PT\mathcal{PT}-Symmetric Quantum State Discrimination for Attack on BB84 Quantum Key Distribution

Quantum Key Distribution or QKD provides symmetric key distribution using the quantum mechanics/channels with new security properties. The security of QKD relies on the difficulty of the quantum state discrimination problem. We discover that the recent developments in $\mathcal{PT}$ symmetry can be used to expedite the quantum state discrimination problem and therefore to attack the BB84 QKD scheme. We analyze the security of the BB84 scheme and show that the attack significantly increases the eavesdropping success rate over the previous Hermitian quantum state discrimination approach. We design and analyze the approaches to attack BB84 QKD protocol exploiting an extra degree of freedom provided by the $\mathcal{PT}$-symmetric quantum mechanics

Особенности применения технологии газлифта на месторождениях Вьетнама

За последние несколько лет о газлифтном методе эксплуатации скважин было написано немало, и добавить к этому что-либо существенное весьма непросто, в работе представлены современные достижения технологии газлифта в сложных условиях при эксплуатации скважин. Был проведен анализ эффективности применения методов для повышения КПД газлифтных скважин в условиях данного месторождения, а так же предложена методика по выбору оптимального режима, обеспечивающая максимальную экономию расхода газа.Much has been written about gas-lift in the past few years, so it is difficult to add new information. The purpose of this work is to present achievements of the technology of gas lift in difficult conditions in the operation of wells. This work also conducts an analysis of the effectiveness of methods to increase the efficiency of gas-lift wells in the field, as well as selecting the optimal mode, which provides a maximum saving of gas consumption

Evaluation of climate changes and their accounting for developing the reclamation measures in western Ukraine

In modern conditions, there are cardinal climate changes on the Earth as at the planetary scale, as at the regional level. According to numerous hydrometeorological characteristics and indicators, climatologists specialists concluded that Ukraine also take place significant climatic changes in the last 10–25 years. In complicated natural-technical systems, which include irrigation and drainage systems (IDS) on drained lands, the selection of regime-technological and technical solutions on different levels of the decision including the time, should be based on the appropriate meteorological information for selecting climatologically optimal management strategies for such systems in the long-term and annual periods. The decisive influence on the formation of water and the overall natural reclamation modes of reclaimed land and harvest crops in many cases depends exactly from climate or weather conditions. Thus, it is necessary to have available data about their implementation to the relevant object as for number of previous years retrospective observations and the forecast period of functioning of the object. Therefore, forecasting of weather and climate conditions become an indispensable condition for implementation of assessing the overall effectiveness of IDS operation. To solve this problem we performed large-scale computer experiment for multi-year retrospective and current data observations in the area of Zhytomyr Polissya. Were planned and implemented the following variants of studies – «Base», «Transitional», «Recent», «CCCM», «UKMO». The forecast was done for five years of typical groups of vegetation periods regarding conditions of heat and moisture provision (very wet – 10%, wet – 30%, average – 50%, dry – 70%, very dry – 90%) on such basic meteorological characteristics: air temperature; precipitation; relative air humidity; defi cit of air humidity; photosynthetically active radiation (PAR); coeffi cient of moisture provision (the ratio of precipitation to evapotranspiration). Obtained results of comparative assess-ment of climatic conditions in Zhytomyr Polissya zone, suggests that for most of the basic meteorological parameters, already there are changes that in the short term may exceed 10% of the critical ecological threshold, which will lead to relevant irreversible changes in the state of the environment in the region