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This study focuses on the effect of the riser lateral vibration on the pressure loss of coarse particles hydraulic lifting by the numerical simulation. Euler-Euler two-fluid model based on kinetic theory is used to simulate the flow behavior of coarse particles in the riser, and the numerical model has been validated by using the experimental data. The dynamic grid technique is employed to simulate the lateral vibration of the riser. According to results of numerical simulation, the lateral vibration leads to the cyclical fluctuation of the pressure loss of coarse particles hydraulic lifting, and the average pressure loss of the dynamic riser is bigger than the static riser in general. The influence of the vibration amplitude, vibration period and modal shape on the pressure loss is analyzed, and the cause of pressure loss is also discussed.

We study the effect of interest rate on phenomenon of business cycle in a Kaldor-Kalecki model. From the information of the People's Bank of China and the Federal Reserve System, we know the interest rate is not a constant but with remarkable periodic volatility. Therefore, we consider periodically forced interest rate in the model and study its dynamics. It is found that, both limit cycle through Hopf bifurcation in unforced system and periodic solutions generated by period doubling bifurcation or resonance in periodically forced system, can lead to cyclical economic fluctuations. Our analysis reveals that the cyclical fluctuation of interest rate is one of a key formation mechanism of business cycle, which agrees well with the pure monetary theory on business cycle. Moreover, this fluctuation can cause chaos in a business cycle system.

Seasonal fluctuations play an important role in the pricing of a timber sale. A good understanding of timber price mechanisms and predictability in the timber market would be very practical for forest owners, managers, and investors, and is crucial for the correct functioning of the timber sector. This research aimed to analyze the effect of sale season on timber (sawlog and lumber) prices of high-value species groups (e.g., oriental beech, chestnut-leaved oak, common alder, velvet maple, and common hornbeam) in the Hyrcanian temperate forests (Northern Iran). The data were collected from official sale documents of the Azarroud Forestry Plan from 1992 to 2015. The relevant data of 592 sale lots at forest roadside were extracted into a data set. Then, the average timber prices (sawlog and lumber) per season/year in quarterly frequency were calculated. In doing so, two-time series of seasonal prices for the sawlog and lumber was obtained. The stationarity of the time series was statistically verified using the augmented Dickey–Fuller test. The effect of sale seasons on timber price was first analyzed using multiple linear regression analysis dummy variables. The results showed that autumn and summer have a significant positive effect on timber prices of 6.5% and 6.1%, respectively. Additionally, the decomposition of time series results showed that the highest prices of the sawlog and lumber were in quarter 3 and quarter 2, respectively, due to an increase in construction activities that picked up in the autumn season. Information about potential price fluctuations will be plausible and allow suppliers and users of sawlogs to adjust their supply and demand. This valuable information can be used in marketing and strategic forest management planning for Hyrcanian temperate forests and other temperate countries with similar conditions.

Majority of the time series carry seasonal effects and show cyclical fluctuation patterns. The Census-X12 seasonal adjustment method and the HP filter method are based on factor decomposition theory, which divides the original time series into four parts: long-term trend, cyclical fluctuation, seasonal characteristics and random fluctuation terms. This paper selects monthly price data of China's major meat products: chicken, beef, mutton and pork from 2009 to 2020 to derive medium and longterm trends, seasonal fluctuations and cyclical patterns in the prices of major meat products. It is found that the X12 seasonal adjustment method and the HP filter method are able to accurately extract the characteristics of different factors in the prices of major meat products in China. The price fluctuation patterns of beef and lamb are basically the same, with a cyclical cycle of 24 and 29 months respectively; the cyclical cycle of pork prices is consistent with that of chicken prices and fluctuates more frequently at random.

In cooperative human communication, the speaker has to mark the connection between his utterance and therefore the given information, because the hearer interprets the utterance regarding the data that has already been obtained. Languages adopt various devices to mark the connection between the utterance and also the context. This paper investigates semantic and pragmatic presupposition in Discourse Representation Theory (DRT) within the Chinese language and enhances the pragmatic perspective of presupposition in DRT.

Brucellosis is a kind of zoonotic disease caused by Gram-negative bacteria of the genus Brucella. In this paper, we propose a stochastic periodic brucellosis model by introducing the effect of environmental white noise on transmission dynamics of brucellosis. By Has’minskii theory of periodic solution and constructing a novel combination of Lyapunov functions, we establish the existence of nontrivial positive periodic solution if the condition R 0 S > 1 holds. Based on the reported data of newly acute human brucellosis cases for each season from 2010 to 2014 in Xinjiang, numerical simulations have been performed to support our result and indicate that brucellosis in Xinjiang takes on the feature of long-term prevalence and cyclical fluctuation.

