Digital Simulation Method Research Articles

An aging simulation method based on the change of input vector inside the critical path

Abstract With the large-scale expansion and process shrinking of modern integrated circuits, aging has become one of the main factors threatening circuit reliability. To evaluate the impact of aging on circuit life, it is important to investigate aging simulation methods. Aiming at the problem of slow speed and insufficient accuracy of large-scale digital circuit aging simulation methods, a circuit aging simulation method based on the change of input vector inside the critical path (CICP) is proposed in this paper. First, the critical path (CP) with the tightest timing is extracted by static timing analysis (STA), and SPICE simulation is carried out to accurately predict the aging of the CP of the circuit. Second, the aging simulation is carried out considering the change of the internal input vector of the CP. The simulation results show that after changing the internal input signal, the aging path delay increases up to 3.5%.

Pore scale modeling of fluid transport in complex reservoirs: Multi-scale digital rock construction, flow experiments and simulation methods

Pore scale modeling of fluid transport in complex reservoirs: Multi-scale digital rock construction, flow experiments and simulation methods

Wireless sequential dual light delivery for programmed PDT in vivo

Using photodynamic therapy (PDT) to treat deep-seated cancers is limited due to inefficient delivery of photosensitizers and low tissue penetration of light. Polymeric nanocarriers are widely used for photosensitizer delivery, while the self-quenching of the encapsulated photosensitizers would impair the PDT efficacy. Furthermore, the generated short-lived reactive oxygen spieces (ROS) can hardly diffuse out of nanocarriers, resulting in low PDT efficacy. Therefore, a smart nanocarrier system which can be degraded by light, followed by photosensitizer activation can potentially overcome these limitations and enhance the PDT efficacy. A light-sensitive polymer nanocarrier encapsulating photosensitizer (RB-M) was synthesized. An implantable wireless dual wavelength microLED device which delivers the two light wavelengths sequentially was developed to programmatically control the release and activation of the loaded photosensitizer. Two transmitter coils with matching resonant frequencies allow activation of the connected LEDs to emit different wavelengths independently. Optimal irradiation time, dose, and RB-M concentration were determined using an agent-based digital simulation method. In vitro and in vivo validation experiments in an orthotopic rat liver hepatocellular carcinoma disease model confirmed that the nanocarrier rupture and sequential low dose light irradiation strategy resulted in successful PDT at reduced photosensitizer and irradiation dose, which is a clinically significant event that enhances treatment safety.

Digital modeling and simulation methods in designing interior spaces

Digital modeling and simulation methods in designing interior spaces

A product performance rapid simulation approach driven by digital twin data: Part 1. For variable product structures

In the product design stage, the effective performance analysis method is the premise to guarantee the application performance of products. However, digital simulation, as a widely used performance analysis method, has a long simulation cycle and high requirements for computer hardware performance, which leads to long product design and iteration time. Facing this problem, a product performance rapid simulation approach driven by digital twin (DT) data for variable product structures is proposed to replace the digital simulation method. Firstly, the framework for variable product structures is designed, which includes a digital simulation module, a data-driven module, and a surrogate-based simulation module. Then, module implementation of the proposed framework is introduced in detail, in which the twin data-driven product performance rapid simulation model (RSM) for variable product structures is studied based on the makeTwin reference architecture. Finally, a case study is conducted on the iterative design of a connecting rod, focusing on equivalent stress evaluation. The result shows that the proposed method is feasible, as well as costs a shorter simulation time than traditional digital simulation.

A product performance rapid simulation approach driven by digital twin data: Part 2. For variable operating conditions

As mentioned in Part 1, for product iterative design, the digital simulation method, as the product performance analysis method, has the problems of time cost and computing resources. To address this issue, a product performance rapid simulation approach driven by digital twin (DT) data for variable product structures in Part 1 was proposed, which could replace the digital simulation method. Meanwhile, for performance analysis under variable operating conditions during the product design and operation phase, digital simulation also has the above problems. Therefore, based on the method for variable product structures proposed in Part 1, a product performance rapid simulation approach driven by DT data for variable operating conditions is proposed in this paper. Firstly, the framework for variable operating conditions is designed based on the makeTwin reference architecture, including twin source data acquisition for the product under different operating conditions, twin data-driven product performance rapid simulation model (RSM) construction for variable operating conditions, and rapid evaluation of product critical performance based on RSM. Then, the implementation of the framework is introduced in detail. At last, a case study for critical loosening load evaluation of bolted joint is carried out. The result indicates that the proposed method is feasible, as well as costs shorter simulation time than the traditional digital simulation method.

