• Journal of Power Electronics
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• 제17권6호
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• pp.1658-1671
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• 2017

To address the inaccurate load demand sharing problems among parallel inverter-interfaced voltage-controlled distributed generation (DG) units in islanded microgrids (MGs) with different DG power ratings and mismatched feeder impedances, an enhanced voltage control scheme based on the active compensation of circulating voltage drops is proposed in this paper. Using the proposed strategy, reactive power and harmonic currents are shared accurately and proportionally without knowledge of the feeder impedances. Since the proposed local controller consists of two well-separated fundamental and harmonic voltage control branches, the reactive power and harmonic currents can be independently shared without having a remarkable effect on the amplitude or quality of the DGs voltage, even if nonlinear (harmonic) loads are directly connected at the output terminals of the units. In addition, accurate load sharing can also be attained when the plug-and-play performance of DGs and various loading conditions are applied to MGs. The effects of communication failures and latency on the performance of the proposed strategy are also explored. The design process of the proposed control system is presented in detail and comprehensive simulation studies on a three-phase MG are provided to validate the effectiveness of the proposed control method.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제22권6호
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• pp.536-544
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• 2019

Purpose: Proper nutrition is essential for brain development during infancy, contributing to the continued development of cognitive, motor, and socio-emotional skills throughout life. Considering the insufficient published data in the Middle East and North Africa, experts drafted a questionnaire to assess the opinions and knowledge of physicians on the impact of nutrition on brain development and cognition in early life. Methods: The questionnaire consisted of two parts: The first focused on the responders' demographic and professional characteristics and the second questioned the role of nutrition in brain development and cognition. Descriptive statistics were used to summarize respondents' characteristics and their responses to questions. Results: A total of 1,500 questionnaires were distributed; 994 physicians responded. The majority of the surveyed physicians (64.4%) felt that nutrition impacts brain development in early childhood (0-4 years), with almost 90% of physicians agreeing/strongly agreeing that preventing iron, zinc, and iodine deficiency would improve global intelligence quotient. The majority of physicians (83%) agreed that head circumference was the most important measure of brain development. The majority of physicians (68.9%) responded that the period from the last trimester until 18 months postdelivery was crucial for brain growth and neurodevelopment, with 76.8% believing that infants breast-fed by vegan mothers have an increased risk of impaired brain development. Conclusion: The results of this study show that practicing physicians significantly agree that nutrition plays an important role in brain and cognitive development and function in early childhood, particularly during the last trimester until 18 months postdelivery.

• Journal of Forest and Environmental Science
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• 제27권2호
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• pp.81-91
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• 2011

An exploratory study was conducted in Gopalganj, a southern district of Bangladesh to explore the role of wild date palm (Phoenix sylvestris Roxb.) husbandry in the rural economy. A total of 36 households in the study area were interviewed using a semi-structured questionnaire. A multistage sampling method with 10% intensity and a semi-structured questionnaire were used for the study. Based on the land holding capacity of the households, the farmers were categorized into five groups as landless, marginal, small, medium, and large. The date palm was distributed over seven different habitats of which roadside support the highest value (31%) followed by agricultural field and orchard (25% each). Though the large category farmers own most of the palms (43%), a considerable portion (562 individuals out of 1980) of it is managed by the landless farmers, who earn a substantial livelihood from the palms. The farmers manage the palm mainly for juice production; juice is either used fresh as drink or after some sort of processing as molasses and/or alcoholic beverage. Date palm husbandry contributes 32,601 Tk., 21,107 Tk., 20,626 Tk., 29,574 Tk. and 35,335 Tk. respectively to the five group seasonally and 50,980 Tk., 77,556 Tk., 90,208 Tk., 112,560 Tk., 140,675 Tk. respectively annually (1 US$ = 70 Tk.). Date palm trees contribute 65.48% of mean annual income to landless farmers followed by 27.21% to marginal farmers. However the poor marketing system result in decreasing the annual return from palm trees. Palm husbandry could be a promising source of rural incomes in Bangladesh if the farmers' traditional management knowledge was linked to more scientific management practices.

