问题 单项选择题

对实际应用问题建立了数学模型后,一般还需要对该模型进行检验。通过检验尽可能找出模型中的问题,以利于改进模型,有时还可能会否定该模型。检验模型的做法有多种,但一般不会()

A.利用实际案例数据对模型进行检验

B.进行逻辑检验,分析该模型是否会出现矛盾

C.用计算机模拟实际问题来检验模型

D.检验该模型所采用的技术能否被企业主管理解

答案

参考答案:D

解析:

针对实际问题建立的数学模型往往是近似的,往往忽略了许多复杂因素。这种模型能否解决实际问题还需要检验。检验的方法有多种。

利用实际案例数据对模型进行检验是很常见的。将模型作为一个黑盒,通过案例数据的输入,检查其输出是否合理。这是应用人员常用的方法。

有时可以请专家来分析模型是否合理。经验丰富的专家一般会根据模型自身的逻辑,再结合实际情况,分析是否会出现矛盾或问题。

有时很难用实际案例或聘请专家来检验模型,例如,试验或实验的代价太大,难以取得实际案例,有的项目技术比较新,缺乏有经验的专家。这时,如果能利用计算机来模拟实际问题,再在计算机上检验该数学模型,这往往是一种有效的办法。例如,对某种核辐射防护建立的数学模型,采用计算机模拟方法来检验就十分有效。

企业负责人需要提供一切必要的支持来解决实际问题。至于解决过程中采用的技术问题,则需要由技术人员研究决定。企业负责人只需要听取汇报,从宏观上认可就可以,不需要理解其中的技术细节。

单项选择题
单项选择题

Shortly after September 11th, President Bush’s father observed that just as Pearl Harbor awakened this country from the notion that we could somehow avoid the call of duty to defend freedom in Europe and Asia in World War Two, so, too, should this most recent surprise attack erase the concept in some quarters that America can somehow go it alone in the fight against terrorism or in anything else for that matter.

But America’s allies have begun to wonder whether that is the lesson that has been learned--or whether the Afghanistan campaign’s apparent success shows that unilateralism works just fine. The United States, that argument goes, is so dominant that it can largely afford to go it alone.

It is true that no nation since Rome has loomed so large above the others, but even Rome eventually collapsed. Only a decade ago, the conventional wisdom lamented an America in decline. Bestseller lists featured books that described America’s fall. Japan would soon become "Number One". That view was wrong at the time, and when I wrote "Bound to Lead" in 1989, I, like others, predicted the continuing rise of American power. But the new conventional wisdom that America is invincible is equally dangerous if it leads to a foreign policy that combines unilateralism, arrogance and parochialism.

A number of advocates of "realist" international-relations theory have also expressed concern about America’s staying-power. Throughout history, coalitions of countries have arisen to balance dominant powers, and the search for traditional shifts in the balance of power and new state challengers is well under way. Some see China as the new enemy; others envisage a Russia-China-India coalition as the threat. But even if China maintains high growth rates of 6% while the United States achieves only 2%, it will not equal the United States in income per head until the last half of the century.

Still others see a uniting Europe as a potential federation that will challenge the United States for primacy. But this forecast depends on a high degree of European political unity, and a low state of transatlantic relations. Although realists raise an important point about the leveling of power in the international arena, their quest for new cold-war-style challengers is largely barking up the wrong tree. They are ignoring deeper changes in the distribution and nature of power in the contemporary world. The paradox of American power in the 21st century is that the largest power since Rome cannot achieve its objectives unilaterally in a global information age.

The author criticizes those who are "barking up the wrong tree" for their()

A. dominance

B. insecurity

C.ignorance

D.sensitivity