• Geophysics and Geophysical Exploration
• /
• v.24 no.4
• /
• pp.180-193
• /
• 2021

The complex resistivity method is an exploration technique that can obtain various characteristic information of underground media by measuring resistivity and phase in the frequency domain, and its utilization has recently increased. In this paper, a three-dimensional inversion algorithm for the CR data was developed to increase the utilization of this method. The Poisson equation, which can be applied when the electromagnetic coupling effect is ignored, was applied to the modeling, and the inversion algorithm was developed by modifying the existing algorithm by adopting comlex variables. In order to increase the stability of the inversion, a technique was introduced to automatically adjust the Lagrangian multiplier according to the ratio of the error vector and the model update vector. Furthermore, to compensate for the loss of data due to noisy phase data, a two-step inversion method that conducts inversion iterations using only resistivity data in the beginning and both of resistivity and phase data in the second half was developed. As a result of the experiment for the synthetic data, stable inversion results were obtained, and the validity to real data was also confirmed by applying the developed 3D inversion algorithm to the analysis of field data acquired near a hydrothermal mine.

• Nutrition Research and Practice
• /
• v.16 no.3
• /
• pp.330-343
• /
• 2022

BACKGROUND/OBJECTIVES: Zanthoxylum schinifolium is traditionally used as a spice for cooking in East Asian countries. This study was undertaken to evaluate the anti-proliferative potential of ethanol extracts of Z. schinifolium leaves (EEZS) against human bladder cancer T24 cells. MATERIALS/METHODS: Subsequent to measuring the cytotoxicity of EEZS, the anti-cancer activity was measured by assessing apoptosis induction, reactive oxygen species (ROS) generation, and mitochondrial membrane potential (MMP). In addition, we determined the underlying mechanism of EEZS-induced apoptosis through various assays, including Western blot analysis. RESULTS: EEZS treatment concentration-dependently inhibited T24 cell survival, which is associated with apoptosis induction. Exposure to EEZS induced the expression of Fas and Fas-ligand, activated caspases, and subsequently resulted to cleavage of poly (ADP-ribose) polymerase. EEZS also enhanced the expression of cytochrome c in the cytoplasm by suppressing MMP, following increase in the ratio of Bax:Bcl-2 expression and truncation of Bid. However, EEZS-mediated growth inhibition and apoptosis were significantly diminished by a pan-caspase inhibitor. Moreover, EEZS inhibited activation of the phosphoinositide 3-kinase (PI3K)/Akt pathway, and the apoptosis-inducing potential of EEZS was promoted in the presence of PI3K/Akt inhibitor. In addition, EEZS enhanced the production of ROS, whereas N-acetyl cysteine (NAC), a ROS scavenger, markedly suppressed growth inhibition and inactivation of the PI3K/Akt signaling pathway induced by EEZS. Furthermore, NAC significantly attenuated the EEZS-induced apoptosis and reduction of cell viability. CONCLUSIONS: Taken together, our results indicate that exposure to EEZS exhibits anti-cancer activity in T24 bladder cancer cells through ROS-dependent induction of apoptosis and inactivation of the PI3K/Akt signaling pathway.

• Nutrition Research and Practice
• /
• v.16 no.sup1
• /
• pp.134-146
• /
• 2022

BACKGROUND/OBJECTIVES: Accumulating evidence has shown the beneficial effects of isoflavone on health. There is limited information on the usual isoflavone intake for Koreans. This study examined the usual intake of total isoflavone and its major food sources in Koreans according to age and gender. SUBJECTS/METHODS: The dietary intake data of 21,271 participants aged 1 yrs and older from the Korea National Health and Nutrition Examination Survey (KNHANES) VII 2016-2018 were analyzed. The average isoflavone intake was estimated based on the 24-h dietary recall data in KNHANES and the isoflavone database from the Korea Rural Development Administration (RDA) and literatures. The usual isoflavone intake was estimated by applying the ratio of within- and between-participant variance estimated from the 2009 KNHANES data to the 7th KNHANES (2016-2018) data. The variance of the isoflavone intake was calculated using MIXTRAN macro with intake data for two days in the 2009 KNHANES. Complex sample analysis with stratified variables and integrated weights was conducted. RESULTS: The mean total isoflavone intake in the Korean population aged 1 yrs and older (n = 21,271) was 139.27 mg/d, which was higher than the usual intake of 47.44mg/d. Legumes were a major contributing food group (91%), with arrowroot being a major individual contributor to the isoflavone intake (67.2%), followed by 21.3% of soybean, 5.4% of bean sprouts, and 2.1% of tofu. The usual isoflavone intake was highest in the participants aged 50 to 64 yrs old and increased with age until 50 to 64 yrs and then decreased with further increases in age. The usual isoflavone intake of participants aged 65 yrs and older was higher for men than for women, showing gender differences. CONCLUSIONS: The usual dietary intake of isoflavone varied according to age and gender in the Korean population. This study showed that the usual isoflavone intake was lower than the average isoflavone intake. The difference between percentiles of the usual isoflavone intake was similarly smaller than the average intake. An estimation of average intake can be hindered by the occasional consumption of foods high in isoflavones, suggesting that the usual intake estimation method can be more appropriate. Further research will be needed to establish isoflavone dietary guidelines regarding the effects of isoflavone intake on health outcomes.

