Numerous Prototypes Research Articles

Granular Description of Data Structures: A Two-Phase Design.

The study is concerned with a description of large numeric data with the aid of building a limited collection of representative information granules with the objective of capturing the structure of the original data. The proposed development scheme consists of two steps. First, a clustering algorithm characterized by high flexibility of coping with the diverse geometry of data structure and efficient computational overhead is invoked. At the second step, a clustering algorithm applied to the clusters already formed during the first phase, yielding a collection of numeric prototypes is involved and the numeric prototypes produced there are then generalized into their granular prototypes. The quality of granular prototypes is quantified while their build-up is supported by the mechanisms of granular computing such as the principle of justifiable granularity. In this paper, the clustering algorithms of DBSCAN and fuzzy C -means were used in successive phases of the processed approach. The experimental studies concerning synthetic data and publicly available data are covered and the performance of the developed approach is assessed along with a comparative analysis.

Service-oriented invisible numerical control application: architecture, implementation, and test

ABSTRACT CNC system has improved greatly upon machining precision and speed over the past six decades but remains vendor-proprietary and working in a stand-alone pattern. Open CNC aims to deal with the vendor-proprietary issue and numerous open CNC prototypes have been developed in the past three decades. But they are heterogeneous, low-flexible, and remain working in a stand-alone pattern. In today's Internet era, the stand-alone working pattern tends to evolve into cloud-based control pattern (cloud-CNC). On the basis of open CNC and cloud-CNC, our team proposes a novel CNC prototype called Invisible Numerical Control (INC). This paper aims to develop the INC application within the constraints of open CNC and cloud-CNC. Service-oriented paradigm is utilised to develop INC application at three levels. First, INC application is a software-as-a-service-style application. Second, CNC modules are exposed as services and CNC functionality is determined by service-oriented architecture. Third, INC application is developed using microservices architecture. Four autonomous INC microservices are defined and their mapping relationships are determined. All INC microservices are implemented as RESTful services and two complex INC microservices are implemented based on domain-driven design. A desktop client and its corresponding API gateway have been developed to test INC application.

Stepwise shape optimization of the surface of a vibrating screen

Screening is a technique that is extensively adopted for the separation of discrete materials according to particle characteristics such as size and shape. Wide application of the discrete element method has sparked much research on the vibrating screen, which is a screening apparatus having a specific vibration mode. The shape of the screen surface is a critical factor affecting the sieving performance of the vibrating screen. In this paper, a stepwise optimization method is employed to optimize the screen surface shape of the vibrating screen in discrete element modeling to obtain a high screening efficiency and large processing capacity simultaneously. Adopting this optimization method, a new curved screen with five decks having various inclination angles is presented. Numerical simulations and prototype experiments are conducted to verify the superior sieving performance of the new curved screen. Experimental results clearly show that the new curved screen greatly outperforms three commonly used screens in terms of sieving performance. The conclusions and methodologies of this work will benefit the design and improvement of vibrating screens.

Lower Limb Design for a Child Test Dummy, based on Osteogenesis Imperfecta characteristics

Active and passive safety have played an essential role in solidifying ground transportation. However, safety-focused on children with some rare diseases is little attacked. This article shows the design of a diseased leg prototype into a crash test dummy Q3, the novelty of this work is based on the morphology and biocompatibility of the lower limbs, which principal characteristics of this prototype replicate the shape of a child with bone-degenerative diseases. In this work, it shows the essential features that a child dummy of this type must contain in order to generate a homologation and approval under the strictest passive safety standards used in the automotive industry. Results show the important kinematics parameters and CAD bones development necessary to conform a new numerical crash test dummy prototype.

Discrete-State Event-Driven Numerical Prototyping of Megawatt Solid-State Transformers and AC/DC Hybrid Microgrids

Solid-state transformers (SSTs) enable electric energy distribution with higher flexibility, sustainability and efficiency, and the AC/DC hybrid microgrid (MG) is one of the representative applications. However, the design and analysis of SSTs and MGs were limited by lack of fast simulation tools that can accurately and efficiently handle systems with massive number of switching devices. This article demonstrates how the discrete-state event-driven (DSED) approach allows an accurate and faster simulation of the SSTs and MGs than the state of the art and benefit the practical design. The numerical prototyping of a hybrid MG composed of a megawatt SST together with multiple converters (e.g. PVs, EVs and batteries) is presented in this article. The performance is compared with existing simulation approaches. Various scenarios are investigated, including the grid-connected mode, the islanded mode, and the mode transition considering the communication delay. A time cost of several hours is decreased to tens of seconds with same accuracy using DSED, enabling faster simulations for complicated tasks. It is discussed how the speed and accuracy benefit the practical SST and MG design.

