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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - End to End Simulation Study of Geostaionary Passive Microwave Atmospheric Sounding
摘要： A numerical simulator for analysis of the geostationary orbit multispectral passive microwave (Geo-MW) mapping and sounding is described, which mainly includes upwelling brightness temperatures forward, microwave radiometer payload simulation and atmospheric profile retrieval. This simulator allows evaluation and optimization of the ability of microwave sensors to retrieve atmospheric temperature and humidity profile. In this paper, end to end simulation study of a Geo-MW radiometer observation at selected frequencies from 50 to 425 GHz with a real-aperture antenna is performed and the accuracy of the brightness temperature measurement and the atmospheric temperature and humidity profile sounding are quantitatively analyzed and evaluated.
关键词： microwave radiative transfer,observation system simulation,GEO microwave imagers,atmospheric profile retrieval,atmospheric sounding
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE PES/IAS PowerAfrica - Cape Town (2018.6.28-2018.6.29)] 2018 IEEE PES/IAS PowerAfrica - Design of a Solar Powered Desalination Plant
摘要： Owing to the lack of perennial streams in the semi-desert to desert parts, two-thirds of South Africa’s surface area is largely dependent on groundwater. This ground water may at times be found to be brackish. Thus, hampering the development economy. A reliable water purification process would be an invaluable tool to those who do not have access to clean drinking water. This paper sets out to trade off this requirement of fresh water with the practical considerations of water quality, quantity, and the energy requirement of affected communities. The goal is to present a meaningful design of a water desalination unit for use in remote and water scarce parts of RSA. The desalination plant will be designed using an outcomes focused methodology and an estimated MATLAB model will be formulated.
关键词： Energy Conversion,Computer Simulation,Water Storage,Desalination,Solar Heating
更新于2025-09-09 09:28:46
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Three-Dimensional Hierarchical Reticular Nanostructure of Fulfora candelaria Wing Decorated by Ag Nanoislands as Practical SERS-Active Substrates
摘要： Although surface-enhanced Raman scattering (SERS) technology has been widely explored nowadays in various fields, the fabrication of practical SERS-active substrates with prominent recognition ability for various analyte molecules is still defective. Natural Fulfora candelaria wing (FCW) with three-dimensional (3D) hierarchical reticular nanostructure was selected as a new bioscaffold for rough silver (Ag) nanoislands to be assembled on to prepare a practical SERS substrate (Ag/FCW substrate). By adjusting the sputtering time of metal Ag, the morphology of the substrates could be easily tuned to control the formation and distribution of “hot spots”. Three-dimensional finite-difference time-domain (3D-FDTD) simulation indicated that the excellent SERS performance under optimal morphology was ascribed to the local enhanced electric field in rough Ag surface and effective “hot spot” areas. The SERS measurement results show that the optimal Ag/FCW substrates had high SERS performance in terms of Raman signal sensitivity, reproducibility, uniformity and recognition ability for various analyte molecules. Coupled with flexibility of the biological substrates and the cost effectiveness, the sensitive SERS detection of varied analytes based on Ag/FCW substrates offered great potential for practical applications.
关键词： surface-enhanced Raman scattering,Fulfora candelaria wing,recognition ability,three-dimensional finite-difference time-domain simulation,practicability
更新于2025-09-09 09:28:46
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3D Measurement Simulation and Relative Pointing Error Verification of the Telescope Mount Assembly Subsystem for the Large Synoptic Survey Telescope
摘要： An engineering validation of a large optical telescope consists of executing major performing tests at the subsystem level to verify the overall engineering performance of the observatory. Thus, the relative pointing error verification of the telescope mount assembly subsystem is of special interest to guarantee the absolute pointing performance of the large synoptic survey telescope. This paper presents a new verification method for the relative pointing error assessment of the telescope mount assembly, based on laser tracker technology and several fiducial points fixed to the floor. Monte-Carlo-based simulation results show that the presented methodology is fit for purpose, even if floor movement occurs due to temperature variation during the measurement acquisition process. A further research about laser tracker technology integration into the telescope structure may suggest that such laser tracker technology could be permanently installed in the telescope in order to provide an active alignment system that aims to detect and correct possible misalignment between mirrors or to provide the required mirror positioning verification accuracy after maintenance activities. The obtained results show that two on-board laser tracker systems combined with eight measurement targets could result in measurement uncertainties that are better than 1 arcsec, which would provide a reliable built-in metrology tool for large telescopes.
