Red Green Research Articles

Developing a Novel Layered Boron Nitride–Carbon Nitride Composite with High Efficiency and Selectivity To Remove Protonated Dyes from Water

A layered boron nitride (BN)–carbon nitride (CN) composite has been successfully synthesized by calcinating a mixture of BN nanoparticles and urea at 600 °C, wherein CN is formed from the thermal polymerization of urea during the calcination process. TEM analyses confirm that the BN-CN composite has a layered structure, being different from the morphologies of BN nanoparticles and CN. FTIR, XRD, and NMR results support that the layered BN-CN composite is most likely formed via the dehydration reaction between the -OH groups in the BN nanoparticles and the -NH2 groups in CN during the calcination process, which links BN nanoparticles and CN together to form the layered composite. The layered BN-CN composite can, with high efficiency, remove Neutral Red (NR) and Malachite Green (MG) from water (NR removal quantity: 1350.1 mg/g, concentration: 220 mg/L; MG removal quantity: 1040.6 mg/g, concentration: 120 mg/L), whereas the layered BN-CN composite has low efficiency to remove Methyl Orange (MO), Methylene Blue (MB), and Crystal Violet (CV) from water. The quantities of MO, MB, and CV removed are all just around 60 mg/g with a concentration of 120 mg/L. NR and MG are both protonated dyes, and their positive charges are from the bound H+. The layered BN-CN composite has high affinity for H+, which can cause the pH of the deionized water to increase to 8.89 from the initial 6.82. This may be responsible for the high removal efficiency of the layered BN-CN composite for NR and MG. Furthermore, the layered BN-CN composite can selectively remove NR (or MG) from NR-MO and NR-MB solutions (or MG-MO and MG-MB solutions).

Synthesis of nitrogen & palladium co-doped mesoporous titanium dioxide nanoparticles via evaporation induced self assembly method and study of their photocatalytic properties

In the present research, nitrogen and palladium co-doped mesoporous titanium dioxide nanoparticles have been synthesized via evaporation induced self-assembly method using titanium tetraisopropoxide, as the precursor of titanium and Pluronic P123 as a surface directing agent. The physicochemical properties of all the samples are determined by various techniques. Study of the X-ray diffraction pattern verified the existence of the tetragonal anatase phase of mesoporous TiO2 nanoparticles with crystallite size in the range of 7.38–11.08 nm. Analysis of ultraviolet–visible spectroscopy and photoluminescence spectroscopy show that the band gap energy and electron-hole recombination rate reduces rapidly with an increase in the concentration of nitrogen & palladium. Scanning electron microscope and transmission electron microscope images show that the assemblies of nanoparticles result in the genesis of nanometer size range mesoporous structure, including a sphere like aggregate and retained ordered structure. The porosity, pore size distribution and surface area of the samples have been studied by using the Brunauer–Emmett–Teller analysis. Study of Fourier-transform infrared spectroscopy supports the existence of OTiO bonding and the impact of co-doping on stretching vibration of OTiO bonding. Three different dyes named methylene blue, congo red, and malachite green are used to study the photocatalytic activities of samples in the presence of visible light.

Assessment of masticatory performance by geometric measurement of the mixing ability with 2-color chewing gum

