Background Color Research Articles

Tomato quality assessment and enhancement through Fuzzy Logic: A ripe perspective on precision agriculture

This study presents a meticulous exploration of tomato quality assessment and enhancement employing Fuzzy Logic, focusing on beefsteak, Roma, and cherry varieties. The research incorporates a multivariate approach encompassing shape, size, texture, and color analysis. Utilizing a controlled imaging system, 165 tomatoes were captured at various ripening stages to ensure uniformity in lighting, camera position, and background color. Image processing and computer vision techniques, including segmentation and feature extraction, were applied to comprehensively evaluate the tomatoes. Quality assessment involved considerations of three stages of skin coloration, defect quantity, and skin texture calculated using the statistical method of entropy. The decision-making process and quality evaluation were facilitated by a Mamdani-type Fuzzy Inference System, leveraging numerical values of external characteristics such as dimension, calyx shape, ripeness stage, and defect regions. The fuzzy logic-based system employed 22 fuzzy rules and three different membership functions (trapezoidal, Gaussian, and triangular), enabling a nuanced mapping of transitions between classes within the input variables. Furthermore, the system underwent rigorous training and validation using 80% and 20% respectively of the captured images. Through the system, we were able to identify and segment areas of tomatoes exhibiting poor conditions. This approach extends beyond conventional methods of estimating fruit ripeness, which typically rely on color assessment or destructive firmness evaluations.

Background contrast affects detection and recognition of courting wolf spiders by intended and unintended receivers

We used video playback of courting male Schizocosa ocreata wolf spiders to examine responses of intended receivers (conspecific females) and eavesdroppers (competitor males, predatory spiders, toads) to manipulations of spider color (natural color, monochromatic gray, monochromatic RBG average) displayed against complex leaf litter backgrounds (color, grayscale). Models of chromatic and achromatic contrast between spider stimuli and backgrounds were used to predict receiver responses. The results support the hypothesis that interactions between spider and background coloration affect detection and recognition, although responses varied with receiver type. Detection responses of intended receivers (female S. ocreata) did not fit predictions of the chromatic contrast model in some cases, but showed a fair fit to the achromatic model. Detection responses of social eavesdroppers (male S. ocreata) fit the chromatic and achromatic contrast models slightly better than did female responses (poor fit and very good fit, respectively). Eavesdropping wolf spider predators (Rabidosa) exhibited detection responses that significantly matched predictions of the chromatic (very good fit) and achromatic (excellent fit) models. Whereas jumping spiders (Phidippus) showed a good fit to the chromatic and achromatic contrast models, toad predators had a good fit only to the chromatic model. Recognition responses revealed a different pattern of fit to the chromatic and achromatic models across receiver types, although Rabidosa again indicated a significant fit to both models. Taken together, the results of this study identify both chromatic and achromatic features of spider appearance as likely explanations for differences in behavioral responses of intended and unintended receivers. This outcome suggests the possibility that both sexual and natural selection likely target different features of male appearance during courtship.

Scorpionfish adjust skin pattern contrast on different backgrounds.

The two scorpionfish species Scorpaena maderensis and S. porcus are well camouflaged ambush predators that rapidly change body colouration to adjust to background colour in less than 1 min. We tested whether individuals of both species also adjust body pattern to that of the background. We placed fish on backgrounds of different pattern granularity and quantified the change in fish body pattern over 1 min. We used calibrated image analysis to analyse the patterns from the visual perspective of a prey fish species using a granularity (pattern energy) analysis and an image clustering approach. In our experiment, fish did not change their most contrasting pattern components as defined by the dominant marking size, but changed their average marking size. Moreover, fish responded with a change in pattern in contrast to the different experimental backgrounds, especially when compared to the acclimation phase. These results indicate that scorpionfish have one main pattern that can be adjusted by modulating its internal contrast. A reduction in pattern contrast could thereby improve background matching, while an increase could promote camouflage via disruptive colouration.

