Existing benchmark systems for assessing global warming potential of buildings – Analysis of IEA EBC Annex 72 cases

Life cycle assessment (LCA) is increasingly being used as a tool by the building industry and actors to assess the global warming potential (GWP) of building activities. In several countries, life cycle based requirements on GWP are currently being incorporated into building regulations. After the establishment of general calculation rules for building LCA, a crucial next step is to evaluate the performance of the specific building design. For this, reference values or benchmarks are needed, but there are several approaches to defining these. This study presents an overview of existing benchmark systems documented in seventeen cases from the IEA EBC Annex 72 project on LCA of buildings. The study characterizes their different types of methodological background and displays the reported values. Full life cycle target values for residential and non-residential buildings are found around 10-20 kg CO$_2$e/m$^2$/y, whereas reference values are found between 20-80 kg CO$_2$e/m$^2$/y. Possible embodied target- and reference values are found between 1-12 kg CO$_2$e/m$^2$/y for both residential and non-residential buildings. Benchmark stakeholders can use the insights from this study to understand the justifications of the background methodological choices and to gain an overview of the level of GWP performance across benchmark systems

Existing benchmark systems for assessing global warming potential of buildings – Analysis of IEA EBC Annex 72 cases

Life cycle assessment (LCA) is increasingly being used as a tool by the building industry and actors to assess the global warming potential (GWP) of building activities. In several countries, life cycle based requirements on GWP are currently being incorporated into building regulations. After the establishment of general calculation rules for building LCA, a crucial next step is to evaluate the performance of the specific building design. For this, reference values or benchmarks are needed, but there are several approaches to defining these. This study presents an overview of existing benchmark systems documented in seventeen cases from the IEA EBC Annex 72 project on LCA of buildings. The study characterizes their different types of methodological background and displays the reported values. Full life cycle target values for residential and non-residential buildings are found around 10-20 kg CO2e/m2/y, whereas reference values are found between 20-80 kg CO2e/m2/y. Possible embodied target- and reference values are found between 1-12 kg CO2e/m2/y for both residential and non-residential buildings. Benchmark stakeholders can use the insights from this study to understand the justifications of the background methodological choices and to gain an overview of the level of GWP performance across benchmark systems.publishedVersio

Comparison of the greenhouse gas emissions of a high-rise residential building assessed with different national LCA approaches – IEA EBC Annex 72

Introduction: The international research project IEA EBC Annex 72 investigates the life cycle related environmental impacts caused by buildings. The project aims inter alia to harmonise LCA approaches on buildings. Methods: To identify major commonalities and discrepancies among national LCA approaches, reference buildings were defined to present and compare the national approaches. A residential high-rise building located in Tianjin, China, was selected as one of the reference buildings. The main construction elements are reinforced concrete shear walls, beams and floor slabs. The building has an energy reference area of 4566 m2 and an operational heating energy demand of 250 MJ/m2a. An expert team provided information on the quantities of building materials and elements required for the construction, established a BIM model and quantified the operational energy demand. Results: The greenhouse gas emissions and environmental impacts of the building were quantified using 17 country-specific national assessment methods and LCA databases. Comparisons of the results are shown on the level of building elements as well as the complete life cycle of the building. Conclusions: The results of these assessments show that the main differences lie in the LCA background data used, the scope of the assessment and the reference study period applied. Despite the variability in the greenhouse gas emissions determined with the 17 national methods, the individual results are relevant in the respective national context of the method, data, tool and benchmark used. It is important that environmental benchmarks correspond to the particular LCA approach and database of a country in which the benchmark is applied. Furthermore, the results imply to include building technologies as their contribution to the overall environmental impacts is not negligible. Grant support: The authors thank the IEA for its organizational support and the funding organizations in the participating countries for their financial support.IEA -International Energy Agency(undefined

Comparison of the environmental assessment of an identical office building with national methods

