Joint maintenance-inventory optimisation of parallel production systems

We model a joint inspection and spare parts inventory policy for maintaining machines in a parallel system, where simultaneous downtime seriously impacts upon production performance and has a significant financial consequence. This dependency between system components means that analysis of realistic maintenance models is intractable. Therefore we use simulation and a numerical optimisation tool to study the cost-optimality of several policies. Inspection maintenance is modelled using the delay-time concept. Critical spare parts replenishment is considered using several variants of a periodic review policy. In particular, our results indicate that the cost-optimal policy is characterised by equal frequencies of inspection and replenishment, and delivery of spare parts that coincides with maintenance intervention. In general, our model provides a framework for studying the interaction of spare parts ordering with maintenance scheduling. The sensitivity analysis that we present offers insights for the effective management of such parallel systems, not only in a paper-making plant, which motivates our modelling development, but also in other manufacturing contexts

A Methodology for Developing Correct Rule-Based Programs for Parallel Implementation

Production systems, also called rule-based systems, are very useful in automating certain human expert tasks, but the current technology exhibits many problems. We believe that parallelism is difficult to exploit in production system programs for two reasons. First, the original serial programs are designed with a priori knowledge of an explicit global control mechanism which must be simulated for correct execution in parallel. The second reason for the difficulty is that no formal language exists in which to express these programs and no verification techniques are utilized to prove properties which guarantee correct execution in parallel. With these two obstacles removed, a correct rule-based program can be designed to exploit increased parallelism when mapped to a parallel production system model for execution. This research will concentrate on the development of parallel production system programs. The objective is to define a theoretical foundation to describe parallel production systems for implementation in parallel architectures. The Swarm language will be used as the vehicle for encoding the programs. Swarm\u27s associated proof theory will be used, and possibly extended, to show correctness of properties necessary to guarantee correct parallel execution of the rule-based programs. Thus, the overall contribution of this research will be a methodology for defining, developing, and encoding correct parallel production system programs

Improving efficiency of information measurement system of coal mine air gas protection

