Computer-aided Design Tools Research Articles

Security-Driven Placement and Routing Tools for Electromagnetic Side-Channel Protection

Side-channel analysis (SCA) attacks are major threats to hardware security. Upon this security threat, various countermeasures at different design layers have been proposed against SCA attacks. These approaches often introduce significant overheads and impose high requirements of side-channel security backgrounds to integrated circuit (IC) designers. In this article, we propose an automatic computer-aided design (CAD) tool that can be utilized to enhance the circuit resistance against electromagnetic (EM) SCA attacks. This new tool will guide security-driven placement and routing processes and can be seamlessly integrated into the modern IC design flow. The protected IC design will be resilient to SCA attacks with negligible area and power overheads. In order to develop this tool, we first investigate the root-cause of EM leakage at the layout level and mathematically demonstrate the feasibility of security-driven placement and routing through the EM leakage modeling. We then identify that the correlation between the data under protection and the EM leakage can be significantly reduced through data-dependent register reallocation and wire length adjustments. Simulation results on cryptographic circuits prove the effectiveness of both the constructed EM leakage model and the EM model-based CAD tool for EM side-channel security.

Design and simulation of a novel concentric silicon drift detector with equal width divider resistor chain and floating cathodes

Enabling the traditional concentric silicon drift detector (CSDD) does not need an external voltage divider in the application; hence, a novel CSDD structure is proposed in this paper, in which resistor chains of equal width are deposited equally between the cathode rings and come in contact with the cathode rings. The new CSDD can achieve voltage division automatically and only needs to bias the voltage on the cathodes of the innermost ring and the outermost ring. In addition, floating cathodes were designed between the cathodes to obtain a nearly straight line drift channel and to reduce the low electric field area near the surface. The electrical properties of three types of floating cathodes (called floating cathodes of a single-ring, floating cathodes of a double-ring, and floating cathodes of a four-ring) were simulated and compared using the technology computer aided design tool. Under the field effect between the floating cathodes and the bulk, the electric field near the surface increased substantially. Moreover, the electric field near the surface of the CSDD with the floating cathodes of a double-ring changes the most uniformly so that the drift path is the straightest.

ІТ в процесах створення та експлуатації об’єктів будівництва

The article presents the results of IT research in the processes of creation and operation of construction projects. An overview of the means of complex accounting automation in Ukraine is given. An overview of the market of computer-aided design tools for architecture and construction is given also their characteristics are given. An overview of integrated market management systems in Ukraine is presented. The field of application of information technologies is constantly expanding, and growing constantly require monitoring of new implementations and search for effective innovations. Awareness provides a competitive advantage for both the developer and the consumer. Thus, the task of IT monitoring arises, and in the presence of a common area of interest, a team of like-minded people faces the problem of IT research in the processes of creation and operation of construction projects. IT in the process of creating and operating construction projects is used in all life cycles of the latter. The software that serves these processes is diverse and mostly disparate and is a set of software products aimed at sectoral use [1]. The issue of introduction of modern IT in this area is relevant and there is a need for development by specialists, which requires their study. The software used can generally be divided into: general purpose software; specialized accounting programs and other accounting systems; computer-aided design systems; integrated management systems of the organization; building management systems; scheduling systems. The so-called specialized accounting programs and accounting systems presented on the Ukrainian market in the construction sector are the same as for other sectors of the economy, there are only certain adaptations to take into account the specifics of the scope. At this stage of economic development of Ukraine in the construction industry ERP systems have not yet become widespread. Building management systems are also waiting to be expanded in Ukraine.

