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长江工程性采砂监测与方量检测技术研究与探讨 被引量:1
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作者 王冬梅 赵钢 +1 位作者 吴杰 黄俊友 《水利水电技术》 CSCD 北大核心 2009年第7期129-131,共3页
近年来长江工程性采砂不断增加,如何科学地进行采砂区的监测和方量的检测也成为日益突出的问题。根据近年来实际监测经验,对各种仪器设备和检测手段进行探讨分析,并对各种技术的特点和适用性进行研究。针对长江工程性采砂实际情况,对今... 近年来长江工程性采砂不断增加,如何科学地进行采砂区的监测和方量的检测也成为日益突出的问题。根据近年来实际监测经验,对各种仪器设备和检测手段进行探讨分析,并对各种技术的特点和适用性进行研究。针对长江工程性采砂实际情况,对今后的采砂监测和研究工作提供经验和参考,并提出了一些可行的建议。 展开更多
关键词 长江 工程性采砂 采砂区监测 方量检测
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基于改进YOLOv8的轻量化小麦病害检测方法 被引量:14
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作者 马超伟 张浩 +3 位作者 马新明 王键霖 张永爽 张小艾 《农业工程学报》 EI CAS CSCD 北大核心 2024年第5期187-195,共9页
为提高小麦病害检测精度,实现将模型方便快速部署到移动端,该研究提出了一种基于改进YOLOv8的轻量化小麦病害检测方法。首先,使用PP-LCNet模型替换YOLOv8网络结构的骨干网络,并在骨干网络层引入深度可分离卷积(depthwise separable conv... 为提高小麦病害检测精度,实现将模型方便快速部署到移动端,该研究提出了一种基于改进YOLOv8的轻量化小麦病害检测方法。首先,使用PP-LCNet模型替换YOLOv8网络结构的骨干网络,并在骨干网络层引入深度可分离卷积(depthwise separable convolution, DepthSepConv)结构,减少模型参数量,提升模型检测性能;其次,在颈部网络部分添加全局注意力机制(global attention mechanism, GAM)模块,强化特征中语义信息和位置信息,提高模型特征融合能力;然后,引入轻量级通用上采样内容感知重组(content-aware reassembly of features,CARAFE)模块,提高模型对重要特征的提取能力;最后,使用Wise-IoU(weighted interpolation of sequential evidence for intersection over union)边界损失函数代替原损失函数,提升网络边界框回归性能和对小目标病害的检测效果。试验结果表明,对于大田环境下所采集的小麦病害数据集,改进后模型的参数量及模型大小相比原YOLOv8n基线模型分别降低了12.5%和11.3%,同时精确度(precision)及平均精度均值(mean average precision,m AP)相较于原模型分别提高了4.5和1.9个百分点,优于其他对比目标检测算法,可为小麦病害检测无人机等移动端检测装备的部署和应用提供参考。 展开更多
关键词 图像识别 深度学习 目标检测 轻量化 小麦病害 YOLOv8 PP-LCNet
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A Method for Detecting Adhesive Related-Factors of Streptococcus suis Serotype 2 by Real-time PCR 被引量:1
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作者 汪伟 何孔旺 +9 位作者 倪艳秀 周俊明 张雪寒 俞正玉 吕立新 茅爱华 温立斌 王小敏 李彬 郭容莉 《Agricultural Science & Technology》 CAS 2013年第10期1378-1382,共5页
[Objective] This study aimed to establish a method for quantitative detection of mRNA transcriptional level of SS2 adhesive related-factors of Streptococcus suis serotype 2 (SS2) by fluorescent quantitative PCR. []V... [Objective] This study aimed to establish a method for quantitative detection of mRNA transcriptional level of SS2 adhesive related-factors of Streptococcus suis serotype 2 (SS2) by fluorescent quantitative PCR. []Vlethod] The gene fragments en- coding SS2 adhesive related-factors MRP, FBPS and CPS2J and a housekeeping gene aroA were amplified by reverse transcription PCR from the total RNA of SS2, cloned, and sequenced. The recombinant plasmids containing the target genes were constructed, and used as templates in Real-time PCR. [Result] Dynamic curves, stan- dard curves and melting curves of the adhesive related-factors and aroA were ob- tained by the optimized Real-time PCR system. The standard curves showed a good linear relationship between template copy number and circulation number, and the correlation coefficients (FF) of the standard curves were over 0.995. Also, these as- says were highly specific a^d there was single specific melting peak for every gene. Moreover, the assays were highly sensitive and had a detection limit of 1.0×102 copies in 1 μl of initial templates. Finally, it was highly repeatable and had a coeffi- cient of variation less than 2% for intra-assay. [Conclusion] This study will provide a way to reveal the adhesion mechanism of SS2 to different host cells at molecular level. 展开更多
关键词 Streptococcus suis serotype 2 Adhesive related-factors (adhesins) Real- time PCR
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Improved metrics for evaluating fault detection efficiency of test suite
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作者 王子元 陈林 +1 位作者 汪鹏 仉雪玲 《Journal of Southeast University(English Edition)》 EI CAS 2014年第3期285-288,共4页
