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This paper proposes a new method for decreasing the complexity of reconfigurable antennas (RAs) with massive switches while increasing their reconfigurability. The proposed method is performed by removing the less important switches of an RA. Therefore, the RA only has a few important switches that have strong influences on the reconfigurability. The importance of a switch is evaluated by the minimum percentage of useful configurations (PUC). A monopole-type omni-directional frequency RA with 85 uniformly-distributed switches is optimized in this paper. For this type of antennas, a reflection coefficient less than -20 dB and a gain greater than 0 dBi at the same frequency makes a useful configuration. After reducing the switch number from 85 to 15, the complexity of the RA is greatly decreased while the reconfigurability is increased by more than 100 times within the band of 2 to 7 GHz. With only 15 optimally deployed switches, the PUC is significantly increased. Therefore, it is easy to find out the states of the switches to let the frequency RA work well at different frequencies. The results show that the proposed method is an efficient way to design RAs with switches in an optimal deployment.

There is an emerging need for high-rate underwater acoustic (UW-A) communication platforms to enable a new generation of underwater monitoring applications including video streaming. At the same time, modern UW-A communication architectures need to be flexible to adapt and optimize their communication parameters in real time based on the environmental conditions. Existing UW-A modems are limited in terms of achievable data rates and ability to adapt the protocol stack in real time. To overcome this limitation, we present the design, implementation, and experimental evaluation of a new high-rate software-defined acoustic modem (SDAM) with real-time adaptation capabilities for UW-A communications. We introduce new physical-layer adaptation mechanisms that enable either joint adaptation of communication parameters such as modulation constellation and channel coding rate or seamless switching between different communication technologies such as orthogonal-frequency-division-multiplexing and direct-sequence-spread-spectrum. The performance of the proposed SDAM has been evaluated in both indoor (water tank) and outdoor (lake) environments. We demonstrated that the SDAM achieves 104 kbit/s with bit-error-rate (BER) of 2 × 10-5, 208 kbit/s with BER of 10-3, and 260 kbit/s with BER of 10-2 in real time over a 200 m horizontal link at a very-shallow lake environment.

An oscillating active integrated antenna (AIA) with a switchable pattern among sum or difference is reported here. The AIA design consists of a passive feedback network and an active device. A two‐port, two‐element patch array coupled electromagnetically through T‐shaped microstrip lines is integrated into the feedback path of the oscillator circuit. This two‐port network acts as a radiator and frequency‐selective network for the oscillator circuit. The proposed AIA can switch in two different radiation pattern states by using p‐i‐n diodes. In the difference pattern, oscillating AIA has a measured null depth of −19.86 dB from the peak. The measured phase noise for both patterns is better than −105.1 dBc/Hz at a 1‐MHz offset from the oscillation frequencies. The dc‐to‐RF efficiencies for both pattern states are better than 20%. The proposed design is suitable to cover the space in a more efficient manner by generating the pattern among broadside or conical.

Abstract Flexible material‐based soft robots are widely used in various areas. In many situations, the suitable soft robots should be rapidly fabricated to complete the urgent tasks (such as rescue), so the facile fabricating methods of the multifunctional soft robots are still in urgent needs. In this work, the origami structure is employed to design vacuum‐powered silicone rubber artificial muscles, which can perform multiple motions, including contraction, bending, twisting, and radial motions. Artificial muscles can be used for rapid reconfiguration of different soft robots, just like the “building bricks”. Based on these artificial muscles, four soft robots with different functions, including an omnidirectional quadruped robot, a flexible gripper, a flexible wrist, and a pipe‐climbing robot, are reconfigured to complete different tasks. The proposed origami artificial muscles offer a facile and rapid fabricating method of flexible material‐based soft robots, and also greatly improve the utilization rate of flexible materials.

