Single machine batch scheduling with release times

Motivated by a high-throughput logging system, we investigate the single machine scheduling problem with batching, where jobs have release times and processing times, and batches require a setup time. Our objective is to minimize the total flow time, in the online setting. For the online problem where all jobs have identical processing times, we propose a 2-competitive algorithm and we prove a corresponding lower bound. Moreover, we show that if jobs with arbitrary processing times can be processed in any order, any online algorithm has a linear competitive ratio in the worst case. A preliminary version of a part of this paper was presented at the 31st International Symposium on Mathematical Foundations of Computer Science (MFCS 2006). We gratefully acknowledge reviewers’ comments that helped to improve the presentation of this work. Supported by the Swiss SBF under contract no. C05.0047 within COST-295 (DYNAMO) of the European Union. Research carried out while B. Weber was affiliated with the Institute of Theoretical Computer Science, ETH Zurich.     

The Crisis Sequence: The Case of Secessionism in Tuscaloosa County,Alabama

Prevailing scholarly approaches to the U.S. Secession Crisis suggest that the crisis reflected either the interests of slaveowners or mounting socioeconomic pressure in the electorate. Both arguments suffer from empirical and analytical challenges, chief among these being that the southern Whig Party and its planter base actively resisted secession until the early 1850s. Why did the largest slaveowners oppose disunion only to fold by 1861? Drawing on beat‐level electoral returns, newspapers, and private correspondence from antebellum Tuscaloosa County, Alabama, I argue that the answer lies in conceiving of the prelude to secession as a “crisis sequence,” so named because it precipitates crises of hegemony, when no one political actor possesses the mass consent to rule and once salient social cleavages cease to resonate. Such sequences destabilize the relationship between parties and their constituents and allow political allegiances to swing wildly from one party to the next, giving such sequences their nonlinear character.     

Time Is of the Essence: An Analytic Autoethnography of Family,Work, and Serious Leisure

While leisure is often represented in public discourse as a realm of freedom and self‐actualization, for most adults the pursuit of serious leisure activities involves negotiating familial and professional constraints. Based on the author's autoethnographic experiences with sport skydiving, this article examines the familial and professional constraints that he has experienced, as well as the challenges to recreational skydivers posed by current trends in the sport. The author describes various only partly successful strategies he has used to manage the tensions between his skydiving pursuits, work, and family. Proposing his analysis as an example of “analytic autoethnography” the author concludes by considering the implications of his research for better understanding serious leisure pursuits more generally, as well as for answering the personal question, should I continue to jump out of planes?     

Representations of Parent–Child Alliances in Children's Family Drawings

The purpose of this study was to investigate relationships between children's representations of parent–child alliances (PCA) and their peer relationship quality, using a new scale that was developed to rate representations of PCA in children's family drawings. The parent–child alliance pattern is characterized by a relationship between parent and child that is stronger than the marital relationship. We used family drawings to assess children's (at the ages of 4–8 years) representations of alliances because it is often difficult for children to express their perceptions of family dynamics verbally. Children whose drawings were rated higher in PCA were rated lower in prosocial behavior and assertiveness and higher in social problems by their teachers. These relationships were stronger for boys than for girls.     

Markov Chain Monte Carlo Techniques for Studying Interoccasion and Intersubject Variability: Application to Pharmacokinetic Data

Values of pharmacokinetic parameters may seem to vary randomly between dosing occasions. An accurate explanation of the pharmacokinetic behaviour of a particular drug within a population therefore requires two major sources of variability to be accounted for, namely interoccasion variability and intersubject variability. A hierarchical model that recognizes these two sources of variation has been developed. Standard Bayesian techniques were applied to this statistical model, and a mathematical algorithm based on a Gibbs sampling strategy was derived. The accuracy of this algorithm's determination of the interoccasion and intersubject variation in pharmacokinetic parameters was evaluated from various population analyses of several sets of simulated data. A comparison of results from these analyses with those obtained from parallel maximum likelihood analyses (NONMEM) showed that, for simple problems, the outputs from the two algorithms agreed well, whereas for more complex situations the NONMEM approach may be less accurate. Statistical analyses of a multioccasion data set of pharmacokinetic measurements on the drug metoprolol (the measurements being of concentrations of drug in blood plasma from human subjects) revealed substantial interoccasion variability for all structural model parameters. For some parameters, interoccasion variability appears to be the primary source of pharmacokinetic variation.     

Expanding Horizons of Risk in Criminology

Few topics in the social sciences have witnessed as dramatic an increase in scholarly attention over the past two decades as the topic of risk. In this essay we examine sociological approaches to risk in criminological research and theory. After briefly describing the concept of risk in classical and neoclassical criminology, we turn our attention to three emerging social science perspectives on risk, those associated with the scholarship on risk society, edgework, and governmentality. We examine the new directions that these emerging ``risk paradigms'' open for criminological theory and research, including new perspectives on the motivation for criminal risk-taking, the organization of policing and criminal justice systems, and public and political responses to crime. We conclude by reviewing critiques of the scholarship associated with the new risk paradigms and by suggesting promising future directions for criminological research seeking to advance these perspectives.     

Predictors of children in foster care being adopted: A classification tree analysis

When returning home is not a viable option, adoption is the primary means by which youth in substitute care achieve permanency. Therefore, understanding the factors that impact adoption is critical to both evaluating and improving the child welfare system. Prior research has mostly studied “main effects” in regard to adoption rates and has not explored the ways in which youth and foster family variables might interact in complex ways to predict adoption. This study uses a classification tree analysis approach known as Optimal Data Analysis (ODA) to predict probability of adoption in 2003 using Adoption and Foster Care Analysis and Reporting System (AFCARS) data. 30,000 adopted youth and 30,000 non-adopted youth were randomly selected for participation in the study. Similar to previous studies, univariate analyses revealed that age, foster parent race/ethnicity, foster parent marital status, and number of previous placements all predicted probability of adoption. However, going further, several combinations of individual variables (multivariate ODA) improved prediction accuracy (e.g., age × structure of foster family × number of previous placements). Results also suggested that the impact of the state on adoption rates varied when essentially controlling for youth and family variables, supporting concerns regarding the crude use of AFCARS data when comparing states.