The Transitivity of Trust Problem in the Interaction of Android Applications

Mobile phones have developed into complex platforms with large numbers of installed applications and a wide range of sensitive data. Application security policies limit the permissions of each installed application. As applications may interact, restricting single applications may create a false sense of security for the end users while data may still leave the mobile phone through other applications. Instead, the information flow needs to be policed for the composite system of applications in a transparent and usable manner. In this paper, we propose to employ static analysis based on the software architecture and focused data flow analysis to scalably detect information flows between components. Specifically, we aim to reveal transitivity of trust problems in multi-component mobile platforms. We demonstrate the feasibility of our approach with Android applications, although the generalization of the analysis to similar composition-based architectures, such as Service-oriented Architecture, can also be explored in the future

Dikvarkovi kao efektivne čestice u tvrdom ekskluzivnom raspršenju

In the context of hard hadronic reactions, diquarks are a useful phenomenological device to model non-perturbative effects still observable in the kinematic range accessible by present-day experiments. In the following, we present diquark-model predictions for γγ → p¯p and ΛΛ. We also sketch how the (pure quark) hard-scattering formalism for exclusive reactions involving baryons can be reformulated in terms of quarks and diquarks. As an application of these considerations, we analyze the magnetic proton form factor with regard to its quark-diquark content.Dikvarkovi su pogodna fenomenološka zamisao u razmatranju tvrdih hadronskih reakcija za modeliranje neperturbativnih efekata koji se opažaju u današnjim mjerenjima dostupnom kinematičkom području. Prikazuju se predviđanja dikvarkovskog modela za γγ → pp¯ i ΛΛ. Opisuje se kako se formalizam (čisto kvarkovskog) tvrdog raspršenja koja uključuju barione može prikazati pomoću kvarkova i dikvarkova. U primjeni tih razmatranja analizira se magnetski faktor oblika protona za sadržaj kvarkova i dikvarkova u protonu

Stimuli for spawning migration of Chondrostoma nasus in a Danubian tributary (fischa) using horizontal hydroacoustic

Der Unterlauf der Fischa, ein Nebenfluss der Donau östlich von Wien, stellt für viele Fischarten der Donau ein wichtiges Gewässer für die Reproduktion dar. Die Einwanderung der laichreifen Fische beginnt Ende Februar. Der erste Einwanderer ist der Hecht (Esox lucius), gefolgt von Hasel (Leuciscus leuciscus), Nase (Chondrostoma nasus), Barbe (Barbus barbus) und Nerfling (Leuciscus idus) (Keckeis & Rakowitz, 2005). In der vorliegenden Arbeit wurde die Laichwanderung der Nase (Chondrostoma nasus) in die Fischa hydroakustisch untersucht. Die ersten Individuen konnten am 12. März 2005 erfasst werden. Die gesamte Wanderungsperiode war von mehreren Aktivitätsspitzen geprägt, besonders in der zweiten und dritten Märzwoche (16.3., 26.3.). Zwar konnte man danach immer wieder stärkere Wanderaktivität beobachten, diese fiel aber gegen Anfang Mai hin immer schwächer aus. Hauptaugenmerk wurde bei der Untersuchung auf die Zusammenhänge der Einwanderungsraten von Chondrostoma nasus mit den abiotischen Faktoren Wassertemperatur, Wasserstand, Trübe sowie Sonneneinstrahlung/Lichtstärke gelegt. Die Einwanderung der Nasen korrelierte am höchsten mit schwach ansteigender Temperatur im Mündungsbereich (> 0.5°C) innerhalb eines Tages, mit starker Erwärmung am Laichplatz (> 2.5°C) innerhalb von fünf Tagen und einem fallenden Wasserspiegel der Donau innerhalb von sechs Tagen. Mittels der Fourier-Analyse konnte ein deutlich diurnales Muster der Nasen-Laichwanderung festgestellt werden, wobei die Morgen- sowie die Abenddämmerung bevorzugt wird. Schwankungen der abiotischen Faktoren (Temperaturanstieg, fallender Wasserstand), besonders in der Fischa, stimulieren die Wanderung von Chondrostoma nasus, was sowohl das zeitliche Muster sowie die Intensität der Einwanderung prägt.The lower part of the River Fischa, a tributary of River Danube east of Vienna represents a important spawning habitat for several rheophilic fish species of the River Danube. Spawning migration starts at the end of February with species like pike (Esox lucius), followed by dace (Leuciscus leuciscus), nase (Chondrostoma nasus), barbel (Barbus barbus) and ide (Leuciscus idus) (Keckeis & Rakowitz, 2005). In this thesis the spawning migration of the most abundant species, Chondrostoma nasus, was analysed. The first individuals of nase were recorded at 12th of March by the hydroacoustic method. Migration was characterised by a series of multiple peaks between mid March and beginning of May. A diurnal pattern in the spawning migration of nase with dusk and dawn as preferred migration time was also observed. The aim was to analyse the role of water temperature, water level, turbidity and solar radiation as a triggering factor for the migrating individuals. Focus laid on short term fluctuations of these abiotic variables. Upstream migration of nase was most significantly correlated with a slight increase of water temperature in the confluence (> 0.5°C) within 1 day, a steep increase of water temperature at the spawning place (> 2.5°C) within 5 days and a decreasing water level in River Danube within 6 days. Fluctuations of the environmental factors, especially in the main river, represent relevant stimuli, which initiate and control the temporal pattern as well as the intensity of the spawning migration in nase. Fourier analysis revealed a clear diurnal pattern in the spawning migration of nase with dusk and dawn as preferred migration time