Optimal Scheduling Using Branch and Bound with SPIN 4.0

The use of model checkers to solve discrete optimisation problems is appealing. A model checker can first be used to verify that the model of the problem is correct. Subsequently, the same model can be used to find an optimal solution for the problem. This paper describes how to apply the new PROMELA primitives of SPIN 4.0 to search effectively for the optimal solution. We show how Branch-and-Bound techniques can be added to the LTL property that is used to find the solution. The LTL property is dynamically changed during the verification. We also show how the syntactical reordering of statements and/or processes in the PROMELA model can improve the search even further. The techniques are illustrated using two running examples: the Travelling Salesman Problem and a job-shop scheduling problem

Optimal Scheduling Using Branch and Bound with SPIN 4.0

The use of model checkers to solve discrete optimisation problems is appealing. A model checker can first be used to verify that the model of the problem is correct. Subsequently, the same model can be used to find an optimal solution for the problem. This paper describes how the new Promela primitives of Spin 4.0 can be applied to search e#ectively for the optimal solution. We show how Branch-and-Bound techniques can be added to the LTL property that is used to find the solution. The LTL property is dynamically changed during the verification

Mental Health of Parents and Life Satisfaction of Children: A Within-Family Analysis of Intergenerational Transmission of Well-Being

This paper addresses the extent to which there is an intergenerational transmission of mental health and subjective well-being within families. Specifically it asks whether parents’ own mental distress influences their child’s life satisfaction, and vice versa. Whilst the evidence on daily contagion of stress and strain between members of the same family is substantial, the evidence on the transmission between parental distress and children’s well-being over a longer period of time is sparse. We tested this idea by examining the within-family transmission of mental distress from parent to child’s life satisfaction, and vice versa, using rich longitudinal data on 1,175 British youths. Results show that parental distress at year t-1 is an important determinant of child’s life satisfaction in the current year. This is true for boys and girls, although boys do not appear to be affected by maternal distress levels. The results also indicated that the child’s own life satisfaction is related with their father’s distress levels in the following year, regardless of the gender of the child. Finally, we examined whether the underlying transmission correlation is due to shared social environment, empathic reactions, or transmission via parent-child interaction

Changes in Prefrontal-Limbic Function in Major Depression after 15 Months of Long-Term Psychotherapy

Neuroimaging studies of depression have demonstrated treatment-specific changes involving the limbic system and regulatory regions in the prefrontal cortex. While these studies have examined the effect of short-term, interpersonal or cognitive-behavioural psychotherapy, the effect of long-term, psychodynamic intervention has never been assessed. Here, we investigated recurrently depressed (DSM-IV) unmedicated outpatients (N = 16) and control participants matched for sex, age, and education (N = 17) before and after 15 months of psychodynamic psychotherapy. Participants were scanned at two time points, during which presentations of attachment-related scenes with neutral descriptions alternated with descriptions containing personal core sentences previously extracted from an attachment interview. Outcome measure was the interaction of the signal difference between personal and neutral presentations with group and time, and its association with symptom improvement during therapy. Signal associated with processing personalized attachment material varied in patients from baseline to endpoint, but not in healthy controls. Patients showed a higher activation in the left anterior hippocampus/amygdala, subgenual cingulate, and medial prefrontal cortex before treatment and a reduction in these areas after 15 months. This reduction was associated with improvement in depressiveness specifically, and in the medial prefrontal cortex with symptom improvement more generally. This is the first study documenting neurobiological changes in circuits implicated in emotional reactivity and control after long-term psychodynamic psychotherapy

Tavistock Adult Depression Study (TADS): a randomised controlled trial of psychoanalytic psychotherapy for treatment-resistant/treatment-refractory forms of depression

ABSTRACT: BACKGROUND: Long-term forms of depression represent a significant mental health problem for which there is a lack of effective evidence-based treatment. This study aims to produce findings about the effectiveness of psychoanalytic psychotherapy in patients with treatment-resistant/treatment-refractory depression and to deepen the understanding of this complex form of depression. METHODS: INDEX GROUP: Patients with treatment resistant/treatment refractory depression. DEFINITION & INCLUSION CRITERIA: Current major depressive disorder, 2 years history of depression, a minimum of two failed treatment attempts, [greater than or equal to]14 on the HRSD or [greater than or equal to]21 on the BDI, plus complex personality and/or psycho-social difficulties. EXCLUSION CRITERIA: Moderate or severe learning disability, psychotic illness, bipolar disorder, substance dependency or receipt of test intervention in the previous two years. DESIGN: Pragmatic, randomised controlled trial with qualitative and clinical components. TEST INTERVENTION: 18 months of weekly psychoanalytic psychotherapy, manualised and fidelity-assessed using the Psychotherapy Process Q-Sort. CONTROL CONDITION: Treatment as usual, managed by the referring practitioner. RECRUITMENT: GP referrals from primary care. RCT MAIN OUTCOME: HRSD (with [less than or equal to]14 as remission). SECONDARY OUTCOMES: depression severity (BDI-II), degree of co-morbid disorders Axis-I and Axis-II (SCID-I and SCID-II-PQ), quality of life and functioning (GAF, CORE, Q-les-Q), object relations (PROQ2a), Cost-effectiveness analysis (CSRI and GP medical records). FOLLOW-UP: 2 years. Plus: a). Qualitative study of participants' and therapists' problem formulation, experience of treatment and of participation in trial. (b) Narrative data from semi-structured pre/post psychodynamic interviews to produce prototypes of responders and non-responders. (c) Clinical case-studies of sub-types of TRD and of change. DISCUSSION: TRD needs complex, long-term intervention and extended research follow-up for the proper evaluation of treatment outcome. This pushes at the limits of the design of randomised therapeutic trials,. We discuss some of the consequent problems and suggest how they may be mitigated. Trial registration Current Controlled Trials ISRCTN40586372

Stochastic Modeling of Processor Scheduling with Application to Database Management Systems

Abstract: This paper is concerned with the stochastic modeling of processor scheduling and of queuing due to contention for re-sources in data base management systems. The processing services rendered in searching the data base and retrieving and processing information are modeled explicitly, as is the algorithm used to schedule these services on the processor. The scheduling of the proces-sor is based on a total priority ordering of a set of queues for processing service. A queuing model incorporating the processor schedul-ing algorithm for IMS (Information Management System) is formulated in order to illustrate the modeling ideas. The model is analyzed under rather general distributional assumptions, based on the observation that certain stochastic processes in the model are cumulative processes defined over the same embedded semiMarkov process. The model is not used in a performance study of IMS, nor is it pro-posed that the model developed here is one upon which a performance study of IMS should be undertaken. The model should be viewed as illustrative of stochastic models which can be constructed to incorporate algorithms for processor scheduling