CAD Design Research Articles

Novel computer aided diagnostic system using hybrid neural network for early detection of pancreatic cancer

One of the most dangerous tumours in the world, pancreatic cancer (PC), has an unimpressive five-year survival rate of about 5%. An early PC identification is crucial for raising patient survival rates. Diagnosis of PC requires computed tomography (CT), magnetic resonance imaging (MRI) with magnetic resonance cholangiopancreatography (MRCP), or biopsy. The proposed CAD design approach includes image preprocessing, segmentation, feature extraction, and classification phases. Preprocessing is done by using Colour conversion and an isotropic diffusion filter approaches. After that, proposed Fuzzy K-NN Equality algorithm used in segmentation procedures. Deep Learning with feature extraction is used as a classification tool. Tumour cells are classified using the features collected from the pancreatic sample. Train values and testing datasets are part of the image classification criterion. For the purpose of detecting pancreatic cancer, a hybrid Deep Convolutional Neural Network with Deep Belief Network (DCNN_DBN) algorithm is used. According to the experimental findings, the current CAD system offers massive prospects as well as safety in the automated diagnosis of both benign as well as malignant cancers and produces the accuracy of 99.6%. Using this classifier, computing complexity is massively diminished. The suggested technique could be enhanced to detect more pancreatic cancer cell abnormalities.

Research on the innovation path of teaching interior design majors in universities based on big data analysis

Abstract Presently, the teaching of interior design in most higher education institutions still uses more traditional and conservative teaching methods, which to some extent, hinders the reform of interior design teaching in the era of big data. Interior design originally required students to grasp the operation fully and use CAD, 3D, and other design software, which makes the operation of complex commands, and model construction diversity, difficult for students to learn. This situation still uses the traditional lecture-based indoctrination teaching can play a very small role. This paper first focuses on the field of interior design education, based on the background of the times, provides a deep overview of the current situation of the relevant research involved in interior design, and explains the purpose, ideas, content, and methods of this paper. Secondly, we use data mining technology to build a smart classroom to visually present interior design. Finally, a comparison experiment between the traditional teaching mode of interior design and the smart teaching mode of big data is carried out, and three groups of experimental subjects are investigated after nearly one month of teaching experience. The results of this study show that the big data wisdom teaching model proposed in this paper compared with the traditional teaching model, through the one-month teaching experience post-test results, the average increase of 7 points in school A, 11 points in school K, and 14 points in school Z. The wisdom teaching system based on big data built in this paper enhanced the relevance and initiative of interior design students’ learning, improved students’ interest in learning and classroom efficiency and promoted students’ comprehensive ability while playing a positive and active role.

Graphic Design Optimization Method Based on Deep Reinforcement Learning Model

Abstract This paper used a new interior graphic modeling research based on CAD and depth enhancement teaching models. A massive database for graphic design has been established. An optimization method is proposed based on intelligent decision making, intelligent monitoring, panoramic vision, professional cooperation and intelligent planning. This system can make many systems of different dimensions share and integrate horizontally. The graphic design of CAD is introduced into 3D CAD. The Boolean method is introduced into the smooth grid instruction to obtain the smooth surface of the target surface. Combining the object of plane decomposition with other geometric shapes by form-fitting instruction achieves object control. Experiments show the effectiveness of the method. The system has good running performance, stability and safety.

