Elliptic partial differential equations that are used to model physical phenomena give rise to large sparse linear systems. Such systems can be symmetric positive definite and can be solved by the preconditioned conjugate gradients method. In this thesis, we develop support graph preconditioners for symmetric positive definite matrices that arise from the finite element discretization of elliptic partial differential equations. An object oriented code is developed for the construction, integration and application of these preconditioners. Experimental results show that the advantages of support graph preconditioners are retained in the proposed extension to the finite element matrices.

Elliptic partial differential equations that are used to model physical phenomena give rise to large sparse linear systems. Such systems can be symmetric positive definite and can be solved by the preconditioned conjugate gradients method. In this thesis, we develop support graph preconditioners for symmetric positive definite matrices that arise from the finite element discretization of elliptic partial differential equations. An object oriented code is developed for the construction, integration and application of these preconditioners. Experimental results show that the advantages of support graph preconditioners are retained in the proposed extension to the finite element matrices.

Simultaneous localization and mapping (SLAM) and Structure from Motion (SfM) are important problems in robotics and computer vision. One of the challenges is to solve a large-scale optimization problem associated with all of the robot poses, camera parameters, landmarks and measurements. Yet neither of the two reigning paradigms, direct and iterative methods, scales well to very large and complex problems. Recently, the subgraph-preconditioned conjugate gradient method has been proposed to combine the advantages of direct and iterative methods. However, how to find a good subgraph is still an open problem. The goal of this dissertation is to address the following two questions: (1) What are good subgraph preconditioners for SLAM and SfM? (2) How to find them? To this end, I introduce support theory and support graph theory to evaluate and design subgraph preconditioners for SLAM and SfM. More specifically, I make the following contributions: First, I develop graphical and probabilistic interpretations of support theory and used them to visualize the quality of subgraph preconditioners. Second, I derive a novel support-theoretic metric for the quality of spanning tree preconditioners and design an MCMC-based algorithm to find high-quality subgraph preconditioners. I further improve the efficiency of finding good subgraph preconditioners by using heuristics and domain knowledge available in the problems. Our results show that the support-theoretic subgraph preconditioners significantly improve the efficiency of solving large SLAM problems. Third, I propose a novel Hessian factor graph representation, and use it to develop a new class of preconditioners, generalized subgraph preconditioners, that combine the advantages of subgraph preconditioners and Hessian-based preconditioners. I apply them to solve large SfM problems and obtain promising results. Fourth, I develop the incremental subgraph-preconditioned conjugate gradient method for large-scale online SLAM problems. The main idea is to combine the advantages of two state-of-the-art methods, incremental smoothing and mapping, and the subgraph-preconditioned conjugate gradient method. I also show that the new method is efficient, optimal and consistent. To sum up, preconditioning can significantly improve the efficiency of solving large-scale SLAM and SfM problems. While existing preconditioning techniques do not utilize the problem structure and have no performance guarantee, I take the first step toward a more general setting and have promising results.

No / Aims and objectives. The current study sought to identify how many mothers from 149 visits carried out by seven health visitors identified support as a feature of the visit, whether this type of support was unique to the health visitor and what support meant to them. These responses were then compared with the taxonomies of social support from the social support literature. Background. Some studies of client perceptions describe support as an element of home visits by health visitors. However, the importance, relevance and impact on the client of this support are not described in detail. Social support theory suggests that there are tangible benefits to people's well-being and their ability to cope with various challenges that may arise from individuals' perceptions of receiving support. Design. Qualitative study using semistructured interviews. Methods. Seven volunteer health visitors recruited 149 women into the study. These clients were interviewed by the researcher, usually within one week of the home visit by their health visitor. The discussions were audio-taped and the resulting transcripts analysed using content analysis. Findings. Thirty-seven women identified receiving support which they said was only available from the health visitor. The relevance of this support to the mother and the impact on her well-being varied within the group suggesting differing perceptions of support by clients according to their personal situation. There was a correspondence between the descriptions of support given by the women and the taxonomies of social support from the social support literature. Conclusion. For some interactions between clients and their health visitors the existing theory of social support may provide an explanation of how health visitors contribute to clients' perceived ability to cope and well-being. Relevance to clinical practice. Social support may be defined as a possible outcome of health visiting. This concept will have use within educational programmes to demonstrate to students how health visiting can have an impact on clients' well-being. Similarly, the concept could be used to investigate and record health visiting practice.

