We consider a single server constant retrial queue,in which a state-dependent service policy is used to control the service rate.Customer arrival follows Poisson process,while service time and retrial time are exponen...We consider a single server constant retrial queue,in which a state-dependent service policy is used to control the service rate.Customer arrival follows Poisson process,while service time and retrial time are exponential distributions.Whenever the server is available,it admits the retrial customers into service based on a first-come first-served rule.The service rate adjusts in real-time based on the retrial queue length.An iterative algorithm is proposed to numerically solve the personal optimal problem in the fully observable scenario.Furthermore,we investigate the impact of parameters on the social optimal threshold.The effectiveness of the results is illustrated by two examples.展开更多
Background Chronic heart failure(CHF)is the end-stage manifestation and main cause of death of cardiovascular system diseases.Ventricular arrhythmia is a common complication,which can increase myocardial oxygen consum...Background Chronic heart failure(CHF)is the end-stage manifestation and main cause of death of cardiovascular system diseases.Ventricular arrhythmia is a common complication,which can increase myocardial oxygen consumption,aggravate the disease,and even cause sudden death due to malignant arrhythmia.As a quantitative method to evaluate cardiac autonomic nervous function,heart rate variability is non-invasive and reproducible,and can quantify the risk associated with various cardiac and non-cardiac diseases.The purpose of this study was to analyze the correlation between heart rate variability and the incidence of cardiovascular adverse events in patients with heart failure.Methods 80 patients with heart failure who were treated in our hospital from May 2020 to May 2022 were selected as the study objects.After 3 months of follow-up,patients were divided into occurrence group(n=44)and nonoccurrence group(n=36)according to the occurrence of adverse cardiovascular events(angina pectoris,myocardial infarction,arrhythmia).The index of heart rate variability and the indicators of cardiac function in patients with heart failure was analyzed by one-way analysis of variance(ANOVA).The Key indicators of heart rate variability include standard deviation of normal RR interval(SDNN),mean standard deviation of consecutive 5-minute heartbeat interval(SDANN),square root of mean square of difference between adjacent heartbeat intervals(RMSSD),and percentage of RR intervals differing more than 50 ms from the preceding one(PNN50).The indicators of cardiac function include the New York Heart Association(NYHA)functional classification,left ventricular ejection fraction(LVEF),brain natriuretic peptide(BNP)and cardiac troponin I(c Tn I).Multivariate logistic regression was used to analyze the incidence of cardiovascular adverse events in patients with heart failure.Receiver operating characteristic(ROC)curve was used to analyze the predictive value of heart rate variability in patient outcomes.The correlation between heart rate variability and the incidence of cardiovascular adverse events was analyzed by Kendall's tau-b analysis.Results There were significant differences in SDNN,SDANN,RMSSD,PNN50,cardiac function grade,LVEF and BNP level between the two groups(P<0.05).Through logistic regression analysis,SDNN,SDANN,RMSSD and PNN50 were independent predictors for the incidence of cardiovascular adverse events(P<0.05).The areas under curve for SDNN,SDANN,RMSSD,and PNN50 predicting of the incidence of cardiovascular adverse events were 0.732,0.732,0.758,and 0.819 respectively,and the sensitivity was 77.27%,81.81%,75.00%and 65.91%,respectively.The specificity was 61.11%,61.11%,80.56%,83.33%(P<0.05),respectively.Through Kendall's tau-b analysis,the index of heart rate variability was negatively correlated with the incidence of adverse cardiovascular events in patients with prognosis(P<0.05).Conclusions Heart rate variability has predictive value for the incidence of adverse cardiovascular events in patients with heart failure.The lower the heart rate variability,the higher incidence of cardiovascular adverse events.[S Chin J Cardiol 2024;25(3):135-141]展开更多
In this article,Deng and Song showed compelling evidence on the connection between heart rate variability(HRV)alterations and cancer in 127 cancer patients compared with healthy reference individuals,highlighting auto...In this article,Deng and Song showed compelling evidence on the connection between heart rate variability(HRV)alterations and cancer in 127 cancer patients compared with healthy reference individuals,highlighting autonomic nervous system dysfunction as a significant physiological manifestation in cancer patients.We discussed that the reduced HRV may be associated with cancer treatments,e.g.,operation,chemotherapy and pain control and psychological response such as depression and anxiety related to the affected cancer.A management such as medicine to mood disturbances related to cancer has been shown a benefit to improve HRV in cancer patients.展开更多
BACKGROUND Heart rate variability(HRV)represents efferent vagus nerve activity,which is suggested to be related to fundamental mechanisms of tumorigenesis and to be a predictor of prognosis in various cancers.Therefor...BACKGROUND Heart rate variability(HRV)represents efferent vagus nerve activity,which is suggested to be related to fundamental mechanisms of tumorigenesis and to be a predictor of prognosis in various cancers.Therefore,this study hypothesized that HRV monitoring could predict perioperative complication(PC)in colorectal cancer(CRC)patients.AIM To investigate the prognostic value of HRV in hospitalized CRC patients.METHODS The observational studies included 87 patients who underwent CRC surgical procedures under enhanced recovery after surgery programs in a first-class hospital.The HRV parameters were compared between the PC group and the non PC(NPC)group from preoperative day 1 to postoperative day(Pod)3.In addition,inflammatory biomarkers and nutritional indicators were also analyzed.RESULTS The complication rate was 14.9%.HRV was markedly abnormal after surgery,especially in the PC group.The frequency-domain parameters(including pNN50)and time-domain parameters[including high-frequency(HF)]of HRV were significantly different between the two groups postoperatively.The pNN50 was significantly greater at Pod1 in the PC group than that in the NPC group and returned to baseline at Pod2,suggesting that patients with complications exhibited autonomic nerve dysfunction in the early postoperative period.In the PC group,HFs were also enhanced from Pod1 and were significantly higher than in the NPC group;inflammatory biomarkers were significantly elevated at Pod2 and Pod3;the levels of nutritional indicators were significantly lower at Pod1 and Pod2;and the white blood cell count was slightly elevated at Pod3.CONCLUSION HRV is independently associated with postoperative complications in patients with CRC.Abnormal HRV could predicted an increased risk of postoperative complications in CRC patients.Continuous HRV could be used to monitor complications in patients with CRC during the perioperative period.展开更多
