训练中齐射尾流自导鱼雷碰撞问题及对策

为满足当前潜艇部队训练的需要，针对尾流自导鱼雷齐射训练中可能出现的碰撞问题，以鱼雷散布为基础，分别对齐射时鱼雷进入尾流前发生碰撞，鱼雷过目标舰时与目标舰发生擦碰以及双雷齐射时两雷进入目标尾流后双雷碰撞的3种可能发生的情况进行分析，提出了采用两雷齐射时，设定1条雷的”操雷航程”，以避免两雷交叉，对两雷设定不同”海况”，使两雷航行在不同深度以及两雷反方向发射等避免碰撞的修正方法。该方法易于操作，可为尾流自导鱼雷安全训练提供有效保证。     

Trade-offs between gaze and working memory use.

Eye movements during natural tasks suggest that observers do not use working memory to capacity but instead use eye movements to acquire relevant information immediately before needed. Results here however, show that this strategy is sensitive to memory load and to observers' expectations about what information will be relevant. Depending upon the predictability of what object features would be needed in a brick sorting task, subjects spontaneously modulated the order in which they sampled and stored visual information using working memory more when the task was predictable and reverting to a just-in-time strategy when the task was unpredictable and the memory load was higher. This self organization was evidenced by subjects' sequence of eye movements and also their sorting decisions following missed feature changes. These results reveal that attentional selection, fixations, and use of working memory reflect a dynamic optimization with respect to a set of constraints, such as task predictablity and memory load. They also reveal that change blindness depends critically on the local task context, by virtue of its influence on the information selected for storage in working memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Generation and context memory.

Generation enhances memory for occurrence but may not enhance other aspects of memory. The present study further delineates the negative generation effect in context memory reported in N. W. Mulligan (2004). First, the negative generation effect occurred for perceptual attributes of the target item (its color and font) but not for extratarget aspects of context (location and background color). Second, nonvisual generation tasks with either semantic or nonsemantic generation rules (antonym and rhyme generation, respectively) produced the same pattern of results. In contrast, a visual (or data-driven) generation task (letter transposition) did not disrupt context memory for color. Third, generating nonwords produced no effect on item memory but persisted in producing a negative effect on context memory for target attributes, implying that (a) the negative generation effect in context memory is not mediated by semantic encoding, and (b) the negative effect on context memory can be dissociated from the positive effect on item memory. The results are interpreted in terms of the processing account of generation. The original, perceptual-conceptual version of this account is too narrow, but a modified processing account, based on a more generic visual versus nonvisual processing distinction, accommodates the results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

建立虚拟武器装备库，从基础践行科技兴训——浅探VRML技术在我军军事训练中的应用

VRML技术作为现代一种新型计算机技术，已广泛应用到军事、教育等各个领域，充分运用现代高新技术成果，进行模拟训练已成为各军事强国在训练改革的重要目标和现代军事训练发展的指导方向。本文初步探讨了VRML技术在我军军事训练中的应用，提出了虚拟武器装备库的概念，并对我军建立虚拟武器装备库的可能性、必要性及建设构想进行了初步探讨。     

A hierarchical model for structure learning based on the physiological characteristics of neurons

Almost all applications of Artificial Neural Networks (ANNs) depend mainly on their memory ability. The characteristics of typical ANN models are fixed connections, with evolved weights, globalized representations, and globalized optimizations, all based on a mathematical approach. This makes those models to be deficient in robustness, efficiency of learning, capacity, anti-jamming between training sets, and correlativity of samples, etc. In this paper, we attempt to address these problems by adopting the characteristics of biological neurons in morphology and signal processing. A hierarchical neural network was designed and realized to implement structure learning and representations based on connected structures. The basic characteristics of this model are localized and random connections, field limitations of neuron fan-in and fan-out, dynamic behavior of neurons, and samples represented through different sub-circuits of neurons specialized into different response patterns. At the end of this paper, some important aspects of error correction, capacity, learning efficiency, and soundness of structural representation are analyzed theoretically. This paper has demonstrated the feasibility and advantages of structure learning and representation. This model can serve as a fundamental element of cognitive systems such as perception and associative memory.     

A Multinomial Model of Event-Based Prospective Memory.

Prospective memory is remembering to perform an action in the future. The authors introduce the 1st formal model of event-based prospective memory, namely, a multinomial model that includes 2 separate parameters related to prospective memory processes. The 1st measures preparatory attentional processes, and the 2nd measures retrospective memory processes. The model was validated in 4 experiments. Manipulations of instructions to place importance on either the prospective memory task or the background task (Experiments 1 and 2) and manipulations of distinctiveness of prospective memory targets (Experiment 2) had expected effects on model parameters, as did a manipulation of the difficulty of prospective memory target encoding (Experiments 3 and 4). An alternative model was also evaluated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Symbolic control of visual attention: The role of working memory and attentional control settings.

This study examined how 1 symbol is selected to control the allocation of attention when several symbols appear in the visual field. In Experiments 1-3, the critical target feature was color, and it was found that uninformative central arrows that matched the color of the target were selected and produced unintentional shifts of attention (i.e., involuntary, initiated slowly, producing long-lasting facilitatory effects). Experiment 4 tested whether such selection is the result of an attentional filter or of a competition bias due to a match of incoming information against integrated object representations stored in working memory. Here, the critical feature was shape and color was irrelevant, but matching color arrows were still selected. Thus, features of objects in working memory will bias the selection of symbols in the visual field, and such selected symbols are capable of producing unintentional shifts of attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

NiTi形状记忆合金激光气体氮化层表面特征

为改善NiTi合金的表面性能，利用2kW连续波Nd：YAG对NiTi合金进行激光气体氮化处理。采用SEM、TEM、XRD、XPS和纳米压痕研究了氮化层的显微组织及表面特征．结果表明：激光气体氮化可以在NiTi合金表面制备连续、无裂纹、厚度为2μm的TiN表面层，该表面层中基本不合有Ni元素且具有很高的硬度，其纳米压痕硬度为29．28GPa．     

形状记忆聚氨酯的结构与性能研究

以 2 ,4 -甲苯二异氰酸酯 (2 ,4 -TDI)、不同分子量的聚己二酸丁二醇酯 (PBAG)和 1,4-丁二醇 (BDO)为原料合成了具有形状记忆功能的聚氨酯材料。通过DSC、弯曲实验和力学实验 ,研究了形状记忆聚氨酯的性能 ,发现软段高度结晶和硬段聚集形成硬段微区是其具有较好形状记忆性能的必要条件。     

An accurate and practical buffer allocation model for the buffer cache based on marginal gains

A new dynamic buffer allocation strategy based on the notion of marginal gains is presented for the buffer cache that is used by the operating system to store frequently accessed disk blocks in main memory, and the performance of the proposed strategy is compared with those of previous allocation strategies. In the proposed strategy, marginal gain values are predicted by exploiting functions that approximate the expected number of buffer hits per unit time. Experimental results from both trace-driven simulation and an actual implementation in the FreeBSD operating system show that the proposed strategy accurately predicts the marginal gain values for various workloads resulting in significantly improved buffer hit ratios.