• 한국정보전자통신기술학회논문지
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• 제15권4호
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• pp.291-297
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• 2022

본 논문은 가전용 교류 전동기 구동을 위한 인버터 회로에 포함된 지능형 스위칭 모듈인 IPM 모듈에 대한 특성 및 신뢰성 계측 회로 설계 방법에 대한 연구이다. IPM은 전동기 구동기의 핵심 부품으로 그 스위칭 특성이 서보 구동 중에 일관되게 유지돼야 한다. 그 특성 중 스위치 온 특성을 결정하는 콜렉터-에미터간 도통 전압 Vce(on) 특성이 중요하다. 인버터 구성의 핵심 부품인 IPM은 여러 브랜드의 제품이 생산되고 있기 때문에 응용시스템의 최적 성능을 위해서는 IPM의 제품군에 따른 IGBT 스위치의 콜렉터-에미터간 도통 전압 Vce(on) 값을 측정하기 위한 방법 및 계측 평가 시스템이 필요하다. 제안된 방법은 제조사별 IPM이 전동기 구동회로에 장착된 상태에서 부하에 따른 Vce(on) 값을 계측 평가할 수 있는 새로운 방법으로 사용자 회사 입장에서는 중요한 설비가 될 수 있다.

• Composites Research
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• 제22권6호
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• pp.13-17
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• 2009

본 연구에서는 컴퓨터 단층촬영 장비의 크레이들에 대한 샌드위치 복합재 3차원 형상을 결정하였고, 유한요소해석을 통해 구조성능 기준을 만족하는 적층 패턴을 제안하였으며, 균일한 X선 투과 성능을 만족하는 생산공법을 제안하였다. 크레이들 설계는 다른 부품과의 공간, 고정 방법, 헤드레스트 부품과의 조립조건을 고려하였다. 정해진 위치에 135 kg 하중이 가해질 때, 크레이들 끝단부 처짐이 20 mm 이하인 기준을 만족하는 적층패턴을 결정하였다. 생산공법 측면에서 우선 카본 소재/폴리에스터 수지로 핸드레이업을 하였으나, 기포 및 과잉수지로 불균일한 X선 투과성능을 보였다. 이를 해결하기 위해 첫 번째 층은 동일소재를 인퓨전 공법으로 하고 나머지 층은 카본 소재/에폭시 수지의 프리프레그 적용으로 X선 투과성능을 개선하였다.

• 천문학회보
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• 제46권1호
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• pp.38.4-39
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• 2021

The Local Volume Mapper (LVM), for the Sloan Digital Sky Survey V, consists of four 16 cm telescopes with three fiber spectrographs in the Las Campanas Observatory in Chile. With the fixed telescopes on optical tables, the Alt-Alt mounted siderostats point and guide targets during spectrograph exposures. We are developing the integrated LVM instrument control software. Considering international travel restrictions caused by the COVID-19 pandemic in 2021, we decided to make a simplified version of siderostat to test the LVM telescope control system in Korea. The prototype siderostat consists of two aluminum flat mirrors, optomechanical housing structures made by aluminum profiles, and the Planewave L-350 mount. We designed the optical mirrors and the optomechanical structure of the siderostat. From structural analysis at various pointing cases, we estimated the tilt misalignments of mirrors within 4 arcsec, which would affect the telescope pointing errors.

• 한국산업정보학회논문지
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• 제28권6호
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• pp.21-27
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• 2023

현대 함정은 외부로 방사되는 적외선 신호를 낮추기 위해 폐기관에 적외선 신호저감 장치(Infra-Red Signature Suppression system, IRSS)를 설치한다. 그리고 함정은 생의 주기가 매우 긴 전략 자산으로 탑재 장비들의 성능에 대한 높은 신뢰성을 충분히 확보해야 한다. 따라서, IRSS와 같은 장비들은 설계 단계에서 모형시험을 통해 성능평가를 하고 있다. IRSS의 모형시험에서는 다양한 계측기기들이 사용된다. 그러므로, 모형시험 단계 이전에 계측기들의 신뢰성을 평가해야 한다. 본 연구에서는 IRSS 모형시험에 사용되는 계측 장비들의 신뢰성 평가에 관한 연구를 수행하였다. 시험 장비와 계측기는 열 풍동 시험기, 피토 튜브와 디지털 차압계, 열전대 센서 그리고 디지털 기록계가 사용되었다. 계측 결과 열 풍동 시험기의 풍속이 증가할수록 유동의 계측 편차가 감소하였으며, 열전대 센서의 온도는 사용 방법에 따라 반응 속도 및 민감도의 차이를 보였다.

