J2MEMicroDB: a new Open Source lightweight database engine for J2ME mobile devices

J2ME is the development platform for mobile devices with larger support and availability in the market right now. Due to the minimalist definition of this architecture it does include neither API’s for data persistence management, like object serialization, and relational database access nor standard APIs to access a remote host. This paper presents J2MEMicroDB, an Open Source software that implements object serialization, a local relational database engine on the mobile device and a remote database access protocol that allows access to any JDBC database. In the design and implementation of J2MEMicroDB specific requirements and limitation of mobile devices have been considered. Even some performance improvements have been developed, like BTree indexing structures which improves significantly the efficiency of the searches, as the presented cross-platform benchmarking proves.     

Comparison of XML serializations: cost benefits versus complexity

More and more data are structured, stored, and sent over a network using the Extensible Markup Language (XML) language. There are, however, concerns about the verbosity of XML in such a way that it may restrain further adoption of the language, especially when exchanging XML-based data over heterogeneous networks, and when it is used within constrained (mobile) devices. Therefore, alternative (binary) serialization formats of the XML data become relevant in order to reduce this overhead. However, usingbinary-encoded XML should not introduce interoperability issues with existing applications nor add additional complexity to new applications. On top of that, it should have a clear cost reduction over the current plain-text serialization format. A first technology is developed within the ISO/IEC Moving Picture Experts Group, namely the Binary MPEG Format for XML. It provides good compression efficiency, ability to (partially) update existing XML trees, and facilitates random access into, and manipulation of, the binary-encoded bit stream. Another technique is based on the Abstract Syntax Notation One specification with the Packed Encoding Rules created by the ITU-T. This paper evaluates both techniques as alternative XML serialization formats and introduces a solution for the interoperability concerns. This solution and the alternative serialization formats are validated against two real-life use cases in terms of processing speed and cost reduction. The efficiency of the alternative serialization formats are compared to a classic plain text compression technique, in particular ZIP compression.     

An XML-based methodology for parametric temporal database model implementation

Parametric data model is one of dimensional data models. It defines attributes as functions, modeling a real world object into a single tuple in a database. Such one-to-one correspondence between an object in the real world and a tuple provides various advantages in modeling dimensional data, avoiding self-joins which frequently appear in temporal data models which fragment an object into multiple tuples. Despite its modeling advantages, it is impractical to implement the parametric data model on top of conventional database systems because of the data model’s variable attribute sizes. However, such implementation challenge can be resolved by XML because XML is flexible for data boundaries. In this paper, we present an XML-based implementation methodology for the parametric temporal data model. In our implementation, we develop our own XML storage called CanStoreX (Canonical Storage for XML) and build the temporal database system on top of the CanStoreX.     

A flexible communications protocol for a distributed surveillance system

On-line surveillance for safety and security is a major requirement of public transport and other public places to address the modern demands of mobility in major urban areas and to effect improvements in quality of life and environment protection. The surveillance task is a complex one involving technology, management procedures and people. Visual surveillance based on Closed Circuit Television system is an important part of such systems, but visual processing is not sufficient and the geographical distribution of devices and management has to be taken into account. In this paper we present a surveillance architecture that reflects the distributed nature of the monitoring task and allows for distributed detection processes, not only dealing with visual processing but also with devices such as acoustic signature detection and mobile smart cards, actuators and a range of other possible sensors. The design uses ideas from control engineering and distributed communications networks resulting in a communications architecture based on CORBA and XML messaging. We have shown how to define a generic device/sensor model appropriate for the surveillance task and sufficiently flexible so as to allow for scalability, expansion and customisation of a practical surveillance task. The paper gives sufficient details on the protocols to show how intelligent detection modules can be integrated as part of this kind of system. The system components have been implemented and integrated in two major successful trials in metropolitan railway stations in London and in Paris, as part of a major EU-funded project (PRISMATICA).     

Personalised code generation from large schema sets for geospatial mobile applications

XML and XML Schema are used in the geospatial domain for the definition of standards that enhance the interoperability between producers and consumers of spatial data. The size and complexity of these geospatial standards and their associated schemas have been growing with time reaching levels of complexity that make it difficult to build systems based on them in a timely and cost-effective manner. The problem of producing XML processing code based on large schemas has been traditionally solved by using XML data binding generators. Unfortunately, this solution is not always effective when code is generated for resource-constrained devices, such as mobile phones. Large and complex schemas often result in the production of code with a large size and a complicated structure that might not fit the device limitations. In this article we present the instance-based XML data binding approach to produce more compact application-specific XML processing code for geospatial applications targeted to mobile devices. The approach tries to reduce the size and complexity of the generated code by using information about how schemas are used by individual applications. Our experimental results suggest a significant simplification of XML Schema sets to the real needs of client applications accompanied by a substantial reduction of size of the generated code.     

