The precision width control is vital for product quality and production economy in plate width control process, so short stroke control method was used in plate rolling by opening or closing edger gap so as to avoid h...The precision width control is vital for product quality and production economy in plate width control process, so short stroke control method was used in plate rolling by opening or closing edger gap so as to avoid head end necking. Head end necking on different broadening ratio was analyzed, and sections of different elongations at edger roiling was calculated; based on the law of volume constancy, the adjustment functions were described by parabolic functions. Control curves were developed with three Gaussian curves by means of additional combining; SSC control curve was changed with different weights of those curves, w1 effect one-third of SSC length, w2 effect two-third of SSC length, w3 effect all three parts of SSC length. In order to adjust the amount of weights for precise quantification, PSO algorithm was used to build sufficiency function so as to obtain best rectangular degree by global optimization. Practical applications showed that the method proposed is available to improve the product rolling yields by 1.0% -2. 0% and worthy to apply to plate rolling.展开更多
Automatic width control is a key issue in hot strip rolling process. The edge rolling has been widely used in the roughing stand of hot strip mill to control the width of the slab. However, the edge rolling and conseq...Automatic width control is a key issue in hot strip rolling process. The edge rolling has been widely used in the roughing stand of hot strip mill to control the width of the slab. However, the edge rolling and consequent hori- zontal rolling will cause a significant width change in the head part and tail part of the slab, which have to be trimmed before the finishing stands. Based on the width reduction deformation curve of the head and tail along the longitudinal direction of slab, the short stroke control (SSC) technology has been developed to overcome this problem. The finite element method has been used to simulate the unsteady edge rolling process. Three short stroke control curves have been compared in order to obtain the best width control result. The optimized short stroke control curve has been ap- plied to the automatic width control system of industrial hot rolling mill, and good performance is obtained.展开更多
According to technological requirement of hot charge rolling and hot direct rolling,in this paper,we investigated the technology of the width control rolling in the rougher mills of hot strip continuous rolling mill t...According to technological requirement of hot charge rolling and hot direct rolling,in this paper,we investigated the technology of the width control rolling in the rougher mills of hot strip continuous rolling mill train.On the basis of improving width range of continuous casting of slab,we obtained a good result of greatly increasing the yield of slab→coil is achieved.展开更多
Purpose: Although proximal stability of the trunk is a prerequisite for balance and gait, to determine the role of trunk rehabilitation on trunk control, balance and gait in patients with chronic stroke is yet unknown...Purpose: Although proximal stability of the trunk is a prerequisite for balance and gait, to determine the role of trunk rehabilitation on trunk control, balance and gait in patients with chronic stroke is yet unknown. Method: Fifteen sub-jects (post-stroke duration (3.53 ± 2.98) years) who had the ability to walk 10 meters independently with or without a walking aid;scoring ≤ 21 on Trunk Impairment Scale (TIS), participated in a selective trunk muscle exercise regime, consisting of 45 minutes training per day, four days a week, and for four weeks duration in an outpatient stroke reha-bilitation centre. Results: The overall effect size index for trunk rehabilitation was 1.07. This study showed large effect size index for Trunk Impairment Scale (1.75), Berg Balance Scale (1.65) than for gait variables (0.65). After trunk rehabilitation, there was a significant improvement for gait speed (p= 0.015), cadence (p= 0.001) and gait symmetry (p=0.019) in patients with chronic stroke. In addition, all the spatial gait parameters had a significant change post-intervention. There was no significant change in temporal gait parameters with the exception of affected single limb support time. The level of significance was set at p < 0.05. Conclusion: The exercises consisted of selective trunk movement of the upper and the lower part of trunk had shown larger effect size index for trunk control and balance than for gait in patients with chronic stroke. Future randomized controlled studies incorporating large sample size would provide insight into the effectiveness and clinical relevance of this intervention.展开更多
This study aimed to investigate the effects of exercise-induced muscle fatigue in the unaffected knee joint on postural control and kinematic changes in stroke patients. Forty participants(20 stroke patients, 20 age-...This study aimed to investigate the effects of exercise-induced muscle fatigue in the unaffected knee joint on postural control and kinematic changes in stroke patients. Forty participants(20 stroke patients, 20 age-matched healthy participants) were recruited. To induce fatigue, maximum voluntary isometric contractions were performed in the unaffected knee joint in a Leg Extension Rehab exercise machine using the pneumatic resistance. We measured static and dynamic balance and lower-limb kinematics during gait. Changes in postural control parameters anteroposterior sway speed and total center of pressure distance differed significantly between the stroke and control groups. In addition, changes in gait kinematic parameters knee and ankle angles of initial contact differed significantly between stroke(paretic and non-paretic) and control groups. Muscle fatigue in the unaffected knee and ankle impaired postural control and debilitates kinematic movement of ipsilateral and contralateral lower limbs, and may place the fatigued stroke patients at greater risk for falls.展开更多
