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From the viewpoint of user management, continuous authentication is effective. However, general biometrics such as fingerprint, iris, vein, and so on are not suitable for the continuous verification since they require conscious presentation of biometric data. As unconscious biometrics, to use a brain wave (electroencephalogram: EEG) has been proposed but conventional approaches require heavy computational load for feature extraction and verification and it becomes a problem for practical applications. In this paper, we propose new features: the concavity and convexity of spectral distribution in the alpha band and propose to fuse them with a spectral variance in verification. The proposed methods are achieved with low computational load. In our experiments using 23 subjects, EER of 11% is obtained and it is comparable with the performance of conventional approaches., source:Proceedings of International Symposium on Intelligent Signal Processing and Communication Systems 2009 (ISPACS2009). 2009, 651-654, source:https://ieeexplore.ieee.org/abstract/document/5383756

In recent years, biometrics such as fingerprints and iris scans has been used in authentication. However, conventional biometrics is vulnerable to identity theft, especially in user management systems. As a new biometric without this vulnerability, we focused on brain waves. In this paper, we show that individuals can be authenticated using evoked potentials when they are subjected to ultrasound. We measured the electroencephalograms (EEGs) of 10 experimental ubjects. Individual features were extracted from the power spectra of the EEGs using the principle component analysis and verification was achieved using the support vector machine. We found that for the proposed authentication method, the equal error rate for a single electrode was about 22-32 %. For a multi-electrode, the equal error rate was 4.4 % using the majority decision rule., source:Nakanishi Isao, Maruoka Takehiro. Biometric authentication using evoked potentials stimulated by personal ultrasound. Proceedings of 2019 42nd International Conference on Telecommunications and Signal Processing (TSP), pp. 365-368, Jul. 2019.

In this paper, we introduce simply partitioned DP (dynamic programming) matching and threshold equalizing into the verification process in DWT (discrete wavelet transform) domain on-line signature verification in order to improve the performance. The simply partitioned DP matching divides both data series (verification and template data) into several partitions and calculate sub DP distance every partition. Even if mismatched pairs are caused in each partition, they are initialized at the beginning of the next partition and matching errors could be reduced. The threshold equalizing suppresses the variation range of optimal thresholds for all users (signatures), so that it prevents the verification performance from degrading by common use of single threshold for all users. In particular, we propose two equalizing methods in which the relation between the number of sampled data and optimal thresholds in signatures are approximated and adjusted by linear and nonlinear functions. In verification experiments using the signature database: SVC2004, it is confirmed that the proposed methods are effective for improving the performance., source:Proceedings of 12th International Conference on Frontiers in Handwriting Recognition (ICFHR2010). 2010, 101-106, source:https://ieeexplore.ieee.org/document/5693507

We investigated the use of intra-palm propagation signals as biometrics. The intra-palm propagation signal is an electromagnetic wave that is propagated in the shallow part of the skin of a palm. However, the use of a support vector machine (SVM), which is a powerful machine learning method, does not enable superior verification performance. In this paper, we focus on problems related to measuring devices. The first problem is the contact stability between the electrodes and a palm, the second problem is the variation of the electrode position on a palm, and the third problem is the size of a palm. We develop new measuring devices by considering these problems and perform experiments to evaluate their effects., source:Proceeding of the International Symposium on Biometrics and Security Technologies 2014 (ISBAST2014) . 2014, 35-38, source:https://ieeexplore.ieee.org/document/7013090

The on-line signature verification method in DWT domain has been proposed. Time-varying pen-position signal of the on-line signature is decomposed into sub-band signals by using the DWT. Individual features are extracted as high frequency signals in sub-band. By using the extracted feature, verification is achieved at each sub-band and then total decision is done by combining such verification results. In this paper, we introduce a user weighting fusion into the total decision. Through verification experiments, it is confirmed that there is an optimal weight combination for each user and verifiaction rate can be improved when the optimal weight combination is applied., source:IEEE International Symposium on Circuits and Systems proceedings 2005 (ISCAS2005). 2005, 1698-1701, source:https://ieeexplore.ieee.org/document/1464933

In the present paper, a new single-channel speech enhancement system is proposed. The proposed system is based on frequency domain adaptive line enhancer; therefore, it is advantageous to non-stationary environments. Also, frequency domain decorrelation parameters are introduced and then adjusted independently. The performance of the proposed system is examined through computer simulations. The effectiveness of the proposed system is confirmed through computer simulations., source:IEEE International Symposium on Circuits and Systems proceedings 2006 (ISCAS2006). 2006, source:https://ieeexplore.ieee.org/abstract/document/1693141

