Transfer of MPEG-2 Transport Stream over MPLS

This study examines how MPEG-2 Transport Stream, used in DVB-T video transmission, can be reliably and efficiently transferred to remote locations over an MPLS network. All the relevant technologies used in this scenario are also discussed in the study. This study was done for Digita Oy, which is a major radio and television content distributor in Finland. The theoretical part of the study begins with the introduction to MPLS technology and continues with explanation of IP Multicast and its components. The fourth section discusses MPEG-2 and the formation and content of MPEG-2 Transport Stream. These technologies were studied in relevant literature and RFC documentation. After the theoretical part of the study, the test setup and the test cases are presented. The results of the test cases, and the conclusions that can be drawn based on them, are discussed in the last section of the study. The tests showed that it is possible to transfer digital video quite reliably over an MPLS network using IP Multicast. By configuring the equipment correctly, the recovery time of the network in case of a failure can be shortened remarkably. Also, the unwanted effect of other traffic on the critical video traffic can be eliminated by defining the Quality of Service parameters correctly. There are, however, some issues that need to be tested further before this setup can be used in broadcast networks. Reliable operation of IP Multicast and proper error correction are the main subjects for future testing.

A mathematical study of fuzzy logic; an algebraic approach

Fuzzy set theory and Fuzzy logic is studied from a mathematical point of view. The main goal is to investigatecommon mathematical structures in various fuzzy logical inference systems and to establish a general mathematical basis for fuzzy logic when considered as multi-valued logic. The study is composed of six distinct publications. The first paper deals with Mattila'sLPC+Ch Calculus. THis fuzzy inference system is an attempt to introduce linguistic objects to mathematical logic without defining these objects mathematically.LPC+Ch Calculus is analyzed from algebraic point of view and it is demonstratedthat suitable factorization of the set of well formed formulae (in fact, Lindenbaum algebra) leads to a structure called ET-algebra and introduced in the beginning of the paper. On its basis, all the theorems presented by Mattila and many others can be proved in a simple way which is demonstrated in the Lemmas 1 and 2and Propositions 1-3. The conclusion critically discusses some other issues of LPC+Ch Calculus, specially that no formal semantics for it is given.In the second paper the characterization of solvability of the relational equation RoX=T, where R, X, T are fuzzy relations, X the unknown one, and o the minimum-induced composition by Sanchez, is extended to compositions induced by more general products in the general value lattice. Moreover, the procedure also applies to systemsof equations. In the third publication common features in various fuzzy logicalsystems are investigated. It turns out that adjoint couples and residuated lattices are very often present, though not always explicitly expressed. Some minor new results are also proved.The fourth study concerns Novak's paper, in which Novak introduced first-order fuzzy logic and proved, among other things, the semantico-syntactical completeness of this logic. He also demonstrated that the algebra of his logic is a generalized residuated lattice. In proving that the examination of Novak's logic can be reduced to the examination of locally finite MV-algebras.In the fifth paper a multi-valued sentential logic with values of truth in an injective MV-algebra is introduced and the axiomatizability of this logic is proved. The paper developes some ideas of Goguen and generalizes the results of Pavelka on the unit interval. Our proof for the completeness is purely algebraic. A corollary of the Completeness Theorem is that fuzzy logic on the unit interval is semantically complete if, and only if the algebra of the valuesof truth is a complete MV-algebra. The Compactness Theorem holds in our well-defined fuzzy sentential logic, while the Deduction Theorem and the Finiteness Theorem do not. Because of its generality and good-behaviour, MV-valued logic can be regarded as a mathematical basis of fuzzy reasoning. The last paper is a continuation of the fifth study. The semantics and syntax of fuzzy predicate logic with values of truth in ana injective MV-algerba are introduced, and a list of universally valid sentences is established. The system is proved to be semanticallycomplete. This proof is based on an idea utilizing some elementary properties of injective MV-algebras and MV-homomorphisms, and is purely algebraic.

