Electronics

1032 KiB

Open AccessArticle

A Validated Analytical Model for Availability Prediction of IPTV Services in VANETs

by Bernd E. Wolfinger, Arian Hübner and Sadaf Momeni

Electronics 2014, 3(4), 689-711; https://doi.org/10.3390/electronics3040689 - 19 Dec 2014

Cited by 4 | Viewed by 6041

In vehicular ad hoc networks (VANETs), besides the original applications typically related to traffic safety, we nowadays can observe an increasing trend toward infotainment applications, such as IPTV services. Quality of experience (QoE), as observed by the end users of IPTV, is highly [...] Read more.

In vehicular ad hoc networks (VANETs), besides the original applications typically related to traffic safety, we nowadays can observe an increasing trend toward infotainment applications, such as IPTV services. Quality of experience (QoE), as observed by the end users of IPTV, is highly important to guarantee adequate user acceptance for the service. In IPTV, QoE is mainly determined by the availability of TV channels for the users. This paper presents an efficient and rather generally applicable analytical model that allows one to predict the blocking probability of TV channels, both for channel-switching-induced, as well as for handover-induced blocking events. We present the successful validation of the model by means of simulation, and we introduce a new measure for QoE. Numerous case studies illustrate how the analytical model and our new QoE measure can be applied successfully for the dimensioning of IPTV systems, taking into account the QoE requirements of the IPTV service users in strongly diverse traffic scenarios. Full article

(This article belongs to the Special Issue Connected Vehicles, V2V Communications, and VANET)

► Show Figures

Graphical abstract

388 KiB

Open AccessArticle

Kronecker-Based Fusion Rule for Cooperative Spectrum Sensingwith Multi-Antenna Receivers

by Sadiq Ali, Magnus Jansson, Gonzalo Seco-Granados and José A. López-Salcedo

Electronics 2014, 3(4), 675-688; https://doi.org/10.3390/electronics3040675 - 10 Dec 2014

Cited by 1 | Viewed by 4197

Abstract

This paper considers a novel fusion rule for spectrum sensing scheme for a cognitive radio network with multi-antenna receivers. The proposed scheme exploits the fact that when any primary signal is present, measurements are spatially correlated due to presence of inter-antenna and inter-receiver [...] Read more.

This paper considers a novel fusion rule for spectrum sensing scheme for a cognitive radio network with multi-antenna receivers. The proposed scheme exploits the fact that when any primary signal is present, measurements are spatially correlated due to presence of inter-antenna and inter-receiver spatial correlation. In order to exploit this spatial structure, the generalized likelihood ratio test (GLRT) operates with the determinant of the sample covariance matrix. Therefore, it depends on the sample size N and the dimensionality of the received data (i.e., the number of receivers K and antennas L). However, when the dimensionality fK; Lg is on the order, or larger than the sample size N, the GLRT degenerates due to the ill-conditioning of the sample covariance matrix. In order to circumvent this issue, we propose two techniques that exploit the inner spatial structure of the received observations by using single pair and multi-pairs Kronecker products. The performance of the proposed detectors is evaluated by means of numerical simulations, showing important advantages with respect to the traditional (i.e., unstructured) GLRT approach. Full article

(This article belongs to the Special Issue Cognitive Radio: Use the Spectrum in a More Efficient Way)

► Show Figures

Figure 1

364 KiB

Open AccessArticle

Optimizing Power Heterogeneous Functional Units for Dynamic and Static Power Reduction

by Toshinori Sato and Yoshimi Shibata

Electronics 2014, 3(4), 661-674; https://doi.org/10.3390/electronics3040661 - 10 Dec 2014

Viewed by 4238

Abstract

Power consumption is the major constraint for modern microprocessor designs. In particular, static power consumption becomes a serious problem as the transistor size shrinks via semiconductor technology improvement. This paper proposes a technique that reduces the static power consumed by functional units. It [...] Read more.

