Lighting systems are usually one of the largest electrical end-uses in underground metro stations. Taking into account that budget restrictions in publicly owned companies hinder energy efficiency retrofit projects that require high initial investments, affordable energy saving strategies are needed. This paper presents a low-cost approach for reducing lighting electricity use in underground stations, without affecting passengers' comfort or the metro operator's service. For this purpose, an adaptive lighting strategy of dimming the illuminance levels of artificial light sources has been developed. Dimming controls are based on the occupancy of the station, and the preventive maintenance and cleaning cycles of the luminaires. The stations' monthly occupancy patterns are defined through the k-means clustering technique. To illustrate its effectiveness, the method was applied to 115 underground stations of the Barcelona metro network. The results revealed overall electricity savings of 255.47 MW h on a biannual basis, which represents 36.22% of the stations' baseline lighting consumption. Individual energy savings were found to range from 25 to 87.5 MW h/year in the stations of the Barcelona metro network, depending on the number and profile of station users. The research findings will undoubtedly be useful for the future energy efficiency project plans of worldwide metro operators and managers of other underground spaces.
Casals, M.; Gangolells, M.; Forcada, N.; Macarulla, M.; Giretti, A.; Vaccarini, M. Applied energy Vol. 166, p. 150-164 DOI: 10.1016/j.apenergy.2016.01.029 Date of publication: 2016-03-15 Journal article
Several previous research initiatives have highlighted the role of Information and Communication Technologies (ICT) as key enablers for decreasing energy usage in buildings. However, few advances have been achieved in underground public spaces. This paper introduces a novel intelligent energy management system for underground stations. The system implements artificial intelligence solutions for autonomous building system control, based on advanced control algorithms that can learn from previous operations and situations. The robustness needed to operate in public spaces is achieved through a seamlessly integrated monitoring grid with self-diagnosis mechanisms. A middleware platform integrates existing devices, subsystems and newly deployed sensor-actuator networks. Results obtained during the implementation of the system in a prototype underground station showed potential yearly energy savings ranging between 74,336 and 87,339 kW h. The highest energy savings potential was found in the ventilation subsystem (30.6% +/- 2.0%), followed by the lighting system (24.1% +/- 1.9%) and escalators (8.5% +/- 1.9%).
Gangolells, M.; Casals, M.; Forcada, N.; Macarulla, M.; Giretti, A. Renewable and sustainable energy reviews Vol. 55, p. 662-667 DOI: 10.1016/j.rser.2015.11.006 Date of publication: 2016-03-01 Journal article
Although energy management systems are expected to result in decreased energy consumption, it is important not to overlook the energy used until commissioning (including raw materials acquisition, manufacturing and transportation) and during the usage phase (including operation and maintenance). This paper examines the energy performance of an intelligent energy management system for underground metro stations. The results show that the energy management system has high energy performance in terms of energy payback time and energy return factor, due to its low cumulative energy demand and its potential for energy savings. When we assumed that the lifespan of energy management systems may vary between 5 and 10 years, their cumulative energy demand was found to range between 505,316 and 852,493 MJp eq. In all cases, the operating energy was found to far outweigh the embodied energy (68-81%). The energy management system was implemented in a pilot underground station and was found to provide an energy saving of 13.2±1.1% of the total energy consumption of the pilot station. The energy payback time of the energy management system for underground stations was found to range between 40 and 55 days. Consequently, the system pays back between 33 and 91 times the energy invested in it. The results of this research provide valuable information for stakeholders in the energy management systems industry, as they contribute to ascertaining the sustainability of products.
Although inspections occur during construction or at handover, customers do not normally participate. This situation creates a gap between the quality perceived by both contractors and customers. An analysis of 52 552 handover defects in 2179 flats in Spain is presented which identified their nature, the building element and trade where these defects are located. These results are compared with previous studies that analysed defects detected during the construction stage and those that remain after handing over the building to the client. The research reveals that structural defects are resolved during construction due to existing quality standards. However, other aesthetic and functional defects remain and/or arise at handover. Some defects are not resolved until customers complain after they first occupy the dwelling. Many functional defects arise due to the lack of involvement of end users in the early project stages.
This is an Accepted Manuscript of an article published by Taylor & Francis Group in Building research and information on 20/05/2015, available online: http://www.tandfonline.com/doi/abs/10.1080/09613218.2015.1039284
Gaspar, K.; Casals, M.; Gangolells, M. Journal of performance of constructed facilities Vol. 30, num. 1, p. 04014187- DOI: 10.1061/(ASCE)CF.1943-5509.0000693 Date of publication: 2016-02 Journal article
Façades play an important role in buildings’ energy demand, and their state of conservation obviously influences thermal performance. The energy performance gap in existing residential buildings due to façade conservation status has not been analyzed in depth. In order to facilitate the systematic analysis of this influence, a system for classifying façades and their corresponding anomalies was developed for the first time. The classification system includes 23 types of façades and eight types of anomalies. It was verified by a panel of experts, and a case study was carried out with a sample of 154 buildings. An analysis of the results showed that the classification system is useful for a future analysis of the energy performance gap in existing residential buildings.
Gangolells, M.; Casals, M.; Forcada, N.; Macarulla, M.; Cuerva, E. Journal of cleaner production Vol. 112, num. 5, p. 3895-3904 DOI: 10.1016/j.jclepro.2015.05.105 Date of publication: 2016-01-20 Journal article
Energy performance certificate databases are a key tool for mapping national building stock and thus fostering greater overall energy efficiency. This paper presents an insight into the energy performance of residential and tertiary sector buildings in Spain, through an analysis of the first 129,635 energy performance certificates issued for existing buildings, collected by the Catalan Institute of Energy. Most of the residential buildings or building units that were studied were “E” class (53.6%). Single-family houses were found to use more energy on average (248.0 kWhp/m2) than individual dwellings (183.2 kWhp/m2). Tertiary sector buildings were found to have slightly better energy performance (26.4% of buildings were rated “D class”), with an average energy consumption of 317.8 kWhp/m2. Modern buildings consume less energy, as they must meet the higher energy performance requirements stated in thermal building regulations. Residential buildings or building units located in hotter climate zones consume slightly less energy than those located in colder zones, mainly because heating accounts for a high percentage of overall energy expenditure (70–75% in residential buildings). A significant proportion of the energy consumed in tertiary sector buildings is for lighting (37.2%). This research defines the current energy consumption baseline of existing buildings in Spain. The results can help to prioritize energy conservation efforts according to building type, construction period, climate zone and specific end-uses. They may also help public authorities to plan future energy policies, and construction practitioners to identify market segments and business strategies.
