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This paper proposes an asymmetric ultra-wideband - radio frequency identification (UWB-RFID) tag with electrocardiogram (ECG)-sensing capability for patients remote-monitoring in hospital environment. A UWB-RFID communication protocol is suggested for real-time transmission of undistorted ECG by interleaving ADC sampling and burst-mode UWB transmission. The proposed system shows a maximum accessing capability of 400 tags/second at 1.5 KHz ECG sampling rate with 10 Mbps UWB pulse rate. The tag consists of UHF-RFID receiver, UWB transmitter, ECG analog front-end, multi-input ADC and baseband circuitry integrated on two silicon dies. It was implemented by 6 mm2 -sized 180 nm CMOS technology. Electrodes for ECG-sensing are manufactured by inkjet-printing on polyimide substrate. Experiment results show that the tag transmits UWB pulses at 1 Mbps rate with 18 µW power. The printed electrodes conduct ECG waveform comparable to commercial electrodes., QC 20151012

Coarse Grained Reconfigurable Architectures (CGRAs) are emerging as enabling platforms to meet the high performance demanded by modern embedded applications. In many application domains (e.g. robotics and cognitive embedded systems), the CGRAs are required to simultaneously host processing (e.g. Audio/video acquisition) and estimation (e.g. audio/video/image recognition) tasks. Recent works have revealed that the efficiency and scalability of the estimation algorithms can be significantly improved by using neural networks. However, existing CGRAs commonly employ homogeneous processing resources for both the tasks. To realize the best of both the worlds (conventional processing and neural networks), we present FIST. FIST allows the processing elements and the network to dynamically morph into either conventional CGRA or a neural network, depending on the hosted application. We have chosen the DRRA as a vehicle to study the feasibility and overheads of our approach. Synthesis results reveal that the proposed enhancements incur negligible overheads (4.4% area and 9.1% power) compared to the original DRRA cell., QC 20160526

Coarse Grained Reconfigurable Architectures (CGRAs) are emerging as enabling platforms to meet the high performance demanded by modern applications. Commonly, CGRAs are composed of a computation layer (that performs computations) and a memory layer (that provides data and config ware to the computation layer). Tempted by higher platform utilization and reliability, recently proposed CGRA soffer dynamic application remapping (for the computation layer). Distributed scratch pad (compiler programmed) memories offer high data rates, predictability and low the power consumption (compared to caches). Therefore, the distributed scratchpad memories are emerging as preferred implementation alternative for the memory layer in recent CGRAs. However, the scratchpad memories are programmed at compile time, and do not support dynamic application remapping. The existing solutions that allow dynamic application remapping either rely on fat binaries (that significantly enhance configuration memory requirements) or consider a centralized memory. To extract the benefits of both runtime remapping and distributed scratchpad memories, we present a design framework called DyMeP. DyMeP relies on late binding and provides the architectural support to dynamically remap data in CGRAs. Compared to the state of the art, the proposed technique reduces the configuration memory requirements (needed by fat binary solutions) and supports distributed shared scratchpad memory. Synthesis/Simulation results reveal that DyMeP promises a significant (up to 60%) reduction in config ware size at the cost of negligible additional overheads (less then 1%)., QC 20161121

