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81.
针对VoLTE视频通话中存在延迟、卡顿等问题,本文提出一种新型闹脑层算法的VoLTE视频通话质量的评估方法。首先,运用脑皮层算法的HTM算法对VoLTE时间序的指标进行检测,然后利用同比环比加权及HTM循环预测加权进行VoLTE感知指标异常值替换,构造能够实时发现指标异常状况的指标监控模型。其次使用时间序列连续性检测及补全功能、同比环比加权平均值再加权的方法提高异常数据训练的准确性。然后通过对比验证VoLTE失败码的预测结果,验证该模型的监控结果的有效性。  相似文献   
82.
    
Although simple to implement, the traditional trilateration technique is generally associated with significant location estimation errors because of highly nonlinear relationship between Received Signal Strength Indicator (RSSI) and distance. In case of agricultural farmland, there is always noise uncertainty in the RSSI measurements because of signal propagation issues such as NLOS, multipath propagation, and reflection. In the context of such environmental dynamicity, the localization algorithm must be efficient in terms of Localization Accuracy and Execution Speed to provide real‐time performance. The Generalized Regression Neural Network (GRNN) is a noniterative highly parallel neural architecture with the capability to get trained quickly using very few training samples. This paper introduces a range free GRNN localization algorithm as an alternative to the traditional range‐based trilateration technique for a large scale wheat farmland. This paper also presents the modified Optimal Fitted Parametric Exponential Decay Model (OFPEDM)‐based signal path loss model to deal with the issue of environmental dynamicity. The evaluation of localization performance of the trilateration and the proposed GRNN‐based approaches is carried out with the help of Wireless Sensor Network (WSN) using three path loss models, namely, Log Normal Shadow Fading (LNSM), Original OFPEDM, and proposed Modified OFPEDM. For all these implementations, the proposed GRNN algorithm demonstrates superior localization performance (localization accuracy of the order of few centimeters) over traditional trilateration irrespective of nonlinear system dynamics, path loss model, and environmental dynamicity. The execution speed of the proposed algorithm is of the order of few milliseconds.  相似文献   
83.
为了定量评估电动汽车充电过程中的安全水平,对电动汽车充电过程中诱发充电安全事故的因素进行了分析,并采用模糊综合评价方法设计了电动汽车充电安全风险评估方案;提出了一种综合赋权的方法来改进灰色关联度主观赋权存在的指标权重不确定的问题,保证了评估结果的合理性与可靠性;首先统计分析指标诱发充电事故的频率获得客观权重,然后经过基于灰色关联度的专家经验判断得到主观权重,最后通过标准离差求出主观权重与客观权重的分配系数;该方法既保留了主观权重中专家的权威性,又充分体现了数据本身所具有的客观特征;其次,将充电安全划分为5个等级并且设定合理的阈值,构建梯形分布的隶属度函数;经过对某充电站充电数据的分析,验证了该风险评估方案的可行性和正确性。  相似文献   
84.
The paper aims to show that mediate indication of environmental acidity conditions in hydromorphic habitats in the West Siberian Plain is possible by means of using indicator values for soil moisture and nutrient factors as substitute predictors. These factors are viewed as interrelated for plant communities located in the wetlands in the West Siberian Plain. Regression equations are introduced to assess the pH of soil solution in wetland plant communities.  相似文献   
85.
为了实现基于STEP-NC的零件加工程序可加工性评价,提出了一种面向STEP-NC的数控加工零件可加工性评价指标体系。在建立机床资源信息模型的基础上,分别以零件装夹性、机床性能、刀具资源、辅助功能等四个方面对零件在特定机床上的可加工性进行评价。使用Visual C#平台开发了零件可加工性评价系统,实现了STEP-NC信息提取及可加工性评价算法。  相似文献   
86.
根据煤炭行业的特点,进行基于项目反应原理的计算机测试。实验选用两参数的逻辑斯蒂模型,使用BILOG来模拟数据和参数估计。选择其中30个考试结果进行分析,得出平均能力值θ为1.266 6,呈正态偏易分布,而且相比传统测试长度缩短了39.00%,平均难度系数b为-0.5241属于偏易。结合Bias、RMSD、E 3个指标来看,均表现良好,基本符合预期。  相似文献   
87.
