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[ACM Press the International Conference - San Diego, California (2018.11.05-2018.11.08)] Proceedings of the International Conference on Computer-Aided Design - ICCAD '18 - Strain-aware performance evaluation and correction for OTFT-based flexible displays
摘要： Organic thin-?lm transistors (OTFTs) are widely used in ?exible circuits, such as ?exible displays, sensor arrays, and radio frequency identi?cation cards (RFIDs), because these technologies offer features such as better ?exibility, lower cost, and easy manufacturability using low-temperature fabrication process. This paper develops a procedure that evaluates the performance of ?exible displays. Due to their very nature, ?exible displays experience signi?cant mechanical strain/stress in the ?eld due to the deformation caused during daily use. These deformations can impact device and circuit performance, potentially causing a loss in functionality. This paper ?rst models the effects of extrinsic strain due to two fundamental deformations modes, bending and twisting. Next, this strain is translated to variations in device mobility, after which analytical models for error analysis in the ?exible display are derived based on the rendered image values in each pixel of the display. Finally, two error correction approaches for ?exible displays are proposed, based on voltage compensation and ?exible clocking.
关键词： Organic thin-?lm transistors (OTFTs),performance evaluation,error correction,strain modeling,?exible displays
更新于2025-09-23 15:21:01
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LiDAR DEM Data for Flood Mapping and Assessment; Opportunities and Challenges: A Review
摘要： Flooding is the most catastrophic, wide spread, and frequent natural hazards causing extensive damages on infrastructure, human life, and the environment. The frequency and severity of flooding has been increasing all over the world attributed to climate change and escalated urbanization. As such, the issue and techniques of monitoring and mapping flood inundated areas are also increasing. Advancement of state-of-the-art technologies have facilitated and improved flood mapping and monitoring. Earth observation plays important role in flood mapping, monitoring, and damage assessment. However, there are fundamental issues that restricts satellite data from being used for flood studies. LiDAR DEM data based flood modeling approach solves some of the limitations of Earth observation. On the other hand, flood modeling using LiDAR DEM data are challenging. The aim of this review is, therefore, to identify the opportunities and challenges of using LIDAR DEM data for flood mapping and assessment. Substantial literature review was done to attain the stated objective. The study revealed that flood modeling techniques could significantly improve the limitations of detecting flood using Earth observation such as detecting flooded areas under dense canopies and in urban areas. This is attributed to the accurate and fine resolution LiDAR DEM. Furthermore, LiDAR technology provide several opportunities such as relatively cost and time effective data collection system, capability of penetrating dense vegetation, and improved flood model accuracy and fine scale flood modeling. On the other hand, LiDAR data filtering (classification), data availability and accessibility, data file size, high computational time, inability to characterize channels bathymetry, and insufficiency of representing complex urban features are some of the challenges. Therefore, multi-platform LiDAR data (i.e., ground-based, airborne and space borne) and data from additional sources such as echo soundings and electronic theodolite surveys should be integrated to increase the effectiveness of the LiDAR technology for flood modeling.
关键词： Opportunities,Flooding,Flood modeling,Challenges,LiDAR DEM data
更新于2025-09-23 15:21:01
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[IEEE 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz2018) - Nagoya, Japan (2018.9.9-2018.9.14)] 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Turning THz Communications into Reality: Status on Technology, Standardization and Regulation
摘要： Already a couple of years ago THz communications have not only become an attractive new research area on channel modeling but also triggered a couple of projects heading to develop appropriate technological solutions to enable the set-up of hardware demonstrators. Also discussions and activities in standardization and regulation already took off. In October 2017, IEEE published Std. IEEE 802.15.3d-2017 the worldwide first wireless communications standard operating in the 300 GHz frequency band. In parallel to the standardization process activities at the ITU-R level targeting on the provision of an appropriate regulatory framework at the World Radio Conference 2019 (WRC-2019) via a dedicated agenda item have taken off. This paper provides a brief overview on the current status of the development of THz Communication systems focusing on recent results on advanced channel characterization at 300 GHz, hardware demonstrators operating in this frequency range, the past and current activities at IEEE 802 and the WRC 2019 preparations.
