Robot teleoperation featuring commercially available wireless network cards

This article describes the design and development of a prototype system that allows real time operation of a teleoperated robot over a wireless link using off-the-shelf commercially available wireless network cards. The hardware architecture and the wireless network are described. Performance of the wireless link is evaluated for 802.11b, 802.11g, and MeshNetwork cards. The 802.11g card was found to be unsuitable for the application.     

Assisted teleoperation in changing environments with a mixture of virtual guides

Haptic guidance is a powerful technique to combine the strengths of humans and autonomous systems for teleoperation. The autonomous system can provide haptic cues to enable the operator to perform precise movements; the operator can interfere with the plan of the autonomous system leveraging his/her superior cognitive capabilities. However, providing haptic cues such that the individual strengths are not impaired is challenging because low forces provide little guidance, whereas strong forces can hinder the operator in realizing his/her plan. Based on variational inference, we learn a Gaussian mixture model (GMM) over trajectories to accomplish a given task. The learned GMM is used to construct a potential field which determines the haptic cues. The potential field smoothly changes during teleoperation based on our updated belief over the plans and their respective phases. Furthermore, new plans are learned online when the operator does not follow any of the proposed plans or after changes in the environment. User studies confirm that our framework helps users perform teleoperation tasks more accurately than without haptic cues and, in some cases, faster. Moreover, we demonstrate the use of our framework to help a subject teleoperate a 7 DoF manipulator in a pick-and-place task.     

Secured miniaturized system-in-package contactless and passive authentication devices featuring NFC

RFID/NFC technology is widely spread nowadays and applications can be found in our everyday life, for example, in payment, transportation, logistics, healthcare, and access control. State-of-the-art contactless and passive authentication solutions implement relatively large coils outside of the chip. Therefore, the minimum size is in the order of a few square centimeters, which limits their use for tagging of certain small-sized goods. On top of that, those miniaturized solutions which are available today provide only limited security measures.Here we introduce miniaturized system-in-package contactless authentication devices. This novel solution integrates Infineon Technologies’ CIPURSE^TMmove IC, which is a state-of-the-art security solution featuring an open security standard, into embedded Wafer Level Ball Grid Array (eWLB) packages, together with HF-antennas, ferrites, as well as discrete elements that improve HF-coupling characteristics.The presented devices provide better HF-coupling characteristics than Coil-on-Chip approaches, which also enable verification of authenticity of tagged products through NFC-enabled smart phones. Thanks to the miniaturized package sizes of 3 × 3 mm, integration into high-priced products, casings, consumable materials, etc., can be achieved in a discreet way. Furthermore, the integrated CIPURSE^TM chip enables not only the anti-counterfeiting use-case, but also micropayment, ticketing, access control, and password storage in a secured way. Therefore, this miniaturized contactless authentication solution will open up whole new fields of applications.     

Mobile agents in wireless devices

The networks that connect handheld wireless devices such as cell phones and PDAs suffer from low bandwidth and a high incidence of network errors. By employing mobile agents, such devices could provide a reliable technology for message transport over wireless links. Mobile agents are inherently distributed software entities that reduce the load on the network when they move. Mobile agents can be employed in wireless handheld devices in two ways: An agent platform could be installed on the device, enabling mobile agents to run directly on it, or devices could access and use remote mobile agents running on wired networks. Each approach is viable and has its own advantages and domain-specific applications. Some high-end devices would benefit from running a mobile agent platform that lets agents run locally, but this would not be beneficial to others because of processing power and memory constraints or for security reasons.     

Micro devices assembly using virtual environments

In this paper, the design and development of a physical and virtual environment to support assembly of micron sized devices is discussed. Micro assembly involves handling and assembling of micron sized parts (10⁻⁶ m). As manual assembly of micron-sized parts is difficult and tedious, the design of computer assisted micro-assembly techniques becomes crucial. An Integrated Physical and Virtual Reality (VR) environment has been created to aid in the assembly of such micro devices, which supports the establishment of an interface between a virtual and physical micro assembly work cell. The overall architecture and the various modules implemented in this environment are outlined in this paper.     

