235 research outputs found
Acoustic manipulation of sound with soft material-based actuators
No full textThis thesis describes a unique parabolic acoustic manipulator with an inflatable structure, which has high gain and directivity. We created a morphable elastomeric reflecting surface with a diameter of 14 cm (6 in). Applying vacuum deforms the device into a concave structure, which provides directional amplification of incoming acoustic waves. In addition, the author characterized the impedance of the soft material employed in the acoustic reflector, Ecoflex 00-10, in an impedance tube. Ecoflex 00-10 has a measured reflection coefficient of approximately 0.9 at frequencies ranging from 500 Hz to 5000 Hz. This new characterization suggests this class of silicone-based elastomers is capable of advanced morphable devices to manipulate sound. Simulations also demonstrate that the soft reflecting surface is capable of transformation into a set of desired parabolic shapes between an initial planar geometry (neutral position) and a configuration with maximum curvature. With an applied vacuum, the membrane reaches its maximum deformation limited by the aluminum housing. At this stage of actuation, experimental results show the deformed membrane has similar gain and directionality (polar response) as rigid parabolic reflectors. This type of system might find future uses for adjustable parabolic microphones and long-range communication devices.M.S.Includes bibliographical referencesby Yanjun Wan
AudioEar: Single-View Ear Reconstruction for Personalized Spatial Audio
No full textAbstract
We introduce AudioEar3D, a high-quality 3D ear dataset consisting of 112 point cloud ear scans with RGB images, to benchmark the ear reconstruction task. We further collect a 2D ear dataset composed of 2,000 images, each one with manual annotation of occlusion and 55 landmarks, named AudioEar2D. To our knowledge, both datasets have the largest scale and best quality of their kinds for public use.
Usage
The code is publicly available at https://github.com/seanywang0408/AudioEar.
The file organization of AudioEar3D is as following:
AudioEar3D
├── 001
# left ear data
├── left.jpg # processed RGB image of left ear
├── left.ply # processed point cloud of left ear in canonical pose (frontal view is negative-X and upper view is positive-Z)
├── left.json # 56 landmark annotations of image
├── mask_left.jpg # mask generated by the outer landmarks
├── masked_left.jpg # exclude background in left.jpg using mask_left.jpg
├── masked_left.png # exclude background in left.jpg using mask_left.jpg, but with four channels of RGB-A
# right ear data
├── right.jpg
...
├── masked_right.png
├── 002
...
├── 056
The file organization of AudioEar2D is as following:
AudioEar2D
├── 00000.png # processed ear image
├── 00000.json # landmark annotations
...
├── 69985.png # the index is aligned with the data source FFHQ.
├── 69985.json
Citation
If you find this project useful, currently please cite the paper as:
Xiaoyang Huang, Yanjun Wang, Yang Liu, Bingbing Ni, Wenjun Zhang, Jinxian Liu, Teng Li. "AudioEar: Single-View Ear Reconstruction for Personalized Spatial Audio". arXiv preprint arXiv:2301.12613, 2023.
or using bibtex:
@article{huang2023audioear,
title={AudioEar: Single-View Ear Reconstruction for Personalized Spatial Audio},
author={Huang, Xiaoyang and Wang, Yanjun and Liu, Yang and Ni, Bingbing and Zhang Wenjun and Liu Jinxian and Li, Teng},
journal={arXiv preprint arXiv:2301.12613},
year={2023}
}
License
The dataset is licensed under Creative Commons Attribution 4.0 International (CC BY 4.0).
The code is under Apache-2.0 License.
Mirror Link
We recommend users to download the data from Zenodo official link. However, if you find any downloading problem, you can also use this mirror link from Google Drive.
Changelog
v1.0: Initial repository of AudioEar3D and AudioEar2D
Imaging the spread of reversible brain inactivations using fluorescent muscimol
No full textAuthor manuscript. Published in final edited form as:
J Neurosci Methods. 2008 June 15; 171(1): 30–38
Recommended from our members
Understanding Visitors’ Cognitive Appraisals at Meteorological Destination
No full text1) Hanqin Qiu
Distinguished Professor, College of Tourism and Service Management, Nankai University. Her research interests are tourist consumer behavior and tourism development and policy.
2) Xiaowei Lei
Postgraduate Student, College of Tourism and Service Management, Nankai University. Her research interests are meteorological tourism, consumer behavior and tourism destination marketing.
3) Yujia Chen
Postdoctoral Fellow, College of Tourism and Service Management, Nankai University. Her research interests are consumer behavior and decision-making, service failure and service recovery.
