• The Korean Journal of Nuclear Medicine
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• v.35 no.4
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• pp.251-257
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• 2001

Purpose: We investigated the possibility of early postoperative Tc-99m DTPA scintigraphy in predicting long-term renal transplant survival. Materials and Methods: 64 living donor (LD) grafts were divided into two groups according to the graft function on early post-operative renal scintigraphy. Survival analysis was performed using Kaplan-Meier method and Cox proportional hazard model. Chi-square test was performed to evaluate the difference in the frequency of acute rejection. Results: Cumulative renal transplant survival was decreased in 11 patients with abnormal renal scintigraphy, but it was not statistically significant. Decreased graft function on early post-operative renal scintigraphy was not a predictor of long-term graft survival. The frequency of acute rejection was higher in abnormal scintigraphy group, and the difference was statistically significant. Conclusion: Decreased graft function on early post-operative renal scintigraphy has no direct effect on long-term renal transplant survival in LD transplantation. But it may have an indirect elect through increasing the frequency of acute rejection.

• Science of Emotion and Sensibility
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• v.12 no.1
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• pp.109-120
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• 2009

This study was carried out in order to investigate color sensation and sensibility for yellowish natural dye fabrics and reddish ones and to establish prediction models for color sensibility factors of them by color sensation and the related physical measurements focusing on 40s middle-aged people. Eight fabric stimuli which were dyed with a variety of yellowish or reddish natural dyes was subjectively evaluated in terms of color sensation and sensibility by 40s aged participants. As results, three color sensibility factors including 'Active', 'Characteristic', and 'Relax' were extracted and they were examined in respect of their relationships with color sensation and physical color properties. Color sensibility factor 'Active', the dominant factor for the naturally dyed fabrics was explained by $L^*$ and sensation 'Deep' in its predictive model and a yellowish fabric dyed with 300% solution of armur cork unmordanted was perceived the strongest in the factor. Factor 'Characteristic' was predicted by both $a^*$ and sensation 'Light' and reddish natural dye fabrics tended to be felt more strongly for it. Color sensation 'Strong' was the only predictor for factor 'Relax' in that naturally dyed fabrics with lower values for the sensation seemed to show higher 'Relax' factor and a reddish fabric dyed with safflower 125% was the highest for the color sensibility factor. These results could be utilized to design color-sensible natural dye fabrics for middle-aged people.

• Journal of Distribution Science
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• v.15 no.6
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• pp.65-76
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• 2017

Purpose - The quality of customer service has been importantly considered as a way of retaining current customers. Recent development of service industry which based on Information & Communication Technology allows firms to utilize different employees for their businesses. Although it is regarded as important to consider emotional labor of employees working for customers in ICT service industry, little was known the role of emotional dissonance. Thus, current paper focused on emotional labor and tried to identify the factors which influence on employees' intrinsic motivation for married women working in call centers. This study highlighted the influence of the emotional dissonance on the employees' intrinsic motivation, and the moderating influences of work-family conflict on the relationship between emotional dissonance and intrinsic motivation. Research design, data, and methodology - The research samples were gathered from seven call centers of Korean financial institutions located in South Korea. The model of emotional dissonance was developed, which emphasizes the influence of emotional dissonance as a predictor on intrinsic motivation, and then the other model was also introduced to explain how employees' intrinsic motivation were aggravated by work-family conflict. To examine these research models, samples were collected from 468 married women working in call centers of Korean financial institutions located in Seoul. A total of 468 samples were used in the analysis after deleting data of missing value. SPSS 22.0 were utilized for data analysis. Results - The results of current study showed that emotional dissonance is negatively related to intrinsic motivation, and there are significant differences in work-family conflict. Those results generally support the proposed hypotheses. Conclusions - These results suggest that the relationship of intrinsic motivation of married women working in call center for customers' service were influenced by emotional dissonance, which outcomes were interacted not by face-to-face contact with their customers, but by emotional contacts. Managerially, these findings suggest the one who emphasize the quality of customer's service of call center need to introduce the programs for minimizing both of emotional dissonance and work-family conflict. These findings also suggest that the service quality via intrinsic motivation of married women working in call center is hard to be accomplished without considering the factors of emotional dissonance and work-family conflict.