In the era of platforms hosting multiple applications with arbitrary performance requirements, providing a worst-case platform-wide voltage/frequency operating point is neither optimal nor desirable. As a solution to this problem, designs commonly employ dynamic voltage and frequency scaling (DVFS). DVFS promises significant energy and power reductions by providing each application with the operating point (and hence the performance) tailored to its needs. To further enhance the optimization potential, recent works interleave dynamic parallelism with conventional DVFS. The induced parallelism results in performance gains that allow an application to lower its operating point even further (thereby saving energy and power consumption). However, the existing works employ costly dedicated hardware (for synchronization) and rely solely on greedy algorithms to make parallelism decisions. To efficiently integrate parallelism with DVFS, compared to state-of-the-art, we exploit the reconfiguration (to reduce DVFS synchronization overheads) and enhance the intelligence of the greedy algorithm (to make optimal parallelism decisions). Specifically, our solution relies on dynamically reconfigurable isolation cells and an autonomous parallelism, voltage, and frequency selection algorithm. The dynamically reconfigurable isolation cells reduce the area overheads of DVFS circuitry by configuring the existing resources to provide synchronization. The autonomous parallelism, voltage, and frequency selection algorithm ensures high power efficiency by combining parallelism with DVFS. It selects that parallelism, voltage, and frequency trio which consumes minimum power to meet the deadlines on available resources. Synthesis and simulation results using various applications/algorithms (WLAN, MPEG4, FFT, FIR, matrix multiplication) show that our solution promises significant reduction in area and power consumption (23% and 51%) compared to state-of-the-art.

This paper presents a phase noise improvement method for fine tuning of type-I ADPLL by exploiting its nonlinear quantization effects. When quantization step approaches the same orders of magnitude of standard deviation of input noise, quantization effects become nonlinear, and additive noise modeling of quantization effects is no longer applicable. By proper offsetting the input signals in this case, the feedback loop of ADPLL can be very sensitive to frequency phase deviation. It results in a larger loop bandwidth, and in turn smaller in-band phase noise than in linear quantization case. A theoretic s-domain noise model is proposed to quantify the phase noise in nonlinear case. Results are verified in Modelsim simulations. Proposed method offers possibility of achieving lower phase noise by lower quantization resolution and less circuit design efforts., QC 20150601

Power management of NoC-based many-core systems with runtime application mapping becomes more challenging in the dark silicon era. It necessitates a multi-objective control approach to consider an upper limit on total power consumption, dynamic behaviour of workloads, processing elements utilization, per-core power consumption, and load on network-on-chip. In this paper, we propose a multi-objective dynamic power management method that simultaneously considers all of these parameters. Fine-grained voltage and frequency scaling, including near-threshold operation, and per-core power gating are utilized to optimize the performance. In addition, a disturbance rejecter is designed that proactively scales down activity in running applications when a new application commences execution, to prevent sharp power budget violations. Simulations of dynamic workloads and mixed time-critical application profiles show that our method is effective in honoring the power budget while considerably boosting the system throughput and reducing power budget violation, compared to the state-of-the-art power management policies., QC 20151218

This paper addresses the issue of UWB signal acquisition in the context of wireless powered UWB RFID systems. In this scenario, the data transmission is based on short packet so as to meet the micro-power budget of autonomous power harvesting. The burst short packet transmission as well as the low duty cycling UWB pulse modulation places a stringent challenge at the UWB receiver for timing acquisition and packet detection. Besides, in a positioning enabled RFID system where variable signal-to-noise ratio (SNR) due to the variable link distance and noise background is unavoidable, conventional packet detection schemes rely on predefined threshold can hardly achieve good performance. In this study, we propose a low complexity method for burst packet detection. It is performed by sensing the preamble signal characteristic instead of the received signal strength, and thus bypassing the necessity of detection threshold. The validity of the proposed approach and its adaptivity to SNR variations is demonstrated by simulation results as well as field test with a UWB software defined radio (SDR) platform., QC 20160404

Increasing dynamic workloads running on NoC-based many-core systems necessitates efficient runtime mapping strategies. With an unpredictable nature of application profiles, selecting a rational region to map an incoming application is an NP-hard problem in view of minimizing congestion and maximizing performance. In this paper, we propose a proactive region selection strategy which prioritizes nodes that offer lower congestion and dispersion. Our proposed strategy, MapPro, quantitatively represents the propagated impact of spatial availability and dispersion on the network with every new mapped application. This allows us to identify a suitable region to accommodate an incoming application that results in minimal congestion and dispersion. We cluster the network into squares of different radii to suit applications of different sizes and proactively select a suitable square for a new application, eliminating the overhead caused with typical reactive mapping approaches. We evaluated our proposed strategy over different traffic patterns and observed gains of up to 41% in energy efficiency, 28% in congestion and 21% dispersion when compared to the state-of-the-art region selection methods., QC 20160212

