Periodic signal extraction of GNSS height time series based on adaptive singular spectrum analysis

Singular spectrum analysis is widely used in geodetic time series analysis.However,when extracting time-varying periodic signals from a large number of Global Navigation Satellite System(GNSS)time series,the selection of appropriate embedding window size and principal components makes this method cumbersome and inefficient.To improve the efficiency and accuracy of singular spectrum analysis,this paper proposes an adaptive singular spectrum analysis method by combining spectrum analysis with a new trace matrix.The running time and correlation analysis indicate that the proposed method can adaptively set the embedding window size to extract the time-varying periodic signals from GNSS time series,and the extraction efficiency of a single time series is six times that of singular spectrum analysis.The method is also accurate and more suitable for time-varying periodic signal analysis of global GNSS sites.

Economic Periodicity Analysis of Shandong Province

The paper analyses the periodical characteristics of the economic development of Shandong Province by using the mini- mum variation analysis model.The analysis shows that the eco- nomic development process of Shandong Province has short, medium and long cycles respectively for 6,12,19 years,and the fluctuation of the economic development becomes gentler with time passing by.The fluctuation of macro-control policy,invest- ment and consumption are the main reasons of the economic fluc- tuation.

Modeling and analysis of piezoelectric beam with periodically variable cross-sections for vibration energy harvesting

A bimorph piezoelectric beam with periodically variable cross-sections is used for the vibration energy harvesting. The effects of two geometrical parameters on the first band gap of this periodic beam are investigated by the generalized differential quadrature rule （GDQR） method. The GDQR method is also used to calculate the forced vibration response of the beam and voltage of each piezoelectric layer when the beam is subject to a sinusoidal base excitation. Results obtained from the analytical method are compared with those obtained from the finite element simulation with ANSYS, and good agreement is found. The voltage output of this periodic beam over its first band gap is calculated and compared with the voltage output of the uniform piezoelectric beam. It is concluded that this periodic beam has three advantages over the uniform piezoelectric beam, i.e., generating more voltage outputs over a wide frequency range, absorbing vibration, and being less weight.

Application of periodic orbit theory in chaos-based security analysis

Chaos-based encryption schemes have been studied extensively, while the security analysis methods for them are still problems to be resolved. Based on the periodic orbit theory, this paper proposes a novel security analysis method. The periodic orbits theory indicates that the fundamental frequency of the spiraling orbits is the natural frequency of associated linearized system, which is decided by the parameters of the chaotic system. Thus, it is possible to recover the plaintext of secure communication systems based on chaotic shift keying by getting the average time on the spiraling orbits. Analysis and simulation results show that the security analysis method can break chaos shift keying secure communication systems, which use the parameters as keys.

Volatile profile and multivariant analysis of Sanhuang chicken breast in combination with Chinese 5-spice blend and garam masala

Sanhuang chicken is a popular native breed in China and well-known for delicious flavour.Spices could enhance the chicken meat flavour and work well in preservation.Chinese 5-spice blend(CS)and garam masala(GM)are routinely using spices in China and Pakistan,respectively.The flavour profiles of Sanhuang chicken breast(CB)and its blends with CS and GM were obtained by electronic nose(E-nose),solid-phase microextraction gas chromatography-mass spectrometry(SPME GC-MS)and GC-ion mobility spectrometry(GC-IMS).Principal component analysis(PCA)efficiently discriminated the aroma profiles of three chicken formulations.The GC-chromatographs revealed the significant aroma alterations of chicken breast meat after marination with spices.Aldehydes were the major contributors of chicken aroma,while most of the aromatic hydrocarbons were generated by spices.Almost all chicken key-compounds produced by oxidation reaction were either reduced or eliminated by marination,showing the antioxidation capacity of spices leading to meat preservation.GC-IMS is not only a rapid and comprehensive detection method,but also proved to be more sensitive than GC-MS.The substantial role of both traditional spices in enhancing flavour quality of chicken meat,and their exposure as functional ingredients in Chinese and Pakistan cuisines could lead to the cross-cultural meat trade opportunities.

Transcriptome analysis of the influence of CPPU application for fruit setting on melon volatile content

In fruit production,the application of the plant growth regulator 1-(2-chloro-4-pyridyl)-3-phenylurea(CPPU)dulls the fruit aroma.Gas chromatography-mass spectrometry and transcriptome analyses were performed on CPPU-treated and pollinated fruits to determine how CPPU affects the production of aroma in melon fruit.The results showed that the contents of two important esters(benzyl acetate and phenethyl acetate)in the CPPU-treated fruits were significantly lower than those in the pollinated fruits.Transcriptome sequencing data revealed that most differentially expressed genes were involved in“phenylalanine metabolism”pathway,and their expression was significantly decreased in the CPPU-treated fruits.Further analysis showed that the phenylalanine content in the CPPU-treated fruits was significantly higher than that in the pollinated fruits.In summary,CPPU application interferes with phenylalanine metabolism in melon fruits and affects the production of aromatic esters.