By analyzing the average percent of faults detected (APFD) metric and its variant versions, which are widely utilized as metrics to evaluate the fault detection efficiency of the test suite, this paper points out so... By analyzing the average percent of faults detected (APFD) metric and its variant versions, which are widely utilized as metrics to evaluate the fault detection efficiency of the test suite, this paper points out some limitations of the APFD series metrics. These limitations include APFD series metrics having inaccurate physical explanations and being unable to precisely describe the process of fault detection. To avoid the limitations of existing metrics, this paper proposes two improved metrics for evaluating fault detection efficiency of a test suite, including relative-APFD and relative-APFDc. The proposed metrics refer to both the speed of fault detection and the constraint of the testing source. The case study shows that the two proposed metrics can provide much more precise descriptions of the fault detection process and the fault detection efficiency of the test suite. 展开更多
关键词 software testing test case prioritization fault detection efficiency METRIC
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信息化系统在大柳塔露天开采区的应用
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作者 白瑞强 《陕西煤炭》 2016年第S1期83-86,109,共5页
根据大柳塔三盘区露天开采区对信息化系统的需求,介绍了煤炭露天开采信息化系统的组网结构、硬件组成、系统平台和软件开发,并对存在问题提出了改进建议,为煤炭露天开采信息化系统的应用及推广积累了经验。
关键词 信息化系统 露天开采 GPS车辆管理 视频监控 方量检测
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Effects of Na^+/K^+ Ratio of Groundwaters on the Gill Ion-Transport Enzyme Activity,Plasma Osmolality and Growth of Cynoglossus semilaevis Juveniles 被引量:2
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作者 YANG Huizan PAN Luqing HU Fawen LIU Hongyu 《Journal of Ocean University of China》 SCIE CAS 2008年第4期447-452,共6页
The effects of environmental Na+/K+ ratio on the gill ion-transport enzyme activity,plasma osmolality and growth of Cynoglossus semilaevis juveniles were investigated. The results showed that,plasma osmolality was sim... The effects of environmental Na+/K+ ratio on the gill ion-transport enzyme activity,plasma osmolality and growth of Cynoglossus semilaevis juveniles were investigated. The results showed that,plasma osmolality was similar among flounder adapted to different Na+/K+ ratios of saline groundwaters (P>0.05),while the growth,gill Na+,K+-ATPase and HCO3--ATPase activities were affected by Na+/K+ ratio significantly (P<0.05). The gill Na+,K+-ATPase activity reached its maximum on day 3,then decreased gradually from day 3 to day 9 and remained constant from day 9 to day 15. The peak values of gill Na+,K+-ATPase activity were detected on day 3 for all Na+/K+ ratios of saline groundwaters,then the enzyme activities descended,and on day 9 the enzyme activi-ties achieved steady state,and the gill HCO3--ATPase activity increased rapidly and achieved steady state after one day. During steady state,the gill Na+,K+-ATPase and HCO3--ATPase activity of Na+/K+ ratios 20 and 40 treatments were significantly higher than those in the control group (Na+/K+ ratio 27.5),while there were no significant differences between the Na+/K+ ratio 30 treatment and the control group; the gill Na+,K+-ATPase activity of Na+/K+ ratio 20 and 40 treatments were significantly higher than that for ratio 30 treatment,but there were no significant differences of gill HCO3--ATPase activity among these treatments. At the end of the 15-day experiment,the weight gain (%) and specific growth rate (SGR) of flounders maintained in seawater were significantly higher than those in groundwaters; significant differences also occurred among the treatments; Na+/K+ ratio 30 treatment had the highest values (33.7% and 1.94 respectively),which were significantly higher than those under Na+/K+ ratios 20 and 40 treatments. There-fore,for the saline groundwater used in this experiment,it is suggested that the Na+/K+ ratio be adjusted to approximately 30,i.e.,as close to that of natural seawater as possible in the culture of flounder. 展开更多
关键词 Na^-/K^- ratio Cynoglossus semilaevi ion-transport enzyme activity plasma osmolality growth
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Novel fiber-optical interferometer with miniaturized probe for in-hole measurements 被引量:3
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作者 Robert Schmitt Tilo Pfeifer +1 位作者 Frank Depiereux Niels Knig 《Optoelectronics Letters》 EI 2008年第2期140-142,共3页
