• The Journal of Korean Academic Society of Nursing Education
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• v.18 no.1
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• pp.95-101
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• 2012

Purpose: This study aimed to analyze the impact of advanced maternal and paternal age on perinatal outcome in Korea. Methods: We conducted a retrospective study involving 1,622 Korean women who delivered at M Woman Hospital from January to December 2010 and their spouses were included. We obtained obstetrics database which included demographic characteristics, medical and obstetrics history, course of the current pregnancy and advised perinatal outcome. Multivariable logistic regression was used to adjust for potential confounding variables. Results: Women giving birth age 35 or older were statistically significant in paternal age, gravidity, spontaneous abortion experience, method of conception, method of delivery, and multiple gestation compared to women aged <34 years. After adjusting for the confounding effects of maternal characteristics, women aged 35 or older were at increased risk for cesarean section delivery (adjusted OR 1.6, 95% CI 1.22-2.13) and preterm birth (adjusted OR 2.2, 95% CI 1.03-4.63). Conclusion: In this population of Korean women, advance maternal and paternal age is independently associated with specific adverse perinatal outcome, especially preterm birth and cesarean section delivery.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.50
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• pp.1-9
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• 1999

The purpose of this study is to establish a basis for assessing construct validity of measures used in organizational research. The classic Campbell and Fiske's(1959) criteria are found to be lacking in their assumptions, diagnostic information, and power. The inherent confounding of measurement error with systematic trait and method effects is a severe limitation for a proper interpretation of convergent and discriminant validity. The confirmatory factor analysis(CFA) approach overcomes most of the limitations found in Campbell and Fiske's(1959) method. However, the CFA approach confounds random error with unique variance specific to a measure. The second-order confirmatory factor analysis(SOCFA) was shown to harbor rather restrictive assumptions and is unlikely to be met in practice. The first-order, multiple-informant, multiple-item(FOMIMI) model is a viable option, but it may also be of limited use because of the large number measures.

• Child Health Nursing Research
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• v.24 no.2
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• pp.148-156
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• 2018

Purpose: The aim of this study was to evaluate the influence of the mothers' native country on influenza vaccinations in adolescents in multicultural families. Methods: Data were gathered from the 13th (2017) Youth Risk Behavior Web-Based Survey. Logistic regression analyses were conducted using a complex sample data analysis method. The participants in this study had a father who was born in Korea and a mother born outside of Korea. The sample included 481 adolescents. Results: The analysis of non-adjusted confounding variables showed that influenza vaccination was higher in multicultural adolescents whose mother's native country had an annual minimum temperature less than $21^{\circ}C$ (odds ratio [OR]: 1.81, 95% confidence interval [CI]: 1.20~2.74). Furthermore, when the analysis was adjusted for confounding variables, an annual minimum temperature less than $21^{\circ}C$ in the mother's native country had a statistically significant association with influenza vaccination (OR: 2.12, 95% CI: 1.36~3.29). Conclusion: Multicultural adolescents belong to a socioeconomically vulnerable class, and their health promotion behaviors are influenced by their mothers' culture. Thus, healthcare providers and school nurses should provide adolescents with appropriate information related to influenza vaccination depending on their mothers' culture and their family's cultural background.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.2
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• pp.132-142
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• 2023

Objective: Dual antiplatelet therapy (DAPT) is usually temporarily used after stent-assisted coil embolization (SACE), and is commonly converted to mono antiplatelet therapy (MAPT) for indefinitely. In this study, we aimed to find the possibility of discontinuing MAPT, and to determine the proper period of DAPT use. Methods: We used the Standard Sample Cohort DB dataset from the National Health Insurance Sharing Service. Among approximately 1 million people in the dataset, SACE was performed in 214 patients whose data this study analyzed. The relationship between discontinuation of antiplatelet therapy and intracranial hemorrhage or cerebral infarction was analyzed using multiple logistic regression, considering all confounding variables. The survival rate according to the continuation of antiplatelet therapy was obtained using Kaplan-Meier analysis, and the difference in survival rate according to the continuation of antiplatelet therapy was verified using the log-rank test. The hazard ratio according to continuation of antiplatelet therapy was obtained using the Cox proportional hazards model. The analysis was conducted by applying the same statistical method to the duration of DAPT use. Results: Among 214 patients who underwent SACE, 50, 159 and five patients continued, discontinued and did not use antiplatelet therapy (except at the time of procedure), respectively. In multiple logistic regression analysis, discontinuation of antiplatelet agents (including aspirin) and the period of DAPT use did not affect the occurrence of intracranial hemorrhage or cerebral infarction, considering various confounding factors. In the survival analysis according to the continuation of antiplatelet agents, patients who continued to use antiplatelet agents had a higher survival rate than those in other groups (p=0.00). The survival rate was higher in the rest of the group than in the group that received DAPT for three months (p=0.00). Conclusions: Continuation of antiplatelet agents or the period of DAPT use did not affect the occurrence of intracranial hemorrhage or cerebral infarction. Considering the survival rate, it would be better to maintain at least three months of antiplatelet therapy and it might be recommended to continue DAPT use for 12 months.

