The only way to sort out cause and effect is to do a randomized trial, moving people around between neighborhoods and tracking their health over several years.
要想找出原因，唯一的方案就是进行随机实验，让人们住进不同的社区，并在几年内坚持跟踪他们的健康状况。
Once enabled, the tracking protection would exist for all Web pages the user visits and would take effect each time they start a new browsing session.
一旦这个功能启用，追逐保护将存在于用户浏览的所有网页中，而且每次打开一个新浏览器会话都会起效。
In effect, the sponsoring groups were crowd-sourcing study subjects to get a larger sampling more quickly, using self-tracking methods for faster research results.
实际上，活动的组织者通过这种方式利用群众的力量，从而在更短时间内获得更大的研究样本，并通过自我跟踪方法更快地获得研究成果。
The study approach is involved analyzing problem, advancing project, tracking and feedback the effect of project actualizing, and conclusion.
研究途径为问题分析、解决方案提出、方案实施效果跟踪及反馈，最后得出研究结果。
The simulation results prove that the neural network controller has self-learning and self-adaptive ability by comparison with PD controller. The position tracking control obtains satisfactory effect.
结果表明，相对于常规PD控制器，该神经网络控制器具有自学习、自适应功能，位置跟踪获得了满意的控制效果。
The effect of thermal noise and vehicle dynamics on carrier tracking loop are also analyzed, and the optimal bandwidth of carrier tracking loop is obtained.
并以相位跟踪环路为例分析了热噪声及载体动态性对环路的影响，得出了环路设计的最佳带宽。
The effect of atmospheric turbulence and vibration of the FSO platform on signal tracking system is discussed.
针对光无线通信的特点，探讨了大气湍流和通信平台抖动对激光传输的影响。
It is therefore logical to use the smallest retinacular incision that has the desired effect on patellar tracking without an unjustified risk of complications.
因此应该使用最小的支持带松解达到满意的纠正髌骨轨迹的效果，以避免不必要的并发症发生，这是合乎逻辑的。
A digital tracking filter method is put forward, its approach realizing adaptive tracking ability is simple and easy, and good effect of noise cancellation can be obtained.
提出了数字跟踪窄带滤波方法，实现的自适应跟踪方法简便，消噪效果良好。
Furthermore, the change of the noise through narrowband filter and detection circuit and the effect on the radar tracking precision are analyzed in quantity.
对噪声经过窄带滤波、检波电路后的变化及其对雷达跟踪精度的影响进行了定量分析。
The results show that the neutral network controller has shelf-learning and self-adaptive functions, and has better control effect in speed tracking, compared with traditional PI controller.
仿真结果表明，相对于常规PI控制器，该神经网络控制器具有自学习，自适应功能，速度跟踪获得了满意的控制效果。
In the seam tracking system, the motion of the cross slipper has an important effect on the torch movement.
十字滑块的微动特性对焊缝跟踪系统中焊枪的运动有着重要影响。
The simulation experiments on the second subsystem of the inverted pendulum show that the effect on improving tracking performance is prominent and the controller's design is reasonable and available.
对倒立摆二阶子系统的仿真，实验表明跟踪性能改善的效果是明显的，证明控制器的设计是合理和有效的。
The error caused by rotary tracking mirror device and cat eye reflector in the laser tracking measure system are discussed, and its effect to the measuring result is analyzed.
论述了在激光跟踪测量系统中由跟踪转镜机构和猫眼逆反射器产生的光学误差，并分析了它们对测量结果产生的影响。
Results of experiment indicate this system can carry through real-time tracking of moving object on simple scene and attain the expectant effect.
实验结果表明，该系统能在简单场景下对运动目标进行实时跟踪，达到预想效果。
Kalman Filtering is used for suppressing the effect of random disturbances on the flexible structural system, and PID-NNC is used for realizing trajectory tracking.
这种新方法通过构造卡尔曼滤波来抑制随机干扰对系统的影响，同时采用PID - NNC来实现馈源舱轨迹跟踪。
According to the system bandwidth, the low pass filter was added in controller to assure the tracking effect of system and filter the super-high frequency in control singles.
根据系统的带宽，在控制器中加入低通滤波器，以保证系统跟踪效果，过滤控制信号中频率过高部分。
In an underwater multi-source detecting and tracking system, the incorrect estimation of source number will do bad effect on DOA estimation and the whole system.
在水下多源探测与跟踪系统中，信号源数目估计不准确对波达方向估计以及整个系统性能会产生严重影响。
A joint data association and bias estimation method is proposed to handle the negative effect of individual radar bias to track association and fusion in radar networks for target tracking.
针对雷达组网目标跟踪系统中，单雷达系统偏差严重影响多雷达航迹数据关联及融合跟踪质量的问题，提出了一种联合数据关联与系统偏差估计的方法。
The real-time target tracking of digital image processing and video image in the high complicated background was realized, and a stable, accurate tracking effect was gotten.
同时利用模板刷新、相关后处理等算法，在高复杂背景下实现实时数字图像信号处理和视频图像的目标跟踪，达到稳定的、准确的跟踪效果。
A robust control term was used to compensate the approximation error of fuzzy systems, which could reduce the effect on tracking accuracy caused by the error.
并用鲁棒控制项对模糊系统逼近误差进行补偿，减少了其对跟踪精度的影响。
The scheme proposed guarantees the system tracking to obtain control effect within finite iterations.
所提出的控制方案保证系统跟踪在有限的迭代步骤内达到较好的控制效果。
The experiments indicate that the vision navigation system has made good tracking effect of these routines in structure surroundings.
实验结果表明，该系统对结构化环境中的这些标识线均能达到良好的跟踪效果。
The effect of grayscale distortion on the correlation tracking algorithm was studied.
针对相关跟踪算法，研究了灰度畸变对它的影响。
The closed expression form of the maximum carrier phase tracking error caused by multipath effect is derived in this paper based on multipath signal characteristics and GPS receiver work mechanism.
推导了GPS接收机中多径效应引入的最大载波相位跟踪误差的闭合形式。
We begin our discussion with a description of an imbalance model, then analyse its effect on carrier tracking loop steady-state lock point and its effect on average BEP.
通过对调制器不均衡的模型讨论，深刻分析了调制器不均衡对载波跟踪环路稳态锁定点和平均BEP的影响。
We begin our discussion with a description of an imbalance OQPSK model, then analyze the effect on carrier tracking loop steady-state lock point and the effect on average BEP.
通过对OQPS K调制器不均衡的模型讨论，深刻分析了调制器不均衡对载波跟踪环路稳态锁定点和平均BEP的影响。
Good tracking effect is shown by varieties of testing for which the algorithm proposed in this thesis.
大量试验表明，文章所提的算法可以取得较好的跟踪效果。
Good tracking effect is shown by varieties of testing for which the algorithm proposed in this thesis.
大量试验表明，文章所提的算法可以取得较好的跟踪效果。
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