4) Yanjun Chen(corresponding author)
Postgraduate Student, College of Tourism and Service Management, Nankai University. Her research interests are meteorological tourism, consumer behavior and tourism destination marketing.While the uncertainty is increasingly becoming a challenge in the supply of meteorological landscape for destinations, little is known about the emotional experiences and behavioural tendencies of visitors triggered by this uncertainty under landscape viewing. Grounded upon cognitive appraisal theory, this study conducted in-depth interviews with 31 visitors who had experience of seeing the meteorological landscape to solicit their perceptions and appraisals of uncertainty. Results revealed that the uncertainty influenced visitors’ cognitive appraisal process, including cognitive appraisal, emotional experiences, coping strategies, and behavioural tendency in the future. Specifically, five positive and four negative emotions, and two coping strategies were identified. In addition, four types of revisit intention were also discussed and summarised. Interestingly, this study found that positive emotions didn’t always trigger positive behavioural tendencies, while negative emotions may also contribute positively to behavioural tendencies. Theoretical and practical implications for destination management are also offered
Production de γ-valerolactone par hydrogénation d'acide lévulinique ou de lévulinates d'alkyle : étude calorimétrique et cinétique
No full textLes énergies fossiles jouent un rôle fondamental dans l'économie, la société et la politique. Il existe différentes énergies renouvelables pouvant présenter une alternative telles le solaire, l'éolien, l'hydro-électrique ou encore la biomasse. Parmi ces énergies renouvelables, la biomasse est la seule source de carbone pouvant être utilisée pour la production de carburants, produits chimiques ou matériaux. Parmi les produits chimiques issus de la biomasse, la production de molécules plateformes comme l'acide lévulinique (AL) et ses esters est une voie attractive. Ces molécules peuvent être obtenues par solvolyse de la cellulose ou hémicellulose. L’hydrogénation de ces molécules plateformes conduit à la production de γ-valerolactone (GVL) qui peut aussi être considéré comme une molécule plateforme. Pour favoriser le passage à l'échelle industrielle et trouver les conditions opératoires optimales vis-à-vis de la sécurité et des coûts de production, les questions suivantes doivent être répondues : - Quel est le risque thermique de cette réaction d' hydrogénation? ; - Quel réactif doit-on utiliser : AL ou ses esters? ; - Afin de favoriser l’intégration énergétique, comment mesurer les enthalpies de réactions? Dans un premier temps l'évaluation des risques thermiques pour l' hydrogénation de l’acide lévulinique en GVL catalysée par Ru/C dans l'eau a été effectuée. Un modèle cinétique simple incluant un bilan énergétique en condition pseudo-adiabatique a été développé pour estimer les constantes cinétiques et les paramètres de risque thermique. Par cette étude, il a été possible de déterminer des conditions opératoires sûres pour ce système afin de prévenir les emballements thermiques. Dans un deuxième temps, une approche structure-réactivité a été effectuée en utilisant le concept de relation linéaire de l’énergie libre, à savoir l’équation de Taft. Cette équation a été utilisée pour l'hydrogénation de l'acide lévulinique et de ses esters en GVL catalysée par Ru/C. Le GVL a été utilisé comme solvant pour solubiliser les différents réactifs : AL, lévulinate de méthyle (LM), d'éthyle (LE) et de n-butyle (LB). Il a été démontré que la première étape cinétique, à savoir l'hydrogénation de LA, LM, LE ou LB en leurs intermédiaires et la cinétique de la deuxième étape, à savoir la cyclisation suivent l'équation de Taft. Les effets polaires et stériques ont été évalués et il a été montré que l'effet polaire gouverne ces étapes réactionnelles. La dernière partie de cette thèse consiste à estimer les enthalpies de réaction par calorimétrie. L'estimation de ces constantes thermodynamiques peut s'avérer complexe parce que le GVL est utilisé comme solvant et qu'il n'y a pas d'informations sur les intermédiaires. L’hydrogénation du lévulinate de méthyle a été sélectionnée pour cette étude. Une méthode utilisant les données calorimétriques et analyse chimique a permis d’évaluer l'enthalpie réactionnelle globale et les enthalpies des 2 réactions consécutives. Il a été montré que l'enthalpie globale a une valeur de -51.5 kJ/mol de GVL produits montrant que le système est dans sa globalité exothermique. L’enthalpie d'hydrogénation a été estimée à -58-66 kJ/mol de LM consommé et celle de cyclisation à +7,16 kJ/mol de GVL produits.Fossil energy plays a fondamental role in the economy, society and politics. Till