PDF-Malware Detection: A Survey and Taxonomy of Current Techniques

Portable Document Format, more commonly known as PDF, has become, in the last 20 years, a standard for document exchange and dissemination due its portable nature and widespread adoption. The flexibility and power of this format are not only leveraged by benign users, but from hackers as well who have been working to exploit various types of vulnerabilities, overcome security restrictions, and then transform the PDF format in one among the leading malicious code spread vectors. Analyzing the content of malicious PDF files to extract the main features that characterize the malware identity and behavior, is a fundamental task for modern threat intelligence platforms that need to learn how to automatically identify new attacks. This paper surveys existing state of the art about systems for the detection of malicious PDF files and organizes them in a taxonomy that separately considers the used approaches and the data analyzed to detect the presence of malicious code. © Springer International Publishing AG, part of Springer Nature 2018

Man and boy: homoeroticism and myth-making in Umberto Saba's Canzoniere.

My thesis investigates the relationship between male same-sex desire and myth-making in the work of the Italian twentieth-century poet Umberto Saba (1883-1957). I analyse the pervasiveness of homoeroticism in Saba's collected poetic work, the Canzoniere, arguing that same-sex desire is not only relevant in itself but also plays a decisive role in relation to the heterosexual and family attachments on which Sabian scholarship has concentrated up till now. The foregrounding of homoeroticism thus results in the first comprehensive reading of the Canzoniere , in which the various poles interacting in it are shown to acquire their full meaning only when viewed as parts of a whole. More specifically, I read the Canzoniere's renowned autobiographism as the articulation of a self-aware homoerotic subject through myth-making. The identification of the nexus between homoeroticism, mythopoeia and the process of construction of identity allows me to demonstrate that, contrary to established critical notions, Saba's ostensible traditionalism serves ideological purposes which sharply diverge from the dominating idealistic framework of the Italian poetic tradition. This surfaces in the way in which poetic language is bent to articulate issues of a complex and strikingly modern psychological nature, and to serve goals which are narrative rather than poetic in the strictest sense. It is also exemplified by Saba's tendency to re-appropriate classical myths (the Odyssey and Oresteia in particular) from a specifically homoerotic perspective, a phenomenon which leads to a proliferation in the Canzoniere of male figures whose resonance is at once personal and archetypal. The connection between mythopoeia and the process of self-understanding and self-fashioning also informs the methodological slant of my research. Whereas scholars still tend to view Freudian psychoanalysis as a major hermeneutic key to Saba's world, I lay great emphasis on the fact that the Canzoniere 's mythopoeia shows numerous significant points of contact with the archetypal psychology of C. G. Jung. Accordingly throughout this study I have made use of a number of theoretical sources (Karol Kerenyi and James Hillman, as well as Jung) which have not previously been applied to Saba and his work

Statistical Methods for the Analysis of Epigenomic Data

Epigenomics, the study of the human genome and its interactions with proteins and other cellular elements, has become of significant interest in the past decade. Several landmark studies have shown that these interactions regulate essential cellular processes (gene transcription, gene silencing, etc.) and are associated with multiple complex disorders such as cancer incidence, cardiovascular disease, etc. Chromatin immunoprecipitation followed by massively-parallel sequencing (ChIP-seq) is one of several techniques used to (1) detect protein-DNA interaction sites, (2) classify differential epigenomic activity across conditions, and (3) characterize subpopulations of single-cells in heterogeneous samples. In this dissertation, we present statistical methods to tackle problems (1-3) in contexts where protein-DNA interaction sites expand across broad genomic domains. First, we present a statistical model that integrates data from multiple epigenomic assays and detects protein-DNA interaction sites in consensus across multiple replicates. We introduce a class of zero-inflated mixed-effects hidden Markov models (HMMs) to account for the excess of observed zeros, the latent sample-specific differences, and the local dependency of sequencing read counts. By integrating multiple samples into a statistical model tailored for broad epigenomic marks, our model shows high sensitivity and specificity in both simulated and real datasets. Second, we present an efficient framework for the detection and classification of regions exhibiting differential epigenomic activity in multi-sample multi-condition designs. The presented model utilizes a finite mixture model embedded into a HMM to classify patterns of broad and short differential epigenomic activity across conditions. We utilize a fast rejection-controlled EM algorithm that makes our implementation among the fastest algorithms available, while showing improvement in performance in data from broad epigenomic marks. Lastly, we analyze data from single-cell ChIP-seq assays and present a statistical model that allows the simultaneous clustering and characterization of single-cell subpopulations. The presented framework is robust for the often observed sparsity in single-cell epigenomic data and accounts for the local dependency of counts. We introduce an initialization scheme for the initialization of the EM algorithm as well as the identification of the number of single-cell subpopulations in the data, a common task in current single-cell epigenomic algorithms.Doctor of Philosoph