Purpose:To explore the clinical value of Electromyography(EMG)and Heart Rate Variability(HRV)in the diagnosis of early DPN and provide the basis for early diagnosis,treatment,and prevention of DPN.Methods:105 patients...Purpose:To explore the clinical value of Electromyography(EMG)and Heart Rate Variability(HRV)in the diagnosis of early DPN and provide the basis for early diagnosis,treatment,and prevention of DPN.Methods:105 patients with type 2 diabetes mellitus(T2DM)in the Changji People’s Hospital were treated from January 2023 to December 2023.They were stratifi ed into DPN-symptomatic(DPN group,n=55)and DPN-asymptomatic(NDPN group,n=50)cohorts based on the presence or absence of clinically confi rmed diabetic peripheral neuropathy.The clinical biochemical indicators,nerve electromyography,and HRV parameters were obtained from electronic medical records,and diff erences in detection results were compared between the two groups.Logistic regression was applied to analyze the infl uencing factors of DPN in diabetes patients.The receiver operating characteristic(ROC)curve was applied to analyze the diagnostic value of EMG combined with other parameters for DPN.Results:From the results of the general information,diabetes duration,glycosylated hemoglobin(HbA1c),low-density lipoprotein cholesterol(LDL-C),total cholesterol(TC)and FBG in the DPN group were significantly differences compared with the NDPN group(p<0.05).There were no statistically significant differences in gender,age years,uric acid,and other general data(p>0.05).Compared with the NDPN group,the motor nerve conduction velocity(MNCV),sensory nerve conduction velocity(SNCV)of the ulnar nerve,median nerve,and tibial nerve in the DPN group were statistically signifi cant(p>0.05).The DPN group had higher average F wave latency and H wave latency in the tested nerve,with statistical signifi cance(p<0.05).HRV parameters decreased signifi cantly(SDNN,rMSSD,PNN50,and SDANN,all p<0.05).ROC analysis showed that the area under the ROC curve(AUC)of the combined diagnosis of DPN by duration of diabetes,HbA1c,EMG,and HRV was 0.897,the accuracy was 82.86%,the sensitivity was 78.00%,and the specifi city was 87.27%.The AUC of the combined diagnosis of the four parameters for DPN was signifi cantly higher than that of each alone(p<0.05).Conclusion:The combination of EMG and HRV has a high value in the assessment of DPN and can be used for early assessment of the extent of the lesion.展开更多
BACKGROUND Depression is a common comorbidity in patients with chronic obstructive pulmonary disease(COPD).Research indicates that COPD affects cardiac au-tonomic control,and heart rate variability(HRV)serves as a sim...BACKGROUND Depression is a common comorbidity in patients with chronic obstructive pulmonary disease(COPD).Research indicates that COPD affects cardiac au-tonomic control,and heart rate variability(HRV)serves as a simple,non-invasive measure of autonomic nerve activity.However,the relationship between HRV and lung function,as well as the impact of depressive symptoms,remains un-clear.METHODS A retrospective cross-sectional study involving 120 COPD patients hospitalized from January 2018 to January 2024 at our institution was conducted.Demographic and clinical characteristics were collected,and depressive symptoms were asse-ssed using the Beck Depression Inventory(BDI).Patients were categorized into a depressed group(BDI≥16)and a non-depressed group(BDI<16).A control group consisting of 60 healthy volunteers who underwent check-ups at the same institution was also included.Statistical analyses were performed using SPSS 26.0 software.Pearson correlation coefficients were calculated to determine and compare the relationships between HRV parameters,lung function measures,and RESULTS Of the 120 patients with COPD,35.8%(43/120)were diagnosed with depression,compared to 5.0%(3/60)in the control group.The HRV index in COPD patients was significantly lower than that in the control group(P<0.05),and the value in the depressed group was significantly lower than that in the non-depressed group(P<0.05).Similarly,the COPD group had a significantly lower pulmonary forced vital capacity(FVC),first-second expiratory volume(FEV1)and FEV1/FVC ratios than the control group(P<0.05),and the depressed group was significantly lower than that in the non-depressed group(P<0.05).Pearson correlation analysis revealed that the standard deviation of normal R-R intervals,standard deviation of the mean of 5-minute normal R-R intervals,root mean square of successive differences of normal R-R intervals,percentage of normal R-R intervals greater than 50 ms,high-frequency,and low-frequency indices showed positive correlations with lung function parameters(P<0.05)and negative correlations with BDI scores(P<0.05).CONCLUSION Compared to patients without COPD,the incidence of depressive symptoms is higher among patients with COPD and is negatively correlated with the patients’HRV indices.In contrast,HRV indices are positively correlated with the patients’pulmonary function parameters.Patients and healthcare professionals should enhance their awareness of depression,actively conduct depression assessment screenings,and incorporate HRV indices into disease management.This approach aims to improve the psychological health of patients and ultimately enhance their prognosis and quality of life.展开更多
BACKGROUND A significant proportion of cancer patients experience autonomic dysfunction,and cancer treatments such as chemotherapy and radiation therapy can exacerbate impairments in the cardiac autonomic nervous syst...BACKGROUND A significant proportion of cancer patients experience autonomic dysfunction,and cancer treatments such as chemotherapy and radiation therapy can exacerbate impairments in the cardiac autonomic nervous system.This study sought to investigate the characteristics of heart rate variability(HRV)in individuals with cancer.AIM To evaluate the relationship between HRV and cancer patients,providing insights and references for cancer treatment.METHODS The study included 127 cancer patients with available 24-hour dynamic electrocardiogram data.HRV differences were analyzed using both time domain and frequency domain methods.These findings were then compared to HRV data from reference individuals,sourced from literature that utilized the same HRV computing algorithm.RESULTS Our findings revealed that cancer patients generally exhibited abnormal HRV compared to the reference group.HRV was found to be correlated with age and clinical type(P<0.05),but no significant correlation was observed with tumor site or gender(P>0.05).CONCLUSION This study indicates that cancer patients have significantly abnormal HRV compared to reference individuals,suggesting the presence of a certain level of cardiac autonomic dysfunction in this patient population.展开更多
In this article,we comment on the study by Yang et al,which demonstrated significant cross-sectional associations between heart rate variability(HRV)indices,depressive symptoms,and lung function in patients with chron...In this article,we comment on the study by Yang et al,which demonstrated significant cross-sectional associations between heart rate variability(HRV)indices,depressive symptoms,and lung function in patients with chronic obstructive pulmonary disease(COPD).Building on these findings,we further explore the underlying mechanisms,particularly inflammatory-autonomic-oxidative stress pathways,as key causal mediators.Moreover,analyzing genetic polymorphisms alongside environmental factors may uncover susceptibility pathways explaining interindividual differences in HRV and comorbidity risk.Additionally,longitudinal studies tracking HRV trajectories could identify thresholds predictive of accelerated lung function decline or cardiovascular events,informing personalized prevention strategies.Integrating longitudinal HRV data with multi-omics biomarkers and machine learning models could enable real-time prediction of depression relapses or COPD exacerbations,facilitating proactive interventions such as personalized biofeedback training or precision anti-inflammatory therapies.By synthesizing these perspectives,this integrative approach promises to advance precision medicine for COPD patients,particularly those with comorbid depression,by addressing both mechanistic insights and clinical translation.展开更多
Autonomic dysfunction(AD)is frequently observed in cirrhotic patients and is associated with poor clinical outcomes and prognoses.Heart rate variability(HRV),a noninvasive tool for assessing autonomic nervous system b...Autonomic dysfunction(AD)is frequently observed in cirrhotic patients and is associated with poor clinical outcomes and prognoses.Heart rate variability(HRV),a noninvasive tool for assessing autonomic nervous system balance,has been extensively studied in a variety of conditions,including chronic liver disease(CLD);however,no recent reviews have focused on its role in CLD.This article examines the mechanisms of AD in CLD and the foundation for HRV assessment,highlighting its diagnostic,prognostic,and therapeutic applications in CLD,including liver transplantation(LT).Changes in HRV,particularly in patients with cirrhotic complications,and its prognostic significance throughout the natural history of CLD are summarized.We show that HRV is consistently reduced in CLD patients,reflecting AD,and is inversely correlated with liver disease severity.Also,low HRV is associated with complications such as hepatic encephalopathy,ascites,and portal hypertension.Moreover,evidence indicates that reduced HRV is an independent risk factor for mortality and circulatory instability in CLD.Furthermore,treatment with beta-blockers and LT improves HRV,underscoring its potential role in patient management.While further studies are needed,HRV emerges as a promising tool for the comprehensive evaluation and clinical management of patients with CLD,offering insights into disease progression and therapeutic response.展开更多
