检索结果-南通市图书馆

A Fast and Accurate LEO Satellite-Based Direct Position Determination Assisted by TDOA Measurements

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

China Communications 2022年第1期19卷 92-103页

作者： Shijie Li qianyun zhang Boyu Deng Biyi Wu Yue Gao School of Cyber Science and Technology BeiHang UniversityBeijing 100191China Tsinghua University ChinaBeijing 100084China Beijing Institute of Technology Beijing 100081China School of Computer Science Fudan University Shanghai 200433China

This paper focuses on the trusted vessel position acquisition using passive localization based on the booming low-earth-orbit(LEO) satellites. As the high signal-to-noise ratio(SNR) reception cannot always be guaranteed at LEO satellites, the recently developed direct position determination(DPD)is adopted. For LEO satellite-based passive localization systems, an efficient DPD is challenging due to the excessive exhaustive search range leading from broad satellite coverage. In order to reduce the computational complexity, we propose a time difference of arrival-assisted DPD(TA-DPD) which minimizes the searching area by the time difference of arrival measurements and their variances. In this way, the size of the searching area is determined by both geometrical constraints and qualities of received signals, and signals with higher SNRs can be positioned more efficiently as their searching areas are generally *** two-dimensional and three-dimensional passive localization simulations using the proposed TA-DPD are provided to demonstrate its efficiency and validity. The superior accuracy performance of the proposed method, especially at low SNRs conditions, is also verified through the comparison to conventional two-step methods. Providing a larger margin in link budget for satellite-based vessel location acquisition,the TA-DPD can be a competitive candidate for trusted marine location service.

关键词： direct position determination LEO satellite constellation passive localization TDOA

Supplementing the early diet of broilers with soy protein concentrate can improve intestinal development and enhance short-chain fatty acid-producing microbes and short-chain fatty acids,especially butyric acid

在线全文

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2023年第1期14卷 278-294页

作者： qianyun zhang Shan zhang Shu Wu Marianne Hjollund Madsen Shourong Shi Poultry Institute Chinese Academy of Agriculture ScienceYangzhou 225125China. TripleA a/s Bjoernkaervej 16DK‑8783 HornsyldDenmark.

Background:Research on nutrition in early-life commonly focuses on the maturation of the intestine because the intestinal system is crucial for ensuring continued *** explore the importance of early nutrition regulation in animals,soy protein concentrate(SPC)was added to the early diet of broilers to investigate its effects on amino acid digestibility,intestinal development,especially intestinal microorganisms,and broiler metabolites.A total of 192 oneday-old Arbor Acres(AA)male broilers were randomly assigned to two experimental treatments with 8 replicates of 12 *** control group was fed a basal diet(control),and the treatment group was fed a basal diet supplemented with 12%SPC(SPC12)during the first 10 d(starter phase).From d 11 to 21(grower phase)and d 22 to 42(finisher phase),a basal diet was fed to both treatment ***:SPC reduced the pH value and acid-binding capacity of the starter diet(P<0.05,d 10);SPC in the early diet enhanced the gizzard weight(P<0.05,d 10 and d 42)and the ileum weight(P<0.05,d 10)and decreased the weight and length of the jejunum(P<0.05,d 10)and the relative length of the duodenum and jejunum(P<0.05,d 10).At the same time,SPC enhanced villus height(P<0.05,d 10)and muscle thickness in the jejunum and ileum(P<0.05,d 10)and increased the number of goblet cells in the duodenum(P<0.05,d 10).Meanwhile,SPC increased the Chao1 index and the ACE index(P<0.05,d 10)and altered the composition of caecal microflora at d *** also increased the relative abundance of Alistipes,Anaerotruncus,Erysipelatoclostridium,Intestinimonas and Flavonifractor bacteria(P<0.05,d 10).At the same time,the concentrations of caecal butyric acid and total short-chain fatty acids(SCFAs)were also increased in the SPC12 group(P<0.05,d 10).Conclusions:In summary,the results showed that supplementing the starter diet of broilers with SPC has a significant effect on the early development of the intestine and the microflora.

