Abnormality Detection in Mammography using Deep Convolutional Neural Networks

Breast cancer is the most common cancer in women worldwide. The most common screening technology is mammography. To reduce the cost and workload of radiologists, we propose a computer aided detection approach for classifying and localizing calcifications and masses in mammogram images. To improve on conventional approaches, we apply deep convolutional neural networks (CNN) for automatic feature learning and classifier building. In computer-aided mammography, deep CNN classifiers cannot be trained directly on full mammogram images because of the loss of image details from resizing at input layers. Instead, our classifiers are trained on labelled image patches and then adapted to work on full mammogram images for localizing the abnormalities. State-of-the-art deep convolutional neural networks are compared on their performance of classifying the abnormalities. Experimental results indicate that VGGNet receives the best overall accuracy at 92.53\% in classifications. For localizing abnormalities, ResNet is selected for computing class activation maps because it is ready to be deployed without structural change or further training. Our approach demonstrates that deep convolutional neural network classifiers have remarkable localization capabilities despite no supervision on the location of abnormalities is provided.Comment: 6 page

Quantitative MRI correlates of hippocampal and neocortical pathology in intractable temporal lobe epilepsy

Intractable or drug-resistant epilepsy occurs in over 30% of epilepsy patients, with many of these patients undergoing surgical excision of the affected brain region to achieve seizure control. Advances in MRI have the potential to improve surgical treatment of epilepsy through improved identification and delineation of lesions. However, validation is currently needed to investigate histopathological correlates of these new imaging techniques. The purpose of this work is to investigate histopathological correlates of quantitative relaxometry and DTI from hippocampal and neocortical specimens of intractable TLE patients. To achieve this goal I developed and evaluated a pipeline for histology to in-vivo MRI image registration, which finds dense spatial correspondence between both modalities. This protocol was divided in two steps whereby sparsely sectioned histology from temporal lobe specimens was first registered to the intermediate ex-vivo MRI which is then registered to the in-vivo MRI, completing a pipeline for histology to in-vivo MRI registration. When correlating relaxometry and DTI with neuronal density and morphology in the temporal lobe neocortex, I found T1 to be a predictor of neuronal density in the neocortical GM and demonstrated that employing multi-parametric MRI (combining T1 and FA together) provided a significantly better fit than each parameter alone in predicting density of neurons. This work was the first to relate in-vivo T1 and FA values to the proportion of neurons in GM. When investigating these quantitative multimodal parameters with histological features within the hippocampal subfields, I demonstrated that MD correlates with neuronal density and size, and can act as a marker for neuron integrity within the hippocampus. More importantly, this work was the first to highlight the potential of subfield relaxometry and diffusion parameters (mainly T2 and MD) as well as volumetry in predicting the extent of cell loss per subfield pre-operatively, with a precision so far unachievable. These results suggest that high-resolution quantitative MRI sequences could impact clinical practice for pre-operative evaluation and prediction of surgical outcomes of intractable epilepsy

Energy Saving Impact of Air Curtains in Commercial Buildings

This study investigates the energy saving impact replacing vestibules with air curtain doors (single doors fitted with air curtain units) has on energy usage of commercial buildings. Laboratory experiments were used to investigate the infiltration characteristics of air curtains in a small size chamber and to validate numerical simulation methods. Experimental flow and pressure as well as particle image velocimetry data confirmed that air curtains can significantly reduce air infiltration when compared to the single and vestibule doors. In addition, the results indicated that the CFD modeling methods used are valid in capturing the characteristics of the airflow at the door with air curtains. CFD simulations were conducted for a full scale door with consideration for the door operation cycle and the existence of people in the doorway. The results of the simulations were used to conduct energy simulations for two reference building models. The end use site-energy performances of the whole buildings with air curtain, vestibule and single doors are compared using two infiltration calculation methods. The energy simulations conducted show that, on a national average level, air curtain doors save energy (in comparison to code requirements). Finally, considering the space saving benefit of air curtains and their lower initial costs, air curtains are concluded to be a valid and energy saving alternative to vestibule doors in climate zones 3 to 8 and a valuable energy saving addition in climate zones 1 & 2