Electrochemical machining(ECM)is an economical and effective method for blisk manufacturing and includes two steps:channel machining and profile machining.The allowance distribution after the channel machining will di...Electrochemical machining(ECM)is an economical and effective method for blisk manufacturing and includes two steps:channel machining and profile machining.The allowance distribution after the channel machining will directly affect the profile machining.Therefore,to improve the uniformity of allowance distribution in the machining of channels,a method that incorporates a variable feed rate mode is developed.During the machining process,the feed rates are dynamically changed according to the needs of the side gap at the different feed depths.As a result,the side gaps at the different feed depths vary,contributing to a decrease in the allowance difference.In this study,the dissolution processes of a blisk channel are simulated using different feed rates,and prediction profiles are obtained.Based on the prediction profiles,the relationship among the feed rate,feed depth,and side gap is established.Then,the feed rates at different feed depths are adjusted according to the relationship.In addition,contrast experiments are conducted.Compared with blisk channel ECM using a constant feed rate of 1 mm/min,using the variable feed rate decreases the allowance differences in the convex and concave parts by 62.2%and 67.4%,respectively.This indicates that using the variable feed rate in the ECM process for a blisk channel is feasible and efficient.展开更多
To investigate the effects of flow rate on phytoplankton dynamics and related environment variables,a set of enclosure experiments with different fl ow rates were conducted in an artificial lake. We monitored nutrient...To investigate the effects of flow rate on phytoplankton dynamics and related environment variables,a set of enclosure experiments with different fl ow rates were conducted in an artificial lake. We monitored nutrients,temperature,dissolved oxygen,p H,conductivity,turbidity,chlorophyll-a and phytoplankton levels. The lower biomass in all flowing enclosures showed that flow rate significantly inhibited the growth of phytoplankton. A critical flow rate occurred near 0.06 m/s,which was the lowest relative inhibitory rate. Changes in flow conditions affected algal competition for light,resulting in a dramatic shift in phytoplankton composition,from blue-green algae in still waters to green algae in flowing conditions. These findings indicate that critical flow rate can be useful in developing methods to reduce algal bloom occurrence. However,flow rate significantly enhanced the inter-relationships among environmental variables,in particular by inducing higher water turbidity and vegetative reproduction of periphyton( Spirogyra). These changes were accompanied by a decrease in underwater light intensity,which consequently inhibited the photosynthetic intensity of phytoplankton. These results warn that a universal critical flow rate might not exist,because the effect of flow rate on phytoplankton is interlinked with many other environmental variables.展开更多
The optimum control strategy and the saving potential of all variable chiller plant under the conditions of changing building cooling load and cooling water supply temperature were investigated. Based on a simulation ...The optimum control strategy and the saving potential of all variable chiller plant under the conditions of changing building cooling load and cooling water supply temperature were investigated. Based on a simulation model of water source chiller plant established in dynamic transient simulation program (TRNSYS),the four-variable quadratic orthogonal regression experiments were carried out by taking cooling load,cooling water supply temperature,cooling water flow rate and chilled water flow rate as variables,and the fitting formulas expressing the relationships between the total energy consumption of chiller plant with the four selected parameters was obtained. With the SAS statistical software and MATHEMATICA mathematical software,the optimal chilled water flow rate and cooling water flow rate which result in the minimum total energy consumption were determined under continuously varying cooling load and cooling water supply temperature. With regard to a chiller plant serving an office building in Shanghai,the total energy consumptions under different control strategies were computed in terms of the forecasting function of cooling load and water source temperature. The results show that applying the optimal control strategy to the chiller plant can bring a saving of 23.27% in power compared with the corresponding conventional variable speed plant,indicating that the optimal control strategy can improve the energy efficiency of chiller plant.展开更多
Recent increases in irrigated hectares in the Southeastern US have enabled growers to obtain higher yields through applying nutrients through irrigation water. Therefore, many growers apply nutrients through irrigatio...Recent increases in irrigated hectares in the Southeastern US have enabled growers to obtain higher yields through applying nutrients through irrigation water. Therefore, many growers apply nutrients through irrigation systems, known as fertigation. Currently, there are no practical decision-making tools available for variable-rate application of nitrogen (N) through overhead sprinkler irrigation systems. Therefore, field tests were conducted on cotton (Gossypium hirsutum L.) during the 2016 and 2017 growing seasons to 1) adapt the Clemson sensor-based N recommendation algorithms from a single side-dress application to multiple applications through an overhead irrigation system;and 2) to compare sensor-based VRFS with conventional nutrient management methods in terms of N use efficiency (NUE) and crop responses on three soil types. Two seasons of testing Clemson N prediction algorithms to apply multiple applications of N were very promising. The multiple applications of N compared to the grower’s conventional methods (even though less N was applied) had no impact on yields in either growing season. There was no difference in cotton yields between 101 and 135 kg/ha N applications in either management zone. Also, there were no differences in yield between sensor-based, multiple N applications and conventional N management techniques. In relation to comparisons of the sensor methods only applying N in three or four applications, statistically increased yields compared to single or split applications in 2016. Applying N in four applications, statistically increased yields compared to single, split or triple applications in 2017. When the sensor-based methods were compared to the grower’s conventional methods averaged over four treatments, the sensor-based N applications reduced fertilizer requirement by 69% in 2016 and 57% in 2017 compared to grower’s conventional methods. When comparing N rates among the four sensor-based methods (three or four) applications, increased N rates by 22 kg/ha in 2016 and 26 kg/ha in 2017 compared to single or split applications but increased the cotton lint yields by 272 and 139 kg/ha, for 2016 and 2017, respectively.展开更多
We consider a risk model with a premium rate which varies with the level of free reserves.In this model,the occurrence of claims is described by a Cox process with Markov intensity process,and the influence of stochas...We consider a risk model with a premium rate which varies with the level of free reserves.In this model,the occurrence of claims is described by a Cox process with Markov intensity process,and the influence of stochastic factors is considered by adding a diffusion process.The integro-differential equation for the ruin probability is derived by a infinitesimal method.展开更多
