A statistical approach to evaluate the subjective perception of the annoyance caused by the vehicle noise was presented in this paper. After recording the noises of Sanfeng, Huali and Xiali at speeds of 30, 40, 50, 60...A statistical approach to evaluate the subjective perception of the annoyance caused by the vehicle noise was presented in this paper. After recording the noises of Sanfeng, Huali and Xiali at speeds of 30, 40, 50, 60, 70 and 80 km/h respectively, the annoyance of the vehicle noises was evaluated in the testing room using paired comparison method, and the sound quality metrics and subjective annoyance were then distilled. Loudness, sharpness, roughness, periodicity and impulsiveness were selected for each of the vehicle noises. By correlation analysis method, it can be found that loudness has a higher correlation （0.91） with annoyance than other parameters. Meanwhile, sharpness, periodicity, roughness and impulsiveness have correlation with subjective perception with correlation coefficients being 0.84, -0.82, 0.62 and 0.87, respectively. The result of multiple regression analysis shows that calculated annoyance obtained by the regression equation can explain the perceptual annoyance and the regressed evaluation model is feasible to evaluate the sound quality of vehicle.展开更多
Acoustic vector sensor consists of pressure and particle velocity sensors,which measure the three-dimensional acoustic particle velocity,as well as the pressure at one location at the same time.By preserving the ampli...Acoustic vector sensor consists of pressure and particle velocity sensors,which measure the three-dimensional acoustic particle velocity,as well as the pressure at one location at the same time.By preserving the amplitude and phase information of the pressure and particle velocity,they possess a number of advantages over traditional scalar sensors.Signal-to-noise ratio (SNR) gain (which is often called array gain) is one of such advantages and is always interested by all of us.But it is not unchangeable if the spatial correlation of the noise field varies.Much more important,it is difficult to be given if the noise becomes complex.In this paper,spatial correlation of the vector field of isotropic volume-noise and surface-generated noise has been introduced briefly.Based on the results,the combined SNR output of a vector linear array is investigated and the maximum gain is given in the specified noise.Computer simulation shows that the output of one array in the same noise is not the same in different gestures.And then we find the best gesture through SNR calculation and obtain the biggest gain,which has important meaning to guide how to deploy an array in practice.We also should use the array with respect to the characteristics of the real ambient noise,especially in anisotropic noise field.展开更多
With the use ofa Geiger proportional counter with sensor tube of Russian and Chinese origin, a comparison was made in this work between measurements of environmental ionizing radiation with these detectors and a sodiu...With the use ofa Geiger proportional counter with sensor tube of Russian and Chinese origin, a comparison was made in this work between measurements of environmental ionizing radiation with these detectors and a sodium iodide scintillator activated with TI （Thallium NaI）. Through measurements carried out in a room located inside a tower 25 meters high on the ITA （Technological Institute of Aeronautics） campus, it was possible to study the efficiency of the three instruments for the environmental measurement of ionizing radiations at that location. Between March 7th and June 2nd of 2017, in that region, nine intense and weak rains were observed with 12 cold fronts coming from southern Brazil. Radiation measurements and the local meteorology involved are analyzed in this work to verify possible correlations.展开更多
OBJECTIVE: To make an open label prospective trial for comparing the therapeutic effects of mycophenolate mofetil (MMF) vs cyclophosphamide (CYC) pulse therapy on patients with diffuse proliferative lupus nephritis (D...OBJECTIVE: To make an open label prospective trial for comparing the therapeutic effects of mycophenolate mofetil (MMF) vs cyclophosphamide (CYC) pulse therapy on patients with diffuse proliferative lupus nephritis (DPLN). METHODS: Forty-six patients with biopsy proven active DPLN were enrolled in this study. Twenty-three patients were given MMF orally at a dosage of 1.0 - 1.5 g/d (MMF Group). Another 23 cases received conventional intermittent CYC pulse therapy (CYC Group). Supplemental steroid treatment was offered in the same manner to both groups. The age, sex distribution and severity of renal damage were matched in two groups. Therapeutic effects were evaluated at the end of six-month treatment. Fifteen patients in the MMF Group and 12 patients in the CYC Group had repeated renal biopsy at that time. RESULTS: MMF therapy was more effective in reducing proteinuria and hematuria. A 50% reduction of urinary protein and urinary red blood cell excretion from baseline value in 69.6% and 91.3% patients in the MMF Group, while only 47.8% and 65.2% in the CYC Group. MMF was more effective in inhibiting autoantibody production (especially anti-dsDNA antibody) and in decreasing serum cryoglobulin levels. Pathologically, the MMF group showed more markedly reduction in glomerular immune deposits with less glomerular necrosis, and less microthrombi, less crescent formation and vascular changes in the repeated renal biopsy as compared with the CYC group. Adverse reactions related to the treatment included gastrointestinal symptoms 26.1% and 43.5% in the MMF and CYC Groups respectively, infection 17.4% in the MMF group and 30.4% in the CYC group. CONCLUSION: MMF was more effective in controlling the clinical activity of DPLN and renal vascular lesions as compared with CYC pulse therapy in a 6 month follow-up study.展开更多
基金Supported by Province and University Cooperation Fund of Yunnan Province (No. 2003HBBAA02A049).
