Network Of Mobile Devices Research Articles

Paradigm Shifts in Global Higher Education and e-learning: An ecological perspective

The digital knowledge age has changed our world in inexplicable ways, and education is not immune to these changes. In a time when online technologies, networked learning spaces, mobile devices, cloud computing, and many other innovative tools have resulted in a paradigm shift, we need to revisit what is known about the current state of the art in higher education and e-learning. This special issue aims to reflect the changes in global higher education with a special focus on e-learning.

Self-heated Ag-decorated SnO2 nanowires with low power consumption used as a predictive virtual multisensor for H2S-selective sensing

Multisensor systems with low-power consumption are emerging for the Internet of Things. In this work, we demonstrate the use of self-heated networked Ag-decorated SnO2 NW sensors integrated into a portable module for selective detection of H2S gas at low power consumption, and the integrated system is simulated as a virtual multisensor under varying heating powers for identifying and quantifying different reducing gases. The H2S gas-sensing characterisations at the different self-heating powers of 2–10 mW showed that the gas response significantly increased with the increase in Ag density decoration and the heated power strongly affected the gas-sensing performance and sensor stability. Excellent response of 21.2 to 0.5 ppm H2S gas was obtained at a low heating power of 2 mW with an acceptable response/recovery time of 18/980 s. The increase of the heating power over 20 mW can destroy the devices. The integrated system could selectively detect H2S at the heating power below 4 mW and H2, C2H5OH and NH3 gases at the heating power upon 4 mW. The virtual multisensor could discriminate qualitatively (with an accuracy of 100%) and quantitatively H2S, H2, NH3, C2H5OH (Ethanol) and CH3COCH3 (Aceton) gases with average errors of 13.5%, 14.7%, 16.8%, 16.9%, and 14.8%, respectively. The proposed sensing platform is a promising candidate for selective detection of H2S gas and virtual multisensor with low power consumption for mobile or wireless network devices.

An End-to-End Automation Framework for Mobile Network Testbeds

This paper describes the end-to-end automation framework developed as part of the TRIANGLE project. The TRIANGLE project is devoted to the benchmarking of apps and devices in mobile networks. For that purpose, it is needed to ensure the repeatability in the behaviour of all the components of the mobile network during the execution of the same test. This is why one of the main objectives of the project was to develop an end-to-end automation framework to provide repeatable testing. This paper describes in detail the design and the implementation of the framework.

Smartphones, Distraction Narratives, and Flexible Pedagogies: Students’ Mobile Technology Practices in Networked Writing Classrooms

Abstract This article reports on how a group of students describe their use of smartphones in writing classrooms. Based on 143 survey responses and 10 interviews, this study found that students often described their smartphone use as a reflection of their classroom environment. When motivated in class, these students used mobile devices as conduits for participation, accessing course materials, learning more about discussion topics, or writing notes. But when instructors failed to make course content relatable, understandable, or engaging, the students turned to their smartphones as sources of distraction. These findings encourage composition instructors to view smartphone use as, in part, a reflection of teaching methods and the course environments, rather than universal indications of students’ distraction or disinterest. And while many researchers have advocated for new course designs or assignments that account for the proliferation of networked composing technologies in university students’ lives (e.g., Yancey, 2009 , Clark, 2010 , Dryer et al., 2014 ), these findings call for further research to address how students’ access to networked mobile devices may require composition instructors to shift teaching methods and models, rather than solely course content.

An Approach to Reinforce Multipath TCP with Path-Aware Information.

Multipath TCP (MPTCP), which enables the use of multiple wireless links (e.g., Wi-Fi and LTE) for data transmissions, is an excellent technology for evolving multi-homing devices in mobile wireless networks. This paper explores concepts and feasibility of realizing MPTCP with path awareness (PA), in which the path-aware information is leveraged to reinforce the MPTCP transmissions. In particular, when aware of a network situation, a device can facilitate a mechanism that dynamically shifts the MPTCP traffic to a single path and vice versa. As a result, MPTCP with PA could solve the significant problem of negative aggregation benefit when the MPTCP throughput over divergent paths is worse than the best one of single-path TCP. We illustrate the feasibility of the proposed concept through our new implementation of a so-called MPTCP-LA (i.e., MPTCP with Loss Awareness). MPTCP-LA keeps the aggregation benefits non-negative by temporarily switching an MPTCP transmission on a path to a standby condition when the on-device observed loss reaches a threshold. We extensively evaluate MPTCP-LA in comparison to the standard MPTCP in an emulated environment. The results show that MPTCP-LA has better performance regarding enhancing throughput and saving networking resources.