关键词： Broiler Caecal microbiota Intestinal development Short-chain fatty acids Soy protein concentrate

An Unmanned Aerial Vehicle Flight Formation for Enhanced Emergency Communication Based on Conformal Antenna Design

在线全文

学校读者我要写书评

暂无评论

Journal of Communications and Information Networks 2020年第3期5卷 294-301页

作者： qianyun zhang Xiaoqian Ren Li Gong Lei Cheng Yue Gao The School of Cyber Science and Technology Beihang UniversityBeijing 100191China National Time Service Center China Academy of ScienceXi’an 710600China Beijing Aerospace Guanghua Electronics Technologies Co. Ltd.Beijing 100091China Shenzhen Research Institute of Big Data Shenzhen 518000China University of Surrey GU27XHU.K. Peng Cheng Laboratory Shenzhen 518000China

Benefiting from the inherent superiorities in flexibility and mobility,the use of unmanned aerial vehicles(UAVs)as flying base stations for wireless coverage has been of significant interest,especially for rescue *** work concerns the reliable emergency communication based on commercial micro-sized UAVs due to their high availability and low *** decrease the weight overloads and to improve the power efficiency,a UAV body conformal and omnidirectional antenna is first presented based on the characteristic mode *** extend the wireless coverage and to improve the communication quality of the UAV network,a UAV flight formation is then proposed and *** addition,the propagation analyses for the proposed UAV transmitter designs are performed in a realistic hilly canyon *** and comparisons are presented to demonstrate the effectiveness of the proposed designs in emergency communications and performance enhancement through the UAV flight formation.

关键词： emergency communication micro UAV UAV flight formation conformal antenna

Real-Time Detection of Cracks on Concrete Bridge Decks Using Deep Learning in the Frequency Domain

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Engineering 2021年第12期7卷 1786-1796页

作者： qianyun zhang Kaveh Barri Saeed K.Babanajad Amir H.Alavi Department of Civil and Environmental Engineering University of PittsburghPittsburghPA 15261USA Wiss JanneyElstner Associates Inc.NorthbrookIL 60062USA Department of Computer Science and Information Engineering Asia UniversityTaichungTaiwan 41354China

This paper presents a vision-based crack detection approach for concrete bridge decks using an integrated one-dimensional convolutional neural network(1D-CNN)and long short-term memory(LSTM)method in the image frequency *** so-called 1D-CNN-LSTM algorithm is trained using thousands of images of cracked and non-cracked concrete bridge *** order to improve the training efficiency,images are first transformed into the frequency domain during a preprocessing *** algorithm is then calibrated using the flattened frequency *** is used to improve the performance of the developed network for long sequence *** accuracy of the developed model is 99.05%,98.9%,and 99.25%,respectively,for training,validation,and testing *** implementation framework is further developed for future application of the trained model for large-scale *** proposed 1D-CNN-LSTM method exhibits superior performance in comparison with existing deep learning methods in terms of accuracy and computation *** fast implementation of the 1D-CNN-LSTM algorithm makes it a promising tool for real-time crack detection.

关键词： Crack detection Concrete bridge deck Deep learning Real-time

Probiotic Escherichia coli Nissle 1917 protect chicks from damage caused by Salmonella enterica serovar Enteritidis colonization

在线全文

学校读者我要写书评

暂无评论

Animal Nutrition 2023年第3期14卷 450-460页

作者： Shu Wu qianyun zhang Guanglei Cong Yunqi Xiao Yiru Shen Shan zhang Wenchang Zhao Shourong Shi Department of Feed and Nutrition Poultry InstituteChinese Academy of Agricultural SciencesYangzhouChina

