| 51. |
- Hakansson, Victor Wattin, et al.
(författare)
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Optimal Transmission-Constrained Scheduling of Spatio-temporally Dependent Observations using Age-of-Information
- 2022
-
Ingår i: IEEE Sensors Journal. - Piscataway, NJ, United States : Institute of Electrical and Electronics Engineers (IEEE). - 1530-437X .- 1558-1748 .- 2379-9153. ; 22:15, s. 15596-15606
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Tidskriftsartikel (refereegranskat)abstract
- This paper proposes an optimal scheduling policy for broadcasting spatio-temporally dependent observations to two remote estimators over a finite time horizon. The system comprises a scheduler that can broadcast one observation from one out of two spatio-temporally dependent processes at each time instant. Since the number of broadcasting instants for each sensor is constrained, the scheduler must plan the broadcasting that minimizes the time-averaged estimation error. As the scheduler cannot observe the measurements, it determines the expected estimation error based on the age-of information (AoI). Using AoI as a state variable, we derive a set of optimal scheduling policies that minimizes the average mean squared error (MSE) for any given time horizon. The policies provide the optimal number of transmission instances for each sensor and time-varying AoI thresholds for when to be scheduled. By studying how the MSE evolves with respect to the AoI generated by a given scheduling sequence, we can obtain an optimal policy using a low-complexity numerical method. Numerical results validate the theory and demonstrate how utilizing spatio-temporal dependencies together with AoI can enhance the estimation accuracy in a communication-constrained sensor network.
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| 52. |
- Haseeb, Mohamed Abudulaziz Ali, et al.
(författare)
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Wisture : Touch-Less Hand Gesture Classification in Unmodified Smartphones Using Wi-Fi Signals
- 2019
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Ingår i: IEEE Sensors Journal. - : Institute of Electrical and Electronics Engineers (IEEE). - 1530-437X .- 1558-1748. ; 19:1, s. 257-267
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Tidskriftsartikel (refereegranskat)abstract
- This paper introduces Wisture, a new online machine learning solution for recognizing touch-less hand gestures on a smartphone (mobile device). Wisture relies on the standard Wi-Fi received signal strength measurements, long short-term memory recurrent neural network (RNN) learning method, thresholding filters, and a traffic induction approach. Unlike other Wi-Fi-based gesture recognition methods, the proposed method does not require a modification of the device hardware or the operating system and performs the gesture recognition without interfering with the normal operation of other smartphone applications. We discuss the characteristics of Wisture and conduct extensive experiments to compare the performance of the RNN learning method against the state-of the-art machine learning solutions regarding both accuracy and efficiency. The experiments include a set of different scenarios with a change in spatial setup and network traffic between the smartphone and Wi-Fi access points. The results show that Wisture achieves an online gesture recognition accuracy of up to 93% (average 78%) in detecting and classifying three gestures.
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| 53. |
- Hassanli, Kourosh, et al.
(författare)
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High Resolution Digital Imager Based on Time Multiplexing Algorithm
- 2017
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Ingår i: IEEE Sensors Journal. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 1530-437X .- 1558-1748. ; 17:9, s. 2831-2840
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a new high-resolution digital imager based on a time multiplexing scheme is proposed. The imager produces a 256-grayscale image through capturing 256 successive frames that each belongs to a specific luminance range. Each pixel includes a 1-b analog-to-digital converter (ADC) and a single bit static memory to improve the fill factor. The in-pixel ADC is designed as a compact and fast converter to achieve a high-resolution and video-rate image sensor. The proposed sensor is designed and implemented in a standard 180-nm CMOS technology. The imager achieves an overall dynamic range of over 140 dB at video rate imaging. The pixel pitch is 18.3 mu m and the fill factor is about 48%. The circuit operates at a supply voltage as low as 800 mV. At this supply voltage and at video rate imaging, its power consumption is about 4.33 nW. The proposed imager can directly perform some pre-processing algorithms, such as image segmentation and binarization. Additionally, the proposed method transfers the memory and process units of the pixels to the external of the sensor array so it provides a suitable structure for designing high-resolution, wide dynamic range, and fast general-purpose image sensors.
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| 54. |
- Hinnemo, Malkolm, 1986-, et al.
