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Self-Supporting Robust Lattice Optimization for Material Extrusion Additive Manufacturing
No full textA lattice optimization procedure is proposed that enables the fabrication of self-supporting topologies via additive manufacturing, while accounting for uncertainties introduced during additive manufacturing through a two-step optimization process. The first step is lattice layout optimization, which removes the strut members with near-zero diameters from an initial topology generated using a newly introduced lattice cell configuration for the purpose of supporting each strut. A support algorithm is developed that identifies strut joints requiring support in the optimized topology. The struts removed from the topology are selectively reintroduced at joints where support is needed to ensure self-supporting structure fabrication. Unlike existing lattice optimization procedures that typically account for uncertainties related to material properties or loading conditions, the proposed procedure also incorporates uncertainties in design variables, specifically, the diameters of struts, into a robust optimization process in the second step. Robust optimization is performed using neural networks trained to predict the as-fabricated strut diameters and material properties based on deterministic design variables. The applicability of the proposed procedure was demonstrated for the material extrusion technique using benchmark examples. The optimized designs were fabricated and tested to verify the effectiveness of the proposed procedure in producing self-supporting structures with improved prediction accuracy under fabrication-induced uncertainties.Scientific and Technological Research Council of Turkiye (TUBITAK) [118M715]This work was supported by the Scientific and Technological Research Council of Turkiye (TUBITAK) with project 118M715
Search for Single-Production of Vector-Like Quarks Decaying into Wb in the Fully Hadronic Final State in Pp Collisions at S = 13 TeV with the ATLAS Detector
No full textA search for T and Y vector-like quarks produced in proton-proton collisions at a centre-of-mass energy of 13 TeV and decaying into Wb in the fully hadronic final state is presented. The search uses 139 fb−1 of data collected by the ATLAS detector at the LHC from 2015 to 2018. The final state is characterised by a hadronically decaying W boson with large Lorentz boost and a b-tagged jet, which are used to reconstruct the invariant mass of the vector-like quark candidate. The main background is QCD multijet production, which is estimated using a data-driven method. Upon finding no significant excess in data, mass limits at 95% confidence level are obtained as a function of the global coupling parameter, κ. The observed lower limits on the masses of Y quarks with κ = 0.5 and κ = 0.7 are 2.0 TeV and 2.4 TeV, respectively. For T quarks, the observed mass limits are 1.4 TeV for κ = 0.5 and 1.9 TeV for κ = 0.7. © 2025 Elsevier B.V., All rights reserved
Application of Radiomics Analysis on Mammography for Differentiating Benign and Malignant Masses
No full textRadiomics is emerging as a promising quantitative tool for extracting imaging features. The diagnostic accuracy of mammography may be altered by the reader’s experience. To build a radiomics model to differentiate benign and malignant mammographic masses and to evaluate whether the diagnostic performance of mammography could be improved by radiomics. In this retrospective study, 101 patients were included in the training set, and 36 patients were included in the test set. A total of 127 radiomics features were extracted from each mammographic mass using both craniocaudal (CC) and mediolateral oblique projection (MLO) images. RELIEF algorithm and Mann–Whitney-U test were used for feature selection. Seven machine learning algorithms were applied to construct a predictive model. Machine learning algorithms were trained by stratified tenfold cross-validation on the training set. The classification performance of the radiomics models was compared with the diagnostic predictions of two radiologists with different experience levels by using receiver operating characteristic curve (ROC) analysis. A total of 15 radiomics features remained after the pre-processing. “XGBoost” presented the best differentiation ability among the seven machine learning methods and yielded 0.871 area under the curve (AUC), 0.888 accuracy, 0.895 sensitivity, and 0.875 specificity. The breast radiologist yielded 0.901 (AUC), 0.916 accuracy, 0.956 sensitivity, and 0.846 specificity. The inexperienced radiologist yielded 0.819 (AUC), 0.833 accuracy, 0.869 sensitivity, and 0.769 specificity. The radiomics-based model shows favorable outcomes in differentiating benign and malignant mammographic masses. Quantifiable assessment of mammography could enhance radiology practice, especially for inexperienced radiologists. © 2025 Elsevier B.V., All rights reserved
Impact of Phase Noise and Power Amplifier Non-Linearities on Downlink Cell-Free Massive MIMO-OFDM Systems
No full textBrowsy; CIS Arge; PTT TeknolojiCell-free massive MIMO (multiple-input multipleoutput) is a key enabler for the sixth generation (6G) of mobile networks, offering significant spectral and energy efficiency gains through user-centric operation of distributed access points (APs). However, its reliance on low-cost APs introduces inevitable hardware impairments, whose combined impact on wideband downlink systems remains unexplored when analyzed using behavioral models. This paper presents a comprehensive analysis of the downlink spectral efficiency (SE) in cell-free massive MIMO-OFDM systems under practical hardware impairments, including phase noise and third-order power amplifier nonlinearities. Both centralized and distributed precoding strategies are examined. By leveraging the Bussgang decomposition, we derive an SE expression and quantify the relative impact of impairments through simulations. Our results reveal that phase noise causes more severe degradation than power amplifier distortions-especially in distributed operation-highlighting the need for future distortion-aware precoding designs. © 2025 Elsevier B.V., All rights reserved
Searches for Direct Slepton Production in the Compressed-Mass Corridor in S = 13 TeV Pp Collisions with the ATLASDetector
