查询词典 condition number

The optimization methods of database SQL query were studied and some available query optimization Methods were given out as follows: The incompatible data type should avoid to be used; More redundancy search parameters should be given as join condition in join query; In some condition, the number of note hitted to target was estimated by optimizing implement using the average density; Some other maths operating symbol should avoid to be used as condition parameters in WHERE clause; Some operating symbol and its sentence should avoid to be used also; When the cluster function was used,the WHERE clause should be paied attention to more,and so on.

作者单位：（重庆工学院商贸信息学院，重庆 400050）摘要：数据库SQL查询语句的优化，须注意：避免使用不兼容数据类型；连接查询中应多给连接条件提供一些冗余的搜索参数；某种条件下优化器只能使用其平均密度以估计命中的记录数；避免对WHERE子句中条件参数使用其它数学操作符；避免使用某些操作符及相应语句；聚簇函数的使用应注意WHERE子句。

For gas flow past cylinder, the characters of flow field in different Mach number and Knudsen number condition were investigated, and especially for low Knudsen number cases, the results were compared with calculating results of Euler's equation. It showed that they are correspondent by comparing the characters of bow shock and wake. The convergence rates of different high resolution and implicit schemes were also investigated. The convergence behavior of the implicit WENO scheme developed in this paper is better than others. For gas flow past NACA 0012 airfoil, the calculating results were compared with results of experiment. It showed that the results of WENO scheme are of higher accuracy for the case with angle of attack.

在圆柱流场时，我们探讨不同马赫数且不同纽森数时的流场特性，并在低纽森数时，与那维尔-史托克方程式的计算结果比较，我们比较了弓形震波及尾流附近的特性，其结果是相当符合的，同时我们也比较不同高解析隐式算则的收敛历程，从收敛历程图可得到，本文发展出来的隐式WENO算则有较佳的收敛效果；在NACA 0012翼形的流场中，我们将与实验结果做比较，发现利用WENO算则计算的结果，对於具有攻角的流场，亦有相当高的准确度。

The switching law is given out according to convex combination condition and the sufficient condition of the stabilization is obtained by switching among a finite number of controllers under the assumption that a single controller cannot make the systems stable and has H-infinity disturbance attenuation.

在假定每个单一的控制器均不能使系统稳定且具有H扰动衰减度的条件下，利用凸组合条件给出了切换律的设计方案，通过在有限个控制器间的切换得到了镇定的充分条件。

The relationship between the inverse number density of particle of the laser transition levels and the discharge condition such as the discharge current, the He pressure and the temperature of Cd-reservior has been achieved. The discharge condition for obtaining maximum laser output was theoretically achieved.

分析了441.6nm谱线的激发机理及各种粒子的相互作用过程，导出了441.6nm谱线跃迁能级激励的理论模型及其粒子数密度速率方程，得到了粒子反转数密度与放电电流、氦气压强和镉炉温度等放电条件的关系，从理论上，定量得出了获得最大输出功率时的放电条件。

Seven experiments were conducted in the present study to test and verify two inferences:(1) In character decision performance, high frequency character have not character stroke and component number effect, but low frequency character is an essential condition to stroke and component number effect;(2) In prime condition, when SOA is very short (SOA=56ms), component character can prime the recognition of low frequency compound characters, but failure to prime the high frequency compound characters.

在此基础上，本文通过7个行为实验验证了这一假设的两个重要推论：(1)在字决定任务中，高频汉字不存在部件数和笔画数效应，而低频字不必然存在笔画数和部件数效应；(2)在启动条件下，当SOA较短（=56毫秒）时，成分字仅对低频合体字有启动效应，而对高频合体字没有启动效应。

Our results improve the former results. For periodic Jacobi matrix, some new spectral properties of periodic Jacobi matrix are given by studying the relationship of the eigenvalues of periodic Jacobi matrix and its n—1 principal submatrix. Applying these spectral properties, we present a necessary and sufficient condition for the solvability of an inverse problem of periodic Jacobi matrices and discuss the number and the relationship of its solutions. Furthermore, we propose a new algorithm to construct its solution and compare it with the former algorithms. As this inverse problem of periodic Jacobi matrix usually has multiple solutions as many other eigenvalue inverse problems, we study the uniqueness of this problem. And a necessary and sufficient condition is given to ensure its uniqueness, under which an algorithm is presented and the stability analysis is also given. Finally, we put forward a new inverse problem for periodic Jacobi matrix which has not been solved.

