Journal articles on the topic 'Spatially open system'
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Hennig, D., A. D. Burbanks, A. H. Osbaldestin, and C. Mulhern. "Transient-chaos induced directed transport in a spatially-open Hamiltonian system." Journal of Physics A: Mathematical and Theoretical 43, no. 34 (July 21, 2010): 345101. http://dx.doi.org/10.1088/1751-8113/43/34/345101.
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Schlienger, Dominik, and Victor Khashchanskiy. "Immersive Spatial Interactivity in Sonic Arts: The Acoustic Localization Positioning System." Computer Music Journal 45, no. 2 (2021): 24–47. http://dx.doi.org/10.1162/comj_a_00605.
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Abstract The Acoustic Localization Positioning System is the outcome of several years of participatory development with musicians and artists having a stake in sonic arts, collaboratively aiming for nonobtrusive tracking and indoors positioning technology that facilitates spatial interaction and immersion. Based on previous work on application scenarios for spatial reproduction of moving sound sources and the conception of the kinaesthetic interface, a tracking system for spatially interactive sonic arts is presented here. It is an open-source implementation in the form of a stand-alone application and associated Max patches. The implementation uses off-the-shelf, ubiquitous technology. Based on the findings of tests and experiments conducted in extensive creative workshops, we show how the approach addresses several technical problems and overcomes some typical obstacles to immersion in spatially interactive applications in sonic arts.
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Ackermann, Jörg, Thomas Kirner, and H. L. Klapp. "Complex Pattern Formation of Simple Biochemical Amplification Reactions in Micro-Structured Flow Reactors." Zeitschrift für Naturforschung A 61, no. 1-2 (February 1, 2006): 60–68. http://dx.doi.org/10.1515/zna-2006-1-209.
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We have studied the dynamics of a simple amplification reaction in micro-structured flow reactors. The autocatalytic amplification reaction A+R → 2A serves as a model to describe the fundamental properties of amplification systems in an open reaction chamber. A constant inflow of resources R feeds the reaction and an outflow keeps the total mass constant. A characterization of the system in a well stirred reaction chamber is presented by discussing the steady states of the system and their bifurcation properties. In the non-stirred case, where the species diffuse freely in a spatially extended chamber, numerical solutions of a reaction-diffusion equation describe the dynamic behavior of the system. It turns out that inhibition reactions and death terms, which are unavoidable in micro-structured reaction chambers, play an essential role in the behavior of the system. The rich dynamical behavior shows three fundamental properties of non-variational nonlinear open systems: temporal order, such as limit cycle oscillation, spatially periodic order, and complex spatial-temporal pattern formation. The results are of special interest for recent experiments with evolutionary molecular ecosystems in micro-structured flow reactors.
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Chang, Albert, Mei Si, Samuel Chabot, Jonathan Mathews, Tomek Strzalkowski, and Jonas Braasch. "A spatially-aware dialogue system for immersive classrooms." Journal of the Acoustical Society of America 151, no. 4 (April 2022): A132. http://dx.doi.org/10.1121/10.0010883.
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Dialogue systems have become a popular research medium as recent advances in task-oriented and open-domain systems combined with deep learning technologies have increased the potential for practical applications across many disciplines. One such vein of applications involves multi-modal dialogue systems deployed in interactive spaces that seek to provide an immersive experience for participants. This project proposes a combination of spatial awareness with a multi-modal, immersive dialogue system as a potential interactive medium to provide an additional layer of immersion. The system employs an array of audio/visual sensors that tracks participants within the interactive space. It responds contextually depending on the application and information domain, for example, by displaying and sonifying conversational agents at accurate spatial locations. The current application of this system involves Mandarin language learning in which the system will act as both a learning medium and conversation augmentation system to provide students with an immersive environment to learn a language and provide real-time feedback during the learning process. This project aims to provide insight into interactive spaces for education and general conversation applications, and demonstrate the capabilities of combining spatial awareness with a multi-modal dialogue system. [Work supported by NSF IIS-1909229, IBM GATOR, and CISL.]
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Deissler, Robert J. "Spatially growing waves, intermittency, and convective chaos in an open-flow system." Physica D: Nonlinear Phenomena 25, no. 1-3 (March 1987): 233–60. http://dx.doi.org/10.1016/0167-2789(87)90103-5.
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Yu, J., L. Wu, Y. Yang, X. Lei, and W. He. "Global Data Spatially Interrelate System for Scientific Big Data Spatial-Seamless Sharing." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-6 (April 23, 2014): 125–30. http://dx.doi.org/10.5194/isprsarchives-xl-6-125-2014.
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A good data sharing system with spatial-seamless services will prevent the scientists from tedious, boring, and time consuming work of spatial transformation, and hence encourage the usage of the scientific data, and increase the scientific innovation. Having been adopted as the framework of Earth datasets by Group on Earth Observation (GEO), Earth System Spatial Grid (ESSG) is potential to be the spatial reference of the Earth datasets. Based on the implementation of ESSG, SDOG-ESSG, a data sharing system named global data spatially interrelate system (GASE) was design to make the data sharing spatial-seamless. The architecture of GASE was introduced. The implementation of the two key components, V-Pools, and interrelating engine, and the prototype is presented. Any dataset is firstly resampled into SDOG-ESSG, and is divided into small blocks, and then are mapped into hierarchical system of the distributed file system in V-Pools, which together makes the data serving at a uniform spatial reference and at a high efficiency. Besides, the datasets from different data centres are interrelated by the interrelating engine at the uniform spatial reference of SDOGESSG, which enables the system to sharing the open datasets in the internet spatial-seamless.
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Duncan, J., K. P. Davies, A. Saipai, L. Vainikolo, N. Wales, R. Varea, E. Bruce, and B. Boruff. "AN OPEN-SOURCE MOBILE GEOSPATIAL PLATFORM FOR AGRICULTURAL LANDSCAPE MAPPING: A CASE STUDY OF WALL-TO-WALL FARM SYSTEMS MAPPING IN TONGA." International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLVIII-4/W1-2022 (August 5, 2022): 119–26. http://dx.doi.org/10.5194/isprs-archives-xlviii-4-w1-2022-119-2022.
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Abstract. Pacific Island Countries (PICs) such as Tonga rely on services provided by agricultural landscapes to support livelihoods, economic activity, and food security. At the same time these landscapes face numerous pressures and risks from factors such as environmental, climate, and market changes. Accurate, spatially explicit, and timely datasets on agricultural systems is required for an array of land and agricultural management tasks. Here, the development of an open-source ICT system providing geospatial tools for landscape monitoring, developed in collaboration between geospatial researchers and Tonga’s Ministry of Agriculture, Food, and Forests (MAFF), is presented. The agile and iterative ICT for Development (ICT4D) framework used to elicit MAFF’s requirements for the ICT system is presented alongside the system architecture and case studies demonstrating its impact. A key goal of the ICT4D development process was to develop an ICT system to support MAFF from transitioning from infrequent, paper-based farm surveys to coordinated, large-team, spatially explicit digital surveying augmented by tools for analysis and reporting. The mature system architecture which includes QField and QFieldCloud, and new open-source geospatial components for spatial visualisation, analysis, and reporting is presented. Case studies where the mature tool was used by MAFF’s are presented and include: (1) how a large survey team captured spatial data for >11,000 farms for country-wide farm monitoring; and (2) how the tool informed MAFF’s landscape decision making including recovery efforts after the 2022 Hunga Tonga–Hunga Ha’apai volcano explosion. The success of the tool demonstrates the importance of stakeholder engagement and the great potential for open-source geospatial tools for landscape management and disaster response in PICs.
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Mattivi, Pietro, Salvatore Eugenio Pappalardo, Nebojša Nikolić, Luca Mandolesi, Antonio Persichetti, Massimo De Marchi, and Roberta Masin. "Can Commercial Low-Cost Drones and Open-Source GIS Technologies Be Suitable for Semi-Automatic Weed Mapping for Smart Farming? A Case Study in NE Italy." Remote Sensing 13, no. 10 (May 11, 2021): 1869. http://dx.doi.org/10.3390/rs13101869.
