Search Results (20)

This paper introduces a passive face-authenticity detection system, designed for integration into an employee work time registration platform. The system is implemented as a stacking ensemble of multiple models. Each model independently assesses whether a camera is capturing a live human face or a spoofed representation, such as a photo or video. The ensemble comprises a convolutional neural network (CNN), a smartphone bezel-detection algorithm to identify faces displayed on electronic devices, a face context analysis module, and additional CNNs for image processing. The outputs of these models are aggregated by a neural network that delivers the final classification decision. We examined various combinations of models within the ensemble and compared the performance of our approach against existing methods through experimental evaluation. Full article

In the present study, we investigated the deformation of polyurethane composite solar cell bezels during the curing process. To address the problem of deformation, thermochemical and curing kinetics models were developed to investigate the mechanical behavior of the resin during the curing process. The importance of the influencing factors was determined through orthogonal experiments and simulation analysis. The results showed that holding pressure had a significant effect on the amount of deformation of the bezel, followed by curing temperature, pultrusion speed, and holding time. The optimal combination of process parameters was a curing temperature of 150 °C, a pultrusion speed of 50 cm/min, a holding time of 12 s, and a holding pressure of 0.14 MPa, which aided in significantly reducing the deformation of the bezel and achieving effective control of curing deformation. Full article

Colony-Forming Unit (CFU) counting is a complex problem without a universal solution in biomedical and food safety domains. A multitude of sophisticated heuristics and segmentation-driven approaches have been proposed by researchers. However, U-Net remains the most frequently cited and used deep learning method in these domains. The latter approach provides a segmentation output map and requires an additional counting procedure to calculate unique segmented regions and detect microbial colonies. However, due to pixel-based targets, it tends to generate irrelevant artifacts or errant pixels, leading to inaccurate and mixed post-processing results. In response to these challenges, this paper proposes a novel hybrid counting approach, incorporating a multi-loss U-Net reformulation and a post-processing Petri dish localization algorithm. Firstly, a unique innovation lies in the multi-loss U-Net reformulation. An additional loss term is introduced in the bottleneck U-Net layer, focusing on the delivery of an auxiliary signal that indicates where to look for distinct CFUs. Secondly, the novel localization algorithm automatically incorporates an agar plate and its bezel into the CFU counting techniques. Finally, the proposition is further enhanced by the integration of a fully automated solution, which comprises a specially designed uniform Petri dish illumination system and a counting web application. The latter application directly receives images from the camera, processes them, and sends the segmentation results to the user. This feature provides an opportunity to correct the CFU counts, offering a feedback loop that contributes to the continued development of the deep learning model. Through extensive experimentation, the authors of this paper have found that all probed multi-loss U-Net architectures incorporated into the proposed hybrid approach consistently outperformed their single-loss counterparts, as well as other comparable models such as self-normalized density maps and YOLOv6, by at least 1% to 3% in mean absolute and symmetric mean absolute percentage errors. Further significant improvements were also reported through the means of the novel localization algorithm. This reaffirms the effectiveness of the proposed hybrid solution in addressing contemporary challenges of precise in vitro CFU counting. Full article

By the end of the 16th century, finger rings in reverse glass painting technique became increasingly popular in Europe. Often, they are used in the context of signet rings with the monogram together with the coat of arms of its beholder depicted on the glass bezel. The following paper concentrates on nine finger rings of this group. Instead of an actual coat of arms though, these finger rings carry the device V(G)MN or FGMN (for-get-me-not) accompanied by a depiction of little blue forget-me-not flowers as the coat of arms. By collecting and describing the so far existing material, the paper aims to contextualize the use and function of the finger rings with the symbol of the forget-me-not flower in the fields of love, friendship and faith. Furthermore, it links the symbol of the for-get-me-not on finger rings and the imperative power of the written letters V(G)MN or FGMN to its tradition in German literature and texts. Full article

