Mitigating Measurement Inaccuracies in Digital Twins of Construction Machinery through Multi-Objective Optimization.

The advent of digital twins facilitates the generation of high-fidelity replicas of actual systems or assets, thereby enhancing the design's performance and feasibility. When developing digital twins, precise measurement data is essential to ensure alignment between the actual and digital models. However, inherent uncertainties in sensors and models lead to disparities between observed and predicted (simulated) behaviors. To mitigate these uncertainties, this study originally proposes a multi-objective optimization strategy utilizing a Gaussian process regression surrogate model, which integrates various uncertain parameters, such as load angle, bucket cylinder stroke, arm cylinder stroke, and boom cylinder stroke. This optimization employs a genetic algorithm to indicate the Pareto frontiers regarding the pressure exerted on the boom, arm, and bucket cylinders. Subsequently, TOPSIS is applied to ascertain the optimal candidate among the identified Pareto optima. The findings reveal a substantial congruence between the experimental and numerical outcomes of the devised virtual model, in conjunction with the TOPSIS-derived optimal parameter configuration.

Conserving the lymphatics from the arm using fluorescence imaging in patients with breast cancer at high risk of postoperative lymphedema: a pilot study.

BACKGROUND: Postoperative lymphedema in breast cancer survivors is a serious complication that develops from axillary lymph node dissection (ALND), chemotherapy, and radiation therapy. Axillary reverse mapping (ARM) was recently introduced to reduce lymphedema. This pilot study aimed to investigate the feasibility of preserving the ARM node using fluorescence imaging for patients at high risk of lymphedema. METHODS: We prospectively screened patients with breast cancer who had pathologic node-positive disease at diagnosis and were scheduled for neoadjuvant chemotherapy (NCT). The sentinel lymph node (SLN) was identified using blue dye and radioisotope, while the ARM node was traced using indocyanine green (ICG). In cases in which SLN was negative on the intraoperative frozen section examination, the ARM node and lymphatics were preserved. RESULTS: Of the 20 screened patients, six whose metastatic axillary lymph node (ALN) was converted to clinically node-negative disease after NCT were enrolled. No patients experienced recurrence at 24 months postoperative. Four patients who had a preserved ARM node did not develop lymphedema. One patient whose ARM node was not preserved due to SLN identification failure did not develop postoperative lymphedema. One patient who underwent ALND without ARM node conservation because of metastatic SLN on frozen section examination developed postoperative lymphedema. CONCLUSIONS: ARM is oncologically safe, decreases the incidence of postoperative lymphedema, and allows for the early detection of postoperative lymphedema in patients who underwent ALND. Ultimately, ARM may help improve the quality of life of patients with pathologic node-positive breast cancer.

Directional bending sensor based on triangular shaped fiber Bragg gratings.

We propose a directional bending sensor by mechanically bonded FBGs in a radially placed triangular shape to measure the bending moment and its applied direction. Bending measurement and the determination of its direction is essential to get the maximum bending stress and to figure out the deflection shape by the curvature information in a wide range of engineering applications. The proposed sensor configuration is original in terms of a pointwise sensing scheme based on the mechanically bonded scheme of three optical fibers and its simple fabrication process only using optical fibers. This set-up made of three FBG sensors provides a simple relationship of the bending moment to the independent strain measurement of each FBG. We demonstrate two sensor configurations such as the self-bending measurement and the structural bending measurement in a surface-mount (or embedded) measurement. Through the verification experiments, the proposed bending sensor is successfully shown to measure the applied bending moment and its direction.

Optimal treatment of pseudoangiomatous stromal hyperplasia of the breast.

BACKGROUND: Pseudoangiomatous stromal hyperplasia (PASH) is a benign mesenchymal proliferative lesion of the breast. Owing to the rarity of PASH, the pathogenesis, clinical manifestation, and optimal treatment of this condition remain unclear. We aimed to clarify the appropriate management of PASH. METHODS: We performed a retrospective analysis of the clinicopathological data of 66 cases with a diagnosis of PASH, confirmed by core needle biopsy (CNB) or surgical excision at Severance Hospital between 2000 and 2016. The primary endpoint was pathologic results after surgical excision of the lesion that confirmed PASH by CNB. The secondary endpoint was progression after the first treatment. RESULT: The median age of patients was 41 years (range, 14-61 years). Findings on medical imaging were nonspecific. CNB was performed in 61 cases, with a diagnosis of PASH confirmed in 39 cases (63.9%). No malignant or premalignant cells directly arising from PASH were identified after surgical excision that confirmed PASH via CNB. The progression rate after the first treatment was 16.6%, with lesion size, enlargement of palpable mass size, and a diagnosis other than PASH on CNB being factors associated with progression. CONCLUSION: CNB is sufficient to confirm PASH what is necessary for an abnormal imaging or suspicious physical examination finding. Surgical excision is not necessarily indicated to rule out occult malignancy after a diagnosis of PASH. Close monitoring or surgical excision are required to manage large lesions (>3 cm) or progressive growth of a PASH lesion.

Optimal design of lattice structures for controllable extremal band gaps.

This paper presents very large complete band gaps at low audible frequency ranges tailored by gradient-based design optimizations of periodic two- and three-dimensional lattices. From the given various lattice topologies, we proceed to create and enlarge band gap properties through controlling neutral axis configuration and cross-section thickness of beam structures, while retaining the periodicity and size of the unit cell. Beam neutral axis configuration and cross-section thickness are parameterized by higher order B-spline basis functions within the isogeometric analysis framework, and controlled by an optimization algorithm using adjoint sensitivity. Our optimal curved designs show much more enhanced wave attenuation properties at audible low frequency region than previously reported straight or simple undulated geometries. Results of harmonic response analyses of beam structures consisting of a number of unit cells demonstrate the validity of the optimal designs. A plane wave propagation in infinite periodic lattice is analyzed within a unit cell using the Bloch periodic boundary condition.