10 research outputs found

    Differentiable Display Photometric Stereo

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    Photometric stereo leverages variations in illumination conditions to reconstruct per-pixel surface normals. The concept of display photometric stereo, which employs a conventional monitor as an illumination source, has the potential to overcome limitations often encountered in bulky and difficult-to-use conventional setups. In this paper, we introduce Differentiable Display Photometric Stereo (DDPS), a method designed to achieve high-fidelity normal reconstruction using an off-the-shelf monitor and camera. DDPS addresses a critical yet often neglected challenge in photometric stereo: the optimization of display patterns for enhanced normal reconstruction. We present a differentiable framework that couples basis-illumination image formation with a photometric-stereo reconstruction method. This facilitates the learning of display patterns that leads to high-quality normal reconstruction through automatic differentiation. Addressing the synthetic-real domain gap inherent in end-to-end optimization, we propose the use of a real-world photometric-stereo training dataset composed of 3D-printed objects. Moreover, to reduce the ill-posed nature of photometric stereo, we exploit the linearly polarized light emitted from the monitor to optically separate diffuse and specular reflections in the captured images. We demonstrate that DDPS allows for learning display patterns optimized for a target configuration and is robust to initialization. We assess DDPS on 3D-printed objects with ground-truth normals and diverse real-world objects, validating that DDPS enables effective photometric-stereo reconstruction

    Analysis of Noise Coupling From a Power Distribution Network to Signal Traces in High-Speed Multilayer Printed Circuit Boards

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    As layout density increases in highly integrated multilayer printed circuit boards (PCBs), the noise that exists in the power distribution network (PDN) is increasingly coupled to the signal traces, and precise modeling to describe the coupling phenomenon becomes necessary. This paper presents a model to describe noise coupling between the power/ground planes and signal traces in multilayer systems. An analytical model for the coupling has been successfully derived, and the coupling mechanism was rigorously analyzed and clarified. Wave equations for a signal trace with power/ground noise were solved by imposing boundary conditions. Measurements in both the frequency and time domains have been conducted to confirm the validity of the proposed model

    Development of biocathode during repeated cycles of bioelectrochemical conversion of carbon dioxide to methane

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    Functioning biocathodes are essential for electromethanogenesis. This study investigated the development of a biocathode from non-acclimated anaerobic sludge in an electromethanogenesis cell at a cathode potential of -0.7 V (vs. standard hydrogen electrode) over four cycles of repeated batch operations. The CO2-to-CH4 conversion rate increased (to 97.7%) while the length of the lag phase decreased as the number of cycles increased, suggesting that a functioning biocathode developed during the repeated sub-culturing cycles. CO2-resupply test results suggested that the biocathode catalyzed the formation of CH4 via both direct and indirect (H-2-mediated) electron transfer mechanisms. The biocathode archaeal community was dominated by the genus Methanobacterium, and most archaeal sequences (>89%) were affiliated with Methanobacterium palustre. The bacterial community was dominated by putative electroactive bacteria, with Arcobacter, which is rarely observed in biocathodes, forming the largest population. These electroactive bacteria were likely involved in electron transfer between the cathode and the methanogens

    Motion Retargetting and Evaluation for VR based Motion Training of Free Motions. Visual Computer

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    Virtual Reality (VR) has emerged as one of the important and effective tools for educa-tion and training. Most VR-based training systems are situation-based, where the trainees are trained for discrete decision-making in special situations presented by the VR environments. In contrast, this paper discusses the application of VR to a different class of training, for learning motions, often required in sports and the arts. We propose a VR-based motion training frame-work that contains an intuitive motion guiding interface, posture-oriented motion retargeting, and an evaluation and advice scheme for corrective feedback. Applications of the proposed framework to a simple fencing training and a dance imitation game are demonstrated

    Motion retargeting and evaluation for VR-based training of free motions

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    A Flexible Patch-Type Strain Sensor Based on Polyaniline for Continuous Monitoring of Pulse Waves

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    A flexible, patch-type strain sensor is described for continuous monitoring of pulse waves. The proposed sensor exploits the piezo-resistivity of the conductive polymer, polyaniline (PANI), to detect dynamic volume changes in blood vessels owing to pulse waves. The proposed PANI film was fabricated through electrodeposition, which is considered as a suitable low-cost technique for mass production in the sensor manufacturing industry. Thus, it is prospective for a disposable wearable sensing system solution in remote healthcare applications. Besides, a flexible sensor packaging can be achieved by laminating the PANI films and an ECOFLEX elastomer to the film bandage. The proposed PANI sensor has high sensitivity (gauge factor of 74.28) and linearity (R-2 = 0.99). It also showed a high correlation with commercially available photoplethysmography (PPG) sensor with the small bias and confidence interval to the PPG sensor: bias < 0.1% and confidence interval < 3% for all subjects. Moreover, the proposed PANI sensor was tested for prospective circulatory system-related applications such as measuring heart rate, stiffness index, and pulse transit time. Finally, the proposed study suggests that the proposed PANI sensor is a promising candidate for continuous, long-term, unobtrusive pulse wave monitoring, which can provide real-time insights into an individual&apos;s health status.11Ysciescopu

    Measurement and Correlation-Based Methodology for Estimating Worst-Case Skew Due to Glass Weave Effect

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    Skew is unintentionally introduced within a differential pair, through misalignment of conductors and glass fiber bundles in Printed Circuit Board (PCB) dielectric layers. Manufacturers do not control interposition of specific glass bundles to supplied board design (artwork). Therefore, an unknown and random factor is added to each produced PCB. Current paper describes a method that utilizes a set of measurements and numerical models to estimate worst-case skew for the aforementioned effect. First, test vehicles are built, and then cross-sections are analyzed with Scanning Electron Microscope (SEM) for precise measurements. Numerical models are constructed to correlate with real DUT; after correlation is achieved, relative location of conductors to glass bundles is swept to obtain best and worst case skew

    Effects of estrogen inhibition formula herbal mixture for danazol-induced precocious puberty in female rats: An experimental study with network pharmacology

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    Background: This study aimed at determining the effect of the herbal mixture estrogen inhibition formula (EIF) and its possible mechanisms by precocious puberty animal models and network pharmacology-based analysis. Methods: Precocious puberty animal models were established by a single injection of 300 μg danazol, then female rats were administered EIF, vaginal openings were monitored, uterus and pituitary indices were determined. The levels of ALP, E2, LH, and FSH were measured using ELISA kits. Real-time PCR was performed to evaluate the mRNA expression of GnRH, UNC5C, and netrin-1 in hypothalamic tissues. We applied network pharmacological analysis to predict potential targets and pathways of EIF. Results: EIF delayed danazol-induced early vaginal opening. In the onset model, EIF reduced the increased levels of serum ALP, E2, LH, and FSH; as well as mRNA expressions of GnRH, Netrin-1, and UNC5C. Moreover, long-term administration of EIF not only diminished all impaired factors but also had no effect on the normal development of the animals. The gene set enrichment analysis showed that the targets of EIF are mainly associated with the GnRH signaling and ovarian steroidogenesis pathways. Conclusion: EIF could be used in preclinical research for the treatment of precocious puberty by the inhibition of HPGA pre-maturation
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