Context-based Pseudonym Changing Scheme for Vehicular Adhoc Networks

Vehicular adhoc networks allow vehicles to share their information for safety and traffic efficiency. However, sharing information may threaten the driver privacy because it includes spatiotemporal information and is broadcast publicly and periodically. In this paper, we propose a context-adaptive pseudonym changing scheme which lets a vehicle decide autonomously when to change its pseudonym and how long it should remain silent to ensure unlinkability. This scheme adapts dynamically based on the density of the surrounding traffic and the user privacy preferences. We employ a multi-target tracking algorithm to measure privacy in terms of traceability in realistic vehicle traces. We use Monte Carlo analysis to estimate the quality of service (QoS) of a forward collision warning application when vehicles apply this scheme. According to the experimental results, the proposed scheme provides a better compromise between traceability and QoS than a random silent period scheme.Comment: Extended version of a previous paper "K. Emara, W. Woerndl, and J. Schlichter, "Poster: Context-Adaptive User-Centric Privacy Scheme for VANET," in Proceedings of the 11th EAI International Conference on Security and Privacy in Communication Networks, SecureComm'15. Dallas, TX, USA: Springer, June 2015.

Probing the QCD Vacuum with Static Sources in Maximal Abelian Projection

Various field strength correlators are investigated in the maximal Abelian projection of pure SU(2) lattice gauge theory. High precision measurements of the colour fields, monopole currents, their curls and divergences allow for detailed checks of the dual superconductor scenario. On this basis, we perform a Ginzburg-Landau type analysis of the flux tube profile from which we derive the size of the penetration length, LAMBDA = 0.16(2) fm, and coherence length of the monopole condensate wave function, XI = 0.27(3) fm. The ratio of these numbers is KAPPA = LAMBDA/XI = 0.59(13) which is below the value 1/SQRT(2) where type II superconductivity sets in.Comment: 15 pages, latex, 8 figures, Talk presented by K. Schilling YKIS97, Kyot

Electricity Portfolio Management: Optimal Peak / Off-Peak Allocations

Electricity purchasers manage a portfolio of contracts in order to purchase the expected future electricity consumption profile of a company or a pool of clients. This paper proposes a mean-variance framework to address the concept of structuring the portfolio and focuses on how to allocate optimal positions in peak and off-peak forward contracts. It is shown that the optimal allocations are based on the difference in risk premiums per unit of day-ahead risk as a measure of relative costs of hedging risk in the day-ahead markets. The outcomes of the model are then applied to show 1) whether it is optimal to purchase a baseload consumption profile with a baseload forward contract and 2) that, under reasonable assumptions, risk taking by the purchaser is rewarded by lower expected costs.G11;electricity portfolio management;forward risk premiums;hedge ratio;optimal electricity sourcing

Hedging Exposure to Electricity Price Risk in a Value at Risk Framework

This paper deals with the question how an electricity end-consumer or distribution company should structure its portfolio with energy forward contracts. This paper introduces a one period framework to determine optimal positions in peak and off-peak contracts in order to purchase future consumption volume. In this framework, the end-consumer or distribution company is assumed to minimize expected costs of purchasing respecting an ex-ante risk limit defined in terms of Value at Risk. Based on prices from the German EEX market, it is shown that a risk-loving agent is able to obtain lower expected costs than for a risk-averse agent.Electricity prices;Forward risk premium;Hedge ratios;Mean variance

Hans-Martin Majewski (1911-1997)

Hans-Martin Majewski wurde am 14.1.1911 in Schlawe (Pommern) als Sohn eines Veterinärrats geboren. Er besuchte zunächst das Gymnasium in Schlawe, bevor er bis 1930 seine Schulausbildung auf einer staatlichen Bildungsanstalt in der Stadt Köslin beendete. Danach nahm er in Königsberg das Studium der Medizin auf. 1932 wechselte Majewski nach Leipzig, studierte am dortigen Konservatorium bei Hermann Grabner, Kurt Thomas (Chorleitung), Robert Teichmüller (Klavier), Max Hochkoffler, Bruno Walter (Dirigieren) und Max Ludwig. Seine Schwerpunkte waren Theorie und Kompositionslehre, Dirigenten- und Opernschule

Halletz, Erwin (1923-2008) : Pseudonym: René Roulette

Erwin Halletz, Sänger, Orchesterleiter, Schlager- und Film-Komponist, wurde am 12.7.1923 in Wien geboren, wo er am 27.10.2008 auch starb

Gert Wilden (1917-) : Geburtsname: Gerhart Alfred Wychodil ; Alternativ- und Publikationsnamen: Gert Wychodil, Frank Colter, V. Vychodil, Gerd Wilden, Jerry Wilton

Gert Wilden wurde am 15.4.1917 in Mährisch-Trübau (Moravská Trebová) im heutigen Nord-Tschechien als Kind einer böhmischen Musikerfamilie geboren. Nach der Kindheit in Mähren nahm Wilden das Studium an der Musikhochschule Prag auf; seine Fächer waren Kompositionslehre, Klavier und Dirigieren, seine akademischen Lehrer George Szell, Fidelio F. Finke und Fritz Rieger. Noch während seines Studiums übernahm er die Leitung des Rundfunkorchesters des Senders Pilsen. Nach dem Krieg komponierte und arrangierte er Tanzmusiken für diverse deutsche Radiosender

How Spanish -speaking parents understand kindergarten and support their children\u27s education within the context of a school

The intention of this study was to examine the experiences of nine Spanish-speaking families in a public kindergarten setting during the 2005-2006 school year to understand how individual agency of parents, access to a community\u27s practices and events, and the resulting interrelationship, shape parent understanding of and participation in school practices and events and ultimately impact student achievement outcomes. In a nation that is becoming increasingly diverse, the Hispanic population is the largest minority group in the country. There are more than two million English-language learners in the U.S. K-3 classrooms with Spanish accounting for almost 80% of the non-English languages (Abedi, Hofstetter & Lord, 2004). The documented trend of educational underachievement of Hispanic students as well as reports of limited parent involvement patterns among diverse families make this study significant both locally and nationally. Added to the landscape of this study are the conditions and provisions of No Child Left Behind with its high-stakes system of accountability, the identification of subgroups based on race, ethnicity, socioeconomic status, English language proficiency, and its impact on practices, programming and educators\u27 assumptions. A case study method was chosen to gain an in-depth understanding of the meaning for the participants with the unit of analysis being the families. Using Cummins\u27 (2001) and Hoover-Dempsey & Sandler\u27s (2005; 1997) frameworks as analytical tools, I found that parents placed high value on their children\u27s education and were motivated to be engaged in the process, yet, parents\u27 role construction and the development of a sense of efficacy in the education of their children were totally dependent on opportunities for engaging in the practices within the community and the perceptions of educators who dictate the ensuing micro-interactions that exist. The conditions for the Latino parents reflected both the existence of collaborative and coercive relations of power (Cummins, 2007; 2001). The findings counter negative assumptions held by wider society concerning Latino parents\u27 orientation toward education and challenge a deficit perspective of language-minority parents. Implications for deep educational reform that will lead to the creation of collaborative school environments for culturally and linguistically diverse families are suggested