868 research outputs found
Supplemental Material, 20180718ZaganasetalCretanAgingCohortSupplementaryRevised - The Cretan Aging Cohort: Cohort Description and Burden of Dementia and Mild Cognitive Impairment
No full textSupplemental Material, 20180718ZaganasetalCretanAgingCohortSupplementaryRevised for The Cretan Aging Cohort: Cohort Description and Burden of Dementia and Mild Cognitive Impairment by Ioannis V. Zaganas, Panagiotis Simos, Maria Basta, Stefania Kapetanaki, Symeon Panagiotakis, Irini Koutentaki, Nikolaos Fountoulakis, Antonios Bertsias, George Duijker, Chariklia Tziraki, Nikolaos Scarmeas, Andreas Plaitakis, Dimitrios Boumpas, Christos Lionis, and Alexandros N. Vgontzas in American Journal of Alzheimer's Disease & Other Dementias</p
Babel, or the local distortion of the Greek language
No full textTitle: Βαβυλωνία ἤ ἡ κατά τόπους διαφθορά τῆς ἑλληνικῆς γλώσσας. Κωµωδία (Babel, or the local distortion of the Greek language: A comedy) Originally published: Ναύπλιο (Nafplio), Τυπογραφεῖsο Κωνσταντίνου Τόµπρα ἐκ Κυδωνιῶν καὶ Κωνσταντίνου Ἰωαννίδη ἐκ Σµύρνης, 1836 Language: Greek The excerpt used is from D. C. Vyzantios, Βαβυλωνία, introduction by Spyros Evangelatos (Athens: Εστία, 1993), pp.1–3. About the author Dimitrios Vyzantios (pseudonym of Dimitrios K. Hatziaslanis) [1790, Constantin..
Dimitrios Tsamis Karatasos : a symbol of Greek, Serbian and Bulgarian friendship
No full textTwo Serbian texts extol the contribution of Dimitrios Tsamis Karatasos to the Balkan joint effort to throw off the Ottoman yoke. These texts are analysed by the author within the historical framework of their period, so that the man’s personality and work may be accurately evaluated from a fresh viewpoint. More specifically, the author conducts a research on the tombstone of Dimitrios Tsamis Karatasos, which he discovered himself at Naoussa, and the octet engraved on it, which is also published here. The work is illustrated by seven plates, of which four have not been published previously
The Remains of authoritarianism : bureaucracy and civil society in post-authoritarian Greece
No full textDimitrios A. Sotiropoulos. 30 cm. He presented this paper at a seminar held at the Center on October 21, 1994. - T.p. Includes bibliographical references (p. 31-35
Erratum: Korkovelos, A., et al. The role of open access data in geospatial electrification planning and the achievement of SDG7. An OnSSET-based case study for Malawi. <i>Energies</i> 2019, 12(7), 1395
No full textThe authors wish to make a change in author names (adding new author—Dimitrios Mentis) to this paper
Kombinatorische und Algorithmische Konstruktionen von Covering Arrays
No full textCovering Arrays sind kombinatorische Designs. Als solche werden diese üblicherweise als Matrizen mit speziellen Eigenschaften betreffend des Vorkommens von Tupeln in gewissen Teilmatrizen definiert. Ziel dieser Arbeit ist es, eine Einführung in Covering Arrays und deren Generalisierungen zu geben, um im Anschluss sowohl kombinatorische als auch algorithmische Konstruktionsmethoden dieser Strukturen zu diskutieren. Im Verlauf dieser Diskussion werden verschiedenste Verbindungen zu anderen Teilbereichen der diskreten Mathematik, wie Gruppentheorie und endliche Körper, hergestellt und angewandt. Bei dem Studium von Covering Arrays ergibt sich das zentrale Problem, optimale Covering Arrays, das sind solche mit der geringsten Anzahl an Zeilen, zu erzeugen. Oft muss das Ziel, Covering Arrays mit der geringsten Anzahl an Zeilen zu finden, aufgegeben und durch ein Streben nach solchen mit einer geringen Anzahl an Zeilen ersetzt werden. Dies zeigt der aktuelle Stand der Forschung, nach welchem Konstruktionen für optimale Covering Arrays nur für spezielle Klassen bekannt sind. Das Generieren optimaler Covering Arrays ist nicht nur aus theoretischer Sicht ein interessantes Problem, sondern auch von praktischem Interesse, da Covering Arrays in Testverfahren, vor allem im Bereich automa-tischer Softwaretests, Anwendung finden.Covering arrays are discrete structures appearing in combinatorial design theory. Most frequently, they are introduced as arrays having specific coverage properties regarding the appearance of tuples in certain subarrays. The aim of this thesis is not only to give a thorough introduction to covering arrays and some of their generalizations, but also to describe combinatorial and algorithmic constructions of these structures. In doing so, links to various fields of discrete mathematics such as group theory and the theory of finite fields are established. Throughout the whole thesis, the reader will be guided by an objective for optimality, as one notorious problem that arises is to find covering arrays that have the smallest number of rows. Often the concept of optimality has to be replaced by the aim for covering arrays that have a small number of rows, as the current state of the art is that constructions of optimal covering arrays are only known for some special classes of covering arrays. The generation of optimal covering arrays is not only a theoretically interesting problem, but is also of interest for practical purposes, as covering arrays find applications in testing, especially in automated software testing
