861 research outputs found

    Asymmetric information as a cause for market failure---Application Service Providing (ASP) in Austria

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    The worldwide ASP market has not developed according to the forecasts of many market researchers. Asymmetric information, also known as quality uncertainty, has hardly been made the subject of discussion in the literature as a potential drawback for the successful development of the ASP market. Therefore, in this paper a theoretical framework is presented, showing three market situations with a varying amount of quality information on the customers’ side and the resulting effects on the market situation and market development. Furthermore, the paper reports on empirical findings that show the existence of quality uncertainty on the Austrian ASP market.Application Service Providing (ASP); ASP quality; ASP market; asymmetric information; quality uncertainty; adverse selection; attribute-based service quality measurement; web-based questionnaire; quality characteristics.

    Radioimmunotherapy consolidation and rituximab maintenance in the initial treatment of follicular lymphoma

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    Several reports have documented similar efficacies and tolerable toxicities of radioimmunotherapy (RIT) consolidation and rituximab maintenance after initial R-chemotherapy of follicular lymphoma. The relative merits of these two interventions are currently under discussion. We now raise the question whether both RIT consolidation and rituximab maintenance should be used together aiming to augment the results achievable with R-chemotherapy

    Coping with False Accusations in Misbehavior Reputation Systems for Mobile Ad-hoc Networks

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    Some misbehavior detection and reputation systems in mobile ad-hoc networks rely on the dissemination of information of observed behavior, which makes them vulnerable to false accusations. This vulnerability could be removed by forbidding the dissemination of information on observed behavior in the first place, but, as we show here, this has more drawbacks than a solution that allows dissemination and copes with false accusations. We propose a method for reducing the impact of false accusations. In our approach, nodes collect first-hand information about the behavior of other nodes by direct observation. In addition, nodes maintain a rating about every other node that they care about, in the form of a continuous variable per node. From time to time nodes exchange their first-hand information with others, but, using the Bayesian approach we designed and present in this paper, only second-hand information that is not incompatible with the current rating is accepted. Ratings are slightly modified by accepted information. The reputation of a given node is the collection of ratings maintained by others about this node. By means of simulation we evaluated the robustness of our approach against several types of adversaries that spread false information, and its efficiency at detecting malicious nodes. The simulation results indicate that our system largely reduces the impact of false accusations, while still benefiting from the accelerated detection of malicious nodes provided by second-hand information. We also found that when information dissemination is not used, the time until malicious nodes are detected can be unacceptable

    Cooperative Routing in Mobile Ad-hoc Networks: Current Efforts Against Malice and Selfishness

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    In mobile ad-hoc networks, nodes do not rely on any routing infrastructure but relay packets for each other. Thus communication in mobile ad-hoc networks functions properly only if the participating nodes cooperate in routing and forwarding. However, it may be advantageous for individual nodes not to cooperate, for example to save power or to launch security attacks such as denial-of-service. In this paper, we give an overview of potential vulnerabilities and requirements of mobile ad-hoc networks, and of proposed prevention, detection and reaction mechanisms to thwart attacks

    Getting Rid of Cheats and Liars in Mobile Ad-hoc Networks

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    presentation with extended abstract (see pdf

    Performance Analysis of the CONFIDANT Protocol (Cooperation Of Nodes - Fairness In Dynamic Ad-hoc NeTworks)

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    Mobile ad-hoc networking works properly only if the par- ticipating nodes cooperate in routing and forwarding. How- ever, it may be advantageous for individual nodes not to cooperate. We propose a protocol, called CONFIDANT, for making misbehavior unattractiv

    Cloning of a Carcinoembryonic Antigen Gene Family Member Expressed in Leukocytes of Chronic Myeloid Leukemia Patients and Bone Marrow

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    The carcinoembryonic antigen (CEA) gene family belongs to the immunoglobulin superfamily and can be subdivided into the CEA and pregnancy-specific glycoprotein subgroups. The basic structure of the encoded proteins consists of, in addition to a leader, one IgV-like and 2, 3, or 6 IgC-like domains. These domains are followed by varying COOH-terminal regions responsible for secretion, transmembrane anchoring, or insertion into the membrane by a glycosyl phosphatidylinositol tail. Here we report on the characterization of CGM6, a new member of the CEA gene subgroup, by complementary DNA cloning. The deduced coding region comprises 349 amino acids and consists of a leader, one IgV-like, two IgC-like domains, and a hydrophobic region, which is replaced by a glycosyl phosphatidylinositol moiety in the mature protein. CGM6 transcripts were only found thus far in leukocytes of chronic myeloid leukemia patients, in normal bone marrow, and in marginal amounts in normal granulocytes. The CGM6 gene product might, therefore, represent a myeloid marker. Analyses of CGM6 protein-expressing HeLa transfectants with monoclonal antibodies strongly indicate that the CGM6 gene codes for the CEA family member NCA-95
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