К вопросу использования «полезных» задач для обеспечения работой блокчейн систем

This paper is a logical continuation of the paper about possible approaches to solving the “Useful Proof-of-work for blockchains” problem. We suggest some alternative ways for searching useful tasks for Proof-of-work systems. These ways are based on the process of the multiple and independent repetition of a simple experiment. The experiment is to chose an element independently and uniformly from a quite large set and then to check if the chosen element has a specific rare property. In the classic blockchain of Bitcoin this experiment is a so-called hash-puzzle. In these terms the process of solving a hash-puzzle may be replaced by searching rare astronomical objects or Go positions with specific conditions. Moreover, we describe a possible attack on the blockchain systems in which the task instance generation algorithm is replaced by the algorithm of selecting the task instance from the existing database with public access for publication of task instances and discuss the way of protection.Статья является продолжением работы о возможных подходах к решению задачи «UsefulProof-of-workforblockchains». Мы предлагаем некоторые альтернативные направления поиска полезных задач для обеспечения работой, основанные на том, что процесс решения хеш-головоломки близок к многократному независимому повторению следующего эксперимента: пусть задано достаточно большое по мощности множество (например, состоящее из 2" элементов, для достаточно большого п), только незначительная часть элементов которого обладает определенным свойством. Эксперимент состоит в равномерном выборе элемента из этого множества с последующей проверкой наличия у него указанного свойства. Таким образом, процесс решения хеш-головоломки может быть заменен, например, поиском редких астрономических объектов или поиском позиций игры Го, удовлетворяющих определенным условиям. Кроме того, мы описываем возможную атаку на блокчейн-систему, в которой алгоритм генерации индивидуальных представителей задач для обеспечения работой заменен алгоритмом выбора индивидуальных представителей из имеющейся базы данных, со стороны недобросовестных поставщиков индивидуальных представителей задач, в случае их публичного сбора, и обсуждаем некоторые способы защиты от этой атаки

О некоторых подходах к решению задачи «Useful Proof-of-work for blockchains»

The blockchain technology is based on the ”Proof-of-work” principles. The essence of this principle is that some event (for example the bill-to-bill money transaction) becomes significant after the confirmation by a certain computer work. So, a demand arose for such computational problems to work on, and we will spend on it about the whole blockchain system computing capacity. Now the main kind of such a problem is a hash-puzzle – the problem to find a bit string with a hash that satisfies some conditions. The important hash-puzzle weakness is the lack of the useful application outside of the blockchain technology. In this work, we offer some approaches to ”Useful Proof-of-work for blockchains” problem, namely, consider some practical variants of the NP-complete problems that could be solved with the help of SAT or LLL-solvers as the Proof-of-Work computational problems. The use of the FPTproblems requires special study. The offered approach allows to provide the following characteristics of the proof-of-work computational problems: usefulness, problems complexity management (through the dimension change, choosing problems of certain kind, the indication of necessary solution precision), mass character. Herewith we admit that not every solved problem can be useful but we consider the opportunity to solve some practical problems with the help of the blockchain technology. Among other things it is also possible to compare the virtual crypto-currency value (through the energy costs spent) and the effective result of the practical problems solution. The most complicated points of the described approach are the realization of the events-problems (providing the computer work for these events) relations and the realization of the problems complexity analysis system. This issue should be viewed as the study program because of many technical details that must be worked out further.Технология блокчейн основана на принципе доказательства работой «Proof-ofwork». Суть данного принципа состоит в том, что некоторое событие (например, перевод денежных средств с одного счета на другой) становится значимым только после того, как оно подтверждено определенным объемом вычислительной работы. Соответственно возникает потребность в вычислительных задачах, над которыми такую работу можно производить, причем на решение этих задач будет тратиться практически вся вычислительная мощность блокчейн-сети. На сегодня в качестве таких задач получили распространение «хэш-головоломки» – задачи поиска битовой строки с хэшем, удовлетворяющим определенным условиям. Существенным недостатком хэш-головоломок является отсутствие у них какого-либо полезного применения за пределами технологии блокчейн. В работе описываются подходы к решению задачи «Useful Proof-of-work for blockchains», а именно предлагается рассматривать в качестве вычислительных задач для доказательства работой возникающие на практике индивидуальные представители NP-полных задач, которые могут решаться, например, SAT- или LLL-решателями. Отдельной проработки требует вопрос об использовании FPT-задач. Предлагаемый подход позволяет обеспечить следующие свойства вычислительных задач для доказательства работой: полезность, управляемость сложностью задач (через изменение размерности, выбор задач определенного вида, указание точности необходимого решения), массовость. При этом допускается, что не каждая решенная задача может оказаться полезной, однако предоставляется возможность решать с помощью технологии блокчейн задачи, возникающие на практике. Кроме прочего, таким образом становится возможным сопоставить стоимость виртуальной криптовалюты через затраты электроэнергии при ее генерации с практическим результатом от решения вычислительных задач. Наиболее трудными вопросами в контексте рассматриваемого подхода являются реализация связи событий и задач, обеспечивающих эти события вычислительной работой, и реализация системы анализа сложности задач. Статью следует воспринимать как программу исследований, поскольку многие технические детали требуют отдельной проработки

