Least absolute value estimation in regression models: an annotated bibliography

This paper presents a comprehensive listing of articles on least absolute value (LAV) estimation as applied to linear and non-linear regression models and in systems of equations. References to the LAV method as applied in approximation theory are also included. Annotations describing the content of each article follow each reference.     

Mechanisms for environmental scanning

Over the past decade long range planning for industrial concerns has needed to take into account an everbroadening spectrum of environmental influences. Whereas at one time planning largely concerned itself with those aspects of the environment to do with the company's markets, nowadays the influence of other parts of the environment may have equal, or even greater influence than markets on the company's operation. The current environment of most industrial concerns appears to be characterized by three main components. Firstly, the environment is increasingly turbulent and uncertain. Secondly, organizations are increasingly less autonomous. Thirdly, other formal organizations are increasingly important components of a company's environment. The environment of most companies is therefore complex and uncertain. This complexity and uncertainty can only be reduced by attempting to analyse and understand the environment as an ongoing process, this process is now being called ‘environmental scanning’. The aim of this article is to describe some of the mechanisms which have been used to help companies scan their environments as a way of planning and controlling their destiny in the turbulent environment in which industry operates.     

The impact of mother's education on indicators of school performance of first through third grade primary school children living in low socioeconomic areas in Khartoum,Sudan

This study examines factors related to school achievement among low-income urban families in the Sudan. Data were obtained during January-February 1992 from a sample of 198 students aged 6-10 years from boys' and girls' schools in Ombada settlement in Khartoum, Elhag-Yousif in Khartoum North, and Arkwait in Khartoum. 53.5% of the sample were first enrolled in school after the age of 7 years. About 30% were enrolled prior to the age of 7 years. 4.5% had repeated a grade. About 25% had perfect attendance. 37% were absent for 1-2% of school days; 18.2% were absent for 3-4% of school days, and a similar percentage were absent for 5% or more of school days. Over 66% were absent due to medical reasons. About 41% of math scores and 58% of language scores were above 50, out of a possible total score of 60. 29% of math scores and 21% of language scores ranged from 41 to 50. 13.5% of math scores and 10.5% of language scores were failing. Class size ranged from 53 to 102 persons per class. Children who were enrolled in the higher grades tended to have been enrolled at a later age. The age of enrollment was negatively related to maternal educational level and weight for age. Poorly educated mothers tended to enroll their children later, and lower weight-for-age children tended to be enrolled later. Students from boys' schools in Khartoum and schools in the Khartoum area had a higher absenteeism rate. Students whose fathers were laborers or self-employed had greater absences. Children whose mothers had lower educational levels had greater absenteeism. Children with lower weight-for-height had more absenteeism. Absenteeism was positively correlated with height-for-age and the number of types of illnesses that the child had during the school year. Students who lived in Khartoum North had higher scores. Findings indicate that educational outcomes were related to home background and health conditions.     

Modelling Resource Allocation in a Decentralized Organization with an AI-Based,Goal-Directive Model*

Modelling the resource allocation decision process in a decentralized organization using mathematical programming decomposition approaches has proven intractable for all but the smallest of problems. In this paper three artificial intelligence (AI) techniques are integrated to model the resource allocation decision process, and the solution for a three-level decentralized organization is illustrated. The techniques are (1) the filtered beam search, which selects a list of potential projects at the subordinate level, (2) the world model, which describes the ordinate and superordinate's worlds and their decision-making processes, and (3) the blackboard model, which allows for global, but selective, storage of information. Benefits of the new approach include: several different mechanisms of managerial control may be modelled, the true information flow in an organization is more closely mirrored, and problems of a more realistic size are now viable. There are three primary ways in which the new model could be useful to management: The desirability and effects of different organizational structures can be modeled, the efficacy of various coordination mechanisms along the organizational structure can be examined, and a subset of projects from a wider list of possibilities can be selected. Also, an example is given showing how the model may be extended to scenarios with asymetric information and divergence of preferences, whereby subordinates have different objectives than their managers and where there is no way for managers to verify the truthfulness of their subordinates' responses.     

Understanding child sexual abuse by Catholic priests from a situational perspective

Most sexual offense research focuses on offender motivation and individual risk factors rather than the criminal events themselves. This article provides an analysis of data from two studies on child sexual abuse by Catholic priests to help understand the opportunities clergy had or created to abuse youth. Findings show that situational factors played a role in victim choice among a heterogeneous group of abusers. Priests abused more male than female victims and had significantly greater access to male youth historically. When access to female youth increased in the 1990s, abuse of females as a percentage of victims also increased. The article concludes with a discussion about how ecological information can be used to craft intervention policies to prevent sexual offenses.     

Changes in small town social capital and civic engagement

Small towns are often depicted as places with many interpersonal relationships and generalized trust, or high social capital. Social capital is a resource which towns can use to solve problems and improve the local quality of life. In this paper, I determined if social capital and civic engagements have declined in small towns in the U.S. Midwest as has happened more generally and tested likely explanations for the change. Quantitative analyses of data from the U.S. Census, other secondary sources, and a longitudinal study of residents of 99 small towns were conducted. Findings revealed that social capital has declined, but one type of civic engagement improved. Towns in counties with more small farms in 1990 had more bonding social capital and civic engagement in 2004 than other towns when other factors were controlled. The proportion of local businesses had no impact on civic engagement and was negatively associated with one kind of social capital. Mixed findings about how income impacted social capital and civic engagement indicated a complex relationship. The retirement of the so called “civic generation” had minimal impact on social capital and civic engagement.     

Avian diversity in a suburban park system: current conditions and strategies for dealing with anticipated change

A growing trend towards increased urbanization emphasizes the role of suburban parks in wildlife conservation. Spatial planning aimed at maintaining biological diversity and functionality must consider how changes at landscape and more local scales will influence the biotic structure of urban areas. From May 2006 to July 2010, bird surveys were conducted in three metropolitan parks in Cleveland, Ohio, USA. Surveys were conducted with the goal of examining the effect of vegetation structure and adjacent land cover on the distribution and species richness of breeding birds within this park system. A total of 65 species were recorded throughout the study area. Avian species richness was linked to several habitat metrics, measured at both the local and landscape scale. Generally, species richness was highest at locations characterized by moderate forest cover. The proportion of canopy cover at survey sites related negatively to species richness and the density of understory vegetation showed a positive relationship with species diversity. Despite the influence of these three metrics, sensitivity analysis indicates that the density of understory vegetation is the most significant correlate to avian diversity within this suburban park system. Management actions aimed at providing habitat for the greatest diversity of breeding songbirds within the study area should allow for moderate canopy cover while retaining or improving the structural complexity of understory vegetatation.     

The Present Retirement Crisis and How Social Workers Can Respond

ABSTRACT

Research on Americans’ retirement readiness indicates a wide range of preparedness for the golden years. Called a “crisis” by researchers, retirement for some may include significant choices: continued employment or utilization of social welfare services. This article describes factors contributing to the retirement crisis and roles social workers can play in assisting older retirees. Disparity in household retirement savings exists by ethnicity. On the front lines serving aging individuals and their families, social work professionals are well situated to collaborate with individuals, and other providers, to address financial, social and emotional pillars necessary in facilitating a safe and secure retirement.     

Agricultural multifunctionality and farmers' entrepreneurial skills: A study of Tuscan and Welsh farmers

The process of agricultural restructuring in Europe has been strongly influenced both by CAP support of multifunctional agriculture and by market liberalisation, and farmers are exhorted to become more entrepreneurial in response. This paper explores the interaction of these policy goals in two regions where a rural development form of multifunctionality is favoured.