Ten years of hardware Trojans: a survey from the attacker's perspective

Hardware Trojan detection techniques have been studied extensively. However, to develop reliable and effective defenses, it is important to figure out how hardware Trojans are implemented in practical scenarios. The authors attempt to make a review of the hardware Trojan design and implementations in the last decade and also provide an outlook. Unlike all previous surveys that discuss Trojans from the defender's perspective, for the first time, the authors study the Trojans from the attacker's perspective, focusing on the attacker's methods, capabilities, and challenges when the attacker designs and implements a hardware Trojan. First, the authors present adversarial models in terms of the adversary's methods, adversary's capabilities, and adversary's challenges in seven practical hardware Trojan implementation scenarios: in-house design team attacks, third-party intellectual property vendor attacks, computer-aided design tools attacks, fabrication stage attacks, testing stage attacks, distribution stage attacks, and field-programmable gate array Trojan attacks. Second, the authors analyse the hardware Trojan implementation methods under each adversarial model in terms of seven aspects/metrics: hardware Trojan attack scenarios, the attacker's motivation, feasibility, detectability (anti-detection capability), protection and prevention suggestions for the designer, overhead analysis, and case studies of Trojan implementations. Finally, future directions on hardware Trojan attacks and defenses are also discussed.

Goal-oriented sensor placement and model updating strategies applied to a real building in the Sense-City equipment under controlled winter and heat wave scenarios

A goal-oriented inverse technique is proposed for the accurate computation of quantities of interest in thermal building problems. In contrast to the standard inverse methods, only the model parameters sensitive to the chosen quantity of interest are updated. The technique is applied to a real building in the Sense-City equipment. A two-zone thermal model described by 15 parameters is used. To study the robustness of the inverse method, two controlled climate scenarios conducted in Sense-City, i.e. the Carpentras (south of France) winter and the Paris 2003 heatwave, and five different quantities of interest are considered. For all the the chosen quantities of interest, it is shown that very few model parameters need to be updated by the inverse technique leading to a better estimation of the quantity of interest. The obtained results are experimentally validated using the sensor outputs and a controlled stationary climate test in the Sense-City equipment. The goal-oriented framework is also used for optimal sensor placement. A first application shows that the number of temperature sensors can be drastically reduced to compute a quantity of interest. Last, for operational use, the proposed method is integrated in a software chain containing computer-aided design and thermal dynamic simulation tools. All sensor outputs are provided in the companion paper [25].

Study of analog performance of common source amplifier using rectangular core–shell based double gate junctionless transistor

A new state of the art double gate junctionless transistor (DGJLT) namely the rectangular core–shell DGJLT (RCS-DGJLT) based common source amplifier circuit is designed to investigate the performance. An RCS-DGJLT device is designed using a visual technology computer aided design tool and look up table-based Verilog-A model has been designed to carry out spice simulation of the circuit. Device simulation of RCS-DGJLT shows the extraordinary performance when compared to conventional DGJLT. The RCS-DGJLT exhibits an OFF current (Ioff ) ∼10−14 A, ON current (Ion ) ∼10−5 A, ON/OFF current ratio (Ion /Ioff ) ∼109, subthreshold slope ∼68.9 mV decade−1 and drain induced barrier lowering ∼52.6 mV V−1. Also, the AC response of RCS-DGJLT exhibits good performance like lower miller capacitances of order 10–16 F, maximum unity gain frequency of 138.8 GHz, transconductance generation efficiency of 40 V−1, and gain-bandwidth product of 25.4 GHz. The common source amplifier circuit using RCS-DGJLT provides the amplification up to 3.3 times which implies gain (Av ) to be 3.3. The low leakage power of 10.4 pW and average power of 31.2 µW of common source amplifier circuit based on RCS-DGJLT shows the greater potential of using the proposed device in analog applications. Also, the complete flow chart of the process used to design an analog circuit based on proposed RCS-DGJLT is discussed. The result shows the potential of using the RCS-DGJLT device in designing high-frequency applications.