The main objective of the EnerGAware project is to achieve a 15-30% energy consumption and emissions reduction in a social housing pilot and increase the social tenants’ understanding and engagement in energy efficiency.
The EnerGAware project will develop and test, in publically owned social housing, a serious game that will be linked to the actual energy consumption (smart meter data) of the game user’s home and embedded in social media and networking tools. The solution fits within all three ICT areas suggested in the topic EE-11 scope: gaming, social networking and personalised data driven applications.
The EnerGAware solution will provide an innovative IT ecosystem in which users can design their own virtual home and Avatar and learn about the potential energy savings from installing energy-efficiency measures and changing user behaviour, whilst maintaining the comfort of their Avatar. The user will need to learn to balance the energy consumption, comfort and financial cost of their actions. Energy savings achieved both virtually in the game, calculated by building performance simulation, and in reality, in the users’ actual homes, measured through smart meter data, will enable progression in the serious game. The social media features will provide users a platform to share data of their achievements, compete with each other, give energy advice, as well as, join together to form virtual energy communities.
The EnerGAware solution will be developed and deployed with the ‘cleanweb’ philosophy in mind: “Capital light, Quick to market and Quick to scale”, therefore the EnerGAware project will aim to go beyond just testing in a social housing pilot, but will seek commercial exploitation of the solution at the end of the project, through our industrial partners, in particular EDF Energy, a global energy provider, with 38 million European energy customers.
This paper presents for the first time the results of a life cycle assessment study for an intelligent energy management system. We considered material acquisition, manufacturing, transportation, assembly, operation and maintenance stages. The results show that the assembly phase had an environmental impact of 897 Eco-indicator 99 points that was mainly due to the monitoring subsystem (87.80%). When the analysis was extended to cover the use phase, the environmental impact ranged from 1963 (useful life of 5 years) to 3029 Eco-indicator 99 points (useful life of 10 years). The environmental impact of the use stage was found to represent 54–70% of the total, whereas the assembly stage represented 46–30%. The maintenance phase contributed to a very small extent to the total environmental impact (less than 0.5%). In any case, the impact on resources was the largest (about 51%), whereas the human health damage category amounted to approximately 35% and the ecosystem quality damage category represented about 14% of the total impact.
In this paper, the implementation of effective waste management practices in construction projects and sites is analyzed, using data from a survey answered by 74 Spanish construction companies based in Catalonia. Most commonly implemented practices were found to be on-site cleanliness and order, correct storage of raw materials, and prioritization of the nearest authorized waste managers. The least widespread practices were the use of a mobile crusher on site, the creation of individualized drawings for each construction site, and the dissemination of the contents of the waste management plan to all workers, to help them to meet its requirements. Waste regulations for construction and demolition, and the corresponding construction waste management facilities, were designed before the recession in the Spanish construction sector. Current waste generation rates are still below predicted levels, and the infrastructure was designed for five times more waste generation. Even so, the percentage of reused and recycled waste currently amounts to 43%. Survey respondents highlighted various instruments and measures that would make the management of construction and demolition waste more sustainable. Most of the opportunities identified by construction firms are within the scope of government and related to a combined system of bonus and penalties and the establishment of environmental awareness and training programmes for all the stakeholders. Within the scope of authorized waste managers, firms suggested improvements such as the standardization of fees, a reduction of the time until the issue of waste management certificates, a higher number of inspections, and a change in the current model of a few large construction waste management facilities. This research is useful to better understand the current status of construction and demolition waste management in construction projects and sites. Thus, the results of this research will guide policy makers and relevant stakeholders such as contractors, clients, architects and engineers to achieve the EU target of recovering 70% of construction and demolition waste in 2020. In this sense, reliable information can help governments and professional associations to set future C&D waste management regulations, training programmes and dissemination tools, inspections, etc.
Giretti, A.; Ansuini, R.; Casals, M.; Gangolells, M.; Amorós, F.; Constantini, V.; Pescatory, G. World Sustainable Building Conference Presentation's date: 2014-10-30 Presentation of work at congresses
This paper outlines the decision support system that is being developing for the performance
and financial analysis of the SEAM4US system, concerned with the implementation of an Intelligent
Energy Management system for Underground Stations. A critical aspect for the design and
implementation of advanced sustainable solutions for the energy saving in complex buildings is the
assessment of the effectiveness of the approach in terms of both the amount of the energy saving and of
the cost benefits. The required dynamic analysis of the building behaviours under different operational
conditions makes it difficult to figure out the relevant operational scenarios. The paper describes a
scenario analysis tool that simulates the operation of an underground station in different climatic
conditions and with different system technology arrangements. The paper provides cost benefit
analysis under different operational scenarios and proposes suitable business models for the overall
Defects are a non-value adding activity seriously affecting the performance and productivity in construction projects that spend unnecessary cost, time materials and manpower. Non-quality represent the 4% of the contract value of the new dwelling or renovation and produce other adverse consequences such as
temporal deviations, affectations in project sustainability as well as safety and reduction ofproject performance.
Developing tools that bring awareness ofthe potential quality risks can help organizations improve their quality performance. Moreover, there are significantly growing evidence linking BIM benefits to decision-making tools.
This paper presents the implementation of a quantitative methodology to forecast potential quality risks into a 40 model (BIM-QRC). BIM-QRC proposes 40 multiple views related to the needs of each practitioner. The methodology ranks the significance of all quality risks of a construction project and is able to compare several
design options in terms of quality performance. While the existing methodology is useful to get consciousness
ofthe quality risks of a project, the adaptive visualisation of different business views improves the understanding
and comprehension of the quality performance of a project and facilitates decision making for both designers and contractors.
The main objective ofthis paper is to study the resilience of current Spanish residential building stock to climate change impacts. Results showed that 72% of current residential building stock in Spain is not
performing properly according to current climate conditions. During the 1981 - 201 O period, mean annual degree days based at l 5ºC diminished in 74% of Spanish provincial capitals, with an average rate decrease of 10.1 % in relation to the 1950-1979 period. Significant accelerating positive trends in cooling degree days and important
decreases in heating degree days were found in the twenty-first century. Strategies and measures to support climate change adaptation of existing and future built environments through building codes and standards have also been explored.