Introduction : Hemorrhagic fever with renal syndrome (HFRS) is a life-threatening public health problem in China, accounting for ~90% of HFRS cases reported globally. Accurate analysis and prediction of the HFRS epidemic could help to establish effective preventive measures.Materials and Methods : In this study, the geographical information system (GIS) explored the spatiotemporal features of HFRS, the wavelet power spectrum (WPS) unfolded the cyclical fluctuation of HFRS, and the wavelet neural network (WNN) model predicted the trends of HFRS outbreaks in mainland China.Results : A total of 209,209 HFRS cases were reported in mainland China from 2004 to 2019, with the annual incidence ranged from 0 to 13.05 per 100,0000 persons at the province level. The WPS proved that the periodicity of HFRS could be half a year, 1 year, and roughly 7-year at different time intervals. The WNN structure of 12-6-1 was set up as the fittest forecasting model for the HFRS epidemic.Conclusions : This study provided several potential support tools for the control and risk-management of HFRS in China.

The measurement and early warning of real estate risk are important to prevent and defuse major financial risks, and they form a basis for high-quality development. This paper assessed the internal and external environments of the real estate market; constructed a real estate risk indicator system from the aspects of market level, real estate enterprises, policy factors and financial institutions; and implemented a PSO-SVM model to measure and warn of real estate risk. Empirical studies were conducted. The results show the following: (1) the synthetic real estate risk index well depicts the cyclical fluctuation of real estate risk in Beijing; (2) the warning model based on the PSO-SVM method exhibits better performance and higher warning accuracy than other models do.

In the course of operation, the construction industry will repeat deviations and adjustments to it equilibrium state. Understanding the development fluctuations of the construction industry is critical to the formulation of a country&rsquo, s sustainable development strategy. The purpose of this paper is to investigate the development trend and fluctuation periodicity of the construction industry, particularly the deviation and characteristics of the development. In this paper, based on the H-P filtering method, the residual method for measurement of macro-economic cycle fluctuation is used to divide the periodic fluctuation of the Chinese construction industry into five rounds of economic cycles since the reform and opening up. The results are tested by a random test model and a self-correlation coefficient test model. The longitudinal time-series of data investigated in this research is the constant-price, gross output values of the construction industry in China in the period of 1980&ndash, 2017 for a total of 38 years based on the national annual statistics. The results of the mathematical test show that the peak or valley of the economic cycle fluctuation of the construction industry in China reappears about every seven years or so. It shows that since the reform and opening up, the peak position of the cycle fluctuation of the Chinese construction industry began to decrease gradually, the valley level began to rise gradually, the volatility showed a downward trend, and the construction industry cycle fluctuation entered a steady and smooth process. The results of this study provide new comprehension of the development trend of construction industry and build the theoretical basis for governments and enterprises to judge the future development trends when formulating the relevant policies.

The EU-28 is one of the largest emitters of CO2 in the world and the most committed to reducing emissions. However, the national environmental strategies of the Member States are still diverse. This study is aimed at evaluating the environmental performance of European economies by analysing the fluctuations of CO2 emissions and their links with economic activity over the period 1950–2012. The methodological framework is based on a dynamic factor analysis to determine an index of the EU fluctuation of CO2 emissions in parametric form. This index can be used to monitor the progress towards common behaviour across Member States, with a time-varying recursive method. Following this approach, we also track the efforts made to decouple CO2 emissions from GDP. Based on these analyses, we develop a CO2 emissions-GDP linkage matrix to attain useful information on the EU Member State environmental performance.

Rather than stabilising aggregate demand, discretionary fiscal policy tends to amplify cyclical fluctuations of output. The commonly accepted reasons are political economy and uncertainty. In the EU, the pro-cyclical nature of discretionary fiscal policy has also been associated with the commonly agreed fiscal rules, which, for some observers, unduly limit the scope for stabilising output. Using panel data covering close to 40 EU and non-EU countries, we provide evidence that the volatility of output gap estimates is not a convincing explanation for pro-cyclical policies. With the exception of very large shocks, discretionary measures remain ill-timed from a stabilisation perspective even when observable and politically more meaningful indicators of the cycle are used. We also show that deviations from fiscal rules and the accumulation of government debt foster pro-cyclical fiscal policy. Lawmakers can run discretionary fiscal policy measures based on political economy considerations up to a point. Once debt grows too high, the leeway to stabilise output with discretionary fiscal policy measures fades. Complying with fiscal rules that limit the increase in government debt or keep a steady course in the face of cyclical fluctuation is conducive to counter-cyclical fiscal policy making.

