MViewer: mobile phone spatiotemporal data viewer

Nowadays movement patterns and people’s behavioral models are needed for traffic engineers and city planners. These observations could be used to reason about mobility and its sustainability and to support decision makers with reliable information. The very same knowledge about human diaspora and behavior extracted from these data is also valuable to the urban planner, so as to localize new services, organize logistics systems and to detect changes as they occur in the movement behavior. Moreover, it is interesting to investigate movement in places like a shopping area or a working district either for commercial purposes or for improving the service quality. These kinds of tracking data are made available by wireless and mobile communication technologies. It is now possible to record and collect a large amount of mobile phone calls in a city. Technologies for object tracking have recently become affordable and reliable and hence we were able to collect mobile phone data from a city in China from January 1, 2008 to December 31, 2008. The large amount of phone call records from mobile operators can be considered as life mates and sensors of persons to inform howmany people are present in any given area and how many are entering or leaving. Each phone call record usually contains the caller and callee IDs, date and time, and the base station where the phone calls are made. As mobile phones are widely used in our daily life, many human behaviors can be revealed by analyzing mobile phone data. Through mobile phones, we can learn the information about locations, communications between mobile phone users during their daily lives. In this work, we propose a comprehensive visual analysis system named as MViewer, Mobile phone spatiotemporal data Viewer, which is the first system to visualize and analyze the population’smobility patterns from millions of phone call records. Our system consists of three major components: 1) visual analysis of user groups in a base station; 2) visual analysis of the mobility patterns on different user groups making phone calls in certain base stations; 3) visual analysis of handoff phone call records. Some well-established visualization techniques such as parallel coordinates and pixelbased representations have been integrated into our system. We also develop a novel visualization schemes, Voronoidiagram-based visual encoding to reveal the unique features of mobile phone data. We have applied our system to real mobile phone datasets that are kindly provided by our project partners and obtained some interesting findings regarding people’s mobility patterns.     

Context Awareness and Mobile Phones

This paper investigates some aspects of how context-awareness can support users of mobile phones, in particular the calling party. The use of mobile and stationary phones is discussed in relation to situational properties of a phone conversation, especially with regards to who might benefit from context-awareness in this context. An initial hypothesis is that mobile phone users communicate context information to each other (verbally) to a much higher degree than do stationary phone users. Mobile phone users could benefit much from context awareness technology, in particular when about to make a call, if they can receive context information regarding the person they are trying to reach prior to establishing the call. We argue that such technology should require low amounts of explicit user interaction, and could lead to less disrupting calls in inappropriate moments, as well as less frustration for the calling party when a call is not answered.     

基于应用分类和系统调用的Android恶意程序检测

针对Android平台恶意程序泛滥的问题,提出一种基于应用分类和系统调用的恶意程序检测方法。以Google Play为依据进行应用程序分类,利用运行时产生的系统调用频数计算每个类别的系统调用使用阈值。当应用程序安装运行时,手机端收集应用程序权限信息和产生的系统调用信息发给远程服务器,远程服务器根据权限信息采用序列最小优化算法给应用程序进行分类,分类后利用系统调用频数计算出系统调用使用值,与该类别的阈值进行比较判断是否恶意程序,将分类结果及判定结果反馈给用户,由用户判断是否需要更改分类重新检测。实验结果表明了该方法的可行性和有效性,不仅减少了手机的资源消耗,又能对产生恶意行为的应用程序及时做出反应。     

