期刊文献+
共找到4,949篇文章
< 1 2 248 >
每页显示 20 50 100
Phosphatidylserine:An overview on functionality,processing techniques,patents,and prospects
1
作者 Jingnan Chen Jun Li +4 位作者 Haoyu Xu Jiaxi Li Yonghong Yuan Xuebing Xu Yanlan Bi 《Grain & Oil Science and Technology》 CAS 2023年第4期206-218,共13页
Phosphatidylserine(PS)is the part of cell structure in the body and has many beneficial functions especially in brain-related aging diseases.Although daily foods can provide PS to human body,the amount is very limited... Phosphatidylserine(PS)is the part of cell structure in the body and has many beneficial functions especially in brain-related aging diseases.Although daily foods can provide PS to human body,the amount is very limited due to its poverty in most foods.To overcome the issue,numerous studies based on PS have been reported to develop PS-related supplements.In this review,PS was comprehensively and critically reviewed from the view of resources,functions,processing techniques,patents,and prospects.For resources,animal,plant,and microorganism origins were all covered with their differences in composition profiles.For functions,benefits regarding memory,cognitive enhancement,exercise performance,reducing Alzheimer’s disease,and attention-deficit hyperactivity disorder symptoms were covered as well as the functional differences among animal-,plant-,and microorganism-based PS-related supplements.For processing techniques,traditional extracting methods from animal,plant,and microorganism tissues were comparatively discussed with enzymatic synthesis based on different reaction systems.Finally,patents of PS-related supplements were evaluated as well as their applications.This review could provide scientific and valuable support for PS industry. 展开更多
关键词 PHOSPHATIDYLSERINE FUNCTIONALITY processing techniques Patents evaluation PROSPECTS
下载PDF
Improving the Segmentation of Arabic Handwriting Using Ligature Detection Technique
2
作者 Husam Ahmad Al Hamad Mohammad Shehab 《Computers, Materials & Continua》 SCIE EI 2024年第5期2015-2034,共20页
Recognizing handwritten characters remains a critical and formidable challenge within the realm of computervision. Although considerable strides have been made in enhancing English handwritten character recognitionthr... Recognizing handwritten characters remains a critical and formidable challenge within the realm of computervision. Although considerable strides have been made in enhancing English handwritten character recognitionthrough various techniques, deciphering Arabic handwritten characters is particularly intricate. This complexityarises from the diverse array of writing styles among individuals, coupled with the various shapes that a singlecharacter can take when positioned differently within document images, rendering the task more perplexing. Inthis study, a novel segmentation method for Arabic handwritten scripts is suggested. This work aims to locatethe local minima of the vertical and diagonal word image densities to precisely identify the segmentation pointsbetween the cursive letters. The proposed method starts with pre-processing the word image without affectingits main features, then calculates the directions pixel density of the word image by scanning it vertically and fromangles 30° to 90° to count the pixel density fromall directions and address the problem of overlapping letters, whichis a commonly attitude in writing Arabic texts by many people. Local minima and thresholds are also determinedto identify the ideal segmentation area. The proposed technique is tested on samples obtained fromtwo datasets: Aself-curated image dataset and the IFN/ENIT dataset. The results demonstrate that the proposed method achievesa significant improvement in the proportions of cursive segmentation of 92.96% on our dataset, as well as 89.37%on the IFN/ENIT dataset. 展开更多
关键词 Arabic handwritten SEGMENTATION image processing ligature detection technique intelligent recognition
下载PDF
Machine Learning-based Identification of Contaminated Images in Light Curve Data Preprocessing
3
作者 Hui Li Rong-Wang Li +1 位作者 Peng Shu Yu-Qiang Li 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第4期287-295,共9页