Statement of problemThe 2-color mixing ability test has been recently introduced for objective assessment of masticatory performance. However, the ideal bicolor specimens have not yet been identified, and the color analysis of digital images requires improvement. PurposeThe purpose of this clinical study was to formulate a custom-made, 2-color chewing gum for the mixing ability test and to develop an image-processing method for color mixing analysis. Material and methodsSpecimens of red-green (RG) chewing gum were prepared as a test food. Twenty dentate participants (10 men, 10 women; mean age 21 years) took part in this study. Each participant masticated 1 piece of RG gum for 3, 6, 9, 15, and 25 cycles, and this task was repeated 3 times consecutively (total n=15 for each participant). The boluses were retrieved and flattened to 1-mm-thick wafers and scanned with a flatbed scanner. The digital images were analyzed using ImageJ software equipped with a custom-built plug-in to measure the geometric dispersion (GD) of baseline red segment. The predictive criterion validity of this method was determined by correlating GD to the number of mastication cycles. The hardness and mass of RG chewing gum were measured before and after mastication. Hardness loss (%) and mass loss (%) were then calculated and compared with those of a commercially available chewing gum. ResultsThe 2-way repeated-measures ANOVA with post hoc Bonferroni test showed that GD was able to discriminate among the groups of different numbers of mastication cycles (P<.001). Pearson correlation coefficient confirmed the significant correlation between GD and the number of mastication cycles (r=0.90, P<.001). The hardness loss and mass loss of RG chewing gum were significantly lower than those of commercial chewing gum (P<.001). ConclusionsThe newly formulated chewing gum provides an appropriate test food material for masticatory performance assessment. The new image-processing method discriminated among the different levels of color mixture and quantified the mixing ability.

Smartphone-based Ellman’s colourimetric methods for the analysis of d-penicillamine formulation and thiolated polymer

A new, smartphone-based colourimetric method for the assay of d-penicillamine formulations relying on the Ellman’s reaction was developed by performing the colourimetric reaction in a microplate. Subsequently, the plate was positioned on a white illuminating screen of an iPad placed in a dark box in order to capture a top-view image using an iPhone 5s back camera. The intensity of yellow colour was converted to Red–Green–Blue pixels using a free mobile application. Under the optimal conditions for the reaction and photography, the intensity of blue colour, which was logarithmically transformed, showed an excellent linearity over the drug concentration range of 5–40 µg/mL. The assay was validated and successfully applied to the assay of drug content and the determination of drug amount released in the dissolution test in the capsule dosage forms. Apart from that, a smartphone was employed for the colour measurement as an alternative to a spectrophotometer in the currently used method for the quantitation of free sulfhydryl groups in polymers. Using cysteine-conjugated chitosan as a sample and l-cysteine as a standard, the smartphone method gave the results in agreement with those obtained from the absorbance measurement on a microplate reader. In conclusion, smartphone-based colourimetry has been proved to be a reliable, fast, simple and affordable alternative means for the analysis of d-penicillamine and cysteine-conjugated polymer and can be potentially applied to other thiol-containing drugs and excipients.

Symbolic Study of Color in Bakhtiyari Textiles with Emphasis on Veris (Card Weaving)

Veris is a narrow weaving with a width of 2-10 cm. and a length of 1-8 m., often woven with woolen yarns by simple tools known as cards. This woven has a variety of applications, in the past for decorating clothes, the collar, the edge of the skirt, the belt, baby wrapping, hat bands, saddles and many other uses, the handmade strips were used. But today, more is used to decorate clothes. For the Veris weaving, the Bakhtiyari tribes use many motifs and designs most of which are based on their customs, habits, perceptions, insights, environment and their culture. In this textile, geometric, human, animal, herbal, inscription, positive and negative motifs are used. Red, black, blue, yellow, and dark green are main color in Bakhtiyari hand woven. Each of the colors in the Bakhtiyari tribes symbolizes an event. For example: red Veris for happy event, green Veris is for fastening infant and black tent, yellow Veris for expensive objects, blue Veris for fastening ordinary objects, black and white Veris for mourning events. In short, the composition of colors in the Veris depends on the type of application. This research, by examining the current literature and applying a fieldwork, implements a descriptive & analytical methodology to analyze and understand the “symbolism” in card weaving. The study will examine different motif shapes and explain the meaning of the motif among the Bakhtiyari tribes. For this purpose, different car woven samples will be illustrated and pictured for the reader. The study concludes that card weaving has decorative and functional meanings.

