Three Performance Models at Work: A Software Designer Perspective

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Програмно-інструментальні системи імітаційного моделювання комп’ютерних мереж та можливість їх розширення мережами петрі

Analyzed and generalized areas of simulation modeling COMPUTER networks; highlighted the general principles of such models and software technology to implement them ; proved the feasibility of using Petri nets in systems simulation modeling COMPUTER networksПроанализированы и обобщены направления развития имитационного моделирования компьютерных сетей ; выделены общие принципы построения таких моделей и программных технологий их реализации ; доказана целесообразность использования сетей Петри в системах имитационного моделирования компьютерных сетейПроаналізовано та узагальнено напрями розвитку імітаційного моделювання комп 'ютерних мереж; виділено загальні принципи побудови таких моделей та програмних технологій їх реалізації; доведена доцільність використання мереж Петрі в системах імітаційного моделювання комп ’ютерних мере

Performance modeling tools with applications

This paper deals with the role of performance modeling tools. It introduces 3 major tool development centers and shows how a given tool can be applied to investigate the performance of a finite-source retrial queueing system

FORECASTING THE OPERATIONAL ACTIVITIES OF THE SEA PASSENGER TERMINAL USING INTELLIGENT TECHNOLOGIES

. Modern transport systems are characterized by the development and implementation of intelligent transport technologies. Today, dynamic forecast models are not used in practice in the operation of a passenger terminal. Decision making is based on some regulatory values for passenger traffic, but this is not sufficient for efficient terminal management. Modern passenger terminals are characterized by dynamic process variability and consideration of diverse options, taking into account the criteria of safety, reliability analysis, and the continuous research of passenger processing. For any modern marine passenger terminal, it is necessary to use the tool to simulate passenger flows in dynamics. Only in this way it is possible to obtain the analytical information and use it for decision making when solving the problem of the amount of personnel required for passenger service, transport safety, some forecasting tasks and so on. Of particular relevance is the choice of the mathematical transport model and the practical conditions for the implementation of the model in the real terminal operation. In this article, the analysis technique of intelligent simulation-based terminal services provides a new mathematical model of passenger movement inside the terminal and presents a new software instrument. Moreover, the conditions of implementation of some transportation models during the operation of marine passenger terminal are examined. The study represents an example of analytical information used for the forecast of the terminal operations, the analysis of the workload and the efficiency of the organization of the marine terminal

Ús de les xarxes de Petri per a la generació automàtica de codi en la programació de robots

Aquest projecte pretén elaborar una eina per a la generació automàtica de codi en la programació de robots, a partir de les xarxes de Petri. Les xarxes de Petri són una eina gràfica formada per llocs, arcs i transicions que, a part de moltes altres finalitats, permet la modelització de cel·les de treball on intervenen tot tipus d’elements automatitzats, principalment robots manipuladors i elements de transport i emmagatzematge. Es vol que el programa permeti l’assimilació de l’entorn real de treball a la xarxa de Petri, dotant-la de les característiques necessàries per a la diferenciació de varis robots i la capacitat d’emmagatzemar i generar posteriorment el codi per programar-los, deixant per a l’usuari només la feina referent a la introducció del codi relacionat estrictament amb el moviment del robots. D’altra banda es vol que estigui desenvolupat com a programari lliure i que també es desenvolupi a través d’aquest. Es parteix d’un programa lliure que permet l’edició i anàlisi de xarxes de Petri i es desenvolupa un mòdul totalment integrat a l’aplicació que genera el codi de programació de forma automàtica. Aquest codi generat és capaç d’implementar tots els elements necessaris per tal d’establir i mantenir la comunicació entre els robots, eximint a l’usuari d’aquesta feina complexa. També és capaç de gestionar espais i recursos accedits per varis robots, així com d’executar tasques en paral·lel al fil principal de cada robot per tal de realitzar càlculs o l’activació de dispositius externs

Context-aware workflow management in eHealth applications

Workflows are a technology to structure work in functional, non-overlapping steps. They define not only the order of execution of the steps, and describe whether steps are executed in parallel, they also specify who or what tool has to fulfill which step. Workflows offer the possibility to automate work, to increase the understandability of processes, and they ease the control of process execution. The tools to manage workflows, so called workflow management systems (WfMSs), are traditionally rigid as they separate workflow definition done at build time from workflow execution done at run time. This makes them ill-suited for managing flexible and unstructured workflows. In this thesis, we focus on the support of flexible processes in eHealth, which are affected by more foreseen than unforeseen events. To bridge the gap between rigid WfMSs and flexible workflows, we developed a concept for dynamic and context-aware workflow management called Flexwoman. Although our focus lies on flexible eHealth processes, Flexwoman is a generic approach that can be applied to several different application domains. Flexwoman supports the usage of context information to adapt processes automatically at run time to foreseen events. Processes can also be manually adapted to handle unforeseen events. To achieve this flexibility, context information from different sensors is unified and thus can be analyzed in the same way. The analysis and adaptation of workflows is executed with a rule engine. A rule engine can store, reason about and apply knowledge automatically and efficiently. Rules and application logic are separated, thus, rules can be changed during run time without affecting application logic or process description. Workflows are internally described by Hierarchical Colored Petri nets (HCPNs) and executed by a HCPN execution engine. HCPNs allow for a deterministic execution of workflows and can represent workflows on different levels of detail. In summary, in Flexwoman, significant context changes (events) trigger automated adaptations that replace parts of the workflow by sub workflows, which can in turn be adapted. The adaptations and the rules for context-aware adaptation are saved in the organizational memory for later reuse. Flexwoman’s event based behavior facilitates proactive adaptations instead of only allowing for adaptations while entering or leaving a task. Replacements are not bound to special places defined at build time but each part of the workflow, which has not been executed yet, can be replaced at run time. We implemented and evaluated the concept. The evaluations show i) that all required functionality is available, ii) that the system scales with a growing number of rules, and iii) that the system correctly handles failure situations