Can the Target Responsibility System of Air Pollution Control Achieve a Win-Win Situation of Pollution Reduction and Efficiency Enhancement?

Whether the environmental target responsibility system, a typical mandatory environmental regulation, can realize the coordinated development of environmental protection and economic growth has attracted widespread attention. With the difference-in-differences (DID) method, this paper utilizes a policy, “China’s Key Cities for Air Pollution Control to Meet the Standards within the Time Limit (APCMS),” as a quasi-natural experiment to empirically examine the target responsibility system of air pollution control’s effect on both firms’ pollutant emissions and their total factor productivity (TFP). The corresponding mechanisms are also investigated. The results show: 1) The policy not only significantly decreases firms’ pollutant emissions, but also improves their TFP. The results are robust to the exclusion of the impact of other policies in the same period, propensity score matching DID (PSM-DID) test, the adoption of alternative dependent variables, and altering sample interval; 2) The dynamic analysis shows that the policy effect on reducing pollutant emissions has increased over years after a lag of 2 years; 3) The policy reduces pollutant emissions mainly through stimulating the internal innovation rather than end-pipe treatment or production cuts. 4) Capital-intensive and private firms and firms in regions with a high degree of marketization or strong environmental law enforcement are found more responsive to the environmental target responsibility system.

High-Precision and High-Resolution Synchrosqueezing Transform via Time-Frequency Instantaneous Phases

Synchrosqueezing transform (SST) can effectively improve time-frequency precision and resolution by squeezing time-frequency spectra via instantaneous frequencies, and it has been applied in many diverse disciplines; however, the precision of estimated instantaneous frequencies during SST is usually affected by the time-sample interval of the inputted signal; this usually leads to low-precision or inaccurate SST results and limits its further application. To obtain high-precision and high-resolution SST results with high efficiency, we propose a high-precision and high-resolution SST via time-frequency instantaneous phases (HSST); in HSST, time-frequency instantaneous phases with period-jumps removal are used for high-precision instantaneous frequencies estimation and SST. Two synthetic signal examples show that HSST can minimize the impact of the time-sample interval to achieve high-precision and high-resolution SST results with high efficiency. A real 3D seismic data application demonstrates that HSST has fantastic performance in time-frequency precision and resolution enhancement, and it can be widely used in digital signals processing and interpretation fields.

Idealized simulation study of the relationship of disdrometer sampling statistics with the precision of precipitation rate measurement

Due to the discretized nature of rain, the measurement of a continuous precipitation rate by disdrometers is subject to statistical sampling errors. Here, Monte Carlo simulations are employed to obtain the precision of rain detection and rate as a function of disdrometer collection area and compared with World Meteorological Organization guidelines for a 1 min sample interval and 95 % probability. To meet these requirements, simulations suggest that measurements of light rain with rain rates R ≤ 0.50 mm h−1 require a collection area of at least 6 cm × 6 cm, and for R = 1 mm h−1, the minimum collection area is 13 cm × 13 cm. For R = 0.01 mm h−1, a collection area of 2 cm × 2 cm is sufficient to detect a single drop. Simulations are compared with field measurements using a new hotplate device, the Differential Emissivity Imaging Disdrometer. The field results suggest an even larger plate may be required to meet the stated accuracy, likely in part due to non-Poissonian hydrometeor clustering.

The Impact of Geopolitical Risk on Systemic Risk Spillover in Commodity Market: An EMD-Based Network Topology Approach

Since the financialization of commodities, portfolio investments have become an important tool for investors to diversify risks. However, due to the nonlinear fluctuations brought about by extreme events, investors face more difficulties in the choice of risk portfolio. We adopt empirical mode decomposition and STVAR model, along with the basis data of optimized original sample interval. In addition, we retain the mature research of multiscale systemic risk under frequency and divide the dimension of systemic risk into two states. When frequency is combined with states, the risk spillover center undergoes subversive changes, particularly in the longest term, and metals become the risk spillover center, substituting the energy commodity, on the condition that the compositions of extreme value add persuasive power to the perspective of long term. We proposed that the joint fluctuation of agricultural commodities and energy commodities makes the former become another important risk spillover point. For investors, holding period and portfolio both need to be considered.