Analysis of the Change Trends of Temperature and Frost-free Period in Xingtai in Recent 53 Years

[Objective] The changes trend of temperature and frost-free period in Xingtai in recent 53 years were studied.[Method] According to the climate data of Xingtai City and Nangong County in 1958-2010,the changes trend of the temperature,the first and the last frost day,and the frost-free days in Xingtai were studied.The characteristics of the changes of temperature and frost-free days in Xingtai in recent 53 years were studied.[Result] No matter in city or countryside,the annual average temperature was increasing.The climate tendency rates in Xingtai and Nangong were about 0.5 and 0.2 ℃/10 a respectively.Especially,since 1996,the annual average temperature increasing trend was about 1.0 ℃/10 a.The average temperature of the four seasons was also climbing and was similar to the increasing span of the annual average temperature.The annual average temperature increasing span was the largest in winter.And the increase of the annual average temperature in winter was the largest and the increase of the annual average temperature was caused by the increase of the average temperature in winter.The urban annual average temperature was obviously higher than that of the countryside,which reflected the characteristics of tropical island effect.No matter in the city or the countryside,the early frost day,final frost day and frost-free day showed same tendency,namely,the delay of early frost day,advance of final-frost day,extension of frost-free day;the day of urban early frost was late than that of the countryside,and the final frost day was earlier than that of the countryside,the frost-free days were longer than that of countryside and indirectly influenced by urban heat effect.[Conclusion] The study provided theoretical basis for the development and application of thermal resources in Xingtai.

Component analysis of volatile oil from Illicium Verum Hook. f.

Volatile oil was extracted from Illicium Verum Hook. f. by using steam distillation. 41 kinds of compounds were separated and identified by GC/MS, and their relative contents were determined by normalization method. Among 41 identified compounds, there are 14 hydrocarbon components and 22 oxygenated hydrocarbon derivatives, and a small amount of nitrogenous compounds. The main component is anethole, accoun ting for 76.23%, and the other components such as anisyl acetone, anisaldehyde, p allylanisole, p cumic aldehyde and p allylpen take up more than 10%.

A grey model with periodic term for sea-level analysis and its application to the Guangxi coast

A grey model with periodic term for sea-level analysis is presented.The present model keeps some advantages of tea GM (1, 1 )model, which well reflects the trend of sea-level changes and gives out the change rate as well as the acceleration of sea level conveniently.level conveniently.In addition, the present model can reproduce the periodic phenomena of sealevel, hence, it overcomes the shortcomings of the GM(1,1) model that is unsuitable for forecasting monthly mean sealevel with apparent periodicity, and its prediction accuracy is improved.The present model is used to analyse Guangxi coast sea level,the results show that the rise rates of relative sea level at Beihai, Weizhou and Bailongwei are 1 .67,2 .51 and 0.89 mm/a respectively, the relative sea level at Shitoubu has a falling trend with a rate of 0. 5- 1 .0 mm/a, the rise rate of eustatic sea level along the Guangxi coast is 2 .0 mm/a. In comparison with the model with a lineartrend term plus a periodic term, the simulation accuracies of both models are about the same.

Band gap analysis of periodic structures based on cell experimental frequency response functions(FRFs)

An approach is proposed to estimate the transfer function of the periodic structure, which is known as an absorber due to its repetitive cells leading to the band gap phenomenon. The band gap is a frequency range in which vibration will be inhibited. A transfer function is usually performed to gain band gap. Previous scholars regard estimation of the transfer function as a forward problem assuming known cell mass and stiffness matrices. However, the estimation of band gap for irregular or complicated cells is hardly accurate because it is difficult to model the cell exactly. Therefore, we treat the estimation as an inverse problem by employing modal identification and curve fitting. A transfer matrix is then established by parameters identitled through modal analysis. Both simulations and experiments have been performed. Some interesting conclusions about the relationship between modal parameters and band gap have been achieved.