Вопросно-ответная система для поддержки абитуриентов с использованием современных мессенджеров

There is an increasing interest to the instant messaging applications, messengers. These applications allow us to interact with other users and include a functionality that can help us to implement bots that automate various business processes or provide information services. In this paper, we consider a specialized question answering system that uses today’s messaging services infrastructure to support university applicants. We gathered a corpus of applicants questions throughout two years and developed an information retrieval model that helps us to find similar questions in the corpus. Applicants can type their questions using a natural language without any formal requirements to phrase construction or using special templates. If the system is unable to find a relevant answer, the user can directly address the question to representatives of the university. The system was implemented with the use of modern cloud services that are provided by Amazon. We used serverless computations and NoSQL data bases, so we had to develop an architecture of the system in that way. Since the system contains sensitive personal data and provide personalized service, we must focus our attention on security. We proposed the means that must improve the safety of the system, more specifically, authentification process that can be used without the explicit use of personal data, however, this is a future work. At present we test our system and evaluate its quality of information retrieval.В настоящее время растет интерес пользователей к приложениям для мгновенного обмена сообщениями, мессенджерам. Они позволяют не только общаться с другими пользователями, но и включают в себя функционал, помогающий создавать автоматических собеседников, автоматизирующих отдельные бизнес-процессы либо удовлетворяющих информационные потребности пользователей. В статье рассматривается узкоспециализированная вопросно-ответная система, которая использует инфраструктуру, предоставляемую современными мессенджерами для обмена сообщениями и предназначенную для информационной поддержки абитуриентов, поступающих в университет. В процессе разработки системы был накоплен корпус характерных вопросов абитуриентов, а также разработана модель, которая позволяет осуществлять поиск близких вопросов по этому корпусу. При этом абитуриент может формулировать свои вопросы на естественном языке без изучения предварительно заданных шаблонов или специальных правил построения сообщений. Для получения ответов на вопросы, которых нет в корпусе системы, привлекаются специалисты приемной комиссии, имеющие свой интерфейс. Система была реализована с использованием современных облачных технологий, предоставляемых компанией Amazon. Среди них бессерверные (serverless) вычисления и NoSQL-базы данных. Для этого была разработана архитектура сервиса, удовлетворяющая этой модели вычислений. Поскольку система может оперировать с чувствительными данными, включая персональные данные, а также предоставлять персонализированный сервис, были проанализированы методы обеспечения безопасности системы, а также подходы к авторизации пользователей. В настоящее время система проходит тестирование и оценку используемых алгоритмов информационного поиска

On the Issue of Using “Useful” Tasks for Proof of Works in Blockchain

This paper is a logical continuation of the paper about possible approaches to solving the “Useful Proof-of-work for blockchains” problem. We suggest some alternative ways for searching useful tasks for Proof-of-work systems. These ways are based on the process of the multiple and independent repetition of a simple experiment. The experiment is to chose an element independently and uniformly from a quite large set and then to check if the chosen element has a specific rare property. In the classic blockchain of Bitcoin this experiment is a so-called hash-puzzle. In these terms the process of solving a hash-puzzle may be replaced by searching rare astronomical objects or Go positions with specific conditions. Moreover, we describe a possible attack on the blockchain systems in which the task instance generation algorithm is replaced by the algorithm of selecting the task instance from the existing database with public access for publication of task instances and discuss the way of protection

On Some Approaches to the Solution of the Problem «Useful Proof-of-work for Blockchains»

The blockchain technology is based on the ”Proof-of-work” principles. The essence of this principle is that some event (for example the bill-to-bill money transaction) becomes significant after the confirmation by a certain computer work. So, a demand arose for such computational problems to work on, and we will spend on it about the whole blockchain system computing capacity. Now the main kind of such a problem is a hash-puzzle – the problem to find a bit string with a hash that satisfies some conditions. The important hash-puzzle weakness is the lack of the useful application outside of the blockchain technology. In this work, we offer some approaches to ”Useful Proof-of-work for blockchains” problem, namely, consider some practical variants of the NP-complete problems that could be solved with the help of SAT or LLL-solvers as the Proof-of-Work computational problems. The use of the FPTproblems requires special study. The offered approach allows to provide the following characteristics of the proof-of-work computational problems: usefulness, problems complexity management (through the dimension change, choosing problems of certain kind, the indication of necessary solution precision), mass character. Herewith we admit that not every solved problem can be useful but we consider the opportunity to solve some practical problems with the help of the blockchain technology. Among other things it is also possible to compare the virtual crypto-currency value (through the energy costs spent) and the effective result of the practical problems solution. The most complicated points of the described approach are the realization of the events-problems (providing the computer work for these events) relations and the realization of the problems complexity analysis system. This issue should be viewed as the study program because of many technical details that must be worked out further