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to en... Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible. 展开更多
关键词 纤维 光干扰术 检测技术 测量方法
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Microwave digestion polarography for determining seven trace elements in Salvia Miltiorrhiza Root and compound Salvia Miltiorrhiza Root injection simultaneously 被引量:1
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作者 黄熠 张泰铭 +1 位作者 曹娟 梁逸曾 《Journal of Central South University of Technology》 EI 2007年第4期514-519,共6页
The sensitive second derivative waves of Cu(Ⅱ),Pb(Ⅱ),Cd(Ⅱ),Ni(Ⅱ),Zn(Ⅱ),Fe(Ⅱ)and Mn(Ⅱ),forming in the substrate solution(pH=9.26)consisting of ammonia,ammonium chlorid,gelatin and ascorbic acid were researched.T... The sensitive second derivative waves of Cu(Ⅱ),Pb(Ⅱ),Cd(Ⅱ),Ni(Ⅱ),Zn(Ⅱ),Fe(Ⅱ)and Mn(Ⅱ),forming in the substrate solution(pH=9.26)consisting of ammonia,ammonium chlorid,gelatin and ascorbic acid were researched.The peak potentials of the polarographic waves of the seven ions are at about 0.48,0.63,0.79,1.04,1.28,1.44 and 1.60 V respectively.Combining with microwave technique,a new method for the simultaneous determination of the seven trace elements in Chinese traditional medicine was developed.The method is easy to operate,rapid,simple and convenient.When the signal-to-noise rate equals 3,the detection limits of Cu,Pb,Cd,Ni,Zn,Fe and Mn are 4.2×10 3,5.3×10 3,2.1×10 3,5.8×10 4,3.0×10 3,7.7×10 4 and 1.1×10 3 μg/mL respectively.Well linear relationships exist between the concentrations and the peak currents when Cu,Pb,Cd,Ni,Zn,Fe and Mn concentrations are within 8.5×10 3 10,9.7×10 3 10,4.5×10 3 10,1.2×10 3 10,6.4×10 3 10,1.5×10 3 10 and 2.8×10 3 10 μg/mL,respectively.The method has been used to the simultaneous determination of the seven trace elements in Salvia Miltiorrhiza Root and compound Salvia Miltiorrhiza Root injection,the relative standard deviations(RSDs)of the Cu,Pb,Cd,Ni,Zn,Fe and Mn in the two medicines are 3.9% and 5.8%,4.0% and 4.1%,4.3% and 5.7%,4.9% and 5.3%,4.4% and 4.7%,3.5% and 4.0%,0.51% and 2.8%,respectively;the comparisons of the determination results with the values obtained by the standard method indicate that the presented method has very well veracity. 展开更多
关键词 derivative polarographic wave microelement Salvia Miltiorrhiza Root compound Salvia Miltiorrhiza Root injection
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Detecting Encrypted Botnet Traffic Using Spatial-Temporal Correlation 被引量:3
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作者 Chen Wei Yu Le Yang Geng 《China Communications》 SCIE CSCD 2012年第10期49-59,共11页
In this paper, we to detect encrypted botnet propose a novel method traffic. During the traffic preprocessing stage, the proposed payload extraction method can identify a large amount of encrypted applications traffic... In this paper, we to detect encrypted botnet propose a novel method traffic. During the traffic preprocessing stage, the proposed payload extraction method can identify a large amount of encrypted applications traffic. It can filter out a large amount of non-malicious traffic, greatly in, roving the detection efficiency. A Sequential Probability Ratio Test (SPRT)-based method can find spatialtemporal correlations in suspicious botnet traffic and make an accurate judgment. Experimental resuks show that the false positive and false nega- tive rates can be controlled within a certain range. 展开更多
关键词 BOTNET encrypted traffic spatial-tenmporal correlation
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Edge detection using directional eigenvalues of potential field gradient tensor data 被引量:2
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作者 ZHOU Shuai HUANG Danian 《Global Geology》 2015年第3期188-195,共8页
