1,515 results for Conference paper

  • Pragmatic account of the process of knowledge creation in a Chinese context – How Socially-Produced Identity is transformed into economic production

    Sunaryo, Lenny (2006-10-18)

    Conference paper
    University of Otago

    Knowledge is regarded as important for creating organisational value and enhancing organisational competitiveness, especially in an unpredictable environment (Nonaka, 1994). However, there is little understanding of how knowledge is created in organisations, nor of how the knowledge creation process can be managed (Tsoukas & Mylonopoulos, 2004). This study is grounded on the idea that understanding contexts is crucial in managing the knowledge creation process (Glisby & Holden, 2003). More specifically, it is based on the idea that it is important to understand how identity is formed in the Chinese context, and how this leads to social knowledge that supports coordination and communication, which facilitates subsequent transformation of identity into economic productivity that creates a firm’s superiority over competitors (Kogut & Zander, 1996). It examines the process of organisational knowledge creation from the perspective of Chinese entrepreneurs in Semarang, Indonesia, for these reasons: first, studies on Chinese businesses have been predominantly based on Western management concepts, and do not represent the real situations in the Chinese context (Tsui, 2006); second, most of the extant studies on organisational knowledge creation have been inspired by Nonaka & Takeuchi’s (1995) generic model of continuous knowledge conversion as the fundamental process for knowledge creation. Despite the popularity of Nonaka’s work, it is based on business practices in large Japanese firms, which limits its generalisability to other social contexts, including the Chinese one under examination here. Further, the study of Chinese entrepreneurs in Indonesia, particularly in Semarang (a close-knit Chinese society), is undeveloped despite their significant contribution to the national economy.

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  • Display of interactive artwork: pilot test of two different interfaces

    Burrows, Gary; Hauber, Joerg; Regenbrecht, Holger (2007-12-06)

    Conference paper
    University of Otago

    The display of interactive artwork plays an increasingly important role in modern museums and galleries. However, the reaction of visitors has not been extensively tested to date. We present a pilot study that investigates viewer's reactions towards two interactive display prototypes that were designed to present famous artwork in a new and more engaging way. We describe the first iteration cycle of a questionnaire we composed which especially targets viewer satisfaction in a gallery context. The results of our first pilot study indicate that (1) interactive displays in galleries can create an engaging and exciting experience and (2) that they can be especially suitable to present education about art in a new and more involving way.

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  • Point allocation inside polygons and GWR: an experimental analysis with survey data

    Francisco, Eduardo de Rezende; Whigham, Peter A; Moore, Antoni (2007-12-06)

    Conference paper
    University of Otago

    The aim of this paper is to analyse different alternative implementations for a problem defined as "point allocation inside polygons" for Geographically Weighted Regression (GWR). The problem involves situations where the precise location of each observation is not known - just its district, municipality or region, i.e. a polygon geographical location. However, associated data were available that could potentially allows point placement of observations. These analyses were applied in a Income predicting model based on electricity consumption from a survey for a power distribution company in Sao Paulo, Brazil. Completely spatially random allocation and allocations based on spatial distributions of population (universe) and of the independent variable (electricity consumption) were utilized. Results showing the coefficients of determination (R2) suggest that a more realistic measure of the relationship between these two constructs could be evaluated.

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  • Evolutionary multiobjective optimisation through spatially-structured non-dominated sorting: a preliminary study

    Dick, Grant (2006-11)

    Conference paper
    University of Otago

    Multiobjective evolutionary algorithms (MOEAs) are useful tools capable of searching problems that contain several conflicting criteria. Although MOEAs have been shown to be capable of finding a wide spread of Pareto-optimal solutions for a given problem, they are still hindered by the requirement for significant computation. This paper investigates a new MOEA that incorporates spatial structure into the population. The introduction of space into the algorithm alters the behaviour of the algorithm so that computational complexity increases linearly with population size. In addition, the paper suggests paths that could be taken to improve the algorithm’s ability to successfully converge upon the global Pareto-optimal front of a given problem.

