Effect of Ambient Lighting on Frequency Dependence in Transcranial Electrical Stimulation-Induced Phosphenes

Inconsistencies have been found in the relationship between ambient lighting conditions and frequency-dependence in transcranial electric current stimulation (tECS) induced phosphenes. Using a within-subjects design across lighting condition (dark, mesopic [dim], photopic [bright]) and tECS stimulation frequency (10, 13, 16, 18, 20 Hz), this study determined phosphene detection thresholds in 24 subjects receiving tECS using an FPz-Cz montage. Minima phosphene thresholds were found at 16 Hz in mesopic, 10 Hz in dark and 20 Hz in photopic lighting conditions, with these thresholds being substantially lower for mesopic than both dark (60% reduction) and photopic (56% reduction), conditions. Further, whereas the phosphene threshold-stimulation frequency relation was linear in the dark (increasing with frequency) and photopic (decreasing with frequency) conditions, a quadratic function was found for the mesopic condition (where it followed the linear increase of the dark condition from 10-16 Hz, and the linear decrease of the photopic condition from 16-20 Hz). The results clearly demonstrate that ambient lighting is an important factor in the detection of tECS-induced phosphenes, and that mesopic conditions are most suitable for obtaining overall phosphene thresholds.

Integrating Daylighting with Task-Ambient Lighting for Enhanced Energy Savings in Office Spaces

Daylighting has been widely studied as a fundamental aspect of spatial illumination and energy efficient façade design. Effective installation and control of shading devices diminishes the adverse effects of prevailing climatic conditions on building envelope performance and reduces resultant lighting and cooling energy consumption. Task-ambient lighting as a free-standing approach has also been proven to reduce lighting energy consumption compared with typical general ambient lighting. This study estimates the energy saving potential of integrating daylighting through fixed external horizontal shading slats with task lighting. Spot measurements were taken in a test room to validate a daylight calculation program. Full year indoor work plane daylight simulations were performed for office spaces of different floor areas and varying window to wall ratios. Indoor daylight quality was assessed using the Useful Daylight Illuminance metric and three different task lighting schemes explored. Lighting energy savings of 10% to 90% were estimated under the three schemes in comparison to similar office spaces with common unshaded heat reflective glazing.

Occurrence of Leaf Spot Caused by Mycocentrospora acerina on Zhujieshen(Panax japonicus C. A. Mey.) in China

Panax japonicus C. A. Mey., known as Japanese ginseng or “Zhujieshen” in China, is a perennial medicinal herb (family Araliaceae) native to China and is widely grown in many provinces including Hubei, Hunan, and Sichuan. In recent years, cultivation of Japanese ginseng has increased tremendously in China because of its high value. Its root is widely used in traditional Chinese medicine for the treatment of inflammation. In early May 2020, severe necrotic lesions on leaves with 40 to 50 % disease incidences were observed on 3-year-old Japanese ginseng plants in a cultivated field in Xuanen County (30°05′N, 109°83′E), Hubei Province, China. The total area affected by the disease was approximately 30 ha. Initial symptoms showed small, circular, brown, necrotic spots uniformly distributed on leaves. The center of the spots was light tan, surrounded by a dark brown ring and a chlorotic halo. As the disease progressed, multiple lesions merged into large disease spots with visible white fungal hyphae, causing leaf wilting. Ten small pieces (0.1 × 0.1 cm in size) of leaf tissue were removed from the lesion margins, surface-sterilized with 0.5 % sodium hypochlorite for 1 min and 75 % alcohol for 20 s, washed with sterile distilled water three times, dried, and placed on Petri plates with potato dextrose agar (PDA) medium containing 10 µg/ml of ampicillin and incubated at 20 °C for 5 days. Colonies with dense mycelia were initially white and gradually becoming black. The hyphae were septate, branched, and 3 to 7 µm in width. Conidiophores were flexuous, not branched, and produced a single spore. Spores (ranged from 95.4 to 255.5 × 6.2 to 13.5 μm) were elongate, multiseptate, with a long, strongly curved beak (ranged from 25.5 to 95.4 μm), The number of septae ranged from 4 to 13. Clamydospores with smooth or slightly rough wall were spherical to ovoid and averaged 8.5 to 25.4 × 7.2 to 16.5 μm. The six isolates were preliminarily identified as Mycocentrospora acerina (R. Hartig) Deightonbased on the morphological characteristics (Gilchrist et al. 2015). To confirm the identification, isolates ZJS1, ZJS3, and ZJS5 were chosen for DNA sequencing. The internal transcribed spacer (ITS) region of rDNA was amplified using the ITS1 and ITS4 primers (White et al. 1990) and sequenced. The identical sequences of the 491 bp amplicons were deposited in GenBank (accession no. ZJS1, MZ277314; ZJS3, OL333859; and ZJS5, OL333860). BLAST analysis of the sequences showed 100 % identity to M. acerina (MH856114). Moreover, the three isolates were further confirmed as M. acerina by amplifying the large subunit (LSU) of the ribosome gene (accession no. ZJS1, MZ277321; ZJS3, OL333861; and ZJS5, OL333862), as their identical sequences exhibited 99.83 % similarities with M. acerina (MH868490). Isolate ZJS1 was chosen to fulfill Koch’s postulates with 30 healthy 2-year-old P. japonicus grown in plastic pots filled with a sterilized mixture of peat moss and vermiculite (3:1). One leaf of each plant was inoculated with one 5-mm-diameter mycelium-agar disc and placed in a greenhouse at 20 ± 1 °C, with ambient lighting and relative humidity of 85 %. By 5 days after inoculation, all inoculated plants showed symptoms identical to those observed in the field, and no symptoms were observed on control plants. The fungus was reisolated from the inoculated plants and identified as M. acerina using the above method. The experiment was conducted thrice with similar results. To our knowledge, this is the first report of leaf spot caused by M. acerina on Japanese ginseng in China and the world. There is a need to develop effective management measures to reduce the occurrence of this disease.