Edge detection of potential field interpretation is an important task. The traditional edge detection methods have poor ability in outlining weak amplitude anomalies clearly. The resolved edges position is blurred.We ... Edge detection of potential field interpretation is an important task. The traditional edge detection methods have poor ability in outlining weak amplitude anomalies clearly. The resolved edges position is blurred.We purposed new edge detection methods based on directional eigenvalues of potential field gradient tensor for the causative sources. In order to balance strong and weak amplitude anomalies simultaneously,we present one normalization method using different orders of vertical derivatives to improve the new filters. The presented filters were tested on synthetic and real potential field data to verify its feasibility. All of the results have shown that the new edge detection methods can not only display the sources edges precisely and clearly,but also bring out more geological subtle details. 展开更多
关键词 directional eigenvalues edge detection potential field
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3D Surface Morphology Measurement and Auto-focusing System
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作者 CHEN Qi ZANG Huai-pei 《Semiconductor Photonics and Technology》 CAS 2005年第3期208-211,共4页
When interference microscope measures the surface rough of the micromechanical device, as soon as the work distance of interference microscope and the depth of field is shortened, the interference images become slur f... When interference microscope measures the surface rough of the micromechanical device, as soon as the work distance of interference microscope and the depth of field is shortened, the interference images become slur for the measured object if there has small interference after clear focus. The auto-focusing system is introduced into the interference microscope, the system can obtain high definition interference image rapidly,and can improve the measuring velocity and measuring precision. The system is characterized by auto-focusing range of ±150 μm, auto-focusing precision of ±0.3 μm, auto-focusing time of 4~8 s. 展开更多
关键词 3D surface morphology Interference microscope AUTO-FOCUSING
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PPP: Towards Parallel Protocol Parsing 被引量:1
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作者 SHAO Yiyang 《China Communications》 SCIE CSCD 2014年第10期106-116,共11页
Network traffic classification plays an important role and benefits many practical network issues,such as Next-Generation Firewalls(NGFW),Quality of Service(QoS),etc.To face the challenges brought by modern high speed... Network traffic classification plays an important role and benefits many practical network issues,such as Next-Generation Firewalls(NGFW),Quality of Service(QoS),etc.To face the challenges brought by modern high speed networks,many inspiring solutions have been proposed to enhance traffic classification.However,taking many factual network conditions into consideration,e.g.,diversity of network environment,traffic classification methods based on Deep Inspection(DI) technique still occupy the top spot in actual usage.In this paper,we propose a novel classification system employing Deep Inspection technique,aiming to achieve Parallel Protocol Parsing(PPP).We start with an analytical study of the existing popular DI methods,namely,regular expression based methods and protocol parsing based methods.Motivated by their relative merits,we extend traditional protocol parsers to achieve parallel matching,which is the representative merit of regular expression.We build a prototype system,and evaluation results show that significant improvement has been made comparing to existing open-source solutions in terms of both memory usage and throughput. 展开更多
关键词 trafficinspection regularparsingclassification deepexpression PROTOCOL
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Quantitative Surface Chirality Detection with Sum Frequency Generation Vibrational Spectroscopy: Twin Polarization Angle Approach
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作者 Feng Wei Yan-yan Xu +2 位作者 Yuan Guo Shi-lin Liu Hong-fei Wang 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2009年第6期592-600,J0001,共10页