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  • Spatial analysis of home range, core area and habitat selection of red deer (Cervus elaphus) on an extensively managed high-country station

    Netzer, Michael; Whigham, Peter A; Dickinson, Katharine; Lord, Janice (2007-12-06)

    Conference paper
    University of Otago

    The aim of this research was to determine the behavior and habitat selection of red deer (Cervus elaphus) hinds during the calving period, on an extensively managed rangeland in the high-country of New Zealand’s South Island. The research was developed using ArcView and eCognition software, GPS collars on five red deer hinds, an aerial photograph and topographic data. The results showed that three out of the five study deer escaped the original study paddock into adjacent extensive paddocks. The deer did not use the entire study paddocks they were in, but instead formed distinct home ranges (total area of movement) and core areas (areas of intensive use, 45% of deer locations). These home ranges were highly variable in size from 225 ha. To 36 ha.. Core areas ranged from 102 ha. To 36 ha.. The variation in size of home ranges and core areas was directly related to the size of the paddock, and indirectly to social constraints within the paddock. The results suggest that deer within these extensive paddocks are under strong densitydependent effects during the calving season that may be forcing some hinds (probably less-dominant hinds) to the marginal edges of the pasture, where they may eventually escape. Habitat selection indicated, that while red deer often selected the naturalized pasture grass areas (high in metabolized energy), tussock grassland, when present in the home range, was also highly selected for. The selection of tussock grasslands was probably a result of tussock habitat providing both good cover/security during the calving season, and the presence of reasonably good forage in the inter-tussock area.

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  • Short Messaging Services (SMS) and banking

    Tanakinjal, Geoffrey Harvey (2006-10-18)

    Conference paper
    University of Otago

    As a direct marketing tool, electronic Short Message Services (SMS) is likely to surpass internet-based advertising before the end of 2006. Younger consumers higher in social class are the most willing to accept SMS direct advertising text and respond favourably to SMS-TV integrated marketing communications (Trappey III & Woodside, 2005). On the same note, online banking is starting to gain its momentum via the internet. Nonetheless, effort has been made to ensure online banking flexibility walks hand in hand with the convenience factor, therefore introducing banking via mobile phone (with GPRS interface). Understanding how companies should interact with their customers and deliver services in electronic environments is of decisive importance (Parasuraman and Zinkhan 2002). Nevertheless, despite these advantages, the consumer uses mobile devices mainly for simple services, such as voice services and text messaging. Based on this factor, it is important to understand the driving forces of consumers’ intentions to use mobile services and to adapt the services to fulfil consumers’ motives for using them (Nysveen, Pedersen, & Thorbjornsen. 2005). Objective of the study The general purpose of this study is to explore Short Messaging Service (SMS) potential as a vehicle of banking services by understanding consumers’ attitude, motivation and behavior towards wireless application channel. Significance of the study The contributions of the study may include: a. For the service providers or network companies, the study will be able to contribute additional information regarding consumer preference toward SMS messages on mobile banking; and b. For the marketers, especially those involved in the banking industry, this research will help understand the approach of wireless application technology.

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  • Beginning research on the quantification of spatial order

    Martin, Peter (2006-11)

    Conference paper
    University of Otago

    This research was conceived to contribute to the theoretical foundations of a general view of the dynamics of the world based on a concept of spatial order, defined and quantified in terms of differences or gradients. The Second Law of thermodynamics, which in its original conception expressed the dynamic potential of differences (of temperature), is central to this study, because of its unique and controversial role in relating spatial order to temporal order, providing an apparent direction to time and to general evolution. It suggests the existence and import of widely-applicable principles of a broader “entropy dynamics”, in which the evolution of order, intentional or otherwise, depends recursively on the dissipation of order; moreover the Second Law itself is understood as a consequence of primordial spatial order—viz. vanishing Weyl tensor of space-time curvature (Penrose 1989). Hence the intention is to explore the foundations and implications of a proposed scientific “paradigm”, of attempted maximal logical economy, in which spatial order is seen as both cause and effect of what we observe. Change of perspective regarding individuals’ relation to their world is the principal aim of the study, to be motivated by elaboration of the applicability of the proposed paradigm to diverse fields and by exploration of computational models which, it is hoped, will reveal some of the unexpected dynamics of the evolution of order.

