An investigation into the concept of and factors leading to impact creep and its management

This study defines and explores the nature of impact creep within the context of two contrasting case studies. The methods applied in undertaking this study consisted of a literature review and development and distribution of questionnaires to visitors at Monkey Mia and an interview of managers at Monkey Mia and Tree Top Walk. The project considered impact creep relevant to both public and private facility developments. Impact creep can be defined as a temporal sequence of changes that lead to a site being more developed. These changes confer both negative and positive impacts. Each impact creep situation may be deemed unique according to different tourism situations and attractions. Both Tree Top Walk and Monkey Mia have a history of increasing visitation which has increased the potential for further impacts. Management has responded accordingly and the resultant actions have reduced negative environmental impacts through site hardening and associated developments. The resultant development in turn appears to have contributed to an increased attractiveness for a wider visitor profile. At both Monkey Mia and the Tree Top Walk increasing visitor numbers were not an immediate concern. Generally visitors to both sites are predominantly first time visitors on a multi-destination trip. Visitors to these sites are most likely to visit in family groups or with friends of two to four persons, aged in the 25 to 49 year age bracket. In both surveys there were a higher proportion of females to males. At Monkey Mia, the majority of respondents are from overseas and Western Australia with the lowest proportion from interstate. In contrast, at Tree Top Walk, the proportion of overseas, Western Australia and interstate visitors was fairly even. Respondents were most likely to travel to the respective regions in passenger vehicles and generally stay for short visits (less than a week). The main attraction for respondents was the natural area attraction, i.e. dolphins at Monkey Mia and the Tingle forest/Tree Top Walk at the Valley of the Giants. The Monkey Mia visitor survey was also used to determine if management actions of site hardening detract from the visitor experience and to determine how visitors feel about highly developed sites such as those that contain permanent accommodation facilities and infrastructure. The survey revealed that visitors generally prefer natural landscapes with limited facilities. However, the facilities provided were not seen as being detractive and had no influence on the quality of the visit. Moreover, facilities may be considered as a positive influence because of the convenience they offer. A major difference between the two case studies is that impact creep has occurred according to different policy directives. Tree Top Walk was developed under a management plan that had clear guidelines. Monkey Mia had no management plan and joint management with the Shire of Shark Bay. When accommodation facilities were developed at Monkey Mia, the Western Australian Department of Conservation and Land Management (CALM) recommendations were ignored in favour for economic returns and political pressure. A notable difference between the two sites, therefore, is that Tree Top Walk has no accommodation facility so the visitation period is short, while Monkey Mia has accommodation which means that limiting visitor use is problematic because as many as 600 people stay in the vicinity of the interaction area overnight. For Tree Top Walk a dispersal strategy in the form of a visitor centre may help to focus attention away from the main attraction during busy periods and during wait times if restrictions are operating due to heavy demand. Because of the potential for increased visitation, crowding, conflicts and reduced visitor satisfaction at Monkey Mia limitations on use may have to be applied. Previous work has shown that use/access restrictions, in the form of a reservation or permit system, may be the best approach

Molecular dynamics as a tool to study heterogeneity in zeolites - Effect of Na cations on diffusion of CO and N in Na-ZSM-5

Zeolites typically contain extra-framework cations to charge-compensate for trivalent Al atom substitutions in the SiO framework. These cations, such as Na, directly interact with quadrupolar guest molecules, such as CO and N, which move through their micropores, causing energetic heterogeneity. To assess the effects of heterogeneity in Na-ZSM-5 on diffusion of CO and N, molecular dynamics (MD) simulations are carried out. In silicalite-1, the pure-silicon form of ZSM-5, the self-diffusivity exhibits a monotonic decrease with molecular loading, while the corrected diffusivity shows a relatively constant value. In contrast, the Na cations cause a maximum or a flat profile over molecular loading for the self- and corrected diffusivities of CO at T=200 and 300K, while the cations only have minimal impact on the diffusivity of N. The MD simulations allow us to identify energy basins or sites at which guest molecules spend a relatively long time, and construct a coarse-grained lattice representation for the pore network. Average residence times at these sites are calculated for both species. The trends observed in the residence times correlate to the trends observed in the diffusivity. The residence times for CO at T=200K are long at low loading, but decrease with loading as additional CO molecules compete to stay close to a cation. In contrast, the residence times for N are relatively insensitive to the cations, only mildly increasing near a cation. This difference in behavior can be associated to the quadrupole moments of these molecules

A Note on Buyer's Agent Commision and Sales Price

The article examines whether and to what extent the level of a buyer’s agent commission will affect the sale price of a house. The estimation results suggest that a higher commission rate leads to a higher sale price, although only for lower-priced houses. It is suggested that, at least for this market segment, there may be a principal-agent problem: buyer’s agents do not act in the best interest of their clients because of the institutional structure of sales commissions.

