• The Pure and Applied Mathematics
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• v.2 no.1
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• pp.53-59
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• 1995

Consider a solution y(t) of the nonlinear equation (E) y" ＋ f(t, y) = 0. A solution y(t) is said to be oscillatory if for every T ＞ 0 there exists $t_{0}$ ＞ T such that y($t_{0}$) = 0. Let F be the class of solutions of (E) which are indefinitely continuable to the right, i.e. y $\in$ F implies y(t) exists as a solution to (E) on some interval of the form [t$\sub$y/, $\infty$). Equation (E) is said to be oscillatory if each solution from F is oscillatory.(omitted)

• Proceedings of the Korea Society for Simulation Conference
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• 1998.03a
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• pp.50-55
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• 1998

In this paper we use discrete simulation method to get the criteria of system evaluation required in the case of designing the complicated probabilistic event system having discrete probabilistic variables and to search the effective and reliable alternatives to satisfy the objective value of the given system through on-line, single run within the short time period. If we find the alternative we construct the algorithm which change values of decision variables and determining alternative by using the stopping algorithm which end the simulation in the steady state of system. In order to prevent the loss of data when we analyze the acquired design alternative in the steady state we provide the background of the estimation of the autoregressive model and mean and confidence interval for evaluating correctly the objective function obtained by the small amount of output data through the short time period simulation.

• International Journal of Control, Automation, and Systems
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• v.4 no.5
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• pp.529-538
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• 2006

Separating a reentry vehicle into warhead and body is a conventional and efficient means of producing a huge decoy and increasing the kinetic energy of the warhead. This procedure causes the radar to track the body, whose radar cross section is larger, and ignore the warhead, which is the most important part of the reentry vehicle. However, the procedure is difficult to perform using standard tracking criteria. This study presents a novel tracking algorithm by integrating input estimation and modified probabilistic data association filter to solve this difficulty in a clear environment. The proposed algorithm with a new defined association probability in this filter provides a good tracking capability for the warhead ignoring the radar cross section. The simulation results indicate that the errors between the estimated and the warhead trajectories are reduced to a small interval in a short time. Therefore, the radar can produce a beam to illuminate to the right area and keep tracking the warhead all the way. In conclusion, this algorithm is worthy of further study and application.

• Journal of the Korean Data and Information Science Society
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• v.19 no.4
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• pp.1429-1440
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• 2008

In a meta-analysis combining the results from different clinical trials, it is important to consider the possible heterogeneity in outcomes between trials. Such variations can be regarded as random effects. Thus, random-effect models such as HGLMs (hierarchical generalized linear models) are very useful. In this paper, we propose a HGLM framework for analyzing the binominal response data which may have variations in the odds-ratios between clinical trials. We also present the prediction intervals for random effects which are in practice useful to investigate the heterogeneity of the trial effects. The proposed method is illustrated with a real-data set on 22 trials about respiratory tract infections. We further demonstrate that an appropriate HGLM can be confirmed via model-selection criteria.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.11
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• pp.1374-1381
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• 1999

This paper describes development of a package for generator maintenance scheduling program with user-friendly interactive mode. Generator maintenance scheduling is to select desirable maintenance periods of generators in the given interval satisfying reliability or economic criteria. Window-based system for user-friendly mode and Oracle-based database system for efficient data management are established in our package. Reserve rate levelization and LOLP minimization are performed in calculation mode, which is composed of DLL programs. Many graphs and charts are illustrated for the user-analysis. Operation is carried out by day-based unit, not by week. The case study has been conducted with the data of practical KEPCO power system in 1999 and successfully demonstrated its effectiveness.

• Journal of applied mathematics & informatics
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• v.41 no.5
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• pp.973-988
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• 2023

In real-life scenarios, we may have to deal with real numbers or numbers in intervals or a combination of both to solve multi-criteria decision-making (MCDM) problems. Also, we may come across a situation where we must combine this interval and actual number membership values into a single real number. The most significant factor in combining these membership values into a single value is by using aggregation operators or scoring algorithms. To overcome such a situation, we suggest the cubic hypersoft set (CHSS) concept as a workaround. Ultimately, this makes it simple for the decision-maker to obtain information without misconceptions. The primary aim of this study is to establish some operational laws for the cubic hypersoft set, present the fundamental properties of aggregation operators and propose an algorithm by using the technique of order of preference by similarity to the ideal solution (TOPSIS) technique based on correlation coefficients to analyze the stress-coping skills of workers.

• Therapeutic Science for Rehabilitation
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• v.9 no.4
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• pp.107-120
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• 2020

Objective : The purpose of this study was to investigate the effectiveness and basis of rehabilitation intervention in patients with spinal cord injury by systematic review and meta-analysis of randomized controlled studies. Methods : Two researchers independently searched and selected a study published in an academic journal using a search term in an international thesis database. A total of 21 studies met the selection criteria, and qualitative evaluation of the study was conducted using the PEDro Scale. Meta-analysis was performed using Comprehensive Meta-Analysis 3.0 program. Results : A total of 713 subjects were included. The results of the meta-analysis showed a score of 0.406 (95.0% confidence interval: 0.221 ~ 0.591) for intervention using physical activity and 0.505 (95.0% confidence interval: 0.449 ~ 1.528) for electronic stimulation therapy, which showed medium effect; educational intervention had a 0.248 (95.0% confidence interval: 0.033 ~ 0.464), and mixed intervention 0.280 (95.0% confidence interval: 0.122 ~ 0.438). It was shown that the effect of small (small). There was a significant heterogeneity in the statistical heterogeneity test, and thus the random effects model was selected and analyzed. Conclusion : The results showed that rehabilitation interventions were effective for patients with spinal cord injury. During the rehabilitation of spinal cord injury patients, clinicians are expected to contribute to the development of programs to improve their lifestyles.

