查询词典 weighted sampling

First, the time series model of the random road roughness running by construction machinery is built up based on the measured data of the random road roughness and by means of the basic theory and method of the time series analysis. A real-time parameter estimation method of fuzzy weighted recurrence least square algorithm is represented through analyzing the conventional recurrence least square algorithm. Then, the new recurrence algorithm and the on-line tuning method of the weighted matrix are given out, and computer simulation is performed.

首先，以实测的地面随机不平度数据为依据，应用时序分析的基本理论和方法，建立了工程机械行驶地面随机不平度的时间序列模型，并在分析传统参数估计方法递推最小二乘算法的基础上，提出了模糊加权递推最小二乘算法的参数实时估计方法，给出了在此基础上的递推算法及加权矩阵的实时在线整定方法，并对其进行了计算机仿真研究。

THD+N: 20-Hz HPF, 20-kHz AES17 LPF Dynamic range: 20-Hz HPF, 20-kHz AES17 LPF, A-weighted Signal-to-noise ratio: 20-Hz HPF, 20-kHz AES17 LPF, A-weighted Channel separation: 20-Hz HPF, 20-kHz AES17 LPF Analog performance specifications are measured using the System Twot Cascade audio measurement system by Audio Precision in the averaging mode.

的THD + N：20 Hz的高通滤波器，20千赫AES17 LPF的动态范围：20 Hz的高通滤波器，20千赫AES17低通滤波器，A加权信号噪音比：20 Hz的高通滤波器，20 kHz的AES17，A加权频道分离低通滤波器：20 Hz的高通滤波器，20千赫AES17 LPF的模拟性能指标均采用了精密音频系统Twot梯级音频测量系统中的平均模式。

However, the weighted geometric mean method is simpler than the weighted arithmetic mean method, and the former can keep the reciprocity of the improved judgement matrix without transformation.

理论分析表明：虽然这2种方法都具有收敛性，且均可对一致性较差的判断矩阵进行修正，但加权几何平均法比加权算术平均法简洁，且前者无需通过转换，直接保持了修正后的判断矩阵的互反性。

G. A weighted pivoting mean method and a robust weighted filtering method for noise reducing of phase fringe.

然后给出了笔者提出的一种改进方法，对比了改进前后的实验结果。

objective to evaluate the role of mr perfusion weighted imaging in preoperation diagnosis of meningiomas.methods mr perfusion weighted images was performed in 47 patients with meningiomas followed by conventional imaging.results the mean rcbv values of angioblastic was the highest in the parenchyma of tumor.the mean rcbv values of malignant group was the lowest.the biggest mean rcbv values among different type meningiomas was statistically significant.the biggest mean rcbv values between benign and malignant group meningiomas was statistically significant,but not in the peri-tumor edema.conclusion the rcbv values were useful in the preoperative differentiation diagnosis of different types of meningiomas.those in the peri-tumor edema were useless in the preoperative differentiation diagnosis of different types of meningiomas.

目的 探讨磁共振灌注成像技术对脑膜瘤术前分型及良恶性鉴别的临床应用价值。方法对47例脑膜瘤病人行mr灌注成像检查，对5种亚型的良性脑膜瘤的mr灌注成像进行分析，并与非典型性及恶性脑膜瘤进行比较。结果血管瘤型脑膜瘤实质部分的rcbv值均数最高，恶性组脑膜瘤的rcbv值均数最低。各亚型间瘤体实质最大rcbv值均数间差异有统计学意义(p＜0.05)，良恶性脑膜瘤实质部分最大rcbv值均数间差异有统计学意义(p＜0.05)。瘤周水肿区的rcbv值均数间差异无统计学意义(p＞0.05)。结论 rcbv值对脑膜瘤术前分型及良恶性鉴别有所帮助，而瘤周水肿区的rcbv值对脑膜瘤分型及良恶性鉴别未显示临床实用价值。

Objective To investigate the value of diffusion weighted imaging and susceptibility weighted imaging in the diagnosis of diffuse axonal injury.

目的 探讨弥散加权和磁敏感加权序列在脑弥漫性轴索损伤中的诊断价值。

Using sagital T1 weighted imaging (T1WI) of MRI and axial Diffusion imaging of MR and axial diffusion weighted imaging is a precise method to diagnosis callosal infarction.

