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The Evaluation of Static Deficiencies of Lower Limbs with the Use of Non-Contact Measurement
摘要： The purpose of this paper is to develop a procedure of the lower limbs volumetric modelling using the laser measurement arm and the evaluation of defects, which can cause disorders in the field of locomotion. The procedure is presented based on the analysis of two specimens: woman (age 22) and man (age 23), whose lower limbs are fully formed. The method includes the laser scanning and the lower limbs regularity evaluation based on the characteristic lines, which were identified during palpation examination of the skin and bones characteristic points or during the radiological examination. The valgus knee and the knee joint hyperextension were determined for the woman’s case and no deficiencies for the man’s case. Presented procedure has a screening application and can support the rehabilitation process. The advantage is that the developed method is noninvasive and the diagnostics can be performed while muscles are active in the natural standing position. The SL method was verified by the Laser Tracker system. On the group of 55 students with the average age of 10.4 years, the measurements were performed in order to define the influence of BMI on the correctness of the results, which were achieved while using the proposed method of the evaluation of the static deficiencies. No relevant influence of BMI on errors occurring in the determination of defects valgus and varus of the lower limbs.
关键词： Valgus,BMI,Characteristic points,Varus,3D modelling,Baseline,Laser scanning
更新于2025-09-10 09:29:36
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Integration of point cloud data and hyperspectral imaging as a data gathering methodology for refurbishment projects using building information modelling (BIM)
摘要： Purpose – Building information modelling (BIM) is a digital representation of the physical and functional characteristics of a building. Its use offers a range of bene?ts in terms of achieving the ef?cient design, construction, operation and maintenance of buildings. Applying BIM at the outset of a new build project should be relatively easy. However, it is often problematic to apply BIM techniques to an existing building, for example, as part of a refurbishment project or as a tool supporting the facilities management strategy, because of inadequacies in the previous management of the dataset that characterises the facility in question. These inadequacies may include information on as built geometry and materials of construction. By the application of automated retrospective data gathering for use in BIM, such problems should be largely overcome and signi?cant bene?ts in terms of ef?ciency gains and cost savings should be achieved. Design/methodology/approach – Laser scanning can be used to collect geometrical and spatial information in the form of a 3D point cloud, and this technique is already used. However, as a point cloud representation does not contain any semantic information or geometrical context, such point cloud data must refer to external sources of data, such as building speci?cation and construction materials, to be in used in BIM. Findings – Hyperspectral imaging techniques can be applied to provide both spectral and spatial information of scenes as a set of high-resolution images. Integrating of a 3D point cloud into hyperspectral images would enable accurate identi?cation and classi?cation of surface materials and would also convert the 3D representation to BIM. Originality/value – This integrated approach has been applied in other areas, for example, in crop management. The transfer of this approach to facilities management and construction would improve the ef?ciency and automation of the data transition from building pathology to BIM. In this study, the technological feasibility and advantages of the integration of laser scanning and hyperspectral imaging (the latter not having previously been used in the construction context in its own right) is discussed, and an example of the use of a new integration technique is presented, applied for the ?rst time in the context of buildings.
关键词： Laser scanning,Information modelling,Refurbishment,BIM,Point cloud,Hyperspectral imaging
更新于2025-09-10 09:29:36
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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - High-Bandwidth Organic Light Emitting Diodes for Ultra-Low Cost Visible Light Communication Links
摘要： Visible light communications (VLC) have attracted considerable interest in recent years due to an increasing need for data communication links in home and enterprise environments. Organic light-emitting diodes (OLEDs) are widely used in display applications owing to their high brightness, high quality colour-rending capability and low cost. As a result, they are attractive candidates for the implementation of ultra-low cost visible light optical links in free-space and guided-wave communications. However, OLEDs need to exhibit a bandwidth of at least ~MHz to be able to support the modest data rates (~Mbps) required in these applications. Although fluorescent OLEDs typically exhibit shorter photon lifetimes than inorganic LEDs, the bandwidth performance of the large size OLEDs used in display applications are limited by their electrical characteristics. In this work, we present a detailed physical simulation that describes well the performance of fast OLED devices that exhibit significant -3 dB bandwidths (f3dB) of 44 MHz obtained for a 0.12 mm2 device. It is demonstrated that the reduction of the device size results in a significant bandwidth improvement due primarily to a reduction in parasitic capacitance of the devices, though this is counteracted by carrier dynamic effects. The model provides an insight into the basic physical properties of the OLED and may be used for optimisation of future generations of OLED devices.
