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- 摘要
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Connecting measured BRDFs to analytic BRDFs by data-driven diffuse-specular separation
摘要： The bidirectional reflectance distribution function (BRDF) is crucial for modeling the appearance of real-world materials. In production rendering, analytic BRDF models are often used to approximate the surface appearance since they are compact and flexible. Measured BRDFs usually have a more realistic appearance, but consume much more storage and are hard to modify. In this paper, we propose a novel framework for connecting measured and analytic BRDFs. First, we develop a robust method for separating a measured BRDF into diffuse and specular components. This is commonly done in analytic models, but has been difficult previously to do explicitly for measured BRDFs. This diffuse-specular separation allows novel measured BRDF editing on the diffuse and specular parts separately. In addition, we conduct analysis on each part of the measured BRDF, and demonstrate a more intuitive and lower-dimensional PCA model than Nielsen et al. [2015]. In fact, our measured BRDF model has the same number of parameters (8 parameters) as the commonly used analytic models, such as the GGX model. Finally, we visualize the analytic and measured BRDFs in the same space, and directly demonstrate their similarities and differences. We also design an analytic fitting algorithm for two-lobe materials, which is more robust, efficient and simple, compared to previous non-convex optimization-based analytic fitting methods.
关键词： Analytic BRDF models,Measured BRDF editing,Measured BRDF models,Analytic BRDF fitting
更新于2025-09-23 15:23:52
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Design and characterization of the double-layered defected ground structure transmission line with less radiation loss
摘要： A double-layered DGS transmission line is proposed with a smaller DGS size and less radiation loss. Changing the air boundary to a dielectric boundary reduces the effective electric length at the DGS aperture area. An equivalent circuit model is introduced to analyze the DGS transmission line and the resonator circuit designs. Due to the increase in the effective dielectric constant, the proposed structure can be realized with less sensitivity to metallic environments. From the experimental results, the proposed double-layered DGS can achieve a reduction of 90.1% in size and insensitivity at up to 5 mm of separation from the DGS aperture to the metallic plate.
关键词： equivalent circuit models,effective dielectric constants,radiation loss,size reduction,defected ground structures
更新于2025-09-23 15:23:52
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Radioiodinated Portable Albumin Binder as a Versatile Agent for in vivo Imaging with Single-Photon Emission Computed Tomography
摘要： In this study, radioiodinated 4-(p-iodophenyl)butyric acid ([131I]IBA) was synthesized and evaluated as a portable albumin-binder for potential applications in SPECT imaging of blood pool, tumor and lymph node with significantly improved pharmacokinetic properties. The [131I]IBA was prepared under the catalyst of Cu2O/1,10-phenanthroline. After that, the albumin-binding capability of [131I]IBA was tested in vitro, ex vivo and in vivo, respectively. [131I]IBA was obtained with very high radiolabeling yield (> 99%) and good radiochemical purity (> 98%) within 10 min. It binds to albumin effectively with high affinity (IC50= 46.5 μM) and has good stability. The results of biodistribution indicated that the [131I]IBA was mainly accumulated in blood with good retention (10.51±2.58%ID/g at 30 min p.i. and 4.63±0.17%ID/g at 4 h p.i.). In the SPECT imaging of mice models with [131I]IBA, blood pool, lymph node and tumors could be imaged clearly with high target-to-background ratio. Overall, the radioiodinated albumin binder of [131I]IBA with long blood half-life and excellent stability could be used to decorate diversified albumin-binding radioligands and developed as a versatile theranostic agent.
关键词： SPECT,in vivo imaging,radioiodination,albumin binder,animal models
更新于2025-09-23 15:23:52
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - ON the Effects of Acquisition Parameters and Surface Properties in Sea Oil Seep Observation by Means of High-Resolution SAR
摘要： In this study, a comprehensive analysis of X-band backscattering from sea oil seeps is undertaken exploiting: 1) a two-scale scattering model to predict vv-polarized sea surface backscattering with and without oil slicks under different wind speeds and incidence angles; 2) a large time-series of co-polarized dual-polarimetric Synthetic Aperture Radar imagery collected by the German TerraSAR-X mission over the well-known oil seep related to the Taylor Energy accident occurred in 2004 in the Gulf of Mexico.
关键词： scattering models,Oil seeps,SAR
更新于2025-09-23 15:23:52
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[IEEE 2018 25th IEEE International Conference on Image Processing (ICIP) - Athens, Greece (2018.10.7-2018.10.10)] 2018 25th IEEE International Conference on Image Processing (ICIP) - Generating a Perspective Image from a Panoramic Image by the Swung-to-Cylinder Projection
摘要： This paper proposes a swung-to-cylinder projection model for mapping a sphere to a plane. It can be used to create a semi-perspective image from a panoramic image. The model has two steps. In the first step, the sphere is projected onto a swung surface constructed by a circular profile and a rounded rectangular trajectory. In the second step, the projected image on the swung surface is mapped onto a cylinder through the perspective projection. We also propose methods for automatically determining proper parameters for the projection model based on image content. The proposed model is simple, efficient and easy to control. Experiments and analysis demonstrate its effectiveness.