文摘A statistical approach to evaluate the subjective perception of the annoyance caused by the vehicle noise was presented in this paper. After recording the noises of Sanfeng, Huali and Xiali at speeds of 30, 40, 50, 60, 70 and 80 km/h respectively, the annoyance of the vehicle noises was evaluated in the testing room using paired comparison method, and the sound quality metrics and subjective annoyance were then distilled. Loudness, sharpness, roughness, periodicity and impulsiveness were selected for each of the vehicle noises. By correlation analysis method, it can be found that loudness has a higher correlation （0.91） with annoyance than other parameters. Meanwhile, sharpness, periodicity, roughness and impulsiveness have correlation with subjective perception with correlation coefficients being 0.84, -0.82, 0.62 and 0.87, respectively. The result of multiple regression analysis shows that calculated annoyance obtained by the regression equation can explain the perceptual annoyance and the regressed evaluation model is feasible to evaluate the sound quality of vehicle.
基金Supported by the National Natural Science Foundation of China under Grant No.50909028
文摘Acoustic vector sensor consists of pressure and particle velocity sensors,which measure the three-dimensional acoustic particle velocity,as well as the pressure at one location at the same time.By preserving the amplitude and phase information of the pressure and particle velocity,they possess a number of advantages over traditional scalar sensors.Signal-to-noise ratio (SNR) gain (which is often called array gain) is one of such advantages and is always interested by all of us.But it is not unchangeable if the spatial correlation of the noise field varies.Much more important,it is difficult to be given if the noise becomes complex.In this paper,spatial correlation of the vector field of isotropic volume-noise and surface-generated noise has been introduced briefly.Based on the results,the combined SNR output of a vector linear array is investigated and the maximum gain is given in the specified noise.Computer simulation shows that the output of one array in the same noise is not the same in different gestures.And then we find the best gesture through SNR calculation and obtain the biggest gain,which has important meaning to guide how to deploy an array in practice.We also should use the array with respect to the characteristics of the real ambient noise,especially in anisotropic noise field.
文摘With the use ofa Geiger proportional counter with sensor tube of Russian and Chinese origin, a comparison was made in this work between measurements of environmental ionizing radiation with these detectors and a sodium iodide scintillator activated with TI （Thallium NaI）. Through measurements carried out in a room located inside a tower 25 meters high on the ITA （Technological Institute of Aeronautics） campus, it was possible to study the efficiency of the three instruments for the environmental measurement of ionizing radiations at that location. Between March 7th and June 2nd of 2017, in that region, nine intense and weak rains were observed with 12 cold fronts coming from southern Brazil. Radiation measurements and the local meteorology involved are analyzed in this work to verify possible correlations.
文摘OBJECTIVE: To make an open label prospective trial for comparing the therapeutic effects of mycophenolate mofetil (MMF) vs cyclophosphamide (CYC) pulse therapy on patients with diffuse proliferative lupus nephritis (DPLN). METHODS: Forty-six patients with biopsy proven active DPLN were enrolled in this study. Twenty-three patients were given MMF orally at a dosage of 1.0 - 1.5 g/d (MMF Group). Another 23 cases received conventional intermittent CYC pulse therapy (CYC Group). Supplemental steroid treatment was offered in the same manner to both groups. The age, sex distribution and severity of renal damage were matched in two groups. Therapeutic effects were evaluated at the end of six-month treatment. Fifteen patients in the MMF Group and 12 patients in the CYC Group had repeated renal biopsy at that time. RESULTS: MMF therapy was more effective in reducing proteinuria and hematuria. A 50% reduction of urinary protein and urinary red blood cell excretion from baseline value in 69.6% and 91.3% patients in the MMF Group, while only 47.8% and 65.2% in the CYC Group. MMF was more effective in inhibiting autoantibody production (especially anti-dsDNA antibody) and in decreasing serum cryoglobulin levels. Pathologically, the MMF group showed more markedly reduction in glomerular immune deposits with less glomerular necrosis, and less microthrombi, less crescent formation and vascular changes in the repeated renal biopsy as compared with the CYC group. Adverse reactions related to the treatment included gastrointestinal symptoms 26.1% and 43.5% in the MMF and CYC Groups respectively, infection 17.4% in the MMF group and 30.4% in the CYC group. CONCLUSION: MMF was more effective in controlling the clinical activity of DPLN and renal vascular lesions as compared with CYC pulse therapy in a 6 month follow-up study.
