Utilising presence in places to support mobile interaction

Physical places are given contextual meaning by the objects and people that make up the space. Presence in physical places can be utilised to support mobile interaction by making access to media and notifications on a smartphone easier and more visible to other people. Smartphone interfaces can be extended into the physical world in a meaningful way by anchoring digital content to artefacts, and interactions situated around physical artefacts can provide contextual meaning to private manipulations with a mobile device. Additionally, places themselves are designed to support a set of tasks, and the logical structure of places can be used to organise content on the smartphone. Menus that adapt the functionality of a smartphone can support the user by presenting the tools most likely to be needed just-in-time, so that information needs can be satisfied quickly and with little cognitive effort. Furthermore, places are often shared with people whom the user knows, and the smartphone can facilitate social situations by providing access to content that stimulates conversation. However, the smartphone can disrupt a collaborative environment, by alerting the user with unimportant notifications, or sucking the user in to the digital world with attractive content that is only shown on a private screen. Sharing smartphone content on a situated display creates an inclusive and unobtrusive user experience, and can increase focus on a primary task by allowing content to be read at a glance. Mobile interaction situated around artefacts of personal places is investigated as a way to support users to access content from their smartphone while managing their physical presence. A menu that adapts to personal places is evaluated to reduce the time and effort of app navigation, and coordinating smartphone content on a situated display is found to support social engagement and the negotiation of notifications. Improving the sensing of smartphone users in places is a challenge that is out-with the scope of this thesis. Instead, interaction designers and developers should be provided with low-cost positioning tools that utilise presence in places, and enable quantitative and qualitative data to be collected in user evaluations. Two lightweight positioning tools are developed with the low-cost sensors that are currently available: The Microsoft Kinect depth sensor allows movements of a smartphone user to be tracked in a limited area of a place, and Bluetooth beacons enable the larger context of a place to be detected. Positioning experiments with each sensor are performed to highlight the capabilities and limitations of current sensing techniques for designing interactions with a smartphone. Both tools enable prototypes to be built with a rapid prototyping approach, and mobile interactions can be tested with more advanced sensing techniques as they become available. Sensing technologies are becoming pervasive, and it will soon be possible to perform reliable place detection in-the-wild. Novel interactions that utilise presence in places can support smartphone users by making access to useful functionality easy and more visible to the people who matter most in everyday life.

Empirical studies on share issuance and repurchase decisions

Financial constraints influence corporate policies of firms, including both investment decisions and external financing policies. The relevance of this phenomenon has become more pronounced during and after the recent financial crisis in 2007/2008. In addition to raising costs of external financing, the effects of financial crisis limited the availability of external financing which had implications for employment, investment, sale of assets, and tech spending. This thesis provides a comprehensive analysis of the effects of financial constraints on share issuance and repurchases decisions. Financial constraints comprise both internal constraints reflecting the demand for external financing and external financial constraints that relate to the supply of external financing. The study also examines both operating performance and stock market reactions associated with equity issuance methods. The first empirical chapter explores the simultaneous effects of financial constraints and market timing on share issuance decisions. Internal financing constraints limit firms’ ability to issue overvalued equity. On the other hand, financial crisis and low market liquidity (external financial constraints) restrict availability of equity financing and consequently increase the costs of external financing. Therefore, the study explores the extent to which internal and external financing constraints limit market timing of equity issues. This study finds that financial constraints play a significant role in whether firms time their equity issues when the shares are overvalued. The conclusion is that financially constrained firms issue overvalued equity when the external equity market or the general economic conditions are favourable. During recessionary periods, costs of external finance increase such that financially constrained firms are less likely to issue overvalued equity. Only unconstrained firms are more likely to issue overvalued equity even during crisis. Similarly, small firms that need cash flows to finance growth projects are less likely to access external equity financing during period of significant economic recessions. Moreover, constrained firms have low average stock returns compared to unconstrained firms, especially when they issue overvalued equity. The second chapter examines the operating performance and stock returns associated with equity issuance methods. Firms in the UK can issue equity through rights issues, open offers, and private placement. This study argues that alternative equity issuance methods are associated with a different level of operating performance and long-term stock returns. Firms using private placement are associated with poor operating performance. However, rights issues are found empirically to be associated with higher operating performance and less negative long-term stock returns after issuance in comparison to counterpart firms that issue private placements and open offers. Thus, rights issuing firms perform better than open offers and private placement because the favourable operating performance at the time of issuance generates subsequent positive long-run stock price response. Right issuing firms are of better quality and outperform firms that adopt open offers and private placement. In the third empirical chapter, the study explores the levered share repurchase of internally financially unconstrained firms. Unconstrained firms are expected to repurchase their shares using internal funds rather than through external borrowings. However, evidence shows that levered share repurchases are common among unconstrained firms. These firms display this repurchase behaviour when they have bond ratings or investment grade ratings that allow them to obtain cheap external debt financing. It is found that internally financially unconstrained firms borrow to finance their share repurchase when they invest more. Levered repurchase firms are associated with less positive abnormal returns than unlevered repurchase firms. For the levered repurchase sample, high investing firms are associated with more positive long-run abnormal stock returns than low investing firms. It appears the market underreact to the levered repurchase in the short-run regardless of the level of investments. These findings indicate that market reactions reflect both undervaluation and signaling hypotheses of positive information associated with share repurchase. As the firms undertake capital investments, they generate future cash flows, limit the effects of leverage on financial distress and ultimately reduce the risk of the equity capital.