Stochastic neurons are efficient hardware accelerators for solving a large variety of combinatorial optimization problems. 'Binary' stochastic neurons (BSN) are those whose states fluctuate randomly between two levels +1 and -1, with the probability of being in either level determined by an external bias. 'Analog' stochastic neurons (ASNs), in contrast, can assume any state between the two levels randomly (hence 'analog') and can perform analog signal processing. They may be leveraged for such tasks as temporal sequence learning, processing and prediction. Both BSNs and ASNs can be used to build efficient and scalable neural networks. Both can be implemented with low (potential energy) barrier nanomagnets (LBMs) whose random magnetization orientations encode the binary or analog state variables. The difference between them is that the potential energy barrier in a BSN LBM, albeit low, is much higher than that in an ASN LBM. As a result, a BSN LBM has a clear double well potential profile , which makes its magnetization orientation assume one of two orientations at any time, resulting in the binary behavior. ASN nanomagnets, on the other hand, hardly have any energy barrier at all and hence lack the double well feature. That makes their magnetizations fluctuate in an analog fashion. Hence, one can reconfigure an ASN to a BSN, and vice-versa, by simply raising and lowering the energy barrier. If the LBM is magnetostrictive , then this can be done with local (electrically generated) strain. Such a reconfiguration capability heralds a powerful field programmable architecture for a p-computer whereby hardware for very different functionalities such as combinatorial optimization and temporal sequence learning can be integrated in the same substrate in the same processing run. This is somewhat reminiscent of heterogeneous integration, except this is integration of functionalities or computational fabrics rather than components. The energy cost of reconfiguration is miniscule. There are also other applications of strain mediated barrier control that do not involve reconfiguring a BSN to an ASN or vice versa, e.g. adaptive annealing in energy minimization computing (Boltzmann or Ising machines), emulating memory hierarchy in a dynamically reconfigurable fashion, and control over belief uncertainty in analog stochastic neurons. Here, we present a study of strain engineered barrier control in unconventional computing., (Creative Commons Attribution license.)

We experimentally demonstrate that the plasmonic heat delivered by a single layer of homogeneously distributed gold nanoparticles (AuNPs), immobilized on a glass substrate, can be optically tuned by taking advantage of the properties of an organic layer based on azobenzene and nematic liquid crystal (NLC) molecules. The effect, which exploits the dependence of the NLC refractive index value on the molecular director orientation, is realized using the polarization-dependent, light-induced molecular reorientation of a thin film of photo-aligning material that the NLC is in contact with. The reversibility of the optically induced molecular director reorientation of the NLC enables an active modulation of the plasmonic photo-induced heat.

A manufacturing system able to perform a high variety of tasks requires different types of resources. Fully automated systems using robots possess high speed, accuracy, tirelessness, and force, but they are expensive. On the other hand, human workers are intelligent, creative, flexible, and able to work with different tools in different situations. A combination of these resources forms a human-machine/robot (hybrid) system, where humans and robots perform a variety of tasks (manual, automated, and hybrid tasks) in a shared workspace. Contrarily to the existing surveys, this study is dedicated to operations management problems (focusing on the applications and features) for human and machine/robot collaborative systems in manufacturing. This research is divided into two types of interactions between human and automated components in manufacturing and assembly systems: dual resource constrained (DRC) and human-robot collaboration (HRC) optimization problems. Moreover, different characteristics of the workforce and machines/robots such as heterogeneity, homogeneity, ergonomics, and flexibility are introduced. Finally, this paper identifies the optimization challenges and problems for hybrid systems. The existing literature on HRC focuses mainly on the robotic point of view and not on the operations management and optimization aspects. Therefore, the future research directions include the design of models and methods to optimize HRC systems in terms of ergonomics, safety, and throughput. In addition, studying flexibility and reconfigurability in hybrid systems is one of the main research avenues for future research. [ABSTRACT FROM AUTHOR]

Dynamic reconfigurability and adaptability are crucial features of the future manufacturing systems that must be supported by adequate software technologies. Currently, they are typically achieved as add-ons to existing software tools and run-time systems, which are not based on any formal foundation such as formal model of computation (MoC). This paper presents the new programming paradigm of service oriented SystemJ (SOSJ), which targets dynamic distributed software systems suited for future manufacturing applications. SOSJ is built on a merger and the synergies of two programming concepts of service oriented architecture, to support dynamic software system composition, and SystemJ programming language based on a formal MoC, which targets correct by construction design of static distributed software systems. The resulting programming paradigm allows the design and implementation of dynamic distributed software systems. [ABSTRACT FROM AUTHOR]