Power consumption is the major constraint for modern microprocessor designs. In particular, static power consumption becomes a serious problem as the transistor size shrinks via semiconductor technology improvement. This paper proposes a technique that reduces the static power consumed by functional units. It exploits the activity rate of functional units and utilizes the power heterogeneous functional units. From detailed simulations, we investigate the conditions in which the proposed technique works effectively for simultaneous dynamic and static power reduction and find that we can reduce the total power by 11.2% if two out of four leaky functional units are replaced by leakless ones in the situation where the static power occupies half of the total power. Full article

► Show Figures

Figure 1

2372 KiB

Open AccessArticle

Cooperative Path-Planning for Multi-Vehicle Systems

by Qichen Wang and Chris Phillips

Electronics 2014, 3(4), 636-660; https://doi.org/10.3390/electronics3040636 - 17 Nov 2014

Cited by 10 | Viewed by 8014

Abstract

In this paper, we propose a collision avoidance algorithm for multi-vehicle systems, which is a common problem in many areas, including navigation and robotics. In dynamic environments, vehicles may become involved in potential collisions with each other, particularly when the vehicle density is [...] Read more.

In this paper, we propose a collision avoidance algorithm for multi-vehicle systems, which is a common problem in many areas, including navigation and robotics. In dynamic environments, vehicles may become involved in potential collisions with each other, particularly when the vehicle density is high and the direction of travel is unrestricted. Cooperatively planning vehicle movement can effectively reduce and fairly distribute the detour inconvenience before subsequently returning vehicles to their intended paths. We present a novel method of cooperative path planning for multi-vehicle systems based on reinforcement learning to address this problem as a decision process. A dynamic system is described as a multi-dimensional space formed by vectors as states to represent all participating vehicles’ position and orientation, whilst considering the kinematic constraints of the vehicles. Actions are defined for the system to transit from one state to another. In order to select appropriate actions whilst satisfying the constraints of path smoothness, constant speed and complying with a minimum distance between vehicles, an approximate value function is iteratively developed to indicate the desirability of every state-action pair from the continuous state space and action space. The proposed scheme comprises two phases. The convergence of the value function takes place in the former learning phase, and it is then used as a path planning guideline in the subsequent action phase. This paper summarizes the concept and methodologies used to implement this online cooperative collision avoidance algorithm and presents results and analysis regarding how this cooperative scheme improves upon two baseline schemes where vehicles make movement decisions independently. Full article

(This article belongs to the Special Issue Intelligent and Cooperative Vehicles)

► Show Figures

Figure 1

2258 KiB

Open AccessArticle

Towards Realizing High-Throughput, Roll-to-Roll Manufacturing of Flexible Electronic Systems

by Xiaohui Lin, Harish Subbaraman, Zeyu Pan, Amir Hosseini, Chris Longe, Klay Kubena, Paul Schleicher, Phillip Foster, Sean Brickey and Ray T. Chen

Electronics 2014, 3(4), 624-635; https://doi.org/10.3390/electronics3040624 - 14 Nov 2014

Cited by 26 | Viewed by 9934

Abstract

High-rate roll-to-roll (R2R) tracker systems are utilized for large volume flexible electronic device manufacturing, and the current alignment mechanism between layers is mainly achieved by relying on passive techniques. In this paper, we present a machine vision based alignment strategy that is used [...] Read more.

High-rate roll-to-roll (R2R) tracker systems are utilized for large volume flexible electronic device manufacturing, and the current alignment mechanism between layers is mainly achieved by relying on passive techniques. In this paper, we present a machine vision based alignment strategy that is used to achieve precise registration for stacking multilayers. Based on this strategy, we demonstrate two-layer printing with alignment accuracy better than 100 μm in web moving direction and 200 μm in lateral direction at a web rate of 5 m/min. Full article

(This article belongs to the Special Issue Flexible Electronics)

► Show Figures

Figure 1

5801 KiB

Open AccessArticle

The Diabetes Assistant: A Smartphone-Based System for Real-Time Control of Blood Glucose

by Patrick Keith-Hynes, Benton Mize, Antoine Robert and Jérôme Place

Electronics 2014, 3(4), 609-623; https://doi.org/10.3390/electronics3040609 - 14 Nov 2014

Cited by 62 | Viewed by 11316

Abstract

Type 1 Diabetes Mellitus (T1DM) is an autoimmune disease in which the insulin-producing beta cells of the pancreas are destroyed and insulin must be injected daily to enable the body to metabolize glucose. Standard therapy for T1DM involves self-monitoring of blood glucose (SMBG) [...] Read more.