Query processing optimization in broadcasting XML data in mobile communications

Todays, XML as a de facto standard is used to broadcast data over mobile wireless networks. In these networks, mobile clients send their XML queries over a wireless broadcast channel and recieve their desired XML data from the channel. However, downloading the whole XML data by a mobile device is a challenge since the mobile devices used by clients are small battery powered devices with limited resources. To meet this challenge, the XML data should be indexed in such a way that the desired XML data can be found easily and only such data can be downloaded instead of the whole XML data by the mobile clients. Several indexing methods are proposed to selectively access the XML data over an XML stream. However, the existing indexing methods cause an increase in the size of XML stream by including some extra information over the XML stream. In this paper, a new XML stream structure is proposed to disseminate the XML data over a broadcast channel by grouping and summarizing the structural information of XML nodes. By summarizing such information, the size of XML stream can be reduced and therefore, the latency of retrieving the desired XML data over a wirless broadcast channel can be reduced. The proposed XML stream structure also contains indexes in order to skip from the irrelevant parts over the XML stream. It therefore can reduce the energy consumption of mobile devices in downloading the results of XML queries. In addition, our proposed XML stream structure can process different types of XML queries and experimental results showed that it improves the performace of XML query processing over the XML data stream compared to the existing research works in terms of access and tuning times.

     

Take your mobile device out from behind the requirements desk

Mobile computing devices are everywhere. Recent technological improvements let most wireless devices connect to the Internet and many Web services. This presents exciting new opportunities for requirements analysts. Shouldn't we be able to capture requirements anywhere, anytime using our mobile devices? Why not capture requirements on your mobile telephone and then phone them in? You can do a lot of neat things with mobile devices in your requirements process. Some of these ideas draw on and demonstrate research that we've undertaken when implementing several requirements applications on mobile devices.     

基于移动增强现实的地震科普馆导览系统

增强现实技术是一种将虚拟信息无缝融合到真实世界的新技术,近年来受到国内外研究者的广泛关注。随着便携性、智能化移动设备的快速发展,增强现实技术越来越多地应用到移动设备上,具有很好的发展前景。以识别特定标志物为目的,研究并实现了一个基于移动增强现实的地震科普馆导览系统。利用Wi-Fi定位和图像处理对标志物进行检测识别;利用标志物的四个顶点,通过确定坐标系之间的变换关系,计算摄像机位姿,实现摄像机跟踪定位;通过坐标系之间的变换,确定虚拟信息在成像平面上的位置,实现虚拟信息的注册。测试结果表明,该系统能够实现地震科普馆导览功能,达到了预期的研究目标。     

Design and Implementation of a PKI-Based End-to-End Secure Infrastructure for Mobile E-Commerce

The popularity of handheld mobile devices and deployment of the public key infrastructure in many parts of the world have led to the development of electronic commerce on mobile devices. For the current version of mobile phones, the main challenge is the limited computing capacity on these devices for PKI-based end-to-end secure transactions. This paper presents a new architecture and protocol for authentication and key exchange as well as the supporting infrastructure that is suitable for the mobile phone environment. The system requirements and our solutions in addressing these requirements in the restrictive environment are discussed. An evaluation of the system performance is also included. The system has been implemented and is supporting some real-life applications.     

基于移动设备的三维产品展示系统研究与实现

对如何在J2ME 平台上实现基于移动设备的三维产品信息展示系统进行了阐述,系统有效地利用 XML格式表示产品信息,并在客户端使用KXML进行解析,实现了移动设备与服务器Servlet的数据通信,实现了M3G格式的三维模型在移动设备上的展示,并提供了用户与系统的交互操作功能.在一定程度上满足了用户利用手机、PDA等移动设备,及时获得企业相关产品的信息和三维模型展示结果的实际需求.     

XML在移动电子商务中的应用

随着移动电子商务的发展,用户对于通过移动终端设备进行网上商务活动的需求越来越强烈,要求也越来越高.在XML流行于Internet的今天,为了方便移动终端同Internet信息交互,描述了J2ME架构下采用XML作为消息格式绑定HTTP协议的网络访问模式,并且研究了它在具体移动电子商务系统中的实现情况.     

A secure energy-efficient m-banking application for mobile devices

Mobile banking is one of the emerging services in telecommunications due to the explosive increase in the number of mobile customers around the world. Solutions for mobile banking are varied, ranging from the use of Wireless Transport Layer Security, Security Socket Layer, or application-layer based options. Whereas security at the transport layer is a good choice for e-banking, using it in a mobile device presents several disadvantages such as high energy consumption. In this work, we present a secure energy-efficient m-banking solution for mobile devices. We propose an application-layer protocol whose message formats and message exchanges are designed to reduce time processing, bandwidth use, and energy consumption. Through experimentation, we demonstrate that our secure solution reduces power and energy consumption in more than 30% compared to a secure web-access from the mobile device.     

Your coffee shop doesn't use two-phase commit [asynchronous messaging architecture]

The real world is often asynchronous. Our daily lives consist of many coordinated but asynchronous interactions. This means that an asynchronous messaging architecture can often be a natural way to model these kinds of interactions. It also means that looking at daily life can help us solve our messaging problems. For example in this article we present how a coffee shop processes customer orders and compare it to the asynchronous processing model.     

