Testing Embedded Memories in Telecommunication Systems

Extensive system testing is mandatory nowadays to achieve high product quality. Telecommunication systems are particularly sensitive to such a requirement; to maintain market competitiveness, manufacturers need to combine reduced costs, shorter life cycles, advanced technologies, and high quality. Moreover, strict reliability constraints usually impose very low fault latencies and a high degree of fault detection for both permanent and transient faults. This article analyzes major problems related to testing complex telecommunication systems, with particular emphasis on their memory modules, often so critical from the reliability point of view. In particular, advanced BIST-based solutions are analyzed, and two significant industrial case studies presente

On the Reverse Engineering of the Citadel Botnet

Citadel is an advanced information-stealing malware which targets financial information. This malware poses a real threat against the confidentiality and integrity of personal and business data. A joint operation was recently conducted by the FBI and the Microsoft Digital Crimes Unit in order to take down Citadel command-and-control servers. The operation caused some disruption in the botnet but has not stopped it completely. Due to the complex structure and advanced anti-reverse engineering techniques, the Citadel malware analysis process is both challenging and time-consuming. This allows cyber criminals to carry on with their attacks while the analysis is still in progress. In this paper, we present the results of the Citadel reverse engineering and provide additional insight into the functionality, inner workings, and open source components of the malware. In order to accelerate the reverse engineering process, we propose a clone-based analysis methodology. Citadel is an offspring of a previously analyzed malware called Zeus; thus, using the former as a reference, we can measure and quantify the similarities and differences of the new variant. Two types of code analysis techniques are provided in the methodology, namely assembly to source code matching and binary clone detection. The methodology can help reduce the number of functions requiring manual analysis. The analysis results prove that the approach is promising in Citadel malware analysis. Furthermore, the same approach is applicable to similar malware analysis scenarios.Comment: 10 pages, 17 figures. This is an updated / edited version of a paper appeared in FPS 201

An Ecological and Longitudinal Perspective

Von der Entscheidung für ein Spiel bis zur Wahl einer Taktik, um die Schlafenszeit hinauszuzögern - wiederholte Entscheidungen sind für Kinder allgegenwärtig. Zwei paradigmatische Entscheidungsphänomene sind probability matching (dt. Angleichen der Wahrscheinlichkeit) und Maximieren. Um Belohnungen zu maximieren, sollte eine Person ausschließlich die Option auswählen, welche die höchste Wahrscheinlichkeit hat. Maximieren wird allgemein al ökonomisch rationales Verhalten angesehen. Probability matching beschreibt, dass eine Person jede Option mit der Wahrscheinlichkeit auswählt, wie deren zugrunde liegende Wahrscheinlichkeit einer Belohnung ist. Ob es sich bei probability matching um einen Fehlschluss oder einen adaptiven Mechanismus handelt, ist umstritten. Frühere Forschung zu probabilistischem Lernen zeigte das paradoxe Ergebnis, dass jüngere Kinder eher maximieren als ältere Kinder. Von älteren Kindern nimmt man hingegen an, dass sie probability matchen. Dabei wurde jedoch kaum berücksichtigt, dass Kinder die Struktur der Umwelt zu ihrem Vorteil nutzen können. Diese Dissertation untersucht die inter- und intraindividuelle Entwicklung des probabilistischen Lernens in der Kindheit unter ökologischen und kognitiven Aspekten. Vier empirischen Kapitel zeigen, dass die Interaktion zwischen heranreifenden kognitiven Funktionen, sowie Merkmalen der Lern- und Entscheidungsumgebung die Entwicklung des adaptiven Entscheidungsverhaltens prägt. Die Entwicklung des probabilistischen Lernens durchläuft in der Kindheit mehrere Phasen: von hoher Persistenz, aber auch hoher interindividueller Variabilität bei jüngeren Kindern zu wachsender Anpassungsfähigkeit durch zunehmende Diversifizierung und Exploration bei älteren Kindern. Die Ergebnisse dieser Dissertation unterstreichen insbesondere den Nutzen einer ökologischen Rationalitätsperspektive bei der Erforschung der Entwicklung des Entscheidungsvermögens.From choosing which game to play to deciding how to effectively delay bedtime—making repeated choices is a ubiquitous part of childhood. Two often contrasted paradigmatic choice behaviors are probability matching and maximizing. Maximizing, described as consistently choosing the option with the highest reward probability, has traditionally been considered economically rational. Probability matching, in contrast, described by proportionately matching choices to underlying reward probabilities, is debated whether it reflects a mistake or an adaptive mechanism. Previous research on the development of probability learning and repeated choice revealed considerable change across childhood and reported the paradoxical finding that younger children are more likely to maximize—outperforming older children who are thought to be more likely to probability match. However, this line of research largely disregarded the mind’s ability to capitalize on the structure of the environment. In this dissertation, I investigate the inter- and intra-individual development of probability learning and repeated choice behavior in childhood under consideration of ecological, cognitive, and methodological aspects. Four empirical chapters demonstrate that the interaction between the maturing mind and characteristics of the learning and choice environment shapes the development of adaptive choice behavior. The development of probability learning and repeated choice behavior in childhood progresses from high persistence but also high inter-individual variability to emerging adaptivity marked by increased diversification and exploration. The present research highlights the benefit of taking an ecological rationality view in research on the development of decision making abilities

