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oe1(光电查) - 科学论文

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  • [IEEE 2018 IEEE 16th International Conference on Embedded and Ubiquitous Computing (EUC) - Bucharest, Romania (2018.10.29-2018.10.31)] 2018 IEEE 16th International Conference on Embedded and Ubiquitous Computing (EUC) - Android Fingerprint Sensor: Pitfalls and Challenges

    摘要: In the last four years, the number of smartphones capable to read user fingerprints in order to perform authorization and authentication has tripled. Also, after the introduction of biometric payment services, fingerprint scanner driven authentication became more popular and the variety of smartphones equipped with this kind of sensor multiplied. However, the implementation methods are directly handled by manufacturers, who are often making decisions under the pressure of a short time-to-market. Starting from these facts, scholars and industry leading experts started to research the documentation in order to analyze the privacy and security flaws of the existing implementations. the assessment of Android good practice advises has revealed that some devices were not compliant, due to the fact that architecture could be attacked by an adversary both from the external world and by using malicious applications. Most common types of attacks against fingerprint authentication which could be demonstrated were aiming either to confuse the user in order to perform a malicious operation without a proper context or by employing custom-made molds of the user thumb minutiae. This paper analyses former and current issues affecting the fingerprint authentication in mobile devices powered by the Android operating system.

    关键词: Android operating system,fingerprint sensor,security flaws

    更新于2025-09-23 15:23:52

  • [IEEE 2018 IEEE Industry Applications Society Annual Meeting (IAS) - Portland, OR, USA (2018.9.23-2018.9.27)] 2018 IEEE Industry Applications Society Annual Meeting (IAS) - Design and Optimization of a Solar Power Conversion System for Space Applications

    摘要: This manuscript details a design method for a 500kW solar power based microgrid system for space applications. The design method utilizes multi-objective optimization with the Genetic Algorithm considering four parameters that characterize solar power based microgrids (battery voltage, PV maximum power, PV maximum power point voltage, and number of panels per string). The final optimization metric is the ratio of daily average deliverable power to total system mass (W/kg) metric. The microgrid system is composed of a number of modular DC-DC micro-converters, of which four topologies (buck, boost, buck-boost and non-inverting buck-boost) are evaluated and compared. The non-inverting buck-boost converter is determined to be the best candidate, and the optimal system characteristics are provided and analyzed. The final system design achieves a specific power of 35.56W/kg, with optimized result of 743.7V battery voltage, 439.5W PV maximum power, 182.7V PV maximum voltage, and three panels per string. Based on the optimizations results, a prototype is designed, tested, and analyzed in terms of efficiency and low temperature reliability. The converter achieved a peak efficiency of 98.4%, a power density of 3.54W/cm3, a specific power of 3.76W/g, and operated for over 267 hours of 11-minute low temperature cycles from 0oC to -140oC.

    关键词: wide band gap semiconductors,microgrids,non-inverting buck-boost,maximum power point trackers,space exploration,photovoltaic systems,design optimization,DC-DC power converters,system-level design,low temperature testing

    更新于2025-09-23 15:23:52

  • Optimized angles of the swing hyperspectral imaging system for single corn plant

    摘要: During recent years, hyperspectral imaging systems have been widely applied in the greenhouses for plant phenotyping purposes. Current systems are typically designed as either top view or side view imaging mode. Top view is an ideal imaging angle for top leaves with flat leaf surfaces. However, most bottom leaves are either blocked or shaded. From side view, the entire plant structure is viewable. However, most leaf surfaces are not facing the camera, which impacts measurement quality. Besides, there could be advantages with certain tilted angle(s) between top view and side view. It’s interesting to explore the impact of different imaging angles to the phenotyping quality. For this purpose, a swing hyperspectral imaging system capable of capturing images at any angle from side view (0°) to top view (90°) by rotating the camera and the lighting source was designed. Corn plants were grown and allocated into 3 different treatments: high nitrogen (N) and well-watered (control), high N and drought-stressed, and low N and well-watered. Each plant was imaged at 7 different angles from 0° to 90° with an interval of 15°. The soil plant analysis development (SPAD) values and relative water content (RWC) ground truth measurements were used to establish treatment effects. The results showed that averaged plant-level Normalized Difference Vegetation Index (NDVI) values of plants in different treatments changed at different imaging angles. The results also indicated that for pixel-level NDVI distributions, the titled imaging angle of 75° was optimal to distinguish different water treatments, whereas, the tilted imaging angle of 15° was optimal to distinguish different N treatments. For pixel-level RWC distributions, the distribution difference between different water treatments was larger at higher imaging angles.

