RAPID prototyping, DECISION making, ANALYTIC hierarchy process, GREY relational analysis, FUZZY numbers, and STRENGTH of materials
A multitude of rapid prototyping (RP) systems and technologies have come up since the introduction of additive process. Owing to the enlarging number of these systems with distinctive efficacy, the problem of selecting an appropriate system for a particular requirement is a cumbersome task. Henceforth, this work comes up with a strategy based on multi-attribute decision making to select a most suitable RP system. The presence of subjectivity in decision making as well as the existence of imprecision from various sources emphasize the methods which must consider uncertainty and vagueness. A decision advisor based on uncertainty theories, including fuzzy analytical hierarchy process (FAHP) and grey relational analysis (GRA) has been introduced. It provides a comprehensive database comprising thirty nine commercially available RP systems. The evaluation attributes consisting of machine cost, accuracy, layer thickness, machine speed, material cost, net build size volume, machine weight, surface roughness, and material strength were utilized to characterize the different machines. The FAHP based on trapezoidal fuzzy number was implemented to determine the priority weights of various attributes, while the GRA was employed to realize the best RP system and technology. The authors believe that this system has the potential to transform into a fully developed RP selection system. [ABSTRACT FROM AUTHOR]
This article presents a novel sensor for detecting and measuring angular rotation and proximity, intended for rapid prototyping machines. The sensor is based on a complementary split-ring resonator (CSRR) driven by a conductor-backed coplanar waveguide (CBCPW). The sensor has a planar topology, which makes it simple and cost-effective to produce and accurate in measuring both physical quantities. The sensor has two components, a rotor and a stator: the first of these (the CSRR) can rotate around its axis and translate along the plane normal to the ground of the CBCPW. A detailed theoretical and numerical analysis, along with a circuit model, of the unique sensor design is presented. The proposed sensor exhibits linear response for measuring angular rotation and proximity in the range of 30°–60° and 0–200 μm, respectively. Another distinctive feature of the rotation and proximity sensor is the wide frequency band of applicability, which is an integral part of its novel design and is implemented through various dielectric material loadings on the CSRR. In the prototype of the proposed device, the stator (CBCPW) is fabricated on a 0.508-mm-thick RF-35 substrate, whereas the CSRR-based rotor is fabricated on TLY-5 and RF-35 substrates. The angular rotation, proximity, operating band selection, and sensitivity are measured using a vector network analyzer and are found to be good matches to the simulated and theoretical results. [ABSTRACT FROM AUTHOR]
Roymohapatra, Sitansusekhar, Gore, Ganesh R., Yadav, Akanksha, Patil, Mahesh B., Rengarajan, Krishnan S., Iyer, Subramanian S., and Baghini, Maryam Shojaei
IEEE Transactions on Computer-Aided Design of Integrated Circuits & Systems. May2020, Vol. 39 Issue 5, p1073-1083. 11p.
RAPID prototyping, TECHNOLOGY, SEMICONDUCTOR devices, and INTERPOLATION
In this paper, a new look-up table (LUT) method is proposed to reduce the simulation time and the run time memory requirement for large logic and mixed signal simulations. In the proposed method, for the first time, circuit with multiple devices is replaced by one LUT model, called circuit LUT. The replacement results in significant reduction of the run time memory requirement. The replacement also reduces the number of interpolation steps to be performed at every Newton–Raphson iteration during the simulation that results in significant reduction of simulation time. With the proposed method, the simulation speed is improved by two times over the conventional LUT models developed for devices. In addition, 25% reduction in the run time memory requirement is also achieved by the proposed method. [ABSTRACT FROM AUTHOR]
WIRELESS power transmission, RAPID prototyping, RADIO frequency, GOLD coatings, and STAINLESS steel