The Effect of Multi-Additional Sampling for Multi-Fidelity Efficient Global Optimization

Powerful computer-aided design tools are presently vital for engineering product development. Efficient global optimization (EGO) is one of the most popular methods for design of a high computational cost problem. The original EGO is proposed for only one additional sample point. In this work, parallel computing is applied to the original EGO process via a multi-additional sampling technique. The weak point of the multi-additional sampling is it has slower convergence rate when compared with the original EGO. This paper applies the multi-fidelity technique to the multi-additional EGO process to see the effect of the number of multi-additional sampling points and the converge rate. A co-kriging method and a hybrid RBF/Kriging surrogate model are selected for the surrogate model in the EGO process to show the advantage of the multi-additional EGO process compared with the single-fidelity Kriging surrogate model. In the experiment, single-additional sampling points and two to four number of multi-additional sampling per iteration are tested with symmetry and asymmetry mathematical test functions. The results show the hybrid RBF/Kriging surrogate model can obtain the similar optimal points when using the multi-additional sampling EGO.

Fundus Image Analysis to Detect Abnormalities in Diabetic Retinopathy using Computer Aided Design Tools A Review

Diabetic retinopathy is becoming a major threat to visual loss in human beings. Many researchers are working to develop early detection techniques, which may reduce the risk of vision loss using image-processing techniques like image enhancement and segmentation. Improving the quality of medical images to detect the disease at an early stage is crucial for further medication. It is gaining more focus with automated techniques for machine learning. Filtering and morphological operators enhance image contrast and interested region can be extracted using segmentation techniques from the fundus image of the retina. For feature analysis the optical disk, localization of blood vessels and segmentation are very useful to observe the parameters like area, length and perimeter of blood vessels etc. Algorithms for this analysis include preprocessing, segmentation, feature extraction and classification. This paper tries to give a detailed review of various image-processing methods used in early detection of diabetic retinopathy and future insights to develop algorithms, which reduces clinician’s time for diagnosis and pathogenesis.

Analyzing Clustering and Partitioning Problems in Selected VLSI Models

As the modern integrated circuit continues to grow in complexity, the design of very large-scale integrated (VLSI) circuits involves massive teams employing state-of-the-art computer-aided design (CAD) tools. An old yet significant CAD problem for VLSI circuits is physical design automation. In physical design automation, we need to compute the best physical layout of millions to billions of circuit components on a tiny silicon surface. The process of mapping an electronic design to a chip involves several physical design stages, one of which is clustering. Even for combinatorial circuits, there are several models for the clustering problem. In particular, we consider the problem of clustering without replication in combinatorial circuits with a view towards minimizing delay (CN). The corresponding problem with replication has been well-studied and solvable in polynomial time. However, replication can become expensive when it is unbounded. Consequently, CN is a problem worth investigating. We establish the computational complexities of several variants of CN. Additionally, we obtain approximability and inapproximability results for some NP-hard variants of CN. We also present approximation and exact exponential algorithms for some variants of CN. We prove that for some cases there exists an approximation factor of strictly less than two and that our exact exponential algorithms beat brute force. Furthermore, we provide the first parameterized approximation algorithm in which the approximation ratio is also a parameter.

Adversarial Perturbation Attacks on ML-based CAD

There is substantial interest in the use of machine learning (ML)-based techniques throughout the electronic computer-aided design (CAD) flow, particularly those based on deep learning. However, while deep learning methods have surpassed state-of-the-art performance in several applications, they have exhibited intrinsic susceptibility to adversarial perturbations—small but deliberate alterations to the input of a neural network, precipitating incorrect predictions. In this article, we seek to investigate whether adversarial perturbations pose risks to ML-based CAD tools, and if so, how these risks can be mitigated. To this end, we use a motivating case study of lithographic hotspot detection, for which convolutional neural networks (CNN) have shown great promise. In this context, we show the first adversarial perturbation attacks on state-of-the-art CNN-based hotspot detectors; specifically, we show that small (on average 0.5% modified area), functionality preserving, and design-constraint-satisfying changes to a layout can nonetheless trick a CNN-based hotspot detector into predicting the modified layout as hotspot free (with up to 99.7% success in finding perturbations that flip a detector’s output prediction, based on a given set of attack constraints). We propose an adversarial retraining strategy to improve the robustness of CNN-based hotspot detection and show that this strategy significantly improves robustness (by a factor of ~3) against adversarial attacks without compromising classification accuracy.