Attitude is one of the crucial parameters for space objects and plays a vital role in collision prediction and debris removal.Analyzing light curves to determine attitude is the most commonly used method.In photometri... Attitude is one of the crucial parameters for space objects and plays a vital role in collision prediction and debris removal.Analyzing light curves to determine attitude is the most commonly used method.In photometric observations,outliers may exist in the obtained light curves due to various reasons.Therefore,preprocessing is required to remove these outliers to obtain high quality light curves.Through statistical analysis,the reasons leading to outliers can be categorized into two main types:first,the brightness of the object significantly increases due to the passage of a star nearby,referred to as“stellar contamination,”and second,the brightness markedly decreases due to cloudy cover,referred to as“cloudy contamination.”The traditional approach of manually inspecting images for contamination is time-consuming and labor-intensive.However,we propose the utilization of machine learning methods as a substitute.Convolutional Neural Networks and SVMs are employed to identify cases of stellar contamination and cloudy contamination,achieving F1 scores of 1.00 and 0.98 on a test set,respectively.We also explore other machine learning methods such as ResNet-18 and Light Gradient Boosting Machine,then conduct comparative analyses of the results. 展开更多
关键词 techniques:image processing methods:data analysis light pollution
下载PDF
Fresh Processing Technology in Polygonatum odoratum Production Area and Its Comparison with Traditional Processing
4
作者 Miao YANG Chufan PENG +4 位作者 Haixia LU Rufeng LIANG Hui TANG Zhongmei QIN Shengjiu GU 《Medicinal Plant》 2024年第1期38-40,44,共4页
[Objectives]To compare the effects of traditional processing and fresh processing on the quality of Polygonatum odoratum decoction piece.[Methods]The effects of fresh processing and traditional processing on the quali... [Objectives]To compare the effects of traditional processing and fresh processing on the quality of Polygonatum odoratum decoction piece.[Methods]The effects of fresh processing and traditional processing on the quality of P.odoratum decoction piece were compared and analyzed with appearance characteristics,total ash content,extract content,total polysaccharides content,and total flavonoids content as the evaluation indexes.[Results]Fresh processing method in different production areas has different effects on P.odoratum decoction piece.P.odoratum was dried in oven of 50℃.When moisture content was 41.44%-59.67%,it was cut.After complete drying at 50℃,the moisture content of dried P.odoratum was 8.94%-9.60%,and ethanol-soluble extract content was 77.29%-78.20%,and water-soluble extract was 77.7%-78.14%.At this time,the appearance characteristics of section of P.odoratum decoction piece were better than that of traditional processing,which was yellowish white.The total polysaccharide content was higher than that of traditional processing,and the content of total flavonoids was statistically significant different from that of traditional processing.[Conclusions]The quality of P.odoratum decoction piece by fresh processing is better than that of the traditional processing,and it is feasible to use fresh processing. 展开更多
关键词 processing technique Plygonatum odoratum Fresh processing Total polysaccharide Total flavonoids
下载PDF
The State-of-the-Art Review on Applications of Intrusive Sensing,Image Processing Techniques,and Machine Learning Methods in Pavement Monitoring and Analysis 被引量:11
5
作者 Yue Hou Qiuhan Li +5 位作者 Chen Zhang Guoyang Lu Zhoujing Ye Yihan Chen Linbing Wang Dandan Cao 《Engineering》 SCIE EI 2021年第6期845-856,共12页
In modern transportation,pavement is one of the most important civil infrastructures for the movement of vehicles and pedestrians.Pavement service quality and service life are of great importance for civil engineers a... In modern transportation,pavement is one of the most important civil infrastructures for the movement of vehicles and pedestrians.Pavement service quality and service life are of great importance for civil engineers as they directly affect the regular service for the users.Therefore,monitoring the health status of pavement before irreversible damage occurs is essential for timely maintenance,which in turn ensures public transportation safety.Many pavement damages can be detected and analyzed by monitoring the structure dynamic responses and evaluating road surface conditions.Advanced technologies can be employed for the collection and analysis of such data,including various intrusive sensing techniques,image processing techniques,and machine learning methods.This review summarizes the state-ofthe-art of these three technologies in pavement engineering in recent years and suggests possible developments for future pavement monitoring and analysis based on these approaches. 展开更多
