构造移动通信中降低能耗的前缀码的动态规划加速

动态规划是一种常用的寻找问题最优解的算法设计方案。当将动态规划中的各个子问题考虑成有向图上的节点时,我们可以将动态规划看作是一个有向无圈图。一些问题的动态规划的有向无圈图有着特殊的结构,我们可以利用这些结构加速动态规划。本文考虑了一种从基站将能源"转移"到移动通信宿主的二进制编码方案构造时采用的动态规划。移动通信中,常常需要考虑优化通信编码方案来降低移动通信宿主的能耗。本文研究的编码方案通过以下方式降低能耗:基站猜测移动通信宿主所要发出的信息并询问宿主,而宿主则在一定的情况下才做出回应,以此来降低宿主发送信息的能耗。对于有n个单词的编码,我们的算法比之前提出的算法降低了O(n2)的时间复杂度。     

地理位置相关移动感知系统任务分配问题研究

随着智能手机应用的普及,移动感知技术已被认为是一种高效且成本低廉的环境数据收集方式.移动感知系统中地理位置相关的最优任务分配问题是一个NP难问题.为了解决该问题,提出了一种多项式时间的近似最优的任务分配算法.该算法首先引入了单位圆盘模型中移动划分的思想,将整个监测地理空间划分为若干个子区间,并使得子区间内的最优分配方案的集合是划分前最优解的〖SX(〗1〖〗1+ε〖SX)〗,这表明所设计的近似算法是一个多项式时间近似机制.随后,证明了最优任务分配问题在每个子区间内是多项式时间可解的,并设计了枚举算法求出该问题的最优解.最后,仿真实验结果表明所设计的近似最优任务分配算法的实际性能与理论分析相吻合.     

A framework for evaluating the usability of mobile phones based on multi-level, hierarchical model of usability factors

As a mobile phone has various advanced functionalities or features, usability issues are increasingly challenging. Due to the particular characteristics of a mobile phone, typical usability evaluation methods and heuristics, most of which are relevant to a software system, might not effectively be applied to a mobile phone. Another point to consider is that usability evaluation activities should help designers find usability problems easily and produce better design solutions. To support usability practitioners of the mobile phone industry, we propose a framework for evaluating the usability of a mobile phone, based on a multi-level, hierarchical model of usability factors, in an analytic way. The model was developed on the basis of a set of collected usability problems and our previous study on a conceptual framework for identifying usability impact factors. It has multi-abstraction levels, each of which considers the usability of a mobile phone from a particular perspective. As there are goal-means relationships between adjacent levels, a range of usability issues can be interpreted in a holistic as well as diagnostic way. Another advantage is that it supports two different types of evaluation approaches: task-based and interface-based. To support both evaluation approaches, we developed four sets of checklists, each of which is concerned, respectively, with task-based evaluation and three different interface types: Logical User Interface (LUI), Physical User Interface (PUI) and Graphical User Interface (GUI). The proposed framework specifies an approach to quantifying usability so that several usability aspects are collectively measured to give a single score with the use of the checklists. A small case study was conducted in order to examine the applicability of the framework and to identify the aspects of the framework to be improved. It showed that it could be a useful tool for evaluating the usability of a mobile phone. Based on the case study, we improved the framework in order that usability practitioners can use it more easily and consistently.     

BREW平台的UIONE手机开发技术研究

BREW平台的UIONE技术是一套端到端完整的关于手机动态界面设计开发、展示、服务和管理的开放的解决方案。通过使用UIONE,运营商可以掌控手机动态界面设计,改变目前由手机厂商主导手机界面的状况。UIONE带来的界面的变化都是和手机底层芯片核心功能相关联的．这些画面都是动态的,一旦点击进去,就能触发一些功能的调用,大大简化手机的研发工作量,加快手机上市的时间。     

Measuring the efficiency of customer satisfaction and loyalty for mobile phone brands with DEA

The concept of customer satisfaction and loyalty (CS&L) has attracted much attention in recent years. A key motivation for the fast growing emphasis on CS&L can be attributed to the fact that higher customer satisfaction and loyalty can lead to stronger competitive position resulting in larger market share and profitability. Using a data envelopment analysis (DEA) approach, in this study we analyzed and compared CS&L efficiency for mobile phone brands in an emerging telecommunication market, Turkey. The constructs of European Customer Satisfaction Index (ECSI) model are treated and used as input and output indicators of our DEA model. Drawing on the perceptual responses of 251 mobile phone users, the DEA models reveal that from the top six mobile phone brands in Turkey, Nokia features as the most efficient brand followed by LG and Sonny Ericsson in terms of CS&L efficiency, while Motorola, Samsung and Panasonic rank as the least efficient brands.     