对周期Jacobi矩阵特征值反问题，通过研究周期Jacobi矩阵与其n-1阶主子阵特征值的关系，给出了周期Jacobi矩阵的一些新的谱性质；利用这些谱性质，研究了一类周期Jacobi矩阵特征值反问题，用新的方法推导出了该类特征值反问题有解的充分必要条件，并讨论了解的个数以及解与解之间的关系；此外，提出了一种新的构造周期Jacobi矩阵反问题解的数值算法，并与前人的算法做了一定比较；由于周期Jacobi矩阵特征值反问题和其他很多特征值反问题一样往往存在多个解，本论文给出了周期Jacobi矩阵反问题解唯一的充要条件，并发现周期Jacobi矩阵特征值反问题的解唯一当且仅当构造的矩阵满足一定的条件；在解唯一的情况下，给出了构造唯一解的数值算法，并做了相应的稳定性分析；最后，提出了一类新的有待于解决的周期Jacobi矩阵特征值反问题。

System of calculation of number of boxes of spars for mechanic was improved, and now many factors will be taken into consideration: price, uniqueness, condition (if the item is in very poor condition you'll receive fewer points, if good - more points, and if the average - the usual number of points ), and presence of the SGM achievement "Mechanic Assistant".

数字系统的计算对机械进行了改进棒材的盒子，现在有很多因素需要考虑：价格，独特性，条件（如果该项目在十分恶劣的条件是你将获得较少的点，如果好-更多的积分，如果平均-通常的积分数），新成就"技工助手"

ABSTRACT It is because that the excellent acceptors for maize transgenic engineering are insufficient in our country, especially in the southwest mountain areas of china and hereditary variation regularity for the two characters such as efficiency of embryonic callus induction and number of regenerating plant (these two characters were abbreviated to the nduction efficiency and number of regenerating in the following of the paper, respectively), which hint the maize culturing capacity, is not very clear. Therefore, aiming at picking out superior acceptors, we had made systematic researches on the two characters with combing traditional quantitative-character genetic analyzing methods such as single-factor genetic mating design, diallel crossing genetic design, genetic effect analyzing method and the modern molecular locating method such as QTLs'. The main results are followed.(1) 50 superior inbred lines and about 30 crosses in our country, especially in the southwest of China were used for identifying and selecting the superior genotypes in the above two investigated characters under the same culturing condition in 2000 and 2001. There was very significant difference among the genotypes in the both characters. But the two characters were not certainly related. Some genotypes such as 18-599 and 18-599 were very good in them. For some ones such as zong 31, induction was higher than 18-599 and 18-599 in the efficiency, but it was only 1/3 to the later in regenerating number. In some genotypes such as S37, R08, R15, P138, A318, induction efficiency was just about 3% and scarcely any regenerating plants were got. On the whole, hybrids acted better than inbreeds in the both characters.(2) Two kind of inbreeds were selected as parents of the Griffing's method 1. 18-599 and 18-599 and the inbred line zong 31 are one kind because they are not only superior in the characters of maize cross breeding, such as CA, resistance to disease and the important agricultural characters, but also excellent in transformation characters as the induction and regeneration.

针对我国、特别是西南山地所需玉米转基因工程育种优良受体极为匮乏和反应玉米幼胚培养能力的2个主要性状，即玉米幼胚胚性愈伤组织诱导率和胚性愈伤组织绿苗发生数的遗传变异规律十分不清楚的实际情况，本研究从筛选玉米转基因工程所需要的优良受体入手，采用单因素遗传交配设计、双列杂交遗传交配设计、世代基因效应等传统数量性状分析方法，以及现代分子标记定位主效QTL分析方法，对玉米幼胚胚性愈伤组织诱导率和胚性愈伤组织绿苗发生数等2个性状进行了较为系统的分析研究，取得以下主要研究结果：(1)于2000年和2001年通过对我国、特别是西南地区近50份优良自交系和近30个杂交组合，在相同培养条件下，对幼胚培养胚性愈伤组织诱导率和胚性愈伤组织绿苗发生数等2个幼胚培养能力性状进行了筛选与鉴定，发现玉米不同基因型具有完全不同的幼胚培养胚性愈伤组织诱导率和胚性愈伤组织绿苗发生数，但幼胚培养胚性愈伤组织诱导率与胚性愈伤组织绿苗发生数并不具有必然的相关关系，有的基因型，如自交系18-599和18-599在胚性愈伤组织诱导率和愈伤组织绿苗发生数等2个性状都表现相当优异；有的基因型，如自交系综31，仅幼胚培养胚性愈伤组织诱导率性状表现高于19-599和18-599，但在胚性愈伤组织绿苗发生数这一性状则与它们有相当大的差距，仅为19-599和18-599的1/3左右；有的基因型，如S37、R08、R15、P138、A318等玉米自交系不仅幼胚培养胚性愈伤组织诱导率很低，平均仅在3％左右，而且胚性愈伤组织绿苗发生数表现也很差，基本上没有分化成苗。

