746 research outputs found

    Exploration and mining evaluation system and price prediction of uranium resources

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    Purpose. The paper introduces the development of the Uranium Resources Technical and Economic Evaluation Expert System (URTEEES) from the viewpoint of requirement analysis, system design, functional structure and application etc. Methods. The system is based on C/B/S mixed mode and applies ASP.NET technology with .Net Framework being selected as the development platform as well as the uranium resources database providing data support at the bottom layer. The paper also proves the efficiency of the system in the context of certain case studies. Findings. Since the system can performs the functions of scenario analysis, sensitivity analysis, shareholder’s returns analysis, horizontal comparison of different projects, it can improve the ability of project senior decision-makers for rapid response to the rivals and meet the demand of pricing negotiations. Moreover, the system demonstrates its efficiency in the context of case studies as the system incorporates a number of advanced methods, e.g. the Quantum Particle Swarm Optimization (QPSO) Back Propagation (BP) QPSO-BP model which can improve the generalization ability of BP network to predict the uranium price. Originality. Technical and economic evaluation model can be set up by users independently according to the current stage of a project (mainly, these are exploration stage, development stage and production stage) as well as according to the selected mining method (e.g. underground mining, surface mining, or in-situ leaching mining). Then, the technical and economic evaluation parameters can be generated. By means of inputting the value of each parameter in a simple and convenient way, the evaluation results can be calculated directly and shown in the form of diagrams; moreover, feasibility evaluation report can be generated automatically, making the process of technical and economic evaluation accurate and efficient. Practical implications. URTEEES performs the functions of decision-making analysis, metal resources database management, data management, comprehensive query etc. The system is a good basis for further development of other expert systems.Мета. Розробка експертно-аналітичної системи техніко-економічного оцінювання запасів урану з точки зору аналізу вимог, системи проектування, функціональної структури і напрямів застосування. Методика. Проектна система повинна включати два основні блоки. Перший – існуючі дані щодо оцінки ресурсів урану для отримання відповідних параметрів, які можуть бути використані для створення моделей оцінки й забезпечення основи для їх порівняння при оцінці нового проекту. Другий – допоміжна інформація, така як закони і правила, культурна інформація, яка насправді є накопиченням даних проекту і досвіду. Пропонована система заснована на використанні комбінованого режиму C/B/S; при цьому система використовує технологію ASP.NET с Nеt Framework, обрану в якості платформи розробки, а також базу даних по запасах урану, що забезпечує інформаційну підтримку на нижньому рівні. Результати. Розроблена нова система URTEEES виконує функції імовірнісного аналізу, аналізу чутливості, аналізу прибутковості для акціонерів, а також горизонтальне порівняння різних проектів, отже, може поліпшити результативність прийняття рішень керівниками проекту для швидкого реагування на дії конкурентів, крім того, дана система відповідає вимогам процесу ціноутворення. Реалізація проектної системи показує високу ефективність, оскільки включає в себе безліч методів з поліпшеними характеристиками, наприклад, модель QPSO-BP, яка удосконалила узагальнюючі можливості нейронної мережі ВР з метою оптимізації та ефективного прогнозування ціни на уран. Наукова новизна. В системі розроблена модель техніко-економічного оцінювання в залежності від стадійності реалізації проекту (в основному, це стадія геологорозвідувальних робіт, стадія розробки родовища і стадія промислового видобутку), а також способу ведення гірничих робіт (наприклад, підземні гірничі роботи, відкриті гірничі роботи або ж роботи, пов’язані з підземним вилуговуванням), а результати оцінювання можна безпосередньо підрахувати і представити наочно у вигляді діаграм. Крім того, представляється можливим автоматично сформувати техніко-економічне обґрунтування, що дозволяє зробити процес техніко-економічного оцінювання точним і ефективним. Практична значимість. Система URTEEES дозволяє виконувати функції аналізу процесу прийняття рішень, управління базою даних запасів металів, управління даними, універсальної пошукової системи в гірничодобувній промисловості.Цель. Разработка экспертно-аналитической системы технико-экономического оценивания запасов урана с точки зрения анализа требований, системы проектирования, функциональной структуры и применения. Методика. Проектная система должна включать два основных блока. Первый – существующие данные об оценке ресурсов урана для получения соответствующих параметров, которые могут быть использованы для создания моделей оценки и обеспечения основы для их сравнения при оценке нового проекта. Второй – вспомогательная информация, такая как законы и правила, культурная информация, которая на самом деле является накоплением данных проекта и опыта. Предлагаемая система основана на использовании комбинированного режима C/B/S; при этом система использует технологию ASP.NET с Net Framework, выбранную в качестве платформы разработки, а также базу данных по запасам урана, что обеспечивает информационную поддержку на нижнем уровне. Результаты. Разработанная система выполняет функции вероятностного анализа, анализа чувствительности, анализа доходности для акционеров, а также горизонтальное сравнение различных проектов, следовательно, может улучшить результативность принятия решений руководителями проекта для быстрого реагирования на действия конкурентов; кроме того, данная система соответствует требованиям процесса ценообразования. Реализация проектной системы показывает высокую эффективность, поскольку включает в себя множество методов с улучшенными характеристиками, например, модель QPSO-BP, которая усовершенствовала обобщающие возможности нейронной сети BP с целью оптимизации и эффективного прогнозирования цены на уран. Научная новизна. В системе разработана модель технико-экономического оценивания в зависимости от стадийности реализации проекта (в основном, это стадия геологоразведочных работ, стадия разработки месторождения и стадия промышленной добычи), а также способа ведения горных работ (например, подземные горные работы, открытые горные работы или же работы, связанные с подземным выщелачиванием), а результаты оценивания можно непосредственно подсчитать и представить наглядно в виде диаграмм. Кроме того, представляется возможным автоматически сформировать технико-экономическое обоснование, что позволяет сделать процесс технико-экономического оценивания точным и эффективным. Практическая значимость. Система URTEEES позволяет выполнять функции анализа процесса принятия решений, управления базой данных запасов металлов, управления данными, универсальной поисковой системы в горнодобывающей промышленности.This research project is made possible through the financial support from National Natural Science Foundation of China (No.51374242, No.51404305 and No.51504286)

