Milatz M.,University of Management and Technology
Unsaturated Soil Mechanics from Theory to Practice - Proceedings of the 6th Asia-Pacific Conference on Unsaturated Soils | Year: 2016
The Soil-Water Characteristic Curve (SWCC) is a basic function of unsaturated soil behaviour. It is essential for the understanding of effective stress in unsaturated soils and for unsaturated flow behaviour. Therefore, the experimental determination of the SWCC is an important issue of research. This task is often time consuming and in many cases, using standard test methods, only the main branches for either drying or wetting can be determined. For some types of soil however, the SWCC encounters rigorous hysteretic behaviour, which is of importance when cyclic flow occurs. Therefore, also test data on hydraulic hysteresis and the scanning curves is needed. In this paper an experimental method is presented, which allows to determine the SWCC of a coarse grained soil in a transient way, taking hysteresis into account. The method applies a flow of water volume to a small soil specimen, subjected to atmospheric air pressure at the top. This allows to prescribe monotonic or cyclic drying or wetting paths in the degree of saturation-suction space. While the degree of saturation can be calculated from the prescribed water outflow, the soil suction is simultaneously measured on top of the specimen using a miniature tensiometer.As a result of the test the SWCC can be obtained as well as different scanning paths and their slope δSr/δs, which is especially important for the development of hydraulic hysteresis models. © 2016 Taylor & Francis Group, London.
Jordan A.,University of East Anglia |
Huitema D.,VU University Amsterdam |
Huitema D.,University of Management and Technology
Global Environmental Change | Year: 2014
States have been widely criticized for failing to advance the international climate regime. Many observers now believe that a "new" climate governance is emerging through transnational and/or local forms of action that will eventually plug the resulting governance gaps. Yet states, which remain oddly absent from most discussions of the "new" governance, will remain key players as governance becomes more polycentric. This paper introduces a special issue that explores the ability of states to rise to these interconnected challenges through the analytical prism of policy innovation. It reveals that policy innovation is much more multi-dimensional than is often thought; it encompasses three vital activities: invention (centering on the 'source' of new policy elements), diffusion (that produces different 'patterns' of policy adoption), and the evaluation of the 'effects' that such innovations create in reality. The papers, which range from qualitative case studies to large '. n' quantitative studies, offer new insights into the varied roles that states play in relation to all three. They show, for instance that: the policy activity of states has risen dramatically in the past decade; that state innovation is affected to similar degrees by internal and external factors; and that policies that offer flexibility to target groups on how to meet policy goals are most effective but that voluntary reporting requirements are ineffective. This paper draws upon these and many other insights to offer a much more nuanced reflection on the future of climate governance; one that deservedly puts states at the front and center of analysis. © 2014 The Authors.
Karpf C.,University of Management and Technology |
Krebs P.,University of Management and Technology
Water Research | Year: 2011
The management of sewer systems requires information about discharge and variability of typical wastewater sources in urban catchments. Especially the infiltration of groundwater and the inflow of surface water (I/I) are important for making decisions about the rehabilitation and operation of sewer networks. This paper presents a methodology to identify I/I and estimate its quantity. For each flow fraction in sewer networks, an individual model approach is formulated whose parameters are optimised by the method of least squares. This method was applied to estimate the contributions to the wastewater flow in the sewer system of the City of Dresden (Germany), where data availability is good. Absolute flows of I/I and their temporal variations are estimated. Further information on the characteristics of infiltration is gained by clustering and grouping sewer pipes according to the attributes construction year and groundwater influence and relating these resulting classes to infiltration behaviour. Further, it is shown that condition classes based on CCTV-data can be used to estimate the infiltration potential of sewer pipes. © 2011 Elsevier Ltd.
Kuo T.C.,University of Management and Technology
Robotics and Computer-Integrated Manufacturing | Year: 2010
Recycling of waste electrical and electronic equipment (WEEE) is a very important subject not only from the viewpoint of waste treatment but also from the viewpoint of recovery of valuable materials. In the past, some obstacles make recycling challenging for today's manufactured products. First, it is difficult to gain all the information necessary to plan for the recycling evaluation, as most design information is owned and kept by suppliers. Another problem in recycling end-of-life (EOL) products is a lack of technologies to handle the very complex products that are being discarded today, because the knowledge of how to do so is owned by the recycler. This research demonstrates how to support WEEE recycling analysis by environmental information with the part of bill of material. A collaborative-design platform is further constructed and collected all the needed information using computer-aided design (CAD), enterprise resource planning (ERP), and product life-cycle management (PLM) systems. Through this platform, suppliers are required to provide component information to enable the manufacturer's design for disassembly and recycling analysis. The results demonstrate that designers can obtain disassembly and recycling information through the model, so that desirable changes can be made in the early stages of a design. An industrial case study from Taiwan is also provided to demonstrate the use of this model. © 2009 Elsevier Ltd. All rights reserved.
Pucker T.,University of Management and Technology |
Grabe J.,University of Management and Technology
Computers and Geotechnics | Year: 2012
Numerical simulations of the installation process of full displacement piles are presented. A Coupled Eulerian-Lagrangian approach is used to simulate the installation process. The influence of different ratios between the rotational and the penetration velocity are analyzed. A hypoplastic constitutive model is used to match the soils behavior realistically. The reaction forces of the drilling tool are determined. Furthermore, the influence of the surrounding soil is investigated. The displacements nearby the drilling tool are analyzed as well as changes of the stress state and the bulk density. The numerical results are used to explain the effects in the soil, that were observed during in situ measurements. © 2012 Elsevier Ltd.