No full textThis paper presents searches for the direct pair production of charged light-flavour sleptons, each decaying into a stable neutralino and an associated Standard Model lepton. The analyses focus on the challenging “corridor” region, where the mass difference, ∆m, between the slepton (e~ or μ~) and the lightest neutralino (χ~10) is less or similar to the mass of the W boson, m(W), with the aim to close a persistent gap in sensitivity to models with ∆m ≲ m(W). Events are required to contain a high-energy jet, significant missing transverse momentum, and two same-flavour opposite-sign leptons (e or μ). The analysis uses pp collision data at s = 13 TeV recorded by the ATLAS detector, corresponding to an integrated luminosity of 140 fb−1. Several kinematic selections are applied, including a set of boosted decision trees. These are each optimised for different ∆m to provide expected sensitivity for the first time across the full ∆m corridor. The results are generally consistent with the Standard Model, with the most significant deviations observed with a local significance of 2.0 σ in the selectron search, and 2.4 σ in the smuon search. While these deviations weaken the observed exclusion reach in some parts of the signal parameter space, the previously present sensitivity gap to this corridor is largely reduced. Constraints at the 95% confidence level are set on simplified models of selectron and smuon pair production, where selectrons (smuons) with masses up to 300 (350) GeV can be excluded for ∆m between 2 GeV and 100 GeV. © 2025 Elsevier B.V., All rights reserved
Büyük Dil Modeli Tabanli Veri Artirimi ile Türkçe Varlık İsmi Çıkarımı
No full textIsik UniversityNamed Entity Recognition (NER) plays a fundamental role in identifying and classifying named entities within texts. However, in resource-scarce languages and applications - particularly in Turkish - the lack of annotated data leads to a decline in model performance. In this study, synthetic examples were generated using Large Language Models (LLMs) to augment the existing primary dataset, with the aim of enhancing the k-shot learning performance of NER models. Experimental results demonstrate that models trained on the augmented dataset achieve performance improvements by a factor of 40 to 60 compared to those trained on the original dataset, indicating that the proposed method offers a cost-effective and viable alternative for resource-scarce applications. © 2025 Elsevier B.V., All rights reserved
Evaluation of the Association Between KEAP1 rs1048290 G/C Genetic Polymorphism and Relapsing-Remitting Multiple Sclerosis
No full textTUBITAK [323S265]This study is supported by TUBITAK (323S265)
Biomechanical Evaluation of Fixation Techniques for Posteromedial Tibial Plateau Fractures: A Cadaveric Model
No full textObjectives: This study aims to compare the biomechanical performances of five fixation techniques, posteroanterior (PA) screw, anteroposterior (AP) screw, posterior locking compression plate (LCP), anatomic posteromedial plate (PMP), and anterolateral plate (ALP), for isolated posteromedial tibial plateau fractures using cadaveric models under static and dynamic axial loading conditions. Materials and methods: Twenty-five fresh-frozen cadaveric tibias were used to create standardized posteromedial split-type fractures. Specimens were divided equally into five groups based on the fixation method. Biomechanical testing involved cyclic axial loading (10-250 N, 2500 cycles at 2 Hz), followed by load-to-failure testing under static compression. Outcome parameters included stiffness, load at 3 mm displacement, ultimate load, displacement at failure, and photographic displacement. Results: The PMP group demonstrated the highest biomechanical stability, with the greatest ultimate load (805.60±218.96 N) and minimal displacement. The PA screw fixation also showed acceptable performance, offering a minimally invasive alternative. In contrast, the AP and ALP groups exhibited the lowest values for load tolerance and fragment control. There were significant differences between the groups, particularly favoring posterior-based techniques (p0.05). Conclusion: Anatomic PMP provides superior biomechanical stability for isolated posteromedial tibial plateau fractures. The PA screw fixation offers a less invasive, yet stable alternative. Anterior-based fixation strategies such as AP screws and ALP should be avoided due to biomechanical insufficiency
The Role of Design Education in Designers’ Pursuit of Entrepreneurial Opportunities
No full textThis article examines the relationship between design education and entrepreneurship by exploring the ways in which design education prepares, or falls short in preparing, students for entrepreneurship. Empirically, it draws on semi-structured interviews with 23 design entrepreneurs. Theoretically, it draws on the entrepreneurial opportunity literature, which highlights the significance of the knowledge, skills and abilities (KSAs) gained in higher education. Our findings propose five ways in which design education prepares students for entrepreneurship. Design education provides students with (1) a unique (“designerly”) way of seeing, reframing and handling problems, (2) a systematic approach to new challenges, (3) KSAs related to materials and production, (4) KSAs and experience related to oral and visual communication and (5) opportunities to discover students’ individual interest areas in design. © 2025 Elsevier B.V., All rights reserved
First Report of the Coexistence of Langerhans Cell Histiocytosis and Epithelioid Hemangioma of the Larynx
No full textLangerhans cell histiocytosis (LCH) is a complex disorder of the mononuclear phagocyte system. Laryngeal epithelioid hemangiomas are rare, benign vascular tumors in adults. Here, we report the first known case of the coexistence of LCH and epithelioid hemangioma in the larynx. A 42-year-old man presented with progressive swelling on the left side of the neck and hoarseness. Endoscopic examination revealed a mass obliterating the left pyriform sinus, false vocal cord, and aryepiglottic fold. Computed tomography (CT) showed a mass destroying the thyroid cartilage, extending to the left false and true vocal cords, and obstructing the airway. Fine-needle aspiration biopsy suggested hemangioendothelioma. However, histopathological examination after total laryngectomy revealed both LCH and epithelioid hemangioma. Positron emission tomography/CT indicated suspected LCH involvement of the pituitary gland and cervical lymph nodes. The patient was treated with chemotherapy. No recurrence was observed at the six-month follow-up. This case highlights the potential association between the mitogen-activated protein kinase pathway, LCH, and epithelioid hemangioma. It also emphasizes the importance of repeating a biopsy in cases of rare laryngeal tumors when initial results are inconclusive