now, different renewable energy are explored to be an alternative for energy supply, such as wind, solar, hydro and biomass energy. Among these renewable energy, biomass is regarded as the organic carbon source which can be applied for production of fuels, chemicals or materials. Among the bio-based chemicals, production of platform molecules such as levulinic acid (LA) and its esters is one of attractive way for biomass valorization. LA and its esters can be obtained through hydrolysis and alcoholysis of cellulose or hemicellulose. By further hydrogenation, γ-valerolactone (GVL) is produced and it is also regarded as a platform molecule for further upgrading to biofuels and chemicals with wide application. To scale-up the hydrogenation reaction and to find the optimum operating conditions towards safety and cost, the following questions must be answered : - What is the thermal risk of this reaction? ; - Which starting materials to choose (LA or esters)? ; - For a better energy integration of this process, how to measure the reaction enthalpies? Herein, at first, thermal risk assessment for hydrogenation of LA to GVL catalyzed by Ru/C in water was performed. A simplified kinetic model including energy balance under near-adiabatic conditions was developed to estimate the kinetic constants and thermal risk parameters of this reaction system. Through this thermal risk assessment, it was possible to know the safe operation conditions for this reaction system, i.e., preventing the risk of thermal runaway. Secondly, a structure-reactivity approach was carried out using the concept of Linear Free Energy Relationships (LFER). i.e., Taft equation. The Taft equation (LFER) was applied to hydrogenation of LA and its corresponding esters to GVL catalyzed over Ru/C. GVL was used as a solvent to allow the solubility of the different reactants, namely, LA, methyl levulinate (ML), ethyl levulinate (EL) and n-butyl levulinate (BL). It was demonstrated that the kinetics of the first step, i.e., hydrogenation of LA, ML, EL or BL to the corresponding intermediates and the kinetics of the second step, i.e., ring-closure follow Taft equation. The polar and steric effect of the substituents were evaluated, and it is shown that polar effect governs the kinetics of both reaction steps. Thirdly, the estimation of reaction enthalpies by calorimetry experiments was done. The estimation of such thermodynamic constants by using different thermodynamic models can be hazardous, because in this study GVL was used as a solvent and there are no data concerning the intermediates. Hydrogenation of methyl levulinate (ML) to GVL catalyzed over Ru/C was selected for this study. A method which links calorimetry measurement with composition analysis was developed to determine the reaction enthalpies of the overall reaction and two consecutive steps. It was found that the overall reaction enthalpy was -51.5 kJ/mol of GVL produced, which indicates that the reaction for production of GVL from ML is exothermic. The reaction enthalpy for the first hydrogenation step was calculated to be -58.66 kJ/mol of ML consumed, and for the reaction enthalpy for the second ring-closure step was calculated to be +7.16 kJ/mol of GVL produced
Accurate Localization with Ultra-Wideband Ranging for Multi-Robot Systems
No full textRÉSUMÉ: Avec l'avancement de la technologie matérielle et logicielle, l'application de l'automatisation et de la robotique se développe rapidement. Les systèmes multi-robots sont particulièrement prometteurs en raison de leur grande efficacité et robustesse. De tels systèmes peuvent être utilisés pour aider les humains à effectuer efficacement des tâches dangereuses ou pénibles, telles que l'intervention en cas de catastrophe, l'exploration souterraine, etc. Pour déployer un système multi-robot dans un environnement sans GPS, la coordination des robots dans le système est un défi crucial. Chaque robot doit avoir une estimation précise de sa propre position pour permettre aux robots du système de collaborer pour la réalisation de leur tâche. Comme cette direction de recherche est relativement nouvelle, les approches existantes ne sont pas encore abouties. Elles consistent principalement en des systèmes centralisés qui reposent sur des signaux GPS. La dépendance sur un signal GPS limite l'application aux espaces extérieurs ouverts. De plus, les systèmes centralisés sont confrontés au risque d'un point de défaillance unique, qui limite la robustesse du système. Par ailleurs, un système centralisé n'est pas toujours approprié à une taille grandissante, comme lors d'ajout de nouveaux groupes de robots ou lors de la fusion de différents groupes. Par conséquent, une solution distribuée, décentralisée, et adaptée à de larges groupes de tailles variables pouvant produire une estimation et un suivi du positionnement