    Risk-based maintenance of critical and complex systems

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    Tableau d’honneur de la Faculté des études supérieures et postdoctorales, 2016-2017.De nos jours, la plupart des systèmes dans divers secteurs critiques tels que l'aviation, le pétrole et les soins de santé sont devenus très complexes et dynamiques, et par conséquent peuvent à tout moment s'arrêter de fonctionner. Pour éviter que cela ne se reproduise et ne devienne incontrôlable ce qui engagera des pertes énormes en matière de coûts et d'indisponibilité; l'adoption de stratégies de contrôle et de maintenance s'avèrent plus que nécessaire et même vitale. Dans le génie des procédés, les stratégies optimales de maintenance pour ces systèmes pourraient avoir un impact significatif sur la réduction des coûts et sur les temps d'arrêt, sur la maximisation de la fiabilité et de la productivité, sur l'amélioration de la qualité et enfin pour atteindre les objectifs souhaités des compagnies. En outre, les risques et les incertitudes associés à ces systèmes sont souvent composés de plusieurs relations de cause à effet de façon extrêmement complexe. Cela pourrait mener à une augmentation du nombre de défaillances de ces systèmes. Par conséquent, un outil d'analyse de défaillance avancée est nécessaire pour considérer les interactions complexes de défaillance des composants dans les différentes phases du cycle de vie du produit pour assurer les niveaux élevés de sécurité et de fiabilité. Dans cette thèse, on aborde dans un premier temps les lacunes des méthodes d'analyse des risques/échec et celles qui permettent la sélection d'une classe de stratégie de maintenance à adopter. Nous développons ensuite des approches globales pour la maintenance et l'analyse du processus de défaillance fondée sur les risques des systèmes et machines complexes connus pour être utilisées dans toutes les industries. Les recherches menées pour la concrétisation de cette thèse ont donné lieu à douze contributions importantes qui se résument comme suit: Dans la première contribution, on aborde les insuffisances des méthodes en cours de sélection de la stratégie de maintenance et on développe un cadre fondé sur les risques en utilisant des méthodes dites du processus de hiérarchie analytique (Analytical Hierarchy Process (AHP), de cartes cognitives floues (Fuzzy Cognitive Maps (FCM)), et la théorie des ensembles flous (Fuzzy Soft Sets (FSS)) pour sélectionner la meilleure politique de maintenance tout en considérant les incertitudes. La deuxième contribution aborde les insuffisances de la méthode de l'analyse des modes de défaillance, de leurs effets et de leur criticité (AMDEC) et son amélioration en utilisant un modèle AMDEC basée sur les FCM. Les contributions 3 et 4, proposent deux outils de modélisation dynamique des risques et d'évaluation à l'aide de la FCM pour faire face aux risques de l'externalisation de la maintenance et des réseaux de collaboration. Ensuite, on étend les outils développés et nous proposons un outil d'aide à la décision avancée pour prédire l'impact de chaque risque sur les autres risques ou sur la performance du système en utilisant la FCM (contribution 5).Dans la sixième contribution, on aborde les risques associés à la maintenance dans le cadre des ERP (Enterprise Resource Planning (ERP)) et on propose une autre approche intégrée basée sur la méthode AMDEC floue pour la priorisation des risques. Dans les contributions 7, 8, 9 et 10, on effectue une revue de la littérature concernant la maintenance basée sur les risques des dispositifs médicaux, puisque ces appareils sont devenus très complexes et sophistiqués et l'application de modèles de maintenance et d'optimisation pour eux est assez nouvelle. Ensuite, on développe trois cadres intégrés pour la planification de la maintenance et le remplacement de dispositifs médicaux axée sur les risques. Outre les contributions ci-dessus, et comme étude de cas, nous avons réalisé un projet intitulé “Mise à jour de guide de pratique clinique (GPC) qui est un cadre axé sur les priorités pour la mise à jour des guides de pratique cliniques existantes” au centre interdisciplinaire de recherche en réadaptation et intégration sociale du Québec (CIRRIS). Nos travaux au sein du CIRRIS ont amené à deux importantes contributions. Dans ces deux contributions (11e et 12e) nous avons effectué un examen systématique de la littérature pour identifier les critères potentiels de mise à jour des GPCs. Nous avons validé et pondéré les critères identifiés par un sondage international. Puis, sur la base des résultats de la onzième contribution, nous