Biometrics have been used in person authentication. However, conventional biometrics have a vulnerability to the identity theft, especially in user management systems. In order to prevent the identity theft, the effective way is to authenticate continuously. However, the continuous authentication requires unconscious biometrics. The authors have been studied to use brain waves as the unconscious biometrics. In conventional studies, the authors had used spontaneous brain waves; however, their verification performance was not so high. Thus, the authors propose to use evoked potentials by supersonic sounds, which cannot be perceived by human beings. In this paper, the authors examine the characteristics of evoked potentials by supersonic sounds and confirm that the spectrum in the band is increased at the electrodes on the back of the head. This phenomenon could be used as an individual feature in person verification., source:TENCON 2017 - 2017 IEEE Region 10 Conference. 2017, 1171-1174, source:https://ieeexplore.ieee.org/abstract/document/8228034

In the case of user management, continuous or on-demand biometric authentication is effective for achieving higher security with a light system load. However, it requires us to present biometric data unconsciously. In this paper, we focus attention on the brain wave as unconscious biometrics. In particular, assuming driver authentication, we measure the brain waves of drivers when they are using a simplified driving simulator. We evaluate verification performance using 23 subjects and obtain the EER of about 20 %., source:Proceedings of the International Conference of Biometrics Special Interest Group (BIOSIG) 2012. 2012, 1-5, source:https://ieeexplore.ieee.org/document/6313562

To use intra-body propagation signals for biometric authentication have been proposed. The intra-body propagation signals are hid in human bodies; therefore, they have tolerability to circumvention using artifacts. Additionally, utilizing the signals in the body enables liveness detection with no additional scheme. The problem is, however, verification performance using the intra-body propagation signal is not so high. In this paper, in order to improve the performance we propose to use user-specific frequency bands for all users in verification. The verification performance is improved to 70 %. Furthermore, we introduce the support vector machine (SVM) into the verification process. It is confirmed that verification rate of about 86 % is achieved., source:Proceedings of IEEE International Conference on Advanced Video and Signal Based Surveillance 2010. 2010, 561-566, source:https://ieeexplore.ieee.org/document/5597077

A novel writer verification method based on fingerwriting of a simple symbol on a tablet is proposed. The symbol is well known, unmistakable to write, and never forgotten, for example, a circle, triangle, or square. In this paper, a development environment for finger-writing the symbols on an Android tablet is constructed and finger-written data are captured from twenty experimental subjects. Using simple on-line and off-line individual features extracted from finger-writing data, the verification performance is examined and as a result, it is hopefully confirmed that the proposed method is feasible especially when relative individual features are used., source:I. Nakanishi and A. Takahashi. A Study on Writer Verification Based on Finger-Writing of a Simple Symbol on a Tablet. Proc. of 2018 IEEE R10 Conference (TENCON2018), pp. 2226-2230, Oct. 2018

This paper presents a multi-matcher on-line signature verification system which fuses the verification scores in pen-position parameter and pen-movement angle parameter at decision level. Features of pen-position and pen-movement angle are extracted by the sub-band decomposition using the Discrete Wavelet Transform (DWT). In the pen-position, high frequency sub-band signals are considered as individual features to enhance the difference between a genuine signature and its forgery. On the other hand, low frequency sub-band signals are utilized as the features for suppressing the intra-class variation in the penmovement angle. Verification is achieved by the adaptive signal processing using the extracted features. Verification scores in the pen-position and the pen-movement angle are integrated by using a weighted sum rule to make total decision. Experimental results show that fusion of pen-position and pen-movement angle can improve verification performance., source:IEEE International Symposium on Circuits and Systems proceedings 2005 (ISCAS2005). 2005, 5413-5416, source:https://ieeexplore.ieee.org/abstract/document/1465860

Thermal management is one of the main concerns in three-dimensional integration due to difficulty of dissipating heat through the stack of the integrated circuit. In a 3D stack involving a data-path accelerator, a base processor and memory components, peak temperature reduction is targeted in this paper. A mapping algorithm has been devised in order to distribute operations of data flow graphs evenly over the processing elements of the target accelerator in two steps involving thermal-aware partitioning of input data flow graphs, and thermal-aware mapping of the partitions onto the processing elements. The efficiency of the proposed technique in reducing peak temperature is demonstrated throughout the experiments.

Telecommunication networks are shifting to multi-cloud environments. This trend is expected to shape the standardization and implementation of future networks. Thus, the protection of virtualized services has become more critical. One of the promising methods to secure virtual resources in that setting is Moving Target Defense (MTD). This paper presents the Network Topology Fuzzer (TopoFuzzer) module, enabling different MTD operations that change the topology of a 5G network. An emphasis is given to live re-instantiations and live migrations of running services and, consequently, security gains against Advanced Persistent Threats (APTs). This work utilizes a 5G testbed to evaluate the TopoFuzzer module and MTD operations on Virtual Network Functions (VNFs).

The combination of physics and engineering information with data-driven methods like machine learning (ML) and deep learning is gaining attention in various research fields. One of the promising practical applications of such hybrid methods is for supporting maintenance decision making in the form of condition-based and predictive maintenance. In this paper we focus on the potential of physics-informed data augmentation for ML algorithms. We demonstrate possible implementations of the concept using three use cases, differing in their technical systems, their algorithms and their tasks ranging from anomaly detection, through fault diagnostics up to prognostics of the remaining useful life. We elaborate on the benefits and prerequisites of each technique and provide guidelines for future practical implementations in other systems.