Underground transportation systems are big energy consumers and have significant impacts on energy consumption at a regional scale. The literature has revealed that the energy consumption for non-traction purposes may be of the same magnitude as the energy used to move rolling stock, and in some cases even greater. However, most of the research conducted so far has focused on the energy demand of rolling stock. This paper investigates the electricity consumption of an underground metro station using data from on-site surveys and measurements. With an average consumption of 217.64 kWh/m(2)/year, the breakdown revealed that the lighting system dominated the underground station's energy consumption (37%). Illuminated advertising signs were found to be responsible for 14% of the total energy consumption, and ventilation accounted for another 14%. The rest of the energy consumption was attributed to systems such as mobile phone signal antenna (12%), the vertical transportation system (8%) and small power devices (5%). Accurate information on energy consumption for non-traction usage is useful for future implementation of energy conservation measures in underground stations, which could result in a reduction of operating costs in the long run.
The building industry is noted for its repeated building defects causing cost increases and time delays during construction. In Spain, despite the Ley de Ordenación de la Edificación (Building Regulation Act), which establishes a general framework to promote overall building quality, construction defects in residential buildings remain a pervasive problem. An analysis of 3647 construction defects is presented which identified the location within the building, subcontractors and building element in 68 residential building developments undertaken by two large Spanish contractors. The research reveals that the most common defects that arise during construction are related to the stability of the structure and inappropriate installation of roofs and facades. These technical faults are caused by poor workmanship rather than by the quality of the materials or products used. By comparing these results with a previous study on defects after handover, it can be concluded that while the nature of defects during construction is basically technical, at handover it is aesthetic or technical.
The research findings fill a gap in the body of knowledge by presenting an effective way to evaluate the significance of on-site environmental impacts of municipal engineering works prior to the construction stage. First, 42 on-site environmental impacts of municipal engineering works were identified by means of a process-oriented approach. Then, 46 indicators and their corresponding significance limits were determined on the basis of a statistical analysis of 25 new-build and remodelling municipal engineering projects. In order to ensure the objectivity of the assessment process, direct and indirect indicators were always based on quantitative data from the municipal engineering project documents. Finally, two case studies were analysed and found to illustrate the practical use of the proposed model. The model highlights the significant environmental impacts of a particular municipal engineering project prior to the construction stage. Consequently, preventive actions can be planned and implemented during on-site activities. The results of the model also allow a comparison of proposed municipal engineering projects and alternatives with respect to the overall on-site environmental impact and the absolute importance of a particular environmental aspect. These findings are useful within the framework of the environmental impact assessment process, as they help to improve the identification and evaluation of on-site environmental aspects of municipal engineering works. The findings may also be of use to construction companies that are willing to implement an environmental management system or simply wish to improve on-site environmental performance in municipal engineering projects.
This paper is aimed at describing an intelligent environmental aware energy management system for underground stations, developed under the auspices of the European project Sustainable Energy mAnageMent for Underground Stations (SEAM4US) and implemented in a pilot underground station. With an average consumption of 217.64kWh/m2·year, the breakdown revealed that the lighting system dominates the energy consumption of the station followed by illuminated advertising signs and ventilation. The SEAM4US energy
management system has been designed to provide smart autonomous control ofthe ventilation, lighting and vertical transportation trough the core, monitoring and control subsystems. Several control policies were simulated and expected energy savings were found to range between 11 % and 20% ofthe total energy consumption.
Building sector is contributing to the 36% of the C02 emissions in Europe, and consurning
the 40% of final energy consurnption. In this context this paper presents a new approach developed under the
ENCOURAGE project to carry out the user awareness. The proposed user awareness is based on a set of KPls,
and done at two levels: energy mangers and university campus users. The KPfs are displayed to the energy
managers using a web-platform. With that information energy managers are able to identify actions and control
algorithms to reduce the energy consun1ption. In the other hand, the university campus users awareness it is
done sending messages to the user through the Twitter platform. A set of messages are defined, andan algorithm
decides which messages have to be published in each moment. The aim is to promote good practices in the use
Forcada, N.; Macarulla, M.; Gangolells, M.; Casals, M.; Fuertes, A.; Roca, X. Journal of performance of constructed facilities Vol. 27, num. 6, p. 756-762 DOI: 10.1061/(ASCE)CF.1943-5509.0000368 Date of publication: 2013-12-01 Journal article
In Spain, the high levels of inexperienced workers and the long chains of subcontracting contribute to poor quality of dwellings. Although the Ley reguladora de la subcontratación en el Sector de la Construcción (Subcontracting law) has established quality measures, the number of customer complaints is still increasing. In this paper, a total of 2351 post-handover defects derived from four Spanish builders and seven residential developments are classified according to their source and origin. The research reveals that the most common defects identified by customers at post-handover were derived from bad workmanship, and were related to construction errors and omissions. Typical defects were found to include incorrect installation, appearance defects, missing item or task mainly related to finishing and considered to be minor. No defects were caused by poor design as they are mainly detected and resolved during construction, or become apparent after some years of use. This study demonstrates the negative impact of re-doing defective work during the final stages of construction, and provides knowledge to define measures to improve the quality of the finished buildings, such as understanding customer expectations and preferences, training programs for workers, specialization of subcontractors and tighten the external controls prior to handover.
In Spain, the high levels of inexperienced workers and the long chains of subcontracting contribute to the poor quality of dwellings.
Ley reguladora de la subcontratación en el Sector de la Construcción
(subcontracting law) has established quality measures, the
number of customer complaints is still increasing. In this paper, a total of 2,351 posthandover defects derived from four Spanish builders and
seven residential developments are classi
ed according to their source and origin. The research reveals that the most common defects identi
by customers at posthandover were derived from bad workmanship and were related to construction errors and omissions. Typical defects were
defects were caused by poor design because they are mainly detected and resolved during construction or become apparent after some years of
use. This study demonstrates the negative impact of redoing defective work during the
nal stages of construction and provides knowledge to
ne measures to improve the quality of the
nished buildings, such as understanding customer expectations and preferences, training
programs for workers, specialization of subcontractors, and tightening external controls prior to handover.