SLATS

As the density of wireless, resource-constrained sensors grows, so does the need to choreograph their actions across both time and space. Recent advances in ultra-wideband RF communication have enabled accurate packet timestamping, which can be used to precisely synchronize time. Location may be further estimated by timing signal propagation, but this requires additional communication overhead to mitigate the effect of relative clock drift. This additional communication lowers overall channel efficiency and increases energy consumption. This article describes a novel approach to simultaneously localizing and time synchronizing networked mobile devices. An Extended Kalman Filter is used to estimate all devices’ positions and clock errors, and packet timestamps serve as measurements that constrain time and overall network geometry. By inspection of the uncertainty in our state estimate, we can adapt the number of messages sent in each communication round to balance accuracy with communication cost. This reduces communication overhead, which decreases channel congestion and power consumption compared to traditional time of arrival and time difference of arrival localization techniques. We demonstrate the performance and efficiency of our approach using a real network of custom RF devices and mobile quadrotors.

Robust resource allocation scheme under channel uncertainties for LTE-A systems

Nowadays, resource allocation is one of the major problems in the cellular networks. Due to the increasing number of autonomous heterogeneous devices in future mobile networks, a proper scheduling scheme is required to provide the adequate resources for the service flow. However, provisioning quality-of-service (QoS) for real-time applications with the constraint on transporting delay is hard to achieve without compromising other QoS parameters. In this paper, an intelligent QoS-aware bandwidth allocation solution is proposed for the uplink traffic when the channel condition is uncertain. The system is designed based on a specific maximum latency assurance for real-time applications as well as considering fairness to the throughput of non-real-time services. The scheduling system employs a channel-aware Kalman filter based interval type-2 fuzzy logic controller to estimate channel uncertainty as well as satisfying the QoS requirements for user equipment. Through simulations, the performance of the proposed system in terms of optimal bandwidth allocation, bandwidth wastage, fairness, jitters, various delays and throughputs for delay sensitive and delay tolerant services is analyzed. The numerical results show that the proposed scheme provides reliable scheduling for real-time services without harming the performance of non-real-time QoS parameters.

Mining Association Rules Based on Deep Pruning Strategies

Today mobile network and various smart devices flourish rapidly. Data collected from the mobile devices and network can bring us huge opportunities to understand some significant characteristics of the users which traditional data cannot. Association rules mining is an extremely important topic in data mining that can make the utmost value of massive data effectively. Apriori algorithm and the improved Apriori ones based on Boolean matrix are the representative ones in association rules mining. Nevertheless, these solutions have their problems. In this paper, we have proposed an algorithm called MAR-DPS, which has some deep pruning strategies containing three methods to compress the size of frequent itemsets and reduce the joining numbers in generating new frequent itemsets. It can also select the appropriate method to generate frequent 2-itemsets when facing different data sets. Extensive experimental results on three different data sets have demonstrated that our MAR-DPS can perform much better than other tested algorithms.

Implementing an electronic observation and early warning score chart in the emergency department: a feasibility study.

Use of automated systems to aid identification of patient deterioration in routine hospital practice is limited and their impact on patient outcomes remains unclear. This study was designed to evaluate the feasibility of implementing an electronic observation chart with automated early warning score (EWS) calculation in the high-acuity area of an emergency department. This study enrolled 3219 participants before and 3352 after implementation of an automated system, using bedside vital-sign entry on networked mobile devices. The primary outcome measure was the percentage of participants for whom an EWS was accurately recorded at each stage. Of the participants, 52.7% before and 92.9% after implementation of the electronic system had an accurate EWS recorded on charts available to the study team. Participant groups were well balanced for baseline characteristics and acuity. In this study, the feasibility and limitations of implementing an electronic observation chart in the ED were demonstrated. Accurate EWS documentation was more frequent after implementation of the electronic observation chart. Retrospective analysis suggests that the use of an electronic observation system may lead to a greater percentage of observations being taken from those patients with a higher EWS.

Improving collaboration efficiency via diverse networked mobile devices

We introduce a framework for distributed or co-located teams to collaborate highly efficiently using diverse mobile devices for design and assessment of complex systems. Our framework enhances the efficiency of collaborations arising in design, simulation or data analysis, including visualization. First, we investigate which requirements on such a collaboration framework exist and which influences between task models have to be taken into account; afterwards we transfer those findings into a prototypical system. The devices provide three views of data to be processed collaboratively: (1) a simulation view; (2) a status report view; and (3) a status update view. These views serve the purpose of providing overview, detail and performance views. A smart watch view shows at-a-glance information, the environment or the process being inspected, possibly influenced by a user. Users can use their mobile devices as control interfaces. The framework is especially effective for combining the synergistic, complementary competencies of a team. We describe the design of our framework and discuss specific applications.