76 Effects of serum type in maturation medium on in vitro development of bovine embryos

This study investigated the effect of bovine serum albumin (BSA), charcoal:dextran stripped fetal bovine serum (CDS FBS), and heat-inactivated FBS (HI FBS) in maturation medium on their ability to support in vitro oocyte maturation, cumulus cell-oocyte gap junctional communication, and development of bovine embryos. Charcoal:dextran treatment of FBS removes lipophilic chemicals, certain steroid hormones, and certain growth factors; however, HI FBS have a lot-to-lot variation in steroid hormones level that can affect the reproducibility of experimental findings. Oocytes were cultured in TCM-199 supplemented with either 8% (w/v) BSA, 10% (v/v) CDS FBS, or 10% (v/v) HI FBS and 1µg mL−1 oestradiol-17β, 10µg mL−1 FSH, 10ng mL−1 epidermal growth factor, 0.6mM cysteine, 0.2mM sodium pyruvate, and followed by IVF, and the zygotes were cultured in SOF-BE1 medium. The developmental ability and quality of bovine embryos were determined by assessing their cell number, lipid content, mitochondrial activity, gene expression, immunocytochemistry, and cryo-tolerance. The differences in embryo development between experimental groups were analysed by 1-way ANOVA. The Duncan’s multiple range tests were used to test the differences between the treatments. The level of statistical significance was set at P&amp;lt;0.05. We have shown that CDS FBS significantly improved (P&amp;lt;0.05) the percentage of MII oocytes compared with that in the BSA supplemented group (77.2±1.0% v. 69.3%±2.3%, respectively). Moreover, CDS FBS had a higher significant (P&amp;lt;0.05) effect on the rate of blastocyst formation compared with HI FBS and BSA (45.2±0.7% v. 37.4±1.5% and 31.1±3.9%, respectively; 6 replicates were performed). Culture of oocytes with CDS FBS increased (P&amp;lt;0.05) the expression of gap junction proteins, CX37 and CX43, at both transcriptional and translation levels as determined by quantitative RT-PCR and immunofluorescence analysis, respectively. We also found that CDS FBS significantly increased total cell number and decreased the apoptotic index in Day-8 blastocysts compared with the BSA group. Furthermore, the beneficial effects of CDS FBS on embryos were associated with significantly reduced intracellular lipid content and increased mitochondrial activity in both oocytes and blastocysts as identified by Nile red and MitoTracker Green staining, respectively. Taken together, these data suggest that supplementation of maturation medium with CDS FBS, as an alternative to HI FBS, affected cumulus cell-oocyte gap junctional communication, and subsequently improved in vitro developmental competence of bovine oocytes and embryos. Research was supported by the Korea Institute of Planning and Evaluation for Technology in Food, Agriculture, Forestry and Fisheries (IPET) through Agri-Bio industry Technology Development Program, funded by Ministry of Agriculture, Food and Rural Affairs (MAFRA) (grant numbers: 117029-3 and 315017-5).

The Use of Unmanned Aerial Systems to Map Intertidal Sediment

This paper describes a new methodology to map intertidal sediment using a commercially available unmanned aerial system (UAS). A fixed-wing UAS was flown with both thermal and multispectral cameras over three study sites comprising of sandy and muddy areas. Thermal signatures of sediment type were not observable in the recorded data and therefore only the multispectral results were used in the sediment classification. The multispectral camera consisted of a Red–Green–Blue (RGB) camera and four multispectral sensors covering the green, red, red edge and near-infrared bands. Statistically significant correlations (&gt;99%) were noted between the multispectral reflectance and both moisture content and median grain size. The best correlation against median grain size was found with the near-infrared band. Three classification methodologies were tested to split the intertidal area into sand and mud: k-means clustering, artificial neural networks, and the random forest approach. Classification methodologies were tested with nine input subsets of the available data channels, including transforming the RGB colorspace to the Hue–Saturation–Value (HSV) colorspace. The classification approach that gave the best performance, based on the j-index, was when an artificial neural network was utilized with near-infrared reflectance and HSV color as input data. Classification performance ranged from good to excellent, with values of Youden’s j-index ranging from 0.6 to 0.97 depending on flight date and site.

