M Hadorn, P Eggenberger Hotz, Multivesicular assemblies as real-world testbeds for embryogenic evolutionary systems, In: 4th Australian Conference on Artificial Life (ACAL 2009), Springer, Berlin und Heidelberg, 2009-12-01. (Conference or Workshop Paper published in Proceedings)
Embryogenic evolution emulates in silico cell-like entities to get more powerful methods for complex evolutionary tasks. As simulations have to abstract from the biological model, implicit information hidden in its physics is lost. Here, we propose to use cell-like entities as a real-world in vitro testbed. In analogy to evolutionary robotics, where solutions evolved in simulations may be tested in real-world on macroscale, the proposed vesicular testbed would do the same for the embryogenic evolutionary tasks on mesoscale. As a first step towards a vesicular testbed emulating growth, cell division, and cell differentiation, we present a modified vesicle production method, providing custom-tailored chemical cargo, and present a novel self-assembly procedure to provide vesicle aggregates of programmable composition. |
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Maik Hadorn, Bo Burla, Peter Eggenberger Hotz, Towards tailored communication networks in assemblies of artificial cells, In: 4th Australian Conference on Artificial Life (ACAL 2009), Springer, Berlin und Heidelberg, 2009-12-01. (Conference or Workshop Paper published in Proceedings)
Living Technology is researching novel IT making strong use of programmable chemical systems. These chemical systems shall finally converge to artificial cells resulting in evolvable complex information systems. We focus on procedural manageability and information processing capabilities of such information systems. Here, we present a novel resource-saving formation, processing, and examination procedure to generate and handle single compartments representing preliminary stages of artificial cells. Its potential is exemplified by testing the influence of different glycerophospholipids on the stability of the compartments. We discuss how the procedure could be used both in evolutionary optimization of self-assembling amphiphilic systems and in engineering tailored communication networks enabling life-like information processing in multicompartment aggregates of programmable composition and spatial configuration. |
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Isaac Vikram Chenchiah, Marc Oliver Rieger, Johannes Zimmer, Gradient flows in asymmetric metric spaces, Nonlinear Analysis: Theory, Methods & Applications, Vol. 71 (11), 2009. (Journal Article)
This article is concerned with gradient flows in asymmetric metric spaces, that is, spaces with a topology induced by an asymmetric metric. Such an asymmetry appears naturally in many applications, e.g., in mathematical models for materials with hysteresis. A framework of asymmetric gradient flows is established under the assumption that the metric is weakly lower-semicontinuous in the second argument (and not necessarily on the first), and an existence theorem for gradient flows defined on an asymmetric metric space is given. |
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Loriano Mancini, Jianqing Fan, Option pricing with model-guided nonparametric methods, Journal of the American Statistical Association, Vol. 104 (488), 2009. (Journal Article)
Parametric option pricing models are widely used in finance. These models capture several features of asset price dynamics; however, their pricing performance can be significantly enhanced when they are combined with nonparametric learning approaches that learn and correct empirically the pricing errors. In this article we propose a new nonparametric method for pricing derivatives assets. Our method relies on the state price distribution instead of the state price density, because the former is easier to estimate nonparametrically than the latter. A parametric model is used as an initial estimate of the state price distribution. Then the pricing errors induced by the parametric model are fitted nonparametrically. This model-guided method, called automatic correction of errors (ACE), estimates the state price distribution nonparametrically. The method is easy to implement and can be combined with any model-based pricing formula to correct the systematic biases of pricing errors. We also develop a nonparametric test based on the generalized likelihood ratio to document the efficacy of the ACE method. Empirical studies based on S&P 500 index options show that our method outperforms several competing pricing models in terms of predictive and hedging abilities. |
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Helmut Max Dietl, U Trinkner, El desarrollo de servicios postales universales en América Latina: una perspectiva económica, In: Más allá del mercado. Las políticas de servicio universal en América Latina, Fundación CIDOB, Barelona, p. 377 - 406, 2009-12. (Book Chapter)
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J Mohrenweiser, T Zwick, Why do firms train apprentices? The net cost puzzle reconsidered, Labour Economics, Vol. 16 (6), 2009. (Journal Article)
