Search

Human mistakes are the main source of fatal accidents and daily traffic congestion. Recent researches have focused on assisting drivers to mitigate traffic fatalities and create more enjoyable drive experiences. Vehicle platooning or cooperative adaptive cruise control (CACC) has been stated as one of the most effective solutions to tackle this problem. Platooning concept involves a group of vehicles act as a single unit through coordination of movements. This concept draws a special attention among academia and governmental and non-governmental organizations. Recently, there have been several demonstrations, which have introduced the potential benefits of this idea, e.g. safety enhancement, increase roadway capacity, and improve traffic efficiency. While many aspects of platooning such as transportation impacts, mechanical and control concerns are still under investigation, very limited amount of work has studied platooning in an adversarial environment. To design safe distributed controllers and networks, it is essential to understand the possible attacks that can be applied against platoons. In this work, we design a set of insider attack and abnormal behaviors that are implemented in a car platoon. For example, an attack has been introduced, in which attacker exploits the platoon controller to cause collisions and disrupt the performance of platoon. In the small platoon, this successful attack can be carried through a malicious member of platoon solely by changing its motion (acceleration and deceleration) and gains of the controller. However, the attack should be executed through a collaborative effort in large platoons. In this case, the main attacker not only adjusts its gains and motion to accomplish the attack but also collaborates with the other attacker. Another attacker only uses the gain modification technique. The strong point of the proposed attack is that attacker stays intact while in existing works from literature, the attacker gets affected during an attack.

For decoding messages, a decoder exchanges single-bit messages for a data channel between a plurality of M parity nodes and a plurality of N symbol nodes. Each parity node has one or more adjacent symbol nodes with a plurality of edges between the parity node and each adjacent symbol node. An extrinsic decision and an extrinsic parity value are calculated based on a time-varying lookup table. The lookup table stores the locally maximum-likelihood extrinsic decision for a quantized number of data channel states as a function of adjacent extrinsic parity values.

The primary energy consumer of smart buildings are Heating, Ventilation, and Air-Conditioning (HVAC) systems, approximately 30% of the building energy use, which usually operate on a fixed schedule. Currently, most modern buildings still condition rooms with a set-point assuming maximum occupancy rather than actual usage. As a result, rooms are often over-conditioned needlessly. Occupancy-based controls can achieve significant energy savings by temporally matching the building energy consumption and building usage, conservative user behavior can save a third of expended energy.  In this paper, we present a simple yet effective algorithm to automatically assign reference temperature set-points based on the occupancy information. Both the binary and detailed occupancy estimation cases are considered. In the first case study, we assume the schedule involves only binary states (occupied or not occupied), i.e. the room is invariant. With long-term observations occupancy levels can be estimated using statistical tools. In the second case study, three techniques are introduced. Firstly, we propose an identification-based approaches. More precisely, we identify the models via Expectation Maximization (EM) approach. The statistical state space model is built in linear form for the mapping between the occupancy measurements and real occupancy states with noise considered. Secondly, we propose a method based on uncertain basis functions for modeling and prediction purposes. In literature, basis functions (e.g., radial basis functions, wavelets) are fixed; instead, we assume that the basis functions are random. We consider basis functions with three different distributions, which are Gaussian, Laplace and Uniform, respectively. Finally, we introduce a novel finite state automata (FSA) which is successfully reconstructed by general systems problem solver (GSPS). As far as we know, no studies have used the finite state machine or general system theory to estimate occupancy in buildings. All above estimates can be used to adaptively update the temperature set-points for HVAC control strategy.  To demonstrate effectiveness of proposed approach, a simulation-based experimental analysis is carried out using occupancy data. We define the estimation accuracy as the total number of correct estimations divided by the total number of estimations, and both Root Mean Squared Error (RMSE) and estimation accuracy analysis are provided. All the proposed estimation techniques could achieve at least 70% accuracy rate. Generally, accuracy for binary states estimation is much higher than that of detailed occupancy. For GSPS model, more training data improves performance of estimation. It should be remarked that although some mismatch exist for non-zero jumps, estimation performance tracks the zero base line (non-occupied status) perfectly. Therefore, the estimation techniques are effective for binary estimation with over 90% accuracy. Finally, the estimated occupancy is applied into temperature set algorithm to generate reference temperature curve. By adjusting temperature set curve, we can achieve significant energy without sacrificing customer’s comfort.  In this paper, we propose three real-time occupancy estimation methods that can be incorporated into HVAC controls . We have shown the effectiveness of all the proposed approaches by simulation examples. We have seen great potential of energy saving by integrating the proposed technique into real HVAC control system.    Â

For low complexity error correction, a decoder modifies each reliability metric of an input data stream with a random perturbation value. The reliability metric comprises a weighted sum of a channel measurement for the input data stream and parity check results for the input data stream. In addition, the decoder may generate an output data stream as a function of the reliability metrics.

This paper evaluates the performance of a 125Mbps Impulse Ratio Ultra-Wideband (IR-UWB) system for cortical implant devices by using low-Q inductive coil link operating in the near-field domain. We examine design tradeoffs between transmitted signal amplitude, reliability, noise and clock jitter. The IR-UWB system is modeled using measured parameters from a reported UWB transceiver implemented in 90nm-CMOS technology. Non-optimized inductive coupling coils with low-Q value for near-field data transmission are modeled in order to build a full channel from the transmitter (Tx) to the receiver (Rx). On-off keying (OOK) modulation is used together with a low- complexity convolutional error correcting code. The simulation results show that even though the low-Q coils decrease the amplitude of the received pulses, the UWB system can still achieve acceptable performance when error correction is used. These results predict that UWB is a good candidate for delivering high data rates in cortical implant devices.

International audience; This paper presents a survey of fault-masking techniques suitable for tolerating short-duration transient upsets in minimum-scale switching devices. Two types of fault masking are considered. The first type, coded dual-modular redundancy (cDMR), represents a family of parity-checking methods suitable for correcting a low rate of transient upsets. The second type, Restorative Feedback (RFB), is a triple-modular solution suitable for compensating a higher rate of transient upsets. We show that cDMR can be used efficiently for crossbar-style logic, but is not efficient in general for all logic styles. By contrast, RFB offers a fixed redundancy, and can be applied in general to any logic circuit. Finally, we propose novel circuits for ternary Muller C implementation based on carbon nanotube FET devices.