We propose a broadband decoupled antenna pair for 5G mobile terminals. The broadband decoupled design of this antenna pair is based on the characteristic mode theory (CMA) and defective ground structure. First, CMA is applied to obtain the characteristic current distribution of the antenna, then the characteristic current sensitive regions are optimized to make the antenna introduce new modes and obtain a wide bandwidth. After that, an antenna pair is added with defective ground structure to obtain a wideband decoupled antenna pair that has small size and high isolation. Next, an eight-element MIMO antenna system is constructed with the obtained broadband decoupled antenna pair, and a composite decoupling technique consisting of defective ground structure (DGS) and decoupling strip is applied to the two antenna pairs on the same side of the bezel to improve the isolation. The simulation and prototype test results show that the eight-element MIMO antenna with −10 dB bandwidth of 3.28~5.85 GHz mainly covers the N77/N78/N79/WLAN 5 GHz band, and the antenna pair are only 1.6 mm apart with good isolation (−16.7 dB), the ECC is less than 0.01, and it has a good total efficiency at the main operating frequency. Finally, the effect of a user’s hand on the antenna is briefly analyzed to verify the robustness of the proposed MIMO antenna system. Full article

Since printed capacitive sensors provide better sensing performance, they can be used in automotive bezel applications. It is necessary to fabricate such sensors and apply an optimization approach for choosing the optimal sensor pattern. In the present work, an effort was made to formulate interdigitated pattern-printed Silver (Ag) electrode flexible sensors and adopt the Taguchi Grey Relational (TGR)-based optimization approach to enhance the flexible sensor’s panel for enhanced automobile infotainment applications. The optimization technique was performed to derive better design considerations and analyze the influence of the sensor’s parameters on change in capacitance when touched and production cost. The fabricated flexible printed sensors can provide better sensing properties. A design pattern which integrates an overlap of 15 mm, an electrode line width of 0.8 mm, and an electrode gap 0.8 mm can produce a higher change in capacitance and achieve a lower weight. The overlap has a greater influence on sensor performance owing to its optimization of spatial interpolation. Full article

To satisfy the demand for 5G communication to smartphone terminal antennas in element quantity and isolation, an eight-element wideband MIMO antenna set of high isolation level is proposed. Each antenna element in the array is a double-L antenna consisting of an L-shaped slot and an L-shaped 50 Ω microstrip line. The L slot is formed by adding an I-shaped open circuit directly to the side of the rectangular slot. In addition, the antenna arrays are located on the long bezels on both sides of the mobile phone motherboard, and the coupling feed is made in the frequency range of 3.6–4.7 GHz through the L-shaped microstrip line, so as to cover the 5G NR band (N77/N78/N79). Finally, the four element pairs (8 components) achieve isolation of greater than 11 dB, the performance frequency range is 3.6–4.7GHz, the return loss is −6 dB, the total efficiency is greater than 85%, and the envelope correlation coefficient is less than 0.08. Other MIMO performances are also calculated, the design process is discussed in detail, and one-handed grip mode and two-handed grip mode are discussed to demonstrate their stabilities in real-world applications. Full article

Increasing numbers of antennas are being placed inside laptop screen bezels. Connections between antennas and laptop bases have become challenging owing to space limitations. Thus, this paper proposes a flexible low-loss thin flimsy stripline structure for high-speed applications. The cable should be sufficiently thin to avoid causing a water ripple effect while under the screen panel. Furthermore, the cable should be sufficiently flexible to traverse the hinges between the laptop screen and base. This study aims to design a cable with a total thickness of less than 0.6 mm and an insertion loss of less than 10 dB/m at a frequency of 6 GHz. Polytetrafluoroethylene (PTFE), a flexible material, can be used to meet these requirements. We simulate the characteristics of various PTFE layer thicknesses. The trend shows a thicker PTFE layer and lower insertion loss. Finally, we fabricate and test two structures with different thicknesses. Both thicknesses are less than 0.6 mm, and the insertion losses are less than 10 dB/m at 6 GHz. We demonstrate the feasibility of the proposed design and fabrication process for these applications through simulations and measurements. Full article

