辨析数据通信中常见的选择性问题

结合串行通信编程的实际经验,作者根据适用范围,辨别和分析了数据通信中一些常见的选择性问题,包括数据通信方式选择、串行通信方式选择、数据格式中位数的选择、校验算法选择、总线标准接口选择、握手协议选择、回路测试方案选择和编程方法选择,以供读者参考。     

贝叶斯优化算法的选择策略分析

针对贝叶斯优化算法的选择策略问题,对变量无关,双变量相关,多变量相关等3类典型函数分别用锦标赛选择、截断选择和比例选择以及自适应比例选择进行了实验。建立了相应的贝叶斯网络概率模型,并分析指出锦标赛选择策略能有效保持样本的多样性,并能建立起准确的网络模型。与比例选择策略和截断选择策略相比较,该选择策略更适用于贝叶斯优化算法。     

多边形图象选择工具的实现

讨论了一种多边形选择工具的实现方法，包括选择区域标志的绘制，选择区域在内存中的存储和选择区域的显示方法，简要介绍了对选择区域各种操作的实现步骤。     

我选择,我喜欢

选择一块文字,复制它;选择一个图片,删除它;选择一个整段,修改它……在我们使用Office组件的时候,选择无处不在。你喜欢选择吗?来看看鼠标、键盘和Office三方关于选择的对话吧。     

遗传算法选择方法的比较分析

本文基于改进的基本遗传算法实验,对选择方法进行了比较分析的研究,测试了四种不同选择方法：轮盘赌选择法、锦标赛选择法、随机遍历选择法以及一种新的基于种群交流的选择方法,分析比较这四种不同选择方法封种群发展及最佳适应值的影响。结果表明各种选择方法各有特点。最後为了防止陷入局部收敛,而对轮盘赌选择方法进行了改进,并比较了改进前後的结果,发现改进后的结果要好一些。     

族群进化算法的选择机制

针对改进族群进化算法(EGEA)中对族群模式的有效采样问题,提出以竞争指数为选择指标的常规选择、以族群为选择单位的常规选择以及基于竞争指数的模拟退火排序选择3种选择机制,并通过多维函数优化问题进行实验分析,结果表明3种选择机制都能够在一定程度上提高EGEA的搜索效率,且基于竞争指数的模拟退火排序选择算子的实现更简便,对EGEA综合性能的提高也更明显。     

遗传算法选择策略比较

以遗传算法中的轮盘赌选择策略和锦标赛选择策略作为研究对象,通过在13个基准测试函数上的测试,对不同选择策略的性能进行了比较和分析.实验结果表明,锦标赛选择策略比轮盘赌选择策略具有更好的通用性,而且性能更优.在锦标赛选择策略中,组规模为种群规模的60%至80%的锦标赛选择策略效果较好.该实验结果为设计更加合理高效的选择策略提供了有用的参考.     

数控机床的选型(下)

五、数控系统的选择 随着市场需求多样化,机床制造商往往提供同一种机床可配置多种数控的选择或数控系统中多种选择功能的选择.     

AutoCAD12.0中指定实体的选择方式

AUtoCAD12．0提供了十几种选择待编辑的目标的方法。正确运用指定实体的选择方式是编辑图形的关键。当您选择目标时,AutoCAD建立起一个临时选择集并点亮这些目标：或者改变它们的颜色、或者使它们闪烁、或者用虚线显示它们，这样可方便您确认选择是否正确。如果在Selectobject：提示下出现了错误，AutoCAD会提示所有有效的模式。选择过程还可用一个名为PICKADD的系统变量来控制。当PICKADD为外关闭）时，后来选择的实体替代原来的选择集，除非您在选择时按住Shift键。在选择附加的实体时按住Shi卜键可将这些实体加入已有的选择…     

一种改进的动态流特征选择算法

流特征选择算法在深度流检测技术中发挥着重要作用,数据流的正确识别和分类都需要选择流特征,通过这些流特征在业务流中的差异区分业务流类型。当前基于信息度量的特征选择算法在整个样本空间中计算特征的信息熵,没有将特征选择过程中的动态变化信息加入计算,因此不能准确地度量特征选择过程中各个特征之间的相互关系程度,冗余信息的存在影响特征选择结果,导致分类算法性能降低。提出一种改进的动态特征选择算法,该算法基于信息标准,充分考虑特征选择过程中信息标准的动态变化,通过删除由信息动态变化导致的冗余及无用信息,避免动态选择过程的干扰,达到准确并高效选择特征的目的。实验数据说明,提出的动态流特征选择算法的分类性能比当前其他选择算法较好。     

External and internal choice with event groups in Event-B

Abrial’s Event-B formalism for refinement-based system development is influenced by Back’s action system approach. Morgan has defined a CSP-like failures-divergence semantics for action systems that distinguishes internal and external choice of actions. Morgan’s semantics has the characteristic that the choice between enabled actions is external while internal choice is represented less directly through nondeterministic effect of actions. Practical experience with Event-B has demonstrated the need to be able to represent both internal and external choice between enabled events more explicitly. In this paper, Morgan’s failures semantics for action systems is modified to allow both internal and external choice to be represented directly. This is achieved by grouping events so that external choice is between event groups and internal choice is within event groups. This leads to a refinement rule for preservation of choice between event groups while allowing for reduction of choice within event groups. We also provide a refinement rule for splitting event groups in order to increase external choice. The refinement rules are justified in terms of failures refinement.     