This article examines whether cyclical fluctuation in India’s output was synchronized with other major economies of the world in post-reform period. Using panel GMM estimation, it is established that in the post-reform period cyclical output of Indian economy shared a common trend with some of the advanced economies and the emerging market economies. The sources of such business cycle synchronization were found to be increased trade intensity, similarities in productive structure, similar monetary policy stance and events of major economic crises. This suggests that Indian economy cannot remain decoupled from major economic crises in the global economy and, therefore, Indian policymakers need to factor in global events in their policy response function.

This paper employs metafrontier Malmquist-Luenberger index to measure green total factor productivity and then builds panel model to investigate the nonlinear effects of both governmental and civil environmental regulation on green total factor productivity in 30 provinces of China in 2007–2016, where the threshold variables are environmental awareness and regulatory foundation. The results show that green total factor productivity takes the characteristic of cyclical fluctuation, and the magnitude and its growth rate in the eastern region are higher than those in the midwestern region. The degrees of the governmental and civil environmental regulation and green total factor productivity display single environmental awareness threshold and regulatory foundation threshold. It should be noted that the sign of governmental and civil environmental regulation on green total factor productivity will transform from negative to positive, if and only if threshold variables ascend and surpass the threshold value. Under the condition of metafrontier technology, governmental environmental awareness threshold value, based on the investigated corruption and malpractice cases by the procuratorates among every hundred thousand people, reaches 0.2158, and civil environmental awareness threshold value based on the per capita education level will attain 12.2330 years, and the corresponding regulatory foundation index threshold values are 0.0163 and 0.0154. These findings show clear policy implications: rather than continually promoting the level of governmental environmental regulation, civil performance, environmental awareness, and regulatory foundation should be considered.

The objective of the study was to verify the applicability and usefulness of time series decomposition in analyzing the variability of timber prices and supply in Poland. The employed multiplicative model was the product of four components: cyclical, seasonal, and irregular fluctuations and the long-term trend. The elements of the time series were determined by means of the Census X11 method, while cyclicality was separated from the trend employing the Hodrick&ndash, Prescott filter. Data included quarterly information about the supply (volume) and prices (value) of the timber sold by the State Forests in the years 2005&ndash, 2018. Analyses were performed for tree species with the greatest economic significance, that is, pine, oak, spruce, beech, birch, and alder, and for their most popular assortments: general purpose large-diameter timber (W0) and medium-diameter timber (S2A). Time series decomposition of quarterly timber production volume and prices revealed irregular, seasonal, and cyclic fluctuations. Within an annual time horizon, irregular fluctuations accounted on average for 6.7% and 28% of overall variability in timber prices and supply, respectively, they exhibited low amplitudes (+5%, &minus, 25%, respectively). Cyclical fluctuations were primarily found for prices and were characterized by substantial variations in cycle length (2&ndash, 4 years) and change amplitude (3&ndash, 27 Euros). Cyclical fluctuations in timber prices and supply were usually negatively correlated with each other: the upper turning points of price cycles fell near the lower turning points of supply cycles (with a shift of 1 to 3 quarters). The seasonality of prices was also inversely correlated with supply: quarters with low supply exhibited higher prices and vice versa. Seasonal fluctuations were more pronounced for timber supply (36%) as compared to timber prices (20.3%). Different seasonality patterns were found for hardwood and softwood. The lowest supply of softwood was found in the first quarter and the highest in the third quarter (spruce) or fourth quarter (pine). The supply of hardwood was the highest in the first quarter and the lowest in the third quarter.