The purpose of this study was to pilot an innovative and supported intervention for individuals with a stroke. A pilot control trial with qualitative interviews was undertaken within a university- community setting. T...The purpose of this study was to pilot an innovative and supported intervention for individuals with a stroke. A pilot control trial with qualitative interviews was undertaken within a university- community setting. Thirteen individuals who had experienced a stroke for periods of least 6 months (6 male, average 71 years) were assigned to the intervention group and 7 individuals (2 male, average age 67.9 years) assigned to the control group. Eight individuals from the intervention group completed a single interview. The procedures that related to recruitment and retention and data collection methods were considered. Outcome measures including;self-efficacy, falls self-efficacy and group membership, for both groups were taken at baseline, 11 weeks, 22 weeks. There was an additional assessment at 52 weeks for the intervention group. The structured interview was designed to focus on experiences of the intervention. Self-efficacy remained stable across time for both groups. An improvement in falls self-efficacy was noted in the intervention group at 11 weeks. Consistent improvement (from baseline) was observed in the identity scale across the 52 weeks. Qualitative data provided additional findings related to identity and confidence. Details considering recruitment and retention are also provided. This pilot study provided data that can be used for a further full-scale trial to be considered.展开更多
This study was to evaluate the efficacy and safety of early application of citicoline in the treatment of patients with acute stroke by meta-analysis. Randomized controlled trials published until May 2015 were electro...This study was to evaluate the efficacy and safety of early application of citicoline in the treatment of patients with acute stroke by meta-analysis. Randomized controlled trials published until May 2015 were electronically searched in MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, WHO International Clinical Trial Registration Platform, Clinical Trial.gov, and China Biology Medicine disc. Two reviewers independently screened the articles and extracted the data based on the inclusion and exclusion criteria. The quality of included articles was evaluated by using Revman5.0, and meta-analysis was performed. The results showed that 1027 articles were obtained in initial retrieval, and finally 7 articles, involving a total of 4039 cases, were included for analysis. The meta-analysis showed that no significant differences were found in the long-term mortality(OR=0.91, 95% CI 0.07 to 1.09, P=0.30), the rate of dependency(OR=1.02, 95% CI 0.87 to 1.24, P=0.85), and the effective rate(OR=0.98, 95% CI 0.84 to 1.14, P=0.82) between citicoline group and control group. The overall rate of adverse events in citicoline group was not significantly different from that in control group(P=0.30). The quality of included articles reached moderate-low level. In conclusion, citicolne cannot reduce long-term mortality and dependence rate in the treatment of acute stroke, and the effective rate of citivoline may be not better than that of controls but with reliable safety.展开更多
Background: Case-control studies have been used extensively in determining the aetiology of rare diseases. However, case-control studies often suffer from participation bias in the control group, resulting in biased o...Background: Case-control studies have been used extensively in determining the aetiology of rare diseases. However, case-control studies often suffer from participation bias in the control group, resulting in biased odds ratios that cause problems with interpretation. Participation bias can be hard to detect and is often ignored. Methods: Population data can be used in place of the possibly biased control group, to investigate whether participation bias may have affected the results in previous studies, or in place of controls in future studies. We demonstrate this approach by reanalysing and comparing the results of two case-control studies: Type 1 diabetes in Yorkshire children and stroke in Indian adults. Findings: Using population data to represent the control groups reduced the width of the confidence intervals given in the original studies and confirmed the findings for the two diabetes risk factors used;caesarean birth (odds ratio (OR) = 2.12 (1.53, 2.95) compared with 1.84 (1.09, 3.10)) and amniocentesis (OR = 3.38 (2.09, 5.47) compared with 3.85 (1.34, 11.04)). The three stroke risk factors investigated were found to have increased odds ratios when using population data;hypertension (OR = 5.645 (5.639, 5.650) compared with 3.807 (2.114, 6.856)), diabetes (OR = 12.212 (12.200, 12.224) compared with 3.473 (1.757, 6.866)) and smoking (OR = 5.701 (5.696, 5.707) compared with 2.242 (1.255, 4.005)). Interpretation: Participation bias can greatly affect the results of a study and cause some potential risk factors to be over-or underestimated. This approach allows previous studies to be investigated for participation bias and presents an alternative to a control group in future studies, while improving precision.展开更多