This paper considers the problem of optimizing robot navigation with respect to a time-varying objective encoded into a navigation density function. We are interested in designing state feedback control laws that lead to an almost everywhere stabilization of the closed-loop system to an equilibrium point while navigating a region optimally and safely (that is, the transient leading to the final equilibrium point is optimal and satisfies safety constraints). Though this problem has been studied in literature within many different communities, it still remains a challenging non-convex control problem. In our approach, under certain assumptions on the time-varying navigation density, we use Koopman and Perron-Frobenius Operator theoretic tools to transform the problem into a convex one in infinite dimensional decision variables. In particular, the cost function and the safety constraints in the transformed formulation become linear in these functional variables. Finally, we present some numerical examples to illustrate our approach, as well as discuss the current limitations and future extensions of our framework to accommodate a wider range of robotics applications., Part of ISBN 978-3-907144-08-4QC 20230911

In this paper, a lightweight spherical Luneburg lens with high performance is introduced for use in the frequency range 1 (FR1). The continuously varying refractive index profile of the lens is implemented using a quasi-isotropic partially metalized periodic structure. Much of the lens volume is made of foam, so the design is lightweight, making it applicable for low-band microwave frequency communication systems and, more specifically, 5G communications in FR1. The periodic structure allows a simple and low-cost layered construction with a quasi-isotropic response. This approach improves the scanning performance of the lens in all angular directions when compared to equivalent lens designs previously reported. Such a structure is an ideal candidate for high-gain multi-beam communication systems., Part of ISBN 978-88-31299-07-7QC 20230911

This paper proposes a high-level path planning strategy under Time Petri net (TPN) formalism for a multi-agent system, which is subject to Metric Interval Temporal Logic (MITL) specifications. The work aims to design a scalable model with respect to the number of agents, as the MITL formula requires multiple agents to ensure similar tasks. The obtained model is denoted Composed Time Petri net and it couples two TPN representations assigned to the motion of the agents, respectively to the MITL specification. The planning approach is based on model-checking methods and the results are evaluated on a case study applied in robotics industry., Part of ISBN 978-3-907144-08-4QC 20230911

This paper focuses on the analysis of the dispersion diagram of a two-dimensional hexagonal periodic structure. The periodic inclusions are placed in a parallel plate waveguide environment and are circular holes located at the vertices of the hexagonal unit cells. The connection between the geometry of the periodic structure and the dispersion diagram is discussed. The wavevector information in the Brillouin zone is illustrated using the reciprocal lattice, from which the shape of the irreducible zone can be derived. The results give insight into the characteristics of the wave propagation characteristic of hexagonal units., Part of ISBN 978-88-31299-07-7QC 20230911

This paper presents a half-lens antenna integrated with a reflectarray. The combination of the half-lens and the reflectarray provides additional design freedom. In this work, this design freedom is used to reduce the refractive index range required to produce a planar wavefront using a half-lens, as compared to the half-Luneburg lens. Specifically, we demonstrate that the properties of a half-Luneburg lens can be mimicked with a lens that has reduced the maximum refractive index by 30% by integrating the reflectarray with the lens., Part of ISBN 978-88-31299-07-7QC 20230911

In this paper we present a lens antenna that can scan in the whole azimuthal plane. This is achieved by using two planar generalized Luneburg lenses that are connected through multiple 3 dB 90 degrees hybrid couplers. The antenna is designed for the 3GPP n260 band operating from 37 to 40 GHz making it suitable for indoor 5G coverage. Simulation results of the antenna are presented to illustrate that it can scan in the full azimuth plane., Part of ISBN 978-88-31299-07-7QC 20230911

This paper proposes a method to navigate a mobile robot by estimating its state over a number of distributed sensor networks (DSNs) such that it can successively accomplish a sequence of tasks, i.e., its state enters each targeted set and stays inside no less than the desired time, under a resource-aware, time-efficient, and computation- and communication-constrained setting. We propose a new robot state estimation and navigation architecture, which integrates an event-triggered task-switching feedback controller for the robot and a two-time-scale distributed state estimator for each sensor. With the controller, the robot is able to accomplish a task by following a reference trajectory and switch to the next task when an event-triggered condition is fulfilled. With the estimator, each active sensor is able to estimate the robot state. We provide conditions to ensure that the state estimation error and the trajectory tracking deviation are upper bounded by two time-varying sequences, respectively. Furthermore, we find a sufficient condition for accomplishing a task and provide an upper bound of running time for the task. Numerical simulations of an indoor robot's localization and navigation are provided to validate the proposed architecture., Part of ISBN 978-3-907144-08-4QC 20230911

