Noctiluca scintillans red tide extraction method from UAV images based on deep learning

Aiming at the problems of low accuracy and poor real-time performance of Noctiluca scintillans red tide extraction in the field of satellite remote sensing,a Noctiluca scintillans red tide extraction method from Unmanned Aerial Vehicle(UAV)images based on deep learning was proposed. Firstly,the high-resolution RGB(Red-Green-Blue)videos collected by UAV were used as the monitoring data,the backbone network was modified to VGG-16(Visual Geometry Group- 16)and the spatial dropout strategy was introduced on the basis of the original UNet++ network to enhance the feature extraction ability and prevent the overfitting respectively. Then,the VGG-16 network pre-trained by using ImageNet dataset was applied to perform transfer learning to increase the network convergence speed. Finally,in order to evaluate the performance of the proposed method,experiments were conducted on the self-built red tide dataset Redtide-DB. The Overall Accuracy(OA),F1 score,and Kappa of the Noctiluca scintillans red tide extraction of the proposed method are up to 94.63%,0.955 2,0.949 6 respectively,which are better than those of three traditional machine learning methods - KNearest Neighbors(KNN),Support Vector Machine(SVM)and Random Forest(RF)as well as three typical semantic segmentation networks(PSPNet(Pyramid Scene Parsing Network),SegNet and U-Net). Meanwhile,the red tide images of different shooting equipment and shooting environments were used to test the generalization ability of the proposed method, and the corresponding OA,F1 score and Kappa are 97.41%,0.965 9 and 0.938 2,respectively,proving that the proposed method has a certain generalization ability. Experimental results show that the proposed method can realize the automatic accurate Noctiluca scintillans red tide extraction in complex environments,and provides a reference for Noctiluca scintillans red tide monitoring and research work

杨桦次生林林分空间结构参数多元分布研究

【目的】运用林分空间结构参数多元分布,系统描述和分析金沟岭林场两种起源(造林失败地天然更新和火灾迹地天然更新)的杨桦次生林林分空间结构特征,为森林经营管理和林分结构优化调整提供有力手段,以期促进林分演替。【方法】每木调查和空间定位6块样地(面积均为30 m×30 m)的林木。利用RStudio forestSAS包计算各样地的空间结构参数,包括角尺度、大小比数、混交度和密集度,统计各起源的频率分布,运用Origin 2018建立结构参数的多元分布图。【结果】杨桦次生林的零元分布表明,两种林分整体呈聚集分布、混交较好的中庸生长状态,而起源Ⅱ较起源Ⅰ密集;一元分布表明,林分内大多数林木呈混交良好、密集或很密集、各大小比数等级占比相近的随机分布。分树种来看,起源Ⅰ中,山杨生长发育良好,绝大多数处于优势及亚优势生长状态;白桦、水曲柳和枫桦整体上均大致处于中庸生长状态。起源Ⅱ中,山杨和白桦优势木多,劣势木少,总体生长发育良好。二至四元分布表明,结构参数的各种组合下,林木大多表现为混交良好或随机分布状态。【结论】相较于传统的利用结构参数零元分布和一元分布描述林分空间结构,运用多元分布描述杨桦次生林林分结构特征是对其经营管理和结构优化的有效方法,蕴含的信息更为丰富和清晰。同时,也是具有可操作性的采伐木遴选方法

Effects of Lingguibafa-based Acupuncture on the Level of Blood Lactic Acid after Exhaustive Exercise

目的:观察灵龟八法针刺消除台阶运动疲劳后血乳酸的作用效果。方法:40名体育专业健康男性大学生随机分为灵龟八法照海开闭穴组(简称照海组)、灵龟八法申脉闭开穴组(简称申脉组)、辩证取穴组(简称三阴交组)和对照组4组,每组10人。实验分两个阶段:第一阶段选在照海穴开穴时间段进行。4组受试者进行台阶运动至疲劳后平卧,照海组、申脉组和三阴交组分别进行针刺,照海组选取双侧照海穴、列缺穴,申脉组选取双侧申脉穴、后溪穴,三阴交组选取双侧三阴交穴、合谷穴。留针30分钟,每10分钟行捻转补法1次。对照组平卧床上,不进行任何恢复干预。第二阶段:第一阶段实验结束24小时后,在申脉穴开穴时间段进行,方法同第一阶段。测定受试者两个阶段台阶运动前、运动停止30分钟后血乳酸值。结果:(1)第一阶段台阶运动停止30分钟后,照海组、申脉组和对照组的血乳酸值显著高于运动前(P0.05)。(2)第一阶段台阶运动24小时后,照海组和三阴交组血乳酸值显著低于运动前(P0.05);照海组和对照组之间比较有显著性差异(P0.05)。结论:灵龟八法针刺和辩证取穴针刺均有促进台阶运动后乳酸清除、降低血乳酸浓度的作用。Objective To observe the effects of Lingguibafa-based acupuncture blood lactic acid （BLA） after exhaustive step test. Methods 40 healthy male students were divided randomly and equally into 4 groups：group Zhaohai （ZH）,group Sh Sanyi-jiao（SYJ） and control group（C）. At first,all examinates began exhaustive step the opening of Zhaohai point according to Lingguibafa on elimination of majoring in sports enmai （SM）, group test precisely from ,then received acupuncture at Zhaohai and Lieque points for group ZH, Shenmai and Houxi points for group SM, and Sanyi-jiao and Hegu points for group SYJ. Needles were retained for 30 minutes. Examinat.es in group C received no acupuncture after exhaustive step test. 24 hours later,second exhaustive step test repeated again precisely from the opening of Shenmai point, and the acupuncture process was the same as the first test. BLA was measured before and 30 minutes after the step test. Results （1）BLAs after 30 minutes of the first step test were higher in groups ZH（P 〈 0.05） ,SM（P 〈 0.05） and C（P 〈 0.01） than that before the test（P 〈 0.05, P 〈 0.01 ）, except in group SYJ （P 〉 0.05 ）. （2）The B I_~s of groups ZH and SYJ were significantly lower than those before the second step test （P 〈 0.01 and P 〈 0.05 ,respectively） ,and BLAs of groups SM and C remained unchanged （P 〉 0.05）. There was significant difference in BLA between groups ZH and C after the second step test （P 〈 0.05）.（3）The BLAs of groups ZH,SM and C were significantly higher than that before the second step test（P 〈 0.01 ） ,except that of group SYJ（P 〉 0.05）. Conclusion Lingguibafa-based acupuncture can eliminate the accumulation of lactic acid after exhaustive exercise