des robots dans un environnement sans GPS est souhaitée. Dans ce travail, nous adoptons une stratégie descendante pour relever ces défis. ABSTRACT: With the advancement of hardware and software technology, the everyday applications of automation and robotics are developing rapidly. Multi-robot systems are particularly promising because of their high efficiency and robustness. Such systems can be used to assist humans in performing dangerous or strenuous tasks, such as disaster response, subterranean exploration, etc. To deploy a multi-robot system in an environment without a global positioning system (GPS), coordinating the robots in the system is a crucial challenge. Each robot needs to have the correct tracking of its own and its teammates positions to enable the robots to cooperate. Because this research direction is relatively new, there are not many mature methods: existing approaches are mainly centralized systems that rely on GPS signals. The dependence on GPS restricts the application to the outdoors or indoor spaces with expensive infrastructure. Centralized systems also face the risk of a single point of failure, which is not acceptable for critical systems. In addition, centralized systems can be hard to scale both statically and dynamically (e.g. adding new groups of robots or merging different groups). Therefore, a distributed and scalable solution with accurate positioning and tracking in a GPS-denied environment is desired. In this work, we follow a top-down strategy to address these challenges
Pomegranate juice consumption reduces simulated ischemic stroke damage and increases brain antioxidant status in rats
No full textPomegranate phytochemicals / Navindra P. Seeram ... [et al.] -- Antioxidative properties of pomegranate : in vitro studies / Mira Rosenblat and Michael Aviram -- Bioavailability of pomegranate polyphenols / Francisco A. Tom?s-Barber?n, Navindra P. Seeram, and Juan Carlos Esp?n -- Protection against cardiovascular disease / Bianca Fuhrman and Michael Aviram -- Protection against stroke / Marva I. Sweeney-Nixon -- Anticancer potential of pomegranate / Shishir Shishodia ... [et al.] -- Molecular mechanisms of chemoprevention of cancer by pomegranate / Deeba Syed ... [et al.] -- Pomegranate and prostate cancer chemoprevention / John T. Leppert and Allan J. Pantuck -- Assessment of estrogenicity of pomegranate in an in vitro bioassay / Diane M. Harris, Emily Besselink, and Navindra P. Seeram -- Absence of significant estrogenic effects in the postmenopausal population / Michelle P. Warren ... [et al.] -- Antimicrobial activities of pomegranate / G.K. Jayaprakasha, P.S. Negi, B.S. Jena -- Commercialization of pomegranates : fresh fruit, beverages, and botanical extracts / Navindra P. Seeram, Yanjun Zhang, and David Heber -- Pomegranates: a botanical perspective / David W. Still -- Postharvest biology and technology of pomegranates / Adel A. Kader
Modelling and simulation of a trombe wall - Analysis for Nordic and Chinese climates
No full textI denne oppgaven blir en ventilert solvarmevegg analysert ved bruk av simuleringsprogramvaren TRNSYS, og Matlab. Arbeidet ble utført i samarbeid med Shanghai Jiao Tong University i Kina, som en del av Joint Research Centre in Sustainable Energy på NTNU og SJTU. Kandidaten sitt opphold i Shanghai, samt eksperimenter utført på Green Energy Lab på SJTU ble avbrutt som følge av Corona-viruspandemien.
I følge the International Energy Association så representerer byggenæringen 36 prosent av all årlig energibruk i verden. Dette tallet er forventet å stige, som følge av at totalt antall utbygd areal i verden stiger og at tilgang til energi i utviklingsland stiger hurtig. I en tid med mye politisk fokus på hvert lands total utslipp er arbeidet med å senke utslippene sentrale. Da er en mer miljøvennlig byggenæring veldig viktig. En måte å redusere byggenæringens utslipp på, er å bruke fornybare energykilder på kostnadsbesparende, enkle og miljøvennlige måter. I denne oppgaven blir bruken av en enkel solvarmevegg presentert. Denne solvarmeveggen blir kalt trombevegg.
I oppgaven presenteres et litteraturstudium utført for å få dypere innsikt i dagens status i den norske og
europeiske byggenæringen, energibruk i byggenæringen globalt, bruk av solenergi i bygg og studier utført på
trombevegglignende systemer. Det finnes mange studier på trombevegger, og det er tydelig at trombevegger
har potensiale. IDA ICE, Polysun, TRNSYS og Matlab blir vurdert som mulig simuleringsprogramvare til
prosjektet. Videre blir grunnleggende teori bak varmeoverføring gjennom stråling, konduksjon og konveksjon
gjennomgått, samt det matematiske grunnlaget til komponentene brukt i simuleringen. Grunnleggende teori og kilder som legger grunnlaget for trombeveggsimuleringen blir gjennomgått. Basisen for Matlab-scriptet blir også gjennomgått.
