| 61. |
- Bor, Martin, et al.
(författare)
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Do LoRa Low-Power Wide-Area Networks Scale?
- 2016
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Ingår i: Proceedings of the 19th ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems. - New York, NY, USA : ACM. - 9781450345026 ; , s. 59-67
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Konferensbidrag (refereegranskat)abstract
- New Internet of Things (IoT) technologies such as LongRange (LoRa) are emerging which enable power ecientwireless communication over very long distances. Devicestypically communicate directly to a sink node which removesthe need of constructing and maintaining a complex multi-hop network. Given the fact that a wide area is coveredand that all devices communicate directly to a few sinknodes a large number of nodes have to share the commu-nication medium. LoRa provides for this reason a rangeof communication options (centre frequency, spreading fac-tor, bandwidth, coding rates) from which a transmitter canchoose. Many combination settings are orthogonal and pro-vide simultaneous collision free communications. Neverthe-less, there is a limit regarding the number of transmitters aLoRa system can support. In this paper we investigate thecapacity limits of LoRa networks. Using experiments wedevelop models describing LoRa communication behaviour.We use these models to parameterise a LoRa simulation tostudy scalability. Our experiments show that a typical smartcity deployment can support 120 nodes per 3.8 ha, which isnot sucient for future IoT deployments. LoRa networkscan scale quite well, however, if they use dynamic commu-nication parameter selection and/or multiple sinks.
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| 62. |
- Braun, Torsten, et al.
(författare)
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Power saving in wireless ad hoc networks without synchronization
- 2005. - 1
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Ingår i: 5th Scandinavian Workshop on Wireless Ad Hoc Networks (ADHOC'05).
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Konferensbidrag (refereegranskat)abstract
- Power saving strategies generally attempt to maximize the time that nodes spend in a low power consumption sleep state. Such strategies often require the sender to notify the receiver about pending traffic using some form of traffic announcement. Although asynchronous traffic announcement mechanisms are particularly suitable for the ad hoc environment, they also provide relatively limited power savings. This paper proposes a mechanism that improves the efficiency of asynchronous traffic announcement mechanisms by reducing the proportion of time that nodes need to spend awake, while still maintaining good connectivity properties. The mechanism is based on allowing traffic announcements to be rebroadcast by neighbouring nodes.
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| 63. |
- Breijaert, T. C., et al.
(författare)
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Self-assembly of ferria – nanocellulose composite fibres
- 2022
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Ingår i: Carbohydrate Polymers. - : Elsevier Ltd. - 0144-8617 .- 1879-1344. ; 291
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Tidskriftsartikel (refereegranskat)abstract
- An environmentally benign synthesis of a magnetically responsive carboxymethylated cellulose nanofibril-based material is reported. Applied experimental conditions lead to the in-situ formation of magnetite nanoparticles with primary particle sizes of 2.0–4.0 nm or secondary particles of 3.6–16.4 nm depending on whether nucleation occurred between individual carboxymethylated cellulose nanofibrils, or on exposed fibril surfaces. The increase in magnetite particle size on the cellulose fibril surfaces was attributed to Ostwald ripening, while the small particles formed within the carboxymethyl cellulose aggregates were presumably due to steric interactions. The magnetite nanoparticles were capable of coordinating to carboxymethylated cellulose nanofibrils to form large “fibre-like” assemblies. The confinement of small particles within aggregates of reductive cellulose molecules was most likely responsible for excellent conservation of magnetic characteristics on storage of this material. The possibility for using the material in drug delivery applications with release rate controlled by daylight illumination is presented. © 2022 The Author(s)
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| 64. |
- Broström, Tor, et al.
