试谈C++的多态性和虚函数     

范秋生 《黄冈职业技术学院学报》2006,8(4):82-84

本文分析了C++中的两种多态性:编译时的多态性和运行时的多态性,通过函数重载和虚函数对其进行了探讨,指出了虚函数是实现动态联编的关键。  相似文献   

基于虚拟现实技术的中考理化生实验考试系统的设计     

李娜 《教育教学论坛》2019,(21):275-276

目前中考理化生实验考试存在考试组织管理工作量大、考试评价标准不统一、考试题目局限性大,探究类题偏少等问题。在构建虚拟实验的基础上,以虚拟实验的自动化评价为核心,结合考务管理信息化,促进中考理化生实验考试的进一步完善,提升实验考试的探究性,达到以考促教的目的。  相似文献   

VRML技术及应用   总被引：1，自引：0，他引：1  

谢杰  姬晓辉 《洛阳工业高等专科学校学报》2006,16(3):28-29,34

虚拟现实技术是一门涉及众多学科的新兴技术,在许多领域具有广泛的应用前景。概括介绍了VRML发展、定义及特点,最后介绍了VRML在机械设计方面的应用。  相似文献   

虚拟团队的内涵及其研究的方向和方法问题探析   总被引：6，自引：0，他引：6  

胡峰 《河南师范大学学报(哲学社会科学版)》2005,32(5):58-62

可以将虚拟团队理解为成员在跨越位置的、时间的和关系的界限进行工作时，在不同程度上使用技术以完成相互依赖任务的团队。近年来西方学者对虚拟团队研究兴趣大增，他们认识到更多的团队是进行虚拟工作的，一定程度的虚拟性是大多数团队的组成部分。学者们现在仅仅开始着手理解虚拟团队是怎样运转的，为了方便这种团队的设计和管理，还有许多工作要做。  相似文献   

虚拟全景的制作——“虚拟现实”系列之一     

郭根生 《现代教育技术》2001,11(4):57-62

360°全景虚拟现实是多媒体技术中的最新内容 ,在网页设计和现代教育技术中有着越来越多的应用。该文通过VRToolbox软件和例证 ,从全景虚拟现实的概念到制作方法详细介绍了这一成果  相似文献   

Virtual local target method for avoiding local minimum in potential field based robot navigation     

邹细勇  诸静 《浙江大学学报(A卷英文版)》2003,4(3):264-269

A novel robot navigation algorithm with global path generation capability is presented. Local minimum is a most intractable but is an encountered frequently problem in potential field based robot navigation. Through appointing appropriately some virtual local targets on the journey, it can be solved effectively. The key concept employed in this algorithm are the rules that govern when and how to appoint these virtual local targets. When the robot finds itself in danger of local minimum, a virtual local target is appointed to replace the global goal temporarily according to the rules. After the virtual target is reached, the robot continues on its journey by heading towards the global goal. The algorithm prevents the robot from running into local minima anymore. Simulation results showed that it is very effective in complex obstacle environments. Project (No. 69904009) supported by the National Natural Science Foundation of China  相似文献   

基于VLAN的网络技术与应用     

操惊雷  张国利 《黄冈职业技术学院学报》2003,5(4):85-87

随着网络技术的迅速发展,基于集线器的共享网络己被基于交换机的交换式网络所替代。虚拟局域网(VLAN)技术给局域网络引入了全新的概念,VLAN为解决网络站点的灵活配置和网络安全性等问题提供了良好的手段。  相似文献   

Surgical management of gastric stump cancer： a report of 37 cases   总被引：3，自引：0，他引：3  

Chen L  Tian H  Chen J  He ZG  Tao SF  Lokesh G  Peng SY 《Journal of Zhejiang University. Science. B》2005,6(1):38-42

Objective: To observe the clinicopathological characteristics of gastric stump cancer (GSC) and evaluate the benefits of radical surgery of GSC. Methods: The clinicopathological characteristics and postoperative survival time of 37 GSC patients who underwent surgery were investigated retrospectively. The survival time was compared according to the type of surgical pTMN stage. Survival curves were traced by using Kaplan-Meier methods. Results: Most GSC (32/37) was detected in patients who had received Billroth Ⅱ reconstruction after partial gastrectomy for benign gastric disease. The lesser curvature side and the suture line of anastomosis were the most frequent sites where GSC occurred (27/37). Differentiated adenocarcinoma was the dominant histopathological type (24/37). The postoperative 5-year survival rate of early stage GSC patients (n=9) was significantly higher than advanced stage GSC (n=12) (55.6% vs 16.5%, xL2=1 1.48, P＜0.01). Five-year survival rate of 21 GSC patients with radical resection were 75% (3/4) for stage Ⅰ, 60% (3/5) for stage Ⅱ, 14.2% (1/7) for stage Ⅲ, and 0% (0/5) for stage Ⅳ respectively.The median survival time of 21 GSC patients who underwent radical resection was longer than those undergoing palliative operation (43.0m vs 13.0m, xL2=36.31, P＜0.01), the median survival time of stage Ⅳ patients with radical resection was 23.8months. Conclusions: Without remote metastasis, radical resection for GSC is possible, and is an effective way to improve the prognosis of GSC. Even in stage Ⅳ GSC, radical resection can still prolong the survival time. It is necessary for the patients with benign gastric diseases who received partial gastrectomy to carry out the endoscopy follow-up, especially in patients with Billroth Ⅱ reconstruction procedure at 15-20 years.  相似文献   

校园网中VLAN的设计与实现     

褚建立  刘彦舫  马雪松 《邢台职业技术学院学报》2002,19(2):56-59

本从分析传统的校园网中逻辑子网之间的通信入手，介绍了在邢台职业技术学院校园网中采用了三层交换机中划分VLAN的办法，来解决子网之间的通信和安全以及广播风暴等问题。  相似文献   

The use of augmented reality to foster conceptual knowledge acquisition in STEM laboratory courses—Theoretical background and empirical results     

Kristin Altmeyer  Sebastian Kapp  Michael Thees  Sarah Malone  Jochen Kuhn  Roland Brünken 《British journal of educational technology : journal of the Council for Educational Technology》2020,51(3):611-628

Learning with hands-on experiments can be supported by providing essential information virtually during lab work. Augmented reality (AR) appears especially suitable for presenting information during experimentation, as it can be used to integrate both physical and virtual lab work. Virtual information can be displayed in close spatial proximity to the correspondent components in the experimentation environment, thereby ensuring a basic design principle for multimedia instruction: the spatial contiguity principle. The latter is assumed to reduce learners' extraneous cognitive load and foster generative processing, which supports conceptual knowledge acquisition. For the present study, a tablet-based AR application has been developed to support learning from hands-on experiments in physics education. Real-time measurement data were displayed directly above the components of electric circuits, which were constructed by the learners during lab work. In a two group pretest–posttest design, we compared university students' (N = 50) perceived cognitive load and conceptual knowledge gain for both the AR-supported and a matching non-AR learning environment. Whereas participants in both conditions gave comparable ratings for cognitive load, learning gains in conceptual knowledge were only detectable for the AR-supported lab work.  相似文献