08221 Abstracts Collection -- Geometric Modeling

From May 26 to May 30 2008 the Dagstuhl Seminar 08221 ``Geometric Modeling\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available

Tire Wet-Pavement Traction Management for Safer Roads

The first part of this paper includes a summary of the most relevant studies on the relationship between accidents and indicators of tire-pavement traction. The results of this research are the basis for the design standards in various Countries in the world for the management of road surface and for defining threshold levels of skid resistance. The second part of this work proposes a review of levels of skid resistance for an existing road and introduces a relationship between the SFC (Sideway-Force Coefficient) parameter and road geometry (radius of curves, superelevation, design speed), and, consequently, with the demand of traction

Bituplaning a low dry friction phenomenon of new bituminous road surfaces

The potential for binder rich bituminous road surfaces to deliver low levels of dry friction was first noted in 1944. Using established test methods exploiting basic principles of physics first tested in criminal court in the 1940s (and still in use today) it has been possible to show statistically that modern negative textured road surfaces (NTS) deliver levels of dry friction significantly below those considered typical by collision investigators for the more traditional positive textured surfaces (PTS). NTS surfaces are shown to perform relatively worse in the absence of ABS (Anti-Blockier System, Anti-lock braking) than PTS equivalents such as Hot Rolled Asphalt (HRA). Skid tests undertaken on DRY NTS surfaces with ABS braking have been shown to manifest momentary low levels of deceleration similar to those experienced during NOABS tests on the same surfaces and to generate dash like skid marks atypical of ABS tests on DRY PTS surfaces. The ratio of peak to sliding friction also appears lower for dry NTS surfaces than for Dry PTS surfaces documented in the literature.Using high-speed video and false colour infrared imaging it has been possible to see the low friction phenomenon termed “bituplaning”. Vehicles equipped with ABS have also been shown to suffer momentary “bituplanes” resulting in less than optimum performance. Tyre deformation during dry skidding on NTS appears reduced in relation to a PTS equivalent.<br/

Use of local available material for inverted pavement technique

This research has the purpose to build infrastructures by using new techniques, new materials and to start a sustainable design with the utilization of local resources. The project also aims to minimize the use of non-renewable sources as hot mix asphalt. Concerning the materials, it is particularly highlighted the use of stone materials available in the Region of Sardinia, currently extracted to create infrastructures and bitumen layers. New techniques have been studied to build up infrastructures such as the Inverted Pavement Technique used in South Africa for more than 30 years. In particular we focused on the realization of the G1 Layer for this paving. Through this work, we are willing to determine the possible use of the materials present in Sardinia to build Inverted Pavement infrastructure. The target is to better use the local obtainable resources in terms of aggregates, trying to make the most of their mechanical and physical features. During the research, a great attention was focused on the illustration of different typologies of paving currently used in Europe and in South Africa, specially those realized through base layers with granular material, examining in depth the anisotropic property of granular bases too. A panoramic of the property of road construction material used in South Africa is presented, by analyzing the issues linked to the type of minerals that are in the rocks and the way through which they affect the resistance and durability of one layer of the paving. In the first phase of the study, we concentrated on the specification of the kinds of materials mined in Sardinia and their location. Then, we chose to investigate about the following materials: andesite, basalt, quartzite, trachite, dolomite and ignimbrite. All these are materials with good features such as mechanical endurance and durability. An in-depth bibliographic research was done about the 'Inverted Pavement’ technique for understanding the behavior of this type of paving during the useful life, compared to a traditional paving. The building technique of the G1 layer was mainly examined, because some phases, such as that called "slushing", are considered complex and the main point for the good result of layer and the whole superstructure. To make sure the material is suitable, we referred to South-African regulations and we carried all the mechanical tests foreseen to categorize it as G1. Chemical analyses and thin sections were analyzed, because they are considered preliminary characterizations on the study of materials. Some triaxial tests were performed with several confining pressures to define the elastic modulus and other strength parameters.Anyway it is not enough to comparison chemistry and petrography to establish that a material is suitable. For this reason, were done other physical-mechanical laboratory tests. Two test sections of Inverted Pavements realized in Atlanta, using granite, were examined and were done some laboratory tests on material. From the monitoring of these two test sections and from the result of tests, it emerged that Inverted pavement has performances greater than conventional paving and that other kinds of materials can be used for realization

Achieving holistic sustainability in Chinese and New Zealand business partnerships : an integrative approach : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Management at Massey University, Albany, Auckland, New Zealand

Tensions in sustainability are a relatively new area and largely unexplored empirically between firms in collaborative business partnerships, particularly drawing from paradox theory and organisational ambidexterity theory. If these tensions cannot be understood and addressed adequately, it will not only have negative impacts on individuals’ interests, but also on the development of organisations and ultimately the prosperity of the society. Hence, this study examines empirically how tensions in addressing divergent sustainability issues arise, and are perceived and managed between Chinese and New Zealand firms in business partnerships. Guided by an interpretivist philosophy, this research adopts a qualitative and abductive approach as the preferred research method. In doing so, 33 in-depth individual interviews alongside one informal group discussion were carried out at 16 relatively large Chinese and NZ firms known for their commitment to sustainability that are in business partnerships. This thesis includes three empirical chapters. The first findings chapter identifies tensions in sustainability between Chinese and New Zealand firms and discovers the reasons for them. The findings reveal that the Chinese and New Zealand firms in business partnership are faced with complex and multiple sustainability tensions which are thus more difficult and challenging for them to address simultaneously. This chapter also shows that the tensions are caused by an integration of multiple reasons from individual, organisational and national levels. The second findings chapter explores how managers make sense of these tensions. The results delineate four kinds of managerial logic – paradoxical, contradictory, business and defensive – which are applied to make sense of different kinds of tensions. In contrast to prior studies, the findings reveal that paradoxical logic is the most common logic adopted by the managers at Chinese and NZ companies in business partnerships; as the other types – contradictory, business and defensive logic – are not commonly used. The third findings chapter investigates the strategies that Chinese and NZ firms adopted to manage the tensions in their business partnerships. The findings show two main approaches: trade-off and integrative. This research highlights that working through sustainability tensions using integrative approaches can bring proactive outcomes which will help these companies to advance their sustainability practice through inter-organisational learning, to enhance their mutual understanding and to strengthen their business partnerships over time, thus achieving holistic sustainability. This research contributes to scholarly understanding of tensions in sustainability between firms in collaborative business partnerships in relation to the nature of the tensions, reasons for the tensions, managerial sensemaking of tensions and the strategies for managing the tensions. This also adds value to paradox theory and organisational ambidexterity theory including structural and contextual ambidexterity, and their theoretical and practical implications for tensions in sustainability research