In this paper,we establish a Rosenthal-type inequality of partial sums for ρ~mixing random variables.As its applications,we get the complete convergence rates in the strong laws for ρ^-mixing random variables.The re...In this paper,we establish a Rosenthal-type inequality of partial sums for ρ~mixing random variables.As its applications,we get the complete convergence rates in the strong laws for ρ^-mixing random variables.The result obtained extends the corresponding result.展开更多
Nonlinear equations systems(NESs)are widely used in real-world problems and they are difficult to solve due to their nonlinearity and multiple roots.Evolutionary algorithms(EAs)are one of the methods for solving NESs,...Nonlinear equations systems(NESs)are widely used in real-world problems and they are difficult to solve due to their nonlinearity and multiple roots.Evolutionary algorithms(EAs)are one of the methods for solving NESs,given their global search capabilities and ability to locate multiple roots of a NES simultaneously within one run.Currently,the majority of research on using EAs to solve NESs focuses on transformation techniques and improving the performance of the used EAs.By contrast,problem domain knowledge of NESs is investigated in this study,where we propose the incorporation of a variable reduction strategy(VRS)into EAs to solve NESs.The VRS makes full use of the systems of expressing a NES and uses some variables(i.e.,core variable)to represent other variables(i.e.,reduced variables)through variable relationships that exist in the equation systems.It enables the reduction of partial variables and equations and shrinks the decision space,thereby reducing the complexity of the problem and improving the search efficiency of the EAs.To test the effectiveness of VRS in dealing with NESs,this paper mainly integrates the VRS into two existing state-of-the-art EA methods(i.e.,MONES and DR-JADE)according to the integration framework of the VRS and EA,respectively.Experimental results show that,with the assistance of the VRS,the EA methods can produce better results than the original methods and other compared methods.Furthermore,extensive experiments regarding the influence of different reduction schemes and EAs substantiate that a better EA for solving a NES with more reduced variables tends to provide better performance.展开更多
The relations of change rate of an independent variable, volumetric strain of the porous skeleton, with the change rates of a kind of constitutive variables, such as porosity, volumetric strain of the solid matrix, ar...The relations of change rate of an independent variable, volumetric strain of the porous skeleton, with the change rates of a kind of constitutive variables, such as porosity, volumetric strain of the solid matrix, are derived from the definition of the porosity of water saturated porous media; and the relations of the change rates of another two independent variables, pressure of the pore liquid water and temperature, with the change rates of another kind of constitutive variables, such as pressure of the pore ice, average pressure of the pore liquid water and ice, and average stress of the solid matrix, are obtained from the Clausius Clapeyron relation in the process of freezing or thawing, definitions of the average pore pressure and effective stress. Based on the hypothesis of linear thermoelasticity, principle of effective stress and these relations, the change rates of all constitutive variables may be described with the change rates of the three independent variables.展开更多
Nutrients are injected through overhead irrigation systems at a uniform rate in a process known as fertigation. The highly variable soils in the Southeastern US pose challenges for effective fertigation. Currently, th...Nutrients are injected through overhead irrigation systems at a uniform rate in a process known as fertigation. The highly variable soils in the Southeastern US pose challenges for effective fertigation. Currently, there is no variable-rate fertigation system available to apply the correct amount of N within a field through an overhead irrigation system. Therefore, the objective of this study was to develop and test a variable-rate N application system that works independently of irrigation water flow for site-specific N application. The variable-rate fertigation system (VRFS) was designed to apply different rates N using a pulse width modulation technique. The VRFS utilized the Clemson Lateral Irrigation Control software which controlled the solenoids in each zone by turning the N supply on and off (pulsing) for each zone. In this study, four tests were conducted to determine the uniformity of the VRFS. In test # 1, the pump output showed a linear slope relationship and was the same for water and N. In test # 2, nozzle flow and uniformity were determined using four different irrigation system travel speeds at N application rates of 31, 59, 88, and 113 kg/ha. There was a strong correlation (R2 = 0.9998) between irrigation system speed and N rate. In test # 3, the uniformity across the length of the irrigation system was determined. The nozzles produced an average flow of 31.1, 58.7, 87.6, and 112.7 kg N/ha with an overall average error of 0.1% across all N rates. Results also showed the system was capable of accurately applying N based on prescription maps with an error of less than 1.8%. Test # 4 was conducted to determine the accuracy of the map-based controller system for applying variable rate N. There was a strong correlation between target N and actual N rates (R2 = 0.9999). In summary, the VRFS applied the correct amounts of N within each zone by either manually controlling the pulsing mechanism or utilizing a prescription map to apply different rates throughout the field.展开更多
A variable-bit-rate characteristic waveform interpolation （VBR-CWI） speech codec with about 1.8 kbit/s average bit rate which integrates phonetic classification into characteristic waveform （CW） decomposition is p...A variable-bit-rate characteristic waveform interpolation （VBR-CWI） speech codec with about 1.8 kbit/s average bit rate which integrates phonetic classification into characteristic waveform （CW） decomposition is proposed. Each input frame is classified into one of 4 phonetic classes. Non-speech frames are represented with Bark-band noise model. The extracted CWs become rapidly evolving waveforms （REWs） or slowly evolving waveforms （SEWs） in the cases of unvoiced or stationary voiced frames respectively, while mixed voiced frames use the same CW decomposition as that in the conventional CWI. Experimental results show that the proposed codec can eliminate most buzzy and noisy artifacts existing in the fixed-bit-rate characteristic waveform interpolation （FBR-CWI） speech codec, the average bit rate can be much lower, and its reconstructed speech quality is much better than FS 1 016 CELP at 4.8 kbit/s and similar to G. 723.1 ACELP at 5.3 kbit/s.展开更多
Fong et al.analyzed variable-rate linear network coding for linear broadcast.However,the authors didn't investigate it for the other three types of linear network codes.In this paper,by simple and clear proofs,it ...Fong et al.analyzed variable-rate linear network coding for linear broadcast.However,the authors didn't investigate it for the other three types of linear network codes.In this paper,by simple and clear proofs,it is found that there are similar results for variable-rate linear generic and linear dispersion if the field size is large enough.It means that linear generics and linear dispersions of different dimensions can be implemented on the same network,while each non-source node is required to store only one copy of the local encoding kernel within a session.Moreover,an example is given to show that there isn't a similar result for linear multicast.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.11971486)。
文摘We consider a single server constant retrial queue,in which a state-dependent service policy is used to control the service rate.Customer arrival follows Poisson process,while service time and retrial time are exponential distributions.Whenever the server is available,it admits the retrial customers into service based on a first-come first-served rule.The service rate adjusts in real-time based on the retrial queue length.An iterative algorithm is proposed to numerically solve the personal optimal problem in the fully observable scenario.Furthermore,we investigate the impact of parameters on the social optimal threshold.The effectiveness of the results is illustrated by two examples.