Macarulla, M.; Forcada, N.; Casals, M.; Gangolells, M.; Fuertes, A.; Roca, X. Journal of construction engineering and management (ASCE) Vol. 139, num. 8, p. 968-976 DOI: 10.1061/(ASCE)CO.1943-7862.0000669 Date of publication: 2013-08 Journal article
Defects produce economic and temporal deviations in construction projects. Although learning from past experiences can help reduce defects and their consequences, usually data is not easily available, or is poorly structured and difficult to analyze. Several structured classification systems for defects exist, but regionally specific construction activities make the data unviable for research use. This paper presents the development and the validation of a defects' classification system for the Spanish housing sector. From the analysis of the existing defect classification systems, a first draft was developed to be discussed and improved in a series of workshops done by a panel of experts. Afterwards, the final classification was validated by experts' interviews. The experts evaluated the epistemological adequacy and reusability of the proposed classification system. The results demonstrate the suitability of the classification system. In addition the validation revealed that the classification can be implemented in tracking systems, and it can be used to analyze defects in the Spanish housing sector. Finally, the classification was used in a case study to analyze the real use and it demonstrated the potential uses of the classification.
Fuertes, A.; Casals, M.; Gangolells, M.; Forcada, N.; Macarulla, M.; Roca, X. Journal of cleaner production Vol. 52, p. 425-437 DOI: 10.1016/j.jclepro.2013.02.005 Date of publication: 2013-08-01 Journal article
Despite the increasing efforts made by the construction sector to reduce the environmental impact of
their processes, construction sites are still a major source of pollution and adverse impacts on the
environment. This paper aims to improve the understanding of construction-related environmental
impacts by identifying on-site causal factors and associated immediate circumstances during construc-
tion processes for residential building projects. Based on the literature and focus group
ndings, we have
developed a construction-related Environmental Impact Causal Model consisting of a process-oriented
causal network of thirty-nine environmental impacts, forty-
ve causal factors and over two hundred
causal relationships. It is intended to contribute to a reduction in construction-related environmental
impacts on building sites by supporting contractors and other decision-makers in the early identi
of factors that are likely to lead to impacts or to exacerbate their consequences, as well as the later
environmental performance evaluation and control. The causal model is validated by investigating over a
hundred environmental incidents. Finally, possible methods to improve construction-related environ-
mental performance are suggested.
Esta metodología está orientada a evaluar el impacto medioambiental de los edificios, su coste económico y su efecto social, teniendo en cuenta todo el ciclo de vida, de una manera sistematizada, flexible, simple, holística y orientada a la comparación de los resultados.Cada edificio tiene sus propias características y la aplicación del análisis de ciclo de vida (ACV) es diferente para cada caso. Pero los edificios también presentan características comunes, como materiales, procesos de construcción, instalaciones, elementos constructivos y uso del edificio. Estas similitudes deberían permitir una fácil comparación entre edificios, especialmente los que son del mismo tipo constructivo. Sin embargo, la interpretación, el objetivo, el alcance y los límites del sistema de un análisis de ciclo de vida hacen que los resultados sean difícilmente comparables entre sí, aunque los edificios a comparar sean semejantes.La metodología estándar de ACV es apta para todos los productos, procesos y servicios. Sin embargo, es muy abierta y requiere que se hagan muchas reiteraciones. La metodología propuesta ajusta la metodología estándar de ACV para su uso exclusivo en los edificios, evitando reiteraciones, adaptándose a todas las maneras de proceder de los usuarios de la metodología, que sirva para todos los edificios y para los diferentes ámbitos de la sostenibilidad. La metodología se compone de cinco fases. En la primera fase se define el sistema y las características generales del estudio. En la segunda fase se reúne la documentación necesaria que se usará en el resto de la metodología. En la tercera fase se procesa esta información contenida en la documentación y se realiza el inventario de datos. En la cuarta fase, utilizando los datos del inventario, se realizan por una parte los cálculos necesarios y por otra el análisis del ciclo de vida. Finalmente en la quinta y última fase se exponen los resultados.También se han realizado tres adaptaciones de la metodología para usos específicos. La primera adaptación es para análisis de alternativas, en el que al variar un parámetro o combinación de parámetros se puede ver qué alternativa es mejor para un cierto propósito. La segunda adaptación es para la rehabilitación, en el que el edificio aún no ha llegado al fin de su vida útil y se desea disminuir el consumo energético y aumentar el bienestar y comodidad de los ocupantes. La última adaptación es para un parque de edificios, que es un conjunto de edificios que conforman un barrio, un distrito, una ciudad, una región, un país o un conjunto de países. La aplicación de la metodología a un caso práctico confirma que la metodología es apta para ser empleada y se obtienen los resultados esperados para la realización del ACV según el método estándar.Un análisis de ciclo de vida adaptado al dominio de los edificios resulta más simple y directo que uno general, llegando a los mismos resultados. La utilización de esta metodología evita una dispersión en la manera de procesar los datos y, junto con la difusión de los datos relevantes de los edificios, permite una mayor facilidad en la comparación de los resultados entre diferentes estudios que apliquen esta metodología.Además, la metodología tiene la utilidad de recoger y organizar la información relativa al edificio. También asiste el proceso de diseño, dejando ver cuáles son los aspectos clave y cuál es su importancia relativa. Por tanto, es considerablemente útil para los actores (promotor, proyectista, propietarios y usuarios) que toman decisiones en la etapa de diseño y que puedan desarrollar estrategias adecuadas a los objetivos propuestos. Esta metodología mejora cada una de las fases del edificio y su conjunto, incrementando la competitividad, la satisfacción social y garantizando la sostenibilidad.
Esta metodología está orientada a evaluar el impacto medioambiental de los edificios, su coste económico y su efecto social, teniendo en cuenta todo el ciclo de vida, de una manera sistematizada, flexible, simple, holística y orientada a la comparación de los resultados.
Cada edificio tiene sus propias características y la aplicación del análisis de ciclo de vida (ACV) es diferente para cada caso. Pero los edificios también presentan características comunes, como materiales, procesos de construcción, instalaciones, elementos constructivos y uso del edificio. Estas similitudes deberían permitir una fácil comparación entre edificios, especialmente los que son del mismo tipo constructivo. Sin embargo, la interpretación, el objetivo, el alcance y los límites del sistema de un análisis de ciclo de vida hacen que los resultados sean difícilmente comparables entre sí, aunque los edificios a comparar sean semejantes.
La metodología estándar de ACV es apta para todos los productos, procesos y servicios. Sin embargo, es muy abierta y requiere que se hagan muchas reiteraciones. La metodología propuesta ajusta la metodología estándar de ACV para su uso exclusivo en los edificios, evitando reiteraciones, adaptándose a todas las maneras de proceder de los usuarios de la metodología, que sirva para todos los edificios y para los diferentes ámbitos de la sostenibilidad.