• Journal of the Korea Society of Computer and Information
• /
• v.27 no.11
• /
• pp.147-155
• /
• 2022

In this study, we developed a system to dynamically balance a daily stock portfolio and performed trading simulations using gradient boosting and genetic algorithms. We collected various stock market data from stocks listed on the KOSPI and KOSDAQ markets, including investor-specific transaction data. Subsequently, we indexed the data as a preprocessing step, and used feature engineering to modify and generate variables for training. First, we experimentally compared the performance of three popular gradient boosting algorithms in terms of accuracy, precision, recall, and F1-score, including XGBoost, LightGBM, and CatBoost. Based on the results, in a second experiment, we used a LightGBM model trained on the collected data along with genetic algorithms to predict and select stocks with a high daily probability of profit. We also conducted simulations of trading during the period of the testing data to analyze the performance of the proposed approach compared with the KOSPI and KOSDAQ indices in terms of the CAGR (Compound Annual Growth Rate), MDD (Maximum Draw Down), Sharpe ratio, and volatility. The results showed that the proposed strategies outperformed those employed by the Korean stock market in terms of all performance metrics. Moreover, our proposed LightGBM model with a genetic algorithm exhibited competitive performance in predicting stock price movements.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.35 no.2
• /
• pp.87-105
• /
• 2022

Objectives: The purpose of this study is to analysis the Clinical Study Trends on Korean Medicine Treatment for Polycystic Ovary Syndrome. Methods: The key words such as 'polycystic ovary syndrome', 'polycystic ovarian syndrome', 'korean medicine', 'herbal medicine', 'acupuncture' are used for the research through 'OASIS', 'KCI', 'KISS', 'RISS'. Results: Ten clinical studies with 73 patients were selected. All studies were the noncomparative studies, and 8 case reports, 1 case series, 1 retrospective chart review. Symptoms accompanied by PCOS were oligomenorrhea, amenorrhea, irregular menstruation, hirsutism, acne, obesity etc. The most used treatment was herbal medicine in all studies with 72 patients (98.6%). The most frequently used acupuncture and moxibustion point was respectively 合谷 (LI4) and 關元 (CV4). The duration of treatment was between 3 months and 10 months, the average 159 days. Outcome measurements were Recovery of menstrual cycle (97.6%), Hormone test (23.8%), Sonogram (61.9%), Indexes of obesity (23.8%). In terms of menstrual recovery, 35 patients (85.4%) have recovered from menstruation in 8 studies with 41 patients. In hormone tests, all 10 patients have decrease of LH/FSH ratio and LH in 3 studies with 10 patients. Through sonogram, Ovulation menstruation was confirmed in all 6 patients. In all 10 patients of 3 studies evaluating weight before and after treatment, weight was reduced. Conclusions: The effect on Korean Medicine treatment for Polycystic Ovary Syndrome had mostly positive results. However, Further large, well-designed clinical trials are needed to establish the foundation of Korean Medicine treatment for Polycystic Ovary Syndrome.

