1,515 results for Conference paper

  • The effect of vapour-control membrane technology on indoor air quality in buildings

    Berry, Terri-Ann; Chiswell, Jordan H.D (2015-11)

    Conference paper
    Unitec

    The impact of the inclusion of a vapour check membrane in timber buildings on indoor air quality, measured as volatile organic compounds (VOCs), was determined by Photo Ionization Detection. Two identical buildings were constructed except one building (test) contained an Intello vapour check membrane and the other building was the control. A VOC source (Wattyl Estapol High Performance Interior Clear Polyurethane Satin varnish) was placed in each building and the subsequent concentrations were monitored until background levels were resumed. Data analysis demonstrated that the VOC levels in the test house were consistently higher than those established in the control house (student t-test > 99.9% confidence). Average concentrations for VOC, temperature and relative humidity respectively were 3.23 ppm (control), 6.54 ppm (test); 17.3°C (control), 17.4°C (test) and 52.4% (control) and 54.7% (test). The humidity was also significantly higher in the test house (student t-test >99.9% confidence). Originally temperature differences were not found to be statistically conclusive; however this appeared to have been because the diurnal pattern of the temperature profile masked the difference in temperature. By removing this diurnal pattern, the temperatures in the houses were found to be significantly different over a 7 day timescale (student t-test >99.9% confidence). Diurnally, there was a strong link between VOC concentration and temperature and an inverse relationship with relative humidity. The use of the vapour control membrane had a significant effect on the indoor air quality of the buildings (based on the concentration of VOCs) which may have been due to: (1) the increased temperature and humidity, (2) the change in air flow from outside the buildings or (3) a combination of all three factors. There is a strong link between VOC concentration and temperature within the houses which may explain the highly variable profile of VOC concentration with time. An inverse relationship was observed with relative humidity.

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  • Understanding water quality in Raglan Harbour

    Greer, S. D.; McIntosh, R.; Harrison, S.; Phillips, David; Mead, S. (2015-09)

    Conference paper
    Unitec

    Raglan (Whaingaroa) Harbour is located on the west coast of New Zealand’s North Island and is bordered by the Raglan township on the southern side close to the entrance. Land use in the watershed is dominated by dairy farming and forestry, which impact harbour water quality. A consented wastewater outfall is located at the harbour mouth close to the densely developed and populated area of the catchment. Over the years, there have been a number of reported spills and unlicensed releases from the treatment facility into the harbour. However, there is little context of the scale of the operation, and of the spills, against contaminant levels from inflowing rivers which are affected by land use practices. We address these uncertainties using a numerical modelling approach. Here we present a calibrated hydrodynamic model linked to a 13-river catchment model. Both of these models are used to drive a subsequent water quality model which simulates the transport and decay of Faecal Coliforms (FC) in the harbour. Model runs include a yearlong simulation of 2012 in its entirety, as well as a wastewater spill event that occurred in June of 2013. Results illustrate the seasonality of the water quality in the harbour with the largest concentrations of FC occurring in winter. It also illustrates the large scale influence of the rivers relative to the outfall with regards to FC concentrations. However, uncertainties remain in the FC component of the water quality model which needs to be addressed in future work

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  • Application of climate change adaptation, resilience, and beach management strategies on coral Islands

    Mead, Shaw; Borrero, Jose; Phillips, David; Atkin, Ed (2015-09)

    Conference paper
    Unitec

    Small Island Developing States (SIDS) are particularly vulnerable to climate change, climate variability and sea level rise. For many island nations, the very existence of some low-lying islands and their associated communities are threatened. International aid funds are now being applied to the development of climate change adaptation and resilience measures on coral islands worldwide. In many areas, identification of vulnerable sites and planning has been completed and climate change adaptation and resilience measures are being implemented. These measures are often directed at ‘buying time’ to develop long-term relocation strategies. However, the coastal processes on coral sand beaches and coasts are significantly different to temperate coasts. There is comparatively little information available that considers the design and application of coastal structures and the associated components of coastal climate change adaptation and resilience measures for coral beaches. Additional challenges include isolation and the lack of suitable equipment and materials with which to implement climate change resilience and adaptation strategies. This paper presents the investigations, detailed designs and implementation of climate change adaptation and resilience measures in Tonga, the Marshall Islands and Mauritius, as well as the development and application of beach management strategies in other parts of the Pacific Islands. There is a common theme between the development of climate change adaptation and resilience measures and beach management strategies for these coral sand beaches with respect to coastal processes and the physical and biological components that produce and transport sand in these systems. Coupling of physical/biological and social/terrestrial/coastal factors is an important consideration for the successful application of coastal strategies on coral sand beaches. The measures that are being applied to the different sites, in order to work with their site specific variables, are detailed.

