Improved Adaptive Harmony Search algorithm for the resource levelling problem with minimal lags

The resource leveling problem (RLP) aims to provide the most efficient resource consumption as well as minimize the resource fluctuations without increasing the prescribed makespan of the construction project. Resource fluctuations are impractical, inefficient and costly when they happen on construction sites. Therefore, previous research has tried to find an efficient way to solve this problem. Metaheuristics using Harmony Search seem to be faster and more efficient than others, but present the same problem of premature convergence closing around local optimums. In order to diminish this issue, this study introduces an innovative Improved and Adaptive Harmony Search (IAHS) algorithm to improve the solution of the RLP with multiple resources. This IAHS algorithm has been tested with the standard Project Scheduling Problem Library for four metrics that provide different levelled profiles from rectangular to bell shapes. The results have been compared with the benchmarks available in the literature presenting a complete discussion of results. Additionally, a case study of 71 construction activities contemplating the widest possible set of conditions including continuity and discontinuity of flow relationships has been solved as example of application for real life construction projects. Finally, a visualizer tool has been developed to compare the effects of applying different metrics with an app for Excel. The IAHS algorithm is faster with better overall results than other metaheuristics. Results also show that the IAHS algorithm is especially fitted for the Sum of Squares Optimization metric. The proposed IAHS algorithm for the RLP is a starting point in order to develop user-friendly and practical computer applications to provide realistic, fast and good solutions for construction project managers.This research was partially supported by the FAPA program of Universidad de Los Andes, Colombia (code P14.246922.005/01). The authors would also like to thank the research group of Construction Engineering and Management (INgeco).Ponz Tienda, JL.; Salcedo-Bernal, A.; Pellicer Armiñana, E.; Benlloch Marco, J. (2017). Improved Adaptive Harmony Search algorithm for the resource levelling problem with minimal lags. Automation in Construction. 77:82-92. https://doi.org/10.1016/j.autcon.2017.01.018S82927

Hierarchical workflow management system for life science applications

In modern laboratories, an increasing number of automated stations and instruments are applied as standalone automated systems such as biological high throughput screening systems, chemical parallel reactors etc. At the same time, the mobile robot transportation solution becomes popular with the development of robotic technologies. In this dissertation, a new superordinate control system, called hierarchical workflow management system (HWMS) is presented to manage and to handle both, automated laboratory systems and logistics systems.In modernen Labors werden immer mehr automatisierte Stationen und Instrumente als eigenständige automatisierte Systeme eingesetzt, wie beispielsweise biologische High-Throughput-Screening-Systeme und chemische Parallelreaktoren. Mit der Entwicklung der Robotertechnologien wird gleichzeitig die mobile Robotertransportlösung populär. In der vorliegenden Arbeit wurde ein hierarchisches Verwaltungssystem für Abeitsablauf, welches auch als HWMS bekannt ist, entwickelt. Das neue übergeordnete Kontrollsystem kann sowohl automatisierte Laborsysteme als auch Logistiksysteme verwalten und behandeln

Meta-heuristic based Construction Supply Chain Modelling and Optimization

Driven by the severe competition within the construction industry, the necessity of improving and optimizing the performance of construction supply chain has been aroused. This thesis proposes three problems with regard to the construction supply chain optimization from three perspectives, namely, deterministic single objective optimization, stochastic optimization and multi-objective optimization respectively. Mathematical models for each problem are constructed accordingly and meta-heuristic algorithms are developed and applied for resolving these three problems

Economic and environmental viability of central solar heating plants with seasonal storage in the European residential sector: A systematic multi-objective optimization approach

