共查询到20条相似文献，搜索用时 171 毫秒
1.
段远志 《南昌教育学院学报》2003,18(2):64-66
数据库最明显的特点是多个用户可共享数据,这固然是数据库的一大长处,但同时也带来了新的问题,这就是并发操作带来的对数据库一致性、完整性的破坏,如果不对并发操作进行必要的控制,那么即使没有任何故障和程序错误也会损坏数据库的完整性. 相似文献
2.
数据库访问的并发控制是数据库管理系统(DBMS)的一个重要功能。通过分析并发访问可能造成的问题和并发执行的正确性准则,重点讨论了一类重要的并发控制方法——基于锁的并发控制协议,最后又分析了加锁可能带来的问题和相应的解决办法。 相似文献
3.
肖颂华 《岳阳职业技术学院学报》2009,24(2)
将120例肝硬化并发上消化道出血的病人随机分为心理组(58例)和对照组(62例).心理组在常规治疗的同时主动进行针对性的心理护理;对照组仅进行常规治疗、护理.采用焦虑自评量表(SAS)对两组病人进行护理干预前后自我评定比较,结果表明:心理组的焦虑评分明显低于对照组(P<0.01);提示在胰源性门脉高压并发消化道出血的治疗中,主动、有针对性的心理护理能有效地缓解病人焦虑症状,减轻严重躯体疾病带来的心理应激. 相似文献
4.
在多用户的数据库系统中,由于事务的并发性而带来了三类的并发问题.为解决这些问题,本文介绍了三种事务的并发控制方法:封锁法、时间印法和乐观法,并分析了它们的优缺点. 相似文献
5.
老年糖尿病并发低血糖误诊原因分析及诊治 总被引：4，自引：0，他引：4
林荣 《河北北方学院学报(医学版)》2005,22(1):76-77
目的:探讨老年糖尿病并发低血糖的临床特点、误诊原因及诊断治疗.方法:回顾性分析我院收治的老年糖尿病并发低血糖病人32例.结果:院内、外误诊18例(56%).结论:通过了解老年糖尿病的生理、临床特点,提高对并发低血糖的警惕,及时检测血糖,同时建议临床医师指导病人合理用药,加强对本病的预防. 相似文献
6.
由于一些自然和人为因素的影响,近代广西的水灾日趋严重。水灾发生的频次较前代明显增多,并有逐年上升的趋势。从空间分布来看,水灾主要集中于梧州、南宁、浔州及郁林州等府县。同时,水灾还呈现出连续性、灾区广、灾情重、多灾并发等特点,给近代广西社会和人民带来了深重灾难。水灾过后,政府和民间社会也在一定程度上对灾民进行了赈济,有利于农业生产的恢复,社会秩序的稳定。 相似文献
7.
《南阳师范学院学报》2020,(3):32-35
提出了一种新型的非线性行为建模方法用于建模并发双波段射频功放的非线性,该建模方法采用分离采样法,能够精确描述子波段1和子波段2为不同信号时并发双波段功放的强非线性,同时还能大大降低对高速模数转换器(ADC)采样速率的要求.本文采用子波段1为1001 CDMA2000,子波段2为单载波WCDMA信号作为测试信号,使用输出峰值功率为47 dBm的LDMOS射频功放作为测试功放进行模型有效性验证.实验结果表明,子波段分离的并发双波段射频功放非线性行为建模方法与传统方法相比,在保证建模能力的同时,能够大大降低对ADC采样率的要求. 相似文献
8.
揭红英 《泰州职业技术学院学报》2007,7(3):61-62
通过对法乐四联症术后并发症尤其是出血、心包填塞同时并发腹腔积液病例的回顾．进一步深入研究探讨法乐四联症矫治术后并发症的多变性、隐蔽性及其发生机制，提高今后的处理能力。 相似文献
9.
民国时期安徽灾荒与农村社会经济 总被引：1，自引：0，他引：1
民国时期安徽灾荒严重。无年不灾,多灾并发,危害面广,是这一时期灾况的基本特征。灾荒使民众的生命财产及农业生产遭到了巨大损失和破坏,民众的生存条件更加恶化,对农村经济发展、民众的生活、社会的进步带来了长久的负面影响,加重了农村的社会经济危机。 相似文献
10.
食管切除，食管——胃吻合术后主要并发很多，而胸内吻合瘘对病人造成很大的威胁．其死亡可达50％，一时发生。处理上非常困难，并且给病人带来极大的痛苦和经济负担．我院行食管——胃吻合术120例，无吻合口瘘发生，疗效满意。值得借鉴． 相似文献
11.
Sara Kim Douglas M. Brock Adam Orkand & Michael L. Astion 《British journal of educational technology : journal of the Council for Educational Technology》2001,32(5):595-605
To examine interface issues in an educational software program, we recruited twenty-two users in health sciences departments for a usability study. Using the GramStain-Tutor™ (GST) CD-ROM, these users performed tasks in navigating the program and using various interactive features. Their actions and comments were recorded with a digital video recorder and an audio recorder. The main results of our study are: (a) the majority of the users did not use the multiple navigational options available in the program; (b) navigational patterns differed based on the training background and content knowledge of the users; (c) several visual cues critical to program use were not discovered by the majority of the users; and (d) icons representing specific functions were not intuitive from users' perspectives. We demonstrated how a usability study of a relatively small number of users can identify specific problems in interface design. We recommend these interface problems be addressed before conducting educational studies that examine how educational software programs affect student learning. 相似文献
12.