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  • Challenges facing BIM education : development of BIM resources for teaching and learning

    Puolitaival, Taija; Forsythe, Perry; Kähkönen, Kalle (2015-07)

    Conference paper
    Unitec

    Building Information Modelling (BIM) is becoming the new norm in the AEC industry and also part of many construction project management (CPM) programmes. In terms of teaching BIM there is the need for specific resources in explaining the theoretical principles of BIM, BIM tools (authoring, audit and analysis) and building models themselves. Theoretical resources that are available for education in the form of books, articles and websites are easy and straightforward to locate. Likewise a good share of various tools are available for educational purposes. On the other hand, actual building models represent a challenge in terms of preparing and optimising usage of the model for high quality educational purposes. This paper addresses the difficulty inwalking the narrow line between an industry ready BIM versus a BIM that is good for student learning and offers a realistic and practical, but simultaneously achievable learning environment. Conducting a case study in an undergraduate CPM education setting, three approaches for obtaining BIM resources were identified with various challenges and benefits. A combination of internally developed models for early exposure and industry models for later courses is proposed.

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  • How will NZ's construction industry escalate productivity to meet the largest predicted construction demand in decades - is a lean approach one of the magic bullets?

    Bosnich, Anthony; Kestle, Linda (2015-12)

    Conference paper
    Unitec

    Low productivity levels for at least twenty years in New Zealand’s construction industry have only realised any improvement by increasing hourly inputs, (a 0.2% per annum rise since the 1990’s). NZ’s Productivity Commission in 2010, and the NZ Sector Report by Minister Joyce in 2013, regards increased productivity in the construction industry as essential for the benefit of all New Zealanders, as it affects the Gross Domestic Product, employment rates and living conditions. The construction industry employs around 170 000 people, and predictions are that there will be unprecedented building and construction growth over the next 5-10 years, due in the main to Auckland’s predicted 25% population growth by 2025, and Christchurch’s rebuild following the major earthquakes four years ago. Auckland will see a 68% increase in new building according to Minster Joyce (2013) outstripping Christchurch’s rebuild demands over the same period. The paper investigated how to potentially and realistically increase productivity and business performance, across design and construction management in the New Zealand Construction Industry, over the next decade or so. An in-depth and critical analysis of relevant international journals, conference papers, and New Zealand government agency and non-agency publications was undertaken. The key findings included a very strong recommendation that senior management personnel in the construction industry need to fully implement a lean management approach in the NZ productivity context, that is then driven by full consultant and on-site employee involvement and ownership.

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  • Simulation model, warm-up period, and simulation length of cellular systems

    Kolahi, Samad (2011-01-25)

    Conference paper
    Unitec

    In this paper, discrete event simulation by batch-means of a M/M/∞ queuing system is utilised to simulate a cellular CDMA system. The details of the simulation model, warm-up period, and simulation run time are discussed. The warm-up period is studied because it affects the accuracy of the results in simulation of communication systems. During the warm-up period-when the simulation system has not reached the steady-state situation-, the system results (eg blocking probability) vary very rapidly from zero to 0.037 for the parameters used. In the batch-means method with 10,000 calls per batch and for 50 batches (500,000 calls), the CDMA blocking probability is 0.0192 with 99% confidence interval.

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  • Bandwidth-IPSec security trade-off in IPv4 and IPv6 in Windows 7 environment

    Kolahi, Samad; Cao, Yuqing (Rico); Chen, Hong (2013-11-12)

    Conference paper
    Unitec

    Due to overheads of security algorithms used in IPSec, transferring data using IPSec is known to be significantly slow compared with open system. In this paper, we present new results on performance of IPSec using 7 encryption systems for both IPv4 and IPv6 using Windows 7 and wireless network access. For the system studied, enabling IPSec results in approximately 60% (IPv4) and 48% (IPv6) less TCP throughput compared to open system. Among encryption mechanisms, 3DES-SHA provides the highest TCP bandwidth for IPv4, while 3DES-MD5 gives the best result for IPv6. We also provide the results for UDP.