In this paper, we consider a planning problem for a hierarchical finite state machine (HFSM) and develop an algorithm for efficiently computing optimal plans between any two states. The algorithm consists of an offline and an online step. In the offline step, one computes exit costs for each machine in the HFSM. It needs to be done only once for a given HFSM, and it is shown to have time complexity scaling linearly with the number of machines in the HFSM. In the online step, one computes an optimal plan from an initial state to a goal state, by first reducing the HFSM (using the exit costs), computing an optimal trajectory for the reduced HFSM, and then expand this trajectory to an optimal plan for the original HFSM. The time complexity is near-linearly with the depth of the HFSM. It is argued that HFSMs arise naturally for large-scale control systems, exemplified by an application where a robot moves between houses to complete tasks. We compare our algorithm with Dijkstra's algorithm on HFSMs consisting of up to 2 million states, where our algorithm outperforms the latter, being several orders of magnitude faster., Part of ISBN 978-3-907144-08-4QC 20230911

This paper reviews the potential of THz photonics in communication and sensing by presenting our experimental results in the 300-500 GHz. Benefiting from the large available bandwidth in both THz and photonics, THz communications with high speed and THz imaging with high resolution have been achieved., QC 20230811

An effective earthing system with new earth resistance reducing agents (ERRA) and purpose-made electrode configuration has been discussed as Active Electrical Earthing System (AEES). This paper is a precursor of a research work that will be presented consequently. Conventional earthing systems pose undefeatable challenges in some instances due to the expansion of system loads, compactness of sites and environmental degradation of the earthing systems. The development of new and more sophisticated electrical systems requires earthing systems that are effective, durable and site-specific. In urban areas with high population density and also at sites of pathological landscapes (such as tower sites in mountain terrains, and lightning protection of urban buildings), the availability of large soil masses for effective earthing systems is a significant challenge. Rapid material degradation of earthing rods is a significant issue in corrosive atmospheres, where both air quality and soil composition may contribute to the aggressiveness of the surrounding electrode material. Thus, more robust, and site-effective earthing technologies that may mitigate these drawbacks, have a high demand on the market front at present. This paper discusses the existing systems and methodology for a new system.

Dynamic instability of hypersonic aircraft was well known. To ensure a stable and controlled flight throughout the hypersonic flight phase, a robust automatic flight control system was needed. In addition, in the unlikely event of a flight control failure, the autopilot must be able to remain operational and maintain flight stability. In this paper, the hypersonic aircraft feedback control system was designed using Linear Quadratic Regulator theory to guarantee dynamic stability and ensure robustness. Not all aircraft state variables were measurable hence, Luenberger estimator was incorporated to estimate the other states. Then a Control Reconfiguration System was incorporated to recover dynamic stability in the event of flight control failure. The work done showed that during single flight control malfunction, the feedback control system, Luenberger estimator and Control Reconfiguration System were able to maintain flight stability. This paper also shows that activities of the remaining working flight controls increased significantly to compensate for the lost, to maintain dynamic stability.

This paper discusses the effect of lightning-induced voltage on a hybrid solar photovoltaic (PV)-battery energy storage system (BESS) without an external lightning protection system (LPS). Solar PV generates electricity by converting solar energy and providing it to the user. In addition, battery energy storage is also utilised to supply consistency and satisfy the need for energy. However, because the system is installed in open spaces, lightning has always been a huge difficulty for it to work at optimal efficiency. In this paper, the single SPD Class I was installed near the inverter on the DC side. The study on cable length with various lightning current amplitude and lightning strike distance is conducted. The simulation findings found that the inverter is well protected by the SPD whereby the impulse withstand voltage is 6 kV, however, the solar PV-BESS is affected by the lightning-induced voltage regardless of any cable length. In this way, providing the requirement for an adequate SPD installation will ensure improved maintenance and extend the equipment’s lifespan.

This paper presents the design strategy of a passive vibration isolator made form combination of elastomers and metal. The objective was to design & develop "Passive vibration isolator" to safeguard the sensitive electronics from vibration transmitted from due to road terrain. These electronics equipment’s were mounted on two racks placed side by side in a customized container, which in turn was fitted on a commercial vehicle. Two types of elastomers (Pure Rubber & Silicon Rubber) were chosen for carrying out the tensile tests to determine the stiffness parameters of these elastomers. Based on test results, elastomer material was chosen & mechanical design was perceived to prepare passive elastomer isolators of two types consisting of single layer and double layers. Mathematical Models were developed for each type of isolators along with electronics boxes. Finite Element Analysis (FEA) was carried out using ANSYS® workbench. In order to verify FEA results and to the effectiveness of both isolators’ types, two mock up electronics boxes were manufactured& integrated with designed single layer as well as double layer isolator. Vibration testing was carried out by employing the loading as per MIL-STD-810G on vertical, longitudinal & transversal directions on the two electronics boxes respectively. Both Finite Element Analysis (FEA) and testing results showed that single layer elastomer (pure rubber) has better isolation as compared to the two-layer elastomer. Later on, the single layered elastomer (pure rubber) passive isolators were manufactured & integrated with electronic units mounted inside mobile vehicle. Experimental data obtained using ISO 10816 Vibration Severity Standard for Vibration Analysis by carrying out the actual road trials of Mobile Vehicle on the intended pathways. The comparison of experimental data with FEA shows that proposed passive vibration isolator fulfills the vibration isolation requirement.

