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The mechanical and thermal setup of the GLORIA spectrometer
摘要： The novel airborne Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) measures infrared emission of atmospheric trace constituents. GLORIA comprises a cooled imaging Fourier transform spectrometer, which is operated in unpressurized aircraft compartments at ambient temperature. The whole spectrometer is pointed by the gimbal towards the atmospheric target. In order to reach the required sensitivity for atmospheric emission measurements, the spectrometer optics needs to operate at a temperature below 220 K. A lightweight and compact design is mandatory due to limited space and high agility requirements. The cooled optical system needs to withstand high pressure and temperature gradients, humidity, and vibrations. A new cooling system based on carbon dioxide and liquid nitrogen combined with high-performance insulation has been developed to meet the mechanical, thermal, and logistical demands. The challenging mechanical and spatial requirements lead to the development of a novel rigid linear slide design in order to achieve the large optical path difference for high spectral resolution. This paper describes the mechanical and thermal setup of GLORIA and presents the performance results on two different research aircrafts.
关键词： cooling system,atmospheric trace constituents,Fourier transform spectrometer,thermal design,mechanical design,GLORIA,infrared emission,airborne
更新于2025-09-10 09:29:36
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Luminaire Dirt Depreciation (LDD): Field Data from Several Exterior Lighting Projects
摘要： Luminaire dirt depreciation (LDD) data were evaluated for seven luminaires from three different project sites in Philadelphia, Pennsylvania, Minneapolis, Minnesota, and Yuma, Arizona. In each case, the luminaires were removed from the installation, carefully packaged and transported to a photometric testing laboratory, and then tested in the “as-is” or dirty condition, cleaned, and retested. In terms of light output, the results showed that the IES RP-36-15 method for estimating LDD was applicable to the light emitting diode (LED) luminaires evaluated. General claims of lower levels of dirt deprecation (or higher LDD values) for LED luminaires than for luminaires using conventional light sources were not supported by the test data for the LED luminaires in these three projects. Though the overall measured lumen depreciation due to accumulated dirt closely matched IES estimates for LDD, the data indicated that the accumulated dirt on the luminaires dramatically altered the luminous intensity distribution of the luminaires, with reductions in intensity of more than 25% at peak angles. These effects on luminous intensity distribution are not accounted for in IES LDD estimates.
关键词： optics and luminaire design,LED sources and systems,luminaires,roadway lighting,maintenance
更新于2025-09-10 09:29:36
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[IEEE 2018 4th International Conference on Computational Intelligence & Communication Technology (CICT) - Ghaziabad (2018.2.9-2018.2.10)] 2018 4th International Conference on Computational Intelligence & Communication Technology (CICT) - A Low Cost Polarized Navigation Sensor Design
摘要： In this paper, a low-cost bionic polarized light collection sensor is designed based on the sand ant navigation mechanism. The paper presents the basic theory and hardware implementation plan. At the same time, the algorithm and principle of polarization angle acquisition are introduced, which describe the calculation method in detail. At the end of the paper, the causes of the polarization angle error are analyzed and the error compensation method is given. The result of experiment shows that the sensor can collect the information of polarized light and the azimuth angle can be gotten effectively. Its error is about 2(cid:101)(cid:101)and cost is low.
关键词： error analysis,polarized light,error compensation,sensor design
更新于2025-09-10 09:29:36
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[IEEE 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Trebic, Czech Republic (2018.9.18-2018.9.20)] 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Evaluation of Lighting Design Based on Computer Simulation
摘要： Photorealistic computer simulations are now a popular method of lighting design. They are usually associated with the illumination of objects, but they are also successfully used in interior lighting, especially representative lighting. The problem of the verifiability of the tool is often discussed and in which cases only visualization without purely analytical calculations can be used to evaluate the lighting design. The article presents both subjective and objective studies of conformity of a project made using photorealistic visualization and its subsequent implementation. Subjectively it means based on the comparison of simulation images made with different accuracy, with post-implementation photographs of these projects, objectively – on the basis of measurements of the luminance of the completed project and their reference to distributions previously generated by computer. The field measurements carried out as well as surveys have clearly shown that computer simulations in the form of raster images are a reliable design tool in the hands of a lighting designer. The future of the lighting design is also presented.