Thick clients for personal wireless devices

A thin-client approach to mobile computing pushes as many services as possible on a remote server. Technology trends indicate, however, that an easy route to improving thin-client functionality will be to add disk storage, RAM, and a more powerful CPU. Thus, thin clients will rapidly become multipurpose thick clients. With time, users may come to consider their mobile system as their primary general-purpose computing device, maintaining their most-used files on the mobile system and relying on their desktop systems primarily for larger displays, keyboards, and other nonmobile interfaces     

Adaptive data access in broadcast-based wireless environments

Power conservation and client waiting time reduction are two important aspects of data access efficiency in broadcast-based wireless communication systems. The intention of data access methods is to optimize client power consumption with the least possible overhead on client waiting time. We propose an adaptive data access method which builds on the strengths of indexing and hashing techniques. We show that this method exhibits better average performance over the well-known index tree-based access methods. A new performance model is also proposed. This model uses more realistic assessment criteria, based on the combination of access and tuning times, for evaluating wireless access methods. This new model provides a dynamic framework to express the degree of importance of access and tuning times in an application. Under this new model, the adaptive method performance also outperforms the other access methods in the majority of cases.     

Disseminating dependent data in wireless broadcast environments

In wireless mobile environments, data broadcasting is an effective approach to disseminate information to mobile clients. In some applications, the access pattern of all the data can be represented by a weighted DAG. In this paper, we explore how to efficiently generate the broadcast schedule in a wireless environment for the data set having a weighted DAG access pattern. Such a broadcast schedule not only minimizes the access latency but also is a topological ordering of the DAG. Minimized access latency ensures the quality of service (QoS). We prove that it is NP-hard to find an optimal broadcast schedule and provide some heuristics. After giving an analysis for these heuristics on the latency and complexity, we implement all the proposed heuristics to compare their performance. Recommended by: Sunil Prabhakar     

Web caching in broadcast mobile wireless environments

Effectively exploiting available communication bandwidth and client resources is vital in wireless mobile environments. One technique for doing so is client-side data caching, which helps reduce latency and conserve network resources. The SliCache generic self-tunable cache-replacement policy addresses these issues by using intelligent slicing of the cache space and novel methods for selecting which objects to purge. Performance evaluations show that SliCache improves mobile clients' access to Web objects compared to other common policies.     

无线传感器网络技术环境应用进展

随着时代的发展,无线传感器网络技术也迅速的被人们熟知与使用,已经成为了现在的一门主要应用技术.无线传感器网络技术的前身是遥感技术,也就是说无线传感器网络技术是由遥感技术发展而来的.本文主要对无线传感器技术在环境应用上的进展展开了简要的论述,希望可以对无线传感器网络技术在环境应用上起到促进的作用,推动相关事业的发展.     

Bringing the wireless Internet to mobile devices

Effectively mapping Internet content to mobile wireless devices requires not only new technologies and standards, but also innovative solutions that minimize cost and maximize efficiency to the benefit of both content providers and consumers. The wireless Internet must deliver information to handheld device users regardless of where they are and how they are connected, and in a suitable format - a challenge complicated by the dizzying array of devices, wireless standards and applications. Transcoding and the Relational Markup Language are promising middleware solutions to the problem of bringing Internet content to the extremely diverse and dynamic mobile wireless device universe     

Efficient validation of mobile transactions in wireless environments

In broadcast environments, the limited bandwidth of the upstream communication channel from the mobile clients to the server bars the application of conventional concurrency control protocols. In this paper, we propose a new variant of the optimistic concurrency control (OCC) protocol that is suitable for broadcast environments. At the server, forward validation of a transaction is done against currently running transactions, including mobile transactions and server transactions. At the mobile clients, partial backward validation of a transaction is done against committed transactions at the beginning of every broadcast cycle. Upon completion of execution, read-only mobile transactions can be validated and committed locally and update mobile transactions are sent to the server for final validation. These update transactions have a better chance of commitment because they have gone through the partial backward validation. In addition to the nice properties of conventional OCC protocols, this protocol provides autonomy between the mobile clients and the server with minimum upstream communication, which is a desirable feature to the scalability of applications running in broadcast environments. This protocol is able to process both update transactions and read-only transactions at the mobile clients at low space and processing overheads.     

Energy-aware distributed speech recognition for wireless mobile devices

Severe limitations in computational, memory, and energy resources make implementing high-quality speech recognition in embedded devices a difficult challenge. In this article, the authors investigate the energy consumption of computation and communication in an embedded distributed speech recognition system and propose optimizations that reduce overall energy consumption while maintaining adequate quality of service for the end user. This article considers the application of DSR traffic to both Bluetooth and 802.11b networks.     