It is possible to employ printed capacitive sensors in car bezel applications because of its lower cost and higher detecting capabilities. In this paper, a flexible sensor for automotive entertainment applications has been developed using an electrode flexible sensor with an interdigitated pattern printed on it using screen printing and 3D printing fabrication processes. Design concerns such as electrode overlap, electrode gap and width on capacitance changes, and production costs were studied. In addition, a new generation of flexible printed sensors has been developed that can outperform conventional human–machine interface (HMI) sensors. The capacitance of the design pattern may be optimized by using a 15mm overlap and 0.5mm electrode line width. Due to the precision of interpolation, overlap has a larger effect on sensor performance than it would have without it. Full article

The fabrication and design of hard magnetic materials for micro-electro-mechanical system applications by electrochemical deposition has to consider not only the intrinsic material properties but also the shape anisotropy of the micro-devices. Within the scope of the present work, an as-plated process for hard magnetic Co-based materials was developed, with the products intended to be used as magnetic scales in a positioning system with a resolution within the nanometer range. First, the process–material correlations are investigated in a laboratory-scale process. The CoP and CoNiP show a maximum coercivity of H_C = 28 and 45 kA/m, respectively, as well as maximum remanence polarizations of J_R = 0.65 and 0.40 T, respectively. The CoP process is transferred to a specially developed 20 L plating cell with paddle convection capabilities and a passive bezel to deposit 50 µm wide scales with different thicknesses of up to 55 µm in an integrated process. The in-plane magnetization of the scale bars shows higher remanence polarization than for the out-of-plane direction. Magnetic field-assisted electrochemical deposition promotes the vertical magnetization component resulting in a remanence polarization of 205 mT (out-of-plane) for a scale thickness of 25 µm. Full article

Bronchoscopic lung volume reduction (BLVR) by endobronchial valve (EBV) implantation has been shown to improve dyspnea, pulmonary function, exercise capacity, and quality of life in highly selected patients with severe emphysema and hyperinflation. The most frequent adverse event is a pneumothorax (PTX), occurring in approximately one-fifth of the cases due to intrathoracic volume shifts. The majority of these incidents are observed within 48 h post-procedure. However, the delayed occurrence of PTX after hospital discharge is a matter of concern. There is currently no approved concept for its prevention. Particularly, it is unknown whether and when respiratory manoeuvers such as spirometry post EBV treatment are feasible and safe. As per standard operating procedure at the University Hospital Zurich, early spirometry is scheduled after BLVR and prior to the discharge of the patient in order to monitor treatment success. The aim of our retrospective study was to investigate the feasibility and safety of early spirometry. In addition, we hypothesized that early spirometry could be useful to identify patients at risk for late PTX, which may occur after hospital discharge. All patients who underwent BLVR using EBVs between January 2018 and January 2020 at our hospital were enrolled in this study. After excluding 16 patients diagnosed post-procedure with PTX and four patients for other reasons, early spirometry was performed in 61 cases. There was neither a clinically relevant PTX during or after early spirometry nor a late PTX following hospital discharge. In conclusion, we found early spirometry, conducted not sooner than three days following EBV treatment, to be feasible and safe. Furthermore, early spirometry seems to be a useful predictor for successful BLVR, and it may help to decide whether a patient can be discharged. Given the small sample size and the retrospective design of our study, a prospective study that includes routine chest imaging after early spirometry to definitively exclude PTX is needed to recommend early spirometry as part of the standard protocol following EBV treatment. Full article