Fabricating high-aspect-ratio (HAR) structures with silicon carbide (SiC) is a challenging task. This paper presents a silicon carbide (SiC) reinforced vertically aligned carbon nanotubes (VACNT) composite as a promising candidate to fabricate HAR MEMS devices for harsh environment applications. The use of a VACNT array allows the fast realization of HAR structures as a template for MEMS fabrication. The template can later be easily filled by amorphous-SiC due to the porous nature of the VACNT forest. The SiC-CNT nanocomposite has electrical properties dominated by VACNT arrays and mechanical stability dominated by the a-SiC. Based on this concept, a thermal actuator is fabricated and proven to function up to 450°C for the first time., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Electronic Components, Technology and Materials, Support EKL

Design fixation, a phenomenon describing designers' adherence to pre-existing ideas or concepts that constrain design outcomes, is particularly prevalent in human-robot interaction (HRI), for example, due to collectively held and stabilised imaginations of what a robot should look like or behave. In this paper, we explore the contribution of creative AI tools to overcome design fixation and enhance creative processes in HRI design. In a four weeks long design exploration, we used generative text-to-image models to ideate and visualise robotic artefacts and robot sociotechnical imaginaries. We exchanged results along with reflections through a digital postcard format. We demonstrate the usefulness of our approach to imagining novel robot concepts, surfacing existing assumptionsand robot stereotypes, and situating robotic artefacts in context.We discuss the contribution to designerly HRI practices and conclude with lessons learnt for using creative AI tools as an emerging design practice in HRI research and beyond., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Design Aesthetics

The thermal-piezoresistive effect in silicon (Si) has attracted great attention toward high-performance resonant devices but still faces major challenges for harsh environment applications. Instead of using Si, this paper, for the first time, reports a thermal-piezoresistive resonator based on a silicon carbide-on-insulator (SiCOI) platform. The resonance frequency simulation, CMOS-compatible fabrication, and thermoresistive properties characterization of the proposed SiCOI resonator are presented. The experimental results show linear current-voltage characteristics and a constant temperature coefficient of resistance (TCR) up to 200 °C., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Electronic Components, Technology and Materials

Electrically-actuated continuum soft robots based on Handed Shearing Auxetics (HSAs) promise rapid actuation capabilities while preserving structural compliance. However, the foundational models of these novel actuators required for precise control strategies are missing. This paper proposes two key components extending discrete Cosserat rod model (DCM) to allow for modeling HSAs. First, we propose a mechanism for incorporating the auxetic trajectory into DCM dynamical simulations. We also propose an implementation of this extension as a plugin for the Elastica simulator. Second, we introduce a Selective Piecewise Constant Strain (SPCS) kinematic parameterization that can describe an HSA segment's shape with fewer configuration variables. We verify both theoretical contributions experimentally. The simulator is used to replicate experimental data of the mechanical characterization of HSA rods. For the second component, we attach motion capture markers at various points to a parallel HSA robot and find that the shape of the HSAs can be kinematically represented with an average accuracy of 0.3 mm for positions and 0.07 rad for orientations., Accepted Author Manuscript, Learning & Autonomous Control

In this paper, we present the ADAPT, a novel reconfigurable force-balanced parallel manipulator for spatial motions and interaction capabilities underneath a drone. The reconfigurable aspect allows different motion-based 3-DoF operation modes like translational, rotational, planar, and so on, without the need for disassembly. For the purpose of this study, the manipulator is used in translation mode only. A kinematic model is developed and validated for the manipulator. The design and motion capabilities are also validated both by conducting dynamics simulations of a simplified model on MSC ADAMS, and experiments on the physical setup. The force-balanced nature of this novel design decouples the motion of the manipulator’s end-effector from the base, zeroing the reaction forces, making this design ideally suited for aerial manipulation applications, or generic floating-base applications., Control & Simulation, Mechatronic Systems Design, Precision and Microsystems Engineering

Multistage or hierarchical distributed cooperative communication on the physical layer is a promising approach to overcome the scalability limitation of Mobile Ad-hoc Networks (MANETs). Standalone nodes that could successfully decode messages join transmission and support each other. They become a virtual transmit cluster and send simultaneously. While information theoretic research has demonstrated that an approximately linear scaling behaviour can be achieved, imperfections and constraints of practical systems have not been taken into account. Within this paper, we present a scalable and modular low-cost demonstration system based on software-defined radios (SDRs) to study distributed cooperative communication in practical MANETs. Furthermore, we apply SNR aggregation in combination with distributed cooperative transmission. To this end, we show a practical implementation approach and investigate the performance by measurements and simulations. Our results clearly highlight the advantages of combining distributed cooperative communication and SNR aggregation, e. g. to overcome larger distances in a distributed long haul multiple-input single-output (MISO) scenario or to enable a more efficient broadcast.

