The use of multiple robots for exploration holds the promise of improved performance over single robot systems. To exploit effectively the advantage of having several robots, the robots must be co-ordinated which requires communication. Previous research relies on a fixed communication network topology, a single lead explorer, and flat communication. This thesis presents a novel architecture to keep a group of robots as a single connected and adaptable communication network to explore and map the environment. This architecture, BERODE (BEhavioural ROle DEcentralized), aims to be robust, efficient and scalable to large numbers of robots. The network is adaptable, the number of explorers variable, and communications hierarchical (local/global). The network is kept connected by an MST (Minimum Spanning Tree) control network, a subnetwork containing only the minimum necessary links to be a fully connected network. As the robots explore, the MST control network is updated either partially (local network) or globally to improve signal quality. The local network for a robot is formed by the robots that are within a certain retransmission distance in the MST control network. BERODE implements a hierarchic approach to distributing information to improve scalability with respect to the number of robots. The robots share information at two levels: frequently within their local network and less frequently to the entire robot network. The robots coordinate by assuming behaviours depending on their connections in the MST control network. The behavioural roles balance between the tasks of exploration and network maintenance where the Explorer role is the most focused on the exploration task. This improves efficiency by allowing varying number of robots to take the Explorer role depending on circumstances. The roles generate reactive plans that ensure the connectivity of the network. These plans are based on the imposition of heterogeneous virtual spring forces. Our simulations show that BERODE is more efficient, scalable and robust with respect to communications than the previous approaches that rely on fixed control networks. BERODE is more efficient because it required less time to build a complete map of the environment than the fixed control networks. BERODE is more scalable because it keeps the robots as a single connected network for more time than the fixed control networks. BERODE is more robust because it has a better success rate at finishing the exploration.

This Thesis explains that the development of a method by which researchers can identify normative behaviour of translators will enable the standardisation of equivalences between English and Arabic. The thesis suggests that achieving such a method will minimise political disputes. In showing that norms have an effect on the behaviour of translators, the thesis examines and evaluates the resulting products of translators, i.e. translations, and presents explanations of why these effects occur. By eliminating the choices of equivalences, which were prejudiced by translators' normative behaviour, the standardisation could be achievable. The thesis underscores the inadequacy of the suggestion that translators should learn a certain set of translational norms and should follow them. It argues, however, that being exposed to various norms whether, translational, cultural or otherwise plays an important role in the quality of translation. In illustrating the latter, the thesis provides an empirical study by which one hundred different translations are analysed by the use of a manual corpora method. The experiment records significant factors, which prove the effects of norms on translators, and offers different measures by which these factors are evaluated. Accordingly, the thesis examines the normative behaviour of translators in their decision-making process in relation to the translation of legal texts as part of international documents only. The thesis uses the 10rdanIsraeli Peace Treaty signed in 1994 as a case study. The key point is that, if legal and political translation between English and Arabic is prejudiced by negative normative behaviour, this will without doubt result in political disputes. The aim of this thesis is to suggest a method by which Arabic equivalences of English legal terms are relatively' standardised and compiled in an index to be referred to by legal translators in iUture cases. The thesis suggests the establishment of a translation planning committee (TPC) to act as the authority responsible for conducting the suggested method.