Worth-centred mobile phone design for older users

The twenty-first century society fights against an inherent tendency to over-classify and label people. In the case of the aged, despite all efforts, the perception of the helpless, feeble older person still prevails. The truth of the matter is that people over sixty often do not fit this profile. The aged are a heterogeneous group with varying different skills and abilities in many different areas. This paper challenges prevalent mobile phone design decisions that appear to have been made based on the erroneous pre-conception of the incapable elder. Designers currently produce “senior” mobile phones that are, at best, inadequate and, at worst, insulting to a sector of society that deserves respect and consideration. Age does indeed influence mobile phone usage, and people over sixty often have specific and special needs, quite apart from age-related limitations, that predict their use of mobile phones. Most mobile phones designed for older users simply reduce the number of features: the so-called simplification approach. Apart from reducing the effectiveness of the phone, this approach often incorporates the fatal design flaw of using numbers or letters, on speed-dial buttons, which requires the user to remember the button–person mappings. In fact, this design rationale reduces the value of the phone to the user. This paper argues that mobile phone design for older users should be worth-centred (Cockton G in Designing worth is worth designing. In: Proceedings of the 4th Nordic conference on human–computer interaction: changing roles. Oslo, Norway, pp 165–174, 2006) rather than simplification-driven. The worth-centred approach maximises worth to the user of the phone. This is achieved by maximising effectiveness while accommodating reduced capabilities. To maximise ease of use, and consequent accessibility, features may have to be reduced in an informed way. To facilitate this, a mapping process is proposed whereby user needs are linked to uses of the phone, and then to the features that facilitate these uses. Needs fall into a number of categories, and each category is characterised by a number of different uses, which form a usage space. Features can be linked to one or more usage spaces, and thus be used to support needs. The first step in the conducted research entailed the identification of the needs of the older mobile phone user. Then, it was determined whether these needs were indeed being met by the uses afforded in existing phones. Having concluded that most users’ needs were not being met, the next step was to capture data on the needs, limitations and expectations of people over the age of sixty. This was achieved by conducting a series of one-to-one interviews with a number of older mobile phone users and also supervising a participatory design experiment. Using the findings of the analysis, a usage space model is proposed, which serves to align feature inclusion with user needs. Based on this usage space model (the theoretical contribution), a prototype mobile phone design is presented as the practical contribution of the paper.     

一种新的基于指纹与移动端协助的口令认证方法

智能手机和互联网应用的广泛普及,使用户可以借助手机结合口令与服务器认证.然而现有的方案需要在手机端存储用户的秘密信息.一旦存于手机的秘密信息被对手获得,将给用户带来不可挽回的损失.针对上述问题,提出了一种基于指纹和口令的认证方案,手机端无需存储秘密信息.其核心思想是,将密文存储在服务器端,用户登录时利用手机辅助其生成私钥,从而对注册阶段生成的密文解密生成认证密钥.生成私钥的过程需要输入口令和指纹,用户在电脑端输入口令后对口令进行盲化再与手机进行交互,这样就可以保护用户口令不被对手得到.理论分析及实验结果表明：该方案提高了用户秘密信息的安全性,可以抵御对手的字典攻击、重放攻击和钓鱼攻击,减少了手机的存储压力,易于部署.     

Context-Aware telephony over WAP

In this paper we introduce a novel approach to sharing context in order to enhance the social quality of remote mobile communication. We provide an analysis of how people start a conversation in situations where they meet physically, especially looking at the influence of the situation. This is then compared to the way remote communication is initiated using mobile phones. The lack of knowledge about the situation at the other end leads to the initiation of calls which are not appropriate to that situation. The solution we propose is to exchange context information before initiating the call. We implemented this concept using the Wireless Application Protocol (WAP). The application Context-Call offers a phone interface that provides information about the receiver when setting up a call. Based on that information, the caller can then decide to place the call, to leave a message or to cancel the call. Privacy issues that arise from this technology are discussed also.     

基于云安全的骚扰电话过滤系统研究

智能手机用户对通信安全的需求日益增加,本文研究目前骚扰电话过滤系统现状,提出一种基于云安全技术的设计方案,对其中的技术做了深入的研究。该系统将过滤服务器集群和大量手机整合到一个云安全体系中,实现对骚扰电话的快速和有效过滤。     

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.     

