Penn State College of Communications

About: Penn State College of Communications is a based out in . It is known for research contribution in the topics: Relay & Cognitive radio. The organization has 2106 authors who have published 2119 publications receiving 24693 citations.

Capacitive humidity sensing behavior of ordered Ni/Si microchannel plate nanocomposites

Abstract: The preparation and humidity sensing of nickel coated silicon microchannel plate (Ni/Si-MCP) materials are studied. The silicon MCP fabricated by electrochemical etching has ordered channels and macro-porous structures. Nickel is coated by electroless plating onto the inner wall of the silicon MCP for the detection of humidity. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) are used to determine the structural and morphological properties. Our results show that the Ni/Si-MCP nanocomposites have high sensitivity and fast response time. They are compatible with current IC processes and have promising applications as integrated micro humidity sensors.

You Can Recharge With Detouring: Optimizing Placement for Roadside Wireless Charger

Abstract: Wireless energy transfer technologies have played an important role in the development of Internet of Things. Most of the previous studies focus on scheduling mobile chargers efficiently for rechargeable sensor nodes. In this paper, we investigate the deployment problem for wireless charging stations (WCSs) in urban areas with respect to the users detouring cost when they move to the candidate WCSs. With pre-known user’s trajectories and given number of WCSs, we deploy the WCSs to maximize the number of recharged users with guaranteed probability. We convert our deployment problem into an NP-hard weighted maximum coverage problem, and prove the objective function is a maximum submodular set function. To this end, a simple but efficient greedy algorithm with approximation factor of $\left({1 - \frac {1}{e}}\right)$ is proposed for the threshold detouring mode. In addition, an improved algorithm with an approximation factor of $\left({1 - \frac {1}{\sqrt {e}}}\right)$ is presented for the linear/nonlinear detouring mode. Finally, we evaluate the performance of our algorithms by comparing them with two typical heuristic algorithms ( flow-centric and random-based ), and the impacts of different detouring thresholds on our algorithms by synthetic traces. Moreover, real trace-driven evaluations validate that our algorithm improves the coverage quality by 75% when compared to the two aforementioned algorithms.

Random Forests Based Path Loss Prediction in Mobile Communication Systems

Abstract: When deploying communication systems, an accurate wireless propagation model is important to ensure the quality of service covering the region. Due to the complex radio environment, the traditional wireless propagation models need massive data for correction and calculation. To address this issue, this paper proposes a wireless propagation method to predict path loss. We use the random forest network structure to fit the complex model, accurately predicting the received signal power in the target area. To improve the training efficiency of the model, we construct the preliminary features according to the previous knowledge. A filtering feature selection method is adopted to select features as input of model. Evaluating the model on four typical terrains, the experiment results show that the proposed model outperforms the four existing models in all types of terrains.

Energy-Accumulation-Based Power-Beacon-Assisted WPCN: Time Allocation and Scheduling Schemes

Abstract: This letter aims to maximize the sum ergodic throughput of a power-beacon (PB)-assisted wireless powered communication network, where the PB located between several sensors and a base station (BS) first performs wireless energy transfer to the sensors and then assists forwarding the information of each sensor to the BS based on TDMA protocol. We consider the energy accumulation effect, i.e., each sensor can harvest additional energy from the PB when the PB forward the information of previous scheduled sensors, and then exhausts the accumulated energy when it starts transmission process. First, we derive the exact and approximate solutions of the ergodic throughput. Second, we prove that the optimization problem is convex and provide numerous new expressions for the optimal time allocation. Moreover, the scheduling sequence for the sensors is also optimized with two proposed methods. Simulations show the considerable gain achieved by the joint optimization scheme.

Reshaping Digital Inequality in the European Union: How Psychological Barriers Affect Internet Adoption Rates

Abstract: In the past years, scholars have assessed the social differences that the Internet has generated from its use (or its non-use). The issue has been largely referred to as Digital Divide, describing the social division between those who are using the technology and those who are not; or in other words, the "haves" and "have nots" of the Internet. Generally, the phenomenon has been explained from a perspective in which infrastructural and demographics aspects are considered as the main barriers to overcome in order to narrow this digital inequality. Albeit partially true, this trend of research does not consider people's perceptions toward the Internet and how they can also explain connectivity, or lack thereof. Analyzing data from 1) the 55th Eurobarometer collected by the EU Commission (N = 16,134); and 2) data collected from the National Statistical Institutes of each State Member of the European Union, this paper suggests that there is a necessity to approach the problem from another perspective. This does not mean that the other trend was wrong, but rather, one explanation of the problem is not enough. Thus, this research enlightens how psychological barriers are involved in impeding EU citizens' complete adoption of the Internet. For instance, perceptions of what opportunities were missed by not accessing the WWW, perceptions of the kind of content that should be on the Net and perceptions of how the Internet would change their daily lives were all factors that indicated that not only demographical or structural obstacles were involved. In a sense, people do not think that they are missing many Job-Training, Consumption or improvement of Social Integration opportunities by not being connected to the Internet. In addition, the content that should be available over the Net is not appealing enough to induce them to seek out Internet access.