Comparison of a Smartphone Application with Ishihara Pseudoisochromatic Plate for Testing Colour Vision

ABSTRACTThe Eye Handbook (EHB) is the most frequently downloaded smartphone application with diagnostic tools for eye-care providers. However, limited data exists validating the EHB test to gold standard colour vision testing. EHB and Ishihara colour vision tests were evaluated and compared under simulated colour vision loss through use of image processing software. Images of both tests were processed through ImageJ to 32 bit-grey scale and blue channel under split RBG channel to model total colour vision loss and red-green (R-G) deficiency, respectively. Two colour plates differentiated R-G deficiency from total colour blindness in EHB compared with eight Ishihara plates. Without colour information, correct numerals were identified in 3.5/15 EHB plates converted to 32-bit greyscale, versus 1/16 in Ishihara. We conclude EHB may underestimate colour vision loss severity in persons with normal contrast sensitivity compared to Ishihara. Eye-care providers need to be aware of the potential inconsistency compared to standardised methods, including limitations in differentiating patients with R-G colour deficiencies from total colour blindness.

Alkaloid Profiles and Activity in Different Mitragyna speciosa Strains

Mitragyna speciosa (K.) H. (Kratom) is a tree that possesses stimulant and opioid-like analgesic effects, and is indigenous to Southeast Asia and Indochina, where it has seen widespread use for hundreds of years. The principal pharmacologically active alkaloids in kratom leaves include mitragynine (MG), 7-hydroxymitragynine (HMG), speciociliatine (SC), speciogynine (SG) and paynantheine (P). The pharmacological effects induced and their potency can vary dramatically according to variations in the proportions of alkaloid compounds present, which are related to geographic origin, stage of maturity and ecotype. Much of the analgesic and opiate-like psychoactive effect of kratom has been associated with the MG and HMG detected in M. speciosa (K.). H. Five different strains of M. speciosa (K.) H., which present differing vein colours and geographic origin, have been studied herein; red vein strains from Thailand, Malaysia and Bali, named Red Thai, Red Malay and Red Bali, a white vein strain from Borneo (White Borneo) and a green vein strain from Malaysia (Green Malay) were included in the study. Plant leaves were extracted under magnetic stirring at room temperature in a MeOH/H2O 1:1 mixture. Purified alkaloids were isolated in a number of organic extraction steps, from either aqueous basic or acidic phases, that culminated in precipitation (yields between 0.94 and 1.43%). These samples have been analysed using HPLC-DAD, HPLC-MS, HPLC-MS/MS and GC-MS to optimize the identification and quantification of the principal alkaloids present in the different strains. 24 alkaloids were detected in Red Bali whereas 11 compounds were found in the other varieties. Red Thai, Red Bali, Green Malay and White Borneo strains had a higher w/w percentage for MG than for P, while P was more abundant in Red Malay. The Green Malay variety (GMK) showed the highest w/w percentages for MG and total alkaloids in its extracts (59.7 and 94.9% respectively). The Green Malay variety was therefore chosen for in vivo pharmacological studies. The Green Malay extract has shown remarkable and significant antinociceptive and anti-inflammatory activity in mouse hot plate and carrageenan-induced paw edema tests.

Fusion of RGB and HSV colour space for foggy image quality enhancement

The physical properties of water cause light-prompted degradation of foggy images. The light quickly loses intensity as it goes in the water, depending upon the shading range wavelength. Visible light is consumed at the longest wavelength first. Red and blue are the most and least absorbed, respectively. Foggy images with low contrast, are captured due to the degradation effects of the light spectrum. Therefore, valuable information from these images cannot be fully extracted for further processing. In this paper, the authors have proposed a new method to increase contrast and reduce the noise of foggy images using CLAHE (Contrast Limited Adaptive Histogram Equalization) algorithm. The proposed method fuses the modification of image histogram into two main colour models, namely, Red–Green–Blue (RGB) and Hue-Saturation-Value (HSV). In the primary stage, the CLAHE is connected just on the red part as in water, red shading is more influenced than the blue or green shading. Furthermore, in the second stage, without influencing the hue, the CLAHE is connected to saturation and value components of the HSV colour model. Finally, enhanced image has been produced using a fusion of output of primary phase and output produced in the second phase. Two parameters, namely, RMSE (Root Mean Squared Error) and the PSNR (Peak Signal to Noise Ratio) have been considered in comparing the experimental results of the proposed system with state-of-the-art work.