• The Journal of the Korean dental association
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• v.58 no.3
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• pp.152-168
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• 2020

The propensity score matching method is a statistical method used to reduce selection bias in observational studies and to show effects similar to random allocation. There are many observational studies in dentistry research, and differences in baseline covariates between the control and case groups affect the outcome. In order to reduce the bias due to confounding variables, the propensity scores are used by equating groups based on the baseline covariates. This method is effective, especially when there are many covariates or the sample size is small. In this paper, the propensity score matching method was explained in a simple way with a dental example by using R software. This simulated data were obtained from one of retrospective study. The control group and the case group were matched according to the propensity score and compared before and after treatment. The propensity score matching method could be an alternative to compensate for the disadvantage of the observation study by reducing the bias based on the covariates with the propensity score.

• Asia pacific journal of information systems
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• v.10 no.3
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• pp.181-197
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• 2000

The purpose of this study is to confirm whether the fit between the task and the information characteristics makes any effects on the user satisfaction. The task is defined as two sub-constructs representing the degree of exception and analyzability. The information characteristics is divided into the degree of aggregation, scope and timeliness of information. User satisfaction was used as a surrogate measure of the performance of information systems. The computer self-efficacy was used to control any confounding effects. Field research method using questionnaires was employed to empirically investigate the relationship among the variables. Findings of the study are summarized as follows: the fit between the task and the aggregation of information and between the task and the scope of information turned out to have significant effects on information system performance. The implication of such results is that under highly exceptional or less analyzable task environment, less-aggregated or broad information is more appropriate.

• Journal of Korean Society for Quality Management
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• v.38 no.1
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• pp.42-51
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• 2010

For the fractional factorial designs, the resolution-IV designs can be used when we want to estimate the main effects and to investigate the structure of the non-negligible two-factor interaction effects, when the three-factor and higher order interaction effects are all negligible. However we need to add the additional treatment combinations in order to identify the influential interactions for the resolution-IV fractional factorial designs. In this paper we investigate the statistical structure for 3-level resolution-IV designs constructed by fold-over scheme and introduce a method for analyzing the influential two-factor interactions.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.6
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• pp.546-552
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• 2016

We present a quantitative evaluation of an algorithm for model-based face recognition. The algorithm actively learns how individual faces vary through video sequences, providing on-line suppression of confounding factors such as expression, lighting and pose. By actively decoupling sources of image variation, the algorithm provides a framework in which identity evidence can be integrated over a sequence. We demonstrate that face recognition can be considerably improved by the analysis of video sequences. The method presented is widely applicable in many multi-class interpretation problems.

• Annals of Clinical Neurophysiology
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• v.10 no.1
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• pp.1-12
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• 2008

Intraoperative neuromonitoring (INM) is well known to be useful method to reduce intraoperative complications during the surgery of nervous system lesions. Evoked potentials are most commonly used among the electrophysiological tests. Brainstem auditory evoked potentials are for detecting the problems along the auditory pathways including the eighth cranial nerve and brainstem. Somatosensory evoked potentials are applied for preventing the spinal cord lesions. The INM is affected by many factors. In order to perform an optimal INM, the confounding factors including technical, anesthetical, and individual factors should be kept well under control. INM has frequent electrophysiologic changes during the surgery and it might be helpful to keep one's eyes on which monitoring modalities are reluctant to change during each operation. The skillful monitoring and timely interpretation of electrophysiologic changes can drive the patient to be undergone surgery, even in high surgical risk group.

• Proceedings of the Korean Society for Quality Management Conference
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• 2010.04a
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• pp.129-138
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• 2010

For the fractional factorial designs, the resolution-IV designs can be used when we want to estimate the main effects and to investigate the structure of the non-negligible two-factor interaction effects, when the three-factor and higher order interaction effects are all negligible. However we need to add the additional treatment combination in order to identify the influential interactions for the resolution-IV fracrtional factorial designs. In this paper we investigate the statistical structure for 3-level resolution-IV designs constructed by fold-over scheme and introduce a method for analyzing the influential two-factor interactions.