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  • Fixation of neutral alleles in spatially structured populations via genetic Drift: Describing the spatial structure of faster-than-panmictic configurations

    Whigham, Peter A; Dick, Grant (2005-11)

    Conference paper
    University of Otago

    This paper considers spatially-structured populations described as a network, and examines the properties of these networks in terms of their affect on fixation of neutral alleles due solely to genetic drift. Individuals are modelled as two allele, one locus haploid, diploid and tetraploid structures. The time to fixation for a variety of network configurations is discovered through simulation. The concept of hyperfixation is introduced, which refers to when time to fixation for a network of n nodes occurs more rapidly than the corresponding panmictic n node structure. A hyperfixation index, h, is developed that attempts to characterise a spatial arrangement such that when h < 1 hyperfixation will occur. Issues regarding fixation with ploidy independence, and possible improvements to the described hyperfixation index are discussed.

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  • The trustree for the visualisation of attribute and spatial uncertainty: usability assessments

    Kardos, Julian; Moore, Antoni; Benwell, George L (2004-11)

    Conference paper
    University of Otago

    Attribute and spatial uncertainty are defined and put into context for this research. This paper then extends on a research programme which has designed a visualisation of attribute and choropleth spatial uncertainty using the Hexagonal or Rhombus (HoR) hierarchical spatial data structure. Using the spatial data model in this fashion is termed – the trustree. To understand this progression, a brief explanation of this research programmes past history must be covered. The New Zealand 2001 census is used as an exemplarity dataset to express attribute uncertainty and choropleth boundary uncertainty (termed spatial uncertainty). An internet survey was conducted to test the usability of the trustree, which was used as a transparent tessellation overlay and a value-by-area (VBA) display within a population choropleth map. Two other visualisation of attribute uncertainty methods – blinking areas and adjacent value were also incorporated into the survey. Participants were required to rank, from 1 to 6, six grid cells which overlaid the uncertainty visualisations, in order from the most accurate to the most uncertain cell, respectively. These ranking results were correlated with the actual ranks, providing a metric of usability for each visualisation method. The blinking areas method was the most effective, followed by adjacent value, VBA trustree and the transparent HoR trustree. The time taken for a participant to rank each visualisation’s cells was collected – there is an 82% correlation between the time taken and the final usability results obtained.

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  • Wine tourism and the generation Y market: any possibilities?

    Treloar, Peter; Hall, C Michael; Mitchell, Richard (2004)

    Conference paper
    University of Otago

    Changes in the operating environment for the wine industry in Australia and New Zealand have led to an increasing focus on wine tourism as a potential distribution method to grow a winery’s individual consumer base. Wine tourism is also seen as a strategy for encouraging growth in consumption amongst new markets. This research investigated the alcohol consumption behaviour of the Generation Y market to determine current purchasing behaviour, and their participation levels and interest in wine tourism. The aim of the research was to establish if potential for growth existed within the Generation Y market, and possible marketing strategies to increase levels of participation in wine consumption and wine tourism. To achieve this aim a survey was conducted of university students in Australia and New Zealand. The results showed that wine purchasing was limited within this group, as other alcohol such as beer and spirits were seen as easier and cheaper alternatives. However, the responses did show a potential for growth within this market. The research found that a large proportion of the respondents thought of wine tourism as an appealing tourism activity, and many had visited a winery. The results suggested that marketing which focuses on the leisure aspects of wine tourism, rather than highlighting the technical elements of a winery such as production and cellaring, would be most effective on this market. Furthermore, highlighting convenient travel methods and value for money was also found to be important, as the Generation Y markets financial situation was noted frequently as a limiting factor in wine purchase.

