145 research outputs found

    The Zurich case study of UrbanSim

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    Abstract-- UrbanSim is an open-source software being developed by Waddell and colleagues(Waddell and Ulfarsson, 2004), simulating land use-development in cities based on the choices of households, businesses, land owners and developers, interacting in urban Real Estate markets and with the option to be connected to a transportation simulation. SustainCity is an EU-funded project with twelve European research-institutions1, coordinated by the IVT of the Swiss Federal Institute of Technology Zurich (ETHZ). Within the project of SustainCity2, UrbanSim is being adapted to European conditions by creation of a European version (UrbanSimE) with new calibration of choice-models and additional models for households, demographics and firmographics. Focus will be on the data-structure in Europe as well as the different behaviour of companies, residents and developers. For this UrbanSim will be used in three case studies: Brussels, Paris and Zurich. Although previous studies have been implemented in all of those region, the previous study in Zurich can be considered as a new set up as it uses another version of UrbanSim. This paper will report on the implementation of this parcel-based version of UrbanSim within the Zurich case study of SustainCity. It will refer to the data acquired and necessary as basis for the simulation, discuss the approach of data preparation through PostGIS and report on the new structure of the data-models defined within UrbanSim. Finally the first results of the UrbanSim runs of the Zurich case study will be presented and compared to the runs of previous versions. Keywords: UrbanSim; Urban Simulation; SustainCity; Zurich case study 02.03.2011

    ‘Forewarned is Forearmed’: Overcoming Multifaceted Challenges of Digital Innovation Units

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    Due to rapidly changing customer needs, enterprises seek to innovate continuously. Incumbent firms need to improve their capabilities to develop, evaluate, and implement digital innovations. Recently, many enterprises established digital innovation units (DIUs) for accelerating their digital innovation endeavors. Although numerous units exist in practice, the number of negative press headlines that address failure or dissolution of DIUs is increasing. Based on a literature review and a qualitative cross-industry study with eleven enterprises, we discuss the relation of DIUs to organizational concepts like ambidexterity, bimodal, and trimodal IT. Furthermore, we substantiated seven multifaceted challenges of DIUs, which span across stages of innovation development, organizational units, and hierarchical levels. Based on these findings, we developed three recommendations for responses to these challenges: (1) DIU-Business-IT collaboration across stages, (2) network of executive responsibilities, and (3) general digital awareness of the organization as a whole

    Towards an Intra- and Interorganizational Perspective: Objectives and Areas of Activity of Digital Innovation Units

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    Incumbent firms increasingly strive to embrace digital innovation, often via implementing dedicated digital innovation units (DIUs). As seizing the rapid and various digital innovation-related market movements may be overwhelming for an individual DIU, collaborations within ecosystems are perceived as crucial for continuously recognizing business opportunities and threats. Although this is a growing field of interest in recent research, insights into the objectives of DIUs and the consequent activities for effectively handling digital innovation are yet scarce. We address this issue by synthesizing 28 cases on DIUs through a qualitative meta-analysis. The analysis revealed that while DIUs enforce an intraorganizational cultural and overarching organizational design change, they also impose an interorganizational perspective with customer-oriented digital expertise and innovation, as well as cultivation of digital innovation ecosystems. Thus, we contribute to the existing DIU research by clarifying these objectives and extending them to achieve a conscious interorganizational perspective with accompanying activities

    The Zurich Case Study of UrbanSim

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    YANA – a software tool for analyzing flux modes, gene-expression and enzyme activities