Type 1 Diabetes Mellitus (T1DM) is an autoimmune disease in which the insulin-producing beta cells of the pancreas are destroyed and insulin must be injected daily to enable the body to metabolize glucose. Standard therapy for T1DM involves self-monitoring of blood glucose (SMBG) several times daily with a blood glucose meter and injecting insulin via a syringe, pen or insulin pump. An “Artificial Pancreas” (AP) is a closed-loop control system that uses a continuous glucose monitor (CGM), an insulin pump and an internal algorithm to automatically manage insulin infusion to keep the subject’s blood glucose within a desired range. Although no fully closed-loop AP systems are currently commercially available there are intense academic and commercial efforts to produce safe and effective AP systems. In this paper we present the Diabetes Assistant (DiAs), an ultraportable AP research platform designed to enable home studies of Closed Loop Control (CLC) of blood glucose in subjects with Type 1 Diabetes Mellitus. DiAs consists of an Android (Google Inc., Mountain View, CA, USA) smartphone equipped with communication, control and user interface software wirelessly connected to a continuous glucose monitor and insulin pump. The software consists of a network of mobile applications with well-defined Application Programming Interfaces (APIs) running atop an enhanced version of Android with non-essential elements removed. CLC and safety applications receive real-time data from the CGM and pump, estimate the patient’s metabolic state and risk of hypo- and hyperglycemia, adjust the insulin infusion rate, raise alarms as needed and transmit de-identified data to a secure remote server. Some applications may be replaced by researchers wishing to conduct outpatient ambulatory studies of novel Closed Loop Control, Safety or User Interface modules. Over the past three years the DiAs platform has been used in a series of AP clinical trials sponsored by the National Institutes of Health, the Juvenile Diabetes Research Foundation, the Helmsley Charitable Trust and the European Union AP@Home project. Results of clinical trials using DiAs indicate that a smartphone with targeted operating system modifications and appropriate system software can be successfully used in outpatient clinical trials of FDA Class III medical devices such as Artificial Pancreas. Full article

(This article belongs to the Special Issue Wearable Electronics)

► Show Figures

Figure 1

264 KiB

Open AccessArticle

RF Infrastructure Cooperative System for in Lane Vehicle Localization

by Nabil Houdali, Thierry Ditchi, Emmanuel Géron, Jérôme Lucas and Stéphane Holé

Electronics 2014, 3(4), 598-608; https://doi.org/10.3390/electronics3040598 - 05 Nov 2014

Cited by 8 | Viewed by 6231

Abstract

This paper presents a sensor which can be included in an Advanced Driver Assistance System (ADAS) that is compliant with the Vehicle to Infrastructure communication standard (V2I). This system allows estimation of the vehicle lateral position in real time by ensuring cooperation between [...] Read more.

This paper presents a sensor which can be included in an Advanced Driver Assistance System (ADAS) that is compliant with the Vehicle to Infrastructure communication standard (V2I). This system allows estimation of the vehicle lateral position in real time by ensuring cooperation between an on-board vehicle system and passive transponders integrated in the lateral white strips of the road. Based on an optimization method, the lateral position vehicle is provided with a distance error less than 3 cm. In this paper, experimental results are presented in order to evaluate the robustness of the proposed system in a realistic environment. Three scenarios are considered to take into account the bitumen properties, the presence of parasitic reflectors in different positions around the system and the interaction between transponders. Full article

(This article belongs to the Special Issue Connected Vehicles, V2V Communications, and VANET)

