探讨小学语文课堂“自主学习”

“教以生为本。”本文探索小学语文“自主学习”的方法以培养学生自主学习的能力,使学生以主人翁的姿态参与到学习过程中,快乐地获取知识。笔者主要从三方面论述：①反思旧的学习方式;②探索新的学习方式;③实践新的小学语文学习方式。     

应用型人才培养模式下的文科类数据库教学

分析高校文科专业数据库教学存在的问题,以培养应用型人才为目标,对数据库教学内容和方法进行探讨,提出一些改革措施:以学生为主体,引导创新性学习和实践;充分发挥学生的主观能动性,从理论教学、实验教学和考核制度上转变观念,提高教学质量,促进学生综合学习能力和应用实践能力的提高。     

小学数学教学点滴谈

小学数学教学有着自身的特点和规律,但它的基本出发点在于为学生进一步学习打下基础,促进学生主体性的发展。体验成功快乐,激发学习热情;坚持课堂结构高效化;鼓励学生质疑,培养学生的探索创新意识;动手实践,激活思维;善于以学生解题之错作为探究错因之源;创设生活化的情境。     

基于任务驱动教学法的Photoshop课程教学设计研究

笔者以从教Photoshop四年多的教学实践,提出实例任务驱动教学法法以激发学生的积极性;运用案例和任务驱动教学法提高学生的实践技能。采取引导发散思维以挖掘与培养学生的个性,特长与创新意识;并建立合理的教学考核方法,树立学生的学习信心。上述创新教学的方法的实施,取得了较好的教学效果。     

基于任务驱动教学法的Photoshop课程教学设计研究

笔者以从教Photoshop四年多的教学实践,提出实例任务驱动教学法法以激发学生的积极性;运用案例和任务驱动教学法提高学生的实践技能。采取引导发散思维以挖掘与培养学生的个性,特长与创新意识;并建立合理的教学考核方法,树立学生的学习信心。上述创新教学的方法的实施,取得了较好的教学效果。     

以培养自主学习能力为目标的阶梯任务驱动教学法在程序设计课程中的应用

学生对程序设计类课程的学习,不应以课程的结束为学习终点,还需学生通过后续学习取得更好的效果,因此培养学生自主学习能力至关重要。以培养学生自主学习能力为目标,提出阶梯任务驱动教学法,对传统任务驱动教学法进行改进,在程序设计课程中进行实践。根据课程内容,设置阶梯任务,在提高学生实践能力的同时培养学生自主学习能力,提高教和学的效率。     

“并行——综合型”课程设计模式探索与实践

课程设计是本科实践教学环节的一个重要组成部分,文章针对工业设计专业本科学生实践能力问题,以杜威"干中学"教育哲学和后现代教育学的基本观点为理论基础,建立以综合性知识互动式学习为目标、以实践课程为载体、以主导课程学习为主线、以教师为引导的"并行—综合型"课程设计模式,并给出应用实例。实践表明,此课程模式能够有效结合学生正在学习的理论知识内容,通过课程设计项目强化实践能力和知识运用能力,提高学生的学习自主性及综合能力。     

软件工程课程教学改革与实践探索

基于软件工程课程的特点,分析了目前教学过程中存在的问题,提出了两阶段教学法：理论讲授阶段以案例分析教学法,通过分析和演示案例,讲述软件工程的过程、理论与方法;在学生实践阶段采用任务驱动教学法,学生通过完成软件项目来巩固理论知识,并锻炼实践能力。实践表明,改进的教学方法能充分调动学生的学习自主性,提高学生的学习兴趣,改善教学效果。     

移动互联网在线学习模式研究

为了提高师生在线学习实践活动价值,本文对3种在线学习模式类型进行分析,提出在线学习实践路径。以某中学开展在线学习活动为例,观察直播教学期间学生的感受,并分析学生成绩变化情况,对在线学习模式进行评价。实践教学结果表明,在线学习模式对激发学生的学习兴趣帮助较大,可以提高部分学生学习成绩,对学习基础较差的学生帮助不是很大。     

历史风格再设计——谈设计史教学改革

文章从合理设计课堂教学内容;教与学的角色互换;"历史风格再设计"的设计实践出发;以注重提高学生艺术设计创新能力的培养等方面去阐述如何更好地对设计史课程进行教学改革,以提高学生学习自主性、学习积极性和设计创新能力,提高设计史课程的教学质量。     

