Deniable encryption protocols based on probabilistic public-key encryption

The paper proposes a new method for designing deniable encryption protocols characterized in using RSA-like probabilistic public-key encryption algorithms. Sender-, receiver-, and bi-deniable protocols are described. To provide bi-deniability in the case of attacks perfored by an active coercer stage of entity authentication is used in one of described protocols

On philosophical premises, state and perspectives of artificial intelligence problem research

The history of idea of artificial intelligence and the ways of its implementation are observed in the paper. The authors select researches based on autoepistemic logic as a perspective line of development of artificial intelligence. Artificial intelligence (AI) is considered as a system that imitates the process of decision making by a man, when a man solves complex tasks. The paper introduces the intellectual tradition of artificial intelligence: this tradition goes back to the Aristotle's "Physics" and Plato's "Dialogs". The premises and grounds for the artificial intelligence theory are disclosed as well. The structure of symbols and operations are considered as basic questions of analysis of artificial intelligence and AI applications. Expert systems are interpreted as a variety of intelligence system. Different methods of knowledge representation (logical model, frame systems and production systems, semantic networks) are designated in the article. These methods are realized within the scope of a cognitive trend of AI investigation. The authors assert that knowledge representation is a methodology of modeling and formalization of conceptual knowledge in the sphere of knowledge engineering

On philosophical premises, state and perspectives of artificial intelligence problem research

The history of idea of artificial intelligence and the ways of its implementation are observed in the paper. The authors select researches based on autoepistemic logic as a perspective line of development of artificial intelligence. Artificial intelligence (AI) is considered as a system that imitates the process of decision making by a man, when a man solves complex tasks. The paper introduces the intellectual tradition of artificial intelligence: this tradition goes back to the Aristotle's "Physics" and Plato's "Dialogs". The premises and grounds for the artificial intelligence theory are disclosed as well. The structure of symbols and operations are considered as basic questions of analysis of artificial intelligence and AI applications. Expert systems are interpreted as a variety of intelligence system. Different methods of knowledge representation (logical model, frame systems and production systems, semantic networks) are designated in the article. These methods are realized within the scope of a cognitive trend of AI investigation. The authors assert that knowledge representation is a methodology of modeling and formalization of conceptual knowledge in the sphere of knowledge engineering

The Nature of Knowledge Power in Communicative Information Society

AbstractDevelopment of communicative information society is described as a process of spreading the applied scientific knowledge converted into information all over the fields of sociality. The idea of “power shift” in the process of development of communicative information sociality is important conceptually. This idea includes disintegration of the existing power structures and rising the new ones, drastic change in the balance of social forces in the power structure, redistribution of power. Development of communicative information sociality is shown to be connected with transformation of knowledge: knowledge converted into information (applied knowledge) gets the ability to transform the socio-cultural ontology. It becomes the most important power resource, transforming the structure of power relations. The key feature of the proposed approach is the intent to study the phenomenon of knowledge transformation under social and philosophical context of society, where the knowledge converted into information gets ontological status of the phenomenon that changes the system of power relations within the framework of communicative sociality also. The positive feedback is shown to be formed during the functioning of such a society: the need for spreading the knowledge stimulates the development of communication system, which in its turn opens the new ways to distribute the knowledge. As a result this society operates as a self-developing system, where communications manifest themselves as the ontology of culture. Communication development acts as a culture-forming factor, generating processes of social and cultural transformations

Calculation of Contact Pressures in Cylindrical Metal-Polymer Sliding Guides

Guides (linear plain bearings) of reciprocating motion are widely used in many areas of human activity. However, at present there are no reasonable methods for their calculation, in particular metal-polymer guides. The author's method of contact strength calculation of cylindrical metal-polymer sliding guides is presented in the article. The effect of load, bushing diameter and radial clearance on the maximum contact pressures and their distribution in the guide was studied on the example of epoxy-based polymer composite material Moglice of the German company DIAMANT Metallplastic GmbH, which is used to restore tribotechnical sliding systems elements. Quantitative and qualitative regularities of dependence of contact pressures on the accepted factors of influence are established: at loading increase four times the maximum contact pressures and contact angles will increase twice irrespective of change of sizes of a radial clearance and diameter of a base; increasing the base diameter leads to a directly proportional decrease in maximum contact pressures; doubling the radial clearance leads to a -fold increase in pressure, regardless of changes in the magnitude of the load and the diameter of the base. Regularities of change of contact parameters from the specified factors are given graphically