Design and FEM modeling of a fire resistant cabinet for fusion environment

Diagnostic systems in fusion environments need to satisfy stringent requirements, often involving radiation and electromagnetic shielding as well as fire protection. A conceptual design of a multilayer cabinet for the RNC (Radial Neutron Camera) diagnostic systems, located in the equatorial port (EP) #01 in ITER, with a required fire rating REI-120 (R - integrity, E - leak tightness to hot gasses and flames, I – thermal) was analyzed from the thermal insulation (I) point of view during external fire scenario (Tmax=805 ℃ for 2 h). The modeling of the fire was based on the convective heat transfer represented by a HTC (heat transfer coefficient) of 35 W/m2K and radiative heat transfer with unit emissivity according to ISO-834. Focusing on the thermal criterion prescribed by the REI requirement, the objective was to demonstrate that the temperatures will remain below specified limits for at least 120 min subjected to given fire loads. The adopted strategy was to exploit an advanced microporous incombustible material – Microtherm® overstitched – selected for the fire insulation and being applicable for the ITER environment. A parametric 3D model was developed and solved using the Finite Element Method (FEM) and the ANSYS code, including not only the heat conduction but internal radiation via SURF252 elements and internal convection via LINK34 elements. The relation between the thickness of fire protection and the maximum temperature after 2 h of fire was analyzed for two types of designs: with internal and external fire protection. In addition to the ideal thermal connection between the layers of the cabinet, the effects of imperfect thermal contacts were analyzed by varying the thermal conductance of CONTA174 elements. The effect of the boundary conditions: adiabatic versus specified temperature was analyzed, as well as the need for protecting the supports of the cabinet. The effect of the cabinet size at constant thickness of the walls was analyzed parametrically revealing increasing temperatures for smaller cabinets – more fire insulation needed. An analytical model used to explain the size effect relate to the competing effects of increasing heat transfer area and increasing heat capacity. The developed methodology provides an easy tool for early dimensioning of the necessary fire protection layer often needed before the start of the detailed CAD design. The necessary thickness of external protection layer for the analyzed cabinet resulted in 10 mm.

3D printed guide tube system for acute Neuropixels probe recordings in non-human primates

Objective. Neuropixels (NP) probes are a significant advance in electrophysiological recording technology that enable monitoring of hundreds of neurons in the brain simultaneously at different depths. Application of this technology has been predominately in rodents, however widespread use in non-human primates (NHPs) such as rhesus macaques has been limited. In this study we sought to overcome two overarching challenges that impede acute NP implantation in NHPs: (1) traditional microdrive systems that mount to cephalic chambers are commonly used to access cortical areas for microelectrode recordings but are not designed to accommodate NP probes, and (2) NHPs have thick dura mater and tissue growth within the cephalic chambers which poses a challenge for insertion of the extremely fragile NP probe. Approach. In this study we present a novel NP guide tube system that can be adapted to commercial microdrive systems and demonstrate an implant method using the NP guide tube system. This system was developed using a combination of CAD design, 3D printing, and small part machining. Software programs, 3D Slicer and SolidWorks were used to target cortical areas, approximate recording depths and locations, and for in-silico implant testing. Main results. We performed in vivo testing to validate our methodology, successfully implanting, explanting, and reimplanting NP probes. We collected stable neurophysiological recordings in the premotor cortex of a rhesus macaque at rest and during performance of a reaching task. Significance. In this study we demonstrate a robust Neuropixels implant system that allows multiple penetrations with the same NP probe and share design files that will facilitate the adoption of this powerful recording technology for NHP studies.

Applying a Combination of Cutting-Edge Industry 4.0 Processes towards Fabricating a Customized Component

3D scanning, 3D printing, and CAD design software are considered important tools in Industry 4.0 product development processes. Each one of them has seen widespread use in a variety of scientific and commercial fields. This work aims to depict the added value of their combined use in a proposed workflow where a customized product needs to be developed. More specifically, the geometry of an existing physical item’s geometry needs to be defined in order to fabricate and seamlessly integrate an additional component. In this instance, a 3D scanning technique was used to digitize an e-bike’s frame geometry. This was essential for creating a peripheral component (in this case, a rear rack) that would be integrated into the frame of the bicycle. In lieu of just developing a tail rack from scratch, a CAD generative design process was chosen in order to produce a design that favored both light weight and optimal mechanical behaviors. FDM 3D printing was utilized to build the final design using ABS-CF10 materials, which, although being a thermoplastic ABS-based material, was introduced as a metal replacement for lighter and more ergonomic component production. Consequently, the component was manufactured in this manner and successfully mounted onto the frame of the e-bike. The proposed process is not limited to the manufacturing of this component, but may be used in the future for the fabrication of additional peripheral components and tooling.