On the Role of Construction in Achieving the SDGs

Construction and real estate have been central to the debates on sustainable development. However, the dominant definition of sustainability in construction and real estate remain centred on the environmental dimension. The 2030 Agenda and its Sustainable Development Goals (SDGs) offer new opportunities for the building sector to expand its focus. The available literature utilizes the existing green ratings, sustainability assessment tools and standards as the basis for investigating how construction and buildings can contribute to the 2030 Agenda for Sustainable Development. However, less focus was placed on exploring the broad intersection between the building sector, on the one hand, and the SDGs and their targets on the other. This paper uses a multi-step methodology to analyze the potential role of construction and real estate in the 2030 Agenda. The paper identifies SDG targets that depend (directly or indirectly) on construction and real estate activities, and reveals that 17% of the SDG targets are directly dependent and 27% of the targets are indirectly dependent on these sectors’ activities. The identified targets are analyzed and are found to be related to all 17 goals—with the largest contributions to SDGs 11, 6, and 7. The results of the analysis are mapped and illustrated in order to provide insights to academics, practitioners and governments. This research contributes to the literature on the implementation of the 2030 Agenda. It also exposes the synergistic possibilities, and the partnerships required, to make use of the potential role of construction and real estate in the implementation of the UN Agenda

A Nested Sensor Array Focusing on Near Field Targets

A nested virtual array subband beamforming system is proposed for applications where broadband signal targets are located within the near field of the array. Subband multirate processing and near field beamforming techniques are used jointly for the nested array to improve the performances and reduce the computational complexity. A new noise model, namely the broadband near field spherically isotropic noise model, is also proposed for the optimization design of near field beamformers. It is shown that near field beamforming is essential for better distance discrimination of near field targets, reduced beampattern variations for broadband signals, and stronger reverberation suppression

Ethanol Vapours to Complement or Replace Sulfur Dioxide Fumigation of Table Grapes

Recent studies have shown that dipping table grapes in ethanol solutions at harvest improved storage of the fruit. We report here the first results obtained by treating "Chasselas" table grapes (Vitis vinifera) with ethanol vapours over the storage period. We tested the effect of ethanol at 0, 4 and 8 g/kg fruit during cold storage for 2, 4 and 6 weeks. We measured berry shatter, stem browning, Botrytis rot incidence and sensory appreciation by tasting panels. Ethanol vapours reduced Botrytis rot incidence and berry shatter, but hastened stem browning. Sensory analyses did not detect any differences between treatments

Robust Near-Field Adaptive Beamforming with Distance Discrimination

This paper proposes a robust near-field adaptive beamformer for microphone array applications in small rooms. Robustness against location errors is crucial for near-field adaptive beamforming due to the difficulty in estimating near-field signal locations especially the radial distances. A near-field regionally constrained adaptive beamformer is proposed to design a set of linear constraints by filtering on a low rank subspace of the near-field signal over a spatial region and frequency band such that the beamformer response over the designed spatial-temporal region can be accurately controlled by a small number of linear constraint vectors. The proposed constraint design method is a systematic approach which guarantees real arithmetic implementation and direct time domain algorithms for broadband beamforming. It improves the robustness against large errors in distance and directions of arrival, and achieves good distance discrimination simultaneously. We show with a nine-element uniform linear array that the proposed near-field adaptive beamformer is robust against distance errors as large as ±32% of the presumed radial distance and angle errors up to ±20⁰. It can suppress a far field interfering signal with the same angle of incidence as a near-field target by more than 20 dB with no loss of the array gain at the near-field target. The significant distance discrimination of the proposed near-field beamformer also helps to improve the dereverberation gain and reduce the desired signal cancellation in reverberant environments

Creativity, Adaptability, Transition: Advancing Sustainable Development in the Built Environment through Transdisciplinary Architectural Design

