• Design & Manufacturing
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• 제14권4호
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• pp.17-24
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• 2020

Products for heating indoors in low temperature and dry winter are largely divided into products using fossil fuels and products using electricity. The fossil fuels can warm the entire space by convection, but there is a high risk of fire and the frequent ventilation due to the increase in carbon monoxide and carbon dioxide. Heaters using electricity are mainly used because they are convenient to use and are cheap. However, these products can not efficiently warm the air because they use radiation energy. In other words, only the front part exposed to the heater is warm, and the rear part has no heating effect at all. Also, because it emits a large amount of light, fatigue of the eyes is very high. Another problem is that when using electric heaters, the room tends to be dry by high heat. Indoor humidity maintenance is a very important factor in the prevention and treatment of respiratory diseases. Especially, it is essential for health care for infants, bronchial organs and people with weak respiratory because humidity is low in winter. In this study, we conducted a study to develop a product that can improve heating efficiency while maintaining proper indoor humidity by combining heat energy and moisture particles. The concept of humidification and heating at the same time, moisture particles generated in the humidifier pass through the heater, include thermal energy, and the moisture particles with thermal energy are diffused into the space by forced convection, thereby warming the entire space. In addition, the heating time is shortened as the feeling temperature is increased with the high relative humidity, and this has the effect that the heating cost in winter is reduced.

• 산업과 과학
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• 제1권2호
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• pp.9-16
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• 2022

본 연구는 이완음악감상이 입원한 정신질환자의 기분상태 및 자율신경계 즉 심박동수에 미치는 영향을 파악하고자 실험군 17명, 대조군 17명을 대상으로 시행한 무작위 대조군 전후설계이다. 수집된 자료는 SPSS V15.0으로 분석하였다. 기분상태와 자율신경계 즉 심박동수는 두 집단 간에 통계적으로 유의한 차이가 있어 이완음악감상의 효과를 객관적으로 검증하였다(<.05). 기분상태의 하위 영역 중 분노(>.39)와 혼돈(>.33)을 제외한 긴장(<.00), 우울(<.00), 활력(<.03), 피로(<.01)에서 유의한 차이가 있는 것으로 나타나 입원한 정신질환자에게 적용할 수 있는 효과적인 중재방법임을 입증하였다. 향후 장기적인 중재 연구개발 및 적용과 개인의 선호음악을 이용하여 기분변화와 자율신경계에 효과연구를 제언하고자 한다.

• Wind and Structures
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• 제34권2호
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• pp.185-197
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• 2022

This study aimed to analyze the wind-induced mechanical energy (WME) of a proposed super high-rise and long-span transmission tower-line system (SHLTTS), which, in 2021, is the tallest tower-line system with the longest span. Anew index - the WME, accounting for the wind-induced vibration behavior of the whole system rather than the local part, was first proposed. The occurrence of the maximum WME for a transmission tower, with or without conductors, under synoptic winds, was analyzed, and the corresponding formulae were derived based on stochastic vibration theory. Some calculation data, such as the drag coefficient, dynamic parameters, windshielding areas, mass, calculation point coordinates, mode shape and influence function, derived from wind tunnel testing on reducedscale models and finite element software were used in calculating the maximum WME of the transmission tower under three cases. Then, the influence of conductors, wind speed, gradient wind height and wind yaw angle on WME components and the energy transfer relationship between substructures (transmission tower and conductor) were analyzed. The study showed that the presence of conductors increases the WME of transmission towers and changes the proportion of the mean component (MC), background component (BC) and resonant component (RC) for WME; The RC of WME is more susceptible to the wind speed change. Affected by the gradient wind height, the WME components decrease. With the RC decreasing the fastest and the MC decreasing the slowest; The WME reaches the its maximum value at the wind yaw angle of 30°. Due to the influence of three factors, namely: the long span of the conductors, the gradient wind height and the complex geometrical profile, it is important that the tower-line coupling effect, the potential for fatigue damage and the most unfavorable wind yaw angle should be given particular attention in the wind-resistant design of SHLTTSs

• Child Health Nursing Research
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• 제29권2호
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• pp.111-127
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• 2023