Precipitation is the main water source for vegetation survival in arid and semi-arid areas. However, previous studies always focus on the effects of precipitation in different time scales, but ignore the effects of precipitation in different spatial scales. To further study the effects of precipitation fluctuation in different spatial scales, we used the wavelet analysis method to analyze its temporal and spatial change based on data from eighteen meteorological stations during 1961–2015 in Horqin region. Results showed that: (1) from the overall tendency of precipitation changes, the precipitation inter-annual variations in Horqin region had the tendency of gradually decreasing from the southeast (District IV) to the northwest; (2) the precipitation anomalies of District I–IV between 1960 and 1980 were small and approximate to the normal value; (3) in the time scale of 23–32 years, the cyclical fluctuations were very significant and the annual precipitation underwent two cyclical fluctuations from a period of low precipitation to a period of high precipitation; and (4) as results of analyzing the spatial wavelet variance of sub-region, the main cycle of precipitation in District I, District II and District III was between 10 and 11 years, while the main cycle of precipitation in District IV was 25 years. The main conclusions include the following. (1) This region tended to be arid, and the precipitation gradually decreased from the southeast (District IV) to northwest (District I). (2) The influence of spatial differentiation characteristics on precipitation fluctuation in this region was cyclical fluctuation, which gradually decreased from the southeast to the northwest. The length of the cyclical change period gradually shortened. In the first main cycle, whose annual precipitation changes were most significant, the changing characteristic was District IV and District I decreased from 25 years to 10 years. (3) Predicated from the cyclical changing law that the annual precipitation decreases from high to low, the Horqin region will remain in a period of low precipitation between 2016 and 2020.

Starting already in the nineteenth century, many economists observed that business fluctuations took place with regularity, though they differed on their periodicity. This chapter discusses briefly the more important theories that have been posited to explain these fluctuations, and pays particular attention to those focusing on the role played by the financial sector, including Keynes and Minsky.

We investigate the cross-correlations between Renminbi (CNY) and four major currencies (USD, EUR, JPY, and KRW) in the Renminbi currency basket, i.e., the cross-correlations of CNY–USD, CNY–EUR, CNY–JPY, and CNY–KRW. Qualitatively , using a statistical test in analogy to the Ljung-Box test, we find that cross-correlations significantly exist in CNY–USD, CNY–EUR, CNY–JPY, and CNY–KRW. Quantitatively , employing the detrended cross-correlation analysis (DCCA) method, we find that the cross-correlations of CNY–USD, CNY–EUR, CNY–JPY, and CNY–KRW are weakly persistent. We use the DCCA cross-correlation coefficient ρ DCCA to quantify the level of cross-correlations and find the currency weight in the Renminbi currency basket is arranged in the order of USD>EUR>JPY >KRW. Using the method of rolling windows, which can capture the time-varying cross-correlation scaling exponents, we find that: (i) CNY and USD are positively cross-correlated over time, but the cross-correlations of CNY–USD are anti-persistent during the US sub-prime crisis and the European debt crisis. (ii) The cross-correlation scaling exponents of CNY-EUR have the cyclical fluctuation with a nearly two-year cycle. (iii) CNY–JPY has long-term negative cross-correlations, during the European debt crisis, but CNY and KRW are positively cross-correlated.

With the gradually maturing super-speed inkjet printing technology, people are pursuing steadier and higher speed as well as better quality presswork for the sake of increasing economic benefit. To provide an overview of the velocity fluctuation of the inkjet machine platform and the cyclical fluctuation of the incremental encoder, external clock and corresponding internal clock were applied separately to print the equally spaced lines under the same platform speed. Then a magnifier was used to measure distance between the lines, according to which the velocity fluctuation mentioned above can be obtained. Thus conclusion can be drawn from the fluctuation analysis that the velocity cycle of platform is 60mm, however, number of those produced by the incremental encoder is up to 3, including 60mm influenced by the platform, 300mm produced by the perimeter of encoders pressure wheel and 600mm produced by the circumference of dance roller. Furthermore, dance roller contributes more influence on narrow coated paper. Through this research, inkjet technician can do directional compensation for every factors to reduce the fluctuation.

The Bank of Korea changed its method of GDP estimation from a fixed-weighted to a chain-weighted measure in 2009. The fixed-weighted method had had problems such as substitution bias and the rewriting of economic history. As a result of the change, annual growth rates calculated using the chain-weighted method from 1970 through 2008 turned out to be 0.8%p higher on average than the existing rates. The quarterly average chain-weighted growth rates were 0.19%p higher than the fixed-weighted ones, but they changed in the same directions. In this paper we analyze whether the differences in rates between the two calculation methods would bring about a difference in the cyclical characteristics of GDP. We conclude that although there were differences in growth rates after introduction of the chain-weighted method, there was no difference in the cyclical fluctuation.