Volumen 23 (2018): Heft 1 (May 2018)

Even though object-oriented approach exists for more than 20 years, there are many issues regarding objectoriented system analysis: ambiguity, incompleteness and redundancy in requirements, difficulties with definition and traceability of non-functional requirements, requirements ignorant of business processes that are important for business operations and others. Although software can be engineered using many methodologies, different approaches to the analysis should be considered as they can provide a solution to the known issues. The paper describes the result of the research on object-oriented system analysis in a form of mapping activities offered in advanced software development methods.

The goal of the paper is to provide a vague summary of currently existing blockchain use cases in the information technology industry. Respective use cases have been examined in already existing scientific papers, Master Theses, industry white papers and blogs of industry experts. The paper also contains a description of blockchain main technological aspects and working principles, which allows making the assessment of the presented use cases. For each use case respective companies or organisations are added that are applying or testing the given solution. Due to research limitations the paper should not be considered an exhaustive blockchain use case description.

The paper also provides short introduction into a feasibility analysis of specific blockchain use case. The authors describe the basic steps of potential idea evaluation with regards to blockchain main aspects. It helps understand the necessity for development of a detailed blockchain feasibility model.

Virtualization has enabled the commoditization of cloud computing, as the hardware resources have become available to run different environments and share computing resources amongst different enterprises. Two technology types are commonly used in virtualization of hardware, namely, hypervisor and container. The present paper concerns only container technologies.

A comprehensive overview of the container technologies for virtualization and the dynamics of their popularity have not been available yet. Without such an overview, the informed fast choice of technologies is hindered. To fill this knowledge gap, a systemic literature review was conducted to reveal the most popular container technologies and the trends in their research.

During object-relational database physical structure design, problems are caused by three factors: ambiguity of transformations of conceptual model, multiplicity of quality assessment criteria, and a lack of constructive model. In the present study a constructive hierarchical model of physical database structure has been developed. Implementations are used in XML, SQL and Java languages. Multi-criterial structure optimisation method has also been developed. Structure variation space is generated using transformation rule database. Prototype has been implemented within the framework of the research.

The paper describes the implementation of organic benchmarks for Java EE and ASP.NET Core, which are used to compare the performance characteristics of the language runtimes. The benchmarks are created as REST services, which process data in the JSON format. The ASP.NET Core implementation utilises the Kestrel web server, while the Java EE implementation uses Apache TomEE, which is based on Apache Tomcat. A separate service is created for invoking the benchmarks and collecting their results. It uses Express with ES6 (for its async features), Redis and MySQL. A web-based interface for utilising this service and displaying the results is also created, using Angular 5.

Social networking sites such as Facebook, Twitter and VKontakte, online stores such as eBay, Amazon and Alibaba as well as many other websites allow users to share their thoughts with their peers. Often those thoughts contain not only factual information, but also users’ opinion and feelings. This subjective information may be extracted using sentiment analysis methods, which are currently a topic of active research. Most studies are carried out on the basis of texts written in English, while other languages are being less researched. The present survey focuses on research conducted on the sentiment analysis for the Latvian and Russian languages.

The present paper considers an open problem of setting hyperparameters for convolutional neural networks aimed at image classification. Since selecting filter spatial extents for convolutional layers is a topical problem, it is approximately solved by accumulating statistics of the neural network performance. The network architecture is taken on the basis of the MNIST database experience. The eight-layered architecture having four convolutional layers is nearly best suitable for classifying small and medium size images. Image databases are formed of grayscale images whose size range is 28 × 28 to 64 × 64 by step 2. Except for the filter spatial extents, the rest of those eight layer hyperparameters are unalterable, and they are chosen scrupulously based on rules of thumb. A sequence of possible filter spatial extents is generated for each size. Then sets of four filter spatial extents producing the best performance are extracted. The rule of this extraction that allows selecting the best filter spatial extents is formalized with two conditions. Mainly, difference between maximal and minimal extents must be as minimal as possible. No unit filter spatial extent is recommended. The secondary condition is that the filter spatial extents should constitute a non-increasing set. Validation on MNIST and CIFAR- 10 databases justifies such a solution, which can be extended for building convolutional neural network classifiers of colour and larger images.

The article investigates different approaches to the design of information systems. Much attention is paid to comparative analysis of criteria for selecting methodologies for software development, and also to not well-known methodology of DevOps (Development & Operation) [1], [2], which aims at consolidation of software developers (Development) and IT professionals’ (Operation) efforts, and automation of implementation process. In conclusion, based on the retrospective analysis and practical experience, the authors formulate regularities and prospects of information systems design methodology development.

With the aim to compare methods for counting the number of lines of a raster matrix, intersecting a round mark image, and a number of pixels belonging to this image for measuring its radius, a numerical simulation is carried out in the present article. It is proved that the application of the method for counting the number of pixels belonging to the image of the round mark allows obtaining more than 30 times gain in the accuracy of this image radius measurement using the same equipment. The formulas proposed in the article are used for software implementation of non-contact vibration measurement systems.

The development of new software to improve the operation of modernised and developed technological facilities in different sectors of the national economy requires a systematic approach. For example, the use of video recording systems obtained during operations with the use of endoscopic equipment allows monitoring the work of doctors. Minor change of the used software allows using additionally processed video fragments for creation of training complexes. The authors of the present article took part in the development of many educational software and hardware systems. The first such system was the “Contact” system, developed in the eighties of the last century at Riga Polytechnic Institute. Later on, car simulators, air plan simulators, walking excavator simulators and the optical software-hardware training system “Three-Dimensional Medical Atlas” were developed. Analysis of various simulators and training systems showed that the computers used in them could not by themselves be a learning system. When creating a learning system, many factors must be considered so that the student does not receive false skills. The goal of the study is to analyse the training systems created for the professional training of medical personnel working with endoscopic equipment, in particular, with equipment equipped with 3D indicators.