Purpose: This study investigated the effects of healthy lifestyle interventions (HLSIs) on health-related quality of life (HR-QoL) in childhood and adolescent cancer survivors (CACS). Methods: Major databases were searched for English-language original articles published between January 1, 2000 and May 2, 2021. Randomized controlled trials (RCTs) and non-RCTs were included. Quality was assessed using the revised Cochrane risk-of-bias tool, and a meta-analysis was conducted using RevMan 5.3 software. Results: Nineteen studies were included. Significant effects on HR-QoL were found for interventions using a multi-modal approach (exercise and education) (d=-0.46; 95% confidence interval [CI]=-0.84 to -0.07, p=.02), lasting not less than 6 months (d=-0.72; 95% CI=-1.15 to -0.29, p=.0010), and using a group approach (d=-0.46; 95% CI=-0.85 to -0.06, p=.02). Self-efficacy showed significant effects when HLSIs provided health education only (d=-0.55; 95% CI=-0.92 to -0.18; p=.003), lasted for less than 6 months (d=-0.40; 95% CI=-0.69 to -0.11, p=.006), and were conducted individually (d=-0.55; 95% CI=-0.92 to -0.18, p=.003). The physical outcomes (physical activity, fatigue, exercise capacity-VO₂, exercise capacity-upper body, body mass index) revealed no statistical significance. Conclusion: Areas of HLSIs for CACS requiring further study were identified, and needs and directions of research for holistic health management were suggested.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.542-545
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• 2022

최근 중대재해의 처벌관련법이 건설 환경에 대한 관심을 끌고 있다. 공사현장의 안전관리를 점검하는 일반적인 방법은 근무자가 직접 그들의 눈으로 현장을 확인하는 것이다. 하지만 이 방식은 근무자의 능력의 한계에 영향을 받을 수밖에 없고, 그 결과 피로와 작업 능률 저하를 일으키게 된다. 이런 이유로, 이는 효율적인 방법이 될 수 없다. 이에 우리는 본 연구를 통해 상기 방법을 보완할 수 있는 효율적인 ICT 안전관리 시스템을 제안하여, 작업환경 및 공사 현장 안전에 도움 주고자 한다. 본 논문은 RFID를 활용한 출입 관리 시스템 설계와 소음 센서 및 미세 먼지 센서를 통한 현장 정보 모니터링 방식을 설명한다. 또한, PIR 센서로 중장비와 사람 간의 사고를 예방하고, 자이로 센서를 통해 작업 중인 건물의 기울기를 파악하여 안전사고를 예방할 수 있는 시스템을 제안한다.

• 청정기술
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• 제15권3호
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• pp.165-171
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• 2009

본 연구에서는 전자산업에서 주로 사용되는 invar 강판재료를 식각한 후 생성되는 $FeCl_2$을 $FeCl_3$로 환원하여 회수한 후 재사용하기 위한 식각액 재생공정에서 $FeCl_3$의 회수 농도와 재생공정의 단수와의 관계를 규명하고 원하는 $FeCl_3$ 회수 농도를 얻기 위한 공정의 최적단수를 얻어낼 수 있는 simulation program을 개발하였다. 이 프로그램을 위한 여러 가지 parameter는 pilot 실험을 통해 얻었다. 개발된 프로그램에 의한 공정 모사는 폐액의 발생량 및 처리비용을 극소화할 수 있다. 또한 개발된 프로그램은 원하는 $FeCl_3$의 농도를 얻기 위한 식각액 재생시스템의 최적단수와 공정시간을 계산할 수 있다. 개발된 프로그램은 실제 전자산업에서 식각액 재생 장치의 최적 용량 산정과 식각액 회수 시스템 최적단수 계산에 활용되었다.

• Journal of Preventive Medicine and Public Health
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• 제56권2호
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• pp.154-163
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• 2023

Objectives: Systemic lupus erythematosus (SLE) or lupus patients usually experience various physical and psychological challenges. Since the coronavirus disease 2019 pandemic, these challenges have become even harsher. Using the participatory action research approach, this study evaluated how an e-wellness program (eWP) impacted SLE-related knowledge and health behaviors, mental health, and quality of life among lupus patients in Thailand. Methods: A 1-group, pretest-posttest design study was conducted among a purposive sample of lupus patients who were members of Thai SLE Foundation. The 2 main intervention components were: (1) online social support, and (2) lifestyle and stress management workshops. Sixty-eight participants completed all the study requirements, including the Physical and Psychosocial Health Assessment questionnaire. Results: After being in the eWP for 3 months, participants' mean score for SLE-related knowledge increased significantly (t=5.3, p<0.001). The increase in sleep hours was statistically significant (Z=-3.1, p<0.01), with the percentage of participants who slept less than 7 hours decreasing from 52.9% to 29.0%. The percentage of participants reporting sun exposure decreased from 17.7% to 8.8%. The participants also reported significantly lower stress (t(66)=-4.4, p<0.001) and anxiety (t(67)=-2.9, p=0.005). The post-eWP quality of life scores for the pain, planning, intimate relationship, burden to others, emotional health, and fatigue domains also improved significantly (p<0.05). Conclusions: The overall outcomes showed promising results of improved self-care knowledge, health behaviors, mental health status, and quality of life. It is recommended that the SLE Foundation continues to use the eWP model to help the lupus patient community.