avons développé un cadre global axé sur les priorités pour les GPCs. Ceci est la première fois qu'une telle méthode quantitative a été proposée dans la littérature des guides de pratiques cliniques. L'évaluation et la priorisation des GPCs existants sur la base des critères validés peuvent favoriser l'acheminement des ressources limitées dans la mise à jour de GPCs qui sont les plus sensibles au changement, améliorant ainsi la qualité et la fiabilité des décisions de santé.Today, most systems in various critical sectors such as aviation, oil and health care have become very complex and dynamic, and consequently can at any time stop working. To prevent this from reoccurring and getting out of control which incur huge losses in terms of costs and downtime; the adoption of control and maintenance strategies are more than necessary and even vital. In process engineering, optimal maintenance strategies for these systems could have a significant impact on reducing costs and downtime, maximizing reliability and productivity, improving the quality and finally achieving the desired objectives of the companies. In addition, the risks and uncertainties associated with these systems are often composed of several extremely complex cause and effect relationships. This could lead to an increase in the number of failures of such systems. Therefore, an advanced failure analysis tool is needed to consider the complex interactions of components’ failures in the different phases of the product life cycle to ensure high levels of safety and reliability. In this thesis, we address the shortcomings of current failure/risk analysis and maintenance policy selection methods in the literature. Then, we develop comprehensive approaches to maintenance and failure analysis process based on the risks of complex systems and equipment which are applicable in all industries. The research conducted for the realization of this thesis has resulted in twelve important contributions, as follows: In the first contribution, we address the shortcomings of the current methods in selecting the optimum maintenance strategy and develop an integrated risk-based framework using Analytical Hierarchy Process (AHP), fuzzy Cognitive Maps (FCM), and fuzzy Soft set (FSS) tools to select the best maintenance policy by considering the uncertainties.The second contribution aims to address the shortcomings of traditional failure mode and effect analysis (FMEA) method and enhance it using a FCM-based FMEA model. Contributions 3 and 4, present two dynamic risk modeling and assessment tools using FCM for dealing with risks of outsourcing maintenance and collaborative networks. Then, we extend the developed tools and propose an advanced decision support tool for predicting the impact of each risk on the other risks or on the performance of system using FCM (contribution 5). In the sixth contribution, we address the associated risks in Enterprise Resource Planning (ERP) maintenance and we propose another integrated approach using fuzzy FMEA method for prioritizing the risks. In the contributions 7, 8, 9, and 10, we perform a literature review regarding the risk-based maintenance of medical devices, since these devices have become very complex and sophisticated and the application of maintenance and optimization models to them is fairly new. Then, we develop three integrated frameworks for risk-based maintenance and replacement planning of medical devices. In addition to above contributions, as a case study, we performed a project titled “Updating Clinical Practice Guidelines; a priority-based framework for updating existing guidelines” in CIRRIS which led to the two important contributions. In these two contributions (11th and 12th) we first performed a systematic literature review to identify potential criteria in updating CPGs. We validated and weighted the identified criteria through an international survey. Then, based on the results of the eleventh contribution, we developed a comprehensive priority-based framework for updating CPGs based on the approaches that we had already developed and applied success fully in other industries. This is the first time that such a quantitative method has been proposed in the literature of guidelines. Evaluation and prioritization of existing CPGs based on the validated criteria can promote channelling limited resources into updating CPGs that are most sensitive to change, thus improving the quality and reliability of healthcare decisions made based on current CPGs. Keywords: Risk-based maintenance, Maintenance strategy selection, FMEA, FCM, Medical devices, Clinical practice guidelines