• International Journal of Knowledge Content Development & Technology
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• 제14권3호
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• pp.39-57
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• 2024

Plagiarism detection software is beneficial in detecting plagiarism in research works of postgraduate students. Despite the benefits of using plagiarism detection software, studies have revealed that most students, including postgraduates, do not use plagiarism detection software as expected. This could depend on the provision of facilitating conditions like internet connectivity, training opportunities and electricity. Thus, this study examined facilitating conditions and the use of plagiarism detection software among postgraduates of the University of Ibadan, Nigeria. A descriptive survey research design of the correlational type was used for this study, with a population of 2143 postgraduates. The multi-stage random sampling technique was used to determine the sample size of 242. The questionnaire was the research instrument, and data was analysed using descriptive statistics. Results showed that most postgraduates agreed that the university provided facilitating conditions like internet connectivity. The majority of the respondents noted that they used Turnitin monthly. Most of the respondents noted that they used plagiarism detection software to paraphrase their work and check the correctness of the grammar in their documents. The most prominent challenges confronting plagiarism detection software use by most respondents were their inability to afford subscription payment to use the plagiarism detection software and slow internet connectivity. There was a significant positive relationship between facilitating conditions and the use of plagiarism detection software by the postgraduates of the University of Ibadan, Nigeria. Some of the recommendations for the institution's management include leveraging the vast network of alumni willing to give back to the institution and intervening in the provision of internet connectivity and electricity.

• Safety and Health at Work
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• 제15권1호
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• pp.80-86
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• 2024

Background: The Work Ability Index (WAI) is an instrument that measures work ability. The wide dispersion of the WAI internationally has led to its adaptation for use in different countries. This study aimed to evaluate the psychometric properties of the Spanish version of the WAI. Methods: A methodological design was used over an opportunistic sample of 233 workers in the aeronautical industry in Spain. Reliability was evaluated through internal consistency. Factorial validity, known groups, and convergent validity were tested. Results: The Cronbach's alpha and item-total correlation indicated an adequate internal consistency. The confirmatory factor analysis, performed to evaluate the factorial validity, found adequate fit indices for a two-factor solution with a high correlation between the factors. Factor 1, "Subjectively estimated work ability and resources", was composed of 3 subscales and factor 2, "Ill-health-related", of 2 subscales. Subscales 4 and 6 had loading in both factors. Workers under 45 years of age obtained higher significant scores than older ones. Convergent validity was also evidenced since WAI was highly correlated with self-assessment of health status. Conclusions: The Spanish version of the WAI has shown evidence of reliability and validity in this study, supporting its use in individual and collective health surveillance by occupational health professionals. The factorial solution that was found has previously been reported in another international context. However, further research is needed to resolve the discrepancies detected in the role of some subscales between other national and international studies.

• International Journal of Knowledge Content Development & Technology
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• 제14권2호
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• pp.81-97
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• 2024

The study investigated computer literacy skills as a determinant of electronic reference sources utilization among selected secondary school students in Ado-Odo Ota Local Government, Ogun State, Nigeria. Four specific objectives with conforming research questions guided the study. Descriptive survey research design was adopted for the study. The population of the study comprises of SSS3 students of the three selected Community Secondary Schools in Ado Odo Ota. A sample size of 150 was used for the study. The instrument for data collection was a self-developed structured questionnaire. Data collected was analyzed using frequency and percentages. Findings of the study revealed that majority of secondary school students were not aware of the availability of electronic reference sources. It also revealed that the level of their computer literacy skills was below average. Majority of them have never used computer before and the few of them that have used computer before used it in their homes, their friend's homes or in the cyber café. It was found that lack of formal training on the use of electronic reference sources, lack of access to computer, lack of awareness of availability of electronic reference sources, lack of funds for internet subscriptions, over dependency on printed reference sources and lack of motivation to use electronic reference sources were the major hindrances to the use of electronic reference sources among secondary school students. It was recommended that the school librarians and teachers should play a role in creating awareness among secondary school students about the availability of online/ electronic reference sources among others.