As a foodborne pathogen of global importance,Salmonella enterica serovar Enteritidis(***)is a threat to public health that is mainly spread by poultry *** Enterobacteriaceae can inhibit the colonization of *** and are regarded as a potential antibiotic *** investigated,in chicks,the *** effects of Escherichia coli(***)Nissle 1917,the most wellknown probiotic member of *** 1-d-old healthy female AA broilers were randomly divided into 4 groups,with 20 in each group,namely the negative control(group P),the *** Nissle 1917-treated group(group N),the ***-infected group(group S)and the *** Nissle1917-treated and ***-infected group(group NS).From d 5 to 7,chicks in groups N and NS were orally gavaged once a day with *** Nissle 1917 and in groups P and S were administered the same volume of sterile *** d 8,the chicks in groups S and NS were orally gavaged with *** and in groups P and N were administered the same volume of sterile *** was conducted 24 h after *** showed that gavage of *** Nissle 1917 reduced the spleen index,Salmonella loads,and inflammation(P<0.05).It improved intestinal morphology and intestinal barrier function(P<0.05).*** infection significantly reduced mRNA expression of angiotensin-converting enzyme 2(ACE2)and solute carrier family 6-member 19(SLC6A19)in the cecum and the content of Gly,Ser,Gln,and Trp in the serum(P<0.05).Pretreatment with *** Nissle 1917 yielded mRNA expression of ACE2and SLC6A19 in the cecum and levels of Gly,Ser,Gln,and Trp in the serum similar to that of uninfected chicks(P<0.05).Additionally,*** Nissle 1917 altered cecum microbiota composition and enriched the abundance of ***,Lactobacillales,and *** findings reveal that the probiotic *** Nissle 1917 reduced *** infection and shows enormous potential as an alternative to antibiot

关键词： S.Enteritidis Gut microbiota Nissle 1917 Angiotensin-converting enzyme 2esolute carrier family 6-member 19 pathway

“以人为本”视角下的国土空间生态修复规划决策研究--以泉州市泉港区为例

在线全文

学校读者我要写书评

暂无评论

中国土地科学 2021年第7期35卷 17-26页

作者：魏伟张倩云薄立明武汉大学城市设计学院湖北武汉430072 武汉大学中国发展战略与规划研究院湖北武汉430072

研究目的:面对现实困境探索统筹多方利益、协调冲突矛盾、促进区域可持续发展的国土空间生态修复规划决策方法。研究方法:基于“以人为本”的国土空间规划理论,通过“自存—共存”和“优化—平衡”矛盾协调模式,以社会整体利益最大化为... 详细信息

研究目的:面对现实困境探索统筹多方利益、协调冲突矛盾、促进区域可持续发展的国土空间生态修复规划决策方法。研究方法:基于“以人为本”的国土空间规划理论,通过“自存—共存”和“优化—平衡”矛盾协调模式,以社会整体利益最大化为准则,构建“确定区域、厘清利益—权衡需求、初判博弈—多维评价、协调矛盾”的国土空间生态修复规划决策路径,并以泉港区为例展开案例研究。研究结果:(1)“权衡需求、初判博弈”阶段,核心需求有偏差的冲突用地,可直接决策出生态修复方向。(2)核心需求冲突较大的用地需进入“多维评价、协调矛盾”阶段。选取泉港区生态修复过程中与农业空间、城镇空间利益冲突较大的两个地块进行矛盾协调,其中耕地转换草地方案的整体利益比值小于门槛值,转换方案不可行;商业用地转换城市公园绿地方案的整体利益比值大于门槛值,转换方案可行。研究结论:“以人为本”的规划决策方法聚焦于整体利益下的自然资源使用与分配,协调利益冲突矛盾,可为推进国土空间生态修复规划实施落地,提供客观、理性、可操作的理论支撑与价值判断。