Burkhardt M.,University of Management and Technology |
Busch G.,University of Management and Technology
Applied Energy | Year: 2013
A new method for the methanation of hydrogen and carbon dioxide is presented. In a novel anaerobic trickle-bed reactor, biochemical catalyzed methanation at mesophilic temperatures and ambient pressure can be realized. The conversion of gaseous substrates by immobilized hydrogenotrophic methanogens is a unique feature of this reactor type. The already patented reactor produces biogas which has a very high quality (cCH4=97.9vol%). Therefore, the storage of biogas in the existing natural gas grid is possible without extensive purification. The specific methane production was measured with P=1.17NmCH43/(mR3d). It is conceivable to realize the process at sites that generate solar or wind energy and sites subject to the conditions for hydrogen electrolysis (or other methods of hydrogen production). The combination with conventional biogas plants under hydrogen addition to methane enrichment is possible as well. The process enables the coupling of various renewable energy sources. © 2013 Elsevier Ltd.
Busse R.,University of Management and Technology |
Blumel M.,University of Management and Technology
Health systems in transition | Year: 2014
This analysis of the German health system reviews recent developments in organization and governance, health financing, health care provision, health reforms and health system performance. In the German health care system, decision-making powers are traditionally shared between national (federal) and state (Land) levels, with much power delegated to self-governing bodies. It provides universal coverage for a wide range of benefits. Since 2009, health insurance has been mandatory for all citizens and permanent residents, through either statutory or private health insurance. A total of 70 million people or 85% of the population are covered by statutory health insurance in one of 132 sickness funds in early 2014. Another 11% are covered by substitutive private health insurance. Characteristics of the system are free choice of providers and unrestricted access to all care levels. A key feature of the health care delivery system in Germany is the clear institutional separation between public health services, ambulatory care and hospital (inpatient) care. This has increasingly been perceived as a barrier to change and so provisions for integrated care are being introduced with the aim of improving cooperation between ambulatory physicians and hospitals. Germany invests a substantial amount of its resources on health care: 11.4% of gross domestic product in 2012, which is one of the highest levels in the European Union. In international terms, the German health care system has a generous benefit basket, one of the highest levels of capacity as well as relatively low cost-sharing. However, the German health care system still needs improvement in some areas, such as the quality of care. In addition, the division into statutory and private health insurance remains one of the largest challenges for the German health care system, as it leads to inequalities. World Health Organization 2014 (acting as the host organization for, and secretariat of, the European Observatory on Health Systems and Policies).
Shehzad K.,University of Management and Technology
IEEE Transactions on Knowledge and Data Engineering | Year: 2012
Discretization is a critical component of data mining whereby continuous attributes of a data set are converted into discrete ones by creating intervals either before or during learning. There are many good reasons for preprocessing discretization, such as increased learning efficiency and classification accuracy, comprehensibility of data mining results, as well as the inherent limitation of a great majority of learning algorithms to handle only discrete data. Many preprocessing discretization techniques have been proposed to date, of which the Entropy-MDLP discretization has been accepted as by far the most effective in the context of both decision tree learning and rule induction algorithms. This paper presents a new discretization technique EDISC which utilizes the entropy-based principle but takes a class-tailored approach to discretization. The technique is applicable in general to any covering algorithm, including those that use the class-per-class rule induction methodology such as CN2 as well as those that use a seed example during the learning phase, such as the RULES family. Experimental evaluation has proved the efficiency and effectiveness of the technique as a preprocessing discretization procedure for CN2 as well as RULES-7, the latest algorithm among the RULES family of inductive learning algorithms. © 1989-2012 IEEE.
Haeussler C.,University of Management and Technology |
Colyvas J.A.,Northwestern University
Research Policy | Year: 2011
We examine engagement in commercial activities (consulting, patenting, and founding) among more than 2200 German and UK life scientists. We test hypotheses that include attributes of individuals, their material and social resources, and perceptions about values and reputation. We find that characteristics reflecting professional security, advantage and productivity are strong predictors for a greater breadth of participation in academic entrepreneurship, but not for all forms of technology transfer that we are able to test. For such academics, science and commerce go hand in hand, as they are best poised to straddle the boundary between industry and academy. We find strong support, however, that scientists perceive the value of patenting differently, and the level of reputational importance placed on scientific compared to commercial achievements matters in shaping commercial involvement. © 2010 Elsevier B.V. All rights reserved.
Haeussler C.,University of Management and Technology
Research Policy | Year: 2011
This paper investigates how scientists decide whether to share information with their colleagues or not. Detailed data on the decisions of 1694 bio-scientists allow to detect similarities and differences between academia-based and industry-based scientists. Arguments from social capital theory are applied to explain why individuals share information even at (temporary) personal cost. In both realms, the results suggest that the likelihood of sharing decreases with the competitive value of the requested information. Factors related to social capital, i.e.; expected reciprocity and the extent to which a scientist's community conforms to the norm of open science, either directly affect information-sharing or moderate competitive interest considerations on information-sharing. The effect depends on the system to which a scientist belongs. © 2010 Elsevier B.V. All rights reserved.