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  • Evaluation of IPv6 with IPSec in IEEE 802.11n Wireless LAN using Fedora 15 Operating System

    Kolahi, Samad; Cao, Yuqing (Rico); Chen, Hong (2013-07-07)

    Conference paper
    Unitec

    IPSec (IP Security) is a robust technique for securing communications over the Internet. Due to security algorithms used, transferring data using IPSec is known to be significantly slow. In this paper using a test bed environment for a site to site IPSec, we present new results on performance of IPSec for both IPv4 and IPv6 using Fedora 15 operating system and wireless network. Compared to open system, enabling IPSec results in approximately 50% and 40% less throughput for IPv4 and IPv6 networks respectively.

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  • The impact of wireless LAN security on performance for different windows operating systems

    Kolahi, Samad; Narayan, Shaneel; Nguyen, Du D.T.; Sunarto, Yonathan; Mani, Paul (2008-07-09)

    Conference paper
    Unitec

    This paper investigates the impact of various encryption techniques (WEP-64, WEP-128 and WPA) on performance of wireless LANs for Windows operating systems (Windows Server 2003, Windows XP and Windows Vista) and for both TCP and UDP protocols. The parameters considered are throughput and response time. The results indicate that security mechanism does influence the wireless performance and different operating systems provide various results.

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  • The tempered edge : waterfront development in an age of climate change.

    Bradbury, Matthew (2014-06)

    Conference paper
    Unitec

    Urban waterfront development has followed the Baltimore waterfront model since the 1970s. This model is characterised by the formation of a thin promenade of public space with carefully choreo- graphed event architecture, behind which lies retail, commercial and residential development. The sustainability of this model has recently been called into question by the consequence of climate change manifested in recent storm events such as Hurricane Sandy. This paper proposes an alternative waterfront design model, one that builds environmental resilience into the typical waterfront development while still generating the expected real estate returns. The author expounds a development methodology using hydrologically modelling tools to measure the production of urban stormwater within the larger urban catchment. Modelling different scenarios, especially the implications in the increase of pervious surfaces, suggests a way in which the contemporary waterfront can become more resilient to the consequences of climate change while at the same time retaining an expected commercial return. A test case site is used to model the proposed methodology. The results show that to accommodate the hydrological consequence of climate change a radically reconfigured master plan must be adopted.

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  • Wealth with green : lessons with exemplary green enterprise

    Mellalieu, Peter (2015-12)

    Conference paper
    Unitec

    The paper reports progress on the launch of a project to empower a multidisciplinary faculty of students and teachers to implement practical actions towards improving environmental sustainability in their multiple contexts. The project focusses on drawing lessons FOR and WITH SMEs who have the ambition to achieve a zero or positive environmental impact as a by-product (or product) of their operations. The rationale for the project is that many efforts to pursue environmental sustainability are insufficient to address the true environmental challenges that face societies. The paper concludes by challenging educators to adopt Education for Sustainability enabling every graduate to think and act as a sustainable practitioner in their employment, their household, their communities, and their professional discipline.

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  • Bring your own device classroom : issues of digital divides in teaching and learning contexts

    Adhikari, Janak; Mathrani, Anuradha; Parsons, David (2015-12)

    Conference paper
    Unitec

    Technology mediated learning provides potentially valuable resources for learners’ academic and social development. However, according to recent researches, as the adoption stages of ICTs advance there arises further levels of digital divides in terms of equity of information literacy and learning outcomes. For the last three years we have been working with one of the earliest secondary school in New Zealand to introduce a Bring Your Own Device (BYOD) policy. Our research has included a number of methods, including surveys, interviews and classroom observations. In this paper we present the findings from the investigation into BYOD project, which offers new insights into the digital divide issues in the context of technology mediated learning. Teaching and learning practices are evolving continually across formal and informal spaces, and this study informs us how the BYOD policy has influenced existing divides in the learning process.

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  • Are higher education institutions delivering customer satisfaction?

    de Jager, Johan W.; Jan, Muhammad Tahir; Hebblethwaite, Denisa (2015-12)

    Conference paper
    Unitec

    Higher education institutions are realising the importance of a customer centred approach to survival in the face of increased domestic competition and the globalisation of higher education. The objective of the study is to determine the impact of different variables on customer satisfaction in the higher education sector. More explicitly, this study aims to identify the effects of: support facilities and infrastructure; location and access; and image and marketing on customer satisfaction. A random sample of 390 students was chosen. A review of the structural model indicates that only the impact of ‘support facilities and infrastructure’ on customer satisfaction can be supported statistically.

