IEEE Transactions on Power Electronics. Sep2019, Vol. 34 Issue 9, p8715-8723. 9p.
RAPID prototyping, CURRENT-voltage characteristics, and FEEDBACK (Psychology)
Using a photovoltaic (PV) emulator (PVE) simplifies the testing of the PV generation system. However, conventional controllers used for PVEs suffer from oscillating output voltage, requiring a high number of iterations, or being too complex to be implemented. This paper proposes a controller based on a resistance feedback control strategy that produces a stable and fast converging operating point for the PVE. The resistance feedback control strategy requires a new type of PV model, which is the current–resistance (I–R) PV model. This model is computed using a binary search method at a fast convergence rate. It is combined with a closed-loop buck converter using a proportional-integral controller to form the resistance feedback control strategy. The PVE's controller is implemented into dSPACE ds1104 hardware platform for experimental validation. The acquired experimental results show that the proposed PVE is able to follow the current–voltage characteristic of the PV module accurately. In addition, the PVE's efficiency is more than 90% under maximum power point operation. The transient response of the proposed PVE is similar to the PV panel during irradiance changes. [ABSTRACT FROM AUTHOR]
This paper presents a discrete-time neural inverse optimal control for induction motors, which is implemented on a rapid control prototyping (RCP) system using a C2000 Microcontroller-Simulink platform. Such controller addresses the solution of three issues: system identification, trajectory tracking, and state estimation, which are solved independently. The neural controller is based on a recurrent high order neural network (RHONN), which is trained with an extended Kalman filter. The RHONN is an identifier to obtain an accurate motor model, which is robust to external disturbances and parameter variations. The inverse optimal controller is used to force the system to track a desired trajectory and to reject undesired disturbances. Moreover, the controller is based on a neural model and does not need the a-priori knowledge of motor parameters. A supertwisting observer is implemented to estimate the rotor magnetic fluxes. The hub of the RCP system is a TMS320f28069M MCU, which is an embedded combination of a 32-bit C28x DSP core and a real-time control accelerator. This Microcontroller is fully programmable from the Simulink environment. Simulation and experimental results illustrate the performance of the proposed controller and the RCP system, and a comparison with a control algorithm without the neural identifier is also included. [ABSTRACT FROM AUTHOR]
TARGET costing, PROTOTYPES, PRODUCT design, RAPID prototyping, and SUPPLIERS
Prototyping allows firms to evaluate the technical feasibility of alternative product designs and to better estimate their costs. We study a collaborative prototyping scenario in which a manufacturer involves a supplier in the prototyping process by letting the supplier make detailed design choices for critical components and provide prototypes for testing. While the supplier can obtain private information about the costs, the manufacturer uses target costing to gain control over the design choice. We show that involving the supplier in the prototyping process has an important influence on the manufacturer's optimal decisions. The collaboration results in information asymmetry, which makes parallel prototyping less attractive and potentially reverses the optimal testing sequence under sequential prototyping: It may be optimal to test designs in increasing order of attractiveness to avoid that the supplier does not release technically and economically feasible prototypes for strategic reasons. We also find that the classical target costing approaches (cost‐ and market‐based) need to be adjusted in the presence of alternative designs: Due to the strategic behavior of suppliers, it is not always optimal to provide identical target costs for designs with similar cost and performance estimates, nor to provide different target costs for dissimilar designs. Furthermore, the timing is important: While committing upfront to carefully chosen target costs reduces the supplier's strategic behavior, in some circumstances, the manufacturer can take advantage of this behavior by remaining flexible and specifying the second prototype's target costs later. [ABSTRACT FROM AUTHOR]
RAPID prototyping, SEARCH algorithms, DIELECTRIC-loaded antennas, THREE-dimensional printing, and PERMITTIVITY
A prototyping method for dielectrically loaded antennas is presented. Dielectric loading has been used with horn antennas, feeds, and lenses. Dielectrics have also been used for coating antennas submerged in water and biological matter and have led to improvements in bandwidth and efficiency as well as antenna miniaturisation. The authors present a new technique to produce variable dielectrics with permittivity from 6 to 28 using two commonly available powders, titanium dioxide (used in foods) and magnesium silicate (used in talcum powder). An example spherical helical ball antenna is used to demonstrate the process. In this antenna, the mixed powders were encased in a 3D printed shell that achieved a reduction in diameter of the spherical antenna by a factor of 1.85. The technique aids rapid prototyping and optimisation using search algorithms. [ABSTRACT FROM AUTHOR]
As relationship marketing research evolved, a number of key constructs emerged. Some scholars have argued that these constructs are not conceptually or empirically distinct. We investigate this phenomenon based on the premise that sustained research effort towards studying conceptually overlapping/redundant constructs, while treating them as independent, can hamper the development of the field. We use prototyping, a method adopted from psychology, to examine consumers’ views of these constructs, and then identify relationship contexts where constructs are distinct or redundant. [ABSTRACT FROM AUTHOR]
Medlej, Maroun, Stuban, Steven M. F., and Dever, Jason R.