    关键词: Pixel-level NDVI and RWC distributions,Optimal imaging angle,Swing hyperspectral imaging system,Plant phenotyping system,Tilted imaging angle

    更新于2025-09-23 15:22:29

  • [IEEE 2018 7th International Conference on Renewable Energy Research and Applications (ICRERA) - Paris, France (2018.10.14-2018.10.17)] 2018 7th International Conference on Renewable Energy Research and Applications (ICRERA) - Simulation Studies for a Multi-MW Hybrid Wind-Solar PV System for Desalination Plants

    摘要: This paper presents a power system configuration and control schemes for a Multi-MW wind-solar hybrid system, which includes multiple wind turbines and solar panels to support a desalination plant. The wind and solar systems are sized such that the desalination plant obtains, as far as possible, its power from the renewable sources, to minimize the dependence on the utility grid. Each section of the wind turbine system includes a variable speed permanent magnet synchronous generator connected to the grid via a back-to-back voltage source converter. The rectifier operates the wind system at the maximum power point, and the inverter provides power to the desalination plant. The solar plant has multiple panels connected to the grid via a three phase converter, performing the dual functions of power transformation and maximum power point tracking. The modeling and validation of this system is performed with the PSCAD/EMTDC, a software typically employed for transient analysis.

    关键词: hybrid system,PV system,Wind turbine,rectifier,inverter,desalination plant

    更新于2025-09-23 15:22:29

  • [IEEE 2018 IEEE Power & Energy Society General Meeting (PESGM) - Portland, OR, USA (2018.8.5-2018.8.10)] 2018 IEEE Power & Energy Society General Meeting (PESGM) - An Optimum Design of Hybrid Energy Storage for PV Power Fluctuation Smoothing Based on Frequency Analysis

    摘要: Proper design of an energy storage system can effectively and economically smooth out the PV power fluctuation and improve the power quality. A frequency analysis based hybrid energy storage devices (ESDs) selection method as well as typical PV data selection method are proposed to determine an optimum energy storage combination to meet the requirement of a power grid. A Fast Fourier Transform (FFT) method is applied to analyze PV output power fluctuations. FFT is also applied to determine the most representative PV output data for the design cycle. The proposed algorithm divided the entire PV output power frequency spectrum into low and high ranges. The divisions are based on the characteristics of individual ESD’s as well as their cycle life and capacity loss. Through the proposed method, the lowest-cost ESD solution can be determined to meet the requirements to smooth out PV output fluctuation under the most representative weather pattern.

    关键词: optimum sizing,PV system,PV output pattern selection,hybrid energy storage system,frequency analysis,power fluctuation smoothing

    更新于2025-09-23 15:22:29

  • [IEEE 2018 4th International Conference on Renewable Energies for Developing Countries (REDEC) - Beirut, Lebanon (2018.11.1-2018.11.2)] 2018 4th International Conference on Renewable Energies for Developing Countries (REDEC) - Modeling, P&O MPPT and PI controls and performance analysis of PV/Energy storage hybrid power system

    摘要: The variable nature of renewable energy sources, coupled with unpredictable changes in load, requires the simultaneous implementation of high power and high energy density storage systems. This work addresses dynamic modeling, a PV/Batteries/Ultra capacitor hybrid energy system connected to a DC load in a remote house located around the town of Rouyn Noranda (Quebec-Canada) during one day in winter period. The P&O MPPT control is used to extract the maximum power of a photovoltaic generator which is considered as the main energy source of the hybrid system. In this paper, batteries and ultra-capacitors (UC) are serving as an energy storage system (ESS) and a main source in winter period. The UC are used for facing high frequency variations of the load, such as in transient state, while the batteries are in charge of slow load/source variations. Classical control of battery current and ultra-capacitor current allows choosing the suitable storage element in order to face correctly the production/consummation variations. Classical PI control strategy is proposed in manner to stabilize the DC bus voltage by controlling the attached DC/DC bidirectional converters. Simulations during 00 AM to 3 PM (during a snowy day) are carried out using Matlab/Simulink which confirm the good performances of the hybrid system and associated control systems.

    关键词: energy storage system,performance analysis,Photovoltaic,hybrid energy system

    更新于2025-09-23 15:22:29

  • Benefits, problems and challenges of plant factories with artificial lighting (PFALs): a short review

    摘要: The benefits and problems to be solved and challenges for plant factories with artificial lighting (PFALs) are discussed. The benefits include high resource-use efficiency, high annual productivity per unit land area, and production of high-quality plants without using pesticides, regardless of weather. A major problem to be solved is high initial investment and operation costs. Challenges for the next-generation smart PFALs include the introduction of advanced technologies such as artificial intelligence with the use of big data, genomics and phenomics (or methodologies and protocols for noninvasive measurement of plant-specific traits related to plant structure and function).

