• Korean Journal of Radiology
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• v.25 no.10
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• pp.876-886
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• 2024

Objective: To develop a nomogram that integrates clinical-pathologic and imaging variables to predict ipsilateral breast tumor recurrence (IBTR) in women with ductal carcinoma in situ (DCIS) treated with breast-conserving surgery (BCS). Materials and Methods: This retrospective study included consecutive women with DCIS who underwent BCS at two hospitals. Patients who underwent BCS between 2003 and 2016 in one hospital and between 2005 and 2013 in another were classified into development and validation cohorts, respectively. Twelve clinical-pathologic variables (age, family history, initial presentation, nuclear grade, necrosis, margin width, number of excisions, DCIS size, estrogen receptor, progesterone receptor, radiation therapy, and endocrine therapy) and six mammography and ultrasound variables (breast density, detection modality, mammography and ultrasound patterns, morphology and distribution of calcifications) were analyzed. A nomogram for predicting 10-year IBTR probabilities was constructed using the variables associated with IBTR identified from the Cox proportional hazard regression analysis in the development cohort. The performance of the developed nomogram was evaluated in the external validation cohort using a calibration plot and 10-year area under the receiver operating characteristic curve (AUROC) and compared with the Memorial Sloan-Kettering Cancer Center (MSKCC) nomogram. Results: The development cohort included 702 women (median age [interquartile range], 50 [44-56] years), of whom 30 (4%) women experienced IBTR. The validation cohort included 182 women (48 [43-54] years), 18 (10%) of whom developed IBTR. A nomogram was constructed using three clinical-pathologic variables (age, margin, and use of adjuvant radiation therapy) and two mammographic variables (breast density and calcification morphology). The nomogram was appropriately calibrated and demonstrated a comparable 10-year AUROC to the MSKCC nomogram (0.73 vs. 0.66, P = 0.534) in the validation cohort. Conclusion: Our nomogram provided individualized risk estimates for women with DCIS treated with BCS, demonstrating a discriminative ability comparable to that of the MSKCC nomogram.

• Journal of Korea Port Economic Association
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• v.40 no.2
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• pp.175-189
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• 2024

Following the introduction of containerized sea transportation, the size of container ships has progressively increased. While the primary objective of this enlargement is to achieve economies of scale, it significantly affects the operational environment of ports where these ships dock, raising concerns about the validity of efficiency gains from ultra large container vessels from a port operational perspective. This study evaluates the efficiency of various ship sizes from January to December 2022, utilizing internal data from the container terminals A and B located in the Busan New Port. The analysis encompasses ships affiliated with The Alliance at Container Terminal A and those associated with 2M at Container Terminal B. Key input variables considered for the study include ship size (TEU), total berth time, and loading/unloading time, with cargo handling performance serving as the only output variable. The findings indicate that larger ship sizes exhibit higher efficiency compared to smaller container ships.

• Clinical and Experimental Reproductive Medicine
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• v.51 no.3
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• pp.260-267
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• 2024

Objective: This study investigated the metabolic status of the spent culture media from embryos of patients with repeated implantation failure (RIF) undergoing in vitro fertilization-intracytoplasmic sperm injection cycles in comparison with the embryos from healthy fertile women. Methods: Metabolite levels in spent culture media were assessed and compared between embryos from RIF patients (n=35) and oocyte donors as controls (n=15). Protein levels of insulin-like growth factor 1 (IGF-1) were determined using Western blotting. Concentrations of glucose, pyruvate, and lactate were measured using spectrophotometry. Ionic colorimetric assay kits were utilized to analyze the concentrations of sodium, chloride, calcium, and magnesium ions. High-performance liquid chromatography was employed to measure the concentrations of glutamic acid, aspartic acid, methionine, phenylalanine, and histidine. Results: Glucose consumption and lactate secretion were higher in the control group than in the RIF group. The magnesium concentration was significantly higher in the control group than in the RIF group, but glutamic acid and aspartic acid concentrations were lower in the control group than in the RIF patients (p<0.05). The levels of IGF-1, sodium, calcium, chloride, methionine, histidine, and phenylalanine did not show statistically significant differences between the two groups. Conclusion: The metabolic profile of the culture medium of the embryos in the RIF group differed from that of the control group. These findings suggest potential factors that may affect implantation capacity in RIF patients and provide a new perspective on embryo selection.