Analiza konstrukcyjno-materiałowa innowacyjnego bębna mieszalnika o pojemności 12 m³

A structural and material analysis of individual elements of the mixing-unloading spiral and shell segments of the innovative mixer drum of the hydraulic truck concrete mixer with a capacity of 12 m3 was developed. A complex CAD design process of individual elements in terms of the developed manufacturing technology was carried out. The construction of the mixer components was verified in the 3D-CAD system and a numerical analysis of stress distribution using the finite element method (FEM) was carried out for key segments of the spiral, which directly determines the implementation of the correct and efficient concrete mixing process. The research resulted in the development of comprehensive technical documentation of the original mixer structure, including executive drawings of the components along with a description of the manufacturing technology and the choice of the initial material–steel with increased abrasion resistance. The results of the completed research process were used in the next stage of research, i.e. bench tests of the innovative design of the 12 m3 mixer drum.

Matlab/Simulink를 이용한 이륜 자율 균형 로봇의 3D 모델링과 제어

The two-wheeled self-balancing robot (TWSBR) based on an inverted pendulum is an attractive research topic that requires not only maneuvering but also postural balancing control. As TWSBRs have secured platforms with flexible movement and ease of operation, they have been rapidly spreading in everyday life rather than industrial sites. Meanwhile, 3D CAD design and analysis tools enable designers and engineers to realize innovative products while they reduce development time and costs. In this paper, we designed the components of TWSBR in 3D using SOLIDWORKS and assembled a 3D model of TWSBR using function blocks in Simscape. In addition, we derived a linearization model of TWSBR at the upright balancing position and designed an LQR controller for this model. Through the integrated simulation and animation environment in Matlab/Simulink using the 3D model of TWSBR, we presented that the LQR controller can effectively perform upright-balancing and maneuvering control.

Forming Parameters and Optimization of A5052 in SPIF Process

Forming a metallic sheet along with the consideration of computer simulation and experiment had benefited the milling industry for a long time. The ideal forming, without an error, is a concerning topic. So, the computer simulation had the advantage then direct forming. To observe the results before doing the real experiments simulation comes handy. Which helped to set the parameters for the milling process for the single point incremental forming (SPIF) process. For milling, a CAD design was converted into a 3D model. For this, a conical shape of 3D modeling was made in fusion 360. After onwards, it was simulated for finding the maximum depth for the cracking point. Next for the experimental part, the maximum forming depth was considered, and used lubricant grease for reducing friction. While forming with the grease, the impact of parameters was also changed. Throughout the process, an optimization approach was set to reduce the cracking areas for the G-code. Along with the lubricant use, smooth milling finished surface was observed. To reducing the depth forming errors, an optimization approach was introduced in this research.

Printability assessment of modified filament deposition modelling three dimensional bioprinter printer using polymeric formulations

Three dimensional (3D) bioprinting is a rapid prototyping technology that can be used to accurately position living cells and biomaterials called bioink, to fabricate functional living tissue constructs or organs. The bioink are deposited in 3D in a layer-by-layer manner using a bioprinter. However, commercially available 3D bioprinters are expensive, limiting the widespread adoption of this technology in low-resource laboratories. To overcome this limitation the conventional Filament Deposition Modelling (FDM) 3D printer can be modified to a 3D bioprinter by replacing the print head unit. During the makeover, The device has to perform in its most efficient capacity in synergy with the bioink used. Hence it is essential to check the bio-printabililty of bioink in the modified FDM printer. In this study we created certain specific G-codes for the evaluation of hybrid bioinks and authenticated the printability. This study focuses on quantifying the printability of a hybrid hydrogel composed of sodium salt carboxymethyl cellulose (CMC) and gelatin using a 3D bioprinter based on the RepRap prototyper. The 3D design and slicing parameters were generated using opensource software and manually edited for printability evaluation. The results of these experiments indicate the importance of printability evaluation of custom bioprinters and provide some key aspects of how to modify CAD design parameters for printability evaluation. This approach can also be adopted to evaluate the printability of other hydrogels for bio-printing. The codes are created to evaluate the printability of bioink using FDM modified bioprinters. The printability evaluation is limited to high viscous bioink for extrusion bioprinting. A user friendly, simple G-Codes and methodology for evaluation of printability of bioink using FDM modified bioprinters. To authors knowledge, this is the first report on 3D printability evaluation of bioink using FDM modified bioprinters. The study also fulfills an identified need to study printability of bioink in biofabrication by additive manufacturing.

