查询词典 difficult problem

From the view of mathematics, it is a NP-hard combinational optimization problem with constraints and it is difficult to find the global optimal solution in theory.

从数学上讲，机组投入问题是一个多约束的NP-hard组合优化问题，很难得到理论上的最优解。

At present it is very difficult to predict all the RNA secondary structures. This paper describes RNA secondary structure prediction methods from 1970\' to this day in a systematic way some. Tracing back and following the tracks of prediction methods the author made a summary of RNA research progress and situation while a enumeration problem of RNA secondary structure is studied with the method of combinatorial enumeration.

目前所有有关RNA二级结构的预测算法要预测出所有序列的二级结构仍然很困难，本文系统介绍了从上世纪70年代以来发展至今的各类RNA二级结构预测算法，从对RNA结构预测方法的追溯和跟踪，对当今RNA研究的进展和形势做了一个总结，并且应用组合计数的技巧解决了一类RNA二级结构的计数问题。

Job-shop scheduling is a typical combinatorial optimization problem, and large scale scheduling optimization is one of such difficult optimization problems.

作业车间调度是一种典型的组合优化问题，大规模的调度优化是该类问题的难点。

This problem is so difficult that I can't come at it.

这个问题太难了，我不懂。

At present, the workers of the eighth oil plant use production logging method to determine single-layer's output and water cut of commingle producing well which produce Putaohua and Fuyu reservoir at the same time. This method takes a long period and high costs. And it's also difficult to determine single-layer's water cut. Aims at this problem, this present writer provides gas phase chromatogram fingerprint methods to determine single-layer's output.

针对目前采油八厂地区葡萄花、扶余两套合采油层采用生产测井方法确定分层产量及含水时成本高、周期长以及分层含水难以确定的问题，本文提出了应用气相色谱指纹技术来确定分层产量的方法。

The study of communication mechanism of tank unit CGF is the main topic, and it's also a difficult problem in current study.

坦克分队CGF中通讯机制的研究是CGF研究的主要课题，也是目前研究的难题。

The study of communication mechanism of tank unit CGF is the main topic, and it's also the difficult problem in current study.

坦克分队CGF中通讯机制的研究是CGF研究的主要课题，也是目前研究的难题。

Aiming at the problem that the condition information of large size steam turbine unit is complex and difficult to evaluate its condition accurately, an evaluation method based on evidential reasoning is proposed.

针对大型汽轮机组状态信息复杂，运行状态难以准确评价的问题，提出基于证据推理的状态评价方法。

Because of the complexness of the co-existence of unsteady three dimensional environmental flow and the jet flow, thorough study of the problem is difficult.

本文试图通过数学模型的方法对这一情况下的污水排放射流问题进行研究，为污水排海工程提供可行的参考模型。

Based on the higher mathematics method proved inequalities are summarized, and the proposed using the function extreme value and the monotonicity and concave and convex function sex, and mean value theorem, Taylor formula, integral these common higher mathematics method, combining with concrete examples of each kind of method to solve the problems for type, and the key problem of the specific steps, and points out that the inequality proof of higher mathematics method used properly, improve the difficult easy to ability to solve problems.

本文对不等式证明中的高等数学方法作了归纳总结，提出了利用函数的单调性，极值与最值，函数凹凸性，中值定理，泰勒公式，积分这些常用的高等数学方法，并结合具体实例阐述了每一种方法的适用类型、解决问题的关键和证明问题的具体步骤，指出在不等式证明中恰当地运用高等数学方法可以化难为易，提高解题能力。

Pachomius manual labour was organized as an essential part of the monastic life; and since it is a principle of the monks as distinguished from the mendicants, that the body shall be self-supporting, external work of one sort or another has been an inevitable part of the life ever since.

根据圣pachomius体力劳动组织作为一个重要组成部分寺院生活；以来，这是一个原则的和尚，作为有别于乞丐，该机构应自支撑，对外工作的这种或那种已一个必然的一部分，生活至今。

In order to study the effects of parametrical rolling on the ship movement and tilts, in allusion to ship's navigating in regular following waves, the equation of ship rolling motion is transformed into normal Mathieu equation by proper variable replacement when strong parametrical excitation in restoring moment varied according to sine or cosine wave.

为研究参数横摇对船舶运动和倾覆的影响，通过对船在规则波上随浪航行时，恢复力矩中出现的1个以正余弦规律变化的强参数激励项进行适当的变量置换，将船舶的横摇运动方程转换成标准形式的Mathieu方程。