• 한국콘텐츠학회논문지
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• 제21권9호
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• pp.34-41
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• 2021

본 연구의 목적은 AI 스피커를 활용한 영어 말하기 수업과 활동이 초등영어학습자들의 정의적 특성과 학습 만족도에 미치는 영향을 살펴보기 위함이다. 총 46명의 초등영어학습자가 실험에 참여하였으며설문지를 사전-사후 배포하여 양적으로 분석하였다. 본 연구를 통해 밝혀낸 결과를 정리하면 다음과 같다. 첫째, AI 기반 영어 학습에 대한 전반적인 이해도 관련 수업 후 AI 기반 활동의 교육적 장점과 효능에 대한 인식이 넓어진 것을 알 수 있었다. 둘째, AI 기반 영어 말하기 활동에 대한 정의적 특성의 변화를 살펴본 결과 사전대비 사후의 평균값이 상승하고 대응표본 t-검정 결과 흥미도, 가치관, 태도 영역에 있어 유의미한 차이가 발견되었다. AI 활용 영어 학습에 대한 만족도를 살펴본 결과 실험 전에 비해 평균 만족도가 상승하고 특히 효능감, 학업 성취감 및 몰입도면에서 높은 상승을 보였다. 끝으로 AI 기반 영어 학습의 만족도과 정의적 특성 간의 상관관계를 분석한 결과 AI 기반 영어 학습에 대한 만족도는 학습자들의 자신감, 흥미도, 태도와 관련이 있는 것으로 나타났다.

• 한국정보통신학회논문지
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• 제24권2호
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• pp.166-171
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• 2020

데이터를 저장하고 분석하여 새로운 지식을 얻을 수 있는 빅데이터 처리기술은 사회의 여러 분야에서 중요성이 강조되고 있으며 정보통신기술 분야의 핵심 이슈로 부각되면서 관련 기술에 대한 관심이 증가하고 있다. 이러한 빅데이터를 분석할 수 있는 도구인 R은 통계 기반의 정보 분석을 가능하게 하는 언어와 환경이다. 본 논문에서는 이를 이용하여 성경데이터를 분석한다. 성경 중에서 신약성경의 4복음서의 데이터를 분석한다. 먼저 성경데이터를 수집하고 분석을 위한 필터링을 수행한다. 이후 R을 이용하여 어떠한 텍스트가 분포되어 있는지를 빈도 조사를 수행하며 정확한 데이터의 분석을 위해 한 문장에서 나오는 단어들을 쌍으로 표현하고 단어 간의 관계성을 분석하는 소셜 네트워크 분석을 통해 성경을 분석한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권1호
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• pp.90-113
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• 2021

Electronic Records Management System (ERMS) is a computer program or set of applications that is utilized for keeping up to date records along with their storage. ERMS has been extensively utilized for enhancing the performance of academic institutions. The system assists in the planning and decision-making processes, which in turn enhances the competencies. However, although ERMS is significant in supporting the process of decision-making, the majority of organizations have failed to take an initiative to implement it, taking into account that are some implementing it without an appropriate framework, and thus resulted in the practice which does not meet the accepted standard. Therefore, this study identifies the factors influencing the adoption of ERMS among employees of HLI in Yemen and the role of such adoption in the decision-making process, using the Unified Theory of Acceptance and Use of Technology (UTAUT) along with Technology, Organization and Environment (TOE) as the underpinning theories. The study conducts a cross-sectional survey with a questionnaire as the technique for data collection, distributed to 364 participants in various Yemeni public Higher Learning Institutions (HLI). Using AMOS as a statistical method, the findings revealed there are significant and positive relationships between technology factors (effort expectancy, performance expectancy, IT infrastructure and security), organizational factors (top management support, financial support, training, and policy),environmental factors (competitiveness pressure, facilitating conditions and trust) and behavioral intention to adopt ERMS, which in return has a significant relationship with the process of decision-making in HLI. The study also presents a variety of theoretical and empirical contributions that enrich the body of knowledge in the field of technology adoption and the electronic record's domain.

• International Journal of Computer Science & Network Security
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• 제21권2호
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• pp.54-65
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• 2021

