• 한국수학교육학회지시리즈B:순수및응용수학
• /
• 제2권1호
• /
• pp.53-59
• /
• 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)

• 한국시뮬레이션학회:학술대회논문집
• /
• 한국시뮬레이션학회 1998년도 The Korea Society for Simulation 98 춘계학술대회 논문집
• /
• pp.50-55
• /
• 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
• /
• 제4권5호
• /
• pp.529-538
• /
• 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
• /
• 제19권4호
• /
• pp.1429-1440
• /
• 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.

• 대한전기학회논문지:전력기술부문A
• /
• 제48권11호
• /
• pp.1374-1381
• /
• 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
• /
• 제41권5호
• /
• pp.973-988
• /
• 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.

• 재활치료과학
• /
• 제9권4호
• /
• pp.107-120
• /
• 2020

목적 : 척수손상환자를 대상으로 한 무작위 대조군 연구의 체계적 고찰과 메타분석을 통해 척수손상환자의 재활 중재의 효과성과 근거를 알아보고자 한다. 연구방법 : 국외 논문데이터베이스에서 검색어를 사용하여 학술지에 게재된 연구를 2명의 연구자가 독립적으로 검색하여 선정하였다. 선정기준에 부합한 연구는 총 21편이었고, PEDro Scale을 사용하여 연구의 질적 평가를 실시하였다. 메타분석은 Comprehensive Meta-Analysis 3.0 프로그램을 사용하였다. 결과 : 분석된 연구에 참여한 연구대상자는 총 713명이었고, 메타분석을 실시한 결과 신체활동을 이용한 중재는 0.406(95.0% 신뢰구간: 0.221~0.591), 전기 자극 치료중재는 0.505(95.0% 신뢰구간: 0.449~1.528)로 중간크기(Medium)의 효과를 보이는 것으로 나타났고 교육적 방법 중재는 0.248(95.0% 신뢰구간: 0.033~0.464), 복합 중재는 0.280(95.0% 신뢰구간: 0.122~0.438)로 작은 크기(Small)의 효과를 보이는 것으로 나타났다. 통계적 이질성 검정에서 유의미한 이질성이 있어 연구결과 통합 시 랜덤효과 모형을 선택하여 분석하였고, 출판편견은 유의미하지 않아 신뢰할만한 연구결과였다. 결론 : 분석된 결과 척수손상환자를 대상으로한 재활 중재는 효과적임을 알 수 있었다. 척수손상환자를 대상으로한 재활분야에서 임상가들이 대상자의 라이프 스타일을 개선하기 위한 프로그램을 구성할 때 기여할 것으로 사료된다.

• Pediatric Infection and Vaccine
• /
• 제30권1호
• /
• pp.12-19
• /
• 2023

목적: 패혈증은 개발도상국에서 연간 사망률의 30-50%를 차지하는 신생아 사망의 가장 흔한 원인이다. 본 연구는 신생아 패혈증 사망률의 예후인자를 알아보고자 하였다. 방법: 2021년 4월부터 2021년 9월까지 R. Sosodoro Djatikoesoemo 주지사 병원 신생아 중환자실에서 패혈증을 진단받은 121명의 신생아를 대상으로 후향적 코호트 연구로 진행되었다. 연구대상자 선정기준은 신생아 중환자실에 입원하고 패혈증을 진단받은 생후 0-28일된신생아였다. 임상 기록이 불완전한 경우와 선천적 기형을 가진 경우는 제외하였다. 성별, 재태주령, 분만방식, 출생체중, APGAR 점수, 출생지, 혈액배양에 대해 카이제곱 검정을 시행하였고 백혈구, 림프구, 호중구, 혈소판, C반응단백 (C-reactive protein, CRP) 및 체류 기간에 대하여서는 정규성 검정을 한 후 Mann-Whitney 테스트로 분석하였다. 결과: 출생체중 (P=0.038), 임신주수 (P=0.009), 혈액배양 (P=0.014)은 신생아 패혈증 결과에 유의한 상관관계를 보였고, Mann-Whitney 검사는 혈소판 (P=0.018), CRP (P=0.002) 및 재원기간 (P<0.001)에서 유의한 차이를 보였다. 다변량 분석에서 신생아 패혈증 사망률과 관련된 세 가지 예후 인자는 미숙아 (오즈비 [odds ratio, OR], 3.906; 95% 신뢰구간 [confidence interval, CI], 1.344-11.356; P=0.012), 저체중 출생 (OR, 2.833; 95% CI, 1.030-7.790; P=0.044), 그람 음성 박테리아 (OR, 4.821; 95% CI, 1.018-22.842; P=0.047)인 것으로 나타났다. 결론: 미숙아, 저체중아, 그람 음성균 감염이 신생아 패혈증의 예후와 관련이 있었다.

• 한국의류학회지
• /
• 제36권4호
• /
• pp.391-399
• /
• 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
• /
• 제48권4호
• /
• pp.251-260
• /
• 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.