查询词典 on the threshold of

Comparing the mean of hearing threshold in each group at different frequency band, the threshold of audibility on 0.5, 1, 2, 3, 4, 6kHz was 22.98±6.28dB, 21.38±7.88dB, 22.04±10.19dB, 26.55±16.69dB, 31.52±18.86dBand 33.75±19.71dB, respectively.

联合组听力异常率明显高于单纯噪声组和对照组(P.05)，高频、语频、Ⅱ级、Ⅲ级及Ⅲ级以上听力损伤率均较噪声组、对照组明显升高(P.05)。

Due to its good effect in the reservation of information of signal abrupt change, mathematical morphology is often applied in the detection and location of short-term power quality disturbance, however, there is still a defect of invalid detection existing in partial detection methods based on mathematical morphology while some zero-crossing disturbances are detected. In this paper three mathematical morphology based disturbance detection and location methods, i.e., the method based on first-order derivation and morphological gradient, the method based on morphological gradient and soft threshold processing and the method based on dq decomposition and top-hat transform, are analyzed, that is, by means of simulation the adaptability of these methods in the analysis on the signals of voltage sag, voltage swell and electromagnetic transient oscillation is compared.

数学形态学因其在保留信号突变点信息方面有很好的效果，因此常用于短时电能质量扰动的检测和定位，但基于数学形态学的部分方法仍存在对某些过零点扰动检测失效的缺点，文章分析了3种基于数学形态学的扰动检测和定位方法，即基于1阶求导和形态梯度的方法、基于形态梯度和软阈值处理的方法、基于dq分解和高帽变换的方法，通过仿真比较了3种方法在分析电压暂降、电压暂升、电磁暂态振荡等信号方面的适应性，结果发现基于dq分解和高帽变换的方法在检测过零点扰动时具有很好的效果，因此选取这种方法对实测扰动数据进行了检测和定位分析。

Based on the principle of Otsu method with maximum variance between threshold algorithm of image segmentation, an improved method derived from Otsu algorithm is put forward, which combines interclass distance with intraclass distance, a partial recursive algorithm is used to search optimum threshold.

基于最大类间方差阈值图像分割算法的基本原理，然后结合目标与背景两类之间间距和类内距离对图像分割效果的影响，提出了一种改进的最大类间方差法，运用递归思想局部搜索图像的最佳阈值。

It includes hardware equipments and foundational theory of the image digitization. This paper expatiates on some digital image processing technologies that the inspecting system may apply to the research and analysis of the collected glass-crack image. Using neighborhood average method and median filter retrains the image noises and make the image edge smooth. Then protract the histogram of the gray image, get the threshold of this image, utilize the threshold method and gray-level slice method to get a binary image, and detect the image edge. Finally calculate the area and perimeter of the glass-crack image, and use the circularity to judge whether this image is a glass-crack image.

本文重点阐述了研究和开发这套玻璃瓶裂纹检测系统所应用到的一些数字图像处理技术，并应用这些技术和方法对采集的裂纹图像进行了处理和分析：应用邻域平均法和中值滤波法来抑制图像的噪声，使图像的边缘平滑；然后绘制出处理过图像的灰度直方图，得到该幅裂纹图像的阈值，利用阈值法和灰度级切片法对裂纹图像进行二值化处理，得到其二值图像，并对图像进行了边缘检测；最后计算出裂纹图像的面积和周长，利用圆形度指标来判断该图像是否为裂纹图像。

Based on the conclusion of experimental law, the photoelectric threshold condition is obtained for the semi-insulating GaAs photoconductive switch under the non-linear mode, pointing it out that, when the optic-energy triggers off the switch to meet the prerequisite that n_0L is greater than or equal to 10~(12)cm~(-2), the necessary condition is achieved for high field domain and meanwhile the threshold electric field serves to produce charge transmission effect within the material.

在总结实验规律的基础上，得到半绝缘GaAs光电导开关非线性模式的光电阈值条件，指出当光能触发使开关满足n0L≥10~(12)cm~(-2)时，达到形成高场畴的必要条件，阈值电场的作用是使材料体内产生电子转移效应。

Automatic threshold choice is difficult and important to color images edge detection, First of all, on the base of human visual properties, threshold versus intensity function of human visual system are researched and analyzed, by using method of mathematic modeling and the result of saturation research, function of least color difference that can be perceptible by visual systems in detecting edge is given.

摘要自动阀值选取是彩色图像边缘检测的难点和关键问题，首先从人类的视觉特性出发，分析了人类视觉系统的亮度感知门限函数，利用数学建模方法和色度学方面的研究成果，给出人类视觉系统对彩色图像边缘所能识别的最小彩色差函数。

This paper brings forward a approach for textile flaw automatic detection based on optimal Gabor filters. At first the niche genetic algorithm is employed to attain the parameters of the optimal Gabor filters and segmentation threshold based on the feature of the unflawed textile,and then apply the optimal Gabor filter and threshold on the fabric image to achieve the resnlts.

为了对织物缺陷进行快速准确的自动检测，建立了一种基于Gabor滤波器的织物缺陷自动检测方法，即首先根据无缺陷织物的结构特征，应用小生境遗传算法寻找最优的Gabor滤波器参数和分割阈值；然后将待检图像通过滤波和分割来得到检测结果，同时根据响应矩阵的极小值点来计算缺陷的形状特征。

Paired t-test analysis was performed on the thresholds of SVR and PTA at each frequency (0.5, 1, 2 and 4kHz), and analysis of variance was performed on the difference between the pure tone audiometry threshold and the evoked potential threshold among different frequency.

对听力正常的46名志愿者，分别对双耳进行0.125~8kHz频率范围内的PTA阈值及0.5~4kHz频率范围内的SVR反应阈测试，通过配对t检验比较0.5、1，2、4kHz频率范围的SVR反应阈与PTA阈值的差异，并运用方差分析比较不同频率间的SVR反应阈与PTA阈值差值的差异。

I will confess that I was far too much taken up with what was going on to be of the slightest use as sentry; indeed, I had already deserted my eastern loophole, and crept up behind the captain, who had now seated himself on the threshold, with his elbows on his knees, his head in his hands, and his eyes fixed on the water, as it bubbled out of the old iron kettle in the sand.

我得承认，我被正在发生的事情完全吸引住了，压根没起到一个警戒哨的作用；事实上，我已经离开了东边的射击孔，趴在了船长的后面，这会儿他正坐在门槛上，肘拄在膝盖上，用手托着头，注视着从那只旧铁锅底的沙中冒出的水。

Methods: The Yifuqing granula was given to rabbit with febrilis caused by the TAB vaccine. The effects of the Yifuqing granula on the ache threshold value of Jimpy mice caused by Hot plate, on auricle inflammatory swelling of Jimpy mice caused by dimethyl benzene, on the bacterium of Jimpy mice in vivo, and on CPE caused by virus were observed.

观察一服清颗粒对三联菌苗所致兔发热的影响；采用小鼠热板法观察一服清颗粒对小鼠痛阈的影响；观察一服清颗粒对二甲苯所致小鼠耳廓炎性肿胀的影响；采用小鼠体内抑菌实验观察一服清颗粒对金葡菌感染小鼠死亡率的影响；采用细胞病变法观察一服清颗粒对病毒致细胞病变作用的影响。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。