• 여성건강간호학회지
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• 제30권2호
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• pp.128-139
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• 2024

Purpose: This study aimed to translate the Perinatal Infant Care Social Support (PICSS) instrument into Chinese and to verify the reliability and validity of the translated version. Methods: This study used a cross-sectional design to examine the reliability and validity of the Chinese version of the PICSS (C-PICSS). A cohort of 150 first-time mothers in China participated, attending hospital follow-up care at 6 weeks postpartum. Data were collected after obtaining informed consent from the mothers. Results: The majority of mothers were aged between 20 and 29 years, with a mean age of 26.25 (±3.90) years. An item analysis of the 19 items in the C-PICSS showed that all items had an item-total score correlation above 0.2. This resulted in a Kaiser-Meyer-Olkin value of 0.92 and a significant Bartlett's test of sphericity (χ²=1,778.65, p<.001), confirming the suitability of the data for factor analysis. Correlation analyses revealed a strong positive relationship between infant care social support and general social support (r=.62, p<.001), and a negative relationship between infant care social support and postpartum depression (r=-. 38, p<.001). Higher scores for infant care social support were associated with reporting positive relationships with their husbands (t=3.72, p<.001) and high levels of spousal involvement (t=4.09, p<.001). In terms of structural support, spouses were identified as the primary source. Conclusion: The research results indicate that C-PICSS is reliable and valid as an indicator of social support for infant care among Chinese mothers.

• 한국지구과학회지
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• 제21권3호
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• pp.208-218
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• 2000

오늘날 인터넷의 일상적인 사용은 웹의 발달을 가져온 것으로 인식되고 있다. 학습도구로서 웹을 사용한 것을 WBI라 한다. WBI의 구축은 교육 현장에 현재 많은 영향을 미치고 있다. 그러나 사이버 공간에서 수많은 WBI 프로그램을 사용할 때 학습자들에 많은 문제점들이 도출되고 있다. 거의 모든 프로그램 사용 시 교사와 학생간의 상호 작용이 충분하지 못하며 필요한 학습자료들을 찾을 때 그들 자료들이 충분하게 마련되어 있지 않다. 학습 현장에서 교사들이 WBI 프로그램을 고안하고 구축하는 것은 매우 어려운 일이다. 그러나 상호 작용하는 WBI 프로그램의 고안과 구축은 그보다는 쉬운 일이다. 그러므로 만약 학생들과 친근한 교사들이 웹 페이지를, 만들어 사이버 공간에 제공한다면, 학생들은 쉽게 사이버 공간에서 접속할 수 있을 것이다. 그들은 e-메일, 여론 광장 또는 채팅을 사용할 수 있을 것이다. 사이버 공간은 학교 생활에서 불충분한 상호관계를 마련하게 될 것이다. 그러나, 이 프로그램은 모든 학생들이 필요한 적절한 장치들을 가지고 있어야 때문에, 이를 마련하지 못하는 학습자에게는 또 다른 형태의 포기를 가져오게 될 것이다. 이렇기 때문에 이 문제는 정부가 이러한 모든 필요한 장치들을 값싸게 보급하고 적절한 프로그램들을 공급할 때 풀릴 수 있다고 사료된다.

• 종양간호연구
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• 제1권2호
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• pp.204-216
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• 2001

The purpose of this study was to test the effects of foot reflexology on pain and mood in patients who have just had a mastectomy. The research design was a nonequivalent control group, non-synchronized design. The participants for this study were 28 patients with breast cancer on first or second day after mastectomy surgery. The first 12 patients were assigned to the control group and the second 16 to the experimental group. The study was conducted from October 28, 2001 to December 22, 2001 on a surgical unit of Y Medical Center in Seoul, Korea. Pain intensity, blood pressure, pulse rate and mood were measured as dependent variables. The instrument used for pain intensity and mood was a 10 cm visual analogue scale. Cronbach alpha for this study was .70. For the experimental group pre and post tests were done immediately before and 15 minutes after completion of foot reflexology. Foot reflexology was performed once for 20 minutes. After the pretest, patients in the control group were instructed to have a quiet time for a 35 minute period and then the post-test was done. The number of participants was small so the data were analyzed by Mann-Whitney U test, and Wilcoxon signed ranks test. The results of this study are as follow : 1. In the experimental group there were significant decreases between the pre and post tests for pain intensity (z=-3.47, p<.001), diastolic blood pressure (z=-2.67, p<.01) and pulse rate (z=-3.44, p<.001) but there was no difference between the two groups on the post test. 2. The systolic blood pressure, diastolic blood pressure and pulse rate were also not significantly different between the experimental group and the control group on the post test. 3. The mood score was significantly improved after foot reflexology(z=-3.52, p=.000) and the difference between the two groups was also significant (u=49.0, p=.03). In conclusion, there was a statistically significant difference in mood between the two groups, but no difference for pain intensity, blood pressure, or pulse rate. However, there were significant differences between the pretest and post-test for pain intensity, diastolic blood pressure and pulse rate in the experimental group. On the basis of the above findings, this study suggests that foot reflexology can be an effective method of relieving pain and improving mood in clinical practice in women who have had mastectomy surgery.