Analysis of a 440C steel roller bearing using finite element method

Abstract One of the important component of working machines or conveyer belt is the roller bearing. They are applied in different sectors ranging from automotive to heavy duty machineries in high speed drills. Their performance greatly affects the machines. This study illustrate the analysis of the contact stress developed in a roller bearing using ANSYS software. The Finite Element simulating results revels maximum stress distribution value of 6.597E-09 MPa under the applied loading condition appearing on the roller balls. The total moment for the variation to time is 2.5868E-07 experienced at 7.7 s while the relative rotation in the Z-direction is at its peak at 6 s. Therefore, this study shows that FEA in ANSYS has provide a faster and cheaper method compared to the production of numerous prototypes.

Construction and Evaluation of Information Granules: From the Perspective of Clustering

While granular computing has experienced rapid growth in the past decades and some milestones have been reached, a comprehensive study of the representation capabilities delivered by numeric prototypes and granular prototypes produced by different techniques still calls for comprehensive research and a comparative analysis. Well-constructed information granules are reflective of the nature of the numeric evidence and serve as backbones of granular classifiers and granular models. The objective of this study is to review a number of clustering paradigms aimed at the construction of information granules, discuss the development of granular prototypes, and conduct a comprehensive evaluation of quality of numeric prototypes and their corresponding augmentations coming in the form of granular prototypes. We have been witnessing many studies devoted to the construction of information granules, but a comparative analysis of the quality of information granules constructed on a basis of prototypes produced by different clustering algorithms is still lacking. In this regard, the review of the clustering algorithms supporting the formation of information granules and the comprehensive comparative study of their usefulness in classification and modeling tasks offered in this study make sense. This will promote the usage of information granules in various future works, especially classification problem and system modeling.

Induced Disassembly of a Virus-like Particle under Physiological Conditions for Venom Peptide Delivery.

Virus-like particles (VLPs) show considerable promise for the in vivo delivery of therapeutic compounds such as bioactive venom peptides. While loading and targeting protocols have been developed for numerous VLP prototypes, induced disassembly under physiological conditions of neutral pH, moderate temperature, and aqueous medium remain a challenge. Here, we implement and evaluate a general mechanism, based on ring-opening metathesis polymerization (ROMP), for controllable VLP disassembly. This mechanism is independent of cell-specific factors or the manipulation of environmental conditions such as pH and temperature that cannot be readily controlled in vivo. The ROMP substrate norbornene is covalently conjugated to surface-exposed lysine residues of a P22 bacteriophage-derived VLP, and ROMP is induced by treatment with the water-soluble ruthenium catalyst AquaMet. Disruption of the P22 shell and release of a GFP reporter is confirmed via native agarose electrophoresis, TEM, and dynamic light scattering (DLS) analyses. Our ROMP disassembly strategy does not depend on the particular structure or morphology of the P22 nanocontainer and is adaptable to other VLP prototypes for the potential delivery of venom peptides for pharmacological applications.

Intermediate band solar cells: Present and future

AbstractIn the quest for high‐efficiency photovoltaics (PV), the intermediate band solar cell (IBSC) was proposed in 1997 as an alternative to tandem solar cells. The IBSC offers 63% efficiency under maximum solar concentration using a single semiconductor material. This high‐efficiency limit attracted the attention of the PV community, yielding to numerous intermediate band (IB) studies and IBSC prototypes employing a plethora of candidate IB materials. As a consequence, the principles of operation of the IBSC have been demonstrated, and the particularities and difficulties inherent to each different technological implementation of the IBSC have been reasonably identified and understood. From a theoretical and experimental point of view, the IBSC research has reached a mature stage. Yet we feel that, driven by the large number of explored materials and technologies so far, there is some confusion about what route the IBSC research should take to transition from the proof of concept to high efficiency. In this work, we give our view on which the next steps should be. For this, first, we briefly review the theoretical framework of the IBSC, the achieved experimental milestones, and the different technological approaches used, with special emphasis on those recently proposed.