关键词 Pavement monitoring and analysis The state-of-the-art review Intrusive sensing Image processing techniques Machine learning methods
下载PDF
Processing Technique of Carbonizing by Stir-Frying for Baked Rheum tanguticum Maxim.ex Balf. Optimized by Orthogonal Design
6
作者 Shihe LIN YANDong YI +2 位作者 Chuanqi HUANG Quanwei YANG Nancai YU 《Medicinal Plant》 CAS 2019年第5期50-52,共3页
[Objectives]To optimize the processing technology of baked Rheum tanguticum carbon.[Methods]Firstly,the baking temperature and baking time were investigated by single factor,and the content of 5-hydroxymethylfurfural(... [Objectives]To optimize the processing technology of baked Rheum tanguticum carbon.[Methods]Firstly,the baking temperature and baking time were investigated by single factor,and the content of 5-hydroxymethylfurfural(5-HMF)was determined by HPLC.The main influencing factors of baking effect were baking temperature,baking time and tablet specifications.The L 9(34)orthogonal design experiment was carried out to optimize the processing technique of R.tanguticum carbon.[Results]The optimum processing technique was as follows:small-sized tablets,controlled oven baking temperature at(210±2)℃,and baking time of 20 min.[Conclusions]The optimum processing technique of R.tanguticum carbon is reasonable and feasible.Thus,this experiment can provide a certain reference for processing method and quality control of R.tanguticum carbon. 展开更多
关键词 RHEUM tanguticum carbon Carbonizing by Stir-Frying BAKING method processing technique
下载PDF
Effect of Different Processing Techniques on the Content of Total Alkaloids in Toddalia asiatica Lam.
7
作者 Long CHEN Miao ZHANG +2 位作者 Daogen LAO Jiaying TANG Qiuyan HUANG 《Agricultural Biotechnology》 CAS 2019年第4期165-168,共4页
[Objectives]Effects of different processing techniques on the total alkaloid content in Toddalia asiatica Lam.were investigated by ultraviolet spectrophotometry.[Methods]T.asiatica was processed by the water washing m... [Objectives]Effects of different processing techniques on the total alkaloid content in Toddalia asiatica Lam.were investigated by ultraviolet spectrophotometry.[Methods]T.asiatica was processed by the water washing method,water boiling method,water steaming method,wine steaming method and wine processing method,and the total alkaloid content was determined by ultraviolet spectrophotometry.[Results]Different processing methods can affect the total alkaloid content in the medicinal materials.Among them,the water steaming method and the wine processing method can increase the total alkaloid content of the medicinal materials,and the degree of improvement was higher in the water steaming method;and the water boiling method,water washing method and wine steaming method can reduce the total alkaloid content of the materials,and showed a reduction order of water boiling method>water washing method>wine steaming method.[Conclusions]The water steaming method and the wine processing method can increase the total alkaloid content in T.asiatica,and the water boiling method,water washing method and wine steaming method can reduce the total alkaloid content of the medicinal material. 展开更多
关键词 Toddalia asiatica Lam. processing technique TOTAL ALKALOIDS ULTRAVIOLET SPECTROPHOTOMETRY
下载PDF
FUNDAMENTAL COMMUNICATIONS THEORIES AND SIGNAL PROCESSING TECHNIQUES FOR AMORPHOUS CELLULAR SYSTEMS
8
作者 Shi Jin Feifei Gao +2 位作者 Kai Luo Yongming Huang Wei Peng 《China Communications》 SCIE CSCD 2016年第12期I0002-I0003,共2页