La metodología se compone de cinco fases. En la primera fase se define el sistema y las características generales del estudio. En la segunda fase se reúne la documentación necesaria que se usará en el resto de la metodología. En la tercera fase se procesa esta información contenida en la documentación y se realiza el inventario de datos. En la cuarta fase, utilizando los datos del inventario, se realizan por una parte los cálculos necesarios y por otra el análisis del ciclo de vida. Finalmente en la quinta y última fase se exponen
También se han realizado tres adaptaciones de la metodología para usos específicos. La primera adaptación es para análisis de alternativas, en el que al variar un parámetro o combinación de parámetros se puede ver qué alternativa es mejor para un cierto propósito. La segunda adaptación es para la rehabilitación, en el que el edificio aún no ha llegado al fin de su vida útil y se desea disminuir el consumo energético y aumentar el bienestar y comodidad de los ocupantes. La última adaptación es para un parque de edificios, que es un conjunto de edificios que conforman un barrio, un distrito, una ciudad, una región, un país o un conjunto de países.
La aplicación de la metodología a un caso práctico confirma que la metodología es apta para ser empleada y se obtienen los resultados esperados para la realización del ACV según el método estándar.
Un análisis de ciclo de vida adaptado al dominio de los edificios resulta más simple y directo que uno general, llegando a los mismos resultados. La utilización de esta metodología evita una dispersión en la manera de procesar los datos y, junto con la difusión de los datos relevantes de los edificios, permite una mayor facilidad en la comparación de los resultados entre diferentes estudios que apliquen esta metodología. Además, la metodología tiene la utilidad de recoger y organizar la información relativa al edificio, lo que permite elaborar un resumen con la función de comunicar. También asiste el proceso de diseño, dejando ver cuáles son los aspectos clave y cuál es su importancia relativa. Por tanto, es considerablemente útil para los actores (promotor, proyectista, propietarios y usuarios) que toman decisiones en la etapa de diseño y que puedan desarrollar estrategias adecuadas a los objetivos propuestos. Esta metodología mejora cada una de las fases del edificio y su conjunto, incrementando la competitividad, la satisfacción social y garantizando la sostenibilidad.
This methodology is aimed at assessing the environmental impact of buildings, their economic cost and social impact, taking into account the entire life cycle in a systematic, flexible, simple, holistic manner and focused on the comparison of results.
Each building has its own characteristics and the application of the life-cycle assessment (LCA) is different in each case. But buildings also have common characteristics, such as materials, construction processes, facilities, building materials and building use. These similarities should enable straightforward comparison between buildings, especially those that are of the same construction type. However, the interpretation, objective, scope and system limits of a life-cycle assessment mean that the results are barely comparable, even if the buildings being compared are similar.
The LCA standard methodology is suitable for all products, processes and services. However, it is very open and requires many iterations. The proposed method adjusts the LCA standard methodology for its exclusive use in buildings, avoiding repetition, adapting to all ways of acting from methodology users, and working for all different buildings and areas of sustainability.
The methodology consists of five phases. In the first phase the system and the general characteristics of the study are defined. In the second phase the necessary documentation to be used in the rest of the methodology is gathered. In the third phase the information found in the documentation is processed and the inventory data is carried out. In the fourth phase, using the inventory data, the required calculations and analysis of the life cycle are carried out. Finally in the fifth and final phase the results are presented.
Three adaptations to the methodology for specific uses have also been made. The first adaptation consists in analysis of alternatives, in which by changing a parameter or combination of parameters, the best alternative for a certain purpose is revealed. The second adjustment consists in refurbishment, in which the building has not yet reached the end of its useful life and it is desired to reduce energy consumption and improve the welfare and comfort of the occupants. The last adjustment consists in dwelling stock, groups of buildings that make up a neighbourhood, district, city, region, country or group of countries.
The application of the methodology to a case study confirms that the methodology is suitable for use and that the results are comparable to those using the LCA standard methodology.
A life-cycle assessment adapted to the domain of the buildings is as simple and straightforward as a general one, obtaining the same results. Using this methodology a dispersion in the way of processing the data is avoided. The spread of relevant data for the buildings allows for greater ease in comparing results between different studies that apply this methodology.
The methodology is useful to gather and organize information about buildings, allowing for the preparation of a summary, with the intention to communicate. It also assists in the design process, highlighting the key issues and what are their relative importance. It is therefore significantly useful for actors who make decisions in the design stage and develop strategies tailored to the objectives. This methodology improves each of the phases of the building process and the whole building, and it increases competitiveness, social satisfaction and ensures sustainability.
Gangolells, M.; Casals, M.; Forcada, N.; Fuertes, A.; Roca, X. Journal of construction engineering and management (ASCE) Vol. 139, num. 2, p. 138-147 DOI: 10.1061/(ASCE)CO.1943-7862.0000579 Date of publication: 2013-02 Journal article
Certifiable management-system standards apply similar management techniques and principles, but each system still tends to have a separate structure in construction companies. Research and practice have demonstrated that management tasks may be duplicated when standards are implemented in parallel. Consequently, integrated management systems are strongly advocated. However, existing literature demonstrates that the integration of planning and control instruments involves a high level of uncertainty. This paper presents an innovative model to enhance the integration of environmental-and health and safety-management systems in construction companies, focusing on the subsystems for identifying, assessing, and operationally controlling environmental aspects and health and safety hazards and using risk as an integrating factor. The findings of this study have direct implications for both designers and contractors because the model helps to explicitly consider on-site environmental impacts and construction-worker safety during the design process and offers on-site guidance to eliminate the remaining impacts and risks or reduce them to acceptable levels. A case study is reported to illustrate the practical use of the proposed model and its benefits.
Certifiable management-system standards apply similar management techniques and principles, but each system still tends to have
a separate structure in construction companies. Research and practice have demonstrated that management tasks may be duplicated when
standards are implemented in parallel. Consequently, integrated management systems are strongly advocated. However, existing literature
demonstrates that the integration of planning and control instruments involves a high level of uncertainty. This paper presents an innovative
model to enhance the integration of environmental- and health and safety
management systems in construction companies, focusing on the
subsystems for identifying, assessing, and operationally controlling environmental aspects and health and safety hazards and using risk as an
integrating factor. The findings of this study have direct implications for both designers and contractors because the model helps to explicitly
consider on-site environmental impacts and construction-worker safety during the design process and offers on-site guidance to eliminate the
remaining impacts and risks or reduce them to acceptable levels. A case study is reported to illustrate the practical use of the proposed model
and its benefits.