Wildlife tourism, science and actor network theory

Wildlife tourism is an important component of tourism worldwide. However, for many species little is known about the possible impacts from tourist-wildlife interactions. Previous research has identified barriers to such science being undertaken but this science-wildlife tourism interface remains poorly understood. Actor-network theory, with its attention to the actors and relationships that make science possible, was used to describe and analyze the development and decline of scientific research into the effects of tourism on wildlife in the Antarctic region. This study concludes that actor-network theory provides a robust description of the complex role and positioning of science in wildlife tourism, while at the same time suggesting that further attention to actors' relative power and scientists' normative beliefs are essential elements of analysis

Polygraph: Automatically generating signatures for polymorphic worms

It is widely believed that content-signature-based intrusion detection systems (IDSes) are easily evaded by polymorphic worms, which vary their payload on every infection attempt. In this paper, we present Polygraph, a signature generation system that successfully produces signatures that match polymorphic worms. Polygraph generates signatures that consist of multiple disjoint content sub-strings. In doing so, Polygraph leverages our insight that for a real-world exploit to function properly, multiple invariant substrings must often be present in all variants of a payload; these substrings typically correspond to protocol framing, return addresses, and in some cases, poorly obfuscated code. We contribute a definition of the polymorphic signature generation problem; propose classes of signature suited for matching polymorphic worm payloads; and present algorithms for automatic generation of signatures in these classes. Our evaluation of these algorithms on a range of polymorphic worms demonstrates that Polygraph produces signatures for polymorphic worms that exhibit low false negatives and false positives. © 2005 IEEE

Agency Representation and the Sale Price of Houses

Multiple Listing Service data are employed to examine how the type of agency representation influences the sale price of a residential property. The results differ by property size. The type of agency representation is relevant only for some segments of the market, mainly smaller- to medium-sized properties. For a certain range of property sizes, buyers who engage a buyer’s agent pay on average 2% less. However, an above average buyer’s agent commission can more than cancel this price effect. Buyers that engage a buyer’s agent that comes from the same firm as the listing agent never pay more for a house.

My story, my identity and my relationship with work: sickle cell disorder

This study explored the narratives people living with sickle cell disorder construct to explain how the experience of employment influences their identity and subsequently their quality of life. Nine individuals with sickle cell disorder were interviewed and gave detailed autobiographical narratives which were transcribed and processed using narratives analysis. Participants were 4 men and 5 women aged between 22 and 60 years. Participants' passion for their job roles was illustrated by their positive work identities. Earlier experiences were felt to be influential on drive and resilience to work challenges. In the narratives, poor understanding of sickle cell disorder by organisations and reduced ability to manage their condition impacted physical health; psychological and emotional wellbeing; social and cultural experiences. This study has implications for the clinical practice and future research of adults living with sickle cell disorder, contributing to the broadening general understanding of sickle cell disorder

Visitor perceptions of captive wildlife tourism in a Western Australian natural setting

Wildlife tourism involves a broad sweep of experiences that includes all of the aspects of the tourism genre with the distinguishing feature of animals as the primary attraction. The uniqueness of Australian wildlife in combination with factors such as remoteness and rarity appear to have provided the ideal context for successful wildlife tourism operations. Barna Mia, located in a large remnant woodland in the central southern wheatbelt of Western Australia, is approximately 165 km southeast of the state's capital, Perth. Dryandra Woodland, the location of Banra Mia consists of a closely grouped and connected cluster of native remnant vegetation blocks. The enclosure is surrounded by electrified, vermin proof fencing to keep feral predators out and the captive fauna in. The results of the visitor survey at Barna Mia suggested the experience provided a great sense of satisfaction amongst respondents. This was both in terms of the overall satisfaction as well as satisfaction with specific parts of the experience. The feeling of being 'in the wild' may have been enhanced by the lack of barriers between visitors and the animals and the absence of constraints on animal movement through the enclosure. Improving the operation of Barna Mia as an attraction in itself and as part of the Dryandra Woodland product may serve to improve its success as an attraction. However, an innately attractive tourism experience cannot work without appropriate integration within the specific wildlife tourism product of Dryandra Woodland, while coordination with tourism on a regional scale is also important

Computation of leading-edge vortex flows

The simulation of the leading edge vortex flow about a series of conical delta wings through solution of the Navier-Stokes and Euler equations is studied. The occurrence, the validity, and the usefulness of separated flow solutions to the Euler equations of particular interest. Central and upwind difference solutions to the governing equations are compared for a series of cross sectional shapes, including both rounded and sharp tip geometries. For the rounded leading edge and the flight condition considered, viscous solutions obtained with either central or upwind difference methods predict the classic structure of vortical flow over a highly swept delta wing. Predicted features include the primary vortex due to leading edge separation and the secondary vortex due to crossflow separation. Central difference solutions to the Euler equations show a marked sensitivity to grid refinement. On a coarse grid, the flow separates due to numerical error and a primary vortex which resembles that of the viscous solution is predicted. In contrast, the upwind difference solutions to the Euler equations predict attached flow even for first-order solutions on coarse grids. On a sufficiently fine grid, both methods agree closely and correctly predict a shock-curvature-induced inviscid separation near the leeward plane of symmetry. Upwind difference solutions to the Navier-Stokes and Euler equations are presented for two sharp leading edge geometries. The viscous solutions are quite similar to the rounded leading edge results with vortices of similar shape and size. The upwind Euler solutions predict attached flow with no separation for both geometries. However, with sufficient grid refinement near the tip or through the use of more accurate spatial differencing, leading edge separation results. Once the leading edge separation is established, the upwind solution agrees with recently published central difference solutions to the Euler equations