You never call: Demoting unused contacts on mobile phones using DMTR

Throughout their lives, people gather contacts on their mobile phones. Some of these are unused contacts—contacts that have not been used for a long time and are less likely to be used in future calls. These contacts compete for the users’ attention and the mobile phone’s limited screen capacity. To address this problem, we developed a prototype contact list interface called DMTR, which automatically demotes unused contacts by presenting them in a smaller font at the bottom of the contact list. In phase I of this research, we asked 18 participants to assess for how long they had not used each of their mobile phone contacts. Results show that 47% of all their contacts had not been used for over 6?months or had never been used at all. In phase II, we demoted these unused contacts using DMTR and asked our participants to locate contacts that they had recently used, with and without the prototype. Results indicate that the use of DMTR reduced both the number of key strokes and the retrieval time significantly. The majority of participants indicated that it was easier for them to access their contacts using DMTR and that they would like to use it in their next mobile phone. The results provide strong evidence for the demotion principle suggested by the user-subjective approach.     

Personality and self reported mobile phone use

As the mobile phone supports interpersonal interaction, mobile phone use might be a function of personality. This study sought to predict amounts and types of mobile phone use from extraversion, agreeableness, conscientiousness, neuroticism and self-esteem. One hundred and twelve mobile phone owners reported on their use of their mobile phones, and completed the NEO-FFI and the Coopersmith self-esteem inventory. Extraverts reported spending more time calling, and changing ring tone and wallpaper, implying the use of the mobile phone as a means of stimulation. Extraverts and perhaps disagreeable individuals were less likely to value incoming calls. Disagreeable extraverts also reported using the mobile phone more, and spent more time adjusting ringtone/wallpaper. The neurotic, disagreeable, unconscientious and extroverted spent more time messaging using SMS. This study concludes that psychological theory can explain patterns of mobile phone use.     

A model of the relationship between psychological characteristics,mobile phone addiction and use of mobile phones by Taiwanese university female students

While many researches have analyzed the psychological antecedents of mobile phone addiction and mobile phone usage behavior, their relationship with psychological characteristics remains mixed. We investigated the relationship between psychological characteristics, mobile phone addiction and use of mobile phones for 269 Taiwanese female university students who were administered Rosenberg’s self-esteem scale, Lai’s personality inventory, and a mobile phone usage questionnaire and mobile phone addiction scale. The result showing that: (1) social extraversion and anxiety have positive effects on mobile phone addiction, and self-esteem has negative effects on mobile phone addiction. (2) Mobile phone addiction has a positive predictive effect on mobile phone usage behavior. The results of this study identify personal psychological characteristics of Taiwanese female university students which can significantly predict mobile phone addiction; female university students with mobile phone addiction will make more phone calls and send more text messages. These results are discussed and suggestions for future research for school and university students are provided.     

Human–battery interaction on mobile phones

Mobile phone users have to deal with limited battery lifetime through a reciprocal process we call human–battery interaction. We conducted three user studies in order to understand human–battery interaction and discover the problems in existing designs that prevent users from effectively dealing with the limited battery lifetime. The studies include a large-scale international survey, two long-term field trials including quantitative battery logging and qualitative inquiries, and structured interviews with twenty additional mobile phone users. We evaluated various aspects of human–battery interaction, including charging behavior, battery indicators, user interfaces for power-saving settings, user knowledge, and user reaction. We find that mobile phone users can be categorized into two types regarding human–battery interaction and often have inadequate knowledge regarding phone power characteristics. We provide qualitative and quantitative evidence that problems in state-of-the-art user interfaces have led to under-utilized power-saving settings, under-utilized battery energy, and dissatisfied users. Our findings provide insights into improving mobile phone design for users to effectively deal with the limited battery lifetime. Our work is the first to systematically address human–battery interaction on mobile phones and is complementary to the extensive research on energy-efficient design for a longer battery lifetime.     

