On keys' meanings and modes: the impact of different key solutions on children's efficiency using a mobile phone

The present study investigates the impact of different key solutions of mobile phones on users' effectiveness and efficiency using the devices. In the first experiment, 36 children (9 - 14 years) and in the second experiment 45 young adults (19 - 33 years) completed four common phone tasks twice consecutively on three simulated phones that had identical menus, but different key solutions. An approach was undertaken to quantify the complexity of keys in three models, incorporating different factors contributing to the keys' complexity (number of key options, number of modes and number of modes with a semantically dissimilar meaning), in order to predict users' performance decrements. As a further main factor, the degree of the users' locus of control (LOC) was measured and interactions with performance outcomes were studied. As dependent measures, the number of inefficient keystrokes, the number of tasks solved and the processing time were determined. Results showed a significant effect of control key solutions on users' efficiency and effectiveness for both children and young adults. Moreover, children's LOC values significantly interacted with performance: children with low LOC values showed the lowest performance and no learnability, especially when using keys with a high complexity. From the three factors contributing to the complexity of keys, keys exerting different functions with semantically inconsistent meanings had the worst effect on performance. It is concluded that in mobile user interface design keys with semantically inconsistent meanings should be generally avoided.     

8096/8098单片机集成开发系统

本集成开发环境集编辑、编译、调试和运行于一体,模拟了MCS-96系列单片机的指令系统,并给教学、实验、应用、科研和单片机的开发提供了强有力的手段。     

用Flash制作会说话的照片

利用Flash5制作会说话的照片，使照片变成一张张有趣的动画卡片。     

A survey of models and algorithms for winter road maintenance. Part IV: Vehicle routing and fleet sizing for plowing and snow disposal

This is the last part of a four-part survey of optimization models and solution algorithms for winter road maintenance planning. The two first parts of the survey address system design problems for winter road maintenance. The third part concentrates mainly on vehicle routing problems for spreading operations. The aim of this paper is to provide a comprehensive survey of optimization models and solution methodologies for the routing of vehicles for plowing and snow disposal operations. We also review models for the fleet sizing and fleet replacement problems.     

基于循环神经网络的电信行业容量数据预测方法

在电信运维的容量预测过程中,存在容量指标和部署业务种类繁多的问题。现有研究未考虑指标数据类型的差异,对所有类型的数据使用同种预测方法,使得预测效果参差不齐。为了提升指标预测效率,提出一种指标数据类型分类方法,利用该方法将数据类型分为趋势型、周期型和不规则型。针对其中的周期型数据预测,提出基于双向循环神经网络（BiRNN）的周期型容量指标预测模型,记作BiRNN-BiLSTM-BI。首先,为分析容量数据的周期特征,提出一种忙闲分布分析算法;其次,搭建循环神经网络（RNN）模型,该模型包含一层BiRNN和一层双向长短时记忆网络（BiLSTM）;最后,充分利用系统忙闲分布信息,对BiRNN输出的结果进行优化。与传统的三次指数平滑、差分自回归移动平均（ARIMA）模型和反向传播（BP）神经网络模型进行比较的实验结果表明,在统一日志数据集和分布式缓存数据集上,提出的BiRNN-BiLSTM-BI模型的均方误差（MSE）分别比对比模型中表现最优的模型降低了15.16%和45.67%,可见预测准确率得到了很大程度的提升。     

动态下拉菜单的技巧与方法

采用可见即所得的操作和程序编制相结合的方法实现动态下拉菜单的制作,充分利用两方面的优势提高操作简便性和实现效率。Dreamweaver制作菜单模板,方法简单、代码生成率高;CSS和ASP对于动态菜单和控制方法逻辑性强、易于理解、实现效果良好,相比常规的JavaScript的代码方式具有更好的优越性。     

利用Photoshop CS制作心形相框

Photoshop是由Adobe公司开发的专业平面设计软件,具有强大的图像设计及处理功能,本文主要介绍如何利用中文Photoshop CS中的工具及菜单指令制作心形相框。     

The optimal control approach to generalized multiprocessor scheduling

In this paper we present several new results in the theory of homogeneous multiprocessor scheduling. We start with some assumptions about the behavior of tasks, with associated precedence constraints, as processor power is applied. We assume that as more processors are applied to a task, the time taken to compute it decreases, yielding some speedup. Because of communication, synchronization, and task scheduling overhead, this speedup increases less than linearly with the number of processors applied. We also assume that the number of processors which can be assigned to a task is a continuous variable, with a view to exploiting continuous mathematics. The optimal scheduling problem is to determine the number of processors assigned to each task, and task sequencing, to minimize the finishing time.These assumptions allow us to recast the optimal scheduling problem in a form which can be addressed by optimal control theory. Various theorems can be proven which characterize the optimal scheduling solution. Most importantly, for the special case where the speedup function of each task isp , wherep is the amount of processing power applied to the task, we can directly solve our equations for the optimal solution. In this case, for task graphs formed from parallel and series connections, the solution can be derived by inspection. The solution can also be shown to be shortest path from the initial to the final state, as measured by anl _1/ distance metric, subject to obstacle constraints imposed by the precedence constraints.This research has been funded in part by the Advanced Research Project Agency monitored by ONR under Grant No. N00014-89-J-1489, in part by Draper Laboratory, in part by DARPA Contract No. N00014-87-K-0825, and in part by NSF Grant No. MIP-9012773. The first author is now with AT&T Bell Laboratories and the second author is with BBN Incorporated.     

Coordination of split deliveries in one-warehouse multi-retailer distribution systems

In this paper, we consider a distribution system where a warehouse is responsible for replenishing the inventories at multiple retailers by a fleet of vehicles of limited capacity. If a distribution policy of the system involves split deliveries, that is, the inventory of at least one retailer is replenished by using multiple vehicle routes, the coordination of the deliveries can further reduce the inventory cost of the retailer. We consider the coordination where two split deliveries are realized by direct shipping and multiple-stop shipping, respectively. To the best of our knowledge, this kind of coordination was never studied in the literature but can find its application in inventory routing problems. This paper proposes and analyses a class of coordination policies for the split deliveries which can reduce the inventory costs of the retailers without increasing transportation costs. A non-linear programming model is established for formulating the class of polices. Because the optimal coordination policy corresponding to an optimal solution of the model may be hard to find and/or implement, two simple but effective coordination policies are proposed. The inventory cost savings realized by the two policies are evaluated analytically and algorithmically. Our theoretical analysis and computational experiments show that both policies are effective. Under certain conditions, they can save 50% of the inventory costs at the retailers without increasing transportation costs.     

基于Windows NT局域网络全真模拟Internet操作测试功能的实现

文章介绍一种基于Ｗｉｎｄｏｗｓ ＮＴ局域网络,在Ｗｉｎｄｏｗｓ ９５／９８平台上使用的全真模拟Ｉｎｔｅｒｎｅｔ操作测试功能的实现方案,重点介绍了题库工作表结构,全真模拟Ｉｎｔｅｒｎｅｔ环境,操作考核主页设计及其相关技术要点。