• Title/Summary/Keyword: hierarchical learning

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A methodology for evaluating human operator's fitness for duty in nuclear power plants

  • Choi, Moon Kyoung;Seong, Poong Hyun
    • Nuclear Engineering and Technology
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    • v.52 no.5
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    • pp.984-994
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    • 2020
  • It is reported that about 20% of accidents at nuclear power plants in Korea and abroad are caused by human error. One of the main factors contributing to human error is fatigue, so it is necessary to prevent human errors that may occur when the task is performed in an improper state by grasping the status of the operator in advance. In this study, we propose a method of evaluating operator's fitness-for-duty (FFD) using various parameters including eye movement data, subjective fatigue ratings, and operator's performance. Parameters for evaluating FFD were selected through a literature survey. We performed experiments that test subjects who felt various levels of fatigue monitor information of indicators and diagnose a system malfunction. In order to find meaningful characteristics in measured data consisting of various parameters, hierarchical clustering analysis, an unsupervised machine-learning technique, is used. The characteristics of each cluster were analyzed; fitness-for-duty of each cluster was evaluated. The appropriateness of the number of clusters obtained through clustering analysis was evaluated using both the Elbow and Silhouette methods. Finally, it was statistically shown that the suggested methodology for evaluating FFD does not generate additional fatigue in subjects. Relevance to industry: The methodology for evaluating an operator's fitness for duty in advance is proposed, and it can prevent human errors that might be caused by inappropriate condition in nuclear industries.

Influence of Cultural Competence on Nursing Professionalism of Nursing Students (간호대학생의 문화적 역량이 간호전문직관에 미치는 영향)

  • Park, Mijeong;Yoo, Hana
    • The Journal of Korean Academic Society of Nursing Education
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    • v.25 no.1
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    • pp.38-47
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    • 2019
  • Purpose: The purpose of this study was to investigate the influence of cultural competence on nursing professionalism among nursing students in South Korea. Methods: A sample of 218 nursing students in three universities answered a self-report questionnaire. Descriptive statistics, t-test, ANOVA, Mann-Whitney U-test, Kruskal-Wallis test, Pearson's correlation analyses, and hierarchical multiple regression were used to analyze the data. Results: There were significant differences in cultural competence depending on the use of foreign language, having foreign friends, frequency of interaction with foreigners, multi-cultural education experiences, and level of demand for multicultural education. There were significant differences in nursing professionalism depending on grade level, satisfaction with major choice, college life satisfaction, and foreign language learning experience. There was a significant positive correlation between cultural competence and nursing professionalism. Lastly, significant predictors of nursing professionalism included satisfaction with major choice (${\beta}=.22$, p=.004), cultural awareness (${\beta}=.22$, p=.007) and cultural experience (${\beta}=.17$, p=.026). The regression model explained 20.2% of nursing professionalism. Conclusion: In order to establish desirable nursing professionalism, strategies for enhancing cultural awareness and cultural experiences in nursing education courses are needed both inside and outside the curriculum.

The Effect of Early Childhood Teachers' Music Attitude and Emotional Leadership on Music Teaching Efficacy (유아교사의 음악에 대한 태도와 감성리더십이 음악교수효능감에 미치는 영향)

  • Lee, Misook;Cho, Songyon
    • Korean Journal of Childcare and Education
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    • v.15 no.2
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    • pp.125-144
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    • 2019
  • Objective: The purpose of this study was to examine the effects of early childhood teachers' music attitude and emotional leadership on their music teaching efficacy in the music education. Methods: 301 early childhood teachers answered the music attitude scale, music teaching efficacy belief instrument, emotional leadership scale, and questionnaire for socio-demographic characteristics and music experiences. Data were analyzed by t-test, one-way ANOVA, Pearson's productive correlation analysis and hierarchical regression analysis. Results: First, early childhood teachers had a higher music teaching efficacy in case of at least 10 years of teaching experiences period, having a post-graduate degree, having a music training experience, enjoying learning musical instruments and singing and listening to music during regular music lessons, and having a long music training experience. Similar results were derived from the subfactors of music teaching efficacy. Second, there were positive correlations(r=.172-.659, p < .001) in the total and subfactors scores among early childhood teachers' music attitude, emotional leadership, and music teaching efficacy. Lastly, early childhood teachers' music attitude and their emotional leadership were explained at 39~52 percent for their music teaching efficacy. Conclusion/Implications: This study suggests that it is important for early childhood teachers' perception of their belief, knowledge and feeling about music education.