Design theory methods and their applications to the science of security
No full textThis Thesis introduces the research program Design Theory Framework for the Science of Security (DEFSYS) and presents its application to four areas of information security. The primary line of presented DEFSYS-activities concerns vulnerability research problems in software security, approached from a software (security) testing point of view, targeting the three areas of system security, injection attacks and security protocol testing. The secondary line of presented DEFSYS-activities evolves around the area of online privacy research, specifically targeting browser fingerprinting. In all applications of DEFSYS given this Thesis, we concentrate on pointing out how discrete mathematical models can be used synergistically together with combinatorial methods to address problems in information security. Two inherent properties of the employed combinatorial design structures play a significant role and provide benefits in all four presented applications within information security: guaranteed coverage (e.g., of tuples or sub-permutations) and – simultaneously – efficiency (e.g., given by reduced test set sizes). Our research on DEFSYS presented in this Thesis has been empirically supported and validated by our achieved combinatorial security testing results in all four given application areas of information security
Combinatorial design theory and applications for software testing
No full textThis thesis pertains to the interplay of combinatorial design theory and software testing. On the one hand, the problem of generating test sets for black-box testing of software systems which are modeled via vectorial input can be abstracted and treated as subject matter of combinatorial design theory and, in a wider sense, as part of discrete mathematics and theoretical computer science. On the other hand, it is subject to this thesis to apply combinatorial designs to solve problems occurring in the realm of software testing. The aforementioned interplay manifests currently in Combinatorial Testing, a software testing methodology centered around test sets that achieve full t-way coverage of a software’s input space. In order to further and strengthen the interconnections between combinatorial design theory for software testing, we will contribute to and advance individual parts of the combinatorial testing process. According to the overall methodology, this thesis is structured in two parts. The first part pertains to the theoretic aspects of this work, such as objects of combinatorial designs, their properties, generation and related problems; the second part comprises concrete applications of combinatorial design theory for testing software and software-aided systems, including dedicated case studies and industrial applications. In the conclusion we capture the individual contributions described throughout this work and outline how they advance the combinatorial testing process, thereby extending the interplay of combinatorial design theory and software testing
Sicherheitstests für das Bluetooth Low Energy Protokoll mit Kombinatorischen Methoden
No full textDer Bluetooth Low Energy (BLE) Standard ist eine weit verbreitete drahtlose Kommunikationstechnologie für Geräte des Internets der Dinge (IoT) und ermöglicht energiesparende Datenübertragung für verschiedene Anwendungen. Da die Verbreitung von BLE rasant zunimmt, wird die Gewährleistung der Sicherheit zum Schutz vor potenziellen Schwachstellen immer wichtiger. Anbieter BLE fähiger Mikrocontroller müssen BLE Protokolle in ihren Geräten entsprechend der Bluetooth Core Specification implementieren. Trotz der Standardisierungsbemühungen wurden in den BLE Implementierungen verschiedener Anbieter mithilfe manueller und automatisierter Methoden Schwachstellen entdeckt, die potentiell Millionen von Geräten betreffen. Dies ist teilweise auf die Komplexität der Protokolle zurückzuführen, die sich aus der überwältigenden Anzahl möglicher Konfigurationen ergibt und darauf, dass ein gründliches Testen der Implementierung aufgrund der Host-Controller-Schnittstelle (HCI) schwierig ist. In den letzten Jahren wurde das GreyHound Fuzzing Framework entwickelt, das mithilfe kostengünstiger Hardware beliebige BLE Pakete bis zur Linklayer Schicht senden kann. Da Fuzzing von Natur aus probabilistisch ist, ersetzen wir die oben genannte Fuzzing Methode durch einen kombinatorischen Sicherheits Test (CST) Ansatz, der eine garantierte Abdeckung des modellierten Eingabebereichs bietet. Durch die Generierung von Testfällen, die mehrere Kombinationen von