A new method for spatial interpretation and visualisation of measured air quality data developed and introduced in 1998 is used for ambient air quality assessment in the Czech Republic. The data from a countrywide air quality monitoring network is collated into the least possible number of factors describing the overall air quality in 1996-1999. The factors identified as 'ambient air pollution', 'ground-level ozone' and 'wet atmospheric deposition' represent three different aspects of ambient air quality and their impact on receptors' evaluation. The monitoring stations are classified for each factor using five categories clearly distinguishing the sites over the Czech Republic territory within the 'best-worst' scale range. The results are presented in maps with spot symbols produced in Arc/View system. The problem areas within the country are identified clearly for each factor. The air quality picture differs considerably for the respective factors within one calendar year. Categorisation of each factor for the entire period under review, however, remains strikingly similar, indicating that in spite of partial improvement and some decreases in air pollutant concentration, the problem areas have remained more or less the same for each factor. Comparison of all three factors shows that the southern part of the country is in a certain simplification very clean as to the 'ambient air pollution' and 'wet atmospheric deposition' factors, while it is impacted as to the 'ground-level ozone' factor. In contrast, the northern part of the country impacted as to the 'ambient air pollution' along with the 'wet atmospheric deposition' and 'ground-level ozone' factors at the higher elevations.  相似文献   
88.
The occurrence and removal of salmonellae and faecal indicators in four conventional municipal wastewater treatment plants (MWTP) were investigated. In addition, we tested the efficiency of a semi-technical scale biological nutrient removal process and three pilot-scale tertiary filtration units in microbial removal. All influent samples collected from MWTPs contained salmonellae from 93 to 11,000 MPN/100 ml and indicator bacteria from about 10(7) to 10(8) CFU/100 ml. The reductions in salmonella numbers achieved in full-scale biological-chemical wastewater treatment and semi-technical scale biological nutrient removal processes were usually between 94% and virtually 100% (99.9%) and indicator bacteria reductions between 2 and 3 log units. Microbial numbers in MWTP effluents could be modelled as a function of effluent residual organic matter, suspended solids and total phosphorus concentrations. Pilot-scale tertiary treatment by rapid sand contact filter, chemical contact filter and biological-chemical contact filter reduced salmonella numbers below the detection limit and faecal coliform numbers on average by 99%, 39% and 71%, respectively. A total of 32 Salmonella serovars were identified among 197 Salmonella isolates from municipal wastewaters. Of the isolates, 32% were resistant to nalidixic acid, indicating reduced sensitivity to ciprofloxacin, the drug of choice in the treatment of salmonellosis. In addition, 18% of the isolates were multiresistant. Our results, especially antibiotic resistant Salmonella strains, indicate that conventional municipal wastewater treatment without efficient tertiary treatment, like filtration or disinfection, may constitute a risk for public health.  相似文献   
89.
Conventional validation testing of UV reactors use cultured microorganisms spiked into test water flowing through a reactor. These tests are limited by the microbe titer it is possible to grow, thus limiting the size of the reactor it is possible to validate. The goal of this study was to examine the UV inactivation of indigenous aerobic spores naturally occurring in raw/unfiltered water supplies and to assess their use as an alternative indicator for validation testing of UV reactor performance, specifically for unfiltered water supplies planning large UV reactors. These spores were found in all raw waters tested in concentrations ranging between 20 and 12,000 CFU/100 mL and were very resistant to UV irradiation compared to a range of different microbes in the literature (i.e. adenovirus, MS-2 coliphage, and Cryptosporidium parvum). The inactivation of indigenous natural aerobic spores followed first-order kinetics with an inactivation coefficient ranging between 0.013 and 0.022 cm2/mJ with a high correlation coefficient. It was determined that naturally occurring aerobic spores, well characterized with respect to UV 253.7 nm inactivation, can be a useful tool when validating plant performance, and might also be used as a regular monitor of UV fluence and performance in a water treatment plant.  相似文献   
90.
建筑工程安全生产管理现状调查与简析   总被引:2,自引:0,他引:2  
康香萍 《煤炭工程》2011,(4):136-138
 安全事故不仅造成巨大的经济损失,而且造成了大量人员的伤亡,严重影响到社会的稳定和发展。在调查的基础上,找出了影响建筑工程安全的主要风险因素,包括安全管理措施有效,但形同虚设,没有落实或落实不下去;四口五临边等危险处没有物的防护或警示标志;操作人员安全意识不高;违章作业、操作人员(工人)的技能和专业技术水平低和对现场安全检查力度不够等等。  相似文献   
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