The rapid developing of the fourth generation(4G)wireless communications has aroused tremendous demands for high speed data transmission due to the dissemination of various types of the intelligent user terminals as w... The rapid developing of the fourth generation(4G)wireless communications has aroused tremendous demands for high speed data transmission due to the dissemination of various types of the intelligent user terminals as well as the wireless multi-media services.It is predicted that the network throughput will increase 展开更多
关键词 IEEE FBMC FUNDAMENTAL COMMUNICATIONS THEORIES AND SIGNAL processing techniqueS FOR AMORPHOUS CELLULAR SYSTEMS MIMO FIR
下载PDF
PROCESSINGTECHNIQUESANDCHARACTERIZATIONOFCERAMICFIBERREINFORCEDALUMINIUMCOMPOSITES
9
作者 Won Jong Choi Lu Ho Choi Department of Materials Engineering,Hankuk Aviation UniversityKoyang,Kyunggi do,Korea 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1996年第1期9-14,共6页
论述了铝基复合材料的制造过程,着重用于涂覆、粉未冶金法与液压金属浸润法制造的材料。用扫描电镜观察材料截面,并用弯曲试验与微硬度试验测试材料的力学性能。结果表明,用液态金属浸润制造的材料性能较好。其原因是由于空隙与纤维... 论述了铝基复合材料的制造过程,着重用于涂覆、粉未冶金法与液压金属浸润法制造的材料。用扫描电镜观察材料截面,并用弯曲试验与微硬度试验测试材料的力学性能。结果表明,用液态金属浸润制造的材料性能较好。其原因是由于空隙与纤维束的减少,纤维与基体结合较好。三点弯曲试验表明,随着增强物的增加,弹性模量也增加。此外,还进行了一系列的微硬度试验。 展开更多
关键词 复合材料 金属基复合材料 加固金属复合材料 处理技术
下载PDF
CONTROL TECHNIQUES FOR DIGESTION IN BAYER PROCESS 被引量:4
10
作者 G.Y.Gan L.Z.Wang 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2000年第6期1174-1178,共5页
The control techniques for indirect heating digestion in Bayer process of alumina production were researched and developed. They include controlling chemical composition of slurry to be digested and controlling diges... The control techniques for indirect heating digestion in Bayer process of alumina production were researched and developed. They include controlling chemical composition of slurry to be digested and controlling digestion status and energy consumption. Very good performances and technical and technical and economical figures for digestion process have been obtained by carefully applying these comprehensive control techniques in Pingguo alumina refinery. 展开更多
关键词 control technique DIGESTION Bayer process
下载PDF
Big Data Testing Techniques:Taxonomy,Challenges and Future Trends
11
作者 Iram Arshad Saeed Hamood Alsamhi Wasif Afzal 《Computers, Materials & Continua》 SCIE EI 2023年第2期2739-2770,共32页
Big Data is reforming many industrial domains by providing decision support through analyzing large data volumes.Big Data testing aims to ensure that Big Data systems run smoothly and error-free while maintaining the ... Big Data is reforming many industrial domains by providing decision support through analyzing large data volumes.Big Data testing aims to ensure that Big Data systems run smoothly and error-free while maintaining the performance and quality of data.However,because of the diversity and complexity of data,testing Big Data is challenging.Though numerous research efforts deal with Big Data testing,a comprehensive review to address testing techniques and challenges of BigData is not available as yet.Therefore,we have systematically reviewed the Big Data testing techniques’evidence occurring in the period 2010–2021.This paper discusses testing data processing by highlighting the techniques used in every processing phase.Furthermore,we discuss the challenges and future directions.Our findings show that diverse functional,non-functional and combined(functional and non-functional)testing techniques have been used to solve specific problems related to Big Data.At the same time,most of the testing challenges have been faced during the MapReduce validation phase.In addition,the combinatorial testing technique is one of the most applied techniques in combination with other techniques(i.e.,random testing,mutation testing,input space partitioning and equivalence testing)to find various functional faults through Big Data testing. 展开更多
关键词 Big data testing techniques testing process
下载PDF
Three-Dimensional Rigid-Plastic FEM Simulation of Bulk Forming Processes with New Contact and Remeshing Techniques 被引量:1
12
作者 Debin Shan and Youngsuk Kim School of Mechanical Engineering, Kyungpook National University, Taegu 702-70 1, South Korea Hyunsoo Kim Graduate School of Mechanical Engineering, Kyungpook National University, Taegu 702-701, South Korea E-mail: shandb@public 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2001年第3期329-332,共4页