Iterative heuristic design of temporal graphic displays with clinical domain experts.

Conventional electronic health record information displays are not optimized for efficient information processing. Graphical displays that integrate patient information can improve information processing, especially in data-rich environments such as critical care. We propose an adaptable and reusable approach to patient information display with modular graphical components (widgets). We had two study objectives. First, reduce numerous widget prototype alternatives to preferred designs. Second, derive widget design feature recommendations. Using iterative human-centered design methods, we interviewed experts to hone design features of widgets displaying frequently measured data elements, e.g., heart rate, for acute care patient monitoring and real-time clinical decision-making. Participant responses to design queries were coded to calculate feature-set agreement, average prototype score, and prototype agreement. Two iterative interview cycles covering 64 design queries and 86 prototypes were needed to reach consensus on six feature sets. Interviewers agreed that line graphs with a smoothed or averaged trendline, 24-h timeframe, and gradient coloring for urgency were useful and informative features. Moreover, users agreed that widgets should include key functions: (1) adjustable reference ranges, (2) expandable timeframes, and (3) access to details on demand. Participants stated graphical widgets would be used to identify correlating patterns and compare abnormal measures across related data elements at a specific time. Combining theoretical principles and validated design methods was an effective and reproducible approach to designing widgets for healthcare displays. The findings suggest our widget design features and recommendations match critical care clinician expectations for graphical information display of continuous and frequently updated patient data.

Evaluating the Euler-Euler approach for predicting a strongly 3D bubble-induced recirculatory flow with OpenFOAM

Wastewater treatment plants use bubbly flows to promote grit removal from the plant’s influent. Computational fluid dynamics is an attractive tool to virtually prototype grit-chamber designs. This study assesses a two-phase unsteady Reynolds-averaged Euler-Euler (uRANS-EE) approach to predict bubble induced recirculatory flow in a laboratory tank of similar complexity to that expected in a full-scale grit-chamber. Numerical results are validated against a comprehensive experimental data set consisting of a 3D reconstruction of the flow field using a multi-plane stereoscopic particle image velocimetry technique, void fraction profiles using an optical probe and bubble rise-velocities using high-speed video. Depending on the combination of modeling parameters the predicted volumetric fluid flux returning towards the diffuser varied between 60 and 97% of the experimental flux. Predicted rise velocities exceeded measured values by a factor between 1.15 to 1.75 and near bed velocities were underpredicted by upwards of 25%. The principal 3D flow field features were predicted to a sufficient accuracy to support the use of the uRANS-EE approach for numerical grit-chamber prototyping.

From numerical prototypes to real models: a progressive study of aerodynamic parameters of nonconventional concrete structures with Computational Fluid Dynamics

Abstract The practical evaluation of aerodynamic coefficients in unconventional concrete structures requires specific studies, which are small-scale models evaluated in wind tunnels. Sophisticated facilities and special sensors are needed, and the tendency is for modern and slender constructions to arise with specific demands on their interaction with the wind. On the other hand, the advances obtained in modern multi-core processors emerge as an alternative for the construction of sophisticated computational models, where the Navier-Stokes differential equations are solved for fluid flow using numerical methods. Computations of this kind require specialized theoretical knowledge, efficient computer programs, and high-performance computers for large-scale calculations. This paper presents recent results involving two real-world applications in concrete structures, where the aerodynamic parameters were estimated with the aid of computational fluid dynamics. Conventional quad-core computers were applied in simulations with the Finite Volume Method and a progressive methodology is presented, highlighting the main aspects of the simulation and allowing its generalization to other types of problems. The results confirm that the proposed methodology is promising in terms of computational cost, drag coefficient estimation and versatility of simulation parameters. These results also indicate that mid-performance computers can be applied for preliminary studies of aerodynamic parameters in design offices.