Energy saving through intelligent coordination among daily used fixed and mobile devices

Network end-user devices such as laptops and desktop PCs are often left powered ON 24/7 while they remain idle most of the time. The main reason behind this is maintaining network connectivity for remote access, VoIP, instant messaging and other Internet-based applications. The Network Connectivity Proxy (NCP) emerged as a quite promising strategy for significantly reducing network energy waste by allowing devices to sleep without losing their presence over Internet. It impersonates presence of devices during their sleeping periods at all layers of TCP/IP stack. The NCP can successfully proxy basic networking protocols (e.g., ARP, PING, DHCP, etc.) but faces challenges in proxying TCP sessions and proprietary closed-source applications with encrypted packets.To overcome the limitations of NCP concept, this paper proposes a new strategy for reducing network energy waste through intelligent coordination among a user's devices (e.g., smartphone, laptop, desktop PC, etc.). In the proposed system, a user's daily used devices autonomously and seamlessly communicate with a centralized control server that decides which user device will maintain presence of applications at a given instant. To allow devices to sleep and wake them up whenever necessary, the proposed system also uses a light-weight Home Gateway Proxy (HGP) with very basic set of practically realizable features. The communication framework for HGP is designed to achieve auto-discovery, seamless networking and communication features. This paper also practically evaluates the proposed system and estimates energy saving for fixed as well as mobile network devices.

Temporal Conflicts and the Purification of Hybrids in the 21st-Century Art Museum: Tate, a Case in Point

Tate, and by implication the modern art museum in general, is struggling with a double paradox. How, on the one hand, can modernity’s notion of linear progressive time be maintained in a world where, through the proliferation of technology and networked mobile devices, our time horizon has shrunk to that of the present; and, on the other, can aesthetic modernism’s atemporal space of exhibition and display be maintained in the face of the multiplicity of times experienced within presentness?

Robust ID based mutual authentication and key agreement scheme preserving user anonymity in mobile networks

With the swift growth of wireless technologies, an increasing number of users rely on the mobile services which can exchange information in mobile networks. Security is of key issue when a user tries to access those services in this network environment. Many authentication schemes have been presented with the purpose of authenticating entities and wishing to communicate securely. Recently, Chou et al. and Farash-Attari presented two ID authentication schemes. They both claimed that their scheme could withstand various attacks. However, we find that the two authentication schemes are vulnerable to trace attack while having a problem of clock synchronization. Additionally, we show that Farash-Attari’s scheme is still susceptible to key-compromise impersonation attack. Therefore, we present an enhanced scheme to remedy the security weaknesses which are troubled in these schemes. We also demonstrate the completeness of the enhanced scheme through the Burrow-Abadi-Needham (BAN) logic. Security analysis shows that our scheme prevents the drawbacks found in the two authentication schemes while supporting better secure attributes. In addition, our scheme owns low computation overheads compared with other related schemes. As a result, our enhanced scheme seems to be more practical and suitable for resource-constrained mobile devices in mobile networks.

Examination of AODV Routing Protocol with Wormhole Attack

In Adhoc Network, Mobile Adhoc Network (MANET) is vibrant Adhoc network. MANET is collection of mobile network devices that are connected through wireless medium i.e., radio signals. These mobile network devices form a dynamic topology i.e., mobile nodes move freely and quickly, in and out from network. These is no central control for co-coordinating these network device i.e. decentralized network .These devices control each other directly i.e, peer-to-peer connection. The dynamic nature of MANET makes it vulnerable to variety of security threats like wormhole attack, eavesdropping etc. The performance and reliability of the network is affected by making alteration in routing protocols by the attacker. Wormhole attack is a type of tunneling attack where an attacker at one end of tunnel attracts data packets from one hop neighbors and transmits these data packets to another attacker of the tunnel which delivers these data packets to destination node. Transmitting data packets through tunnel may result various security attacks like wormhole attack, black hole attack, eavesdropping attack. This proposed paper examines the consequences of wormhole attack in AODV routing protocol based MANET using OPNET Simulator.

MCSQAM: Service Quality Assessment Model in Mobile Cloud Services Environment

Cloud computing is high technology that extends existing IT capabilities and requirements. Recently, the cloud computing paradigm is towards mobile with advances of mobile network and personal devices. As concept of mobile cloud, the number of providers rapidly increases for various mobile cloud services. Despite development of cloud computing, most service providers used their own policies to deliver their services to user. In other words, quality criteria for mobile cloud service assessment are not clearly established yet. To solve the problem, there were some researches that proposed models for service quality assessment. However, they did not consider various metrics to assess service quality. Although existing research considers various metrics, they did not consider newly generated Service Level Agreement. In this paper, to solve the problem, we proposed a mobile cloud service assessment model called mCSQAM and verify our model through few case researches. To apply the mobile cloud, proposed assessment model is transformed from ISO/IEC 9126 which is an international standard for software quality assessment. mCSQAM can provide service quality assessment and determine raking of the service. Furthermore, if Cloud Service Broker includes mCSQAM, appropriate services can be recommended for service users using user and service conditions.