Knowledge management (KM) has been studied extensively in recent years. Some consider knowledge to be the most strategically important resource for any company, but the fragmented, project-based and task-oriented nature of construction work makes it more difficult to implement KM in this sector.
This paper presents a survey of perceptions of KM implementation in the Spanish construction sector and compares the results obtained from design and construction firms. Data were collected from the leading civil engineering companies in Spain.
The survey found that the Spanish construction industry is aware of the benefits of KM but that systematic KM is not generally implemented. The findings clearly demonstrate that changes in organizational culture are critical to successful KM. The survey also revealed some distinctions between the KM perception of design firms and that of construction firms.
Article publicat originalment a "Revista ingeniería de construcción", vol. 27, núm. 3, Desembre 2012, p. 103-127. ISSN 0716 - 2952. http://www.ricuc.cl/index.php/ric/article/view/417/pdf
Este artículo tiene como objetivo favorecer la implementación de sistemas integrados de gestión ambiental y de seguridad salud en empresas constructoras, centrándose en el subsistema de control de los impactos ambientales y los riesgos de seguridad y salud en obra.
La gran compatibilidad que presentan los requerimientos vinculados al control operacional establecidos en la normas ISO 14001:2004 y OHSAS 18001:2007 así como las interacciones existentes entre impactos ambientales y riesgos de seguridad y salud (Gangolells et al., 2009, Gangolells et al., 2010) han motivado el desarrollo de una ontología que permite construir un modelo integrado para el control operacional en obras de construcción. La aproximación desarrollada está fuertemente influenciada por la metodología de Noy y McGuiness (2001) y modela los conceptos clave y las relaciones del dominio de forma estructurada, extensibe, flexible, reutilizable y compartible. Esta aproximación basada en ontologías ha sido implementada mediante Protégé 3.4 beta y correctamente evaluada utilizando cuestiones de competencia, verificaciones internas y entrevistas de validación con expertos. Este artículo desarrolla la primera aproximación que permite representar, compartir, reutilizar y gestionar el conocimiento relacionado con el control operacional integrado en obra de las incidencias medioambientales y de seguridad y salud y sienta las bases para poder superar la mayoría de las barreras que las empresas constructoras deben afrontar durante el proceso de implementación de un sistema de gestión integrada.
The resilíence of the current Spanish residentia[ building stock to increased temperatures is modelled. Homogenized dai[y temperature data recorded at 50 Spanish meteorological stations for the periods 1950-1979 and 1981-2010 were used to investigate anticipated dimate warming on the Spanish residential building stock by means of the degree-day method. Impacts on residential buildings were investigated for three different future time periods (2011-2040, 2041-2070 and 2071-2100) for three representative Spanish provincial capitals. Future dimate change scenarios comprising two statistical downscaling methods, three general circulation mode[s and two carbon emission scenarios were used to project [ocal dimate. Results show that 72% of current residential building stock in Spain is thermally unprotected. In addítion, the energy demand for heating the building sector in Spain is expected to decrease by between 30% (Barcelona, B2 scenario) and 36% (Valencia, A2 scenario) by 2100, while the respective energy demand for cooling could increase by between 107% (Valencia, B2 scenario) and 296% (Madrid, A2 scenario) by 2100. To inerease resilience to higher winter and summer temperatures, strategies for modifying the built environment are needed, particu[arly for the role of building codes and standards.
Forcada, N.; Macarulla, M.; Fuertes, A.; Casals, M.; Gangolells, M.; Roca, X. Journal of performance of constructed facilities Vol. 26, num. 4, p. 433-440 DOI: 10.1061/(ASCE)CF.1943-5509.0000225 Date of publication: 2012-08 Journal article
Clients’ lack of involvement in defining quality requirements for dwellings built by developers leads to a perception of poor quality at the time of purchase. The research presented in this paper aims to broaden previous research on defects by analyzing the defects that remain in the post-handover stage, which usually lasts 12 months after the handover period, and identifying the factors that influence the appearance of these defects, determining whether a significant difference exists in the quality of the two main residential building types built by developers: flats and detached houses. It also analyzes and discusses the areas and elements in which the defects were detected. The data were obtained from client complaint forms completed after the handover of 95 dwellings in Spain. The data were then statistically analyzed using a t-test analysis, a Pearson’s parametric correlation, and a chi-square test. The research reveals that clients detect more defects in flats than in detached houses. The lower quality of the materials used in flats and the tighter schedule to which flats are subject may cause these differences.
Underground transportation systems are big energy consumers (e.g. 63,1 millions of kWh / year), and have significant impacts on energy consumption at a regional scale. One third of the networks' energy is required for operating the subsystems of metro stations and surroundings, such as ventilation, vertical transportation and lightning. Although a relatively small percentage of energy can be saved with an optimal management of these subsystems, a large energy saving in absolute terms can be obtained. The objective of SEAM4US is to develop advanced technologies for optimal and scalable control of metro stations that will produce a 5% saving in non-traction electricity consumption in one year, which is equivalent to the electricity consumed in more than 700 households. The project's main outcomes will be the creation of systems for optimized integrated energy management, and the development of a decision support system to drive mid-term investments. SEAM4US will integrate additional energy metering and sensor-actuator networks with the existing systems (e.g. surveillance, passenger information and train scheduling), by means of middleware as abstraction layer, to acquire grounded user, environmental and scheduling data. The data set will update and enable a set of adaptive energy consumption and environmental models to proactively and optimally control the metro stations. The consortium consists of a large metro network operator, TMB; a major player in energy-efficient system management sector, COFELY; building and environmental physics and construction experts UNIVPM and UPC, respectively; R&D experts in middleware, FhG FIT and VTT; R&D experts in user and agent-based scheduling modeling, ALMENDE and UNIK; system integrator, CNET.
