基于 Redis 的水务云系统缓存替换策略设计

水务云系统在海量数据高并发访问情况下存在Web服务性能急剧降低的问题,对此,设计一种基于Redis的水务云系统数据库缓存方案,对影响数据库缓存效率的关键因素进行分析、提取和量化计算,将水务数据类型、用户对数据对象的兴趣度及用户访问行为等因素与缓存数据替换过程结合,对现有GDSF缓存替换算法加以改进,并结合实际的水务云系统数据集实现该缓存方案和仿真实验。实验结果表明,基于Redis的水务云系统数据库缓存方案可以有效改善水务云系统的服务性能,也可为类似水利数据管理平台建设提供有益的借鉴。     

A low-complexity and efficient encoder rate control solution for distributed residual video coding

Multimedia Tools and Applications - Existing encoder rate control (ERC) solutions have two technical limitations that prevent them from being widely used in real-world applications. One is that...     

空化效应对高强度聚焦超声产生的组织损伤的影响

高强度聚焦超声（High intensity focused ultrasound,HIFU）已在临床治疗肿瘤领域展示了较好的应用前景,但目前的治疗计划中未考虑空化效应的影响。本文通过离体实验研究了空化效应对HIFU治疗中组织损伤形成的影响。首先采用KZK非线性方程和Pennes生物传热模型,在理论上模拟了不同超声激励参数的HIFU热效应产生的组织损伤。然后在实验中改变脉冲长度和声压,比较了实验和理论上产生的损伤形成。最后采用B型成像系统定量监测产生的声空化,从而定量分析空化效应对损伤形成的影响,为HIFU治疗策略的设计提供更好的指导。     

Stretchable Anti-Fogging Tapes for Diverse Transparent Materials

Surface wetting prevents surface fogging on transparent materials by facilitating filmwise condensation with specific chemistry, but suffers from material and geometry selectivity. Extreme environments associated with high humidity and mechanical loading further limit their anti-fogging persistence. Here, a stretchable anti-fogging tape (SAT) that can be applied to diverse transparent materials with varied curvatures for persistent fogging prevention is reported. The SAT consists of three synergistically combined transparent layers: i) a stretchable and tough layer with large elastic recovery, ii) an endurant anti-fogging layer insensitive to ambient humidity, and iii) a robustly and reversibly adhesive layer. The SAT maintains high total transmittance (>90%) and low diffuse transmittance (<5%) in high-humidity environments, under various modes of mechanical deformations, and over a prolonged lifetime (193 days tested so far). Two applications are demonstrated, including the SAT-adhered eyeglasses and goggles for clear fog-free vision, and the SAT-adhered condensation cover for efficient solar-powered freshwater production.     

Morphology Transformation Pathway of Block Copolymer-Directed Cooperative Self-Assembly of ZnO Hybrid Films Monitored In Situ during Slot-Die Coating

Cooperative self-assembly (co-assembly) of diblock copolymers (DBCs) and inorganic precursors that takes inspiration from the rich phase separation behavior of DBCs can enable the realization of a broad spectrum of functional nanostructures with the desired sizes. In a DBC assisted sol–gel chemistry approach with polystyrene-block-poly(ethylene oxide) and ZnO, hybrid films are formed with slot-die coating. Pure DBC films are printed as control. In situ grazing-incidence small-angle X-ray scattering measurements are performed to investigate the self-assembly and co-assembly process during the film formation. Combining complementary ex situ characterizations, several distinct regimes are differentiated to describe the morphological transformations from the initially solvent-dispersed to the ultimately solidified films. The comparison of the assembly pathway evidences that the key step in the establishment of the pure DBC film is the coalescence of spherical micelles toward cylindrical domains. Due to the presence of the phase-selective precursor, the formation of cylindrical aggregates in the solution is crucial for the structural development of the hybrid film. The pre-existing cylinders in the ink impede the domain growth of the hybrid film during the subsequent drying process. The precursor reduces the degree of order, prevents crystallization of the PEO block, and introduces additional length scales in the hybrid films.     

A visual discomfort recognition model based on the fusion of multisource information

An experiment was performed to explore the influence of image attributes (white level, black level, color saturation, and sharpness) on visual discomfort, with measurements of the subjective questionnaire, eye movement, and electrocardiogram. The objective and subjective results showed that these image attributes influenced visual discomfort significantly. A visual discomfort recognition model based on Dempster–Shafer evidence theory was proposed according to the experiment results. With multiple features and weighting coefficients, the model could recognize visual discomfort states well.     

基于GaN FET的LED微显示单片集成技术研究进展

发光二极管(LED)微显示技术由于其潜在应用而倍受关注.与主流的基于硅基驱动器的LED微显示技术不同,采用GaN场效应晶体管(FET)驱动的LED微显示技术制作的器件具有可靠性高和制作工艺简单等优势.总结了各种GaN FET驱动LED微显示的器件结构及性能,这些器件结构包括:直接利用LED外延结构制作FET驱动微型LED发光像素的横向集成结构、HEMT驱动微型LED发光像素的横向叠层结构、纳米线GaN FET驱动LED发光像素的垂直叠层结构.对基于GaN FET驱动的LED微显示技术的进展进行了综述.对GaN FET驱动的LED微显示技术的应用前景和研究方向进行了展望.     

ViMediaNet: an emulation system for interactive multimedia based telepresence services

The telepresence service (TPS) leverages advanced communication, virtual reality, and cooperative web technologies to provide remote engaged users an immersive experience of being fully present, which are widely used in teleconferencing, remote surgery, and hazardous environment exploration. The common feature of TPS-based applications lies in that the users’ experiences heavily depend on the quality of interactive multimedia services, that is, most deliveries of multimedia contents are mission-critical, as well as time-critical, to ensure the control and operation accuracy for telerobots. Therefore, the delivery performance of multimedia contents over heterogeneous networks becomes the primary concern in the TPS system design, especially for those delay sensitive applications, like remote surgery and environment exploration. In this paper, we incorporate video processing tools with the network simulator to design and implement a joint emulation system, named as the virtual media network (ViMediaNet), through which, the TPS designer can readily deploy the TPS system over a heterogeneous network virtualized by the network emulator, investigate the critical network performance metrics in the multimedia content delivery, such as transmission delay and packet jitter, and observe control results in real time. To verify the capability of ViMediaNet in emulating the real-setting TPS system, we take a mobile device based vision navigation system as an example to evaluate performance impacts of the rate adaptation technology in the telerobot control. The experimental results reveal that the adaptive video streaming is a promising solution to significantly enhance the control accuracy of telerobots in TPS systems.     

汉字在陶瓷装饰中运用

本文从汉字的特点说起，结合中国汉字与陶瓷装饰的联系，指出汉字在陶瓷装饰中逐渐摆脱实用性的范围，走向审美性的装饰艺术。陶瓷艺术的发展离不开汉字在陶瓷装饰中的应用，顺应多元化审美取向，创造汉字装饰的新前景，是时代赋予我们的要求。     

低分子量高固体分丙烯酸聚合物的合成及应用研究

采用均匀设计实验法及凝胶渗透色谱(GPC)分析，详细考查了影响聚合物分子量及其分布的主要因素，并在此基础上对实验结果进行了回归分析及多目标优化计算。结果表明，单体加入速度、聚合温度及引发剂用量是决定聚合物分子量的主要因素。在此基础上，采用合成的丙烯酸树脂制得了性能优异的双组分聚氨酯涂料。