(författare)
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A method to assess the potential for and consequences of energy retrofits in Swedish historic buildings
- 2014
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Ingår i: The Historic Environment. - : Maney Publishing. - 1756-7505 .- 1756-7513. ; 5:2, s. 150-166
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Tidskriftsartikel (refereegranskat)abstract
- Tor Broström is a Professor in Conservation at Uppsala University, Campus Gotland, Sweden. With a background in engineering, his research focuses on indoor climate and energy conservation in historic buildings. He is coordinator of the Swedish national research programme on energy efficiency in historic buildings. Petra Eriksson, is a lecturer and PhD candidate in conservation at Uppsala University, Campus Gotland, Sweden. Petra has a background in the applied field of conservation and her research is in the field of heritage conservation in relation to energy efficiency. Linn Liu is a PhD candidate in the Division of Energy Systems, Department of Management and Engineering at Linköping University, Sweden. Her research area is within energy efficiency and cost efficiency of multifamily buildings and historic buildings. Patrik Rohdin is Associate Professor in the Division of Energy Systems, Department of Management and Engineering at Linköping University, Sweden. Patrik is conducting research related to energy efficiency in the built environment and building simulation and is active within the national interdisciplinary research programme, program energy systems. Bahram Moshfegh is a Professor and Head of the Division of Energy Systems, Department of Management and Engineering at Linköping University, Sweden. Professor Moshfegh has been active in the following research areas: mathematical modelling and measuring techniques for air and energy flow in buildings, energy-efficient HVAC systems and local and regional energy systems. Fredrik Ståhl is Senior Researcher in the Department of Energy Technology at SP Swedish Technical Research Institute. Currently, his research is focused on energy efficiency in historic buildings. The Swedish research project 'Potential and Policies for Energy Efficiency in Swedish Historic Buildings' aims to investigate the interdependency between political energy targets and effects on the built heritage. The fi rst part of this paper presents an iterative and interactive method to assess the potential for and consequences of improving the energy performance in a stock of historic buildings. Key elements in the method are: categorisation of the building stock, identifying targets, assessment of measures, and life-cycle cost optimisation. In the second part of the paper, the method is applied to a typical Swedish building. The selected case study shows how the method allows for an interaction between the quantitative assessment of the technoeconomic optimisation and the qualitative assessment of vulnerability and other risks. Through a multidisciplinary dialogue and iteration it is possible to arrive at a solution that best balances energy conservation and building conservation in a given decision context.
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| 65. |
- Buljan, Maja, et al.
(författare)
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A Tale of Four Parsers : Methodological Reflections on Diagnostic Evaluation and In-Depth Error Analysis for Meaning Representation Parsing
- 2022
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Ingår i: Language Resources and Evaluation. - : Springer Science and Business Media LLC. - 1574-020X .- 1574-0218. ; 56:4, s. 1075-1102
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Tidskriftsartikel (refereegranskat)abstract
- We discuss methodological choices in diagnostic evaluation and error analysis in meaning representation parsing (MRP), i.e. mapping from natural language utterances to graph-based encodings of semantic structure. We expand on a pilot quantitative study in contrastive diagnostic evaluation, inspired by earlier work in syntactic dependency parsing, and propose a novel methodology for qualitative error analysis. This two-pronged study is performed using a selection of submissions, data, and evaluation tools featured in the 2019 shared task on MRP. Our aim is to devise methods for identifying strengths and weaknesses in different broad families of parsing techniques, as well as investigating the relations between specific parsing approaches, different meaning representation frameworks, and individual linguistic phenomena—by identifying and comparing common error patterns. Our preliminary empirical results suggest that the proposed methodologies can be meaningfully applied to parsing into graph-structured target representations, as a side-effect uncovering hitherto unknown properties of the different systems that can inform future development and cross-fertilization across approaches.
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| 66. |
- Bånkestad, Maria, et al.