Study on the Measurability of Gear Analytical Parameters in Double-Flank Measurement.

Double-flank measurement is the most commonly used full inspection method on the shop floor. However, the double-flank measurement method cannot measure analytical parameters such as pitch deviations and profile deviations, and this limitation is a pain point in the field of gear measurement. This paper studies the measurability of the analytical parameters of gears based on the results of double-flank measurement, proposes the definition of measurable area, and gives the relationship between the size of the measurable area and the number of teeth and the pressure angle and the gear error. Digital simulation methods were used to conduct measurement experiments on gear analytical parameters. In the experiments, the measurability of the analytical parameters of gears with various typical profile deviations in the double-flank measurement process was verified and analyzed. The test results show that not all profile deviations are unmeasurable in the process of double-flank measurement, but there exists a profile region in which the analytical parameters of the gear can be measured accurately. The size of the measurable area of the profile is mainly determined by the number of teeth and pressure angle of the gear, while the pitch deviations are always measurable under normal conditions.

Design of Visualization Simulation Software for Fire Planning Based on Unity 3D Technology

How to evaluate the effective firepower intensity generated by ammunition in war is an important basis for tactical decision-making. In order to calculate the firepower kill range formed by the combined action of multiple high explosive bombs, this paper uses digital simulation methods to establish a firepower planning model for multiple high explosive bombs based on the hit rate model and power model of the ammunition. A visual simulation software for explosive bomb firepower planning based on C + + programming language and Unity 3D engine is designed to support rapid calculation and visual display of firepower planning results. The results show that the visual simulation software for fire plan can effectively calculate the distribution pattern and fire damage of ammunition, dynamically visualize the entire terminal damage process, evaluate the effective fire distribution results, and lay a foundation for the design of warheads and the efficient use of ammunition.

Digital Twin-Based Numerical Simulation Method for Cee-Shape Cold-Formed Steel Members

Cold-formed steel (CFS) structures are widely used in construction and infrastructure due to their lightweight and high-strength properties. However, their thin-walled nature makes them geometrically sensitive to compressive loading. The Digital Twin (DT)-based numerical simulation method is developed using the actual geometries of CFS shapes, which are acquired by a 3D laser scanner. The DT-based numerical simulation incorporates the reconstructed measurement point clouds into the finite element modeling, ensuring that actual geometric features are retained. A series of tests, including material and axial compression testing, are conducted to validate the modeling parameters, such as mesh sizes and boundary conditions. The advantages of the DT-based numerical simulation method are highlighted compared to the traditional CFS member numerical simulation, which incorporates only the first mode of geometric imperfection. Additionally, DT-based numerical simulations offer more accurate load capacities and deformation predictions. Moreover, the automated and validated DT-based numerical simulation demonstrates prevalence in modeling efficiency and computation effectiveness. The DT-based numerical simulation method holds potential for application in smart structural analysis, where accurate geometries derived from extensive measurement point clouds are integrated into numerical modeling.

A Digital Simulation and Re-Editing Method for Clothing Patterns Based on Deep Learning and Somatosensory Interaction

To address the issues in clothing pattern style migration, this paper proposes a digital simulation and re-editing method for clothing patterns based on deep learning and somatosensory interaction. First, the proposed method encodes the black-and-white line drawing image, generating random noise images through a diffusion process, introducing color information for synthesis, and using a decoder to reconstruct a colored image. Afterwards, an improved VGG19 model is used to reconstruct content features and perform linear color transformation on style images, enabling pattern style migration through the construction of a Gram matrix and resulting in colored clothing texture patterns. Finally, a KinectV2 is utilized for fabric simulation, overlaying colorful clothing texture patterns to achieve 3D virtual dressing. The experimental results show that the proposed method improves the structural similarity index measure (SSIM) by 9–11% and the peak signal-to-noise ratio (PSNR) by 3–8% when compared to existing algorithms. The experiments provide evidence that the proposed method effectively mitigates color overflow, delivers precise image coloring, and accomplishes realistic restoration of clothing texture. Furthermore, the method offers an improved garment fit to fulfill the user’s interaction requirements.

