• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.6
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• pp.367-373
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• 2021

In this study, deep learning model was set up to predict the wave heights inside a harbour. Various machine learning techniques were applied to the model in consideration of the transformation characteristics of offshore waves while propagating into the harbour. Pohang New Port was selected for model application, which had a serious problem of unloading due to swell and has lots of available wave data. Wave height, wave period, and wave direction at offshore sites and wave heights inside the harbour were used for the model input and output, respectively, and then the model was trained using deep learning method. By considering the correlation between the time series wave data of offshore and inside the harbour, the data set was separated into prevailing wave directions as a pre-processing method. As a result, It was confirmed that accuracy and stability of the model prediction are considerably increased.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.489-497
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• 2022

In this study, the fluidity, mechanical properties and microstructure of cement pastes with carbon nanotube (CNT) were experimentally investigated. The 6 types of cement paste mixes with different PCE:CNT and w/b had been manufactured, and several tests including flow, compressive strength, absorption and water porosity were performed on cement pastes with or without CNT.Additionally, microstructural observations such as x-ray diffraction (XRD) and scanning electron microscopy (SEM) were carried out to examine hydrates formed in cement paste with CNT. As a result, it was found that the performance of cement pastes with CNT was better compared to that of control cement paste (OPC) due to both of hydration acceleration effect and filling effect. Furthermore, the SEM images clearly showed that CNT can bridge cracks formed in cement matrix. Conclusively, it is believed that the CNT, if mixed appropriately, could be an option as nono-materials to improve performance of concrete structures.

• Anxiety and mood
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• v.19 no.2
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• pp.83-93
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• 2023

Objective : This study aimed to develop a customized EAP program for post office workder, incorporating mindfulness and positive psychology, and to test the effectiveness of the intervention on job burnout and well-being of the postal workers. Methods : Participants were currently working postal employees and were recruited voluntarily through the website of the Korea post human resources development institute. A total of 42 workers participated in the program until the end and completed preprogram and post program questionnaires. Results : The results showed that the mindfulness-positive psychology EAP program significantly improved the participants' mindfulness (t=-5.021, p<0.001), job burnout (t=5.824, p<0.001), self-esteem (t=-4.852, p<0.001), positive affect (t=-4.534, p<0.001), negative affect (t=5.635, p<0.001), and body tension (t=6.355, p<0.001), with statistically significant effects on all measures. Conclusion : The results indicated that the mindfulness-positive psychology EAP class had a significantly positive effect on increasing mindfulness, self-esteem, and positive affect and decreasing job burnout, negative affect, and body tension among postal workers, demonstrating the usefulness of an integrated approach.

• Journal of Yeungnam Medical Science
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• v.37 no.4
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• pp.321-328
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• 2020

Background: This study aimed to investigate the incidences of and risk factors for perioperative events following anticoagulant discontinuation in patients with non-valvular atrial fibrillation (NVAF) undergoing non-cardiac surgery. Methods: A total of 216 consecutive patients who underwent cardiac consultation for suspending perioperative anticoagulants were enrolled. A perioperative event was defined as a composite of thromboembolism and major bleeding. Results: The mean anticoagulant discontinuation duration was 5.7 (±4.2) days and was significantly longer in the warfarin group (p<0.001). Four perioperative thromboembolic (1.9%; three strokes and one systemic embolization) and three major bleeding events (1.4%) were observed. The high CHA₂DS₂-VASc and HAS-BLED scores and a prolonged preoperative anticoagulant discontinuation duration (4.4±2.1 vs. 2.9±1.8 days; p=0.028) were associated with perioperative events, whereas the anticoagulant type (non-vitamin K antagonist oral anticoagulants or warfarin) was not. The best cut-off levels of the HAS-BLED and CHA₂DS₂-VASc scores were 3.5 and 2.5, respectively, and the preoperative anticoagulant discontinuation duration for predicting perioperative events was 2.5 days. Significant differences in the perioperative event rates were observed among the four risk groups categorized according to the sum of these values: risk 0, 0%; risk 1, 0%; risk 2, 5.9%; and risk 3, 50.0% (p<0.001). Multivariate logistic regression analysis showed that the HAS-BLED score was an independent predictor for perioperative events. Conclusion: Thromboembolic events and major bleeding are not uncommon during perioperative anticoagulant discontinuation in patients with NVAF, and interrupted anticoagulation strategies are needed to minimize these.