XML数据绑定及对象序列化的应用研究

分析研究了JAVA序列化和XML数据绑定的技术，突出了XML数据绑定在大多数场合上的应用优势。并且在一个电子政务的项目中。实现了XML数据绑定的模型。     

Mobile Web services: a new agent-based framework

Mobile devices and server applications often run on different platforms, which can make integration problematic. Web services might offer a solution, but they typically include XML protocols that are too "heavy" for mobile devices. In this article, we describe agent-based mobile services framework. It uses wireless portal networks and eliminates XML processing on mobile clients. It also offers dynamic service selection and rapid application development and deployment for Web service providers.     

A mobile crowd sensing ecosystem enabled by CUPUS: Cloud-based publish/subscribe middleware for the Internet of Things

Mobile crowd sensing (MCS) is a novel class of mobile Internet of Things (IoT) applications for community sensing where sensors and mobile devices jointly collect and share data of interest to observe phenomena over a large geographic area. The inherent device mobility and high sensing frequency has the capacity to produce dense and rich spatiotemporal information about our environment, but also creates new challenges due to device dynamicity and energy constraints, as well as large volumes of generated raw sensor data which need to be processed and analyzed to extract useful information for end users. The paper presents an ecosystem for mobile crowd sensing which relies on the CloUd-based PUblish/Subscribe middleware (CUPUS) to acquire sensor data from mobile devices in a flexible and energy-efficient manner and to perform near real-time processing of Big Data streams. CUPUS has unique features compared to other MCS platforms: It enables management of mobile sensor resources within the cloud, supports filtering and aggregation of sensor data on mobile devices prior to its transmission into the cloud based on global data requirements, and can push information of interest from the cloud to user devices in near real-time. We present our experience with implementation and deployment of an MCS application for air quality monitoring built on top of the CUPUS middleware. Our experimental evaluation shows that CUPUS offers scalable processing performance, both on mobile devices and within the cloud, while its data propagation delay is mainly affected by transmission delay on wireless links.     

Implementing collaborative learning activities in the classroom supported by one-to-one mobile computing: A design-based process

Mobile devices such as PDAs, smartphones and tablet computers are becoming increasingly popular, setting out opportunities for new ways of communicating and collaborating. Research initiatives have ascertained the potential of mobile devices in education, and particularly, the benefits of incorporating them in the classroom for eliciting collaborative learning and active student participation. However, the development of technology-supported learning environments poses challenges to education researchers, practitioners, and software technologists in creating educational tools that respond to real needs of instructors and learners, meet clearly defined didactic purposes, and are practical for the intended audience. This article reports on a technology for facilitating the implementation of collaborative learning environments in the classroom supported by one-to-one mobile computing. The approach encompasses a framework supporting the design and implementation of the mobile software, and a design-based process that guides interdisciplinary efforts utilizing the framework, towards creating effective pedagogical models based on collaborative learning. The proposed design-based process allowed us to develop pedagogical models that respond to real needs of learners and instructors, where development is grounded on rigorous scientific research, allowing to reuse both knowledge and software, and showing an improvement of the mobile software built based on continuous experimentation and evaluation. A case study illustrating the application of the technology is presented and plans for future research are discussed.     

Group-Based Mobile Messaging in Support of the Social Side of Leisure

Communication on mobile devices plays an important role in people’s use of technology for leisure, but to date this communication has largely been one-to-one. Mobile internet connectivity can support a variety of group-based messaging and media sharing scenarios. Switching to group-based messaging should enhance the social and leisure aspects of the communication, but in what ways and to what extent? An experimental system for text and photo messaging on mobile devices was tested in a research deployment to four groups of 6–8 participants who used both a group-based and one-to-one version of the system. Results highlight a significant increase in message sending, in mobile device “fun”, and in the social qualities of mobile communication when messaging group-wide, along with a few minor costs. Qualitative feedback provides further explanation of the social benefits.     

The impact and implementation of XML on business-to-business commerce

This paper discusses the impact analysis of the Extensible Markup Language (XML). Each business partner within a supply chain will be allowed to generate its own data exchange format by adopting an XML meta-data management system in the local side. Followed after a brief introduction of the information technology for Business to Customer (B2C) and Business to Business (B2B) Electronic Commerce (EC), the impact of XML on the tomorrow business world is discussed. A real case study for impact analysis on information exchange platform, Microsoft's BizTalk platform which is actually an XML schema builder and the implementation of XML commerce application will provide an interest insight for users' future implementation.     

XML消息传递协议的分析与研究

在XML消息通信架构中，传递协议是其中的重要一环。本文在讨论了目前已有方案的可行之处和存在的问题后，提出了一种利用面向对象方法来构建模块化的传递协议，为面向复杂电子商务、电子银行应用的XML消息传递提供了一种有效可行的方法。