A Shiny Update to an Old Experiment Game

ABSTRACT

Games can be a powerful tool for learning about statistical methodology. Effective game design involves a fine balance between caricature and realism, to simultaneously illustrate salient concepts in a controlled setting and serve as a testament to real-world applicability. Striking that balance is particularly challenging in response surface and design domains, where real-world scenarios often play out over long time scales, during which theories are revised, model and inferential techniques are improved, and knowledge is updated. Here, I present a game, borrowing liberally from one first played over 40 years ago, which attempts to achieve that balance while reinforcing a cascade of topics in modern nonparametric response surfaces, sequential design, and optimization. The game embeds a blackbox simulation within a shiny app whose interface is designed to simulate a realistic information–availability setting, while offering a stimulating, competitive environment wherein students can try out new methodology, and ultimately appreciate its power and limitations. Interface, rules, timing with course material, and evaluation are described, along with a “case study” involving a cohort of students at Virginia Tech. Supplementary materials for this article are available online.     

莫斯科的国际中心城市地位研究

20世纪90年代,莫斯科的政治、经济和社会结构经历了重大变革,改变了莫斯科的国家地位和国际排名。本文研究莫斯科在俄罗斯国内和在欧洲城市中的地位。毫无疑问,莫斯科的发展特点是：在逐渐脱离国家城市体系的同时,也逐渐朝着国际方向发展。以经济指标来衡量,莫斯科在国内找不到竞争对手。它远远领先于国内其他城市,因为这些城市正快速融入国内和区域经济的潮流,只在很小的程度上参与经济全球化。相反,莫斯科越来越多地争取融入跨国公司和国际经济体系的行列。虽然莫斯科作为一个国际性城市的概念往往只是城市的政治工具,但事实上,如果俄罗斯的首都想要融入世界,其资本是有限的。从中欧的角度来看,目前莫斯科最重要的功能,是连结中欧、西欧和俄罗斯。但现实是,莫斯科与俄罗斯其他城市之间的差距将会继续扩大。     

Loss of urban forest canopy and the effects on neighborhood soundscapes

Urban Ecosystems - The urban landscape constitutes a key aspect of human - nature interactions, as more than 60% of the world’s population resides in cities and their suburbs. This study...     

Urban ecosystem Services in Latin America: mismatch between global concepts and regional realities?

Urban Ecosystems - Latin America and the Caribbean (LAC) is one of the most urbanized and biologically diverse regions in the world but is often characterized by weak environmental governance and...     

Part-Time Work in the EEC Countries: Evolution during the 1980s

Whereas part-time working remains the exponent par excellence of the flexibility of female employment, its relative growth seems to have come to a standstill in both Denmark and the United Kingdom as far as women are concerned, and for men it is now becoming more a matter of young people offsetting studies and work. In France, the Netherlands, Belgium, the UK, Ireland and Germany, the increase in female employment between 1983 and 1989 is largely attributable to the growth of part-time employment. The difference with respect to the countries of the South of Europe is striking since the proportion of part-time working there is low, and has not increased significantly since 1983. Its concentration in already very close sectors, its non-optional nature, insecurity and awkward working hours make part-time employment of very little personal value for employees.     

The Impact of Learning and Labor Attrition on Worker Flexibility in Dual Resource Constrained Job Shops

This study investigates the impact of worker learning, worker flexibility, and labor attrition on the system performance of a dual resource constrained (DRC) job-shop. The effects of learning and labor attrition have not been previously addressed in DRC literature. Results from the study, consistent with previous literature, show that the greatest benefits are achieved when inter-departmental worker flexibility is incrementally introduced into the system. In addition, the learning environment, which depends on the initial processing time of jobs and the learning rates of workers, is shown to impact the acquisition of flexibility. The study also shows that the impact of labor attrition on system performance under certain shop conditions may be significant.     

A semi-parametric method for estimating the beta coefficients of the hidden two-sided asset return jumps

ABSTRACT

We introduce a new methodology for estimating the parameters of a two-sided jump model, which aims at decomposing the daily stock return evolution into (unobservable) positive and negative jumps as well as Brownian noise. The parameters of interest are the jump beta coefficients which measure the influence of the market jumps on the stock returns, and are latent components. For this purpose, at first we use the Variance Gamma (VG) distribution which is frequently used in modeling financial time series and leads to the revelation of the hidden market jumps' distributions. Then, our method is based on the central moments of the stock returns for estimating the parameters of the model. It is proved that the proposed method provides always a solution in terms of the jump beta coefficients. We thus achieve a semi-parametric fit to the empirical data. The methodology itself serves as a criterion to test the fit of any sets of parameters to the empirical returns. The analysis is applied to NASDAQ and Google returns during the 2006–2008 period.