To solve the problem of the large Doppler frequency offset in the LEO communication system, this paper studies a rapid PN code acquisition method based on the PMF-FFT architecture, which searches the phase and frequen...To solve the problem of the large Doppler frequency offset in the LEO communication system, this paper studies a rapid PN code acquisition method based on the PMF-FFT architecture, which searches the phase and frequency offset and at the same time reduces the acquisition time. It presents an improved method equivalent to windowing function and uses windowing process to overcome the attenuation of related peak envelope caused by partial matched filters.展开更多
Background: The conventional HIV testing algorithm in most of the developed countries consists of two tests: an HIV enzyme immunoassay capable of identifying HIV-1 and HIV-2 antibodies and a confirmatory HIV-1 Western...Background: The conventional HIV testing algorithm in most of the developed countries consists of two tests: an HIV enzyme immunoassay capable of identifying HIV-1 and HIV-2 antibodies and a confirmatory HIV-1 Western blot or immunofluorescence assay. However, the current algorithm for HIV diagnosis in India uses three sequential antibody assays. There has always been doubt regarding the benefits of this algorithm. Objective: To determine the utility of the current diagnostic algorithm and to find out the proportion of indeterminate or discrepant results. Methods: Retrospective analysis of HIV antibody testing data was carried out over a period of five years after institutional ethics committee approval. The specimens positive with the screening test and negative with both the supplemental tests were labeled as discrepant. Specimens positive with any of the two tests (screening and one of the supplemental tests) and negative with the remaining supplemental test were labeled as indeterminate. These indeterminate specimens were confirmed by immunoblotting. Results: A total of 141,296 samples were tested. Of these, 71 (0.05%) samples were indeterminate and 292 (0.21%) were discrepant. Western blot was done on 60 indeterminate samples of which 10 (16.67%) were positive for HIV 1 antibodies, 14 (23.33%) were negative for HIV antibodies and 36 (60%) had indeterminate result. Conclusion: In view of the low numbers of indeterminate and discrepant results, the current algorithm appears to be appropriate in our resource constrained setting. However, the algorithm for HIV testing should also include DNA PCR testing facility to resolve western blot indeterminate results.展开更多
Rapid solidifiation is a kind of new process for enhancing the hardness and electrical conductivity of Cu-Cr-Zr copper alloy.The use of BP neural network(NN) is presented to model the non-linear relationship between p...Rapid solidifiation is a kind of new process for enhancing the hardness and electrical conductivity of Cu-Cr-Zr copper alloy.The use of BP neural network(NN) is presented to model the non-linear relationship between parameters of age hardening processes and the mechanical and electrical properties of rapdily solidified Cu-Cr-Zr alloy.The improved model is developed by the Levenberg-Marquardt training algorithm and the good generalization performance is demonstrated.So,an important foundation has been laid for optimisticaly controlling the rapidly solidified aging processes of Cu-Cr-Zr alloy.展开更多
面对采摘作业的复杂环境,提出了一种终点区域RRT(Goal Area RRT,GA-RRT)算法,以提高路径生成的效率并降低路径成本。根据环境系数确定初始步长与终点区域,当拓展节点进入终点区域后,随机点生成范围缩小至终点区域,同时调整步长;然后,在...面对采摘作业的复杂环境,提出了一种终点区域RRT(Goal Area RRT,GA-RRT)算法,以提高路径生成的效率并降低路径成本。根据环境系数确定初始步长与终点区域,当拓展节点进入终点区域后,随机点生成范围缩小至终点区域,同时调整步长;然后,在此基础上引入目标概率偏向方法,提高路径搜索效率;最后,对生成的路径进行简化节点处理以减少路径代价,并使用三次B样条方法平滑路径。仿真实验结果表明:二维环境下,GA-RRT算法相较于RRT、RRT-Connect算法,耗时缩短85.15%、29.86%,路径代价减少19.18%、18.26%;机械臂仿真环境下,与引入目标概率偏向方法的RRT算法进行比较,耗时缩短54.70%,路径代价减少51.59°。利用IRB120机械臂实验平台,验证了算法的可行性。展开更多
