This thesis is concerned with the characterisation of the parameters governing the tension-softening relations of the cohesive crack model. Parameter identification is an important area in fracture mechanics as it enables the use of a fracture model for the simulation of fracture processes in structures. Research, however, has shown that such a task is not trivial and continues to pose challenging problems to experimentalists and analysts alike. This dissertation presents general and efficient indirect methods for the characterisation of mode I fracture parameters defining the cohesive crack model. The identification problem is formulated as a special type of inverse problem. The formulation is in the form of a constrained optimisation problem known as a mathematical program with equilibrium constraints characterised, in the present instance, by complementarity conditions involving the orthogonality of two-sign constrained vectors. The solution of such a mathematical program is computationally challenging as it is disjunctive and nonconvex by nature. A number of nonlinear programming based approaches are proposed, after appropriate reformulation of the mathematical program as an equivalent nonlinear programming problem. Actual experimental data are used to validate and determine the most suitable algorithm for parameter identification. It was found that the smoothing-based method is by far superior than other schemes. As the problem is nonconvex and the nonlinear program can only guarantee a local or stationary point, global optimisation procedures are introduced in order to verify the accuracy of the solutions obtained by the algorithm. Two evolutionary search methods capable of finding the global optimum are implemented for parameter identification. The results generated by the evolutionary search techniques confirm the reliability of the solutions identified by the best nonlinear programming algorithm. All computations carried out in the thesis suggest the suitability and robustness of the selected algorithm for parameter identification.

From an organisational perspective, the potential benefits of enhancing workplace cohesion are many, amongst which an increase in employee performance would be the most tangible and possibly the most desirable. The primary aim of the present research was to explore the capacity to increase levels of cohesion, and therefore facilitate team building, through the use of cooperative multiplayer computer gaming (CMCG). Study 1, involving 26 male and 23 female university students, required participants to play two, twenty minute, games of the commercially available computer game QUAKE(tm) as teams of 3 or of 4, against an equal number of computer generated artificial intelligence opposition. The interpersonal attraction and task focus facets of Cohesion, as well as Stress and Mood State, were measured using self-report questionnaires at both the pre- and post-test stages of the experiment. Results supported the prediction that exposing individuals to a computer game of a cooperative and interdependent nature would increase self-rated levels of cohesion, on both the interpersonal attraction and task focus sub-scales. Study 2 aimed to expand upon the findings of study 1, increasing the generalisability of the study 1 findings by surveying existing teams engaging in CMCG via the Internet. Those surveyed were individuals who currently played the Team Fortress module of QUAKE�, and who belonged to a Team Fortress Clan - the CMCG equivalent of a social sporting team. Individuals playing QUAKE(tm) via the Internet were found to be as cohesed with their team members as were the laboratory participants after the CMCG intervention. Further, important group dynamic factors evident in Team Fortress Clans, such as success being linked with higher levels of cohesion, were consistent with literary considerations regarding conventional, non-CMCG teams. Additional research exploration is required regarding the utility of CMCG, however, the present research indicates that such an exploration is warranted and should produce positive and practical results.

Research on the families of the disabled suggest that the advent of a child with a disability will cause a far-reaching effect on the mother, father, siblings and the family's relationship with the outside world. Researchers have differed on the extent and causes of difficulties faced by the siblings, with many inconsistencies and contradictions shown. Some studies have found behavioural problems and lowered self-esteem, and others suggest an increase in altruism and compassion. An investigative study was implemented, with siblings from 29 families with a disabled child, matched with siblings from 29 families with no identified disabled sibling. Patterns of family outings, the use of support services and perceptions of difficulties faced by the family were examined. The matched siblings were compared on the Coopersmith Self-Esteem Inventory, measures of altruism, and behaviour as seen by both teachers and parents. The children also were questioned on their perception of family cohesion and their involvement with other family members. Major findings of the study were a pattern of social isolation for the families, and perception of isolation within and outside the family for both the parents and the siblings. The siblings scored significantly lower on the Coopersmith Inventory, and parents perceived them as having more behavioural difficulties than the controls' parents. No significant difference in altruism was found between the two groups of siblings. The finding that some siblings are coping well, whilst others are showing severe difficulties is ilustrated by four case studies. A number of limitation s of the study are discussed. particularly the wide range of variables investigated, and difficulties with some instruments. Further areas of research are suggested, including exploring the relationships and interactions within the family. It is concluded that for both the siblings and the whole family, the development of strong support networks and help in reframing perceptions and expectations may help to overcome the feelings of intra-family and extra-family isolation.

Thesis (M.Ed.)--University of Hong Kong, 1989. / Includes bibliographical references. Also available in print.

This study investigated the impact of family factors on individual differences in the social and emotional development of children with autism and their families. Based on the modifier model hypothesis suggested by Mundy, Henderson, Inge, and Coman (2007), family factors may serve as a modifier that contributes to the variability in the phenotypic presentation of children with higher functioning autism. Results indicated that Expressed Emotion (EE) was associated with parent-reported hyperactivity and anxiety in children and adolescents. Family cohesion was associated with parent-reported aggression and depression. These results differed for typically developing and HFA children; higher EE or lower cohesion was associated with greater impairment in the HFA group and less impairment in the typically developing children. Family factors were not associated with social symptoms, indicating these effects may be more related to the development of comorbidity than to the core symptoms of autism. Expressed emotion was related meaningfully to neutral attributions on the FMSS and provided validity for the measure. Family factors were not associated with parental stress, which was not expected. Implications for clinical interventions and future directions are discussed.

