This study unfolds an innovative approach aiming to address the critical role of building design in global energy consumption, focusing on optimizing the Window-to-Wall Ratio (WWR), since buildings account for approxi...This study unfolds an innovative approach aiming to address the critical role of building design in global energy consumption, focusing on optimizing the Window-to-Wall Ratio (WWR), since buildings account for approximately 30% of total energy consumed worldwide. The greatest contributors to energy expenditure in buildings are internal artificial lighting and heating and cooling systems. The WWR, determined by the proportion of the building’s glazed area to its wall area, is a significant factor influencing energy efficiency and minimizing energy load. This study introduces the development of a semi-automated computer model designed to offer a real-time, interactive simulation environment, fostering improving communication and engagement between designers and owners. The said model serves to optimize both the WWR and building orientation to align with occupants’ needs and expectations, subsequently reducing annual energy consumption and enhancing the overall building energy performance. The integrated model incorporates Building Information Modeling (BIM), Virtual Reality (VR), and Energy Analysis tools deployed at the conceptual design stage, allowing for the amalgamation of owners’ inputs in the design process and facilitating the creation of more realistic and effective design strategies.展开更多
An adaptive approach to select analysis window param- eters for linear frequency modulated （LFM） signals is proposed to obtain the optimal 3 dB signal-to-noise ratio （SNR） in the short- time Fourier transform （S...An adaptive approach to select analysis window param- eters for linear frequency modulated （LFM） signals is proposed to obtain the optimal 3 dB signal-to-noise ratio （SNR） in the short- time Fourier transform （STFT） domain. After analyzing the instan- taneous frequency and instantaneous bandwidth to deduce the relation between the window length and deviation of the Gaus- sian window, high-order statistics is used to select the appropriate window length for STFT and get the optimal SNR with the right time-frequency resolution according to the signal characteristic under a fixed sampling rate. Computer simulations have verified the effectiveness of the new method.展开更多
In the practical measurement of signal to noise ratio(SNR)of analog-to-digital converters(ADCs)by using fast Fourier transformation(FFT)method,the non-coherent sampling is inevitable,leading to spectral leakage which ...In the practical measurement of signal to noise ratio(SNR)of analog-to-digital converters(ADCs)by using fast Fourier transformation(FFT)method,the non-coherent sampling is inevitable,leading to spectral leakage which in turn affects the calculation accuracy and final measurement results.In this paper,a new method based on the Blackman-Harris windowed triple-spectrum-line interpolation is presented for the measurement of ADCs SNR by FFT.The simulation platform is built based on MATLAB and the behavioral dynamic models of the high-speed ADC products of Analog Devices Inc.(ADI)are simulated.The simulation results show that,even in the case of the maximum non-coherent degree,the SNR error is less than0.23dB and reaches the testing standards provided by ADI,confirming that the proposed method is effective for suppressing the spectral leakage effects and improving the SNR test accuracy.展开更多
In this study, a new R-δf-type welding window on charge parameters is constructed by determining the boundary conditions of the explosive ratio. The R-δf-type welding window synthetically considers the explosive pro...In this study, a new R-δf-type welding window on charge parameters is constructed by determining the boundary conditions of the explosive ratio. The R-δf-type welding window synthetically considers the explosive properties and material properties, and can quickly determine the explosive charge at different welding materials with different thickness. In order to test the practicability and accuracy of the R-δf-type welding window, 410S stainless steel and Q345R low alloy steel plates were explosively welded using 15 mm charge determined by the new window. Microstructures of the bonded sections were examined and then shear tests were carried out on the bonded specimens. Microstructural examination showed the joint interface was transformed from micro wavy to small wavy appearance without microstructure defects. Shear tests results showed inter inacial shear strength was much higher than that of the national first grade standard. So the R-δf-type welding window has strong practicability and accuracy and is helpful to the practical production and application of explosive welding composite materials.展开更多
中国积极推进300万平方公里海洋国土建设,目前正在大力建设南海的西沙群岛和南沙群岛海域.海洋中的岛屿、岛礁气候与陆地气候差异较大,具有高温、高湿、强辐射的海洋气候特点.在这种特殊的气候条件下,结合岛上资源匮乏的事实,研发低能...中国积极推进300万平方公里海洋国土建设,目前正在大力建设南海的西沙群岛和南沙群岛海域.海洋中的岛屿、岛礁气候与陆地气候差异较大,具有高温、高湿、强辐射的海洋气候特点.在这种特殊的气候条件下,结合岛上资源匮乏的事实,研发低能耗建筑成为必然.为确定与岛礁气候相适宜的低能耗建筑的围护结构特点,以西沙的气象实测数据为例分析海洋气候特点,采用动态模拟的方法,以岛礁上拟建宾馆建筑为对象,分析不同朝向窗墙比变化对建筑全年能耗的影响.结果表明:湿负荷约占空调负荷的40%,在夏季西向房间空调负荷最高,南向最低;窗墙比每增加0.1,单位建筑面积空调负荷可增加3~5 k Wh,但空调负荷随东西向窗墙比的增长速度较南北向快;采用综合遮阳方式的节能率最高,约为7%.本研究结果旨在为中国南部海域岛礁建筑窗墙比的合理取值提供参考.展开更多
文摘This study unfolds an innovative approach aiming to address the critical role of building design in global energy consumption, focusing on optimizing the Window-to-Wall Ratio (WWR), since buildings account for approximately 30% of total energy consumed worldwide. The greatest contributors to energy expenditure in buildings are internal artificial lighting and heating and cooling systems. The WWR, determined by the proportion of the building’s glazed area to its wall area, is a significant factor influencing energy efficiency and minimizing energy load. This study introduces the development of a semi-automated computer model designed to offer a real-time, interactive simulation environment, fostering improving communication and engagement between designers and owners. The said model serves to optimize both the WWR and building orientation to align with occupants’ needs and expectations, subsequently reducing annual energy consumption and enhancing the overall building energy performance. The integrated model incorporates Building Information Modeling (BIM), Virtual Reality (VR), and Energy Analysis tools deployed at the conceptual design stage, allowing for the amalgamation of owners’ inputs in the design process and facilitating the creation of more realistic and effective design strategies.
