The problem of track control is studied for a class of strict-feedback stochastic nonlinear systems in which unknown virtual control gain function is the main feature. First, the so-called stochastic LaSalle theory is...The problem of track control is studied for a class of strict-feedback stochastic nonlinear systems in which unknown virtual control gain function is the main feature. First, the so-called stochastic LaSalle theory is extended to some extent, and accordingly, the results of global ultimate boundedness for stochastic nonlinear systems are developed. Next, a new design scheme of fuzzy adaptive control is proposed. The advantage of it is that it does not require priori knowledge of virtual control gain function sign, which is usually demanded in many designs. At the same time, the track performance of closed-loop systems is improved by adaptive modifying the estimated error upper bound. By theoretical analysis, the signals of closed-loop systems are globally ultimately bounded in probability and the track error converges to a small residual set around the origin in 4th-power expectation.展开更多
The present opinion article, while dealing with the debated origin of “Severe Acute Respiratory Syndrome-Coronavirus-2” (SARS-CoV-2), the betacoronavirus responsible for “Corona Virus Disease-2019” (COVID-19), pro...The present opinion article, while dealing with the debated origin of “Severe Acute Respiratory Syndrome-Coronavirus-2” (SARS-CoV-2), the betacoronavirus responsible for “Corona Virus Disease-2019” (COVID-19), provides a speculative insight into the so-called “gain of function” (GOF), a process resulting in the acquirement of new phenotypic features on behalf of the viral pathogen. More in detail, a GOF-related phenomenon leading to increased SARS-CoV-2 virulence and/or transmissibility—as clearly exemplified by the “delta” and the “omicron” as well as by other “variants of concern”—would not necessarily imply that viral genetic manipulations made in the laboratory are its exclusive drivers, provided that GOF may also occur as a consequence of a natural selection process. In order to gain a better understanding of SARS-CoV-2 GOF and GOF-associated phenomena, an in-depth knowledge of the complex viral-host interaction dynamics is absolutely needed, while also paying special attention to the human-animal-viral ecological interfaces within an “ad hoc” multidisciplinary, “holistic”, scientific evidence-based and “One Health”-based approach.展开更多
在基于短时傅里叶变换(short-time Fourier transform,STFT)的智能音乐生成系统中,引入梅尔倒谱系数(Mel frequency cepstrum coefficient,MFCC)作为输入特征,并对STFT的损失函数进行优化设计,以提升音乐生成的质量。在对音符输入信号...在基于短时傅里叶变换(short-time Fourier transform,STFT)的智能音乐生成系统中,引入梅尔倒谱系数(Mel frequency cepstrum coefficient,MFCC)作为输入特征,并对STFT的损失函数进行优化设计,以提升音乐生成的质量。在对音符输入信号进行短时傅里叶变换时,需要对时域信号进行截断并添加窗函数,对信号添加时域窗等效于在频域信号中进行卷积。时域信号在截断过程中存在频谱分析误差,使得频谱以实际频率值为中心,以窗函数频谱波形的形状向两侧扩散,从而产生频谱泄漏。不同窗函数的选择对最终生成音乐的品质具有显著影响。为此,提出一种基于能量校正因子、频域最大副瓣和主瓣增益的窗函数分析与选择方法,并开发相应脚本工具,从而完成基于符号域音乐的混合窗函数设计。实验结果表明,混合窗函数在不同的MIDI(musical instrument digital interface)数据集上均可有效减少频谱泄漏对信号截断的影响,具有很好的适应性和灵活性,从而更好地作用于基于STFT的智能音乐生成系统中。展开更多
目的:分析高压氧联合前庭康复训练对耳鸣伴头晕患者的双重增益效应。方法:本研究为回顾性分析,选择于2022年1月至2025年1月在我院门诊就诊的90例耳鸣伴头晕患者展开研究,依据治疗方法分为观察组与对照组,各45例。对照组患者采取常规药...目的:分析高压氧联合前庭康复训练对耳鸣伴头晕患者的双重增益效应。方法:本研究为回顾性分析,选择于2022年1月至2025年1月在我院门诊就诊的90例耳鸣伴头晕患者展开研究,依据治疗方法分为观察组与对照组,各45例。对照组患者采取常规药物治疗,观察组在对照组基础上增加高压氧联合前庭康复训练,比较2组临床疗效,治疗前后大脑皮层氧合血红蛋白浓度,前庭功能,耳鸣严重程度及头晕严重程度。结果:观察组总有效率高于对照组(P<0.05);治疗后两组顶叶、枕叶皮层氧合血红蛋白浓度无明显变化(P>0.05),但颞叶、背外侧前额叶及额极皮层氧合血红蛋白浓度均升高,观察组高于对照组(P<0.05);治疗后两组半规管轻瘫值、重心移动总面积(Total area of center of gravity movement,CA)、重心移动总长度(Total length of center of gravity movement,PL)水平均降低,观察组较对照组低(P<0.05);治疗后两组耳鸣严重程度评分均降低,观察组较对照组低(P<0.05);治疗后两组眩晕障碍程度评分均降低,观察组较对照组低(P<0.05)。结论:高压氧联合前庭康复训练对耳鸣伴头晕患者的双重增益效应显著,可提升患者临床疗效,促进大脑皮层神经活动,改善前庭功能,从而减轻耳鸣、头晕严重程度。展开更多
