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We consider a multigroup multicast cell-free multiple-input multiple-output (MIMO) downlink system with short-term power constraints. In particular, the normalized conjugate beamforming scheme is adopted at each access point (AP) to keep the downlink power strictly under the power budget regardless of small scale fading. In the considered scenario, APs multicast signals to multiple groups of users whereby users in the same group receive the same message. Under this setup, we are interested in maximizing the minimum achievable rate of all groups, commonly known as the max-min fairness problem, which has not been studied before in this context. To solve the considered problem, we first present a bisection method which in fact has been widely used in previous studies for cell-free massive MIMO, and then propose an accelerated projected gradient (APG) method. We show that the proposed APG method outperforms the bisection method requiring lesser run time while still achieving the same objective value. Moreover, the considered power control scheme provides significantly improved performance and more fairness among the users compared to the equal power allocation scheme.

This special issue of the IEEE Transactions on Biomedical Circuits and Systems presents a selection of high-quality research papers from the 2016 IEEE Biomedical Circuits and Systems Conference (BioCAS) in Shanghai, China, from October 17–19, 2016. Similar to previous years, BioCAS 2016 was jointly sponsored by the IEEE Circuits and Systems (CAS) Society and the IEEE Engineering in Medicine and Biology (EMB) Society.

A post mortem analysis of scrapped transformers provides an opportunity to directly measure the properties of in-service aged paper insulation. Investigations on 10 scrapped 275 kV and 400 kV power transformers were carried out, where Tensile Index (TI) and Low Molecular Weight Acid (LMA) of the paper insulation sampled from various locations were measured. Multiple-layer TI profile demonstrated the effect of oxidized oil on paper ageing which was confirmed by laboratory ageing experiments. It is LMA rather than High Molecular Weight Acid (HMA) that accelerates the paper degradation. LMA acts as the paper ageing accelerator and also as the paper degradation by-product, supporting the view that self-accelerated hydrolysis process is the main paper ageing mechanism. Finally, a generic relationship between LMA in paper and TI of paper was revealed based on both in-service and laboratory ageing data, i.e. the lower the TI of paper, the higher value of LMA in paper is measured. It implies that LMA in oil can be a potential paper ageing indicator pro viding a link between LMA in oil and paper is found.

A post mortem analysis of scrapped transformers provides an opportunity to directly measure the properties of in-service aged paper insulation. Investigations on 10 scrapped 275 kV and 400 kV power transformers were carried out, where Tensile Index (TI) and Low Molecular Weight Acid (LMA) of the paper insulation sampled from various locations were measured. Multiple-layer TI profile demonstrated the effect of oxidized oil on paper ageing which was confirmed by laboratory ageing experiments. It is LMA rather than High Molecular Weight Acid (HMA) that accelerates the paper degradation. LMA acts as the paper ageing accelerator and also as the paper degradation by-product, supporting the view that self-accelerated hydrolysis process is the main paper ageing mechanism. Finally, a generic relationship between LMA in paper and TI of paper was revealed based on both in-service and laboratory ageing data, i.e. the lower the TI of paper, the higher value of LMA in paper is measured. It implies that LMA in oil can be a potential paper ageing indicator pro viding a link between LMA in oil and paper is found.

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The capacity of organizations to deal with changing market and societal conditions becomes an important success factor. This property reflects on the way the modus operandi of an organization is organized. Based on a real-world case study, we outline a method that integrates mass customization as an organization concept from industry with an analysis of the foundational elements that constitute business processes. The purpose of this exercise is to explore if such method contributes to business process flexibility through a rigorous modularization of these processes. Its ‘parts and patterns’ approach results from a deliberate engineering attitude, whereby business operations, business information systems and information technology are operationalized based on a single architecture. The paper proposes a business process elements catalog as a facility to search and employ process constructs, thereby supporting their reuse. In doing so, the goal of this paper is to make the first step of a larger, three-step design science research effort into the support of business process modularization through mass customization.

The capacity of organizations to deal with changing market and societal conditions becomes an important success factor. This property reflects on the way the modus operandi of an organization is organized. Based on a real-world case study, we outline a method that integrates mass customization as an organization concept from industry with an analysis of the foundational elements that constitute business processes. The purpose of this exercise is to explore if such method contributes to business process flexibility through a rigorous modularization of these processes. Its ‘parts and patterns’ approach results from a deliberate engineering attitude, whereby business operations, business information systems and information technology are operationalized based on a single architecture. The paper proposes a business process elements catalog as a facility to search and employ process constructs, thereby supporting their reuse. In doing so, the goal of this paper is to make the first step of a larger, three-step design science research effort into the support of business process modularization through mass customization.