Purpose. Development of scientific approaches to creation of high-precision and high-speed optoelectronic measurement systems within the complex of air gas safety of coal mines by means of the developed and implemented methods and means of measurement systems efficiency improvement taking into account compensation of the effect of destabilizing factors. Methods. Experimental studies have been carried out in mine production conditions and laboratories on the physical models of information measurement systems using metrologically certified measuring instruments. Findings. It has been proposed to determine the efficiency of the developed information and measurement systems on the basis of the arithmetic mean of n groups and the geometric mean of the information data rate of m meters measuring mine atmosphere parameters in coal mines for each group separately. It has been found that the use of the developed information system measuring methane and dust concentration within the UTSSC increases data rate of mine air gas protection system by 16.5 bits/s. Originality. For the first time, logical design of information and measurement system of methane and dust concentration has been proposed and implemented, which, in contrast to the existing ones, is based on increasing accuracy and speed of measuring channels response to methane and dust concentration, which allowed to increase probability of detecting explosive situations from 0.90 to 0.98 and provide enhancement of mine air gas protection. Practical implications. The developed methods and techniques allowed to implement a number of projects for the mining industry: high-speed measurement system evaluating methane concentration in a mine complex of monitoring telephone communication and notification “SAT” (private company “Deyta Express”, Ukraine); measurement system of polydisperse dust concentration for unified telecommunication systems of supervisory control and automated management of mining machines and technological complexes “UTSSC” (State Enterprise “Petrovsky Plant of Mining Machinery”, Ukraine).Мета. Розробка наукових підходів до створення високоточних швидкодіючих оптоелектронних вимірювальних систем у складі комплексу забезпечення аерогазової безпеки шахт за рахунок використання запропонованих і реалізованих методів та засобів підвищення ефективності вимірювальних систем на основі обліку й компенсації впливу дестабілізуючих факторів. Методика. Експериментальні дослідження виконано у виробничих умовах шахт і в лабораторіях на фізичних моделях інформаційно-вимірювальних систем з використанням метрологічно-атестованих засобів вимірювань. Результати. Запропоновано визначати ефективність досліджуваної інформаційно-вимірювальної системи на основі середнього арифметичного n груп від середнього геометричних значень інформаційних пропускних спроможностей m вимірювачів параметрів рудничної атмосфери вугільних шахт за кожною групою окремо. Встановлено, що використання розробленої інформаційно-вимірювальної системи концентрації метану та пилу у складі УТАС підвищує пропускну спроможність системи аерогазового захисту шахт на 16.5 біт/с. Наукова новизна. Вперше запропоновано і реалізовано логічну побудову інформаційно-вимірювальної системи концентрації метану та пилу, яка, на відміну від існуючих, заснована на підвищенні точності та швидкодії вимірювальних каналів концентрації метану і пилу, що дозволило збільшити вірогідність виявлення вибухонебезпечних ситуацій з 0.90 до 0.98 та забезпечити зростання рівня аерогазового захисту шахт. Практична значимість. Розроблені методи і засоби дозволили реалізувати низку проектів для підприємств гірничої промисловості: швидкодіюча вимірювальна система концентрації метану для комплексу шахтного диспетчерського телефонного зв’язку та оповіщення “САТ” (Приватна компанія “Дейта Експрес”, Україна); вимірювальна система концентрації полідисперсного пилу для уніфікованої телекомунікаційної системи диспетчерського контролю та автоматизованого управління гірничими машинами і технологічними комплексами “УТАС” (Державне підприємство “Петровський завод вугільного машинобудування”, Україна).Цель. Разработка научных подходов к созданию высокоточных быстродействующих оптоэлектронных измерительных систем в составе комплекса обеспечения аэрогазовой безопасности шахт за счет использования предложенных и реализованных методов и средств повышения эффективности измерительных систем на основе учета и компенсации влияния дестабилизирующих факторов. Методика. Экспериментальные исследования выполнены в производственных условиях шахт и в лабораториях на физических моделях информационно-измерительных систем с использованием метрологически-аттестованных средств измерений. Результаты. Предложено определять эффективность исследуемой информационно-измерительной системы на основе среднего арифметического n групп среднего геометрических значений информационных пропускных способностей m измерителей параметров рудничной атмосферы угольных шахт по каждой группе отдельно. Установлено, что использование разработанной информационно-измерительной системы концентрации метана и пыли в составе УТАС повышает пропускную способность системы аэрогазового защиты шахт на 16.5 бит/с. Научная новизна. Впервые предложено и реализовано логическое построение информационно-измерительной системы концентрации метана и пыли, которая, в отличие от существующих, основана на повышении точности и быстродействия измерительных каналов концентрации метана и пыли, что позволило увеличить вероятность обнаружения взрывоопасных ситуаций с 0.90 до 0.98 и обеспечить рост уровня аэрогазовой защиты шахт. Практическая значимость. Разработанные методы и средства позволили реализовать ряд проектов для предприятий горной промышленности: быстродействующая измерительная система концентрации метана для комплекса шахтной диспетчерской телефонной связи и оповещения “САТ” (Частная компания “Дейта Экспресс”, Украина); измерительная система концентрации полидисперсной пыли для унифицированной телекоммуникационной системы диспетчерского контроля и автоматизированного управления горными машинами и технологическими комплексами “УТАС” (Государственное предприятие “Петровский завод угольного машиностроения”, Украина).This work would be impossible without the financial support of the Ministry of Education and Science of Ukraine during the execution of the project No 0115U002655 “Research and development of an experimental sample of optical meter of methane concentration for coal mines”. Additional financial support was provided during the implementation of the Inter-Regional Programme of the European Neighbourhood and Partnership Instrument Tempus VI on the project 544010 – TEMPUS – 1 – 2013 – 1 – DE – TEMPUS – JPHES “TATU: Trainings in Automation Technologies for Ukraine”. The authors express gratitude to the employees of the State Enterprise “Petrovsky Plant of Mining Machinery” and the private company “Deyta Express” for participating in creation of research sample meters of methane and dust concentration for coal mine conditions, as well as support in conducting research in industrial conditions