(författare)
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Carbohydrate NMR chemical shift prediction by GeqShift employing E(3) equivariant graph neural networks
- 2024
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Ingår i: RSC Advances. - : Royal Society of Chemistry. - 2046-2069. ; 14:36, s. 26585-26595
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Tidskriftsartikel (refereegranskat)abstract
- Carbohydrates, vital components of biological systems, are well-known for their structural diversity. Nuclear Magnetic Resonance (NMR) spectroscopy plays a crucial role in understanding their intricate molecular arrangements and is essential in assessing and verifying the molecular structure of organic molecules. An important part of this process is to predict the NMR chemical shift from the molecular structure. This work introduces a novel approach that leverages E(3) equivariant graph neural networks to predict carbohydrate NMR spectral data. Notably, our model achieves a substantial reduction in mean absolute error, up to threefold, compared to traditional models that rely solely on two-dimensional molecular structure. Even with limited data, the model excels, highlighting its robustness and generalization capabilities. The model is dubbed GeqShift (geometric equivariant shift) and uses equivariant graph self-attention layers to learn about NMR chemical shifts, in particular since stereochemical arrangements in carbohydrate molecules are characteristics of their structures.
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| 67. |
- Cai, Gui-Hong, et al.
(författare)
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Fungal DNA, allergens, mycotoxins and associations with asthmatic symptoms among pupils in schools from Johor Bahru, Malaysia
- 2011
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Ingår i: Pediatric Allergy and Immunology. - : Wiley. - 0905-6157 .- 1399-3038. ; 22:3, s. 290-297
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Tidskriftsartikel (refereegranskat)abstract
- P>While there is a large variation of prevalence of asthma symptoms worldwide, what we do know is that it is on the rise in developing countries. However, there are few studies on allergens, moulds and mycotoxin exposure in schools in tropical countries. The aims were to measure selected fungal DNA, furry pet allergens and mycotoxins in dust samples from schools in Malaysia and to study associations with pupils' respiratory health effects. Eight secondary schools and 32 classrooms in Johor Bahru, Malaysia were randomly selected. A questionnaire with standardized questions was used for health assessment in 15 randomly selected pupils from each class. The school buildings were inspected and both indoor and outdoor climate were measured. Dust samples were collected by cotton swabs and Petri dishes for fungal DNA, mycotoxins and allergens analysis. The participation rate was 96% (462/480 invited pupils), with a mean age of 14 yr (range 14-16). The pupils mostly reported daytime breathlessness (41%), parental asthma or allergy (22%), pollen or pet allergy (21%) and doctor-diagnosed asthma (13%) but rarely reported night-time breathlessness (7%), asthma in the last 12 months (3%), medication for asthma (4%) or smoking (5%). The inspection showed that no school had any mechanical ventilation system, but all classrooms had openable windows that were kept open during lectures. The mean building age was 16 yr (range 3-40) and the mean indoor and outdoor CO2 levels were 492 ppm and 408 ppm, respectively. The mean values of indoor and outdoor temperature and relative humidity were the same, 29 degrees C and 70% respectively. In cotton swab dust samples, the Geometric Mean (GM) value for total fungal DNA and Aspergillus/Penicillium (Asp/Pen) DNA in swab samples (Cell Equivalents (CE)/m2) was 5.7*108 and 0.5*108, respectively. The arithmetic mean (CE/m2) for Aspergillus versicolor DNA was 8780, Stachybotrys chartarum DNA was 26 and Streptomyces DNA was 893. The arithmetic means (pg/m2) for the mycotoxins sterigmatocystin and verrucarol were 2547 and 17, respectively. In Petri dish dust samples, the GM value for total fungal DNA and Asp/Pen DNA (CE/m2 per day) was 9.2*106 and 1.6*106, respectively. The arithmetic mean (CE/m2 per day) for A. versicolor DNA was 1478, S. chartarum DNA was 105 and Streptomyces DNA was 1271, respectively. The GM value for cat (Fel d1) allergen was 5.9 ng/m2 per day. There were positive associations between A. versicolor DNA, wheeze and daytime breathlessness and between Streptomyces DNA and doctor-diagnosed asthma. However, the associations were inverse between S. chartarum DNA and daytime breathlessness and between verrucarol and daytime breathlessness. In conclusion, fungal DNA and cat allergen contamination were common in schools from Malaysia and there was a high prevalence of respiratory symptoms among pupils. Moreover, there were associations between levels of some fungal DNA and reported respiratory health in the pupils.
