28,450 research outputs found

    Refinement of Techniques Metallographic Analysis of Highly Dispersed Structures

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    Flaws are regularly made while developing standards and technical specifications. They can come out as minor misprints, as an insufficient description of a technique. In spite the fact that the flaws are well known, it does not come to the stage of introducing changes to standards. In this paper shows that in the normative documents is necessary to clarify the requirements for metallurgical microscopes, which are used for analysis of finely-dispersed

    Data Protection

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    What is information? Information is a resource, regardless of its presentation perceived by the person and / or special devices as a reflection of the material world of the facts in communication process (GOST 7.0-99). There are 3 properties of information: integrity, availability and confidentiality

    Стойкость ГОСТ 28147-89 при использовании таблицы подстановок из ГОСТ 34.311-95

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    Розглядається стійкість ГОСТ 28147-89 при використанні довгострокового ключа, що наведений у стандарті хешування ГОСТ 34.311-95. Наводяться приклади побудови диференційних характеристик та доводиться неможливість диференційної та лінійної атаки на ГОСТ 28147-89 з цією таблицею підстановок. Пропонується використовувати довгостроковий ключ як стандартний для ГОСТ 28147-89.The resistance of the GOST 28147-89 encryption algorithm with the S-boxes from the hash function standard GOST 34.311-95 is considered. The examples of the differential characteristics are given and the invulnerableness of the cipher with these S-boxes to the differential and linear cryptanalysis is proved. The S-boxes from the GOST 34.311-95 are proposed as a standard for the GOST 28147-89

    Optical and evaporative cooling of cesium atoms in the gravito-optical surface trap

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    We report on cooling of an atomic cesium gas closely above an evanescent-wave atom mirror. At high densitities, optical cooling based on inelastic reflections is found to be limited by a density-dependent excess temperature and trap loss due to ultracold collisions involving repulsive molecular states. Nevertheless, very good starting conditions for subsequent evaporative cooling are obtained. Our first evaporation experiments show a temperature reduction from 10muK down to 300nK along with a gain in phase-space density of almost two orders of magnitude.Comment: 8 pages, 6 figures, submitted to Journal of Modern Optics, special issue "Fundamentals of Quantum Optics V", edited by F. Ehlotzk

    An Improved Differential Attack on Full GOST

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    GOST 28147-89 is a well-known block cipher. Its large key size of 256 bits and incredibly low implementation cost make it a plausible alternative for AES-256 and triple DES. Until 2010 \despite considerable cryptanalytic efforts spent in the past 20 years", GOST was not broken see [30]. Accordingly, in 2010 GOST was submitted to ISO 18033 to become a worldwide industrial encryption standard. In paper we focus on the question of how far one can go in a dedicated Depth-First-Search approach with several stages of progressive guessing and filtering with successive distinguishers. We want to design and optimized guess-then-truncated differential attack on full 32-bit GOST and make as as efficient as we can. The main result of this paper is a single key attack against full 32-round 256-bit GOST with time complexity of 2^179 which is substantially faster than any other known single key attack on GOS

    Indicators and methods for assessing the quality of logistic activity processes

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    Purpose: This article is aimed at identifying and evaluating the quality and safety indicators of processes in the logistics system and solving the problems of product control in the goods’ distribution process. Design/Methodology/Approach: In order to assess the risks and quality of control methods in the goods’ distribution processes, studies were carried out in the process of grain supply, on which the risk assessment was tested using the fault tree using a qualitative approach with a deductive logic, which allowed to identify events at the lower levels of the system. To evaluate the results when comparing various methods of monitoring the characteristics of products in the product distribution process certain statistical tools were used. The evaluation with comparative tests is required in order to determine the way of measuring products in the goods distribution logistics system. The study uses the methods of formalization, analysis, measurement, experimental and comparison. Findings: The considered risk assessment method and the given example allow us to recommend its use for the product distribution processes for various purposes. A technique is proposed for comparing various control methods based on statistical tools that can be recommended for various goods’ distribution operations. Practical implications: The results of the study can be applied in practice to improve the quality of goods’ distribution processes and reduce risks in the various supply chains. Originality/value: The main contribution of this study is to shift the emphasis on the assessment of processes in goods’ distribution to the positions of a risk-based approach and the use of various statistical tools in logistics’ activities.peer-reviewe
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