Health warning labels on cannabis products. What is the best design?

BackgroundHealth warning label on cannabis products has been recently studied, and with the latest trends of regulation around the world, there is a need to determine the most effective ways to apply this strategy. The current study aimed to examine the effects of different health warning label designs (pictorial vs text-only, background color, warning themes) on cannabis products. MethodsAn online experiment study (N=533) was carried out in Colombia with a between-subject design. Participants were randomly assigned to five package conditions: without warning, text-only white warning, text-only yellow warning, pictorial white warning, and pictorial yellow warning. Participants performed an attention task and rated each of the stimuli based on product appeal, perceived addictiveness, harm perception, and interest in trying cannabis products. ResultsPictorial health warnings were generally the most effective. Especially, pictorial health warnings with a yellow background were found to decrease product appeal and interest in trying cannabis products, as well as increase harm perception compared to other designs. The most effective warning themes were mental health, smoke toxicity, aesthetic implications, and traffic accidents. ConclusionThe current study provides empirical evidence on the effectiveness of different designs of cannabis health warnings. Our results suggest that graphic yellow warnings are the most effective in communicating the risks of cannabis use.

Deep Learning-Based Real-Time Detection of Surface Landmines Using Optical Imaging

This paper presents a pioneering study in the application of real-time surface landmine detection using a combination of robotics and deep learning. We introduce a novel system integrated within a demining robot, capable of detecting landmines in real time with high recall. Utilizing YOLOv8 models, we leverage both optical imaging and artificial intelligence to identify two common types of surface landmines: PFM-1 (butterfly) and PMA-2 (starfish with tripwire). Our system runs at 2 FPS on a mobile device missing at most 1.6% of targets. It demonstrates significant advancements in operational speed and autonomy, surpassing conventional methods while being compatible with other approaches like UAV. In addition to the proposed system, we release two datasets with remarkable differences in landmine and background colors, built to train and test the model performances.

ZEISS PLEX Elite 9000 Widefield Optical Coherence Tomography Angiography as Screening Method for Early Detection of Retinal Hemangioblastomas in von Hippel-Lindau Disease.

To evaluate early detection of retinal hemangioblastomas (RHs) in von Hippel-Lindau disease (VHLD) with widefield optical coherence tomography angiography (wOCTA) compared to the standard of care in ophthalmologic VHLD screening in a routine clinical setting. We conducted prospective comparisons of three screening methods: wOCTA, standard ophthalmoscopy, and fluorescein angiography (FA), which was performed only in uncertain cases. The numbers of detected RHs were compared among the three screening methods. The underlying causes for the lack of detection were investigated. In 91 eyes (48 patients), 67 RHs were observed (mean, 0.74 ± 1.59 RH per eye). FA was performed in eight eyes. Ophthalmoscopy overlooked 25 of the 35 RHs detected by wOCTA (71.4%) due to the background color of the choroid (n = 5), small tumor size (n = 13), masking by a bright fundus reflex (n = 2), and masking by surrounding retinal scars (n = 5). However, wOCTA missed 29 RHs due to peripheral location (43.3%). The overall detection rates were up to 37% on the basis of ophthalmoscopy alone, up to 52% for wOCTA, and 89% for FA. Within the retinal area covered by wOCTA, the detection rates were up to 46.7% for ophthalmoscopy alone, up to 92.1% for wOCTA, and 73.3% for FA. The overall low detection rate of RHs using wOCTA is almost exclusively caused by its inability to visualize the entire peripheral retina. Therefore, in unclear cases, FA is necessary after ophthalmoscopy. Within the imageable retinal area, wOCTA shows a high detection rate of RHs and therefore may be suitable to improve screening for RHs in VHLD.

