Urban parks can function as a proper sink of noise pollution.However,lack of universally-agreed upon methodologies and differing urban conditions have fueled controversy surrounding the effectuation of this urban park...Urban parks can function as a proper sink of noise pollution.However,lack of universally-agreed upon methodologies and differing urban conditions have fueled controversy surrounding the effectuation of this urban park function around the world.Hence,to address this controversy in narrow urban parks(with a mean width of∼109 m)in Isfahan City,Central Iran,noise levels(Lq30)were measured along two longitudinal transects placed along the interior northern river-and adjacent to the southern edge of the parks bordered by a heavily-conjected road.We used statistical tests and models to determine the association of noise levels measured along the northern transect with the distance to,and the intensity of noise emitted from,the road,vegetation biomass,and vegetation height within two 50 and 100 m buffer rings drawn around northern sites and the richness of bird species.The average Lq30 values differed significantly between the southern(∼73.21 dB)and northern(∼66.43 dB)transects and correlated negatively with species richness(r(98)=−0.324,p<0.01).Three variables including mean NDVIwithin the 100 m buffer ring,distance from the road and mean Lq30 values of the nearest three southern sites were included to build the best predictive multiple-linear regression model through the step-wise procedure with r2 of 0.52.These findings suggest that further attempts aiming to alleviate the parks’interior noise level should be attentive to distance to road,traffic at the nearest road part,and the interior vegetation characteristics.展开更多
This paper presents a general solution procedure and an interactive fuzzy satisfying method for a kind of fuzzy multi-objective linear programming-problems based on interval valued fuzzy sets. Firstly, a fuzzy set of ...This paper presents a general solution procedure and an interactive fuzzy satisfying method for a kind of fuzzy multi-objective linear programming-problems based on interval valued fuzzy sets. Firstly, a fuzzy set of the fuzzy solutions, which can be focused on providing complete information for the final decision, can be obtained by the proposed tolerance analysis of a non-dominated set. Secondly, the satisfying solution for the decisionmaker can be derived from Pareto optimal solutions by updating the current reference membership levels on the basis of the current levels of the membership functions together with the trade-off rates between the membership functions.展开更多
在舰船升沉信息的实时测量过程中,升沉滤波器实现了低频衰减和特定频段二次积分,但其存在输出相位超前的问题,并且超前相位的大小随输入信号频率变化。首先分析了升沉滤波器的误差特性,然后针对相位超前和噪声、零偏对系统影响的问题,...在舰船升沉信息的实时测量过程中,升沉滤波器实现了低频衰减和特定频段二次积分,但其存在输出相位超前的问题,并且超前相位的大小随输入信号频率变化。首先分析了升沉滤波器的误差特性,然后针对相位超前和噪声、零偏对系统影响的问题,提出了基于带限傅里叶线性组合(band-limited multiple Fourier linear combiner,BMFLC)算法校正滤波器输出的方法,并分析了算法中参数的选取和算法的计算量,实现了在抑制噪声和零偏的影响下对滤波器的输出进行幅度和相位补偿,进而提高了测量精度。仿真结果表明,提出的基于BMFLC算法的舰船升沉测量方法对升沉滤波器的输出进行了补偿,能够很好地解决超前相位误差和噪声、零偏影响的问题,实现了舰船升沉信息测量的实时性和准确性。展开更多
文摘Urban parks can function as a proper sink of noise pollution.However,lack of universally-agreed upon methodologies and differing urban conditions have fueled controversy surrounding the effectuation of this urban park function around the world.Hence,to address this controversy in narrow urban parks(with a mean width of∼109 m)in Isfahan City,Central Iran,noise levels(Lq30)were measured along two longitudinal transects placed along the interior northern river-and adjacent to the southern edge of the parks bordered by a heavily-conjected road.We used statistical tests and models to determine the association of noise levels measured along the northern transect with the distance to,and the intensity of noise emitted from,the road,vegetation biomass,and vegetation height within two 50 and 100 m buffer rings drawn around northern sites and the richness of bird species.The average Lq30 values differed significantly between the southern(∼73.21 dB)and northern(∼66.43 dB)transects and correlated negatively with species richness(r(98)=−0.324,p<0.01).Three variables including mean NDVIwithin the 100 m buffer ring,distance from the road and mean Lq30 values of the nearest three southern sites were included to build the best predictive multiple-linear regression model through the step-wise procedure with r2 of 0.52.These findings suggest that further attempts aiming to alleviate the parks’interior noise level should be attentive to distance to road,traffic at the nearest road part,and the interior vegetation characteristics.
基金This work is supported by the National Natural Science Foundation of China(No. 79670060).
文摘This paper presents a general solution procedure and an interactive fuzzy satisfying method for a kind of fuzzy multi-objective linear programming-problems based on interval valued fuzzy sets. Firstly, a fuzzy set of the fuzzy solutions, which can be focused on providing complete information for the final decision, can be obtained by the proposed tolerance analysis of a non-dominated set. Secondly, the satisfying solution for the decisionmaker can be derived from Pareto optimal solutions by updating the current reference membership levels on the basis of the current levels of the membership functions together with the trade-off rates between the membership functions.
文摘在舰船升沉信息的实时测量过程中,升沉滤波器实现了低频衰减和特定频段二次积分,但其存在输出相位超前的问题,并且超前相位的大小随输入信号频率变化。首先分析了升沉滤波器的误差特性,然后针对相位超前和噪声、零偏对系统影响的问题,提出了基于带限傅里叶线性组合(band-limited multiple Fourier linear combiner,BMFLC)算法校正滤波器输出的方法,并分析了算法中参数的选取和算法的计算量,实现了在抑制噪声和零偏的影响下对滤波器的输出进行幅度和相位补偿,进而提高了测量精度。仿真结果表明,提出的基于BMFLC算法的舰船升沉测量方法对升沉滤波器的输出进行了补偿,能够很好地解决超前相位误差和噪声、零偏影响的问题,实现了舰船升沉信息测量的实时性和准确性。