Here we report a novel twin polarization angle (TPA) approach in the quantitative chirality detection with the surface sum-frequency generation vibrational spectroscopy (SFG-VS). Generally, the achiral contributio... Here we report a novel twin polarization angle (TPA) approach in the quantitative chirality detection with the surface sum-frequency generation vibrational spectroscopy (SFG-VS). Generally, the achiral contribution dominates the surface SFG-VS signal, and the pure chiral signal is usually two or three orders of magnitude smaller. Therefore, it has been difficult to make quantitative detection and analysis of the chiral contributions to the surface SFG- VS signal. In the TPA method, by varying together the polarization angles of the incoming visible light and the sum frequency signal at fixed s or p polarization of the incoming infrared beam, the polarization dependent SFG signal can give not only direct signature of the chiral contribution in the total SFG-VS signal, but also the accurate measurement of the chiral and achiral components in the surface SFG signal. The general description of the TPA method is presented and the experiment test of the TPA approach is also presented for the SFG-VS from the S- and R-limonene chiral liquid surfaces. The most accurate degree of chiral excess values thus obtained for the 2878 cm^-1 spectral peak of the S- and R-limonene liquid surfaces are (23.7±0.4)% and (-25.4±1.3)%, respectively. 展开更多
关键词 Sum-frequency generation vibrational spectroscopy Twin polarization angle approach SURFACE CHIRALITY LIMONENE
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Detection Methods for MEMS-Based Xylophone Bar Magnetometer for Pico Satellites
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作者 Sylvain Ranvier Veronique Rochus +3 位作者 Sylvain Druart Herve Lamy Pierre Rochus Laurent A. Francis 《Journal of Mechanics Engineering and Automation》 2011年第5期342-350,共9页
Initially studied and developed by students in universities, the very small pico satellites (with a mass lower than 1 kg) are more and more considered for science applications. In particular, there are plans to use ... Initially studied and developed by students in universities, the very small pico satellites (with a mass lower than 1 kg) are more and more considered for science applications. In particular, there are plans to use them in constellations of small spacecraft for remote sensing of various regions of the magnetosphere. They require a payload with specific size, weight and power consumption. In order to respond to this demand, new instruments have to be developed. Those instruments should exhibit at least the same performances as those used in larger satellites while fulfilling the specific requirements imposed by the satellites size. For this reason, the authors currently develop a xylophone bar magnetometer (XBM) based on micro-electromechanical systems (MEMS) with integrated detector electronics. The principle of this magnetometer is based on a classical resonating xylophone bar. A sinnsoidal current oscillating at the fundamental bending resonant frequency of the bar is applied through the device, and when an external magnetic field is present, the resulting Lorentz force yields the bar to vibrate at its fundamental mode with a displacement directly proportional to the amplitude in one direction of the ambient magnetic field. When designing a MEMS XBM, the detection method is a crucial aspect. The measurement method largely influences the geometry of the magnetometer as well as the manufacturing technology. Due to the constraints in terms of size, weight and power consumption, the two most promising measurement methods are capacitive and piezoelectric ones. Several designs including these measurement techniques are presented and simulated under realistic conditions. First, designs including lateral electrodes for capacitive measurement are tackled based on Silicon-On-Insulator (SOI) process. For the piezoelectric detection, a new configuration based on Lead Zirconate Titanate (PZT)/Pt structure is introduced and leads to much better sensitivity than the traditional Pt/PZT/Pt sandwich structure. Finally, the principle of electronic circuits enabling high sensitivity and low power consumption are proposed. 展开更多
关键词 MAGNETOMETER MEMS (micro-electromechanical systems) pico satellites piezoelectric.
