假设某磁盘的每个磁道划分成11个物理块,每块存放1个逻辑记录。逻辑记录R0,R1,...,R9,R10存放在同一个磁道上,记录的存放顺序如下表所示:物理块1234567891011逻辑记录R0R1R2R3R4R5R6R7R8R9R10 如果磁盘的旋转周期为33ms,磁头当前处在R0的开始处。若系统使用单缓冲区顺序处理这些记录,每个记录处理时间为3ms,则处理这11个记录的最长时间为______;若对信息存储进行优化分布后,处理11个记录的最少时间为______。 单元属性是指 。
A. 单个单元还是区域或组合单元
B. 单元内容的性质如数字、字符还是表样
C. 数据单位
D. 数据的显示格式
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有八种化学药品A、B、C、D、W、X、Y、Z要装箱运输。虽然量不大,仅装1箱也装不满,但出于安全考虑,有些药品不能同装一箱。在下表中,符号“×”表示相应的两种药品不能同装一箱。运输这八种化学药品至少需要装 39 箱,实现这种最少箱数的装箱方案(不计装箱顺序)可有 40 个。A B C× D ×× W × X×× × Y ×××× Z×× × ABCDWXYZ Software Architecture Evaluation Model(SAEM)是一种软件架构的评估模型,以下关于该模型的叙述中,错误的是______。
A. 在SAEM中,从开发人员和用户两个角度考虑体系结构的描述,并应用于系统设计阶段
B. SAEM将质量需求、度量标准和体系结构的内部属性与最终的系统联系起来
C. SAEM的一个特别之处在于为了评估现存系统的体系结构,可以使用这个系统自身
D. SAEM认为体系结构开发过程限制了内部属性,所以度量过程的结果作为某种形式的反馈可以改进体系结构
假设某磁盘的每个磁道划分成11个物理块,每块存放1个逻辑记录。逻辑记录R0,R1,...,R9,R10存放在同一个磁道上,记录的存放顺序如下表所示:物理块1234567891011逻辑记录R0R1R2R3R4R5R6R7R8R9R10 如果磁盘的旋转周期为33ms,磁头当前处在R0的开始处。若系统使用单缓冲区顺序处理这些记录,每个记录处理时间为3ms,则处理这11个记录的最长时间为______;若对信息存储进行优化分布后,处理11个记录的最少时间为______。 ______标准的目标是制定一个开放的多媒体应用框架标准。
A. H.264
B. MPEG-21
C. XML
D. X3D
In the following essay, each blank has four choices. Choose the best answer and write down on the answer sheet. With the implementation of 5 , the so - called network has become a reality. The provision of such facilities is the most important part of the network requirements. However, 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 6 interface between user(application) program, normally referred to, as application processes, and the underlying communication services may be 7 . For example, one computer may be a small single - user computer, while another may be a large 8 system. In the earlier days of computer communication, these issues meant that 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 interconnected 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, 9 , 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 be placed into perspective with one another.
A. same
B. similar
C. different
D. dependent
In the following essay, each blank has four choices. Choose the best answer and write down on the answer sheet. With the implementation of 5 , the so - called network has become a reality. The provision of such facilities is the most important part of the network requirements. However, 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 6 interface between user(application) program, normally referred to, as application processes, and the underlying communication services may be 7 . For example, one computer may be a small single - user computer, while another may be a large 8 system. In the earlier days of computer communication, these issues meant that 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 interconnected 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, 9 , 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 be placed into perspective with one another.
A. database
B. data representation
C. protocols
D. data communication