scholarly journals Non-resonant power-efficient directional Nd:YAG ceramic laser using a scattering cavity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
KyeoReh Lee ◽  
Ho Jin Ma ◽  
Fabian Rotermund ◽  
Do Kyung Kim ◽  
YongKeun Park
Keyword(s):  
Power Efficiency ◽  
Laser Emission ◽  
Light Trap ◽  
Light Sources ◽  
Trap Design ◽  
Power Efficient ◽  
Practical Applications ◽  
Laser Gain ◽  
Resonant Laser ◽  
Operation Characteristics

AbstractNon-resonant lasers exhibit the potential for stable and consistent narrowband light sources. Furthermore, non-resonant lasers do not require well-defined optics, and thus has considerably diversified the available types of laser gain materials including powders, films, and turbid ceramics. Despite these intrinsic advantages, the practical applications of non-resonant lasers have been limited so far, mainly because of their low power efficiency and omnidirectional emission. To overcome these limitations, here we propose a light trap design for non-resonant lasers based on a spherical scattering cavity with a small entrance. Using a porous Nd3+:YAG ceramic, directional laser emission could be observed with significant enhancements in the slope efficiency and linewidth (down to 32 pm). A theoretical model is also developed to describe and predict the operation characteristics of proposed non-resonant laser.

scholarly journals An Automated Light Trap to Monitor Moths (Lepidoptera) Using Computer Vision-Based Tracking and Deep Learning

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 343
Author(s):  
Kim Bjerge ◽  
Jakob Bonde Nielsen ◽  
Martin Videbæk Sepstrup ◽  
Flemming Helsing-Nielsen ◽  
Toke Thomas Høye
Keyword(s):  
Computer Vision ◽  
Deep Learning ◽  
Vision System ◽  
Low Cost ◽  
Light Trap ◽  
Automatic Monitoring ◽  
Light Sources ◽  
Monitoring Methods ◽  
Computer Vision System ◽  
Substantial Investment

Insect monitoring methods are typically very time-consuming and involve substantial investment in species identification following manual trapping in the field. Insect traps are often only serviced weekly, resulting in low temporal resolution of the monitoring data, which hampers the ecological interpretation. This paper presents a portable computer vision system capable of attracting and detecting live insects. More specifically, the paper proposes detection and classification of species by recording images of live individuals attracted to a light trap. An Automated Moth Trap (AMT) with multiple light sources and a camera was designed to attract and monitor live insects during twilight and night hours. A computer vision algorithm referred to as Moth Classification and Counting (MCC), based on deep learning analysis of the captured images, tracked and counted the number of insects and identified moth species. Observations over 48 nights resulted in the capture of more than 250,000 images with an average of 5675 images per night. A customized convolutional neural network was trained on 2000 labeled images of live moths represented by eight different classes, achieving a high validation F1-score of 0.93. The algorithm measured an average classification and tracking F1-score of 0.71 and a tracking detection rate of 0.79. Overall, the proposed computer vision system and algorithm showed promising results as a low-cost solution for non-destructive and automatic monitoring of moths.

scholarly journals Do Different LED Colours Influence Sand Fly Collection by Light Trap in the Mediterranean?

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Gabriella Gaglio ◽  
Ettore Napoli ◽  
Francesca Arfuso ◽  
Jessica Maria Abbate ◽  
Salvatore Giannetto ◽  
...  
Keyword(s):  
Light Trap ◽  
Mediterranean Area ◽  
Sand Fly ◽  
Sand Flies ◽  
Light Traps ◽  
Trap Design ◽  
Phlebotomine Sand Flies ◽  
Positive Effects ◽  
Uv Led ◽  
The Mediterranean

