• Communications for Statistical Applications and Methods
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• 제28권2호
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• pp.171-188
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• 2021

Due to an increased demand for longevity risk analysis, various stochastic models have been suggested to evaluate uncertainly in estimated life expectancy and the associated value of future annuity payments. Recently updated data allow us to analyze mortality for a longer historical period and extended age ranges. This study followed up previous case studies using up-to-date empirical data on Korean mortality and the recently developed R package StMoMo for stochastic mortality models analysis. The suitability of stochastic mortality models, focusing on retirement ages, was investigated with goodness-of-fit, validity of models, and ability of generating reasonable sets of simulation paths of future mortality. Comparisons were made across various types of models. Based on the selected models, the variability of important estimated measures associated with pension, annuity, and reverse mortgage were quantified using simulations.

• Advances in materials Research
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• 제13권3호
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• pp.203-210
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• 2024

Science mapping is a visual representation of the structure and dynamics of scholarly knowledge. Gas adsorption on catalyst supports is a crucial process in many catalytic reactions. The R package "Bibliometrix" and VosViewer software were employed for science mapping analysis. The results show that the upward trend but fluctuates from year to year for both annual scientific production and average article citations per year. Co-occurrence of the keywords were used to identify the primary fields of study and to map the existing state of research. Trending topics reveal some interesting features that support the growth of research in this field and are associated with emerging disciplines or areas of study that have not been extensively explored.

• 마이크로전자및패키징학회지
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• 제26권3호
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• pp.81-88
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• 2019

본 연구에서는 그래핀 산화(graphene oxide, GO) 분말 첨가가 ball grid array(BGA) 패키지와 printed circuit board(PCB)간 Sn-3.0Ag-0.5Cu(SAC305) 무연솔더 접합부의 electromigration(EM) 수명에 미치는 영향에 대하여 보고 하였다. 솔더 접합 직후, Ni/Au표면처리된 패키지 접합계면에서는 $(Cu,Ni)_6Sn_5$가 생성되었으며 organic solderability preservative(OSP) 표면처리 된 PCB 접합계면에서는 $Cu_6Sn_5$ 금속간화합물(intermetallic compound, IMC)이 생성되었다. $130^{\circ}C$, $1.0{\times}10^3A/cm^2$ 전류밀도 하에서 EM 수명평가 결과, GO를 첨가하지 않은 솔더 접합부의 평균 파괴 시간은 189.9 hrs으로 도출되었고, GO를 첨가한 솔더 접합부의 평균 파괴 시간은 367.1 hrs으로 도출되었다. EM에 의한 손상은 패키지 접합계면에 비하여 pad 직경이 작은 PCB 접합계면에서 전자 유입에 의한 Cu의 소모로 인하여 발생하였다. 한편, 첨가된 GO는 하부계면의 $Cu_6Sn_5$ IMC와 솔더 사이에 분포하는 것을 확인하였다. 따라서, SAC305 무연솔더에 첨가된 GO가 전류 집중 영역에서 Cu의 빠른 확산을 억제하여 우수한 EM 신뢰성을 갖는 것으로 생각된다.

• 대한감각통합치료학회지
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• 제10권2호
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• pp.33-39
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• 2012

목적 : 본 연구의 목적은 대학생들의 감각처리유형과 학습 능력, 자존감의 상관관계를 알아보는 것이었다. 연구방법 : 본 연구는 2010년 10월 3일부터 2011년 4월 1일까지 실시하였고, 연구대상자는 경상남도 C 대학의 작업치료과 학생 총 84명이었다. 설문조사방법을 사용하였고, 설문지 내용은 일반적 사항, 청소년/성인 감각프로파일, 자아존중감 척도, 학점으로 구성하였다. 통계처리는 SPSS version 15를 사용하여 피어슨 상관분석하였다. 결과 : 감각처리유형의 감각 회피(r=-.25), 감각 민감(r=-.22), 감각 저하(r=-.31)는 자아존중감과 음의 상관관계를 보였다. 또한, 감각처리유형 중 감각추구(r=.22)와 학점은 양의 상관관계를 보였다. 결론 : 아동뿐만 아니라 성인에서도 감각처리능력이 자존감 및 학습능력과 상관관계가 있음을 나타내어 성인의 감각처리능력을 강조하는데 그 의의가 있다.