Alineant-se amb l'ambiciós paquet de mesures de la UE per 2030 que pretén reduir les emissions de gasos d'efecte hivernacle i reemplaçar les fonts de calor convencionals amb fonts renovables dins de nuclis urbans, les plantes centralitzades de calefacció solar amb emmagatzemament estacional (CSHPSS) es troben entre les tecnologies més prometedores per estalviar energia en els sectors industrial i residencial-comercial. Aquest treball presenta una avaluació exhaustiva de la possibilitat d'integrar CSHPSS al sector residencial de diversos estats membres de la UE a través d'un enfocament sistemàtic d'optimització d'aquests sistemes tenint en compte els criteris econòmics i ambientals. Aquest enfocament incorpora simultàniament les anàlisis de cicle de vida econòmic i mediambiental al mateix temps que procura satisfer tècnicament tant la demanda de calefacció com els serveis domèstics d'aigua calenta. La metodologia s'aplica a una comunitat residencial de 1120 habitatges en diverses zones de la UE, amb Barcelona, Madrid, Atenes, Berlín i Hèlsinki com a exemples de diferents tipus climàtics europeus. L'avaluació ambiental mostra una millora significativa comparant la CSHPSS amb un sistema de calefacció de gas natural, arribant en alguns casos fins a un 87% de reduccions. D'altra banda, una àmplia millora econòmica és especialment limitada a la zona climàtica mediterrània (Atenes) a causa de les baixes demandes de calefacció i els preus dels recursos no renovables, el cost econòmic total de la CSHPSS pot superar fins a un 50.8% un sistema de calefacció de gas natural. No obstant això, tenint en compte l'actual tendència creixent en els preus del gas natural a tota la UE, l'estudi dels costos futurs de la planta confirma la seva viabilitat econòmica a llarg termini. En general, la nostra eina pot guiar els enginyers i arquitectes en la transició cap a un sector residencial més sostenible.Alineándose con el ambicioso paquete de medidas de la UE para 2030 que pretende reducir las emisiones de gases de efecto invernadero y reemplazar las fuentes de calor convencionales con fuentes renovables dentro de núcleos urbanos, las plantas centralizadas de calefacción solar con almacenamiento estacional (CSHPSS) se encuentran entre las tecnologías más prometedoras para ahorrar energía en los sectores industrial y residencial-comercial. Este trabajo presenta una evaluación exhaustiva de la posibilidad de integrar CSHPSS en el sector residencial de varios estados miembros de la UE a través de un enfoque sistemático de optimización de estos sistemas teniendo en cuenta los criterios económicos y ambientales. Este enfoque incorpora simultáneamente los análisis de ciclo de vida económico y medioambiental al mismo tiempo que procura satisfacer técnicamente tanto la demanda de calefacción como los servicios domésticos de agua caliente. La metodología se aplica a una comunidad residencial de 1120 viviendas en diversas zonas de la UE, con Barcelona, Madrid, Atenas, Berlín y Helsinki como ejemplos de diferentes tipos climáticos europeos. La evaluación ambiental muestra una mejora significativa comparando la CSHPSS con un sistema de calefacción de gas natural, llegando en algunos casos hasta un 87% de reducciones. Por otro lado, una amplia mejora económica es especialmente limitada en la zona climática mediterránea (Atenas) debido a las bajas demandas de calefacción y los precios de los recursos no renovables, el costo económico total de la CSHPSS puede superar hasta un 50.8% un sistema de calefacción de gas natural. Sin embargo, teniendo en cuenta la actual tendencia creciente en los precios del gas natural en toda la UE, el estudio de los costos futuros de la planta confirma su viabilidad económica a largo plazo. En general, nuestra herramienta puede guiar a los ingenieros y arquitectos en la transición hacia un sector residencial más sostenible.Aligning with the ambitious EU 2030 climate and energy package for cutting the greenhouse emissions and replacing conventional heat sources through the presence of renewable energy share inside efficient district heating fields, central solar heating plants coupled with seasonal storage (CSHPSS) are among the most promising technologies to save energy in the industrial and residential-commercial building sectors. This work presents a comprehensive evaluation for the possibility of integrating CSHPSS in the residential sector in various EU member states through the introduction of a systematic approach to optimize these systems according to economic and environmental criteria. This approach comprises simultaneously the life cycle cost analysis for the economic evaluation and the life cycle assessment for the environmental impact estimation while technically satisfying both the space heating demand and the domestic hot water services. The methodology framework is applied to a residential neighborhood community of 1120 dwellings in various EU zones with Barcelona, Madrid, Athens, Berlin, and Helsinki acting as proxy for different European climate types. The environmental assessment shows a significant improvement when using the CSHPSS in comparison to a natural gas heating system, arriving in some cases up to 87% reductions. On the other hand, an extensive economic improvement is especially limited in the Mediterranean climate zone (Athens) due to low heating demands and the prices of the non-renewable resources, there the total economic cost of the CSHPSS can increase up to 50.8% compared to a natural gas heating system. However, considering the incremental tendency in natural gas prices all over EU nowadays, the study of future plant costs confirms its favorable long term economic feasibility. Overall, our tool can guide engineers and architects in the transition towards a more sustainable residential sector