Eingabeparametern abdecken, wollen wir Schwachstellen identifizieren, die mit herkömmlichen Testmethoden möglicherweise nicht entdeckt werden. Wir evaluieren unseren Ansatz anhand von Tests mit zehn verschiedenen BLE-Geräten mit unterschiedlichen Firmware Versionen. Insgesamt identifizieren wir 19 verschiedene Probleme, reproduzieren Ergebnisse früherer Arbeiten und decken zusätzliche Fehler auf. Um die Wirksamkeit unserer Methode zu überprüfen, vergleichen wir zusätzlich die Leistung unseres CST-Tools mit der des ursprünglichen Fuzzers und vergleichen deren Ausführungszeit und Fehlererkennungsfähigkeiten.The Bluetooth Low Energy (BLE) standard is a widely used wireless communication technology for Internet of Things (IoT) devices, enabling low-power data transmission for various applications. As the adoption of BLE continues to grow rapidly, ensuring their security becomes more and more important to protect against potential vulnerabilities. Vendors of BLE capable micro controllers are required to implement BLE protocols in their manufactured devices compliant to the Bluetooth Core Specification. Despite the efforts of standardization, several vulnerabilities were discovered in the BLE protocol implementations of multiple vendors using manual and automated methods, potentially affecting millions of devices. This can partially be attributed to the protocol's complexity, stemming from an overwhelming number of possible configurations and the fact that it is difficult to test implementations thoroughly due to the Host Controller Interface (HCI). In recent years, the GreyHound fuzzing framework was developed, which is able to send arbitrary BLE packets down to the link layer, using inexpensive consumer hardware. Since fuzzing is inherently probabilistic, we replace the aforementioned fuzzing method with a Combinatorial Security Testing (CST) approach that provides a guaranteed degree of input space coverage over the parameter model. By generating test cases that cover multiple combinations of input parameters, we aim to identify vulnerabilities that may not be uncovered through traditional testing methods. We evaluate our approach by testing 10 different BLE devices with a variety of firmware versions. In total we identify 19 distinct issues, replicating findings of the previous work and uncovering additional faults. To examine the effectiveness of our method, we additionally provide a performance comparison of our CST tool against the original fuzzer, contrasting their execution time and fault detection capabilities
Algebraic methods for experimental design theory
No full textDie Integration von algebraischen Methoden in die Statistik in den frühen und mittleren 1990er Jahren [33, 105] hat beide Forschungsgebiete von den entstandenen Synergien profitieren lassen [4, 104]. Diese Arbeit beschäftigt sich mit kombinatorischen Designs, welche im relativ neuen Bereich des kombinatorischen Testen (KT) für Software als Teilgebiet der statistischen Versuchsplanung verwendet werden [81]. Der Begriff der “Abdeckung”, der als eine Verallgemeinerung des bekannten -fachen Auftretens von t-Tupeln in orthogonalen Arrays angesehen werden kann, steht an zentraler Stelle in dem KT und findet sich auch in den definierenden Eigenschaften der in diesem Bereich betrachteten Strukturen wieder. Zu den betrachteten Strukturen zählen abdeckende Arrays, welche man als spezielle Klasse von kombinatorischen Designs ansehen kann, sowie auch gewisse Klassen von endlichen Sequenzen [28]. Das Ziel dieser Arbeit ist zu analysieren und darstellen, wie algebraische Methoden in der Spezifikation, Erzeugung und der Charakterisierung von Eigenschaften dieser Strukturen verwendet werden können [40]. Die zugrundeliegenden algebraischen Methoden basieren auf Polynomen [16].Since the introduction of algebraic techniques into the field of statistics in the start and middle of the 1990s [33, 105], both fields have immensely benefited from the resulting synergies [4, 104]. This Thesis is concerned with classes of combinatorial designs, that appear in a relatively new subfield called Combinatorial Testing (CT) for Software of Design of Experiments [81]. The notion of “coverage requirement”, which represents a generalization of the well established notion of exactly -way appearance of t-tuples in orthogonal arrays, is fundamental to the field of CT and is also a fundamental property in the discrete structures that are considered in CT. These structures include covering arrays, which can be regarded as a special class of combinatorial designs, and certain classes of finite sequences [28]. The aim of this Thesis is to analyse and depict how algebraic techniques can help in the specification, generation and property assessment of these structures [40]. Polynomial algebraic techniques are the basic methodologies which are to be applied in this domain [16]
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