• Journal of Animal Science and Technology
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• 제51권4호
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• pp.289-294
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• 2009

본 연구는 한우 inositol 1,4,5-triphosphate receptor type1(IP3R1) 유전자를 대상으로 SNP를 발굴하고, 도체형질과의 관련성 분석을 위하여 수행하였다. PCR 및 염기서열 결정법을 통해 IP3R1 유전자내 3개의 SNP를 발굴하였고, 이중 intron 29에 위치하는 SNP의 경우 미 보고된 신규 SNP로 확인되었다. 발굴된 3개의 SNP를 대상으로 표현형 기록치를 보유한 후대검정우 583두에 대하여 유전자형 분석 및 관련성 분석을 수행하였다. 분석결과 3개의 SNP 중 g.1428617A>G SNP가 생시체중(P<0.05) 및 도체중(P<0.01)과 유의적인 상관관계가 있음을 확인할 수 있었다. 이러한 결과는 추후 한우 개량을 위한 유전자 마커로 활용이 가능할 것으로 판단된다.

• 마이크로전자및패키징학회지
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• 제30권2호
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• pp.33-42
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• 2023

전기자동차 산업은 전 세계적 환경규제 정책과 더불어 각 국 정부의 지원이 맞물려 성장이 가속화 되고 있다. 따라서 전기자동차용 배터리에 대한 수요는 지속적으로 증가할 것으로 예상된다. 전기자동차 배터리 시스템은 다수의 배터리 셀 및 모듈을 전기적으로 연결시켜 하나의 배터리 팩으로 적용된다. 이러한 배터리 셀 및 모듈을 접합하는 기술은 성능, 용량 및 안정성에 직접적인 영향을 주기 때문에 매우 중요하다. 따라서 기계적, 전기적 특성 등 여러 기준들을 고려하여 견고하게 조립되어야 한다. 각각의 접합 기술은 서로 다른 장점과 한계를 가지고 있으며, 배터리 셀에 적용할 때에는 몇 가지 기준이 고려되어야 한다. 본 논문에서는 다양한 배터리 셀 형태에 따른 접합기술의 적용 현황을 조사하고, 저항 용접 및 레이저, 초음파 등 대표적 접합기술에 대한 특징과 장단점을 제공하고자 한다.

• 여성건강간호학회지
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• 제7권2호
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• pp.157-168
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• 2001

The purpose of this study was to investigate of the relationship of the urinary incontinence, menopausal symptom and life satisfaction in middle aged women. The subjects of this study were 235 middle aged women, living in M city, during the period from June 21 to August 31, 2000. The instruments for this study were the urinary incontinence modified and adding by Lee Young Sook(1994), the menopausal symptom developed by Song Ae Ri and Chung Eun Soon(1998) and the life satisfaction translated and modified by Suh Kyung Hee(1988). Collected data were analyzed using descriptive statistics, t-test, ANOVA, Pearson correlation coefficients and stepwise multiple regression with SAS package. The result of this are as follows : 1. The total mean score of urinary incontinence was $1.56{\pm}0.58$ with a range of 0 to 4. The mean score on the menopausal symptom was $2.05{\pm}0.43$ with a range of 1 to 4. The mean life satisfaction score was $1.14{\pm}0.41$ with a range of 0 to 2. 2.General characteristics ralated to urinary incontinence were age and numbers of children (F=7.66, p=0.000, F=2.86, p=0.037). General characteristics ralated to menopausal symptom were age (F=7.37, p=0.000), occupation (t=5.33, p=0.021), problem of children (t=6.46, p=0.011) and marital satisfaction (F=5.65, p=0.004). General characteristics ralated to life satisfaction were type of housing (t=12.06, p=0.000), problem of children (t=6.96, p=0.008) and marital satisfaction (F=18.86, p=0.000). 3.The urinary incontinence and menopausal symptom were correlated positively (r=.235, p=.000). The urinary incontinence and life satisfaction were correlated negatively (r=-.114, p=.007). The menopausal symptom and life satisfaction were correlated negatively (r=-.277, p=.000). 4.The menopausal symptom, type of housing and marital satisfaction explained 16.6% of the variance for life satisfaction in the middle aged women.