This paper presents a fault‐tolerant secondary and adaptive primary microgrid control scheme using a hybrid multi‐agent system (MAS), capable of operating either in a semi‐centralised or distributed manner. The proposed scheme includes a droop‐based primary level that considers the microgrid energy reserves in production and storage. The secondary level is responsible for: a) the microgrid units' coordination, b) voltage and frequency restoration and c) calculation of the droop/ reversed‐droop coefficients. The suggested architecture is arranged upon a group of dedicated asset agents that collect local measurements, take decisions independently and, collaborate in order to achieve more complex control objectives. Additionally, a supervising agent is added to fulfill secondary level objectives. The hybrid MAS can operate either with or without the supervising agent operational, manifesting fast redistribution of the supervising agent tasks. The proposed hybrid scheme is tested in simulation upon two separate physical microgrids using three scenarios. Additionally, a comparison with conventional control methodologies is performed in order to illustrate further the operation of a hybrid approach. Overall, results show that the proposed control framework exhibits unique characteristics regarding reconfigurability and fault‐tolerance, while power quality and improved load sharing are ensured even in case of critical component failure. [ABSTRACT FROM AUTHOR]

Today's manufacturing environment is highly uncertain, and it is continuously changing. It is characterized by shorter life cycles of products and technologies, shorter delivery times, an increased level of customization at the price of a standard product, increased product variety, quality as well as demand variability and intense global competition. Academicians, as well as practitioners, agree that uncertainty will continue to grow in the twenty-first century. To deal with the uncertainties in demand variation and production capacity a manufacturing system is required which can be easily reconfigured when there is a need at low cost. A reconfigurable manufacturing system is such a type of system. In the present work, the concept of the reconfigurable manufacturing system has been discussed and reviewed. It has been compared with dedicated systems and flexible manufacturing systems. Part family formation and barriers of reconfiguration also have been discussed. This work is an attempt to contribute to the conceptual systematization of the reconfigurable manufacturing system and reconfigurability by synthesizing the vast literature available after a systematic review. [ABSTRACT FROM AUTHOR]

Copyright of Control Theory & Applications / Kongzhi Lilun Yu Yinyong is the property of Editorial Department of Control Theory & Applications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Reconfigurable machine tools (RMT) are the core facility of reconfigurable manufacturing systems (RMS), and structure design is the fundamental research involving RMT. The existing prototypes of RMT are limited to a specific part family, which suffers from reconfiguration difficulty and module sustainability issues. Therefore, a design philosophy of RMT for multi-part families with new design principles based on reconfigurability is proposed in this paper. Modularity and integrability are the basic principles, scalability, convertibility, and customization are the primary design principles, and reusability and symmetry are the auxiliary design principles. By implementing the new design principles, a two-step design method of RMT is proposed. First, a basic three-main-module structure, including the base, function arm, and workstation, is created. Second, customized components are selected to customize the functions for a specific part family, which can be reconfigured to meet the demand of other part families using other customized components. A prototype of RMT illustrates the proposed design philosophy to specify the basic three-main-module structure. The basic configurations of the RMT prototype are given, as well. The reconfigurability of the RMT prototype is analyzed from the perspectives of scalability, convertibility, and reconfiguration time. Based on topology optimization, the performance of the RMT prototype is improved. The case study implements milling and turning functions, demonstrating the practicality of the proposed design philosophy, where the processing of typical parts is also analyzed. Furthermore, the reconfiguration process among multi-part families is discussed in the case study. [ABSTRACT FROM AUTHOR]

