- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Analysis of the Application of Laser Welding Technology on Maintenance of the Underwater Components of Nuclear Power Station
摘要： This paper put its eyes on the PWR’s underwater components which have the risk of early failure after long-term inservice because the material tends to deteriorate and embrittle due to irradiation and other factors, and should be maintenanced. In this paper, we contrastively analyse two main technologies used as underwater welding, named underwater wet laser welding and underwater local dry laser welding. It is difficult to obtain high quality weld seam by underwater wet laser welding for the reason of some disadvantages on laser beam underwater, such as water attenuation, bubble reflection and so on. On constract, underwater local dry laser-welding can obtain high quality weld-joints, and becomes the current hotshot. But, there are still some problems to be settled, such as the way to obtain stable underwater chamber and the protection of back of full penetration weld. Analysis of the retrieva of underwater laser welding on Web Science, we can find that underwater laser welding technology has step out laboratory to engineering application and the in-depth theoretical research is also actively carried out on the fields of picosecond, femtosecond laser.
关键词： local dry laser welding,PWR,underwater laser welding,maintenance,wet laser welding
更新于2025-09-16 10:30:52
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[IEEE 2019 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Guangzhou, China (2019.5.19-2019.5.22)] 2019 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Quasi-Time-Invariant Range-Angle-Decoupled Beampattern Synthesis of Frequency Diverse Arrays
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2025-09-16 10:30:52
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[IEEE 2019 IEEE International Conference on Image Processing (ICIP) - Taipei, Taiwan (2019.9.22-2019.9.25)] 2019 IEEE International Conference on Image Processing (ICIP) - Learning Lightweight Pedestrian Detector with Hierarchical Knowledge Distillation
摘要： In order to transfer 3000-MW capacity of electricity from the mine-mouth coal-fired power plants in South Sumatra to the load center in Java, PLN Indonesia intends to build the Java-Sumatra Power Interconnection System. The scopes of these works of the Power Interconnection System are including: high voltage alternating current (HVAC) 500 kV Transmission Line in Java, HVAC 500 kV Transmission Line in Sumatra, high voltage direct current (HVDC) 500 kV Transmission Line in Java, HVDC 500 kV Transmission Line in Sumatra, and HVDC 500 kV Java-Sumatra submarine cables. This paper will analyze the financial feasibility study to ensure whether the project has economic benefit, and the asset would be used effectively and efficiently along its benefit period using life cycle cost analysis (LCCA). In this paper, an LCCA will be simulated to analyze three alternatives and to decide which alternative is the most profitable. Monte Carlo simulations and a break-even chart for a period of 30 years' operation of the interconnection system are part of the LCCA models to achieve the objectives of this paper.
关键词： cost benefit analysis,underwater,decision making,Risk analysis,project engineering,power transmission,availability,maintenance,cables,reliability
更新于2025-09-16 10:30:52
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Spatial Aggregation of Small-scale Photovoltaic Generation Using Voronoi Decomposition
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,maintenance,prognostics and systems health management,reliability,Internet of things
更新于2025-09-16 10:30:52
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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) - CdMgTe as an Electron Reflector for MgZnO/CdSeTe/CdTe Solar Cells
摘要： Evolutionary algorithms (EAs) have been shown to be powerful tools for complex optimization problems, which are ubiquitous in both communication and big data analytics. This paper presents a new EA, namely negatively correlated search (NCS), which maintains multiple individual search processes in parallel and models the search behaviors of individual search processes as probability distributions. NCS explicitly promotes negatively correlated search behaviors by encouraging differences among the probability distributions (search behaviors). By this means, individual search processes share information and cooperate with each other to search diverse regions of a search space, which makes NCS a promising method for nonconvex optimization. The co-operation scheme of NCS could also be regarded as a novel diversity preservation scheme that, different from other existing schemes, directly promotes diversity at the level of search behaviors rather than merely trying to maintain diversity among candidate solutions. Empirical studies showed that NCS is competitive to well-established search methods in the sense that NCS achieved the best overall performance on 20 multimodal (nonconvex) continuous optimization problems. The advantages of NCS over state-of-the-art approaches are also demonstrated with a case study on the synthesis of unequally spaced linear antenna arrays.
关键词： Evolutionary algorithms,diversity maintenance,negative correlation,optimization in communication systems
更新于2025-09-16 10:30:52
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Cluster identification of sensor data for predictive maintenance in a Selective Laser Melting machine tool
摘要： Selective laser melting has become one of the most current new technologies used to produce complex components in comparison to conventional manufacturing technologies. Especially, existing selective laser melting machine tools are not equipped with analytics tools that evaluate sensor data. This paper describes an approach to analyze and visualize offline data from different sources based on machine learning algorithms. Data from three sensors were utilized to identify clusters. They illustrate the normal operation of the machine tool and three faulty conditions. With these results, a condition monitoring system can be implemented that enables those machine tools for predictive maintenance solutions.