The influence of content-relevant background color as a retrieval cue on learning with multimedia

Color has been investigated as a signaling cue in multimedia learning environments, guiding the learner’s attention and as an emotional design element, increasing the learner’s motivation and, thus, improving learning outcomes. Retrieval cues (e.g., visual cues, odor, sound) facilitating memory retrieval have been primarily investigated in learning simple word lists. Contrary to additional retrieval cues, the background color is a component that is always present in multimedia learning environments. This study investigates if the background color of learning texts as retrieval cue can enhance learning and affect cognitive load and motivation. Hypotheses are formulated according to the Cognitive-Affective Theory of Learning with Multimedia (CATLM) and in the setting of context-dependent memory, specifically the Information, associated Context, and Ensemble Theory (ICE). A 2 (related vs. unrelated background color) × 2 (with vs. without colors in the learning test) -factorial between-subjects design with an additional control group was utilized. For the control group, the background of the learning texts and learning questions was white. In total, 191 native German speakers were randomly assigned to the five groups. The findings indicate that relying solely on the background color as a retrieval cue is insufficient. Instead of facilitating memory retrieval, the background color remains context information stored separately from the item information. However, the results should be approached carefully as learning outcomes may be subject to ceiling and floor effects.

An Unstructured Orchard Grape Detection Method Utilizing YOLOv5s

Rising labor costs and a workforce shortage have impeded the development and economic benefits of the global grape industry. Research and development of intelligent grape harvesting technologies is desperately needed. Therefore, rapid and accurate identification of grapes is crucial for intelligent grape harvesting. However, object detection algorithms encounter multiple challenges in unstructured vineyards, such as similar background colors, light obstruction from greenhouses and leaves, and fruit occlusion. All of these factors contribute to the difficulty of correctly identifying grapes. The GrapeDetectNet (GDN), based on the YOLO (You Only Look Once) v5s, is proposed to improve grape detection accuracy and recall in unstructured vineyards. dual-channel feature extraction attention (DCFE) is a new attention structure introduced in GDN. We also use dynamic snake convolution (DS-Conv) in the backbone network. We collected an independent dataset of 1280 images after a strict selection process to evaluate GDN’s performance. The dataset encompasses examples of Shine Muscat and unripe Kyoho grapes, covering a range of complex outdoor situations. The results of the experiment demonstrate that GDN performed outstandingly on this dataset. Compared to YOLOv5s, this model increased metrics such as 2.02% of mAP0.5:0.95, 2.5% of mAP0.5, 1.4% of precision, 1.6% of recall, and 1.5% of F1 score. Finally, we test the method on a grape-picking robot, and the results show that our algorithm works remarkably well in harvesting experiments. The results indicate that the GDN grape detection model in this study exhibits high detection accuracy. It is proficient in identifying grapes and demonstrates good robustness in unstructured vineyards, providing a valuable empirical reference for the practical application of intelligent grape harvesting technology.

Visibly Transparent Multifunctional Metascreen for Tunable Infrared Coloration and Microwave Transmission

AbstractMetascreens are remarkable optical materials that have attracted significant research interest owing to their ability to manipulate electromagnetic waves by selectively transmitting, reflecting, and absorbing specific wavelengths. The present study introduces a new metascreen concept called visibly transparent multifunctional metascreen (VTMM), which is capable of simultaneously transmitting visible light, selectively transmitting microwaves, and modulating infrared (IR) emissions, all through a single surface. The VTMM is fabricated by patterning a thin metal film in a square‐loop pattern on a transparent substrate, resulting in frequency‐selective transmission characteristics in the X‐band and visible transparency. Before demonstrating independent control of the visible and IR coloration of the VTMM by varying the metal film thickness and using color backgrounds, the visible and IR coloration characteristics of the ultrathin metal film on glass (MFG) are analyzed. Based on the findings, the VTMM preserves optical images behind the metascreen while reducing the average IR signature from 89.0 to 69.3 W m−2 sr‐1, with up to 23.5% reduction compared to a glass substrate, as the metal film thickness increases from 40 to 100 nm is confirmed. Furthermore, the designed selective transmission characteristics are shown to remain consistent across varying metal film thicknesses.