A frequency compensation control method for the opposed-piston two-stroke folded-cranktrain( OPFC) diesel engine's common rail system is presented as a result of the study of the loop-shaping theory. A common rail ...A frequency compensation control method for the opposed-piston two-stroke folded-cranktrain( OPFC) diesel engine's common rail system is presented as a result of the study of the loop-shaping theory. A common rail working process and the classical frequency control theory are combined to construct a frequency restriction of common rail pressure. A frequency compensator is utilized to improve the robustness of multiplicative perturbations and disturbance. The loop-shaping method has been applied to design the common rail pressure controller of the OPFC diesel engine. Simulation and bench test results show that in the condition of perturbation that comes from the effect of injection,multi-injection,fuel pumping of a pre-cylinder,and instantaneous pressure fluctuation,the controller indicates high precision. Compared with the original controller,this method improves the control precision by 67. 3%.展开更多
Nutrient application systems are designed to apply a relatively uniform amount of a fertilizer to agricultural fields. However, considerable variation in soil texture and other characteristics often occurs within and ...Nutrient application systems are designed to apply a relatively uniform amount of a fertilizer to agricultural fields. However, considerable variation in soil texture and other characteristics often occurs within and across production fields, which could have a major impact on fertilizer management strategies. Therefore, uniform application of a fertilizer over the entire field can be both costly and environmentally unsound. Due to their rugged and fool-proof design, crankshaft type piston pumps are widely used in agriculture. The on-the-go outlet flow of these pumps can only be varied by changing the drive shaft speed for each pump stroke setting. But only a limited range of flow rates can be achieved by changing the drive shaft speed. There is a need for an electronic controller, which can adjust the pump stroke on-the-go, for real-time, variable-rate application of crop nutrients. The Clemson “Electro-me-chanical controller for adjusting pump stroke on-the-go” was designed to replace the current manual stroke adjustment system on positive displacement piston pumps. This affordable system can be retrofitted on most John Blue - piston pumps for real-time adjustment of the pump stroke and can be controlled using pre-described position sequences (map-based) or real-time sensor commands (such as optical, pressure, and flow sensors) combined with fertilizer calculation algorithms. In addition, it can adjust pump stroke manually, using an eclectic dial from the tractor’s cab.展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.51001023)the Fundamental Research Funds for the Central Universities(Grant No.N100307004)
文摘The precision width control is vital for product quality and production economy in plate width control process, so short stroke control method was used in plate rolling by opening or closing edger gap so as to avoid head end necking. Head end necking on different broadening ratio was analyzed, and sections of different elongations at edger roiling was calculated; based on the law of volume constancy, the adjustment functions were described by parabolic functions. Control curves were developed with three Gaussian curves by means of additional combining; SSC control curve was changed with different weights of those curves, w1 effect one-third of SSC length, w2 effect two-third of SSC length, w3 effect all three parts of SSC length. In order to adjust the amount of weights for precise quantification, PSO algorithm was used to build sufficiency function so as to obtain best rectangular degree by global optimization. Practical applications showed that the method proposed is available to improve the product rolling yields by 1.0% -2. 0% and worthy to apply to plate rolling.
基金Item Sponsored by National Science and Technology Support Programfor 11th Five-Year Plan of China (2006BAE03A13)International Cooperation Research Project of Shanxi Province (2009081013)
文摘Automatic width control is a key issue in hot strip rolling process. The edge rolling has been widely used in the roughing stand of hot strip mill to control the width of the slab. However, the edge rolling and consequent hori- zontal rolling will cause a significant width change in the head part and tail part of the slab, which have to be trimmed before the finishing stands. Based on the width reduction deformation curve of the head and tail along the longitudinal direction of slab, the short stroke control (SSC) technology has been developed to overcome this problem. The finite element method has been used to simulate the unsteady edge rolling process. Three short stroke control curves have been compared in order to obtain the best width control result. The optimized short stroke control curve has been ap- plied to the automatic width control system of industrial hot rolling mill, and good performance is obtained.
文摘According to technological requirement of hot charge rolling and hot direct rolling,in this paper,we investigated the technology of the width control rolling in the rougher mills of hot strip continuous rolling mill train.On the basis of improving width range of continuous casting of slab,we obtained a good result of greatly increasing the yield of slab→coil is achieved.