A disruption recovery plan in a three-stage production-inventory system

This paper proposes a recovery plan for managing disruptions in a three-stage production-inventory system under a mixed production environment. First, a mathematical model is developed to deal with a disruption at any stage while maximizing total profit during the recovery-time window. The model is solved after the occurrence of a disruption event, with changed data used to generate a revised plan. We also propose a new and efficient heuristic for solving the developed mathematical model. Second, multiple disruptions are considered, where a new disruption may or may not affect the recovery plans of earlier disruptions. The heuristic, developed for a single disruption, is extended to deal with a series of disruptions so that it can be implemented for disruption recovery on a real-time basis. We compare the heuristic solutions with those obtained by a standard search algorithm for a set of randomly generated disruption test problems, and that show the consistent performance of our developed heuristic with lower computational times. Finally, some numerical examples and a real-world case study are presented to demonstrate the benefits and usefulness of our proposed approach.     

ROD-based hybrid TH precoding and combining for mmWave large-scale MIMO systems

Hybrid precoding is one of key techniques for millimeter wave (mmWave) large-scale multiple-input multiple-output (MIMO) systems. This paper considers a nonlinear hybrid precoding architecture which consists of a nonlinear unit, a reductive digital precoder and a constant modulus radio frequency (RF) precoder, and presents a novel hybrid Tomlinson-Harashima (TH) precoding and combining algorithm. Firstly, due to the intractability of the sum rates maximization problem for such a nonlinear hybrid precoding architecture, a tractable three-stage optimization problem is constructed through the lower bound of the sum rates, which allows the digital precoding matrix, the RF precoding matrix and the RF combining matrix to be optimized sequentially and independently. Then, in order to solve the three-stage optimization problem effectively, a novel row orthogonal decomposition (ROD) is defined. Based on the ROD, it is interesting that the necessary and sufficient condition of the optimal digital precoding matrix can be obtained, and a near-optimal RF precoding matrix can be derived. Finally, the optimization of the RF combining matrix is reformulated as a unimodular quadratic programming and solved by a generalized power method. Theoretical analyses and simulations indicate that the proposed ROD-based hybrid TH precoding and combining algorithm can offer a higher sum rates and a lower bit error rate with a comparable complexity in comparison to the previous works.     

关于一种网格运行时结构的若干注记

进程是传统计算机系统的一个核心概念，自1960年出现以来一直沿用至今，进程的一个主要目的是为主体提供一种运行时结构，在操作系统和处理器硬件支持下，代表主体访问和使用各种资源，与传统的单机和并行机计算平台相比，网格计算机中进程所对应的概念面临新的挑战，包括网格资源繁杂、自主控制的条件下的单一系统映像和资源的共享与协同、与特定操作系统的松耦合、时间和空间的流动性、更高级的交互性，提出一种称为网程(grip)的运行时结构，试图解决上述问题，网程运行在网格操作系统之上，代表网格主体，访问和使用网格资源。     

Genetic algorithm-based optimisation of load-balanced routing for AMI with wireless mesh networks

The advanced metering infrastructure (AMI) in a smart grid contains hardware, software, and other electronic components connected through a communication infrastructure. AMI transfers meter-reading data between a group of smart meters and a utility centre. Herein, a wireless mesh network (WMN) with a random mesh topology is used to deploy the AMI communication network. In a WMN, paths are identified using a hybrid wireless mesh routing protocol (HWMP) with a load balancing feature called load aware-HWMP (LA-HWMP). These paths reduce the demand on links with a minimal air time metric; however, the delay in the data transmission of certain smart meters is high, given the large number of retransmissions caused by packet drop. To avert this problem and enhance the end-to-end delay, a genetic algorithm is applied on the LA-HWMP to obtain the optimal path. The optimisation process will result in the selection of paths with minimal delay. The genetic algorithm is developed with a rank-based selection, a two-point crossover, and a random reset mutation with a repair function to eliminate duplicate entries. The proposed method is compared with the HWMP, the LA-HWMP, and a state-of-the-art method that uses a combination of the ant colony algorithm and simulated annealing (ACA-SA) for AMI networks of different sizes. The obtained results show that the path identified by the proposed method yields a shorter delay and higher throughput than paths identified using the other methods.     