FWAVina: A novel optimization algorithm for protein-ligand docking based on the fireworks algorithm

Protein-ligand docking is an essential process that has accelerated drug discovery. How to accurately and effectively optimize the predominant position and orientation of ligands in the binding pocket of a target protein is a major challenge. This paper proposed a novel ligand binding pose search method called FWAVina based on the fireworks algorithm, which combined the fireworks algorithm with the efficient Broyden-Fletcher-Goldfarb-Shannon local search method adopted in AutoDock Vina to address the pose search problem in docking. The FWA was used as a global optimizer to rapidly search promising poses, and the Broyden-Fletcher-Goldfarb-Shannon method was incorporated into FWAVina to perform an exact local search. FWAVina was developed and tested on the PDBbind and DUD-E datasets. The docking performance of FWAVina was compared with the original Vina program. The results showed that FWAVina achieves a remarkable execution time reduction of more than 50 % than Vina without compromising the prediction accuracies in the docking and virtual screening experiments. In addition, the increase in the number of ligand rotatable bonds has almost no effect on the efficiency of FWAVina. The higher accuracy, faster convergence and improved stability make the FWAVina method a better choice of docking tool for computer-aided drug design. The source code is available at https://github.com/eddyblue/FWAVina/.

Application of 3D Prototyping to Promote Size-Inclusive Design Practices for Plus-Size Apparel

Although innovative computer-aided design tools offer opportunities for advancing size-inclusive apparel design, minimal design research has been conducted to document the applications of these technologies. The purpose of this study is to identify plus-size women’s needs through mixed method research and to integrate 3D prototyping technology to enhance plus-size apparel design. The research includes a) an online survey of plus-size consumers and market analysis to identify clothing needs and perceived problems, and b) development of a virtual and physical prototype through technology integration methods. This study responds to current needs to enhance apparel design for plus-size consumers; the integration of 3D prototyping and the functional, expressive, and aesthetic (FEA) process is a novel approach that places plus-size women at the center of the model. Results from this study may also provide practical guidelines for designers and students with limited knowledge of plus-size women’s body types and bolster their interest in designing for larger body figures to promote a sense of inclusivity.

Computer-Aided Whole-Cell Design: Taking a Holistic Approach by Integrating Synthetic With Systems Biology.

Computer-aided design (CAD) for synthetic biology promises to accelerate the rational and robust engineering of biological systems. It requires both detailed and quantitative mathematical and experimental models of the processes to (re)design biology, and software and tools for genetic engineering and DNA assembly. Ultimately, the increased precision in the design phase will have a dramatic impact on the production of designer cells and organisms with bespoke functions and increased modularity. CAD strategies require quantitative models of cells that can capture multiscale processes and link genotypes to phenotypes. Here, we present a perspective on how whole-cell, multiscale models could transform design-build-test-learn cycles in synthetic biology. We show how these models could significantly aid in the design and learn phases while reducing experimental testing by presenting case studies spanning from genome minimization to cell-free systems. We also discuss several challenges for the realization of our vision. The possibility to describe and build whole-cells in silico offers an opportunity to develop increasingly automatized, precise and accessible CAD tools and strategies.

Vision-Based Robotic Traversal of Textureless Smooth Surfaces

This investigation focuses on servoing a robot's tool with respect to a smooth workpiece surface by making use of the surface's characteristic local differential properties. A novel formulation for 6 degree-of-freedom (DoF) textureless visual servoing based on these properties is proposed, which extends an existing 3-DoF scheme. Our approach naturally combines the geometric tools of computer-aided design and machining (CAD/CAM) theory with the manipulator control tools of visual servoing synergistically to achieve full 6-DoF pose control. A novel family of observed feature sets and their associated interaction matrices are presented. A geometric condition on the surface shape is derived under which local asymptotic stability for 6-DoF is guaranteed. Validation of the proposed method is performed in simulation and experiment using an articulated desktop robot equipped with only a monocular camera and 16 laser pointers.

Combined Spectroscopic and TD-DFT Analysis to Elucidate Substituent and Acidochromic Effects in Organic Dyes: A Case Study on Amino- versus Nitro-Substituted 2,4-Diphenylquinolines.