This article presents an electromagnetically powered stent designed for hyperthermia treatment of in-stent restenosis. The stent device based on medical-grade stainless steel serves as a radio frequency (RF) inductive receiver to produce mild heating wirelessly through resonant-coupling power transfer, while acting as a mechanical scaffold inside an artery similar to commercial stents. The device and its custom transmitter are prototyped and optimized to show efficient wireless power transfer and stent heating through in vitro tests. The inductive stent with its helical pattern is gold coated to achieve a $3.5\times $ higher quality ($Q$) factor, improving heating performance of the device. The combinational use of independent resonant antennas with the power antenna is found to significantly boost stent temperature by up to 96% with an intermediate tissue layer. Upon matching the frequencies at which the $Q$ factors of the inductive stent, power antenna, and booster antenna are peaked, the stent excited through 10 mm-thick tissue exhibits a temperature increase of 18 °C, well over a necessary level for targeted hyperthermia treatment. The prototype achieves heating efficiencies (HEs) of 15.5–3.2 °C/W with a tissue thickness of 5–15 mm. These results indicate that the proposed resonant-heating stent system with the prototyped transmitter is promising for further development toward its clinical application. [ABSTRACT FROM AUTHOR]
To develop a thermal model for air-cooled plate–fin heatsink and evaluate its thermal performance, empirical equations are available to rapidly calculate the pressure drop and heat transfer coefficients for the fins. Besides the heat transfer coefficients, the local air temperature also affects the heat transfer of the fins, which rises along the channel by absorbing the released heat from the fins. In this article, a heatsink model to account for the air temperature rise is proposed, and a thermal circuit model is used to correlate the increased air temperature and the absorbed heat at the fin boundary. With this convective boundary, the temperature distribution for the base plate of the heatsink is calculated by adopting finite-difference method (FDM), which analyzes the conductive heat transfer for the base plate. Both of them have been programed in MATLAB software, and the calculated temperature by the proposed models is compared with the computational fluid dynamics (CFD) simulation. A fan-cooled plate–fin heatsink for a half-bridge power electronics inverter is tested in the laboratory as an example, and the thermal results obtained from the proposed models are within 10% of error with respect to the CFD simulation results and experimental results. The proposed method is also faster than the CFD simulation. The proposed accurate and rapid thermal modeling method will be essential for virtual prototyping and layout/geometry optimization of power electronics systems. [ABSTRACT FROM AUTHOR]
Recently, multi-FPGA platforms have become a popular choice to prototype complex digital systems. This is because of unique advantages such as high frequency and real world testing experience that are offered when compared to other pre-silicon testing techniques. However, one of several challenges faced by multi-FPGA prototyping is the requirement of an efficient back end flow. Partitioning is a key part of the back end flow of multi-FPGA systems and it directly affects the quality of final prototyped design. In this work, we explore two different partitioning approaches: one is multilevel; while the other is hierarchical partitioning approach. For experimentation, we use a suite of fourteen large benchmarks. Experimental results reveal that the multilevel approach gives 12.5% better frequency results for mono-cluster benchmarks while the hierarchical approach gives 13% better results for multi-cluster benchmarks. Furthermore, the hierarchical approach requires, on average, 60% less execution time when compared to the multilevel partitioning approach. [ABSTRACT FROM AUTHOR]
IEEE Transactions on Power Electronics. Sep2019, Vol. 34 Issue 9, p8715-8723. 9p.
RAPID prototyping, CURRENT-voltage characteristics, and ELECTRONIC feedback
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]
The huge model size and high computational complexity make emerging convolutional neural network (CNN) models unsuitable to deploy on current embedded or edge computing devices. Recently the binary neural network (BNN) is explored to help reduce network model size and avoid complex multiplication. In this paper, a binary network acceleration framework for rapid system prototyping is proposed to promote the deployment of CNNs on embedded devices. Firstly trainable scaling factors are adopted in binary network training to improve network accuracy performance. The hardware/software co-design framework supports various compact network structures such as residual block, 1 × 1 squeeze convolution layer, and depthwise separable convolution. With flexible network binarization and efficient hardware architecture optimization, the acceleration system is able to achieve over 2 TOPS throughput performance comparable to modern desktop GPU with much higher power efficiency. [ABSTRACT FROM AUTHOR]
Journal of Information Systems Education. Summer2020, Vol. 31 Issue 3, p179-186. 8p.