• The Korean Journal of Franchise Management
• /
• v.13 no.1
• /
• pp.47-57
• /
• 2022

Purpose: Recently, it is common to see cases where an amount similar to the cost of a meal is spent on dessert, or an amount greater than the cost of a meal is spent on dessert. The generation MZ is showing a tendency of 'value consumption' by consuming values and beliefs in consideration of the recent impact on society and the environment. Therefore, this study aims to analyze the effect of dessert cafe quality and eco-friendly behavior on customer trust and loyalty targeting the generation MZ who have visited desert cafés. This study examined the mediating role of customer trust in the relationships between desert café quality, eco-friendly behavior and customer loyalty, and also the moderating effect of and eco-friendly behavior on customer trust and customer loyalty. Research design, data, and methodology: To achieve purposes of this study, 229 data were collected from respondents who visited desert café and analyzed using measurement model (reliability test and correlation analysis), Fornell-Larcker Criterion and Heterotrait-Monotrait Ratio (HTMT) assessment, and structural equation model (PLS-SEM) with SPSS 22.0 and SmartPLS 3.3.7. Results: The research results are as follows. First, desert cafes' quality positively influenced customer trust but did not customer loyalty. Second, desert cafes' eco-friendly behavior positively influenced customer trust and customer loyalty. Fourth, the interaction term of dessert cafe quality and eco-friendly behavior did not influence customer trust and customer loyalty. Conclusions: This study emphasized the necessity of service quality and eco-friendly behavior of dessert cafes by examining the relationship between the quality of dessert cafes and eco-friendly behaviors, customer trust and loyalty. It also found the importance of the role of trust in securing loyal customers. In order to secure and retain loyal customers, the owners of dessert cafes should make effortsto improve the quality of the cafes' products and services so that customers can feel a sense of trust, and actively publicize that they are practicing eco-friendly management. As a result of this study, it is intended to provide practical implications for the management of dessert cafes by understand ing the effects of product and service quality and eco-friendly behaviors of companies to bakery industry workers and start-ups.

• Journal of Korean Neurosurgical Society
• /
• v.65 no.2
• /
• pp.269-275
• /
• 2022

Objective : The coronavirus disease 2019 (COVID-19) pandemic is affecting the characteristics of patients with head injuries. This study aimed to evaluate the effect of the COVID-19 pandemic on patients with head injuries at a regional emergency medical center in South Korea. Methods : From April 2019 to November 2020, 350 patients with head injuries were admitted to our hospital. The study period was divided into the pre-COVID-19 (n=169) and COVID-19 (n=181) eras (10 months each). Patients with severe head injuries requiring surgery (n=74) were categorized into those who underwent surgery (n=41) and those who refused surgery (n=33). Results : Head injuries in pediatric patients (<3 years) were more frequent in the COVID-19 era than in the pre-COVID-19 era (8.8% vs. 3.6%, p=0.048). More patients refused surgery in the COVID-19 era than in the pre-COVID-19 era (57.9% vs. 30.6%, p=0.021). Refusal of surgery was associated with old age (67.7±14.5 vs. 52.4±19.1, p<0.001), marital status (married, 84.8% vs. 61.0%, p=0.037), unemployment (42.4% vs. 68.3%, p=0.034), COVID-19 era (66.7% vs. 39.0%, p=0.021), and lower Glasgow coma scale scores (6.12±3.08 vs. 10.6±3.80, p<0.001). Multivariable logistic regression analysis revealed that refusal of surgery was independently associated with old age (adjusted odds ratio [OR], 1.084; 95% confidence interval [CI], 1.030-1.140; p=0.002), COVID-19 era (adjusted OR, 6.869; 95% CI, 1.624-29.054; p=0.009), and lower Glasgow coma scale scores (adjusted OR, 0.694; 95% CI, 0.568-0.848; p<0.001). Conclusion : We observed an increased prevalence of head injuries in pediatric patients (<3 years) during the COVID-19 pandemic. Additionally, among patients with severe head injuries requiring surgery, more patients refused to undergo surgery during the COVID-19 pandemic.