Some techniques such as die surface description, contact judgement algorithm and remeshing are proposed to improve the robustness of the numerical solution. Based on these techniques, a three-dimensional rigid-plastic... Some techniques such as die surface description, contact judgement algorithm and remeshing are proposed to improve the robustness of the numerical solution. Based on these techniques, a three-dimensional rigid-plastic FEM code has been developed. Isothermal forging process of a cylindrical housing has been simulated. The simulation results show that the given techniques and the FEM code are reasonable and feasible for three-dimensional bulk forming processes. 展开更多
关键词 Three-Dimensional Rigid-Plastic FEM Simulation of Bulk Forming processes with New Contact and Remeshing techniques FEM Simulation
下载PDF
Processing and analysis of transient pressure measurements from permanent down-hole gauges 被引量:2
13
作者 Wang Fei 《Petroleum Science》 SCIE CAS CSCD 2012年第3期330-335,共6页
With permanent down-hole gauges (PDGs) widely installed in oilfields around the world in recent years, a continuous stream of transient pressure data in real time is now available, which motivates a new round of res... With permanent down-hole gauges (PDGs) widely installed in oilfields around the world in recent years, a continuous stream of transient pressure data in real time is now available, which motivates a new round of research interests in further developing pressure transient processing and analysis techniques. Transient pressure measurements from PDG are characterized by long term and high volume data. These data are recorded under unconstrained circumstances, so effects due to noise, rate fluctuation and interference from other wells cannot be avoided. These effects make the measured pressure trends decline or rise and then obscure or distort the actual flow behavior, which makes subsequent analysis difficult. In this paper, the problems encountered in analysis of PDG transient pressure are investigated. A newly developed workflow for processing and analyzing PDG transient pressure data is proposed. Numerical well testing synthetic studies are performed to demonstrate these procedures. The results prove that this new technique works well and the potential for practical application looks very promising. 展开更多
关键词 Permanent down-hole gauge transient pressure data processing deconvolution technique numerical well testing
下载PDF
Welding technique studies on the “West-East” pipeline project 被引量:1
14
作者 隋永莉 杜则裕 +1 位作者 黄福祥 祁励春 《China Welding》 EI CAS 2006年第2期73-76,共4页
This paper described the work of welding process design for the " West-East" pipeline project, which is high pressure, large diameter and heavy wall thickness. According to the different geographical situation, clim... This paper described the work of welding process design for the " West-East" pipeline project, which is high pressure, large diameter and heavy wall thickness. According to the different geographical situation, climate, culture and the flexibility of the welding methods, this work recommended the semi-automatic process at the east and middle sections and automatic process at the west section of the pipeline project. The manual process is recommended on the tie-in joints and repairs. The double joint pipe and the 3 joint pipe are recommended at the water net place and some in-ditch welding place to reduce the welding volume. Also the special redesigned bevels are recommended for the automatic process and the semiautomatic process. Through all destructive tests, the results shows the welds are meet the requirements of related standards, specifications and design documents. 展开更多
关键词 "West-East" welding technique process design mechanical properties of welded joint
下载PDF
A Novel Auto-Annotation Technique for Aspect Level Sentiment Analysis 被引量:1
15
作者 Muhammad Aasim Qureshi Muhammad Asif +4 位作者 Mohd Fadzil Hassan Ghulam Mustafa Muhammad Khurram Ehsan Aasim Ali Unaza Sajid 《Computers, Materials & Continua》 SCIE EI 2022年第3期4987-5004,共18页
