Results 111 to 120 of about 164,546 (209)
文章提出了一种仿真单模光纤数字传输系统的方法,在模型中分别对信号模型、光纤模型和器件模型逐一进行了分析,并分析了评价系统性能的误码率和眼图两个参数。
龙雷, 张驰, 周正利, 宋宁
doaj
Democratic Values in Citizen Participation: What Citizens Prioritize in Participation
ABSTRACT Citizen participation is often initiated to strengthen democracy. While participatory innovations are typically assessed through normative frameworks emphasizing democratic values, little is known about which of these values are prioritized by citizens.
Take Sipma, Frank Hendriks
wiley +1 more source
ANSWERS2 0 0 0是一个用于流域土壤侵蚀过程模拟的分散型物理模型 ,将此模型运用于三峡库区小流域侵蚀产沙、地表径流以及不同土地利用类型水沙分布状况的模拟中。通过两个不同小流域模拟结果的对比 ,采用误差百分比、线性回归以及 Nash- Sutcliffe效率 3种方法 ,分析和评价了模型的模拟效果。结果表明 ,模型在应用于我国三峡库区小流域土壤侵蚀模拟时 ,其模拟结果与实测结果具有较高的吻合度 ,模拟结果基本可信。但是 ,对于一些陡坡林地等特殊地类 ,模型的模拟误差较大 ...
doaj
变压器抗短路能力不足,严重影响了电网的运行安全,因而针对变压器绕组抗短路能力开展抗短路校核工作很有必要。目前在变压器绕组的理论建模方面,较多使用的是二维轴对称分区模型,少量也有使用具体的线饼模型。为了对比两种模型的仿真结果,文中首先分析了分区模型和线饼模型的特点,然后以一台220 k V三绕组的电力变压器为例,在ANSYS中计算和比较了这两种模型下绕组中的漏磁场及短路电动力的分布情况,结果显示两种模型计算有一定差异,但整体分布趋于一致。因此在精度要求不高的情况下 ...
徐肖伟 +7 more
doaj
Focusing Events, Agenda Setting, and Narrative Numbing
ABSTRACT Focusing events are important in understanding policy change, as demonstrated in Birkland's work on agenda setting, the multiple streams framework, and the narrative policy framework. These frameworks emphasize the role of focusing events in drawing public attention to broader issues.
Megan K. Warnement Wrobel +1 more
wiley +1 more source
ABSTRACT Background Canine atopic dermatitis (cAD) is a multifactorial, inherited skin disease, estimated to affect ≤ 15% of dogs. Studies of skin messenger mRNA in cAD currently use invasive methods, including blood sampling and biopsy collection, whilst advances in human atopic dermatitis study methodology have demonstrated reliable use of minimally ...
Xavier Langon +5 more
wiley +1 more source
为了描述减振器的动态特性,将集总参数模型和神经网络模型进行结合,提出了一种能够精确描述减振器非线性动态特性的集总参数‑神经网络联合模型。首先,在减振器测试台架上对一个减振器的动态特性进行测量,激励工况包括谐波激励和瞬态激励两大类,测试得到减振器的动态力响应;其次,提出了联合模型的集总参数建模方法与参数辨识方法,并使用谐波激励下的测试数据完成了模型参数辨识;然后,利用神经网络模型补偿减振器的力‑速度非线性特征;最后,使用联合模型计算在瞬态激励下减振器的输出力 ...
doaj +1 more source
Spatially Downscaling of Future Food Demand for Policy Planning
ABSTRACT Understanding the subnational dynamics of food demand, while accounting for the evolution of the agrifood system at the global level, remains a challenge for designing food policy to ensure food security. To link global agrifood systems with subnational food policy planning, we downscale per capita food demand for 62 food commodities at the ...
Chun Song +3 more
wiley +1 more source
负荷建模在电力系统的运行和控制方面扮演着至关重要的角色,找到一种有效、可靠的负荷建模参数辨识优化方法具有重要的实际意义。文中利用支持向量机(support vector machine,SVM)方法对电力系统负荷进行建模研究,通过高斯径向基函数作为核函数,选择支持向量机模型的基础结构。在模型辨识过程中,以PMU实测电流、电压以及相角数据作为输入变量,以有功功率和无功功率作为输出变量。基于测量的负荷建模方法使用留一交叉验证法(leave-one-out cross-validation,LOOCV ...
邢超, 王朋林, 何鑫, 邓灿
doaj
ABSTRACT Diabetic wound infections are a common complication of diabetes, which severely impact patients' quality of life. Effective treatment of diabetic wound infections remains one major challenge in the clinic, partially due to the formation of bacterial biofilm and antibiotic resistance.
Liang Zhou +8 more
wiley +1 more source