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| 68. |
- Campeau, Audrey, et al.
(författare)
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Current forest carbon fixation fuels stream CO 2 emissions
- 2019
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Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Stream CO 2 emissions contribute significantly to atmospheric climate forcing. While there are strong indications that groundwater inputs sustain these emissions, the specific biogeochemical pathways and timescales involved in this lateral CO 2 export are still obscure. Here, via an extensive radiocarbon ( 14 C) characterisation of CO 2 and DOC in stream water and its groundwater sources in an old-growth boreal forest, we demonstrate that the 14 C-CO 2 is consistently in tune with the current atmospheric 14 C-CO 2 level and shows little association with the 14 C-DOC in the same waters. Our findings thus indicate that stream CO 2 emissions act as a shortcut that returns CO 2 recently fixed by the forest vegetation to the atmosphere. Our results expose a positive feedback mechanism within the C budget of forested catchments, where stream CO 2 emissions will be highly sensitive to changes in forest C allocation patterns associated with climate and land-use changes. © 2019, The Author(s).
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| 69. |
- Cappelletto, Elia, et al.
(författare)
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Impact of Post Manufacturing Handling of Protein-Based Biologic Drugs on Product Quality and User Centricity
- 2024
-
Ingår i: Journal of Pharmaceutical Sciences. - : Elsevier. - 0022-3549 .- 1520-6017.
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Tidskriftsartikel (refereegranskat)abstract
- This article evaluates the current gaps around the impact of post-manufacturing processes on the product qualities of protein-based biologics, with a focus on user centricity. It includes the evaluation of the regulatory guidance available, describes a collection of scientific literature and case studies to showcase the impact of post-manufacturing stresses on product and dosing solution quality. It also outlines the complexity of clinical handling and the need for communication, and alignment between drug providers, healthcare professionals, users, and patients. Regulatory agencies provide clear expectations for drug manufacturing processes, however, guidance supporting post-product manufacturing handling is less defined and often misaligned. This is problematic as the pharmaceutical products experience numerous stresses and processes which can potentially impact drug quality, safety and efficacy. This article aims to stimulate discussion amongst pharmaceutical developers, health care providers, device manufacturers, and public researchers to improve these processes. Patients and caregivers' awareness can be achieved by providing relevant educational material on pharmaceutical product handling.
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| 70. |
- Carlos, Pérez-Penichet, et al.
(författare)
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Battery-Free 802.15.4 Receiver
- 2018
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Ingår i: 2018 17th ACM/IEEE International Conference on Information Processing in Sensor Networks (IPSN). - : IEEE. - 9781538652985 ; , s. 164-175
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Konferensbidrag (refereegranskat)abstract
- We present the architecture of an 802.15.4 receiver that, for the first time, operates at a few hundred microwatts, enabling new battery-free applications. To reach the required micro-power consumption, the architecture diverges from that of commodity receivers in two important ways. First, it offloads the power-hungry local oscillator to an external device, much like backscatter transmitters do. Second, we avoid the energy cost of demodulating a phase-modulated signal by treating 802.15.4 as a frequency-modulated one, which allows us to receive with a simple passive detector and an energy-efficient thresholding circuit. We describe a prototype that can receive 802.15.4 frames with a power consumption of 361 μW. Our receiver prototype achieves sufficient communication range to integrate with deployed wireless sensor networks (WSNs).We illustrate this integration by pairing the prototype with an 802.15.4 backscatter transmitter and integrating it with unmodified 802.15.4 sensor nodes running the TSCH and Glossy protocols.
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