Within cellular manufacturing systems (CMSs), families of parts are assigned to manufacturing cells, composed by homogeneous sets of machines. In conventional CMSs, each cell is devoted to the production of a specific part family, reducing material handling and work-in-process. Despite their flexibility, such systems still suffer from coping with the present market challenges asking for dynamic part mix and the need of agility in manufacturing. To meet these challenges, the recent literature explores the idea of including elements of the emerging reconfigurable manufacturing paradigm in the design and management of CMSs, leading to the cellular reconfigurable manufacturing system (CRMS) concept. The aim of this paper is to propose an original linear programming optimization model for the design of CRMSs with alternative part routing and multiple time periods. The production environment consists of multiple cells equipped with reconfigurable machine tools (RMTs) made of basic and auxiliary custom modules. By changing the auxiliary modules, different operations become available on the same RMT. The proposed approach determines the part routing mix and the auxiliary module allocation best balancing the part flows among RMTs and the effort to install the modules on the machines. The approach discussion is supported by a literature case study, while a multi-scenario analysis is performed to assess the impact of different CMS configurations on the system performances, varying both the number of cells and the RMT assignment to each of them. A benchmarking concludes the paper comparing the proposed CRMS against a conventional CMS configuration. The analysis shows relevant benefits in terms of reduction of the intercellular travel time (− 58.6%) getting a global time saving of about 53.3%. Results prove that reconfigurability is an opportunity for industries to face the dynamics of global markets. [ABSTRACT FROM AUTHOR]

In this work, we theoretically present a reconfigurable plasmonic chiral metasurface based on a sandwiched metal–insulator–metal structure, which can strongly, spin-selectively absorb circularly polarized light. Through finite-difference time-domain simulation, the absorption of left- or right-handed circularly polarized light can reach nearly 100% at the resonant position, and the magnitude of the circular dichroism can be 80%, which is larger than most of the previously reported value. This strong chiroptical effect originates from plasmonic resonances induced by the incident circularly polarized light. Furthermore, the proposed plasmonic chiral metasurface is able to be reconfigurable by either changing its intrinsic or extrinsic chirality, which can be numerically confirmed by the change of the sign and magnitude of the CD. Such a reconfigurable plasmonic chiral metasurface could find many potential applications in chirality detection/sensing, polarimetric imaging, spin–orbit communications, etc. [ABSTRACT FROM AUTHOR]

In this brief, a power efficient reconfigurable non-maximally decimated filter bank-based modified frequency response masking technique is proposed to generate sharp transition width channels for wideband applications. The structure enables cost and power efficient processing of wideband signals. The main benefit of the proposed scheme is that the computational workload and hardware complexity of the modified frequency response masking technique is considerably less than that of the approaches existing in the literature. The hardware complexity of the design is further reduced by joint optimization of all the canonical signed digit represented filters using Pareto-based meta-heuristic algorithm. [ABSTRACT FROM AUTHOR]

The observation of topological edge states (TESs) revolutionized our understanding of scattering and propagation of electromagnetic (EM) waves. Supported by topological robustness, the TES at the interface between trivial and non-trivial insulators was not reflected from the structural disorders and imperfections. Recently topological photonic crystals (PhCs) were demonstrated to obtain remarkable one-way propagation of the TES, having the advantages of lossless propagation, dense integration, and high fabrication tolerance over conventional PhCs. Nevertheless, the lack of reversible switching of TES possesses significant limitations in helicity/spin filtering and tunable photonic devices. We proposed a topological PhC based on a prototypical phase-change material, Ge 2 Sb 2 Te 5 (GST225) to solve the problem. We find that at a particular frequency, the TES within the structure can be reversibly switched between "on" and "off" by transiting the GST225 structural state between amorphous and crystalline. Moreover, the topology of the PhC was maintained since the tuning of TES was achieved by varying the refractive index of GST225 instead of the structural geometry. This provides a continuous change of the spectral position of the photonic bandgap and TES by gradually crystallising the GST225. We show that the phase change of GST225 from amorphous to crystalline and vice versa can be engineered in nanoseconds. Our proof of concept may offer a platform for dynamically tuning the TESs that might otherwise be challenging to attain in photonic systems. We expect it to have potential applications for photonic devices in topological optical circuits and scatter-free one-way light propagation. [ABSTRACT FROM AUTHOR]