I kapittel 4, Method, presenteres arbeidet med å bygge opp simuleringen kronologisk. For å bedre finne feil og
mangler i simuleringen underveis bygges simuleringen opp delvis. Det enkle kontrollsystemet blir også
presentert. Enkel validering av simuleringen blir også gjennomført, ved brukt av eksperimenter funnet i litteratur.
En analyse av trombeveggens effekt i Kina og Norden blir gjennomført og presentert. Gøteborg i Sverige, Reykjavik på Island og Kashgar og Shanghai i Kina er valgt som lokasjoner. Dette er for å representere et varmt og et kaldt område fra både Kina og Norden. En årlig simulering, samt ukentlig sommer- og vintersimuleringer, blir gjennomført på alle fire lokasjoner. For å bedre hjelpe arbeidet med videreutvikling av trombevegger presenteres påvirkningen trombeveggens og luftåpningens tykkelse har på effekten av veggen, i Shanghai og Gøteborg. En drivhusgassanalyse blir gjennomført, og alle lokasjonene blir kalkulert som miljøvennlige. Til slutt blir simuleringens treffsikkerhet gjennomgått, og lærdommen fra resultatene presentert videre. Anbefalt videre arbeid med trombevegger presenteres til slutt.
Matlab-scriptet som legger grunnlaget for simuleringen legges ved i sin helhet.According to the International Energy Association, the building sector represents 36 percent of the yearly total final energy demand in the world. This number is expected to continue to rise, with the ever-increasing global building floor area and the rising demand for and access to energy in developing countries being two of the main reasons. And, in today's political landscape, with the growing global focus of lowering each country's total energy use, the benefits of a more energy-efficient building sector is evident. One way to reduce the energy need of a building, is to utilize some of the renewable energy sources in a cost-effective, realistic and environmentally friendly manner. In this assignment, the use of a simple solar power installation will be researched. The installation is called a trombe wall.
The work presented in this report consist of a literature review, a review of the relevant theory, the setup of a simulation, validation, calibration, and results from the simulation and an assessment of further work on this project. The literature review section begin by presenting the current status of the research and regulations on the energy demand of buildings. Subsequently the worldwide research into trombe wall, solar heating wall and solar chimney technology is presented, to clarify which aspects of the trombe wall that is firmly established in literature and which should be researched further by the author. At the end, different simulation software is presented, as choosing a fitting simulation software is crucial for the project. IDA ICE, Solar Plus and TRNSYS are found to be the three most relevant software.
In the theory section, basic physical mechanics and governing equations in the system is presented. Radiation, conduction and convection heat transfer modes is presented briefly. Then, some aspect of the simulation of building simulation are presented. It is presented generally, and specifically on how TRNSYS operates. The mathematical foundations of different components of the TRNSYS simulation are also presented. The framework for doing green house gas emission calculations is presented as well.
The control strategy for the simulation is presented as well. To validate the simulation, some recreation of experiments from literature is performed and presented in this section.
In the method section, the work with producing the simulation is presented chronologically. The simulation was defined step by step, with the purpose of testing and verifying the simulation by comparison to literature at each major step. This was to prevent large inaccuracies in vital components of the simulation, and to ease error detection when creating the simulation. Here, the viability of each simulation is discussed, and key parameters are measured against relevant numbers from sources presented in the literature review. A more thorough validation is performed as well, by replicating experiments found in litterature.
The result section details the results from the different simulation. Four different locations, two in China and two in the Nordic countries are simulated and presented. Summer and winter simulation for each of these locations, as well as simulations for different slit and wall sizes are presented as well. These results are discussed in this section. In the discussion section, sources of error in the simulation is presented. More broad results from the simulations is discussed as well, and further work is discussed
Estimating the duration of the Branch and Bound algorithm for 0-1 Knapsack problems
No full textThe Branch and Bound method is a very useful method for nding solutions to optimization problems. However it does come with some problems as the search tree used for the Branch and Bound algorithm can be very large in size and can result in very long processing times as well as a large memory use. There is currently no known way to exactly know how large this tree will be and how long the algorithm will take, therefore having more information on this algorithm can be of great interest.This report will look into the method used in the article Early Estimates of the Size of Branch-and-Bound Trees by Gerard Cornuejols, Miroslav Karamanov and Yanjun Li [1]. In this report their method will be tested against a specic set of problems, the 0-1 Knapsack problems. Their time estimation method will be tested against a variety of 0-1 Knapsack problems and the estimation will be compared to the real time it takes to solve the problems. This will give an idea of how good the method works for the method works for the 0-1 Knapsack problems and show any issues it might run into.Applied Mathematic
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