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Weed management is a crucial issue in agriculture, resulting in environmental in-field and off-field impacts. Within Agriculture 4.0, adoption of UASs combined with spatially explicit approaches may drastically reduce doses of herbicides, increasing sustainability in weed management. However, Agriculture 4.0 technologies are barely adopted in small-medium size farms. Recently, small and low-cost UASs, together with open-source software packages, may represent a low-cost spatially explicit system to map weed distribution in crop fields. The general aim is to map weed distribution by a low-cost UASs and a replicable workflow, completely based on open GIS software and algorithms: OpenDroneMap, QGIS, SAGA and OpenCV classification algorithms. Specific objectives are: (i) testing a low-cost UAS for weed mapping; (ii) assessing open-source packages for semi-automatic weed classification; (iii) performing a sustainable management scenario by prescription maps. Results showed high performances along the whole process: in orthomosaic generation at very high spatial resolution (0.01 m/pixel), in testing weed detection (Matthews Correlation Coefficient: 0.67–0.74), and in the production of prescription maps, reducing herbicide treatment to only 3.47% of the entire field. This study reveals the feasibility of low-cost UASs combined with open-source software, enabling a spatially explicit approach for weed management in small-medium size farmlands.
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Heinz, Carsten, Jaco Hofmann, Jens Korinth, Lukas Sommer, Lukas Weber, and Andreas Koch. "The TaPaSCo Open-Source Toolflow." Journal of Signal Processing Systems 93, no. 5 (May 2021): 545–63. http://dx.doi.org/10.1007/s11265-021-01640-8.
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AbstractThe integration of FPGA-based accelerators into a complete heterogeneous system is a challenging task faced by many researchers and engineers, especially now that FPGAs enjoy increasing popularity as implementation platforms for efficient, application-specific accelerators for domains such as signal processing, machine learning and intelligent storage. To lighten the burden of system integration from the developers of accelerators, the open-source TaPaSCo framework presented in this work provides an automated toolflow for the construction of heterogeneous many-core architectures from custom processing elements, and a simple, uniform programming interface to utilize spatially distributed, parallel computation on FPGAs. TaPaSCo aims to increase the scalability and portability of FPGA designs through automated design space exploration, greatly simplifying the scaling of hardware designs and facilitating iterative growth and portability across FPGA devices and families. This work describes TaPaSCo with its primary design abstractions and shows how TaPaSCo addresses portability and extensibility of FPGA hardware designs for systems-on-chip. A study of successful projects using TaPaSCo shows its versatility and can serve as inspiration and reference for future users, with more details on the usage of TaPaSCo presented in an in-depth case study and a short overview of the workflow.
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Fleischer, Christian Etienne. "A data processing approach with built-in spatial resolution reduction methods to construct energy system models." Open Research Europe 1 (February 10, 2022): 36. http://dx.doi.org/10.12688/openreseurope.13420.2.
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Introduction: Data processing is a crucial step in energy system modelling which prepares input data from various sources into a format needed to formulate a model. Multiple open-source web-hosted databases offer pre-processed input data within the European context. However, the number of documented open-source data processing workflows that allow for the construction of energy system models with specified spatial resolution reduction methods is still limited. Methods: The first step of the data-processing method builds a dataset using web-hosted pre-processed data and open-source software. The second step aggregates the dataset using a specified spatial aggregation method. The spatially aggregated dataset is used as input data to construct sector-coupled energy system models. Results: To demonstrate the application of the data processing process, three power and heat optimisation models of Germany were constructed using the proposed data processing approach. Significant variation in generation, transmission and storage capacity of electricity were observed between the optimisation results of the energy system models. Conclusions: This paper presents a novel data processing approach to construct sector-coupled energy system models with integrated spatial aggregations methods.
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Trivedi, Rahul, Kevin Fischer, Shanhui Fan, and Jelena Vuckovic. "Few-particle scattering from localized quantum systems in spatially structured bosonic baths." Quantum 6 (April 15, 2022): 691. http://dx.doi.org/10.22331/q-2022-04-15-691.
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Understanding dynamics of localized quantum systems embedded in engineered bosonic environments is a central problem in quantum optics and open quantum system theory. We present a formalism for studying few-particle scattering from a localized quantum system interacting with an bosonic bath described by an inhomogeneous wave-equation. In particular, we provide exact relationships between the quantum scattering matrix of this interacting system and frequency domain solutions of the inhomogeneous wave-equation thus providing access to the spatial distribution of the scattered few-particle wave-packet. The formalism developed in this paper paves the way to computationally understanding the impact of structured media on the scattering properties of localized quantum systems embedded in them without simplifying assumptions on the physics of the structured media.
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Mackenzie, Roderick, Farideh Zarei, Vincent Le Men, and Joonhee Lee. "Spatial uniformity tolerances for sound masking systems in open-plan offices." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 263, no. 1 (August 1, 2021): 5643–49. http://dx.doi.org/10.3397/in-2021-3199.
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Electronic sound masking systems raise the ambient sound level in offices to a controlled minimum sound level in order to increase speech privacy and reduce distractions. Sound masking systems are calibrated to provide the most uniform sound field achievable, as a spatially non-uniform masking sound field could result in occupant perception and uneven speech privacy conditions. Tolerances for acceptable spatial uniformity vary between specifiers, and may be based on different evaluation methods using only a few discrete measurement points to represent an entire office space. However, the actual uniformity of a masking sound field across an office, and the parameters influencing it, has not been widely investigated. Thus, this study aims to investigate the masking sound uniformity in a typical open-plan office space using fine-grid measurements conforming to measurement method of ASTM E1573-18. Percentages of measured locations where the sound pressure levels were within specified tolerances (with increments of 0.5 dB) were calculated using the measured 1/3 octave band levels. The research also utilized geometric acoustical simulations to investigate how physical office parameters (number of loudspeakers, partition heights, ceiling absorption, and diffusion characteristics) affect the sound field uniformity of the sound masking system.
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Rawal, D., A. K. Sharma, A. Vyas, and A. S. Rajawat. "DEVELOPMENT OF WEB BASED HIMALAYAN GLACIER INFORMATION SYSTEM USING OPEN SOURCE." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-4/W8 (July 11, 2018): 181–86. http://dx.doi.org/10.5194/isprs-archives-xlii-4-w8-181-2018.
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<p><strong>Abstract.</strong> Systematic inventory of glaciers is required for a variety of applications needed for the comprehensive development of the Himalayan region such as: a) disaster warning, b) estimation of irrigation potential, c) planning and operation of mini and micro hydroelectric power stations, etc.</p><p> A systematic inventory of the Himalayan glaciers at 1<span class="thinspace"></span>:<span class="thinspace"></span>50,000 scale was created for Indus, Ganga and Brahmaputra basins using Indian Remote Sensing Satellite data and attempted to modified global standards in GIS environment (Sharma et al, 2013). A robust, user- friendly web-based Himalayan Glacier Information System (HGIS), a first of its kind in the country is developed which facilitates any user to selectively display, query, analyse, compose maps and graphs and print, spatial and <i>aspatial</i> information on glaciers relevant to respective interests.</p><p> The HGIS architecture is based on Open Geospatial Consortium (OGC) standards and utilises OpenGeo Suite bundled software comprising of Postgresql (PostGIS), Geoserver, GeoWebCache and GeoExplorer each of those having a different function (Anonymous 2010). The spatial and aspatial glacier data sets were stored in a pre-defined format (Sharma et al, 2008) and imbibed into spatially enabled database (PostGIS), having sophisticated functions for spatial data analysis and query. For publishing the data on web page OGC-compliant services are used.</p><p> The HGIS information content comprise of a) glacier inventory maps and b) inventory data sheet. The map displays the glacier morphology features like accumulation zone and ablation (ice exposed and debris covered) zones, snout location, de-glaciated valleys, moraines and glacier lakes. The basin, sub-basin and administrative boundaries form the background. The inventory data sheet attributes for each glacier provides information on glacier Location, Identification, Dimension, Orientation, Elevation, Classification, etc. The spatial map and datasheet are linked by unique glacier identification number (galc_id) which is a key field present in all corresponding glacier related point, polygon or line layers. All the glacier attribute were made amenable to query and analysis by users. HGIS represents a significant step towards mapping and compiling individual glacier level inventory data in spatial form to fill the void in data and information on the status of Glaciers in the Himalaya and Trans-Himalayan Karakoram region. HGIS provides a basis for assessing the glacier inventory data which has applications in studies related to climate change, water resource planning, hydropower site selection and mitigation of glacial lake outburst flood (GLOF) hazards.</p>
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Olmos, Adriana, Nicolas Bouillot, Trevor Knight, Nordhal Mabire, Josh Redel, and Jeremy R. Cooperstock. "A High-Fidelity Orchestra Simulator for Individual Musicians’ Practice." Computer Music Journal 36, no. 2 (June 2012): 55–73. http://dx.doi.org/10.1162/comj_a_00119.