Bioimpedance is a noninvasive measurement method that facilitates body composition analysis, besides being indicative of many other health parameters. In this work a novel programmable, low complexity, high output impedance, high voltage compliance and wideband current source for bioimpedance applications is presented. Previously, we designed, fabricated and tested in vivo a bio-patch for acquisition of multiple bio-signals [1]. Upon integration with our previous work, this circuit is envisioned to constitute part of a personalized health assistant. Simulation at worst case corners and real operation conditions was carried out using UMC-180 nm 1 poly 6 metal CMOS process. Full duty cycle, shortened or stepped square waves can be generated. Amplitude control of 8 different current levels is supported. Frequency can be tuned up to 1 MHz and an output impedance of 2.8 MO @ 250 KHz is achieved at full current capacity. Total current consumption is comparable to the injected current, making the circuit highly efficient., QC 20151215

Increasing dynamic workloads running on NoC-based many-core systems necessitates efficient runtime mapping strategies. With an unpredictable nature of application profiles, selecting a rational region to map an incoming application is an NP-hard problem in view of minimizing congestion and maximizing performance. In this paper, we propose a proactive region selection strategy which prioritizes nodes that offer lower congestion and dispersion. Our proposed strategy, MapPro, quantitatively represents the propagated impact of spatial availability and dispersion on the network with every new mapped application. This allows us to identify a suitable region to accommodate an incoming application that results in minimal congestion and dispersion. We cluster the network into squares of different radii to suit applications of different sizes and proactively select a suitable square for a new application, eliminating the overhead caused with typical reactive mapping approaches. We evaluated our proposed strategy over different traffic patterns and observed gains of up to 41% in energy efficiency, 28% in congestion and 21% dispersion when compared to the state-of-the-art region selection methods. Copyright 2015 ACM., Funding Details: Academy of Finland. QC 20161115

Internet of Things based systems provides a viable and organized approach to improve health and wellbeing of mankind. Particularly, health monitoring systems based on wireless body sensor networks become attainable due to increasing number of elderly people that needs healthcare services frequently. In such system, power consumption of a sensor node is an important issue. In order to handle the issue, a smart gateway with fog computing capabilities is presented. Fog computing includes several services such as distributed database management, Electrocardiography (ECG) feature extraction, user graphical interface with access management and push notations. With fog computing, the burden of a cloud server can be reduced and more than 50% of power consumption can be saved at a sensor node. Additionally, through fog computing, the system ensures that the obtained health data can be visualized and diagnosed in real-time even though there is a disconnection between the gateway and cloud server., QC 20150623

In this paper, a secure and efficient authentication and authorization architecture for IoT-based healthcare is developed. Security and privacy of patients’ medical data are crucial for the acceptance and ubiquitous use of IoT in healthcare. Secure authentication and authorization of a remote healthcare professional is the main focus of this work. Due to resource constraints of medical sensors, it is infeasible to utilize conventional cryptography in IoT-based healthcare. In addition, gateways in existing IoTs focus only on trivial tasks without alleviating the authentication and authorization challenges. In the presented architecture, authentication and authorization of a remote end-user is done by distributed smart e-health gateways to unburden the medical sensors from performing these tasks. The proposed architecture relies on the certificate-based DTLS handshake protocol as it is the main IP security solution for IoT. The proposed authentication and authorization architecture is tested by developing a prototype IoT-based healthcare system. The prototype is built of a Pandaboard, a TI SmartRF06 board and WiSMotes. The CC2538 module integrated into the TI board acts as a smart gateway and the WisMotes act as medical sensor nodes. The proposed architecture is more secure than a state-of-the-art centralized delegation-based architecture because it uses a more secure key management scheme between sensor nodes and the smart gateway. Furthermore, the impact of DoS attacks is reduced due to the distributed nature of the architecture. Our performance evaluation results show that compared to the delegation-based architecture, the proposed architecture reduces communication overhead by 26% and communication latency from the smart gateway to the end-user by 16%., QC 20150618