文摘Background Chronic heart failure(CHF)is the end-stage manifestation and main cause of death of cardiovascular system diseases.Ventricular arrhythmia is a common complication,which can increase myocardial oxygen consumption,aggravate the disease,and even cause sudden death due to malignant arrhythmia.As a quantitative method to evaluate cardiac autonomic nervous function,heart rate variability is non-invasive and reproducible,and can quantify the risk associated with various cardiac and non-cardiac diseases.The purpose of this study was to analyze the correlation between heart rate variability and the incidence of cardiovascular adverse events in patients with heart failure.Methods 80 patients with heart failure who were treated in our hospital from May 2020 to May 2022 were selected as the study objects.After 3 months of follow-up,patients were divided into occurrence group(n=44)and nonoccurrence group(n=36)according to the occurrence of adverse cardiovascular events(angina pectoris,myocardial infarction,arrhythmia).The index of heart rate variability and the indicators of cardiac function in patients with heart failure was analyzed by one-way analysis of variance(ANOVA).The Key indicators of heart rate variability include standard deviation of normal RR interval(SDNN),mean standard deviation of consecutive 5-minute heartbeat interval(SDANN),square root of mean square of difference between adjacent heartbeat intervals(RMSSD),and percentage of RR intervals differing more than 50 ms from the preceding one(PNN50).The indicators of cardiac function include the New York Heart Association(NYHA)functional classification,left ventricular ejection fraction(LVEF),brain natriuretic peptide(BNP)and cardiac troponin I(c Tn I).Multivariate logistic regression was used to analyze the incidence of cardiovascular adverse events in patients with heart failure.Receiver operating characteristic(ROC)curve was used to analyze the predictive value of heart rate variability in patient outcomes.The correlation between heart rate variability and the incidence of cardiovascular adverse events was analyzed by Kendall's tau-b analysis.Results There were significant differences in SDNN,SDANN,RMSSD,PNN50,cardiac function grade,LVEF and BNP level between the two groups(P<0.05).Through logistic regression analysis,SDNN,SDANN,RMSSD and PNN50 were independent predictors for the incidence of cardiovascular adverse events(P<0.05).The areas under curve for SDNN,SDANN,RMSSD,and PNN50 predicting of the incidence of cardiovascular adverse events were 0.732,0.732,0.758,and 0.819 respectively,and the sensitivity was 77.27%,81.81%,75.00%and 65.91%,respectively.The specificity was 61.11%,61.11%,80.56%,83.33%(P<0.05),respectively.Through Kendall's tau-b analysis,the index of heart rate variability was negatively correlated with the incidence of adverse cardiovascular events in patients with prognosis(P<0.05).Conclusions Heart rate variability has predictive value for the incidence of adverse cardiovascular events in patients with heart failure.The lower the heart rate variability,the higher incidence of cardiovascular adverse events.[S Chin J Cardiol 2024;25(3):135-141]
文摘In this article,Deng and Song showed compelling evidence on the connection between heart rate variability(HRV)alterations and cancer in 127 cancer patients compared with healthy reference individuals,highlighting autonomic nervous system dysfunction as a significant physiological manifestation in cancer patients.We discussed that the reduced HRV may be associated with cancer treatments,e.g.,operation,chemotherapy and pain control and psychological response such as depression and anxiety related to the affected cancer.A management such as medicine to mood disturbances related to cancer has been shown a benefit to improve HRV in cancer patients.
基金Supported by The Natural Science Foundation of Nanjing University of Chinese Medicine,No.XZR2021019The Outstanding Young Doctor Program of Jiangsu Province of Chinese Medicine,No.2023QB0140+1 种基金Project of National Clinical Research Base of Traditional Chinese Medicine in Jiangsu Province,No.JD2022SZ18The Natural Science Foundation of Nanjing University of Chinese Medicine,No.KYCX21_1710.
文摘BACKGROUND Heart rate variability(HRV)represents efferent vagus nerve activity,which is suggested to be related to fundamental mechanisms of tumorigenesis and to be a predictor of prognosis in various cancers.Therefore,this study hypothesized that HRV monitoring could predict perioperative complication(PC)in colorectal cancer(CRC)patients.AIM To investigate the prognostic value of HRV in hospitalized CRC patients.METHODS The observational studies included 87 patients who underwent CRC surgical procedures under enhanced recovery after surgery programs in a first-class hospital.The HRV parameters were compared between the PC group and the non PC(NPC)group from preoperative day 1 to postoperative day(Pod)3.In addition,inflammatory biomarkers and nutritional indicators were also analyzed.RESULTS The complication rate was 14.9%.HRV was markedly abnormal after surgery,especially in the PC group.The frequency-domain parameters(including pNN50)and time-domain parameters[including high-frequency(HF)]of HRV were significantly different between the two groups postoperatively.The pNN50 was significantly greater at Pod1 in the PC group than that in the NPC group and returned to baseline at Pod2,suggesting that patients with complications exhibited autonomic nerve dysfunction in the early postoperative period.In the PC group,HFs were also enhanced from Pod1 and were significantly higher than in the NPC group;inflammatory biomarkers were significantly elevated at Pod2 and Pod3;the levels of nutritional indicators were significantly lower at Pod1 and Pod2;and the white blood cell count was slightly elevated at Pod3.CONCLUSION HRV is independently associated with postoperative complications in patients with CRC.Abnormal HRV could predicted an increased risk of postoperative complications in CRC patients.Continuous HRV could be used to monitor complications in patients with CRC during the perioperative period.