The presence of power generating plants owned by prosumers may lead to unbalanced bidirectional energy flows at the points of connection to the relevant distribution systems. This will impact future energy communities, where appropriate metering within the community is a crucial issue for billing purposes. This paper shows that the current metrics for active energy measurement and the registration of three-phase revenue meters may fail to fairly charge unbalanced prosumers for their use of the distribution system as an inherent phase-to-phase balancer. On the other hand, it is proven here that adopting metrics based on positive sequence power/energy measurement would lead to more fair billing within the community. A comparative study was performed using a simplified but realistic model of a distribution system feeding two prosumers (i.e., an archetype of an energy community). First, representative case studies were considered. Then, a more realistic simulation of a single day of operation was conducted. The main contribution of the paper is a detailed and systematic comparison of the methods used for measuring and sorting energy into registers in revenue meters to support the ongoing discussions about fair metering within future energy communities.

The presence of power generating plants owned by prosumers may lead to unbalanced bidirectional energy flows at the points of connection to the relevant distribution systems. This will impact future energy communities, where appropriate metering within the community is a crucial issue for billing purposes. This paper shows that the current metrics for active energy measurement and the registration of three-phase revenue meters may fail to fairly charge unbalanced prosumers for their use of the distribution system as an inherent phase-to-phase balancer. On the other hand, it is proven here that adopting metrics based on positive sequence power/energy measurement would lead to more fair billing within the community. A comparative study was performed using a simplified but realistic model of a distribution system feeding two prosumers (i.e., an archetype of an energy community). First, representative case studies were considered. Then, a more realistic simulation of a single day of operation was conducted. The main contribution of the paper is a detailed and systematic comparison of the methods used for measuring and sorting energy into registers in revenue meters to support the ongoing discussions about fair metering within future energy communities.

This paper presents a static-equilibrium oriented interaction force modeling and control approach of aerial manipulation employing uni-directional thrust (UDT) multirotors interacting with variously defined environments. First, a simplified system model for a quadrotor-based aerial manipulator is introduced considering parameterized work surfaces under assumptions, and then a range of meaningful manipulation tasks are utilized to explore the system properties in a quasistatic equilibrium state. An explicit interaction force model in relation with the aerial manipulator pose configuration and the environment parameter is derived from the static equilibrium analysis, based on which singularity is pointed out. Then a hybrid attitude/force interaction control strategy is presented to verify the proposed interaction force model, which involves high gain attitude control and feedforward plus feedback force control. This paper represents preliminary results. We study the properties of UDT-based aerial manipulators via specific tasks, and propose a novel framework for interaction force modeling and control aiming at maximizing the commercial values of UDT platforms for aerial manipulation purpose.

There are many teaching strategies in higher education; one of these is discussion-based teaching which aims to stimulate conversation and peer learning. Although this teaching strategy has many benefits for students, such as learning how to argue, it has not gained much traction in STEM subjects like Computer Science. However, soft skills have become increasingly important within these fields. A focus when recruiting for roles is not only on hard skills such as programming but also on the ability to communicate well with stakeholders. This paper explores and evaluates an approach to incorporate discussion-based teaching within computer science education, focusing on teaching hard and soft skills. To achieve this, we organised an emulated program committee type of activity for MSc students at our university. We evaluated the activity by asking the students to complete a survey and followed this up by interviewing several students to gather more in-depth reactions from the cohort. The results show that students feel they learnt about the topics tackled within the papers we have chosen, gained more confidence to tackle paper writing, understood the requirements of academic work, and improved their soft skills such as academic writing. The interviews show that students thoroughly enjoyed the activity and are keen to have more interactive discussion sessions like this.

In this paper, we consider observations from a series of smart meters that are either completely or partially aggregated, and our aim is to estimate the metering hierarchy. We propose to estimate this important metadata through a novel adaptation of the Chow–Liu tree learning procedure. Our approach takes into account prior knowledge from a set of dominance conditions that are easily elicited from the consumption data. In addition to more traditional correlation-based approaches we also introduce a distance-correlation-based method for detecting edges. Synthetic experiments show the benefits of distance correlation and the dominance conditions in recovering tree structure. The paper concludes with a real-world application of the method to infer energy metering hierarchies in a library building.

Due to the low availability of carers worldwide, technological means to meet the ever-increasing demand for care services are increasingly necessary. This paper discusses how the IoT is being used in the domiciliary care sector in the UK. It begins with market research and industry analysis to identify stakeholders and the possible application of IoT technology and devices in home care for elderly people. Since IoT technology is inherently vulnerable to security threats, the paper discusses security in home care automation, and also conducts a risk evaluation. This analysis and evaluation can be used to learn more about the target audience’s mindset. The results of this research can motivate and inform technology companies to enter the IoT market.