Garbage collection optimization for non uniform memory access architectures

Cache-coherent non uniform memory access (ccNUMA) architecture is a standard design pattern for contemporary multicore processors, and future generations of architectures are likely to be NUMA. NUMA architectures create new challenges for managed runtime systems. Memory-intensive applications use the system’s distributed memory banks to allocate data, and the automatic memory manager collects garbage left in these memory banks. The garbage collector may need to access remote memory banks, which entails access latency overhead and potential bandwidth saturation for the interconnection between memory banks. This dissertation makes five significant contributions to garbage collection on NUMA systems, with a case study implementation using the Hotspot Java Virtual Machine. It empirically studies data locality for a Stop-The-World garbage collector when tracing connected objects in NUMA heaps. First, it identifies a locality richness which exists naturally in connected objects that contain a root object and its reachable set— ‘rooted sub-graphs’. Second, this dissertation leverages the locality characteristic of rooted sub-graphs to develop a new NUMA-aware garbage collection mechanism. A garbage collector thread processes a local root and its reachable set, which is likely to have a large number of objects in the same NUMA node. Third, a garbage collector thread steals references from sibling threads that run on the same NUMA node to improve data locality. This research evaluates the new NUMA-aware garbage collector using seven benchmarks of an established real-world DaCapo benchmark suite. In addition, evaluation involves a widely used SPECjbb benchmark and Neo4J graph database Java benchmark, as well as an artificial benchmark. The results of the NUMA-aware garbage collector on a multi-hop NUMA architecture show an average of 15% performance improvement. Furthermore, this performance gain is shown to be as a result of an improved NUMA memory access in a ccNUMA system. Fourth, the existing Hotspot JVM adaptive policy for configuring the number of garbage collection threads is shown to be suboptimal for current NUMA machines. The policy uses outdated assumptions and it generates a constant thread count. In fact, the Hotspot JVM still uses this policy in the production version. This research shows that the optimal number of garbage collection threads is application-specific and configuring the optimal number of garbage collection threads yields better collection throughput than the default policy. Fifth, this dissertation designs and implements a runtime technique, which involves heuristics from dynamic collection behavior to calculate an optimal number of garbage collector threads for each collection cycle. The results show an average of 21% improvements to the garbage collection performance for DaCapo benchmarks.

A house, not a home? Examining the use of the private rented sector to resolve homelessness in Scotland

