Experimental Research on the Feature Extraction of Underwater Transient Signal

2013 ◽  
Vol 572 ◽  
pp. 463-466
Author(s):  
Shi Jun Sun ◽  
Yang Li
Keyword(s):  
Feature Extraction ◽  
Theoretical Analysis ◽  
Experimental Research ◽  
Pulse Signal ◽  
Water Entry ◽  
Transient Signal ◽  
Water Splash

After the aerial object enters the water, splash sound forms. It composes of water entry pulse signal, quiet interval, and bubbles fluctuant signal. To extract the characteristics of the splash sound, characteristics of the three parts of the signal are analyzed in theoretically. And then experimental research is done, in which five different targets are adopted to be launched under different conditions. Comparing with the results of different conditions, we draw some conclusions which coincide with the theoretical analysis.

Theoretical Analysis and Experimental Research on the Broken Critical-Position of Coating Interface

2008 ◽  
Vol 35 (11) ◽  
pp. 1746-1751 ◽  
Author(s):  
冯爱新 Feng Aixin ◽  
叶勇 Ye Yong ◽  
殷苏民 Yin Sumin ◽  
程昌 Cheng Chang ◽  
曹宇鹏 Cao Yupeng
Keyword(s):  
Theoretical Analysis ◽  
Experimental Research ◽  
Critical Position

scholarly journals Micro-Motion Feature Extraction of a Rotating Target Based on Interrupted Transmitting and Receiving Pulse Signal in an Anechoic Chamber

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1028
Author(s):  
Feng Zhao ◽  
Xiaobin Liu ◽  
Zhiming Xu ◽  
Yuan Liu ◽  
Xiaofeng Ai
Keyword(s):  
Feature Extraction ◽  
Coupling Effect ◽  
Pulse Repetition Frequency ◽  
Pulse Signal ◽  
Anechoic Chamber ◽  
Repetition Frequency ◽  
Motion Feature ◽  
Whole Process ◽  
Micro Motion ◽  
Rotating Target

The pulse signal is widely used in micro-motion feature extraction of rapidly rotating targets as its pulse repetition frequency (PRF) can be high. However, when the pulse signal is implemented in a range-limited anechoic chamber for micro-motion feature extraction, the transmitted and reflected pulse signals may be coupled at the receiver. To solve this problem, the interrupted transmitting and receiving (ITR) method is applied to transmit the pulse signal with hundreds of sub-pulses. The target echo can be received when the sub-pulse is not transmitted. Hence, it avoids the coupling effect of transmitted signals and echoes. Then, the whole process of micro-motion feature extraction for rotating target is proposed based on the ITR method. At last, the simulations and experiments verify that the rotating target micro-Doppler can be extracted by the ITR pulse signal.

STABILITY PROBLEMS OF STEEL‐CONCRETE MEMBERS COMPOSED OF HIGH‐STRENGTH MATERIALS

2010 ◽  
Vol 16 (3) ◽  
pp. 352-362 ◽  
Author(s):  
Zdeněk Kala ◽  
Libor Puklický ◽  
Abayomi Omishore ◽  
Marcela Karmazínová ◽  
Jindřich Melcher
Keyword(s):  
Theoretical Analysis ◽  
Experimental Research ◽  
Carrying Capacity ◽  
High Strength ◽  
Statistical Characteristics ◽  
Load Carrying Capacity ◽  
Limit States ◽  
Load Carrying ◽  
Geometrical Imperfections

The presented paper deals with the stochastic analysis of the ultimate limit states of steel‐concrete building members. The load carrying capacity of steel‐concrete columns, comprising of steel profiles encased in high strength concrete, in compression is analyzed. The first part of the paper lists assumptions for the determination of the theoretical load carrying capacity of the column. Principles of elasticity and plasticity are used to determine stresses in the concrete and steel sections. Statistical characteristics of input material and geometrical imperfections are listed. Results of the theoretical analysis are then compared with results of experimental research. Statistical characteristics of obtained results of the theoretical analysis were verified using statistical characteristics obtained from experimental research. Numerical simulation LHS and Monte Carlo methods, which take into account the influences of variability of input imperfections, were employed. The influence of the utilization of the plastic reserve in the determination of the load carrying capacity of the analysed strut is shown. The influence of the initial geometric imperfections of initial strut curvature on the load carrying capacity is also presented. Santrauka Straipsnyje pateikta plienbetonio pastatu elementu didžiausiu ribiniu būkliu stochastine analize, analizuojama plienbetonio kolonu, sudarytu iš plieniniu profiliuočiu, padengtu didelio stiprio betonu, laikomoji galia gniuždant. Pirmoje straipsnio dalyje išvardytos kolonos teorines laikomosios galios nustatymo prielaidos. Tamprumo ir plastiškumo principai taikyti itempiams betono ir plieno skerspjūviuose nustatyti. Nustatytos medžiagu ir geometriniu defektu statistines charakteristikos, teorines analizes rezultatai palyginti su eksperimentiniu tyrimu rezultatais. Teorines analizes metu gautu rezultatu statistines charakteristikos patikrintos taikant iš eksperimentiniu tyrimu gautus statistinius rodiklius. Pritaikytas skaitinis modeliavimas LHS ir Monte Karlo metodais, kurie ivertina pradiniu defektu kintamumo itaka. Parodyta plastiškumo atsargos naudojimo itaka, nustatant analizuojamojo statramsčio laikomaja galia, pateikta pradinio statramsčio išlinkio pirminiu geometriniu defektu itaka laikomajai galiai.

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