一种基于构件的手机可重构虚拟仪器技术

针对手机测试系统对便携式测量提出的在线升级和功能调整的要求,提出了基于构件的手机动态可重构测试系统。采用动态XML解析器模型实现了手机端测试系统的动态解析、构件的查找和装配,形成一个测试功能可以根据测试任务快速重组的测试系统。提出了支持面向发布/订阅模式的仪器构件模型,在此基础上设计了系统数据模型和事件模型来实现构件之间消息的传递与数据的更新。以声音信号采集分析仪器和3种人体生理信号采集测试系统为应用例子,进行测试。结果证明了该平台的可实现性,并能够满足手机测试系统对便携式测量提出的在线重构和功能调整的要求。     

Forecasting of manufacturing cost in mobile phone products by case-based reasoning and artificial neural network models

The mobile phone manufacturers in Taiwan have made great efforts in proposing the rational quotations to the international phone companies with the ambition to win the bids by out beating other phone manufacturers. However, there are a lot of uncertainties and issues to be resolved in estimating the manufacturing costs for mobile phone manufacturers. As far as we know, there is no existing model which can be applied directly in forecasting the manufacturing costs. This research makes the first attempt to develop a hybrid system by integrated Case-Based Reasoning (CBR) and Artificial Neural Networks (ANN) as a Product Unit Cost (PUC) forecasting model for Mobile Phone Company. According to the cost formula of the mobile phone and experts’ opinions, a set of qualitative and quantitative factors are analyzed and determined. Qualitative factors are applied in CBR to retrieve a similar case from the case bases for a new phone product and ANN is used to find the relationship between the quantitative factors and the predicted PUC. Finally, intensive experiments are conducted to test the effectiveness of six different forecasting models. The model proposed in this research is compared with the other five models and the MAPE value of the proposed model is the smallest. This research provides a new prediction model with high accuracy for mobile phone manufacturing companies.     

Optimal pricing for mobile manufacturers in competitive market using genetic algorithm

As mobile communication market grows rapidly, in Korea, competitive strategies in mobile phone manufacturers are crucial. However, the way the mobile phone manufacturers adopt a pricing policy is not flexible enough to maximize the profit under the competitive environment. In this paper, we derive a dynamic pricing model for considering the price change of product itself but also the relative price change of competing products. Scenario analysis is performed to find optimal pricing policy based on genetic algorithm. Our proposed model is expected to provide adaptable pricing policy in a competitive market for a mobile phone set.     

Duration of stay based weighted scheduling framework for mobile phone sensor data collection in opportunistic crowd sensing

Advancement of mobile phone based new sensing paradigm like opportunistic and participatory crowd sensing has lead to increase in both multimedia and scalar sensor data traffic over wireless networks. In opportunistic crowd sensing, there are more chances of missing required mobile phones sensor data due to unpredictable mobility nature of users. Analysis of scheduling schemes under realistic human mobility models has become an important issue for pervasive sensing applications specifically for mobile phone based crowd sensing. This paper refers to a weighted scheduling framework for collecting mobile phone sensor data under Levy Walk mobility model. The proposed method uses duration of stay of mobile phone users as one of the important parameter to improve the scheduling performance in terms of reducing the rate of missing of mobile nodes and thereby increasing the rate of collection of required sensor data. The simulation results show that for improving the scheduling performance in opportunistic crowd sensing, high weight value should be given for duration of stay parameter, when mobile nodes stay within the data collection region for more than schedule iteration time with high probability.     

Reconstruction of human movement trajectories from large-scale low-frequency mobile phone data

Understanding human mobility is significant in many fields, such as geography, transportation, and sociology. Due to the wide spatiotemporal coverage and low operational cost, mobile phone data have been recognized as a major resource for human mobility research. However, due to conflicts between the data sparsity problem of mobile phone data and the requirement of fine-scale solutions, trajectory reconstruction is of considerable importance. Although there have been initial studies on this problem, existing methods rarely consider the effect of similarities among individuals and the patterns of missing data. To address this issue, we propose a multi-criteria data partitioning trajectory reconstruction (MDP-TR) method for large-scale mobile phone data. In the proposed method, a multi-criteria data partitioning (MDP) technique is used to measure the similarity among individuals in near real-time and investigate the spatiotemporal patterns of missing data. With this technique, the trajectory reconstruction from mobile phone data is then conducted with machine learning models. We verified the method using a real mobile phone dataset in a large city. Results indicate that the MDP-TR method outperforms competing methods in both accuracy and robustness. We argue that the MDP-TR method can be effectively utilized for grasping highly dynamic human movement status and improving the spatiotemporal resolution of human mobility research.     

一个面向智能电话的移动可信平台设计

由于手机病毒或设备失窃,导致手机上的私密数据面临泄漏的危险。为了满足移动平台的安全需求,TCG的MPWG提出移动可信平台规范。然而MPWG并没有明确规定特定的技术方法来实现移动可信模块(MTM),现有研究中没有整体的可实际部署于智能手机环境的MTM平台框架性设计,对可信软件栈(TSS)也没有可以实施的详细的部署方案。设计了一个面向智能手机的移动可信平台服务模型,它将基于TrustZone的纯软件MTM实现与基于Java Card的智能卡MTM实现结合起来构建两个可信引擎。提出其中可信构建块的部署流程并对其安全性进行了分析。     

