• Korean Circulation Journal
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• v.54 no.3
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• pp.113-123
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• 2024

Background and Objectives: Previous studies have reported an association between impaired renal function and poor outcomes after radiofrequency catheter ablation in patients with atrial fibrillation (AF). However, outcomes of cryoballoon ablation (CBA) in patients with renal insufficiency are not fully elucidated. This study aimed to compare outcomes of CBA in AF patients with chronic kidney disease (CKD) versus those without CKD and to assess changes in renal function over 12 months following CBA. Methods: A total of 839 patients (65.1% with non-paroxysmal AF [PAF]) who underwent de novo CBA were prospectively enrolled. We divided patients into two groups based on creatinine clearance rate (CCr) and performed intracardiac echocardiography (ICE)-guided contrast agent-free CBA. Results: In comparison with patients without CKD (CCr >50, n=722), those with CKD (CCr ≤50, n=117) were older and predominantly female, had a lower body mass index, and showed a higher prevalence of heart failure and hypertension. Mean CHA₂DS₂-VAS score was significantly higher in CKD group than in non-CKD group. Procedure-related complications were not significantly different between two groups. During a mean follow-up period of 25.4±11.9 months, clinical recurrence occurred in 182 patients (21.7%) and not significantly different between two groups. In multivariate analysis, non-PAF and left atrial size were independent predictors of AF recurrence. CCr levels significantly improved over 12 months after CBA in CKD group. Conclusions: ICE-guided contrast-agent-free CBA showed comparable long-term clinical outcomes without increasing procedure-related complications and improvement of renal function over 12 months following CBA in AF patients with CKD.

• Journal of the Korean Institute of Gas
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• v.5 no.1
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• pp.21-28
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• 2001

Expert system for automating HAZOP analysis of batch processes In contrast with continuous processes must consider the discrete variables such as time and sequence. So in this study, we have developed the expert system for automating HAZOP analysis of batch processes to analyse time and sequence on the basis of the relation between discrete variables and continuous ones. Because these variables can not be explained by the method used in the HAZOP analysis of continuous processes. The proposed expert system have been discussed on a Latex batch process to evaluate its effectiveness.

• Journal of the Korean Institute of Gas
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• v.3 no.2 s.7
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• pp.34-42
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• 1999

The discrete variables such as time and sequence must be considered for automating HAZOP analysis of batch processes in contrast with continuous processes. Because these variables can not be explained by the method used in the HAZOP analysis of continuous processes, we have developed the methodology for HAZOP analysis of batch processes on the basis of the relation between discrete variables and continuous ones. In this study, we have discussed the performance of the methodology on a Latex batch process to evaluate its effectiveness.

• Journal of Korea Technology Innovation Society
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• v.1 no.3
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• pp.299-312
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• 1998

This paper explores the possibility of improving R&D management system through researchers' satisfaction analysis. The relationship between job satisfaction and performance has traditionally been one of the engaging topics in organization psychology. However, the research results of the past showed the relatively low level of correlation between satisfaction and performance at the individual level. In contrast to these past research results, recent research results on this relationship at the organizational level revealed the higher correlation between these two factors, The present study extends this 'satisfaction and performance' hypothesis to the development and improvement of R&D management system. That is, we used the results of researchers' satisfaction analysis to devise appropriate criteria for the design and implementation of more effective R&D management systems. This paper seeks to show that we can make fruitful use of researchers' satisfaction analysis in order to choose a more effective one among alternative R&D management systems.

• Steel and Composite Structures
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• v.1 no.1
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• pp.111-130
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• 2001

This paper presents an effective, reliable and accurate method for prediction of structural behaviour of steel frames at elevated temperature. The refined plastic hinge method, which has been used successfully in the second-order elasto-plastic analysis of steel frames at ambient conditions, is adopted here to allow for time-independent fire effects. In contrast to the existing rigorous finite element programs, the present method uses the advanced analysis technique that provides a simple and reliable means for practical study of the behaviour of steel frames at elevated temperature by a limiting stress model. The present method is validated against other test and numerical results.

• Journal of KIEE
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• v.11 no.1
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• pp.1-7
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• 2001

Various methods for blind source separation (BSS) are based on independent component analysis (ICA) which can be viewed as a nonlinear extension of principal component analysis (PCA). Most existing ICA methods require certain nonlinear functions (which leads to higher-order statistics) depending on the probability distributions of sources, whereas PCA is a linear learning method based on second-order statistics. In this paper we show that the PCA can be applied to the task of BBS, provided that source are spatially uncorrelated but temporally correlated. Since the resulting method is based on only second-order statistics, it avoids the nonlinear function and is able to separate mixtures of several colored Gaussian sources, in contrast to the conventional ICA methods.