关键词： simulation,visible light communications,modelling,OLED
更新于2025-09-10 09:29:36
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Kinetic Modelling of Transient Photoluminescence from Thermally Activated Delayed Fluorescence
摘要： A simplified state model and associated rate equations are used to extract the reverse intersystem crossing and other key rate constants from transient photoluminescence measurements of two high performance thermally activated delayed fluorescence materials. The values of the reverse intersystem crossing rate constant are in close agreement with established methods, but do not require a priori assumption of exponential decay kinetics, nor any additional steady state measurements. The model is also applied to measurements at different temperatures and found to reproduce previously reported thermal activation energies for the thermally activated delayed fluorescence process. Transient absorption measurements provide independent confirmation that triplet decay channels (neglected here) have no adverse effect on the fitting.
关键词： Thermally Activated Delayed Fluorescence,Transient Photoluminescence,Reverse Intersystem Crossing,Kinetic Modelling
更新于2025-09-10 09:29:36
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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - Time Domain Modeling of Multimode Selenide-Chalcogenide Glass Fiber Based Mid Infrared Spontaneous Emission Sources
摘要： We develop time domain models of selenide-chalcogenide glass fiber based MIR spontaneous emission sources. The modeling parameters used are derived from experimentally obtained data. The models are based on the rate equations’ approach to simulate the distribution of ions between the relevant energy levels. The optical power distribution within the fiber is calculated by solving a set of partial differential equations using specially developed finite difference schemes that allow for a direct inclusion of the step discontinuities appearing at the fiber facets. The results obtained allow for a thorough analysis of luminescence from lanthanide ion doped chalcogenide fibers.
关键词： mid infrared photonics,chalcogenide glass fibers,numerical modelling
更新于2025-09-10 09:29:36
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Novel Four-Port DC-DC Converter for Interfacing Solar PV-Fuel Cell Hybrid Sources with Low-Voltage Bipolar DC Microgrids
摘要： Bipolarity in dc microgrids is desirable as it enhances the system reliability and efficiency. However, a bipolar dc microgrid (BDCMG) demands multiple conventional dc-dc converters to feed power to both the poles of the bipolar dc grid. To handle this requirement and to maintain high efficiency, a new four-port, dual-input-dual-output (DIDO) converter topology is proposed for interfacing the solar PV and fuel cell (FC) sources to a low-voltage BDCMG. The proposed topology is unidirectional, efficient, and compact. It has fewer circuit elements with only one inductor as compared to the conventional non-isolated dc-dc converters. The proposed converter regulates one of the pole voltages of the dc bus and also ensures MPPT of the PV source. Further, the converter can be operated as a single-input-dual-output (SIDO) converter. The control complexity of the proposed converter is low as it can be operated in various modes with only one set of controllers. To design the control system for the proposed converter, a small-signal model is derived for each operating mode. Loss modelling and efficiency analysis of the proposed converter are carried out and its efficacy and performance are validated by detailed simulation and experimental results under various operating conditions.
关键词： dc-dc converter,small-signal modelling,Bipolar dc microgrid (BDCMG),fuel cell (FC),state-space averaging,photovoltaic (PV)
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE 17th International Conference on Mathematical Methods in Electromagnetic Theory (MMET) - Kiev (2018.7.2-2018.7.5)] 2018 IEEE 17th International Conference on Mathematical Methods in Electromagnetic Theory (MMET) - Modeling of Electromagnetic Wave Scattering and Propagation in the Presence of a Pre-Fractal PEC Strip Grating
摘要： Classes of one-dimensional self-similar fractals with variable Hausdorff–Besicovitch dimension are presented. They can be used in the pre-fractal modelling in electromagnetic and acoustic wave theory: wave scattering by pre-fractal gratings and wave propagation in pre-fractal systems of microstrip lines.