关键词： advanced lighting simulation,lighting design,virtual reality of lighting,floodlighting
更新于2025-09-10 09:29:36
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Efficient Algorithms for Synthesizing Probing Waveforms with Desired Spectral Shapes
摘要： We consider the design of constant-modulus probing waveforms to improve the spectral compatibility of radar systems with the congested radio frequency (RF) environments. We seek to synthesize radar probing waveforms with desired spectral shapes. We use a weighted least-squares (WLS) fitting approach to formulate the spectral shaping problem. We introduce two algorithms to tackle the optimization problem we encounter. Both algorithms are devised based on cyclic approaches and have guaranteed convergence of the objective values. Moreover, the proposed algorithms can be implemented via fast Fourier transforms (FFT) and hence is computationally efficient. Furthermore, we extend the proposed algorithms to deal with peak-to-average-power-ratio (PAPR) and similarity constraints, which are desirable in some radar applications. Finally, we provide several numerical examples to demonstrate the effectiveness of the proposed algorithms.
关键词： waveform design,cyclic optimization,spectral shaping,Spectrum congestion,constant-modulus,similarity constraint,peak-to-average-power-ratio (PAPR)
更新于2025-09-10 09:29:36
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[IEEE 2018 17th ACM/IEEE International Conference on Information Processing in Sensor Networks (IPSN) - Porto (2018.4.11-2018.4.13)] 2018 17th ACM/IEEE International Conference on Information Processing in Sensor Networks (IPSN) - Poster Abstract: Zero-Power Receiver for Touch Communication and Touch Sensing
摘要： Intra-body and extra-body communication is an attractive wireless communication method for wearable devices and their applications. In this work, we present the architecture, the design and the implementation of a novel zero-power receiver optimized for intra-body and extra-body communication and on-off keying modulation. The receiver includes an energy-harvesting subsystem that extracts energy from the received message to supply the low power circuits. The proposed zero-power receiver is able to receive and to parse data, as well as wake up external logic when a specific address is detected. The receiver can be used both as an always-on touch sensor to be deployed in the field and as a body communication wake up radio to other nodes on the human body. Experimental results with in-field measurements demonstrate the zero-power of the proposed device and that it is possible to achieve more than 1.70m in intra-body communication and hand-shake information exchange without the use of any external battery.
关键词： Zero-Power sensing,Body communication,Wearable devices,Zero-Power communication,Low Power Design
更新于2025-09-10 09:29:36
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Sharp Skirt Bandpass Filter-Integrated Single-Pole Double-Throw Switch With Absorptive off-State
摘要： This paper presents a type of bandpass filter (BPF)-integrated single-pole double-throw (SPDT) switch using common shorted stepped-impedance resonator technique. The BPF-integrated ON-state with reverse-biased p-i-n diodes can be synthesized by classical coupled-resonator filter design theory, and the OFF-state with forward-biased p-i-n diodes is detuned which exhibits high OFF-state suppression (OSS). The transmission zeros due to the direct coupled feed, the cross-couplings and the cancelling effect of mixed electric and magnetic coupling are produced to improve the ON-state passband selectivity significantly. As examples, the third-order/fourth-order BPF-integrated SPDT switches at center frequency f0 = 1 GHz with ripple bandwidth of 110/100 MHz are designed, which show low insertion losses of 1.08/1.58 dB, sharp skirts, high roll-off rate of sidebands, high OSSs of 40.9/40.1 dB as well as high port-to-port isolation of 57.4/47.8 dB. Then, the switched 50-(cid:2) matching circuits are in series with two output ports of above BPF-integrated SPDT switches, resulting in the absorptive OFF-state. The fabricated third-order/fourth-order BPF-integrated SPDT switches with absorptive OFF-state have the matched return losses of 30/28.2 dB, and their OSSs and port-to-port isolations are also improved.
