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1.
The underlying “architecture of the decision to pursue a degree in psychology was quantified using the Method of Sorting technique to identifying the critical issues necessary to make this choice. Multidimentsional scaling procedures were employed to construct a three-dimensional map representing the relationships between reasons for selecting psychology as a major. Freshman and senior psychology majors (N = 165) from a regional university and a large research-based institution rated the relative importance of items in their decision-making process. Hierarchical clustering procedures revealed seven different groups of students. Although significant differences associated with class standing were not found, institutional affiliation did influence cluster composition. Reflecting local emphases, students at the regional institution had a greater interest in Counseling Psychology, whereas those at the research-based school focused on Clinical Psychology. This semantic map and the associated item clusters arising from psychology student data provides an empirical basis for, amongst other things, course selection, faculty-initiated program design or revision, strategic niche marketing, and student retention.  相似文献   
2.
利用辐射源目标的频移动态特征进行盲分选时,针对已有的分选方法不能很好解决非合作接收数据非周期、间断、交叠的问题,提出了一种改进的逻辑回归分选算法,将信号分选转化为轨迹分类的问题来处理。首先,借鉴多目标航迹起始模型中的M/N逻辑法的框架,设计新的数据关联门限,以建立目标起始曲线;其次,采用最小二乘拟合方法替代卡尔曼滤波,设计新的外推规则,建立载频变化预测曲线;分析新的接收数据与预测曲线的关联性,不断迭代回归或形成新的分支,最后获得目标分选结果。仿真与实测试验表明,利用逻辑回归分选算法,对不同运动目标搭载的同频辐射源可进行自动分选,4个仿真目标与2个真实目标的分选正确率达到100%。同时,该方法拓展了辐射源目标盲分选中的动态频移特征应用,为辐射源个体识别提供了新的支持。  相似文献   
3.
This paper contributes to the literature on the relationship between city size and firm productivity by focusing on agglomeration, selection (market competition), and sorting (presence of firms with diverse productivity) effects using Chinese firm-level data for 1998–2013. Contrary to the existing literature, our parametric regression estimates from nearly two million firms show that when the selection effect is controlled, productivity advantage in big cities is reversed. This outcome is explained through a quantile regression showing the existence of left-sided sorting (inefficient firms sort themselves to larger cities) in big cities which is not captured in existing empirical literature. We further find that (1) left-sided sorting is stronger in exporters than non-exporters; (2) is also generated mainly in enterprises with high asset-liability ratios; and (3) selection has a positive effect on firm productivity, suggesting that market competition is key in an explanation of the rapid growth of big cities in China.  相似文献   
4.
农村垃圾污染问题已成为当前农村最急需解决的环境问题。介绍了我国农村垃圾排放现状、特点以及污染危害,通过分析目前垃圾分类处理不充分的原因,因地制宜提出基于农村循环经济的垃圾分类处理方法及运行管理模式,以提高垃圾分类处理的科学性,满足环境保护的要求。  相似文献   
5.
从2007年太湖蓝藻事件社会影响的货币损益计量角度出发,运用费用评价法、后果阻止法和市场价值法就蓝藻事件对无锡市城市居民垃圾分类意识的影响进行了计量研究。结果表明,太湖蓝藻事件发生后的3年内因为居民垃圾分类意识的提高给无锡市带来的经济效益为4 276.49万元。  相似文献   
6.
Many street‐level bureaucrats have the dual task of helping some clients, while sanctioning others. We develop a model of a street‐level bureaucracy, and we study the implications of its personnel policy on the self‐selection and allocation decisions of agents who differ in altruism towards clients. When bureaucrats are paid flat wages, they do not sanction, and the most altruistic types sort into bureaucracy. Pay‐for‐performance induces some bureaucrats to sanction, but it necessitates an increase in compensation, which can result in sorting from the top and bottom of the altruism distribution. We also explain why street‐level bureaucrats often experience an overload of clients.  相似文献   
7.
We examine differences in altruism and laziness between public sector employees and private sector employees. Our theoretical model predicts that the likelihood of public sector employment increases with a worker's altruism, and increases or decreases with a worker's laziness depending on his altruism. Using questionnaire data from the German Socio‐Economic Panel Study, we find that public sector employees are significantly more altruistic and lazy than observationally equivalent private sector employees. A series of robustness checks show that these patterns are stronger among higher educated workers; that the sorting of altruistic people to the public sector takes place only within the caring industries; and that the difference in altruism is already present at the start of people's career, while the difference in laziness is only present for employees with sufficiently long work experience.  相似文献   
8.
分析了目前自动化物流分拣输送系统在物料导入输送环节的工艺特点和设备控制现状,并结合应用光电检测、工业可编程控制等技术,针对水平交叉带分拣输送机应用场景,对其中物料导入控制环节所面临的物料外形尺寸测量和计算问题,提出了基于物料轮廓最大值检测、尺寸特征捕捉、长宽比关系判断等要素来对物料投影尺寸进行测量的计算方法,具有数据采集实时、程序编写简单、运算量少等特点;同时基于对导入输送的物料进行横向、纵向的截面段断层扫描测量并累加计算,以较低的器件成本及较少的控制器程序运算量,实现对物料体积的近似测量计算,是一种较为经济和可取的控制计算方法。  相似文献   
9.
玉米经破渣后,经过初步分级将含胚玉米渣分离出来,经提胚、压胚、筛选等工序,将玉米胚芽提取出来,玉米胚芽再经精选可以得到较为纯净的胚芽,用于榨油或者其他用途.  相似文献   
10.
We develop a dynamic multiregion model, where a household's choice of housing location depends on its current wealth and its current type, and involves both consumption and investment considerations. The relative strength of the consumption motive and the investment motive determines the equilibrium pattern of residential sorting. A strong investment (consumption) motive implies sorting according to household type (wealth). The model predicts that large house‐price fluctuations are associated with a low degree of sorting by type. This prediction is consistent with evidence from US metropolitan areas when income, education, and age are used as proxies for household type.  相似文献   
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