INFORMATION storage & retrieval systems, USER interfaces, HUMAN-computer interaction, SYSTEM analysis, SOFTWARE engineering, DESIGN students, ACTIVE learning, and EDUCATION software
Given the ubiquity of interfaces on computing devices, it is essential for future Information Systems (IS) professionals to understand the ramifications of good user interface (UI) design. This article provides instructions on how to efficiently and effectively teach IS students about "fit," a Human-Computer Interaction (HCI) concept, through a paper prototyping activity. Although easy to explain, the concept of "fit" can be difficult to understand without repeated practice. Practically, designing "fit" into UIs can be cost-prohibitive because working prototypes are often beyond students' technical skillset. Accordingly, based on principles of active learning, we show how to use paper prototyping to demonstrate "fit" in a hands-on class exercise. We provide detailed step-by-step instructions to plan, setup, and present the exercise to guide students through the process of "fit" in UI design. As a result of this activity, students are better able to employ both theoretical and practical applications of "fit" in UI design and implementation. This exercise is applicable in any course that includes UI design, such as principles of HCI, systems analysis and design, software engineering, and project management. [ABSTRACT FROM AUTHOR]
RENEWABLE energy sources, POWER distribution networks, WIND power plants, and DIGITAL media
Trends of incorporating distributed renewable energy sources into the power distribution network through power electronic mediums have substantially increased. It results in a decaying inertial response and, consequently, the natural damping. Eventually, the distribution network is increasingly becoming sensitive towards the uncertainties. The increasing sensitivity issue in the power system drives the present research trends towards a solution termed virtual synchronous generator (VSG). A VSG has the potentiality to mimic the characteristics of a physical synchronous generator (SG). In this study, to expose the suppressed potentiality of a VSG, an innovative concept of virtual gyratory mass is proposed. To achieve a satisfactory performance, the model parameters of the VSG have to be well chosen. Conventionally, optimal parameters are selected by comparing it with a physical SG and thus, it remains constant in its operational period. However, the constant inertial VSG cannot suppress the system sensitivity under the random degree of uncertainty. Therefore, to ride through this issue, the concept of dynamic damping co-efficient is introduced in this study. The damping coefficient is tuned in real-time through the proposed fuzzy tuned dynamic synthetic inertia mechanism. The improvement in the performance is validated in the real-time experimental prototype setup. [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]
Systems Research & Behavioral Science. Nov2019, Vol. 36 Issue 6, p835-844. 10p.
NEW product development, SYSTEMS design, SYSTEMS theory, COMPUTER graphics, COMPUTER simulation, HUMAN anatomical models, and PSYCHOPHYSICS
In almost all areas of the industry and more generally in the sector of development of manufacturing products, the realization of the product passes through several successive stages going from the design to the realization of the product. The most critical phase is prototyping because it is at this point that usually the most important decisions are made. In several sectors this step is very expensive, and in any case, the prototype undergoes several modifications and requires several validations before it is definitive for the transition to production. The prototype must generally constitute a model of the product that has all or part of the technical qualities and operating characteristics that must appear in the final product, to demonstrate or affirm the validity of the concept and thus its final validation, which increases the overall cost of the prototyping phase. In the vast majority of prototyping devices available for the moment, be it by additive or subtractive process, the realization of the prototype requires a lot of time, and once the prototype is made, it can only be modified by destructive techniques because the materials used are frozen and do not allow easy reuse. This study proposes a device for the prototyping of product, allowing a modification of the geometry of the prototype by means of a deformable composite membrane with shape memory, reusable and programmable. The device in question consists of a flexible composite membrane whose matrix is a flexible polymer, and the reinforcement is a shape‐memory alloy fibre and rubber effect, having a given electrical resistance. These shape memory fibres are woven in such a way as to ensure deformations in the direction normal to the plane of the membrane by injecting the current into each fibre. This is ensured by a cross weave allowing the control of the direction of the overall deformation through the deformation specific to each fibre. In this research work, we present the results of the modelling and simulation of the behaviour of a composite membrane with shape memory. [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]
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]
NOMA is a promising way to increase spectral efficiency recently discussed in the IEEE 802.11 Working Group that develops WiFi standards. NOMA can be very beneficial in a WiFi network where the qualities of the channel between the access point and associated stations are significantly different. In such scenarios, NOMA allows the access point to transmit several data streams to various stations in parallel using one antenna and the same time-frequency resources. This article presents and evaluates the first-ever prototype of a WiFi device supporting NOMA, implemented in a software-defined radio platform. The prototype is backward compatible with legacy WiFi versions. Specifically, one of the multiplexed streams may be received by a legacy station not supporting NOMA. This feature is favorable for heterogeneous deployments with various generations of WiFi devices. This article provides a detailed description of the prototype as well as experimental results showing from 37 percent to 100 percent gain achieved by including NOMA in the future 802.11 standards. [ABSTRACT FROM AUTHOR]