• 한국직업건강간호학회지
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• 제20권2호
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• pp.195-203
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• 2011

Purpose: The purpose of this study was to identify the trends of occupational health nursing research by analyzing the Korean Journal of Occupational Health Nursing for the last 20 years. Methods: A total of 268 published papers during the 20 year period were analyzed with structured analysis forms. Results: Most of the articles were descriptive, but the number of experimental studies increased. Fifty-five percents of the subjects were healthy workers. Most common selection of subjects appeared to be based on convenience. Sixty-eight percent of research instruments were questionnaires and the reliability and the validity of instruments were described in approximately half of the studies. Parametric statistics were the main methods of data analysis, but some advanced statistics were often used rather than simple descriptive statistics. Mainly "health" has been studied (47.9%) among four meta-paradigms of nursing science. Conclusion: It is necessary to develop more rigorous and various research methodology such as longitudinal design, experimental study, or randomized controlled trial. Also, special attention must be paid to studying the environment of workers.

• 한국기계가공학회지
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• 제15권2호
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• pp.57-65
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• 2016

The suspension system of a subway vehicle is composed of $1^{st}$ and $2^{nd}$ springs. The suspension system is the most important parameter in determining the vibration ride comfort. If the $1^{st}$ suspension spring is designed as a spring with strong stiffness to improve the running stability at high speed, it causes vehicle vibrations. In this paper, by testing and analyzing changes of the characteristics of Chevron springs, which have been the primary suspension springs used for about 20 years, we study how changing the characteristics affects vehicle acceleration and ride comfort. The lateral and longitudinal vibrational ride comfort index levels were lower than the vertical ones. Therefore, as increasing the stiffness of Chevron springs has the greatest effect on the vertical vibrational ride comfort index level, a countermeasure for vertical vibration reduction is needed when the stiffness increases owing to aging. Finally, maintenance guidelines, including the replacement time for the Chevron rubber, were proposed based on these findings.

• Human Ecology Research
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• 제56권1호
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• pp.55-69
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• 2018

This study examined how the resources from work, family and community lowered family-to-work conflict (FWC) and enhanced family-to-work facilitation (FWF) of employed women with a child younger than 18 years old in order to provide empirical support for the Korean government's effort to create a family-friendly community as a way to help employed mothers balance work and family life. Information from 608 employed mothers living in 45 different communities were extracted from the 4th-wave of the Korean Longitudinal Survey of Women and Families in 2012, while community resources indicators were selected from the 2012 database of the Korean Statistical Information Service. Findings from the HLM analysis were as follows. First, there were significant variation in FWC and FWF among employed mothers depending on the communities they resided in. Second, work satisfaction, representative of work resource, relieved FWC and enhanced FWF, but spousal support, which represents family resource, affected neither FWC nor FWF. Third, community resources, as represented by family-friendly environment and frequent volunteering by community residents, lowered FWC but failed to enhance FWF. Lastly, family-friendly community resources served to mitigate the negative relationship between work satisfaction and FWC. This study is meaningful in that it provided empirical evidence for the contribution of community resources to work-family balance of employed mothers.

• 대한산업공학회지
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• 제39권3호
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• pp.222-232
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• 2013

In recent years, 'technological fusion or convergence' has drawn a lot of attention of innovation researchers and governmental policy makers as the driving force of technological innovation and industrial growth. There are, however, few studies on the analysis of longitudinal trends of technological convergence and its comparison between global and national level. In this study, with the citation data of about 18 million articles, we analyzed 1) the growth of representative convergence research areas, 2) the convergence of citing patterns between research fields, and 3) the changing trend of diversity index of all research fields. We conclude that technological convergence in korea shows the relatively strong orientation to the combination of neighboring fields than that of heterogenous fields in comparison to global trend. In particular, the relatively weak activity of cognitive science and the low level of mutual exchange between arts/humanities/social sciences and natural/engineering sciences in Korea are emphasized.