Question Answering System for Applicant Support by Using Modern Messengers

There is an increasing interest to the instant messaging applications, messengers. These applications allow us to interact with other users and include a functionality that can help us to implement bots that automate various business processes or provide information services. In this paper, we consider a specialized question answering system that uses today’s messaging services infrastructure to support university applicants. We gathered a corpus of applicants questions throughout two years and developed an information retrieval model that helps us to find similar questions in the corpus. Applicants can type their questions using a natural language without any formal requirements to phrase construction or using special templates. If the system is unable to find a relevant answer, the user can directly address the question to representatives of the university. The system was implemented with the use of modern cloud services that are provided by Amazon. We used serverless computations and NoSQL data bases, so we had to develop an architecture of the system in that way. Since the system contains sensitive personal data and provide personalized service, we must focus our attention on security. We proposed the means that must improve the safety of the system, more specifically, authentification process that can be used without the explicit use of personal data, however, this is a future work. At present we test our system and evaluate its quality of information retrieval

Covalent conjugates based on nanodiamonds with doxorubicin and a cytostatic drug from the group of 1,3,5-triazines::Synthesis, biocompatibility and biological activity

We report the synthesis of covalent conjugates of nanodiamonds with doxorubicin and a cytostatic drug from the class of 1,3,5-triazines. The obtained conjugates were identified using a number of physicochemical methods (IR-spectroscopy, NMR-spectroscopy, XRD, XPS, TEM). As a result of our study, it was found that ND-СONH-Dox and ND-COO-Diox showed good hemocompatibility, since they did not affect plasma coagulation hemostasis, platelet functional activity, and erythrocyte membrane. The ND-COO-Diox conjugates are also capable of binding to human serum albumin due to the presence of ND in their composition. In the study of the cytotoxic properties of ND-СONH-Dox and ND-COO-Diox in the T98G glioblastoma cell line, indicating that ND-СONH-Dox and ND-COO-Diox demonstrate greater cytotoxicity at lower concentrations of Dox and Diox in the composition of the conjugates compared to individual drugs; the cytotoxic effect of ND-COO-Diox was statistically significantly higher than that of ND-СONH-Dox at all concentrations studied. Greater cytotoxicity at lower concentrations of Dox and Diox in the composition of conjugates compared to individual cytostatics makes it promising to further study the specific antitumor activity and acute toxicity of these conjugates in models of glioblastoma in vivo. Our results demonstrated that ND-СONH-Dox and ND-COO-Diox enter HeLa cells predominantly via a nonspecific actin-dependent mechanism, while for ND-СONH-Dox a clathrin-dependent endocytosis pathway. All data obtained provide that the synthesized nanomaterials show a potential application as the agents for intertumoral administration. [Abstract copyright: Copyright © 2023. Published by Elsevier B.V.

Protective action of water-soluble fullerene adducts on the example of an adduct with L-arginine

We present radioprotective, antiglycating, and photoprotective properties of a water-soluble C60 fullerene derivative with L-arginine (C60-Arg) and composite films based on collagen containing C60-Arg. The synthesis of these materials is described. The identification of the synthesised materials was carried out using modern physicochemical methods of analysis. The physicochemical properties of aqueous solutions of C60-Arg, such as, particle size distribution, zeta potentials, distribution coefficient in the octan-1-ol–water system were measured. The computer simulation of the process of C60-Arg association in aqueous and isotonic solutions was carried out using Molecular Dynamics. Composite films based on collagen containing C60-Arg demonstrate significant improvement in mechanical properties, cell adhesion, and cell proliferation when the nano-modifier is added. This shows high potential for the use of the C60-Arg adduct in biomedicine

Study of strange matter production in the heavy ion collisions at NUCLOTRON

It is proposed to install an experimental setup in the fixed-target hall of the Nuclotron with the final goal to perform a research program focused on the production of strange matter in heavyion collisions at beam energies between 2 and 6 A GeV. The basic setup will comprise a large acceptance dipole magnet with inner tracking detector modules based on double-sided Silicon micro-strip sensors and GEMs. The outer tracking will be based on the drift chambers and straw tube detector. Particle identification will be based on the time-of-flight measurements. This setup will be sufficient perform a comprehensive study of strangeness production in heavy-ion collisions, including multi-strange hyperons, multi-strange hypernuclei, and exotic multi-strange heavy objects. These pioneering measurements would provide the first data on the production of these particles in heavy-ion collisions at Nuclotron beam energies, and would open an avenue to explore the third (strangeness) axis of the nuclear chart. The extension of the experimental program is related with the study of in-medium effects for vector mesons decaying in hadronic modes. The studies of the NN and NA reactions for the reference is assumed