基金supported by the Key Program of the Changji Prefecture Science and Technology Program(2023S04-10,2023S06-03).
文摘Purpose:To explore the clinical value of Electromyography(EMG)and Heart Rate Variability(HRV)in the diagnosis of early DPN and provide the basis for early diagnosis,treatment,and prevention of DPN.Methods:105 patients with type 2 diabetes mellitus(T2DM)in the Changji People’s Hospital were treated from January 2023 to December 2023.They were stratifi ed into DPN-symptomatic(DPN group,n=55)and DPN-asymptomatic(NDPN group,n=50)cohorts based on the presence or absence of clinically confi rmed diabetic peripheral neuropathy.The clinical biochemical indicators,nerve electromyography,and HRV parameters were obtained from electronic medical records,and diff erences in detection results were compared between the two groups.Logistic regression was applied to analyze the infl uencing factors of DPN in diabetes patients.The receiver operating characteristic(ROC)curve was applied to analyze the diagnostic value of EMG combined with other parameters for DPN.Results:From the results of the general information,diabetes duration,glycosylated hemoglobin(HbA1c),low-density lipoprotein cholesterol(LDL-C),total cholesterol(TC)and FBG in the DPN group were significantly differences compared with the NDPN group(p<0.05).There were no statistically significant differences in gender,age years,uric acid,and other general data(p>0.05).Compared with the NDPN group,the motor nerve conduction velocity(MNCV),sensory nerve conduction velocity(SNCV)of the ulnar nerve,median nerve,and tibial nerve in the DPN group were statistically signifi cant(p>0.05).The DPN group had higher average F wave latency and H wave latency in the tested nerve,with statistical signifi cance(p<0.05).HRV parameters decreased signifi cantly(SDNN,rMSSD,PNN50,and SDANN,all p<0.05).ROC analysis showed that the area under the ROC curve(AUC)of the combined diagnosis of DPN by duration of diabetes,HbA1c,EMG,and HRV was 0.897,the accuracy was 82.86%,the sensitivity was 78.00%,and the specifi city was 87.27%.The AUC of the combined diagnosis of the four parameters for DPN was signifi cantly higher than that of each alone(p<0.05).Conclusion:The combination of EMG and HRV has a high value in the assessment of DPN and can be used for early assessment of the extent of the lesion.
基金Supported by the Zhangjiakou City Science and Technology Research Plan,No.1821110D.
文摘BACKGROUND Depression is a common comorbidity in patients with chronic obstructive pulmonary disease(COPD).Research indicates that COPD affects cardiac au-tonomic control,and heart rate variability(HRV)serves as a simple,non-invasive measure of autonomic nerve activity.However,the relationship between HRV and lung function,as well as the impact of depressive symptoms,remains un-clear.METHODS A retrospective cross-sectional study involving 120 COPD patients hospitalized from January 2018 to January 2024 at our institution was conducted.Demographic and clinical characteristics were collected,and depressive symptoms were asse-ssed using the Beck Depression Inventory(BDI).Patients were categorized into a depressed group(BDI≥16)and a non-depressed group(BDI<16).A control group consisting of 60 healthy volunteers who underwent check-ups at the same institution was also included.Statistical analyses were performed using SPSS 26.0 software.Pearson correlation coefficients were calculated to determine and compare the relationships between HRV parameters,lung function measures,and RESULTS Of the 120 patients with COPD,35.8%(43/120)were diagnosed with depression,compared to 5.0%(3/60)in the control group.The HRV index in COPD patients was significantly lower than that in the control group(P<0.05),and the value in the depressed group was significantly lower than that in the non-depressed group(P<0.05).Similarly,the COPD group had a significantly lower pulmonary forced vital capacity(FVC),first-second expiratory volume(FEV1)and FEV1/FVC ratios than the control group(P<0.05),and the depressed group was significantly lower than that in the non-depressed group(P<0.05).Pearson correlation analysis revealed that the standard deviation of normal R-R intervals,standard deviation of the mean of 5-minute normal R-R intervals,root mean square of successive differences of normal R-R intervals,percentage of normal R-R intervals greater than 50 ms,high-frequency,and low-frequency indices showed positive correlations with lung function parameters(P<0.05)and negative correlations with BDI scores(P<0.05).CONCLUSION Compared to patients without COPD,the incidence of depressive symptoms is higher among patients with COPD and is negatively correlated with the patients’HRV indices.In contrast,HRV indices are positively correlated with the patients’pulmonary function parameters.Patients and healthcare professionals should enhance their awareness of depression,actively conduct depression assessment screenings,and incorporate HRV indices into disease management.This approach aims to improve the psychological health of patients and ultimately enhance their prognosis and quality of life.
基金the Medical Ethics Committee of the Hefei Cancer Hospital,Chinese Academy of Sciences(No.PJ-KY-2024-025).
文摘BACKGROUND A significant proportion of cancer patients experience autonomic dysfunction,and cancer treatments such as chemotherapy and radiation therapy can exacerbate impairments in the cardiac autonomic nervous system.This study sought to investigate the characteristics of heart rate variability(HRV)in individuals with cancer.AIM To evaluate the relationship between HRV and cancer patients,providing insights and references for cancer treatment.METHODS The study included 127 cancer patients with available 24-hour dynamic electrocardiogram data.HRV differences were analyzed using both time domain and frequency domain methods.These findings were then compared to HRV data from reference individuals,sourced from literature that utilized the same HRV computing algorithm.RESULTS Our findings revealed that cancer patients generally exhibited abnormal HRV compared to the reference group.HRV was found to be correlated with age and clinical type(P<0.05),but no significant correlation was observed with tumor site or gender(P>0.05).CONCLUSION This study indicates that cancer patients have significantly abnormal HRV compared to reference individuals,suggesting the presence of a certain level of cardiac autonomic dysfunction in this patient population.
文摘In this article,we comment on the study by Yang et al,which demonstrated significant cross-sectional associations between heart rate variability(HRV)indices,depressive symptoms,and lung function in patients with chronic obstructive pulmonary disease(COPD).Building on these findings,we further explore the underlying mechanisms,particularly inflammatory-autonomic-oxidative stress pathways,as key causal mediators.Moreover,analyzing genetic polymorphisms alongside environmental factors may uncover susceptibility pathways explaining interindividual differences in HRV and comorbidity risk.Additionally,longitudinal studies tracking HRV trajectories could identify thresholds predictive of accelerated lung function decline or cardiovascular events,informing personalized prevention strategies.Integrating longitudinal HRV data with multi-omics biomarkers and machine learning models could enable real-time prediction of depression relapses or COPD exacerbations,facilitating proactive interventions such as personalized biofeedback training or precision anti-inflammatory therapies.By synthesizing these perspectives,this integrative approach promises to advance precision medicine for COPD patients,particularly those with comorbid depression,by addressing both mechanistic insights and clinical translation.
