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101.
Two studies investigated the effects of conditioning to masked stimuli on visuospatial attention. During the conditioning phase, masked snakes and spiders were paired with a burst of white noise, or paired with an innocuous tone, in the conditioned stimulus (CS)+ and CS- conditions, respectively. Attentional allocation to the CSs was then assessed with a visual probe task, in which the CSs were presented unmasked (Experiment 1) or both unmasked and masked (Experiment 2), together with fear-irrelevant control stimuli (flowers and mushrooms). In Experiment 1, participants preferentially allocated attention to CS+ relative to control stimuli. Experiment 2 suggested that this attentional bias depended on the perceived aversiveness of the unconditioned stimulus and did not require conscious recognition of the CSs during both acquisition and expression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
102.
盲聚合签名方案   总被引:1,自引:0,他引:1  
在电子货币系统中,用户Alice要从不同的银行得到签名支票(这是一个盲签名过程),然后将这些支票付给Bob.Bob再拿着这些支票到各个银行进行验证取款.这个过程需要耗费大量的时间和存储控件.提出了一个盲聚合签名方案,可以让Bob得到一个唯一的签名,从而大大节省时间和空间并且降低对带宽的要求.该方案结合了盲签名和聚合签名优点,能使生成的盲签名聚合为一个聚合签名.  相似文献   
103.
104.
How can the measurement of attitudes and opinions, by the use of scales involving the method of paired comparisons, be improved? An attempt was made to describe the relationship between scale values derived from partial and complete paired comparison judgments. "One complete and five partial pairing schedules were used, and 60 Ss, who had been randomly assigned to one of these six conditions, scaled the names of 30 nationality groups. The results of the study indicated that partial pairing scale values rather closely approximated those obtained from a complete pairing when the number of observations was reduced as much as 50% of the complete pairing matrix. Beyond this point further reduction seemed to yield a more drastic modification in the scale values obtained. The rating task implications of partial pairing were discussed." (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
105.
Intraspecific pairing of the planaria,Dugesia tigrina andD. dorotocephala, was studied for 24 hr at 22 ± 1 °C in Petri dish cultures containing an agar substrate and a water overlay. Pairing of fed planaria in the light and dark and starved planaria in the light was studied, and worms in contact or within 5 mm of each other were considered paired. Fed planaria of both species paired significantly in the light and dark, whereas starved planaria did not pair. Our results suggest that worm-emitted chemical factors are involved in intraspecific pairing of planaria. Thin-layer chromatographic analysis was used to study the release of lipophilic worm products. Phospholipids, free sterols, and free fatty acids were detected in all trials, and triglycerides in most. Thin-layer densitometric analysis was used to quantitate the weight of free sterols released by planaria.  相似文献   
106.
移动Ad hoc网络是一种资源有限的移动多跳无线网络。在网络中构建组密钥协商协议时应尽可能地减少资源开销。文中在基于身份的网络安全环境下,设计了一种基于环状结构的组密钥协商协议。该协议采用椭圆曲线上的双线性配对,仅通过单轮通信完成组密钥协商。经过分析,该协议具有等献性,已知密钥安全,无密钥控制等安全属性,适用于Ad hoc网络。  相似文献   
107.
蔡永泉  张可 《电子学报》2008,36(10):1966-1969
 本文针对Paterson无需随机预言的签名方案,提出了一种新的基于身份的无需随机预言的(t,n)门限签名方案,并分析了新方案的正确性和安全性.分析结果表明,在离散对数难题下,参与者能方便的产生个体签名,公开验证者可通过验证公式,决定是否接受个体签名和门限签名.而任何攻击者不能伪造个体签名,不能通过窃听个体签名、门限签名和其他公开信息得到系统秘密值,即使已知所有参与者的秘密值,也无法伪造门限签名.该方案在各种可能的攻击下是安全的.  相似文献   
108.
高效的基于ID的无证书签名方案   总被引:4,自引:0,他引:4  
通过利用gap diffie-hellman(GDH)群,提出了一种高效的基于ID的无证书签名方案,该方案通过将2个部分公钥绑定相同的一个ID,从而解决了密钥托管问题.在这个方案中,私钥生成中心(PKG,private key generator)不能够伪造合法者的签名,因为只能生成一部分私钥,其安全性依赖于CDHP(computational diffie-hellman problem).在随机预言机模型下,新方案被证明能够抵抗适应性选择消息攻击和ID攻击下的存在性伪造.该方案不仅解决了密钥托管问题而且与许多已有的方案相比具有较高的效率.  相似文献   
109.
The airline industry is a representative industry with high cost and low profitability. Therefore, airlines should carefully plan their schedules to ensure that overall profit is maximized. We review the literature on airline planning and scheduling and focus on mathematical formulations and solution methodologies. Our research framework is anchored on three major problems in the airline scheduling, namely, fleet assignment, aircraft routing, and crew scheduling. General formulation, widely used solution approaches, and important extensions are presented for each problem and integrated problems. We conclude the review by identifying promising areas for further research.  相似文献   
110.
The deniable authentication protocol is an important notion that allows a receiver to identify the source of a given message, but not to prove the identity of the sender to a third party. Such property is very useful for providing secure negotiation over the Internet. The ID-based deniable authentication protocol based on elliptic Diffie-Hellman key agreement protocol cannot defend the sender spoofing attack and message modification attack. In this paper, we present an improved protocol based on double elliptic Diffie-Hellman scheme. According to the comparison result, the proposed protocol performs better.  相似文献   
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