A decomposition technique for quantifying real process performance

A decomposition technique for quantifying the impacts of changes in product mix and process performance on aggregate process-related indicators is presented. Through application of the technique, the real performance of a process can be quantified. Changes in real performance over time can be monitored to provide useful information for process evaluation and production planning. Two case studies, one related to the aggregate defective rate for an assembly line of an integrated circuit fabrication plant and the other to the aggregate inventory turnover for a tyre distribution company, are presented to illustrate the application of the technique.     

Supplementing a survey with respondent Twitter data to measure e-cigarette information exposure

ABSTRACT

Social media data are increasingly used by researchers to gain insights on individuals’ behaviors and opinions. Platforms like Twitter provide access to individuals’ postings, networks of friends and followers, and the content to which they are exposed. This article presents the methods and results of an exploratory study to supplement survey data with respondents’ Twitter postings, networks of Twitter friends and followers, and information to which they were exposed about e-cigarettes. Twitter use is important to consider in e-cigarette research and other topics influenced by online information sharing and exposure. Further, Twitter metadata provide direct measures of user’s friends and followers as opposed to survey self-reports. We find that Twitter metadata provide similar information to survey questions on Twitter network size without inducing recall error or other measurement issues. Using sentiment coding and machine learning methods, we find Twitter can elucidate on topics difficult to measure via surveys such as online expressed opinions and network composition. We present and discuss models predicting whether respondents’ tweet positively about e-cigarettes using survey and Twitter data, finding the combined data to provide broader measures than either source alone.     

Sex life after 65: How does erectile dysfunction affect ageing and elderly men?

Introduction. We report the findings pertinent to the ageing and elderly participants of a population-based study of erectile dysfunction (ED).

Method. We examined the sociodemographic characteristics, self-reported morbidities and responses to the 5-item International Index of Erectile Function (IIEF-5) of participants aged ≥65 years and ≥80 years.

Results. Most (73%) participants were married or had partners. Among the participants aged ≥65 years, the prevalence of ED (IIEF-5 scores <22) was 67% and of severe ED (IIEF-5 scores <8) 48%. About 32% were sexually active, and 11% had regular sexual intercourse. Cardiovascular disease (CVD) was reported in 37% and diabetes mellitus (DM) in 13%, with odds of ED at 3.91 and 4.68, respectively. Among those aged ≥80 years, the prevalence of ED was 68% and of severe ED 57%. About 12% were sexually active, and 3% had regular sexual intercourse. CVD was reported in 44% and DM in 11%, with corresponding odds of ED at 2.55 and 2.90.

Conclusions. Most ageing and elderly men are in a relationship and many are sexually active. ED is prevalent and severe. Morbidities are common and significantly associated with ED, impairing the sex lives of affected men.     

A real option theoretic fuzzy evaluation model for enterprise resource planning investment

The high failure rate of ERP implementation is due to a common pitfall that ERP projects are often enacted as merely investment into installation of IT infrastructure, rather than systematic planning of operation changes, business process re-engineering and a paradigm shift for the operation and management. To manage ERP investment in a changing environment for high payoff, this paper adopts a real option theoretic method. Fuzzy payoff valuation is introduced to deal with uncertainties in order to minimize the risk of failure. The proposed ERP evaluation model is geared towards small and medium enterprises. A case study is presented to validate the proposed fuzzy real options. The results indicate the potential of modeling ERP investment as “Expand”, “Contain” and “Abandon” options in different scenarios. The fuzzy real option model bestows a novel ex-ante cost analysis for justifying ERP investment in the implementation cycle.     

Assessing localization with its local sociocultural dynamics: how Hong Kong’s localized clubculture was undermined by wealth and power disparities

ABSTRACT

Localization has largely been assessed, by both its supporters and critics, with its local-global sociocultural dynamics. The local sociocultural dynamics of localization have either been ignored or simplistically understood as a ‘preference for the local’ or ‘local empowerment’. This study argues that localization’s local dynamics can be very complex and can yield negative social implications. There are likely multiple subgroups of local consumers, who localize in different ways and degrees due to their different resources, interests, and power positions. These differences likely generate emergent patterns of social contestations, stratification, and inequality. I empirically substantiate this argument by analyzing how Hong Kong’s rave-based clubculture was undermined by wealth and power disparities as it localized in the late 1990s and early 2000s. This study’s major methods include observant participation in dance clubs and rave parties in Hong Kong and informal and formal interviews of consumers and producers of clubculture.     

A Bayesian Approach to Modeling Time-Varying Cointegration and Cointegrating Rank

A multivariate model that allows for both a time-varying cointegrating matrix and time-varying cointegrating rank is presented. The model addresses the issue that, in real data, the validity of a constant cointegrating relationship may be questionable. The model nests the submodels implied by alternative cointegrating matrix ranks and allows for transitions between stationarity and nonstationarity, and cointegrating and noncointegrating relationships in accordance with the observed behavior of the data. A Bayesian test of cointegration is also developed. The model is used to assess the validity of the Fisher effect and is also applied to equity market data.