(författare)
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Protein sensing beyond the Debye Length Using Graphene Field-effect Transistors
- 2018
-
Ingår i: IEEE Sensors Journal. - : Institute of Electrical and Electronics Engineers (IEEE). - 1530-437X .- 1558-1748. ; 18:16, s. 6497-6503
-
Tidskriftsartikel (refereegranskat)abstract
- Sensing biomolecules in electrolytes of high ionic strength has been a difficult challenge for field-effect transistor-based sensors. Here, we present a graphene-based transistor sensor that is capable of detection of antibodies against protein p53 in electrolytes of physiological ionic strength without dilution. As these molecules are much larger than the Debye screening length at physiological ionic strengths, this paper proves the concept of detection beyond the Debye length. The measured signal associated with the expected specific binding of the antibodies to p53 is concluded to result from resistance changes at the graphene-electrolyte interface, since a sensor responding to resistance changes rather than charge variations is not limited by Debye screening. The conclusion with changes in interface resistance as the underlying phenomena that lead to the observed signal is validated by impedance spectroscopy, which indeed shows an increase of the total impedance in proportion to the amounts of bound antibodies. This finding opens up a new route for electrical detection of large-size and even neutral biomolecules for biomedical detection applications with miniaturized sensors.
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| 55. |
- Hostettler, Roland, et al.
(författare)
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Joint Vehicle Trajectory and Model Parameter Estimation using Road Side Sensors
- 2015
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Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 15:9, s. 5075-5086
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Tidskriftsartikel (refereegranskat)abstract
- This article shows how a particle smoother based system identification method can be applied for estimating the trajectory of road vehicles. As sensors, a combination of an accelerometer measuring the road surface vibrations and a magnetometer measuring magnetic disturbances mounted on the side of the road are considered. First, sensor models describing the measurements of the two sensors are introduced. It is shown that these depend on unknown, static parameters that have to be considered in the estimation. Second, the sensor models are combined with a two-dimensional constant velocity motion model. Third, the system identification algorithm is introduced which iteratively runs a Rao-Blackwellized particle smoother to estimate the vehicle trajectory followed by an expectation-maximization step to estimate the parameters. Finally, the method is applied to both simulation and measurement data. It is found that the method works well in general and some issues when real data is considered are identified as future work.
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| 56. |
- Huang, Chuan, et al.
(författare)
-
MAINS: A Magnetic-Field-Aided Inertial Navigation System for Indoor Positioning
- 2024
-
Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 24:9, s. 15156-15166
-
Tidskriftsartikel (refereegranskat)abstract
- A Magnetic-field-Aided Inertial Navigation System (MAINS) for indoor navigation is proposed in this paper. MAINS leverages an array of magnetometers to measure spatial variations in the magnetic field, which are then used to estimate the displacement and orientation changes of the system, thereby aiding the inertial navigation system (INS). Experiments show that MAINS significantly outperforms the stand-alone INS, demonstrating a remarkable two orders of magnitude reduction in position error. Furthermore, when compared to the state-of-the-art magnetic-field-aided navigation approach, the proposed method exhibits slightly improved horizontal position accuracy. On the other hand, it has noticeably larger vertical error on datasets with large magnetic field variations. However, one of the main advantages of MAINS compared to the state-of-the-art is that it enables flexible sensor configurations. The experimental results show that the position error after 2 minutes of navigation in most cases is less than 3 meters when using an array of 30 magnetometers. Thus, the proposed navigation solution has the potential to solve one of the key challenges faced with current magnetic-field simultaneous localization and mapping (SLAM) solutions — the very limited allowable length of the exploration phase during which unvisited areas are mapped.
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| 57. |
- Hök, Bertil, et al.
(författare)
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Breath Analyzer for Alcolocks and Screening Devices
- 2010
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Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 10, s. 10-15
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Tidskriftsartikel (refereegranskat)abstract
- Alcolocks and alcohol screening devices are becoming commonplace, and their use is expected to grow rapidly with cost reduction and improved usability. A new breath analyzer prototype is demonstrated, with the prospects of eliminating the mouthpiece, reducing expiration time and volume, improving long-term stability, and reducing life cycle cost. Simultaneous CO2 measurements compensate for the sample dilution and unsaturated expiration. Infrared transmission spectroscopy is used for both the alcohol and CO2 measurement, yet the entire system is contained within a small handheld unit. Experimental results are reported on the device sensitivity, linearity, resolution, and influence from varying measuring distance. The correlation between early and full-time sampling was established in 60 subjects. Basic concept verification was obtained, whereas resolution and selectivity still needs to be improved. Further improvements are expected by system optimization and integration.
