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Among numerous approaches that have been presented for computational contact analysis, the node-to-segment (NTS) approach is widely adopted in industrial applications, particularly with the penalty method. However, the pure penalty-method-based NTS approach fails the patch test even with the area regularization (AR) technique. There have been relatively few solutions for this problem compared to those for Lagrange-multiplier-method-based NTS approaches. This paper presents an improved AR technique and attempts to make the penalty-method-based NTS approach pass the patch test. The proposed approach improves the accuracy without the need to introduce additional geometry to the conventional penalty-method-based NTS approach. The entire competence area of a slave node is not directly utilized as a penalty weighting factor. Instead, a part of the competence area is extracted in accordance with the projection from a master node to a slave segment. In a complementary manner, a two-pass algorithm is used for the selected master nodes to achieve segment-wise force/moment equivalence. The results obtained using the proposed approach are introduced in a two-dimensional frictionless context. It is observed that the proposed approach passes the patch test. Furthermore, a significant improvement in accuracy compared to the conventional NTS and NTS-AR approaches is observed. We aim to extend the approach to three-dimensional applications in the future work.

The goal of this paper is to examine the computational approaches for predicting both of the overall sound pressure level (OASPL) at a few locations and acceleration power spectral density (APSD) of surrounding thin plates due to the aero-acoustic pressure generated by a cold jet with M = 1.8. First, computational fluid dynamics (CFD), particularly delayed detached eddy simulation, are applied to predict the OASPL at the near-field and compute the acoustic properties. Second, the linearized boundary element method (BEM), that is, the Helmholtz-Kirchhoff method is utilized to propagate the pressure and obtain the OASPL at the far-field. Finally, the finite element method is implemented to predict the APSD for a clamped thin plate based on the optimal triangle membrane element, discrete Kirchhoff triangle plate bending element, and Newmark- β time integration scheme. Using the present CFD and BEM, the OASPLs are compared with the experimental results measured by microphones at both the near- and far-fields, respectively. Moreover, APSDs are compared with the experimental results obtained by an accelerometer at a few different locations. Although OASPLs are overestimated because of the coarse meshes in the higher-angle area and low order scheme of the present CFD analysis, the present integrated aero-vibro-acoustic analysis is capable of predicting the OASPL and APSD generated by a cold jet with M = 1.8.

The conventional representative volume element approach may not be accurate enough in examining stress distribution near singularity in a composite. However, enormous number of degrees of freedom (DOFs) is usually required to discretize the subcomponents within the composite structure; hence, it may not be handled in a single CPU. In this study, the finite element tearing and interconnecting algorithm, a domain decomposition method, is proposed to address the challenges posed by such enormous number of DOFs via parallel computation. Owing to the message passing interface, analyses in this study will be conducted on the parallel computing environment. Furthermore, the METIS algorithm is adopted to automatically divide the solid domain into certain number of subdomains. Consequently, the fiber-reinforced polymer which possesses either a crack or notch discretized by over 10 million DOFs will be readily analyzed. The computational time is reduced significantly compared against the original one. Also, the stress and stiffness predictions show good agreement with those by the other existing analyses or experiments. Therefore, this study is expected to be fast and accurate in analyzing composite structures with enormous number of DOFs.

Forced vibration analysis is an indispensable process for the design of a rotating component. However, rather expensive nonlinear static and linear frequency response analyses are usually accompanied by a frequency domain analysis. The traditional mode-superposition method (MSM) effectively reduces the cost of the frequency response analysis. However, the nonlinear static analysis of earlier processes remains as the computational bottleneck. In this paper, the application of the hyper-reduction method will be proposed along with the model order reduction (MOR) framework for rotating component forced vibration analysis. The energy-conserving sampling and weighting (ECSW) method will be employed for the nonlinear iterative computation. The pre-stressed stiffness matrix of the reduced finite elements (FEs) resulting from the ECSW will be used for the post computation stage. Also, a variety of MOR will be attempted for the performance comparison, including MSM, proper orthogonal decomposition (POD)-based reduced order model (ROM), and a hybrid approach. It is found that the present ECSW-combined MOR will significantly relieve the computational bottleneck, provide a minimal loss of accuracy, and be compatible with both nonlinear and linear analyses of the rotating component forced vibration analysis.

An improved nonintrusive parametric model order reduction (pMOR) approach is proposed for the flow field interpolation regarding fluid–structure interaction (FSI) objects. Flow field computation using computational fluid dynamics (CFD) requires excessive computational time and memory. Nonintrusive and data-driven MOR schemes have been proposed to overcome such limitations. The present methodology is implemented by both proper orthogonal decomposition (POD) and a modified Nouveau variational autoencoder (mNVAE). POD attempts to reduce the number of degrees of freedom (DOFs) on the precomputed series of the full-order model parametric result. The reduced DOF yields parametrically independent reduced bases and dependent coefficients. Then, mNVAE is employed for the interpolation of POD coefficients, which will be combined with POD modes for parametrically interpolated flow field generation. The present approach is assessed on the benchmark problem of a two-dimensional plunging airfoil and the highly nonlinear FSI phenomenon of the limit cycle oscillation. The comparison was executed against other POD-based generative neural network approaches. The proposed methodology demonstrates applicability on highly nonlinear FSI objects with improved accuracy and efficiency.

A Phase I clinical trial is currently underway to test Nelmastobart (hSTC810), an antibody targeting butyrophilin 1A1 (BTN1A1), a novel immune checkpoint protein. This Phase I clinical trial is using a standard 3 + 3 escalation design to (i) explore safety, tolerability, dose-limiting toxicities, and pharmacokinetics, (ii) define a recommended Phase II dose, and (iii) evaluate preliminary efficacy in patients with advanced solid tumors. The current dose range for the clinical trial is 0.3 mg/kg to 15 mg/kg. Currently, all the dose levels have been completed without any dose-limiting toxicity having been observed. Here, we provide an update on the clinical trial data shown previously. First, we provide the results of the pharmacokinetics study of these patients for the selected doses and dosing intervals, including the peak plasma concentration (Cmax), the time to reach Cmax (tmax), and the average plasma concentration of hSTC810 over the dosing interval in steady state (Cavg). The change in cytokine expression and immune cell concentrations in patient blood samples were also analyzed. Specifically, a panel of cytokines was measured including IFN- γ, IL-2, IL-4, IL-6, IL-10, TNF-α, MCP-1, and TGF- β, while flow cytometry was used to detect a panel of immunological marker proteins including CD3, CD4, CD8, CD19, CD14, CD16, CD56, CD25, CD45. For pharmacokinetic studies, the concentrations of hSTC810 and anti-hSTC810 antibodies were quantified. Immunohistochemistry was performed on patient tumor biopsies that were stained for PD-L1, CD3, CD4, CD8, and BTN1A1 expression. The resultant slides were analyzed for PD-L1 tumor proportional score (TPS), PD-L1 combined positive score (CPS), BTN1A1 scoring, the percentage of CD3+ lymphocytes, CD4+ lymphocytes, CD8+ lymphocytes, tumor-infiltrating lymphocytes, and necrosis. Citation Format: Stephen Sunghan Yoo, Soohyeon Lee, Sangjoon Shin, Hyunjin Jung, David S. Hong. Pharmacokinetic analyses and immunophenotyping of patients treated with Nelmastobart (hSTC810), a novel immune checkpoint inhibitor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT238.