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  • Clients’ motivations, perceptions, expectations and satisfaction levels: The New Zealand mountain guiding industry

    Carr, Anna M (1997-11)

    Conference paper
    University of Otago

    Mountain guiding has been offered as an activity for tourists to New Zealand for over a century. In the late Nineteenth Century European guides, accompanying clients, introduced techniques to New Zealanders working at the first Hermitage Hotel at Mt Cook who then chose mountain guiding as their profession. Guides today continue a tradition based on experience, skills and knowledge that enables them to operate as successfully as the mountains will allow. The New Zealand Mountain Guides association (NZMGA) has a qualification framework, certification and safety standards that are internationally recognised by the International Union of Mountain Guides (UIAGM). Companies offer year-round activities such as heli-skiing, avalanche courses, glacier walks, trekking, mountaineering and rock climbing courses, ice climbing and high guiding. The latter ranges from high altitude tramping, e.g. the Copland Pass, to ascents of major peaks in New Zealand or overseas in Europe, Nepal, South America, Alaska and Antarctica. Issues faced by the NZMGA include competition from overseas companies, concession procedures, maintaining traditional markets and seeking new ones, access to Mt Cook/Aoraki under Treaty claims, increased aircraft noise affecting product quality and potential conflict with other user groups. Over the 1997/98 summer climbing season the writer will conduct research focussing on the clients of NZMGA guides.

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  • Customer Orientation in E-government: The Managers’ Perspectives

    Hannah, Polson; Theivananthampillai, Paul (2005)

    Conference paper
    University of Otago

    With the increasing focus on technology, the demand for the electronic provision of services is growing. Public sector organisations are beginning to consider whether they too should integrate technology into their operations, specifically with projects such as websites, intranets or systems for communication. This study aims to consider whether the implentation of e-government in a local public sector organisation has enabled this organisation to achieve their customer orientation in order to realise improved levels of performance. This study provides a number of useful insights. Firstly all managers appear to understand the customer orientation of the organisation and thus the importance of a focus on the customer. There seems to be a difficulty however of implementing this customer orientation in practice. The lack of effective customer measures means managers tend to focus on internal measures. While managers perceive there to be a number of potential benefits, the majority of these tend to be related to efficiency and the achievement of outputs. For departments with low customer orientation there is not likely to be a strong link between outputs and outcomes therefore there is a potential danger that technology will divert their attention away from the customer. While e-government may result in achievement of output objectives this are not necessarily conducive to achieving the organisations overall mission. In summary, the results of this study imply that despite the orientatation-performance link, e- government can provide benefits. These however are more likely to be related to operational efficienicy at low levels of customer orientation. In other cases, what gets measured is what gets done. For the real potential of e-government to be realised there must be a strong alignment of customer orientation and e-government. Managers must be clear as to what the overall mission is and how e-government can assist them in achieving this.

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  • The Use of Objective and Subjective Measures: Implications for Incentive System Design

    Stringer, Carolyn; Theivananthampillai, Paul (2009)