Analysis of Meteorological Conditions during the Blossom Period of Apple and Peach in Haiyang City

Through observing the phenology of two kinds of fruit trees,apple and peach trees,during their flowering periods in the past seven years,the meteorological conditions in the flowering stages were analyzed and summarized in this paper.The late frost weather situation occurred in late April in Haiyang City also was elaborated in the paper.According to the data analysis,the terrain effect had induced a large temperature differences between north and south in April in Haiyang.Early flowering of fruit trees is as early as 5 to 8 days in the northern region than that in the southern region;accumulated temperature which was greater than or equal to 0 ℃ and the date of the temperature stably through a boundary,were the important meteorological indicators of the fruit trees' early flowering.The late frost in mid-late April is meteorological disasters of the fruit trees flowering period.The weather background of the occurred late frost,the disaster reasons and the measures for the prevention of late frost were proposed.

An Analysis of Structural-Acoustic Coupling Band Gaps in a Fluid-Filled Periodic Pipe

A periodic pipe system composed of steel pipes and rubber hoses with the same inner radius is designed based on the theory of phononic crystals. Using the transfer matrix method, the band structure of the periodic pipe is calculated considering the structural-acoustic coupling. The results show that longitudinal vibration band gaps and acoustic band gaps can coexist in the fluid-filled periodic pipe. The formation of the band gap mechanism is further analyzed. The band gaps are validated by the sound transmission loss and vibration-frequency response functions calculated using the finite element method. The effect of the damp on the band gap is analyzed by calculating the complex band structure. The periodic pipe system can be used not only in the field of vibration reduction but also for noise elimination.

Comparative analysis of volatile constituents between herbal pair flos lonicerae-caulis lonicerae and its single herbs

Gas chromatography-mass spectrometry(GC-MS) and the chemometric resolution method(alternative moving window factor analysis,AMWFA) were used for comparative analysis of volatile constituents in herbal pair(HP) flos lonicerae-caulis lonicerae(FL-CL) and its single herbs.The temperature-programmed retention index(PTRI) was also employed for the identification of compounds.In total,44,39,and 50 volatile chemical components in volatile oil of FL,CL and HP FL-CL were separately determined qualitatively and quantitatively,accounting for 87.22%,94.54% and 90.08% total contents of volatile oil of FL,CL and HP FL-CL,respectively.The results show that there are 32 common volatile constituents between HP FL-CL and single herb FL,33 common volatile constituents between HP FL-CL and single herb CL,and 10 new constituents in the volatile oil of HP FL-CL.

The Analysis on the Temporal and Spatial Variation of Strong Precipitation Caused Flood and Agricultural Disaster Loss in Huaihe River Basin of Anhui Province during Meiyu Period of 2007

[Objective] The research aimed to analyze temporal and spatial variation of strong precipitation caused flood and agricultural disaster loss in Huaihe River basin of Anhui Province during Meiyu period of 2007.[Method] On the basis of rainfalls of each station in Huaihe River basin of Anhui,rainfall data during Meiyu period of 2007 and flood disaster data in the same period,the temporal and spatial distribution characteristics of strong precipitation caused flood during Meiyu period of 2007 and its harm on agriculture were analyzed.The variation rule,distribution characteristics of strong precipitation during Meiyu period in Huaihe River basin of Anhui and its relationship with agricultural disaster loss were discussed.[Result] During Meiyu period of 2007 in Huaihe River basin of Anhui,the rainstorm was more,and the rainfall was large.The precipitation variation showed 'three-peak' trend.Rainfall in Huaihe River basin during Meiyu period of 2007 was greatly more than that homochronously in Yangtze River basin.The rain area over 400.0 mm during Meiyu period mainly located in Huaihe River basin,and the rain area over 600.0 mm mainly located from area along Huaihe River to central Huaibei.The rainfall during Meiyu period gradually decreased toward south and north by the north bank of Huaihe River as the symmetry axis.The rainfall in area along Huaihe River showed wavy distribution in east-west direction.The flood disaster loss index and disaster area of crops in Huaihe River basin of Anhui both increased as rainfall in Meiyu period.[Conclusion] The research provided theoretical basis for flood prevention,disaster reduction and agricultural flood-avoiding development in Huaihe River basin.

Research on the spectral analysis and testmethod of period signals in monthly mean sea level

This paper summarizes the general methods,existing problems and their causes of the period analysis for the monthly mean sea level and points out that it is the key to the analysing period signals and forecasting the change trend of the monthly mean sea level that the periods of the signals are selected reasonably. As there are often many period signals in these series, nonlinear effects exist between pairs of period signals. In order to avoid the false periods that may be introduced due to the effects of side lobes and the periods with statistical phase significance coherence that may be introduced due to the effects of nonlinear effects and their restraint to other period signals, the maximum entropy spectral analysis and the corresponding significance period test may be performed repeatedly on the basis of the bispectrum analysis and meanwhile the most significant period component is filtered out by the least square filtering method, i. e., the method of the significance period analysis with mixed spectra modeled by a nonlinear system is adopted and the signal periods approaching the reality are selected one by one. The examples of the bispectrum analysis, the signal period analysis by mixed spectra and the fitting parameters for combined period components with linear trend in the time series of monthly mean sea level are given in this paper.