• Clinical and Experimental Reproductive Medicine
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• v.51 no.3
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• pp.268-275
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• 2024

Objective: The purpose of this study was to evaluate the impact of preimplantation genetic testing for aneuploidy (PGT-A) on clinical outcomes among high-risk patients. Methods: This retrospective study involved 1,368 patients and the same number of cycles, including 520 cycles with PGT-A and 848 cycles without PGT-A. The study participants comprised women of advanced maternal age (AMA) and those affected by recurrent implantation failure (RIF), recurrent pregnancy loss (RPL), or severe male factor infertility (SMF). Results: PGT-A was associated with significant improvements in the implantation rate (IR) and the ongoing pregnancy rate/live birth rate (OPR/LBR) per embryo transfer cycle in the AMA (39.3% vs. 16.2% [p<0.001] and 42.0% vs. 21.8% [p<0.001], respectively), RIF (41.7% vs. 22.0% [p<0.001] and 47.0% vs. 28.6% [p<0.001], respectively), and RPL (45.6% vs. 19.5% [p<0.001] and 49.1% vs. 24.2% [p<0.001], respectively) groups, as well as the IR in the SMF group (43.3% vs. 26.5%, p=0.011). Additionally, PGT-A was associated with lower overall incidence rates of pregnancy loss in the AMA (16.7% vs. 34.3%, p=0.001) and RPL (16.7% vs. 50.0%, p<0.001) groups. However, the OPR/LBR per total cycle across all PGT-A groups did not significantly exceed that for the control groups. Conclusion: PGT-A demonstrated beneficial effects in high-risk patients. However, our findings indicate that these benefits are more pronounced in carefully selected candidates than in the entire high-risk patient population.

• Restorative Dentistry and Endodontics
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• v.49 no.3
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• pp.29.1-29.11
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• 2024

This study aimed to identify and analyze articles on enamel microabrasion for the treatment of white spot lesions. A search was conducted on the Web of Science. The following parameters were recorded and analyzed: number of citations, year, journal, impact factor, study design, theme, country and continent, institution, authors, and keywords. Data was analyzed using VOSviewer software. The initial search resulted in 1,126 documents, of which 94 articles were included. The highest number of citations an article received was 65. The oldest article was published in 1975, and the most recent in 2023. The most frequent study design was case report (n = 42). Regarding the themes, it was observed that the main objective of the studies was to evaluate the clinical performance of enamel microabrasion (n = 75), primarily using Opalustre (Ultradent Products Inc., South Jordan, UT, USA) (n = 37) for treating white stains caused by dental fluorosis (n = 41). Most articles originated from Latin America (n = 31), mainly from Brazil (n = 26). The most frequent author was Sundfeld RH (n = 10). This study reveals research trends in the field of enamel microabrasion. The publications were mainly case reports/series using Opalustre for the removal of fluorosis stains.

• Nuclear Engineering and Technology
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• v.56 no.8
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• pp.3123-3128
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• 2024

The dicentric chromosome assay is a gold standard method to estimate radiation exposure by calculating the ratio of dicentric chromosomes existing in cells. The objective of this study was to propose an automatic dicentric chromosome discrimination method based on deep convolutional neural networks using radiation exposure patient data. From 45 patients with radiation exposure, conventional Giemsa-stained images of 116,258 normal and 2800 dicentric chromosomes were confirmed. ImageNet was used to pre-train VGG19, which was modified and fine-tuned. The proposed modified VGG19 demonstrated dicentric chromosome discrimination performance, with a true positive rate of 0.927, a true negative rate of 0.997, a positive predictive value of 0.882, a negative predictive value of 0.998, and an area under the receiver operating characteristic curve of 0.997.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.152-159
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• 2024