    Conference paper
    University of Otago

    This study examines the question, is the use of subjective measures an ex post adjustment of objective measures to take into account three types of risk: target difficulty (after controlling for budget loss), shared risk (after controlling for business unit strategy) and downside risk? We examine this question using data from a sample of 522 managers and professionals in period 0 (and 434 in period 1) from a large Australasian corporation over a two year period. Period 0 is a pre shock period and period 1 is a post shock period. We find that for the overall two years that the subjective is an upward adjustment to the objective to take into account: (1) target difficulty, the spread between upper limit and lower limit of unit performance; (2) shared risk, that is organizational interdependencies; and (3) downside risk, which is the opportunity loss function that the employees faced in not meeting the maximum bonus allowed. However, in examining the pre shock period and post shock period, the results indicate that the subjective evaluation has been used differently for each period for two type of risk (target difficulty, shared risk). (1) With regard to target difficulty for the pre shock period, the subjective makes an upward adjustment to the objective; but for the post shock, the subjective makes a downward adjustment. One plausible explanation is that during the post shock, quite a few managers and professionals were already on the maximum of the objective measures (given that there may have been gamesmanship at setting targets and upper limits for an anticipated poor economic period). Therefore, the subjective can be a downward adjustment to reflect this gamesmanship. (2) In regard to shared risk (the percentage of transfer revenues), for the pre shock period the subjective was a downward adjustment, while for the post shock period the subjective adjustment is an upward adjustment to the objective measure. This implies that for the pre shock or times of economic stability, the subjective could be used to reduce some of the free rider challenges that face incentive systems. Conversely for the post shock period, or during times of economic instability, the subjective adjustment is to encourage resource sharing and greater coordination and communication. Overall, our results indicate that the subjective measure is used as an ex post adjustment to the objective measure. This could be in response to flaws in the objective (financial) performance measures as subjective measures as this enables other factors to be taken into account.

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  • Using molecular genetics to gain insight into allopatric and sympatric speciation of topshells and their parasitic trematodes

    Donald, Kirsten; Spencer, Hamish (2003-12)

    Conference paper
    University of Otago

    Prevailing theory suggests that many parasite species have evolved in tight congruence with their hosts, with the parasite phylogeny mirroring that of the host. This theory is based largely on studies of host-parasite interactions between species where strong links would be expected. For example, the highly congruent evolutionary trees of procellariform seabirds and their feather lice (Paterson et al., 1993) are expected as oceanic seabirds breed in large, often monospecific, colonies and lice do not survive long away from their host. Consequently, in this case, there are few opportunities for host switching. Our research employs molecular techniques to test the theory of tight host-parasite congruence in a host-parasite system where high host specificity is not necessarily expected; Trochoidea (topshell snails) and digenean trematodes (flatworms). Due to the fine-scale sympatry of the topshell hosts and the complex life cycle of digeneans, the parasites are likely to encounter a range of potential hosts, allowing ample opportunity for host-switching. Topshells belonging to the genera Melagraphia and Diloma are ubiquitous in the New Zealand intertidal zone, with seven species currently recognised. Six of these species are endemic, the exception being D. nigerrima, which also occurs in Chile. Related topshells are found in other parts of the Pacific, most notably along the southern coast of Australia, where seven species are classified as belonging to the genus Austrocochlea. Despite different topshell species having slightly different ecological requirements, species may exist in sympatry e.g. during a preliminary study at Purakaunui Inlet, near Dunedin, six species were found within a 20 m radius. Melagraphia, Diloma and Austrocochlea are all potential first-intermediate hosts of digenean trematodes, which infest the snail’s digestive gland. During their life cycle digeneans usually parasitise three hosts. The second-intermediate and definitive hosts of these digeneans are unknown, but are likely to be a crustacean and a fish, respectively. Digenean eggs are shed into the water column in the faeces of the definitive host and so, due to the sympatric nature of topshell distribution, developing larvae are likely to encounter a number of potential host species and opportunities for host-switching are great. Topshell phylogeny is currently unresolved, with poorly defined generic boundaries and digenean phylogeny is even less well understood; digeneans which parasitise Melagraphia, Diloma and Austrocochlea consist of a single morphotype which has tentatively been placed in Opecoelidae (Clark, 1958; Miller and Poulin, 2001). Species assignments and phylogenies of both topshells and their digeneans trematodes are being resolved using DNA sequence data. Questions concerning the dispersal, biogeography and evolution of both host and parasite are being addressed by analysing this molecular data in conjunction with data on their geographic distributions. Ultimately the goal of this research is to answer questions about the co-evolution of topshells and their parasites, such as: are the two trees congruent? is there evidence of host-switching and host-addition?