• Gut and Liver
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• v.12 no.6
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• pp.714-721
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• 2018

Background/Aims: Recently reported prognostic models for primary biliary cholangitis (PBC) have been shown to be effective in Western populations but have not been well-validated in Asian patients. This study aimed to compare the performance of prognostic models in Korean patients and to investigate whether inflammation-based scores can further help in prognosis prediction. Methods: This study included 271 consecutive patients diagnosed with PBC in Korea. The following prognostic models were evaluated: the Barcelona model, the Paris-I/II model, the Rotterdam criteria, the GLOBE score and the UK-PBC score. The neutrophil-to-lymphocyte ratio (NLR) was analyzed with reference to its association with prognosis. Results: For predicting liver transplant or death at the 5-year and 10-year follow-up examinations, the UK-PBC score (areas under the receiver operating characteristic curve [AUCs], 0.88 and 0.82) and GLOBE score (AUCs, 0.85 and 0.83) were significantly more accurate in predicting prognosis than the other scoring systems (all p<0.05). There was no significant difference between the performance of the UK-PBC and GLOBE scores. In addition to the prognostic models, a high NLR (>2.46) at baseline was an independent predictor of reduced transplant-free survival in the multivariate analysis (adjusted hazard ratio, 3.74; p<0.01). When the NLR was applied to the prognostic models, it significantly differentiated the prognosis of patients. Conclusions: The UK-PBC and GLOBE scores showed good prognostic performance in Korean patients with PBC. In addition, a high NLR was associated with a poorer prognosis. Including the NLR in prognostic models may further help to stratify patients with PBC.

• Journal of the Korean Society of Radiology
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• v.79 no.5
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• pp.264-270
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• 2018

Purpose: To evaluate the effect of portal hypertension on the tumor recurrence in patients with hepatocellular carcinoma (HCC) and without hepatic decompression following radiofrequency ablation (RFA). Materials and Methods: Treatment-naïve HCC patients within the Milan criteria and with Child-Pugh class A were included in this study, who had performed RFA in our hospital between January 2010 and March 2017. Univariate and multivariate analyses using the Cox proportional hazard model were performed to find the predictors of local or distant tumor recurrence. Results: Overall, 178 patients were included in this study. Median follow-up period was 40.2 months. The difference in the local tumor progression rates depending on the absence or presence of portal hypertension was not statistically significant (p = 0.195). The 1-, 3-, and 5-year distant intrahepatic tumor spread rates were 6.6%, 29.5%, and 537% in patients without portal hypertension, and 23.4%, 51.9%, and 63.6% in patients with portal hypertension, respectively. The difference was statistically significant (p = 0.011). Univariate and multivariate analysis showed that portal hypertension was an independent predictor for distant intrahepatic tumor spread (p = 0.008). Conclusion: For HCC patients with Child-Pugh class A, portal hypertension adversely affected distant intrahepatic tumor progression.

• Journal of Gastric Cancer
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• v.21 no.4
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• pp.368-378
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• 2021

Purpose: When patients with early gastric cancer (EGC) undergo non-curative endoscopic submucosal dissection requiring gastrectomy (NC-ESD-RG), additional medical resources and expenses are required for surgery. To reduce this burden, predictive model for NC-ESD-RG is required. Materials and Methods: Data from 2,997 patients undergoing ESD for 3,127 forceps biopsy-proven differentiated-type EGCs (2,345 and 782 in training and validation sets, respectively) were reviewed. Using the training set, the logistic stepwise regression analysis determined the independent predictors of NC-ESD-RG (NC-ESD other than cases with lateral resection margin involvement or piecemeal resection as the only non-curative factor). Using these predictors, a risk-scoring system for predicting NC-ESD-RG was developed. Performance of the predictive model was examined internally with the validation set. Results: Rate of NC-ESD-RG was 17.3%. Independent pre-ESD predictors for NC-ESD-RG included moderately differentiated or papillary EGC, large tumor size, proximal tumor location, lesion at greater curvature, elevated or depressed morphology, and presence of ulcers. A risk-score was assigned to each predictor of NC-ESD-RG. The area under the receiver operating characteristic curve for predicting NC-ESD-RG was 0.672 in both training and validation sets. A risk-score of 5 points was the optimal cut-off value for predicting NC-ESD-RG, and the overall accuracy was 72.7%. As the total risk score increased, the predicted risk for NC-ESD-RG increased from 3.8% to 72.6%. Conclusions: We developed and validated a risk-scoring system for predicting NC-ESD-RG based on pre-ESD variables. Our risk-scoring system can facilitate informed consent and decision-making for preoperative treatment selection between ESD and surgery in patients with EGC.