    Assessment of municipal solid waste disposal options using analytical hierarchy process and life cycle analysis

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    Disposal of municipal solid waste (MSW) generated in the city of Johor Bahru has been one of the challenges to the authorities and the public. Population sizes and MSW generation rates are increasing every year. The two existing landfills which are located at Seelong and Tanjung Langsat, can no longer cope with the amount of the MSW. This imposes more negative burden on the environment and public health; thus calling for better MSW disposal alternatives. However, local authorities are confronted with problems, protests and resistance as well as financial constraints in choosing and implementing waste disposals facilities. Solving the problem involves a complex evaluation procedure because compromises and tradeoffs among stakeholders and other interest groups are difficult to reach. In the current study, two concepts, analytical hierarchy process (AHP) and life cycle assessment (LCA) were used. The objectives are to identify stakeholders’ opinion on MSW disposal (through visits, meetings, conferences and symposia sessions) and use AHP to structure those opinions in proposing disposal alternatives (landfilling, recycling, incineration, composting) along environmental, economic and social implications. LCA was finally conducted to assess environmental impacts of the disposals so that informed and sustained disposal decisions can be implemented. AHP results showed that habitat depletion, land use, stream ecology, air quality and flora & fauna dominated environmental concerns of the stakeholders. Capital cost, operation and maintenance cost, landfill capacity and regulation influence were the most critical criteria in economic factors. Concern for public health and safety, public awareness, cooperation among others were found to dominate the social factors. The four alternative disposal options (i.e. landfilling, recycling, incineration, composting) were assessed and ranked according to the preferences of the stakeholders. Incineration and composting were most preferred to landfilling and recycling. Landfilling was not preferred and was perceived to be most environmentally polluting, economically unsustainable and socially unacceptable by the stakeholders. LCA results showed that Landfill has the highest impacts among the selected environmental impact categories namely, global warming (992 kg Carbon dioxide eq), acidification (0.104 moles of Nitrogen or Sulphur-eq), photochemical ozone formation (0.686 kg Non-Methane Volatile Organic Compounds) (MNVOC) and eutrophication (0.104 moles of Nitrogen or Sulphureq); except for ozone depletion potential having the highest impacts (0.686 kg Chlorofluorocarbon 11-eq) in the incineration plan due to the presence of Chlorofluorocarbon-based chemicals utilized in flue gas purification. Incineration with energy recovery and composting with stable organic compost were found to have least environmental impacts. Finally, views of concerns of stakeholder on MSW disposal in Johor Bahru city were identified and modelled with AHP. Practical environmental performance of the disposal alternatives were demonstrated through the LCA. Combination of the concepts (i.e. AHP and LCA) revealled better information in sustainability of disposing MSW by incineration and composting. This can aid more guided information on selecting better MSW disposal alternatives. Thus it will be possible to avoid misunderstandings on MSW treatments e.g. incineration since the public are involved in the decision making processes