Cracks in structural materials present a critical challenge to infrastructure safety and long-term durability. Timely and precise crack detection is essential for proactive maintenance and the prevention of catastrophic structural failures. This study introduces an innovative approach to tackle this issue using U-Net deep learning architecture. The primary objective of the intended research is to explore the potential of U-Net in enhancing the precision and efficiency of crack detection across various concrete crack detection under various environmental conditions. Commencing with the assembling by a comprehensive dataset featuring diverse images of concrete cracks, optimizing crack visibility and facilitating feature extraction through advanced image processing techniques. A wide range of concrete crack images were collected and used advanced techniques to enhance their visibility. The U-Net model, well recognized for its proficiency in image segmentation tasks, is implemented to achieve precise segmentation and localization of concrete cracks. In terms of accuracy, our research attests to a substantial advancement in automated of 95% across all tested concrete materials, surpassing traditional manual inspection methods. The accuracy extends to detecting cracks of varying sizes, orientations, and challenging lighting conditions, underlining the systems robustness and reliability. The reliability of the proposed model is measured using performance metrics such as, precision(93%), Recall(96%), and F1-score(94%). For validation, the model was tested on a different set of data and confirmed an accuracy of 94%. The results shows that the system consistently performs well, even with different concrete types and lighting conditions. With real-time monitoring capabilities, the system ensures the prompt detection of cracks as they emerge, holding significant potential for reducing risks associated with structural damage and achieving substantial cost savings.

• Design & Manufacturing
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• v.18 no.3
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• pp.44-53
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• 2024

A injection mold usually requires 30 to 50 revisions, and as the number of revisions increases, the burden of increased costs, schedule delays, and decreased reliability increases, reducing the competitiveness of companies. In addition, these costs become a more serious problem when the customer is far away, which is an obstacle to the export of domestic mold companies with excellent technology. The objective of this study is to develop an augmented reality platform that will facilitate the sharing of realistic 3D virtual objects in real time and enable mold designers to collaborate using a range of tools in remote locations and virtual environments. The platform collaboration solution enables simultaneous participation and synchronization of design collaboration with four types of devices (PC, mobile, VR, and MR). The efficiency and precision of the high-speed injection molding analysis module were validated through rigorous testing, demonstrating a processing speed that ranges from 500 to 3,000 times faster than that of the conventional numerical analysis method, with a relative error of less than 15% and a service performance of more than 80 fps. The user-friendly and intuitive UI/UX was configured and the usability was verified through scenario verification.

• Journal of Aerospace System Engineering
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• v.18 no.5
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• pp.33-40
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• 2024

The objective of this study was to analyze influence of heat treatment of nano-silica particles on rheological characteristics of shear thickening fluid. Heat treatment was conducted for nano-silica particles with a diameter of 7 nm at temperatures of 120 ℃ and 180 ℃, followed by dispersion in polyethylene glycol as a solvent to fabricate shear thickening fluids with a concentration of 15 wt%. Subsequently, rheological characteristics were investigated using a rheometer. Findings revealed that shear thickening fluids produced with thermally treated nano-silica particles exhibited a notable increase in maximum viscosity, ranging from 8.96% to 213.17%, accompanied by a decrease in critical shear rate, ranging from 14.89% to 57.25%. Furthermore, it was confirmed that the shear thickening effect was enhanced up to 54.17%. These results are anticipated to facilitate the fabrication of high-performance shear thickening fluids with rheological properties that align with design requirements for application in aerospace structures.

• The Journal of Korean Medicine
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• v.45 no.2
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• pp.74-82
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• 2024

Objectives: The objective of this study was to explore the integration of Traditional Korean Medicine (TKM) into existing clinical pathways for the treatment of gastric cancer. focusing on enhancing treatment outcomes and improving patient quality of life. Methods: Employing a prospective observational design, the study targeted adults aged 20-75 diagnosed with gastric cancer. It assessed the TKM pathway's impact on quality of life, tumor markers, complete blood count test values, and patient satisfaction, and monitored adverse reactions to evaluate effectiveness and safety. Results: The study demonstrated improved quality of life(QOL), as indicated by increased Karnofsky Performance Scale(KPS) scores Mean Difference(MD)=20.37, and better quality of life (MD=19.79) assessments. Blood test results showed notable enhancements in immune function markers such as Neutrophil (MD=-7.34%) and Lymphocyte (6.80%), and Erythrocyte Sedimentation Rate (ESR)(MD=-11.05mm/hr). Both patient and medical staff satisfaction (MD=0.33) improved, although changes in tumor markers were not statistically significant. Conclusions: The integration of TKM into the treatment of gastric cancer can significantly improve patient quality of life and satisfaction. To further substantiate these results, developing and implementing more critical pathways across varied clinical settings, along with larger-scaled studies, are essential.