文摘Purpose: Although proximal stability of the trunk is a prerequisite for balance and gait, to determine the role of trunk rehabilitation on trunk control, balance and gait in patients with chronic stroke is yet unknown. Method: Fifteen sub-jects (post-stroke duration (3.53 ± 2.98) years) who had the ability to walk 10 meters independently with or without a walking aid;scoring ≤ 21 on Trunk Impairment Scale (TIS), participated in a selective trunk muscle exercise regime, consisting of 45 minutes training per day, four days a week, and for four weeks duration in an outpatient stroke reha-bilitation centre. Results: The overall effect size index for trunk rehabilitation was 1.07. This study showed large effect size index for Trunk Impairment Scale (1.75), Berg Balance Scale (1.65) than for gait variables (0.65). After trunk rehabilitation, there was a significant improvement for gait speed (p= 0.015), cadence (p= 0.001) and gait symmetry (p=0.019) in patients with chronic stroke. In addition, all the spatial gait parameters had a significant change post-intervention. There was no significant change in temporal gait parameters with the exception of affected single limb support time. The level of significance was set at p < 0.05. Conclusion: The exercises consisted of selective trunk movement of the upper and the lower part of trunk had shown larger effect size index for trunk control and balance than for gait in patients with chronic stroke. Future randomized controlled studies incorporating large sample size would provide insight into the effectiveness and clinical relevance of this intervention.
文摘This study aimed to investigate the effects of exercise-induced muscle fatigue in the unaffected knee joint on postural control and kinematic changes in stroke patients. Forty participants(20 stroke patients, 20 age-matched healthy participants) were recruited. To induce fatigue, maximum voluntary isometric contractions were performed in the unaffected knee joint in a Leg Extension Rehab exercise machine using the pneumatic resistance. We measured static and dynamic balance and lower-limb kinematics during gait. Changes in postural control parameters anteroposterior sway speed and total center of pressure distance differed significantly between the stroke and control groups. In addition, changes in gait kinematic parameters knee and ankle angles of initial contact differed significantly between stroke(paretic and non-paretic) and control groups. Muscle fatigue in the unaffected knee and ankle impaired postural control and debilitates kinematic movement of ipsilateral and contralateral lower limbs, and may place the fatigued stroke patients at greater risk for falls.
文摘The purpose of this study was to pilot an innovative and supported intervention for individuals with a stroke. A pilot control trial with qualitative interviews was undertaken within a university- community setting. Thirteen individuals who had experienced a stroke for periods of least 6 months (6 male, average 71 years) were assigned to the intervention group and 7 individuals (2 male, average age 67.9 years) assigned to the control group. Eight individuals from the intervention group completed a single interview. The procedures that related to recruitment and retention and data collection methods were considered. Outcome measures including;self-efficacy, falls self-efficacy and group membership, for both groups were taken at baseline, 11 weeks, 22 weeks. There was an additional assessment at 52 weeks for the intervention group. The structured interview was designed to focus on experiences of the intervention. Self-efficacy remained stable across time for both groups. An improvement in falls self-efficacy was noted in the intervention group at 11 weeks. Consistent improvement (from baseline) was observed in the identity scale across the 52 weeks. Qualitative data provided additional findings related to identity and confidence. Details considering recruitment and retention are also provided. This pilot study provided data that can be used for a further full-scale trial to be considered.
文摘This study was to evaluate the efficacy and safety of early application of citicoline in the treatment of patients with acute stroke by meta-analysis. Randomized controlled trials published until May 2015 were electronically searched in MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, WHO International Clinical Trial Registration Platform, Clinical Trial.gov, and China Biology Medicine disc. Two reviewers independently screened the articles and extracted the data based on the inclusion and exclusion criteria. The quality of included articles was evaluated by using Revman5.0, and meta-analysis was performed. The results showed that 1027 articles were obtained in initial retrieval, and finally 7 articles, involving a total of 4039 cases, were included for analysis. The meta-analysis showed that no significant differences were found in the long-term mortality(OR=0.91, 95% CI 0.07 to 1.09, P=0.30), the rate of dependency(OR=1.02, 95% CI 0.87 to 1.24, P=0.85), and the effective rate(OR=0.98, 95% CI 0.84 to 1.14, P=0.82) between citicoline group and control group. The overall rate of adverse events in citicoline group was not significantly different from that in control group(P=0.30). The quality of included articles reached moderate-low level. In conclusion, citicolne cannot reduce long-term mortality and dependence rate in the treatment of acute stroke, and the effective rate of citivoline may be not better than that of controls but with reliable safety.