This paper demonstrates a smart catheter system with intracranial pressure (ICP) and temperature sensing capability which is designed for real-time monitoring in traumatic brain injury (TBI) therapy. It uses a single flexible catheter with a 1 mm (3 Fr) diameter that integrates electrodes and sophisticated silicon chip on flexible substrates, enabling multimodality monitoring of physiological signals. A micro-electromechanical-system (MEMS) catheter pressure sensor is mounted on the distal end. It can be used for detecting both pressure and temperature by different switch configurations, which minimizes the size of catheter and reduces the cost. The interconnects (signalling conductors) are printed on a bio-compatible flexible substrate, and the sensor is interfaced with an embedded electronic system at the far-end. The electronic system consists of analog front end with analog-to-digital converter (ADC), a microcontroller, and data interface to the hospital infrastructure with a graphical user interface (GUI). The overall smart catheter system achieves a pressure sensing root mean square error (RMSE) of ±1.5 mmHg measured from 20 mmHg to 300 mmHg above 1 atm and a temperature sensing RMSE of ±0.08°C measured from 32°C to 42°C. The sampling rate can be up to 10S/s. The in vivo performance is demonstrated in laboratory animals., QC 20151014. QC 20160212

A critical challenge faced in Internet of Things (IoT) is the heterogeneous nature of its nodes from the network protocol and platform point of view. To tackle the heterogeneous nature, we introduce a distributed and lightweight service bus, LISA, which fits into network stack of a real-time operating system for constrained nodes in IoT. LISA provides an application programming interface for developers of IoT on tiny devices. It hides platform and protocol variations underneath it, thus facilitating interoperability challenges in IoT implementations. LISA is inspired by the Network on Terminal Architecture (NoTA), a service centric open architecture by Nokia Research Center. Unlike many other interoperability frameworks, LISA is designed specifically for resource constrained nodes and it provides essential features of a service bus for easy service oriented architecture implementation., QC 20150618

There have been significant advances in the field of Internet of Things (IoT) recently. At the same time there exists an ever-growing demand for ubiquitous healthcare systems to improve human health and well-being. In most of IoT-based patient monitoring systems, especially at smart homes or hospitals, there exists a bridging point (i.e., gateway) between a sensor network and the Internet which often just performs basic functions such as translating between the protocols used in the Internet and sensor networks. These gateways have beneficial knowledge and constructive control over both the sensor network and the data to be transmitted through the Internet. In this paper, we exploit the strategic position of such gateways to offer several higher-level services such as local storage, real-time local data processing, embedded data mining, etc., proposing thus a Smart e-Health Gateway. By taking responsibility for handling some burdens of the sensor network and a remote healthcare center, a Smart e-Health Gateway can cope with many challenges in ubiquitous healthcare systems such as energy efficiency, scalability, and reliability issues. A successful implementation of Smart e-Health Gateways enables massive deployment of ubiquitous health monitoring systems especially in clinical environments. We also present a case study of a Smart e-Health Gateway called UTGATE where some of the discussed higher-level features have been implemented. Our proof-of-concept design demonstrates an IoT-based health monitoring system with enhanced overall system energy efficiency, performance, interoperability, security, and reliability., QC 20161017

Efficiency of Network-on-Chip based many-core microprocessors to implement parallel fault simulation methods for different circuit sizes is explored in this paper. We show that a naive and straightforward execution of fault simulation programs on such systems does not provide the maximum speedup due to severe bottlenecks in off-chip shared memory access at memory controllers. In order to exploit the available massive parallelism of homogenous many-core microprocessors, a runtime approach capable of adaptively balancing the load during the fault simulation process is proposed. We demonstrate the proposed adaptive fault simulation approach on a many-core platfonn, Intels Single-chip Cloud Computer showing up to 45X speedup compared to a serial fault simulation approach., QC 20161024. QC 20200630