Light traps represent the most used attractive system to collect and monitor phlebotomine sand flies. Recent studies have suggested that light traps can be easily upgraded by the use of light-emitting diode (LED) with positive effects on trap design, weight, and battery life. However, scant data on the effect of different LED colours on the attractiveness to phlebotomine sand fly species are available in literature. In this study, the capture performances of light traps equipped with different LED colours on phlebotomine sand fly species indigenous in the Mediterranean area were evaluated. Phlebotomine sand fly collections were performed using a classical light trap (CLT), equipped with a traditional incandescent lamp, and five Laika 4.0 light traps supplied, each with LED of different colours and wavelengths: (i) white; (ii) red; (iii) green; (iv) blue; (v) UV. Light traps were set for three consecutive nights fortnightly from May to October 2017 and climate data recorded using a meteorological station. A total of 411 phlebotomine sand flies (191 males and 220 females), belonging to three different species, namely, Phlebotomus perniciosus (n= 298, 141 males and 157 females), Sergentomyia minuta (n=110, 48 males and 62 females), and Phlebotomus neglectus (n=3, 2 males and 1 females) were collected. Abundance of capture was influenced by colours of LED and time. The highest number of phlebotomine sand flies was captured on June (P<0.01) and by UV LED (P<0.01). As regard to species, P. perniciosus was mainly captured by UV LED on June (P<0.01). No effect of time (P>0.05) or LED colour (P>0.05) was recorded for S. minuta and P. neglectus. According to the results of the present study light trap equipped with UV LED can represent an effective tool for the capture of sand fly species in the Mediterranean area.

scholarly journals FPGA-Based On-Board Hyperspectral Imaging Compression: Benchmarking Performance and Energy Efficiency against GPU Implementations

2020 ◽  
Vol 12 (22) ◽  
pp. 3741 ◽  
Author(s):  
Julián Caba ◽  
María Díaz ◽  
Jesús Barba ◽  
Raúl Guerra ◽  
Jose A. de la Torre and Sebastián López
Keyword(s):  
Reconfigurable Computing ◽  
Power Efficiency ◽  
Real Life ◽  
Hyperspectral Data ◽  
Actual Behavior ◽  
Power Budget ◽  
Image Block ◽  
Power Efficient ◽  
Time Requirements ◽  
Computing Platforms

Remote-sensing platforms, such as Unmanned Aerial Vehicles, are characterized by limited power budget and low-bandwidth downlinks. Therefore, handling hyperspectral data in this context can jeopardize the operational time of the system. FPGAs have been traditionally regarded as the most power-efficient computing platforms. However, there is little experimental evidence to support this claim, which is especially critical since the actual behavior of the solutions based on reconfigurable technology is highly dependent on the type of application. In this work, a highly optimized implementation of an FPGA accelerator of the novel HyperLCA algorithm has been developed and thoughtfully analyzed in terms of performance and power efficiency. In this regard, a modification of the aforementioned lossy compression solution has also been proposed to be efficiently executed into FPGA devices using fixed-point arithmetic. Single and multi-core versions of the reconfigurable computing platforms are compared with three GPU-based implementations of the algorithm on as many NVIDIA computing boards: Jetson Nano, Jetson TX2 and Jetson Xavier NX. Results show that the single-core version of our FPGA-based solution fulfils the real-time requirements of a real-life hyperspectral application using a mid-range Xilinx Zynq-7000 SoC chip (XC7Z020-CLG484). Performance levels of the custom hardware accelerator are above the figures obtained by the Jetson Nano and TX2 boards, and power efficiency is higher for smaller sizes of the image block to be processed. To close the performance gap between our proposal and the Jetson Xavier NX, a multi-core version is proposed. The results demonstrate that a solution based on the use of various instances of the FPGA hardware compressor core achieves similar levels of performance than the state-of-the-art GPU, with better efficiency in terms of processed frames by watt.

Power-efficient solution-processed red organic light-emitting diodes based on an exciplex host and a novel phosphorescent iridium complex

2016 ◽  
Vol 4 (24) ◽  
pp. 5787-5794 ◽  
Author(s):  
Xuejing Liu ◽  
Bing Yao ◽  
Zilong Zhang ◽  
Xiaofei Zhao ◽  
Baohua Zhang ◽  
...  
Keyword(s):  
Power Efficiency ◽  
Efficient Solution ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Iridium Complex ◽  
Solution Processed ◽  
Power Efficient ◽  
Light Emitting ◽  
Organic Light ◽  
Cie Coordinates

A novel red heteroleptic iridium complex, Ir(DPA-Flpy-CF3)2acac, was synthesized and whose corresponding solution-processed PhOLED shows a record power efficiency of 44.5 lm W−1 with CIE coordinates of (0.64, 0.36).

