“It Takes All Kinds”: A Simulation Modeling Perspective on Motivation and Coordination in Libre Software Development Projects

This paper presents a stochastic simulation model to study implications of the mechanisms by which individual software developers’ efforts are allocated within large and complex open source software projects. It illuminates the role of different forms of “motivations-at-the-margin” in the micro-level resource allocation process of distributed and decentralized multi-agent engineering undertakings of this kind. We parameterize the model by isolating the parameter ranges in which it generates structures of code that share certain empirical regularities found to characterize actual projects. We find that, in this range, a variety of different motivations are represented within the community of developers. There is a correspondence between the indicated mixture of motivations and the distribution of avowed motivations for engaging in FLOSS development, found in the survey responses of developers who were participants in large projects.free and open source software (FLOSS), libre software engineering, maintainability, reliability, functional diversity, modularity, developers’ motivations, user-innovation, peer-esteem, reputational reward systems, agent-based modeling, stochastic simulation, stigmergy, morphogenesis.

An experimental study of the efficiency of optimal control for lifting machines

The article is devoted to the synthesis of optimal speed performance control, in which the Pontryagin maximum principle and the phase-plane method are used to search for switching points of the relay control function. A crane trolley model and computer control system, able to implement the automatic movement of the trolley according to the optimal laws, were developed. The conducted experimental study allowed us to establish that the operating cycle of the traveling mechanism can be reduced by 1.5-3.1 times using optimal speed performance control

Information Technology as Coordination Infrastructure

Business information technology is traditionally viewed as information provision technology. In this view, organizations use their IT to implement databases that provide people with information when they want it. This view is persistent even though information provision is never an end in itself but always has the further purpose to support the coordination of activities of people. The role if IT as coordination technology became more prominent in the 1980s with the advent of network technology, that allowed activities across different businesses to be coordinated. This trend has accellerated since the growth of Internet usage, and today IT is used to support an increasingly varied range of processes performed by a variety of partners that do not all have a hierarchical relation to each other. This makes it difficult to analyze requirements for IT support and specify IT solutions: Business processes may not be well-defined, and interests of different businesses may clash. This report argues that to deal with this in requirements engineering and IT solution specification, business information technology should not be viewed as IT support for business processes but as IT support for the coordination of activities in one or more businesses. We will identify three basic coordination mechanisms, namely coordination by price, by management, and by shared norms, and for each of these mechanisms, we will identify requirements for IT support. The advent of flexible and standardized networking technology has facilitated the creation of novel coordination mechanisms within these three general paradigms, and we will give an inventory of generalized coordination mechanisms made possible by current IT. Finally, we will draw conclusions for requirements engineering methods for IT support for each of the coordination mechanisms identified by the framework

Numerical methods of geomechanics tasks solution during coal deposits’ development

Purpose. Generalization of numerical modeling of geomechanical processes in the vicinity of mine workings by finite elements method and making recommendations for substantiation of suitable construction and behavior of rock massif physical model. Methods. Software packages SolidWorks Simulation (COSMOS/М) and ANSYS are used for geomechanical tasks solution. Findings. Solutions of geomechanical tasks dealing with topical issues of estimating stress-strain state of rock massif around underground workings of different functions are given. Data on the rock massif stress-strain state are received and recommendations on adequate and authentic reflection of its structural peculiarities (stratification and fracturing) are made. Physical model of rock condition (elastic, elastic-plastic, rheological diagrams and complete diagram of deformation taking into account weakening and fracturing) is presented. Originality. New data about the mechanism of movement processes of coal-bearing massif around mine workings considering stratification and cracks content, limit and out-of-limit deflection state in separate areas, and also the impact of rheological rock properties are received. Practical implications. Complex of geomechanical tasks solutions allow to increase credibility of rock pressure manifestations prediction and substantiate technical solutions for effective and safe operations at coal mines.Цель. Обобщение опыта численного моделирования методом конечных элементов геомеханических процессов вокруг горных выработок и формирование рекомендаций по обоснованию адекватного строения и поведения физической модели горного массива. Методика. Для решения задач геомеханики использованы пакеты прикладных программ SolidWorks Simulation (COSMOS/М) и ANSYS. Результаты. Приведены решения геомеханических задач по актуальным вопросам оценки НДС горного массива вокруг подземных выработок различного назначения. Получены закономерности поведения горного массива и даны рекомендации по адекватному и достоверному отражению его текстурных особенностей (слоистость и трещиноватость) и физической модели состояния горной породы (упругая, упруго-пластическая, реологическая, полная диаграмма деформирования с учетом разупрочнения и разрыхления). Научная новизна. Получен ряд новых закономерностей развития процессов сдвижения углевмещающего массива вокруг горных выработок с учетом его слоистости и трещиноватости, предельного и запредельного состояния в отдельных областях, а также влияния реологических свойств горных пород. Практическая значимость. Комплекс решений геомеханических задач позволяет повысить достоверность прогноза проявлений горного давления и обосновать технические решения по эффективному и безопасному ведению горных работ на угольных шахтах.Мета. Узагальнення досвіду чисельного моделювання методом скінченних елементів геомеханічних процесів навколо гірничих виробок і формування рекомендацій з обґрунтування адекватної будови й поведінки фізичної моделі гірського масиву. Методика. Для розв’язання задач геомеханіки використані пакети прикладних програм Solidworks Simulation (COSMOS/М) і ANSYS. Результати. Наведено розв’язання геомеханічних задач з актуальних питань оцінки НДС гірського масиву навколо підземних виробок різного призначення. Отримано закономірності поведінки гірського масиву й надано рекомендації з адекватного й достовірного відображення його текстурних особливостей (шаруватість і тріщинуватість) та фізичної моделі стану гірської породи (пружна, пружно-пластична, реологічна, повна діаграма деформування з урахуванням знеміцнення і розпушення). Наукова новизна. Отримано низку нових закономірностей розвитку процесів зрушення вуглевміщуючого масиву навколо гірничих виробок з урахуванням його шаруватості й тріщинуватості, граничного й позамежного станів в окремих областях, а також впливу реологічних властивостей гірських порід. Практична значимість. Комплекс розв’язань геомеханічних задач дозволяє підвищити вірогідність прогнозу проявів гірського тиску й обґрунтувати технічні розв’язання з ефективного й безпечного ведення гірничих робіт на вугільних шахтах.The materials discussed in the article were received while performing a complex of research works at the request of a number of industrial enterprises in coal mining in Donbas. The authors are grateful to M. Illiashov, M. Barabash, Yu. Cherednychenko, O. Vivcharenko, V. Chervatiuk, O. Husiev for providing mine-and-geological and technical information on features of conducting mining operations at their enterprises, and also for useful recommendations and fruitful discussion of the received results which are intended to provide an effective solution to mine-technical issues in coal mining

Family of 2-simplex cognitive tools and their application for decision-making and its justifications

Urgency of application and development of cognitive graphic tools for usage in intelligent systems of data analysis, decision making and its justifications is given. Cognitive graphic tool "2-simplex prism" and examples of its usage are presented. Specificity of program realization of cognitive graphics tools invariant to problem areas is described. Most significant results are given and discussed. Future investigations are connected with usage of new approach to rendering, cross-platform realization, cognitive features improving and expanding of n-simplex family.Comment: 14 pages, 6 figures, conferenc