A quantitative analysis of parametric CAD model complexity and its relationship to perceived modeling complexity

Digital product data quality and reusability has been proven a critical aspect of the Model-Based Enterprise to enable the efficient design and redesign of products. The extent to which a history-based parametric CAD model can be edited or reused depends on the geometric complexity of the part and the procedure employed to build it. As a prerequisite for defining metrics that can quantify the quality of the modeling process, it is necessary to have CAD datasets that are sorted and ranked according to the complexity of the modeling process. In this paper, we examine the concept of perceived CAD modeling complexity, defined as the degree to which a parametric CAD model is perceived as difficult to create, use, and/or modify by expert CAD designers. We present a novel method to integrate pair-wise comparisons of CAD modeling complexity made by experts into a single metric that can be used as ground truth. Next, we discuss a comprehensive study of quantitative metrics which are derived primarily from the geometric characteristics of the models and the graph structure that represents the parent/child relationships between features. Our results show that the perceived CAD modeling complexity metric derived from experts’ assessment correlates particularly strongly with graph-based metrics. The Spearman coefficients for five of these metrics suggest that they can be effectively used to study the parameters that influence the reusability of models and as a basis to implement effective personalized learning strategies in online CAD training scenarios.

Design and Characterization of a Novel FinFET based NCL Cell Library for High Performance Asynchronous Circuits

In recent times, synchronous circuits are facing design related issues like clock skew, glitch power, EMI, leakage power, etc. The clock-less design paradigm – Asynchronous design challenges most of these issues and accepted as a better alternative to clocked circuits. QDI based Null Convention Logic (NCL) is such a clock-less design concept. However, NCL designs couldn’t get wide spread acceptance due to unavailability of commercial CAD tools and design compatible NCL standard cell library. The proposed research work in this paper demonstrates design and characterization of FinFET based NCL cell library to facilitate QDI based asynchronous circuit design. The NCL cells are designed with ASAP 7nm PDK. A complete set of 27 NCL threshold gates are developed and characterized in cadence using ocean scripting. Various time and energy models are extracted for different process corners using EDA platform. The proposed work will help research scholars to implement NCL based asynchronous circuits. This paper also demonstrates comparative performance analysis of bulk-CMOS and multi-gate FinFET based NCL threshold gates in 16 nanometer technology. The analysis has concluded average 19% of improvement in power-delay produce for FinFET based cells compared to its CMOS counterparts. To showcase two-dimensional comparison, various static and semi-static NCL gate structures are also compared in term of their power and speed. Various arithmetic circuits are designed using these standard NCL cells to demonstrate its application. The results indicated substantial performance improvement in terms of power and speed.

Организация практико-ориентированного обучения на кафедре «Инженерная графика» РТУ МИРЭА

The article discusses the organization of practice-oriented learning at the Department of Engineering Graphics of the RTU MIREA, the essence of which is the development of not only design documentation, but also the production of a prototype device for which design documentation has been made. Geoinformatics students create 3D models of terrain objects: buildings, terrain and vegetation based on photo and video data from drones. The course project serves as the basis for a deeper study of geometric and graphic disciplines in the form of competitive works, scientific reports and publications, or can serve as the basis for the final qualification work.
 As part of the course work, students of the Institute of Radio Electronics and Informatics perform a multi-level study of an electronic device - a sensor using "smart home" technology. Not only a significant amount of design documentation is developed with the help of circuitry and design CAD: diagrams, printed circuit boards with tracing, assembly drawings, specifications and other text documents, but also a working prototype of the sensor is made.
 As part of the course work, chemists-technologists design a workshop for large- and medium-tonnage chemical production and develop a complete set of design documentation for one of the main apparatuses of this workshop. Based on the created 3D models, students print a model of the apparatus on a 3D printer.
 As part of the "Fundamentals of Design" course, some students develop design documentation and make one of the two printed circuit boards of a dog robot based on it. Another part of the students creates 3D models of robot parts and prints them on a 3D printer. Both groups jointly assemble and program a robot dog.