A combined spectroscopic and TD-DFT case study was performed, to identify a robust method to calculate the complex near UV/Vis absorption spectra of various amino- vs. nitro-substituted 2,4-diphenylquinolines, which vary strongly under neutral and successively acidic conditions. For this, different DFT functionals were tested for geometry optimization and the TD part to calculate the neutral and different protonated species in a fast screening approach, i. e. using single point calculations in an implicit solvent. Offset-corrected M06HF, hitherto only applied to polymers, was identified as a suitable method to reproduce the absorption spectra in a reasonable fashion for all different substitution pattern and all different protonated species at different pH values; moreover, the method properly predicts the energetic ordering of low-lying n-π* and ππ* transitions, which is decisive for the non-/emissive nature of the different compounds. In all, this might provide a valuable tool for computer-aided design of related classes of compounds.

Towards Customer-Centric Additive Manufacturing: Making Human-Centered 3D Design Tools through a Handheld-Based Multi-Touch User Interface.

Seeking a more flexible and efficient production, additive manufacturing (AM) has emerged as a major player in the industrial field, streamlining the fabrication of custom tangible assets by directly 3D printing them. However, production still takes too long due to printing, but also due to the product design stage, in which the customer works together with an expert to create a 3D model of the targeted product by means of computer-aided design (CAD) software. Skipping intermediate agents and making customers responsible for the design process will reduce waiting times and speed up the manufacturing process. This work is conceived as a first step towards that optimized AM model, being aimed at bringing CAD tools closer to clients through an enhanced user experience, and consequently at simplifying pre-manufacturing design tasks. Specifically, as an alternative to the traditional user interface operated with the keyboard and mouse duo, standard in CAD and AM, the paper presents a comprehensive multi-touch interaction system conceived as a customer-centric human-machine interface. To depict the proposed solutions, we adopt furniture manufacturing as a case study and, supported by a CAD-like software prototype for 3D modeling of custom cabinets introduced in a previous work of the authors, we assess our approach’s validity in terms of usability by conducting in-lab and remote user studies. The comparison between the designed multi-touch interaction and its desktop alternative yields promising results, showing improved performance and higher satisfaction of the end-user for the touch-based approach, that lay the groundwork for a smarter factory vision based on remotely-operated AM.

Registration method for maintenance-work support based on augmented-reality-model generation from drawing data

Abstract The importance of operations and maintenance (O&M) and piping inspection in shipbuilding and offshore plant industries has significantly increased recently. Therefore, this study proposes a system that uses augmented reality (AR) to support these operations. AR in O&M and inspection systems can increase work comprehension and efficiency by utilizing 3D graphics, instead of drawings, to describe specific work functions. To realize this improvement, the augmented model should correspond to the reality; if accurate registration is not achieved, it can disrupt the work functions. Therefore, marker-based AR is used to generate specific recognition objects and correct the location of the augmented model. However, owing to certain characteristics of the shipbuilding and offshore plant industries, the markers are likely to be damaged, and thus the cameras fail to clearly detect them. In this study, a 3D camera was used to generate a point cloud based on 3D image information. Accordingly, the area around the model to be detected was designated as the region of interest (ROI). Furthermore, it is difficult to support a high-end device environment because it is tested as a portable device that can be used in a working environment; therefore, superfluous data were removed by detecting the 3D edges in the ROI, thereby minimizing data operation. The scalability of this work was enhanced using the computer-aided design (CAD) file information extracted from the CAD tool (used in the shipbuilding industry) and converting it into a point cloud. The proposed system is expected to eliminate the issues related to understanding the O&M work by addressing registration errors that might occur in constrained environments and to improve the torsional phenomenon of the augmented models.