关键词： swung surfaces,Projection models
更新于2025-09-23 15:22:29
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Living WALES — National Level Mapping and Monitoring Though Earth Observations, Ground Data and Models
摘要： Living Wales is new initiative that aims to capture the state and dynamics of Wales’s landscape, in near real time, historically and into the future (over the long term) through integration of earth observation (EO) data from multiple sensors, supportive ground measurements and process models. Living Wales is building on existing capability, working with relevant national and international organisations in the field, and strengthening research capacity in Wales as well as internationally. Data layers representing land cover, land cover change and a diverse range of environmental variables are being generated and made available to provide better support for government policies and initiatives but also for societal, economic and environmental benefit. Ultimately, Living Wales is anticipated to contribute to more sustainable use and planning of the Welsh landscape and its resources over short to long time (50 year +) scales. The concepts and approach will also be transferable to other countries and regions.
关键词： ground data,environmental variables,change detection,Land cover classification,earth observation,process models
更新于2025-09-23 15:22:29
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[IEEE 2018 Eleventh International Conference "Management of large-scale system development" (MLSD 2018) - Moscow (2018.10.1-2018.10.3)] 2018 Eleventh International Conference "Management of large-scale system development" (MLSD - Optimization of the Structure and Parameters of the Light Cycle Aimed at Improving Traffic Safety at an Intersection
摘要： Formulas for evaluating structural safety for an arbitrary scheme of the road network segment are proposed. On their basis the problem of structural optimization of the traffic light cycle aimed at improving traffic safety is set. The similar optimization problem with respect to traffic intensity is set as well. Approaches to their solution are offered.
关键词： scheme of phase separation,microscopic models of traffic flows,optimization,safety of the road network segment,controlled intersection,computational experiments
更新于2025-09-23 15:22:29
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An improved 2D–3D model for charge transport based on the maximum entropy principle
摘要： To study the electron transport in a some tens of nanometers long channel of a metal oxide ?eld effect transistor, in order to reduce the computational cost of simulations, it can be convenient to divide the electrons into a 2D and a 3D population. Near the silicon/oxide interface the two populations coexist, while in the remaining part of the device only the 3D component needs to be considered because quantum effects are negligible there. The major issue is the description of the scattering mechanisms between the 2D and the 3D electron populations, due to interactions of electrons with nonpolar optical phonons and interface modes. Here, we propose a rigorous treatment of these collisions based on an approach similar to that used in Fischetti and Laux (Phys Rev B 48:2244–2274, 1993), in the context of a Monte Carlo simulation. We also consider all the other main scatterings, which are those with acoustic phonons, surface roughness, and impurities.
关键词： Semiconductors,2DEG,Quantum con?nement,Maximum entropy principle,Hydrodynamical models
更新于2025-09-23 15:22:29
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[IEEE 2018 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD) - Austin, TX, USA (2018.9.24-2018.9.26)] 2018 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD) - The efficient DTCO Compact Modeling Solutions to Improve MHC and Reduce TAT
摘要： This paper introduces the recent modeling challenges of the Process Development Kit (PDK) development due to the limitations of transistor scaling and the impact of new process technologies. And a new modeling solution, Agile PDK is presented to break though these development challenges by enabling the Design Technology Co-Optimization (DTCO) activities in the manufacturing levels. A series of advanced algorithms are newly introduced to not only reduce the PDK development time (TAT), but also improve the model accuracies and Model-to-Hardware Correlation (MHC). It is applied to the latest DRAM technology and dramatically reduces development TAT up to 50% with improved model accuracies.
关键词： PDK,DTCO,Regression,SPICE Models,MHC,Full binning,TCAD TEG,API,Optimization
更新于2025-09-23 15:22:29
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Long-term Characterization of Retinal Degeneration in Royal College of Surgeons Rats Using Spectral-Domain Optical Coherence Tomography
摘要： PURPOSE. Prospective treatments for age-related macular degeneration and inherited retinal degenerations are commonly evaluated in the Royal College of Surgeons (RCS) rat before translation into clinical application. Historically, retinal thickness obtained through postmortem anatomic assessments has been a key outcome measure; however, utility of this measurement is limited because it precludes the ability to perform longitudinal studies. To overcome this limitation, the present study was designed to provide a baseline longitudinal quantification of retinal thickness in the RCS rat by using spectral-domain optical coherence tomography (SD-OCT). METHODS. Horizontal and vertical linear SD-OCT scans centered on the optic nerve were captured from Long-Evans control rats at P30, P60, P90 and from RCS rats between P17 and P90. Total retina (TR), outer nuclear layer+ (ONL+), inner nuclear layer (INL), and retinal pigment epithelium (RPE) thicknesses were quantified. Histologic sections of RCS retina obtained from P21 to P60 were compared to SD-OCT images. RESULTS. In RCS rats, TR and ONL+ thickness decreased significantly as compared to Long-Evans controls. Changes in INL and RPE thickness were not significantly different between control and RCS retinas. From P30 to P90 a subretinal hyperreflective layer (HRL) was observed and quantified in RCS rats. After correlation with histology, the HRL was identified as disorganized outer segments and the location of accumulated debris. CONCLUSIONS. Retinal layer thickness can be quantified longitudinally throughout the course of retinal degeneration in the RCS rat by using SD-OCT. Thickness measurements obtained with SD-OCT were consistent with previous anatomic thickness assessments. This study provides baseline data for future longitudinal assessment of therapeutic agents in the RCS rat.
关键词： MERTK,spectral-domain optical coherence tomography,inherited retinal degeneration,animal models,Royal College of Surgeons Rat
更新于2025-09-23 15:22:29