关键词： RPE,mirror positioning,laser tracker,telescope mount assembly (TMA),large synoptic survey telescope (LSST),active alignment system,simulation
更新于2025-09-09 09:28:46
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High-mobility material research for thin-film transistor with amorphous thallium–zinc–tin oxide semiconductor
摘要： The applicability of thallium–zinc–tin oxide (TlZnSnO) as a channel material for a thin-?lm transistor (TFT) was investigated by ?rst-principles simulation and cosputtering experiment with XZnSnO (X = Al, Ga or In). The electron effective mass (m*) of Tl0.4ZnSnO was simulated to be >0.153, which is much smaller than that of In0.4ZnSnO (0.246). An In0.4ZnSnO TFT exhibited a mobility (μ) of 32.0 cm2 V%1 s%1 in the experiment; therefore, the Tl0.4ZnSnO TFT was expected to have a higher mobility of approximately 50 cm2 V%1 s%1 following the relation (μ / 1/m*). Moreover, the Tl-related oxide semiconductor would provide better TFT stability because its oxide vacancy is more stable than that of an In-related oxide semiconductor.
关键词： first-principles simulation,thallium–zinc–tin oxide,mobility,cosputtering,electron effective mass,thin-?lm transistor
更新于2025-09-09 09:28:46
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Integrating Google Glass into simulation-based training: experiences and future directions
摘要： Background: Education experts are starting to explore the potential uses of wearable technology and augmented reality in simulation-based training. In this article, we summarize our experiences with using Google Glass in simulation-based training and discuss potential future directions with this advanced technology. Methods: Emergency medicine residents and medical students participated in a pilot study where each team captain was asked to wear Google Glass during 15 separate simulation-based training sessions. Video obtained from Google Glass was analyzed and utilized during debriefing sessions for the residents and medical students. Results: We were able to successfully integrate Google Glass into simulation-based training and debriefing. During the analysis of each recording, observations were noted about the events that transpired and this data was used to provide instructional feedback to the residents and medical students for self-reflection and appraisal. Post-exercise surveys were conducted after each simulation session and all participants noted that Google Glass did not interfere with their simulation experience. Google Glass enabled the observers to analyze the team captain’s primary visual focus during the entire simulation scenario and feedback was provided based on the data recorded. Conclusions: Wearable technologies such as Google Glass can be successfully integrated into simulation-based training exercises without disrupting the learners’ experience. Data obtained from this integration can be utilized to improve debriefing sessions and self-reflection. Future research is underway and required to evaluate other potential uses for wearable technology in simulation-based training.
关键词： Medical education,Augmented reality,Google Glass,Wearable technology,Simulation-based training
更新于2025-09-09 09:28:46
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Design of Bias-Free Operational Uni-traveling-Carrier Photodiodes by Transient Simulation for High-power Pulsed Millimeter-Wave Signal Generation in the Sub-THz Regime
摘要： In this paper, bias-free operational uni-traveling-carrier photodiodes (UTC-PDs) for high-power pulsed millimeter-wave signal generation in the sub-terahertz regime are designed and investigated. The reliability of the physics-based transient simulation is first demonstrated by comparing with reported experimental results. Then, the epitaxial layers are analyzed and optimized through transient simulation for bias-free operation and high-power pulsed millimeter-wave signal generation. The performance between original and optimal structure is compared under excitation of pulse train and sinusoidal optical signals. The results show that the peak output power of the modified UTC-PD under 100-GHz, 200-GHz, and 312.5-GHz pulse train excitation is 4.685 dBm, 1.128 dBm, and ? 4.653 dBm, improved by 2.05 dB, 5.15 dB, and 9.36 dB, respectively.