• Journal of Welding and Joining
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• 제26권5호
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• pp.66-73
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• 2008

Welding work in pre-erection or erection stage of shipbuilding construction to be carried out in flat and vertical upward position mostly and Electrogas welding(EGW) is actively applied especially for vertical butt joint of thicker steel plate recently. In this study considered how to develope and improve mechanical properties of weld metal and HAZ in high heat input welding processes such as EGW and Electroslag welding(ESW) with its welding equipment in order to extend the application range to the longitudinal members and hatch coaming parts of container ship. Some components of welding system and parameters were modified to get the faster travel speed and reduce weld heat input, and also by adding additional filler rods or tubes increase the amount of deposited weld metal. With the test get some good date can apply to actual fabrication work and recommend items to manufacture welding materials make better. Above all things it's a fruition that to prepare the possibility of application of ESW to shipbuilding construction which fill up the gap of stoppage days of more than 20 years.

• Computers and Concrete
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• 제23권1호
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• pp.49-60
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• 2019

In recent years, multiple experimental studies have been performed on using fiber reinforced polymer (FRP) bars in reinforced concrete (RC) structural members. FRP bars provide a new type of reinforcement that avoids the corrosion of traditional steel reinforcement. In this study, predicting the shear strength of RC beams with FRP longitudinal bars using artificial neural networks (ANNs) is investigated as a different approach from the current specific codes. An ANN model was developed using the experimental data of 104 FRP-RC specimens from an existing database in the literature. Seven different input parameters affecting the shear strength of FRP bar reinforced RC beams were selected to create the ANN structure. The most convenient ANN algorithm was determined as traingdx. The results from current codes (ACI440.1R-15 and JSCE) and existing literature in predicting the shear strength of FRP-RC beams were investigated using the identical test data. The study shows that the ANN model produces acceptable predictions for the ultimate shear strength of FRP-RC beams (maximum $R^2{\approx}0.97$). Additionally, the ANN model provides more accurate predictions for the shear capacity than the other computed methods in the ACI440.1R-15, JSCE codes and existing literature for considering different performance parameters.

• Safety and Health at Work
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• 제13권2호
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• pp.201-206
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• 2022

Background: The present objective was to verify whether burnout (emotional exhaustion [EE], depersonalization [DP] and low professional efficacy [PE]) is a risk factor for long-term sickness absence (LTSA; 30 consecutive days) from the teaching role. Methods: This was a prospective cohort study with two years of follow-up that investigated 509 elementary and high-school teachers. Burnout was identified by Maslach Burnout Inventory. Poisson regression with robust variance was used to adjust for possible confounders. Results: The incidence of LTSA was 9.4%. High EE levels were associated with LTSA in the crude analysis, but the association lost statistical significance after adjustments (for sex, age, perception of work-life balance, general self-rated health, chronic pain and depression). High DP levels were associated with this outcome, even after all adjustments (relative risk = 1.80; 95% confidence interval: 1.05-3.09). Low PE levels were not related to LTSA. Conclusion: The results reinforce the need to improve teachers' work conditions to reduce burnout, particularly DP, and its consequences.

• 대한치과교정학회지
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• 제29권2호
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• pp.183-195
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• 1999

