排序方式: 共有39条查询结果,搜索用时 15 毫秒
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针对幼童自我控制能力和抵抗力较弱,易因踢被子引发感冒等疾病这一特定场景,通过将微型传感器植入蚕丝被特定部位中,以蓝牙通信方式广播传感器采集到的温度数据,手机APP读取到数据后,利用踢被温度变化逻辑判断模型进行分析,达到设定的逻辑判定条件后,在手机端发出声音和振动示警,开发出能够对踢被进行识别和示警的蚕丝被新产品。最后,根据检测评价指标与方法对试制产品进行了测试。结果显示:在报警时间阈值大于或等于7 min和踢掉全部被子条件下,报警成功率为100%;报警时间阈值偏差延时小于或等于3 min、正常睡眠过程中无误报警;对部分踢被等特殊情况也有一定辨识度。 相似文献
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星载雷达系统由于其工作环境和高速信号传输特性,在数据传输过程中无可避免的会因为各种干扰而出现误码.为了加固高速信号抵抗传输过程中的误码干扰,采用能纠错3位的完备码格雷码,经添加一位奇偶校验位扩展得到的扩展格雷码设计了编译码电路.根据扩展格雷码的生成矩阵和校验矩阵,以及一种硬判决译码算法,基于FPGA实现了扩展格雷码的并行信息编译码器以及串行信息编译码器.行为仿真结果表明该扩展格雷码编码器能正常实现连续编码,同时在模拟星载雷达系统因为干扰而出现的误码时,该译码器能自我纠正编码分组内3个以内的任意误码组合,达到了数据传输加固的目的. 相似文献
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将矩量法和小波变换理论结合起来,应用于求解电磁场积分方程,分析计算了环形微带缝隙天线磁流分布、驻波、阻抗特性和辐射方向图,通过用小波基代替一般的分域基矩量法中的权函数和基函数,使矩量法中与算子相对应的阻抗矩阵变成为大量元素为零的稀疏矩阵,减小了数值方法对存储量的要求,在达到允许精度的前提下,使计算量显著降低。文中给出计算实例,验证该方法,计算结果与用一般矩量法计算结果和实际测试结果相比,吻合较好。 相似文献
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人因失误研究的最终目的是为了减少或者消除人误的再次发生。有效的人误分类是人因失误的关键问题之一,但目前还没有一种统一、固定的分类方法。首先,从人因失误的定义出发,给出了人因失误的工程分类方法和认知行为分类方法,并在此基础上,针对各类可控型人因失误,给出其综合评价指标;其次,借助人因失误综合评价指标的高低,能够有效地指导生产系统中人因失误控制活动;最后,结合人因失误分类方法对某汽车变速箱总成装配中的二轴分装中典型的人因失误进行了分类,首次对机械产品装配中的人因失误进行了分类和实例分析。实例证明,该方法能够客观、准确地为人因失误控制提供决策支持。 相似文献
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《Ceramics International》2023,49(10):14957-14963
The high-performance single-phase semiconductor materials with higher ionic conductivity have drawn substantial attention in fuel cell applications. Semiconductor materials play a key role to enhance ionic conductivity subsequently promoting low temperature solid oxide fuel cell (LT-SOFC) research. Herein, we proposed a semiconductor Co doped Y2O3 (YCO) samples with different molar ratios, which may easily access the high ionic conductivity and electrochemical performances at low operating temperatures. The resulting fabricated fuel cell 10% Co doped Y2O3 (YCO-10) device exhibits high ionic conductivity of ∼0.16 S cm−1 and a feasible peak power density of 856 mW cm−2 along with 1.09 OCV at 530 °C under H2/air conditions. The electrochemical impedance spectroscopy (EIS) reveals that YCO-10 electrolyte based SOFC device delivers the least ohmic resistance of 0.11–0.16 Ω cm2 at 530-450 °C. Electrode polarization resistance of the constructed fuel cell device noticed from 0.59 Ω cm2 to 0.28 Ω cm2 in H2/air environment at different elevated temperatures (450 °C to 530 °C). This work suggests that YCO-10 can be a promising alternative electrolyte, owing to its high fuel cell performance and enhanced ionic conductivity for LT-SOFC. 相似文献
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《Ceramics International》2022,48(24):36193-36200
High-quality AlGaN/GaN/AlN heterostructures with thin GaN channel and thick AlN buffer layer were grown by metal organic chemical vapor deposition (MOCVD) on SiC substrate. By analyzing growth modes of GaN films on AlN buffer layers with different thicknesses, it is revealed that film-forming point of GaN grown on AlN buffer increases with the increase in AlN buffer thickness. Accordingly, new growth model of GaN on AlN buffer was proposed, which shows that there is an optimal matching value between Ga source flow rate and AlN thickness when GaN is grown on AlN buffer of different thicknesses. Under optimal conditions, AlGaN/GaN/AlN heterostructures with 120 nm thin GaN channel layer and thick AlN buffer show excellent carrier-limited domain, high crystalline quality, and good transport properties. Results in this work would be useful for preparing high-quality heterostructures on AlN buffer and high electron mobility transistor (HEMT) devices. Moreover, these findings can also be applied to the growth of other hyperfine structures (quantum wells, superlattices, and digital alloys) in the future. 相似文献
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《AEUE-International Journal of Electronics and Communications》2014,68(2):90-96
In this paper, inner T-shaped defected microstrip structure (DMS) is studied, and new bandstop filters with a single band, dual-band and tri-band are developed. The new designs have adjustable multi-band operation and simple circuit topologies, and the symmetrical periodic T-shaped DMS introduces transmission zeros which improve the filter frequency selectivity greatly. The circuit sizes are also reduced because of the inner T-shaped DMS introduces more resonances in a frequency range of 10 GHz but without the requirement of certain coupled lines or resonators. The dual-band and tri-band designs are demonstrated by measurement. 相似文献
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In this paper, we propose Unbiased Weighted Mean Filter (UWMF) for removing high-density impulse noise. Asymmetric distribution of corrupted pixels in the filtering window creates a spatial-bias towards the center of uncorrupted pixels. UWMF eliminates this bias by recalibrating the contribution factor (weight) of each uncorrupted pixel in such a way that the center shifts back to the center of the filtering window. The restoration process involves three sequential operations while convolving a filtering window over a contaminated image. Noise is detected, weights are recalibrated and the new intensity value is replaced by weighted mean using the recalibrated weights. Compared to the state-of-the-art impulse noise removal methods, UWMF provides superior performance, without requiring a fine-tuning for its parameters, in terms of both objective measurements and subjective assessments. 相似文献