Disruption is something that we must negotiate as part of our everyday lives. The context of disruption can vary in nature from being positive to being negative in nature. However, the emotional effects of the disruption have not been investigated in the social psychological literature. This study utilizes structuralized ritualization affect theory of social exchange, attribution theory, and the theory of relational cohesion in order to investigate the effects of disruption on the overall positive emotion of the actors involved and their feelings of cohesiveness with regard to their group.

To date, most of the research on group cohesion has focused on team sports, with little known about how this body of knowledge relates to individual sports. The case of the male French whitewater slalom canoe and kayak team was chosen because of the success of the team at World Championships and Olympic Games. The purpose of the present case study was to investigate how the coaches and athletes of this highly successful team worked together in training and competition within a highly competitive environment. Data were collected through in-depth interviews with six athletes and four coaches. Three themes, each containing numerous sub-themes, emerged from the analysis: (a) the nature of collaboration within the team environment, (b) coach leadership, and (c) the fragility of collaboration. The results of the present study have advanced our understanding of what collaboration within an individual sport team may look like. For a period of time, the leadership skills of the coaches, as well as their technical coaching expertise, and the willingness of the talented and driven athletes to work together, contributed significantly to a collaborative environment for this team. Then a change in the Olympic entry rules, the departure of an influential coach, and the inevitable change in the ages and experiences of the athletes themselves all combined to erode the foundation of that productive and collaborative environment.

The current dissertation is comprised of two studies that examined the relationship between group dynamics, attachment anxiety, and post-treatment outcomes in a sample of women (N = 102) with binge eating disorder (BED) who received Group Psychodynamic Interpersonal Psychotherapy. The first study explored the relationship between the development of group cohesion, the individuals’ level of attachment anxiety, and frequency of binge eating, symptoms of depression, and self-esteem at post-treatment. The second study explored the relationship between the interpersonal learning, individuals’ level of attachment anxiety, and outcomes. Interpersonal learning was conceptualized as the convergence between multiple perspectives of group cohesion: one’s own and the group’s perception of one’s cohesion to the group. Parallel measures of individual self-rated cohesion (CQ-I) and mean group-rated cohesion (CQ-G) were developed based on the original Cohesion Questionnaire (CQ; Piper et al., 1983) for this study. Participants were assigned to homogeneous groups composed of either high or low attachment anxiety to assess the impact of pre-treatment attachment anxiety. Findings indicated significant growth in cohesion over time, and a significant convergence in multiple ratings of cohesion. These processes did not differ significantly based on level of attachment anxiety. Growth in cohesion was related to greater reductions in binge eating for those high in attachment anxiety, while the convergence in ratings of cohesion (i.e., interpersonal learning) was related to improvements in self-esteem for individuals in both attachment anxiety conditions. The findings support the importance of group interventions for BED that are sensitive to individuals’ attachment anxiety, and that emphasize cohesiveness, and interpersonal learning to improve outcomes.

To date, most of the research on group cohesion has focused on team sports, with little known about how this body of knowledge relates to individual sports. The case of the male French whitewater slalom canoe and kayak team was chosen because of the success of the team at World Championships and Olympic Games. The purpose of the present case study was to investigate how the coaches and athletes of this highly successful team worked together in training and competition within a highly competitive environment. Data were collected through in-depth interviews with six athletes and four coaches. Three themes, each containing numerous sub-themes, emerged from the analysis: (a) the nature of collaboration within the team environment, (b) coach leadership, and (c) the fragility of collaboration. The results of the present study have advanced our understanding of what collaboration within an individual sport team may look like. For a period of time, the leadership skills of the coaches, as well as their technical coaching expertise, and the willingness of the talented and driven athletes to work together, contributed significantly to a collaborative environment for this team. Then a change in the Olympic entry rules, the departure of an influential coach, and the inevitable change in the ages and experiences of the athletes themselves all combined to erode the foundation of that productive and collaborative environment.

This longitudinal study examines whether family processes (family cohesion and family conflict) mediate the relationship between family separation experiences and the development of peer relationships (quality and conflict). The study includes a sample of 199 early adolescent Latinos from immigrant families. Family conflict mediated the relationship between separation experiences from fathers and peer conflict at year 1 but not year 2 such that more separation from father was associated with higher family conflict and higher peer conflict at year 1. Family cohesion did not mediate associations between mother or father separation and peer relationship outcomes. Family cohesion predicted more positive peer relationship quality at year 1 and family conflict predicted more peer conflict at year 1 indicating some distinction between these characteristics of relationships for families and peers. Mother separation predicted more peer conflict at year 1. This is consistent with qualitative studies of immigration experiences and separation (e.g., Baccallo & Smokowski, 2007; Suarez-Orozco et al., 2002). This study has added empirical quantitative support to show high levels of family conflict associated with family separation. Further, this study has demonstrated that youth who experience greater separation from fathers are likely to experience higher family conflict that is associated with greater peer conflict. In contrast, mother separation has a more direct association with peer conflict. Although family separations are associated with more peer conflict, they do not appear to influence change over time in peer conflict. The different paths of influence for mother separation and father separation warrant further research to explicate the unique associations between each parent‟s separation and family dynamics.