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We developed the Open Orchestra system to provide individual musicians with a high-fidelity experience of ensemble rehearsal or performance, combined with the convenience and flexibility of solo study. This builds on the theme of an immersive orchestral simulator that also supports the pedagogical objective of instructor feedback on individual recordings, as needed to improve one's performance. Unlike previous systems intended for musical rehearsal, Open Orchestra attempts to offer both an auditory and a visual representation of the rest of the orchestra, spatially rendered from the perspective of the practicing musician. We review the objectives and architecture of our system, describe the functions of our digital music stand, discuss the challenges of generating the media content needed for this system, and describe provisions for offering feedback during rehearsal.
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Bernard, Josef, Tomáš Kostelecký, and Martin Šimon. "Are there spatially contextual influences on voter behaviour even in a relatively nationalised party system? The case of Czechia." Geografie 119, no. 3 (2014): 240–58. http://dx.doi.org/10.37040/geografie2014119030240.
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The paper discusses the contextual effects on voting behaviour. Part of the Czech professional literature concludes that spatial contextual effects on voting behaviour in Czechia are weak and that the spatial patterns of election results can be basically explained as a reflection of territorial differences in social structure, i.e. compositionally. This study examines the existence of contextual effects using spatially very detailed data. When the determinants of election results are studied at the municipal level by spatial statistical methods, areas of different size can be found in Czechia, in which election results can’t be explained by the composition of voters. Instead it becomes more appropriate to consider the contextual effects impacting on them. Some results of our analysis can be interpreted as a manifestation of neighbourhood effects, unambiguous confirmation of its existence, however, remains open.
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Brevdo, Leonid. "A dynamical system approach to the absolute instability of spatially developing localized open flows and media." Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences 458, no. 2022 (June 8, 2002): 1375–97. http://dx.doi.org/10.1098/rspa.2001.0912.
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ZALALETDINOV, ROUSTAM. "THE AVERAGING PROBLEM IN COSMOLOGY AND MACROSCOPIC GRAVITY." International Journal of Modern Physics A 23, no. 08 (March 30, 2008): 1173–81. http://dx.doi.org/10.1142/s0217751x08040032.
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The averaging problem in cosmology and the approach of macroscopic gravity to resolve the problem is discussed. The averaged Einstein equations of macroscopic gravity are modified on cosmological scales by the macroscopic gravitational correlation tensor terms as compared with the Einstein equations of general relativity. This correlation tensor satisfies a system of structure and field equations. An exact cosmological solution to the macroscopic gravity equations for a constant macroscopic gravitational connection correlation tensor for a flat spatially homogeneous, isotropic macroscopic space-time is presented. The correlation tensor term in the macroscopic Einstein equations has been found to take the form of either a negative or positive spatial curvature term. Thus, macroscopic gravity provides a cosmological model for a flat spatially homogeneous, isotropic Universe which obeys the dynamical law for either an open or closed Universe.
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Merkli, Marco. "Dynamics of Open Quantum Systems I, Oscillation and Decay." Quantum 6 (January 3, 2022): 615. http://dx.doi.org/10.22331/q-2022-01-03-615.
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We develop a framework to analyze the dynamics of a finite-dimensional quantum system S in contact with a reservoir R. The full, interacting SR dynamics is unitary. The reservoir has a stationary state but otherwise dissipative dynamics. We identify a main part of the full dynamics, which approximates it for small values of the SR coupling constant, uniformly for all times t≥0. The main part consists of explicit oscillating and decaying parts. We show that the reduced system evolution is Markovian for all times. The technical novelty is a detailed analysis of the link between the dynamics and the spectral properties of the generator of the SR dynamics, based on Mourre theory. We allow for SR interactions with little regularity, meaning that the decay of the reservoir correlation function only needs to be polynomial in time, improving on the previously required exponential decay.In this work we distill the structural and technical ingredients causing the characteristic features of oscillation and decay of the SR dynamics. In the companion paper [27] we apply the formalism to the concrete case of an N-level system linearly coupled to a spatially infinitely extended thermal bath of non-interacting Bosons.
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Saxena, Rajat, Warsha Barde, and Sachin S. Deshmukh. "Inexpensive, scalable camera system for tracking rats in large spaces." Journal of Neurophysiology 120, no. 5 (November 1, 2018): 2383–95. http://dx.doi.org/10.1152/jn.00215.2018.
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Most studies of neural correlates of spatial navigation are restricted to small arenas (≤1 m2) because of the limits imposed by the recording cables. New wireless recording systems have a larger recording range. However, these neuronal recording systems lack the ability to track animals in large area, constraining the size of the arena. We developed and benchmarked an open-source, scalable multicamera tracking system based on low-cost hardware. This “Picamera system” was used in combination with a wireless recording system for characterizing neural correlates of space in environments of sizes up to 16.5 m2. The Picamera system showed substantially better temporal accuracy than a popular commercial system. An explicit comparison of one camera from the Picamera system with a camera from the commercial system showed improved accuracy in estimating spatial firing characteristics and head direction tuning of neurons. This improved temporal accuracy is crucial for accurately aligning videos from multiple cameras in large spaces and characterizing spatially modulated cells in a large environment. NEW & NOTEWORTHY Studies of neural correlates of space are limited to biologically unrealistically small spaces by neural recording and position tracking hardware. We developed a camera system capable of tracking animals in large spaces at a high temporal accuracy. Together with the new wireless recording systems, this system facilitates the study of neural correlates of space at biologically relevant scale. This increased temporal accuracy of tracking also improves the estimates of spatiotemporal correlates of neural activity.
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Laposata, M., CM Krueger, and JE Saffitz. "Selective uptake of [3H]arachidonic acid into the dense tubular system of human platelets." Blood 70, no. 3 (September 1, 1987): 832–37. http://dx.doi.org/10.1182/blood.v70.3.832.832.
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Abstract We have used quantitative electron microscopic autoradiography to characterize the subcellular distribution of arachidonoyl phospholipids following brief (5 minutes) exposure of unstimulated human platelets to [3H]arachidonic acid. Labeled arachidonate was taken up rapidly and incorporated into phospholipids. Phospholipid radioactivity was preserved and spatially fixed during tissue processing for electron microscopy. Analysis of autoradiographs showed that following a brief exposure to 750 nmol/L [3H]arachidonate, there is selective labeling of an internal membrane compartment composed of the dense tubular system and the open canalicular system. The plasma membrane, platelet granules, and nonmembranous cytoplasm were not labeled. Since the open canalicular system is continuous with the plasma membrane and since phospholipids in continuous membranes are freely diffusible, our observations indicate that [3H]arachidonate was incorporated into phospholipids within the dense tubular system and not the open canalicular system. Thus, the dense tubular system, known to contain cyclooxygenase activity, incorporates arachidonate selectively following brief exposure to this fatty acid, presumably to concentrate it in proximity to enzymes for icosanoid synthesis.
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Laposata, M., CM Krueger, and JE Saffitz. "Selective uptake of [3H]arachidonic acid into the dense tubular system of human platelets." Blood 70, no. 3 (September 1, 1987): 832–37. http://dx.doi.org/10.1182/blood.v70.3.832.bloodjournal703832.