The next-generation wireless technology that can fulfill such a demand, namely the fifth-generation (5G) technology, should provide 1000 times larger capacity. Moreover, sixth-generation (6G) communication, which represents a significant upgrade from the fifth-generation (5G) network and is anticipated to operate from 100 GHz to 3 THz band, will be required in the years after 2030 due to newly developed data-hungry applications and the greatly expanded wireless network. To meet the ever-growing demands of wireless carriers, an efficient wireless access method that can improve wireless area throughput without expanding bandwidth or cell size is required. Radio Frequency (RF) Orbital Angular Momentum vortex waves (which is now on referred to as OAM waves) to address the concerns mentioned above have attracted much attention in recent years. Due to their orthogonality, different OAM waves of different modes can be multiplexed in the same frequency channel, which can greatly increase the channel capacity. Using the orthogonal modes, a new type of multiple access scheme known as Mode Domain Multiple Access (MDMA) can be used by multiple users using the same frequency channel without additional resources such as frequency and time. As a result, the channel capacity for the next generation wireless communication systems can be enhanced as well as the overall spectrum efficiency can be improved. This review paper begins with an overview of the next generation communication such as 5G communication technology and beyond. This paper first briefly discusses the theory of OAM waves and several methods to generate OAM waves. Various different designs have also been analyzed for their ability to generate OAM waves and discussion on several restrictions and solutions to resolve. Open concerns and development trends are discussed for possible future RF OAM antenna upgrades. This study also proposes that for next generation wireless communication employing OAM, the typicall

In this paper, we propose a coreless axial gap flux resonant induction motor that utilizes properties of magnetic resonant coupling. The stator and rotor cores of the motor are made with reinforced plastic fiber. Preliminary attempts to study the characteristics of the motor is achieved using an equivalent analysis model through a complete 3-D finite element analysis (FEA). The analysis model has four sets of rectangular-shaped coils, and uniform current density is considered in these rectangular-shaped coils. Evaluations are conducted, and design considerations for these categories of motors are established in this paper. The configuration of the machine constitutes a new domain with largely unstudied potential. Furthermore, the lightweight advantage of these machines makes them a potential candidate for very lightweight applications.

Variable flux motors with adjustable magnetic flux have been gaining attention because of their capability to simultaneously achieve a high torque density and high efficiency. In addition, the output power characteristic, which is related to acceleration performance, in high-speed areas is important in traction applications. However, typical traction motors have lower output power in high-speed areas. In this paper, a Hybrid-Excitation Variable Flux Memory Motor (HE-VFMM) is therefore proposed to enhance output power characteristics under six-step operation mode in high-speed area. The proposed HE-VFMM can perform magnetic flux adjustment with two components: field winding and variable flux permanent magnet (VPM), thus dramatically increasing flux adjustment range. The simulation results show the proposed HE-VFMM achieves 23.7% higher output power at 17,000 rpm than that of an existing traction motor in Prius 4th generation that has the same size while maintaining high efficiency in the frequently used operating area. Additionally, it was found that variable magnetic flux is very effective in enhancing the output power, especially in the high-speed region because the magnetic saturation in the stator core is mitigated by field-weakening control. Consequently, as the rotational speed increases, an increase ratio of the output power caused by the adjustable magnetic flux becomes higher. This paper shows that the proposed HE-VFMM is an effective method for improving the problem of low output power in high-speed regions in traction motors.