STACK OVERWRITING ATTACKS AND DEFENCES IN UNIX ENVIRONMENT

Työn tarkoituksena on tutkia pinon ylikirjoitukseen perustuvien hyökkäysten toimintaa ja osoittaa kokeellisesti nykyisten suojaustekniikoiden olevan riittämättömiä. Tutkimus suoritetaan testaamalla miten valitut tietoturvatuotteet toimivat eri testitilanteissa. Testatut tuotteet ovat Openwall, PaX, Libsafe 2.0 ja Immunix 6.2. Testaus suoritetaan pääasiassa RedHat 7.0 ympäristössä testiohjelman avulla. Testeissä mitataan sekä tuotteiden kyky havaita hyökkäyksiä että niiden nopeusvaikutukset. Myös erityyppisten hyökkäysten ja niitä vastaan kehitettyjen metodien toimintaperiaatteet esitellään seikkaperäisesti ja havainnollistetaan yksinkertaistetuilla esimerkeillä. Esitellyt tekniikat sisältävät puskurin ylivuodot, laittomat muotoiluparametrit, loppumerkittömät merkkijonot ja taulukoiden ylivuodot. Testit osoittavat, etteivät valitut tuotteet estä kaikkia hyökkäyksiä, joten lopuksi perehdytään myös vahinkojen minimointiin onnistuneiden hyökkäysten varalta.

Detection of denial of service attacks

This thesis studies techniques used for detection of distributed denial of service attacks which during last decade became one of the most serious network security threats. To evaluate different detection algorithms and further improve them we need to test their performance under conditions as close to real-life situations as possible. Currently the only feasible solution for large-scale tests is the simulated environment. The thesis describes implementation of recursive non-parametric CUSUM algorithm for detection of distributed denial of service attacks in ns-2 network simulator – a standard de-facto for network simulation.

Many valued algebraic structures as measures of comparison

This thesis studies the properties and usability of operators called t-norms, t-conorms, uninorms, as well as many valued implications and equivalences. Into these operators, weights and a generalized mean are embedded for aggregation, and they are used for comparison tasks and for this reason they are referred to as comparison measures. The thesis illustrates how these operators can be weighted with a differential evolution and aggregated with a generalized mean, and the kinds of measures of comparison that can be achieved from this procedure. New operators suitable for comparison measures are suggested. These operators are combination measures based on the use of t-norms and t-conorms, the generalized 3_-uninorm and pseudo equivalence measures based on S-type implications. The empirical part of this thesis demonstrates how these new comparison measures work in the field of classification, for example, in the classification of medical data. The second application area is from the field of sports medicine and it represents an expert system for defining an athlete's aerobic and anaerobic thresholds. The core of this thesis offers definitions for comparison measures and illustrates that there is no actual difference in the results achieved in comparison tasks, by the use of comparison measures based on distance, versus comparison measures based on many valued logical structures. The approach has been highly practical in this thesis and all usage of the measures has been validated mainly by practical testing. In general, many different types of operators suitable for comparison tasks have been presented in fuzzy logic literature and there has been little or no experimental work with these operators.

Fuzzy subgroups, algebraic and topological points of view and complex analysis

Fuzzy subsets and fuzzy subgroups are basic concepts in fuzzy mathematics. We shall concentrate on fuzzy subgroups dealing with some of their algebraic, topological and complex analytical properties. Explorations are theoretical belonging to pure mathematics. One of our ideas is to show how widely fuzzy subgroups can be used in mathematics, which brings out the wealth of this concept. In complex analysis we focus on Möbius transformations, combining them with fuzzy subgroups in the algebraic and topological sense. We also survey MV spaces with or without a link to fuzzy subgroups. Spectral space is known in MV algebra. We are interested in its topological properties in MV-semilinear space. Later on, we shall study MV algebras in connection with Riemann surfaces. In fact, the Riemann surface as a concept belongs to complex analysis. On the other hand, Möbius transformations form a part of the theory of Riemann surfaces. In general, this work gives a good understanding how it is possible to fit together different fields of mathematics.