• International Journal of Computer Science & Network Security
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• v.21 no.9
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• pp.155-162
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• 2021

The expansion of the world wide web has led to a huge amount of user generated content over different forums and social media platforms, these rich data resources offer the opportunity to reflect, and track changing public sentiments and help to develop proactive reactions strategies for decision and policy makers. Analysis of public emotions and opinions towards events and sentimental trends can help to address unforeseen areas of public concerns. The need of developing systems to analyze these sentiments and the topics behind them has emerged tremendously. While most existing works reported in the literature have been carried out in English, this paper, in contrast, aims to review recent research works in Arabic language in the field of thematic sentiment analysis and which techniques they have utilized to accomplish this task. The findings show that the prevailing techniques in Arabic topic-based sentiment analysis are based on traditional approaches and machine learning methods. In addition, it has been found that considerably limited recent studies have utilized deep learning approaches to build high performance models.

• Phonetics and Speech Sciences
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• v.6 no.3
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• pp.41-48
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• 2014

This study investigated the differences between emotional parameters BDI, VHI, STAI-X-I and STAI-X-II according to the menstrual cycles of the female and the relation between changes of the depression index and voice characteristics (jitter, shimmer, CPP, HNR, $pF0{\cdot}F1{\cdot}F2{\cdot}F3$, sF0, sF4, sB1, $H1_{c/u}$, $A1_u$, $A3_c$, $H1A3_{c/u}$, $H1A1_u$). Twenty three females ($30{\pm}4.4$ years old) living in Seoul and Gyeonggi Province were participated in this study to answer the questionnaires and record their voice. The participants prolonged /a/ vowel for 5 seconds in a natural condition for their voice recording. Voice data were analyzed using the Matlab and Praat program. A t-test and a correlation analysis were conducted by using SPSS for the statistical analysis. The results are as follows. First, the BDI is significantly higher in group I (lurear phase contrast the menstrual period) and group II (follicular phase against the menstrual period) than group III (luteal phase for follicular phase) (p<.05). Second, shimmer, CPP, pF0 showed a statistically high correlation regarding the BDI in group I (lurear phase contrast the menstrual period). Voice parameters may be useful as supplement in evaluating the emotional change in the phase of menstrual cycle.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.5
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• pp.861-868
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• 2017

Near band infrared imaging technique has adopted for imaging EL2 and shallow level distributions in undoped semi-insulating LEC GaAs. This technique, which relies on the mapping of near bandgap infrared transmission, is both rapid and non-destructive. Until now no quantitative analysis has been reported for near band edge region which gives the reverse contrast on EL2 absorption images. This paper presents the spectral, spatial and temperature dependence of photoquenching forward and inverse mechanism in the band edge domain for cells and walls and for direct and inverted contrast conditions during transitory regimes. The difference in the threshold for the EL2w and EL2b defects could be attributed to the contribution of a different electrical assistance due to a different species of impurities. Quantitative analysis results show an increased density of EL2w and a small reduction of EL2b in the region of the walls where there is a high density of dislocations.

• Health Policy and Management
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• v.6 no.1
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• pp.110-143
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• 1996

The purpose of this study is to assess the extent of inequality in health outcomes and the distribution of health services according to health need under National Health Insurance System in Korea. For the empirical analysis, data were collected through an interview survey during one month of October, 1994. Interview were conducted with a total of 10, 875 of the employees and the self-employed selected through cluster, systematic sampling. The major findings of this research are as follows: 1. The analysis of the differentials in morbidity rates by socio-economic group showed that health inequality in the pro-higher groups existed in all self-reported morbidity indicators. 2. The findings of the conventional use measures showed that the lower socio-economic groups had more ambulatory and inpatient services than the higher groups. In contrast to the level of the medical care utilization, however, the higher socio-economic groups were more likely to use the high-quality source of care in terms of their treatment place compared to the lower groups. 3. By using the need-based use measures, the results were different from each use-disability ration indicator. Using the use-disability ration measured by physician visits per 100 restricted-activity days in the population, it was found that there was no evidence favoring the higher socio-economic groups. In contrast, the use-disability ration based on physician visits per a chronic patient in one year displayed that there was remarkable relative difference by income group as well as the evidence of the pro-higher income groups. 4. The results of logistic regression analysis and two-stage estimation method indicated that although the utilization is significantly affected by type and duration of insurance coverage, the use or nonuse of service and the volume of physician care consumed is determined by health need and demographic characteristics rater than economic status. In sum, these findings suggest that physician service is equitably distributed according to health need under national health insurance system in Korea. As there were some evidences of inequality including the differential in physician visits of chronic patients by income group, however, the government should strengthen the activities to guarantee the equity of health services utilization.