The methods and strategies used to screen for syp-hilis and to confirm initially reactive results can vary significantly across clinical laboratories. While the performance characteristics of these different appro-ach...The methods and strategies used to screen for syp-hilis and to confirm initially reactive results can vary significantly across clinical laboratories. While the performance characteristics of these different appro-aches have been evaluated by multiple studies, there is not, as of yet, a single, universally recommendedalgorithm for syphilis testing. To clarify the currently available options for syphilis testing, this update will summarize the clinical challenges to diagnosis, review the specific performance characteristics of treponemal and non-treponemal tests, and fnally, summarize select studies published over the past decade which have evaluated these approaches. Specifcally, this review will discuss the traditional and reverse sequence syphilis screening algorithms commonly used in the United States, alongside a discussion of the European Centre for Disease Prevention and Control syphilis algorithm. Ultimately, in the United States, the decision of which algorithm to use is largely dependent on laboratory resources, the local incidence of syphilis and patient demographics. Key words： Syphilis; Treponemal infection; Immuno-assay; Reverse sequence screening; Rapid plasma regain; Treponema pallidum particle agglutination test; Automation; Algorithm; Primary infection; Late latent infection展开更多
基于近红外偏最小二乘法(near-infrared partial least squares,NIR-PLS)开发了一种近红外光谱快速检测模型,用于快速、无损检测清蒸高粱糊化度。同时分析了白酒酿造生产关键指标相关性,以清蒸高粱糊化度为基础,结合清蒸高粱感官评价、...基于近红外偏最小二乘法(near-infrared partial least squares,NIR-PLS)开发了一种近红外光谱快速检测模型,用于快速、无损检测清蒸高粱糊化度。同时分析了白酒酿造生产关键指标相关性,以清蒸高粱糊化度为基础,结合清蒸高粱感官评价、出入窖糟醅理化、出酒率、基础酒理化及评分,利用自适应权重算法(adaptive weights,AW)建立了一种清蒸高粱蒸粮效果评价方法。该检测模型在预测清蒸高粱糊化度方面具有较高的相关性,模型预测值与建模参考值之间的决定系数R^(2)=0.9771。此外,蒸粮效果评价方法验证结果与经验丰富的酿酒师的感官评定相吻合。当75≤糊化度检测值≤80时,清蒸高粱糊化效果评价为优级;65≤糊化度检测值<75时,评价为一级;55<糊化度检测值<65或80<糊化度检测值<90时,评价为二级;糊化度检测值≥90或糊化度检测值≤55时,评价为不合格。该评价方法量化了白酒生产中清蒸高粱蒸粮效果的评定,将依赖经验的感官评估方式转化为标准化、数字化的手段,有助于加强生产过程和产品质量的可控性,减少粮食损耗。展开更多
文摘To solve the problem of the large Doppler frequency offset in the LEO communication system, this paper studies a rapid PN code acquisition method based on the PMF-FFT architecture, which searches the phase and frequency offset and at the same time reduces the acquisition time. It presents an improved method equivalent to windowing function and uses windowing process to overcome the attenuation of related peak envelope caused by partial matched filters.
文摘Background: The conventional HIV testing algorithm in most of the developed countries consists of two tests: an HIV enzyme immunoassay capable of identifying HIV-1 and HIV-2 antibodies and a confirmatory HIV-1 Western blot or immunofluorescence assay. However, the current algorithm for HIV diagnosis in India uses three sequential antibody assays. There has always been doubt regarding the benefits of this algorithm. Objective: To determine the utility of the current diagnostic algorithm and to find out the proportion of indeterminate or discrepant results. Methods: Retrospective analysis of HIV antibody testing data was carried out over a period of five years after institutional ethics committee approval. The specimens positive with the screening test and negative with both the supplemental tests were labeled as discrepant. Specimens positive with any of the two tests (screening and one of the supplemental tests) and negative with the remaining supplemental test were labeled as indeterminate. These indeterminate specimens were confirmed by immunoblotting. Results: A total of 141,296 samples were tested. Of these, 71 (0.05%) samples were indeterminate and 292 (0.21%) were discrepant. Western blot was done on 60 indeterminate samples of which 10 (16.67%) were positive for HIV 1 antibodies, 14 (23.33%) were negative for HIV antibodies and 36 (60%) had indeterminate result. Conclusion: In view of the low numbers of indeterminate and discrepant results, the current algorithm appears to be appropriate in our resource constrained setting. However, the algorithm for HIV testing should also include DNA PCR testing facility to resolve western blot indeterminate results.
