kinds of animal and vehicle models of rather similar shapes. For the total 8800 tests, the correct recognition rate is 99.87%. The rejection rate is 0.13% and on the condition of zero error rates, the correct rate of BPR was much better than that of RBF-SVM.

Relationship between load/unload response ratio and damage variable and its application

The physics-based parameter: load/unload response ratio (LURR) was proposed to measure the proximity of a strong earthquake, which achieved good results in earthquake prediction. As LURR can be used to describe the damage degree of the focal media qualitatively, there must be a relationship between LURR and damage variable (D) which describes damaged materials quantitatively in damage mechanics. Hence, based on damage mechanics and LURR theory, taking Weibull distribution as the probability distribution function, the relationship between LURR and D is set up and analyzed. This relationship directs LURR applied in damage analysis of materials quantitatively from being qualitative earlier, which not only provides the LURR method with a more solid basis in physics, but may also give a new approach to the damage evaluation of big scale structures and prediction of engineering catastrophic failure. Copyright (c) 2009 John Wiley & Sons, Ltd.

Relationship between load/unload response ratio and damage variable and its application

The physics-based parameter: load/unload response ratio (LURR) was proposed to measure the proximity of a strong earthquake, which achieved good results in earthquake prediction. As LURR can be used to describe the damage degree of the focal media qualitatively, there must be a relationship between LURR and damage variable (D) which describes damaged materials quantitatively in damage mechanics. Hence, based on damage mechanics and LURR theory, taking Weibull distribution as the probability distribution function, the relationship between LURR and D is set up and analyzed. This relationship directs LURR applied in damage analysis of materials quantitatively from being qualitative earlier, which not only provides the LURR method with a more solid basis in physics, but may also give a new approach to the damage evaluation of big scale structures and prediction of engineering catastrophic failure. Copyright (c) 2009 John Wiley & Sons, Ltd.

听力障碍与听力正常群体视觉注意发展及其机制的比较

One of the most important functions in the individual development is the interaction and integration of each sensory input. There exist two competing theories, i.e. the deficiency theory and the compensatory theory, regarding the origin and nature of changes in visual functions observed after auditory deprivation. The deficiency theory proposed that integrative processes are essential for normal development. In contrast, the compensatory theory stated that the loss of one sense may be met by a greater reliance upon, therefore an enhancement of the remaining senses. Given that hearing impaired children’s learning depends primarily on visual information, it is important to recognize the differences of visual attention between them and their hearing age-mates. Differences among age groups could exist in either selectivity or sustained attention. Study 1 and study 2 explored the selective and sustained attention development of hearing impaired and hearing students with average cognitive ability, aged from 7 years to college students. The analysis and discussion of the results are based on the visual attention development as well as deficiency theory and compensatory theory. According to the results of the study 1 and study 2, the spatial distribution and controlling of the visual attention between hearing impaired and hearing students were also investigated in the study 3 and study 4. The present work showed that: Firstly, both hearing impaired and hearing participants had the similar developmental trajectory of the sustained attention. The ability of children’s sustained attention appeared to improve with age, and in adolescence it reached the peak. The hearing impaired participants had the comparable sustained attention skills to the matched hearing ones. Besides, the results of the hearing impaired participants showed that they could maintain their attention and vigilance on the current task over the observation period. Secondly, group differences of visual attention development were found between hearing impaired and hearing participants. In the childhood, the visual attention developmental speed of the hearing impaired children was slower than that of the hearing ones. The selective attention skill of the hearing impaired were not comparable to the hearing ones, however, their selective skill improved with age, so in the adulthood, hearing impaired students showed the slight advantage in the selective attention skill over the hearing ones. Thirdly, hearing impaired and hearing participants showed the similar spatial distribution in the attention resources. In the low perceptual load condition, both participants were suffered great interference of the distrator at the fixation. In contrast, in the high perceptual load condition, hearing impaired adults were suffered more interference of the peripheral distractor, which suggested that they distributed more attention resources to the peripheral field when faced difficult tasks. Fourthly, both groups showed similar processing in the visual attention tasks. That is, they both searched the target with only the color feature in a parallel way, but in a serial way while processing orientation feature and the features with the combination of the color and orientation. Furthermore, the results indicated that two groups show similar ways in the attention controlling. In summary, the present study showed that visual attention development was dependent upon the integration of multimodal sensory information. Because of the interaction and integration of the input from various sensory, it has a negative impact on the intact sensory at the early stage of one sensory loss, however, it can better the functions of other intact sensory gradually with development and practice.