Trend Analysis of Thyroid Cancer Research in Korea with Text Mining Techniques

  • Lee, Tae-Gyeong;Heo, Seong-Min;Shin, Seung-Hyeok;Yang, Ji-Yeon
    • Journal of the Korea Society of Computer and Information
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    • v.23 no.12
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    • pp.153-161
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    • 2018
  • In this paper, we propose a text-centered approach to identify the research trend of thyroid cancer in Korea. We incorporate statistical analysis, text mining and machine learning techniques with our clinical insights to find connective associations between terminologies and to discover informative clusters of literatures. The incidence of thyroid cancer in Korea increased rapidly in the 2000s, which fueled the debate regarding overdiagnosis, but recently the number of patients undergoing surgery has decreased significantly due to conscious reform efforts from various circles. We analyzed the abstracts and keywords of related research papers from DBpia. It was found that most were case reports in the 1980s, and some papers in the 1990s discussed the early detection of thyroid cancer by mass screening. While many papers focused on different diagnostic techniques and the detection of small cancers in the 2000s, many emphasized more on the quality of life of patients in the 2010s. There was an apparent change in the topics of thyroid cancer research over past decades. The results of this study would serve as a reference guide for current and future research directions.

The Mediating Effect of Self-Regulatory Skills on the Relationship between Mothers' Parenting Attitude and School Adjustment

  • LEE, Anne-Marie Soo Youn;LEE, Soo-Young
    • Educational Technology International
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    • v.22 no.2
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    • pp.139-167
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    • 2021
  • After experiencing school closures and online learning caused by COVID-19, the important role of school education was reinforced. Elementary school is the foundation of life and allows students to develop both social and academic skills. The purpose of this study was to examine the mediational role of Self-Regulatory Skills (SRS) on the relationship between Maternal Parenting Attitude (MPA) and School Adjustment (SA) of elementary school students. A total of 99 students enrolled in an international school in Seoul, Korea from grades 3 to 6 participated in this study. Data were analyzed through Independent Sample T-Test, one way ANOVA, Multiple Regression Analysis, and Hierarchical Regression Analysis using the SPSS 23.0. The findings of the study were as follows. First, there is a difference between genders and among grades. Second, only acceptance was significantly related to school adjustment. Third, acceptance, strict control, and accepted control are significantly related to SRS. Fourth, Self-Regulatory Skills (Sustained Attention) fully mediate the relationship between Maternal Parenting Attitude (Acceptance) and School Adjustment (Academic Attitude/ Rule compliance). Educational implications for understanding the role of parenting attitude and future directions are discussed.

A survey of the primary school teachers에 appreciation of the 7th national primary science curriculum (제7차 과학과 교육과정에 관한 초등교사의 인식)

  • 노석구;여상인;장병기;임채성;송민영
    • Journal of Korean Elementary Science Education
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    • v.21 no.2
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    • pp.213-226
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    • 2002
  • The purpose of this research is to direct the 7th national primary science curriculum to be performed properly. The research is based on the questionnaire to investigate the primary teachers' appreciation of the curriculum. The questions are about the general aspect of the 7th curriculum and special treatises on science curriculum. Questionnaires were distributed to 1000 teachers, and 822 teachers answered them. According to the survey results the teachers' thoughts were as following: First, there must be enough time to develop a new curriculum. It is not desirable to change the old curriculum totally. There should be some continuity between the old and the new curriculum. Second, teachers appreciated that the learning resources and supplements were helpful, and interested students. Teachers thought that If equipment at class or school was not enough. Third, according to them the hierarchical structure of science curriculum was appropriate, but the contents need to be improved. Fourth, most teachers restructured the 7th science curriculum to adapt it to the class and school. They cooperated with one another in teaching science, and applied diverse teaching-learning methods according to the curricular contents and the grade levels. Teachers tried to evaluate all aspects of the students with various methods, but they felt it was hard. They were not active in developing evaluation tools as a team, and in objectifying the information about students. Fifth, teachers felt it was hard to implement the science curriculum according to different levels of the students. Based on the survey of teachers' thoughts, the following can be suggested for successful implementation and reorientation of the curriculum. First, teachers need learning opportunities to appreciate and adapt the 7th curriculum creatively. Second, they need guidances in implementing the different levels of the curriculum, and the information about the appropriate resources for it. Third, we need to control the relative difficulty of the curricular contents, and reduce the hours and quantity of the study. Fourth, we need to improve the school equipment and facilities. Networking and cooperation among education-related institutions are essential for better education. Fifth, it is desirable to develop concrete and diverse teaming models.