• Geomechanics and Engineering
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• v.35 no.2
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• pp.121-133
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• 2023

The demand for cement and limestone crushed materials has increased many folds due to the tremendous increase in construction activities in Pakistan during the past few decades. The number of cement production industries has increased correspondingly, and so the rock-blasting operations at the limestone quarry sites. However, the safety procedures warranted at these sites for the blast-induced ground vibrations (BIGV) have not been adequately developed and/or implemented. Proper prediction and monitoring of BIGV are necessary to ensure the safety of structures in the vicinity of these quarry sites. In this paper, an attempt has been made to predict BIGV using artificial neural network (ANN) at three selected limestone quarries of Pakistan. The ANN has been developed in Python using Keras with sequential model and dense layers. The hyper parameters and neurons in each of the activation layers has been optimized using randomized and grid search method. The input parameters for the model include distance, a maximum charge per delay (MCPD), depth of hole, burden, spacing, and number of blast holes, whereas, peak particle velocity (PPV) is taken as the only output parameter. A total of 110 blast vibrations datasets were recorded from three different limestone quarries. The dataset has been divided into 85% for neural network training, and 15% for testing of the network. A five-layer ANN is trained with Rectified Linear Unit (ReLU) activation function, Adam optimization algorithm with a learning rate of 0.001, and batch size of 32 with the topology of 6-32-32-256-1. The blast datasets were utilized to compare the performance of ANN, multivariate regression analysis (MVRA), and empirical predictors. The performance was evaluated using the coefficient of determination (R²), mean absolute error (MAE), mean squared error (MSE), mean absolute percentage error (MAPE), and root mean squared error (RMSE)for predicted and measured PPV. To determine the relative influence of each parameter on the PPV, sensitivity analyses were performed for all input parameters. The analyses reveal that ANN performs superior than MVRA and other empirical predictors, andthat83% PPV is affected by distance and MCPD while hole depth, number of blast holes, burden and spacing contribute for the remaining 17%. This research provides valuable insights into improving safety measures and ensuring the structural integrity of buildings near limestone quarry sites.

• Korean Journal of Radiology
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• v.23 no.6
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• pp.664-673
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• 2022

Objective: To evaluate the performance of baseline clinical characteristics and pretherapeutic histogram parameters derived from T2 mapping of the extraocular muscles (EOMs) in the prediction of treatment response to intravenous glucocorticoid (IVGC) therapy for active and moderate-to-severe thyroid-associated ophthalmopathy (TAO) and to investigate the effect of fat-suppression (FS) in T2 mapping in this prediction. Materials and Methods: A total of 79 patients clinically diagnosed with active, moderate-to-severe TAO (47 female, 32 male; mean age ± standard deviation, 46.1 ± 10 years), including 43 patients with a total of 86 orbits in the responsive group and 36 patients with a total of 72 orbits in the unresponsive group, were enrolled. Baseline clinical characteristics and pretherapeutic histogram parameters derived from T2 mapping with FS (i.e., FS T2 mapping) or without FS (i.e., conventional T2 mapping) of EOMs were compared between the two groups. Independent predictors of treatment response to IVGC were identified using multivariable analysis. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the predictive performance of the prediction models. Differences between the models were examined using the DeLong test. Results: Compared to the unresponsive group, the responsive group had a shorter disease duration, lower kurtosis (FS-kurtosis), lower standard deviation, larger 75th, 90th, and 95th (FS-95th) T2 relaxation times in FS mapping and lower kurtosis in conventional T2 mapping. Multivariable analysis revealed that disease duration, FS-95th percentile, and FS-kurtosis were independent predictors of treatment response. The combined model, integrating all identified predictors, had an optimized area under the ROC curve of 0.797, 88.4% sensitivity, and 62.5% specificity, which were significantly superior to those of the imaging model (p = 0.013). Conclusion: An integrated combination of disease duration, FS-95th percentile, and FS-kurtosis was a potential predictor of treatment response to IVGC in patients with active and moderate-to-severe TAO. FS T2 mapping was superior to conventional T2 mapping in terms of prediction.