A dual-modal photothermal and smartphone colorimetric aptamer sensing platform for tobramycin assay

The gold nanoparticles (AuNPs) aggregation-induced colorimetric aptamer sensing platform is commonly employed in bioassays. However, it has certain limitations, such as the requirement of instruments like a spectrophotometer for accurate quantitative readout and the background color interference. In this work, a dual-mode photothermal (PT) and smartphone colorimetric aptamer sensing platform was developed for tobramycin (TOB) assay using a digital thermometer or smartphone. Single-standard DNA (ssDNA) was utilized to bind the surface of AuNPs and maintain the dispersion of AuNPs at high salt concentrations. After the addition of the TOB, aptamer will specifically bind with it and separate from the gold surface. Then the aggregation of AuNPs can be observed in salt conditions, accompanying the AuNPs solution color change (red–purple-blue) and enhancing the PT effect. The DNA structural influence was carefully investigated. Under optimum conditions, the TOB assay by PT and RGB colorimetric mode have the limits of detection (LODs) of 1.7 μM and 1.3 μM, respectively. Furthermore, it is well demonstrated by the determination of TOB in food samples, offering high selectivity and sensitivity. It has potential for future application in point-of-care testing (POCT) with the benefits of inexpensive, easy to operate, and high specificity.

Dermoscopic Features of Cutaneous Vasculitis.

Dermoscopy has become widespread in the diagnosis of inflammatory skin diseases. Cutaneous vasculitis (CV) is characterized by inflammation of vessels, and a rapid and reliable technique is required for the diagnosis. We aimed to define CV dermoscopic features and increase the diagnostic accuracy of dermoscopy with machine learning (ML) methods. Eighty-nine patients with clinically suspected CV were included in the study. Dermoscopic images were obtained before biopsy using a polarized dermoscopy. Dermoscopic images were independently evaluated, and interobserver variability was calculated. Decision Tree, Random Forest, and K-Nearest Neighbors were used as ML classification models. The histopathological diagnosis of 58 patients was CV. Three patterns were observed: homogeneous pattern, mottled pattern, and meshy pattern. There was a significant difference in background color between the CV and non-CV groups (P = 0.001). The milky red and livedoid background color were specific markers in the differential diagnosis of CV (sensitivity 56.7%, specificity 96.3%, sensitivity 29.4%, specificity 99.2%, respectively). Red blotches were significantly more common in CV lesions (P = 0.038). Red dots, comma vessels, and scales were more common in the non-CV group (P = 0.002, P = 0.002, P = 0.003, respectively). Interobserver agreement was very good for both pattern (κ = 0.869) and background color analysis (κ = 0.846) (P < 0.001). According to ML classifiers, the background color and lack of scales were the most significant dermoscopic aspects of CV. Dermoscopy may guide as a rapid and reliable technique in CV diagnosis. High accuracy rates obtained with ML methods may increase the success of dermoscopy.

Investigating the Effect of Internal Bleaching With 10% Carbamide Peroxide on the Color Change of Three Types of Common Endodontic Sealers.

