Integrated control/structure optimization by multilevel decomposition

A method for integrated control/structure optimization by multilevel decomposition is presented. It is shown that several previously reported methods were actually partial decompositions wherein only the control was decomposed into a subsystem design. One of these partially decomposed problems was selected as a benchmark example for comparison. The system is fully decomposed into structural and control subsystem designs and an improved design is produced. Theory, implementation, and results for the method are presented and compared with the benchmark example

Visualizing Convolutional Networks for MRI-based Diagnosis of Alzheimer's Disease

Visualizing and interpreting convolutional neural networks (CNNs) is an important task to increase trust in automatic medical decision making systems. In this study, we train a 3D CNN to detect Alzheimer's disease based on structural MRI scans of the brain. Then, we apply four different gradient-based and occlusion-based visualization methods that explain the network's classification decisions by highlighting relevant areas in the input image. We compare the methods qualitatively and quantitatively. We find that all four methods focus on brain regions known to be involved in Alzheimer's disease, such as inferior and middle temporal gyrus. While the occlusion-based methods focus more on specific regions, the gradient-based methods pick up distributed relevance patterns. Additionally, we find that the distribution of relevance varies across patients, with some having a stronger focus on the temporal lobe, whereas for others more cortical areas are relevant. In summary, we show that applying different visualization methods is important to understand the decisions of a CNN, a step that is crucial to increase clinical impact and trust in computer-based decision support systems.Comment: MLCN 201

Ventilation of Dutch schools; an integral approach to improve design

Indoor Air Quality and thermal climate in schools is very important as it has a direct relation to the health and performance of the pupils. The status quo in the Netherlands is presented (e.g. average CO2 levels in schools, quality of ventilation). The goal of a first study was to evaluate the performance of exhaust-only ventilation systems. The performance was rather disappointed there were a lot of problems and insufficient situations found. During the next years different master students [1,2,3,4] together with the staff of Technische Universiteit Eindhoven were researching different aspects of the problem and trying to find solutions. In a following study, 6 schools with different ventilation systems were studied. Main conclusions from these studies were: IAQ in the evaluated schools did not meet the requirements and more ventilation was essential for better IAQ. A new integrated approach to design adequate solutions for ventilation of school buildings was developed. First design results are described in the paper

Double facades a more sustainable solution than a optimal single facade

Facade parameters influence the energy flows coming through the facade, in order to optimize the indoor environment for the comfort of the individual building occupant with minimal energy use. How can the facade make optimal use of the free incoming energy flows to maximize the comfort level of the individual building occupant at minimal energy use? The type of façade described as a second skin façade is characterised by a single glass layer on the outside and an isolated façade layer on the inside, which often includes an insulated glass layer. The application of the single glass layer as a second skin around the insulated layer results in an air cavity between these two layers. The property that distinguishes a second skin façade from other DSF is that it relies on natural ventilation of the cavity, in comparison to other facades which use mechanical systems to induce the airflow. The advantage of merely using natural ventilation in the façade cavity is the lower energy consumption. However, it also results in some unresolved issues which require further attention. This project is concerned with the behaviour of a highly complex shaped second skin facade on a Dutch office building, and the thermal comfort impact on the building user. During 3 weeks different measurements were done to determine the main characteristics of the glass and the facade. These measurements were related to earlier measurements done by other buildings with a second skin facade. A key difference between a second skin facade, as well as other climate facades, and more traditional opaque facades is its dynamic behaviour

Double facades a more sustainable solution than a optimal single facade

Facade parameters influence the energy flows coming through the facade, in order to optimize the indoor environment for the comfort of the individual building occupant with minimal energy use. How can the facade make optimal use of the free incoming energy flows to maximize the comfort level of the individual building occupant at minimal energy use? The type of façade described as a second skin façade is characterised by a single glass layer on the outside and an isolated façade layer on the inside, which often includes an insulated glass layer. The application of the single glass layer as a second skin around the insulated layer results in an air cavity between these two layers. The property that distinguishes a second skin façade from other DSF is that it relies on natural ventilation of the cavity, in comparison to other facades which use mechanical systems to induce the airflow. The advantage of merely using natural ventilation in the façade cavity is the lower energy consumption. However, it also results in some unresolved issues which require further attention. This project is concerned with the behaviour of a highly complex shaped second skin facade on a Dutch office building, and the thermal comfort impact on the building user. During 3 weeks different measurements were done to determine the main characteristics of the glass and the facade. These measurements were related to earlier measurements done by other buildings with a second skin facade. A key difference between a second skin facade, as well as other climate facades, and more traditional opaque facades is its dynamic behaviour

Synergy Between Building Rating Systems and Design Methodology for Intelligent and Green Buildings

There is a strong need for more efficient and more sustainable buildings. At present it is difficult to define the performance of buildings in an objective way to efficiency and sustainability. Goal of this project is to examine and to understand differences between different building rating systems considering what makes a good building, results in multiple interpretations based on the different background, training and experiences of the people who answer the question about how good a building is. What is needed is a new integral design approach which enables to integrate the different aspects of green and intelligent buildings in a supportive framework during the design process. Especially the focus is on Multi Criteria Decision making within the design process and how to support this, so that the decisions about fulfilling ‘green’ aspects in the design are made transparent for all share holders within the design process

Visualizing convolutional neural networks to improve decision support for skin lesion classification

Because of their state-of-the-art performance in computer vision, CNNs are becoming increasingly popular in a variety of fields, including medicine. However, as neural networks are black box function approximators, it is difficult, if not impossible, for a medical expert to reason about their output. This could potentially result in the expert distrusting the network when he or she does not agree with its output. In such a case, explaining why the CNN makes a certain decision becomes valuable information. In this paper, we try to open the black box of the CNN by inspecting and visualizing the learned feature maps, in the field of dermatology. We show that, to some extent, CNNs focus on features similar to those used by dermatologists to make a diagnosis. However, more research is required for fully explaining their output.Comment: 8 pages, 6 figures, Workshop on Interpretability of Machine Intelligence in Medical Image Computing at MICCAI 201

Wireless Sensor Technology to Optimize the Occupant's Dynamic Demand Pattern Within the Building

Energy needs to be used as effectively as possible by anticipating on the human behaviour with the purpose of providing optimal comfort. The purpose of this research is to assess the energy saving potential by sending the energy to those spots (hotspots) where needed and to determine how the user can be taken into account in the design to improve the performances of office buildings. Possibilities for human position tracking measurements by means of a WSN were investigated to determine the user behavior of aoocpants of a building. An experimental set-up was developed which was implemented on the 3th floor of one of the offices of Royal Haskoning consulting engineers. This showed the positive effect of using wireless technology to optimize the occupants comfort while minimizing the energy consumption