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  • The Use of Objective and Subjective Measures: Implications for Incentive System Design

    Stringer, Carolyn; Theivananthampillai, Paul (2009)

    Conference paper
    University of Otago

    This study examines the question, is the use of subjective measures an ex post adjustment of objective measures to take into account three types of risk: target difficulty (after controlling for budget loss), shared risk (after controlling for business unit strategy) and downside risk? We examine this question using data from a sample of 522 managers and professionals in period 0 (and 434 in period 1) from a large Australasian corporation over a two year period. Period 0 is a pre shock period and period 1 is a post shock period. We find that for the overall two years that the subjective is an upward adjustment to the objective to take into account: (1) target difficulty, the spread between upper limit and lower limit of unit performance; (2) shared risk, that is organizational interdependencies; and (3) downside risk, which is the opportunity loss function that the employees faced in not meeting the maximum bonus allowed. However, in examining the pre shock period and post shock period, the results indicate that the subjective evaluation has been used differently for each period for two type of risk (target difficulty, shared risk). (1) With regard to target difficulty for the pre shock period, the subjective makes an upward adjustment to the objective; but for the post shock, the subjective makes a downward adjustment. One plausible explanation is that during the post shock, quite a few managers and professionals were already on the maximum of the objective measures (given that there may have been gamesmanship at setting targets and upper limits for an anticipated poor economic period). Therefore, the subjective can be a downward adjustment to reflect this gamesmanship. (2) In regard to shared risk (the percentage of transfer revenues), for the pre shock period the subjective was a downward adjustment, while for the post shock period the subjective adjustment is an upward adjustment to the objective measure. This implies that for the pre shock or times of economic stability, the subjective could be used to reduce some of the free rider challenges that face incentive systems. Conversely for the post shock period, or during times of economic instability, the subjective adjustment is to encourage resource sharing and greater coordination and communication. Overall, our results indicate that the subjective measure is used as an ex post adjustment to the objective measure. This could be in response to flaws in the objective (financial) performance measures as subjective measures as this enables other factors to be taken into account.

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  • A framework for a destination reputation management process: A case study of three destinations

    Ermen, David (2006-10-18)

    Conference paper
    University of Otago

    The thesis to be discussed in this paper is at the middle to late stage of development. Since the 2005 Otago PhD Colloquium I have completed the first stage of data collection and am currently analysing the data from this exploratory stage. This paper introduces PhD research into communications management in tourism destinations, where it is proposed that in order to manage the reputation of the destinations as a whole, proactive communication and cooperation between stakeholders is necessary. An application of network (Hakansson and Snehota 1995) theory to destinations provides the basis for the discussion of how effective communication facilitates the strategic interaction between relevant industry players and their stakeholders in order to develop a sustainable competitive advantage for the destination. Theories of corporate communications management (Cornelissen 2004; Goodman 2000) and reputation management (Fombrun and Shanley 1990; Fombrun 1996; Fombrun and Van Riel 2004; Greyser 1999) are used as examples of these processes in large corporate organisations. The key argument is that just like large corporate structures, tourism destinations need to communicate effectively, internally and externally, They are socio-economic organizations and their profit objectives need to be well balanced with the social and environmental concerns of stakeholders in order for tourism to be a legitimate method of economic development in regions that are dependent on it (Flagestad and Hope 2001). Therefore, it is necessary to see beyond the business networks that operate at a destination level and open the analysis to the interaction amongst all stakeholders that form parts of the social context in which economic action is embedded. Three comparative cases, Wanaka in New Zealand, Åre in Sweden and St Moritz in Switzerland are examined in two research stages to construct a model of communication dynamics amongst stakeholders within tourism destinations. The thesis aims to provide both theoretical contributions to strategic network management as well as tourism destination management and practical guidance for practitioners who are managing in the context of destination networks. The paper presented here will briefly introduce the relevant literature and then move on to a more detailed discussion of research propositions and methodological issues, which are presently most relevant to the development of the thesis. No results will be presented in this paper, since the data analysis is still in progress, but first results will be available for presentation at the Colloquium. For this reason, the paper is intended to provide an overview of what has been done so far and how it was done, so that discussants will be able to understand the results when they are presented. These results will provide the basis for a more detailed second round of data collection.

