| 1. |
- Coll, M., et al.
(författare)
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Towards Oxide Electronics: a Roadmap
- 2019
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Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 482, s. 1-93
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Tidskriftsartikel (refereegranskat)abstract
- At the end of a rush lasting over half a century, in which CMOS technology has been experiencing a constant and breathtaking increase of device speed and density, Moore’s law is approaching the insurmountable barrier given by the ultimate atomic nature of matter. A major challenge for 21st century scientists is finding novel strategies, concepts and materials for replacing silicon-based CMOS semiconductor technologies and guaranteeing a continued and steady technological progress in next decades. Among the materials classes candidate to contribute to this momentous challenge, oxide films and heterostructures are a particularly appealing hunting ground. The vastity, intended in pure chemical terms, of this class of compounds, the complexity of their correlated behaviour, and the wealth of functional properties they display, has already made these systems the subject of choice, worldwide, of a strongly networked, dynamic and interdisciplinary research community. Oxide science and technology has been the target of a wide four-year project, named Towards Oxide-Based Electronics (TO-BE), that has been recently running in Europe and has involved as participants several hundred scientists from 29 EU countries. In this review and perspective paper, published as a final deliverable of the TO-BE Action, the opportunities of oxides as future electronic materials for Information and Communication Technologies ICT and Energy are discussed. The paper is organized as a set of contributions, all selected and ordered as individual building blocks of a wider general scheme. After a brief preface by the editors and an introductory contribution, two sections follow. The first is mainly devoted to providing a perspective on the latest theoretical and experimental methods that are employed to investigate oxides and to produce oxide-based films, heterostructures and devices. In the second, all contributions are dedicated to different specific fields of applications of oxide thin films and heterostructures, in sectors as data storage and computing, optics and plasmonics, magnonics, energy conversion and harvesting, and power electronics.
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| 2. |
- Forsberg, Daniel
(författare)
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Robust Image Registration for Improved Clinical Efficiency : Using Local Structure Analysis and Model-Based Processing
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Medical imaging plays an increasingly important role in modern healthcare. In medical imaging, it is often relevant to relate different images to each other, something which can prove challenging, since there rarely exists a pre-defined mapping between the pixels in different images. Hence, there is a need to find such a mapping/transformation, a procedure known as image registration. Over the years, image registration has been proved useful in a number of clinical situations. Despite this, current use of image registration in clinical practice is rather limited, typically only used for image fusion. The limited use is, to a large extent, caused by excessive computation times, lack of established validation methods/metrics and a general skepticism toward the trustworthiness of the estimated transformations in deformable image registration.This thesis aims to overcome some of the issues limiting the use of image registration, by proposing a set of technical contributions and two clinical applications targeted at improved clinical efficiency. The contributions are made in the context of a generic framework for non-parametric image registration and using an image registration method known as the Morphon. In image registration, regularization of the estimated transformation forms an integral part in controlling the registration process, and in this thesis, two regularizers are proposed and their applicability demonstrated. Although the regularizers are similar in that they rely on local structure analysis, they differ in regard to implementation, where one is implemented as applying a set of filter kernels, and where the other is implemented as solving a global optimization problem. Furthermore, it is proposed to use a set of quadrature filters with parallel scales when estimating the phase-difference, driving the registration. A proposal that brings both accuracy and robustness to the registration process, as shown on a set of challenging image sequences. Computational complexity, in general, is addressed by porting the employed Morphon algorithm to the GPU, by which a performance improvement of 38-44x is achieved, when compared to a single-threaded CPU implementation.The suggested clinical applications are based upon the concept paint on priors, which was formulated in conjunction with the initial presentation of the Morphon, and which denotes the notion of assigning a model a set of properties (local operators), guiding the registration process. In this thesis, this is taken one step further, in which properties of a model are assigned to the patient data after completed registration. Based upon this, an application using the concept of anatomical transfer functions is presented, in which different organs can be visualized with separate transfer functions. This has been implemented for both 2D slice visualization and 3D volume rendering. A second application is proposed, in which landmarks, relevant for determining various measures describing the anatomy, are transferred to the patient data. In particular, this is applied to idiopathic scoliosis and used to obtain various measures relevant for assessing spinal deformity. In addition, a data analysis scheme is proposed, useful for quantifying the linear dependence between the different measures used to describe spinal deformities.
