The breeding biology of a captive, isolated population of Dalmatian Pelicans (Pelecanus crispus) at theShanghaiZoo,China, was studied from 2007 to 2019. The breeding age of the Dalmatian Pelicans was estimated at thre...The breeding biology of a captive, isolated population of Dalmatian Pelicans (Pelecanus crispus) at theShanghaiZoo,China, was studied from 2007 to 2019. The breeding age of the Dalmatian Pelicans was estimated at three to four years old, and they started breeding in late October or early November. The clutch size varied between one and two eggs per nest, and the eggs were 83.2 ±4.8 mmin length, 55.6 ±2.9 mmin breadth and 136.1 ±21.5 gin weight. The fertility fluctuated slightly, with an average rate of 38.7% ± 9.7%, but remained consistently low. The survival rate of chicks fluctuated substantially from 0% to 100%, with an average survival rate of 68.6% ± 27.6%. The averaged values of observed heterozygosity, expected heterozygosity and polymorphism information content were 0.468, 0.465 and 0.446, respectively. It indicated that the population had a low heterozygosity and genetic diversity. There was a significant change in the breeding index compared to that recorded 40 years ago, which indicates that inbreeding depression has occurred in this small, isolated, captive population of Dalmatian Pelicans. These results can be used to improve management of Dalmatian Pelicans in captivity.展开更多
Alternating direction method of multipliers(ADMM)receives much attention in the recent years due to various demands from machine learning and big data related optimization.In 2013,Ouyang et al.extend the ADMM to the s...Alternating direction method of multipliers(ADMM)receives much attention in the recent years due to various demands from machine learning and big data related optimization.In 2013,Ouyang et al.extend the ADMM to the stochastic setting for solving some stochastic optimization problems,inspired by the structural risk minimization principle.In this paper,we consider a stochastic variant of symmetric ADMM,named symmetric stochastic linearized ADMM(SSL-ADMM).In particular,using the framework of variational inequality,we analyze the convergence properties of SSL-ADMM.Moreover,we show that,with high probability,SSL-ADMM has O((ln N)·N^(-1/2))constraint violation bound and objective error bound for convex problems,and has O((ln N)^(2)·N^(-1))constraint violation bound and objective error bound for strongly convex problems,where N is the iteration number.Symmetric ADMM can improve the algorithmic performance compared to classical ADMM,numerical experiments for statistical machine learning show that such an improvement is also present in the stochastic setting.展开更多
In financial analysis risk quantification is essential for efficient portfolio management in a stochastic framework. In this paper we study the value at risk, the expected shortfall, marginal expected shortfall and va...In financial analysis risk quantification is essential for efficient portfolio management in a stochastic framework. In this paper we study the value at risk, the expected shortfall, marginal expected shortfall and value at risk, incremental value at risk and expected shortfall, the marginal and discrete marginal contributions of a portfolio. Each asset in the portfolio is characterized by a trend, a volatility and a price following a three-dimensional diffusion process. The interest rate of each asset evolves according to the Hull and White model. Furthermore, we propose the optimization of this portfolio according to the value at risk model.展开更多
Is the ＂non-existence＂ of the Phillips curve in China a truth or just an illusion due to the deficiency of data？ Should policy analysis follow the light of New-Keynesian or New-classical economics？ These questions...Is the ＂non-existence＂ of the Phillips curve in China a truth or just an illusion due to the deficiency of data？ Should policy analysis follow the light of New-Keynesian or New-classical economics？ These questions require empirical work on the Phillips curve, which has long been limited in China due to an inaccurate unemployment rate and unreliable estimated output gap. Instead of the insignificant or self-contradicting results in previous work, this paper puts forward a significant estimation, creatively using the vacancy-jobseeker ratio instead of the unemployment rate. It is suggested that a robust Phillips curve cannot be ignored and New-Keynesian economics should be employed in policy analysis in the short run.展开更多
文摘The breeding biology of a captive, isolated population of Dalmatian Pelicans (Pelecanus crispus) at theShanghaiZoo,China, was studied from 2007 to 2019. The breeding age of the Dalmatian Pelicans was estimated at three to four years old, and they started breeding in late October or early November. The clutch size varied between one and two eggs per nest, and the eggs were 83.2 ±4.8 mmin length, 55.6 ±2.9 mmin breadth and 136.1 ±21.5 gin weight. The fertility fluctuated slightly, with an average rate of 38.7% ± 9.7%, but remained consistently low. The survival rate of chicks fluctuated substantially from 0% to 100%, with an average survival rate of 68.6% ± 27.6%. The averaged values of observed heterozygosity, expected heterozygosity and polymorphism information content were 0.468, 0.465 and 0.446, respectively. It indicated that the population had a low heterozygosity and genetic diversity. There was a significant change in the breeding index compared to that recorded 40 years ago, which indicates that inbreeding depression has occurred in this small, isolated, captive population of Dalmatian Pelicans. These results can be used to improve management of Dalmatian Pelicans in captivity.
基金Supported by National Natural Science Foundation of China (61662036)。
文摘Alternating direction method of multipliers(ADMM)receives much attention in the recent years due to various demands from machine learning and big data related optimization.In 2013,Ouyang et al.extend the ADMM to the stochastic setting for solving some stochastic optimization problems,inspired by the structural risk minimization principle.In this paper,we consider a stochastic variant of symmetric ADMM,named symmetric stochastic linearized ADMM(SSL-ADMM).In particular,using the framework of variational inequality,we analyze the convergence properties of SSL-ADMM.Moreover,we show that,with high probability,SSL-ADMM has O((ln N)·N^(-1/2))constraint violation bound and objective error bound for convex problems,and has O((ln N)^(2)·N^(-1))constraint violation bound and objective error bound for strongly convex problems,where N is the iteration number.Symmetric ADMM can improve the algorithmic performance compared to classical ADMM,numerical experiments for statistical machine learning show that such an improvement is also present in the stochastic setting.
文摘In financial analysis risk quantification is essential for efficient portfolio management in a stochastic framework. In this paper we study the value at risk, the expected shortfall, marginal expected shortfall and value at risk, incremental value at risk and expected shortfall, the marginal and discrete marginal contributions of a portfolio. Each asset in the portfolio is characterized by a trend, a volatility and a price following a three-dimensional diffusion process. The interest rate of each asset evolves according to the Hull and White model. Furthermore, we propose the optimization of this portfolio according to the value at risk model.
文摘Is the ＂non-existence＂ of the Phillips curve in China a truth or just an illusion due to the deficiency of data？ Should policy analysis follow the light of New-Keynesian or New-classical economics？ These questions require empirical work on the Phillips curve, which has long been limited in China due to an inaccurate unemployment rate and unreliable estimated output gap. Instead of the insignificant or self-contradicting results in previous work, this paper puts forward a significant estimation, creatively using the vacancy-jobseeker ratio instead of the unemployment rate. It is suggested that a robust Phillips curve cannot be ignored and New-Keynesian economics should be employed in policy analysis in the short run.
