搜题请搜索小程序“爱下问搜题”
问题 单项选择题

( )是指数据搜集和测量过程中由于仪器不准确、标准不规范等原因，造成观察结果呈倾向性的偏大或偏小。

A．系统误差

B．风险误差

C．变量

D．随机误差

答案

参考答案：B

解析： 系统误差的特点为具有累加性。

问答题 简答题

夏季空调室外计算湿球温度是如何确定的？夏季空调室外计算干球温度是如何确定？理论依据是什么？他们有什么不同？
查看答案
单项选择题

Typically, these are concern with the establishment of (66) the network and with the control of the flow of messages across this channel. The provision of such facilities is only part of the network requirements, however, since in many applications the communicating computers may be of different types. This means that they may use different programming languages and, more importantly, different forms of (67) interface between user(application)program, normally referred to, as application processes or APs, and the underlying communication services may be (68) For example, one computer may be a small single -user computer, while another may be a large (69) system. In the earlier days of computer communication, these issues meantthat only closed communities of computers ( that is, from the same manufacturer) could communicate with each other in a meaningful way. IBM’s Systems Network.
Architecture (SNA) and DEC’s Digital Network Architecture (DNA) are just two examples of Communication software packages produced by manufacturers to allow their systems to be int erconnected together. These proprietary packages, however, of which there am still many inexistence, do not address the problem of universal interconnect ability, or open systems interconnection. In an attempt to alleviate this problem, (70) , in the late 1970s, formulated a reference model to provide a common basis ( or the coordination of standards developments and to allow existing and evolving standards activities to beplaced into perspective with one another.

A. same B. similar C. different D. dependent
查看答案