This paper analyses the impact of increasing the share of apprentices at the cost of the share of unskilled or semi-skilled employees on establishment performance. We use representative matched employer–employee panel data and correct for estimation biases. We show that an increase of the apprentice share in trade, commercial, craft or construction occupations has a positive impact on establishment performance. Establishments that increase the apprentice share in manufacturing occupations face a negative impact on performance, however. These results shed a new light on the stylised fact that apprenticeship training always leads to net costs during the apprenticeship period in Germany: we argue that establishments only hire apprentices at a cost if their skills are relatively specific, their retention rate is high and skilled employees are hard to hire. |
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Daria Knoch, Frédéric-Guillaume Schneider, Daniel Schunk, Martin Hohmann, Ernst Fehr, Disrupting the prefrontal cortex diminishes the human ability to build a good reputation, Proceedings of the National Academy of Sciences of the United States of America (PNAS), Vol. 106 (49), 2009. (Journal Article)
Reputation formation pervades human social life. In fact, many people go to great lengths to acquire a good reputation, even though building a good reputation is costly in many cases. Little is known about the neural underpinnings of this important social mechanism, however. In the present study, we show that disruption of the right, but not the left, lateral prefrontal cortex (PFC) with low-frequency repetitive transcranial magnetic stimulation (rTMS) diminishes subjects' ability to build a favorable reputation. This effect occurs even though subjects' ability to behave altruistically in the absence of reputation incentives remains intact, and even though they are still able to recognize both the fairness standards necessary for acquiring and the future benefits of a good reputation. Thus, subjects with a disrupted right lateral PFC no longer seem to be able to resist the temptation to defect, even though they know that this has detrimental effects on their future reputation. This suggests an important dissociation between the knowledge about one's own best interests and the ability to act accordingly in social contexts. These results link findings on the neural underpinnings of self-control and temptation with the study of human social behavior, and they may help explain why reputation formation remains less prominent in most other species with less developed prefrontal cortices. |
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Bruno Frey, Economists in the PITS?, International Review of Economics, Vol. 56 (4), 2009. (Journal Article)
Academic economists today are caught in a “Publication
Impossibility Theorem System” or PITS. To further their careers, they are required to publish in A-journals, but for the vast majority this is impossible because there are few slots open in such journals. Such academic competition maybe useful to generate hard work, however, there may be serious negative consequences: the wrong output may be
produced in an inefficient way, the wrong people may be selected, and losers may react in a harmful way. This paper suggests several ways to remedy this situation. |
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R T McKay, D C Dennett, The evolution of misbelief, Behavioral and Brain Sciences, Vol. 32 (06), 2009. (Journal Article)
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Thomas Baumgartner, Urs Fischbacher, Anja Feierabend, Kai Lutz, Ernst Fehr, The neural circuitry of a broken promise, Neuron, Vol. 64 (5), 2009. (Journal Article)
Promises are one of the oldest human-specific psychological mechanisms fostering cooperation and trust. Here, we study the neural underpinnings of promise keeping and promise breaking. Subjects first make a promise decision (promise stage), then they anticipate whether the promise affects the interaction partner's decision (anticipation stage), and are subsequently free to keep or break the promise (decision stage). Findings revealed that the breaking of the promise is associated with increased activation in the DLPFC, ACC, and amygdala, suggesting that the dishonest act involves an emotional conflict due to the suppression of the honest response. Moreover, the breach of the promise can be predicted by a perfidious brain activity pattern (anterior insula, ACC, inferior frontal gyrus) during the promise and anticipation stage, indicating that brain measurements may reveal malevolent intentions before dishonest or deceitful acts are actually committed. |
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Andreas Kuhn, Rafael Lalive, Josef Zweimüller, The public health costs of job loss, Journal of Health Economics, Vol. 28 (6), 2009. (Journal Article)
We study the short-run effect of involuntary job loss on comprehensive measures of public health costs. We focus on job loss induced by plant closure, thereby addressing the reverse causality problem as job displacements due to plant closure are unlikely caused by workers' health status, but potentially have important effects on individual workers' health and associated public health costs. Our empirical analysis is based on a rich data set from Austria providing comprehensive information on various types of health care costs and day-by-day work history at the individual level. Our central findings are: (i) overall expenditures on medical treatments are not strongly affected by job displacement; (ii) job loss significantly increases expenditures for antidepressants and related drugs, as well as for hospitalizations due to mental health problems for men (but not for women) although the effects are economically rather small; and (iii) sickness benefits strongly increase due to job loss. |