Changes to homelessness legislation in post-devolution Scotland have resulted in an expansion of rights for homeless households seeking formal assistance from local authorities. These changes have led to Scotland’s homelessness arrangements being considered among the most progressive in Europe. In recent years, however, the Scottish Government has increasingly promoted homelessness prevention and Housing Options approaches as a means by which homelessness might be avoided or resolved without recourse to statutory rights. As part of that, they have promoted greater use of the private rented sector (PRS) as a key housing option, with the potential to meet the needs of homeless households. The arguments made to support use of the PRS have much in common with arguments for privatisation in other areas of social policy, notably greater choice for the individual promoting better welfare outcomes, and competition among providers encouraging improvements in quality of service provision. Critics have argued that such benefits may not be realised and that, on the contrary, privatisation may lead to exclusion or act to worsen households’ outcomes. This thesis considers the extent to which the PRS has been utilised in Scotland to accommodate homeless households, and the consequences of this for their welfare. The thesis uses a combination of quantitative and qualitative methods. To examine trends in the use of the PRS, it presents quantitative analysis of the data on the operation of the statutory system and Housing Options arrangements, and of data from a survey of local authority homelessness strategy officers. To examine the consequences of this for homeless households, the thesis uses qualitative research involving face-to-face interviews with 35 homeless households across three local authority areas. This research considers the extent to which households’ experiences of homelessness, housing need and the PRS reflect the arguments presented in the literature, and how settled accommodation has impacted on households’ ability to participate fully in society. The research found an increasing but still limited role for the PRS in resolving statutory homelessness in Scotland, with indications that the PRS is being increasingly used as part of the Housing Options approach and as a means of resolving homelessness outside the statutory system. The PRS is being utilised to varying degrees across different local authority areas, and a variety of methods are being used to do so. While local authorities saw clear advantages to making greater use of the sector, a number of significant barriers including affordability, available stock and landlord preferences - made this difficult in practice. Research with previously homeless households in the PRS similarly found broadly positive experiences and views of the sector, particularly with regard to enabling households to access good quality accommodation in desirable areas of their choosing, with many households highlighting improvements relating to social inclusion and participation. Nevertheless, concerns around the security of tenure offered by the sector, repairs, service standards and unequal power relations between landlord and tenant persisted. As such, homeless households frequently expressed their decision to enter the sector in terms of a trade-off between choice and security.

Recent educational changes at higher educational level in Pakistan: English language teachers' perceptions and practices

Higher Education Institutes (HEIs) of any country could be a source of providing professionals to the country in many fields. By doing so, HEIs could play a pivotal role in the economic growth of the country. In Pakistan, it seems that, in the wake of this realization, steps have been taken to reform Higher Education. Drawing on the Triple I model of educational change covering Initiation, Implementation and Institutionalization (Fullan, 2007) this study focuses on the planning and implementation of reforms in the Education system of Pakistan at higher education level that have been introduced by the Higher Education Commission (HEC) since its inception in 2002. Kennedy’s model of hierarchical subsystems affecting innovation and Chin and Benne’s (1985) description of strategies for implementing change also provided guidelines for analyzing the changes in education in the country to highlight the role that the authorities expect the language teacher to play in the process of implementing these changes. A qualitative method is followed in this study to gather data from English language teachers at three universities of the Khyber Pakhtunkhwa province of Pakistan. A questionnaire was developed to look into the perceptions of English language teachers regarding the impact of these reforms. This was followed up by interviews. Responses from 28 teachers were received through questionnaire out of which 9 teachers were interviewed for detailed analysis of their perceptions. Thematic Content analysis was used to analyze and interpret the data. Some of the most significant changes that the respondents reported knowledge of included the introduction of Semester System, extending the Bachelors degree to four years from two years, promotion of research culture, and increased teachers’ autonomy in classroom practices. Implications of these reforms for English teachers’ professional development were also explored. The data indicate that the teachers generally have a positive attitude towards the changes. However, the data also show concerns that teachers have about the practical effectiveness of these changes in improving English language teaching and learning in Pakistani Universities. Some of the areas of concern are worries regarding resources, the assessment system, the number of qualified teachers, and instability in the educational policy. They are concerned about the training facilities and quality of the professional training available to them. Moreover, they report that training opportunities for their professional development are not available to all the teachers equally. Despite the HEC claims of providing regular training opportunities, the majority of the teachers did not receive any formal training in the last three years, while some teachers were able to access these opportunities multiple times. Through the recent reforms HEC has empowered the teachers in conducting the learning/teacher processes but this extra power has reduced their accountability and they can exercise these powers without any check on them. This empowerment is limited to the classroom and there appears to be no or minimal involvement in decision making at the top level of policy making. Such lack of involvement in the policy decisions seems to be generating a lack of sense of ownership among the teachers (Fullan 2003a:6). Although Quality Enhancement Cells have been developed in the universities to assure the desired quality of education, they might need a more active role to contribute in achieving the level of enhancement in education expected from them. Based on the perceptions of the respondents of this study and the review of the relevant literature, it is argued that it is unlikely for the reforms to be institutionalized if teachers are not given the right kind of awareness at the initiation stage and are not prepared at the implementation stage to cope with the challenge of a complex process. The teachers participating in this study, in general, have positive and enthusiastic attitudes towards most of the changes, in spite of some reservations. It could also be interesting to see if the power centers of the Pakistani Higher Education appreciate this enthusiasm and channel it for a strong Higher Education system in the country.