Process Parameter Optimization of FDM 3D Printer Using PETG and Carbon Fiber PETG

In the modern world, the difficulty of manufacturing has gradually decreased by many new technologies. 3D printing is one of those technologies which completely improved the flexibility of manufacturing to overcome any complex design where any complex part can be manufactured using different types of 3D printers with different materials indeed. 3D printers are differentiated by materials FDM is one of the 3D printers used to print plastic and composite materials. A CAD design is converted into STL file and sent to slicing software to check any tessellation errors. Component is then fed into MakerBot software to check for proper orientation and changing the printing parameters. 3D printers also have input parameters like conventional manufacturing process, which have high impact on the printed part. In this paper we mainly focused on Input parameters like printing temperature, layer thickness, raster angle is changed using Taguchi method to observe the changes in the material properties.

Xenon Difluoride Dry Etching for the Microfabrication of Solid Microneedles as a Potential Strategy in Transdermal Drug Delivery.

Although hypodermic needles are a "gold standard" for transdermal drug delivery (TDD), microneedle (MN)-mediated TDD denotes an unconventional approach in which drug compounds are delivered via micron-size needles. Herein, an isotropic XeF2 dry etching process is explored to fabricate silicon-based solid MNs. A photolithographic process, including mask writing, UV exposure, and dry etching with XeF2 is employed, and the MN fabrication is successfully customized by modifying the CAD designs, photolithographic process, and etching conditions. This study enables fabrication of a very dense MNs (up to 1452 MNs cm-2 ) with height varying between 80 and 300µm. Geometrical features are also assessed using scanning electron microscopy (SEM) and 3D laser scanning microscope. Roughness of the MNs are improved from 0.71 to 0.35µm after titanium and chromium coating. Mechanical failure test is conducted using dynamic mechanical analyzer to determine displacement and stress/strain values. The coated MNs are subjected to less displacement (≈15µm) upon theapplied force. COMSOL Multiphysics analysis indicates thatMNs are safe to use in real-life applications with no fracture. This technique alsoenables the production of MNs with distinct shape and dimensions. The optimized process provides a wide range of solid MN types to be utilized for epidermis targeting.

Construction of 1DCAE Virtual Engineering System Centered on the 3D CAD for Mechanical Design

It is proposed to incorporate 1DCAE into a virtual engineering system in mechanical system design. In order to continue using an established virtual engineering system for a long time, it is necessary to modify it in line with the evolution of CAD, CAE, analysis, and evaluation technologies. If information in CAD or the like is coded directly in the system, it will be necessary to make changes to the system. Meanwhile, if the evaluation method, etc. is changed, the user interface of the system may need to be changed. These changes require software engineers and are costly and time-consuming.

Investigation of Micro CT based method for porosity estimation of sintered-wick heat pipes

The use of sintered-wick heat pipes in heat exchanger performance-related studies gained popularity owing to the simplicity and affordability of heat pipes. Evaluation of the system performance may be based on various arrangements and numbers of heat pipes applicable to the literature. Wick porosity and permeability are critical parameters for the investigation of wick capillary pumping, which will ultimately determine heat pipe performance. Despite the significance of these parameters to thermal performance, they are difficult to obtain, as the methods for obtaining these parameters before installing the heat pipes are time-consuming and destructive. This study aims to investigate the feasibility of Micro Tomography (Micro CT) to observe the porosity of copper sintered-wick heat pipes. Visual data from three heat pipe samples, namely HP1, HP2, and HP3 are quantified and analyzed. Analysis of the average porosity of HP1 and HP2 samples showed a similar value of 47.6 and 48.1%, respectively; however, the value of porosity along the length of the scanned area shows a bigger range of 42–54%. The accuracy of Micro CT was tested by testing three porosity samples with designed porosity of 26%, 22.3%, and 16.6% which were 3D printed using atomic diffusion additive manufacturing technology. Each sample was designed with pore shapes hexagonal, circular, and elliptical, respectively. Micro CT visualization and analysis showed the porosity reduction of the 3D printed porosity samples compared to the CAD design. Due to the smallest reduction of porosity after the sintered process, the 3D printed sample with a hexagonal pore shape, and the designed porosity of 26%, this sample was recommended for sintered wick fabrication using this technology and to test the accuracy of Micro CT.