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    BACKGROUND: A number of algorithms for steady state analysis of metabolic networks have been developed over the years. Of these, Elementary Mode Analysis (EMA) has proven especially useful. Despite its low user-friendliness, METATOOL as a reliable high-performance implementation of the algorithm has been the instrument of choice up to now. As reported here, the analysis of metabolic networks has been improved by an editor and analyzer of metabolic flux modes. Analysis routines for expression levels and the most central, well connected metabolites and their metabolic connections are of particular interest. RESULTS: YANA features a platform-independent, dedicated toolbox for metabolic networks with a graphical user interface to calculate (integrating METATOOL), edit (including support for the SBML format), visualize, centralize, and compare elementary flux modes. Further, YANA calculates expected flux distributions for a given Elementary Mode (EM) activity pattern and vice versa. Moreover, a dissection algorithm, a centralization algorithm, and an average diameter routine can be used to simplify and analyze complex networks. Proteomics or gene expression data give a rough indication of some individual enzyme activities, whereas the complete flux distribution in the network is often not known. As such data are noisy, YANA features a fast evolutionary algorithm (EA) for the prediction of EM activities with minimum error, including alerts for inconsistent experimental data. We offer the possibility to include further known constraints (e.g. growth constraints) in the EA calculation process. The redox metabolism around glutathione reductase serves as an illustration example. All software and documentation are available for download at . CONCLUSION: A graphical toolbox and an editor for METATOOL as well as a series of additional routines for metabolic network analyses constitute a new user-friendly software for such efforts

    The role of location in residential location choice models: a review of literature

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    JTLU vol. 7, no. 2, pp. 3-21 (2014)Geospatial data available to researchers has increased tremendously over the last several decades, opening up opportunities to define residential location in multiple ways. This has led to a myriad of variables to define "location'' in residential location choice models. In this paper, we propose a common classification for location variables and categorize findings from a wide range of studies. We find similar preferences but different measurement methods and market segments for locations across different study regions. Recent studies consider the residential unit as choice alternative, making it possible to include a detailed description of the built environment. However, these studies are still limited in number and the inclusion of socioeconomic environment is more common. Transport land-use models can benefit from the inclusion of points of interest, such as schools, network distances, and the distance to previous locations. For the results of location choice models to be transferable to different disciplines, and avoid multi-collinearity, it is necessary to present different model specifications, including variables of interest in different disciplines

    Weighing the Giants - I. Weak-lensing masses for 51 massive galaxy clusters: project overview, data analysis methods and cluster images

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    This is the first in a series of papers in which we measure accurate weak-lensing masses for 51 of the most X-ray luminous galaxy clusters known at redshifts 0.15<z<0.7, in order to calibrate X-ray and other mass proxies for cosmological cluster experiments. The primary aim is to improve the absolute mass calibration of cluster observables, currently the dominant systematic uncertainty for cluster count experiments. Key elements of this work are the rigorous quantification of systematic uncertainties, high-quality data reduction and photometric calibration, and the "blind" nature of the analysis to avoid confirmation bias. Our target clusters are drawn from RASS X-ray catalogs, and provide a versatile calibration sample for many aspects of cluster cosmology. We have acquired wide-field, high-quality imaging using the Subaru and CFHT telescopes for all 51 clusters, in at least three bands per cluster. For a subset of 27 clusters, we have data in at least five bands, allowing accurate photo-z estimates of lensed galaxies. In this paper, we describe the cluster sample and observations, and detail the processing of the SuprimeCam data to yield high-quality images suitable for robust weak-lensing shape measurements and precision photometry. For each cluster, we present wide-field color optical images and maps of the weak-lensing mass distribution, the optical light distribution, and the X-ray emission, providing insights into the large-scale structure in which the clusters are embedded. We measure the offsets between X-ray centroids and Brightest Cluster Galaxies in the clusters, finding these to be small in general, with a median of 20kpc. For offsets <100kpc, weak-lensing mass measurements centered on the BCGs agree well with values determined relative to the X-ray centroids; miscentering is therefore not a significant source of systematic uncertainty for our mass measurements. [abridged]Comment: 26 pages, 19 figures (Appendix C not included). Accepted after minor revisio

    Clinical review: Practical recommendations on the management of perioperative heart failure in cardiac surgery