Systems that are subject to both time-delay in state and input saturation are considered. We synthesize the anti-windup gain to enlarge the estimation of domain of attraction while guaranteeing the stability of the cl...Systems that are subject to both time-delay in state and input saturation are considered. We synthesize the anti-windup gain to enlarge the estimation of domain of attraction while guaranteeing the stability of the closed-loop system. An ellipsoid and a polyhedral set are used to bound the state of the system, which make a new sector condition valid. Other than an iterative algorithm, a direct designing algorithm is derived to compute the anti-windup compensator gain, which reduces the conservatism greatly. We analyze the delay-independent and delay-dependent cases, respectively. Finally, an optimization algorithm in the form of LMIs is constructed to compute the compensator gain which maximizes the estimation of domain of attraction. Numerical examples are presented to demonstrate the effectiveness of our approach.展开更多
AIM: To evaluate the body mass index(BMI) change in arthroplasty patients and its impact on the patients' functional results. METHODS: Between October 2010 and May 2013, 606 patients who were operated due to gonar...AIM: To evaluate the body mass index(BMI) change in arthroplasty patients and its impact on the patients' functional results. METHODS: Between October 2010 and May 2013, 606 patients who were operated due to gonarthrosis, coxarthrosis, aseptic loosening of the total knee and hip prosthesis were evaluated prospectively. Patients were operated by three surgeons in three medical centers. Patients who were between 30-90 years of age and who were underwent total knee arthroplasty, total hip arthroplasty, revision knee arthroplasty, or revision hip arthroplasty were included in the study. We excluded the patients who cannot tolerate our standard postoperative rehabilitation program. Additionally, patients who had systemic inflammatory diseases, diabetes mellitus, or endochrinopathies were excluded from the study. The remaining 513 patients comprised our study group. Preoperative functional joint scores, height, weightand BMI of all patients were recorded. We used the Knee Society Score(KSS) for knee and Harris Hip Score(HHS) for hip patients. Postoperative functional scores were measured at 1^(st), 6^(th) and 12^(th) months and recorded separately at outpatient visits. RESULTS: The mean age of the patients was 64.7(range: 30-90) years(207 males/306 females) and the mean follow-up duration was 14.3(range: 12-26) mo. We found that arthroplasty patients had weight gain and had an increase in BMI at the postoperative 1^(st), 6^(th) and 12^(th) months. The mean BMI of the patients was 27.7 preoperatively, 27.8 at the postoperative 1^(st) month, 28.1 at the 6^(th) month and 28.6 at the 12^(th) month(P < 0.01). At the last visit, the mean postoperative HHS of the hip arthroplasty patients was 82.2 ± 7.12(preoperatively, 52.3; 1st month, 78.2; 6^(th) month, 81.1; 12^(th) month, 82.2), and the mean KSS of the knee arthroplasty patients was 79.3 ± 4.31(preoperatively, 35.8; 1^(st) month, 75.2; 6^(th) month, 79.1; 12^(th) month, 79.3). Worse functional results were noted in the patients who had a BMI increase, however, this correlation was statistically significant only at the postoperative 6^(th) month(P = 0.03). CONCLUSION: To prevent the negative functional effects of this weight gain during the postoperative period, arthroplasty patients should be advised for weight control and risky patients should consult with a dietician.展开更多