基金Supported by National Agency of Research and Development(ANID),Government of Chile(https://anid.cl/about-us/),through the Initiation in Research FONDECYT grant No.11241548.
文摘Autonomic dysfunction(AD)is frequently observed in cirrhotic patients and is associated with poor clinical outcomes and prognoses.Heart rate variability(HRV),a noninvasive tool for assessing autonomic nervous system balance,has been extensively studied in a variety of conditions,including chronic liver disease(CLD);however,no recent reviews have focused on its role in CLD.This article examines the mechanisms of AD in CLD and the foundation for HRV assessment,highlighting its diagnostic,prognostic,and therapeutic applications in CLD,including liver transplantation(LT).Changes in HRV,particularly in patients with cirrhotic complications,and its prognostic significance throughout the natural history of CLD are summarized.We show that HRV is consistently reduced in CLD patients,reflecting AD,and is inversely correlated with liver disease severity.Also,low HRV is associated with complications such as hepatic encephalopathy,ascites,and portal hypertension.Moreover,evidence indicates that reduced HRV is an independent risk factor for mortality and circulatory instability in CLD.Furthermore,treatment with beta-blockers and LT improves HRV,underscoring its potential role in patient management.While further studies are needed,HRV emerges as a promising tool for the comprehensive evaluation and clinical management of patients with CLD,offering insights into disease progression and therapeutic response.
基金the National Science and Technology Major Project(No.2017-VII-0004-0097)the Natural Science Foundation for Distinguished Young Scholars of Jiangsu Province(No.BK20170031)。
文摘Electrochemical machining(ECM)is an economical and effective method for blisk manufacturing and includes two steps:channel machining and profile machining.The allowance distribution after the channel machining will directly affect the profile machining.Therefore,to improve the uniformity of allowance distribution in the machining of channels,a method that incorporates a variable feed rate mode is developed.During the machining process,the feed rates are dynamically changed according to the needs of the side gap at the different feed depths.As a result,the side gaps at the different feed depths vary,contributing to a decrease in the allowance difference.In this study,the dissolution processes of a blisk channel are simulated using different feed rates,and prediction profiles are obtained.Based on the prediction profiles,the relationship among the feed rate,feed depth,and side gap is established.Then,the feed rates at different feed depths are adjusted according to the relationship.In addition,contrast experiments are conducted.Compared with blisk channel ECM using a constant feed rate of 1 mm/min,using the variable feed rate decreases the allowance differences in the convex and concave parts by 62.2%and 67.4%,respectively.This indicates that using the variable feed rate in the ECM process for a blisk channel is feasible and efficient.
基金Supported by the National Natural Science Foundation of China(Nos.51379146,51409190)the National Science Foundation for Post-Doctoral Scientists of China(No.2013M531218)
文摘To investigate the effects of flow rate on phytoplankton dynamics and related environment variables,a set of enclosure experiments with different fl ow rates were conducted in an artificial lake. We monitored nutrients,temperature,dissolved oxygen,p H,conductivity,turbidity,chlorophyll-a and phytoplankton levels. The lower biomass in all flowing enclosures showed that flow rate significantly inhibited the growth of phytoplankton. A critical flow rate occurred near 0.06 m/s,which was the lowest relative inhibitory rate. Changes in flow conditions affected algal competition for light,resulting in a dramatic shift in phytoplankton composition,from blue-green algae in still waters to green algae in flowing conditions. These findings indicate that critical flow rate can be useful in developing methods to reduce algal bloom occurrence. However,flow rate significantly enhanced the inter-relationships among environmental variables,in particular by inducing higher water turbidity and vegetative reproduction of periphyton( Spirogyra). These changes were accompanied by a decrease in underwater light intensity,which consequently inhibited the photosynthetic intensity of phytoplankton. These results warn that a universal critical flow rate might not exist,because the effect of flow rate on phytoplankton is interlinked with many other environmental variables.
基金Project(G-0805-10156) supported by US Energy Foundation
文摘The optimum control strategy and the saving potential of all variable chiller plant under the conditions of changing building cooling load and cooling water supply temperature were investigated. Based on a simulation model of water source chiller plant established in dynamic transient simulation program (TRNSYS),the four-variable quadratic orthogonal regression experiments were carried out by taking cooling load,cooling water supply temperature,cooling water flow rate and chilled water flow rate as variables,and the fitting formulas expressing the relationships between the total energy consumption of chiller plant with the four selected parameters was obtained. With the SAS statistical software and MATHEMATICA mathematical software,the optimal chilled water flow rate and cooling water flow rate which result in the minimum total energy consumption were determined under continuously varying cooling load and cooling water supply temperature. With regard to a chiller plant serving an office building in Shanghai,the total energy consumptions under different control strategies were computed in terms of the forecasting function of cooling load and water source temperature. The results show that applying the optimal control strategy to the chiller plant can bring a saving of 23.27% in power compared with the corresponding conventional variable speed plant,indicating that the optimal control strategy can improve the energy efficiency of chiller plant.
文摘Recent increases in irrigated hectares in the Southeastern US have enabled growers to obtain higher yields through applying nutrients through irrigation water. Therefore, many growers apply nutrients through irrigation systems, known as fertigation. Currently, there are no practical decision-making tools available for variable-rate application of nitrogen (N) through overhead sprinkler irrigation systems. Therefore, field tests were conducted on cotton (Gossypium hirsutum L.) during the 2016 and 2017 growing seasons to 1) adapt the Clemson sensor-based N recommendation algorithms from a single side-dress application to multiple applications through an overhead irrigation system;and 2) to compare sensor-based VRFS with conventional nutrient management methods in terms of N use efficiency (NUE) and crop responses on three soil types. Two seasons of testing Clemson N prediction algorithms to apply multiple applications of N were very promising. The multiple applications of N compared to the grower’s conventional methods (even though less N was applied) had no impact on yields in either growing season. There was no difference in cotton yields between 101 and 135 kg/ha N applications in either management zone. Also, there were no differences in yield between sensor-based, multiple N applications and conventional N management techniques. In relation to comparisons of the sensor methods only applying N in three or four applications, statistically increased yields compared to single or split applications in 2016. Applying N in four applications, statistically increased yields compared to single, split or triple applications in 2017. When the sensor-based methods were compared to the grower’s conventional methods averaged over four treatments, the sensor-based N applications reduced fertilizer requirement by 69% in 2016 and 57% in 2017 compared to grower’s conventional methods. When comparing N rates among the four sensor-based methods (three or four) applications, increased N rates by 22 kg/ha in 2016 and 26 kg/ha in 2017 compared to single or split applications but increased the cotton lint yields by 272 and 139 kg/ha, for 2016 and 2017, respectively.
