共查询到20条相似文献，搜索用时 31 毫秒
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Pigeons categorized binomial samples produced by two complementary random processes. Samples were 1, 2, 4, or 8 successively presented outcomes (vertical or horizontal lines) of, in effect, tossing one of two equally likely coins. One coin (A) was biased in favor of vertical, and the other coin (B) was similarly biased in favor of horizontal. Choosing red or green stimuli presented after each sample was reinforced with food if coin A or coin B had been tossed, respectively. In that sense, choosing red or green was logically analogous to inferring that the statistical evidence reflected tossing of coin A or coin B, respectively. The statistical diagnosticity of a sample, the relative likelihood of its having been produced by a particular coin, equaled, except for sampling fluctuation, the relative frequency of reinforcement of a particular color given that sample, and was experimentally varied by the bias on the coins and by sample size. All the variables that affect optimal, formal inference about binomial samples also affected intuitive inference. But inferences were very suboptimal: “undermatching” was obtained in part due to control of categorization by the sequential structure of binomial samples. These results reveal limitations of optimality theories for animal decision making in the face of uncertainty when observations in samples are presented successively. On the other hand, they are generally compatible with molecular analyses of instrumental learning which assign an important role to the local temporal organization of events preceding reinforcement. Most generally, they show that maladaptive control over intuitive statistical inference by a variable upon which optimal performance does not depend is neither a uniquely human phenomenon nor dependent upon linguistic strategies. 相似文献
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杨巨平 《北京师范大学学报(社会科学版)》2007,(6):40-46
希腊式钱币出现于亚历山大开创的希腊化时代之初,流行演变于丝绸之路开通之后,消失于萨珊波斯灭亡与阿拉伯帝国建立之际。虽经千年历史变迁,但从整体上看,这类钱币的基本形制、材质、币值、重量、名称都没有根本的改变,只有正反两面的图案轮廓和铭文语种因王朝更替或发行者的变化而呈现出较大的差异。希腊式钱币是多元文化环境下的产物,它本身的创制、流通和演变就是丝绸之路上东西方文化交流融合的又一个缩影。 相似文献
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Pigeons categorized binomial samples. One of two “coins” was tossed on each trial, and birds learned to infer from observing the outcomes which of the two equally likely coins had been tossed. Outcomes (“heads” or “tails”) appeared as successively presented red or green center keys. Coin R was biased in favor of red, and coin G was similarly biased in favor of green. A categorization consisted of a choice of a left or right side key and was reinforced with food if it was to the key (left for coin R and right for coin G) corresponding to the coin that produced that trial’s sample. Coin bias and minimum sample size required for reinforcement were experimentally manipulated. When sample size was greatest (n=8), categorizing a sample as having been produced by coin R tended to undermatch the probability that the sample was produced by coin R. When sample size was smallest (n=1), categorizing a sample overmatched, provided that the context did not include other trials with large samples. This context effect reconciles an otherwise inconsistent literature on intuitive statistical inference in pigeons but suggests a new and difficult goal for research-the general clarification of the effects of sampling context on inference. 相似文献
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周玉英 《福建师范大学学报(哲学社会科学版)》2005,(5):107-111
清前期为平抑市场上铜钱价格,清政府采取如下措施:一,增加铸币量.二,增加铸铜的主要原料供应;购铜资金主要动用关税、芦、盐课税;而购铜行为又屡经变化.康熙开海后还购洋铜以弥补滇铜不足.三,处理阻碍铜钱流通中的私铸及毁钱制器等问题.随着市场铜钱量的增加,到乾隆中期以后,已改变了钱贵银贱的局面.此后,清朝政府的重心已不是平抑钱价,而改为平抑银价了. 相似文献
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王晓洁 《临沂师范学院学报》2007,29(6):25-26
给出了用一台天平搜索两个坏硬币的最优化过程,并且这两个坏硬币的重量是相等的.一台天平所提供的坏硬币的信息,是通过比较两个由硬币组成集合的重量而获得的. 相似文献
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赵善轩 《江西师范大学学报(哲学社会科学版)》2010,43(1):70-73
著名历史学家全汉升认为＂中古自然经济＂是自汉魏以后开始出现的,可是种种迹象显示,自然经济化情况在两汉之际已开始出现。两汉俸给由西汉时以钱币为主转变为东汉时的半钱半谷,汉晋以后则发展为以实物支付为主的模式,可见,中古自然经济的发展有其历史渊源,而战争及币材不足只是当中较表面的原因,更重要的可能是受到当时货币思想倒退,甚至出现反货币思想的影响。 相似文献
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在海南出土的钱币中,最早的是“半两”钱。自宋代开始,海南社会经济的发展在大量移民进入、生产技术和生产力显著提高、海外贸易空前发展的推动下,进入到一个真正的全面开发时期,使得货币在一定的范围和领域得到使用和流通。两宋时期的货币在海南各地大量出土便是佐证之一。宋代以前的钱币在海南只是作为一种财富贮藏手段,而真正发挥货币的价值尺度、流通和支付手段应始于宋代。 相似文献
