Background: Athletes, coaches, sport psychology practitioners, and researchers suggest that mental toughness represents an important construct that is associated with athletic performance. Unfortunately, the absence o...Background: Athletes, coaches, sport psychology practitioners, and researchers suggest that mental toughness represents an important construct that is associated with athletic performance. Unfortunately, the absence of real-world performance as a dependent variable has limited our ability to substantiate this claim. The concern of a lack of ecologically valid measures of sports performance might be addressed by examining the relationship between mental toughness and sports performance using a standardized measure of personal best(PB) triathlon time and a validated unidimensional measure of mental toughness.Methods: Three hundred and sixteen triathletes completed the 8-item mental toughness index(MTI), reported their age, and provided a PB Olympic distance triathlon time and the total number of triathlons they had completed to date. Given that males are typically quicker than females, a standardized time was calculated by dividing the PB by the current Olympic record for gender; we also hypothesized that more experienced triathletes would report quicker PB times because of greater frequency and duration of training. Once we had controlled for gender and experience,we predicted that mental toughness would be negatively associated with triathlon time and the size of the relationship would be of a moderate magnitude.Results: Results revealed small-to moderate-sized negative relationships between both completed number of triathlons and mental toughness with standardized PB time.Conclusion: The hierarchical regression analysis showed that mental toughness provided a unique contribution to the variability in standardized Olympic triathlon PB after controlling for the total number of triathlons completed.展开更多
The best time of stem cells transplantation for treating acute myocardial infarction (AMI) is still to be followed with interest and a focus issue for clinical cardiologist. A brief meta-analysis of clinical trials ab...The best time of stem cells transplantation for treating acute myocardial infarction (AMI) is still to be followed with interest and a focus issue for clinical cardiologist. A brief meta-analysis of clinical trials about timing-window and therapeutic effects of stem cell transplantation for treating AMI will be made out in this article.展开更多
MODIS-EVI time series data from 2000 to 2009 in Chongqing were selected for this study.By the use of best index slope extraction （BISE） method for cloud elimination,analysis on the change vector of EVI time series d...MODIS-EVI time series data from 2000 to 2009 in Chongqing were selected for this study.By the use of best index slope extraction （BISE） method for cloud elimination,analysis on the change vector of EVI time series data were conducted to investigate the EVI response on drought; then,four typical regions were selected to study the relationship between precipitation,temperature and EVI when the sever drought occurred in 2006; finally,based on the time series of vegetation condition index （VCI） and precipitation abnormity percentage,the temporal and spatial distributions of drought were studied.The results showed that,the EVI value of the summer in 2006 was significantly lower than the average EVI at the corresponding period of the other years in Chongqing.In addition,summer drought occurred mainly during the hot and dry weather.Except the southeast area,most of the other regions in Chongqing were all under severe drought.展开更多
In this paper, a representative set of QoS models and QoS-aware on-demand routing protocols are reviewed with emphasis on their ability to support QoS in mobile ad-hoc networks (MANETs) possibly used in WSNs. In parti...In this paper, a representative set of QoS models and QoS-aware on-demand routing protocols are reviewed with emphasis on their ability to support QoS in mobile ad-hoc networks (MANETs) possibly used in WSNs. In particular IntServ, DiffServ, FQMM, and SWAN QoS models are reviewed followed by different QoS-aware on-demand routings in MANETs from different perspectives such as the challenges, classifications, algorithmic aspects in QoS provisions. Tradeoff in providing support to real time (RT) and best effort (BE) traffic is highlighted. Finally, a detailed and comprehensive comparison table is provided for better understanding of QoS provision in MANETs.展开更多
The status of material delivery of an automobile general assembly line is analyzed, and the technique to achieve the real-time tracking of assembly status information is proposed based on RFID（ Radio Frequency Identi...The status of material delivery of an automobile general assembly line is analyzed, and the technique to achieve the real-time tracking of assembly status information is proposed based on RFID（ Radio Frequency Identification）. Thus the consumption of line-side buffer is obtained dynamically, then the type and quantity of needed material are fed back to the subsystem of material handling; the algorithm for determining the best time departure time of delivery driver based on minimizing of total time penalty function is proposed. This approach makes the material amount of a single delivery trip maximized and improves the efficiency of delivery drivers significantly in the case of does not affect the assembly line normal throughput. Additionally, although this dynamic material handling method is developed for the automobile assembly plant, it should be pointed out that this method is also applicable to other mixed model assembly plants such as electronics, semiconductor and aerospace industry.展开更多
文摘Background: Athletes, coaches, sport psychology practitioners, and researchers suggest that mental toughness represents an important construct that is associated with athletic performance. Unfortunately, the absence of real-world performance as a dependent variable has limited our ability to substantiate this claim. The concern of a lack of ecologically valid measures of sports performance might be addressed by examining the relationship between mental toughness and sports performance using a standardized measure of personal best(PB) triathlon time and a validated unidimensional measure of mental toughness.Methods: Three hundred and sixteen triathletes completed the 8-item mental toughness index(MTI), reported their age, and provided a PB Olympic distance triathlon time and the total number of triathlons they had completed to date. Given that males are typically quicker than females, a standardized time was calculated by dividing the PB by the current Olympic record for gender; we also hypothesized that more experienced triathletes would report quicker PB times because of greater frequency and duration of training. Once we had controlled for gender and experience,we predicted that mental toughness would be negatively associated with triathlon time and the size of the relationship would be of a moderate magnitude.Results: Results revealed small-to moderate-sized negative relationships between both completed number of triathlons and mental toughness with standardized PB time.Conclusion: The hierarchical regression analysis showed that mental toughness provided a unique contribution to the variability in standardized Olympic triathlon PB after controlling for the total number of triathlons completed.