Bi-deniable public-encryption protocols based on standard PKI

The paper proposes new deniable encryption protocols providing bi-deniability in the case of both the passive coercive attack and the active one. It is supposed the coercive adversary intercepts all data sent during the protocol. The protocols use no shared secret keys that are pre-agreed by parties of the protocol. Bi-deniability is based on computational indistinguishability between deniable encryption and probabilistic one. Significant merit of the proposed protocols is their using the standard public key infrastructure

Математична модель утворення зубців циліндричної прямозубої передачі гіперболічним вихідним контуром

The aim of this work is to create a fundamentals of mathematical model which consists in definition of geometry of a generating surface and machining gearing for novel cylindrical spur transmission. The generating surface is considered as rack-cutter with teeth, which profiled by hyperbola – a curve which is smooth at whole addendum and dedendum parts of reference profile. The equations of teeth surfaces which help the basic performances of this generating surface surveyed, namely quadratic forms and normal curvatures in the given directions are presented. The equations of machining gearings which help to obtain the equations of surfaces of teeth which can be applied both for working surfaces and for their fillets are obtained. For these surfaces quadratic forms also defined. Boundaries of a contact zone are defined. The results obtained in a paper can be used for definition of quality indicators of serviceability of novel transmissions which will allow carrying out a comparative estimation of novel transmission with conventional one and with other types of transmissionsПредставлено теоретичне дослідження внутрішньої геометрії виробної поверхні та верстатного зачеплення для утворення зубців циліндричних прямозубих передач нового типу. Виробна поверхня розглядається як інструментальна рейка з вихідним контуром, що спрофільовано гіперболою. Наведено рівняння поверхонь зубців інструментальної рейки, розглянуто основні характеристики цієї виробної поверхні, а саме квадратичні форми і нормальні кривизни в заданих напрямках. Представлено рівняння верстатного зачеплення, за допомогою якого одержано рівняння поверхонь зубців, як робочих так і перехідних. Для цих поверхонь також визначено коефіцієнти квадратичних форм та кривизни. Визначено межі поля зачеплення. Результати, одержані в статті, в подальшому можна використовувати для визначення якісних показників працездатності нового типу передач, що дозволить проводити їх порівняльну оцінку із традиційними та іншими видами передач

Onion-like surface design of upconverting nanophosphors modified with polyethylenimine : shielding toxicity versus keeping brightness?

Background: Upconverting nanoparticles (UCNPs) represent a unique class of nanomaterials, able to convert infrared excitation light into long lifetime visible and infrared photoluminescence, within the "optical transparency window" of biological tissues. This makes UCNPs an attractive contrast agent for background-free bioimaging. However, assynthesized UCNPs are hydrophobic and need additional surface coating for stability in water-based solutions and further functionalization. Polyethylenimine (PEI), a polycationic amphiphilic polymer, is a well-known transfection agent for gene delivery and a popular material for UCNPs surface hydrophilization. Combining the functional properties of UCNPs and PEI is extremely useful for precise visualization of genetic manipulations and intracellular drug delivery. At the same time, PEI is toxic to cells, while the photoluminescent properties of UCNPs are very sensitive to surface chemistry and environment. Then, creation of hydrophilic, biocompatible and simultaneously bright UCNPs, modified by PEI (UCNP-PEI), is a challenging task. Objectives: To analyze the effects of multilayer shielding coatings on cytotoxicity, cellular uptake and photoluminescent properties of UCNP-PEI. Methods and results: UCNP-PEI were modified with additional two or three layers of various polymers and characterized by size, surface charge and photophysical properties. HaCaT keratinocytes were exposed to the particles for 24 or 120 h to study the cytotoxicity and cellular uptake. The results show that onion-like coatings of UCNP-PEI simultaneously decrease cytotoxicity and relative luminescence of the particles, depending on structure and method of formation of multilayer coating. Conclusions: Rational design of UCNP-PEI using extra coatings layers can help to keep acceptable levels of biocompatibility and photoluminescence intensity.5 page(s