关键词： co-design,switch,single-pole double-throw (SPDT),p-i-n diode,Bandpass filter (BPF)
更新于2025-09-10 09:29:36
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Dynamic Daylight Metrics for Electricity Savings in Offices: Window Size and Climate Smart Lighting Management
摘要： Daylight performance metrics provide a promising approach for the design and optimization of lighting strategies in buildings and their management. Smart controls for electric lighting can reduce power consumption and promote visual comfort using different control strategies, based on affordable technologies and low building impact. The aim of this research is to assess the energy efficiency of these smart controls by means of dynamic daylight performance metrics, to determine suitable solutions based on the geometry of the architecture and the weather conditions. The analysis considers different room dimensions, with variable window size and two mean surface reflectance values. DaySim 3.1 lighting software provides the simulations for the study, determining the necessary quantification of dynamic metrics to evaluate the usefulness of the proposed smart controls and their impact on energy efficiency. The validation of dynamic metrics is carried out by monitoring a mesh of illuminance-meters in test cells throughout one year. The results showed that, for most rooms more than 3.00 m deep, smart controls achieve worthwhile energy savings and a low payback period, regardless of weather conditions and for worst-case situations. It is also concluded that dimming systems provide a higher net present value and allow the use of smaller window size than other control solutions.
关键词： energy saving,window design,daylight autonomy,smart control
更新于2025-09-10 09:29:36
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Molecular Design Strategies for Efficient Intramolecular Singlet Exciton Fission
摘要： The process of carrier multiplication via singlet fission can potentially exceed Shockley–Queisser limit on the efficiency of single-junction photovoltaics. In the recent past, theoretical analysis provided the principal guidelines on molecular design strategies for singlet fission. In this perspective, we focus instead on correlating experimental results for different classes of reported singlet fission materials to identify principles to aid in the design of new molecules for efficient intramolecular singlet fission. Building on an evaluation of several series of multichromophoric and polymeric singlet fission materials, we extract new suggested strategies for molecular design.
关键词： singlet fission,photovoltaics,exciton multiplication,intramolecular singlet fission,molecular design
更新于2025-09-10 09:29:36
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[Lecture Notes in Electrical Engineering] Microelectronics, Electromagnetics and Telecommunications Volume 521 (Proceedings of the Fourth ICMEET 2018) || Design and Simulation of a MIM Capacitor Type RF MEMS Switch for Surface Radar Application
摘要： A Dielectric on Metal (DOM) capacitor in RF MEMS capacitive parallel switches which are generally used for microwave and radar applications in media transmission field, encounter the evil impacts of genuine drawbacks. By the surface repulsiveness of the dielectric layer, there will diminish in the downstate capacitance, in this manner a basic move is found in the deafening repeat. This impediment can be proficient by changing DOM change to a MIM switch that is putting away a thin layer of skimming metal on the dielectric layer. In MIM switch the major factor achieved that is the flexibility in working repeat. The equipotential thought of the coasting metal is suitably utilized and a framework is proposed in this paper. Without a change in the assistant model, the deafening repeat can be varied by changing the length of the skimming metal in case of this MIM change when stood out from a DOM switch. By this blueprint, we can finish the switch working at different frequencies on a comparative wafer. The uneasiness bars are used as a piece of the arrangement remembering the ultimate objective to sidestep the fastening factor. As demonstrated by the arrangement in the paper the switch is worked, duplicated, made and depicted in the K-band extent of a repeat. The most stress is found in this layout. The sketched out switch portrays a diminishment in the full repeat with respect to increase in the floating metal by researching the arrangement versatility in this paper.
关键词： RF MEMS capacitive switch,Stress,MIM switch,Design flexibility,Floating metal
更新于2025-09-10 09:29:36