• The Korean Journal of Malacology
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• v.30 no.4
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• pp.429-431
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• 2014

Since we reported a BLAST server for the mollusk in 2004, no work has reported the usability or modification of the server. To improve its usability, the BLAST server for the mollusk has been updated as version II (http://www.malacol.or.kr/blast) in the present study. The database was constructed by using the Intel server Platform ZSS130 dual Xeon 3.20 GHz CPU and Linux CentOS system and with NCBI WebBLAST package. We downloaded the mollusk nucleotide, amino acid, EST, GSS and mitochondrial genome sequences which can be opened through NCBI web BLAST and used them to build up the database. The updated database consists of 520,977 nucleotide sequences, 229,857 amino acid sequences, 586,498 EST sequences, 23,112 GSS and 565 mitochondrial genome sequences. Total database size is 1.2 GB. Furthermore, we have added repeat sequences, Escherichia coli sequences and vector sequences to facilitate data validation. The newly updated BLAST server for the mollusk will be useful for many malacological researchers as it will save time to identify and study various molluscan genes.

• Biomolecules & Therapeutics
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• v.25 no.5
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• pp.511-518
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• 2017

Ultraviolet (UV) irradiation is a relevant environment factor to induce cellular senescence and photoaging. Both autophagy- and silent information regulator T1 (SIRT1)-dependent pathways are critical cellular processes of not only maintaining normal cellular functions, but also protecting cellular senescence in skin exposed to UV irradiation. In the present studies, we investigated whether modulation of autophagy induction using a novel synthetic SIRT1 activator, heptasodium hexacarboxymethyl dipeptide-12 (named as Aquatide), suppresses the UVB irradiation-induced skin aging. Treatment with Aquatide directly activates SIRT1 and stimulates autophagy induction in cultured human dermal fibroblasts. Next, we found that Aquatide-mediated activation of SIRT1 increases autophagy induction via deacetylation of forkhead box class O (FOXO) 1. Finally, UVB irradiation-induced cellular senescence measured by $SA-{\beta}-gal$ staining was significantly decreased in cells treated with Aquatide in parallel to occurring SIRT1 activation-dependent autophagy. Together, Aquatide modulates autophagy through SIRT1 activation, contributing to suppression of skin aging caused by UV irradiation.

• Journal of Yeungnam Medical Science
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• v.38 no.4
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• pp.337-343
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• 2021

Background: Chromogranin A (CgA) levels have been reported to predict mortality in patients with heart failure. However, information on the prognostic value and clinical availability of CgA is limited. We compared the prognostic value of CgA to that of previously proven natriuretic peptide biomarkers in patients with acute heart failure. Methods: We retrospectively evaluated 272 patients (mean age, 68.5±15.6 years; 62.9% male) who underwent CgA test in the acute stage of heart failure hospitalization between June 2017 and June 2018. The median follow-up period was 348 days. Prognosis was assessed using the composite events of 1-year death and heart failure hospitalization. Results: In-hospital mortality rate during index admission was 7.0% (n=19). During the 1-year follow-up, a composite event rate was observed in 12.1% (n=33) of the patients. The areas under the receiver-operating characteristic curves for predicting 1-year adverse events were 0.737 and 0.697 for N-terminal pro-B-type natriuretic peptide (NT-proBNP) and CgA, respectively. During follow-up, patients with high CgA levels (>158 pmol/L) had worse outcomes than those with low CgA levels (≤158 pmol/L) (85.2% vs. 58.6%, p<0.001). When stratifying the patients into four subgroups based on CgA and NT-proBNP levels, patients with high NT-proBNP and high CgA had the worst outcome. CgA had an incremental prognostic value when added to the combination of NT-proBNP and clinically relevant risk factors. Conclusion: The prognostic power of CgA was comparable to that of NT-proBNP in patients with acute heart failure. The combination of CgA and NT-proBNP can improve prognosis prediction in these patients.