Base Station type Software versionTypes of carrier frequency board adoptedTypes of combiner adoptedWhether had obtained the network license or notIndoor type or outdoor type Whether the master port is separated from the remote-port The maximum carrier frequency capacity of single cabinet The maximum supportable sector numbers of single cabinetWhether it is dual-carrier frequency board or notMust it be paired configuration if it's dual-carrier frequency board (namely, the type of single carrier frequency station could only configure the dual-carrier frequency on hardware) The maximum achievable configuration of a single station of the single cabinetReceiver sensitivity The maximum expand capacity of a single base station (the maximum number of TRX in configuration / the number of cabinets which is required)(fill in according with the three sectors) Top box transmitted power (given separately a grade one combine and a grade two combine) The maximum output power of amplifier (voice, a single logical carrier frequency) The maximum output power of amplifier (EGPRS, a single logical carrier frequency)Whether it has tower-interfaceWhether it has built-in lightning protectionWhether it support the ultra-long cover / whether it need for software support (give simple description that how hardware and software could achieve this) The supporting condition of EGSM (it should be supported including by the carrier frequency, combiner) Dual-band carrier wave (whether it supports the mixed use of 900 M/1800M in the same cabinet) The commonality of duplicate parts Whether it can built-in transmission unitThe single cabinet size (high × width × deep) Installation method Whether it can place against the wallThe basic frame full-configured weight and the supportable number of carrier frequencyThe expansion frame full-configured weight and the supportable number of carrier frequency

基站型号软件版本号采用载频板型号采用合路器型号是否已取得入网许可室内型or室外型是否是主远端分离单机柜最大载频容量单机柜最大支持的扇区数是否是双载频板如是双载频板，是否必须成对配置(即单载频站型只能硬件配置双载频)单机柜可达到的单站最大配置接收机灵敏度单基站最大扩展能力(最大配置TRX数/需机柜数)(按3扇区填写)机顶发射功率(分别给出一级合路与两级合路)功放最大输出功率功放最大输出功率(EGPRS，单个逻辑载频)有无塔放接口有无内置避雷装置是否支持超远覆盖/是否需要软件支持(简单描述软硬件如何实现)EGSM支持情况(包括载频、合路器均应支持)双频段载波（是否支持900M/1800M在同一机柜内混合使用）备件通用性是否可以内置传输单元单机柜尺寸安装方式可否靠墙放置基本架满配重量及支持载频数扩容架满配重量及支持载频数是否支持基本架与扩容架跨扇区满配功耗满配时重量供电方式机柜进出线方式合路器损耗合路能力：几合一单扇区最大支持几载频合路到一副天线/采用几个合路器单扇区载频达到需要增加一副天线时，是否支持两级合路换以不增加天线如两级合路插损为是否支持基带跳频和合成跳频每单个合路器在从低载频数向高载频数扩容时，是否还需要增加硬件可用性指标MTBFMTTR系统中断服务时间硬件是否支持EGPRS本次报价软件版本号开始支持EGPRS的软件版本号其他特点注： 1 应分别填写出来按照本次报价要求所采用的全部BTS型号和采用的合路器型号 2 列出本报价要求的全部室外型基站与高功放单元

Evidence suggests that 1 under more stable stratification, the basic flow, if moving faster at low and high levels (particularly in the presence of jets there), allows a resulting meso-β unsteady wave to propagate eastward with respect to basic flow and even at greater velocity compared with it; 2 vertical windspeed shear of basic flow causes instabilities of the TWT perturbation; 3 considering the second derivative of basic-flow wind with respect to z (denoted by zz≠ 0 which is simply given as β* hereafter) the expression for the phase velocity of vortex Rossby wave is obtained, which is unidirectional in propagation with respect to basic flow; 4 VRoW has its physical origin from β*, i.e., from z-varying heterogeneities of y-direction averaged vorticity of the basic flow field; 5 VRoW phase velocity is associated with zonal wave number k, its energy is dispersive and the group velocity exists in the x direction; 6 when windspeed meets the condition of β*, TWT disturbance instability may be that of mixed VRoW and gravity wave; 7 if basic flow is subject to linear shear but does not meet the condition of β*, the TWT instability is that of inertia-gravity wave.

在大气层结比较稳定的情况下，如果基本气流在低层和高层较大(有可能存在低空急流和高空急流)，此时产生的β中尺度不稳定扰动相对于基流向东传播，甚至于快速向东传播。基本气流在垂直方向上的风速切变对于中尺度横波型的扰动起着不稳定的作用。如果考虑基流的二次切变，可以得到涡旋Rossby波的相速度表达式，涡旋Rossby波相对于基本气流是单向传播的。涡旋Rossby波产生的物理根源是基本流场的风速二次切变，亦即基本流场y方向的平均涡度在空间z方向上的不均匀所致。涡旋Rossby波的相速度与纬向波数也有关，它的能量是频散的，其在纬向x方向也存在群速度。在基本流场的风速存在二次切变时，横波型不稳定可能是混合的涡旋Rossby重力波的不稳定；而在基本流场的风速仅仅存在线性切变，不存在二次切变时，横波型扰动的不稳定则是重力惯性波的不稳定。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。