Utilitarian Welfare Optimization in the Generalized Vertex Coloring Games: An Implication to Venue Selection in Events Planning

We consider a general class of multi-agent games in networks, namely the generalized vertex coloring games (G-VCGs), inspired by real-life applications of the venue selection problem in events planning. Certain utility responding to the contemporary coloring assignment will be received by each agent under some particular mechanism, who, striving to maximize his own utility, is restricted to local information thus self-organizing when choosing another color. Our focus is on maximizing some utilitarian-looking welfare objective function concerning the cumulative utilities across the network in a decentralized fashion. Firstly, we investigate on a special class of the G-VCGs, namely Identical Preference VCGs (IP-VCGs) which recovers the rudimentary work by \cite{chaudhuri2008network}. We reveal its convergence even under a completely greedy policy and completely synchronous settings, with a stochastic bound on the converging rate provided. Secondly, regarding the general G-VCGs, a greediness-preserved Metropolis-Hasting based policy is proposed for each agent to initiate with the limited information and its optimality under asynchronous settings is proved using theories from the regular perturbed Markov processes. The policy was also empirically witnessed to be robust under independently synchronous settings. Thirdly, in the spirit of ``robust coloring'', we include an expected loss term in our objective function to balance between the utilities and robustness. An optimal coloring for this robust welfare optimization would be derived through a second-stage MH-policy driven algorithm. Simulation experiments are given to showcase the efficiency of our proposed strategy.Comment: 35 Page

Application of Power Electronics Converters in Smart Grids and Renewable Energy Systems

This book focuses on the applications of Power Electronics Converters in smart grids and renewable energy systems. The topics covered include methods to CO2 emission control, schemes for electric vehicle charging, reliable renewable energy forecasting methods, and various power electronics converters. The converters include the quasi neutral point clamped inverter, MPPT algorithms, the bidirectional DC-DC converter, and the push–pull converter with a fuzzy logic controller

Differential Evolution in Wireless Communications: A Review

Differential Evolution (DE) is an evolutionary computational method inspired by the biological processes of evolution and mutation. DE has been applied in numerous scientific fields. The paper presents a literature review of DE and its application in wireless communication. The detailed history, characteristics, strengths, variants and weaknesses of DE were presented. Seven broad areas were identified as different domains of application of DE in wireless communications. It was observed that coverage area maximisation and energy consumption minimisation are the two major areas where DE is applied. Others areas are quality of service, updating mechanism where candidate positions learn from a large diversified search region, security and related field applications. Problems in wireless communications are often modelled as multiobjective optimisation which can easily be tackled by the use of DE or hybrid of DE with other algorithms. Different research areas can be explored and DE will continue to be utilized in this contex

Microgrids/Nanogrids Implementation, Planning, and Operation

Today’s power system is facing the challenges of increasing global demand for electricity, high-reliability requirements, the need for clean energy and environmental protection, and planning restrictions. To move towards a green and smart electric power system, centralized generation facilities are being transformed into smaller and more distributed ones. As a result, the microgrid concept is emerging, where a microgrid can operate as a single controllable system and can be viewed as a group of distributed energy loads and resources, which can include many renewable energy sources and energy storage systems. The energy management of a large number of distributed energy resources is required for the reliable operation of the microgrid. Microgrids and nanogrids can allow for better integration of distributed energy storage capacity and renewable energy sources into the power grid, therefore increasing its efficiency and resilience to natural and technical disruptive events. Microgrid networking with optimal energy management will lead to a sort of smart grid with numerous benefits such as reduced cost and enhanced reliability and resiliency. They include small-scale renewable energy harvesters and fixed energy storage units typically installed in commercial and residential buildings. In this challenging context, the objective of this book is to address and disseminate state-of-the-art research and development results on the implementation, planning, and operation of microgrids/nanogrids, where energy management is one of the core issues