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This paper examines the Random Walk Hypothesis (RWH) for aggregate New Zealand share market returns, as well as the CRSP NYSE‐AMEX (USA) index during the 1980‐2001 period…
This paper examines the Random Walk Hypothesis (RWH) for aggregate New Zealand share market returns, as well as the CRSP NYSE‐AMEX (USA) index during the 1980‐2001 period. Using several indices, we rely on the variance‐ratio test and find evidence to support the rejection of the RWH with some evidence of a momentum effect. However, we find evidence to suggest the behaviour of share prices to be time‐dependent in New Zealand. For example, we find the indices tested were closer to random after the 1987 share market crash. Further analysis showed even stronger results for periods subsequent to the passage of the Companies Act 1993 and the Financial Reporting Act 1993. We also find evidence that indices based on large capitalisation stocks are more likely to follow a random walk compared to those based on smaller stocks. For the USA index, we find stronger evidence of random behaviour in our sample period compared to the earlier period examined by Lo and Mackinlay (1988)
The bulk of jet engine noise developed at high powers arises from the turbulent mixing of the jet efflux in the surrounding air, as judged from model experiments, and has…
The bulk of jet engine noise developed at high powers arises from the turbulent mixing of the jet efflux in the surrounding air, as judged from model experiments, and has a continuous spectrum with a single flat maximum. The high frequency sound arises from fairly close to the orifice, and reaches its maximum intensity at fairly large acute angles to the jet direction. Lower frequency noise arises from lower down stream and its maxima make smaller acute angles with the jet axis. The possible origins are briefly discussed in view of Lighthill's theory and refraction effects. The most intensesound has a wave‐length of the order of three or four exit diameters, and originates between five and ten diameters from the orifice. A semi‐empirical rule of noise energy depending on the jet velocity to the eighth power and the jet diameter squared gives a rough estimate of the noise level for both cold and heated jets. Further noise from heated or supersonic jets may occur through eddies travelling at supersonic speed and so producing small Shockwaves. Model experiments have shown that interaction between shock‐wave configurations in choked jets and passing eddy trains generates sound and this initiates further eddies at the orifice. The directional properties of this sound are quite distinctive, the maximum being in the upstream direction. Methods of reducing jet noise are briefly discussed.
THE nuisance caused by the noise produced by aircraft is a matter which has been arousing antagonism now for some forty years and there have been repeated demands that ‘something should be done about it’.
THE St. Venant theory as applied to long beams of constant cross‐section could generally be used with sufficient accuracy for the solution of the structures encountered in…
THE St. Venant theory as applied to long beams of constant cross‐section could generally be used with sufficient accuracy for the solution of the structures encountered in aircraft until the last few years. The wings of high‐speed aircraft, with smaller aspect ratios, large angles of sweep‐back, and small thickness/chord ratios, introduce a new problem. There is an extensive literature on the subject, and all the methods which have been proposed are necessarily studies of redundant systems, the degree of redundancy varying according to the accuracy required. As these solutions require that the scantlings of the structure be known in advance, it was thought interesting to establish a simple method which would determine to a good approximation the skin thicknesses required. This is based on the application of the theorem of least work, which gives exact solutions of elasticity problems so long as all the terms in the strain energy expression are taken into account.
A Theoretical Approach to Assessing the Thermodynamic Process Within the Combustion Chamber of the Propulsive Duct, an Examination of the Potential of the Duct with Special Reference to the Application of Feedback and Spark Discharge Techniques. Development of the propulsive duct has been retarded by the absence of a suitable theoretical analysis. This paper, based on four years of experimental investigation by the author, discusses the problems involved and puts forward a theory which closely follows practical results. The theory is then used to examine the potential of the duct and it is shown that by applying feedback and spark‐discharge techniques, a low specific fuel consumption and unlimited thrust, outside the audible range, is theoretically possible. Finally, it is shown that the marriage of the duct to electrical power generated from atomic sources otters attractive possibilities for V.T.O.L. and aircraft propulsion of the future.
The purpose of this paper is to report on an evaluation of the UK Healthy Universities Network (UKHUN), which explored engagement of network members; identified what…
The purpose of this paper is to report on an evaluation of the UK Healthy Universities Network (UKHUN), which explored engagement of network members; identified what members value about the network; examined facilitators and barriers to engagement; and informed the network’s future development.
The study was a two phase mixed-method study, with participants being staff from Higher Education institutions. Phase 1 involved a documentary review and an online 14-question survey (n=32). Phase 2 comprised follow-up semi-structured interviews and focus groups, conducted using Skype (n=11). These were audio recorded and transcripts were thematically analysed in a two-stage process.
A number of key themes emerged from the thematic analysis: value of network meetings and events; popularity of the network website; increased communication and collaboration; sense of leadership offered by the network; interest and inclusion of an international perspective; importance of institutional support.
Only six universities who are involved in the network took part in Phase 2. Although a range of organisations were chosen purposively, it is possible that additional key issues at other universities were excluded.
The UKHUN is valued by its membership, particularly its biannual meetings, online presence, leadership, ethos and communication methods. Key barriers include the capacity of staff to attend meetings and contribute to the network, influenced by a lack of institutional commitment and prioritisation. Findings from the evaluation have informed a “refresh” of the network’s website and a revision of its membership structure, as well as guiding its positioning to achieve greater strategic influence.
This article describes the evaluation of the ACE club, a service for younger people with dementia in North Wales. The evaluation was conducted by the ACE club members and…
This article describes the evaluation of the ACE club, a service for younger people with dementia in North Wales. The evaluation was conducted by the ACE club members and conducted through a relationship‐centred approach expressed through the Senses Framework (achievement, belonging, continuity, purpose, security, significance) (Nolan et al, 2006). Members of the ACE club found the sense of significance to be the most important and meaningful ‘sense’ in helping to structure their evaluation and use of the ACE club. The clinical interventions outline is shared within the text to help provide a grounded and inductively generated practice structure. The funding of ‘normalising’ activities for younger people with dementia is an area of dementia care that needs urgent attention.
This study unpacks how organizational members construct a collective entrepreneurial identity within an organization and attempt to instill entrepreneurial features in the…
This study unpacks how organizational members construct a collective entrepreneurial identity within an organization and attempt to instill entrepreneurial features in the organization's existing identity.
The study draws on the cases of two venturing units, perceived as entrepreneurial groups within their respective parent companies. Semi-structured interviews and secondary data were collected and analyzed inductively and abductively.
The data revealed that organizational members co-constructed a “corporate entrepreneur” role identity to form a collective shared belief and communities of practice around what it meant to act as an entrepreneurial group within their local corporate context and how it differentiated them from others. Members also clustered around the emergent collective entrepreneurial identity through sensegiving efforts to instill entrepreneurial features in the organization's identity, despite the tensions this caused.
Previous studies in corporate entrepreneurship have theorized on the top-down dynamics instilling entrepreneurial features in an organization's identity, but have neglected the role of bottom-up dynamics. This study reveals two bottom-up dynamics that involve organizational members' agentic role in co-constructing and clustering around a collective entrepreneurial identity. This study contributes to the middle-management literature, uncovering champions' identity work in constructing a “corporate entrepreneur” role identity, with implications for followers' engagement in constructing a collective entrepreneurial identity. This study also contributes to the organizational identity literature, showing how tensions around the entrepreneurial group's distinctiveness may hinder the process of instilling entrepreneurial features in an organization's identity.