Economically optimal markovian sampling policies for process monitoring

A variable delay process sampling procedure is considered in a Markov chain structure. The paper extends the basic sampling method given in Arnold (1970). Analytic properties of the process are developed for expected sample size and distribution of the sample size. A primary concern in the paper is the development of an objective function to enhance ability to select optimal sampling policies. The objective function involves cost due to sampling and protection costs for detecting undesirable conditions.     

Spatial and Temporal Aspects of the Density-Distance Relationship

Abstract

Numerous studies of the relationship between urban population density and distance from the city's center have shown that: (1) Cross-sectionally, the relationship between density and distance is negative, such that density crests in the interior of the city and declines toward the periphery. (2) Longitudinally, the slope of the density-distance relationship becomes flatter as central densities decline as neighborhoods age and thin and as fringe areas develop and increase in population. Most studies have worked with the total relationship between density and distance, ignoring cross-sectional and longitudinal variants from the general pattern for subareas of the metropolis. Large cities seldom develop uniformily in concentric patterns focused upon the CBD. More typical is the axial pattern described by Hurd or the sectoral pattern by Hoyt in which development is axial along principal arteries of transportation with inner-axial areas developing at later points in time. This paper pursues intra-urban differences in growth and development as expressed in the density-distance relationship. Our focus is on between-sector differences in the density-distance relationship at given points in time and upon temporal differences in the relationship through time for individual sectors. Our aim is to specify in a more detailed fashion the link between general urban dynamics and the changing density-distance relationship. The data are for the Cleveland metropolitan area, 1930–1970.     

Support Networks of Gay Male and Lesbian Youth

The support networks of 90 self-identified urban gay male and lesbian youth (ages 14 to 21 years) are examined. The youth, who are predominantly black and Latino/a, indicated an average of eight persons in their support networks, most of whom were close friends. Other significant groups included were parents, siblings, other relatives, and lovers or partners. A large majority of the support network members knew that the youth were gay or lesbian. Youth were moderately to very satisfied with the support they received from the network members—being more satisfied with the support provided by those who knew of their homosexuality compared to those who suspected or were unaware. Nonetheless, most youth felt that they did not have enough friends, and that they often to seldom felt lonely. These two feelings correlated positively with suicide ideation and attempts; and feeling lonely also correlated positively with drug use.     

#Funeral and Instagram: death,social media,and platform vernacular

This paper presents findings from a study of Instagram use and funerary practices that analysed photographs shared on public profiles tagged with ‘#funeral’. We found that the majority of images uploaded with the hashtag #funeral often communicated a person's emotional circumstances and affective context, and allowed them to reposition their funeral experience amongst wider networks of acquaintances, friends, and family. We argue that photo-sharing through Instagram echoes broader shifts in commemorative and memorialization practices, moving away from formal and institutionalized rituals to informal and personalized, vernacular practices. Finally, we consider how Instagram's ‘platform vernacular’ unfolds in relation to traditions and contexts of death, mourning, and memorialization. This research contributes to a broader understanding of how platform vernaculars are shaped through the logics of architecture and use. This research also directly contributes to the understanding of death and digital media by examining how social media is being mobilized in relation to death, the differences that different media platforms make, and the ways social media are increasingly entwined with the places, events, and rituals of mourning.     

Sozialpsychologische Beiträge zur Diskussion um die Zukunft der Schulen in Deutschland

At present, there is an intensive debate on the development of the German school system. Main topics concern teaching methods and how to deal with individual differences, but there are also questions about the need to pursue other aims than cognitive learning and how to cooperate with parents. Last but not least, it has become obvious that schools and teachers need support. The article argues that concepts and results of research in social psychology may be important to manage tasks in the current situation. Important topics of future research are pointed out.     

Uniformly best estimation in linear regression when prior information is fuzzy

Modeling prior information as a fuzzy set and using Zadeh’s extension principle, a general approach is presented how to rate linear affine estimators in linear regression. This general approach is applied to fuzzy prior information sets given by ellipsoidal α-cuts. Here, in an important and meaningful subclass, a uniformly best linear affine estimator can be determined explicitly. Surprisingly, such a uniformly best linear affine estimator is optimal with respect to a corresponding relative squared error approach. Two illustrative special cases are discussed, where a generalized least squares estimator on the one hand and a general ridge or Kuks–Olman estimator on the other hand turn out to be uniformly best.     

Sample size requirements for rare or abundant attribute sampling

Two approximation procedures to determine required sample size for a Fixed width binomial confidence interval are given and compared to exact calculations as well as the normal and Poisson approximations. The approximation procedures are found to be quite simple but very accurate for estimating sample sizes for either rare or abundant attributes.