Examining the cognitive costs of counterfactual language comprehension: Evidence from ERPs

Recent empirical research suggests that understanding a counterfactual event (e.g. ‘If Josie had revised, she would have passed her exams’) activates mental representations of both the factual and counterfactual versions of events. However, it remains unclear when readers switch between these models during comprehension, and whether representing multiple ‘worlds’ is cognitively effortful. This paper reports two ERP studies where participants read contexts that set up a factual or counterfactual scenario, followed by a second sentence describing a consequence of this event. Critically, this sentence included a noun that was either consistent or inconsistent with the preceding context, and either included a modal verb to indicate reference to the counterfactual-world or not (thus referring to the factual-world). Experiment 2 used adapted versions of the materials used in Experiment 1 to examine the degree to which representing multiple versions of a counterfactual situation makes heavy demands on cognitive resources by measuring individuals’ working memory capacity. Results showed that when reference to the counterfactual-world was maintained by the ongoing discourse, readers correctly interpreted events according to the counterfactual-world (i.e. showed larger N400 for inconsistent than consistent words). In contrast, when cues referred back to the factual-world, readers showed no difference between consistent and inconsistent critical words, suggesting that they simultaneously compared information against both possible worlds. These results support previous dual-representation accounts for counterfactuals, and provide new evidence that linguistic cues can guide the reader in selecting which world model to evaluate incoming information against. Crucially, we reveal evidence that maintaining and updating a hypothetical model over time relies upon the availability of cognitive resources

Current mode monolithic active pixel sensor with correlated double sampling for charged particle detection

A monolithic active pixel sensor operating in current mode for charged particle detection is described. The sensing element in each pixel is an n-well/p-sub diode with a PMOS transistor integrated in an n-well. The drop of the n-well potential from the collection of charge modulates the transistor channel current. Each pixel features two current mode memory cells. The subtraction of distant-in-time samples frees the signal of fixed pattern noise (FPN) and of the correlated low-frequency temporal noise components, resulting in extraction of the particle footprint. The subtraction circuits are placed at each column end. A transimpedance amplifier, integrating in sequence two current samples and subtracting the results in an arithmetic operation, was adopted. The integrated version of the transimpedance amplifier, designed with a maximized conversion gain, is burdened by a risk of an early saturation, imperiling its operation, if the dispersions of the dc current component are too big. The degree of dispersions could not be estimated during the design. Some number of columns is available as a backup with the direct current readout. An external realization of the subtracting circuit, based on the same principle, is used to process direct output columns. The concept of the data acquisition setup developed, the tested performance of an array of cells, and the processing circuitry are described