文摘Background: Case-control studies have been used extensively in determining the aetiology of rare diseases. However, case-control studies often suffer from participation bias in the control group, resulting in biased odds ratios that cause problems with interpretation. Participation bias can be hard to detect and is often ignored. Methods: Population data can be used in place of the possibly biased control group, to investigate whether participation bias may have affected the results in previous studies, or in place of controls in future studies. We demonstrate this approach by reanalysing and comparing the results of two case-control studies: Type 1 diabetes in Yorkshire children and stroke in Indian adults. Findings: Using population data to represent the control groups reduced the width of the confidence intervals given in the original studies and confirmed the findings for the two diabetes risk factors used;caesarean birth (odds ratio (OR) = 2.12 (1.53, 2.95) compared with 1.84 (1.09, 3.10)) and amniocentesis (OR = 3.38 (2.09, 5.47) compared with 3.85 (1.34, 11.04)). The three stroke risk factors investigated were found to have increased odds ratios when using population data;hypertension (OR = 5.645 (5.639, 5.650) compared with 3.807 (2.114, 6.856)), diabetes (OR = 12.212 (12.200, 12.224) compared with 3.473 (1.757, 6.866)) and smoking (OR = 5.701 (5.696, 5.707) compared with 2.242 (1.255, 4.005)). Interpretation: Participation bias can greatly affect the results of a study and cause some potential risk factors to be over-or underestimated. This approach allows previous studies to be investigated for participation bias and presents an alternative to a control group in future studies, while improving precision.
基金Supported by the National Natural Science Foundation of China(51406013)
文摘A frequency compensation control method for the opposed-piston two-stroke folded-cranktrain( OPFC) diesel engine's common rail system is presented as a result of the study of the loop-shaping theory. A common rail working process and the classical frequency control theory are combined to construct a frequency restriction of common rail pressure. A frequency compensator is utilized to improve the robustness of multiplicative perturbations and disturbance. The loop-shaping method has been applied to design the common rail pressure controller of the OPFC diesel engine. Simulation and bench test results show that in the condition of perturbation that comes from the effect of injection,multi-injection,fuel pumping of a pre-cylinder,and instantaneous pressure fluctuation,the controller indicates high precision. Compared with the original controller,this method improves the control precision by 67. 3%.
文摘Nutrient application systems are designed to apply a relatively uniform amount of a fertilizer to agricultural fields. However, considerable variation in soil texture and other characteristics often occurs within and across production fields, which could have a major impact on fertilizer management strategies. Therefore, uniform application of a fertilizer over the entire field can be both costly and environmentally unsound. Due to their rugged and fool-proof design, crankshaft type piston pumps are widely used in agriculture. The on-the-go outlet flow of these pumps can only be varied by changing the drive shaft speed for each pump stroke setting. But only a limited range of flow rates can be achieved by changing the drive shaft speed. There is a need for an electronic controller, which can adjust the pump stroke on-the-go, for real-time, variable-rate application of crop nutrients. The Clemson “Electro-me-chanical controller for adjusting pump stroke on-the-go” was designed to replace the current manual stroke adjustment system on positive displacement piston pumps. This affordable system can be retrofitted on most John Blue - piston pumps for real-time adjustment of the pump stroke and can be controlled using pre-described position sequences (map-based) or real-time sensor commands (such as optical, pressure, and flow sensors) combined with fertilizer calculation algorithms. In addition, it can adjust pump stroke manually, using an eclectic dial from the tractor’s cab.
文摘目的对豨莶通栓胶囊/丸治疗缺血性脑卒中的疗效进行系统评价。方法计算机检索中国知识资源总库(CNKI)、中国生物医学文献服务系统(SinoMed)、中文科技期刊数据库(VIP)、中国学术期刊数据库(Wanfang Data)、PubMed、Medline、Embase、Cochrane Library、Web of Science建库至2023年2月28日豨莶通栓制剂联合西医常规疗法治疗急性缺血性脑卒中相关文献,对可量化分析的研究作Meta分析,对有效率和其他疗效指标进行合并。结果共纳入7篇文献用于Meta分析。结果显示,西医常规疗法治疗急性缺血性脑卒中加用豨莶通栓胶囊/丸剂有效率(RR=0.34,95%CI[0.23,0.51],P<0.01)、美国国立卫生研究院卒中量表(NIHSS)评分(MD=-2.90,95%CI[-3.74,-2.06],P<0.01)、日常生活活动能力量表(BI)评分(MD=-10.08,95%CI[-13.47,-6.68],P<0.01)、纤维蛋白原(MD=-1.18,95%CI[-1.59,-0.77],P<0.01)差异有统计学意义,白细胞介素-6(MD=-15.4,95%CI[-33.3,2.49],P=0.09)差异无统计学意义。不同剂型和用药疗程对有效率和NIHSS评分的影响差异无统计学意义。结论联合使用豨莶通栓胶囊/丸可更好地改善急性缺血性脑卒中患者的NIHSS和BI评分,辅助患者的神经功能恢复,还可通过减少纤维蛋白原含量改善血液的高凝状态风险,且安全性良好。