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| 3. |
- Condo Neira, Edith, 1979
(författare)
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Antenna Evaluation for Vehicular Applications in Multipath Environment
- 2017
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Antennas are essential components in any wireless communication system. To evaluate them is challenging, especially when new technologies are emerging.Future intelligent transport systems, where vehicular communications play an important role will cover important aspects such as traffic safety and traffic efficiency. These applications will be covered by technologies such as IEEE 802.11p and LTE. For these emerging technologies, traditional methods for measuring the vehicular antennas such as anechoic chamber measurements or expensive and time-consuming field measurements may not be enough or suitable. Thus a new method for evaluating the antennas performance is desirable. A method that includes the multipath environment to give an idea of the antenna performance in the whole system and at the same time be able to be applied at early stages of product development. This thesis aims to provide such method.The thesis is divided in two parts. The first part contains an overview and background of important concepts needed for development of methods for evaluation of vehicular antennas. In the second part, the papers that constitute the core of this work are appended. In Paper A, we evaluate the vehicle’s antenna performance using only simulations. We start by defining the multipath environment for vehicle-to-vehicle and vehicle-to-infrastructure (V2X) communication. Then, the V2X environment is simulated using a multipath simulation tool to evaluate the vehicle’s antennas radiation patterns placed at different positions on the vehicle. This will result in the received power cumulative distribution functions (CDFs) for the voltage samples at the receiving antennas port. In Paper B, we present the design and evaluation of an antenna module for IEEE 802.11p and LTE technologies. The module is designed taking into consideration the available space and suitable placement on the vehicle. The proposed module is in accordance with the requirements for LTE and IEEE 802.11p technologies. This is validated with the analysis of the antenna efficiencies, S-parameters, radiation patterns, and diversity performance for the simulated and measured antenna module.Finally, Paper C presents a method for the evaluation of V2V antennas in a simulated measurement-based multipath environment. Here, a measurement campaign is performed to obtain the parameters (i.e., the angular received power spectrum) that define a realistic V2V multipath environment. These parameters are then introduced in a multipath simulation tool where the antennas radiation patterns are evaluated. Results are expressed in terms of received power CDFs. This method is validated by comparing the simulated and measured received power for two roof-top vehicle antennas.
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| 4. |
- Marhendraswari, M. B.D., et al.
(författare)
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Production of edible fungal (Rhizopus delemar CBS 145940) biomass from organosolv-pretreated oil palm empty fruit bunch (OPEFB) in submerged fermentation
- 2020
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Ingår i: IOP Conference Series: Materials Science and Engineering. - : Institute of Physics (IOP). - 1757-8981 .- 1757-899X. ; 991:1
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Konferensbidrag (refereegranskat)abstract
- Accumulation of oil palm empty fruit bunches (OPEFB) from palm oil industry poses challenges for the disposal process, which leads to environmental damage. For this reason, valorization of OPEFB fractions to produce edible fungal biomass was carried out in this research. The fungus was Rhizopus delemar CBS 145940, which is an edible fungus, Indonesian indigenous, and is favorable for the production of several end products. Organosolv pretreatment was first conducted on OPEFB using ethanol (50%) as the solvent. Enzymatic hydrolysis was then performed using Cellic® Ctec3 on the pretreated-OPEFB fractions. Hydrolyzates from cellulose-rich fraction, slurry (a mixture of cellulose-rich fraction and hemicellulose-rich fraction), and hemicellulose-rich fraction were used as the cultivation media for fungal growth. The corresponding yield of fungal biomass from each medium was 0.62 ± 0.07 g/g glucose; 0.41 ± 0.02; and 0.61 ± 0.13 g/g fermentable sugars, respectively. These results showed that Rhizopus delemar CBS 145940 could be grown in all the hydrolyzates from the OPEFB fractions. Nevertheless, in order to obtain higher fungal biomass, supplementation of nutrition was needed.