Gangolells, M.; Casals, M.; Gasso, S.; Forcada, N.; Roca, X.; Fuertes, A. Building and environment Vol. 46, num. 5, p. 1023-1037 DOI: 10.1016/j.buildenv.2010.11.004 Date of publication: 2011-05-02 Journal article
The most common challenges and obstacles encountered by construction organizations during the process of implementing and using environmental management systems are related to the inherent peculiarities of the construction sector. Several studies have shown that one of the issues involving the greatest level of uncertainty is the identification and assessment of environmental impacts. In order to improve the identification of the significance of environmental impacts of construction projects and sites, which will lead to greater efficiency and robustness in environmental management systems, this paper extends the systematic approach for identifying and assessing potential adverse environmental impacts at the pre-construction stage presented in Gangolells et al. (2009) by introducing the assessment of the concerns of interested parties. By considering concerns amongst internal and external interested parties, one can assess the significance of environmental impacts taking into account not only the severity of the impacts but also local perceptions and international challenges, thereby ensuring that the determination of the impacts’ significance is appropriate to the particular socioeconomic and biophysical environments surrounding construction sites. In order to quantitatively measure concerns among internal and external interested parties for each of the 37 environmental impacts related to a construction project, we developed corresponding indicators and assessment scales with the help of a panel of experts. A series of χ2 tests conducted over 76 new-start construction projects clearly revealed that the severity of environmental impacts is not correlated with the concerns of interested parties. The development of a formal quantitative method and the subsequent definition of a threshold make it possible to obtain advance knowledge of the significance – and, therefore, the acceptability – of each potential environmental impact for a particular construction project. A total score for each construction project alternative is also obtained, so the improved methodology provides a consistent basis for comparing construction companies and construction sites. Finally, two case studies are presented in order to demonstrate the benefits of the improved methodology.
Guasch, D.; Dotras, P.; Llinares, M.; Aguado, M.; Bestraten, S.C.; Bordas, M.; Casals, M.; Català Roig, N.; Corbalan, M.; Esquerra, I.; Ferran, C.; Gangolells, M.; Hormias, E.; Jaen, C.; Lamich, M.; Roca, X.; Roman, J.; Ruiz, I.; Salan, N.; Simo, E.; Usandizaga, M. Date of publication: 2010-11-12 Book
Fuertes, A.; Forcada, N.; Casals, M.; Gangolells, M.; Roca, X.; Ballester, F.; Diego, R.; De la Horra, J. ISPE International Conference on Concurrent Engineering p. 231-238 Presentation's date: 2010-09-07 Presentation of work at congresses
This paper describes a Knowledge management system (SGAC - Active Knowledge Management System) to manage the knowledge generated in a research project. This system aims both at organizing project information during the project and at transferring this knowledge to other researches from the same scientific domain so as to enhance e-learning. This paper approaches the problem of knowledge transfer from a case study angle.The system is developed inside "The Multidimensional City" project, which is a multi-disciplinary research project that promotes the development and implementation of Spanish technological innovation in undergrond construction. The SGAC system aims at achieving full integration of large set of contents created in research projects related to underground construction sites. Then, the project has developed several types of metadata for tagging and enriching contents. All this enriched information becomes the base of different e-learning courses in underground construction, promoting an updated education in this knowledge area and the dissemination of the results generated in the research project.
Researchers often have to go to multiple information sources in order to identify high-quality, time-critical information. Due to the dynamic and unstructured nature of research results, they are faced with such problems as distributed sources and inter-disciplinary differences in terminology that prevent them from accessing the information they need. This paper presents the System for Active Knowledge Management (SAKM), a web-based system that addresses these problems by supporting effective information search and analysis, and by enhancing communication and collaboration among researchers.
The system was implemented in the underground construction field, which has experienced tremendous growth and is facing increasingly complex and challenging research issues.
Preliminary testing suggested that a tool like the SAKM could improve the information transfer of research results. The validation stage confirmed that the system met the requirements of the initially defined scenarios.
Previous researches have demonstrated that decisions made during the pre-construction stage have a big influence on the construction worker safety. This paper introduces a systematic approach for
dealing with health and safety risks during the pre-construction stage. The developed methodology helps designers to calculate the safety-related performance of their residential construction designs, providing a consistent basis for comparisons between them. In order to avoid a typical shortcoming in the evaluation of health and safety risks, indicators are based on quantitative data available in the project documents. Significance limits are statistically obtained with the analysis of 25 new-start construction projects
Hernandez-Sanchez, J.M.; Roca, X.; Domenech, J.; Garcia-Almiñana, Daniel; Casals, M.; Vilella, Q.; Gangolells, M.; Forcada, N.; Fuertes, A. Sustainable Building Conference Presentation's date: 2010-04-29 Presentation of work at congresses
Introduction: Research and practice have demonstrated that decisions made prior to work at construction
sites can influence construction worker safety. However, it has also been argued that most architects and
design engineers possess neither the knowledge of construction safety nor the knowledge of construction
processes necessary to effectively perform Construction Hazards Prevention through Design (CHPtD).
Method: This paper introduces a quantitative methodology that supports designers by providing a way to
evaluate the safety-related performance of residential construction designs using a risk analysis–based
approach. The methodology compares the overall safety risk level of various construction designs and ranks
the significance of the various safety risks of each of these designs. The methodology also compares the
absolute importance of a particular safety risk in various construction designs. Results: Because the
methodology identifies the relevance of each safety risk at a particular site prior to the construction stage,
significant risks are highlighted in advance. Thus, a range of measures for mitigating safety risks can then be
implemented during on-site construction. Impact on industry: The methodology is specially worthwhile for
designers, who can compare construction techniques and systems during the design phase and determine
the corresponding level of safety risk without their creative talents being restricted. By using this
methodology, construction companies can improve their on-site safety performance.
Resum de la tesi (màxim 4000 caràcters. Si se supera aquest límit, el resum es tallarà automàticament al caràcter 4000)
Molts dels problemes i obstacles que més freqüentment han d’encarar les empreses constructores durant el procés d’implementació i ús de sistemes integrats de gestió mediambiental i de seguretat i salut estan relacionats amb les peculiaritats pròpies del sector de la construcció. D’acord amb investigacions prèvies realitzades per diferents autors, una de les qüestions que tradicionalment comporta un major grau d’incertesa és la integració dels instruments de planificació i control, on s’inclouen els elements per a la identificació i l’avaluació dels impactes ambientals i dels riscos de seguretat i salut i l’aplicació de les subseqüents mesures de control.