• Pediatric Infection and Vaccine
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• v.30 no.1
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• pp.12-19
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• 2023

Purpose: Sepsis is the most common cause of neonatal death accounting for 30-50% of mortality annually in developing countries. This study was to determine the prognostic factors of neonatal sepsis mortality. Methods: A retrospective cohort was conducted in Dr. R. Sosodoro Djatikoesoemo Governor Hospital from April 2021 to September 2021 on 121 neonates in the neonatal intensive care unit (NICU) diagnosed with sepsis. The inclusion criteria were neonates aged 0-28 days, admitted to the NICU, and diagnosed with sepsis. The exclusion criteria were incomplete data and the presence of congenital abnormalities. A χ² test was performed on the sex, gestational age, mode of delivery, birth weight, APGAR score, birthplace, and blood culture. A normality test was performed on leukocytes, lymphocytes, neutrophils, platelets, C-reactive protein (CRP), and length of stay. Then performed a Mann-Whitney test. Results: Birth weight (P=0.038), gestational age (P=0.009), and blood culture (P=0.014) showed a significant relationship with the neonatal sepsis outcome while Mann-Whitney test showed significant differences in the platelets (P=0.018), CRP (P=0.002), and length of stay (P<0.001). Multivariate analysis showed that 3 prognostic factors associated with neonatal sepsis mortality were prematurity (odds ratio [OR], 3.906; 95% confidence interval [CI], 1.344-11.356; P=0.012), low birth weight (LBW, OR, 2.833; 95% CI, 1.030-7.790; P=0.044), and gram-negative bacteria (OR, 4.821; 95% CI, 1.018-22.842; P=0.047). Conclusions: Prematurity, LBW, and gram-negative bacteria were associated with the prognostic factors of neonatal sepsis.

• Journal of the Korean Society of Clothing and Textiles
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• v.36 no.4
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• pp.391-399
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• 2012

This study helps out-size consumers purchase swimsuits and improves fitness by classifying the torso of middle-aged obese women; in addition, it creates a size system based on each size interval for obese types. The criteria for subjects in this study were over 25kg/$m^2$ of the BMI, over 85cm of waist, and over 95cm of bust; 199 females were surveyed. Three torso types were categorized by a cluster analysis into X type (the vertical size of hip girth was the biggest of the three and the waist was slender), H-O type (larger than other groups in bust girth with more fat above the circumstance of the abdomen), and Y type (the upper half of body development type and lower body fatness were between those of type X and those of type H-O). As a consequence of size system establishment according to obesity types, the basic body sizes and reference body sizes were different according to types even in commonly-appeared size names at sections of respective types. The research findings show the necessity to understand obesity types according to bust girth and hip girth sizes that represent basic sizes as well as to design patterns in consideration of the characteristics of obese body shapes when swimsuits are designed for obese groups. The findings can be used as basic data to decide the desirable output of production according to respective body types.

• Journal of Periodontal and Implant Science
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• v.48 no.4
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• pp.251-260
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• 2018

Purpose: The aim of this retrospective cross-sectional study was to evaluate whether salivary findings of active matrix-metalloproteinase 8 (aMMP-8) chairside (point of care; POC) tests were associated with periodontal risk assessment parameters in patients receiving supportive periodontal therapy (SPT). Methods: A total of 125 patients receiving regular SPT were included, and their records were examined. The following inclusion criteria were used: a diagnosis of chronic periodontitis, at least 1 non-surgical periodontal treatment (scaling and root planning) with following regular SPT (minimum once a year), at least 6 remaining teeth, and clinical and aMMP-8 findings that were obtained at the same appointment. In addition to anamnestic factors (e.g., smoking and diabetes), oral hygiene indices (modified sulcus bleeding index [mSBI] and approximal plaque index), periodontal probing depth simultaneously with bleeding on probing, and dental findings (number of decayed, missing, and filled teeth) were recorded. Salivary aMMP-8 levels were tested using a commercial POC test system (Periomarker, Hager & Werken, Duisburg, Germany). Statistical analysis was performed using the t-test, Mann-Whitney U test, Fisher's exact test, and ${\chi}^2$ test, as appropriate (P<0.05). Results: Only the mSBI was significantly associated with positive salivary aMMP-8 findings (aMMP-8 positive: $27.8%{\pm}20.9%$ vs. aMMP-8 negative: $18.0%{\pm}14.5%$; P=0.017). No significant associations were found between aMMP-8 and smoking, diabetes, periodontal parameters, or parameters related to the maintenance interval (P>0.05). Conclusions: Salivary aMMP-8 chairside findings were not associated with common parameters used for periodontal risk assessment in patients receiving SPT. The diagnostic benefit of POC salivary aMMP-8 testing in risk assessment and maintenance interval adjustment during SPT remains unclear.