Towards an ecological account of media choice: a case study on pluralistic reasoning while choosing email

The discourse around media choice has generated a diverse array of media choice factors originating from both the media‐based and social interaction‐based approaches. The multitude of these factors hints at the adaptive nature of media choice. Alas, how a user engages with such factors and adaptively carries out media choice has remained understudied. We undertake a field study to explore the role of a plurality of choice factors and their interactions in shaping media choice processes and outcomes. In particular, we focus on how a user identifies relationships among plural choice factors while he or she works on his or her particular choice resulting in a similar outcome – email – given a large number of alternatives. Drawing upon a theory of affordances, we propose a systemic way of narrating the dynamics of media choice as a multi‐dimensional process where a user explores her or his surroundings – a niche – as to establish media affordances that will then help her or him achieve a communication goal. We identify five relational patterns of interactions among specific choice factors: reciprocity, emergence, complementarity, re‐exploration and actualisation. These patterns are shown to be emergent and highly interdependent. We conclude by reviewing future research avenues to formulate richer ‘ecological’ accounts of media choice.     

基于适应度的驾驶员路径选择模型及仿真

针对车辆的路径选择问题,首先描述路径选择单元的划分规则,然后从影响车辆路径选择的路径历史经验和路径最近经验入手,分别定义车辆对路径的初始适应度、历史适应度、最近适应度及路径选择行为概率,并对车辆记忆属性及其变化流程进行说明,最终给出车辆路径选择规则。在上述分析的基础上进行多次重复时间步仿真,仿真结果表明,本文给出的路径选择规则虽然相对较简单,但能够较好地模拟车辆路径选择行为,为交通仿真中车辆路径选择模型提供了一种新的思路。     

The effect of advertisement choice,sex, and need for cognition on attention

A recent study showed that choice of advertisement content affected attention for female but not male viewers (Nettelhorst & Brannon, 2012). This study extended that work by assessing the effect of choice difficulty and the moderation of viewers’ need for cognition (Cacioppo & Petty, 1982) on attention. Participants were either allowed or not allowed to choose which advertisement to watch after watching a television skit. Next, participants watched an advertisement and rated their amount of attention towards it. Results showed that males were not influenced by the choice manipulation, but females had significantly greater attention after making the difficult choice. Similarly, high need for cognition individuals were not influenced by the choice manipulation, but low need for cognition individuals had significantly greater attention after making the difficult choice. These results suggest that choice in of itself is not a sufficient means of increasing viewer attention towards an advertisement. Instead the choice must be between options which are attractive to the viewer. In addition, advertisement choice should be an effective marketing tool particularly for female viewers or those with low need for cognition in general.     

Obtaining more information from conjoint experiments by best-worst choices

Conjoint choice experiments elicit individuals’ preferences for the attributes of a good by asking respondents to indicate repeatedly their most preferred alternative in a number of choice sets. However, conjoint choice experiments can be used to obtain more information than that revealed by the individuals’ single best choices. A way to obtain extra information is by means of best-worst choice experiments in which respondents are asked to indicate not only their most preferred alternative but also their least preferred one in each choice set. To create D-optimal designs for these experiments, an expression for the Fisher information matrix for the maximum-difference model is developed. Semi-Bayesian D-optimal best-worst choice designs are derived and compared with commonly used design strategies in marketing in terms of the D-optimality criterion and prediction accuracy. Finally, it is shown that best-worst choice experiments yield considerably more information than choice experiments.     

Usability is more valuable predictor than product personality for product choice in human-product physical interaction

Product personality and product usability are two important factors which can influence consumers' product choice. Published literature are available regarding independent impact of product personality and product usability on product choice but no research has been reported so far for understanding their collective influence on product choice. In addition, which factor between usability and product personality contributing more in product choice is still not clear. Current research thus aimed to bridge these research gaps by establishing inter-relationships among product personality, usability and product choice. To achieve this goal, two separate experiments were conducted. Results of first experiment revealed that products having high product usability also possessed strong product personality. Following second experiment, it was observed that solitary influence of product usability on product choice was more than the standalone influence of product personality in human-product physical interaction. Moreover, it unfolded the fact that product usability mediates the influence of product personality towards product choice. Established interrelationships among product personality, usability and product choice, would help designer and ergonomists to decide how product attributes could be manipulated to enhance product personality and/or product usability to ensure product choice.     

Technology adaptation: a typology for strategic human resource management

Organizational adjustment to technological change and its impact upon human resources should be based on an understanding of employee perceptions and behavioural responses to such developments. An analytic framework which relates strategic choice to internal labour market and employee determinism is derived from the methods employed by organizational theorists and psychologists to generate a set of typologies. The framework divides variables in four classes: (1) natural selection, with minimum choice and adaptation or selection out; (2) differentiation, with high choice and high employee determinism and adaptation within constraints; (3) strategic choice, with maximum choice and adaptation by design; and (4) undifferentiated choice, with incremental choice and adaptation by chance. Useful in reconciling previously inconsistent or incompatible theories of technological change, the framework is offered as a co-ordination device to integrate the results of divergent approaches to technological adaptation studies.     

Local operators in models of social choice

A social choice function is constructed from choice functions of individuals by using local operators defined in the paper. The conditions for closedness of basic choice functions, described in the literature, with respect to local operators are studied. Ways in which analogues of Arrow's paradox arise when using choice functions rather than orderings are demonstrated.     

Lexical choice in text generation and machine translation

We present in this article the state of the art in lexical choice research in text generation and machine translation. The existing implementations are discussed with respect to four topics: (i) the place of lexical choice in the overall generation process, (ii) the information flow within the generation process and the consequences thereof for lexical choice, (iii) the internal organization of the lexical choice process, (iv) the phenomena covered by lexical choice. Possible future directions in lexical choice research are identified.