• Journal of Dental Anesthesia and Pain Medicine
• /
• v.22 no.3
• /
• pp.205-216
• /
• 2022

Background: People with special needs tend to require diverse behavioral management in dentistry. They may feel anxious or uncomfortable or may not respond to any communication with the dentists. Patients with medical, physical, or psychological disorders may not cooperate and therefore require sedation (SED) or general anesthesia (GA) to receive dental treatment. Using the healthcare big data in Korea, this study aimed to analyze the trends of SED and GA in special needs patients undergoing dental treatment. It is believed that these data can be used as reference material for hospitals and for preparation of guidelines and related policy decisions of associations or governments for special needs patients in dentistry. Methods: The study used selected health information data provided by the Korean National Health Insurance Service. Patients with a record of use of one of the eight selected drugs used in dental SED between January 2007 and September 2019, those with International Classification of Diseases-10 codes for attention deficit hyperactivity disorder (ADHD), phobia, brain disease, cerebral palsy, epilepsy, genetic disease, autism, mental disorder, mental retardation, and dementia were selected. The insurance claims data were analyzed for age, sex, sedative use, GA, year, and institution. Results: The number of special needs patients who received dental treatment under SED or GA from January 2007 to September 2019 was 116,623. Number of SED cases was 136,018, performed on 69,265 patients, and the number of GA cases was 56,308, implemented on 47,257 patients. In 2007, 3100 special needs patients received dental treatment under SED while in 2018 the number of cases increased 6 times to 18,528 SED cases. In dentistry, ADHD was the most common disability for SED cases while phobia was the most common cause of disability for GA. The male-to-female ratio with respect to SED cases was higher for males (M : F = 64.36% : 35.64%). Conclusion: The application of the SED method and GA for patients with special needs in dentistry is increasing rapidly; thus, preparing guidelines and reinforcing the education and system are necessary.

• Animal Bioscience
• /
• v.35 no.5
• /
• pp.690-697
• /
• 2022

Objective: This study aimed to evaluate the effect of the ad libitum and restricted feeding regimen on fasting heat production (FHP) and body composition. Methods: Twelve Hubbard broilers breeders were selected with the same body weight and submitted in two feeding regimes: Restricted (T1) with feed intake of 150 g/bird/d and ad libitum (T2). The birds were randomly distributed on the treatments in two runs with three replications per treatment (per run). The birds were adapted to the feed regimens for ten days. After that, they were allocated in the open-circuit chambers and kept for three days for adaptation. On the last day, oxygen consumption (VO₂) and carbon dioxide production (VCO₂) were measured by 30 h under fasting. The respiratory quotient (RQ) was calculated as the VCO₂/VO₂ ratio, and the heat production (HP) was obtained using the Brower equation (1985). The FHP was estimated throughout the plateau of HP 12 hours after the feed deprivation. The body composition was analyzed by dual-energy X-ray absorptiometry scanning at the end of each period. Data were analyzed for one-way analysis of variance using the Minitab software. Results: The daily feed intake was 30 g higher to T2 (p<0.01) than the T1. Also, the birds of the T2 had significatively (p<0.05) more oxygen consumption (+3.1 L/kg^0.75/d) and CO₂ production (+2.2 L/kg^0.75/d). That resulted in a higher FHP 359±14 kJ/kg^0.75/d for T2 than T1 296±17.23 kJ/kg^0.75/d. In contrast, the RQ was not different between treatments, with an average of 0.77 for the fasting condition. In addition, protein and fat composition were not affected by the treatment, while a tendency (p<0.1) was shown to higher bone mineral content on the T1. Conclusion: The birds under ad libitum feeding had a higher maintenance energy requirement but their body composition was not affected compared to restricted feeding.

• Computers and Concrete
• /
• v.31 no.3
• /
• pp.267-276
• /
• 2023

The main purpose of the current research is to develop an efficient two variables trigonometric shear deformation beam theory to investigate the buckling behavior of symmetric and non-symmetric functionally graded carbon nanotubes reinforced composite (FG-CNTRC) beam resting on an elastic foundation with various boundary conditions. The proposed theory obviates the use to shear correction factors as it satisfies the parabolic variation of through-thickness shear stress distribution. The composite beam is made of a polymeric matrix reinforced by aligned and distributed single-walled carbon nanotubes (SWCNTs) with different patterns of reinforcement. The material properties of the FG-CNTRC beam are estimated by using the rule of mixture. The governing equilibrium equations are solved by using new analytical solutions based on the Galerkin method. The robustness and accuracy of the proposed analytical model are demonstrated by comparing its results with those available by other researchers in the existing literature. Moreover, a comprehensive parametric study is presented and discussed in detail to show the effects of CNTs volume fraction, distribution patterns of CNTs, boundary conditions, length-to-thickness ratio, and spring constant factors on the buckling response of FG-CNTRC beam. Some new referential results are reported for the first time, which will serve as a benchmark for future research.