Structural Design and Theoretical Analysis of Jetting Spin Type Lotus Root Digging Machine Based on CFD

In order to solve the problem that digging lotus roots manually was high in labor intensity, low in efficiency and easy to damage lotus roots, and, in view of the defects of the high cost of existing digging lotus roots equipment and the cumbersome operating process needing a certain experience in technology, a jetting spin type digging lotus root machine is designed. Combined with the mechanism of hydraulic digging lotus root, a rotation pipeline is designed, so as to simplify the whole machine structure and increase the digging width. It takes only manpower or vehicles to push forward to perform digging lotus root work, with simple operation and low manufacturing cost. Pro/Engineer 3D design software and CAD 2D drawing software are used to design key working parts such as rotation pipeline, spray-head, nozzle, etc. In addition, key parameters of nozzle structure are designed. Through validation, the intensity of jet flow impact force produced by the diameter 17 mm nozzle to lotus root surface is 97.22 N, and the pressure is 0.20 MPa, which produces no damage to lotus root. By means of a mechanical analysis method, combined with CFD flow field analysis and fluid dynamics analysis, the rotational speed mathematical model of rotation pipeline in water is established through MATLAB software solving and calculating. In addition, the influence of nozzle structural parameters on rotational speed of rotation pipeline is made clear. By using the kinematic analysis method, the rotational speed mathematical model of rotation pipeline associated with the jetting impact frequency of single point and the time of each impact is established, and from which the restricting factors of the working speed of jetting spin type digging lotus root machine is obtained, so as to improve the efficiency of digging lotus roots machine under the premise of ensuring the digging depth and the quality of lotus roots. Through the CFD flow field analysis and dynamic analysis, the mathematical model of loss power of rotating pipeline is established. Through comprehensive analysis, the mathematical model of working speed associated with digging time and speed of rotary pipe and effective range radius of jet impact for digging lotus root machine is obtained, which provides a theoretical basis for adjustment of working parameters of digging lotus root machine.

Design and construction of automated mechanical ventilation equipment to assist respiratory failure

This document presents the requirements met for the design, construction and first validation of a mechanical ventilation system to be used in patients with respiratory failure, which in the initial context was due to the COVID-19 pandemic. The design required the use of computer aided drawing software (Computer Aided Design) CAD and the construction required the use of installed capabilities in mechanical, electropneumatic, electronic, biomedical and automation manufacturing of Don Bosco University (El Salvador) institutes and centers. The adjustment, configuration and programming works were in charge of research professors specialized in these disciplines. The elements used for its construction were available in the Salvadoran market, considering the closure of the borders as a government measure in face of the expansion of the pandemic. After the design, manufacture and commissioning stage, measurements of the conditions of the supplied air were made with the help of professionals dedicated to the maintenance of medical equipment and with the approval of internist doctors. The results achieved are those obtained with paramedical equipment and with first aid equipment, for which it has been foreseen that the equipment can be tested in a subsequent instance with the certified medical union.

Additive Manufacturing of Polyhydroxyalkanoate-Based Blends Using Fused Deposition Modelling for the Development of Biomedical Devices.

In the last few decades Additive Manufacturing has advanced and is becoming important for biomedical applications. In this study we look at a variety of biomedical devices including, bone implants, tooth implants, osteochondral tissue repair patches, general tissue repair patches, nerve guidance conduits (NGCs) and coronary artery stents to which fused deposition modelling (FDM) can be applied. We have proposed CAD designs for these devices and employed a cost-effective 3D printer to fabricate proof-of-concept prototypes. We highlight issues with current CAD design and slicing and suggest optimisations of more complex designs targeted towards biomedical applications. We demonstrate the ability to print patient specific implants from real CT scans and reconstruct missing structures by means of mirroring and mesh mixing. A blend of Polyhydroxyalkanoates (PHAs), a family of biocompatible and bioresorbable natural polymers and Poly(L-lactic acid) (PLLA), a known bioresorbable medical polymer is used. Our characterisation of the PLA/PHA filament suggest that its tensile properties might be useful to applications such as stents, NGCs, and bone scaffolds. In addition to this, the proof-of-concept work for other applications shows that FDM is very useful for a large variety of other soft tissue applications, however other more elastomeric MCL-PHAs need to be used.