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A Noise-Tolerant Hierarchical Image Classification System based on Autoencoder Models (오토인코더 기반의 잡음에 강인한 계층적 이미지 분류 시스템)

  • Lee, Jong-kwan
    • Journal of Internet Computing and Services
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    • v.22 no.1
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    • pp.23-30
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    • 2021
  • This paper proposes a noise-tolerant image classification system using multiple autoencoders. The development of deep learning technology has dramatically improved the performance of image classifiers. However, if the images are contaminated by noise, the performance degrades rapidly. Noise added to the image is inevitably generated in the process of obtaining and transmitting the image. Therefore, in order to use the classifier in a real environment, we have to deal with the noise. On the other hand, the autoencoder is an artificial neural network model that is trained to have similar input and output values. If the input data is similar to the training data, the error between the input data and output data of the autoencoder will be small. However, if the input data is not similar to the training data, the error will be large. The proposed system uses the relationship between the input data and the output data of the autoencoder, and it has two phases to classify the images. In the first phase, the classes with the highest likelihood of classification are selected and subject to the procedure again in the second phase. For the performance analysis of the proposed system, classification accuracy was tested on a Gaussian noise-contaminated MNIST dataset. As a result of the experiment, it was confirmed that the proposed system in the noisy environment has higher accuracy than the CNN-based classification technique.

Conflict Management Strategies of Police Managers - A case study - (경찰 관리자들의 조직 내 갈등 관리 전략 - 사례 연구를 중심으로 -)

  • Jung, Jeyong;Shin, So-Young
    • Korean Security Journal
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    • no.58
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    • pp.137-154
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    • 2019
  • Conflict management within a police organization is one of the most significant areas from the organization management point of view. This study aims to explore procedural entrepreneurship of police mangers when they face difficulties in their workplaces. Adopting a case study strategy, this study examines real cases from three police agencies from Japan, the US, and South Korea. Interviewing police officers from theses different countries, six main themes are identified: (1) the pervasiveness of hierarchical authority, (2) procedural conflict, (3) organizational cultures, (4) the origin of their values and assumptions, (5) characteristics of the strategy, and (6) organizational learning. Research findings pointed out that there were more similarities than differences among the three cases, such as the pervasiveness of hierarchical authority, the significance of informal networks, and characteristics of informal networks. The main finding was that police managers used informal networks in order to overcome the procedural conflicts regardless of their nationality. All the participants relied on informal communications to raise the adaptability and survivability of their organizations. It was found that the Asian culture and American culture respectively permeated the three police agencies, supporting the role of informal networks in the formal organizations. This presents a paradox which well reflects the reality of organizations: informality within formality.

Process Networks of Ecohydrological Systems in a Temperate Deciduous Forest: A Complex Systems Perspective (온대활엽수림 생태수문계의 과정망: 복잡계 관점)

  • Yun, Juyeol;Kim, Sehee;Kang, Minseok;Cho, Chun-Ho;Chun, Jung-Hwa;Kim, Joon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.16 no.3
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    • pp.157-168
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    • 2014
  • From a complex systems perspective, ecohydrological systems in forests may be characterized with (1) large networks of components which give rise to complex collective behaviors, (2) sophisticated information processing, and (3) adaptation through self-organization and learning processes. In order to demonstrate such characteristics, we applied the recently proposed 'process networks' approach to a temperate deciduous forest in Gwangneung National Arboretum in Korea. The process network analysis clearly delineated the forest ecohydrological systems as the hierarchical networks of information flows and feedback loops with various time scales among different variables. Several subsystems were identified such as synoptic subsystem (SS), atmospheric boundary layer subsystem (ABLS), biophysical subsystem (BPS), and biophysicochemical subsystem (BPCS). These subsystems were assembled/disassembled through the couplings/decouplings of feedback loops to form/deform newly aggregated subsystems (e.g., regional subsystem) - an evidence for self-organizing processes of a complex system. Our results imply that, despite natural and human disturbances, ecosystems grow and develop through self-organization while maintaining dynamic equilibrium, thereby continuously adapting to environmental changes. Ecosystem integrity is preserved when the system's self-organizing processes are preserved, something that happens naturally if we maintain the context for self-organization. From this perspective, the process networks approach makes sense.

Analysis of Elementary School Students' Visual Representation Competence for Shadow Phenomenon (그림자 현상에 대한 초등학생의 시각적 표상 능력)

  • Yoon, Hye-Gyoung
    • Journal of The Korean Association For Science Education
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    • v.39 no.2
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    • pp.295-305
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    • 2019
  • In previous study, visual representation competence taxonomy (VRC-T), which is composed of two dimensions, was developed for the purpose of promoting effective visual representation use and research in science education. In this study, elementary school students' visual representation competence for shadow phenomenon was investigated using VRC-T. In terms of visual representation competence, 'interpretation' was the highest score, followed by 'construction' and 'integration'. It also showed that students' visual representation competence was not high even after learning shadow-related units in the regular curriculum. On the other hand, text-based scientific knowledge was not correlated with all categories of visual representation competence. This indicates that there is a need to emphasize visual representation more in science class. Finally, hierarchical relationship among cognitive processes of VRC-T was explored according to ordering theory. If the tolerance level is somewhat loosened, a linear hierarchical relationship was found between the six cognitive processes. This suggests that VRC-T is an analytical framework that can be useful when designing assessment tools, tasks, and science class activities to enhance visual representation competence.