Characteristics of the maximal independent set ZDD

Zero-suppressed binary decision diagrams (ZDDs) are important data structures that are used in a number of combinatorial optimization settings. This paper explores a ZDD characterization for the maximal independent sets of a graph; a necessary and sufficient condition for when nodes in the ZDD can be merged is provided, and vertex orderings of the graph are studied to determine which orderings produce smaller ZDDs. A bound on the width of the maximal independent set ZDD is obtained, relating it to the Fibonacci numbers. Finally, computational results are reported.     

Inviting intimacy: The interview as therapeutic opportunity

This paper explores the notions of time and texture --or the interplay of the temporal and cultural dimensions of social life--as the conceptual foundation for the development of longitudinal qualitative (LQ) methodologies. It illustrates the different ways in which time is theorized among both qualitative and quantitative researchers in order to draw out the creative potential offered by LQ methodologies for understanding the dynamics of everyday life. The paper concludes by exploring how LQ methodologies might be used in the context of childhood research and for revisioning the process of 'growing up'.     

Question wording and the house vote choice : some experimental evidence

Since 1978, the vote reported for House incumbents in the American National Election Studies (NES) has been significantly higher than the actual incumbents' vote in the districts surveyed; in NES surveys before 1978, the reported vote was much closer to the actual vote. The prime suspect for the source of this bias is the new question format introduced in 1978 and used in all subsequent studies. We document the problem and review the results of several question-wording experiments that confirm the superior accuracy of a format that does not mention the candidates' names over the ballot format currently in use. We also find evidence that a modified version of the ballot format may reduce the pro-incumbent bias, so that improvement may be possible without a major interruption of the post-1978 NES times series.     

The impact of the family on diabetes adjustment: A developmental perspective

This study investigated how pubertal development may influence the relation between aspects of the family environment and diabetes adjustment. Subjects were 49 youngsters with newly diagnosed insulin-dependent diabetes mellitus (IDDM) and their parents. Pearson correlations between aspects of the family environment and diabetes adjustment revealed many significant findings for the total sample and separately by pubertal development. Tests of differences between these correlations revealed support for our hypotheses in expected directions. These results suggest the adoption of a developmental perspective when considering how family life is related to a youngster's diabetes adjustment.     

Modeling unemployment duration in a dependent competing risks framework: Identification and estimation

Three Mixed Proportional Hazard models for estimation of unemployment duration when attrition is present are considered. The virtue of these models is that they take account of dependence between failure times in a multivariate failure time distribution context. However, identification in dependent competing risks models is not straightforward. We show that these models, independently derived, are special cases of a general frailty model. It is also demonstrated that the three models are identified by means of identification of the general model. An empirical example illustrates the approach to model dependent failure times.     

A model for outpatient treatment of young adolescents with anorexia nervosa

The recent literature is reviewed and interpreted as supporting the view that anorexia nervosa is a disorder with discrete subgroups. Two cases are presented which suggest that one particular subgroup of anorexics shares a common dynamic of failure to resolve the issues inherent in the rapprochement crisis of the separation-individuation sequence. The reworking of residuals from the rapprochement crisis, particularly the union of good and bad self, modulation of omnipotence, and integration of hostility, are essential aspects of therapy with these anorexics. The treatment of choice for anorexics in this subgroup is described as an outpatient team approach which separates medical from psychotherapeutic interventions, adolescent therapy from that of parents, and avoids hospitalization if at all possible.Maxine L. Penn is in Private Practice in Potomac, Maryland.