Quantum-Assisted Joint Multi-Objective Routing and Load Balancing for Socially-Aware Networks

The widespread use of mobile networking devices, such as smart phones and tablets, has substantially increased the number of nodes in the operational networks. These devices often suffer from the lack of power and bandwidth. Hence, we have to optimize their message routing for the sake of maximizing their capabilities. However, the optimal routing typically relies on a delicate balance of diverse and often conflicting objectives, such as the route's delay and power consumption. The network design also has to consider the nodes' user-centric social behavior. Hence, the employment of socially aware load balancing becomes imperative for avoiding the potential formation of bottlenecks in the network's packet-flow. In this paper, we propose a novel algorithm, referred to as the multi-objective decomposition quantum optimization (MODQO) algorithm, which exploits the quantum parallelism to its full potential by reducing the database correlations for performing multi-objective routing optimization, while at the same time balancing the teletraffic load among the nodes without imposing a substantial degradation on the network's delay and power consumption. Furthermore, we introduce a novel socially aware load balancing metric, namely, the normalized entropy of the normalized composite betweenness of the associated socially aware network, for striking a better tradeoff between the network's delay and power consumption. We analytically prove that the MODQO algorithm achieves the full-search based accuracy at a significantly reduced complexity, which is several orders of magnitude lower than that of the full search. Finally, we compare the MODQO algorithm to the classic non-dominated sort genetic algorithm II evolutionary algorithm and demonstrate that the MODQO succeeds in halving the network's average delay, while simultaneously reducing the network's average power consumption by 6 dB without increasing the computational complexity.

Guest Editorial Special Issue on Mobile Crowd Sensing for IoT

The papers in this special section provide the opportunity for researchers, practitioners, and application developers to review and discuss the state-of-the-art and trends of MCS (mobile crowd sensing)techniques and applications or propose new solutions. The ubiquitous sensor-rich mobile devices (e.g., smartphones, wearable devices, and smart vehicles) have been playing an increasing important role in the evolution of the Internet of Things (IoTs), which bridges the digital space and physical space at a societal scale. Their powerful computing/communication capacities, huge population, and inherent mobility make mobile-device networks a much more flexible and cost-effective IoT solution than static sensor networks.

Context Weaver: Awareness and feedback in networked mobile crowdsourcing tools

Mobile crowdsourcing allows people to collect data using a large pool of participants. In this paper, we focus on mobile crowdsourcing for citizens to solve local issues in context. We argue that such crowdsourcing environments need to support exploration, a continuous, opportunistic, and multi-perspective process that existing crowd sensing systems cannot easily support. We have developed a system called Context Weaver, which connects participants using networked mobile devices in order to support collaborative exploration, and conducted field trials to understand the effect of networking participants in the crowdsourced data-collection activities that encompass planning, execution, and analysis phases. We discuss a methodology for exploratory mobile crowdsourcing by citizens based on the provision of mutual awareness and rapid feedback in context. The proposed methodology can provide a basis for a model of networked mobile crowdsourcing which can exploit not only the man-power but also the creativity of citizens to gather relevant data.

위치기반서비스의 측위시스템 정확도 향상에 관한 연구

Location-Based Services can be defined as services that integrated a mobile network device's position with other information so as to provide added value to users. One of the most important elements in the LBS is the ability to locate objects. In this paper, the positioning techniques using radio signal were introduced, and the positioning principles and accuracies for LBS of smart phone were analyzed. As a result, the some techniques for improving user security were suggested.

An energy consumption minimization routing scheme based on rate adaptation with QoS guarantee for the mobile environment

Reducing energy consumption with quality-of-service (QoS) guarantee and extending the lifetime of mobile terminal devices are important to construct green mobile networks. The rate adaptation of mobile devices is an effective approach to optimize energy consumption and improve energy efficiency. This paper proposes an energy consumption optimization routing scheme on the basis of rate adaptation for mobile networks with base stations (BSs) support in a mobile environment from a global point of view. According to the service characteristics of mobile devices in mobile networks, we establish an energy consumption model by abstracting the service components of mobile devices as a processing domain. We utilize a queuing system model with variable service rates to solve the service process of the processing domain model and to obtain the service rate and the switching number of running modes in a processing domain. We then construct an energy consumption optimization model with delay constraint to minimize energy consumption and design a suitable genetic algorithm to solve the energy consumption optimization problem. Simulation results show that the proposed energy consumption optimization routing scheme can effectively reduce the energy consumption and prolong the lifetime of mobile devices under a delay constraint.