基金Supported by the National Natural Science Foundation of China(10071058,70273029)
文摘We consider a risk model with a premium rate which varies with the level of free reserves.In this model,the occurrence of claims is described by a Cox process with Markov intensity process,and the influence of stochastic factors is considered by adding a diffusion process.The integro-differential equation for the ruin probability is derived by a infinitesimal method.
基金Supported by the National Science Foundation（10661006） Supported by Innovation Project of Guangxi Graduate Education（2007105960812M18）
文摘In this paper,we establish a Rosenthal-type inequality of partial sums for ρ~mixing random variables.As its applications,we get the complete convergence rates in the strong laws for ρ^-mixing random variables.The result obtained extends the corresponding result.
基金This work was supported by the National Natural Science Foundation of China(62073341)in part by the Natural Science Fund for Distinguished Young Scholars of Hunan Province(2019JJ20026).
文摘Nonlinear equations systems(NESs)are widely used in real-world problems and they are difficult to solve due to their nonlinearity and multiple roots.Evolutionary algorithms(EAs)are one of the methods for solving NESs,given their global search capabilities and ability to locate multiple roots of a NES simultaneously within one run.Currently,the majority of research on using EAs to solve NESs focuses on transformation techniques and improving the performance of the used EAs.By contrast,problem domain knowledge of NESs is investigated in this study,where we propose the incorporation of a variable reduction strategy(VRS)into EAs to solve NESs.The VRS makes full use of the systems of expressing a NES and uses some variables(i.e.,core variable)to represent other variables(i.e.,reduced variables)through variable relationships that exist in the equation systems.It enables the reduction of partial variables and equations and shrinks the decision space,thereby reducing the complexity of the problem and improving the search efficiency of the EAs.To test the effectiveness of VRS in dealing with NESs,this paper mainly integrates the VRS into two existing state-of-the-art EA methods(i.e.,MONES and DR-JADE)according to the integration framework of the VRS and EA,respectively.Experimental results show that,with the assistance of the VRS,the EA methods can produce better results than the original methods and other compared methods.Furthermore,extensive experiments regarding the influence of different reduction schemes and EAs substantiate that a better EA for solving a NES with more reduced variables tends to provide better performance.
文摘The relations of change rate of an independent variable, volumetric strain of the porous skeleton, with the change rates of a kind of constitutive variables, such as porosity, volumetric strain of the solid matrix, are derived from the definition of the porosity of water saturated porous media; and the relations of the change rates of another two independent variables, pressure of the pore liquid water and temperature, with the change rates of another kind of constitutive variables, such as pressure of the pore ice, average pressure of the pore liquid water and ice, and average stress of the solid matrix, are obtained from the Clausius Clapeyron relation in the process of freezing or thawing, definitions of the average pore pressure and effective stress. Based on the hypothesis of linear thermoelasticity, principle of effective stress and these relations, the change rates of all constitutive variables may be described with the change rates of the three independent variables.
文摘Nutrients are injected through overhead irrigation systems at a uniform rate in a process known as fertigation. The highly variable soils in the Southeastern US pose challenges for effective fertigation. Currently, there is no variable-rate fertigation system available to apply the correct amount of N within a field through an overhead irrigation system. Therefore, the objective of this study was to develop and test a variable-rate N application system that works independently of irrigation water flow for site-specific N application. The variable-rate fertigation system (VRFS) was designed to apply different rates N using a pulse width modulation technique. The VRFS utilized the Clemson Lateral Irrigation Control software which controlled the solenoids in each zone by turning the N supply on and off (pulsing) for each zone. In this study, four tests were conducted to determine the uniformity of the VRFS. In test # 1, the pump output showed a linear slope relationship and was the same for water and N. In test # 2, nozzle flow and uniformity were determined using four different irrigation system travel speeds at N application rates of 31, 59, 88, and 113 kg/ha. There was a strong correlation (R2 = 0.9998) between irrigation system speed and N rate. In test # 3, the uniformity across the length of the irrigation system was determined. The nozzles produced an average flow of 31.1, 58.7, 87.6, and 112.7 kg N/ha with an overall average error of 0.1% across all N rates. Results also showed the system was capable of accurately applying N based on prescription maps with an error of less than 1.8%. Test # 4 was conducted to determine the accuracy of the map-based controller system for applying variable rate N. There was a strong correlation between target N and actual N rates (R2 = 0.9999). In summary, the VRFS applied the correct amounts of N within each zone by either manually controlling the pulsing mechanism or utilizing a prescription map to apply different rates throughout the field.
文摘A variable-bit-rate characteristic waveform interpolation （VBR-CWI） speech codec with about 1.8 kbit/s average bit rate which integrates phonetic classification into characteristic waveform （CW） decomposition is proposed. Each input frame is classified into one of 4 phonetic classes. Non-speech frames are represented with Bark-band noise model. The extracted CWs become rapidly evolving waveforms （REWs） or slowly evolving waveforms （SEWs） in the cases of unvoiced or stationary voiced frames respectively, while mixed voiced frames use the same CW decomposition as that in the conventional CWI. Experimental results show that the proposed codec can eliminate most buzzy and noisy artifacts existing in the fixed-bit-rate characteristic waveform interpolation （FBR-CWI） speech codec, the average bit rate can be much lower, and its reconstructed speech quality is much better than FS 1 016 CELP at 4.8 kbit/s and similar to G. 723.1 ACELP at 5.3 kbit/s.
基金Sponsored by the National Natural Science Foundation of China and the Research Grants Council of Hong Kong Joint Research Scheme(Grant No.60731160626)the National Natural Science Foundation of China(Grant No.60821001and61003287)+1 种基金the 111 Project(Grant No.B08004)the Fundamental Research Funds for the Central Universities(Grant No.BUPT2009RC0220)
文摘Fong et al.analyzed variable-rate linear network coding for linear broadcast.However,the authors didn't investigate it for the other three types of linear network codes.In this paper,by simple and clear proofs,it is found that there are similar results for variable-rate linear generic and linear dispersion if the field size is large enough.It means that linear generics and linear dispersions of different dimensions can be implemented on the same network,while each non-source node is required to store only one copy of the local encoding kernel within a session.Moreover,an example is given to show that there isn't a similar result for linear multicast.