The link between creativity, design thinking, and interdisciplinarity has been explored by Darbellay et al. (2017). They proposed that the three dimensions are not contradictory, but instead, they form triadicfeedback loops that cannot be resolved in a unified synthesis. This triadic model underscores that, in fact, the creative, interdisciplinary (or transdisciplinary) design thinking is an outcome of dialectic, or even dialogical (Lybeck, 2010), processes among disciplines, stakeholders, the problem at hand, and the variety of possible design solutions. Harvey (2014) proposes that this type of creative synthesis can only generate breakthrough ideas if it integrates multiple understandings for the same problem. Specifically, in Harvey’s (2014) model, breakthrough ideas require a context where ideas are enacted, similarities are built upon, and collective attention is secured – and it is only through a sort of reflection in action (Schön, 1984) that creative synthesis can generate exemplars that are iteratively improved until breakthrough. With global population growth and urbanization trends rising (Department of Economic and Social Affairs (Population Division), 2017; United Nations - Department of Economic and Social Affairs Population Division, 2018), it is now imperative that we move towards a state of creative sustainability in the built environment. The publication of the 2030 Agenda and the sustainable development goals (SDGs) (United Nations, 2015) has signalled a new course for practitioners, scholars, and designers by institutionalizing a more comprehensive understanding of sustainable development, which is supported by clear targets and indicators (Pedersen, 2018). While the SDGs are global in scope, their application requires action to be taken on individual project levels, including building projects, on the local scale (T. Walker & Goubran, 2020). Most importantly, the SDGs enabled sustainability action to remain reliant on the interpretation of the problems, along with the framing of the design problem (Goubran & Cucuzzella, 2019). Thus, it can be argued that the SDGs have reframed the sustainable built environment challenge as a complex design problem, open for interpretation, judgment, and theorization and leading to multiple solutions and innovations (Nelson & Stolterman, 2012), that requires the synthesis of knowledge between a multitude of disciplines (Kroes et al., 2008). In this paper, we argue that architecture, as a field of research and practice, is both inductive and inclusive of the creative transdisciplinary approaches needed to tackle sustainable development challenges in the built environment (Goubran, 2018). The paper presents a theoretical development, followed by a synthesis supported by published case studies. In essence, the paper capitalizes on the value of architecture as a transdisciplinary field that allows for transformative sustainable practices within the building and construction industries. Thus, it establishes a scheme where architectural design, as a transdisciplinary field, is an inclusive thinking process that has the potential to push boundaries of “just building” to “building for”

A Microphone Array System for Multimedia Applications with Near-Field Signal Targets

A microphone array beamforming system is proposed for multimedia communication applications using four sets of small planar arrays mounted on a computer monitor. A new virtual array approach is employed such that the original signals received by the array elements are weighted and delayed to synthesize a large, nonuniformly spaced, harmonically nested virtual array covering the frequency band [50, 7000] Hz of the wideband telephony. Subband multirate processing and near-field beamforming techniques are then used jointly by the nested virtual array to improve the performances in reverberant environments. A new beamforming algorithm is also proposed using a broadband near-field spherically isotropic noise model for array optimization. The near-field noise model assumes a large number of broadband random noises uniformly distributed over a sphere with a finite radius in contrast to the conventional far-field isotropic noise model which has an infinite radius. The radius of the noise model, thus, adds a design parameter in addition to its power for tradeoffs between performance and robustness. It is shown that the near-field beamformers designed by the new algorithm can achieve more than 8-dB reverberation suppression while maintaining sufficient robustness against background noises and signal location errors. Computer simulations and real room experiments also show that the proposed array beamforming system reduces beampattern variations for broadband signals, obtains strong noise and reverberation suppression, and improves the sound quality for near-field targets

Integrating the Sustainable Development Goals in Building Projects

Building designers are struggling to deeply integrate the 2030 Agenda and its Sustainable Development Goals (SDGs) in projects. The review of the literature revealed that the available research is focused on linking the current practices, including sustainable building practices, with the SDGs. This has, in turn, limited the development of novel approaches as well as new building design methodologies that specifically aim at attaining the agenda’s targets. To help building design teams achieve the meaningful integration of the agenda’s five Ps, this paper proposes two analytical mapping tools which can be used during the integrated design process to track the integration of SDGs in the building projects, and to analyze the building design approaches and visions in reference to the topics of the goals. The research uses a case study for an energy-positive building in Quebec to test the proposed tools. The analysis focuses on the integration of 8 of 17 SDGs, discusses the specific building features which were used to achieve this integration, and analyzes the team’s design visions regarding the goals. The results reveal that in the case studied, the integration of the 8 SDGs moves beyond the current standards by mostly applying design approaches which are future-driven and focused on products and technologies. This research provides important practical tools that can inform building practices in the private and the public sector and contributes to the theory and practice of sustainable building design. It also supports the current effort towards the implementation and localization of the SDGs