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| 5. |
- Danhäll, D, et al.
(författare)
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Naturligt grupperat arbete vid Volvo Lastvagnar – Delrapport 2
- 1989
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Consumer report for the company in question (the Volvo Truck Company) which is financed by the company and partly also by a research foundation. It is a matter of a work that in this particular case were carried out during nine years in a number of experimental workshops located outside the Chalmers University of Technology. These workshops were financed by the Volvo Automobile and Truck companies. This achievement, as the final contribution to the Swedish automotive industry after having already treated this research field/problem area for more than two decades before this particular period if time (involving several junior and senior research competencies, as well as industrial and governmental foundings). Specifically (and as stated for the previous report), this publication explains how the authors dealt with the product architecture and product variation of the automotive products disassembled, which proved to necessary to be carried out in one of the experimental workshops (several complete automobiles and one heavy truck chassis were disassembled combined with having product data accessible in form of paper print-outs as well as by appropriate computer connections to the two Volvo companies etc.). That is, by using a special sort of “design analysis by means of axonometric hand-drawn illustrations” (see a conference contribution from 1992 that also is registered and available as o PDF-document at Chalmers Public Library (CPL) (a self-developed method found out together with a junior research competency from the School of Architecture at Chalmers).
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| 6. |
- Katzourakis, D. I., et al.
(författare)
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Driver Steering Override for Lane-Keeping Aid Using Computer-Aided Engineering
- 2015
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Ingår i: IEEE/ASME Transactions on Mechatronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 1083-4435 .- 1941-014X. ; 20:4, s. 1543-1552
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Tidskriftsartikel (refereegranskat)abstract
- The decreasing cost of radar and camera sensory technology has established advanced driver assistance systems (ADAS) to the standard equipment of modern vehicles. ADAS employ semi-autonomous interventions in longitudinal (e.g., adaptive cruise control, ACC) and lateral (e.g., lane-keeping aid, LKA) direction. ACC and LKA constitute the milestones of ADAS technology and have shown to correspondingly reduce driving effort and unintended lane-drifts. ADAS and driver share the vehicle control; this in-turn creates a nonfinite number of test cases that have to be tested-verified so-as to enable safe software (SW) release. Adjacent to ADAS, vehicle dynamics-related systems, such as the antilock braking system and the dynamic-stability and traction control, have also to undergo through an exhaustive SW verification. Distilling the previous statements, this paper cultivates the concept of virtual SW verification by evaluating Volvo's production and a concept driver steering override (DSO) for LKA systems. The DSO concept addresses the driver's interaction with the LKA system and adapts the intervention level. The driver's activation is quantified though the steering torque and road/vehicle information. Two different test-runs per DSO strategy are presented and the real-car (physical) testing results are reproduced in simulation. Both the real and postprocessed simulation results show: 1) the importance of the override strategy on the LKA benefits; and 2) the importance of computer-aided engineering for studying/designing ADAS.
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| 7. |
- Sundell, Jonas, 1984, et al.