In this paper, we propose a novel reconfigurable ferroelectric FET (R-FEFET), which can reconfigure its operation between volatile and nonvolatile modes during run-time by dynamically modulating its hysteresis. The R-FEFET comprises of two gates with ferroelectric (FE) in both the gate stacks. One of these terminals serves as a regular gate, while the other is used as a control to introduce reconfigurability. Employing Landau–Khalatnikov equation-based FEFET model, we extensively analyze the device characteristics in both FinFET and planar technologies. We show that by changing the control voltage between 0 and 1 V, the hysteresis width (HW) can be modulated between 1.1 and 0.3 V. In addition, we show the device characteristics and advantages that R-FEFETs possess to overcome the drawbacks encountered with gate leakage in standard FEFETs. The hold margins in the nonvolatile mode of R-FEFETs increase by ~ $10\times $ with respect to standard FEFETs, and the drive current strengths in the volatile mode show 13% improvements when compared to standard FETs. Using the proposed R-FEFETs, we examine a low-power nonvolatile memory design in Part II of this paper. [ABSTRACT FROM AUTHOR]

In this paper, we report the design, analysis, and development of spoof surface plasmon polariton (SSPP)-based reconfigurable band-pass filter using a planar ring resonator. A transition from quasi-transverse electromagnetic (QTEM) mode of microstrip to SSPP mode was implemented which has been subsequently used to develop a reconfigurable band-pass filter. Trapezoidal shape periodically corrugated metallic grooves etched on the planar metallic surface have been used in the implementation of this transition. In the designed transition, impedance and mode matching between QTEM mode and SSPP mode have been achieved using gradient grooves. The developed transition has been used in the characterization of a ring resonator corrugated with the periodical array of the trapezoidal shape grooves. This SSPP ring resonator shows multiple passbands at different frequencies within the specified frequency range. Varactor diodes have been incorporated in the SSPP ring resonator to obtain tunable passband. Three types of varactor-tuned circuits have been experimentally implemented and characterized using SMV2019-079LF diode package. These circuits will pave the path for development of other front-end circuit elements using the concept of spoof SPP. [ABSTRACT FROM AUTHOR]

Industrie 4.0 principles demand increasing flexibility and modularity for automated production systems. Current system architectures provide an isolated view of specific applications and use cases, but lack a global, more generic approach. Based on the specific architectures of two EU projects and one German Industrie 4.0 project, a generic system architecture is proposed. This system architecture features the strengths of the three isolated proposals, such as cross-enterprise data sharing, service orchestration, and real-time capabilities, and can be applied to a wide field of applications. Future research should be directed towards considering the applicability of the architecture to other equal applications. [ABSTRACT FROM AUTHOR]

This paper proposes a reconfigurable dual-active-bridge (DAB) converter that is capable of switching between two converter structures for enhancing its performances at different output power levels. For 50%–100% load, the converter operates in full-bridge mode and achieves soft-switching in all switches independently of the input-to-output voltage ratio. Below 50% load, the converter is reconfigured to operate in half-bridge mode for reduced circulating current and improved light-load efficiency while maintaining the desired soft-switching characteristic of full-bridge mode. The achievement of soft-switching is aided by the use of a tuned $LCL$ resonant tank, which enables an accurate prediction of the phases of tank currents with respect to tank voltages, and therefore simplifies the realization of soft-switching. The effects of dead time are discussed and expressions for guiding the selection of appropriate dead time for ensuring soft-switching in practical implementation are derived. The proposed converter and the modulation scheme are experimentally verified with a 1.6-kW converter prototype, which demonstrates their merits in comparison with a nonreconfigurable, full-bridge DAB topology and conventional modulation schemes. [ABSTRACT FROM AUTHOR]

Copyright of Electronic Components & Materials is the property of Electronic Components & Materials and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper proposes a fully reconfigurable universal sensor analog front-end for the Internet of Things era. It is implemented to be able to process different types (R, C, V, and I) of sensor output by using a single input bond pad and a single reconfigurable analog front-end. In addition, a reconfigurable acquisition mode selection method is applied to measure a wide magnitude range of sensor output. Furthermore, the compensation method for the baseline of the sensor is proposed, which can suppress the saturation of the circuit and improve the sensitivity of the sensor output. Also, the correlated double sampling technique is adopted to reduce the low-frequency noise that can affect the sensor output. The proposed system can detect within a relative error of about 1% by using only one input bond pad and analog front-end for the target sensor output range. The proposed system is implemented using TSMC 0.25- $\mu \text{m}$ CMOS process. [ABSTRACT FROM AUTHOR]