Aquesta tesi doctoral contribueix a la implementació i ús de sistemes integrats de gestió mediambiental i de seguretat i salut en empreses constructores amb un enfocament orientat al procés i emprant el risc com a factor d’integració. A nivell de projecte constructiu, aquesta recerca proposa una metodologia quantitativa per tal d’identificar i avaluar aquells riscos de salut i seguretat i impactes ambientals potencialment adversos que poden originar-se en obres residencials o d’altres tipologies similars durant les etapes pre-constructives.
La metodologia desenvolupada facilita als dissenyadors la consideració de forma explícita dels impactes ambientals i la seguretat dels treballadors a l’obra durant el procés de disseny d’edificis residencials. Els dissenyadors poden comparar diferents alternatives de disseny i determinar, per a cada una de les solucions, el corresponent nivell d'impacte ambiental global així com el nivell de risc de seguretat i salut global, sense limitar el seu talent creatiu. La metodologia és especialment útil per a aquells dissenyadors menys experimentats que presenten una manca d’habilitats i coneixements per al reconeixement d’aspectes mediambientals i de riscos de seguretat i salut, ajudant-los a desenvolupar dissenys més òptims des d’aquestes perspectives. La metodologia també serveix com a eina d'avaluació per a que les empreses constructores puguin mesurar el comportament mediambiental i en termes de salut i de seguretat dels projectes constructius que duran a terme i les subseqüents activitats constructives, proporcionant una base consistent per a realitzar comparacions i per a l’establiment de futures etiquetes en termes mediambientals i de seguretat i salut entre diferents projectes de construcció i empreses constructores. La metodologia proposada també permet a les empreses constructores la optimització del seu comportament a l’obra en termes mediambientals i de salut i seguretat durant les etapes de planificació i preparació.
La metodologia desenvolupada no només proporciona als dissenyadors un forma d’avaluar el comportament mediambiental i en termes de seguretat i salut dels seus dissenys residencials sinó que també ajuda a les empreses constructores a millorar el seu comportament mediambiental i en termes de seguretat i salut a l’obra. Una vegada s’ha assolit el disseny final, la metodologia subratlla aquells impactes ambientals i riscos de seguretat i salut que encara són significatius. Una millor identificació d'impactes ambientals i de riscos de seguretat i salut porta indubtablement a una gestió mediambiental i de seguretat in situ més exitosa. D’aquesta manera, es poden implementar a l’obra un conjunt d’instruccions de treball orientades a eliminar o reduir fins a un nivell acceptable els impactes ambientals i els riscos de seguretat i salut restants. Per tal de promoure el control operacional integrat a l’obra dels impactes ambientals i riscos de salut i seguretat, aquesta tesi doctoral proposa una aproximació basada en les ontologies. Entendre les relacions existents entre impactes ambientals, riscos de salut i seguretat, processos constructius i instruccions de treball proporciona una aproximació integrada que pot ajudar als contractistes a gestionar i controlar els impactes ambientals i els riscos de seguretat i salut relacionats amb el procés constructiu.
Amb l’objectiu d’incrementar l'ús d'aquesta recerca, la metodologia desenvolupada s'ha implementat en un sistema web de gestió del coneixement i la informació. Per una banda, aquesta aplicació permet significativament reduir el temps dedicat a l'avaluació de cada projecte de construcció. D'altra banda, la formalització i visualització de l’aproximació basada en ontologies que s’ha desenvolupat durant la tesi confereix una guia per als contractistes en la gestió de moltes de les incidències mediambientals i de seguretat i salut que poden tenir lloc a les obres de construcció.
Finalment, aquesta tesi doctoral documenta la verificació i la validació de la metodologia desenvolupada i de la corresponent eina d’implementació. La tesi doctoral conclou subratllant les principals contribucions d'aquesta investigació. Aquells temes que sobrepassen l’abast d’aquesta tesi són comentats i proposats com a futurs treballs.
Most common challenges and obstacles encountered by construction organizations during the implementation process and use of integrated environmental and health and safety management systems are related to the inherent peculiarities of the construction sector. According to several research authors, one of the issues involving a higher level of uncertainty is the integration of planning and control instruments, including elements for identifying and assessing environmental impacts and health and safety risks and implementing subsequent necessary control measures.
This dissertation contributes to the implementation of environmental and health and safety management systems in construction companies by proposing a process-oriented approach and using risk as an integrating factor. At a project level, this research proposes a quantitative methodology for dealing with potential adverse environmental impacts and health and safety risks during the pre-construction stages of residential buildings and other similar typologies. The strength of this methodology lies in the fact that it helps designers to explicitly consider on-site environmental impacts and construction worker safety during the design process. Designers can compare several design alternatives during the design phase and determine corresponding overall environmental impact level and overall safety risk level of a construction project without their creative talents being restricted. The methodology is especially worthwhile for those less-experienced designers who lack the skills and knowledge required to recognize environmental aspects and safety hazards, developing optimal designs. The methodology also serves as an assessment tool for construction companies to measure the environmental and health and safety performance of construction projects and its subsequent construction activities, providing a consistent basis for comparisons, future labelling and environmental and safety benchmarking among construction projects and construction companies. The suggested methodology also allows construction companies to optimize its on-site performance in the environmental and the health and safety domains during the planning and preparation stages.
The developed methodology not only provides designers with a risk-analysis-based way of evaluating the environmental and safety-related performance of their residential construction designs, but also helps construction companies improve their on-site environmental and safety performance. Once a final design is reached, the methodology highlights the significant remaining environmental impacts and health and safety risks. Improved levels of environmental impacts and safety risks identification undoubtedly lead to successful on-site environmental and safety management. A range of measures can then be implemented at the construction site to eliminate the remaining impacts and risks or reduce them to an acceptable level. In order to promote the integrated operational control of on-site environmental impacts and health and safety risks, this research proposes an ontology-based approach. Understanding relationships between environmental impacts, health and safety risks, construction processes and work instructions provides an integrated approach to help contractors managing and controlling environmental impacts and health and safety risks related to the construction process.
In order to increase the usability of this research, the developed methodology has been implemented in a web-based information-and knowledge-management system. On one hand, this application allows significantly reducing the time devoted to the assessment of each construction project. On the other hand, formalizing and visualizing the developed ontology-based approach offers guidance to contractors on the integrated management of many of the environmental and health and safety incidences at the construction site.
Finally, this dissertation documents the verification and validation of the developed methodology and corresponding web-based implementation tool. The dissertation concludes by outlining the main contributions of this research. Those subjects that exceed this dissertation scope are commented and proposed as future work.