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本文采用FFT和戈泽尔算法对计算机模拟产生双音多频信号进行检测;并基于短时能量和过零率,分割一串语音信号;考虑到录制信号含有噪声,提出将双声道合并成单声道,进而增强了语音,同时,设计出高低群双边带带通滤波器,得到了就很好的检测效果,使得两种算法也更好的适应于含噪信号的检测。 相似文献
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在地震勘探中决定地震分辨率的关键是获取的反射信号的有效频带宽度,而信号传播过程中由于地层吸收的作用有部分能量被衰减,特别是高频成份的衰减是反射信号频带宽度变窄的主要因素。因此,补偿能量的扩散和衰减,提高反射信号的高频能量,拓展地震记录的有效频带宽度,对提高地震分辨率具有重要意义,这是高分辨率勘探技术进一步发展所必须要解决的关键问题之一。常规的标量波动方程延拓只是考虑了地震波的几何传播规律,没考虑能量的衰减和扩散[1]。因此本文使用粘声波动方程来进行波场延拓,将偏移和能量补偿结合在一起,理论上证实了此方法可以很好地补偿能量的衰减和扩散。 相似文献
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数学形态学是一种非线性信号处理方法,不同于其他信号处理方法,数学形态学变换完全在时域中进行,无需进行时域和频域的转换,运算简单,速度快。工程现场拾取的振动信号往往含有大量噪声干扰,本文采用开闭和闭开的形态学组合滤波方法对振动信号进行处理。通过仿真信号和实测振动信号的处理结果表明,形态学组合滤波方法不仅能保留信号中的低频成分,具有优良的低通特性,同时处理后的信号具有相位保持的优点,对于脉冲干扰或白噪声均真有良好的抑制作用。 相似文献
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介绍了一种基于单线圈振弦式传感器的矿压检测系统,以STM32F103C8T6为主控芯片,采用反馈式低压扫频激振方法,使振弦在短时间内达到共振状态,经过两级信号放大电路、带通滤波器电路和迟滞比较器电路处理后,由主控芯片的输入捕获单元采集频率信号同时采集温度信号,对振弦式传感器信号进行补偿,通过电力载波通信模块把信号远距离传输到井上上位机,实现矿山压力的实时在线检测系统。 相似文献
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信号检测技术中,在给定检测概率和虚警概率进行检测要求的情况下,所需的检测时间与信号的信噪比成反比.一般的信号检测方法是在给定的固定检测时长内进行判断信号是否存在.然而信噪比较高时,以较小的检测时间就能满足系统要求的检测性能,减小检测时延.本文针对能量检测方法,提出一种检测时间自适应的快速能量检测方法,并通过理论分析和仿真验证了提出方法的有效性. 相似文献
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在讨论水球运动员们吃什么样的食物能达到他们的最佳状态之前,我们先来了解水球运动的能量需求。人体能够通过肌肉相互见的协调收缩而进行活动,这正是其完美之处。当大脑给身体发出活动信号,神经信号就通过一个叫做三磷酸腺苷(ATP)的特殊分子引发强有力的肌肉能量释放。ATP是高能分子,当这个聚集的化学结合物突然猛地散开,释放能量,并被肌 相似文献
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《体育科技文献通报》2002,(6)
G806 20022575运动时噪声对身心健康的影响[刊,中,I]/梁俏梅//辽宁体育科技.-2002.-24(2).-75-76表2参7(XH)体育锻炼//环境//机体//神经//机能//噪音//危害噪声同污染的空气和水一样对人体有危害。在运动比赛中,由于受到噪声的影响,而导致失败的事是屡见不鲜的。本文着重讨论噪声对定量负荷体时机体神经机能,激素调节机能以及由此引起的物质能量机能的影响。 相似文献
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本文根据能量供应的特点,将周期性运动项目的能力划分为15种,并制定出其适合各运动项目能力提高的训练方法。 相似文献
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This study examined the effect of carbohydrate ingestion on metabolic and performance-related responses during and after a simulated 1h cycling time trial. Eight trained male cyclists (VO 2 peak = 66.5ml kg -1 min -1 ) rode their own bicycles mounted on a windload simulator to imitate real riding conditions. At a self-selected maximal pace, the cyclists performed two 1h rides (separated by 7 days) and were fed either an 8% carbohydrate or placebo solution. The beverages were administered 25 min before (4.5ml kg -1 ) and at the end (4.5ml kg -1 ) of the ride. With carbohydrate feeding, plasma glucose tended (P = 0.21) to rise before the time trial. Compared with rest, the plasma glucose concentration decreased significantly (P < 0.05) at the end of both rides, with no statistically significant difference being observed between treatments. Thereafter, plasma glucose increased significantly (P < 0.05) at 15 and 30 min into recovery, and was significantly higher at 30 min during the carbohydrate trial compared with the placebo trial. No significant changes in plasma free fatty acids were observed during the ride. However, a significant increase (P < 0.05) in free fatty acids was found at 15 and 30 min into recovery, with no difference between trials. Mean power output was significantly (P < 0.05) greater during the carbohydrate compared with the placebo trial (mean - S.E.: 277-3 and 269-3W, respectively). The greater distance covered in the carbohydrate compared with the placebo trial (41.5-1.06 and 41.0–1.06km, respectively; P < 0.05) was equivalent to a 44s improvement. We conclude that pre-exercise carbohydrate ingestion significantly increases endurance performance in trained cyclists during a 1h simulated time trial. Although the mechanism for this enhancement in performance with carbohydrate ingestion cannot be surmised from the present results, it could be related to a higher rate of carbohydrate oxidation, or to favourable effects of carbohydrate ingestion on the central component of fatigue. 相似文献
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Roy J. Shephard 《Journal of sports sciences》2013,31(7):603-620