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  • Nitrogen species distribution in the Taieri Plain aquifer, New Zealand

    Kensington, Christopher; Richards, Katrina; Murray, Dave; Peake, Barrie (2003-12)

    Conference paper
    University of Otago

    Nitrogen contamination of drinking water has been linked to health risks including ‘blue baby syndrome’. In New Zealand, up to 51% of people use at least some groundwater for drinking, and there is growing concern that the rapid growth of intensive dairying may lead to aquifer contamination. The distribution of nitrogen species nitrate (NO3-), ammonium (NH4+), nitrite (NO2-) and organic nitrogen were measured in groundwater bores in the Taieri Plain aquifer, New Zealand, during March-November 2002. There was significant spatial variation in the concentration of nitrate and ammonium across the aquifer. Concentrations of nitrate were low in the confined aquifer in West Taieri, but high in unconfined bores in East Taieri and in bores in alluvial fans, i.e. where infiltration of surface runoff can occur. Ammonium showed the reverse pattern, i.e. low concentrations in the unconfined aquifer, and high concentrations in parts of the confined aquifer. Nitrite concentrations were low everywhere. Mean nitrate concentrations for confined and unconfined bores were well below the maximum limit for drinking water in New Zealand (11.3 ppm NO3-N), but in the unconfined zone some individual measurements approached or slightly exceeded this limit. Some individual measurements for ammonium species exceeded the aesthetic guideline for drinking water (1.2 ppm NH4-N). No temporal variations were seen in species concentrations over the relatively short time scale of the study, and there was little correlation between concentrations and bore depth. Fortuitously, the Waihola silt-sand unit protects the underlying aquifer and mitigates the potential for contamination in the areas where intensive dairying occurs on the Taieri Plain. The unconfined/semiconfined aquifer in East Taieri, and alluvial fan areas, are far more vulnerable to contamination from nitrogen species. Ideally, conditions and land use practices in these areas should be closely monitored and, perhaps, regulated.

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  • Object-oriented classification and Ikonos multispectral imagery for mapping vegetation communities in urban areas

    Mathieu, Renaud; Aryal, Jagannath (2005-11)

    Conference paper
    University of Otago

    The management of vegetated areas by urban planners relies on detailed and updated knowledge of their nature and distribution. Manual photo-interpretation of aerial photographs is efficient, but is time consuming. Image segmentation and object-oriented classifications provide a tool to automatically delineate and label vegetation units. Object-oriented techniques were tested with a very high-resolution multispectral Ikonos image to produce fine scale maps of vegetation communities in Dunedin (New Zealand). The Ikonos image was orthorectified and a first classification produced a map with 4 strata: industrial/commercial (with amenity pastures and tree groups), residential (with amenity pastures and private gardens), vegetation (with other vegetation classes), and water. A hierarchical network of image objects was built to extract vegetation patches of various sizes such as small private gardens and larger exotic plantations. The classification of the image objects was performed using the nearest neighbour (NN) method. Thirteen variables were considered to build the NN feature space, including mean object spectral value and standard deviation for each spectral band, and object compactness. The vegetation map was validated using an independent dataset collected in the field. The original classification scheme included 17 vegetation categories, of which ten were successfully discriminated: forests, exotic plantations, tree groups, exotic scrubs, mixed scrubs, native scrubs, pastures, amenity grasslands, rough grasslands, private gardens. Classes of ecological interest characterized by various canopy densities could not be discriminated (e.g. low and high density gardens, shrublands and scrubs). Vegetation patches smaller than 0.05 ha were efficiently extracted within the city. The overall classification accuracy was 92% and the kappa coefficient was 0.89 (i.e. 89% more accurate than a random classification). Object-oriented techniques and Ikonos imagery proved to be a promising technique to produce GISready vegetation map.

