Zur Verwendbarkeit von Kunststoffen bei der Rekonstruktion der Ohrmuschel

Four porous synthetics were tested for their applicability as cartilage replacement in the reconstruction of the auricle: teflon velour, filamentous dacron, porous polyethylene and proplast II. After formation of a fold, the implants were sutured into subcutaneous cavities of the abdominal skin of rats or fixed with fibrin adhesive. Histological and scanning-electron-microscopic examinations have so far been performed after 1 and 3 months. Form stability with persistence of the desired skin fold was good when the material was not too thin or too thick. The infection rate was surprisingly low; skin necroses occurred largely in the area of transfixion sutures. The porosity appears to promote adaptation of the skin to the material and to thus counteract an effacement of the skin fold. The best form stability was evidenced by thermoplastic polyethylene, which was thus also chosen for first clinical applications

Income and distance elasticities of values of travel time savings: New Swiss results

This paper presents the findings of a study looking into the valuation of travel time savings (VTTS) in Switzerland, across modes as well as across purpose groups. The study makes several departures from the usual practice in VTTS studies, with the main one being a direct representation of the income and distance elasticity of the VTTS measures. Here, important gains in model performance and significantly different results are obtained through this approach. Additionally, the analysis shows that the estimation of robust coefficients for congested car travel time is hampered by the low share of congested time in the overall travel time, and the use of an additional rate-of-congestion coefficient, in addition to a generic car travel time coefficient, is preferable. Finally, the analysis demonstrates that the population mean of the indicators calculated is quite different from the sample means and presents methods to calculate those, along with the associated variances. These variances are of great interest as they allow the generation of confidence intervals, which can be extremely useful in cost-benefit analyses

Complexity aided design: The FuturICT technological innovation paradigm

"In the next century, planet earth will don an electronic skin. It will use the Internet as a scaffold to support and transmit its sensations. This skin is already being stitched together. It consists of millions of embedded electronic measuring devices: thermostats, pressure gauges, pollution detectors, cameras, microphones, glucose sensors, EKGs, electroencephalographs. These will probe and monitor cities and endangered species, the atmosphere, our ships, highways and fleets of trucks, our conversations, our bodies-even our dreams ....What will the earth's new skin permit us to feel? How will we use its surges of sensation? For several years-maybe for a decade-there will be no central nervous system to manage this vast signaling network. Certainly there will be no central intelligence...some qualities of self-awareness will emerge once the Net is sensually enhanced. Sensuality is only one force pushing the Net toward intelligence”. These statements are quoted by an interview by Cherry Murray, Dean of the Harvard School of Engineering and Applied Sciences and Professor of Physics. It is interesting to outline the timeliness and highly predicting power of these statements. In particular, we would like to point to the relevance of the question "What will the earth's new skin permit us to feel?” to the work we are going to discuss in this paper. There are many additional compelling questions, as for example: "How can the electronic earth's skin be made more resilient?”; "How can the earth's electronic skin be improved to better satisfy the need of our society?”;"What can the science of complex systems contribute to this endeavour?” Graphical abstrac

Spatial risk for a superspreading environment: Insights from six urban facilities in six global cities across four continents

Introduction: This study sets out to provide scientific evidence on the spatial risk for the formation of a superspreading environment. Methods: Focusing on six common types of urban facilities (bars, cinemas, gyms and fitness centers, places of worship, public libraries and shopping malls), it first tests whether visitors' mobility characteristics differ systematically for different types of facility and at different locations. The study collects detailed human mobility and other locational data in Chicago, Hong Kong, London, São Paulo, Seoul and Zurich. Then, considering facility agglomeration, visitors' profile and the density of the population, facilities are classified into four potential spatial risk (PSR) classes. Finally, a kernel density function is employed to derive the risk surface in each city based on the spatial risk class and nature of activities. Results: Results of the human mobility analysis reflect the geographical and cultural context of various facilities, transport characteristics and people's lifestyle across cities. Consistent across the six global cities, geographical agglomeration is a risk factor for bars. For other urban facilities, the lack of agglomeration is a risk factor. Based on the spatial risk maps, some high-risk areas of superspreading are identified and discussed in each city. Discussion: Integrating activity-travel patterns in risk models can help identify areas that attract highly mobile visitors and are conducive to superspreading. Based on the findings, this study proposes a place-based strategy of non-pharmaceutical interventions that balance the control of the pandemic and the daily life of the urban population

Capturing human activity spaces: New geometries

Activity space, defined as “the local areas within which people move or travel during the course of their activities during a specified time period”, is a measure of an individual’s spatial behavior which captures individual and environmental differences and offers an alternative approach to studying the spatial reach of travelers. The shape and area of activity space is a product of how it is conceptualized and measured. This paper enlarges the set of geometries which can be used to describe activity space. It tests four parametric geometries (ellipse, superellipse, Cassini oval, and bean curve), which are identified as those capturing a specific share of all locations visited, i.e. 95%, while minimizing the area covered. They are estimated for a number of long-duration data sets while distinguishing between trip purposes. We present both a flexible, easily adaptable method for calculating activity spaces of different shapes and a qualitative comparison of the four above-mentioned shape types on the basis of the given surveys. We can thus demonstrate that the choice of an appropriate shape representing an individual’s activity space is highly dependent on the spatial distributions and frequencies of the locations visited by the person in the given time period

Fatigue in long-duration travel diaries

This paper introduces a new long-duration travel diary survey undertaken in a small town and rural environment, which complements the existing urban Mobidrive survey of 1999. Policy-making is dominated by the 1-day view of the world provided by the usual diaries. Long-duration surveys can balance this by highlighting the strong intrapersonal variance in choices, modes used and other aspects of travel behaviour. They also allow us to gain an understanding of the activity space of the travellers. The new 2003 Thurgau data followed the protocol of the earlier study, but developed the set of questions further. These new questions concerned the social context of respondents as well as trip-related items, such as planning horizon of the activity, previous frequency of visits or the groups involved in the trip or activity. The descriptive and model-based analysis of the data showed that respondent fatigue is not an issue in either survey. Where significant deviations from a steady number of reported trips were found, they showed positive tendencies, i.e. learning. The skill accrued in the intensive round of contacts between respondent and interviewer is significant. Papers on travel diaries tend not to report interviewer effects, although their impacts are clearly discernable. The analysis shows that the four interviewers employed in this survey had a substantial effect on the number of reported trip

Analysis of driver's response to real-time information in Switzerland

We present behavioral models designed to capture the response of drivers to real-time traffic information. In 2003, we have conducted a survey in Switzerland in order to collect both Revealed Preferences (RP) and Stated Preferences (SP) about choice decisions in terms of route and mode. The RP data contains socioeconomic characteristics of the individuals in our samples, their actual usage of ITS as well as their actual route and mode choice behavior. The SP data provide us with stated route and mode choices when drivers are faced with different hypothetical choice situations involving real-time information about the state of the network. First we present a Mixed Binary Logit model with panel data to analyze the drivers' decisions when traffic information is provided during their trip by the mean of Radio Data System (RDS) or variable message signs (VMS). This model is referred to en-route choice model. Second we present Nested Logit models capturing the behavior of drivers when they are aware of traffic conditions before their trip. These last models allow to predict pre-trip route choice decisions with regard to route and mode when traffic information is available. The calibrated models are subsequently included in a simulator which predicts travelers' behavior in specific scenarios (described by adjustable parameters) allowing the sensitivity analysis of the demand with regard to the variations of various parameters. In this paper, we discuss the results of the estimation process, including some comments about the Value of Travel Time Savings (VTTS) and present some scenarios developed with our simulator