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Asymptotic normality of error density estimator in stationary and explosive autoregressive models

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 140-158页

作者： WU Shi-peng YANG Wen-zhi gao Min HU shu-he School of Mathematical Sciences&School of Big Data and Statistics Anhui UniversityHefei 230601China School of Statistics Shanxi University of Finance and EconomicsTaiyuan030006China

In this paper,we consider the limit distribution of the error density function estima-tor in the rst-order autoregressive models with negatively associated and positively associated random *** mild regularity assumptions,some asymptotic normality results of the residual density estimator are obtained when the autoregressive models are stationary process and explosive *** order to illustrate these results,some simulations such as con dence intervals and mean integrated square errors are provided in this *** shows that the residual density estimator can replace the density\estimator"which contains errors.

关键词： explosive autoregressive models residual density estimator asymptotic distribution association sequence

The effects of cool materials,façade orientation,and morphological parameters on energy consumption at the residential neighborhood scale

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Building Simulation 2024年第4期17卷 525-542页

作者： Fusuo Xu Dongdong Tian zhi gao Jianshun Jensen Zhang Department of Mechanical and Aerospace Engineering Syracuse UniversitySyracuseNY13210USA School of Architecture and Urban Planning Nanjing University22 Hankou RoadNanjingJiangsu Province210093China

Building surface cool materials are novel materials that can reduce urban heat island intensity and decrease building energy *** study investigated the impact of radiative properties of materials,façade orientation,and morphological parameters on energy consumption in six typical residential neighborhoods in Nanjing,*** neighborhood energy consumption of 16 application schemes considering the façade orientation factor is compared to determine the best energy-saving *** and annual energy-saving rates,savings in electricity costs,and the price ceiling for materials per unit area are *** results show that for low-rise buildings,using cool materials only on the roof can reduce the annual energy consumption by 1%.When cool or super cool materials are also used on the building façade,the annual energy saving rate can be up to 3.4%and 4.3%,*** cool materials on the south façade of buildings is not recommended due to significant heat loss in *** savings in electricity costs and the price ceiling for materials per unit area,the price of cool and super cool materials should be less than 3.0 and 3.7 RMB/m2,respectively,assuming a lifespan of eight years in Nanjing.

关键词： cool materials building energy saving neighborhood morphology façade orientation

Spatial covariant gravity with two degrees of freedom in the presence of an auxiliary scalar field:Perturbation analysis

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Chinese Physics C 2024年第8期48卷 198-212页

作者： zhi-Chao Wang Xian gao School of Physics and Astronomy Sun Yat-sen UniversityZhuhai 519082China

We investigate a class of gravity theories respecting only spatial covariance,termed spatially covariant gravity,in the presence of an auxiliary scalar *** examine the conditions on the Lagrangian required to eliminate scalar degrees of freedom,allowing only two tensorial degrees of freedom to *** of strict constraint analysis,in this paper,we employ the perturbation method and focus on the necessary conditions to evade the scalar mode at the linear order in perturbations around a cosmological *** with a general action and solving the auxiliary perturbation variables in terms of a would-be dynamical scalar mode,we derive the condition to remove its kinetic term,thus ensuring that no scalar mode *** an application of the general condition,we study a polynomial-type Lagrangian as a concrete example,in which all monomials are spatially covariant scalars containing two *** find that the auxiliary scalar field is essential,and new terms in the Lagrangian are *** analysis provides insights into constructing gravity theories with two degrees of freedom in the extended framework of spatially covariant gravity.