Fast and effective optic disk localization based on convolutional neural network

As a benchmark structure in the retina, the precise localization of the Optic Disc (OD) has received considerable attention from researchers owning to its importance for ophthalmic image analysis and retinopathy screening. In most literature works, although OD localization has achieved fairly good performance, rather less attention has been paid to supervised techniques. As the ODs are common in characteristics and form a fixed pattern, we propose in this paper an OD localization method based on Convolutional Neural Networks (CNNs). In data preparation, the blue channel in the fundus image, which is always empty or noisy and tends to be uninformative, is replaced by coarsely segmented vasculature maps (Red channel, Green channel and vasculatures are denoted as RGV). In addition, the input of the CNN structures is rectangular instead of square in order to involve more context information of the vasculatures. For training, a two-stage process is designed to alleviate the class-imbalance problem by choosing large number of positive samples at the first stage and choosing samples at the center of OD to fine-tune the fist-stage model at the second stage. Then a probability guided search algorithm is developed to improve the efficiency of OD localization by selectively searching patches with large chances to be an OD and their neighbors. Finally, the precise OD position is located as center of the highest probability regions after weighted voting. Extensive experiments on four publicly available databases demonstrate the effectiveness and efficiency of the proposed method, with an average detection rate of 99.11% and detection time less than 15 s per image.

Colourimetric Determination of High-Density Lipoprotein (HDL) Cholesterol Using Red–Green–Blue Digital Colour Imaging

ABSTRACTA rapid, low-cost, and sensitive method was developed for the quantification of high-density lipoprotein cholesterol based on enzymatic colorimetric reactions and digital image analysis. The proposed method was adapted to a 96-microwell enzyme-linked immunosorbent assay plate and imaging acquisition was performed using a conventional desktop scanner. The images were recorded using the red–green–blue color system in which the resolved absorbance for each color channel was used for multiple linear regression. The regression model presented a root mean squared error of calibration and a correlation coefficient (R2) value of 1.53 mg dL−1 and 0.995, respectively. Prediction was obtained with a root mean square error of prediction of 2.42 mg dL−1 and R2 of 0.993, thereby showing accurate prediction response. A limit of detection of 0.43 mg dL−1 and precision better than 1.72% reinforced these results. This method was compared with a reference methodology using ultraviolet–visible spectroscopic measurements at 500 nm and no statistical differences were observed at the 95% confidence level, showing the potential for future clinical applications.

A novel and proposed comprehensive methodology using deep convolutional neural networks for flue cured tobacco leaves classification

In this paper, a solution is defined based on convolutional neural networks (CNN) for the grading of flue-cured tobacco leaves. A performance analysis of CNN on 120 samples of cured tobacco leaves is reduced from 1450 × 1680 Red–Green–Blue (RGB) to 256 × 256, consisting 16, 32 and 64 feature kernels for hidden layers respectively. The neural network comprised of four hidden layers where the performance of convolution and pooling on first three hidden layers and fourth layer a fully connected as in regular neural networks. Max pooling technique (MPT) is used in the proposed model to reduce the size. Classification is done on three major classes’ namely Class-1, Class-2 and Class-3 for obtaining global efficiency of 85.10% on the test set consisting about fifteen images of each cluster. A comparative study is performed on the results from the proposed model with existing models of tobacco leaf classification.

Color Vision in Aniridia.