The paper presents a low complexity algorithm for extracting features of an electrocardiogram (QRS complex, P wave and T wave). A low power and resource optimal architecture is designed to implement this algorithm efficiently. The algorithm's parameters are chosen appropriately to avoid any floating-point compute-intensive arithmetic operation enabling us to implement it using comparators, shifters and adders only, which leads to efficient hardware resource utilization. The proposed architecture employs techniques such as clock gating to optimize power consumption. The modules delineating different peaks and boundaries of the ECG signal can be turned off when they are not operational or as per the medical requirements. The algorithm and architecture proposed in this paper are validated using MIT-BIH and QT database from Physionet. The proposed algorithm is implemented using the Virtex - 7 FPGA platform with average resource utilization of 0.42%, which is the least compared to other methods. The implementation is synthesized using 180 nm CMOS technology. The proposed design utilizes 7.38 mu W and 7.38 pJ of power and energy respectively, at an operating frequency of 1 MHz at 1.98 V. The energy consumption of the proposed architecture is reduced by factor of 1.28 compared to other known methods due to minimal utilization of Flip-Flops and LUTs. Therefore, our architecture can be efficiently deployed in low power and resource-constrained wearable healthcare applications., Článek představuje algoritmus s nízkou složitostí pro extrakci vlastností elektrokardiogramu (QRS komplex, vlna P a vlna T). Pro efektivní implementaci tohoto algoritmu je navržena architektura s nízkou spotřebou energie a optimálními zdroji. Parametry algoritmu jsou vhodně zvoleny tak, aby se vyhnuly jakýmkoli aritmetickým operacím náročným na výpočty v plovoucí řádové čárce, což nám umožňuje implementovat jej pouze pomocí komparátorů, posunovačů a sčítačů, což vede k efektivnímu využití hardwarových prostředků. Navržená architektura využívá techniky, jako je taktování, k optimalizaci spotřeby energie. Moduly vymezující různé špičky a hranice EKG signálu lze vypnout, pokud nejsou v činnosti nebo podle lékařských požadavků. Algoritmus a architektura navržené v tomto článku jsou ověřeny pomocí databáze MIT-BIH a QT z Physionet. Navržený algoritmus je implementován na platformě Virtex - 7 FPGA s průměrným využitím prostředků 0,42 %, což je nejméně ve srovnání s jinými metodami. Implementace je syntetizována pomocí 180 nm technologie CMOS. Navržený návrh využívá 7,38 mu W, respektive 7,38 pJ výkonu a energie při pracovní frekvenci 1 MHz a napětí 1,98 V. Spotřeba energie navržené architektury je ve srovnání s ostatními známými metodami snížena o faktor 1,28 díky minimálnímu využití Flip-Flops a LUT. Proto lze naši architekturu efektivně nasadit v aplikacích nositelné zdravotní péče s nízkou spotřebou energie a omezenými zdroji.

In this paper, we develop a FCM using a "concept template" instead of a concrete concept description. The concept template consists of a predicate and the case elements of the predicate, and they are used for both input concept and output concept in relation rules. The input concept templates accept the variation of similar input concepts and the output concept templates are used to generate the content of the output concept based on the content of input concepts. The inference process will be repeated until the concept state reaches convergence. We created 207 concept templates and a weighted matrix to show the relationship between concept templates. When 23 concepts were inputted to our system, 71 concepts were totally activated and the content of all output concepts were generated correctly.

It has been recently suggested by a number of researchers that emotional systems in agents might have great practical value. In this paper, we propose a system that makes decision about a plan, basing its judgement on emotion (i.e. pleasure/displeasure) extracted from knowledge, in an attempt to build a human-like computer agent, better able to communicate with users. We present an emotion-based plan evaluation method, and then provide the result simulated on naturally occurring short-story scinarios and show that plan evaluation based on artificial emotion generated by our method successfully matches the one based on human emotion., Meeting Date : 30 Aug 2000-01 Sep 2000

We previously proposed a method that uses grammatical features to detect inadequate utterances of doctors. However, nonverbal information such as that conveyed by gestures, facial expression, and tone of voice are also important. In this paper, we propose a method that uses eight acoustic features to detect three types of mental states (sincerity, confidence, and doubtfulness/acceptance). A Support Vector Machine (SVM) is used to learn these features. Experiments showed that the system’s accuracy and recall rates respectively ranged from 0.79-0.91 and 0.80-0.94.

This paper explores micro-foundations for digital business model innovation. This is pertinent because little is known regarding how decision-makers manage the digitalization processes that require business model innovation. Building on dynamic capability and upper echelon theories, this paper sheds light on the dynamic capability driven antecedents of the digital business model innovation of developing market international new ventures (INVs). Using survey data from 145 Pakistani INV, the study reports that internet capabilities (platform and web capabilities) positively influence digital business model innovation. The direct influences are mediated by strategic agility and moderated by the functional diversity of the top management team (TMT). The influence of strategic agility on the digital business innovation model is also positively moderated by TMT's functional diversity. The findings contribute to the nascent literature on antecedents for the digital business model innovation in an under-explored context of developing market INVs. Practical and policy related implications are also discussed.