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We have used quantitative electron microscopic autoradiography to characterize the subcellular distribution of arachidonoyl phospholipids following brief (5 minutes) exposure of unstimulated human platelets to [3H]arachidonic acid. Labeled arachidonate was taken up rapidly and incorporated into phospholipids. Phospholipid radioactivity was preserved and spatially fixed during tissue processing for electron microscopy. Analysis of autoradiographs showed that following a brief exposure to 750 nmol/L [3H]arachidonate, there is selective labeling of an internal membrane compartment composed of the dense tubular system and the open canalicular system. The plasma membrane, platelet granules, and nonmembranous cytoplasm were not labeled. Since the open canalicular system is continuous with the plasma membrane and since phospholipids in continuous membranes are freely diffusible, our observations indicate that [3H]arachidonate was incorporated into phospholipids within the dense tubular system and not the open canalicular system. Thus, the dense tubular system, known to contain cyclooxygenase activity, incorporates arachidonate selectively following brief exposure to this fatty acid, presumably to concentrate it in proximity to enzymes for icosanoid synthesis.
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Dolder, Danisa, Gustavious P. Williams, A. Woodruff Miller, Everett James Nelson, Norman L. Jones, and Daniel P. Ames. "Introducing an Open-Source Regional Water Quality Data Viewer Tool to Support Research Data Access." Hydrology 8, no. 2 (June 10, 2021): 91. http://dx.doi.org/10.3390/hydrology8020091.
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Water quality data collection, storage, and access is a difficult task and significant work has gone into methods to store and disseminate these data. We present a tool to disseminate research in a simple method that does not replace but extends and leverages these tools. The tool is not geo-graphically limited and works with any spatially-referenced data. In most regions, government agencies maintain central repositories for water quality data. In the United States, the federal government maintains two systems to fill that role for hydrological data: the U.S. Geological Survey (USGS) National Water Information System (NWIS) and the U.S. Environmental Protection Agency (EPA) Storage and Retrieval System (STORET), since superseded by the Water Quality Portal (WQP). The Consortium of the Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) has developed the Hydrologic Information System (HIS) to standardize the search and discovery of these data as well as other observational time series datasets. Additionally, CUAHSI developed and maintains HydroShare.org (5 May 2021) as a web portal for researchers to store and share hydrology data in a variety of formats including spatial geographic information system data. We present the Tethys Platform based Water Quality Data Viewer (WQDV) web application that uses these systems to provide researchers and local monitoring organizations with a simple method to archive, view, analyze, and distribute water quality data. WQDV provides an archive for non-official or preliminary research data and access to those data that have been collected but need to be distributed prior to review or inclusion in the state database. WQDV can also accept subsets of data downloaded from other sources, such as the EPA WQP. WQDV helps users understand what local data are available and how they relate to the data in larger databases. WQDV presents data in spatial (maps) and temporal (time series graphs) forms to help the users analyze and potentially screen the data sources before export for additional analysis. WQDV provides a convenient method for interim data to be widely disseminated and easily accessible in the context of a subset of official data. We present WQDV using a case study of data from Utah Lake, Utah, United States of America.
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Lane, Steven A., Robert L. Clark, and Steve C. Southward. "Active Control of Low Frequency Modes in an Aircraft Fuselage Using Spatially Weighted Arrays." Journal of Vibration and Acoustics 122, no. 3 (March 1, 2000): 227–34. http://dx.doi.org/10.1115/1.1303848.
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Acoustic enclosures such as aircraft cabins often display lightly damped modal behavior at low frequencies where passive treatments are impractical due to mass and volume constraints. This work presents a feedback control approach using dynamic H2 controllers implemented with spatially weighted arrays of collocated pressure sensors and constant volume-velocity actuators. The open-loop system is shaped using spatially weighted transducer arrays to yield increased pole-zero separation, which results in better closed-loop performance. The transducer arrays are weighted to emphasize coupling to a particular acoustic mode or modes, which facilitates global control of the targeted dynamics. This work presents a method to determine the spatial weighting vectors for the transducer arrays from frequency response measurements. The development and implementation of low-order, dynamic H2 control laws is also discussed. Experimental results are presented for a single-mode and a multiple-mode controller implemented on an aircraft fuselage section, and demonstrate significant reduction of the targeted acoustic modes. To the best of the authors’ knowledge, this is the first experimental implementation of a feedback controller of this type capable of achieving such levels of global reduction in a three-dimensional acoustic system. [S0739-3717(00)02303-5]
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Lorenzo, María Inés, Juan M. Díaz de Astarloa, Walter Norbis, and María B. Cousseau. "Long term fish assemblages as units of management in a temperate estuary (Rio de La Plata - SW Atlantic Ocean)." Brazilian Journal of Oceanography 59, no. 1 (March 2011): 43–59. http://dx.doi.org/10.1590/s1679-87592011000100004.
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Demersal fish assemblages from trawl surveys in the Rio de la Plata estuary and its inner continental shelf were analyzed from 1975 to 1995. The first two factors of Principal Component Analysis explained 48% of the variance in species distribution, and they are consistent with the results of a cluster analysis. The analysis indicated the existence of three spatially and temporally distinct fish assemblages: internal and external estuarine and inner continental shelf (Uruguayan coastal assemblages). These assemblages were persistent considering the environmental characteristics and their species composition. Despite the changes registered in the species density during the period surveyed, the fish assemblages tend to persist over time. It was demonstrated that the assemblages can be considered as open systems and that there exists a reciprocal flow of organisms between adjacent associations. However, each assemblage showed high spatial and temporal persistence in accordance with the environmental characteristics of the system analyzed. Therefore, and according to the multispecies fisheries operating in the system, each assemblage defined could be considered a unit of management.
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Siangchaew, K., D. Arayasantiparb, and M. Libera. "Electron Energy-Loss Spectrum Profiling of Polymer-Polymer Interfaces." Microscopy and Microanalysis 3, S2 (August 1997): 951–52. http://dx.doi.org/10.1017/s1431927600011648.
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The spatially-resolved structure and composition of amorphous or semicrystalline polymer-polymer interfaces are poorly understood. The absence of atomic-level periodicity precludes many of the transmission electron-optical techniques that have been so fruitful in studying interfaces in polycrystalline inorganic materials. Similarly, there has been relatively little work done on spatially-resolved spectroscopic analysis of polymer-polymer interfaces to determine chemical widths, largely because of concerns over electron-beam damage. Digital microscope control and parallel spectral acquisition provide for low-dose exposure, quantification of dose, and efficient data collection which open new windows to study polymer interfaces.This research is studying various multiphase polymer systems by focused-probe spectroscopic analysis to identify appropriate spectral features, data acquisition protocols, and background-modeling/data-processing algorithms in order to establish chemical widths characteristic of specific polymer-polymer interfaces (1). This research uses a 200keV Philips CM20 FEG TEM/STEM with a Gatan 666 PEELS spectrometer and an Emispec digital data acquisition/control system.
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Garzon-Lopez, Carol X., Tarek Hattab, Sandra Skowronek, Raf Aerts, Michael Ewald, Hannes Feilhauer, Olivier Honnay, et al. "The DIARS toolbox: a spatially explicit approach to monitor alien plant invasions through remote sensing." Research Ideas and Outcomes 4 (March 30, 2018): e25301. http://dx.doi.org/10.3897/rio.4.e25301.
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The synergies between remote sensing technologies and ecological research have opened new avenues for the study of alien plant invasions worldwide. Such scientific advances have greatly improved our capacity to issue warnings, develop early-response systems and assess the impacts of alien plant invasions on biodiversity and ecosystem functioning. Hitherto, practical applications of remote sensing approaches to support nature conservation actions are lagging far behind scientific advances. Yet, for some of these technologies, knowledge transfer is difficult due to the complexity of the different data handling procedures and the huge amounts of data it involves per spatial unit. In this context, the next logical step is to develop clear guidelines for the application of remote sensing data to monitor and assess the impacts of alien plant invasions, that enable scientists, landscape managers and policy makers to fully exploit the tools which are currently available. It is desirable to have such guidelines accompanied by freely available remote sensing data and generated in a free and open source environment that increases the availability and affordability of these new technologies. Here we present a toolbox that provides an easy-to-use, flexible, transparent and open source set of tools to sample, map, model and assess the impact of alien plant invasions using two high-resolution remote sensing products (hyperspectral and LiDAR images). This online toolbox includes a real case dataset designed to facilitate testing and training in any computer system and processing capacity.
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Lauber, U., W. Ufrecht, and N. Goldscheider. "Spatially resolved information on karst conduit flow from in-cave dye tracing." Hydrology and Earth System Sciences 18, no. 2 (February 5, 2014): 435–45. http://dx.doi.org/10.5194/hess-18-435-2014.