Circular, zero waste formwork - Sustainable and reusable systems for complex concrete elements

The construction sector contributes significantly to global carbon emissions, leading to a new need and demand for sustainable and material-efficient construction technologies. Digital form-finding, simulation, and optimization methods are advancing, resulting in highly efficient, but often geometrically complex components. Concrete construction, which is currently dominant worldwide and crucial for sustainable material savings due to its large market volume, still faces challenges in implementing complex geometries. The significant requirements for formwork material and limitations in feasibility and cost at the current state of the art contribute to these challenges. This research presents a zero waste process using recyclable and reusable digitally fabricated formwork made from waste ingredients that can be immediately implemented in the construction industry. Residual sands (quartz and ceramics) were investigated as a basic moulding material in combination with biogenic binders (bentonite, eco-resin, sodium silicate, starch) for the production of stable formwork composites. The material compound were shaped into precise complex forms using 5-axis milling, and the removed material was recycled in a closed material cycle. Testing and characterization methods for evaluating mechanical properties such as compressive forces (20.1 N/mm2), surface roughness (Ra 9.1 μm), tolerances (0), and moulding processes indicate that the presented procedure conforms to common industry standards. Demonstrating feasibility, complex ultra-thin 1:1 concrete prototypes were designed and manufactured under industrial conditions using prefabricated formworks made of researched bio composite. The resulting high-resolution formwork surfaces and exposed concrete precast elements correspond to the highest fair-faced concrete class (SB04), with line roughness values of Ra 14.4 μm. The developed circulation concept allows reproducibility of different geometries and repeated concreting of formwork moulds. The formwork process is free from harmful additives, enabling recycling through grinding and reintegration into a closed material cycle. Sustainability has been continuously monitored and evaluated through a life cycle assessment. This system utilizes standard machines and offers an accessible and easily integrated approach for a holistic zero waste solution, suitable for efficient industrial applications.

Towards string order melting of spin-1 particle chains in superconducting transmons using optimal control

Utilizing optimal control to simulate a model Hamiltonian is an emerging strategy that leverages the intrinsic physics of a device with digital quantum simulation methods. Here we evaluate optimal control for probing the nonequilibrium properties of symmetry-protected topological (SPT) states simulated with superconducting hardware. Assuming a tunable transmon architecture, we cast the evolution of these SPT states as a series of one- and two-site pulse optimization problems that are solved in the presence of leakage constraints. From the generated pulses, we classically simulate the time-dependent melting of the perturbed SPT string order across a six-site model with an average state infidelity of ${10}^{\ensuremath{-}3}$. The feasibility of these pulses as well as their efficient application indicate that high-fidelity simulations of string order melting are within reach of current quantum computing systems.

Clinical Accuracy of Splintless Maxillary Positioning with Aid of CAD/CAM Fabricated Surgical Cutting Guides and Titanium Plates

New digital technologies are improving the accuracy of orthognathic surgery. One of the new approaches transfers the surgical plan into real surgery without using an occlusal splint. This pilot study aims to validate the splintless approach to orthognathic surgery on a series of cases. Five patients were enrolled. Surgeries were planned using a digital surgical simulation method thanks to three-dimensional images. The splintless surgical approach was planned for maxillary reposition. This consisted of cutting guides and three-dimensionally (3D) printed custom titanium plates. These two were created using the computer-aided design and computer-aided manufacturing (CAD-CAM) technique and were used intraoperatively to guide the osteotomy and repositioning of the bony segments without the use of the surgical splint. The difference between the planned surgery and the real final position was analyzed thanks to superimposition techniques and landmark analysis. Statistical tests were performed to detect significant differences. No difference was found in any of the landmarks. Midline landmarks differed from the planned position by 0.34 mm. Higher variability was found in the posterior landmark. These findings suggest that a splintless approach is useful in transferring the surgical plan without using an occlusal splint.