Group living primates utilise a number of characteristic post-conflict behaviours as a means of regulating the impact of escalated intragroup disputes. Although immature group members are typically implicated in disproportionate levels of aggression in many cercopithecine taxa, the conflict management abilities of young animals remain relatively unstudied as most previous investigations have focused solely upon adults or pooled data across age classes. This study therefore utilised a cross-sectional design to examine the immediate consequences of aggressive confrontations and the patterning of both affiliative and agonistic post-conflict interactions with former opponents and previously uninvolved bystanders, in free-ranging immature rhesus macaques (Macaca mulatta) at Cayo Santiago, Puerto Rico. Subjects of both sexes (n = 108) and between 1 and 4 years of age were drawn from two social groups, upon which 451 pairs of 10-minute post-conflict and matched-control observations were collected over a 10 month period in 1996. These data were supplemented by 10-minute post-conflict intervals extracted from an additional 432 hours of continuous focal observations conducted upon a balanced subset of 36 juveniles, together with a total of 549 group-wide scan samples concentrating upon affiliative behaviour. Involvement in aggression was found to have both social and ecological costs for former victims, which were subject to elevated rates of subsequent threats and attacks in the minutes following a conflict, a period in which they also spent more time in locomotion and less time upon feeding. Nevertheless the behaviour of aggressors was also affected, as contestants in both roles exhibited some degree of post-conflict elevation in self- (e.g. scratching) and object-directed activities (e.g. gnawing or manipulating) likely to be indicative of tension or anxiety, although these increases were often more pronounced in the recipient as opposed to the perpetrator of aggression. Affiliative reunions between former adversaries in the wake of aggression were demonstrable in even the youngest subject cohort and the patterning of these "reconciliatory" events was similar to that documented in previous work on adult macaques, with the context of the preceding conflict (over food versus of no discernible cause) and the quality of relationship between the protagonists (whether close kin or favoured affiliates, or not) significantly reducing or elevating, respectively, the likelihood that a reunion would take place. In the former case, variation in conciliatory tendency was also paralleled by a difference in the degree to which rates of self-scratching were elevated under post-conflict conditions, whilst in the latter case it was not - confrontations between close associates produced levels of scratching no higher than those after a dispute between less favoured affiliates. Immature subjects were also more likely to interact with certain other partner classes under post-conflict as opposed to baseline conditions. For example, there was a pronounced increase in affiliative contacts between former coalition partners following polyadic conflicts, these overtures typically being instigated by the beneficiary of support. Affinitive interactions between both aggressors and victims and previously urtinvolved bystanders were also significantly elevated, being preferentially directed toward the contestant's close relatives and those of its opponent; the latter type of interaction appeared more frequent in the youngest subjects and partner selection was not merely a side-effect of proximity to members of the opponent's family. The degree to which kinship between former opponents, or with bystanders, influenced the likelihood of post-conflict affiliation was greater in female subjects, but the sexes behaved similarly in all other respects. Significant differences in behaviour between birth cohorts were also largely absent, although older immatures were more likely to "redirect" aggression toward third parties when victimised. These attacks against bystanders in the wake of conflicts were exhibited by both aggressors and victims, although aggressive responses were more likely when in the latter role. It is suggested that redirection by former victims may function predominantly as a signal to other group members, as these aggressive events were particularly likely to take place within view of former opponents and were associated with a high incidence of vocal threats; furthermore, redirection was associated with a significant reduction in the amount of aggression the subject subsequently received from others. Immature rhesus macaques therefore appear to possess a rich repertoire of post-conflict behaviour, in many ways resembling that reported in previous studies based upon mixed-age subject samples. However, relatively small size and on average low rank may place greater constraints upon the behaviour of juvenile group members, which therefore may need to reach a certain age or size before fully expressing their potential. Further work is now needed to ducidatc the functional cons~quences for immature contestants of the patterns of post-conflict hehaviour documented. partIcularly those involving partners other than the former opponent.

This research study is located in the field of consumer behaviour. It positions means-end theory in the interpretivist philosophical tradition and follows a cognitive approach to understanding purchase motivation. The thesis reports on the collection of empirical data to examine the relationship between consumer benefit and price sensitivity as a way of extending means-end theory. The subjects are purchasers of women's fine fragrances and trainers, in the UK and Germany. The literature review covers values research, in which means-end theory is contrasted with the macro approach, and price sensitivity, where the advantages of using the price sensitivity mechanism are discussed. The fieldwork is presented as a three-part process. In the pilot stage, constructs for laddering interviews and basic price sensitivity data were elicited from purchasers of the two product categories across the two markets. The results of the second stage, in-depth interviews are reported as ı hierarchical value maps (produced manually) and price sensitivity charts (produced using' Lotus 1-2-3). Stage three involved a large scale survey carried out in both markets and this is then reported along with the results of the final analysis (produced using SPSS). Notwithstanding poor response rates among the German samples, the findings support the first research proposition that there is a relationship between consumer benefit and. price sensitivity. The correlation results reveal that a high level of benefit is associated with low price sensitivity among purchasers of trainers in the UK (with a near zero correlation recorded for the German sample). In the case of perfume, a high level of benefit is shown to be associated. with high price sensitivity. Implications of the findings are discussed with reference to both marketing theory and practice. Finally, the strengths and weaknesses of the research design are reviewed, followed by the presentation of 14 items for future research.

D.Phil. / The aim of this study was to explore the psychosocial factors which impact on smoking behaviour and to consider the impact of these factors on the formulation of national policy, as well as business and management practices around the marketing and promotion of tobacco products. An analytic induction approach was followed in analysing the data of multiple cases. Interviews and observations were used to gather in-depth information on nine participants (smokers, ex-smokers, social smokers and non-smokers). The data was subjected to analytic induction in order to build a typology of smoking behaviour. This theoretical tool was compared to current knowledge and culminated in a model of psychosocial factors that influence smoking behaviour, which was tested against a further four cases. No negative cases were found. The outcome of this study suggests that promoters of tobacco products should follow a more focused approach towards dark marketing. It also highlights that government and other anti-smoking agencies are not always effective in reducing smoking and counteracting covert marketing practices. The study also illustrated that analytic induction can be applied successfully in consumer behaviour studies. Finally, it contributed to local knowledge of qualitative research, as analytic induction has not been applied fully in a local study before.