Background and purpose Color change caused by materials used for endodontic treatment is an important clinical issue. The current research examined the impact of internal bleaching with 10% carbamide peroxide on discolored teeth resulting from various types of sealers. Materials and methods In this study, 36 anterior teeth were cut from 1 mm beneath the cementoenamel junction (CEJ), and the samples were divided into three groups of 12. Then, AH26 (Tulsa Dental, Tulsa, OK), Endofill (Herpo Produtos Dentários Ltda, Petrópolis, Brazil), and AH Plus (DentsplyDeTrey, Konstanz, Germany) color change potential sealers were placed inside the pulp chamber. The cervical access cavity was covered with a thin layer of glass ionomer. After one month, the material was removed, and bleaching was done with 10% carbamide peroxide. The color of the samples was measured by a spectrophotometer before bleaching, one week after bleaching, and one week after bleaching again. The data were subjected to statistical analysis using the Statistical Package for Social Sciences (SPSS)software version 16 (IBM SPSS Statistics, Armonk, NY), with a significance level set at P<0.05. Results The results showed that the factor of time and material used and the opposing effect of these two on the amount of L and ΔE were statistically significant (P<0.05). After one to two weeks of internal bleaching, all groups showed some degree of reduction in sealer-induced discoloration. In addition, in all groups, the largest difference in L was related to the difference in L0 and L2 (before bleaching and one week after bleaching again), and the lowest difference was related to the difference in L0 and L1. Also, the highest ΔE(T0,T1) belonged to the Endofill group, and this significantly differed from the AH26 group. AH26 showed the lowest value of ΔE(T0,T1), and after two weeks, the ΔE of all groups was higher than the clinically observable limit. The highest ΔE(T2,T0) among the groups belonged to the Endofill group. The ΔE(T2,T0) of AH26 and Endofill was significantly higher than AH Plus. Among all ΔE values, the AH Plus group had the lowest values. Conclusion Color change caused by Endofill and AH26 sealers showed a better response to internal bleaching than the AH Plus sealer.

Body composition estimates using a 2D image analysis system across different environmental conditions: An agreement study.

This study examined the agreement between %Fat measurements using a smartphone-based application (IMAGE) across different environmental conditions. A single reference image was obtained using an 8 MP smartphone camera under Ambient Light in front of a white background. Additional photos were obtained using a 0.7 MP, 5 MP, and 12 MP smartphone cameras; low-, moderate-, and bright-lighting conditions; and various color backgrounds including black, green, orange, and gray. %Fat measured using the 0.7 MP camera (27.8 ± 6.2 %Fat) was higher than the reference (26.8 ± 6.1 %Fat) (p < 0.001). The black (32.0 ± 12.0 %Fat), green (27.5 ± 6.3 %Fat), and gray (27.8 ± 6.3 %Fat) backgrounds yielded higher %Fat than the white (p = 0.03, 0.01, and 0.001). All camera, lighting, and background conditions were strongly correlated with the reference (all intraclass correlation coefficient [ICC] >0.98, all standard error of the estimate [SEE] <1.5 %Fat, all p < 0.001), except the black background which yielded poorer agreement with the white background (ICC = 0.69, SEE = 4.5%, p < 0.001). %Fat from IMAGE were strongly correlated across various environmental conditions.

Effects of Water Temperature on the Body Color and Expression of the Genes Related to Body Color Regulation in the Goldfish.

Melanin-concentrating hormone (MCH), melanocyte-stimulating hormone (MSH), and somatolactin (SL) in the hypothalamus-pituitary axis are associated with body color regulation in teleost fish. Although these hormones' production and secretion respond well to light environments, such as background color, little is known about the effects of different water temperatures. We investigated the effects of water temperature, 10°C, 20°C, and 30°C, on body color and the expression of these genes and corresponding receptor genes in goldfish. The body color in white background (WBG) becomes paler at the higher water temperature, although no difference was observed in black background (BBG). Brain mRNA contents of proMCH genes (pmch1 and pmch2) increased at 30°C and 20°C compared to 10°C in WBG, respectively. Apparent effects of background color and temperature on the pituitary mRNA contents of a POMC gene (pomc) were not observed. The pituitary mRNA contents of the SLα gene were almost double those on a WBG at any temperature, while those of the SLβ gene (slb) at 30°C tended to be higher than those at 10°C and 20°C on WBG and BBG. The scale mRNA contents of the MCH receptor gene (mchr2) in WBG were higher than those in BBG at 30°C. The highest scale mRNA contents of MSH receptor (mc1r and mc5r) on BBG were observed at 20°C, while the lowest respective mRNA levels were observed at 30°C on WBG. These results highlight the importance of temperature for the endocrinological regulation of body color, and darker background color may stabilize those endocrine functions.