Computational study of phase interface properties for energy extraction and storage process

The interactions between gas and liquid have an important role in energy extraction and storage. For example, the interfacial tension (IFT) between the two phases has an important effect on developing crude oil in low-permeability reservoirs and compressed air energy storage in aquifers (CAESA). For the mechanism of two-phase fluid interaction in energy extraction and storage, the study of gas-liquid interface properties is carried out in the paper. Firstly, molecular dynamics simulations are used to study the molecular simulation progress of nitrogen and water under different environmental conditions, and the effects of different temperatures and pressures on IFT are studied. The results show that IFT increases with the temperature increase at constant pressure. When the temperature is constant, an increase in the pressure of the system will decrease the surface tension of the system. Then the effect of IFT on the distribution of gas-liquid phases in the pores of low-permeability rocks is studied by digital core technology and simulation methods. The results show that the lower the IFT of gas and liquid is, the better the displacement effect is and the higher the recovery ratio is in the low-permeability rocks. This study analyzes the IFT and influencing factors between the gas-liquid two-phase interface, and it guides the efficient development and utilization of energy extraction and energy storage.

Civil Aircraft Cabin Lighting Design and Verification

Regarding the equipment in the cabin of a civil aircraft, the complexity of their shapes, the huge quantity, and the high requirements for engineering experience in cabin lighting design will result in huge change costs when design errors occur. This paper proposes a general cabin lighting design method, summarizes the elements that need to be considered in the cabin lighting design, and completes the cabin lighting design according to the design elements. In addition, the digital simulation method is used for verification during the design process. Finally, the data will be verified on the real sample, which checks the correctness of the design process, and lays the foundation for the future aircraft cabin lighting design and verification.

Design and Implementation of Digital Twin-Assisted Simulation Method for Autonomous Vehicle in Car-Following Scenario

The automated system replaces the driver, which makes autonomous vehicle to improve safety and convenience, so the market of autonomous vehicle is huge. However, the real-world application of autonomous vehicles faces many challenges due to the immaturity of automated systems. As a consequence, simulation verification plays an irreplaceable role in the application of autonomous vehicle (AV). Car-following is the most common driving scenario in mixed traffic flows, so it is essential to develop an appropriate and effective simulation method for AV. Combined with the existing AV simulation methods and digital twin (DT) technology, this paper proposes a DT-assisted method for AV simulation in a car-following scenario. The method makes the physical vehicle interact with the DT vehicle, and the DT vehicle can dynamically regulate the physical entities through real-time simulation data; the simulation verification can be displayed in the DT scenario to ensure the security of the simulation. Meanwhile, a DT-assisted simulation framework of AV is proposed, the framework includes physical entity components, DT components, and data processing and evaluation components. Besides, a DT-assisted simulation platform is developed base on Unity engine. Finally, the DT-assisted simulation of AV in the car-following scenario is implemented in field experiment. The experimental results show that the proposed method can be effectively conducted AV simulation in car-following, and the average of communication latency is 52.3 ms, which is smaller than the update frequency 15 Hz (66.6 ms) between DT-assisted platform and AV. The DT-assisted simulation method of AV proposed in this paper is applied in the car-following scenario, which effectively solves the challenges of car-following scenario simulation through virtual-real interaction.

Analysis of fluid-solid-thermal coupling characteristics of axial-symmetric vectoring exhaust nozzle