scholarly journals Multiple-Color Reflectors Using Bichiral Liquid Crystal Polymer Films and Their Applications in Liquid Crystal Displays

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3031
Author(s):  
Cheng-Kai Liu ◽  
Ming-Hsien Li ◽  
Chi-Lun Ting ◽  
Andy Ying-Guey Fuh ◽  
Ko-Ting Cheng
Keyword(s):  
Optical Properties ◽  
Liquid Crystal ◽  
Polymer Films ◽  
Cholesteric Liquid Crystal ◽  
Liquid Crystal Polymer ◽  
Utilization Efficiency ◽  
Light Sources ◽  
Practical Applications ◽  
Crystal Polymer ◽  
Pitch Length

Multiple-color reflectors using bichiral liquid crystal polymer films (BLCPFs) are investigated. The BLCPFs consist of alternate layers of two different single-pitch cholesteric liquid crystal (CLC) layers, named CLC#A and CLC#B. The thickness of each CLC layer equals its single pitch length. The optical properties in terms of reflections, reflection-wavelength ranges, and distributions of reflection spectra of the BLCPFs that result from the fixed pitch length of CLC#A along with the decrease of the pitch length of CLC#B are qualitatively simulated and investigated. The results indicate that the above optical properties of the BLCPFs depend on the LC birefringence and pitch lengths of CLC#A and CLC#B layers. The concept of fabrication method of the BLCPFs by using polymerizable CLCs and thin films of poly(vinylalcohol) or photoalignment materials is discussed. They have potential practical applications in functional color filters, asymmetrical transmission systems, etc., owing to the multiple reflection bands of BLCPFs. Moreover, the BLCPFs, which can enhance the color gamut and light-utilization efficiency of light sources/LC displays, are reported herein.

scholarly journals Power-Efficient Driver Circuit for Piezo Electric Actuator with Passive Charge Recovery

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2866 ◽  
Author(s):  
Takashi Ozaki ◽  
Norikazu Ohta
Keyword(s):  
Power Consumption ◽  
Piezoelectric Actuator ◽  
Power Efficiency ◽  
Parasitic Capacitance ◽  
Passive Components ◽  
Power Efficient ◽  
Electric Actuator ◽  
Driver Circuit ◽  
Aerial Vehicle ◽  
Charge Recovery

Piezoelectric actuation is a promising principle for insect-scaled robots. A major concern while utilizing a piezoelectric actuator is energy loss due to its parasitic capacitance. In this paper, we propose a new concept to recover the charge stored in the parasitic capacitance; it requires only three additional lightweight passive components: two diodes and a resistor. The advantages of our concept are its small additional mass and simple operating procedure compared with existing charge recovery circuits. We provided a guideline for selecting a resistor using a simplified theoretical model and found that half of the charge can be recovered by employing a resistor that has a resistance sufficiently larger than the forward resistance of the additional diode. In addition, we experimentally demonstrated the concept. With a capacitive load (as a replacement for the piezoelectric actuator), it was successfully observed that the proposed concept decreased the power consumption to 58% of that in a circuit without charge recovery. Considering micro aerial vehicle (MAV) applications, we measured the lift-to-power efficiency of a flapping wing piezoelectric actuator by applying the proposed concept. The lift force was not affected by charge recovery; however, the power consumption was reduced. As a result, the efficiency was improved to 30.0%. We expect that the proposed circuit will contribute to the advancement of energy-saving microrobotics.

scholarly journals Reduced Graphene Oxide–P25 Nanocomposites as Efficient Photocatalysts for Degradation of Bisphenol A in Water

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 607 ◽  
Author(s):  
Fei Yu ◽  
Xueting Bai ◽  
Changfu Yang ◽  
Lijie Xu ◽  
Jie Ma
Keyword(s):  
Graphene Oxide ◽  
Bisphenol A ◽  
Reduced Graphene Oxide ◽  
Catalytic Effect ◽  
Light Sources ◽  
Solution Ph ◽  
Sunlight Irradiation ◽  
Practical Applications ◽  
Reduced Graphene