移动平台的定制化位置隐私保护方案及实现

提出在为不同类别的用户提供个性化位置服务时兼顾位置服务与隐私保护的目的,当用户好友对用户进行定位时,系统将在服务器中查找用户对其好友的隐私策略分组,并得到对应的隐私开放类别,对用户的位置信息进行处理,从而实现个性化位置隐私保护的目标。方案已在IOS和Java环境下实现。     

An efficient nonuniform index in the wireless broadcast environments

Data broadcast is an efficient dissemination method to deliver information to mobile clients through the wireless channel. It allows a huge number of the mobile clients simultaneously access data in the wireless environments. In real-life applications, more popular data may be frequently accessed by clients than less popular ones. Under such scenarios, Acharya et al.’s Broadcast Disks algorithm (BD) allocates more popular data appeared more times in a broadcast period than less popular ones, i.e., the nonuniform broadcast, and provides a good performance on reducing client waiting time. However, mobile devices should constantly tune in to the wireless broadcast channel to examine data, consuming a lot of energy. Using index technologies on the broadcast file can reduce a lot of energy consumption of the mobile devices without significantly increasing client waiting time. In this paper, we propose an efficient nonuniform index called the skewed index, SI, over BD. The proposed algorithm builds an index tree according to skewed access patterns of clients, and allocates index nodes for the popular data more times than those for the less popular ones in a broadcast cycle. From our experimental study, we have shown that our proposed algorithm outperforms the flexible index and the flexible distributed index.     

A k-anonymity privacy-preserving approach in wireless medical monitoring environments

With the proliferation of wireless sensor networks and mobile technologies in general, it is possible to provide improved medical services and also to reduce costs as well as to manage the shortage of specialized personnel. Monitoring a person’s health condition using sensors provides a lot of benefits but also exposes personal sensitive information to a number of privacy threats. By recording user-related data, it is often feasible for a malicious or negligent data provider to expose these data to an unauthorized user. One solution is to protect the patient’s privacy by making difficult a linkage between specific measurements with a patient’s identity. In this paper we present a privacy-preserving architecture which builds upon the concept of k-anonymity; we present a clustering-based anonymity scheme for effective network management and data aggregation, which also protects user’s privacy by making an entity indistinguishable from other k similar entities. The presented algorithm is resource aware, as it minimizes energy consumption with respect to other more costly, cryptography-based approaches. The system is evaluated from an energy-consuming and network performance perspective, under different simulation scenarios.     

Benefits of inserting support devices in electronic learning environments

Research on support device-usage reveals that support devices are seldom used, and if used often in an inadequate way such that it is no longer a learning opportunity [Aleven, V., Stahl, E., Schworm, S., Fischer, F., & Wallace, R. (2003). Help seeking and help design in interactive learning environments. Review of Educational Research,73, 277–320; Clarebout, G., & Elen, J. (2006). Tool use in computer-based learning environments: Towards a research framework. Computers in Human Behavior,22, 389–411.]. In view of establishing a solid research agenda on the optimization of the use of instructional interventions and support devices, this article discusses three experimental studies, each dealing with different aspects of support device use. In a first study, the impact on support device use of different types and numbers of adjunct aids was investigated. In a second study, the influence of advice on support device use in an open learning environment is studied, while also considering various learner related variables. A third study addresses the use of support devices in a text-based environment.     

The use of support devices in electronic learning environments

This special issue addresses the use of support devices in electronic learning environments. Five articles each discus a study or several studies where the use of support devices is not evident. Factors influencing the use of support devices are addressed: elements of the learning environment, characteristics of the learner, etc.     

Identification of malicious edge devices in fog computing environments

Device security is one of the major challenges for successful implementation of Internet of Things (IoT) and fog computing. Researchers and IT organizations have explored many solutions to protect systems from unauthenticated device attacks (known as outside device attacks). Fog computing uses many edge devices (e.g., router, switch, and hub) for latency-aware processing of collected data. So, identification of malicious edge devices is one of the critical activities in data security of fog computing. Preventing attacks from malicious edge devices is more difficult because they have certain granted privileges to store and process the data. In this article, a proposed framework uses three technologies, a Markov model, an intrusion detection system (IDS), and a virtual honeypot device (VHD) to identify malicious edge devices in a fog computing environment. A two-stage Markov model is used to categorize edge devices effectively into four different levels. The VHD is designed to store and maintain a log repository of all identified malicious devices, which assists the system to defend itself from any unknown attacks in the future. The proposed model is tested in a simulated environment, and results indicate the effectiveness of the system. The proposed model is successful in identifying the malicious device as well as reducing the false IDS alarm rate.