- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2019 IEEE 13th International Conference on ASIC (ASICON) - Chongqing, China (2019.10.29-2019.11.1)] 2019 IEEE 13th International Conference on ASIC (ASICON) - A 63.3ps TDC Measurement System Based on FPGA for Pulsed Laser Ranging
摘要： The resistive-switching memory (RRAM) is currently under consideration for fast nonvolatile memory thanks to its relatively low cost and high performance. A key concern for RRAM reliability is stochastic switching, which impacts the operation of the digital memory due to distribution broadening. On the other hand, stochastic behaviors are enabling mechanisms for some computing tasks, such as physical unclonable function (PUF) and random number generation (RNG). Here, we present new circuit blocks for physical RNG, based on the coupling of two RRAM devices. The two-resistance scheme allows to overcome the need of probability tracking, where the operation voltage must be tuned to adjust the generation probabilities of 0 and 1. Probability tests are proved successful for one of the three proposed schemes.
关键词： random number generation (RNG),resistive-switching memory (RRAM),Memory reliability
更新于2025-09-19 17:13:59
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Calculation of the optical losses in perovskite solar cells
摘要： Terminal network reliability problems appear in many real-life applications, such as transportation grids, social and computer networks, communication systems, etc. In this paper, we focus on monotone binary systems with identical component reliabilities. The reliability of such systems depends only on the number of failure sets of all possible sizes, which is an essential system invariant. For large problems, no analytical solution for calculating this invariant in a reasonable time is known to exist, and one has to rely on different approximation techniques. An example of such a method is Permutation Monte Carlo. It is known that this simple plan is not sufficient for adequate estimation of network reliability due to the rare-event problem. As an alternative, we propose a different sampling strategy that is based on the recently pioneered Stochastic Enumeration algorithm for tree cost estimation. We show that, thanks to its built-in splitting mechanism, this method is able to deliver accurate results while employing a relatively modest sample size. Moreover, our numerical results indicate that the proposed sampling scheme is capable of solving problems that are far beyond the reach of the simple Permutation Monte Carlo approach.
关键词： System structure function,splitting,network reliability,rare events,stochastic enumeration,permutation Monte Carlo
更新于2025-09-19 17:13:59
-
Reliability and agreement of a novel portable laser height metre
摘要： Background Human height is a simple measure with great applicability. Usually, stadiometers are used to measure height accurately. However, these may be impractical to transport and expensive. Therefore, we developed a portable and low-cost laser height metre (LHM). Objective We aimed to (1) determine intrarater and interrater reliability of our LHM and compare it to a wall-fixed stadiometer, (2) examine its agreement with the same stadiometer, and (3) determine the minimum number of recordings needed to obtain an accurate and reliable height measurement using the LHM. Methods We recruited 32 participants (18+ years)–both men and women. Two raters performed assessments on the same day blinded to each other and their reference standard measurements. We calculated intraclass correlation coefficient (ICC), coefficient of variation (CV), standard error of measurement (SEM), and Bland-Altman plots with limits of agreement (LOA). Results For both the LHM and stadiometer, we found ICC values of 0.99–1.00 (95% CI: 0.997–1.000) for both intrarater and interrater reliability. Regarding LHM intrarater reliability, SEM, CV, and LOA were 0.34 cm, 0.16%, and -1.07 to 0.73 cm, respectively. In terms of LHM interrater reliability, SEM, CV, and LOA were 0.27 cm, 0.12%, and -0.32 to 0.84 cm, respectively. As to agreement with stadiometers using one measurement, the mean difference was -0.14 cm and LOA ranged from -0.81 to 0.77 cm. Conclusion A portable and low-cost LHM, for measuring body height once, showed an excellent reproducibility within and between raters along with an acceptable agreement with a stadiometer thereby representing a suitable alternative.
关键词： portable,laser height metre,stadiometer,reliability,agreement
更新于2025-09-19 17:13:59
-
Investigation of Electrical Properties and Reliability of GaN-Based Micro-LEDs
摘要： In this paper, we report high-performance Micro-LEDs on sapphire substrates, with pixel size scaling to 20 μm and an ultra-high current density of 9902 A/cm2. The forward voltages (VF) of the devices ranged from 2.32 V to 2.39 V under an injection current density of 10 A/cm2. The size and structure-dependent effects were subsequently investigated to optimize the device design. The reliability of Micro-LED devices was evaluated under long-aging, high-temperature, and high-humidity conditions. It was found that Micro-LED devices can maintain comparable performance with an emission wavelength of about 445 nm and a full width at half maximum (FWHM) of 22 nm under extreme environments. Following this, specific analysis with four detailed factors of forward voltage, forward current, slope, and leakage current was carried out in order to show the influence of the different environments on different aspects of the devices.
关键词： GaN-based micro-LEDs,micro-LED display,reliability test
更新于2025-09-19 17:13:59
-
Analysis of moisture-induced degradation of thin-film photovoltaic module
摘要： To enhance the reliability of the thin-film solar cell technologies, it is required to analyze and understand the moisture-induced degradation. In this study, the moisture induced degradation of glass-to-glass CIGS module are comprehensively analyzed. CIGS modules are fabricated and tested under damp-heat conditions with periodical measurement of the electrical characteristics. Individual layers of the module are also investigated experimentally and the moisture induced degradation is discussed. A modified method to extract the diode model parameters from degraded I–V curves is proposed and applied to the degraded data. Finally, the degradation rates are modelled and the effect of model parameters degradation on the power of module are quantitatively compared. It suggests that the power degradation of CIGS module under the damp-heat environment is more affected by the enhanced recombination of the absorber layer than the degradation of the metal layer or the leakage over layers.