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Abstract. Artificial tracers are powerful tools for investigating karst systems. Tracers are commonly injected into sinking streams or dolines, while springs serve as monitoring sites. The obtained flow and transport parameters represent mixed information from the vadose, epiphreatic and phreatic zones (that is, the aquifer remains a black box). Accessible active caves constitute valuable but underexploited natural laboratories to gain detailed insights into the hydrologic functioning of the aquifer. Two multi-tracer tests in the catchment of a major karst spring (Blautopf, Germany) with injections and monitoring in two associated water caves aimed at obtaining spatially and temporally resolved information on groundwater flow in different compartments of the system. Two tracers were injected into the caves to characterize the hydraulic connections between them and with the spring. Two injections at the land surface, far from the spring, aimed at resolving the aquifer's internal drainage structure. Tracer breakthrough curves were monitored by field fluorimeters in caves and at the spring. Results demonstrate the dendritic drainage structure of the aquifer. It was possible to obtain relevant flow and transport parameters for different sections of this system. The highest mean flow velocities (275 m h−1) were observed in the near-spring epiphreatic section (open-channel flow), while velocities in the phreatic zone (pressurized flow) were one order of magnitude lower. Determined conduit water volumes confirm results of water balances and hydrograph analyses. In conclusion, experiments and monitoring in caves can deliver spatially resolved information on karst aquifer heterogeneity and dynamics that cannot be obtained by traditional investigative methods.
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Lauber, U., W. Ufrecht, and N. Goldscheider. "Spatially resolved information on karst conduit flow from in-cave dye-tracing." Hydrology and Earth System Sciences Discussions 10, no. 9 (September 5, 2013): 11311–35. http://dx.doi.org/10.5194/hessd-10-11311-2013.
Full textAbstract:
Abstract. Artificial tracers are powerful tools to investigate karst systems. Tracers are commonly injected into sinking streams or dolines, while springs serve as monitoring sites. The obtained flow and transport parameters represent mixed information from the vadose, epiphreatic and phreatic zones, i.e., the aquifer remains a black box. Accessible active caves constitute valuable but underexploited natural laboratories to gain detailed insights into the hydrologic functioning of the aquifer. Two multi-tracer tests in the catchment of a major karst spring (Blautopf, Germany) with injections and monitoring in two associated water caves aimed at obtaining spatially and temporally resolved information on groundwater flow in different compartments of the system. Two tracers were injected in the caves to characterize the hydraulic connections between them and with the spring. Two injections at the land surface, far from the spring, aimed at resolving the aquifer's internal drainage structure. Tracer breakthrough curves were monitored by field fluorimeters in caves and at the spring. Results demonstrate the dendritic drainage structure of the aquifer. It was possible to obtain relevant flow and transport parameters for different sections of this system. The highest mean flow velocities (275 m h−1) were observed in the near-spring epiphreatic section (open-channel flow), while velocities in the phreatic zone (pressurized flow) were one order of magnitude lower. Determined conduit water volumes confirm results of water balances and hydrograph analyses. In conclusion, experiments and monitoring in caves can deliver spatially resolved information on karst aquifer heterogeneity and dynamics that cannot be obtained by traditional investigative methods.
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Raković, Dejan, Miroljub Dugić, Jasmina Jeknić-Dugić, Milenko Plavšić, Stevo Jaćimovski, and Jovan Šetrajčić. "On Macroscopic Quantum Phenomena in Biomolecules and Cells: From Levinthal to Hopfield." BioMed Research International 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/580491.
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In the context of the macroscopic quantum phenomena of the second kind, we hereby seek for a solution-in-principle of the long standing problem of the polymer folding, which was considered by Levinthal as (semi)classically intractable. To illuminate it, we applied quantum-chemical and quantum decoherence approaches to conformational transitions. Our analyses imply the existence of novel macroscopic quantum biomolecular phenomena, with biomolecular chain folding in an open environment considered as a subtle interplay between energy and conformation eigenstates of this biomolecule, governed by quantum-chemical and quantum decoherence laws. On the other hand, within an open biological cell, a system of all identical (noninteracting and dynamically noncoupled) biomolecular proteins might be considered as corresponding spatial quantum ensemble of these identical biomolecular processors, providing spatially distributed quantum solution to a single corresponding biomolecular chain folding, whose density of conformational states might be represented as Hopfield-like quantum-holographic associative neural network too (providing an equivalent global quantum-informational alternative to standard molecular-biology local biochemical approach in biomolecules and cells and higher hierarchical levels of organism, as well).
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Martínez-Cañada, Pablo, Christian Morillas, and Francisco Pelayo. "A Neuronal Network Model of the Primate Visual System: Color Mechanisms in the Retina, LGN and V1." International Journal of Neural Systems 29, no. 02 (February 21, 2019): 1850036. http://dx.doi.org/10.1142/s0129065718500363.
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Color plays a key role in human vision but the neural machinery that underlies the transformation from stimulus to perception is not well understood. Here, we implemented a two-dimensional network model of the first stages in the primate parvocellular pathway (retina, lateral geniculate nucleus and layer 4C[Formula: see text] in V1) consisting of conductance-based point neurons. Model parameters were tuned based on physiological and anatomical data from the primate foveal and parafoveal vision, the most relevant visual field areas for color vision. We exhaustively benchmarked the model against well-established chromatic and achromatic visual stimuli, showing spatial and temporal responses of the model to disk- and ring-shaped light flashes, spatially uniform squares and sine-wave gratings of varying spatial frequency. The spatiotemporal patterns of parvocellular cells and cortical cells are consistent with their classification into chromatically single-opponent and double-opponent groups, and nonopponent cells selective for luminance stimuli. The model was implemented in the widely used neural simulation tool NEST and released as open source software. The aim of our modeling is to provide a biologically realistic framework within which a broad range of neuronal interactions can be examined at several different levels, with a focus on understanding how color information is processed.
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Vijay, Ritesh, S. S. Ramya, P. R. Pujari, and P. K. Mohapatra. "Spatio-temporal assessment of groundwater level and quality in urban coastal city Puri, India." Water Supply 11, no. 2 (April 1, 2011): 194–201. http://dx.doi.org/10.2166/ws.2011.021.
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Puri city is situated on the shoreline of Bay of Bengal and groundwater is the only source available to meet the city water supply mainly from two demarcated water fields. Due to the anthropogenic activities and absence of sewerage system, groundwater quality is deteriorating through open discharges of domestic waste, open defecation, septic tanks, soak pits, contaminated water pools, unorganized waste dumping etc. The objective of the paper was to assess seasonal groundwater fluctuation and water quality in terms of physcio-chemical and bacteriological parameters. For this, groundwater levels were measured and samples were collected during post-monsoon (November 2006) and pre-monsoon (June 2007) from the water fields and city area. Groundwater quality was represented spatially and temporally using geographical information system and evaluated with national and international drinking water standards. Based on the groundwater quality, suitable measures were suggested to minimize further groundwater contamination.
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Cillis, Giuseppe, Biagio Tucci, Valentina Santarsiero, Gabriele Nolè, and Antonio Lanorte. "Understanding Land Changes for Sustainable Environmental Management: The Case of Basilicata Region (Southern Italy)." Pollutants 1, no. 4 (November 28, 2021): 217–33. http://dx.doi.org/10.3390/pollutants1040018.
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Sustainable land management is one of the key actions for the achievement of objectives set by the 2030 Agenda for Sustainable Development. In particular, land represents a fundamental resource to address issues of climate change, biodiversity preservation, maintaining ecosystem services, and at the same time ensuring shared prosperity and well-being. Therefore, it is necessary to activate strategies to monitor changes in land use and land cover in order to evaluate strategies for proper management. To do this, the new open source geospatial analysis tools and the increasing availability of remote sensed open data can allow the activation of methodologies for monitoring changes in land use and land cover in order to provide data usable in other research areas or, for example, to implement a decision support system for environmental sustainability. In this study, a GIS approach based on open remote sensing data has been used to perform a spatial analysis of land cover changes within the Basilicata region (Southern Italy) that is spatially expeditious yet accurate. The results showed a very evident land transformation with important repercussions on the environmental components. The ease of use of techniques makes this methodology replicable in other territory and can be used as a preliminary approach to sustainable development model.