PurposeTo assess color vision and its association with retinal structure in persons with congenital aniridia.MethodsWe included 36 persons with congenital aniridia (10–66 years), and 52 healthy, normal trichromatic controls (10–74 years) in the study. Color vision was assessed with Hardy-Rand-Rittler (HRR) pseudo-isochromatic plates (4th ed., 2002); Cambridge Color Test and a low-vision version of the Color Assessment and Diagnosis test (CAD-LV). Cone-opsin genes were analyzed to confirm normal versus congenital color vision deficiencies. Visual acuity and ocular media opacities were assessed. The central 30° of both eyes were imaged with the Heidelberg Spectralis OCT2 to grade the severity of foveal hypoplasia (FH, normal to complete: 0–4).ResultsFive participants with aniridia had cone opsin genes conferring deutan color vision deficiency and were excluded from further analysis. Of the 31 with aniridia and normal opsin genes, 11 made two or more red-green (RG) errors on HRR, four of whom also made yellow-blue (YB) errors; one made YB errors only. A total of 19 participants had higher CAD-LV RG thresholds, of which eight also had higher CAD-LV YB thresholds, than normal controls. In aniridia, the thresholds were higher along the RG than the YB axis, and those with a complete FH had significantly higher RG thresholds than those with mild FH (P = 0.038). Additional increase in YB threshold was associated with secondary ocular pathology.ConclusionsArrested foveal formation and associated alterations in retinal processing are likely to be the primary reason for impaired red-green color vision in aniridia.

Color‐by‐Blue QD‐Emissive LCD Enabled by Replacing RGB Color Filters with Narrow‐Band GR InP/ZnSeS/ZnS QD Films

AbstractColor‐by‐blue quantum dot (QD)‐emissive liquid‐crystal displays (LCDs) with eco‐friendly, green, red (GR) InP/ZnSeS/ZnS QD films are introduced to overcome the disadvantages of conventional color‐by‐white color filter (CF)‐assisted LCDs, such as a narrow viewing angle, low external device efficiency of these types of LCDs, and a restricted color gamut. In this study, the color‐by‐blue InP‐based QD‐emissive LCD consists of a blue (B) light‐emitting diode (LED) and GR InP‐based QD films sandwiched between a light recycling filter and a long‐wavelength pass dichroic filter. The GR InP‐based QDs are synthesized with a high photoluminescence quantum yield (&gt;77%) and narrow bandwidth (&lt;40 nm), which are suitable for display applications. The overall enhancement of InP‐based QD‐emissive LCDs, in this case by the enhanced efficiency of a blue LED backlight transmitted through the LC shutter compared to a white LED backlight and the improved efficiency of the enlarged color gamut, is 2.42 times that of a conventional red, green, and blue (RGB) CF‐LCD with a GR phosphor‐converted (pc)‐LED (a B LED + R K2SiF6:Mn + G β‐SiAlON:Eu phosphor) backlight. Therefore, this considerable enhancement of the external efficiency of a QD‐emissive LCD makes it more feasible as a replacement for conventional RGB CF‐assisted LCDs.

Detection of stored-grain insects using deep learning

A detection and identification method for stored-grain insects was developed by applying deep neural network. Adults of following six species of common stored-grain insects mixed with grain and dockage were artificially added into the developed insect-trapping device: Cryptoleste Pusillus(S.), Sitophilus Oryzae(L.), Oryzaephilus Surinamensis(L.), Tribolium Confusum(Jaquelin Du Val), Rhizopertha Dominica(F.). Database of Red Green and Blue (RGB) images of these live insects was established. We used Faster R-CNN to extract areas which might contain the insects in these images and classify the insects in these areas. An improved inception network was developed to extract feature maps. Excellent results for the detection and classification of these insects were achieved. The test results showed that the developed method could detect and identify insects under stored grain condition, and its mean Average Precision (mAP) reached 88.

Double light-emitting layer implementing three-color emission: Using DCJTB lightly doping in Alq3 as red-green emitting layer and APEAn1N as blue-green emitting layer