• Journal of Preventive Medicine and Public Health
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• v.30 no.3 s.58
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• pp.630-642
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• 1997

The purpose of this study was to examine the mortality risk associated with cognitive impairment among the rural elderly. The subjective of study was 558 of 'A Study on the Depression and Cognitive Impairment in the Rural Elderly' of Jung Ae Rhee and Hyang Gyun Jung's study(1993). Cognitive impairment and other social and health factors were assessed in 558 elderly rural community residents. For this study, a Korean version of the Mini-Mental State Examination(MMSEK) was used as a global indicator of cognitive functioning. And mortality risk factors for each cognitive impairment subgroup were identified by univariate and multivariate Cox regression analysis. At baseline 22.6% of the sample were mildly impaired and 14.2% were severely impaired. As the age increased, the cognitive function was more impaired. Sexual difference was existed in the cognitive function level. Also the variables such as smoking habits, physical disorders had the significant relationship with cognitive function impairment. Across a 3-year observation period the mortality rate was 8.5% for the cognitively unimpaired, 11.1% for the mildly impaired, and 16.5% for the severly impaired respendents. And the survival probability was .92 for the cognitively unimpaired, .90 for the mildly impaired, and .86 for the severly impaired respondents. Compared to survival curve for the cognitively unimpaired group, each survival curve for the mildly and the severely impaired group was not significantly different. When adjustments models were not made for the effects of other health and social covariates, each hazard ratio of death of mildly and severely impaired persons was not significantly different as compared with the cognitively unimpaired. But, as MMSEK score increased, significantly hazard ratio of death decreased. Employing Cox univariate proportional hazards model, statistically other significant variables were age, monthly income, smoking habits, physical disorders. Also when adjustments were made for the effects of other health and social covariates, there was no difference in hazard ratio of death between those with severe or mild impairment and unimpaired persons. And as MMSEK score increased, significantly hazard ratio of death did not decrease. Employing Cox multivariate proportional hazards model, statistically other significant variables were age, monthly income, physical disorders. Employing Cox multivariate proportional hazards model by sex, at men and women statistically significant variable was only age. For both men and women, also cognitive impairment was not a significant risk factor. Other investigators have found that cognitive impairment is a significant predictor of mortality. But we didn't find that it is a significant predictor of mortality. Even though the conclusions of our study were not related to cognitive impairment and mortality, early detection of impaired cognition and attention to associated health problems could improve the quality of life of these older adults and perhaps extend their survival.

• Tuberculosis and Respiratory Diseases
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• v.66 no.4
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• pp.280-287
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• 2009

Background: The epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), became an attractive therapeutic option for advanced non-small-cell lung cancer (NSCLC). Several studies suggested that there might be some different efficacy or response predictors between gefitinib and erlotinib. We compared the efficacy and toxicity of gefitinib and erlotinib in Korean patients with advanced NSCLC and evaluated specific predictors of response for both gefitinib and erlotinib. Methods: We collected the clinical information on patients with advanced NSCLC, who were treated with gefitinib or erlotinib at the Ewha Womans University Hospital, between July 2003 and February 2009. Median survival times were calculated using the Kaplan-Meier method. Results: Eighty-six patients (52 gefitinib vs. 34 erlotinib) were enrolled. Patient median age was 64 years; 53 (62%) subjects were male. Out of the 86 patients treated, 83 received response evaluation. Of the 83 patients, 35 achieved a response and 12 experienced stable disease while 36 experienced progressive disease, resulting in a response rate of 42% and a disease control rate of 57%. After a median follow-up of 502 days, the median progression-free and overall survival time was 129 and 259 days, respectively. Comparing patients by treatment (gefitinib vs erlotinib), there were no significant differences in the overall response rate (44% vs. 39%, p=0.678), median survival time (301 days vs. 202 days, p=0.151), or time to progression (136 days vs. 92 days, p=0.672). Both EGFR-TKIs showed similar toxicity. In a multivariate analysis using Cox regression model, adenocarcinoma was an independent predictor of survival (p=0.006; hazard ratio [HR], 0.487; 95% confidence interval [CI], 0.292-0.811). Analyses of subgroups did not show any difference in response predictors between gefitinib and erlotinib. Conclusion: Comparing gefitinib to erlotinib, there were no differences in the response rate, overall survival, progression-free survival, or toxicity. No specific predictor of response to each EGFR-TKI was identified.