COS:度量分布式大数据处理系统的效率

【目的】在大数据处理领域,分布式计算系统得到广泛应用,它们的可扩展性得到重点关注,但其绝对性能往往没有得到重视。我们希望提出科学合理、与时俱进的度量标准,对分布式系统的性能进行评估。【方法】本文通过对比特定任务的单机实现和分布式实现来讨论分布式系统的性能,提出COS(Configuration that Outperforms a Single machine)这一指标,来衡量分布式系统在达到单台机器的性能时,需要的硬件资源数量。我们选取k-means聚类和逻辑回归两个经典机器学习算法,对其进行单机多线程实现,并通过向量化计算、优化内存分配与访问等方式对性能进行了优化,为分布式多机系统的性能提供参考。【结果】以Apache Spark作为对标系统,实验发现无论是使用其原生编程接口,还是经过悉心优化的机器学习库,都要使用数倍甚至数百倍的机器,才能达到单机多线程实现的性能。【局限】分布式系统与单机实现进行性能对比并不是完全公平的,分布式系统的额外开销客观存在。【结论】但COS指标仍能反映分布式系统存在的绝对性能较差、没有充分利用硬件优势等问题。     

Editing 3D models on smart devices

This study proposes a 3D CAD system available on smart devices, which are now a part of everyday life and which are widely applied in various domains, such as education and robot industry. If an engineer has a new idea while traveling or on the move, or in the case of collaboration between more than two engineers, this 3D CAD system allows modeling to be performed in a rapid and simple manner on a smart device. This 3D CAD system uses the common multi-touch gestures associated with smart devices to keep the modeling operations simple and easy for users. However, it is difficult to input the precise geometric information to generate 3D CAD models by such gestures. It is also impractical to provide a full set of modeling operations on a smart device due to hardware limitations. For this reason, the system excludes several complicated modeling operations. This work provides a scheme to regenerate a parametric 3D model on a PC-based CAD system via a macro-parametrics approach by transferring the 3D model created on a smart device in an editable form to a PC-based CAD system. If fine editing is needed, the user can perform additional work on a PC after reconstruction. Through the developed system, it is possible to produce a 3D editable model swiftly and simply in the smart device environment, allowing for reduced design time while also facilitating collaboration. This paper discusses the first-ever system design of a 3D CAD system on a smart device, the selection of the modeling operations, the assignment of gestures to these operations, and use of operation modes. This is followed by an introduction of the implementation methods, and finally a demonstration of case studies using a prototype system with examples.     

Better combination of thickness and hardness of mattress topper for supine sleeping posture: A physiological measurements evaluation

Placing a topper on a sleeping system is common practice to enhance sleeping comfort. The aim of this study was to determine the thickness and hardness effect of a mattress topper by measuring the four physiological measurements from 40 healthy males. The results showed that the use of a thin mattress topper (30 mm) significantly induced lower body pressure and temperature, higher muscle activities in the biceps femoris, and a straighter spinal alignment in the T12–L4 vertebrae. The use of a hard mattress topper significantly induced a higher body pressure, a lower body temperature in the lower extremities, a higher EMG (%MVC) in the trapezius, but a lower EMG (%MVC) in the biceps femoris, and a straighter spinal alignment at T1–T4, T4–T6, and T6–T8. Overall, a soft topper of 30-mm thickness was suggested as the best combination. The findings can provide very useful information for topper design and selection.     

图模型匹配:一种新的凹松弛函数及算法

将问题中的置换矩阵放松为双随机矩阵是近年来近似图匹配算法的一个重要发展方向. 它的本质在于将离散的图匹配问题转换成一个连续优化问题,而一般来讲, 相对于离散优化,连续优化问题的近似求解将更为容易. 但随之带来的一个问题是如何有效地将连续优化得到的双随机矩阵重新映射回一个置换矩阵. 最近文献中提出了一种针对于无向无自环图的凹松弛(Concave relaxation)函数,使得算法中的双随机矩阵可以平滑地收敛到一个置换矩阵, 并得到优异的匹配精度.但除了无向且无自环图,文献中还没有针对其他类型图模型的凹松弛函数. 本文提出一种针对于有向无自环图匹配问题的凹松弛函数, 并在此基础上给出一种图匹配算法.大量对比实验验证了本文提出模型及算法的有效性.     

BL-代数的弱（相对）零化子

基于格的相对零化子概念提出了[BL-]代数的弱相对零化子概念。讨论了弱相对零化子的基本性质,证明了弱相对零化子是[BL-]代数的滤子,给出了弱相对零化子的表示定理。进一步提出了弱零化子概念,给出了零化子等价于弱零化子的充要条件,刻画了[BL-]代数全体滤子集的结构。结论为今后研究[BL-]代数的弱广义相对零化子提供了基础。