Reactive with tags classifier system applied to real robot navigation

7th IEEE International Conference on Emerging Technologies and Factory Automation. Barcelona, 18-21 October 1999.A reactive with tags classifier system (RTCS) is a special classifier system. This system combines the execution capabilities of symbolic systems and the learning capabilities of genetic algorithms. A RTCS is able to learn symbolic rules that allow to generate sequence of actions, chaining rules among different time instants, and react to new environmental situations, considering the last environmental situation to take a decision. The capacity of RTCS to learn good rules has been prove in robotics navigation problem. Results show the suitability of this approximation to the navigation problem and the coherence of extracted rules

A New Strategy to Improve the Performance of PDP-Systems Simulators

One of the major challenges that current P systems simulators have to deal with is to be as efficient as possible. A P system is syntactically described as a membrane structure delimiting regions where multisets of objects evolve by means of evolution rules. According to that, on each computation step, the applicability of the rules for the current P system configuration must be calculated. In this paper we extend previous works that use Rete-based simulation algorithm in order to improve the time consumed during the checking phase in the selection of rules. A new approach is presented, oriented to the acceleration of Population Dynamics P Systems simulations.Ministerio de Economía y Competitividad TIN2012- 3743

Efficiency evaluation of parallel interdependent processes systems: an application to Chinese 985 Project universities

Data envelopment analysis (DEA) has been widely applied in measuring the efficiency of homogeneous decision-making units. Network DEA, as an important branch of DEA, was built to examine the internal structure of a system, whereas traditional DEA models regard a system as a ‘black box’. However, only a few previous studies on parallel systems have considered the interdependent relationship between system components. In recent years, parallel interdependent processes systems commonly exist in production systems because of serious competition among organisations. Thus, an approach to measure the efficiency of such systems should be proposed. This paper builds an additive DEA model to measure a parallel interdependent processes system with two components which have an interdependent relationship. Then, the model is applied to analyse the ‘985 Project’ universities in China, and certain policy implications are explained

Rete Algorithm for P System Simulators

The Rete algorithm is a well-known algorithm in rule-based production systems which builds directed acyclic graphs that represent higher-level rule sets. This allows the rule-based systems to avoid complete re-evaluation of all conditions of the rules each step in order to check the applicability of the rules and, therefore, the computational e ciency of the production systems is improved. In this paper we study how these ideas can be applied in the improvement of the design of computational simulators in the framework of Membrane Computing.Junta de Andalucía P08-TIC-04200Ministerio de Economía y Competitividad TIN2012-3743

US hospital performance: A dynamic network analysis

Workshop 2013 on Dynamic and Network DEA (January 29-30, 2013)Healthcare is a critical and costly industry. In the U.S. a significant component of healthcare costs are expenses generated in hospitals. This paper reports the results of analyzing 607 U.S. hospitals between 2006-2009 using a dynamic network slack-based Data Envelopment Analysis (DEA) Model. We find accounting for the dynamic and network structure of the hospital lowers efficiency estimates. Further, hospitals are more efficient at providing hospital services compared to hotel services, but the efficiency of hospitals is not correlated with their size. Regarding the dynamic network slack-based DEA Model, we find slack-based approaches combine technical and allocative aspects of inefficiency and thus tend to have significantly lower efficiency levels than just radial technical efficiency measures. Further when applying an envelopment method like DEA, there are some benefits to averaging multiple years of data to remove variation and avoid estimating a frontier based on observations that might have significant noise in their measurement.This workshop is supported by JSPS KAKENHI Grant Number 22310092 under the title “Theory and Applications of Dynamic DEA with Network Structure.

Optimal component-type allocation and replacement time policies for parallel systems having multi-types dependent components

In this work, we discuss some challenging open problems and conjectures recently proposed in the literature for parallel systems with dependent components of multiple types. Specifically, we present necessary conditions for the existence of the unique optimal value which minimizes the mean cost rate for two optimization problems. In the first place, the aim is to find the optimal number of components of each type which minimizes the associated mean cost rate, and secondly, to find the optimal replacement time before system failure. In both cases, we consider copulas to model the dependence structure for components whose lifetimes follow any distribution function. Moreover, in order to illustrate the theoretical results, we provide some numerical studies for specific copulas and marginal distribution functionsThis work was partially supported by Ministerio de Ciencia e Innovación of Spain under grant number PID2019-108079GB-C22/AEI/ 10.13039/50110001103