This paper presents a control method of fully digital active gate drivers to simultaneously realize surge voltage reduction and efficiency enhancement in a three-phase inverter for motor drive applications. Generally, the surge voltages of power devices in each switching are affected by the operation principle of the three-phase current values and phases. In the proposed method, the active gate driving patterns of fully six gate drivers are suitably changed according to the phase angle of the three-phase current to minimize the highest surge voltage and the switching loss in a fundamental period. A prototype of the three-phase inverter using a 6-in-1 SiC power module and six digital active gate driver ICs was developed to verify the improvement effect of the proposed active gate control. It was experimentally shown that the surge voltage could be reduced from 418.6 V to 369.4 V, fixing a high efficiency., Conference Location: Orlando, FL, USA

This study aims to improve the torque performance and manufacturability of axial-flux permanent magnet (AFPM) machines. Hence, we propose a novel AFPM machine that employs a soft magnetic composite (SMC) core with tooth-tips constructed by a one-pressing process and die. In this paper, the proposed AFPM machine is compared to two conventional AFPM machines using an SMC core. One of them has open-slot structure without tooth-tips. Another model employs an SMC core with tooth-tips pressed by a conventional pressing process that requires multiple operations and dies. As a result of the comparison, the proposed AFPM machine realizes a much higher torque than the two conventional machines. Additionally, the manufacturability of an SMC core with tooth-tips pressed by the proposed method is superior to the conventional one because the proposed structure can be realized by the one-pressing process and die. Furthermore, two prototypes of the proposed AFPM machine and the conventional one with an open-slot structure are fabricated, and then, they are compared by experiments. Consequently, the proposed AFPM machine achieves a 15.7% higher torque than that of the conventional machine using an open-slot structure. Finally, this paper presents an improved design of an AFPM machine with SMC cores using the proposed pressing process. As a result, the proposed AFPM realizes a 20% larger torque than that of a conventional model employing an open-slot structure.

Subsea residential autonomous systems will reduce the cost and CO 2 footprint of future subsea operations. This concept includes subsea docking stations (SDS) and Autonomous Underwater Vehicles (AUVs). To ensure the AUVs are capable of interfacing with the SDS, a driftless and accurate close-range navigation schema is required. Thus, this paper proposes a visual method for navigation utilizing a defined set of ArUco markers printed on the SDS. To increase the accuracy of the system, the set of ArUco markers is defined to a common frame of reference, introducing more points in the camera frame for a more accurate solution to the Perspective-n-Point problem. This makes the system robust against partial occlusion. The paper has also implemented a modified Line of Sight (LOS) schema for the guidance of the vehicle. The results show stable pose estimates at up to 6 meters above the SDS, and successful autonomous docking of an underwater vehicle. The navigational estimates provided by the system get more stable when the vehicle is closer to the SDS

The recovery of motor functions after stroke is fostered by the functional integration of large-scale brain networks, including the motor network (MN) and high-order cognitive controls networks, such as the default mode (DMN) and executive control (ECN) networks. In this paper, electroencephalography signals are used to investigate interactions among these three resting state networks (RSNs) in subacute stroke patients after motor rehabilitation. A novel metric, the O-information rate (OIR), is used to quantify the balance between redundancy and synergy in the complex high-order interactions among RSNs, as well as its causal decomposition to identify the direction of information flow. The paper also employs conditional spectral Granger causality to assess pairwise directed functional connectivity between RSNs. After rehabilitation, a synergy increase among these RSNs is found, especially driven by MN. From the pairwise description, a reduced directed functional connectivity towards MN is enhanced after treatment. Besides, inter-network connectivity changes are associated with motor recovery, for which the mediation role of ECN seems to play a relevant role, both from pairwise and high-order interactions perspective.

Since 2016, the implementation of EU product rules requires a mandatory risk assessment for all electronic products, as outlined in the European "Blue Guide." To comply with the risk-based approach introduced by this guide, it is crucial to have a better understanding of the electromagnetic (EM) environment. However, existing methodologies for characterizing the EM environment have limitations. From it, an alternative methodology is briefly proposed to aid the risk assessment process by exploring the concept of spatial sampling EM fields. This paper will focus on efficiently implementing the concept by using a test framework. The latter part of the paper illustrates how the test framework is used to compare two sampling strategies in a low-complexity scenario.

This paper presents novel qualitative assessment guidelines for grading MSc graduation projects in the Electrical Engineering (EE) Faculty of the Eindhoven University of Technology (TU/e). The goals of the guidelines are to provide a grading system that is impartial, time-efficient, consistent, reproducible, transparent, and conducive to enhancing the learning experience. Furthermore, the guidelines establish a taxonomy for evaluating final projects, creating a shared language and a set of criteria across the extensive and varied faculty of EE. The grading is based on five categories: student-centric, work-centric, process-centric, documentation-centric, and communication-centric aspects, where each category features four aspects. For each category and every aspect of it, this paper provides a qualitative scale, totaling in 24 different qualitative gradients.