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  • A wave concept related to the 2nd law

    Hashmi, Dean (2004-11)

    Conference paper
    University of Otago

    Existing wave concepts are based on energy conservation (1st law) and on measurable variables like wavelength, amplitude, frequency or velocity which define the energy and the behaviour of waves in space and time. A wave concept related to the 2nd law treats living systems as self-propagating wavefronts. These wavefronts are defined by the degradation of energy per unit time and by constituent sets of lineages of information which are in the most abstract case defined by positions in one spatial dimension, relatedness along the time axis, masses, energy flux shares, mass-specific metabolic rates, and adaptability; if the adaptability of the lineages is constrained, it is necessary to define the conditions in multidimensional niche space which permit lineages to propagate. The dynamics of the wavefront is defined by the likelihood and magnitude of exchanges of energy flux shares between the lineages, the macroevolutionary drift of mass and drift of mass-specific metabolic rate, the ratio of energy flux share to metabolic rate in relation to thresholds for the dissipation and amplification of lineages, and by niche drift which can be replaced by spatial drift if adaptability is unconstrained. This concept allows to create an at its roots simple numerical physics, the difference between animate and conventional inanimate physics being a higher number of relevant dimensions and the replacement of constants by measurable variables. From the physical point of view, this concept, in which the evolutionary drift is the consequence of variable natural selection in combination with constrained adaptability and genetic drift, is not restricted to any particular form of life (i.e. mechanics of information storage or processing). Cellular automata permit to apply this concept to abstract as well as realistic settings so that the causation of patterns, which are drawn from large sets of lineages and based on the variables mentioned, can be studied in one to three spatial dimensions within multidimensional niche spaces under application of arbitrarily defined rules. In application to real systems, the strategy is to determine time-independent virtual equilibria based on measurable axioms, including the assumption of energy flux conservation, and to identify neglected facts (like time dependence, demographic or microevolutionary processes/phenomena) which explain differences between the virtual, purely macroevolutionary computer worlds and reality.

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  • Geostatistical modelling, analysis and mapping of epidemiology of Dengue Fever in Johor State, Malaysia

    Seng, Su Bee; Chong, Albert K; Moore, Antoni (2005-11)

    Conference paper
    University of Otago

    Dengue fever, and especially the life-threatening form - DHF is an infectious mosquitoborne disease that places a heavy burden on public health systems in Malaysia as well as on most of the tropical countries around the world. Various environmental factors such as rainfall, temperature, living conditions, demography structure domestic waste management and population distribution are important in determining the mosquito survival and reproduction. A geostatistical modelling, analysis and mapping approach has been utilised in this research to understand the correlation between dengue fever prevalence, population distribution and meteorological factor, and the characteristics of space-time clusters in the Johor State. By supplementing GIS with geostatistical analysis and space-time permutation scan statistic tools, the spatial variation of dengue incidence can be mapped. Geographical weighted regression (GWR) analysis has revealed a strong (R2= 0.87) positive spatial association between dengue fever prevalence and population distribution in the Johor State. The dengue prevalence is expected to be higher in densely populated urban area, such as in Johor Bahru: however, there is a “rule” change in the Johor Bahru sub-district due to the positive impact from a dengue control and prevention programme. GWR analysis has also identified that ten to 14 days of accumulative rainfall is sufficient to support the mosquito breeding cycle and the dengue virus incubation period (vector + host) in the Johor Bahru district is 15 days. Space-time clusters showed that dengue transmission is a contagious type as the spacetime extent is limited at 200m and 20 days and mainly involved household transmission. Results from this study reveal the ability of an augmented GIS surveillance system by incorporating the disease epidemiology and a geostatistical approach to provide reliable information for infectious disease management, control and surveillance. This research is the first study that has utilised GWR in infectious vector-borne disease, especially the attempt to “spatialise” the time in Hypothesis 2. In addition, it is also the first study which makes use of spatial-scan statistic permutation model to study the characteristics of dengue fever space-time clusters.

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