MSc , Faculty of Science, University of the Witwatersrand, 1980

ABSTRACT The increasing prevalence of suicidal behaviour especially among adolescents is an important public health problem. With the increasing adverse global economic conditions and HIV/AIDS prevalence, especially in developing world, the problem of suicidal behaviours is expected to get worse, and the impact on the healthcare systems will increase. Objective: This study was done to evaluate the socio-demographic and clinical profile of the patients who were admitted into Leratong Hospital for suicidal behaviours, and the factors associated with these suicidal behaviours. In the context of worsening social and economic problems, and the increasing HIV/AIDS epidemic, it is hoped that the results of this study will help in quantifying needs, defining appropriate management protocols and referral systems, and informing capacity building processes. Methods: This was a descriptive cross-sectional study. All patients admitted to the medical wards for parasuicides and attempted suicide from November 2007 to February 2008 (n=162) were interviewed during the course of their admission. Data on their socio-demographic characteristics, history of previous suicide ideations and attempts, methods of and reasons for the present suicidal behaviours, and past personal and family histories of the patients were extracted and analyzed. Results: Patients admitted for suicidal behaviours constituted about 5% of all medical patients. More than 67% of the patients were younger than 30 years, and more than 60% were females. Only about 16% of the patients were married, and about 45% were unemployed, and among those employed about 40% were unskilled, though more than 60% were living in either formal or RDP houses. Majority of the patients (60%) completed only grade 11 or less. Majority of the patients attempted suicide by ingesting overdose of medications (43%) and organophosphates (32%). The commonest reason given by patients for attempting suicide was domestic or relationship conflicts (75%). About 21% and 14% of the patients had histories of previous suicide ideation and attempt respectively. Common adverse events in the background histories of the patients were stress from their families (56%), unemployment (38%), alcohol abuse (32%), and abandoned by spouse (25%). Common adverse events in the family histories of these patients include at least one death in family in the last two years (70%), alcohol abuse (60%), family member in prison (46%), family member was a victim of crime (46%), and family member had a severe disease (42%). Risk factors found to be significantly associated with suicidal behaviours and the different methods of suicidal attempt include race, sex, younger age group, type of house, and family history of severe illness, death, divorce and substance abuse. The study has demonstrated the socio-demographic profile of these patients, the burden posed by suicidal behaviours on our health systems, and the risk factors associated with such behaviours. Based on these results, it is therefore recommended that health workers should look out for, and assess all patients for, risk factors associated with suicidal behaviours, and patients admitted for suicidal behaviours should be evaluated and managed properly, with appropriate referrals, before they are discharged.

MSc (Med), Epidemiology and Biostatistics, School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, 2009 / Objective The study examined the relationship between socioeconomic status (SES) and risky sexual behaviour in young women living in the Limpopo Province of South Africa. Methods Quantitative data were drawn from the 2001–2005 Intervention with Microfinance and Gender Equity Study. The analyses were restricted to 705 sexually active young women aged 14–35 years. Logistic regression models were employed to assess the effect of socioeconomic status (estimated from household asset index and employment status, on risky sexual behaviours). Odds ratios (OR), adjusted odds ratios (AOR) and 95% confidence intervals (CI) are reported. Results After controlling for the potential confounding effects of wealth perception, age, level of education, marital status, birth control and HIV knowledge; there was no statistically significant association between asset index, or employment status and most of the risky sexual behaviours. However, students were significantly more likely to have experienced first sex at or before age 17 years (AOR: 3.80, 95% CI: 2.63, 6.11), and significantly less likely to have had more than three lifetime sex partners (AOR: 0.47, 95% CI: 0.29, 0.78). Discussion Given that age had emerged as a definite predictor of the sexual behaviours that were significantly associated with being a student, and that 75% of the students were aged 14-19 years, it is possible that the associations may be due to an age effect, or a cohort effect. That aside, the results suggest that women in general are equally at risk of HIV infection, hence further research is needed to determine other factors that enhance young rural women’s vulnerability to HIV/AIDS. Conclusion The study did not show any strong evidence to suggest that socio-economic status is associated with risky sexual behaviour. The findings underscore the need to re-examine the assumption that poverty drives risky sexual behaviour so that efforts to ensure that HIV prevention messages get across all strata of society. However, it is possible that SES as used in this study did not differentiate people well enough to be able to identify factors associated with risky sexual behaviour. It is recommended that more research be done to establish how other major factors besides wealth may enhance the vulnerability of women to HIV/AIDS. The current study however contributes to the growing evidence that the relationship between wealth and HIV/AIDS is either exaggerated or is very complex and should be considered when designing new policies, programs and interventions to alleviate the growing HIV incidence

Owing to the ever increasing prevalence of software piracy and the alarming rise in costs to global economies, this research evaluated the Theory of Planned Behaviour and looked to determine if there are any relationships between the constructs under the model and intentions to carry out a specific behaviour, namely the copying of unauthorised computer software. The theory suggests that should attitudes and social norms favour the pirating of software and should the individual have the necessary perceived behavioural control and selfefficacy then they will be more likely to have intention to commit a certain act. A quantitative study looking at 225 individuals from organisations in the fields of manufacturing, finance and information technology was carried out to evaluate the theory’s claims. Correlations and linear regressions were run to analyse the data and it emerged that attitudes were the major predictor of intentions to pirate software accounting for up to 55% of the variance. Despite the perceived behavioural control variable there was significant support for the predictive value of the different constructs under the Theory of Planned Behaviour as well as the construct of self-efficacy.

No description available.