Reduced graphene oxide–titanium dioxide photocatalyst (rGO–TiO2) was successfully synthesized by the hydrothermal method. The rGO–TiO2 was used as photocatalyst for the degradation of bisphenol A (BPA), which is a typical endocrine disruptor of the environment. Characterization of photocatalysts and photocatalytic experiments under different conditions were performed for studying the structure and properties of photocatalysts. The characterization results showed that part of the anatase type TiO2 was converted into rutile type TiO2 after hydrothermal treatment and 1% rGO–P25 had the largest specific surface area (52.174 m2/g). Photocatalytic experiments indicated that 1% rGO–P25 had the best catalytic effect, and the most suitable concentration was 0.5 g/L. When the solution pH was 5.98, the catalyst was the most active. Under visible light, the three photocatalytic mechanisms were ranked as follows: O2•− > •OH > h+. 1% rGO–P25 also had strong photocatalytic activity in the photocatalytic degradation of BPA under sunlight irradiation. 1% rGO–P25 with 0.5 g/L may be a very promising photocatalyst with a variety of light sources, especially under sunlight for practical applications.

Observation of whispering-gallery and directional resonant laser emission in ellipsoidal microcavities

2006 ◽  
Vol 23 (9) ◽  
pp. 1793 ◽  
Author(s):  
Liangmin Zhang ◽  
You-Xiong Wang ◽  
Fajian Zhang ◽  
Richard O. Claus
Keyword(s):  
Laser Emission ◽  
Whispering Gallery ◽  
Resonant Laser

Improved Baugh Wooley Multiplier Using Cadence Register Transfer Level Logic for Power Consumption

2017 ◽  
Vol 14 (1) ◽  
pp. 277-283
Author(s):  
V Rajmohan ◽  
O. Uma Maheswari
Keyword(s):  
Power Consumption ◽  
Low Power ◽  
Vlsi Design ◽  
Register Transfer Level ◽  
Low Power Consumption ◽  
Power Efficient ◽  
Practical Applications ◽  
Efficient Process ◽  
Array Multiplier ◽  
Register Transfer

In modern days of VLSI design, speedy operations and low-power consumption is a key requirement for any circuits. When it comes to multipliers, the power efficient multiplier plays an important role. The main aim of this work is to develop the system with faster and less power multiplier for an efficient process by using Baugh-Wooley multipliers. The optimized Baugh-Wooley multiplier consumes least power, area and produces less delay. The proposed architecture is 193× times faster than Conventional array multiplier in the practical applications and 213× times faster than a conventional Baugh-Wooley multiplier. The Improved Baugh-Wooley multiplier consumes the power of 09.02 mW and area of 52426 μm2.

scholarly journals A Power-Efficient Soft-Output Detector for Spatial-Multiplexing MIMO Communications

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Hsiao-Chi Wang ◽  
Tung-Lin Liu ◽  
Yuan-Wei Wu ◽  
Hsi-Pin Ma
Keyword(s):  
Power Efficiency ◽  
Search Algorithm ◽  
Power Saving ◽  
Spatial Multiplexing ◽  
Cmos Process ◽  
Tree Search ◽  
Timing Error ◽  
Power Efficient ◽  
Sphere Decoder ◽  
Tree Search Algorithm

VLSI implementation of a configurable power-efficient MIMO detector is proposed to support4×4spatial multiplexing and modulation from QPSK to 64-QAM. A novel tree search algorithm is proposed to enable the detector to provide soft outputs and to be implemented in parallel and pipelined hardware architecture. The frame error rate (FER) of the detector approaches the quasi-optimal sphere decoder, with 0.5-dB degradation. Moreover, the proposed detector can operate at the optimal voltage under different configurations and detect/recover timing error at run time by a novel adaptive voltage scaling technique with double sampling circuitry. The proposed detector, using TSMC 0.18 μm single-poly six-metal CMOS process with a core area of1.17×1.17 mm2, provides fixed throughput of 45 Mbps in 64-QAM configuration, 120 Mbps in 16-QAM configuration, and 60 Mbps in QPSK configuration. The normalized power efficiency of the design for 64-QAM and 16-QAM configurations is 1.56 Mbps/mW and 2.53 Mbps/mW, respectively. Compared with the conservative margin-based design, the proposed design achieves a 48.8% power saving.

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