Анализ типизированных зависимостей включения с неопределенными значениями

Null values have become an urgent problem since the creation of the relational data model. The impact of the uncertainty affects all types of dependencies used in the design and operation of the database. This fully applies to the inclusion dependencies, which are the theoretical basis for referential integrity on the data. Attempts to solve this problem contain inaccuracy in the statement of the problem and its solution. The errors in formulation of the problem can be associated with the use in the definition of untyped inclusion dependencies, which leads to permutations of the attributes, although, the attributes in database technology are identified by name and not by their place. In addition, linking with the use of the inclusion dependencies of heterogeneous attributes, even of the same type, is a sign of lost functional dependencies and leads to interaction of inclusion dependencies and non-trivial functional dependencies. Inaccuracies in the solution of the problem are contained in the statements of axioms and the proof of their properties, including completeness. In this paper we propose an original solution of this problem only for typed inclusion dependencies in the presence of Null values: a new axiom system is proposed, its completeness and soundness are proved. On the basis of inference rules we developed an algorithm for the construction of a not surplus set of typed inclusion dependencies. The correctness of the algorithm is proved.Неопределенные значения стали актуальной проблемой с момента создания реляционной модели данных. Влияние неопределенностей сказывается на всех видах зависимостей, используемых при проектировании и эксплуатации базы данных. В полной мере это относится и к зависимостям включения, которые являются теоретической основой ссылочной целостности на данные. Попытки решения указанной проблемы содержат неточности как в постановке задачи, так и в самом ее решении. К постановочным ошибкам можно отнести использование в определении нетипизированных зависимостей включения, что приводит к перестановкам атрибутов, хотя в технологиях баз данных атрибуты идентифицируются по имени, а не по их позиции. Кроме того, связывание зависимостью включения разнородных, пусть даже однотипных, атрибутов является признаком потерянной функциональной зависимости и приводит к взаимодействию нетривиальных зависимостей включения и функциональных зависимостей. Зависимости включения должны определять количественное соотнесение объектов друг с другом, а не значений атрибутов. Неточности в решении указанной проблемы содержатся в формулировках аксиом и доказательстве их свойств, в том числе полноты. В этой статье предлагается оригинальное решение этой проблемы только для типизированных зависимостей включения при наличии неопределенных значений: предложена система аксиом, доказана ее полнота и непротиворечивость. На основе правил вывода разработан алгоритм построения не избыточного множества типизированных зависимостей включения. Доказана корректность этого алгоритма

Автоматизация формирования табличных приложений

The paper considers automation problems of the interface formation between a table and a relational database. The task description is formalized and the description of the existing approaches to formation of data representations on an example of widely widespread CASE-tools is submitted. The definition of intermediate data representation as a ”join table” is offered, which is used for maintenance of correctness of data representation formation, and also is necessary for direct and inverse data transformations. On the basis of lossless join property and realized dependencies, the concept and a way of context formation of the application and restrictions is introduced. The considered material is further used for constructing an inverse data transformation from tabular presentation into a relational one. On the basis of relationships properties on a database scheme, the partial order on the relations is established, and the restriction of acyclic databases schemes is introduced. The received results are further used at the analysis of principles of formation of inverse data transformation, and the basic details of such a transformation algorithm are considered.Рассмотрены проблемы автоматизации формирования интерфейса между таблицей и реляционной базой данных. Формализована постановка задачи и представлено описание существующих подходов к формированию представлений данных на примере широко распространенных CASE-инструментов. Предложено определение промежуточного представления данных в виде таблицы соединений, которая используется для обеспечения корректности формирования представления данных и также необходима для прямого и обратного преобразования данных. На основе свойства соединения без потери информации и реализованных зависимостей вводится понятие и способ формирования контекстов приложения и ограничений на данные. Рассмотренный материал далее используется для построения обратного преобразования данных из табличного представления в реляционное. На основе использования свойств связей на схеме базы данных устанавливается частичный порядок над отношениями, вводится ограничение ацикличности на допустимые схемы баз данных. Полученные результаты далее используются при анализе принципов формирования обратного преобразования данных, рассмотрена схема алгоритма такого преобразования