• 임상간호연구
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• 제16권3호
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• pp.145-155
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• 2010

Purpose: The purpose of this study was to investigate oncology nurses' professional quality of life and its correlations with job satisfaction and job stress in a tertiary hospital in Seoul, South Korea. Methods: A cross-sectional survey design was utilized to investigate 210 oncology nurses from various oncology and hemato-oncology units. Professional quality of life (ProQOL), which is conceptualized with three sub-dimensions (compassion satisfaction, burnout, and secondary traumatic stress), job satisfaction, job stress, demographic and work-related variables were measured. Results: The participants were all women, with the mean age of 28.4. The participants with high ProQOL was only 14.8%, and 75.3% and 77.6% of the participants reported a moderate to high level of burnout and secondary traumatic stress respectively. Job satisfaction, age, and the total years of nursing practice have positive correlations with compassion satisfaction. Also, compassion satisfaction was significantly different according to age group, work units, the level of education, nursing positions, and the years of practice. Conclusion: Since the level of professional quality of life among oncology nurses was relatively low, the program for oncology nurses to improve compassion satisfaction and to decrease compassion fatigue needs to be developed.

• 대한토목학회논문집
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• 제26권3D호
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• pp.445-451
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• 2006

본 연구는 노후 콘크리트 포장의 아스팔트 덧씌우기에서 발생하는 반사균열을 억제하기 위한 방안으로 노후 콘크리트와 아스팔트 표층 사이에 응력을 흡수할 수 있는 중간층 혼합물을 개발하기 위하여 수행되었다. 고탄성 응력흡수층은 휨 변형과 수평변형으로 인하여 발생하는 균열응력을 흡수 또는 분산 시킬 수 있는 탄성과 유연성, 균일성 및 불투수성이 요구된다. 본 연구로부터 국외제품을 모델로 국산 바인더를 개발 하였으며 이를 사용하여 제작된 혼합물 시편은 시방규격에 만족하였다. 기존 덧씌우기 공법과 비교한 시험으로부터 고탄성 응력흡수 중간층이 설치된 경우 설치되지 않은 경우에 비하여 전단파괴수명과 수평변위저항도는 약 4배가 증가되었으며 표층재료의 선정에 따라 전단파괴수명은 5배, 수평변위저항도는 9배가 증가되어 고탄성 응력흡수 중간층이 반사균열 억제에 우수한 것으로 본 연구에 나타났다.

• Structural Engineering and Mechanics
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• 제90권1호
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• pp.27-40
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• 2024

The prediction of VIV amplitude is essential for the design and fatigue life estimation of steel tubes in tubular transmission towers. Limited to costly and time-consuming traditional experimental and computational fluid dynamics (CFD) methods, a machine learning (ML)-based method is proposed to efficiently predict the VIV amplitude of steel tubes in transmission towers. Firstly, by introducing the first-order mode shape to the two-dimensional CFD method, a simplified response analysis method (SRAM) is presented to calculate the VIV amplitude of steel tubes in transmission towers, which enables to build a dataset for training ML models. Then, by taking mass ratio M^*, damping ratio ξ, and reduced velocity U^* as the input variables, a Kriging-based prediction method (KPM) is further proposed to estimate the VIV amplitude of steel tubes in transmission towers by combining the SRAM with the Kriging-based ML model. Finally, the feasibility and effectiveness of the proposed methods are demonstrated by using three full-scale steel tubes with C-shaped, Cross-shaped, and Flange-plate joints, respectively. The results show that the SRAM can reasonably calculate the VIV amplitude, in which the relative errors of VIV maximum amplitude in three examples are less than 6%. Meanwhile, the KPM can well predict the VIV amplitude of steel tubes in transmission towers within the studied range of M^*, ξ and U^*. Particularly, the KPM presents an excellent capability in estimating the VIV maximum amplitude by using the reduced damping parameter S_G.