(författare)
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A framework for Risk Assessment of Groundwater Drawdown Induced Subsidence
- 2015
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Ingår i: 5th International Symposium on Geotechnical Safety and Risk (ISGSR). - Amsterdam : Ios Press. - 9781614995807 ; , s. 256-262
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Konferensbidrag (refereegranskat)abstract
- Sub-surface constructions generally involve drainage of groundwater, which can induce land subsidence in compressible soil deposits and cause extensive damage costs in urban areas. A probabilistic framework, in accordance with the risk management framework outlined by the International Standard Organization (ISO), for assessing risks of groundwater drawdown induced subsidence is presented here. The framework consists of five modules: (1) A stratified geostatistical (Kriging) procedure for probabilistic spatial analysis of soil layers. This module is necessary for a detailed understanding of the soil stratification, drainage paths, and their potential spatial variations; (2) A stochastic hydrogeological model capable of representing possible groundwater drawdowns for a specific sub-surface construction; (3) A stochastic subsidence model; (4) A model for estimating the economic consequences and calculating the risk, i. e. the expected cost, of groundwater induced subsidence; and (5) A module for evaluating the need for additional information to reduce the risk of erroneous decisions with respect to risk acceptance criteria based on economic Value of Information Analysis (VOIA), i. e. a cost-benefit analysis (CBA) of additional information collection alternatives for suggested strategies to reduce or control subsidence. The modelled land-area is represented by a grid with calculation points. When the three first modules are linked together in a Monte Carlo-simulation, it is possible to estimate the spatial distribution of probability of subsidence and evaluate the sensitivity to different model and parameter assumptions. An estimation of the risk of subsidence is performed by combining the probability of land subsidence with the locations and expected damage costs of existing buildings across the modeled area (module 4). With sensitivity analysis, significant weaknesses can be identified and robust safety measures at locations with significant risks for subsidence can be planned for. Uncertainties can be communicated by mapping and comparing different outcomes of the model, e. g. the expected value and the 95th percentile of the risk. Together with affected stakeholders the assumptions and the outcomes of the model should be discussed - both how well the model describes the system dynamics and how safety measures should be implemented.
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| 8. |
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| 9. |
- Harmini, Sri, et al.
(författare)
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Fungal Pretreatment of Oil Palm Empty Fruit Bunch : Effect of Manganese and Nitrogen
- 2013
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Ingår i: Cellulose Chemistry and Technology. - : Editura Academiei Romane. - 0576-9787. ; 47:9-10, s. 751-757
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Tidskriftsartikel (refereegranskat)abstract
- Oil palm empty fruit bunch (OPEFB) was biologically pretreated using Pleurotus floridanus LIPIMC996 supplemented with various concentrations of manganese and nitrogen and incubated for 35 days at 30°C, and enzyme activities of manganese peroxidase (MnP) and laccase were examined. When OPEFB was supplemented with manganese, the highest lignin reduction was achieved up to 25.0±5.6% at the addition of 200 μg Mn2+/g OPEFB.In addition, Pleurotus floridanus LIPIMC996 grew best on OPEFB supplemented with 800 μg Mn2+/g OPEFB. When OPEFB was supplemented with nitrogen, the highest lignin reduction was achieved up to 27.2± 3.5% at the addition of 20 mM nitrogen. The best growth of Pleurotus floridanus was also achieved with the addition of 20 mM nitrogen. The addition of nitrogen and manganese on OPEFB did not significantly affect the activity of MnP and laccase.
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| 10. |
- Kish, L. B., et al.
(författare)
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Facts and myths about zero-point thermal noise, and information entropy versus thermal entropy
- 2017
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Ingår i: 2017 International Conference on Noise and Fluctuations (ICNF). - New York : IEEE. - 9781509027606 - 9781509027613
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Konferensbidrag (refereegranskat)abstract
- In this talk, we are briefly surveying our recent results [1-3] about two very popular yet often misunderstood concepts in physical informatics: (i) The existence of Johnson noise at near to absolute zero temperature has been debated many times yet it is generally accepted [1]. We point out the fundamental problems [2] with the particular approach the related quantum theories [4] of Fluctuation-Dissipation Theorem are using. Then we prove that the existence of zero-point noise would allow the construction of a perpetual motion machine [1]. Finally, we cite early works pointing out that the observed “zeropoint” noise in experiments [7] with phase-sensitive linear amplifiers is an amplifier-noise [5,6] due to the uncertainty principle, and it does not exist in the resistor in an objective way, independently from the measurement [1,2]. Thus a correct derivation of the Fluctuation-Dissipation Theorem must include [1] the type of experimental setup used for the measurement. (ii) The general opinion is that information entropy and thermal entropy are interchangeable. This belief triggered Brillouin's negentropy principle of information [8], and Landauer's claimed principle [9] about energy dissipation during information erasure that has been debated on many occasions [10-19]. Here we show the newest and perhaps the simplest arguments [3] proving that the two types of entropies are apples and oranges and are not interchangeable.
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