Development of Consumers' Behavior Business Model on Energy Market

The pace of transformation in the electric power industry around the world is gaining momentum due to the rapid development of technology. The possibilities for choosing the electric power company, as well as consumers of their products, are increasing. The role of the distributed energy is enhancing, which contributes to the development of supply and demand in this market. In this regard, approaches to management in the energy markets are changing to address the problems of cross-subsidization. The introduction of new technologies in the management of generating and network facilities makes it possible to become ‘active consumers' in the energy market. The purpose of our study is to assess the impact of cross-subsidies on changing the active consumers' behavior in the energy market. We propose a mathematical model of the behavior of ‘active consumers' of the energy market, which allows the participants of the energy market to make decisions to ‘buy' or to ‘produce their own' electrical energy and provides recommendations for determining the economic benefits for active consumers of the energy market. The results of our study showed that the proposed model could be effective for energy sales companies and regulators for multi-agent modeling of consumers' response to tariff mechanisms of demand-side management; it also can be useful for assessing the economic effect for the consumer who participates in demand-side management. Keywords: active consumer, energy market, demand-side management, tariff; mathematical model. JEL Classifications: D24; Q43; M3

Two Novel Amyloid Proteins, RopA and RopB, from the Root Nodule Bacterium Rhizobium leguminosarum

Amyloids represent protein fibrils with a highly ordered spatial structure, which not only cause dozens of incurable human and animal diseases but also play vital biological roles in Archaea, Bacteria, and Eukarya. Despite the fact that association of bacterial amyloids with microbial pathogenesis and infectious diseases is well known, there is a lack of information concerning the amyloids of symbiotic bacteria. In this study, using the previously developed proteomic method for screening and identification of amyloids (PSIA), we identified amyloidogenic proteins in the proteome of the root nodule bacterium Rhizobium leguminosarum. Among 54 proteins identified, we selected two proteins, RopA and RopB, which are predicted to have β-barrel structure and are likely to be involved in the control of plant-microbial symbiosis. We demonstrated that the full-length RopA and RopB form bona fide amyloid fibrils in vitro. In particular, these fibrils are β-sheet-rich, bind Thioflavin T (ThT), exhibit green birefringence upon staining with Congo Red (CR), and resist treatment with ionic detergents and proteases. The heterologously expressed RopA and RopB intracellularly aggregate in yeast and assemble into amyloid fibrils at the surface of Escherichia coli. The capsules of the R. leguminosarum cells bind CR, exhibit green birefringence, and contain fibrils of RopA and RopB in vivo.This work was supported by the Russian Science Foundation, grant 17-16-01100

Automation of Tabular Application Formation

The paper considers automation problems of the interface formation between a table and a relational database. The task description is formalized and the description of the existing approaches to formation of data representations on an example of widely widespread CASE-tools is submitted. The definition of intermediate data representation as a ”join table” is offered, which is used for maintenance of correctness of data representation formation, and also is necessary for direct and inverse data transformations. On the basis of lossless join property and realized dependencies, the concept and a way of context formation of the application and restrictions is introduced. The considered material is further used for constructing an inverse data transformation from tabular presentation into a relational one. On the basis of relationships properties on a database scheme, the partial order on the relations is established, and the restriction of acyclic databases schemes is introduced. The received results are further used at the analysis of principles of formation of inverse data transformation, and the basic details of such a transformation algorithm are considered.</p

Automation of Tabular Application Formation

The paper considers automation problems of the interface formation between a table and a relational database. The task description is formalized and the description of the existing approaches to formation of data representations on an example of widely widespread CASE-tools is submitted. The definition of intermediate data representation as a ”join table” is offered, which is used for maintenance of correctness of data representation formation, and also is necessary for direct and inverse data transformations. On the basis of lossless join property and realized dependencies, the concept and a way of context formation of the application and restrictions is introduced. The considered material is further used for constructing an inverse data transformation from tabular presentation into a relational one. On the basis of relationships properties on a database scheme, the partial order on the relations is established, and the restriction of acyclic databases schemes is introduced. The received results are further used at the analysis of principles of formation of inverse data transformation, and the basic details of such a transformation algorithm are considered

Кэширование запросов к реляционной базе данных с использованием областей истинности