Estimasi Jumlah Penghuni Ruangan Berdasarkan Konsentrasi CO2 Dengan Metode Bayesian MCMC

<span lang="PT-BR">The number of occupants in the building is important information for building management because it is related to security issues, evacuation, and energy saving. This article focuses on estimating the number of occupants using the Bayesian Monte Carlo Markov chain (MCMC) method based on indoor CO₂ levels. Probability theory underlies the Bayesian MCMC principle, where the mass balance equation of indoor CO₂ is used as a physical model of estimation calculations. Determination of the variables in the mass balance equation is investigated to obtain the effect on the accuracy of the estimated number of occupants. It found that the higher the standard deviation of the input variable on the physical model, the higher the error estimation produced. In addition, the Bayesian MCMC algorithm is tested in a real-time scheme of test</span><span lang="IN">-</span><span lang="PT-BR">chamber. The result shows an estimated error of 39%. Rapid changes influence estimation errors in actual occupants relative to the sample interval and the time delay of the estimation.</span>

Statistical-Economic Design of Control Chart If The Vector of Target Values of Multi-Variables Shifts With Time

In this paper, the statistical-economic design of a multivariate special triangle control chart is proposed to control the processes of the quality characteristics or financial indices shifting with time. A multi-objective programming with several constraints is used to determine optimal solutions of control region (probability of false alarm), the power of finding out assignable cause(s), sample interval and sample size. An application of the statistical-economic design of a Multivariate special triangle control chart is illustrated to control the soundness of insurers of U.S

The Impact of Margin and Short Selling on Stock Pricing Efficiency – Based on the Growth Enterprise Market and the Science and Technology Innovation Board

This paper takes the margin and short selling targets of the science and technology innovation board and the growth enterprise board of China’s stock market as the research object, and selects the sample interval from July 2019 to November 2020, Uses the unbalanced data panel model, discusses the effect of short selling and margin trading on the pricing efficiency of stock from the perspectives of the reaction speed and information content of stock information. The results show that margin trading is generally beneficial to the improvement of the pricing efficiency of the stock market; the effect of margin trading and short selling on the improvement of pricing efficiency of different stocks is different. The imbalance of power between margin trading and margin trading has a negative impact on the pricing efficiency of the stock market. The conclusion is helpful for subsequent scholars to continue to study the development level of the securities market and provide suggestions for the development direction of China’s securities market.

Interval and Point Direction Finding of Radio Emission Sources for Broadband Radio Monitoring

Introduction. The point and interval direction finding of radio sources is used for broadband radio monitoring in the frequency domain. The initial data for broadband radio monitoring are spectral samples obtained from an M-element antenna array by multichannel reception. Point direction finding is based on a grouping of point estimates of azimuth and elevation angle formed for each frequency sample, in which signal components are detected. A single estimate of azimuth and elevation angle is made based on the grouped point estimates in the range of neighbouring frequency samples. Interval direction finding is based on the azimuth and elevation estimates formed entirely from the interval of adjacent frequency samples, in which the signal components are found, and the subsequent refinement of frequency sample interval boundaries for each radio source in multisignal mode by spatial selection methods. Point direction finding is mainly implemented in single-signal mode in modern operating broadband radio monitoring complexes, while the multi-signal mode based on MUSIC or ESPRIT is implemented in the time domain in a narrow frequency band.Aim. Development and investigation of methods for point and interval direction finding in multi-signal mode, as well as development of recommendations for their practical application in multi-signal and single-signal modes.Methods. Multi-signal mode for point and interval direction finding was implemented using MUSIC and ESPRIT. An experimental study of the developed direction finding methods in single-signal and multi-signal (on ESPRIT) modes with overlapping signal spectra was carried out by processing the recorded real signals. The records were made using a seven-channel coherent synchronous receiver connected to a seven-element 60° angle antenna array.Results. The research results are presented by frequency-azimuth panoramas and estimates of the amplitude spectra of separated signals and direction finding accuracy indicators.Conclusion. It was experimentally demonstrated that point direction finding should be used in single-signal mode provided the absence of information on the number of signals in the observed data. Interval direction finding is recom-mended in multi-signal mode for improving the accuracy and real-time feasibility of the process.