关键词： Bias-free,Optical communication,Millimeter-wave,Transient simulation,Terahertz communications,Sub-terahertz,Uni-traveling-carrier photodiodes (UTC-PD)
更新于2025-09-09 09:28:46
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Pattern recognition of messily grown nanowire morphologies applying multi-layer connected self-organized feature maps
摘要： Multi-layer connected self-organizing feature maps (SOFMs) and the associated learning procedure were proposed to achieve efficient recognition and clustering of messily grown nanowire morphologies. The network is made up by several paratactic 2-D SOFMs with inter-layer connections. By means of Monte Carlo simulations, virtual morphologies were generated to be the training samples. With the unsupervised inner-layer and inter-layer learning, the neural network can cluster different morphologies of messily grown nanowires and build connections between the morphological microstructure and geometrical features of nanowires within. Then, the as-proposed networks were applied on recognitions and quantitative estimations of the experimental morphologies. Results show that the as-trained SOFMs are able to cluster the morphologies and recognize the average length and quantity of the messily grown nanowires within. The inter-layer connections between winning neurons on each competitive layer have significant influence on the relations between the microstructure of the morphology and physical parameters of the nanowires within.
关键词： Messily grown nanowire morphologies,Artificial neural networks,Monte Carlo simulation,Pattern recognition,Self-organizing feature maps
更新于2025-09-09 09:28:46
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Actuator-Control Circuit Based on OTFTs and Flow-Rate Estimation for an All-Organic Fluid Pump
摘要： In this paper, we report the design of an organic thin-film transistor (OTFT) driver circuit for the actuator of an organic fluid pump, which can be integrated in a portable-size fully-organic artificial lung. Compared to traditional pump designs, lightness, compactness and scalability are achieved by adopting a creative pumping mechanism with a completely organic-material-based system concept. The transportable fluid volume is verified to be flexibly adjustable, enabling on-demand controllability and scalability of the pump’s fluid-flow rate. The simulations, based on an accurate surface-potential OTFT compact model, demonstrate that the necessary driving waveforms can be efficiently generated and adjusted to the actuator requirements. At the actuator-driving-circuit frequency of 0.98 Hz, an all-organic fluid pump with 40 cm length and 0.2 cm height is able to achieve a flow rate of 0.847 L/min, which satisfies the requirements for artificial-lung assist systems to a weakened normal lung.
关键词： organic thin-film transistor,fluid volume,organic actuator,organic circuit,HiSIM-organic model,artificial lung,circuit simulation
更新于2025-09-09 09:28:46
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Nanometer-Sized Crystalline Clusters of IGZO Films Determined from the Grazing Incidence X-ray Scattering and Anomalous X-ray Scattering Data Combined with Reverse Monte Carlo Simulations
摘要： Grazing incidence X-ray scattering measurements have been carried out on c-axis aligned crystalline-indium gallium zinc oxide (CAAC-IGZO) ?lm and nanocrystalline category-indium gallium zinc oxide (NC-IGZO) ?lm and the following results were obtained: (1) the characteristic layered structure of the IGZO crystal did not hold its shape and the X-ray scattering pro?le showed only a relatively sharp ?rst peak at the wave vector (Q) = 21.8 for CAAC ?lm and 23.1 nm11 for NC ?lm, respectively, and additional weak broad peaks were observed at a higher angle. (2) In the case of the CAAC ?lm, tiny peaks were observed at Q = 7 and 14 nm11, corresponding to the positions of the 003 and 006 re?ections, respectively, of the IGZO crystal. Such tiny peaks were not detected in the case of NC ?lm but the asymmetry of the ?rst peak at the low angle side was clearly observed. (3) These structural features implied that more than three polyhedral units, such as InOx (x = 4-6), GaOy (y = 4-6), and ZnOz (z = 4-6), were likely to coexist. It is appropriate to call this structural feature as cluster-1. (4) A composite-type structure formed by combining these polyhedral units is also likely to exist and leads to middle-range ordering. This structure is called cluster-2. The size of such cluster-2 has been estimated to be 2.2 nm for CAAC ?lm and 1.8 nm for NC ?lm using the measured pair distribution function. To gain insights into the structural features of IGZO ?lms, realistic atomic-scale models were obtained to ?t not only the ordinary interference function of grazing incidence X-ray scattering but also the environmental interference function of the anomalous X-ray scattering (AXS) with Zn-absorption edge using reverse Monte Carlo (RMC) simulation. (5) The resultant models indicated the complex and irregular atomic arrangements of two types of IGZO ?lms, which are well characterized by nanometer-sized crystalline clusters. This characteristic feature may be referred to as crystalline-cluster-composite (triple C) structure.
关键词： anomalous X-ray scattering,nanometer-sized crystalline clusters,IGZO ?lm,grazing incidence X-ray scattering,reverse Monte Carlo (RMC) simulation
更新于2025-09-09 09:28:46