A new low-frame-rate active-matrix organic light-emitting diode (AMOLED) pixel circuit with low-temperature poly-Si and oxide (LTPO) thin-film transistors (TFTs) for portable displays with high pixel density is reported. The proposed pixel circuit has the excellent ability to compensate for the threshold voltage variation of the driving TFT (ΔV_{TH_DTFT}). By the results of simulation based on a fabricated LTPS TFT and a-IZTO TFT, we found that the error rates of the OLED current were all lower than 2.71% over the range of input data voltages when ΔV_{TH_DTFT} = ±0.33 V, and a low frame rate of 1 Hz could be achieved with no flicker phenomenon. Moreover, with only one capacitor and two signal lines in the pixel circuit, a high pixel density and narrow bezel are expected to be realized. We revealed that the proposed 7T1C pixel circuit with low driving voltage and low frame rate is suitable for portable displays. Full article

In the present scenario, a considerable assiduity is provided to develop novel human-machine interface technologies that rapidly outpace the capabilities of display technology in automotive industries. It is necessary to use a new cockpit design in conjunction with a fully automated driving environment in order to enhance the driving experience. It can create a seamless and futuristic dashboard for automotive infotainment application. In the present study, an endeavor was made to equip the In-vehicle bezels with printed capacitive sensors for providing superior sensing capabilities. Silver Nanoparticles based interdigitated pattern electrodes were formed over polycarbonate substrates to make printed capacitive sensors using screen printing process. The developed sensor was investigated to evaluate the qualitative and quantitative measures using direct and in-direct contact of touch. The proposed approach for sensors pattern and fabrication can highly impact on sensor performance in automotive infotainment application due to the excellent spatial interpolation with lower cost, light weight, and mechanical flexibility. Full article

This study aimed to investigate consumers’ visual image evaluation of wrist wearables based on Kansei engineering. A total of 8 representative samples were screened from 99 samples using the multidimensional scaling (MDS) method. Five groups of adjectives were identified to allow participants to express their visual impressions of wrist wearable devices through a questionnaire survey and factor analysis. The evaluation of eight samples using the five groups of adjectives was analyzed utilizing the triangle fuzzy theory. The results showed a relatively different evaluation of the eight samples in the groups of “fashionable and individual” and “rational and decent”, but little distinction in the groups of “practical and durable”, “modern and smart” and “convenient and multiple”. Furthermore, wrist wearables with a shape close to a traditional watch dial (round), with a bezel and mechanical buttons (moderate complexity) and asymmetric forms received a higher evaluation. The acceptance of square- and elliptical-shaped wrist wearables was relatively low. Among the square- and rectangular-shaped wrist wearables, the greater the curvature of the chamfer, the higher the acceptance. Apparent contrast between the color of the screen and the casing had good acceptance. The influence of display size on consumer evaluations was relatively small. Similar results were obtained in the evaluation of preferences and willingness to purchase. The results of this study objectively and effectively reflect consumers’ evaluation and potential demand for the visual images of wrist wearables and provide a reference for designers and industry professionals. Full article

To attain the narrow bezel characteristic of information displays, functional sealing composite materials should possess high adhesion strength and water barrier performance due to their narrow line widths. In this study, highly adhesive UV/heat dual-curable epoxy–acrylate composites with outstanding water-resistant performance have been proposed using photoreactive organic–inorganic hybrid nanoparticles that can react with an acrylate resin, creating a crosslinked nanoparticle network within the sealing composite. The hybrid nanoparticles consisted of reactive methacrylate groups as a shell and an inorganic core of silica or aluminum oxide, and were facilely synthesized through sol–gel reaction and chemisorption process. The curing characteristics, adhesive strength, and moisture permeability of the proposed sealing composite have been compared to those of a conventional epoxy–acrylate composite containing inorganic silica particles. The composites including hybrid nanoparticles exhibited high UV and heat curing ratios owing to the numerous methacrylate groups on the nanoparticle surface and high compatibility with organic resins. Moreover, the proposed sealing composite showed high adhesion strength and extremely low water permeability due to the creation of densely photocrosslinked network with matrix resins. In addition, the sealing composite exhibited excellent narrow dispensing width as well as relatively low viscosity, suggesting the potential application in narrow bezel display. Full article