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[IEEE 2019 Tenth International Conference on Intelligent Control and Information Processing (ICICIP) - Marrakesh, Morocco (2019.12.14-2019.12.19)] 2019 Tenth International Conference on Intelligent Control and Information Processing (ICICIP) - An Improved Scan Matching Method Based on Laser Reflection Intensity
摘要： High-precision localization performance of mobile robots in featureless environments plays an important role in the field of navigation. This paper describes an effective localization solution using a landmark whose surface is covered with two different materials resulting in different laser reflection intensities. Based on the landmark, a feature extraction algorithm is proposed and an improved scan matching method for mobile robot localization in featureless environments is described. Unlike traditional scan matching methods which only use geometric features, the proposed method mixes geometric information extracted from environment and laser reflection intensity extracted from the landmark to achieve accurate pose estimation. Experiments show that our method has higher precision than previous methods.
关键词： high-precision localization,scan matching,laser reflection intensity,featureless environment
更新于2025-09-23 15:19:57
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Investigation of spontaneous emission dynamics of dye molecules coupled into transverse Anderson localized cavities in a hyperbolic waveguide
摘要： Spontaneous emission dynamics of rhodamine 6G molecules coupled into transverse Anderson localized modes in a hyperbolic waveguide is investigated using time-resolved experiments. Four hyperbolic waveguides are simultaneously formed inside a deltoid-shaped fused-silica microtube via the capillary effect. The disordered photonic environment consisting of a rhodamine-doped polymeric material with randomly distributed air inclusions is attributed to localize photons at various resonant wavelengths of the quasi-optical cavities, randomly positioned throughout the guiding medium. The hyperbolic waveguides allow obtaining a single, double, and multimode resonant structures, trapping photons at various frequencies as explored in the form of sharp spectral resonances within the photoluminescence spectrum bandwidth of the dye molecules. Experimental results reveal that the coupling of the fluorescent emitters into multimode localizations in each hyperbolic waveguide corresponds to obtaining quasi-optical cavities at various resonant frequencies, which alter the emission characteristics of the emitters distinctively. The spontaneous emission rate of the dye molecules coupled into the isolated transverse Anderson localized modes is observed to increase by a factor of up to 6.7; thus, the vacuum fluctuations at certain resonant wavelengths are considerably enhanced.
关键词： Spontaneous emission,Transverse Anderson localization,Optical mode,Nano-cavity,Fluorescence lifetime
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE International Conference on Real-time Computing and Robotics (RCAR) - Irkutsk, Russia (2019.8.4-2019.8.9)] 2019 IEEE International Conference on Real-time Computing and Robotics (RCAR) - A Hierarchical Searching Approach for Laser SLAM Re-localization on Mobile Robot Platform
摘要： Simultaneous localization and mapping (SLAM) is an important issue for mobile robot system. Re-localization, as a part of close loop checking of SLAM, focuses on localize the position of a robot agent when it is restarted. Traditional localization methods couldn’t reach both a high accuracy and a little time cost. In this paper, we proposed a newly hierarchical searching approach for laser SLAM re-localization. We do hierarchically searching to match an input laser frame with the whole 2-D map, instead of comparing it with each frame in the map. By using such approach, we could accelerate re-localization speed, so the performance of SLAM is improved. Our SLAM system is well organized on a mobile robot platform. After ?eld test, our approach reaches a average precision (AP) of 90.6% on a 20m× 20m map area, and the time cost is averagely 30ms. The result shows our hierarchical searching approach is effective for re-localization problems on laser SLAM.
关键词： SLAM,laser SLAM,hierarchical searching,mobile robot,re-localization
更新于2025-09-23 15:19:57
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Super-resolution imaging of self-assembled nanocarriers using quantitative spectroscopic analysis for cluster extraction
摘要： Self-assembled nanocarriers have inspired a range of applications for bioimaging, diagnostics, and drug delivery. Non-invasive visualization and characterization of nanocarriers are important for understanding their structure to function relationship. However, quantitative visualization of nanocarriers in the sample’s native environment remains challenging using existing technologies. Single-molecule localization microscopy (SMLM) has the potential to provide both high-resolution visualization and quantitative analysis of nanocarriers in their native environment. However, non-specific binding of fluorescent probes used in SMLM can introduce artifacts, which impose challenges in quantitative analysis of SMLM images. We showed the feasibility of using spectroscopic point accumulation for imaging in nanoscale topography (sPAINT) to visualize self-assembled polymersomes (PS) with molecular specificity. Furthermore, we analyzed the unique spectral signatures of Nile Red (NR) molecules bound to the PS to reject artifacts from non-specific NR bindings. We further developed quantitative spectroscopic analysis for cluster extraction (qSPACE) to increase the localization density by 4-fold compared to sPAINT; thus, reducing variations in PS size measurements to less than 5%. Finally, using qSPACE we quantitatively imaged PS at various concentrations in aqueous solutions with ~20-nm localization precision and 97% reduction in sample misidentification relative to conventional SMLM.