The movement control order and shutting down educational institution in Saudi Arabia has jeopardized the teaching and learning process. Education was shifted to distance learning in order to avoid any academic loss. In the middle of the Covid-19 crisis, there is a need to assess the full image of e-learning in Saudi Arabia. To investigate student and teachers' perception and acceptance, parents' attitudes and believes about distance education are the main goals of the study. The mix-method research design was employed to collect data. Three surveys were distributed to 100 students and 50 teachers and 50 parents from different educational institutions in Saudi Arabia, while semi-structured interviews were conducted with 10 parents. Random stratified and convenient sampling methods were adopted. Both descriptive and content analysis was conducted using SPSS25.0 and NVIVO software for quantitative and qualitative data accordingly. The findings showed that students are comfortable with remote education and are receiving enough support from schools and instructors but they think online education can't replace conventional face-to-face learning. Moreover, the results showed that teachers are having challenges in preparing online classes because of the development of conducting online classes and the lack of training. However, parents showed negative attitudes regarding the benefits and values of remote education and preferred conventional learning styles in elementary schools. Parents tended to reject and resist distance learning for several reasons: professional knowledge and lack of time to support their young kids in online classes, the shortcomings of e-learning, young children's inadequate self-regulation. Saudi parents are neither trained nor ready to use e-learning. The study provided suggestion and implications for teacher education and policymakers.

• 한국지구과학회지
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• 제42권1호
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• pp.55-64
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• 2021

화산재연대학은 화산재층을 지질학적 사건과 대비하거나 연대를 측정하는 연구이다. 화산재층은 건층으로 사용될 수 있기 때문에 제4기 퇴적층의 연대측정에 매우 중요하다. 이번 연구에서는 울산의 산하동과 정자동 지역에 분포하는 해안단구 퇴적층의 상하부에서 두 종류의 화산재가 발견되었다. 화산유리의 형태학적 특징과 굴절률, 주원소조성과 상관계수 분석을 통해 상부와 하부의 화산재는 각각 약 25 ka 전에 분출한 AT 화산재와 약 105-110 ka 전에 분출한 Ata 화산재로 밝혀졌다. Ata 화산재는 한국의 육상퇴적층에서 공식적으로 처음 보고되는 것이다. 이번 연구결과는 향후 한국의 제4기 고기후와 고환경 및 한국 동남부의 활성단층 연구에 큰 도움이 될 수 있을 것으로 기대된다.

• 한국응급구조학회지
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• 제25권2호
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• pp.129-143
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• 2021

Purpose: This study aimed to identify the current status of school safety education and the differences in knowledge and practice of middle school students. Methods: A structured questionnaire was distributed to 418 middle school students in J province. The questionnaires consisted of 35 questions on the status of school safety education as well as the four school safety education domains of first aid, disaster safety, traffic safety, and daily life. Data were analyzed using frequency analysis, cross-tabulation analysis, a t-test, analysis of variance, and Pearson's correlations. Results: Awareness regarding the top seven standards for school safety and interest in school safety education were both relatively low. Among all the different kinds of safety accidents, those related to school violence(33.8%) and life safety(24.9%) were experienced the most in school. A more pleasant school life and better peer relationships led to interest in school safety(p=.000)(p=.000), awareness regarding the top seven standards for school safety(p=.022)(p=.009), adoption of coping measures(p=.000)(p=.000), and practice(p=.000)(p=.000) in case of safety accidents(p=.000)(p=.000). Conclusion: To increase awareness regarding the seven standards for school safety education and raise interest in safety education, it is necessary to cultivate experts and actively utilize them and to prepare systematic and continuous school safety education programs.

• Safety and Health at Work
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• 제13권1호
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• pp.86-92
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• 2022

Background: A laboratory where chemicals are handled can be considered a hazardous environment, and hence, prudent practices should be strictly enforced. If not, deadly accidents and incidents could occur due to a lack of safety practices and poor safety culture. The purpose of this study is to analyze the existing safety culture and propose potential recommendations to enhance the level of safety education in the chemical laboratories in the Western Province of Sri Lanka. Methods: A survey questionnaire was administered among the laboratory supervisors of the chemical laboratories in the Western Province of Sri Lanka in 2019. Results: Even though 80 surveys were distributed among prospective participants, only 46 surveys were submitted, which is 58% of the response rate. Most of the individuals who participated in the survey were females below 35 years old, and approximately 96% of the participants had at least one year of working experience in the same laboratory setting. The majority considered safety as an important factor that requires further improvements with third-party safety inspections; however, 54% of the respondents mentioned that those inspections were conducted by the employees from their laboratory. Conclusion: From the study, it has been discovered that employees have knowledge of safety culture to a certain extent. A significant percentage (83%) of participants believed that further safety measures are required for a safer laboratory. However, the study revealed that the attitudes of some employees should be changed to have a better safety culture. Hence the authors would like to suggest having annual training sessions and well-formulated safety policies to improve the safety culture.