基金supported by the National Natural Science Foundation of China(6107313361175053+8 种基金6127236960975019)the Heilongjiang Postdoctoral Grant(LRB08362)the Fundamental Research Funds for the Central Universities of China(2011QN0272011QN1262012QN0302011ZD010)the Science and Technology Planning Project of Dalian City(2011A17GX0732010E15SF153)
文摘An adaptive approach to select analysis window param- eters for linear frequency modulated （LFM） signals is proposed to obtain the optimal 3 dB signal-to-noise ratio （SNR） in the short- time Fourier transform （STFT） domain. After analyzing the instan- taneous frequency and instantaneous bandwidth to deduce the relation between the window length and deviation of the Gaus- sian window, high-order statistics is used to select the appropriate window length for STFT and get the optimal SNR with the right time-frequency resolution according to the signal characteristic under a fixed sampling rate. Computer simulations have verified the effectiveness of the new method.
基金Summit of the Six Top Talents Program of Jiangsu Province(No.2013-DZXX-027)Fundamental Research Funds for the Central Universities(Nos.JUSRP51510,JUSRP51323B)Graduate Student Innovation Program for Universities of Jiangsu Province(Nos.SJLX16_0500,KYLX16_0776,SJCX17_0510)
文摘In the practical measurement of signal to noise ratio(SNR)of analog-to-digital converters(ADCs)by using fast Fourier transformation(FFT)method,the non-coherent sampling is inevitable,leading to spectral leakage which in turn affects the calculation accuracy and final measurement results.In this paper,a new method based on the Blackman-Harris windowed triple-spectrum-line interpolation is presented for the measurement of ADCs SNR by FFT.The simulation platform is built based on MATLAB and the behavioral dynamic models of the high-speed ADC products of Analog Devices Inc.(ADI)are simulated.The simulation results show that,even in the case of the maximum non-coherent degree,the SNR error is less than0.23dB and reaches the testing standards provided by ADI,confirming that the proposed method is effective for suppressing the spectral leakage effects and improving the SNR test accuracy.
基金supported by the National Natural Science Foundation of China(Grant No.51541112)
文摘In this study, a new R-δf-type welding window on charge parameters is constructed by determining the boundary conditions of the explosive ratio. The R-δf-type welding window synthetically considers the explosive properties and material properties, and can quickly determine the explosive charge at different welding materials with different thickness. In order to test the practicability and accuracy of the R-δf-type welding window, 410S stainless steel and Q345R low alloy steel plates were explosively welded using 15 mm charge determined by the new window. Microstructures of the bonded sections were examined and then shear tests were carried out on the bonded specimens. Microstructural examination showed the joint interface was transformed from micro wavy to small wavy appearance without microstructure defects. Shear tests results showed inter inacial shear strength was much higher than that of the national first grade standard. So the R-δf-type welding window has strong practicability and accuracy and is helpful to the practical production and application of explosive welding composite materials.
文摘中国积极推进300万平方公里海洋国土建设,目前正在大力建设南海的西沙群岛和南沙群岛海域.海洋中的岛屿、岛礁气候与陆地气候差异较大,具有高温、高湿、强辐射的海洋气候特点.在这种特殊的气候条件下,结合岛上资源匮乏的事实,研发低能耗建筑成为必然.为确定与岛礁气候相适宜的低能耗建筑的围护结构特点,以西沙的气象实测数据为例分析海洋气候特点,采用动态模拟的方法,以岛礁上拟建宾馆建筑为对象,分析不同朝向窗墙比变化对建筑全年能耗的影响.结果表明:湿负荷约占空调负荷的40%,在夏季西向房间空调负荷最高,南向最低;窗墙比每增加0.1,单位建筑面积空调负荷可增加3~5 k Wh,但空调负荷随东西向窗墙比的增长速度较南北向快;采用综合遮阳方式的节能率最高,约为7%.本研究结果旨在为中国南部海域岛礁建筑窗墙比的合理取值提供参考.