关键词： nanocarriers,Nile Red,super-resolution imaging,single-molecule localization microscopy,spectroscopic analysis,polymersomes
更新于2025-09-23 15:19:57
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Nanoscale Characterization of Surface Plasmon-Coupled Photoluminescence Enhancement in Pseudo Micro Blue LEDs Using Near-Field Scanning Optical Microscopy
摘要： The microcave array with extreme large aspect ratio was fabricated on the p-GaN capping layer followed by Ag nanoparticles preparation. The coupling distance between the dual-wavelength InGaN/GaN multiple quantum wells and the localized surface plasmon resonance was carefully characterized in nanometer scale by scanning near-field optical microscopy. The effects of coupling distance and excitation power on the enhancement of photoluminescence were investigated. The penetration depth was measured in the range of 39–55 nm depending on the excitation density. At low excitation power density, the maximum enhancement of 103 was achieved at the optimum coupling distance of 25 nm. Time-resolved photoluminescence shows that the recombination life time was shortened from 5.86 to 1.47 ns by the introduction of Ag nanoparticle plasmon resonance.
关键词： near-field scanning optical microscopy,micro-LEDs,localization surface plasmon
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Post-Deposition Recrystallization of Co-Evaporated CuIn <sub/>x</sub> Ga <sub/>(1-x)</sub> Se <sub/>2</sub> Films by Bromide Vapor Treatments
摘要： In recent years, smart devices have become ubiquitous. Many of these devices are equipped with global positioning system (GPS), Wi-Fi, and other sensors. With their high mobility, the idea of mobile devices as probes has been attracting more and more attention. Mobility and flexibility offered by smart mobile devices are what traditional fixed sensors lack. However, mobile devices’ power supplies are quite limited. Although GPS is accurate, its high power consumption somewhat limits its accessibility and sustainability. In contrast, Wi-Fi is less power hungry, but at the same time, less accurate. For the sake of sustainability, by adopting Wi-Fi as an alternative to GPS, longer operation is attainable at the cost of losing some degree of accuracy. In this paper, a Wi-Fi-based algorithm based on log-normal probability distribution of distances with respect to received signal strength is proposed. It is suitable for an outdoor environment, where Wi-Fi access points (APs) are abundant. Simulations are conducted over known AP locations, and results show that the proposed algorithm can save, on average, as much as 35% more battery power than GPS does. The average localization error is ～18 m, and the average velocity estimation error is ～25%.
关键词： Mobile phone sensing,log-normal distribution,positioning algorithm,Wi-Fi-based localization,received signal strength indicator
更新于2025-09-23 15:19:57
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Cross density of states and mode connectivity: Probing wave localization in complex media
摘要： We introduce the mode connectivity as a measure of the number of eigenmodes of a wave equation connecting two points at a given frequency. Based on numerical simulations of scattering of electromagnetic waves in disordered media, we show that the connectivity discriminates between the diffusive and the Anderson localized regimes. For practical measurements, the connectivity is encoded in the second-order coherence function characterizing the intensity emitted by two incoherent classical or quantum dipole sources. The analysis applies to all processes in which spatially localized modes build up, and to all kinds of waves.