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    Acute cardiovascular dysfunction occurs perioperatively in more than 20% of cardiosurgical patients, yet current acute heart failure (HF) classification is not applicable to this period. Indicators of major perioperative risk include unstable coronary syndromes, decompensated HF, significant arrhythmias and valvular disease. Clinical risk factors include history of heart disease, compensated HF, cerebrovascular disease, presence of diabetes mellitus, renal insufficiency and high-risk surgery. EuroSCORE reliably predicts perioperative cardiovascular alteration in patients aged less than 80 years. Preoperative B-type natriuretic peptide level is an additional risk stratification factor. Aggressively preserving heart function during cardiosurgery is a major goal. Volatile anaesthetics and levosimendan seem to be promising cardioprotective agents, but large trials are still needed to assess the best cardioprotective agent(s) and optimal protocol(s). The aim of monitoring is early detection and assessment of mechanisms of perioperative cardiovascular dysfunction. Ideally, volume status should be assessed by 'dynamic' measurement of haemodynamic parameters. Assess heart function first by echocardiography, then using a pulmonary artery catheter (especially in right heart dysfunction). If volaemia and heart function are in the normal range, cardiovascular dysfunction is very likely related to vascular dysfunction. In treating myocardial dysfunction, consider the following options, either alone or in combination: low-to-moderate doses of dobutamine and epinephrine, milrinone or levosimendan. In vasoplegia-induced hypotension, use norepinephrine to maintain adequate perfusion pressure. Exclude hypovolaemia in patients under vasopressors, through repeated volume assessments. Optimal perioperative use of inotropes/vasopressors in cardiosurgery remains controversial, and further large multinational studies are needed. Cardiosurgical perioperative classification of cardiac impairment should be based on time of occurrence (precardiotomy, failure to wean, postcardiotomy) and haemodynamic severity of the patient's condition (crash and burn, deteriorating fast, stable but inotrope dependent). In heart dysfunction with suspected coronary hypoperfusion, an intra-aortic balloon pump is highly recommended. A ventricular assist device should be considered before end organ dysfunction becomes evident. Extra-corporeal membrane oxygenation is an elegant solution as a bridge to recovery and/or decision making. This paper offers practical recommendations for management of perioperative HF in cardiosurgery based on European experts' opinion. It also emphasizes the need for large surveys and studies to assess the optimal way to manage perioperative HF in cardiac surgery

    Influence of Microplastics on Microbial Structure, Function, and Mechanical Properties of Stream Periphyton

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    Este artículo contiene 17 páginas, 5 figuras, 4 tablas.Periphyton is a freshwater biofilm composed of prokaryotic and eukaryotic communities that occupy rocks and sediments, forming the base of the food web and playing a key role in nutrient cycling. Given the large surface that periphyton comprises, it may also act as a sink for a diverse range of man-made pollutants, including microplastics (MP). Here we investigated the effect of 1–4 μm and 63–75 µm sized, spherical polyethylene MP with native and ultraviolet (UV)-weathered surface on developing natural stream periphyton communities over 28 days. In order to ensure proper particle exposure, we first tested MP suspension in water or in water containing either Tween 80, extracellular polymeric substances – EPS, fulvic acids, or protein. We found the extract of EPS from natural periphyton to be most suitable to create MP suspensions in preparation of exposure. Upon exposure, all tested types of MP were found to be associated with the periphyton, independent of their size and other properties. While biomass accrual and phenotypic community structure of the photoautotrophs remained unchanged, the prokaryotic and eukaryotic communities experienced a significant change in composition and relative abundances. Moreover, alpha diversity was affected in eukaryotes, but not in prokaryotes. The observed changes were more prominent in periphyton exposed to UV-treated as compared with native surface MP. Mechanical properties, as assessed by compression rheology, showed that MP-exposed periphyton had longer filamentous streamers, higher stiffness, lower force recovery and a higher viscoelasticity than control periphyton. Despite the observed structural and mechanical changes of periphyton, functional parameters (i.e., photosynthetic yield, respiration and nutrient uptake efficiencies) were not altered by MP, indicating the absence of MP toxicity, and suggesting functional redundancy in the communities. Together, our results provide further proof that periphyton is a sink for MP and demonstrate that MP can impact local microbial community composition and mechanical properties of the biofilms. Consequences of these findings might be a change in dislodgement behavior of periphyton, a propagation through the food chains and impacts on nutrient cycling and energy transfer. Hence, taking the omnipresence, high persistence and material and size diversity of MP in the aquatic environment into account, their ecological consequences need further investigation.The study was financially supported by the Velux foundation, project number 1039, Switzerland. Additional lab work was funded by Tailwind grant of Eawag Switzerland. Open access funding was provided by Eawag–Swiss Federal Institute of Aquatic Science And Technology.Peer reviewe
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