难以控制

To solve the problems in adjusting and controlling shapes of developable surfaces, following the important idea of duality between points and planes in 3D projective space, two direct explicit and efficient methods of computer aided design for developable surfaces are proposed.

为了解决工程中可展曲面位置与形状难以调整和控制的问题，基于3D射影空间中点和平面间的对偶性这一重要思想，提出了2种直接、简单有效的可展曲面设计新方法。

My cock, well I guess I should call it my penis, as cock doesn't seem fitting for something that's hardly used, has been locked away in my modified Reinhold belt. My penis is the property of Marsha. She has had control of my orgasms for the past 6 months.

我的公鸡，那么我猜我应该叫我的阴茎，公鸡似乎并不适合的东西的，难以用，已被锁定在距离我的改性霍尔德带我的阴茎是财产marsha ，她已控制我的高潮，为过去6个月。

It is very difficult to realize high precision of rolling mill's calculation of the traditional mathematical model.

带钢热连轧宽度控制过程是一个复杂的非线性过程、难以建立精确的数学模型，对于传统的数学模型的轧机计算很难实现精度要求。

At last, the application of above modeling and control strategies has been demonstrated by the simulations of a nonlinear dc motor control problem. Under this control strategy, system identification phase is not needed, and only a controller based on the recurrent neural network is provided. Because the control and learning laws are designed with stable theory, stability and convergence problems are solved here with rigorous analysis, which can not been analyzed easily when usual BP neural networks are used.

最后通过非线性电机模型的仿真研究，表明了基于上述动态动态递归神经网络模型对非线性系统进行自适应控制的实际可行性，并且采用这种方法不需要对系统进行离线辨识，整个系统只采用了一个基于动态递归神经网络的控制器，由于整个系统是基于稳定性理论设计的，有效地解决了应用BP网络等其它前向网络时系统的稳定性和收敛性难以分析的问题。

So this paper focuses on the application of fuzzy modeling and control method in strip heating furnace system.

完全通过总结专家经验获取模糊规则的方法难以胜任对加热炉系统的控制。

The tube mill is a typical MIMO system with long time delay and time changing apparently. It has the characteristics of simple lagging, great inertia and non-linearity. The mathematical model is hard to be established and changed slowly with the elapse of time.

球磨机制粉系统是一个典型的多变量非线性时变系统，各控制量和被控量之间存在着相当严重的耦合，且球磨机具有纯滞后，大惯性的特点，数学模型难以建立且随时间缓慢变化。

Mostly because it is relatively uncontrolled; quite frankly, when you are up in the air today, you

来说是很危险的，因为它的确难以被控制，坦白地说，在今天，你仍然被建议在飞行途中注

Due to the development of computer and the popularization of Internet, more and more enterprises have adopted the computer network for the data communication to achieve the commercial business transaction or factory control. However, the data transmission in network is complicated and unforeknown. Thus, it will get some problems or affect the system operation if data are lost during the data transmission. The TCP/IP protocol is currently one of the most popular communication protocols. And the service quality from user request will be higher and higher. Therefore, How to provide the high–quality data communication and avoid the data loss is the goal of this thesis.

随著电脑技术的进步以及电脑网路的普及，愈来愈多企业体系利用电脑网路来做资讯交换，以达到商业交易或工厂控制的目的，而网路传输状况难以预测，若在资料传输过程中发生资料遗失，小则造成资料不对，大则造成应用系统无法正常运作，现今工商业对网路应用的依赖度愈来愈大，稍有闪失，都有可能招致莫大的损失， TCP/IP协定是目前网际网路上最被广泛使用的通讯协定，而目前使用者对其服务品质的要求也愈来愈严格，因此，如何在现有的网路下避免资料遗失及提高通讯品质，就是本篇论文所要探讨的课题。

The process of uniform velocity temperature control is a complicated process and has the characteristics of big inertia,pure time-delay and nonlinearity,and it is hard to obtain the exact mathematic model.

匀速升温控制是个复杂的过程，具有大惯性、纯滞后、非线性等特点，难以得到精确的数学模型。

Software sensors, which can provide on-line estimations of unmeasurable process variables from available sensors, are very useful and promising tools in biochemical industry.

然而，目前缺乏可靠的生物量在线测量方法，使及时、迅速的控制与优化难以实现。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。