Defense Acquisition Research Journal: A Publication of the Defense Acquisition University. Oct2017, Vol. 24 Issue 4, p626-655. 30p.
SYSTEMS engineering, RAPID prototyping, DEFENSE industries, MANUFACTURING processes, and LIKELIHOOD ratio tests
In 2007, John Young, then-Under Secretary of Defense for Acquisition, Technology and Logistics, mandated the use of "competitive prototyping" strategies in defense acquisition. Further, Department of Defense Instruction 5000.02 includes considerations for prototyping in the acquisition strategy. A 2017 memorandum circulated by Young lists five prototyping benefits, which are expected to "reduce technical risk, validate designs, validate cost estimates, evaluate manufacturing processes, and refine requirements." However, a process to assess whether, and to what extent, a prototype will be or has been successful in achieving these benefits is not currently in use by the Department of Defense. Because cost increases and schedule extension downsides are inherent in prototyping, such an assessment is critical. This research proposes an approach for assessing the likelihood of achieving expected prototyping benefits based on identifying the factors yielding these benefits as well as their relative weights. [ABSTRACT FROM AUTHOR]
MAGNETIC resonance imaging, RADIO frequency, HIGH resolution imaging, LASER beam cutting, and HUMAN body
Magnetic resonance imaging (MRI) is one of the most powerful imaging modality in clinics and is essential for the diagnosis of strokes through carotid artery imaging. The limiting factor for high-quality MRI is the signal-to-noise ratio (SNR) performance of the radio frequency (RF) coils. The current RF surface coils, however, are made of rigid or semiflexible materials with very limited bending properties. As a result, their SNR is limited because they cannot be placed very close to the imaging area, thus receiving noises from parts of the human body, which are not intended to be imaged. Taking advantage of the computerized embroidery and laser cutting technology, in this paper, we utilize electrotextile to design, fabricate, and measure multilayer RF coil array system for 3 Tesla (3T) MRI to improve the SNR performance. The proposed RF coil array system provides an ergonomic and high-performance solution to the 3T MRI systems. A roadmap to systematically design electrotextile RF coil arrays is proposed. RF coil array is characterized to have the accurate resonant frequency, good impedance matching, and low mutual coupling. In addition, magnetic field distribution, bending effects, and human body effects are also discussed. A systematic method to characterize the performance of the electrotextile pattern is studied and used to assist the development and performance characterization. Finally, the high resolution and high SNR images of various kinds of phantoms are obtained using the University of California at Los Angeles (UCLA) Antenna Lab electrotextile coil array after its integration with the 3T MRI scanners at UCLA David Geffen School of Medicine Translational Research Imaging Center. Compared with the conventional surface coil, more than 10 dB SNR increase is observed at the depth of 0.5 cm and 3 dB increase at the depth of 3 cm. [ABSTRACT FROM AUTHOR]
PROTOTYPES, INDUSTRIAL design, ENGINEERING design, TECHNOLOGICAL innovations, and NEW product development
Prototyping can be seen as the heart of the innovation process. Typically, engineers and designers both work on prototyping activities, but their diverse backgrounds make for different perspectives on prototyping. Based on earlier literature, this study investigates commonalities and differences in the prototyping behavior of engineers and designers. For this study, semi‐structured interviews and workshops with different experiments were conducted. Using low‐fidelity prototypes, our results indicated that there are differences in the early phase of prototyping. Engineers focused on the features and functions of a prototype and needed to meet specific goals in order to push the process forward. Designers, on the other hand, used prototypes to investigate the design space for new possibilities, and were more open to a variety of prototyping materials and tools, especially for low‐fidelity prototypes. In the later prototyping phases, the prototyping behaviors of engineers and designers became similar. Our study contributes to the understanding of prototyping purposes, activities, and processes across disciplines, and supports the management of prototyping in new product development processes. [ABSTRACT FROM AUTHOR]
Information Services & Use. 2016, Vol. 35 Issue 1/2, p71-75. 5p. 2 Color Photographs, 1 Black and White Photograph.
RAPID prototyping, INFORMATION technology, TECHNOLOGICAL innovations, and BUSINESS partnerships
To build a platform for (high, sustainable) use, we need to know what will thrill users. Finding the right concoction of technology, functionality and design to delight users takes a thousand decisions, pivots and changes. The JSTOR Labs team has been using Flash Builds -- high-intensity, short-burst, user-driven development efforts -- in order to prototype new ideas and get to a user saying "Wow" in as little as a week. In this paper, a distillation of a presentation I gave at NFAIS 2015, I will describe how we have done this, highlighting the partnerships, skills, tools and content that help us innovate. [ABSTRACT FROM AUTHOR]