High performance with color stability and simplified device structure with uncomplicated fabrication processes are research focuses in white organic light-emitting diodes (WOLEDs). But it is not easy to simultaneously combine these characteristics into WOLEDs. Herein, efficient and color-stable WOLEDs with double light-emitting layer are constructed. The double light-emitting layer structure is composed of a red-green (RG) emitting light which originate from incomplete energy transfer from the host of tris-(8-hydroxyquinolinato)aluminum (Alq3) to guest of 4-(Dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidin-4-yl-vinyl)−4H-pyran (DCJTB), and a blue-green emitting light from (E)-9-(4-(2-(anthracen-9-yl)vinyl)phenyl)-10-(naphthalen-1-yl)anthracene (APEAn1N). In these WOLEDs, the different doping concentrations of DCJTB in Alq3 were optimized. Finally, a WOLEDs with relatively simple preparation was obtained with a maximum brightness of 9296cdm−2, maximum current efficiency (CE) of 10.17cdA−1, maximum power efficiency (PE) of 5.80lmW−1, maximum external quantum efficiency (EQE) of 4.09%, Commission Internationale de L'Eclairage (CIE) coordinate of (0.41, 0.46) and color rendering index (CRI) of 75 (85), respectively. And the chromaticity coordinate is stable at (0.41, 0.46) with increasing operation voltage. These results reveal that the fluorescent WOLEDs possess simplified fabrication, low cost, relatively high efficiency, acceptable CRI and stable color, simultaneously.

A 2.5D Map-Based Mobile Robot Localization via Cooperation of Aerial and Ground Robots.

Recently, there has been increasing interest in studying the task coordination of aerial and ground robots. When a robot begins navigation in an unknown area, it has no information about the surrounding environment. Accordingly, for robots to perform tasks based on location information, they need a simultaneous localization and mapping (SLAM) process that uses sensor information to draw a map of the environment, while simultaneously estimating the current location of the robot on the map. This paper aims to present a localization method based in cooperation between aerial and ground robots in an indoor environment. The proposed method allows a ground robot to reach accurate destination by using a 2.5D elevation map built by a low-cost RGB-D (Red Green and Blue-Depth) sensor and 2D Laser sensor attached onto an aerial robot. A 2.5D elevation map is formed by projecting height information of an obstacle using depth information obtained by the RGB-D sensor onto a grid map, which is generated by using the 2D Laser sensor and scan matching. Experimental results demonstrate the effectiveness of the proposed method for its accuracy in location recognition and computing speed.

Differences in Chromatic Sensitivity Estimated Using Static and Dynamic Colour Stimuli

Abstract The current study reports on a novel computerised colour vision test employing static and dynamic stimuli. The aim of the study was to assess if static and dynamic stimuli result in comparable chromatic discrimination thresholds when participant’s age is taken into account. Participants (n = 20) were 21 to 77 years old, had normal colour vision and no history of any eye disease. They all participated in two sessions estimating chromatic sensitivity with static and dynamic stimuli, respectively, with six directions in colour space varying either along the red-green (RG) or yellow- blue (YB) directions. We found no significant differences in chromatic thresholds along a tritan axis obtained with static and dynamic stimuli. However, along protan and deitan axes, chromatic thresholds were lower if estimated using static stimuli than those estimated using the dynamic stimuli. As anticipated, chromatic sensitivity decreased with age and with greater chromatic sensitivity loss along the tritan confusion line. Research results suggest that differences between chromatic thresholds measured with static and dynamic stimuli become more apparent with increasing age of study participant.

Red–Green–Blue (RGB) colour system approach to study the segregation and percolation in a mixture of white wheat flour and bleached wheat bran

SummaryIn this work, we applied a nonintrusive measurement method based on the Red–Green–Blue (RGB) image analysis system to study the segregation and percolation in a mixture of white wheat flour and bleached wheat bran. This method intended to quantify the presence of one or several colours in the surface of mixed ingredients. The mixing of flour particles with bleached and unbleached wheat bran was studied using a 90 mm closed rotating cube. This system forced the particles to roll relative to each other so as to favourite the segregation by percolation in order to hide one colour by another. The obtained results showed a possibility of obtaining homogeneous colour when the wheat flour was mixed with the bleached wheat bran at a volume ratio of 20/5%–10%. By increasing to ratio up to 20/15% (flour/bran), the RGB system showed a presence of two colours in the surface of the mixture. Moreover, the RGB method confirmed the presence of two heterogeneous colours when the wheat flour was mixed with the unbleached wheat bran whatever the ratio (20/5%, 10% and 15%).