关键词： Reliability,Diode model parameter extraction,Moisture-induced degradation,Thin-film photovoltaics,CIGS
更新于2025-09-19 17:13:59
-
[IEEE 2019 International Conference on Power Electronics, Control and Automation (ICPECA) - New Delhi, India (2019.11.16-2019.11.17)] 2019 International Conference on Power Electronics, Control and Automation (ICPECA) - Hybrid algorithm for reactive power control in grid integrated Photovoltaic inverters
摘要： Prognostics and systems health management (PHM) is an enabling discipline that uses sensors to assess the health of systems, diagnoses anomalous behavior, and predicts the remaining useful performance over the life of the asset. The advent of the Internet of Things (IoT) enables PHM to be applied to all types of assets across all sectors, thereby creating a paradigm shift that is opening up significant new business opportunities. This paper introduces the concepts of PHM and discusses the opportunities provided by the IoT. Developments are illustrated with examples of innovations from manufacturing, consumer products, and infrastructure. From this review, a number of challenges that result from the rapid adoption of IoT-based PHM are identified. These include appropriate analytics, security, IoT platforms, sensor energy harvesting, IoT business models, and licensing approaches.
关键词： remaining useful life,reliability,Internet of things,prognostics and systems health management,maintenance
更新于2025-09-19 17:13:59
-
Comparative Evaluation of Lifetime of Three-Level Inverters in Grid-Connected Photovoltaic Systems
摘要： The cost of the PV energy reduction is still required to increase the penetration level of PV systems in the energy market. The reliability of PV inverters is one of the important aspects to be enhanced in order to reduce the cost of PV energy, since it is closely related to the maintenance cost and the annual energy production. In this paper, the lifetime of NPC and T-type inverters, which are three-level inverter topologies that are widely used for PV systems, are comparatively evaluated with a 30 kW grid-connected PV system. It is performed by focusing on power devices since the power electronic components of both converters are the same except for the power devices. Therefore, this result can represent the comparison of the reliability performance of the NPC and T-type inverters. The power loss and temperature distributions of power devices are analyzed and their e?ciencies are compared at di?erent power levels with di?erent switching frequencies. The lifetimes of the reliability-critical power devices in the NPC and T-type inverters are estimated, respectively with a one-year mission pro?le of the PV system, and the results are compared.
关键词： three-level inverter,IGBT module,PV inverter,reliability,power device,lifetime
更新于2025-09-19 17:13:59
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Novel Foil Interconnects for Back-Contact Silicon Solar Cells
摘要： Large area back-contact solar cells enable module costs almost as low as those of PERCs but with higher efficiency. Traditional tabbing and stringing interconnects are problematic for back-contact cells, however, as placing all the tabs on one side of the wafer causes bowing due to CTE mismatch. Back-contact cells can be effectively encapsulated using Cu conductive back-sheets (CBS) with electrically conductive adhesive (ECA) interconnects but the cost is higher than for ribbon tabbing. In this paper we present a method for replacing the Cu CBS with a cheaper Al version and the ECA with several cheaper and potentially more robust methods for connecting the foil to the cell.
关键词： laser welding,conductive adhesives,reliability,Back-contact modules,aluminum interconnects,conductive back-sheets
更新于2025-09-19 17:13:59
-
The analysis on simulation and invalidation of hot-spot temperature distribution in micro-defective crystalline silicon solar cells
摘要： According to the distribution of reverse biased leakage current of micro-defective solar cells, the mathematic models of the hot spot thermal power of photovoltaic(PV) modules are established. The uniform and non-uniform distribution of thermal power in hot spot solar cell are theoretically calculated and experimentally analyzed in different shading conditions. Based on the model, the hot spot temperature distribution of different defective cells is simulated by ANSYS software. Then a novel experimental platform is set up to validate the simulation results in outdoor conditions. The mechanism of hot spot failure and the worst hot spot condition are analyzed. According to the results of experiment and simulation, the relative deviation between simulation and experimental data is less than 10% through the model proposed in this paper. Furthermore, in the normal modules, according to the result of simulation and experiment, the worst case of hot spots happens when the heat power is maximum and the shading ratio is about 10-20%. In the defective modules, it happens when the heat power is not maximum and the shading ratio is about 50-60%.
关键词： reliability,non-uniform distribution,Hot spots,micro-defective solar cells
更新于2025-09-16 10:30:52
-
[IEEE 2019 International Conference on Engineering, Science, and Industrial Applications (ICESI) - Tokyo, Japan (2019.8.22-2019.8.24)] 2019 International Conference on Engineering, Science, and Industrial Applications (ICESI) - Process Reliable Laser Welding of Hairpin Windings for Automotive Traction Drives
摘要： Driven by current developments the electrification of the automotive drive chain, new technologies for the production of windings for electric drives are focused in automotive industry and research institutes. Especially for the manufacturing of drives with high power density for battery electric vehicles (BEV), the application of distributed windings produced from conductors with rectangular cross-sections gains in importance. To be able to manufacture these windings, hairpin technology is pushed forward at present. The essential feature of this kind of winding is that it consists of pre-formed elements, the so called hairpins, that are assembled to the stator laminations and contacted afterwards to produce the winding. One key process within the production chain for this kind of winding is the contacting operation, because a high number of contacts needs to be realized. However, this production step poses several challenges for which in particular laser welding processes show potentials. Another complication is the fact that no established methods for the quantification of the quality of these joints are available at present. In addition, the suitability of the laser welding process for this application must be proven and error influencing variables must be identified in order to be able to advance the serial application of this process. For that reason in this paper quality criteria from the requirements contacts in electric traction drives have to face are analysed. Based on these, the achievable process capability is evaluated and the welding strategy is optimized.
关键词： laser welding,automotive traction drives,process reliability,quality criteria,hairpin windings
更新于2025-09-16 10:30:52