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茹士春 《十堰职业技术学院学报》2005,18(2):19-22
在刑法第310条第2款和第349条第3款的适用过程中,可能出现几个罪刑关系轻重失衡的悖论,应通过立法的完善和合理解释予以消解。 相似文献
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David Buckingham 《Cultura y Educación》2019,31(2):213-231
AbstractDigital literacy is often proposed as a means of dealing with the problems apparently caused by ‘fake news’. This positioning article considers some of the difficulties with this approach. It argues that fake news is not an isolated phenomenon, but one that needs to be understood in a much broader social, economic and cultural context. It also addresses the practical possibilities and difficulties of teaching in this area. The notion of ‘digital literacy’ appears to define the phenomenon in technological terms. By contrast, this article suggests that we need a broader notion of media literacy, which is based on critical thinking about the economic, ideological and cultural dimensions of media. Even so, the article suggests, the broader problems that are at the root of the problem of ‘fake news’ are unlikely to be solved very easily. 相似文献
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网络在线评论对于商家和顾客具有重要价值,因而日益受到虚假评论行为的冲击。作为两个重要的在线评论领域,产品类评论（如亚马逊、淘宝）和店铺类评论（如点评网、Yelp）在语言特性、评论行为等方面存在显著差异。虽然研究者们已提出大量针对产品类虚假评论的检测方法,但对于店铺类虚假评论的研究仍然较少。针对Yelp.com网站上旅店、饭店有标注的点评数据,提取并分析各种评论欺诈特征,利用多种有监督学习方法进行虚假评论检测。实验结果表明,检测精度最高可达74%,AUC值可达75%。虽然店铺类虚假评论具有极强的隐蔽性,但通过权衡检测精度和召回率,可利用有监督学习方法对店铺类虚假评论进行有效检测。 相似文献
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一般而言,在采集到的指纹灰度图像中均含有大量噪声,而指纹识别技术在很大程度上依赖于指纹图像的质量,所以对指纹图像中的伪信息要加以滤除。在指纹的预处理阶段,利用多种方法可有效地去除图像中的大部分伪信息。在二值化过程中充分考虑指纹脊线的特性,利用指纹图像中点梯度的方向信息,提出了用相位编组法确定块方向,然后基于块方向进行方向滤波,收到了较好的效果。 相似文献
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张良桥 《顺德职业技术学院学报》2009,7(1):36-39
假冒商品可以给消费者带来虚荣效用而使得消费者产生购买激励,同时假冒商品由于其成本低价格相对高而使生产者存在生产激励？因此,使现实中假冒商品盛行于市场,另外文章也运用进化博弈模型对现实中假冒商品存在的现象、原因及其影响因素进行了动态分析。 相似文献
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印度是世界上最大的电影生产国,它的电影也因国情颇具独特的风格。而更引人注目的则是它那别具一格的电影观众。他们与他国的观众迥然不同,他们是参与和互动型的。在电影院,观众们往往会冲着银幕上的人物吹口哨并欢呼雀跃,甚或朝着银幕上投掷硬币或附和着音乐吼唱舞动。这是一个有趣并令人困惑的现象。本文通过对此现象的研究,发现印度的电影院原来是电影人和消费人之间相互作用的集体表现欲的展示场所,进而成为印度大众文化的一道亮丽的景观与缩影。 相似文献
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Akitoshi Uchida Kazuo Mori 《International Journal of Science and Mathematics Education》2018,16(6):1115-1126
International surveys repeatedly showed that Japanese children were good at mathematics but disliking it. We hypothesized there were a considerable number of “fake math-dislikes” among Japanese students who claimed they disliked mathematics explicitly but accepted it implicitly. To examine this hypothesis, we administered questionnaires and paper-based implicit association tests (IAT) to 204 Japanese junior high school students (13–14 years old) and found 38 fake math-dislikes (Study 1). We hypothesized further that those fake math-dislikes would become real math-dislikes eventually and that informing of their implicit attitude toward mathematics might work preventing this undesirable transition. Then, in Study 2, we randomly assigned them into experimental and control groups and informed only the experimental students of their positive implicit attitude toward mathematics we revealed with the IAT. One year later, we found 15 of the 16 experimental students improved their math achievement scores while only 9 of the 17 control students did. The simple practice of informing of their implicit attitude worked effectively for improving their math achievement. As hypothesized, it prevented the fake math-dislike students from turning into real math-dislikes. 相似文献
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陈园园 《齐齐哈尔师范高等专科学校学报》2014,(5):46-47
《孔乙己》是鲁迅最重要的小说之一,虽然历经数十年研究、探讨,但的的微妙细节仍然没有挖掘出来。对孔乙己排出的“大钱”,孔乙己最后欠的二九个钱,孔乙己的偷书,这几个细节的深入探究,对鲁迅作品的语言魄力、鲁迅小说的特色有重要意义。 相似文献
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我国《刑法修正案（八）》将醉驾行为作为犯罪处理。＂醉驾＂入罪实施一年来,醉酒驾驶高发势头得到了有效遏制,但是司法实践中缺乏对醉驾判处缓刑、免刑、从轻、从重处罚的详细标准,导致各地法院对同样的案件处理结果不一样。细化醉驾的量刑标准,区别对待不同的醉驾案件,避免选择性司法,才能更好地体现法律对每个醉驾者的公正裁决。 相似文献
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台湾自古以来一直流通和使用着中原各中央封建王朝所颁行的各种货币,台湾的商品经济发展、贷币形态演化和货币文化的形成等与祖国大陆一直是同根同源的。根据目前的出土情况和史籍记载,台湾正式使用的金属铸币应从宋代铜钱计起。清朝统一台湾后,为了向天下昭示主权,弘扬国咸,从根本上解决台湾铜钱缺少的问题,破例特许台湾府就地开炉鼓铸“康熙通宝”,这是历代中央封建政府首次在台湾设立机构、就地铸币,掀起了台湾贷币史的新篇章,是清王朝争取实现和维护国家统一政治目标的产物。一部台湾贷币形态演化史,就是台湾自古以来即为中国领土的最有说服力的佐证。 相似文献