Using Product/Service-System Family Design for Efficient Customization with Lean Principles: Model, Method, and Tool

Facing the need to address environmental issues of our society and individual customer needs and wants along with the trend of offering hybrids of services and products, the ability to efficiently design hybrid offerings is imperative to provide high levels of added value. This ability is much needed throughout the industry, while this type of design is highly challenging due to its high complexity. To date, however, there have been only a few proposals for methods that tackle this challenge at the conceptual design stage. This article proposes a model, a method, and a computerized tool that together support the conceptual design of families of product/service systems (PSSs). First, a PSS family model is presented and then implemented as an add-on to an existing computer-aided design (CAD) tool. Next, a method building upon the model and lean principles is developed as a design procedure. The software and the method are verified through an industrial example of designing a family of logistic services. The proposed model, method, and tool were found effective for describing different key elements of PSS family design. The power of the CAD tool was also demonstrated by taking advantage of a database of model building blocks and semi-automatic calculations.

Simulation design of a high-breakdown-voltage p-GaN-gate GaN HEMT with a hybrid AlGaN buffer layer for power electronics applications

We propose a novel GaN high-breakdown-voltage high-electron-mobility transistor (HB-HEMT) with a p-GaN gate and hybrid AlGaN buffer to improve the breakdown voltage and Baliga’s figure of merit. The hybrid AlGaN buffer is composed of a horizontally arranged AlaGa1−aN zone and an AlbGa1−bN zone, each having different Al compositions a and b. The proposed HB-HEMT is simulated using the Silvaco technology computer-aided design (TCAD) tool ATLAS, considering the polarization model, low-field mobility, high-field mobility, and Selberherr’s impact ionization model to simulate the direct-current (DC), breakdown, and C–V properties of the proposed HB-HEMT. The breakdown voltage of the HB-HEMT is significantly improved by introducing the hybrid AlGaN buffer structure, which can effectively modulate the electric field distributions within the channel and the buffer. A high breakdown voltage (1450 V), a low specific on-state resistance (0.47 mΩ cm2), and a high Baliga’s figure of merit (4.47 GW/cm2) are obtained at the same time with an Lgd (gate-to-drain distance) of 6 µm, a distance from the gate to the AlaGa1−aN/AlbGa1−bN interface of 4 µm, and Al compositions of a = 0.25 and b = 0.1. The simulated C–V results also reveal that the GaN HB-HEMT shows better switching characteristics than the conventional GaN HEMT with a p-GaN gate.

Rationally engineered prolyl endopeptidases from Sphingomonas capsulata with improved hydrolytic activity towards pathogenic peptides of celiac diseases

Celiac disease affects approximately 1% of the population and is a major public health problem worldwide. It is trigged by gluten-derived peptides, which have unusually high proline-glutamine motif content and are highly resistant to proteolysis by digestive enzymes of the gastrointestinal tract. The only treatment for celiac disease is strict, lifelong adherence to a gluten-free diet, which is effective but costly and difficult to maintain. Therefore, novel non-dietary therapies for celiac disease are urgently needed. Gluten-degrading enzymes are promising non-dietary treatments, and some enzymes have been investigated in preclinical or clinical studies. A combination of prolyl endopeptidase from Sphingomonas capsulata (SC PEP) and a glutamine-specific endoprotease (EP-B2 from barley) known as latiglutenase showed insufficient benefits in phase II clinical trials, likely because of its low enzyme activity in the gastric environment. Therefore, improving enzyme activity is essential for the clinical application of SC PEP. Enzyme activity can be enhanced using computer-aided rational protein design tools. In this study, we combined molecular docking and molecular dynamics simulation to rationally design SC PEP mutants and experimentally evaluated their activities. We identified mutants with up to 90–103% increases in specific activity and up to 80–202% increases in the catalytic rate. We have investigated the mechanism underlying the enhanced activity of these mutants, and found that a conformational transition of the β-propeller domain and catalytic domain of SC PEP was important for enzyme activity, and this transition was affected by residues in the catalytic domain and at the domain interface; a shorter distance between the substrate Pro and the oxyanion holes was also crucial for improving SC PEP catalytic activity. Our results provide useful information for the rational design of highly active SC PEPs to accelerate the development of enzyme therapeutics candidates for Celiac disease.