    Intelligent Decision Support System for Energy Management in Demand Response Programs and Residential and Industrial Sectors of the Smart Grid

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    This PhD thesis addresses the complexity of the energy efficiency control problem in residential and industrial customers of Smart electrical Grid, and examines the main factors that affect energy demand, and proposes an intelligent decision support system for applications of demand response. A multi criteria decision making algorithm is combined with a combinatorial optimization technique to assist energy managers to decide whether to participate in demand response programs or obtain energy from distributed energy resources

    A Decision Aiding Framework for Concentrated Solar Thermal Power Technologies Assessment in Developing Countries

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    The diversification of electricity generation is necessary for sustainable development. The planning for renewable energy sources (RESs) integration is an essential goal set by many developing countries. Enormous investments are allocated accordingly to renewable energy projects, including solar power utilities. Concentrated solar thermal power (CSP) technologies are advancing and are expected to play a significant role in energy portfolios in the future. CSP planning is a complex process owing to the involvement of various contradicting factors and players. This thesis proposes a structured aiding framework to assess utility-scale CSP alternatives to support national grids in developing countries. It is common in many fast growing developing countries that the power plants are owned by the state, which enlarges the scope of electric power projects beyond the technical and economic drivers to include environmental, social, and political aspects, which accordingly increases the planning process complexity. The developed methodology consists of three main phases. The first phase is concerned with formulating a value tree for CSP technologies evaluation. This phase is intended to explicitly capture a generic evaluation criteria through a rigorous process of expert deliberation and consensus-seeking. Expert elicitation is conducted through the Delphi method, with a total of 140 experts participating from multidisciplinary solar thermal power fields from 32 countries. Based on participants’ judgments, as expressed during two rounds of Delphi questionnaires, parameters with importance and consensus degrees > 50% are incorporated to construct the final value tree. The recommendations of this phase set a foundation for stakeholders’ assessment of regional CSP utilities planning in developing countries. The second phase considers analyzing, defining, and simulating alternative scenarios. Large-scale CSP deployment is in its infancy with a lack of sufficient data in many developing countries and various available technology combinations. Accordingly, this phase intends to focus the planning process toward practical alternatives given the regional requirements. A techno-economic analysis is conducted that considers the strengths, weaknesses, opportunities, and threats (SWOT) for each technology. As RESs are location dependent, Saudi Arabia defines the scope of this phase. The analysis outcomes are incorporated with the Saudi energy sector requirements and local weather conditions to define alternative scenarios. Six power plant scenarios are defined for performance and financial evaluation. A simulation is subsequently carried out through the System Advisor Model. The alternative scenarios are assessed by defining weather, technical, and financial parameters. Satellite observations and field measured data are integrated to synthesize a typical meteorological year weather profile. The outputs of this phase provide accurate results that represent a solid ground for the assessment of alternative CSP scenarios with consideration of all relevant parameters. The third phase considers a comprehensive assessment of the scenario-based CSP alternatives. A multi-criteria decision-making (MCDM) model is developed in a fuzzy environment to tackle uncertainty, ambiguity, and imprecision. The evaluation is conducted based on extensive analysis of the performances of each alternative scenario in accordance with 4 main criteria and 29 sub-criteria. Quantitative and qualitative data as well as input from 44 local stakeholders are incorporated. The obtained results constitute an accurate basis to derive recommendations for CSP integration to national grids and relate them to stakeholders’ priorities