关键词： modified gravity cosmological perturbation theory gravitational theory

Precise Asymptotics in Limit Theorems for a Supercritical Branching Process with Immigration in a Random Environment

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Acta Mathematica Sinica,English Series 2024年第8期40卷 1850-1874页

作者： Chun Mao HUANG Rui ZHANG zhi Qiang gao Department of Mathematics Harbin Institute of Technology(Weihai)Weihai 264209P.R.China School of Mathematical Sciences Beijing Normal UniversityBeijing 100875P.R.China

Let(Zn)be a supercritical branching process with immigration in an independent and identically distributed random *** necessary moment conditions,we show the exact convergence rate in the central limit theorem on log Zn and establish the corresponding local limit theorem by using the moments of the natural submartingale and the convergence rates of its *** similar approach and with the help of a change of measure,we also present the so-called integrolocal theorem and integral large deviation theorem to characterize the precise asymptotics of the upper large deviations.

关键词： Branching process with immigration random environment central limit theorem large deviation

Autonomous navigation of an asteroid orbiter enhanced by a beacon satellite in a high-altitude orbit

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Astrodynamics 2024年第3期8卷 375-400页

作者： Weidong Yin Yu Shi Leizheng shu Yang gao University of Chinese Academy of Sciences Beijing100049China Key Laboratory of Space Utilization Technology and Engineering Center for Space UtilizationChinese Academy of SciencesBeijing100094China

This study aims to assess the autonomous navigation performance of an asteroid orbiter enhanced using an inter-satellite link to a beacon *** navigation includes the orbit determination of the orbiter and beacon,and asteroid gravity estimation without any ground station *** measurements were acquired using satellite-to-satellite tracking(SST)and optical observation of asteroid surface *** study presents a new orbiter-beacon SST scheme,in which the orbiter circumnavigates the asteroid in a low-altitude strongly-perturbed orbit,and the beacon remains in a high-altitude weakly-perturbed *** used Asteroid 433 Eros as an example,and analyzed and designed low-and high-altitude orbits for the orbiter and *** navigation measurements were precisely modeled,extended Kalman filters were devised,and observation configuration was analyzed using the Cramer-Rao lower bound(CRLB).Monte Carlo simulations were carried out to assess the effects of the orbital inclination and altitudes of the orbiter and beacon as key influencing *** simulation results showed that the proposed SST scheme was an effective solution for enhancing the autonomous navigation performance of the orbiter,particularly for improving the accuracy of gravity estimation.

关键词： asteroid exploration gravity estimation orbit determination satellite-to-satellite tracking(SST) optical observation

Exploring the impact of economic growth and energy consumption on SO2 emissions in China based on the Environmental Kuznets Curve hypothesis

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Petroleum Science 2024年第4期21卷 2892-2900页

作者： Bing-Jie Xu Yi-Fei Shen Hui Qiao zhi gao Faculty of Business City University of Macau Rural Development Institute Chinese Academy of Social Sciences School of Marxism Shenzhen Polytechnic University

This study aims to analysis the influence of economic growth(EG) and energy consumption(EC) on sulfur dioxide emissions(SE) in China. Accordingly, this study explores the link between EG, EC, and SE for 30 provinces in China over the span of 2000-2019. This study also analyzes cross-sectional dependence tests, panel unit root tests, Westerlund panel cointegration tests, Dumitrescu-Hurlin(D-H) causality tests. According to the test results, there is an inverted U-shaped association between EG and SE,and the assumption of the Environmental Kuznets Curve(EKC) is verified. The signs of EG and EC in the fixed effect(FE) and random effect(RE) methods are in line with those in the dynamic ordinary least squares(DOLS), fully modified ordinary least squares(FMOLS) and autoregressive distributed lag(ARDL)estimators. Moreover, the results verified that EC can obviously positive impact the SE. To reduce SE in China, government and policymakers can improve air quality by developing cleaner energy sources and improving energy efficiency. This requires the comprehensive use of policies, regulations, economic incentives, and public participation to promote sustainable development.