Potential Vorticity Diagnostic Analysis on the Impact of the Easterlies Vortex on the Short-term Movement of the Subtropical Anticyclone over the Western Pacific in the Mei-yu Period

By employing NCEP−NCAR 1°×1°reanalysis datasets,the mechanism of the easterlies vortex(EV)affecting the short-term movement of the subtropical anticyclone over the western Pacific(WPSA)in the mei-yu period is examined using potential vorticity(PV)theory.The results show that when the EV and the westerlies vortex(WV)travel west/east to the same longitude of 120°E,the WPSA suddenly retreats.The EV and WV manifest as the downward transport of PV in the upper troposphere,and the variation of the corresponding high-value regions of PV significantly reflects the intensity changes of the EV and WV.The meridional propagation of PV causes the intensity change of the EV.The vertical movement on both sides of the EV is related to the position of the EV relative to the WPSA and the South Asian high(SAH).When the high PV in the easterlies and westerlies arrive at the same longitude in the meridional direction,the special circulation pattern will lower the position of PV isolines at the ridge line of the WPSA.Thus,the cyclonic circulation at the lower level will be strengthened,causing the abnormally eastward retreat of the WPSA.Analysis of the PV equation at the isentropic surface indicates that when the positive PV variation west of the EV intensifies,it connects with the positive PV variation east of the WV,forming a positive PV band and making the WPSA retreat abnormally.The horizontal advection of the PV has the greatest effect.The contribution of the vertical advection of PV and the vertical differential of heating is also positive,but the values are relatively small.The contribution of the residual was negative and it becomes smaller before and after the WPSA retreats.

Well-posed analysis for a class of Helmholtz equation with periodic coefficients

The scattering theory in periodic structures has many applications in modern microoptics and industry. Periodic structures are often referred to as diffraction gratings. In this paper we consider a planar dielectric-layer modulated grating problem. The diffraction problem may be modeled by a Helmholtz equation with periodic coefficients. Results on existence and uniqueness of the solution for the diffraction problem are obtained by variational method and integral equation method, respectively. At the end of the paper, we also discuss the Born approximation to the solution of an equivalent integral equation.

Effect of Base Width and Stiffness of the Structure on Period of Vibration of RC Framed Buildings in Seismic Analysis

Fundamental natural period of vibration T of the building is an important parameter for evaluation of seismic base shear. Empirical equations given in the Indian seismic code for the calculation of the fundamental period of a framed structure, primarily as a function of height, do not consider the effect of stiffness of the structure, base dimensions of the structure, number of panels in both the directions, amount of infill and properties of the infill. The fundamental period can be evaluated using simplified expressions found in codes, which are based on earthquake recordings in existing buildings, laboratory tests, numerical or analytical computations. These technical codes provide expressions which depend on basic parameters such as building height or number of stories. Building periods predicted by these expressions are widely used in practice although it has been observed that there is scope for further improvement in these equations since the height alone is inadequate to explain period variability. It is also known that the period of a RC frame structure differs depending on whether the longitudinal or transverse direction of the structure is considered. The aim of this study is to find the effects of building base width in both the directions, stiffness of the structure etc. and to predict the fundamental period of vibration of reinforced concrete buildings with moment resisting frames (MRF). A few examples of dynamic analysis are presented in this study to show the effect of base dimensions and stiffness of the structure in calculating the time period of the structure. And it is recommended to be incorporated in the formula for evaluating the natural period of vibration of structures.

ANALYSIS OF VOLATILE CONSTITUENTS OF CHINESE MEDICINAL HERBS BY FLASH DISTILLATION/CAPILLARY GAS CHROMATOGRAPHY/MASS SPECTROMETRY

In present work,the volatile constituents of Curcuma longa L.,A.lancea (Thunb.) DC.,Foeniculum vulgare Mill,and Cinnamomun cassia Presl.have been analyzed by flash distillation/capillary gas chro-matography/mass spectrometry.The results are consistent with those obtained by conventional steam distillation extraction method.The optimum condition of flash distillation has been studied.The experimental results showed that this new technique proved to be a simple,rapid and efficient tool for microanalysis of volatile constituents of Chinese medicinal herbs.