The biology and medicine of rowing are briefly reviewed. Effort in a 2000 -m race is about 70% aerobic. Because the boat (and in some instances a cox) must be propelled, successful competitors are very tall, with a large lean mass and aerobic power. Large hearts may lead to erroneous diagnoses of a cardiomyopathy. Large respiratory minute volumes must be developed by chest muscles that are also involved in rowing. The vital capacity is typically large, and breathing becomes entrained. Expiration cannot be slowed relative to inspiration (as normally occurs at high rates of ventilation) and the limiting flow velocity may be reached, with the potential for airway collapse. Performance is strongly related to the power output at the ‘anaerobic threshold’, and lactate measures provide a guide to an appropriate intensity of endurance training. Peak blood lactate levels are higher in males (commonly 11–19 mmol·l -1 and occasionally as high as 25 mmol·l -1) than in females (9–11 mmol·l -1), probably because males have a greater muscle mass in relation to blood volume. The skeletal muscles are predominantly slow twitch in type, developing an unusual force and power at low contraction velocities. Many rowers have a suboptimal diet, eating excessive amounts of fat. Lightweight rowers also have problems of weight cycling. Aerobic power and muscle endurance often change by 10% over the season, but such fluctuations can be largely avoided by a well-designed winter training programme. Injuries include back and knee problems, tenosynovitis of the wrist and, since the introduction of large blades, fractures of the costae. 相似文献
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Alan M. Nevill Roger L. Holder Andrew Bardsley Helen Calvert Stephen Jones 《Journal of sports sciences》2013,31(4):437-443
A regression analysis of competitors' tournament results in relation to their world rankings was proposed to identify the effect of home advantage in international ‘grand-slam’ tennis and ‘major’ golf tournaments. The results provided little evidence of home advantage in either the grand-slam tennis or the golf tournaments held in 1993. The only possible evidence of home advantage was found in the Wimbledon tennis and the US Open golf championships. Even these findings can be explained, at least partially, by (1) the availability of information concerning the low world rankings of the British tennis players competing at Wimbledon, and (2) selective entry, allowing only the world's top-ranked foreign golfers into the US open golf tournament. In both cases, the lower ranking home competitors have a greater opportunity to perform above their anticipated world rankings. Therefore, provided entry into tennis and golf tournaments is truly ‘open’ to both the host nation's representatives and foreign competitors alike, home advantage does not appear to be a major factor influencing the competitors' performance in such competitions. These findings may be explained by the relatively objective nature of the scoring systems used in tennis and golf, unlike the subjective influence of refereeing decisions on the results of team-games such as soccer. 相似文献
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许良 《体育科技文献通报》2011,19(2):1-4
基于1985、1995和2005年全国学生体质调研数据,对各时期我国城乡学生形态、机能、体能发展水平进行系统地定量研究,动态分析20年全国城乡学生体质发展的特点与规律。主要研究结果：（1）近20年城乡学生生长发育持续提前,城市学生各项形态指标生长水平高于乡村,身高城乡差距缩小,体重、胸围城乡差距加大;（2）城市学生肺活量水平高于乡村,城乡学生肺活量20年持续下降,前10年乡村学生下降快、后10年城市学生下降快;（3）乡村学生800m、1000m跑水平高于城市,城市女生50m跑、仰卧起坐水平高于乡村,其他素质城乡学生水平波动较大;（4）城市女生50m跑20年持续下降,城乡学生800m和1000m跑、城市学生50m×8往返跑20年加速下降,其他素质20年间有增有降发展极不平稳。 相似文献
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采用测量、问卷调查、数理统计等方法,分析定向运动学习前后对大学生身心健康的影响.结果经T检验和x2检验且表明：定向运动不仅能增强学生体质健康水平,而且有助于学生的情绪调节,增强自信心与创新意识,培养勇敢顽强的意志品质,建立良好的人际关系,能有效地促进学生身心健康发展.为了全面提高大学生整体素质,积极实践,构建定向运动课内外一体化教学模式,进行定向运动课程模块化教学,以满足学生的多元化需求. 相似文献
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重新认识体育的社会关联 总被引：3，自引：1，他引：2
体育与政治之间存在一个悖论，体育的发展与经济实力之间没有直线相关，体育与教育部分重叠，体育与宗教最为近缘，体育可借用科学手段，体育的艺术禀性日益明显，体育与养生反映着两种人生观。 相似文献
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本文在专家访谈、问卷调查、数理统计和文献资料分析的基础上,探析了上海社区体育竞赛参与者的特点、参与者对社区体育赛事运作管理的看法等问题。在此基础上从引进社区体育赛事的志愿者、整合社区体育赛事的各种资源、开发社区体育竞赛的无形资产、组建非营利性的专业团队、规范社区体育赛事的服务管理等方面提出了进一步满足上海社区居民日益增长的体育竞赛参赛需求的对策与措施。 相似文献
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对全面把握游泳训练环节的探讨 总被引：4，自引：0，他引：4
从系统观点出发,结合训练实践,对全面把握游泳训练环节进行探讨。认为应强化非智力因素在运动员多年训练中的作用,在育材全过程中不断选材,从整体上把握动态训练的全过程,把培养高水平运动员的整个过程置于一个严格的科学控制之下。 相似文献