文摘The best time of stem cells transplantation for treating acute myocardial infarction (AMI) is still to be followed with interest and a focus issue for clinical cardiologist. A brief meta-analysis of clinical trials about timing-window and therapeutic effects of stem cell transplantation for treating AMI will be made out in this article.
基金Supported by Foundation for Science and Technology Research Project of Chongqing (2009AC0125)Natural Science Foundation of Chongqing (2008BB1379)The Major Project of Ministry of Science and Technology," Science and Technology Action for Western Development" (2005BA901A01)~~
文摘MODIS-EVI time series data from 2000 to 2009 in Chongqing were selected for this study.By the use of best index slope extraction （BISE） method for cloud elimination,analysis on the change vector of EVI time series data were conducted to investigate the EVI response on drought; then,four typical regions were selected to study the relationship between precipitation,temperature and EVI when the sever drought occurred in 2006; finally,based on the time series of vegetation condition index （VCI） and precipitation abnormity percentage,the temporal and spatial distributions of drought were studied.The results showed that,the EVI value of the summer in 2006 was significantly lower than the average EVI at the corresponding period of the other years in Chongqing.In addition,summer drought occurred mainly during the hot and dry weather.Except the southeast area,most of the other regions in Chongqing were all under severe drought.
文摘In this paper, a representative set of QoS models and QoS-aware on-demand routing protocols are reviewed with emphasis on their ability to support QoS in mobile ad-hoc networks (MANETs) possibly used in WSNs. In particular IntServ, DiffServ, FQMM, and SWAN QoS models are reviewed followed by different QoS-aware on-demand routings in MANETs from different perspectives such as the challenges, classifications, algorithmic aspects in QoS provisions. Tradeoff in providing support to real time (RT) and best effort (BE) traffic is highlighted. Finally, a detailed and comprehensive comparison table is provided for better understanding of QoS provision in MANETs.
文摘The status of material delivery of an automobile general assembly line is analyzed, and the technique to achieve the real-time tracking of assembly status information is proposed based on RFID（ Radio Frequency Identification）. Thus the consumption of line-side buffer is obtained dynamically, then the type and quantity of needed material are fed back to the subsystem of material handling; the algorithm for determining the best time departure time of delivery driver based on minimizing of total time penalty function is proposed. This approach makes the material amount of a single delivery trip maximized and improves the efficiency of delivery drivers significantly in the case of does not affect the assembly line normal throughput. Additionally, although this dynamic material handling method is developed for the automobile assembly plant, it should be pointed out that this method is also applicable to other mixed model assembly plants such as electronics, semiconductor and aerospace industry.
文摘针对基于谐波特征分析的时间调制阵列(time-modulated array,TMA)测向技术中信息利用率低的问题,提出了一种基于信号频谱特征分析的多谐波TMA测向方法.通过分析接收信号的频谱特征,构建了基于信号频谱特征多谐波测向模型,推导了基于频谱特征的来波方向最优线性无偏估计(best linear unbiased estimation,BLUE)表达式,从而提高了测向精度及稳定性.以BPSK信号为例,通过仿真实验验证了所提算法的有效性,同时搭建了工作于S频段的二单元TMA测向系统证实了所提方法的可行性.