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Codiga, Daniel L. "A Marine Autonomous Surface Craft for Long-Duration, Spatially Explicit, Multidisciplinary Water Column Sampling in Coastal and Estuarine Systems." Journal of Atmospheric and Oceanic Technology 32, no. 3 (March 2015): 627–41. http://dx.doi.org/10.1175/jtech-d-14-00171.1.
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AbstractThe Surveying Coastal Ocean Autonomous Profiler (SCOAP) is a large catamaran marine autonomous surface craft (MASC) for unattended weeks-long, spatially explicit, multidisciplinary oceanographic water column profile sampling in coastal/estuarine waterbodies. Material transport rates/pathways, crucial to understanding these ecosystems, are typically poorly known. SCOAP addresses demanding spatiotemporal sampling needs and operational challenges (strong currents, open coastal sea states, complex bathymetry, heavy vessel traffic). Its large size (11-m length, 5-m beam) provides seaworthiness/stability. The average speed of 2.5 m s−1 meets the representative goal to traverse an 18-km transect, sampling 10 min at each of 10 stations 2 km apart, nominally 4 times daily. Efficient hulls and a diesel–electric energy system can provide the needed endurance. The U.S. Coast Guard guidelines are followed: lighting, code flags, the Automatic Identification System (AIS), and collision avoidance regulations (COLREGs)-based collision avoidance (CA) by onboard autonomy software. Large energy reserves obviate low-power optimization of sensors, enabling truly multidisciplinary sampling, and provide on-demand propulsion for effective CA. Vessel stability facilitates high-quality current profile observations and will aid engineering/operation of the planned winched profiling system, performance of an anticipated radar system to detect/track non-AIS vessels, and potential research-quality meteorological sensor operation. A Narragansett Bay test deployment, attended by an escort vessel, met design goals; an unattended open coastal deployment is planned for Rhode Island Sound. Scientific and operational strengths of large catamaran MASCs suggest they could be an important cost-effective complement to other sampling platforms (e.g., improved spatiotemporal coverage and resolution, extending farther inshore, with a broader range of sensors, compared to underwater gliders) in coastal/estuarine waters.
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Adaktylou, Nektaria, Dimitris Stratoulias, and Rick Landenberger. "Wildfire Risk Assessment Based on Geospatial Open Data: Application on Chios, Greece." ISPRS International Journal of Geo-Information 9, no. 9 (August 28, 2020): 516. http://dx.doi.org/10.3390/ijgi9090516.
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Wildfires burn tens of thousands of hectares of forest, chaparral and grassland in Mediterranean countries every year, giving rise to landscape, ecologic, economic, and public safety concerns. On the Greek island of Chios and in many other Mediterranean landscapes, areas affected by fire are difficult to access and control due to rugged terrain, requiring wildfire preparedness and response plans that support fire fighting. This study utilized open source data and a weighted linear combination to extract factors that determine wildfire risk. Landsat satellite imagery and publicly available geospatial data were used to create a Geographic Information System and a multi-criteria analysis to develop a methodology for spatially modeling fire risk on Chios, a Greek island with frequent fire occurrence. This study focused on the static, structural component of the risk assessment to produce a spatial distribution of fire risk as a thematic map. Fire weather conditions were accounted for using Fuel Moisture Content, which reflected dryness of dead fuels and water deficit of live biomass. To assess the results, historic fire data representing actual occurrence of fire incidents were compared with probable fire locations predicted by our GIS model. It was found that there was a good agreement between the ground reference data and the results of the created fire risk model. The findings will help fire authorities identify areas of high risk for wildfire and plan the allocation of resources accordingly. This is because the outputs of the designed fire risk model are not complex or challenging to use in Chios, Greece and other landscapes.
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Jovanović, Mihailo R. "From Bypass Transition to Flow Control and Data-Driven Turbulence Modeling: An Input–Output Viewpoint." Annual Review of Fluid Mechanics 53, no. 1 (January 5, 2021): 311–45. http://dx.doi.org/10.1146/annurev-fluid-010719-060244.
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Transient growth and resolvent analyses are routinely used to assess nonasymptotic properties of fluid flows. In particular, resolvent analysis can be interpreted as a special case of viewing flow dynamics as an open system in which free-stream turbulence, surface roughness, and other irregularities provide sources of input forcing. We offer a comprehensive summary of the tools that can be employed to probe the dynamics of fluctuations around a laminar or turbulent base flow in the presence of such stochastic or deterministic input forcing and describe how input–output techniques enhance resolvent analysis. Specifically, physical insights that may remain hidden in the resolvent analysis are gained by detailed examination of input–output responses between spatially localized body forces and selected linear combinations of state variables. This differentiating feature plays a key role in quantifying the importance of different mechanisms for bypass transition in wall-bounded shear flows and in explaining how turbulent jets generate noise. We highlight the utility of a stochastic framework, with white or colored inputs, in addressing a variety of open challenges including transition in complex fluids, flow control, and physics-aware data-driven turbulence modeling. Applications with temporally or spatially periodic base flows are discussed and future research directions are outlined.
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Righetti, Damiano, Meike Vogt, Niklaus E. Zimmermann, Michael D. Guiry, and Nicolas Gruber. "PhytoBase: A global synthesis of open-ocean phytoplankton occurrences." Earth System Science Data 12, no. 2 (April 24, 2020): 907–33. http://dx.doi.org/10.5194/essd-12-907-2020.
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Abstract. Marine phytoplankton are responsible for half of the global net primary production and perform multiple other ecological functions and services of the global ocean. These photosynthetic organisms comprise more than 4300 marine species, but their biogeographic patterns and the resulting species diversity are poorly known, mostly owing to severe data limitations. Here, we compile, synthesize, and harmonize marine phytoplankton occurrence records from the two largest biological occurrence archives (Ocean Biogeographic Information System, OBIS; and Global Biodiversity Information Facility, GBIF) and three independent recent data collections. We bring together over 1.36 million phytoplankton occurrence records (1.28 million at the level of species) for a total of 1704 species, spanning the principal groups of the diatoms, dinoflagellates, and haptophytes, as well as several other groups. This data compilation increases the amount of marine phytoplankton records available through the single largest contributing archive (OBIS) by 65 %. Data span all ocean basins, latitudes, and most seasons. Analyzing the oceanic inventory of sampled phytoplankton species richness at the broadest spatial scales possible using a resampling procedure, we find that richness tends to saturate at ∼93 % of all species in our database in the pantropics, at ∼64 % in temperate waters, and at ∼35 % in the cold Northern Hemisphere, while the Southern Hemisphere remains under-explored. We provide metadata on the cruise, research institution, depth, and date for each data record, and we include phytoplankton cell counts for 193 763 records. We strongly recommend consideration of spatiotemporal biases in sampling intensity and varying taxonomic sampling scopes between research cruises or institutions when analyzing the occurrence data spatially. Including such information into predictive tools, such as statistical species distribution models, may serve to project the diversity, niches, and distribution of species in the contemporary and future ocean, opening the door for quantitative macroecological analyses of phytoplankton. PhytoBase can be downloaded from PANGAEA: https://doi.org/10.1594/PANGAEA.904397 (Righetti et al., 2019a).
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Müller, Ulf Philipp, Birgit Schachler, Malte Scharf, Wolf-Dieter Bunke, Stephan Günther, Julian Bartels, and Guido Pleßmann. "Integrated Techno-Economic Power System Planning of Transmission and Distribution Grids." Energies 12, no. 11 (May 31, 2019): 2091. http://dx.doi.org/10.3390/en12112091.
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The energy transition towards renewable and more distributed power production triggers the need for grid and storage expansion on all voltage levels. Today’s power system planning focuses on certain voltage levels or spatial resolutions. In this work we present an open source software tool eGo which is able to optimize grid and storage expansion throughout all voltage levels in a developed top-down approach. Operation and investment costs are minimized by applying a multi-period linear optimal power flow considering the grid infrastructure of the extra-high and high-voltage (380 to 110 kV) level. Hence, the common differentiation of transmission and distribution grid is partly dissolved, integrating the high-voltage level into the optimization problem. Consecutively, optimized curtailment and storage units are allocated in the medium voltage grid in order to lower medium and low voltage grid expansion needs, that are consequently determined. Here, heuristic optimization methods using the non-linear power flow were developed. Applying the tool on future scenarios we derived cost-efficient grid and storage expansion for all voltage levels in Germany. Due to the integrated approach, storage expansion and curtailment can significantly lower grid expansion costs in medium and low voltage grids and at the same time serve the optimal functioning of the overall system. Nevertheless, the cost-reducing effect for the whole of Germany was marginal. Instead, the consideration of realistic, spatially differentiated time series led to substantial overall savings.