    关键词: resource-use efficiency (RUE),cultivation system module (CSM),standardization,smart LED lighting system,annual productivity,artificial intelligence,phenotyping

    更新于2025-09-23 15:22:29

  • Manipulating Living Systems by Light; 生命現象の光操作技術の創出;

    摘要: Complex gene networks are essential for diverse biological phenomena, such as cellular programming, metabolism, homeostasis, memory formation, and circadian rhythm. To understand these biological phenomena, including diseases, and to utilize or modify them, approaches that enable optical control of the genome are required. We developed new tools for targeted gene manipulation based on optical control of the CRISPR-Cas9 system and Cre-loxP system. These tools could greatly facilitate understanding of a variety of gene functions and prove useful in biomedical applications. Genome engineering technology and optogenetics technology have emerged as different technologies from each other so far. Our studies merge these emerging research fields together.

    关键词: optogenetics,photoswitching protein,cell differentiation,Cre-loxP system,genome editing,CRISPR-Cas9 system

    更新于2025-09-23 15:22:29

  • Peculiarities of the dielectric properties of ternary 0.5(Y0.1Zr0.9O2) – 0.5(0.6SrTiO3 – 0.4BiScO3) ceramic system

    摘要: Ceramic samples of ternary 0.5(Y0.1Zr0.9O2) – 0.5(0.6SrTiO3 – 0.4BiScO3) system consisting of individual Y0.1Zr0.9O2 and 0.6SrTiO3 – 0.4BiScO3 subsystems were synthesized via solid-state processing techniques. By XRD analysis, a coexistence of tetragonal P42/nmc phase related to the Y0.1Zr0.9O2 subsystem, and cubic Pm m3? and tetragonal P4mm phases associated with the 0.6SrTiO3 – 0.4BiScO3 subsystem was found. A deviation of real composition from nominal one for both Y0.1Zr0.9O2 and SrTiO3 – BiScO3 subsystems due to Sc substituting for Zr in the Y0.1Zr0.9O2 subsystem and, vice versa, Zr substituting for Sc in the SrTiO3 – BiScO3 subsystem was also observed. Peculiarities of the dielectric properties related to both di?use ferroelectric phase transition and dielectric relaxation processes were found and analyzed in comparison with the dielectric properties of two-component 0.6SrTiO3 – 0.4BiScO3 system. It was found that the di?use phase transition in ternary system, ?rstly, shifts to lower temperatures and, secondly, has a less degree of di?useness as compared to two-component system. Such kind of behavior could be attributed to a di?erence of ionic radii of ions Zr4+ and Sc3+. Dielectric relaxation processes associated with the O2- ions migration were observed within temperature 500–800 K for both ternary and two-component systems. Two dielectric relaxation processes related to the Y0.1Zr0.9O2 and 0.6SrTiO3 – 0.4BiScO3 subsystems were found in ternary system, whereas one dielectric relaxation process was observed in two-component system. The activation energies for the dielectric relaxation processes were estimated as ~ 1.3 eV and ~ 0.9 eV for Y0.1Zr0.9O2 and 0.6SrTiO3 – 0.4BiScO3 subsystems, respectively, for ternary system, and ~ 0.75 eV for two-component system.

    关键词: Dielectric relaxation process,Two-component ceramic system,Y0.1Zr0.9O2 and 0.6SrTiO3 – 0.4BiScO3 subsystems,Ternary ceramic system,Di?use phase transition

    更新于2025-09-23 15:22:29

  • [IEEE 2018 Wave Electronics and its Application in Information and Telecommunication Systems (WECONF) - Saint-Petersburg, Russia (2018.11.26-2018.11.30)] 2018 Wave Electronics and its Application in Information and Telecommunication Systems (WECONF) - The Problem of Determination of Coordinates of Unmanned Aerial Vehicles Using a Two-Position System Ground Radar

    摘要: the features of modern methods for detecting and determining the coordinates of small unmanned aerial vehicles using a two-position ground radar system are considered. It is proposed to use the methods developed for multi-sensor radar systems. The limitations and advantages of the two-position radar system are shown. The main potential characteristics of the system and the corresponding restrictions on the conditions of its effective application are determined. Potential characteristics are obtained by simulation methods using mathematical models built on the basis of experimental data.

    关键词: two-position system,radar system,detection of objects,trajectory coordinates,unmanned aerial vehicle,determination of coordinates,air object,joint information processing

    更新于2025-09-23 15:22:29