结合MRI矢状T1加权(T1WI)扫描，和弥散加权成像横断扫描是诊断胼胝体梗死的准确的方法。

Results:(1) Spin-echo sequence included axial, coronal and sagittal images. In T1-weighted images,the medulla oblongata is isointense,the cistern is hypointense; in T2-weighted images,the medulla oblongata is isointense, CSF shows hyperintense, and the arteries of posterior fossa appear hypointense flow voids. The cisternal cranial nerves are not clearly demonstrated in the routine spin-echo images. In 3D-time of flight images, the brain tissue shows isointense, CSF is hypointense, the artery shows hyperintense,and the cranial nerves show linear isointense.

2，结果：(1)常规SE序列横断面、冠状面及矢状面T1WI显示延髓等脑组织呈等信号，延髓周围池脑脊液呈黑色低信号，T2WI显示脑组织为等信号、脑脊液为白色高信号，脑底动脉在池内高信号背景下由于&流空效应&而表现为低信号，常规序列由于成像参数关系而不能直接显示脑池内颅神经；三维时间飞跃(3D-TOF)成像序列显示脑组织为等信号，脑脊液为低信号，而脑池内脑底动脉则呈高信号、脑池内后组颅神经为线状等信号。

The fundamental imaging features of osteosarcoma were showed bone destruction, periosteal reaction, neoplastic bone and soft-tissue mass. Among 49 cases examined by radiography, osteoblastic pattern sarcoma was found in 19 cases, osteolytic pattern sarcoma was found in 13 cases and mixed pattern sarcoma was found in 17 cases. The detection rates of bone destruction, periosteal reaction, soft-tissue mass, neoplastic bone and Codman triangle by radiography were respectively 61.2%, 95.9%, 71.4%, 73.5%and 27.7%. All 10 cases with CT scan were showed bone destruction, soft - tissue mass and neoplastic bone. The detection rates of periosteal reaction,憇ieve sign挶 and Codman triangle with CT scan were respectively 90%, 90% and 11%. The tiny neoplastic bone and"sieve sign"were showed sensitively by CT, but Codman triangle was showed by radiography superior to CT.32 cases with MRI scan presented the normal marrow was replaced by the tumor, which was showed low to intermediate signal intensity on T1-weighted images and promiscuity signal intensity on T2-weighted images. 7 cases presented hemorrhage and 24 cases presented necrosis.

骨肉瘤基本影像表现为骨质破坏、骨膜反应、瘤骨和软组织肿块。49例X线表现为成骨型19例，溶骨型13例，混合型17例；X线对骨质破坏、骨膜反应、软组织肿块、瘤骨和Codman三角的检出率分别为61.2%、95.9%、71.4%、73.5%和27.7%；10例CT表现均可见骨质破坏、软组织肿块及瘤骨，CT对骨膜反应、筛孔征和Codman三角的检出率为90%、90%和11%；CT对显示细小肿瘤骨和筛孔征最敏感，但对Codman三角的显示不如X线平片；32例MRI表现为骨髓腔内正常的骨髓高信号被肿瘤信号所取代，T1WI呈低～等信号，T2WI呈混杂信号，7例合并出血，24例中央坏死囊变，32例增强扫描均呈不均匀强化及瘤周可见水肿区。

Of the other 16 patients with ALS whose upper motor neurone signs were not so manifest (cases 6-21), high signal was seen in the corticospinal tract on T2-weighted images was seen in 11 (cases 6-12, 16-18 and 21); five (cases 6, 7, 11, 12 and 16) of these also showed high signal on the PD-weighted images.

另外16例ALS患者（病例6~21）上运动神经元症状体征不明显，在T2像上有11例可见皮质脊髓束高信号病灶（病例6~12、16~18、21）；在PdWI像上有5例也可见高信号病灶（病例6、7、11、12、16）。

There are different types of personal loans available.

有许多不同类型的个人贷款优惠。

The above mentioned teaching model of spiral rising can be used to avoid rigidness in teaching.

上述螺旋式上升的教学模式，可以避免教学形成模式後的僵化现象。