Integrated value model for sustainability assessment of residential solar energy systems towards minimizing urban air pollution in Tehran

Renewable energy applications are lucrative alternatives to minimize urban environmental impacts. Solar energy, the most abundant, inexhaustible, and cleanest of all renewable sources, provides an opportunity to transform buildings from energy consumers into active energy producers. Nevertheless, photovoltaic (PV) and hybrid photovoltaic/thermal (PV/T) are considered the most viable alternatives for urban settlements. This study, as part of a broader research project, develops a new model to evaluate solar systems' air pollution mitigation capacity and assist decision-makers in adopting the most suitable solution. The approach is based on the integrated value model for sustainability assessment (MIVES), combined with the analytic hierarchy process (AHP) and sensitivity analysis. This multi-objective tool is applied to residential buildings in Tehran, a megacity example with unused rooftops, solar energy harvest potential, and air pollution reduction needs. Results reveal one square meter of PV and PV/T enables avoiding 211 and 488 kg CO2 emissions annually, as well as 1.2 and 1.9 g PM pollutants, respectively. Although PV achieves higher sustainability indexes as a better socio-economic alternative, PV/T can be a robust solution when stakeholders are more sensitive to environmental requirements and air pollution decrement potential. The critical obstacle to PV/T deployment is the lack of financial incentives. However, allocating 38 % of solar electricity feed-in tariffs to solar thermal energy could solve this issue. Compared to green roofs, solar systems stand out with CO2 saving and energy production potential. Researchers expect future solar collectors’ improvements, such as lower resource consumption, thus, becoming more environmentally friendly and cost-effective solutions.Peer ReviewedPostprint (published version

Multicriteria decision-making method for sustainable site location of post-disaster temporary housing in urban areas

Many people lose their homes around the world every year because of natural disasters, such as earthquakes, tsunamis, and hurricanes. In the aftermath of a natural disaster, the displaced people (DP) have to move to temporary housing (TH) and do not have the ability to choose the settlement dimensions, distributions, neighborhood, or other characteristics of their TH. Additionally, post-disaster settlement construction causes neighborhood changes, environmental degradation, and large-scale public expenditures. This paper presents a new model to support decision makers in choosing site locations for TH. The model is capable of determining the optimal site location based on the integration of economic, social, and environmental aspects into the whole life cycle of these houses. The integrated value model for sustainable assessment (MIVES), a multicriteria decision making (MCDM) model, is used to assess the sustainability of the aforementioned aspects, and MIVES includes the value function concept, which permits indicator homogenization by taking into account the satisfaction of the involved stakeholders.Peer ReviewedPostprint (author's final draft

The effect of macroeconomic factors on credit risk in the banking system of Iran

These days, there are increasing changes on environmental and economic networks and different risks of various institutions affect the financial structure. Different institutions including financial and credit institutions are facing with the risk of lack of their timely obligations to make sure the repayment of the funds is granted. In this study, the effects of economic factors not affected by intentional behavior of customers are investigated. Statistical study of the banking system includes all public and private banks. Statistical research community from 2005 to 2010 is considered. The cross-sectional data of the study and a combination of regression analysis is used. The regression analysis of combined data, fixed effects model based on the data is a cross-sectional fit. According to results of regression analysis, Pearson and Spearman's Correlation Coefficient, there is no significant relationship between the inflation rate, employment rate, unemployment rate, the dollar, the euro, with import growth of credit risk in the banking system in Iran. Therefore, based on probability theory, it can be stated that the credit risk in the banking system in Iran under the influence of variables is not mentioned. In addition, positive and significant relationship between stock index and credit risk in the banking system in Iran has increased by Weber in this index increases and reducing credit risk is reduced

Innovative approach to assist architecture teachers in choosing practical sessions

This article presents the first results of the project Architecture 360, which focuses on learning alternatives for developing working skills in higher education courses, and specifically construction competences for architecture students. The project aims to help teachers to choose the best learning solutions for their classes from numerous alternatives of strategies, dynamics and activities. The assistance is based on developing a new approach that combines several methods (strengths, weaknesses, opportunities and threats (SWOT); multi-criteria decision-making; Delphi; and the Knapsack problem) and draws from teachers’ experience, a panel of experts’ expertise, the revised Bloom Taxonomy and neuroscience for education. The new approach to assisting university teachers in choosing the best practical learning alternatives was successfully developed and validated for the case study of a course at Barcelona Architecture School. In general, the approach defined the main strengths, weaknesses, opportunities and threats of 26 learning alternatives. In the case study, the following optimized set of alternatives were identified: blended learning, challenge-based learning, reflective learning, videos of real cases, case studies, site visits, interactive simulation and gamification. Moreover, 23 activities were analysed. It was concluded, for instance, that active alternatives would improve implementation, including teachers’ available teaching materials and dedication outside class.Peer ReviewedObjectius de Desenvolupament Sostenible::4 - Educació de QualitatPostprint (published version