In the paradigm of industry 4.0, manufacturing enterprises need a high level of agility to adapt fast and with low costs to small batches of diversified products. They also need to reduce the environmental impact and adopt the paradigm of the circular economy. In the configuration space defined by this duality, manufacturing systems must embed a high level of reconfigurability at the level of their equipment. Finding the most appropriate concept of each reconfigurable equipment that composes an eco-smart manufacturing system is challenging because every system is unique in the context of an enterprise’s business model and technological focus. To reduce the entropy and to minimize the loss function in the design process of reconfigurable equipment, an evolutionary algorithm is proposed in this paper. It combines the particle swarm optimization (PSO) method with the theory of inventive problem-solving (TRIZ) to systematically guide the creative potential of design engineers towards the definition of the optimal concept over equipment’s lifecycle: what and when you need, no more, no less. The algorithm reduces the number of iterations in designing the optimal solution. An example for configuration design of a reconfigurable machine tool with adjustable functionality is included to demonstrate the effectiveness of the proposed algorithm.

A reconfigurable stateful logic circuit based on one-transistor-one-memristor (1T1M) crossbar array is proposed by combining the advantages of stateful logic and 1T1M array. Boolean logic operations can be realized not only on the row but also on the column of 1T1M array, which improves the flexibility and computing capability of the array. The same logic circuit can be reconfigured to perform different Boolean logic operations. Then, based on the parallelism of the array and the proposed stateful logic, the 2-bit multiplier and the encryption and decryption circuit of binary images are designed, reducing the logic operating steps. Finally, the circuit simulations of the proposed row-wise logic, the column-wise logic, the 2-bit multiplier as well as the encryption and decryption of SWU binary images are carried out in the 1T1M array. In the proposed stateful logic, the storage of logic inputs, the logic operation process, and the storage of operation results are all executed in 1T1M array, which integrates storage and computation, and effectively overcomes the sneak path problem. The entire scheme provides the application potential of memristor based on two-dimensional materials or conventional materials, opening up a new approach for the next-generation computing. [ABSTRACT FROM AUTHOR]

This paper presents the development of reconfigurable virtual environment for programming, control, simulation, and monitoring of multiple robots and its application in the process of education. During the development special attention is devoted to the fulfillment of the modularity, scalability, and openness that represent the basic requirements of reconfigurability. The reconfigurability of the virtual laboratory can be considered from two aspects: as a possibility of reconfiguring operating mode and as a possibility of reconfiguring virtual robots and virtual laboratory. It represents an integrated environment for programming, control, simulation and monitoring of multiple robots with continuous adjustment to the real laboratory environment and robots’ usage. With the possibility to adjust the virtual environment in accordance with the students’ foreknowledge and experience by combining different operating modes and virtual environments, from the educational viewpoint, it is expected that the proposed solution will improve the process of gaining knowledge.

Parallel robots with configurable platforms are a class of robots in which the end-effector has an inner mobility, so that its overall shape can be reconfigured: in most cases, the end-effector is thus a closed-loop kinematic chain composed of rigid links. These robots have a greater flexibility in their motion and control with respect to rigid-platform parallel architectures, but their kinematics is more challenging to analyze. In our work, we consider n-RRR planar configurable robots, in which the end-effector is a chain composed of n links and revolute joints, and is controlled by n rotary actuators located on the base of the mechanism. In particular, we study the geometrical design of such robots and their direct and inverse kinematics for n=4, n=5 and n=6; we employ the bilateration method, which can simplify the kinematic analysis and allows us to generalize the approach and the results obtained for the 3-RRR mechanism to n-RRR robots (with n>3). Then, we study the singularity configurations of these robot architectures. Finally, we present the results from experimental tests that have been performed on a 5–RRR robot prototype.