• 한국학교ㆍ지역보건교육학회지
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• 제16권3호
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• pp.1-15
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• 2015

Objectives: The purpose of this study was to examine the state of ADHD disposition among college students and the impact of their self-esteem on ADHD in an effort to provide useful information on the prevention of ADHD in adults. Methods: A survey was conducted from April 4 to June 30, 2015, on 264 selected students at two different universities that were respectively located in the Daegu and Gyeongsan city. As for data analysis, a statistical package SPSS WIN 18.0 was employed. Results: The findings of the study were as follows: There were significant differences in overall ADHD disposition according to academic year, religion and academic standing, and self-esteem varied with gender, presence or absence of a friend of the opposite gender, academic year and academic standing. There were differences in inattention-memory problems scores, one of the sub factors of adult ADHD, according to presence or absence of a friend of the opposite gender, academic year and academic standing. Self-esteem had a negative correlation with inattention-memory (r=-0.463), hyperactivity(r=-0.269) and impulsiveness(r=-0.233). When a regression analysis was made to determine influential factors for inattention-memory, religion(${\beta}=0.121$), academic standing(${\beta}=-0.153$) and self-esteem(${\beta}=-0.422$) were influential. Conclusions: Adult ADHD disposition and self-esteem of college students seems to be relationship. There was a positive correlation among inattention-memory, hyperactivity and impulsiveness that were three subfactors of adult ADHD.

• 한국보건간호학회지
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• 제9권1호
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• pp.44-58
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• 1995

This study was to investigated the relationship between health locus of control and health promoting behavior of College students. For this study, questionnaires were given to 300 students in the H University of Seoul and collected during the period from Nomber 17 to November 24, 1994. Health locus of control and health promoting behavior were measured by using the MHLC scale and a modified HPLP scale. Healthiness of life style is parameterized by self actualization, health responsibility, exercise, nutrition, stress management, and internal support. The data were analyzed using the statistics package SAS, yielding frequency, percentage, mean, standard deviation, t-test, ANOVA, Pearson's Correlation. The result of this analysis are as follows: 1. Among the components of health locus of control, internal health locus of control showed the highestscore (mean: 3. 12, standard deviation: 0.46). Powerful others health locus of control followed next with the mean of 2. 30 and the standard deviation of 0.44. Chance health locus of control showed the mean of 2.29, and the standard deviation of 0.43 2. The HPLP mean score and the standard deviation of practice of health promoting behavior were 2.51 and 0.31 respectively. 3. HPLP correlated positively with internal health locus of control (r= 0.20, p<.01) and powerful others locus of control (r= 0.21. p<.001). However, HPLP inversely correlated with chance locus of control (r=-0.13, p<.05) 4. The demographic variables representing sex (t= 2.26, p<.05), health status (F = 5.52, p<.01) showed connections to health promoting behavior. Therefore, nurses should consider health locus of control when they take care of College students to improve such health promoting behavior as self actualization, exercise, internal support, stress management, and health responsibility. Further research is required to discover factors influencing health promoting behavior of College students.

• International Journal of Reliability and Applications
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• 제7권1호
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• pp.27-39
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• 2006

Many real world cases in material failure analysis do not follow perfectly the normal distribution. Forcing of the normality assumption may lead to inaccurate predictions and poor product quality. We examine the failure process of the internal bond (IB or tensile strength) of medium density fiberboard (MDF). We propose a forced censoring technique that closer fits the lower tails of strength distributions and better estimates extremely smaller percentiles, which may be valuable to continuous quality improvement initiatives. Further analyses are performed to build an accelerated common-shaped Weibull model for different product types using the $JMP^{(R)}$ Survival and Reliability platform. In this paper, a forced censoring technique is implemented for the first time as a software module, using $JMP^{(R)}$ Scripting Language (JSL) to expedite data processing, which is crucial for real-time manufacturing settings. Also, we use JSL to automate the task of fitting an accelerated Weibull model and testing model homogeneity in the shape parameter. Finally, a package script is written to readily provide field engineers customized reporting for model visualization, parameter estimation, and percentile forecasting. Our approach may be more accurate for product conformance evaluation, plus help reduce the cost of destructive testing and data management due to reduced frequency of testing. It may also be valuable for preventing field failure and improved product safety even when destructive testing is not reduced by yielding higher precision intervals at the same confidence level.