High Load Control Mechanism for SIP Servers

To start voice, image, instant messaging, and generally multimedia communication, session communication must begin between two participants. SIP (session initiation protocol) that is an application layer control induces management and terminates this kind of sessions. As far as the independence of SIP from transport layer protocols is concerned, SIP messages can be transferred on a variety of transport layer protocols including TCP or UDP. Mechanism of Retransmission that is embedded in SIP could compensate for the missing packet loss, in case of need. This mechanism is applied when SIP messages are transmitted on an unreliable transmission layer protocol like UDP. Also, while facing SIP proxy with overload, it could cause excessive filling of proxy queue, postpone increase of other contacts, and add to the amount of the proxy overload. In the present work, while using UDP as transport layer protocol, invite retransmission timer (T1) was appropriately regulated and SIP functionality was improved. Therefore, by proposing an adaptive timer of invite message retransmission, attempts were made to improve the time of session initiation and consequently improve the performance. Performance of the proposed SIP was implemented and evaluated by SIPP software in a real network environment and its accuracy and performance were demonstrated

Sustainability model to select optimal site location for temporary housing units: combining GIS and the MIVES–Knapsack model

Selecting the best site location for temporary housing (TH) is one of the most critical decision-making processes in the aftermath of disasters. Many spatial variables and multi-criteria indicator problems are involved in the decision-making analysis. Incorrect treatment of these components often led to failure in previous post-disaster recovery programmes. Wrong decisions caused short- and long-term negative impacts on the environment and people as well as wasting capital spending. In this regard, this research paper aims to present a novel multi-criteria decision-making approach that helps decision makers select optimal site locations to consider spatial and sustainability-related aims by assessing numerous alternatives. This new model is based on combining a knapsack algorithm and the integrated value model for sustainability assessment (MIVES) to derive optimal alternatives. This model makes it possible to objectively quantify sustainability indicators (economic, environmental, and social aspects) and derive satisfaction indices for each site (or set of sites) in terms of TH location. The model is designed to receive and filter data from a geographic information system (GIS). Using this model in future post-disaster recovery programs is believed to increase stakeholders’ satisfaction and maximise the sustainability associated with the selection.Peer ReviewedPostprint (published version

High Load Diminution by Regulating Timers in SIP Servers

To start voice, image, instant messaging, and generally multimedia communication, session communication must begin between two participants. SIP (session initiation protocol) that is an application layer control induces management and terminates this kind of sessions. As far as the independence of SIP from transport layer protocols is concerned, SIP messages can be transferred on a variety of transport layer protocols including TCP or UDP. Mechanism of Retransmission that is embedded in SIP could compensate for the missing packet loss, in case of need. This mechanism is applied when SIP messages are transmitted on an unreliable transmission layer protocol like UDP. Also, while facing SIP proxy with overload, it could cause excessive filling of proxy queue, postpone increase of other contacts, and add to the amount of the proxy overload. In the present work, while using UDP as transport layer protocol, invite retransmission timer (T1) was appropriately regulated and SIP functionality was improved. Therefore, by proposing an adaptive timer of invite message retransmission, attempts were made to improve the time of session initiation and consequently improve the performance. Performance of the proposed SIP was implemented and evaluated by SIPP software in a real network environment and its accuracy and performance were demonstrated

Environmental performance assessment: a comparison and improvement of three existing social housing projects

The energy consumption of buildings accounts for 22% of total global energy use and 13% of global greenhouse gas emissions. In this context, this study aims to evaluate the environmental performance of three social housing designs located in emerging economies by analysing sustainability indicators adopting different technical solutions. The analysis incorporates eleven construction strategies to improve the environmental performance of the buildings. The performance assessment is analysed by using EDGE (Excellence in Design for Greater Efficiencies) Methodology. Therefore, this study aims to help identify the construction strategies, with the aim of improving the operational energy performance (kWh/year/m2floor), operational CO2 emissions (tCO2eq/Year/m2floor), embodied energy (MJ/m2floor) and operational water consumption of housing (m3/year/m2floor). The results showed that when the technical measures are implemented, the energy demand decreases by 38.52% in Case A, 19% in Case B, and 41% in Case C. The embodied energy savings in materials in Case A 3%, Case B 0% and Case C 36% Regarding water consumption, the demand decreases by 46%, 4%, and 12% in Case A, B, and C respectively.Peer ReviewedPostprint (published version