Aiming at the problems of axial-symmetric vectoring exhaust nozzle (AVEN) mechanism due to its complex structure, which leads to the large amount of digital simulation calculation under the coupling of multi-physics, and it is difficult to establish the fluid domain model, a complex AVEN structure is proposed as the research object, the method of AVEN flow field simplify model in cylindrical coordinate system. This method simplifies the contact domain between the expansion regulator plate, the cruciform joint, the convergent regulator plate and the flow field into a cylindrical overall physical model, and constructs a fluid-solid coupling heat transfer physical model. The feasibility of the model is verified. The AVEN fluid-solid-thermal coupling digital simulation calculation is carried out using the sequential one-way coupling method. First, based on computational fluid dynamics, the AVEN fluid-solid coupling heat transfer calculation is carried out to calculate the coupling surface temperature and pressure field. Second, the calculated coupling surface temperature is used as the thermal analysis boundary condition. Then, the temperature field calculated by the thermal analysis and the pressure field calculated by the fluid-solid coupling heat transfer analysis are used as the boundary conditions of the structural strength analysis. Finally, fluid-solid-thermal coupling analysis of AVEN including aerodynamic load and thermal load is carried out. The calculation results show that the digital simulation method proposed in this paper can be used in engineering practice. The temperature and pressure of the AVEN coupling surface show a trend of first decreasing, then increasing, and then decreasing with the change of the position from the throat. Some AVEN mechanical components and parts have stress singular phenomena. The deformation of the AVEN structure is obviously affected by the thermal load, and the minimum change of rate is 9.54%, the maximum change of rate is 1845.37%.

Geological and economic risk assessment for territories of hazardous geological and technogenic processes (exemplified by Solotvyno township)

Purpose. Assessing the risks of economic and social losses caused by the activization of hazardous natural geological and technogenic processes to establish the hazards of living in post-mining areas, with a view to developing strategies for their amelioration. Methodology. Field observations were carried out to determine the state of the geological environment of the territory and individual engineering objects. The assessment of the territory stability was done relying on the mechanical and mathematical basics of engineering geology in conjunction with the approaches of system analysis and the theory of engineering and geological similarity. Methods of probability theory and mathematical statistics were used for the expert assessment and risk analysis. Cartographic materials were compiled using GIS and digital simulation methods implemented on the example of Solotvyno township. As the source material, the GIS database (geological, engineering-geological, hydrogeological, and so on), compiled at the Institute of Geological Sciences of the National Academy of Sciences of Ukraine for the territory of Solotvyno, was used alongside with the works assessing the occurrence of natural as well as man-induced processes. Findings. It has been established that the most dangerous geological and technogenic hazards on the territory examined are karst-suffusion processes, whose probability in the central part of the territory is 1. At the object level, the economic risk (4.35 10-3 thousand UAH/m2 year) has been estimated, which shows the need for protective engineering measures due to an individual risk (5.86 10-4 people/person year). This is a significant value as compared with the average one for the territory of Ukraine. Integrated and differentiated economic risks have been calculated for the territory of Solotvyno, with the distribution of risks visualized on schematic maps. Originality. The scheme for assessing the risk of hazardous geological and technogenic processes on the post-mining territory has been developed. The combined use of differentiated and integrated assessments of economic risks at the locality and object levels would optimize managerial decisions on protection against geological hazards and would permit the development of a high-quality system for settlement monitoring. Practical value. The implementation of the S&T results obtained will enhance the efficiency of the monitoring and engineering protection systems developed for the territories with the possible occurrence of major emergencies.

Role of digital simulation in employee training

The development in the digital world has influenced training programs for the employees; this indicates that skills and information provided by the traditional training programs need up-gradation in the digital environment. Tools of digital technology act handy in the training programs of the employees. These digital technologies such as simulation in training promote creativity and high order thinking among the employees. The main focus of the present study is to indicate the level of effectiveness of digital simulation methods of trainingin the organization. The study was conducted on two groups of employees from information technology companies based in Bangalore. The first group responded with regards to the training method and the second group of trainees included the digital simulation method of training. The results indicated that the digital simulation method of training was more effective than the traditional method of training. This suggests that the application of digital simulation training tools assists in training programs to train employees in the digital economy.

The Method of Calculating the Optimal Shape of the Electrode-Tool for Electrochemical Treatment of Gas Turbine Engine Blades

The article outlines the method of digital simulation of electrochemical processing, which allows calculating the shape of the electrode-tool in conjunction with the mode, taking into account the real conditions of processing. The technique allows you to ensure the maximum possible performance with specified processing accuracy and limitations that exclude critical phenomena in the channel between electrodes during intensification of modes. Mathematically, the task is presented in the form of minimax problem with application of penalty functions.