关键词： self-similar fractals,wave scattering,wave propagation,pre-fractal modelling,fractal dimension
更新于2025-09-09 09:28:46
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ECCD characterization of monotopically binding guests in host-guest complexes with a bis-(zinc porphyrin) tweezer
摘要： We have investigated the possibility to use a stiff-stilbene linked bisporphyrin tweezer with inherent helicity for Exciton-Coupled Circular Dichroism (ECCD) characterization of a series of monotopically binding amine guest molecules. CD signals were observed for a variety of monoamines at relatively low tweezer:amine (host:guest) ratios between 1:10 to 1:70. For the amines producing the most intense CD signals a binding stoichiometry of 1:2 was found. A likely explanation is the presence of guest-guest interactions in the complexes. This is supported by observing a correlation between CD signal intensity and magnitude of possible non-covalent binding between the guests, which we can divide into three groups showing no, moderate or strong response, respectively. Further support for this rationalization comes from molecular modelling.
关键词： absolute stereochemistry,molecular modelling,bis-porphyrin tweezers,monotopic binding,exciton-coupled circular dichroism
更新于2025-09-09 09:28:46
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Energy yield of all thin-film perovskite/CIGS tandem solar modules
摘要： Perovskite/CuIn1 ? xGaxSe2 (CIGS) tandem photovoltaics (PV) promises high power conversion efficiencies in combination with the advantages of a light weight and an all thin-film PV technology. However, the complexity of perovskite/CIGS tandem solar module architectures requires careful optimization of the layer stack under realistic solar irradiation conditions. Here, we provide a systematic numerical study on the energy yield (EY) of perovskite/CIGS tandem solar modules, optimizing the device architecture with regard to irradiance in various climate zones. In particular, variations of the spectral irradiation and the average photon energy are of decisive importance for the location-specific optimization of the device architecture. Compared with the reference single-junction CIGS thin-film PV technology, we demonstrate a strong improvement in EY (>30%) in perovskite/CIGS thin-film PV for perovskites of a wide range of bandgaps (1.55 - 2.0 eV), reaching up to 52% improvement in EY for the optimal bandgap (around 1.8 eV). Of the two most favored architectures, the two-terminal and four-terminal devices, perovskite/CIGS tandem solar modules with low bandgap (～1.55 eV) perovskite absorbers in the four-terminal architecture outperform those in the two-terminal architecture in average by 3.5% relative. However, for wide perovskite bandgaps ranging from 1.75 eV to 1.85 eV, both architectures perform comparably. The improvements in EY for perovskite/CIGS tandem solar modules highlight the potential of this technology but also the vital need for light management in tandem photovoltaics.
关键词： perovskite/CIGS tandem photovoltaics,energy yield modelling,realistic conditions
更新于2025-09-09 09:28:46
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Improved field emission from appropriately packed TiO2 nanorods: Designing the miniaturization
摘要： An improved electron field emission (FE) property from vertically aligned TiO2 nanorods (TNR) on conducting fluorine doped tin oxide coated glass substrate, prepared by hydrothermal technique, has been reported here. The TNRs having high aspect ratio with appropriate separation were prepared by optimizing the nucleation temperature. The TNR density has been optimized to cease the screening effect in closely packed nanorods. The well aligned rods have been designed so that the applied field is equally distributes on each rod to improve the electron emission. The morphology of the nanorod has been studied using scanning electron microscopy and observed FE current density-field response has been analysed within the frame work of Fowler-Nordheim modelling. Two orders of magnitude enhancement in the electric field has been observed for this kind of geometry giving improved turn on field and field enhancement factor of 0.2 V/m m and 37 thousands respectively.
关键词： Fowler-Nordheim modelling,Hydrothermal technique,Field emission,TiO2 nanorods,Field enhancement factor
更新于2025-09-09 09:28:46