基金Supported by National Natural Science Foundation of P. R. China (60572070, 60325311, 60534010) Natural Science Foundation of Liaoning Province (20022030)
文摘The problem of track control is studied for a class of strict-feedback stochastic nonlinear systems in which unknown virtual control gain function is the main feature. First, the so-called stochastic LaSalle theory is extended to some extent, and accordingly, the results of global ultimate boundedness for stochastic nonlinear systems are developed. Next, a new design scheme of fuzzy adaptive control is proposed. The advantage of it is that it does not require priori knowledge of virtual control gain function sign, which is usually demanded in many designs. At the same time, the track performance of closed-loop systems is improved by adaptive modifying the estimated error upper bound. By theoretical analysis, the signals of closed-loop systems are globally ultimately bounded in probability and the track error converges to a small residual set around the origin in 4th-power expectation.
文摘The present opinion article, while dealing with the debated origin of “Severe Acute Respiratory Syndrome-Coronavirus-2” (SARS-CoV-2), the betacoronavirus responsible for “Corona Virus Disease-2019” (COVID-19), provides a speculative insight into the so-called “gain of function” (GOF), a process resulting in the acquirement of new phenotypic features on behalf of the viral pathogen. More in detail, a GOF-related phenomenon leading to increased SARS-CoV-2 virulence and/or transmissibility—as clearly exemplified by the “delta” and the “omicron” as well as by other “variants of concern”—would not necessarily imply that viral genetic manipulations made in the laboratory are its exclusive drivers, provided that GOF may also occur as a consequence of a natural selection process. In order to gain a better understanding of SARS-CoV-2 GOF and GOF-associated phenomena, an in-depth knowledge of the complex viral-host interaction dynamics is absolutely needed, while also paying special attention to the human-animal-viral ecological interfaces within an “ad hoc” multidisciplinary, “holistic”, scientific evidence-based and “One Health”-based approach.
文摘在基于短时傅里叶变换(short-time Fourier transform,STFT)的智能音乐生成系统中,引入梅尔倒谱系数(Mel frequency cepstrum coefficient,MFCC)作为输入特征,并对STFT的损失函数进行优化设计,以提升音乐生成的质量。在对音符输入信号进行短时傅里叶变换时,需要对时域信号进行截断并添加窗函数,对信号添加时域窗等效于在频域信号中进行卷积。时域信号在截断过程中存在频谱分析误差,使得频谱以实际频率值为中心,以窗函数频谱波形的形状向两侧扩散,从而产生频谱泄漏。不同窗函数的选择对最终生成音乐的品质具有显著影响。为此,提出一种基于能量校正因子、频域最大副瓣和主瓣增益的窗函数分析与选择方法,并开发相应脚本工具,从而完成基于符号域音乐的混合窗函数设计。实验结果表明,混合窗函数在不同的MIDI(musical instrument digital interface)数据集上均可有效减少频谱泄漏对信号截断的影响,具有很好的适应性和灵活性,从而更好地作用于基于STFT的智能音乐生成系统中。
文摘目的:分析高压氧联合前庭康复训练对耳鸣伴头晕患者的双重增益效应。方法:本研究为回顾性分析,选择于2022年1月至2025年1月在我院门诊就诊的90例耳鸣伴头晕患者展开研究,依据治疗方法分为观察组与对照组,各45例。对照组患者采取常规药物治疗,观察组在对照组基础上增加高压氧联合前庭康复训练,比较2组临床疗效,治疗前后大脑皮层氧合血红蛋白浓度,前庭功能,耳鸣严重程度及头晕严重程度。结果:观察组总有效率高于对照组(P<0.05);治疗后两组顶叶、枕叶皮层氧合血红蛋白浓度无明显变化(P>0.05),但颞叶、背外侧前额叶及额极皮层氧合血红蛋白浓度均升高,观察组高于对照组(P<0.05);治疗后两组半规管轻瘫值、重心移动总面积(Total area of center of gravity movement,CA)、重心移动总长度(Total length of center of gravity movement,PL)水平均降低,观察组较对照组低(P<0.05);治疗后两组耳鸣严重程度评分均降低,观察组较对照组低(P<0.05);治疗后两组眩晕障碍程度评分均降低,观察组较对照组低(P<0.05)。结论:高压氧联合前庭康复训练对耳鸣伴头晕患者的双重增益效应显著,可提升患者临床疗效,促进大脑皮层神经活动,改善前庭功能,从而减轻耳鸣、头晕严重程度。