文摘Rapid solidifiation is a kind of new process for enhancing the hardness and electrical conductivity of Cu-Cr-Zr copper alloy.The use of BP neural network(NN) is presented to model the non-linear relationship between parameters of age hardening processes and the mechanical and electrical properties of rapdily solidified Cu-Cr-Zr alloy.The improved model is developed by the Levenberg-Marquardt training algorithm and the good generalization performance is demonstrated.So,an important foundation has been laid for optimisticaly controlling the rapidly solidified aging processes of Cu-Cr-Zr alloy.
文摘面对采摘作业的复杂环境,提出了一种终点区域RRT(Goal Area RRT,GA-RRT)算法,以提高路径生成的效率并降低路径成本。根据环境系数确定初始步长与终点区域,当拓展节点进入终点区域后,随机点生成范围缩小至终点区域,同时调整步长;然后,在此基础上引入目标概率偏向方法,提高路径搜索效率;最后,对生成的路径进行简化节点处理以减少路径代价,并使用三次B样条方法平滑路径。仿真实验结果表明:二维环境下,GA-RRT算法相较于RRT、RRT-Connect算法,耗时缩短85.15%、29.86%,路径代价减少19.18%、18.26%;机械臂仿真环境下,与引入目标概率偏向方法的RRT算法进行比较,耗时缩短54.70%,路径代价减少51.59°。利用IRB120机械臂实验平台,验证了算法的可行性。
文摘The methods and strategies used to screen for syp-hilis and to confirm initially reactive results can vary significantly across clinical laboratories. While the performance characteristics of these different appro-aches have been evaluated by multiple studies, there is not, as of yet, a single, universally recommendedalgorithm for syphilis testing. To clarify the currently available options for syphilis testing, this update will summarize the clinical challenges to diagnosis, review the specific performance characteristics of treponemal and non-treponemal tests, and fnally, summarize select studies published over the past decade which have evaluated these approaches. Specifcally, this review will discuss the traditional and reverse sequence syphilis screening algorithms commonly used in the United States, alongside a discussion of the European Centre for Disease Prevention and Control syphilis algorithm. Ultimately, in the United States, the decision of which algorithm to use is largely dependent on laboratory resources, the local incidence of syphilis and patient demographics. Key words： Syphilis; Treponemal infection; Immuno-assay; Reverse sequence screening; Rapid plasma regain; Treponema pallidum particle agglutination test; Automation; Algorithm; Primary infection; Late latent infection
文摘基于近红外偏最小二乘法(near-infrared partial least squares,NIR-PLS)开发了一种近红外光谱快速检测模型,用于快速、无损检测清蒸高粱糊化度。同时分析了白酒酿造生产关键指标相关性,以清蒸高粱糊化度为基础,结合清蒸高粱感官评价、出入窖糟醅理化、出酒率、基础酒理化及评分,利用自适应权重算法(adaptive weights,AW)建立了一种清蒸高粱蒸粮效果评价方法。该检测模型在预测清蒸高粱糊化度方面具有较高的相关性,模型预测值与建模参考值之间的决定系数R^(2)=0.9771。此外,蒸粮效果评价方法验证结果与经验丰富的酿酒师的感官评定相吻合。当75≤糊化度检测值≤80时,清蒸高粱糊化效果评价为优级;65≤糊化度检测值<75时,评价为一级;55<糊化度检测值<65或80<糊化度检测值<90时,评价为二级;糊化度检测值≥90或糊化度检测值≤55时,评价为不合格。该评价方法量化了白酒生产中清蒸高粱蒸粮效果的评定,将依赖经验的感官评估方式转化为标准化、数字化的手段,有助于加强生产过程和产品质量的可控性,减少粮食损耗。