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THE MODEL TEST RESEARCH OF HORIZONTAL FORCE ON RIGID SHAFT FURNITURE IN DEEP MINE
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作者 刘志强 史天生 +1 位作者 郭晋蒲 王东权 《Journal of Coal Science & Engineering(China)》 1998年第1期15-19,共5页
The state of deep mine rigid shaft fUrniture horizontal force calculation in China is introduced and the calculating model of horizontal force is determined. Based on the interaction between hoisting vessel and shaft ... The state of deep mine rigid shaft fUrniture horizontal force calculation in China is introduced and the calculating model of horizontal force is determined. Based on the interaction between hoisting vessel and shaft furniture, the vertical mobel test device is built and a large number of model tests and analyses are carried out. At last, the relationship between horizontal force and hoisting end load, hoisting speed or bunton level interval is gained. The three parameters horizontal force calculating equation of beep mine rigid shaft furniture is given and it can guide the design and calculation of shaft engineering. 展开更多
关键词 rigid shaft furniture model test horizontal force calculating method
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Network Management of Food Additives Quality Analysis and Inspection 被引量:3
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作者 Hairui Zhang Guofu Zhang Li Zhang 《Journal of Chemistry and Chemical Engineering》 2015年第7期468-471,共4页
In this paper, on the basis of the implementation of the national chemical industry standard analytical test methods and analysis of test items, a food additive quality analysis and inspection of network management ap... In this paper, on the basis of the implementation of the national chemical industry standard analytical test methods and analysis of test items, a food additive quality analysis and inspection of network management applications are developed using the development technology of Visual Basic language and computer system operating environment, to achieve a network management software for users on food additives of quality analytical testing. The software sets up an information sharing network platform for enterprise and quality management departments, which is a major innovation in the food additive quality analysis on test management methods and tools. 展开更多
关键词 Food additives quality analysis Visual Basic language network management software development.
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An Integration Testing Framework and Evaluation Metric for Vulnerability Mining Methods
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作者 Jin Li Jinfu Chen +5 位作者 Minhuan Huang Minmin Zhou Wanggen Xie Zhifeng Zeng Shujie Chen Zufa Zhang 《China Communications》 SCIE CSCD 2018年第2期190-208,共19页
Software an important way to vulnerability mining is detect whether there are some loopholes existing in the software, and also is an important way to ensure the secu- rity of information systems. With the rapid devel... Software an important way to vulnerability mining is detect whether there are some loopholes existing in the software, and also is an important way to ensure the secu- rity of information systems. With the rapid development of information technology and software industry, most of the software has not been rigorously tested before being put in use, so that the hidden vulnerabilities in software will be exploited by the attackers. Therefore, it is of great significance for us to actively de- tect the software vulnerabilities in the security maintenance of information systems. In this paper, we firstly studied some of the common- ly used vulnerability detection methods and detection tools, and analyzed the advantages and disadvantages of each method in different scenarios. Secondly, we designed a set of eval- uation criteria for different mining methods in the loopholes evaluation. Thirdly, we also proposed and designed an integration testing framework, on which we can test the typical static analysis methods and dynamic mining methods as well as make the comparison, so that we can obtain an intuitive comparative analysis for the experimental results. Final- ly, we reported the experimental analysis to verify the feasibility and effectiveness of the proposed evaluation method and the testingframework, with the results showing that the final test results will serve as a form of guid- ance to aid the selection of the most appropri- ate and effective method or tools in vulnera- bility detection activity. 展开更多
关键词 software vulnerability detection LOOPHOLES information security evaluationmethod testing framework
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A novel orientation measurement using optical sensor for spherical motor 被引量:10
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作者 XIN JianGuo XIA ChangLiang +1 位作者 LI HongFeng SHI TingNa 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第6期1330-1339,共10页