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| 58. |
- Ikram, Mohd Kamran, et al.
(författare)
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Voltage Independent Reactive Current Based Sensor for Static VAr Control Applications
- 2023
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Ingår i: IEEE Sensors Journal. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 1530-437X .- 1558-1748. ; 23:9, s. 10023-10031
-
Tidskriftsartikel (refereegranskat)abstract
- The use of renewable energy-based converters is continuously increasing in modern power systems which inject voltage harmonics in the line. In this work, a novel, simple technique based on a binary (on/off) control of an analog switch is proposed to measure reactive current and reactive power. This method eliminates the requirement of finding sin(f) and its multiplication with the current signal in reactive power computation. The proposed transducer gives a dc signal proportional to the reactive current of a power system, i.e., Isin(f), which is suitable for static VAr compensator (SVC) applications. This transducer output is sufficient as the terminal voltage is common for the measurement as well as for the compensation current. Thus, the required current of SVC for compensation is equal to or proportional to Isin(f). Moreover, voltage harmonics are common in a power system. These harmonics affect the measurement of fundamental reactive power. This method eliminates the need for voltage measurement and hence the measurement is independent of the harmonics of the voltage, which reduces the measurement error. The proposed method is proved mathematically, and its performance is successfully validated through simulation analysis and hardware implementation. The advantages of the proposed technique are linearity of the transducer output, simple working, inexpensive hardware realization, fast response, and online measurement capability. The response time of the transducer is one cycle of supply voltage which is suitable for SVC applications.
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| 59. |
- Iqbal, W., et al.
(författare)
-
PCSS : Privacy Preserving Communication Scheme for SDN Enabled Smart Homes
- 2022
-
Ingår i: IEEE Sensors Journal. - : Institute of Electrical and Electronics Engineers (IEEE). - 1530-437X .- 1558-1748. ; 22:18, s. 17677-17690
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Tidskriftsartikel (refereegranskat)abstract
- Smart home technology aka home automation system allows the homeowner and residents to control and monitor the smart devices like HVAC, fridge, doors, cameras etc. These features offer peace of mind to users by providing a safe and well-suited environment. However, at the same time the connected devices are exploited by the cybercriminals for carrying out various sophisticated attacks due to no or minimal security functionalities in the currently produced smart devices. Due to no authentication and plain text data transmission, intruders can get user profiles, learn user behavior, and can even inject malwares in the un-authenticated devices. Therefore, authentication and privacy preserving user queries remains the key issues in wide adaptation of such technologies. Adding to this dilemma, the traditional security solutions cannot be deployed in the low processing devices. Therefore, to overcome the security issues of these low processing gadgets, a network level, lightweight cryptographic security mechanisms are necessitated where the processing is done at the network level middle box rather than low resources end devices. In this aspect, the evolving networking paradigm Software Defined Networking (SDN) offers such properties like programmability, agility, centralized management, and vendor neutrality that overcome the conventional networking control, management, and security problems. The controller of SDN at the control layer manages all the computation and complexities at the network level, rather than at the smart devices. Therefore, in this research, we present a privacy preserving communication scheme for SDN enabled smart homes (PCSS), which aims at provisioning user and smart device authentication, privacy for data (rest and transit) and user queries. It hinders the learning and modification of data by any intruder during the transmission and features mutual authentication of user, controller, and smart device. PCSS, also offers privacy preserving user queries for the smart homes. This is achieved by proposing a symmetric key based lightweight authentication and searchable encrypted queries protocol. We further highlight that the experimental results show the efficacy and usefulness of PCSS scheme when compared with existing secure smart home/system protocols.
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| 60. |
- Jason, Johan, et al.
(författare)
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Experimental Study of an Intensity Modulated Fiber-Optic Position Sensor with a Novel Readout System
- 2008
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Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 8:7, s. 1105-1113
-
Tidskriftsartikel (refereegranskat)abstract
- An intensity modulated fiber-optic position sensor, based on a fiber to bundle coupling and a readout system using a CMOS image camera together with fast routines for position extraction and calibration, is experimentally demonstrated. Further a simulation of the complete sensor system setup is made, and possible sources of error are analyzed experimentally. Our analysis indicates the theoretical limit of the system and identifies the causes of system errors. The results are encouraging for further development of the system setup.
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