关键词： SO 2 emissions Economic growth Energy consumption EKC China

Adaptive Algorithms on Maximizing Monotone Nonsubmodular Functions

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Journal of the Operations Research Society of China 2024年第2期12卷 428-445页

作者： Bin Liu Hui Su shu-Fang Gong Qi-zhi Fang School of Mathematical Sciences Ocean Universityof ChinaQingdao266100ShandongChina

Submodular optimization is widely used in large *** order to speed up the problems solving,it is essential to design low-adaptive algorithms to achieve acceleration in *** general,the function values are given by a value oracle,but in practice,the oracle queries may consume a lot of ***,how to strike a balance between optimizing them is *** this paper,we focus on maximizing a normalized and strictly monotone set function with the diminishing-return ratio under a cardinality constraint,and propose two algorithms to deal with *** apply the adaptive sequencing technique to devise the first algorithm,whose approximation ratio is arbitrarily close to 1-e^(-γ)in O(logn·log(log k/γ)) adaptive rounds,and requires O(logn^(2)·log(log k/γ)) *** by adding preprocessing and parameter estimation steps to the first algorithm,we get the second *** second algorithm trades a small sacrifice in adaptive complexity for a significant improvement in query *** the same approximation and adaptive complexity,the query complexity is improved *** the best of our knowledge,this is the first paper of designing adaptive algorithms for maximizing a monotone function using the diminishing-return ratio.

关键词： Approximation algorithm Adaptivity Nonsubmodular maximization Cardinality constraint

Mechanism Design for Ancillary Service Market Considering Social Welfare and Fairness

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1000-1010页

作者： zhi Wu Yuanxi Wu Wei Gu Zheng Xu shu Zheng Jingtao Zhao School of Electrical Engineering Southeast UniversityNanjing 210096China NARI Technology Co. Ltd.Nanjing 211106China IEEE CSEE

Increasing penetration of distributed energy resources in the distribution network(DN)is threatening safe operation of the DN,which necessitates setup of the ancillary service market in the *** the ancillary service market,distribution system operator(DSO)is responsible for safety of the DN by procuring available capacities of *** existing studies,this paper proposes a novel market mechanism composed of two parts:choice rule and payment *** proposed choice rule simultaneously considers social welfare and fairness,encouraging risk-averse aggregators to participate in the ancillary service *** is then formulated as a linear programming problem,and a distributed solution using the multi-cut Benders decomposition is ***,successful implementation of the choice rule depends on each aggregator’s truthful adoption of private ***,a payment rule is also designed,which is proved to possess two properties:incentive compatibility and individual *** results demonstrate effectiveness of the proposed choice rule on improving fairness and verify properties of the payment rule.

关键词： Aggregator ancillary service market distributed mechanism fairness mechanism design

Influence of friction-lubrication characteristics varying with rolling speed on instability of chatter and slip in cold tandem rolling process

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Journal of Iron and Steel Research International 2024年第4期31卷 894-908页

作者： Yan-li Xin zhi-ying gao Bo Tian Qing-dong Zhang School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China

In the high-speed cold tandem rolling process of thin plate,chatter or slip instability gives rise to the deterioration of equipment and product *** instability behavior is closely related to interfacial friction-lubrication con-dition which is generally characterized by the friction ***,with higher and higher speed requirements,the commonly used model of friction coefficient is no longer applicable and accurate.A novel approach is suggested to calculate the speed-dependent friction coefficient,in which the viscosity-pressure-temperature effects of the lubricant,surface roughness states of work rolls and rolled piece are comprehensively involved and the mixed flm lubrication theory is ***,the influences of friction coefficient on the instability of slip and chatter are investigated for a five-stand cold tandem rolling *** one side,the critical friction coefficient for each stand is determined by calculating the corresponding slip factor;on the other hand,the friction coefficient varying with rolling speed is combined with the model of theoretical critical rolling speed presented under constant friction coefficient,so that the speed threshold is ***,the stable and unstable regions corresponding to the rear three stands are individually discussed,and the technical strategies are proposed to suppress both slip and chatter frequently occurring in the actual rolling process.

关键词： Cold tandem rolling:Oil film thickness Speed-dependent friction coefficient-Slip:Chatter