In machine learning,sentiment analysis is a technique to find and analyze the sentiments hidden in the text.For sentiment analysis,annotated data is a basic requirement.Generally,this data is manually annotated.Manual... In machine learning,sentiment analysis is a technique to find and analyze the sentiments hidden in the text.For sentiment analysis,annotated data is a basic requirement.Generally,this data is manually annotated.Manual annotation is time consuming,costly and laborious process.To overcome these resource constraints this research has proposed a fully automated annotation technique for aspect level sentiment analysis.Dataset is created from the reviews of ten most popular songs on YouTube.Reviews of five aspects—voice,video,music,lyrics and song,are extracted.An N-Gram based technique is proposed.Complete dataset consists of 369436 reviews that took 173.53 s to annotate using the proposed technique while this dataset might have taken approximately 2.07 million seconds(575 h)if it was annotated manually.For the validation of the proposed technique,a sub-dataset—Voice,is annotated manually as well as with the proposed technique.Cohen’s Kappa statistics is used to evaluate the degree of agreement between the two annotations.The high Kappa value(i.e.,0.9571%)shows the high level of agreement between the two.This validates that the quality of annotation of the proposed technique is as good as manual annotation even with far less computational cost.This research also contributes in consolidating the guidelines for the manual annotation process. 展开更多
关键词 Machine learning natural language processing ANNOTATION semi-annotated technique reviews annotation text annotation corpus annotation
下载PDF
Data processing and initial results of Chang'e-3 lunar penetrating radar 被引量:13
16
作者 Yan Su Guang-You Fang +8 位作者 Jian-Qing Feng Shu-Guo Xing Yi-Cai Ji Bin Zhou Yun-Ze Gao Han Li Shun Dai Yuan Xiao Chun-Lai Li 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2014年第12期1623-1632,共10页
To improve our understanding of the formation and evolution of the Moon, one of the payloads onboard the Chang'e-3 (CE-3) rover is Lunar Penetrating Radar (LPR). This investigation is the first attempt to explore... To improve our understanding of the formation and evolution of the Moon, one of the payloads onboard the Chang'e-3 (CE-3) rover is Lunar Penetrating Radar (LPR). This investigation is the first attempt to explore the lunar subsurface structure by using ground penetrating radar with high resolution. We have probed the subsur- face to a depth of several hundred meters using LPR. In-orbit testing, data processing and the preliminary results are presented. These observations have revealed the con- figuration of regolith where the thickness of regolith varies from about 4 m to 6 m. In addition, one layer of lunar rock, which is about 330 m deep and might have been accumulated during the depositional hiatus of mare basalts, was detected. 展开更多
关键词 space vehicles: instruments: Lunar Penetrating Radar -- techniques:radar astronomy -- methods: data processing -- Moon: lunar subsurface -- Moon:regolith
下载PDF
A Triple-Channel Encrypted Hybrid Fusion Technique to Improve Security of Medical Images 被引量:1
17
作者 Ahmed S.Salama Mohamed Amr Mokhtar +2 位作者 Mazhar B.Tayel Esraa Eldesouky Ahmed Ali 《Computers, Materials & Continua》 SCIE EI 2021年第7期431-446,共16页
Assuring medical images protection and robustness is a compulsory necessity nowadays.In this paper,a novel technique is proposed that fuses the wavelet-induced multi-resolution decomposition of the Discrete Wavelet Tr... Assuring medical images protection and robustness is a compulsory necessity nowadays.In this paper,a novel technique is proposed that fuses the wavelet-induced multi-resolution decomposition of the Discrete Wavelet Transform(DWT)with the energy compaction of the Discrete Wavelet Transform(DCT).The multi-level Encryption-based Hybrid Fusion Technique(EbhFT)aims to achieve great advances in terms of imperceptibility and security of medical images.A DWT disintegrated sub-band of a cover image is reformed simultaneously using the DCT transform.Afterwards,a 64-bit hex key is employed to encrypt the host image as well as participate in the second key creation process to encode the watermark.Lastly,a PN-sequence key is formed along with a supplementary key in the third layer of the EbHFT.Thus,the watermarked image is generated by enclosing both keys into DWT and DCT coefficients.The fusions ability of the proposed EbHFT technique makes the best use of the distinct privileges of using both DWT and DCT methods.In order to validate the proposed technique,a standard dataset of medical images is used.Simulation results show higher performance of the visual quality(i.e.,57.65)for the watermarked forms of all types of medical images.In addition,EbHFT robustness outperforms an existing scheme tested for the same dataset in terms of Normalized Correlation(NC).Finally,extra protection for digital images from against illegal replicating and unapproved tampering using the proposed technique. 展开更多