一种基于并发冲突间隔时间的隐蔽信道检测方法

采用多级安全策略的信息系统中,事务的并发冲突会导致数据冲突隐蔽信道.现有的隐蔽信道检测方法存在以下问题:1)分析角度单一,入侵者可以通过分散记录的方式逃避检测;2)使用单一的检测指标,存在一定的误判和漏判.提出了一种基于冲突间隔时间的隐蔽信道检测方法CTIBDA.该方法解决了以上问题:1)从主体和客体2种角度对冲突记录进行划分,以防止入侵者通过分散冲突记录的方式逃避检测;2)使用冲突间隔时间分布和冲突间隔时间序列2种规律性特征指标作为检测依据.实验结果证实,该方法能够降低检测结果的误报率和漏报率,提高准确率.同时该方法结构简单适合在线实施,对于其他的并发冲突隐蔽信道场景具有普遍的适用性.Concurrency conflicts may bring data conflict covert channel in multi-level secure systems. The existing covert channel detection methods have the following flaws: 1) Analyzing conflict records with single point, so the invaders can evade to be detected; 2) Using single indicator will bring false positive and false negative. We present a detection method based on conflict interval time called CTIBDA in this paper. This method solves the above problems: 1) Analyzing the conflict records with subject and object can prevent intruders from dispersing; 2) Using both the distribution and the sequence of intervals between transactions conflicts as indicators. The experimental results show that this approach can reduce the false positive and false negative and increase the accuracy. CTIBDA is suitable for online implementation and can be universally applied to concurrency conflict covert channels in other scenarios

HPLC法测定玉米浆中游离氨基酸的含量

建立测定玉米浆中游离氨基酸的反相高效液相色谱法。Diamonsil C18(2)反相柱(5μm,250mm×4.6mm);梯度洗脱,流动相A相:0.05mol/L醋酸钠缓冲溶液(pH6.50),B相:乙腈-水(v/v=1∶1),流速1.0mL/min,检测波长360nm。在该条件下所得各氨基酸的线性回归方程相关系数均在0.999以上。测定17种氨基酸的加样回收率94%~105%,相对标准偏差小于2.0%

covert channel research

隐蔽信道是指允许进程以危害系统安全策略的方式传输信息的通信信道,是对安全信息系统的重要威胁,并普遍存在于安全操作系统、安全网络、安全数据库系统中.国内外的安全标准都要求对高等级的安全信息系统进行隐蔽信道分析.首先分析隐蔽信道的基本概念,研究领域、技术组成及分类,然后从信道识别、度量、消除、限制、审计和检测几个技术层面综述隐蔽信道研究中经典的技术和方法,系统地总结隐蔽信道领域30多年来的研究成果,尤其对近年来隐蔽信道度量和处置新技术作了较为详尽的介绍.试图为该研究方向勾画出一个较为全面和清晰的概貌,为隐蔽信道分析领域的研究者提供有益的参考

地理过程的案例表达与组织——以南海区海洋涡旋为例

案例模型是基于案例推理方法(CBR)的推理基础,而时空数据模型是地理信息系统时空表达的概念基础。基于案例的推理方法应用于地理领域,案例表达则不能仅采取传统的表示方法,需要结合地理问题的特点;但时态地理信息系统(T-GIS)的时空数据模型又不能直接采用,需要考虑地理案例表达和推理的需求。通过对地理案例应用的分析和时空过程特点的总结,提出分级描述框架的地理案例时空过程概念表达模型,并构建其物理表达模型。本文以中国南海海洋涡旋为例进行了验证,表明此模型可应用于具有完整生命周期且变化是连续渐进地理现象的研究

Preliminary Study on Allelopathy of Pinus thunbergii

以大白菜作为受体;研究了黑松根、叶、枝条、树皮以及林下凋落物和表土浸提液对大白菜种子萌发及幼苗生长的化感作用。结果表明:各浸提液均可显著降低大白菜种子的发芽率、胚根长度及生物量;对平均发芽速率及胚轴长度则无显著影响;叶浸提液和凋落物浸提液在浓度为0.1 g/ml时可显著降低其发芽势;随浓度降低;影响则不显著;其余各浸提液则对发芽势无显著影响;在实验室条件下;叶浸提液对发芽率的影响最大;树皮浸提液对胚根生长抑制作用最强;而根浸提液在最终的生物量上抑制效果最为显著