基金Supported by National Natural Science Foundation of P.R.China (60474045)973 Program of P.R.China (2002CB312200)the project sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars of State Education Ministry, Zhejiang Province, and Zhejiang University
文摘Systems that are subject to both time-delay in state and input saturation are considered. We synthesize the anti-windup gain to enlarge the estimation of domain of attraction while guaranteeing the stability of the closed-loop system. An ellipsoid and a polyhedral set are used to bound the state of the system, which make a new sector condition valid. Other than an iterative algorithm, a direct designing algorithm is derived to compute the anti-windup compensator gain, which reduces the conservatism greatly. We analyze the delay-independent and delay-dependent cases, respectively. Finally, an optimization algorithm in the form of LMIs is constructed to compute the compensator gain which maximizes the estimation of domain of attraction. Numerical examples are presented to demonstrate the effectiveness of our approach.
文摘AIM: To evaluate the body mass index(BMI) change in arthroplasty patients and its impact on the patients' functional results. METHODS: Between October 2010 and May 2013, 606 patients who were operated due to gonarthrosis, coxarthrosis, aseptic loosening of the total knee and hip prosthesis were evaluated prospectively. Patients were operated by three surgeons in three medical centers. Patients who were between 30-90 years of age and who were underwent total knee arthroplasty, total hip arthroplasty, revision knee arthroplasty, or revision hip arthroplasty were included in the study. We excluded the patients who cannot tolerate our standard postoperative rehabilitation program. Additionally, patients who had systemic inflammatory diseases, diabetes mellitus, or endochrinopathies were excluded from the study. The remaining 513 patients comprised our study group. Preoperative functional joint scores, height, weightand BMI of all patients were recorded. We used the Knee Society Score(KSS) for knee and Harris Hip Score(HHS) for hip patients. Postoperative functional scores were measured at 1^(st), 6^(th) and 12^(th) months and recorded separately at outpatient visits. RESULTS: The mean age of the patients was 64.7(range: 30-90) years(207 males/306 females) and the mean follow-up duration was 14.3(range: 12-26) mo. We found that arthroplasty patients had weight gain and had an increase in BMI at the postoperative 1^(st), 6^(th) and 12^(th) months. The mean BMI of the patients was 27.7 preoperatively, 27.8 at the postoperative 1^(st) month, 28.1 at the 6^(th) month and 28.6 at the 12^(th) month(P < 0.01). At the last visit, the mean postoperative HHS of the hip arthroplasty patients was 82.2 ± 7.12(preoperatively, 52.3; 1st month, 78.2; 6^(th) month, 81.1; 12^(th) month, 82.2), and the mean KSS of the knee arthroplasty patients was 79.3 ± 4.31(preoperatively, 35.8; 1^(st) month, 75.2; 6^(th) month, 79.1; 12^(th) month, 79.3). Worse functional results were noted in the patients who had a BMI increase, however, this correlation was statistically significant only at the postoperative 6^(th) month(P = 0.03). CONCLUSION: To prevent the negative functional effects of this weight gain during the postoperative period, arthroplasty patients should be advised for weight control and risky patients should consult with a dietician.