Limit Synchronization in Markov Decision Processes

Markov decision processes (MDP) are finite-state systems with both strategic and probabilistic choices. After fixing a strategy, an MDP produces a sequence of probability distributions over states. The sequence is eventually synchronizing if the probability mass accumulates in a single state, possibly in the limit. Precisely, for 0 <= p <= 1 the sequence is p-synchronizing if a probability distribution in the sequence assigns probability at least p to some state, and we distinguish three synchronization modes: (i) sure winning if there exists a strategy that produces a 1-synchronizing sequence; (ii) almost-sure winning if there exists a strategy that produces a sequence that is, for all epsilon > 0, a (1-epsilon)-synchronizing sequence; (iii) limit-sure winning if for all epsilon > 0, there exists a strategy that produces a (1-epsilon)-synchronizing sequence. We consider the problem of deciding whether an MDP is sure, almost-sure, limit-sure winning, and we establish the decidability and optimal complexity for all modes, as well as the memory requirements for winning strategies. Our main contributions are as follows: (a) for each winning modes we present characterizations that give a PSPACE complexity for the decision problems, and we establish matching PSPACE lower bounds; (b) we show that for sure winning strategies, exponential memory is sufficient and may be necessary, and that in general infinite memory is necessary for almost-sure winning, and unbounded memory is necessary for limit-sure winning; (c) along with our results, we establish new complexity results for alternating finite automata over a one-letter alphabet

Molekularna karakterizacija starog stabla masline Olea europea na Brijunima analizom SSR markera

Investigations were carried out on molecular characterization of a 1600 years old olive tree located on the Brijuni islands (Croatia) by SSR markers analysis. Measurements of fruits and leaves features were carried out on the old tree Brijunka and on the standard Istrian cultivar Buga (Buža). Measurement data on fruits and leaves were calculated statistically.Istraživanja obuhvaćaju molekularnu karakterizaciju 1600 godina starog stabla masline Olea europea na Brijunima analizom SSR markera. Provedene su izmjere svojstava ploda i lišća starog stabla masline Brijunke i standardne istarske sorte Buga (Buža). Rezultati istraživanja obrađeni su varijacijsko-statistički

Suppression of SERK gene expression affects fungus tolerance and somatic embryogenesis in transgenic lettuce.

Made available in DSpace on 2018-06-11T17:31:48Z (GMT). No. of bitstreams: 1 SP19599ID31651.pdf: 249594 bytes, checksum: 6c950985490eca25a86caaf4a73346a7 (MD5) Previous issue date: 2009-04-06bitstream/item/178429/1/SP-19599-ID-31651.pd

Reasoning about Communicating Agents in the Semantic Web

Abstract. In this article we interpret the Semantic Web and Web Service issues in the framework of multi-agent interoperating systems. We will advocate the application of results achieved in the research area of reasoning about actions and change by showing scenarios and techniques that could be applied.

PBFT vs proof-of-authority: Applying the CAP theorem to permissioned blockchain

Permissioned blockchains are arising as a solution to federate companies prompting accountable interactions. A variety of consensus algorithms for such blockchains have been proposed, each of which has different benefits and drawbacks. Proof-of-Authority (PoA) is a new family of Byzantine fault-tolerant (BFT) consensus algorithms largely used in practice to ensure better performance than traditional Practical Byzantine Fault Tolerance (PBFT). However, the lack of adequate analysis of PoA hinders any cautious evaluation of their effectiveness in real-world permissioned blockchains deployed over the Internet, hence on an eventually synchronous network experimenting Byzantine nodes. In this paper, we analyse two of the main PoA algorithms, named Aura and Clique, both in terms of provided guarantees and performances. First, we derive their functioning including how messages are exchanged, then we weight, by relying on the CAP theorem, consistency, availability and partition tolerance guarantees. We also report a qualitative latency analysis based on message rounds. The analysis advocates that PoA for permissioned blockchains, deployed over the Internet with Byzantine nodes, do not provide adequate consistency guarantees for scenarios where data integrity is essential. We claim that PBFT can fit better such scenarios, despite a limited loss in terms of performance

Erythrocyte morphology automated analysis: proposal for a new prediction tool of essential hypertension diagnosis

Erythrocyte morphology has already been studied in essential hypertension (EH) and cell membrane alterations have been observed. Relationships among red cell rheological, biochemical, and morphological properties still appear complex and are not clearly understood