    Optimal Design and Analysis of Grid-Connected Solar Photovoltaic Systems

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    Many countries consider utilizing renewable energy sources such as solar photovoltaic (PV), wind, and biomass to boost their potential for more clean and sustainable development and to gain revenues by export. In this thesis, a top-down approach of solar PV planning and optimization methodology is developed to enable high-performance at minimum costs. The first problem evaluates renewable resources and prioritizes their importance towards sustainable power generation. In the second problem, possible sites for solar PV potential are examined. In the third problem, optimal design of a grid-connected solar PV system is performed using HOMER software. A techno-economic feasibility of different system configurations including seven designs of tracking systems is conducted. In the fourth and the final problem, the optimal tilt and azimuth angles for maximum solar power generation are found. Using a detailed estimation model coded in MATLAB software, the solar irradiation on a tilted angle was estimated using a ground measurement of solar irradiation on a horizontal surface. A case study for Saudi Arabia is conducted. The results of our prioritization study show solar PV followed by concentrated solar power are the most favorable technologies followed by wind energy. Using a real climatology and legislation data, such as roads, mountains, and protected areas, land suitability is determined via AHP-GIS model. The overlaid result suitability map shows that 16% (300,000 km2) of the study area is promising for deploying utility-size PV power plants in the north and northwest of Saudi Arabia. The optimal PV system design for Makkah, Saudi Arabia shows that the two-axis tracker can produce 34% more power than the fixed system. Horizontal tracker with continuous adjustment shows the highest net present cost (NPC) and the highest levelized cost of energy (LCOE), with a high penetration of solar energy to the grid. At different tilt and azimuth angles, the solar irradiation, potential power, and system revenue were calculated for 18 cities in Saudi Arabia. For Riyadh city (high suitable site), the monthly adjustment increases the harvested solar energy by 4%. It is recommended to adjust the tilt angle five times per year to achieve near-optimal results and minimize the cost associated with workforce or solar trackers for monthly adjustments. The proposed work can be exploited by decision-makers in the solar energy area for optimal design and analysis of grid-connected solar photovoltaic systems

    Sustainability as a Multi-criteria Concept

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    Sustainability is a fairly old concept, born in the 18th century in the field of forestry, within a mono-functionality perspective. The concept has considerably evolved in the last few years towards a multi-functionality context, with applications reported in practically all areas of economic interest. On the other hand, modern sustainability is a complex problem, for two reasons: a) The multiplicity of functions of a very different nature involved in the process and b) The manner in which different segments of the society or stakeholders perceive the relative importance of these functions. For the above reasons, a realistic approach for dealing with the sustainability issue requires taking into consideration multiple criteria of different nature (economic, environmental and social), and in many cases within a participatory decision making framework. This book presents a collection of papers, dealing with different theoretical and applied issues of sustainability, with the help of a modern multi-criteria decision-making theory, with a single as well as several stakeholders involved in the decision-making process. Hopefully, this material will encourage academics and practitioners to alter their research in this hot and vital topic. After all, the sustainable management of the environment and its embedded resources is one of the most important, if not the major challenge of the 21st century

    Applying a new systematic fuzzy FMEA technique for risk management in light steel frame systems

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    Light Steel Frame (LSF) system is mainly used for construction of short and intermediate-height buildings in developed countries whereas considerable heed is not given to it in developing countries. Unfamiliarity to LSF risks is one of the main reasons for this averseness so risk management can remedy this challenge and develop application of the LSF. Hence, this paper investigates the risk management of LSF system considering design, construction and operation phase. Three main steps entailing risk identification, assessment and responding using fuzzy Failure Mode and Effect Analysis (FMEA) technique are suggested for risk management implementation and for validation of responses, a novel index with respect to weighted combination of project quality, time and cost are calculated. The methodology is demonstrated on a pilot study in a developing country. By using interview, 29 significant risks are extracted in design, construction and operation and then evaluated by proposed fuzzy method. Results showed that the share of the risks in these steps are 21%, 31% and 48% respectively. The results revealed that the risks in the construction and operation phases are higher than those in the design phase. The results also show that involving safety as a project object in the risk management process could eventuate acceptable results

    Sustainable Assessment in Supply Chain and Infrastructure Management

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    In the competitive business environment or public domain, the sustainability assessment in supply chain and infrastructure management are important for any organization. Organizations are currently striving to improve their sustainable strategies through preparedness, response, and recovery because of increasing competitiveness, community, and regulatory pressure. Thus, it is necessary to develop a meaningful and more focused understanding of sustainability in supply chain management and infrastructure management practices. In the context of a supply chain, sustainability implies that companies identify, assess, and manage impacts and risks in all the echelons of the supply chain, considering downstream and upstream activities. Similarly, the sustainable infrastructure management indicates the ability of infrastructure to meet the requirements of the present without sacrificing the ability of future generations to address their needs. The complexities regarding sustainable supply chain and infrastructure management have driven managers and professionals to seek different solutions. This Special Issue aims to provide readers with the most recent research results on the aforementioned subjects. In addition, it offers some solutions and also raises some questions for further research and development toward sustainable supply chain and infrastructure management
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