Hybrid recommendations for mobile commerce based on mobile phone features

Mobile data communications have evolved as the number of third generation (3G) subscribers has increased. The evolution has triggered an increase in the use of mobile devices, such as mobile phones, to conduct mobile commerce and mobile shopping on the mobile web. There are fewer products to browse on the mobile web; hence, one‐to‐one marketing with product recommendations is important. Typical collaborative filtering (CF) recommendation systems make recommendations to potential customers based on the purchase behaviour of customers with similar preferences. However, this method may suffer from the so‐called sparsity problem, which means there may not be sufficient similar users because the user‐item rating matrix is sparse. In mobile shopping environments, the features of users' mobile phones provide different functionalities for using mobile services; thus, the features may be used to identify users with similar purchase behaviour. In this paper, we propose a mobile phone feature (MPF)‐based hybrid method to resolve the sparsity issue of the typical CF method in mobile environments. We use the features of mobile phones to identify users' characteristics and then cluster users into groups with similar interests. The hybrid method combines the MPF‐based method and a preference‐based method that uses association rule mining to extract recommendation rules from user groups and make recommendations. Our experiment results show that the proposed hybrid method performs better than other recommendation methods.     

A regression-based approach for mining user movement patterns from random sample data

Mobile computing systems usually express a user movement trajectory as a sequence of areas that capture the user movement trace. Given a set of user movement trajectories, user movement patterns refer to the sequences of areas through which a user frequently travels. In an attempt to obtain user movement patterns for mobile applications, prior studies explore the problem of mining user movement patterns from the movement logs of mobile users. These movement logs generate a data record whenever a mobile user crosses base station coverage areas. However, this type of movement log does not exist in the system and thus generates extra overheads. By exploiting an existing log, namely, call detail records, this article proposes a Regression-based approach for mining User Movement Patterns (abbreviated as RUMP). This approach views call detail records as random sample trajectory data, and thus, user movement patterns are represented as movement functions in this article. We propose algorithm LS (standing for Large Sequence) to extract the call detail records that capture frequent user movement behaviors. By exploring the spatio-temporal locality of continuous movements (i.e., a mobile user is likely to be in nearby areas if the time interval between consecutive calls is small), we develop algorithm TC (standing for Time Clustering) to cluster call detail records. Then, by utilizing regression analysis, we develop algorithm MF (standing for Movement Function) to derive movement functions. Experimental studies involving both synthetic and real datasets show that RUMP is able to derive user movement functions close to the frequent movement behaviors of mobile users.     

Comparative studies of perceived vibration strength for commercial mobile phones

A mobile phone, also known as cell phone or hand phone, is among the most popular electrical devices used by people all over the world. The present study examines the vibration perception of mobile phones by co-relating the relevant design parameters such as excitation frequency, and size and mass of mobile phones to the vibration perception survey by volunteers. Five popular commercially available mobile phone models were tested. The main findings for the perception surveys were that higher vibration frequency and amplitude of the peak acceleration would result in stronger vibration perception of the mobile phones. A larger contact surface area with the palms and figures, higher peak acceleration and the associated larger peak inertia force may be the main factors for the relatively higher vibration perception. The future design for the vibration alert of the mobile phones is likely to follow this trend.     

Predictive text entry methods for mobile phones

Mobile phone networks are increasingly supporting the transmission of textual messages between mobile phones and between mobile phones and other services. This paper describes the current text entry method on mobile phones and describes a new text entry method using a single key-press per letter together with a large dictionary of words for disambiguation. This approach, which is similar to technology recently licensed, independently, to several phone companies, is then extended with automatic word completion. The paper reports the results of initial user tests comparing the text entry methods, analysis of word clashes with the dictionary-based methods and keystroke level modelling of the different input methods.     