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Reto Hodel, spotting - Realisation and Analysis of a Location Recommender System Based on Facebook, University of Zurich, Faculty of Economics, Business Administration and Information Technology, 2009. (Master's Thesis)
Generating accurate recommendations for items, such as locations, movies or books, is challenging. Common Web-based recommender systems require information about the users’ past to generate suitable recommendations for them. In this thesis we first present spotting.li, a location recommender system based on Facebook, which allows users to rate locations and generates recommendations inferred by their friends’ ratings. In doing so, we examine requirments to successfully implement such a system using the latest web technologies (i.e., Grails) and describe key elements of our approach. Our focus is put on performance and providing an easy-to-use interface incorporating Google Maps.
Furthermore, we analyse different recommendation approaches which leverage structural information from a social network to predict ratings. In particular, we examine the use of social network patterns, such as cliques and trendsetters, as well as direct friends and two levels of indirect friends. We finally conduct an extensive evaluation of these approaches, based on real data collected during the time of the thesis.
To prove our findings, we test our dataset, based on 139 users, for statistical significance. We demonstrate that even a simple algorithm, such as the average rating, bares similar results to more elaborate algorithms. |
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Nicolas Brügger, RDB-RDF Mapping Generation from Relational Database Schemata, University of Zurich, Faculty of Economics, Business Administration and Information Technology, 2009. (Master's Thesis)
Over the years relational databases were optimized to handle large amounts of data. While they provide scalability, they do not fully preserve the semantics of the application domain. The Semantic Web however provides a common framework to give the data a well defined meaning using RDF to describe the data and OWL to define the vocabulary. The explicit definition of the semantics facilitates the exchange and integration of data, hence the data from relational databases could be mapped to a Semantic Web representation to gain ontology-based access. To bridge the conceptual gap between the relational model and an ontology, we must create a mapping of an existing relational database schema. This process should be largely automated since creating a mapping manually is time-consuming and error-prone. Certainly, an automated mapping generation cannot meet all user needs, therefore customization is necessary afterwards. However, it is highly desirable to provide additional tool support for customization to further decrease the user effort and error rate. In this thesis, we present how such a mapping can be generated automatically from an existing relational database schema. Therefore we implement a Mapping Library that is applicable to a wide range of database systems and can be embedded into other applications. In addition, we provide graphical tool support to customize the generated mapping. The prototype is developed as a plugin for the ontology editor Protege. |
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Katharina Reinecke, Culturally Adaptivity in User Interfaces, In: Doctoral Consortium at the International Conference of Information Systems (ICIS), December 2009. (Conference or Workshop Paper)
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Florian Hegner, Conceptual Design and Development of a Management Platform for Biometric Data using the Google Web Toolkit, University of Zurich, Faculty of Economics, Business Administration and Information Technology, 2009. (Bachelor's Thesis)
Biometry and its appliance in everyday life is used today and assures an increasing scope
of application for the future. The advantages which result from connecting access keys to
the human body will reduce the complexity and costs of managing access information to
a minimum. Furthermore, technical improvements and the resulting enhanced reliability
on the devices assure increased application of biometric identication and verication in
many elds of application for the future.
In this bachelor thesis a conceptual design of a distributed solution has been composed
that allows the management of biometric devices and data. The archetype for this applica-
tion is the management software Bioxes (developed at the University of Zurich). Further, a
prototype was developed with help of the Google Web Toolkit that implements two screens
of the original application and their functionality. On the device screen the management of
biometric devices is provided and with help of the user screen all user and their biometric
templates are administrable.
