Publications

We study a competitive multiline insurance industry, in which insurance companies with limited liability choose which insurance lines to cover and the amount of capital to hold. The results are developed under the realistic assumptions that insurers face friction costs in holding capital and that the losses created by insurer default are shared among policyholders following an ex post, pro rata, sharing rule. We characterize the situations in which monoline and multiline insurance structures will be optimal. Markets characterized by a large number of essentially independent risks will be served by multiline firms. Markets for which the risks are asymmetric or correlated may best served by monoline insurers. The results are directly relevant to such catastrophe lines as bond and mortgage default insurance, and may be applicable more generally to industries in which risky activities can be carried out by either monoline or conglomerate entities. We illustrate the results with examples.

A software system to provide intuitive navigation for MRI-guided robotic transperineal prostate therapy is presented. In the system, the robot control unit, the MRI scanner, and the open-source navigation software are connected together via Ethernet to exchange commands, coordinates, and images using an open network communication protocol, OpenIGTLink. The system has six states called "workphases" that provide the necessary synchronization of all components during each stage of the clinical workflow, and the user interface guides the operator linearly through these workphases. On top of this framework, the software provides the following features for needle guidance: interactive target planning; 3D image visualization with current needle position; treatment monitoring through real-time MR images of needle trajectories in the prostate. These features are supported by calibration of robot and image coordinates by fiducial-based registration. Performance tests show that the registration error of the system was 2.6mm within the prostate volume. Registered real-time 2D images were displayed 1.97 s after the image location is specified.

BACKGROUND: OpenIGTLink is a new, open, simple and extensible network communication protocol for image-guided therapy (IGT). The protocol provides a standardized mechanism to connect hardware and software by the transfer of coordinate transforms, images, and status messages. MeVisLab is a framework for the development of image processing algorithms and visualization and interaction methods, with a focus on medical imaging. METHODS: The paper describes the integration of the OpenIGTLink network protocol for IGT with the medical prototyping platform MeVisLab. The integration of OpenIGTLink into MeVisLab has been realized by developing a software module using the C++ programming language. RESULTS: The integration was evaluated with tracker clients that are available online. Furthermore, the integration was used to connect MeVisLab to Slicer and a NDI tracking system over the network. The latency time during navigation with a real instrument was measured to show that the integration can be used clinically. CONCLUSIONS: Researchers using MeVisLab can interface their software to hardware devices that already support the OpenIGTLink protocol, such as the NDI Aurora magnetic tracking system. In addition, the OpenIGTLink module can also be used to communicate directly with Slicer, a free, open source software package for visualization and image analysis. Copyright (c) 2012 John Wiley & Sons, Ltd.

This paper analyzes the problem faced by a risk-averse firm considering how much to invest in a risky project. The firm receives a signal about the value of the project. We derive necessary and sufficient conditions on the signal distribution such that (i) the agent’s investment is nondecreasing in the realization of the signal, and (ii) different signals can be ranked according to their ex ante information value. Finally, we provide conditions under which it is possible to compare the incentive to acquire information across agents with different risk preferences, and we identify a class of utility functions for which agents who are less risk averse purchase more information.

T. 1. Kommentar zu Hiob Kap. 1-4. In Zusammenarbeit mit dem Ägyptischen Museum zu Kairo hrsg., übers., erläutert von A. Henrichs.--T. 2. Kommentar zu Hiob Kap. 5, 1-6, 29. In Zusammenarbeit mit dem Ägyptischen Museum zu Kairo hrsg., übers., erläutert von A. Henrichs.--T. 3. Kommentar zu Hiob Kap.7, 20C-11. In Zusammenarbeit mit dem Ägyptischen Museum zu Kairo, hrsg., übers., erläutert von U. Hagedorn, D. Hagedorn und L. Koenen.--T. 4. 1. Kommentar zu Hiob Kap. 12, 1-16, 8a (Einleitung, Text, Übersetzung). In Zusammenarbeit mit dem Ägyptischen Museum zu Kairo, hrsg. und übers. von U. Hagedorn, D. Hagedorn und L. Koenen.

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