Behavior-Based Intrusion Detection in Mobile Phone Systems

The field of mobile and wireless networking is reemerging amid unprecedented growth in the scale and diversity of computer networking. However, further increases in network security are necessary before the promise of mobile communication can be fulfilled. In this paper, we describe how neural networks and tools can be applied against frauds in analog mobile telecommunication networks. To the best of our knowledge there has been a lot of work done to secure the usage of mobile phones at the hardware level, but very little at the software level. In this paper, we present an on-line security system for fraud detection of impostors and improper use of mobile phone operations based on a neural network (NN) classifier. It acts solely on the recent information and past history of the mobile phone owner activities, and classifies the telephone users into classes according to their usage logs. Such logs contain the relevant characteristics for every call made by the user. As soon as the system identifies a fraud, it notifies both the carrier telecom and the victim about it immediately and not at the end of the monthly bill cycle. In our implementation, we make use of the radial basis function (RBF) model because of its simplicity and its flexibility to adapt to pattern changes, i.e., it encompasses the important characteristic of learning. By learning, a RBF NN can discover some regular patterns and the relation across them, and organize itself for making these associations. As a consequence it is widely used for solving classification and pattern recognition problems. Our results indicate that our system reduces significantly the telecom carriers's profit losses as well as the damage that might be passed to the clients. This might help the carriers to reduce the cost of phone calls and will, in turn, benefit the users.     

Planners, navigators, and pragmatists: collaborative wayfinding using a single mobile phone

Shared use of mobile devices is increasingly prevalent in both research prototypes and in practice, however, little is known as to how to support best this interaction paradigm. In this paper, we present a study examining how pairs share a single mobile phone during a collaborative wayfinding activity. We provide a classification of strategies, role relationships and phone interactions employed to conduct the wayfinding activities in our study. While acknowledging that the factors determining how the phone was shared are nuanced and intertwined, our results illustrate how differences in the mobile application’s interface influenced shared use, wayfinding strategy and outcome.

基于J2ME平台的手机实时监视系统的设计

随着3G时代的逐步到来,集办公、娱乐、通讯等多功能于一体的智能化手机已成为各移动设备开发商的开发热点。J2ME(Java 2 Mobile Edition)平台被认为是最杰出的手机程序开发平台,J2ME应用程序可运行在不同制造商的不同设备上,真正体现了Sun公司所倡导的"write once,run anywhere"。讨论了在Windows下的J2ME开发环境下的手机(或PDA等手持移动设备)实时监视系统问题,设计并实现了对远程计算机的实时监视。     

手机仿真取证系统浅析——Android系统仿真实战

随着各种手机的推广,手机应用程序的极大丰富,在实际取证工作中,我们经常会遇到对各种手机的应用程序取证,而现有对手机应用程序的分析技术刚刚起步,要实现对大部分应用程序使用痕迹的取证需要一段较长的时间。如何快速对手机应用程序进行取证成为取证工作的一个重要。因此本文提出了一个手机仿真取证系统的解决方案,并以Android系统为例进行介绍。     

基于J2ME的手机掼蛋网络游戏的研究

随着3G时代的到来,以及手机性能的不断提高,手机娱乐休闲的功能日益彰显。使用J2ME作为手机网络游戏的开发平台,结合Servlet技术构建手机掼蛋网络对战游戏,利用多线程实现手机客户端随机接收服务器消息。为了让玩家按服务器发送的顺序接收消息,采用队列进行存储,使消息按队列先进先出顺序供客户端接收。通过实验模拟,达到了设计的效果。     

Investigating Modern‐Day Talaria: Mobile Phones and the Mobility‐Impaired in Singapore

Revisiting the medical and social models of disability, this study adopted the integrated biopsychosocial approach to examine experiences of 25 mobility‐impaired respondents in Singapore with using mobile phones. We found that mobile phones provided respondents a greater degree of mobility, a sense of control, and opportunities to escape the stigma of disability, thus challenging the boundaries between the able‐bodied and the disabled. Mobile phone appropriation allowed the management of personal identities and social networks, leading to a sense of empowerment. However, mobile phone usage might act as a double‐edged sword for disabled people, creating mobile dependencies and a spatial narrowing of social connections. Theoretical and practical implications are discussed.     

Multivariate context collection in mobile sensor networks

We focus on the treatment of quality-stamped contextual information in mobile sensor networks. Sensing nodes capture and forward context for consumption by mobile context aware applications. Due to the dynamic network topology the quality indicators seen by consumers vary over time. Context quality is a decreasing function of time and context can be consumed with a certain delay from its capturing time. We propose the sequential assessment of the network-circulated context information according to the Generalized Secretary Problem, a known paradigm in the Optimal Stopping Theory. The consumer node delays the processing (consumption) of incoming context until better quality is attained. We extend this basic model to include the cardinality of contextual components (i.e., different types of measurements coming from, possibly, different sources). Hence, the consumer node is interested not only in the higher possible quality of context but also in the widest possible range of context parameters (context “quantity”). We compare our findings to simple consumption strategies and pinpoint the advantages of the proposed model.     

基于手机的取证调查模型研究

给出了手机取证的概念,并与计算机取证进行了比较,分析了手机取证和计算机取证的差异。结合手机取证的特点和难点,提出了基于手机的取证调查模型,分析了模型中各个阶段的具体活动。该模型对取证人员具有一定的指导意义。