The influence of online customer reviews (OCRs) on consumer behaviour has recently gained considerable attention, from both academic and business communities. Technology allows customers to freely and easily post their comments and opinions online about any product or service. These types of customer reviews can have a significant effect on customers’ purchase decisions and have become an essential part of the experience when shopping online. However, knowledge of the role of the perceived derived attributes of OCRs on consumer behaviour remains vague. Previous studies have mainly focused on the influence of the virtual attributes of OCRs, such as volume and valence, on consumers’ intentions, while limited attention has been paid to understanding the effects of the derived attributes. This study, thus, aims to understand the effects of the social and functional perceived derived attributes of OCRs on customer trust and intention to shop online. Hence, we develop a research model - Perceived Derived Attributes (PDA) -, based on the integration of social support with functional support derived from OCRs. The PDA model provides an in-depth understanding of the role of the social support of OCRs by applying and utilising theories of social support, social presence and a sense of belonging. The PDA model also investigates the influence of the functional support arising from OCRs through the inclusion of perceived control, from the Theory of Planned Behaviour (TPB) with the Technology Acceptance Model (TAM). The PDA model characterises perceived social support through informational and emotional supports, social presence, and a sense of belonging; whereas, functional supports are characterised by perceived usefulness, perceived ease of use, perceived enjoyment, and perceived control. A total of 489 responses to a survey were collected from users of amazon.com. The results from this study suggest that customer trust in an e-vendor and their intention to shop online are significantly affected by social and functional supports derived from OCRs. In particular, informational support, social presence and a sense of belonging, derived from OCRs were found to positively and significantly affect both customer trust in the online vendor and consumer behavioural intention. However, emotional support was only found to affect customers’ intentions and not their trust in the e-vendor. Additionally, customer trust in an e-vendor and their intention to shop online are significantly affected by perceived usefulness, perceived ease of use and perceived enjoyment of OCRs. Furthermore, the sense of control derived from OCRs significantly affects customer intention and significantly affects customer trust in e-vendors but only for customers who frequently check OCRs before making a purchase. This study is the first to introduce and empirically test the effects of perceived derived attributes of OCRs on customer trust and behavioural intention. Understanding the effects of such influencing factors is of utmost importance for both theoretical development and business practices. Clearly, these attributes of OCRs are linked to the development of the shopping environment, representing a promising marketing tool that positively affects customers’ behaviour.

Increasing evidence illustrates an involvement of stress in a large variety of physical and mental illness. Together with the evolutionary development of the social behavior in humans, the traditional interpretations of the attachment theory and the social support theory underscores the importance of affection, belonging and appreciation for human well-being. Not only can an imbalanced stress system be the cause of severe pathological consequences, insufficient social contact can also hamper recovery. Frequent usage of animals in various settings steadily illustrates both physiological and psychological benefits on both the young and the old, the healthy and the ill. Through the study of neurobiological factors, with oxytocin as a central mediator of social behavior and its  impact in turn on the stress- and cortisol system, this paper examines the possibility of animals to function as social support. The potential of animals to reduce the suffering in patients with stress related psychiatric disorders, such as the highly frequent exhaustion disorder, human-animal interactions might offer a non-invasive complementary tool to current treatment methods.

I investigate how nonprofessional investors’ confidence in the financial statements and the audit report is influenced by the firm specific details of a critical audit matter (CAM) disclosure in conjunction with the description of the audit procedures engaged to address the CAM in the audit report. Using participants recruited from Amazon Mechanical Turk as a proxy for nonprofessional investors in a 2x2 +1 (control) between-participants experiment manipulating CAM disclosure detail (Detailed/Generic) and the description of the audit procedures engaged to address the CAM (Detail/Generic) I find that greater detail in the description of the CAM results in higher confidence in the accuracy and reliability of the financial statements than a generic description of the CAM, consistent with boundary condition of Support Theory. Further, I find that greater detail in the description of the related audit procedures engaged to address the CAM increases nonprofessional investors’ perceptions of audit quality. Evidence of an effect of CAM and audit procedure disclosure language on investment judgments is also presented. These results have implications for researchers, practitioners, and regulators to carefully consider the language used to disclose CAMs in the auditor’s report.