蔡向阳 《黄冈职业技术学院学报》2010,12(6):20-22
U盘是一种以其体积小、便于携带等优点被广大用户普遍选用的移动存储介质,但由于其使用频率高,易于出现故障造成数据的丢失或损坏,给使用者带来了很大的不便,针对U盘使用过程中常出现的一些故障进行诊断,并尝试着进行数据恢复。 相似文献
13.
龚文生 《思茅师范高等专科学校学报》2010,26(3):43-45
ASP开发的Web应用程序中调用Access数据库,在多用户并发访问时有一定的极限,很多时候不能达到实用的要求。通过《学生成绩查询管理系统》开发过程中Access数据库的表由大变小、逐级分类（分班建表）、多表关联查询的方法,有效的提高Access数据库WEB访问速度,使Access数据库WEB多用户并发访问达到完全实用的效果。从实用的角度出发,对开发过程中的经验及ASP代码实例进行分析,对从事ASP中使用Access数据库开发者,有一定的参考价值。 相似文献
14.
Summary This examination of electronic encyclopedias has led to several interesting observations that may be made for each encyclopedia.
TheCompton’s product is considered to be the product most accessible by lower level elementary school students. Its audio and visual features
are considered most important for purchase decision-making and turn out to be the most useful features after the purchase.
BothWorld Book andGrolier’s are comparable in the suggestion of a minimum grade level appropriate for use (at the fourth or fifth grade levels), suggesting
that reading is not the only ability needed to operate either product to its fullest extent. For bothWorld Book andGrolier’s, the boolean searching, keyword searching, quick reference and quality of the screen display features were important purchase
considerations. Hardware compatibility and price, while rated important, may prove to be the factors that determine whether
an electronic encyclopedia is purchased at all (since all products evaluated were roughly the same price and all ran on IBM
hardware). The majority ofWorld Book users considered only the dictionary feature to be useful after purchase.Grolier’s users considered boolean and keyword searching, menu searching, and help screens to be most useful. 相似文献
15.
For a TELE to become adopted by the vast majority of individual learners as a tool for learning, adoption at the institutional level must be considered, because the vast majority of a population of technology users depends on external stimuli to adopt the technology. This article analyses a case where a social simulation game, a prize-winning e-learning product, which is based on theory of, and dedicated to, self-regulated learning – in other words, a product predestined to succeed in supporting self-regulated learning – was implemented for training in academic information literacy. Applying a systemic, Bateson-inspired, understanding of learning and based on data from observation, qualitative interviews, and surveys, a number of barriers to adoption at the organisational level are identified, all requiring management initiatives if the application is to fully unfold its potential. 相似文献
16.
刘小武 《宜宾师范高等专科学校学报》2013,(12):67-71
随着计算机网络技术的发展,FTTH的普及,方便快捷的云存储逐步被广大的用户所接受,随之,云存储文件安全性存在问题受人质疑.通过对现有云存储存在的安全问题分析,提出了对用户原文件加密分割为多个块文件,进行多账号随机离散残缺云存储,使任何一个云上的文件块都不能被正确还原为原用户文件,彻底解决云存储文件的安全问题. 相似文献
17.
杨志国 《河北能源职业技术学院学报》2006,6(3):82-83
在企业中,很多部门的员工并不是集中办公,他们分布在不同的楼层或地域,做为网络用户,他们需要集中管理;也有很多部门在网络上需要越来越高的安全性,不能和其他的部门混用同一个以太网段,以防止数据窃听.这些新问题需要更灵活地配置局域网,虚拟局域网技术解决了这个问题,用户不受地理位置的限制,在逻辑上组成新的局域网,缩小了广播域,提高了网络安全性. 相似文献
18.
Elderly people are exposed to information technologies to keep them in touch with younger generations. Among various technologies, social network sites (SNSs) are seldom used by the majority of elderly people. To bridge the digital divide, it is necessary to dig deeply into the minority elderly users of SNSs. This study explores usage patterns of elderly Facebook users and further investigates how their diverse characteristics influence their usage and social circles. Three findings were derived. First, a sharp digital divide on SNSs does exist, and existing elderly Facebook users are mainly the dabblers. Second, personality profiling could predict elderly people’s SNS usage behaviors. Elderly users with a high level of openness and extroversion have more friends, status updates, and group memberships, and those with a high level of conscientiousness have fewer likes and status updates. Elderly users are likely to seek insightful content on SNSs. Moreover, they may have a higher degree of emotional stability than young users when using SNSs. Third, elderly people tend to build small social circles on SNSs that “copy” the family relationship in the real world; whereas, they build large social circles with interests and hobbies that are difficult to share in the real world. Based on these results, detailed suggestions are presented for better targeting elderly people in ways that move them toward SNSs. 相似文献
19.
虚拟网(VLAN)在逻辑上等价于广播域。用户可以处在不同的物理LAN上,但他们之间可以像在同一个LAN上那样自收通信而不受物理位置的限制。 相似文献
20.
具备抄核收全程自动化功能的二次系统改造方案研究 总被引：1，自引：0，他引：1
以2008年恒山线的降损综合改造为试点,对其全线的50kVA及以上大用户、台区、居民户安装实施无线集中抄表装置改造,同时将威胜大主站系统和北京煜邦关口系统进行对接,实现了从关口、大用户、台区到居民计量装置的全集抄,可对供入、供出运行全程的电量参数、负荷变化实时监控、抄读和应用分析,基本达到了抄核全程的自动化管理要求。 相似文献