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Leite, I., A. Cabral, M. Abreu, and N. Santos. "Imaging sensors for PoET: a spatially resolved solar spectroscopy instrument." Journal of Physics: Conference Series 2407, no. 1 (December 1, 2022): 012020. http://dx.doi.org/10.1088/1742-6596/2407/1/012020.
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Abstract The study of the Sun is an area still open in several topics of astrophysics, in a field that has seen an expansion in recent years - therefore, it is critical that collected data is thoroughly traceable and accurate to be used in new study cases or predictive models. A ground based, portable, optimized system, consisting of a Schmidt-Cassegrain telescope coupled to a refractor telescope acting as a pointing telescope, is being designed to provide high resolution imaging of smaller areas on the Sun’s surface, being able to obtain disk-resolved, high spectral resolution data, at a relative low cost (compared to large consortium developed instruments). The light collected by the telescope will be fibre-fed to a spectrograph - the injection of light in the fibre is critical and requires an imaging sensor to aid the light guiding process. The goal of the present work was to explore the best candidates for the image sensors, their architectures, requirements, and constraints, as well as their expected performance range and signal noise. The trade-off analysis between CMOS and CCD based sensors was made and it was concluded, that for the intended application, either type of architecture is admissible, provided the sensor is within desired parameters.
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Endsley, K. A., and M. G. Billmire. "Distributed visualization of gridded geophysical data: a web API for carbon flux." Geoscientific Model Development Discussions 8, no. 7 (July 23, 2015): 5741–61. http://dx.doi.org/10.5194/gmdd-8-5741-2015.
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Abstract. Due to the proliferation of geophysical models, particularly climate models, the increasing resolution of their spatiotemporal estimates of Earth system processes, and the desire to easily share results with collaborators, there is a genuine need for tools to manage, aggregate, visualize, and share datasets. We present a new, web-based software tool – the Carbon Data Explorer – that provides these capabilities for gridded geophysical datasets. While originally developed for visualizing carbon flux, this tool can accommodate any time-varying, spatially explicit scientific dataset, particularly NASA Earth system science Level III products. In addition, the tool's open-source licensing and web presence facilitate distributed scientific visualization, comparison with other datasets and uncertainty estimates, and data publishing and distribution.
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Mohamed, Abdel-Baset A., and Hichem Eleuch. "Nonclassical Effects Based on Husimi Distributions in Two Open Cavities Linked by an Optical Waveguide." Entropy 22, no. 7 (July 13, 2020): 767. http://dx.doi.org/10.3390/e22070767.
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Nonclassical effects are investigated in a system formed by two quantum wells, each of which is inside an open cavity. The cavities are spatially separated, linked by a fiber, and filled with a linear optical medium. Based on Husimi distributions (HDs) and Wehrl entropy, we explore the effects of the physical parameters on the generation and the robustness of the mixedness and HD information in the phase space. The generated quantum coherence and the HD information depend crucially on the cavity-exciton and fiber cavity couplings as well as on the optical medium density. The HD information and purity are lost due to the dissipation. This loss may be inhibited by increasing the optical susceptibility as well as the couplings of the exciton-cavity and the fiber-cavity. These parameters control the regularity, amplitudes, and frequencies of the generated mixedness.
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Shivakumar, Abhishek, Thomas Alfstad, and Taco Niet. "A clustering approach to improve spatial representation in water-energy-food models." Environmental Research Letters 16, no. 11 (October 29, 2021): 114027. http://dx.doi.org/10.1088/1748-9326/ac2ce9.
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Abstract Currently available water-energy-food (WEF) modelling frameworks to analyse cross-sectoral interactions often share one or more of the following gaps: (a) lack of integration between sectors, (b) coarse spatial representation, and (c) lack of reproducible methods of nexus assessment. In this paper, we present a novel clustering tool as an expansion to the Climate-Land-Energy-Water-Systems modelling framework used to quantify inter-sectoral linkages between water, energy, and food systems. The clustering tool uses Agglomerative Hierarchical clustering to aggregate spatial data related to the land and water sectors. Using clusters of aggregated data reconciles the need for a spatially resolved representation of the land-use and water sectors with the computational and data requirements to efficiently solve such a model. The aggregated clusters, combined together with energy system components, form an integrated resource planning structure. The modelling framework is underpinned by an open-source energy system modelling tool—OSeMOSYS—and uses publicly available data with global coverage. By doing so, the modelling framework allows for reproducible WEF nexus assessments. The approach is used to explore the inter-sectoral linkages between the energy, land-use, and water sectors of Viet Nam out to 2030. A validation of the clustering approach confirms that underlying trends actual crop yield data are preserved in the resultant clusters. Finally, changes in cultivated area of selected crops are observed and differences in levels of crop migration are identified.
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Nishiyama, Akihiro, Shigenori Tanaka, and Jack A. Tuszynski. "Non-Equilibrium Quantum Electrodynamics in Open Systems as a Realizable Representation of Quantum Field Theory of the Brain." Entropy 22, no. 1 (December 27, 2019): 43. http://dx.doi.org/10.3390/e22010043.
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We derive time evolution equations, namely the Klein–Gordon equations for coherent fields and the Kadanoff–Baym equations in quantum electrodynamics (QED) for open systems (with a central region and two reservoirs) as a practical model of quantum field theory of the brain. Next, we introduce a kinetic entropy current and show the H-theorem in the Hartree–Fock approximation with the leading-order (LO) tunneling variable expansion in the 1st order approximation for the gradient expansion. Finally, we find the total conserved energy and the potential energy for time evolution equations in a spatially homogeneous system. We derive the Josephson current due to quantum tunneling between neighbouring regions by starting with the two-particle irreducible effective action technique. As an example of potential applications, we can analyze microtubules coupled to a water battery surrounded by a biochemical energy supply. Our approach can be also applied to the information transfer between two coherent regions via microtubules or that in networks (the central region and the N res reservoirs) with the presence of quantum tunneling.
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Kaspari, S., D. A. Dixon, S. B. Sneed, and M. J. Handley. "Sources and transport pathways of marine aerosol species into West Antarctica." Annals of Glaciology 41 (2005): 1–9. http://dx.doi.org/10.3189/172756405781813221.
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AbstractSixteen high-resolution marine aerosol (Na+, SO42–) records from spatially distributed International Trans-Antarctic Scientific Expedition (ITASE) ice cores spanning the last ~200 years from the Pine Island–Thwaites and Ross drainage systems and the South Pole are used to examine sources (sea spray and frost flowers) and transport pathways of marine aerosols into West Antarctica. Factors contributing to the amount of marine aerosols transported inland include sea-ice extent, the presence of open-water features (polynyas, leads), wind strength and direction, and the strength and positioning of low-pressure systems. Analysis of SO42–/Na+ ratios indicates that frost flowers can contribute significantly (40%) to the Na+ budget of Antarctic ice cores. Higher Na+ concentrations in the Ross drainage system may result from greater production of marine aerosols related to frost flowers in the Ross Sea region in association with greater sea-ice extent and larger open-water areas. Significant positive correlations of sea-ice extent and the Na+ time series exist in some regions of West Antarctica. Higher wind speeds in winter and higher Na+ concentrations when sea-level pressure is lower indicate that intensified atmospheric circulation enhances transport and production of marine aerosols.
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Lovelace, Robin, Martijn Tennekes, and Dustin Carlino. "ClockBoard: A zoning system for urban analysis." Journal of Spatial Information Science, no. 24 (June 20, 2022): 63–85. http://dx.doi.org/10.5311/josis.2022.24.172.