QC 20150807

Internet of Things technology provides a competent and structured approach to improve health and wellbeing of mankind. One of the feasible ways to offer healthcare services based on IoT is to monitor humans health in real-time using ubiquitous health monitoring systems which have the ability to acquire bio-signals from sensor nodes and send the data to the gateway via a particular wireless communication protocol. The real-time data is then transmitted to a remote cloud server for real-time processing, visualization, and diagnosis. In this paper, we enhance such a health monitoring system by exploiting the concept of fog computing at smart gateways providing advanced techniques and services such as embedded data mining, distributed storage, and notification service at the edge of network. Particularly, we choose Electrocardiogram (ECG) feature extraction as the case study as it plays an important role in diagnosis of many cardiac diseases. ECG signals are analyzed in smart gateways with features extracted including heart rate, P wave and T wave via a flexible template based on a lightweight wavelet transform mechanism. Our experimental results reveal that fog computing helps achieving more than 90% bandwidth efficiency and offering low-latency real time response at the edge of the network., QC 20160523 QC 20160922

Facial expression recognition has broad application prospects in the fields of psychological study, nursing care, Human Computer Interaction as well as affective computing. The method with surface Electromyogram (sEMG), which is one of vital bio-signals, has its superiority in several aspects such as high temporal resolution and data processing efficiency over other methods. Researches regarding EMG signal to study emotional expression have started since the second half of last century. Meanwhile, studies on myoelectrical control systems focusing on the computation of bio-signal processing and data analysis have been blooming in the recent twenty years. To have a comprehensive view of utilizing facial sEMG method, a systematic review is presented in this paper for facial expression recognition from experiment design to measurement systems, and data analysis steps., QC 20160527

We study a static model for 2-D and 3-D networks that accurately represents the average distance travelled by packets under deflection routing, which is a specific form of adaptive routing. The model captures static properties of the network topology and the spatial distribution of traffic, but does not take into account traffic loading and congestion. Even though this static model cannot accurately predict packet latency under high load, we contend that it is a perfect predictor of deflection routing networks’ relative performance under any load condition below saturation, and thus always correctly predicts the optimum network configuration. This is verified through cycle-accurate simulations of congested and uncongested networks with fully adaptive, deflection routing for regular traffic patterns such as uniform random, localised, bursty, and others, as well as irregular patterns in both regular and irregular networks. As the networks with minimal average distance perform best even under high traffic load, the average distance model establishes a robust relation between a static network property, average distance, and network performance under load, providing new insight into network behaviour and an opportunity to identify the optimal network configuration without time-consuming simulations., QC 20151221. QC 20160121

Frequency signature chipless RFID tag based on spurline resonator is presented in this letter. Resonant response of spurline is explained by analyzing the surface current distribution. Chipless tag consists of a data encoding circuit and two cross polarised monopole antennas. The tag has a data capacity of 16 bits in the range 2.13 to 4.1 GHz. Data capacity of data encoding circuit is enhanced by repositioning the spurlines. The prototype of the tag is fabricated on FR4 substrate. Developed tag can be used for cost effective identification of items in the industry., QC 20151103

In this paper, a session resumption-based end-toend security scheme for healthcare Internet of things (IoT) is proposed. The proposed scheme is realized by employing certificatebased DTLS handshake between end-users and smart gateways as well as utilizing DTLS session resumption technique. Smart gateways enable the sensors to no longer need to authenticate and authorize remote end-users by handing over the necessary security context Session resumption technique enables end-users and medical sensors to directly communicate without the need for establishing the communication from the initial handshake. Session resumption technique has an abbreviated form of DTLS handshake and neither requires certificate-related nor public-key funtionalities. This alleviates some burden of medical sensors to no longer need to perform expensive operations. The energyperformance evaluations of the proposed scheme are evaluated by developing a remote patient monitoring prototype based on healthcare IoT. The energy-performance evaluation results show that our scheme is about 97% and 10% faster than certificatebased and symmetric key-based DTLS, respectively. Also, the certificate-based DTLS consumes about 2.2X more RAM and 2.9X more ROM resources required by our scheme. While, our scheme and symmetric key-based DTLS have almost similar RAM and ROM requirements. The security analysis reveals that the proposed scheme fulfills the requirements of end-to-end security and provides higher security level than related approaches found in the literature. Thus, the presented scheme is a wellsuited solution to provide end-to-end security for healthcare IoT., QC 20160601