Waste Stream Investigation from Perspective of Changing Waste Legislation at Green Sand Foundries

The update of the Finnish legislation concerning waste was unavoidable, to comply with the European Union (EU) requirements defined in the EU-Directive on Waste. The new waste law updates were enacted into the Finnish legislation on the 11.03.2011 and targeted for applicability by the 11.03.2012. This thesis investigates the implications of the new amendments to the waste legislation from the perspective of green sand foundries. The investigations are conducted by comparing two of Componenta’s green sand foundries and evaluating their waste streams. Additionally, the impacts of legislation amendments are critiqued on their environmental and economic aspects. The study’s comparison of waste fractions at the two foundries reveals that sand is dominant in absolute tonnage and costs. The increments of waste taxes forces foundries to focus on waste management, recycling and disposing. The new legislation’s promotion of material efficiency, also guides foundries towards the prevention of waste. A potential preventive measure is to regenerate waste sand resulting to cost savings on both raw-materials and waste management. However, the lack of absolute targets for waste prevention or recycling rates discourages the interests towards creating or adopting new technologies and methods for the waste handling.

Is All Fair in Law and War? The Ambiguous Principle of Proportionality of Collateral Damage and the CIA Drone Attacks in Pakistan

Tutkielma käsittelee Yhdysvaltain CIAn miehittämättömiä lennokki-iskuja Pakistanissa kansainvälisen humanitaarisen oikeuden suhteellisuusperiaatteen näkökulmasta. Suhteellisuusperiaatteen mukaan aseellisista iskuista saatavan sotilaallisen hyödyn tulee olla suhteellinen verrattuna siviileille aiheutuvaan haittaan. CIAn iskuja Pakistanissa on kritisoitu, että ne eivät täytä suhteellisuusperiaatteen asettamia vaatimuksia. Tutkielmassa perehdytään ensinnäkin selvittämään ne velvollisuudet, jotka suhteellisuusperiaate asettaa hyökkääjille. Sen jälkeen CIAn lennokki-iskuja tutkitaan näiden velvollisuuksien valossa. Tutkielmassa pyritään selvittämään antaako suhteellisuusperiaatteen luomat oikeudelliset velvollisuudet riittävää suojaa Pakistanin siviileille lennokki-iskujen tuhoja vastaan. Lisäksi pyritään selvittämään, onko lennokki-iskuissa viitteitä suhteellisuusperiaatteen vastaisista iskuista. Tutkimusmenetelmänä käytetään positivistista lainopin metodia, jonka avulla selvitetään voimassa olevaa kansainvälisen humanitaarisen tapaoikeuden suhteellisuusperiaatteen sisältöä. Oikeudellisina lähteinä käytetään pääasiassa humanitaarista tapaoikeutta, mutta tulkinnallisena apuna myös kansainvälisiä sopimuksia sekä oikeuden päätöksiä. Lisäksi oikeudellinen kirjallisuus on tutkimuksessa tärkeässä asemassa. Tutkimuksessa päädytään siihen, että suhteellisuusperiaatteen asettamat velvollisuudet hyökkääjälle ovat niin epämääräiset, että ne eivät anna riittävää suojaa siviileille. Ensinnäkin hyökkääjä voi määrittää sotilaallisen hyödyn omien päämääriensä mukaisesti suhteellisuusanalyysissä. Lisäksi kynnys sille, mikä katsotaan suhteellisuusperiaatteen vastaisuudeksi on hyvin epämääräinen ja korkea. Tämän vuoksi varotoimenpiteet iskujen suunnittelussa ovat hyvin tärkeässä asemassa myös suhteellisuusanalyysissä. Kuitenkin jos hyökkääjä edes jossain määrin osoittaa, että on tehnyt iskut hyvässä uskossa niiden laillisuudesta, iskujen katsotaan yleensä olevan suhteellisuusperiaatteen mukaisia. CIAn lennokki-iskuissa Pakistanissa on viitteitä suhteellisuusperiaatteen vastaisuudesta erityisesti ”tunnusmerkki-iskujen” osalta. ”Tunnusmerkki-iskut” johtavat yleensä vain vähäiseen sotilaalliseen hyötyyn aiheuttaen silti siviiliuhreja. Lisäksi erityisesti tunnusmerkki-iskuissa edellytetään korkeampaa tarkkuutta varotoimenpiteissä. Kuitenkin useat siviiliuhrit voivat merkitä sitä, että näitä varotoimenpiteitä ei ole noudatettu iskuissa.