성장기 환자의 교정치료에서 신체의 성장 발육상태를 파악하는 것은 중요한 의미를 갖는다. 특히 부정교합에 따라 성장 발육시기가 차이를 보인다면 교정치료 시기의 선택에 있어서 이에 대한 고려가 있어야 하므로 부정교합의 양상에 따른 성장 발육상태를 평가하는 것이 필요할 것이다. 이에 본 연구에서는 부정교합 분류에 따라 골성숙도에 차이가 있는지를 조사하기 위해, 8-10세의 여자 I급 부정교합자 38명, II급 부정교합자 36명, III급 부정교합자 33명을 대상으로 약 6개월 간격으로 12-13세까지 누년적으로 촬영한 수완부골 방사선 사진을 이용하여 골성숙도를 평가한 결과 다음과 같은 결론을 얻었다. 1. 부정교합에 따른 골성숙도의 차이는 없었다. 2. 유구골의 구상돌기 (hamular process)는 $9.16{\pm}0.72$세, 두상골(pisiform bone)은 $9.13{\pm}0.71$세, 모지척측 종자골(ulnar sesamoid)은 $10.34{\pm}0.84$세에 관찰되었다. 3. 골단이 골간을 둘러싸는 시기는 셋째 수지의 원심부 지절과 중간 지절에서 각각 $10.96{\pm}0.80$세, $11.27{\pm}0.87$세였으며, 첫째 수지의 근심부 지절에서는 $11.12{\pm}0.86$세, 요골에서는 $11.21{\pm}0.82$세, 다섯째 수지의 중간 지절에서는 $11.62{\pm}0.85$세였다. 4. 두상골의 출현은 유구골 구상돌기의 출현과(r=0.91), 모지척측 종자골의 출현은 구상돌기의 진행성 화골시기와 높은 상관관계를 보였으며(r=0.86), 골단이 골간을 둘러싸는 시기는 여러 부위가 상호간에 높은 상관관계를 나타내었다(r=0.80-0.90). 5. 다섯째 수지의 중간 지절의 형태가 가장 변이가 심하였다($20.6\%$).

• 간호행정학회지
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• 제15권3호
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• pp.305-313
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• 2009

Purpose: This study was done to identify the current status of burnout research on Korean nurses and to suggest the directions for future research. Method: Fifty two articles between 1998 and 2007 were selected using the key words such as "Nurse" and "Burnout" from the database (RISS4U et al.). Results: 77.9% of studies were master's theses unpublished in the nursing journals. All studies were cross-sectional and therefore did not allow casual inference. Hospital nurses were the most common subjects (21 studies). The most frequently used burnout measurement instrument was the Burnout Measure, while the Maslach Burnout Inventory was used in only 6 studies. 55.7% of studies reported the average burnout score as higher than the middle level. Among individual factors, variables significantly correlated to burnout were age, position, work experience, coping, and personality. Some of job factors including shift work, workloads, job stress, and organizational commitment were also significantly related to burnout. There was very little discussion about the influence of organizational factors analyzed by unit or institution level. Conclusion: In Korea, the next phase of nurse burnout research needs to consider the measurement tool selection for the international comparison and longitudinal design to find more specific causal relationships.

• 대한치과교정학회지
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• 제25권3호
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• pp.287-297
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• 1995

경북대학교 치과 대학에서 두개안면골 성장에 관한 누년적 연구의 일환으로 남자 25명, 여자 21명을 대상으로 평균 연령 8.5세에서 16.5세까지 격년 간격으로 촬영한 두부X선 규격사진을 이용하여 Ricketts분석법의 항목중 V.T.O.작성의 초기 단계인 치료전의 성장 예견시에 필요한 각도 및 거리 계측 항목을 선정 계측하여 다음과 같은 결론을 얻었다. 1. 계측항목중 연령에 따른 변화를 보이지 않는 항목은 성장 방향을 나타내는 facial axis angle, FH to palatal plane angle, BA-NA-A angle, lower facial height 및 lower incisor protrusion이었다. 2. 연령에 따라 지속적으로 증가하는 항목(anterior and posterior cranial base length, facial axis length, condyle axis length, corpus axis length)에서 연간 성장 변화량, 평균 연성장량 및 8년간 변화량을 구하였다. 3. 연령에 따라 지속적으로 증가하는 모든 계측 항목에서 12세 이후의 대부분의 연간 성장변화량, 평균 연성장량 및 8년간 변화량에서 남녀간 유의차를 나타내었다(P<0.05). 4. 남녀별로 각 연령에서 각 계측치의 평균치를 이용하여 visual norm을 작성하였다. 남자의 경우 각 기간동안 상당한 성장을 보였으며 특히 12-14세 기간에 가장 많은 성장을 나타내었고, 여자의 성장 변화에서는 10-12세 사이에서 가장 많은 성장을 나타내었으며 이후 점차 감소를 보였다.