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  • WPA2 security-bandwith trade-off in 802.11n peer-peer WLAN for IPv4 and IPv6 using Windows XP and Windows 7 operating systems

    Kolahi, Samad; Li, Peng; Safdari, Mustafa; Argawe, Mulugeta (2012-07-01)

    Conference paper
    Unitec

    In this paper, we present new results on the performance of IEEE 802.11n using open system (no security) and WPA2 security for Windows XP and Windows 7. Enabling WPA2 security results in approximately 4.4 Mbps less TCP throughput than open system for both IPv4 and IPv6 on Windows XP and up to 2.8 Mbps less TCP throughput for Windows 7. For both open system and WPA2 security, Windows 7 provides higher IPv4 and IPv6 bandwidth than Windows XP and IPv4 provides higher bandwidth than IPv6.

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  • Performance evaluation of virtual private network protocols in Windows 2003 environment

    Narayan, Shaneel; Kolahi, Samad; Brooking, Kris; de Vere, Simon (2008-12-20)

    Conference paper
    Unitec

    Virtual Private Network (VPN) is a technology that provides secure communication for data as it transits through insecure regions of information technology infrastructure. With prolific development of the Internet, businesses nowadays implement VPN tunnels using different protocols that guarantee data authenticity and security between multiple sites connected using public telecommunication infrastructure. VPN provides a low-cost alternative to leasing a line to establish communication between sites. In this research we empirically evaluate performance difference between three commonly used VPN protocols, namely Internet Protocol Security (IPSec), Point-to-Point Tunneling Protocol (PPTP) and Secure Socket Layer (SSL). We compare performance differences in these protocols by implementing each using different algorithms in a Windows Server 2003 environment. Results obtained indicate that throughput in a VPN tunnel can range from approximately 40 to 90Mbps depending on the choice of protocol, algorithm and window size. These three attributes also govern CPU utilization of VPN servers.

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  • Peace without Perfection: The intersections of Realist and Pacifist thought

    Moses, J. (2015)

    Conference paper
    University of Canterbury Library

    It is generally assumed that realist political thought is the polar opposite of pacifism on questions of war and peace. In debates over the justifiability of violence in response to physical threats to ourselves or to others, pacifists will generally be confronted with ‘realistic’ analogies of personal self-defence against an assailant or to what are seen as the most obvious and compelling examples of ‘just wars’ from human history. Thus, as Duane Cady puts it, ‘[e]ntertaining pacifist thoughts means being prepared repeatedly to face questions about reacting to a mugger and confronting Hitler as well as being realistic, self-righteous, and self-sacrificial’ (Cady, 1989, p. 95). Thus, in constructing his ‘moral continuum’ from ‘warism to pacifism’, Cady himself places ‘war realism’, the view that ‘war itself is not an appropriate object of moral consideration’, at the ‘most extreme’ end of his spectrum. Realist views on war, therefore, are seen as being more distant from and irreconcilable with pacifist thinking than the via media of ‘just-warism’ (Cady, 1989, pp. 21-23). As a consequence of this kind of thinking, it is generally assumed that pacifists at the ‘pragmatic’ or ‘realistic’ end of the scale will normally allow for the possibility of fighting just wars in certain limited circumstances, as has been the case in just war theory from Augustine onwards. In contrast to this popular view, this paper will propose that the realist placing of war outside of questions of morality and justice actually has more in common with a pacifist position than is normally acknowledged and that this connection could be more fruitfully developed. Just war theory, from this point of view, represents a proliferation of malleable moral arguments for war that are not available from a realist perspective, which is deeply concerned with the limiting of moral arguments in favour of war for demonstrably ethical reasons. Yet this still leaves a number of important questions to consider. First and foremost, if we accept that the world is and always will be an imperfect place, as any realist thinker must, is there still any sense – or even any consistent possibility – in maintaining an opposition to all war? How does the realist reading of the imperfectability of man relate to problems of politics and war? And how might those theoretical claims connect to a politics of non-violence or pacifism?

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  • How do you like your BIM?