关键词： clustering,machine learning,Selective laser melting,sensor data,predictive maintenance
更新于2025-09-12 10:27:22
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Luminaire Dirt Depreciation (LDD): Field Data from Several Exterior Lighting Projects
摘要： Luminaire dirt depreciation (LDD) data were evaluated for seven luminaires from three different project sites in Philadelphia, Pennsylvania, Minneapolis, Minnesota, and Yuma, Arizona. In each case, the luminaires were removed from the installation, carefully packaged and transported to a photometric testing laboratory, and then tested in the “as-is” or dirty condition, cleaned, and retested. In terms of light output, the results showed that the IES RP-36-15 method for estimating LDD was applicable to the light emitting diode (LED) luminaires evaluated. General claims of lower levels of dirt deprecation (or higher LDD values) for LED luminaires than for luminaires using conventional light sources were not supported by the test data for the LED luminaires in these three projects. Though the overall measured lumen depreciation due to accumulated dirt closely matched IES estimates for LDD, the data indicated that the accumulated dirt on the luminaires dramatically altered the luminous intensity distribution of the luminaires, with reductions in intensity of more than 25% at peak angles. These effects on luminous intensity distribution are not accounted for in IES LDD estimates.
关键词： optics and luminaire design,LED sources and systems,luminaires,roadway lighting,maintenance
更新于2025-09-10 09:29:36
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A study on the UAV image-based efficiency improvement of bridge maintenance and inspection
摘要： This study reviewed ef?cient bridge management using UAVs (Unmanned Arial Vehicles) that have much potential for facility maintenance such as the possibility of regular inspection on inaccessible parts of bridges, easy operation regardless of the operators’ specialty, and economic maintenance. For this study, images were obtained from a UAV and a 3D viewer was created with them for the work ef?ciency of bridge inspectors, so that the inspectors can see and check inaccessible areas regardless of inspector’s location. It compared various existing inspection methods for problems such as cracks, ef?orescence and leakage with the UAV inspection method to analyze the work ef?ciency as well as sustainable economic bene?t. The main purpose of this study was to ?gure out whether the proposed inspection using the images from the UAV and 3D viewer can replace the existing inspection methods that cannot be performed easily and analyze the economic bene?t of the new method. The study result showed that the UAV image-based bridge maintenance and inspection is possible even though it was found inef?cient when images of uneven quality were provided depending on operation of the UAV. Therefore, a UAV operation manual that can help generate images of even quality must be produced.
关键词： UAV photogrammetry,bridge maintenance and inspection,3D viewer,inspection ef?ciency
更新于2025-09-04 15:30:14
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A Novel Industrial Safety IoTs Architecture for External Corrosion Perception Based on Infrared
摘要： In this paper, a novel external corrosion risk online perception method is proposed to solve the dangerous external corrosion threat and supply a measurable safe risk perception ability for the industrial safe Internet of Things (IoTs) with the infrared thermal wave as the direct sensors. The three layers model is established with direct variables measuring layer, external corrosion risk soft measuring layer and monitoring cycle decision-making layer. And in the direct variable measuring layer the infrared thermal wave is applied to measure the three direct variables, area ratio of cladding defects,cladding layer thickness reading and overlapping between external and internal corrosion defects, in the direct variables measuring layer. In the external corrosion risk soft measuring layer and monitoring cycle decision-making layer, external corrosion risk can be soft measured through a cladding-condition-based risk matrix and the most optimal monitoring cycle can also be determined through a decision-making tree based on the three direct variables.
关键词： Internet of things,Industrial safety,Maintenance decision tree
更新于2025-09-04 15:30:14
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Role of structural anisotropy in geometric birefringence of high-birefringence index-guiding PCFs: analysis by moment of inertia
摘要： We have studied the role of structural anisotropy on the geometric birefringence of four typical high-birefringence (HB) index-guiding photonic crystal fibers (PCFs) with the same air-silica structure and circular, ellipse, and rectangle air holes, respectively. The normalized difference between the moment of inertia ΔI in x and y direction of the PCF structure is utilized to quantificationally describe the structural anisotropy. We demonstrate that the phase birefringence B increases monotonously when the normalized ΔI rises in different cases of PCFs structures. In order to obtain high birefringence B, it can be an effective method to optimize the parameters of the structure to increase the normalized ΔI. This work can be not only a reference of founding the essence of geometric birefringence and proposing the optimal design of HB-IG-PCFs, but also an enlightenment for bringing the different method (compared to the finite element) into the investigation of PCFs.
关键词： Photonic crystal fiber (PCF),Polarization maintenance,Structural anisotropy,Geometric birefringence,Birefringence,Moment of inertia
更新于2025-09-04 15:30:14