We propose a new method of client-side data caching for relational databases with a central server and distant clients. Data are loaded into the client cache based on queries executed on the server. Every query has the corresponding DB table – the result of the query execution. These queries have a special form called "universal relational query" based on three fundamental Relational Algebra operations: selection, projection and natural join. We have to mention that such a form is the closest one to the natural language and the majority of database search queries can be expressed in this way. Besides, this form allows us to analyze query correctness by checking lossless join property. A subsequent query may be executed in a client’s local cache if we can determine that the query result is entirely contained in the cache. For this we compare truth spaces of the logical restrictions in a new user’s query and the results of the queries execution in the cache. Such a comparison can be performed analytically , without need in additional Database queries. This method may be used to define lacking data in the cache and execute the query on the server only for these data. To do this the analytical approach is also used, what distinguishes our paper from the existing technologies. We propose four theorems for testing the required conditions. The first and the third theorems conditions allow us to define the existence of required data in cache. The second and the fourth theorems state conditions to execute queries with cache only. The problem of cache data actualizations is not discussed in this paper. However, it can be solved by cataloging queries on the server and their serving by triggers in background mode. The article is published in the author’s wording.В данной статье предлагается новый метод кэширования запросов к реляционной базе данных для систем с центральным сервером и распределенными клиентами. Данные загружаются в клиентский кэш, основываясь на запросах, выполненных на сервере БД. Каждому запросу ставится в соответствие таблица – результат выполнения запроса. Эти запросы имеют специальный вид, называемый "универсальный реляционный запрос", основанный на трех базисных операциях реляционной алгеб- ры: селекции, проекции, естественном соединении (natural join). Следует отметить, что такая форма запроса наиболее близка к естественному языку и большинство запросов может быть записано в этом виде. Кроме того, эта форма записи позволяет анализировать корректность запроса, проверяя свойство соединения без потери информации (СБПИ). Последовательные запросы могут исполняться на клиенте, используя кэш, если удастся определить, что результаты искомого запроса полностью содержатся в кэше. Для осуществления такой проверки анализируются области истинности логических ограничений искомого запроса и запросов, результаты которых уже содержатся в кэше. Требуемые операции могут быть проведены аналитически, без необходимости дополнительных запросов к базе банных. Предложенный метод может быть использован для определения недостающих в кэше данных и последующего запроса только на эти данные. Для этого также используются аналитические вычисления, что является принципиальным отличием данной статьи от существующих технологий. Для этой цели в статье представлено четыре теоремы. В первой и третьей теореме получены условия, позволяющие определить наличие необходимых данных, а во второй и четвертой получены условия вычисления данных только с использованием кэша. Проблема актуализации данных не затрагивается в этой статье. Однако она может быть решена путем учета запросов на сервере и обновлении данных при помощи триггеров. Статья публикуется в авторской редакции

BONE GRAFTING ENHANCED BY PLATELET-RICH PLASMA IN TREATMENT OF AVASCULAR NECROSIS OF FEMORAL HEAD

Treatment of avascular necrosis of the femoral head is an issue of current interest while it affects young and employable people. So far there is no well-defined strategy of management which would help to postpone hip arthroplasty and further revision procedure. Hip sparing surgical treatment of avascular necrosis of the femoral head by bone grafting prior to head collapse proved to be a viable option not only during early stages of disease but also at advanced stages. Platelet-rich plasma (PRP) addition to treatment plan potentially helps improving bone regeneration in situ.In this article the authors present a case of a 37 years old patient with avascular necrosis of the femoral head at a fragmentation stage (type 4B by ARCO). The authors centrifuged 15 ml of autologous whole blood (1500 RPM) obtained by a special double-contoured syringe. During the surgical stage of treatment PRP and morselized bone graft were mixed to introduce and impact into the debrided zone of avascular necrosis. The authors also introduced 0.3–0.4 ml of PRP into the debrided zone of avascular necrosis after bone grafting. At 6 months follow-up CT images of the studied patient demonstrated signs of bone reorganization and no loss of femoral head sphericity. Preoperative Visual Analogue Scale (VAS), Harris Hip Score (HHS) and Hip disability and Osteoarthritis Outcome Score (HOOS) prior to treatment were 60, 45 and 33 points respectively. Postoperative VAS, HHS and HOOS scores were 10, 78 and 78 respectively. In the authors’ opinion, impaction bone grafting enhanced by PRP helps obtaining good and excellent outcomes not only at early but also at advanced stages of avascular necrosis