关键词： Anderson localization,disordered media,cross density of states,wave localization,electromagnetic waves,mode connectivity
更新于2025-09-19 17:15:36
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Computed tomography criteria for the use of advanced localization techniques in minimally invasive thoracoscopic lung resection
摘要： Background: The significant improvement of patient outcomes from minimally invasive lung surgery has led to the development of advanced lung nodule localization techniques to help manage patients with small suspicious lung nodules or to help resect patients with small pulmonary metastases. However, there are no clear computed tomography (CT) criteria to guide the use of advanced localization techniques for this group of patients. Methods: We conducted a retrospective chart review of patients who had undergone initial wedge resection of single or multiple lung nodules. We collected demographics, surgical information and surgical outcomes as well as CT scan features. Multiple logistic regression was performed to determine which factors were most predictive of the need for advanced localization techniques. Results: A total of 45 patients (73%) were resected by direct identification alone while 17 patients (27%) required advanced localization techniques. Of those requiring advanced localization, 11 patients had cone beam CT, 3 patients had transbronchial localization using electromagnetic navigation and 3 patients had preoperative CT guided wire localization. Patients requiring advanced localization had significantly smaller lung nodules at 0.8 cm compared to 1.4 cm (P=0.01), nodules that were further away from the pleura at 1.3 cm compared 0.1 cm (P<0.001) and were more likely to have ground glass nodules (P=0.01) compared to patients who were resected by direct identification alone. Multiple logistic regression confirmed that nodule size, distance to pleura and ground glass attenuation were predictive factors for requiring advanced localizing techniques. Every patient was treated with minimally invasive lung resection. A 1.3-cm or greater solitary pulmonary nodule less than 5 mm from the pleura can be removed without advanced techniques with a 96% success rate. Conclusions: Overall, in patients undergoing resection of a suspicious primary or metastatic lung nodule, advanced localization techniques should be considered in those with small non-solid nodules, which are not near the pleural surface on CT scan.
关键词： computed tomography guided localization (CT guided localization),navigation bronchoscopy,cone beam computed tomography (cone beam CT),lung cancer,Lung nodule
更新于2025-09-19 17:15:36
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[ACM Press the 33rd Annual ACM Symposium - Pau, France (2018.04.09-2018.04.13)] Proceedings of the 33rd Annual ACM Symposium on Applied Computing - SAC '18 - Accelerated exhaustive eye glints localization method for infrared video oculography
摘要： Human eye glints localization could significantly and directly improve accuracy of gaze tracking, especially when several glints are localized precisely at the same time. However, traditional algorithms have not ensured the accuracy of glints localization to be used for gaze tracking. Aiming at the problem in infrared video oculography that those glints reflected on the surface of eye iris could be hard to identify and localize, we propose an algorithm for precisely and exhaustively locating eye glints of high accuracy with accelerated process. Our contributions are two-folded. (1). We propose an exhaustive eye glints localization algorithm, which could guarantee both 94.9% recognition rate and < 1 pixel positional accuracy under various brightness conditions. (2). We propose methods to accelerate our algorithm, including a modified quadratic ellipse difference algorithm and video frame difference examination, which guarantee the real-time video processing requirement for gaze tracking system.
关键词： glints tracking,gaze tracking,glints localization,ellipse difference method,pupil detection
更新于2025-09-19 17:15:36
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Nanobody Detection of Standard Fluorescent Proteins Enables Multi-Target DNA-PAINT with High Resolution and Minimal Displacement Errors
摘要： DNA point accumulation for imaging in nanoscale topography (PAINT) is a rapidly developing fluorescence super-resolution technique, which allows for reaching spatial resolutions below 10 nm. It also enables the imaging of multiple targets in the same sample. However, using DNA-PAINT to observe cellular structures at such resolution remains challenging. Antibodies, which are commonly used for this purpose, lead to a displacement between the target protein and the reporting fluorophore of 20–25 nm, thus limiting the resolving power. Here, we used nanobodies to minimize this linkage error to ~4 nm. We demonstrate multiplexed imaging by using three nanobodies, each able to bind to a different family of fluorescent proteins. We couple the nanobodies with single DNA strands via a straight forward and stoichiometric chemical conjugation. Additionally, we built a versatile computer-controlled microfluidic setup to enable multiplexed DNA-PAINT in an efficient manner. As a proof of principle, we labeled and imaged proteins on mitochondria, the Golgi apparatus, and chromatin. We obtained super-resolved images of the three targets with 20 nm resolution, and within only 35 minutes acquisition time.
关键词： DNA-PAINT,microfluidics,super-resolution microscopy,fluorescent proteins,molecular localization,multi-color imaging,multiplexing,single domain antibodies (sdAb),linkage error,nanobodies
更新于2025-09-19 17:15:36