This paper presents optimizations on guard time and synchronization cycle for Time Division Multiple Access (TDMA) based deterministic Radio Frequency Identification (RFID) system. The TDMA scheme can provide guaranteed latency and high throughput for RFID system that includes fixed number of users (tags) and requests long-message transmission. However, collisions due to accumulated clock drifts of the active RFID tags equipped with independent self-clocked microcontrollers are the major challenge. In this work, we model relations between guard time and synchronization cycle used to tolerate the accumulated clock drift and reduce the probability of collisions for an extended-star RFID system. Constraints of safe guard time and synchronization cycle are proposed to consider energy efficiency and time efficiency. Moreover, optimization on guard time and synchronization cycle are explored in terms of transmission time, tag number, energy efficiency and time efficiency. The simulation results indicate that system with long transmission time (around 1 ms) enjoys higher time and energy efficiency under optimal configuration of guard time and synchronization cycle., QC 20160616

This paper introduces a new, practical routing algorithm, Maze-routing, to tolerate faults in network-on-chips. The algorithm is the first to provide all of the following properties at the same time: 1) fully-distributed with no centralized component, 2) guaranteed delivery (it guarantees to deliver packets when a path exists between nodes, or otherwise indicate that destination is unreachable, while being deadlock and livelock free), 3) low area cost, 4) low reconfiguration overhead upon a fault. To achieve all these properties, we propose Maze-routing, a new variant of face routing in on-chip networks and make use of deflections in routing. Our evaluations show that Maze-routing has 16X less area overhead than other algorithms that provide guaranteed delivery. Our Maze-routing algorithm is also high performance: for example, when up to 5 links are broken, it provides 50% higher saturation throughput compared to the state-of-the-art. Copyright 2015 ACM., Funding Details: SRC, Semiconductor Research Corporation. QC 20161115

This work gives a unique insight into evaluating sustainability, life cycle assessment and environmental emissions of the specified RFID tag antenna that validates the potential for ultra-low cost mass production for green electronics. We have designed a printed RFID antenna that employs commercially available paper substrates, and has capability to endure itself at varying environmental effects. The geometry and dimension of the antenna has been set as per requirement of read range of RFID tag. The environmental emissions profiles global warming, acidification potential, ozone layer depletion and human toxicity potentials are illustrated in this paper., QC 20170629

Cyber Physical Systems (CPS) are typically implemented on multicore platforms to handle computational pressure and performance requirements. Complex data flows in those applications cause contention among networked processors, resulting in unpredictable performance. In this work, we explore the impact of application mapping on network contention and predictability. A mapping algorithm focusing on minimizing the number of shared paths while not worsening the total path count is proposed. This algorithm is verified against other recent works over synthetic and realistic traffic patterns. The proposed algorithm considerably improved predictability with 0% shared paths and reasonable latency constraints compared to the other recently proposed algorithms., QC 20160527

Early warning score (EWS) is an approach to detect the deterioration of a patient. It is based on a fact that there are several changes in the physiological parameters prior a clinical deterioration of a patient. Currently, EWS procedure is mostly used for in-hospital clinical cases and is performed in a manual paper-based fashion. In this paper, we propose an automated EWS health monitoring system to intelligently monitor vital signs and prevent health deterioration for in-home patients using Internet-of-Things (IoT) technologies. IoT enables our solution to provide a real-Time 24/7 service for health professionals to remotely monitor inhome patients via Internet and receive notifications in case of emergency. We also demonstrate a proof-of-concept EWS system where continuous reading, transferring, recording, and processing of vital signs have been implemented., QC 20200928