The measurement of spherical rotor orientation is crucial to the close-loop control of spherical motors. This paper presents a novel method for the measuring of three-degree-of-freedom (DOF) rotor orientation of spher... The measurement of spherical rotor orientation is crucial to the close-loop control of spherical motors. This paper presents a novel method for the measuring of three-degree-of-freedom (DOF) rotor orientation of spherical motors using optical sensors. The spatial orientation of spherical rotor is output in the form of ZXZ Euler angles. Firstly, the structure of the measuring system composed of optical sensors and the patterns on the rotor surface are presented, and the operational principle of recognizing intersection points between the optical ring detectors and the latitude/longitude on the rotor surface is illustrated. The analytical model of input-output characteristic is established for the measuring system of three-DOF rotor orientation. Afterwards, the effect of parameters of the optical ring detectors on the linearity, sensitivity, resolving power and measuring range of the measuring system is analyzed using the analytical model. Finally, the feasibility of the measurement is validated through experiments of prototype measuring system. The analysis is expected to be a basis for the design parameter optimization of the orientation measuring system of a PM spherical motor. 展开更多
关键词 Euler angles optical sensor orientation measurement spherical motor three-DOF
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Analysis of XCO_2 retrieval sensitivity using simulated Chinese Carbon Satellite(TanSat) measurements 被引量:5
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作者 CAI ZhaoNan LIU Yi YANG DongXu 《Science China Earth Sciences》 SCIE EI CAS 2014年第8期1919-1928,共10页
We present a study on the retrieval sensitivity of the column-averaged dry-air mole fraction of CO2(XCO2) for the Chinese carbon dioxide observation satellite(TanSat) with a full physical forward model and the optimal... We present a study on the retrieval sensitivity of the column-averaged dry-air mole fraction of CO2(XCO2) for the Chinese carbon dioxide observation satellite(TanSat) with a full physical forward model and the optimal estimation technique. The forward model is based on the vector linearized discrete ordinate radiative transfer model(VLIDORT) and considers surface reflectance, gas absorption, and the scattering of air molecules, aerosol particles, and cloud particles. XCO2 retrieval errors from synthetic TanSat measurements show solar zenith angle(SZA), albedo dependence with values varying from 0.3 to 1 ppm for bright land surface in nadir mode and 2 to 8 ppm for dark surfaces like snow. The use of glint mode over dark oceans significantly improves the CO2 information retrieved. The aerosol type and profile are more important than the aerosol optical depth, and underestimation of aerosol plume height will introduce a bias of 1.5 ppm in XCO2. The systematic errors due to radiometric calibration are also estimated using a forward model simulation approach. 展开更多
关键词 TanSat retrieval sensitivity retrieval error simulation XCO2
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Study of mode transformation and energy attenuation of wedge waves with different apex angles by laser ultrasonic techniques 被引量:1
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作者 JIA Jing WANG LiJuan +2 位作者 SHEN ZhongHua YUAN Ling NI XiaoWu 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2012年第4期593-598,共6页
This research focuses on measuring the mode transformation and energy attenuation of wedge waves for different apex angle wedges by using laser ultrasound techniques.Pulsed laser excitation and optical deflection beam... This research focuses on measuring the mode transformation and energy attenuation of wedge waves for different apex angle wedges by using laser ultrasound techniques.Pulsed laser excitation and optical deflection beam methods for detection were used to measure the wedge waves.In experiment,various wedge waves at different locations were recorded by scanning the excitation laser along the wedge tip,and different orders of wedge waves were observed.By fixing the distance between the excitation and detection positions and scanning the samples along the direction normal to the wedge tip,the modes transformation process was obtained.It was found that the energy of the acoustic waves for 20°,25° and 30° wedges decreased exponentially to a steady energy of Rayleigh wave within the main wavelength range of the acoustic modes,while the energy of acoustic waves of 45° and 60° wedge remained stable as the propagation line was scanned away from the wedge tip. 展开更多
关键词 wedge waves laser ultrasonic mode transformation energy attenuation
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