An Android-Based Mechanism for Energy Efficient Localization Depending on Indoor/Outdoor Context

Today, there is widespread use of mobile applications that take advantage of a user\u27s location. Popular usages of location information include geotagging on social media websites, driver assistance and navigation, and querying nearby locations of interest. However, the average user may not realize the high energy costs of using location services (namely the GPS) or may not make smart decisions regarding when to enable or disable location services-for example, when indoors. As a result, a mechanism that can make these decisions on the user\u27s behalf can significantly improve a smartphone\u27s battery life. In this paper, we present an energy consumption analysis of the localization methods available on modern Android smartphones and propose the addition of an indoor localization mechanism that can be triggered depending on whether a user is detected to be indoors or outdoors. Based on our energy analysis and implementation of our proposed system, we provide experimental results-monitoring battery life over time-and show that an indoor localization method triggered by indoor or outdoor context can improve smartphone battery life and, potentially, location accuracy

The Modified Trapezoidal Rule for Computing Hypersingular Integral on Interval

The modified trapezoidal rule for the computation of hypersingular integrals in boundary element methods is discussed. When the special function of the error functional equals zero, the convergence rate is one order higher than the general case. A new quadrature rule is presented and the asymptotic expansion of error function is obtained. Based on the error expansion, not only do we obtain a high order of accuracy, but also a posteriori error estimate is conveniently derived. Some numerical results are also reported to confirm the theoretical results and show the efficiency of the algorithms

Latency-Optimized and Energy-Efficient MAC Protocol for Underwater Acoustic Sensor Networks: A Cross-Layer Approach

Considering the energy constraint for fixed sensor nodes and the unacceptable long propagation delay, especially for latency sensitive applications of underwater acoustic sensor networks, we propose a MAC protocol that is latency-optimized and energy-efficient scheme and combines the physical layer and the MAC layer to shorten transmission delay. On physical layer, we apply convolution coding and interleaver for transmitted information. Moreover, dynamic code rate is exploited at the receiver side to accelerate data reception rate. On MAC layer, unfixed frame length scheme is applied to reduce transmission delay, and to ensure the data successful transmission rate at the same time. Furthermore, we propose a network topology: an underwater acoustic sensor network with mobile agent. Through fully utilizing the supper capabilities on computation and mobility of autonomous underwater vehicles, the energy consumption for fixed sensor nodes can be extremely reduced, so that the lifetime of networks is extended

A Merging Cluster Algorithm for QoS-Oriented Supply and Demand

Discovering service-on-demand for large numbers of functionality-similar web services is one of the key issues in services discovery study. According to the functionality-similar web services, a service-on-demand discovery process is proposed in this paper. To meet the target, FCM clustering is adopted for agglomerative clustering between the user\u27s QoS demand information and the QoS information of Web Service resource. Then, the sequence could be determined by similarity computation in the same classification clustering. Lastly, the numerical example is presented to illustrate that the service-on-demand can be discovered efficiently to optimize network resources and improve the efficiency

A practical comparison of two K-Means clustering algorithms

This is an open access article distributed under the terms of the Creative Commons Attribution Licens

On PTAS for planar graph problems

Approximation algorithms for a class of planar graph problems, including planar independent set, planar vertex cover and planar dominating set, were intensively studied. The current upper bound on the running time of the polynomial time approximation schemes (PTAS) for these planar graph problems is of 2O(1/∈ )nO(1). Here we study the lower bound on the running time of the PTAS for these planar graph problems. We prove that there is no PTAS of time 2=(√(1/∈ )nO(1) for planar independent set, planar vertex cover and planar dominating set unless an unlikely collapse occurs in parameterized complexity theory. For the gap between our lower bound and the current known upper bound, we speci cally show that to further improve the upper bound on the running time of the PTAS for planar vertex cover, we can concentrate on planar vertex cover on pla- nar graphs of degree bounded by three.4th IFIP International Conference on Theoretical Computer ScienceRed de Universidades con Carreras en Informática (RedUNCI

Strategies for Talent’s Digital Competence Development at Higher Vocational Colleges for Digital Transformation

Digital transformation has brought unprecedented opportunities and challenges to economic and social development, and the development of talent’s digital competence is of growing importance. Under an ideal situation, digitization, digitalization and digital transformation are three stages of gradual digital development. However, influenced by the difference in social and economic development among regions, higher vocational colleges, as an educational system closest to the labor market, vary by their own strengths and digital competence. From the perspective of game theory and based on the model of the boxed pig game, this paper provides strategies and suggestions for the cultivation of talent’s digital competence in terms of non-cooperative strategy at higher vocational colleges. The supply-demand model of talent’s digital competence cultivation is established to provide further suggestions for the top-down cooperation strategy among higher vocational colleges

Virtual Track: Applications and Challenges of the RFID System on Roads

The RFID System on Roads (RSR), which includes RFID tags deployed on roads and RFID readers installed on vehicles, is an essential platform for future transportation systems. It can provide unique features that are missing from the current systems, including lane level position, road traffic control information, vehicle distance estimation, real time driving behavior analysis, and so on. Based on these features, several novel vehicular applications can be implemented, which can significantly improve the transportation safety and efficiency. Specifically, the proposed applications on RSR include Assisted Navigation Systems, Electrical Traffic Control, Unmanned Patrol Systems, Vehicle Distance Estimation, Parking Assistant System, Route Tracing and Access Control, Unmanned Ground Vehicles. We also investigate the corresponding engineering/system and research challenges for implementing RSR and its applications in this article

A game theoretic analysis on block withholding attacks using the zero-determinant strategy

In Bitcoin's incentive system that supports open mining pools, block withholding attacks incur huge security threats. In this paper, we investigate the mutual attacks among pools as this determines the macroscopic utility of the whole distributed system. Existing studies on pools' interactive attacks usually employ the conventional game theory, where the strategies of the players are considered pure and equal, neglecting the existence of powerful strategies and the corresponding favorable game results. In this study, we take advantage of the Zero-Determinant (ZD) strategy to analyze the block withholding attack between any two pools, where the ZD adopter has the unilateral control on the expected payoffs of its opponent and itself. In this case, we are faced with the following questions: who can adopt the ZD strategy? individually or simultaneously? what can the ZD player achieve? In order to answer these questions, we derive the conditions under which two pools can individually or simultaneously employ the ZD strategy and demonstrate the effectiveness. To the best of our knowledge, we are the first to use the ZD strategy to analyze the block withholding attack among pools