Personalized blog content recommender system for mobile phone users

Compared to newspaper columnists and broadcast media commentators, bloggers do not have organizations actively promoting their content to users; instead, they rely on word-of-mouth or casual visits by web surfers. We believe the WAP Push service feature of mobile phones can help bridge the gap between internet and mobile services, and expand the number of potential blog readers. Since mobile phone screen size is very limited, content providers must be familiar with individual user preferences in order to recommend content that matches narrowly defined personal interests. To help identify popular blog topics, we have created (a) an information retrieval process that clusters blogs into groups based on keyword analyses, and (b) a mobile content recommender system (M-CRS) for calculating user preferences for new blog documents. Here we describe results from a case study involving 20,000 mobile phone users in which we examined the effects of personalized content recommendations. Browsing habits and user histories were recorded and analyzed to determine individual preferences for making content recommendations via the WAP Push feature. The evaluation results of our recommender system indicate significant increases in both blog-related push service click rates and user time spent reading personalized web pages. The process used in this study supports accurate recommendations of personalized mobile content according to user interests. This approach can be applied to other embedded systems with device limitations, since document subject lines are elaborated and more attractive to intended users.     

User interface guidelines for the control of interactive television systems via smart phone applications

There are a growing number of smart phone applications allowing the user to control their television, set-top box or other entertainment devices. The success of these applications is limited. Based on findings from media studies in Austria and France focusing on how people currently use their TV and iTV systems and associated devices, this article describes recommendations for the design of a smart phone application enabling users to control Internet Protocol Television (IPTV) systems including all connected entertainment devices. Recommendations include the need to allow users to control devices that are related to the IPTV experience (not only the set-top box or television set) and the focus on scenarios of usage like supporting listening to music, enjoying a movie or controlling the connected home. Based on similarities and differences found in the two samples, future smart phone applications for controlling TV will only succeed if they provide meaningful functionalities that satisfy the (varying) user needs, support personalisation and personal usage and respect the limitations of mobile phones with respect to possible parallel activities performed.     

From the private into the public: privacy-respecting mobile interaction techniques for sharing data on surfaces

Interactive horizontal surfaces provide large semi-public or public displays for colocated collaboration. In many cases, users want to show, discuss, and copy personal information or media, which are typically stored on their mobile phones, on such a surface. This paper presents three novel direct interaction techniques (Select&Place2Share, Select&Touch2Share, and Shield&Share) that allow users to select in private which information they want to share on the surface. All techniques are based on physical contact between mobile phone and surface. Users touch the surface with their phone or place it on the surface to determine the location for information or media to be shared. We compared these three techniques with the most frequently reported approach that immediately shows all media files on the table after placing the phone on a shared surface. The results of our user study show that such privacy-preserving techniques are considered as crucial in this context and highlight in particular the advantages of Select&Place2Share and Select&Touch2Share in terms of user preferences, task load, and task completion time.     

Dynamic RAT selection for multiple calls in heterogeneous wireless networks using group decision-making technique

Existing radio access technology (RAT)-selection algorithms for heterogeneous wireless networks (HWNs) do not consider the problem of RAT selection for a group of calls from a multimode terminal (MT). Multimode terminals (MTs) for next generation wireless networks have the capability to support two or more classes of calls simultaneously. When a new call is initiated on an MT already having an ongoing call in an HWN, the current RAT may no longer be suitable for the two calls (incoming call and the existing call). Thus, a new RAT may be more suitable for the two calls. The problem of RAT selection for two or more calls from an MT in an HWN is a group decision problem. This paper addresses the problem of RAT selection for a group of calls from an MT in an HWN by using the modified TOPSIS group decision-making technique. The paper proposes a dynamic RAT-selection algorithm that selects the most suitable RAT for a single call or group of calls from an MT in an HWN. The algorithm considers users’ preferences for individual RATs, which vary with each class of calls, in making RAT selection decisions in an HWN. A user’s preference for each of the available RATs is specified by weights assigned by the user to RAT selection criteria for different classes of calls. Based on the assigned weights, the proposed algorithm aggregates individual calls’ weights specified by the user to make a RAT-selection decision for a group of calls. In order to reduce the frequency of vertical handover, the proposed algorithm uses RAT preference margin in making RAT selection decisions. RAT preference margin is a measure of the degree to which the newly preferred RAT is better than the current RAT. Performance of the proposed algorithm is evaluated through numerical simulations. Results are given to show the effectiveness of the proposed RAT-selection algorithm.