The IEA EBC Annex 72 focuses on the assessment of the primary energy demand, greenhouse gas emissions and environmental impacts of buildings during production, construction, use (including repair and replacement) and end of life (dismantling), i.e. during the entire life cycle of buildings. In one of its activities, reference buildings (size, materialisation, operational energy demand, etc.) were defined on which the existing national assessment methods are applied using national (if available) databases and (national/regional) approaches. The ?be2226? office building in Lustenau, Austria was selected as one of the reference buildings. TU Graz established a BIM model and quantified the amount of building elements as well as construction materials required and the operational energy demand. The building assessment was carried out using the same material and energy demand but applying the LCA approach used in the different countries represented by the participating Annex experts. The results of these assessments are compared in view of identifying major discrepancies. Preliminary findings show that the greenhouse gas emissions per kg of building material differ up to a factor of two and more. Major differences in the building assessments are observed in the transports to the construction site (imports) and the construction activities as well as in the greenhouse gas emissions of the operational energy demand (electricity). The experts document their practical difficulties and how they overcame them. The results of this activity are used to better target harmonisation efforts.IEA -International Association for the Evaluation of Educational Achievement(Slovenia

Decision Device Comparison for Model-based Analysis of ITD Perception in Normal Hearing Listeners

Interaural time differences (ITDs) play an important role in sound localization and speech understanding in noise. Previously (Moncada-Torres et al., 2016), we developed a framework capable of predicting ITD just noticeable differences (JNDs) based on a physiological model of the auditory nerve (AN). However, the decision device employed there did not take into account the variability of the used data in a straightforward manner. In this work, we predicted ITD JNDs using two different decision devices in normal hearing listeners using information at the AN level. AN responses to acoustic stimuli from both ears (in the form of spikes) with and without introduced ITDs were simulated using the phenomenological model proposed by Zilany et al. (2009). Next, we used the shuffled cross-correlogram analysis (SCCs, Joris, et al., 2006) to quantify ITD encoding across the AN of both channels. Assuming that the auditory system is more sensitive to smaller ITDs, we corrected the SCC curves using the weighting function proposed by Stern and Shear (1996). Then, we predicted the imposed ITD by choosing the global maximum of the corrected curves. The distributions of the predicted reference and imposed ITDs were fed to two different decision modules: the receiver operating characteristic (ROC) and the detection index (d'). These allowed us to calculate the ITD JND as the 79.4% and 1.5 point, respectively, of the neurometric curve. Finally, we evaluated the performance of the decision devices' predictions by comparing them against literature behavioural data using pure tones with frequencies from 250 to 1400 Hz. The proposed framework showed similar trends as in psychoacoustical data, with the d' metric being higher correlated with it. Future work will be focused in using the framework’s improved pipeline to predict ITD discrimination performance in hearing impaired listeners and well as in optimizing hearing aids/cochlear implants signal processing.status: publishe

Functional modelling of just noticeable differences in interaural time difference discrimination for bimodal and bilateral cochlear implant stimulation

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Model-based Analysis of ITD Perception in Normal & Hearing Impaired Listeners

