Fun with formal methods is more than fun

Almost half of a century has passed since Robert W. Floyd published the first research that explicitly discussed formally how to assign meaning to programs. But recently David L. Parnas have called Really Rethinking "Formal Methods", to question the assumptions underlying the well-known current formal software development methods to see why they have not been widely adopted and what should be changed. So, things are right where they started decades ago? Not at all, since industrial applications of Formal Methods are not the unique measure of success. Another dimension where we can discuss utility of Formal Methods could be better education. A very popular (in Russia) aphorism of Mikhail Lomonosov (the first Russian academician) says: "Mathematics should be learned just because it disciplines and bring up the mind". Similarly, Formal Methods discipline and bring up minds in Computer Science. and help to bridge a "cultural gap" (E.W.Dijkstra) between Mathematics and Computer Science

ALIAS calculus for a simple imperative language

This research has been supported by Nazarbayev University Seed Grant KF-14/16 "Research of Formal Models for analysis of programs with Dynamic Memory"

Mutual Fund Theorem for continuous time markets with random coefficients

We study the optimal investment problem for a continuous time incomplete market model such that the risk-free rate, the appreciation rates and the volatility of the stocks are all random; they are assumed to be independent from the driving Brownian motion, and they are supposed to be currently observable. It is shown that some weakened version of Mutual Fund Theorem holds for this market for general class of utilities; more precisely, it is shown that the supremum of expected utilities can be achieved on a sequence of strategies with a certain distribution of risky assets that does not depend on risk preferences described by different utilities.Comment: 17 page

Developing Students’ Skills of Identifying Reliable Scientific Sources: The Role of a Librarian

Purpose. The purpose of this paper is to provide modes of teaching Russian undergraduate students fundamental critical analysis of scientifc papers and ways of identifying misinformation and disinformation in “Academic Writing” discipline. design/methodology/approach. “Academic Writing” discipline was taught to frst-year undergraduate students by scientifc library experts. At a starting period students were asked to complete a questionnaire and perform a test, and then write an essay to identify how students were able to assess Web scientifc literature and verify their “tolerance” to inaccurate and fake scientifc information. Then contact hours on theory and practice of identifying and assessing information were introduced into the curriculum. At the end of the semester lists of works cited in original essays and fnal assays were compared.Findings. The fndings reveal that entirely all frst year undergraduate students lack the ability to differentiate between qualitative certain scientifc information and misinformation and disinformation, and they willingly borrow anything from the Web. However, students acquired necessary skills to assess information critically using socio-technical systems infrastructures.This was demonstrated with list of literature analysis in students’ essays and peer-checking. originality. It is headline news and social networks when it is necessary to distinguish from authentic and inaccurate information. However, skills of critical assessment of scientifc publications are of vital importance at a starting period of studies. In publications of that sort falsifcations, fabrications and other fake discoveries can lead to reputational and fnancial risks, and then trigger unethical demeanour of future researchers. It is qualifed librarians being experts in electronic resources and data based use who are able to get students to “digital hygiene”.Practical implications. The results of the paper can be used for teaching in university curriculum. Embedding information literacy and academic writing as well as involving information resources into students’ curriculum are aimed at the ability to identify misinformation and disinformation. Librarian-developed “Academic writing” discipline component might be introduced into curriculum as a self-contained short course or a composing element of any students’ academic discipline. All this mitigate the risks of applying low-equality, unverifed and openly fake information in educational and scientifc works

Верификация шаблонов алгоритмов для метода отката и метода ветвей и границ

The Design and Analysis of Computer Algorithms is a must of Computer Curricula. It covers many topics that group around several core themes. These themes range from data structures to the complexity theory, but one very special theme is algorithmic design patterns, including greedy method, divide-and-conquer, dynamic programming, backtracking and branch-and-bound. Naturally, all the listed design patterns are taught, learned and comprehended by examples. But they can be semi-formalized as design templates, semi-specified by correctness conditions, and semi-formally verified by means of Floyd method. Moreover, this approach can lead to new insights and better comprehension of the design patterns, specification and verification methods. In this paper we demonstrate an utility of the approach by study of backtracking and branch-and-bound design patterns. In particular, we prove correctness of the suggested templates when the boundary condition is monotone, but the decision condition is anti-monotone on sets of "visited" vertices.Курс проектирования и анализа алгоритмов является обязательной составляющей учебных программ по информатике всех уровней. В университетах этот курс обязательно включает изучение структур данных, методы проектирования алгоритмов, теорию сложности и т.д. Этот курс знакомит с такими методами проектирования алгоритмов, как жадные алгоритмы, динамическое программирование, метод разделяй и властвуй, метод отката, метод ветвей и границ. Обычно знакомство с этими методами происходит на примерах. Но (как показано в данной статье) они могут быть (полу)формализованы в виде "паттернов", специфицированы условиями частичной и/или тотальной корректности и обоснованы (доказаны) методом Флойда верификации алгоритмов. Такой формализованный подход может привести к новому, более глубокому пониманию этих методов. В статье демонстрируется перспективность такого подхода на примере метода отката и метода ветвей и границ. В частности, мы доказываем, что разработанные шаблоны корректны, если граничное условие - монотонная функция, а решающее условие - антимонотонная функция от множества уже проверенных вершин

SOIL-AGRO-ECOLOGICAL ASSESSMENT OF THE ARABLE LAND OF THE VALDAI UPLAND BASED ON THE GENERAL SURVEY

A methodical approach to the digital mapping of the arable lands area depending on their soil-agroecological and positional conditions is proposed. The approach was tested on a model plot located on the Valdai Upland with an area of 160 thousand ha. Small-scale agricultural development of the poorly dissected moraine plains is limited by the wide distribution of overmoistened soils. Using the traditional discriminant analysis, a measure of the topographically determined duration of soil overmoistening was calculated based on a comparison of the morphological diagnostics of water regime and topography runoff properties according to the grid elements of 30 × 30 m. The drainability range was determined for the arable lands of XVIII century, reconstructed according to the materials of the General Survey. This allowed us to determine the potential area of the arable lands for this period. The area of arable lands, which is characterized by favorable conditions of transport accessibility and soil drainability, was 12 %. At the same time, reconstructed area contained 5 %. In the subsistence economy of the XVIII century more than a half of the potential arable lands of the model region turned out to be undeveloped