Federated Learning (FL) is a secure distributed learning paradigm, which enables potentially a large number of devices to collaboratively train a global model based on their local dataset. FL exhibits two distinctive features in job requirement and client participation, where FL jobs may have different training criteria, and clients possess diverse device capabilities and data characteristics. In order to capture such heterogeneities, this paper proposes a new FL framework, Hca, which aims to strike a balance between the job completion time and model accuracy. Specifically, Hca builds upon a number of innovations in the following three phases: i) pre-estimation: we first derive the optimal set of parameters used in training in terms of the number of training rounds, the number of iterations and the number of participating clients in each round; ii) client selection: we design a novel device selection algorithm, which selects the most effective clients for participation based on both client historical contributions and data effectiveness; iii) model aggregation: we improve the classic FedAvg algorithm by integrating the model loss reduction in consecutive rounds as a weighted factor into aggregation computation. To evaluate the performance and effectiveness of Hca, we conduct theoretical analysis and testbed experiments over an FL platform FAVOR. Extensive results show that Hca can improve the job completion time by up to 34% and the model accuracy by up to 9.1%, and can reduce the number of communication rounds required in FL by up to 75% compared with two state-of-the-art FL frameworks.

The panorama image can simultaneously demonstrate complete information of the surrounding environment and has many advantages in virtual tourism, games, robotics, etc. However, the progress of panorama depth estimation cannot completely solve the problems of distortion and discontinuity caused by the commonly used projection methods. This paper proposes SphereDepth, a novel panorama depth estimation method that predicts the depth directly on the spherical mesh without projection preprocessing. The core idea is to establish the relationship between the panorama image and the spherical mesh and then use a deep neural network to extract features on the spherical domain to predict depth. To address the efficiency challenges brought by the high-resolution panorama data, we introduce two hyper-parameters for the proposed spherical mesh processing framework to balance the inference speed and accuracy. Validated on three public panorama datasets, SphereDepth achieves comparable results with the state-of-the-art methods of panorama depth estimation. Benefiting from the spherical domain setting, SphereDepth can generate a high-quality point cloud and significantly alleviate the issues of distortion and discontinuity.

This paper provided empirical knowledge of the user experience for using collaborative visualization in a distributed asymmetrical setting through controlled user studies. With the ability to access various computing devices, such as Virtual Reality (VR) head-mounted displays, scenarios emerge when collaborators have to or prefer to use different computing environments in different places. However, we still lack an understanding of using VR in an asymmetric setting for collaborative visualization. To get an initial understanding and better inform the designs for asymmetric systems, we first conducted a formative study with 12 pairs of participants. All participants collaborated in asymmetric (PC-VR) and symmetric settings (PC-PC and VR-VR). We then improved our asymmetric design based on the key findings and observations from the first study. Another ten pairs of participants collaborated with enhanced PC-VR and PC-PC conditions in a follow-up study. We found that a well-designed asymmetric collaboration system could be as effective as a symmetric system. Surprisingly, participants using PC perceived less mental demand and effort in the asymmetric setting (PC-VR) compared to the symmetric setting (PC-PC). We provided fine-grained discussions about the trade-offs between different collaboration settings.

The authors present the visual display installation as the basis for creating the artwork series 'Metanalysis'. The work explores the visual algorithmic representation of traditional Chinese ink painting and provides a video installation designed to showcase this visualization project. Exploring these visual representations is an attempt to understand and modernize expressions in the developing digital age visually. These visual displays are rendered in real-time and produced one after another in a continuous overlap and accumulation of black ink lines to reflect the specific random and malleable characteristics of the ink. They were eventually using mathematical algorithms to generate synthetic images that mimic the process of staining ink. The value of this paper lies in the fact that it proposes a new path for the expression of traditional Chinese ink painting and aims to bring the nonvitality classic art back to the stage through digital forms and to provide contemporary artists with new ideas to promote traditional culture. © 2022 IEEE.

This paper discusses optimal batch-to-batch (B2B) control problems and presents a gradient descent method solution for unknown linear batch process systems. Using historical process data, we design a model-free method for B2B optimization that eliminates the need for model information about the system. By using quadratic programming (QP) to formulate the optimal controller design, we first present the optimal iterative learning control (ILC) results. Next, using the gradient descent method, we replace the uncertain term with the actual measurements and develop a new ILC approach based on convex hull representations of uncertain realizations. As compared to the norm-optimal ILC, our proposed ILC can guarantee superior performance with reasonably selected parameters. Finally, we demonstrate our design with an illustrative numerical example. © 2023 IEEE.

The Asymmetrical Numeral Systems (ANS) coding has received significant attention in well-integrated compression systems. One particularly insightful technique that has emerged is the interleaved ANS coder (IAC), which substantially enhances the throughput by using multiple encoders and decoders. However, IAC has a limitation that even a single bit error in the compressed bitstream may diffuse across multiple decoders, resulting in many symbols to be incorrectly decoded. In this paper, we propose a parallel method to mitigate the diffusion for a class of error patterns, by limiting the errors to affect only a single decoder. The simulation results show that compared with IAC, our proposal can reduce the average number of incorrectly decoded symbols by about 50% while maintaining comparable encoding and decoding throughput.