• Journal of Veterinary Clinics
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• v.25 no.6
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• pp.482-487
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• 2008

This study was performed to investigate the ophthalmic findings of the Korean traditional 'Sapsaree' dogs, and to provide ophthalmic references. Five hundred forty-seven Sapsaree dogs were randomly chosen without any criteria preference. Ophthalmic examination was performed bilaterally using ocular equipments, including slit-lamp biomicroscope, tonometer, direct and indirect ophthalmoscope. The obtained data for ophthalmic findings were analysis by the multivariate linear regression model to identify effects of sex, age and hair coat type. For congenital conditions, the incidence of persistent pupillary membrane (PPM) was the most common defect and there was present 8.8 % whereas for acquired ophthalmic diseases, cataract was the most commonly observed (3.7 %) in Sapsaree dog. Other frequent ocular finding included persistent hyaloid vessel remnant (PHVR, 6.2 %) in congenital conditions, and postinflammatory retinal degeneration (PIRD, 3.1 %) and corneal dystrophy (2.4 %) in acquired ophthalmic diseases. Only one significant effect was age of the Sapsaree for PIRD (P=0.040). There are no any significant effect for sex and hair coat types. This study will provide useful guidelines to clinicians and breeders for the basic ophthalmic information on this breed.

• Quality Improvement in Health Care
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• v.30 no.1
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• pp.120-131
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• 2024

Purpose: This study aimed to evaluate the impact of implementing a clinical pathways (CPs) on the clinical outcomes and costs of patients undergoing breast cancer surgery. Methods: This retrospective cohort study included patients who were newly diagnosed with primary breast cancer at the Samsung Medical Center between 2014 and 2019 (N=8482; 2931 patients in the pre-path and 5551 patients in the post-path). Clinical outcomes included reoperation during hospitalization, readmission, and emergency room visits within 30 days of discharge. The cost data for each unit were obtained from an activity-based management accounting system. We performed an interrupted time series analysis. Results: The post-path period showed a significantly shorter hospital length of stay (LOS) than the pre-path period (6.3 days in pre-path vs. 5.0 days in post-path; -1.3 days' difference; p=.001), and fewer reoperations during hospitalization and within 30 days after discharge than the pre-path period. After adjusting for inflation rates and relative value scores, the model demonstrated savings of $146 per patient in the post-path for total costs, and $537 per patient for patient out-of-pocket costs (p=.001). Conclusion: CPs can help reduce costs without compromising the quality of care by reducing the number of reoperations, readmissions, and complications.

• Korean Journal of Radiology
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• v.23 no.1
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• pp.77-88
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• 2022

Objective: Our study aimed to evaluate the quality of radiomics studies on brain metastases based on the radiomics quality score (RQS), Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) checklist, and the Image Biomarker Standardization Initiative (IBSI) guidelines. Materials and Methods: PubMed MEDLINE, and EMBASE were searched for articles on radiomics for evaluating brain metastases, published until February 2021. Of the 572 articles, 29 relevant original research articles were included and evaluated according to the RQS, TRIPOD checklist, and IBSI guidelines. Results: External validation was performed in only three studies (10.3%). The median RQS was 3.0 (range, -6 to 12), with a low basic adherence rate of 50.0%. The adherence rate was low in comparison to the "gold standard" (10.3%), stating the potential clinical utility (10.3%), performing the cut-off analysis (3.4%), reporting calibration statistics (6.9%), and providing open science and data (3.4%). None of the studies involved test-retest or phantom studies, prospective studies, or cost-effectiveness analyses. The overall rate of adherence to the TRIPOD checklist was 60.3% and low for reporting title (3.4%), blind assessment of outcome (0%), description of the handling of missing data (0%), and presentation of the full prediction model (0%). The majority of studies lacked pre-processing steps, with bias-field correction, isovoxel resampling, skull stripping, and gray-level discretization performed in only six (20.7%), nine (31.0%), four (3.8%), and four (13.8%) studies, respectively. Conclusion: The overall scientific and reporting quality of radiomics studies on brain metastases published during the study period was insufficient. Radiomics studies should adhere to the RQS, TRIPOD, and IBSI guidelines to facilitate the translation of radiomics into the clinical field.