An evaluation on GWT Widget Libraries has been performed to nd the best tting
Widget Library for the planned application and its requirements. This comparison is based
on dierent criteria concerning the licensing, the size of the community, the diversity of the
widgets and the code itself as well as its documentation. The evaluation illustrates that
GWT Mosaic is the most suitable Widget Library for this application and its requirements. |
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Bekim Meta, Entwicklung eines Moduls für die Generierung der Auswertung eines persönlichen 360 Grad- oder Team Feedback-Berichts, University of Zurich, Faculty of Economics, Business Administration and Information Technology, 2009. (Bachelor's Thesis)
This document describes in detail the developed module for generating evaluations of personal or team feedbacks. These feedbacks are being generated by the main webobject web application, which provides an xml file with all required data to the module. The module should mainly replace the currently implemented method of generating evaluations and bring some new features. Apart from that the windows server, which is being used for the generation of evaluations, should not be used any more. The generation will take place only in the main server. The module receives a xml file from the main application and generates several html pages. The customer can directly view them online. It will also create a PDF version of the evaluation. Finally also a zip package with all needed resources for the offline view of the evaluation will be generated. Design changes are very easy to manage, as only some small modifications in the CSS file or html code are required. |
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Andri Lareida, Development of a GUI for Self-Assembly Simulator Configuration, University of Zurich, Faculty of Economics, Business Administration and Information Technology, 2009. (Bachelor's Thesis)
Self-Assembly is a process where simple parts autonomously form organized structures, simulations are used in research to find or optimize new promising parts and structures. This thesis describes the extension of a self-assembly simulator by a graphical user interface to configure experiments and the reengineering of certain parts of the simulator. The development is documented in three parts: requirements, design and implementation. In the end an evaluation of the chosen solution is made and an outlook is given on how to further improve the application. |
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Konstantin Beck, Die Soziale Krankenversicherung würde schon bald Defizite in Milliardenhöhe schreiben, Infosantésuisse, Vol. 2009 (10), 2009. (Journal Article)
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Burkhard Stiller, D Hausheer, T Hoßfeld, A Liotta, S Spirou, M Waldburger, A discussion of socio-economic management and incentives for the future Internet, In: IEEE Globecom Workshops 2009, IEEE Computer Society, Honolulu, Hawaii, USA, 2009-11-30. (Conference or Workshop Paper published in Proceedings)
This paper outlines the outcome of a socioeconomics (SE) and incentives work group during the "Management of the Future Internet" seminar, held in Dagstuhl, Germany. This covers an indication of key questions and issues, which are classified as important for next steps in network management. Furthermore, the process of dealing with aspects of "Socio-economic Management" is discussed, which determines a hybrid and innovative approach besides traditional network management approaches. This determines a network management in which control is delegated via socio-economic means and to a certain extent to the user and provider with the goal to maximize the overall social welfare and the networks technical efficiency at the same time. This is refined by a set of SE-driven management mechanisms, the discussion of abstract user/network interfaces (stakeholder relations), and an example case for managing overlay traffic in such a network management system. Finally, based on a set of ideal SE requirements derived from the analysis of existing approaches, a set of preliminary conclusions is drawn. |
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P Schlegel, Renato Pajarola, Layered volume splatting, In: International Symposium on Visual Computing, 2009-11-30. (Conference or Workshop Paper published in Proceedings)
We present a new layered, hardware-accelerated splatting
algorithm for volume rendering. Layered volume splatting features the speed benefits of fast axis-aligned pre-classified sheet-buffer splatting while at the same time exhibiting display quality comparable to high-quality post-classified view-aligned sheet-buffer splatting. Additionally, we enhance the quality by using a more accurate approximation of the volume rendering integral. Commonly, the extinction coefficient of the volume rendering integral is approximated by the first two elements of its Taylor series expansion to allow for simple α-blending. In our approach we use the original, exponential extinction coefficient to achieve a better approximation. In this paper we describe the layered splatting algorithm and how it can be implemented on the GPU. We compare the results in terms of performance and quality to prior state-of-the-art
volume splatting methods. |
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