Precision Fibre Angle Inspection for Carbon Fibre Composite Structures Using Polarisation Vision

This paper evaluates the precision of polarisation imaging technology for the inspection of carbon fibre composite components. Specifically, it assesses the feasibility of the technology for fibre orientation measurements based on the premise that light is polarised by reflection from such anisotropically conductive surfaces. A recently commercialised Sony IMX250MZR sensor is used for data capture by using various lighting conditions. The paper shows that it is possible to obtain sub-degree accuracy for cured and dry woven and unidirectional materials in ideal conditions, which comprised dark field illumination. Indeed, in ideal conditions, the average relative angles can be measured to an accuracy of 0.1–0.2°. The results also demonstrate a precision of the order 1° for more general illumination, such as dome illumination and ambient lighting, for certain material type/lens combinations. However, it is also shown that the precision varies considerably depending on illumination, lens choice and material type, with some results having errors above 2°. Finally, a feasibility study into the inspection of three-dimensional components suggests that only limited application is possible for non-planar regions without further research. Nevertheless, the observed phenomena for such components are, at least, qualitatively understood based on physics theory.

Software package for testing three-dimensional shape measurement methods using structured lighting

This work aims at creating a universal software package for the development and testing of triangulation methods using structured lighting for measuring the three-dimensional geometry of objects in difficult ambient lighting conditions. As a result, a software package meeting the stated requirements is created. Lighting is based on the Fong model. A method for preloading objects is implemented to optimize the operation of the software package. An accelerated method for creating shadow maps is proposed and implemented. The developed software package is shown to successfully perform all required functions.

Automatic (Headlight) Beam Controlling module for two-wheelers

Automatic High Beam controller is a device made due to the rising number of accidents at night because of LED headlamps temporarily affecting the vision of the driver on the opposite lane. According to AAA, LED lights do a much better job of illuminating the roadway, particularly in the low-beam application versus a halogen reflector at 150 feet more during testing. But, still, that brings the max vehicle speed to about 52 miles an hour, which is still falling short of highway speeds. So, the users are suggested to drive with high beam on if there is no oncoming traffic within a reasonable distance and the roadway is improperly lit. But in practice most people drive with the high beam settings in places with or without traffic great from the user's standpoint. However, even on low beam, they have such a high intensity that on 2-lane roads, especially when the oncoming driver of a car or small pickup approaches the LED equipped truck at night, in rain, fog, or snow the oncoming driver is blinded at a level equal to or greater than if the LED equipped vehicle were using conventional halogen high beams. This device is made without distance or ambient lighting being deciding factors and entirely based on user’s discretion. The transmitter model is fitted with a button that sends a signal to the receiver model using nrf24L01 modules and AT Mega 8 microcontroller (programmed using Arduino UNO). The pressing of button causes the state of the button to be set to HIGH. This signals the receiving circuit to set the LED pin to LOW. Therefore, the High Beam is set to Low Beam for 5 seconds when the impulse is received. Due to the use of H4 C6 headlamps which are rated for 36W with a minimum power requirement of 12W an adapter was connected to convert 220V AC supply to 12V, 3A DC supply for the LED and the rest of the circuit.

ANÁLISE DE MÉTODOS DE DETECÇÃO E RECONHECIMENTO DE FACES UTILIZANDO VISÃO COMPUTACIONAL E ALGORITMOS DE APRENDIZADO DE MÁQUINA

The advancement in technology in recent decades has provided many facilities for humanity in various applications, and facial recognition technology is one of them. There are several problemsto be solved to perform face recognition from digital images, such as varying ambient lighting, changing the face physical characteristics and resolution of the images used. This work aimed to perform a comparative analysis between some of thedetection and facial recognition methods, as well as their execution time. We use the Eigenface, Fisherface and LBPH facial recognition algorithms in conjunction with the Haar Cascade facedetection algorithm, all from the OpenCV library. We also explored the use of CNN neural network for facial recognition in conjunction with the HOG facial detection algorithm, these from the Dlib library. The work aimed, besides analyzing the algorithms in relation to hit rates, factors such as reliability and execution time were also considered

White Light Communication: A Design for High School Experiment

As wireless communication carrier frequencies continually increase to respond to growing bandwidth demands, from hundreds of MHz (3G/4G) to dozens of GHz (5G), it would only be logical to postulate that the next step in this technological revolution would be to move to hundreds of THz, also known as visible light. This completely alleviates the carrier frequency induced bandwidth limitations while serving as ambient lighting. In this paper, a visible light communication setup capable of moderate bitrate serial communication with interference from ambient lighting will be presented. Furthermore, this paper proposes the implementation of a similar setup as a form of hands-on experiential learning for high school and undergraduate engineering students.