关键词： channel modeling,standardization,THz communications,regulation,hardware demonstrators
更新于2025-09-23 15:21:01
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Suppression of amplitude modulation induced by polarization mode dispersion using a multi-degree-of-freedom fiber filter
摘要： Polarization mode dispersion (PMD) in ?bers for high-power lasers can induce signi?cant frequency modulation to amplitude modulation (FM-to-AM) conversion. However, existing techniques are not suf?ciently ?exible to achieve ef?cient compensation for such FM-to-AM conversion. By analyzing the nonuniform transmission spectrum caused by PMD, we found that the large-scale envelope of the transmission spectrum has more serious impacts on the amount of AM. In order to suppress the PMD-induced FM-to-AM conversion, we propose a novel tunable spectral ?lter with multiple degrees of freedom based on a half-wave plate, a nematic liquid crystal, and an axis-rotated polarization-maintaining ?ber. Peak wavelength, free spectral range (FSR), and modulation depth of the ?lter are decoupled and can be controlled independently, which is veri?ed through both simulations and experiments. The ?lter is utilized to compensate for the PMD-induced FM-to-AM conversion in the front end of a high-power laser facility. The results indicate that, for a pulse with phase-modulation frequency of 22.82 GHz, the FM-to-AM conversion could be reduced from 18% to 3.2% within a short time and maintained below 6.5% for 3 h. The proposed ?lter is also promising for other applications that require ?exible spectral control such as high-speed channel selection in optical communication networks.
关键词： laser facility,laser systems,optimization,high-power laser,laser facility and engineering,advanced laser technology and applications,?ber laser and applications,modeling,design
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE SENSORS - Montreal, QC, Canada (2019.10.27-2019.10.30)] 2019 IEEE SENSORS - Industrial gas analytics using a compact ultraviolet laser
摘要： In this paper, we propose a simple, yet reliable methodology to expedite yield estimation and optimization of microwave structures. In our approach, the analysis of the entire response of the structure at hand (e.g., S-parameters as a function of frequency) is replaced by response surface modeling of suitably selected feature points. On the one hand, this is sufficient to determine whether a design satisfies given performance specifications. On the other, by exploiting the almost linear dependence of the feature points on the designable parameters of the structure, reliable yield estimates can be realized at low computational cost. Our methodology is verified using two examples of waveguide filters and one microstrip hairpin filter and compared with conventional Monte Carlo analysis based on repetitive electromagnetic simulations, as well as with statistical analysis exploiting linear response expansions around the nominal design. Finally, we perform yield-driven design optimizations on these filters.
关键词： microwave component modeling,yield-driven design,electromagnetic (EM) modeling,yield estimation,tolerance-aware design,Design centering,statistical analysis
更新于2025-09-23 15:19:57
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Multi-scale process simulation for additive manufacturing through particle filled vat photopolymerization
摘要： The majority of research into vat photopolymerization (VP), has been focused on experimental investigations of the influence of process and material parameters. In a specific application of the VP technique, where the resin is filled with particles, this empirical approach has its limitations. In order to fully understand the relation between process parameters and the material properties a detailed numerical analysis is needed. In this paper we present a multi-scale and multi-physical simulation approach to unravel such relations in the complex production process. Using a homogenization approach, the influence of the filler particles, in this case alumina, on the light scattering, conversion characteristics and resulting effective thermal and mechanical properties is determined. The effective composite material and scattering properties are then used as input in a process simulation framework. This enables prediction of key filled-VP characteristics at a structural level. A mesh sensitivity analysis at the component scale reveals that adequate predictions may be obtained with a rather course discretization, facilitating multi-physics VP part simulations.
关键词： Homogenization framework,Multi-physical modeling,Process simulation,Ceramics,Additive manufacturing,Vat photopolymerization,Multi-scale modeling
更新于2025-09-23 15:19:57
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High-Precision 3D Object Capturing with Static and Kinematic Terrestrial Laser Scanning in Industrial Applicationsa??Approaches of Quality Assessment
摘要： Terrestrial laser scanning is used in many disciplines of engineering. Examples include mobile mapping, architecture surveying, archaeology, as well as monitoring and surveillance measurements. For most of the mentioned applications, 3D object capturing in an accuracy range of several millimeters up to a few centimeters is sufficient. However, in engineering geodesy, particularly in industrial surveying or monitoring measurements, accuracies in a range of a few millimeters are required. Additional increased quality requirements apply to these applications. This paper focuses on the quality investigation of data captured with static and kinematic terrestrial laser scanning. For this purpose, suitable sensors, which are typically used in the approach of a multi-sensor-system, as well as the corresponding data capturing/acquisition strategies, are presented. The aim of such systems is a geometry- and surface-based analysis in an industrial environment with an accuracy of +/? 1–2 mm or better.