    McGarrigle, Malachy (2015-07)

    Conference paper
    Unitec

    This paper’s objective is to investigate what practitioners across various disciplines in NZ construction including academia expect to find in BIM models. What specific information do they actually want from models and can this be provided in reality? Traditionally building designers received and developed client briefs to help produce successful designs but it seems not enough time is spent presently at BIM briefing stages determining what information is explicitly required from digital models, producing frustrating results for end users expecting to find selective, productive information embedded therein. This situation arises in academia also where some BIM endeavours investigate its’ potential as an educational tool. However, if lecturing colleagues fail to adequately brief model authors on how the final model will be used pedagogically, it will inevitably fail to benefit teaching as envisaged. At the moment it appears not enough BIM briefing is actually taking place across the New Zealand construction industry nor sufficient use made of published guidance. Helping people better express their BIM requirements at briefing stage, exploring their feasibility for present and future work roles should result in more effective briefing of BIM authoring colleagues. Hopefully leading to more valuable, information rich models benefitting the entire construction sector.

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  • Biculturalism in New Zealand correctional facilities

    Laidlaw, Reagan; Schnoor, Christoph (2015-07)

    Conference paper
    Unitec

    In New Zealand architecture, notions of biculturalism have been addressed in a slowly increasing manner over the past 30 years. But has architecture in New Zealand taken these notions seriously in institutions, such as correctional facilities, as well? The introduction of the term biculturalism was first linked to New Zealand architecture during the 1970s. This was a period where the significance of Māori art and culture was becoming apparent in New Zealand. This was due largely in part to the migration of Māori from rural areas to the cities, prior to the 1980s, which also coincided with an overall increase in the Māori population. Some bicultural ideas have been incorporated into New Zealand architecture, and this can be seen through notable examples such as John Scott’s Futuna Chapel (1961) and the Māori Battalion Building (1964), however, biculturalism is only recently being seen in institutional architecture around New Zealand. Correctional facilities Ngawha (2005) and Spring Hill Corrections Facility (2007) by Stephenson & Turner have incorporated spatial and design qualities into their designs which are intended to rehabilitate inmates through directly relating to their cultures and beliefs to engage mental, physical and spiritual recovery. This paper suggests that the marae, the traditional Māori meeting house (as one of the few stable remnants of Māori culture over the centuries), has had an effect on the development of bicultural notions in New Zealand prisons. Building on an historical overview of bicultural aspects over the last 150 years, this paper focuses on the recent prison design of Ngawha in Northland in order to trace how notions of biculturalism have been addressed, taking into account the importance of the marae for Māori culture.

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  • Ernst Plischke and the Dixon Street Flats

    Schnoor, Christoph (2015-07)

    Conference paper
    Unitec

    Ernst Plischke’s life and work have been thoroughly researched and written about. However, one crucial moment still remains uncertain – and it seems that, for New Zealand Architectural History, much hinges on this one uncertain episode: the project in question is the first high-rise housing block in Wellington of 1942, the Dixon Street Flats. New Zealand-based architectural historians have spent much time and effort to establish the facts, asking: was the project mainly designed by Ernst Plischke, or by the Head of the Department of Housing Construction, Gordon Wilson? Linda Tyler did not question Plischke’s version of the events. Later, Robin Skinner has argued one way, Julia Gatley the other way. It is Plischke’s position within the Department of Housing Construction that is the cause for this uncertainty. As the department’s head, Gordon Wilson was responsible for the buildings designed in the department. And as such, he received a New Zealand Institute of Architects Gold Medal for the Dixon Street Flats in 1947. The bigger issue behind this one event is whether modernist architecture in New Zealand did develop from ‘within’ or whether it was mostly introduced via the input from European emigrants, specifically Ernst Plischke. Through the study of private archival material and through the revisiting of published and unpublished material, this paper extends the current knowledge on the circumstances of the designs of the Dixon Street Flats and other projects by the Department of Housing construction, thus adding to the larger lines of development of modern architecture in New Zealand, and to aspects of Ernst Plischke’s involvement with the project of state modernisation in New Zealand.

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  • Effect of WPA2 Security on IEEE 802.11n bandwidth and round trip time in peer-peer wireless local area networks

    Li, Peng; Kolahi, Samad; Safdari, Mustafa; Argawe, Mulugeta (2011-03-22)

    Conference paper
    Unitec

    In this paper 802.11 wireless peer-peer network is evaluated for both IPv4 and IPv6 in Windows 7 and Fedora 12 operating systems. IPv4 has higher throughput than IPv6 for all packet sizes for both Windows 7 and Fedora 12 operating systems. Results further indicate that implementing WPA2 wireless security reduces bandwidth and increase delay in wireless networks.

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