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Zones are the building blocks of urban analysis. Fields ranging from demographics to transport planning routinely use zones - spatially contiguous areal units that break-up continuous space into discrete chunks - as the foundation for diverse analysis techniques. Key methods such as origin-destination analysis and choropleth mapping rely on zones with appropriate sizes, shapes and coverage. However, existing zoning systems are sub-optimal in many urban analysis contexts, for three main reasons: 1) administrative zoning systems are often based on somewhat arbitrary factors; 2) zoning systems that are evidence-based (e.g., based on equal population size) are often highly variable in size and shape, reducing their utility for inter-city comparison; and 3) official zoning systems in many places simply do not exist or are unavailable. We set out to develop a flexible, open and scalable solution to these problems. The result is the zonebuilder project (with R, Rust and Python implementations), which was used to create the ClockBoard zoning system. ClockBoard consists of 12 segments emanating from a central place and divided by concentric rings with radii that increase in line with the triangular number sequence (1, 3, 6 km etc). 'ClockBoards' thus create a consistent visual frame of reference for monocentric cities that is reminiscent of clocks and a dartboard. This paper outlines the design and potential uses of the ClockBoard zoning system in the historical context, and discusses future avenues for research into the design and assessment of zoning systems.
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Feng, Leyang, Steven J. Smith, Caleb Braun, Monica Crippa, Matthew J. Gidden, Rachel Hoesly, Zbigniew Klimont, Margreet van Marle, Maarten van den Berg, and Guido R. van der Werf. "The generation of gridded emissions data for CMIP6." Geoscientific Model Development 13, no. 2 (February 6, 2020): 461–82. http://dx.doi.org/10.5194/gmd-13-461-2020.
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Abstract. Spatially distributed anthropogenic and open burning emissions are fundamental data needed by Earth system models. We describe the methods used for generating gridded datasets produced for use by the modeling community, particularly for the Coupled Model Intercomparison Project Phase 6. The development of three sets of gridded data for historical open burning, historical anthropogenic, and future scenarios was coordinated to produce consistent data over 1750–2100. Historical data up to 2014 were provided with annual resolution and future scenario data in 10-year intervals. Emissions are provided on a sectoral basis, along with additional files for speciated non-methane volatile organic compounds (NMVOCs). An automated framework was developed to produce these datasets to ensure that they are reproducible and facilitate future improvements. We discuss the methodologies used to produce these data along with limitations and potential for future work.
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Xu, Haifeng. "Sub-half-wavelength atom localization via two standing waves." Canadian Journal of Physics 95, no. 3 (March 2017): 305–9. http://dx.doi.org/10.1139/cjp-2016-0611.
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We present a simple scheme of high-efficiency one-dimensional (1D) atom localization via manipulation of excited state population in a four-level inverted-Y atomic system. Because of the joint quantum interference induced by the two standing-wave fields, the 100% detecting probability of the atom in the subwavelength domain appears when the corresponding conditions are satisfied. The proposed scheme may open a promising way to achieve high-precision and high-efficiency 1D atom localization, which provides some potential applications to spatially selective single-qubit phase gate, entangling gates, and quantum error correction for quantum information processing.
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Serrano, Manuel, Kevin Larkin, Sergei Tretiak, and Abdessattar Abdelkefi. "Piezoelectric Energy Harvesting Gyroscopes: Comparative Modeling and Effectiveness." Energies 16, no. 4 (February 17, 2023): 2000. http://dx.doi.org/10.3390/en16042000.
Full textAbstract:
Given its versatility in drawing power from many sources in the natural world, piezoelectric energy harvesting (PEH) has become increasingly popular. However, its energy harvesting capacities could be enhanced further. Here, a mathematical model that accurately simulates the dynamic behavior and energy harvested can facilitate further improvements in the performance of piezoelectric devices. One of the goals of this study is to create a dependable reduced-order model of a multi-purpose gyroscope. This model will make it possible to compute the harvested voltage and electrical power in a semi-analytical manner. The harvested voltage is often modeled as an average value across the whole electrode surface in piezoelectric devices. We propose a model which provides practical insights toward optimizing the performance of the system by considering a spatially varying electric field across the electrode surface length. Our framework allows investigation of the limits of applicability of the modeling assumptions across a range of load resistances. The differential quadrature method (DQM) provides the basis for the suggested numerical solution. The model is also employed to examine energy harvesting under various resistance loads. The newly developed spatially varying model is evaluated for open- and closed-circuit conditions and is proved to be accurate for various values of load resistance that have not previously been considered. The results show that using a spatially varying model is more versatile when modeling the performance of the piezoelectric multifunctional energy harvester. The performance may be accurately captured by the model for load resistances ranging between 103 Ω and 108 Ω. At optimum load resistance and near 65 KHz, the maximum power output predicted by the spatially varying (SV) model is 1.3 mV, 1.5 mV for the open-circuit (OC) model, and 2.1 mV for the closed circuit (CE) model. At a high-load resistance, the SV and OC models all predict the maximum power output to be 1.9 mV while the CE model predicted the maximum voltage to be 3 mV.
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Piano, Valentina, Amal Alex, Patricia Stege, Stefano Maffini, Gerardo A. Stoppiello, Pim J. Huis in ’t Veld, Ingrid R. Vetter, and Andrea Musacchio. "CDC20 assists its catalytic incorporation in the mitotic checkpoint complex." Science 371, no. 6524 (December 31, 2020): 67–71. http://dx.doi.org/10.1126/science.abc1152.
Full textAbstract:
Open (O) and closed (C) topologies of HORMA-domain proteins are respectively associated with inactive and active states of fundamental cellular pathways. The HORMA protein O-MAD2 converts to C-MAD2 upon binding CDC20. This is rate limiting for assembly of the mitotic checkpoint complex (MCC), the effector of a checkpoint required for mitotic fidelity. A catalyst assembled at kinetochores accelerates MAD2:CDC20 association through a poorly understood mechanism. Using a reconstituted SAC system, we discovered that CDC20 is an impervious substrate for which access to MAD2 requires simultaneous docking on several sites of the catalytic complex. Our analysis indicates that the checkpoint catalyst is substrate assisted and promotes MCC assembly through spatially and temporally coordinated conformational changes in both MAD2 and CDC20. This may define a paradigm for other HORMA-controlled systems.
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Endsley, K. A., and M. G. Billmire. "Distributed visualization of gridded geophysical data: the Carbon Data Explorer, version 0.2.3." Geoscientific Model Development 9, no. 1 (January 29, 2016): 383–92. http://dx.doi.org/10.5194/gmd-9-383-2016.
Full textAbstract:
Abstract. Due to the proliferation of geophysical models, particularly climate models, the increasing resolution of their spatiotemporal estimates of Earth system processes, and the desire to easily share results with collaborators, there is a genuine need for tools to manage, aggregate, visualize, and share data sets. We present a new, web-based software tool – the Carbon Data Explorer – that provides these capabilities for gridded geophysical data sets. While originally developed for visualizing carbon flux, this tool can accommodate any time-varying, spatially explicit scientific data set, particularly NASA Earth system science level III products. In addition, the tool's open-source licensing and web presence facilitate distributed scientific visualization, comparison with other data sets and uncertainty estimates, and data publishing and distribution.
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Link, Robert, Abigail Snyder, Cary Lynch, Corinne Hartin, Ben Kravitz, and Ben Bond-Lamberty. "Fldgen v1.0: an emulator with internal variability and space–time correlation for Earth system models." Geoscientific Model Development 12, no. 4 (April 12, 2019): 1477–89. http://dx.doi.org/10.5194/gmd-12-1477-2019.
Full textAbstract:
Abstract. Earth system models (ESMs) are the gold standard for producing future projections of climate change, but running them is difficult and costly, and thus researchers are generally limited to a small selection of scenarios. This paper presents a technique for detailed emulation of the Earth system model (ESM) temperature output, based on the construction of a deterministic model for the mean response to global temperature. The residuals between the mean response and the ESM output temperature fields are used to construct variability fields that are added to the mean response to produce the final product. The method produces grid-level output with spatially and temporally coherent variability. Output fields include random components, so the system may be run as many times as necessary to produce large ensembles of fields for applications that require them. We describe the method, show example outputs, and present statistical verification that it reproduces the ESM properties it is intended to capture. This method, available as an open-source R package, should be useful in the study of climate variability and its contribution to uncertainties in the interactions between human and Earth systems.