Job stress is a common occurrence and of the utmost concern for management (Avey, Luthans, & Jensen, 2009). Canadian employees report workplace stress as a primary cause of mental health concerns which can subsequently impact workplace productivity and job performance (Mental Health Commission of Canada, 2019). In addition, the novel Coronavirus has had several negative consequences on people including for example the forced closure of work which has resulted in financial, social and health-related problems in part due to the consequences of stress (Brooks et al., 2020; Hossain, Sultana, & Purohit, 2020; Probst, Humer, Stippl, & Pieh, 2020; Sharma et al., 2020). Sports organizations are their employees are certainly not immune to the deleterious effects of stress (c.f., MacIntosh & Burton, 2019). Consequently, one of the management considerations to attenuate for stress is known as job characteristics (c.f., Hackman & Oldham, 1976). Hackman and Oldham (1976) developed the job characteristics theory, which can be used to understand the relationship between job characteristics, job design with various outcomes of interests such as performance. They suggested five characteristics of the job (i.e., skill variety, task identity, task significance, autonomy, and feedback) that influenced personal and work-related outcomes (Hackman & Oldham, 1976). Research has shown that when employees are faced with stressful conditions and high job demands, moral and economic support from the organization is needed (Krishnan & Mary, 2012). Organizational support theory (OST) proposes that employees form a general perception and belief concerning how the organizational management values their contributions and cares about their well-being (Eisenberger et al., 1986; Rhoades & Eisenberger, 2002). According to OST, such perceptions could have considerable effects on work outcomes (Eisenberger & Stinglhamber, 2011; Rhoades & Eisenberger, 2002), employees’ work attitudes and behaviors including feelings of stress (Kurtessis et al., 2015). The purpose of this study was to investigate the causal relationship between job characteristics, perceived organizational support, job stress, and job performance. This research was conducted on the employees within the sports sectors in Canada (N = 146) during the Covid-19 pandemic. Using a structural equation model (SEM), this study describes the relationships which exist based upon validated existing measures, specifically: Job Characteristics questionnaires (Morgeson & Humphrey, 2006), Perceived Organizational Support (SPOS) short version questionnaire (Eisenberger, Cummings, Armeli, & Lynch, 1997), Job Stress Scale (Parker & DeCotiis, 1983) and Williams and Anderson’s job performance questionnaire (Williams & Anderson, 1991). The results of the study confirm that job characteristics components can decrease overall job stress and improve job performance amongst sports employees even during a pandemic. Moreover, there is a significant impact between the level of organizational support and job stress. Specifically, when organizational support increases, job stress will be reduced. This study contributes to the extant sport management literature within organizational behavior and provides an account of the importance for management to take a person-centered approach, particularly during high-stress times such as the Covid-19 Pandemic.

China is facing severe aging problems. It is estimated that in 2050, people over 60 in China will cover more than 25 percent population. How to make the elderly people’s life more meaningful and more fruitful becomes an urgent issue. To obtain the goal of setting up a learning society, as well as to loosen the heavy burden aroused by aging problem, community education is applied as an effective way to the elderly people widely to enhance their living standard. A lot of researches have been done on community education and the elderly education respectively abroad. China started to do such topic study later than Western countries but the speed of aging has soared during last 20 years. The blank of study especially the elderly people who live in rural area should aroused the attention of this society.  This field study is to find out the factors that may lead to the elderly people’s subjective factors of participation into community education. According to Maslow’s hierarchy of needs and society support theory, with the help of questionnaire and interview, the author finds out the current situation of the elderly’s participation in community education in Shuyuan Township, and factors that may influence the frequency of participation. The author proposes several suggestions which can be used to improve current situation as policy adviser.

The issues surrounding asylum seekers in host countries like Sweden are severe concerns that need immediate attention, issues ranging from daily stressors constitute major problems to their mental health. There is therefore a need for both governmnet and non-government organizations to provide services that will upkeep the mental health status of these people. Notwithstanding, this study aimed to have a holistic view on the services provided by Soulidarity and Human Rights and Svenska Kyrkan organizations in Sweden. Through semi-structured interviews conducted with represntatives from these organizations based on the research questions that target the perception of their services, challenges, and recommendations. The empiricial data collected were analyzed using the theoretical framework of social support theory. The empricial result from this study shows that; asylum helped organizations provided a dimension of services ranging from individual, counseling, and leisure support services. Also, the services provided by these organizations were impactful to; build the self-confidence, abilities to perform tasks and build the self-esteem of these traumatic stress asylum seekers who came for help.  Furthermore, the workers in these organizations encountered challenges with working under complex migration and intergration policies that do not favor these asylum seekers, financial challenges, language difficulties, and internal problematic behaviors displaced from traumatic stresses asylum seekers. Finally, the workers in these organizations recommend that; changes in policies, financial improvement, and recruitment of more staff, strengthening sensitization, and empowerment of group rights are better ways of improving their services.