关键词：国土空间规划生态修复以人为本决策方法泉港区

在线全文

学校读者我要写书评

暂无评论

基于感性工学的服装菱形纹结构参数分析

纺织高校基础科学学报 2017年第3期30卷 417-422,443页

作者：周莉英张倩芸陕西科技大学设计与艺术学院陕西西安710021

对服装菱形纹样参数进行定量化分析.根据感性工学基本原理及方法,筛选30种不同角度、不同纹样宽度的菱形纹针织服装和6对感性评价形容词,以18~25岁的消费群体为调查对象,运用统计软件对调查数据进行统计分析,获取菱形纹设计参数与感性... 详细信息

对服装菱形纹样参数进行定量化分析.根据感性工学基本原理及方法,筛选30种不同角度、不同纹样宽度的菱形纹针织服装和6对感性评价形容词,以18~25岁的消费群体为调查对象,运用统计软件对调查数据进行统计分析,获取菱形纹设计参数与感性词语间的关联性.得到受试者对不同样本间差异性的感性评价,以及可以量化、直观地反映出菱形纹设计元素与感性心理之间关系的象限分析.旨在为设计师提供不同类型消费者的设计参数,设计出适合市场需求的菱形纹服装,提高品牌对消费者的吸引力.

关键词：感性工学菱形纹参数分析感性评价

妊娠期糖尿病分娩后高脂血症各孕期血脂水平及发病因素分析

在线全文

学校读者我要写书评

暂无评论

大医生 2020年第11期5卷 29-31页

作者：章倩云淮安市妇幼保健院江苏淮安223002

目的分析妊娠期糖尿病(GDM)患者分娩后高脂血症患者不同孕期血脂代谢情况和高脂血症影响因素。方法选取2018年12月至2019年12月江苏省淮安市妇幼保健院收治的96例妊娠期糖尿病患者进行研究,根据分娩后是否发生高脂血症分为A组(25例,高... 详细信息

目的分析妊娠期糖尿病(GDM)患者分娩后高脂血症患者不同孕期血脂代谢情况和高脂血症影响因素。方法选取2018年12月至2019年12月江苏省淮安市妇幼保健院收治的96例妊娠期糖尿病患者进行研究,根据分娩后是否发生高脂血症分为A组(25例,高脂血症组)与B组(71例,血脂正常组)。对比两组一般资料和不同孕期血脂代谢指标,采用Logsitc回归分析法分析分娩后高脂血症影响因素。结果A组患者的各孕期总胆固醇(TC)、三酰甘油(TG)指标和妊娠早期、中期低密度脂蛋白(LDL)值均高于B组(P<0.05)。与B组相比,A组患者的年龄更大,既往分娩次数更多,孕期体质量增长率及胰岛素治疗率更高(P<0.05)。孕期体质量增长率和孕早期TC高水平是分娩后高脂血症独立危险因素(P<0.05)。结论需对孕期体质量增长过快和孕早期TC异常升高的GDM孕妇加强高脂血症预防。

关键词：妊娠期糖尿病高脂血症体质量增长率总胆固醇

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

地震对灾民创伤后应激障碍的长期影响

心理科学进展 2016年第10期24卷 1534-1543页

作者：郭静周倩云张振涛华中科技大学社会学院武汉430074

创伤后应激障碍是震后最常见的心理创伤。以往研究多关注灾民在震后短时间内的应激反应,地震两年后创伤心理研究非常缺乏。本研究拟结合汶川地震后进行的6次重复测量数据（2008～2016）重点探讨：创伤后应激障碍在震后不同时点的变化轨... 详细信息

创伤后应激障碍是震后最常见的心理创伤。以往研究多关注灾民在震后短时间内的应激反应,地震两年后创伤心理研究非常缺乏。本研究拟结合汶川地震后进行的6次重复测量数据（2008～2016）重点探讨：创伤后应激障碍在震后不同时点的变化轨迹及影响因素;震后针对创伤后应激障碍在不同时点的干预内容。预期研究成果不仅是对灾后心理创伤长期影响研究的补充,也将为灾后救助政策以及心理干预提供依据。

关键词：地震创伤后应激障碍长期影响