Effects of Background Color on Growth, Stress, Biochemical, Hematological, and Immunological Responses, and Expression of Growth-Related Genes in Oscar Fish (Astronotus ocellatus)

The aim of the current study was to assess the impacts of tank color on the growth, stress, biochemical, hematological, and immunological responses, and expression of growth-related genes in juvenile Oscar (Astronotus ocellatus). Therefore, a total of 120 fish (9.14 ± 0.34 g) were distributed into 12 aquariums (60 × 50 × 35 cm) and divided into four treatments (aquariums with blue, white, yellow, and red colors) in three replicates (10 fish per aquarium). The fish were daily hand-fed ad libitum in three meals at 7:00, 12:00, and 17:00 hr for 56 days. Results showed that Oscar fish cultured in the red aquariums had higher final weight and weight gain and lower feed conversion ratio. Plasma cortisol, glucose, and lactate values of fish were significantly higher, and the amount of white blood cells was lower in the blue aquariums compared to other tank colors. Plasma triglyceride values were significantly higher in the white and yellow groups than the blue aquariums. Moreover, fish cultured in yellow and red aquariums had significantly higher melatonin levels than the blue aquariums. Plasma cholesterol, total protein, albumin, complement 3, and total immunoglobulin values were highest in Oscar fish cultured in the red aquariums. Also, lysozyme and alternative complement (ACH50) activities and complement 4 values of fish cultured in yellow and red aquariums were meaningfully higher compared to blue and white groups. Growth hormone relative gene expression levels were meaningfully higher in Oscar fish cultured in white, yellow, and red aquariums than the blue aquariums. Furthermore, insulin-like growth factor-1 (IGF-1) relative gene expression levels were significantly higher in fish cultured in yellow and red aquariums compared to those cultured in blue and white tank colors. Thus, the most suitable tank color for rearing juvenile A. ocellatus is red, while blue tank color is unsuitable.

Synthetic Document Images with Diverse Shadows for Deep Shadow Removal Networks.

Shadow removal for document images is an essential task for digitized document applications. Recent shadow removal models have been trained on pairs of shadow images and shadow-free images. However, obtaining a large, diverse dataset for document shadow removal takes time and effort. Thus, only small real datasets are available. Graphic renderers have been used to synthesize shadows to create relatively large datasets. However, the limited number of unique documents and the limited lighting environments adversely affect the network performance. This paper presents a large-scale, diverse dataset called the Synthetic Document with Diverse Shadows (SynDocDS) dataset. The SynDocDS comprises rendered images with diverse shadows augmented by a physics-based illumination model, which can be utilized to obtain a more robust and high-performance deep shadow removal network. In this paper, we further propose a Dual Shadow Fusion Network (DSFN). Unlike natural images, document images often have constant background colors requiring a high understanding of global color features for training a deep shadow removal network. The DSFN has a high global color comprehension and understanding of shadow regions and merges shadow attentions and features efficiently. We conduct experiments on three publicly available datasets, the OSR, Kligler's, and Jung's datasets, to validate our proposed method's effectiveness. In comparison to training on existing synthetic datasets, our model training on the SynDocDS dataset achieves an enhancement in the PSNR and SSIM, increasing them from 23.00 dB to 25.70 dB and 0.959 to 0.971 on average. In addition, the experiments demonstrated that our DSFN clearly outperformed other networks across multiple metrics, including the PSNR, the SSIM, and its impact on OCR performance.

A new species of silverline butterfly, Cigaritis Donzel, 1847 (Lepidoptera: Lycaenidae), from the Western Ghats biodiversity hotspot, India.