关键词 Medical image processing digital image watermarking discrete wavelet transforms discrete cosine transform encryption image fusion hybrid fusion technique
下载PDF
DEVELOPMENT OF FAST TWO-DIMENSIONAL HIGH-RESOLUTION DIRECTION-FINDING TECHNIQUES
18
作者 吴仁彪 《Journal of Electronics(China)》 1994年第1期11-21,共11页
A fast separable approach based on a cross array is presented, which has coarsegrained parallelism. Its computational load is far less than that of the two-dimensional (2-D) direct processing method and other existing... A fast separable approach based on a cross array is presented, which has coarsegrained parallelism. Its computational load is far less than that of the two-dimensional (2-D) direct processing method and other existing separable approaches. In order to compensate for the performance degradation due to separable processing, two postprocessing schemes are also proposed. Some computer simulation results are provided for illustration in the end. 展开更多
关键词 Array SIGNAL processing HIGH-RESOLUTION direction-finding techniqueS SEPARABLE processing
下载PDF
Applied the Large Scale Particle Image Velocimetry Technique for Measurement the Velocity of Gravity Currents in the Laboratory
19
作者 Dhafar Ibrahim Ahmed Noureddine Latrache Blaise Nsom 《Journal of Water Resource and Protection》 2015年第8期597-604,共8页
This study includes a series of laboratory experiments for investigated the gravity current of fresh water with density ρ-?ρ, and initial speed u0 upon the free surface of an ambient liquid (salty water) with densi... This study includes a series of laboratory experiments for investigated the gravity current of fresh water with density ρ-?ρ, and initial speed u0 upon the free surface of an ambient liquid (salty water) with density ρ at rest in a basin. It’s have been presented to illuminate the dominant flow and transport phenomena in the presence of river, stream and wetland ecology, stream corridor restoration, in the case of accidental pollution spills. The characterized of the local kinematic field, i.e. the local velocity and vorticity fields, the measurement methods include particle image velocimetry (PIV) at the water surface using a technique similar to large scale of particle image velocimetry (LSPIV). 展开更多
关键词 Gravity CURRENTS IMAGE processing Large-Scale Particle IMAGE VELOCIMETRY technique SPATIOTEMPORAL DIAGRAMS technique
下载PDF
A NOVEL UNIVERSAL PREPROCESSING APPROACH FOR HIGH-RESOLUTION DIRECTION-OF-ARRIVAL ESTIMATION
20
作者 吴仁彪 《Journal of Electronics(China)》 1993年第3期249-254,共6页
A novel universal preprocessing method is proposed to estimate angles of arrival,which is applicable to one-or two-dimensional high resolution processing based on arbitrarycenter-symmetric arrays (such as uniform line... A novel universal preprocessing method is proposed to estimate angles of arrival,which is applicable to one-or two-dimensional high resolution processing based on arbitrarycenter-symmetric arrays (such as uniform linear arrays, equal-spaced rectangular planar arraysand symmetric circular arrays). By mapping the complex signal space into the real one, the newmethod can effectively reduce the computation needed by the signal subspace direction findingtechniques without any performance degradation. In addition, the new preprocessing scheme itselfcan decorrelate the coherent signals received on the array. For regular array geometry such asuniform linear arrays and equal-spaced rectangular planar arrays, the popular spatial smoothingpreprocessing technique can be combined with the novel approach to improve the decorrelatingability. Simulation results confirm the above conclusions. 展开更多
关键词 Array SIGNAL processing Direction finding SPECTRUM estimation High RESOLUTION techniques
下载PDF
上一页 1 2 248 下一页 到第
使用帮助 返回顶部