Characterization of the system behaviour of a variable compression ratio (VCR) connecting rod with eccentrically piston pin suspension and hydraulic moment support

Making the geometrical compression ratio an adjustable parameter is considered the last remaining significant technological step in combustion engine design. Numerous prototype engines with variable compression ratio (VCR) were designed and tested. The implementation of VCR technology increases the averaged energy conversion efficiency in stoichiometric spark ignition (SI) engines ranging from 3 to 8% depending on the driving cycle, the fuel and the degree of turbo charging. The approach of a connecting rod with an adjustable length, a so called VCR connecting rod, is considered a promising solution because it can be implemented in almost every reciprocating engine regardless the type (inline, V or boxer engine) with a minimum of changes on existing engine layout. One design approach for a VCR connecting rod consists on an eccentrically piston pin suspension in combination with two hydraulic cylinders keeping the eccentric in a desired angular position. A change in compression ratio (CR) is initiated by means of actuating a hydraulic switch valve on the VCR connecting rod. The gas and mass forces acting on the piston pin result into a moment acting on the eccentric. In order to optimize the design of a VCR connecting rod with respect to robustness, weight and manufacturing costs, the dynamic behaviour and any arising phenomena must be known and understood. The aim of this work was to investigate this dynamic behaviour by means of fired engine testing. For this purpose, a VCR connecting rod was instrumented with sensors and the measured data was acquired synchronously to the crank angle. During these tests, operational parameters such as engine speed and load and the oil feed stream conditions were assessed for the two compression ratios stages and during the transitions from one to another compression ratio.

A semantic facial expression intensity descriptor based on information granules

This paper investigates a granular description for facial expression intensity in which characterization of motion-based expression features is presented by a collection of information granules. First, the motion-based features are extracted based on the facial landmarks to encode the expression intensity. Secondly, the semantic concepts are then generated by involving various mechanisms of fuzzy clustering based on the motion-based features. The resulting clusters can be viewed as numeric prototypes of the descriptors. The information granules are formed around the prototypes according to the principle of justifiable granularity, which is the fundamental idea of Granular Computing. The proposed granular descriptor for expression intensity is tested on the BU-3DFE database, and the experimental results illustrate that the proposed descriptors based on information granules not only can characterize the semantics of facial changes caused by expressions, but also can facilitate the semantic estimation of facial expression intensity.

A Vibration-Related Design Parameter Optimization Method for High-Speed Elevator Horizontal Vibration Reduction

High-speed elevator horizontal vibration (HsEHV) is a problem that seriously affects ride comfort. To solve this problem, a design parameter optimization method for HsEHV reduction was studied. A dynamic equation of HsEHV was established, and its response value was calculated using a precise integration method. The influence of the design parameters on horizontal vibration was also analyzed. An optimization model of the design parameters for HsEHV reduction was constructed, and the response surface model of objective function (the peak-to-peak value of horizontal vibration acceleration) was constructed using Latin hypercube sampling. We adopted a multiobjective genetic algorithm to optimize the design parameters for horizontal vibration reduction and used the min-max standardization method to select an optimal solution set. Finally, a KLK2 high-speed elevator made by Canny Elevator Co., Ltd., was utilized as an example to analyze the influencing factors of HsEHV, optimize the design parameters to reduce horizontal vibration, and verify the optimized results using numerical calculation and prototype testing.

Finite element analysis of flood discharge atomization based on water–air two-phase flow

Flood discharge atomization is a phenomenon of water fog diffusion caused by the discharge of water from a spillway structure, which brings strong wind and heavy rainfall. These unnatural winds and rainfall are harmful for the safe operation of hydropower stations with high water heads. Compared to the method of prototype observations, physical models and mathematical models, which are semi-theoretical and semi-empirical, numerical simulation methods have the advantage of being not limited by a similar scale and are more economical. A finite element model is presented to simulate flood discharge atomization based on water–air two-phase flow in this paper. Equations governing flood discharge atomization are composed of partial differential equations of mass and momentum conservation laws with unknowns for pressure, velocity and the water concentration. The finite element method is used to solve the governing equations by adopting appropriate solution strategies to increase the convergence and numerical stability. Then, the finite element model is applied to a practical project, the Shuibuya hydropower station, which experienced a flood discharge in 2016. Simulation results show that the proposed model can simulate flood discharge atomization with efficient convergence and numerical stability in three dimensions, and good agreement was observed between numerical simulations and prototype observational data. Based on the simulation results, the mechanism of flood discharge atomization was analyzed.