A new species, Cigaritis conjuncta sp. nov. (Lepidoptera: Lycaenidae), is described based on five male and four female specimens from Honey Valley, Kodagu District, Karnataka, which is part of the Western Ghats biodiversity hotspot, India. Cigaritis conjuncta sp. nov. is distinguished from all other congeners in India and Sri Lanka based on the following combination of diagnostic characters in the male: (a) dorsal forewing outer half, costal margin and nearly upper half of the cell black without orange markings, the remaining wing shining deep blue, (b) dorsal hindwing tornus pale orange-red with two black spots, (c) ventral forewing bands at end of discal cell conjoined, and (e) ventral hindwing subbasal and discal bands composed of spots that are not separated but conjoined to form broad bands that have irregular outlines, leaving only a narrow background colour in between. Female is similar on the ventral side, but entirely dark brown above. Male and female genitalia are dissected and figured for two paratypes of each sex, and natural history notes on the species are provided.

Bioinspired multi-dimensional anti-counterfeiting device by combining electrochromism and structural color

Multi-dimensional anti-counterfeiting technologies possess multiple color/pattern variations under different conditions, opening up new avenues in information security. Herein, inspired by the blue-ringed octopus, novel multi-dimensional anti-counterfeiting devices are reported by combining electrochromism and structural color with different coloration mechanisms, that is, by introducing colloidal photonic crystals (PCs) in electrolyte of the electrochromic devices (ECDs). Through actively manipulating voltage or passively changing environment background, the degree of light reflectance and transmittance of PCs can be finely modulated, thus realizing the display and hiding of structural colors of devices. Besides, they also feature distinct color evolution under different viewing angles, enabling more optical information to be carried. Laser-etched patterned devices have also been successfully achieved, showcasing superior triple anti-counterfeiting abilities in terms of optical information. Notably, such inherent patterns can further be innovatively switched to different preset background patterns through the synergy of voltage stimulation and background colors. Based on this, a high-level anti-counterfeiting system has been demonstrated, providing the ability to deliver multiple distinct optical information on-demand. Itis believed that such strategy of combining electrochromic and structural color will pave a new platform for designing advanced multi-dimensional anti-counterfeiting devices.

Using interface preferences as evidence of user identity: A feasibility study

Research on human-computer interaction currently focuses on enhancing system usability by establishing an appropriate user interface (UI) that depends on users’ features. Online users typically have different perceptions of their favored interface design depending on their preferences. Thus, those interface preferences could be utilized to recognize online users’ identities. User authentication is another critical issue that should be considered to improve online security mechanisms without compromising usability. This study investigates the feasibility of using UI preferences as evidence of user identity. The proposed method applies to the design preferences of users dealing with online systems (e.g., e-exam and e-banking). These preferences are closely associated with individual characteristics, whether physical, cognitive, psychological, psychomotor, demographic, or experience based. Many design characteristics could be used in online systems; for example, the e-exam interface design may use features such as the font (size, color, and face), the number of questions per page, background color, questions group, timer type, and sound alert. The feasibility evaluation of this study indicated that 96.8% of research participants have variations in their preferences, and each participant kept 94.5% of their design preferences throughout different sessions.

Web Accessibility Evaluation Using WCAG 2.0 and User-Centered Design Method

ITENAS e-learning has problems such as the flow of access to complex features, and the color of the display and buttons that overlap with the background color. The design of the web interface in this study uses the WCAG 2.0 standard. With the success points of Criterion 1.4.11 Non-text Contrast in the Produce Design Solution stage in the User-Centered Design method. The results of the WCAG 2.0 test show the highest contrast ratio of 15.16:1 which has met the required contrast ratio, the criteria are successfully applied. In the design evaluation stage, this study used SUS to test the usability of the prototype. User experience testing in this study uses UEQ. The results of the evaluation of the usability of the interface with SUS in the initial test resulted in a score of 38.93 which was in grade F or bad to grade B with a score of 74.38 or good after the redesign process. The results of user experience testing with UEQ obtained an average Efficiency scale of 1.875. The Attractiveness scale is 1.667, the Clarity scale is 1.750, the Accuracy scale is 1.375, the Stimulation scale is 1.525, the last is the Novelty scale of 1.350 according to the UEQ average scale which is at a positive level. From the results of the two SUS and UEQ tests, the Usability aspect and the User Experience aspect of the Itenas e-learning web can be said to have improved.