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33operations to form a separate MPI communicators for each node and execute an algorithm of collective opera-
tion level-by-level.
The most used double copy algorithms (copy-in/copy-out) involve a shared buffer space used by local pro-
cesses to exchange messages. The root process copies the content of the message into the shared buffer be-
fore the receiver reads from it. In this paper we propose kernel-assisted (CMA, KNEM and XPMEM) and CICO-
based NUMA-aware algorithms for MPI_Bcast operation. In contrast to other works our algorithms explicitly
allocate memory for queues from local NUMA nodes even with active linux page cache readahead subsystem.
We show how to find optimal size f of buffer and length s of the queue what takes no more than b bytes and
provides minimum algorithm time. On NUMA machines with Xeon Nehalem and Xeon Broadwell processors,
our implementation based on Open MPI achieves on average 20�60% speedup over algorithms of Open MPI
coll/sm and MVAPICH (mv2_shm_bcast).
This work was (partially) supported by the Siberian Branch of Russian Academy of Science and the Russian Founda-
tion of Basic Research (grant 20-07-00039).
Aggregation errors in project schedulling
O. A. Lyakhov
Institute of Computational Mathematics and Mathematical Geophysics SB RAS
Email: loa@rav.sscc.ru
DOI 10.24412/cl-35065-2021-1-02-28
The problem of resources evaluation in network projects models with constant and variable intensity of
operations is discussed. The exactness of plans depends on a degree of resources aggregation and a time scale,
which consists of some intervals (quanta). A quantum is the least time period (called so by analogy with phys-
ics) for measuring resources and other purposes in scheduling. A sum of quanta is equal to planning period.
Resources demands for schedules are calculated separately per each quantum taken as a whole. A decrease of
a number of quanta (one way of aggregation) reduces models dimensions, but at the same time it leads to
growth of systematic mistakes of resources calculation, which doesn�t allow seeing schedules in proper per-
spective. The results of numerical experiments using the package for solving network optimization problems
[1] are presented.
This work was carried out under state contract with ICMMG SB RAS (0251-2021-0005).
References
1. Lyakhov O.A., Software package for network planning and scheduling. Novosibirsk, Foundation of algorithms and
programs, ICM&MG SB RAS, No. PR12002, 2012.
The diameter vulnerability of two-dimensional optimal circulant networks
E. A. Monakhova, O. G. Monakhov
Institute of Computational Mathematics and Mathematical Geophysics SB RAS
Email: monakhov@rav.sscc.ru
DOI 10.24412/cl-35065-2021-1-02-30
This paper studies the effect of changing the diameter of circulant networks of dimension two with unreli-
able elements. The well-known (Deg, D, D1, S)-problem is to find (Deg, D)-graphs with maximum degree Deg
and diameter D such that the subgraphs obtained from the original graph by deleting any set of up to S verti-
ces (edges) have diameter at most D1. For a family of optimal circulants of degree four we found the ranges of
orders of the graphs that preserve the diameter of the graph for one (two) vertex or edge failures. It is proved
that in the investigated circulant networks in case of failure of one or two edges (vertices), the diameter can
increase by no more than one, and in case of failure of three elements by no more than two (edge failures) or
three (vertex failures). It is shown that the graphs investigated, in comparison with two-dimensional tori, have
a better diameter in case of element failures.
The work has been carried out under the budget project of ICMMG SB RAS N 0251-2021-0005.
Application of Big Data technologies to assess the natural moisture of the territory
A. I. Pavlova
Novosibirsk State University of Economics and Management
Email: annstab@mail.ru
DOI 10.24412/cl-35065-2021-1-02-31
Due to the sharp changes in climatic conditions in Western Siberia, the most pressing problem is food se-
curity associated with forecasting crop yields [1�2]. There is a need to estimate the natural wetness of the area
on the basis of agroclimatic indicators, among which the sum of active air temperatures and precipitation is
currently the most widely used. However, for a comprehensive assessment of the wetness of the territory, it is
necessary to take into account the climate energy resources associated with evaporation of different time res-
olutions (day, decades, months, vegetation period, year). The initial meteorological parameters are described
in the form of poorly structured information of a large volume [3]. Therefore, various technologies and algo-
rithms of machine processing are used in the work. With the help of the high-level Python programming lan-
guage and engineering libraries, a comprehensive assessment of the territory was carried out using the exam-
ple of Mirny of the Kochenevsky District of the Novosibirsk Region in the context of long-term average data
and two years 2019 and 2020. that the use of machine processing technologies related to NoSQL data re-
quests, creation of data set and big data slices allows to store and process meteorological parameters using
cloud services of different time resolution. This makes it possible to significantly reduce the time for a com-
prehensive assessment of the territory according to agroclimatic parameters. As a result of the work, precipi-
tation distribution, temperature, relative air humidity, evaporability, humidification coefficients (Ivanov-
Vysotsky [4] and Selyaninov hydrothermal coefficient [5]) were obtained.
References
1. Mayorova M.A. & Markin, M.I. Digital agriculture in the production and economic activities of agro-industrial
enterprises // Theoretical economy. 2019. N. 2. [Electron. resource]. URL: https://cyberleninka.ru/article/v/tsifrovoe-
zemledelie-v-proizvodstvenno-ekonomicheskoy-deyatelnosti-predpriyatiy-apk (the date of access: 07.05.2021).
2. Yakushev V.P. Digital technologies of precision agriculture in the implementation of the priority "smart
agriculture" of Russia // Bulletin of the Russian Academy of Sciences. 2019. N. 2. P. 11-15.
3. Pavlova, A.I. & Kalichkin, V.K. (2018). Databases for agro-ecological assessment of agricultural land. Siberian
Bulletin of Agricultural Science, 1, Is. 48. P. 80-88. [Electron. resource]. URL: https://doi.org/10.26898/0370-8799-2018-1-
11 (the date of access: 07.05.2021).
4. Selyaninov, G.T. Principles of agroclimatic zoning of the USSR Issues of agroclimatic zoning of the USSR. M.:
Publishing house mine-va selsk. khoz-va of the USSR, 1958. P. 3-13.
5. Ivanov, N. N. Landscape and climatic zones of the globe. (Ed.). Moscow, Leningrad, Publishing House of the USSR
Academy of Sciences, 1948. 224 p.