关键词： synchronization,quality analysis,laser tracker,high-precision terrestrial laser scanning,multi-sensor-systems,calibration,industrial surveying,kinematic laser scanning,forward modeling,backward modeling
更新于2025-09-23 15:19:57
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Robust code-based modeling approach for advanced photovoltaics of the future
摘要： Modeling and simulation of photovoltaics help to reduce development costs, design turnaround time and facilitates better techno-economic decisions. However, there is a current need to generate new theories, algorithms, applications and software in order to increase the contribution of solar energy to the global energy supply. For future advancements in the field of photovoltaics, robust techniques for PV modeling, simulation, visualisation and design are required to overcome the limitations of the current approaches. This study proposes the Code-Based Modeling (CBM) approach as a potent approach to facilitate the study of PV technologies. Experimental data were synthesised and used for coding and training of the code-based (CB) model; followed by a validation of the trained model using commercial PV modules. Results clearly show that the model can repeatedly and reliably predict the short circuit current, maximum power point, open circuit voltage with 0%, < 2% and < 10% deviations, respectively. Furthermore, instances of the applicability of the CBM approach in the study of the thermodynamics of PV, solar cell materials characterisation, PV systems design and power monitoring were presented. Above all, CBM approach accepts user-defined functions and therefore presents new opportunities for scientists and engineers to advance model-based investigations of the photovoltaics beyond the current state-of-the-art.
关键词： Code-based modeling,Block-based modeling,Photovoltaic tools,Simulation,Photovoltaic systems
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) - Advanced Characterisation of Black Silicon Surface Topography with 3D PFIB-SEM
摘要： Modeling complex natural and human systems to support policy or management decision making is becoming increasingly common. The resulting models are often designed and implemented by researchers or domain experts with limited software engineering expertise. To help this important audience, we present our experience and share lessons learned from the design and implementation of an agent-based model of agricultural production systems in the Argentine Pampas, emphasizing the software engineering perspective. We discuss the model’s design including the model classes; the activity diagram, and data flow; the package and folder layout; the use of design patterns; performance optimization; initialization approaches; the analysis of results; and model measurement, validation, and verification.
关键词： agent-based modeling,coupled human and natural systems,Complex adaptive systems,software engineering,model design and implementation
更新于2025-09-23 15:19:57
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Design of a laser control system with continuously variable power and its application in additive manufacturing
摘要： system adjusts the laser position. This paper will also discuss the development and advanced laser control techniques enable a higher level of control over the processing process relies heavily on understanding and controlling the thermodynamics of the polymer melt temperatures and lead to more uniform components. Currently, there are no commercial options for a laser power controller that allows continuously variable power to be used as a galvanometer process. One of the biggest challenges SLS faces is lack of adequate process control, which leads to comparatively high component variations. It has been shown that implementing more manufacturing processes with applications in aerospace, biomedical, tooling, prototyping, and beyond. SLS is capable of creating unique, functional parts with little waste and no tooling by using a high-powered laser to selectively melt powdered polymer into desired shapes. This Selective laser sintering (SLS) is one of the most popular industrial polymer additive implementation of a galvanometer controller solution that works in conjunction with an off-the-shelf unit to enable this crucial functionality and will present results showing that, when applied laser sintering (SLS) additive manufacturing. The work contained in this paper is a continuation of previous work that developed a method of controlling laser power is SLS in order to improve the consistency of components built [1]. This previous effort was capable of improving temperature uniformity of SLS components by up to 57% and strength uniformity by up to 45%. Powder Bed Fusion
关键词： Laser Control,Additive Manufacturing,Surrogate Modeling,Powder Bed Fusion,Process Control
更新于2025-09-23 15:19:57