Double Stage Double Output DC–DC Converters for High Voltage Loads in Fuel Cell Vehicles

This article aims to enhance the output voltage magnitude of fuel cells (FCs), since the actual generation is low. The traditional technique is too complicated and has a cascaded or parallel connection solution to achieve high voltage for multiple loads in vehicles. In this case, electronic power converters are a viable solution with compact size and cost. Hence, double or multiple output DC–DC converters with high voltage step up are required to feed multiple high voltage loads at the same time. In this article, novel double stage double output (DSDO) DC–DC converters are formulated to feed multiple high voltage loads of FC vehicular system. Four DSDO DC–DC converters called DSDO L–L, DSDO L-2L, DSDO L-2LC, and DSDO L-2LC are developed in this research work and all the converters are derived based on the arrangement of different reactive networks. The primary power circuitry, conceptual operation, and output voltage gain derivation are given in detail with valid proof. The proposed converters are compared with possible parallel combinations of conventional converters and recently available configuration. Comprehensive numerical simulation and experimental prototype results show that our theoretical predictions are valid and that the configuration is applicable for real time application in FC technologies for ‘more-electric vehicles’.

Design and Analysis of a Self-Supporting Bamboo Roof Structure with Flexible Connections

The presented study investigates a mobile bamboo roof structure with flexible connections. The developed ultralight structural system built with modular space frames, tensile pantographic grids, textile joints in polyester ropes and biocomposites, is capable of supporting itself. Prefabricated hinged flexible connections (HFC), designed for the structure, allow for a deployable mechanism, free of torsional stresses in the bamboo bars. Nonlinear analysis using the finite element method (FEM) was used to determine the forces in the structure. Static loading patterns for wind loads were investigated and it was determined that the applied forces can be safely resisted by the structural members. A numerical model, physical models and full-scale prototypes were used to investigate the complex mechanical behavior of the bamboo structure. Selected design guidelines are also introduced.

Study of Domino Number Game Development for Early Children’s Ability to Recognize Numbers

This study aims to develop and produce feasible and effective numerical domino game prototype used as learning to recognize symbols of number 1-10 for children aged 4-5 years. The design of study is research and development research adapted from Borg & Gall research and development using Single one shot case study and One Pretest-Posttest Design Group. But the writers used only 9 steps. The subject in this study are Group A children aged 4-5 years in 6 kindergartens in Duduk sampeyan Subdistrict, Gresik District. Data were analyzed using descriptive quantitative. The results of this developmental research are numerical domino game prototype to develop 4-5 years old children’s ability to recognize number 1-10. The operational field testing stage shows The average score is 0.84, categorized as high. Therefore, it can be concluded that the numeric domino game is feasible and effective game used as learning to recognize the symbol of numbers 1-10 in children aged 4-5 years.

Toward Intelligent Machine Tool

Abstract With the development of modern information technology—and particularly of the new generation of artificial intelligence (AI) technology—new opportunities are available for the development of the intelligent machine tool (IMT). Based on the three classical paradigms of intelligent manufacturing as defined by the Chinese Academy of Engineering, the concept, characteristics, and systemic structure of the IMT are presented in this paper. Three stages of machine tool evolution—from the manually operated machine tool (MOMT) to the IMT—are discussed, including the numerical control machine tool (NCMT), the smart machine tool (SMT), and the IMT. Furthermore, the four intelligent control principles of the IMT—namely, autonomous sensing and connection, autonomous learning and modeling, autonomous optimization and decision-making, and autonomous control and execution—are presented in detail. This paper then points out that the essential characteristic of the IMT is to acquire and accumulate knowledge through learning, and presents original key enabling technologies, including the instruction-domain-based analytical approach, theoretical and big-data-based hybrid modeling technology, and the double-code control method. Based on this research, an intelligent numerical control (INC) system and industrial prototypes of IMTs are developed. Three intelligent practices are conducted, demonstrating that the integration of the new generation of AI technology with advanced manufacturing technology is a feasible and convenient way to advance machine tools toward the IMT.