► Show Figures

Graphical abstract

164 KiB

Open AccessEditorial

Organic Semiconductors: Past, Present and Future

by Mohan V. Jacob

Electronics 2014, 3(4), 594-597; https://doi.org/10.3390/electronics3040594 - 30 Sep 2014

Cited by 31 | Viewed by 7737

Abstract

Organic electronics, such as displays, photovoltaics and electronics circuits and components, offer several advantages over the conventional inorganic-based electronics because they are inexpensive, flexible, unbreakable, optically transparent, lightweight and have low power consumption. In particular, organic displays exhibit high brightness, fast response time, [...] Read more.

Organic electronics, such as displays, photovoltaics and electronics circuits and components, offer several advantages over the conventional inorganic-based electronics because they are inexpensive, flexible, unbreakable, optically transparent, lightweight and have low power consumption. In particular, organic displays exhibit high brightness, fast response time, wide viewing angle, and low operating voltage. [...] Full article

(This article belongs to the Special Issue Organic Semiconductors)

1898 KiB

Open AccessReview

A Brief Review of Heavy-Ion Radiation Degradation and Failure of Silicon UMOS Power Transistors

by Kenneth F. Galloway

Electronics 2014, 3(4), 582-593; https://doi.org/10.3390/electronics3040582 - 30 Sep 2014

Cited by 15 | Viewed by 8551

Abstract

Silicon VDMOS power MOSFET technology is being supplanted by UMOS (or trench) power MOSFET technology. Designers of spaceborne power electronics systems incorporating this newer power MOSFET technology need to be aware of several unique threats that this technology may encounter in space. Space [...] Read more.

Silicon VDMOS power MOSFET technology is being supplanted by UMOS (or trench) power MOSFET technology. Designers of spaceborne power electronics systems incorporating this newer power MOSFET technology need to be aware of several unique threats that this technology may encounter in space. Space radiation threats to UMOS power devices include vulnerabilities to SEB, SEGR, and microdose. There have been relatively few studies presented or published on the effects of radiation on this device technology. The S-O-A knowledge of UMOS power device degradation and failure under heavy-ion exposure is reviewed. Full article

► Show Figures

Figure 1

1709 KiB

Open AccessArticle

Garment-Integrated Bend Sensor

by Guido Gioberto and Lucy E. Dunne

Electronics 2014, 3(4), 564-581; https://doi.org/10.3390/electronics3040564 - 26 Sep 2014

Cited by 6 | Viewed by 7066

Abstract

Garment-integrated sensors equip clothes with a smart sensing capability, while preserving the comfort of the user. However, this benefit can be to the detriment of sensing accuracy due to the unpredictability of garment movement (which affects sensor positioning) and textile folds (which can [...] Read more.

Garment-integrated sensors equip clothes with a smart sensing capability, while preserving the comfort of the user. However, this benefit can be to the detriment of sensing accuracy due to the unpredictability of garment movement (which affects sensor positioning) and textile folds (which can affect sensor orientation). However, sensors integrated directly into garments or fabric structures can also be used to detect the movement of the garment during wearing. Specifically, a textile bend sensor could be used to sense folds in the garment. We tested a garment-integrated stitched sensor for five types of folds, stitched on five different weights of un-stretchable denim fabric and analyzed the effects of fold complexity and fabric stiffness, under un-insulated and insulated conditions. Results show that insulation improves the linearity and repeatability of the sensor response, particularly for higher fold complexity. Stiffer fabrics show greater sensitivity, but less linearity. Sensor response amplitude is larger for more complex fold geometries. The utility of a linear bending response (insulated) and a binary shorting response (un-insulated) is discussed. Overall, the sensor exhibits excellent repeatability and accuracy, particularly for a fiber-based, textile-integrated sensor. Full article

(This article belongs to the Special Issue Wearable Electronics)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Electronics, Volume 3, Issue 4 (December 2014) – 10 articles , Pages 564-711

Further Information

Guidelines

MDPI Initiatives

Follow MDPI