Interaural time differences (ITDs) are a fundamental cue for sound localization. Sensorineural hearing impaired (HI) listeners frequently have worsened localization and lateralization performance compared to normal hearing (NH) listeners, also reflected in deficient detection and discrimination of ITDs. It has been suggested that ITDs are processed by specialized cells that receive input from the auditory nerve (AN) from both ears and function as coincidence detectors. In this work, we developed a physiologically motivated model framework to evaluate temporal coding of ITDs at the periphery level of NH and HI listeners. AN responses to acoustic stimuli from both ears (in the form of spikes) with introduced ITDs (including a reference condition with ITD = 0 μs) were simulated using the phenomenological model proposed by Zilany et al. (2009). Next, we utilized shuffled cross-correlograms (SCCs, Joris, et al., 2006) to quantify the encoded ITD across the AN of both channels. Assuming that the auditory system favors the perception of smaller ITDs, we corrected the SCC curves using the weighting function proposed by Shackleton et al. (1992). Then, we predicted the imposed ITD by choosing the global maximum. As a decision variable, the distributions of the predicted reference and imposed ITDs were processed to obtain a receiver operating characteristic (ROC) in a 2 alternative force choice (AFC) procedure. This allowed us to compute the ITD just noticeable difference (JND) as the 75 % point of the psychometric curve. Finally, we evaluated the model by comparing the simulated ITD JNDs against literature behavioural data using bandpass noise with a center frequency and a bandwidth of 500 and 100 Hz, respectively. For the HI case, we used the same framework, but modified the AN model to account for different degrees of inner/outer haircell (IHC/OHC) impairment based on audiogram information. The proposed framework successfully predicted bandpass noise ITD JNDs of NH listeners. In the case of HI listeners, the model was able to account for trends in the data, although the high variability of participants' performance make the comparison to data difficult. These results provide the basis for a model-based quantification of ITD coding in NH and HI listeners at the periphery level. Future work will be focused in using the current approach to predict ITD discrimination performance in listeners with acoustic and electric hearing to optimize the representation of spatial information in hearing devices signal processing.status: publishe

Functional modelling of interaural time difference discrimination in acoustical and electrical hearing

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A framework for computational modelling of interaural time difference discrimination of normal and hearing-impaired listeners

Different computational models have been developed to study the interaural time difference (ITD) perception. However, only few have used a physiologically inspired architecture to study ITD discrimination. Furthermore, they do not include aspects of hearing impairment. In this work, a framework was developed to predict ITD thresholds in listeners with normal and impaired hearing. It combines the physiologically inspired model of the auditory periphery proposed by Zilany, Bruce, Nelson, and Carney [(2009). J. Acoust. Soc. Am. 126(5), 2390–2412] as a front end with a coincidence detection stage and a neurometric decision device as a back end. It was validated by comparing its predictions against behavioral data for narrowband stimuli from literature. The framework is able to model ITD discrimination of normal-hearing and hearing-impaired listeners at a group level. Additionally, it was used to explore the effect of different proportions of outer- and inner-hair cell impairment on ITD discrimination.status: Published onlin

Cervical cancer screening program and Human Papillomavirus (HPV) testing, part II: Update on HPV primary screening.

Key Findings &nbsp; HPV testing is more sensitive for precancerous lesions CIN2 and CIN3 than cytology. The downside is that the transversal specificity is&nbsp;lower. The protective effect of HPV screening compared to cytology on the incidence of invasive cervical cancer is directly demonstrated in randomized&nbsp;trials. No protective effect is demonstrated under 30&nbsp;years. The risk of CIN3+ or invasive cervical cancer after a negative hrHPV DNA test is significantly lower than after a negative Pap smear. This means that screening intervals can be extended safely up to five and&nbsp;more. A two-step triage scenario with twice cytology at cutoff ASC-US+ offers a good balance of efficiency (4 to 9 referrals to detect one CIN3+, ~40% of referral) and safety (risk of CIN3+ in triage-negative women of 0.5% to&nbsp;0.9%). For the interpretation of cervical cytology specimen, there is no quality control programme&nbsp;yet. In Belgium, an ISO15189 accreditation (including participation in external quality assessments) for high-risk HPV detection in cervicovaginal samples using a molecular method&#8239;—&thinsp;but not for cytopathology&#8239;—&thinsp;is mandatory for&nbsp;reimbursement. The use of colposcopies in Belgium, with high numbers performed without previous cytology result is not in line with the internationally agreed recommendations, where colposcopies should be used to examine women with abnormal cytology&nbsp;findings. Proportions of abnormal cytology results varies widely between&nbsp;laboratories. It is unlikely that the introduction of HPV screening would lead to a large increase in confirmation tests in the Belgian&nbsp;context. HPV screening every 5 year is a dominant option, compared to current practice of cytology screening every 3&nbsp;years. </ul