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• ROLE OF LIGHTNING IN THE CLOUD TRANSITION FROM THUNDERSTORM TO HURRICANE AND THEIR ARTIFICIAL INITIATION AS A METHOD OF PREVENTING HURRICANE AND PRECIPITATIONS REDISTRIBUTION

  М. N. Beituganov , K. H. Chochaev

  170-180

  2026-09-10

  Abstract ▼

  The transition of the cloud, thunderstorm state, accompanied by intensive lightning discharges, to hail occurs as a result of the nucleation and growth of hail nuclei in the drop and grain forms. The vertical extent of the volume where nuclei where are formed on giant particles of micro-impurities in the atmosphere (GPA) is between the isotherms from -2 ⁰C to -15 ⁰C. Ice crystals grow due to sublimation and coagulation with supercooled cloud droplets. In the same volume, between the isotherms of temperatures from -5 ⁰C to -16 ⁰C, discharges occur with the maximum number of lightning strikes at an altitude
  of -10 ⁰C. Lightning strikes introduce an excess volume charge with an ion concentration of about 10¹⁷ cm^-3 into the cloud space. Positive lightning strikes introduce positive ions, while negative lightning strikes introduce negative ions. These ions are deposited on the GPA, which have concentrations of about 10⁵ m^-3 in pre-hail situations. The negative charge on the GPA, contributing to the nucleation of planar crystal structures on the particle, forms a granular hailstone. The positive charge on the GPA forms filamentous structures that break off, and the fragments, when they come into contact with supercooled large droplets and freeze them, lead to the formation of droplet hailstones. To prevent hail, ground lightning, and the redistribution of precipitation, a method based on the initiation of artificial lightning has been proposed. Methods of initiating artificial lightning are given using: plasma formations resulting from the detonation of 100 mm artillery shells in thunderstorm-hail clouds, a special rocket with a detonating cord, and an anti-hail rocket with a conductive surface. A significant change in the radar reflectivity of a thunderstorm-hail cloud has been observed under the influence of an artificially initiated lightning strike. Based on the results of preliminary experiments on hail prevention, the method of preventing and interrupting hail using "reagent plus artificially initiated lightning" has been proposed. Given the established fact that approximately 10 tons of precipitation are released with each lightning strike, it is possible to redistribute precipitation, prevent ground-based lightning, and more using artificially initiated lightning. In the future, unmanned aerial systems should be used to initiate artificial lightning within thunderstorm clouds, while quadcopters should be used in the vicinity of clouds

• DEVELOPMENT OF THE DETAILED PLACEMENT ALGORITHM FOR FPGAS

  D.B. Shokarev, R.Z. Chochaev, А.N. Schelokov, S.V. Gavrilov

  2023-12-11

  Abstract ▼

  Hierarchical field-programmable gate arrays (FPGAs) consist of an array of programmable
  logic blocks arranged into groups. Successful routing requires optimal placement of logic elements
  within the groups, considering the architectural features of the local interconnections. Classical
  algorithms are not able to consider these features. That’s why, the development of new algorithms
  is required. In this paper, we present a detailed placement algorithm with a new metric that
  allows us to estimate the number of available local interconnections inside the groups of logic
  blocks, considering the architectural features of the local interconnections. The detailed placement
  algorithm consists of several stages. At the first stage, the group of logic elements is transformed
  into a directed graph. Then, the placement order of logic elements in the group is determined using
  the breadth-first search algorithm. At the final stage, for each element, according to the obtained
  order, the optimal placement in the group is determined, considering the new metric.
  If there is no optimal position in the group among the free ones, the occupied positions are
  checked. The current element is placed in the occupied position, and a new position is searched
  for the replaced element. Such replacements can be performed repeatedly, increasing the probability
  of finding the optimal placement configuration. The proposed algorithm was verified on a set
  of benchmark circuits ISCAS’85, ISCAS’89, Cpu8080 and VGA. Experimental results show that
  the developed algorithm reduces the number of global interconnections used for global routing by
  10% on average and increases the number of local interconnections used for detailed routing by
  30% on average compared to the sequential placement algorithm. The average routing time remained
  unchanged.