• Journal of Advanced Research in Ocean Engineering
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• v.4 no.2
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• pp.78-85
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• 2018

This paper presents a study of the effects of the free surface to marine propeller including the mesh effect of the models. In the present study, we conduct the numerical simulation for propeller performance employing the openwater test. The numerical simulations compare the meshing strategies for the propeller and show the effects on both thrust and torque. OpenFOAM is applied to solve the propeller problem and then open water performances of KCS propeller (KP505) are estimated using a Reynold-averaged Navier-Stokes equations (RANS) solver and the turbulence of the $K-{\omega}$ SST model. Unstructured meshes are used in the numerical simulation employing hexahedral meshing for mesh generation. The arbitrary mesh interfacing (AMI) and multiple rotating frame (MRF) are compared to define the best meshing strategy. The meshing strategies are evaluated through 3 classifications, i.e., coarse, medium, and fine mesh. Thus, the propeller can be performed utilizing the best mesh strategy. The computational results are validated by comparison with the experimental results. The $K_T$, $K_Q$, and efficiency of the propeller are compared to an experimental result and for all of the meshing strategies. Thus, the simulations show the influence of meshing in order to perform the propeller performances.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.217-221
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• 2017

Proactive prevention is important for crime. Past crimes have focused on coping after death and punishing them. But with Big Data technology, crime can be prevented spontaneously. Big data can predict the behavior of criminals or potential criminals. This article discusses how to build a big data system for crime prevention. Specifically, it deals with the way to combine unstructured data of big data with basic form data, and as a result, designs crime prevention system. Through this study, it is expected that the possibility of using big data for crime prevention is described through fingerprints, and it is expected to help crime prevention program and research in future.

• Women's Health Nursing
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• v.14 no.1
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• pp.44-55
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• 2008

Purpose: This study was done to assess the personal experiences of the coping process during pregnancy for single mothers. Methods: The participants were 17 single mothers who had stayed in a social welfare facility. Data was collected with an in-depth unstructured interview. Data analysis was done by the grounded theory method. Results: One-hundred twelve concepts and 49 sub-categories were confirmed in the analysis. The sub-categories were grouped into 19 categories; escape from a miserable family, wrong meeting, openness of sex, defenseless state of pregnancy, inevitable result of pregnancy, heartbreak by herself, closure, isolation, difficult situation of being alone, stigma, supporting & protecting, helplessness, seeking, empowering, feeling of loss, conflict, facing issues, assuring a fresh start and becoming-mature. "Being driven over the edge of a cliff" was the key phenomenon which the single mothers experienced during the process of pregnancy. Conclusion: The above results will help nurses assessing single pregnancy mothers' needs and developing a nursing intervention program for supporting them. Therefore, nurses will be able to stop them from "being driven over the edge of cliff". A more vigorous nursing intervention is suggested for the research of the vulnerable classes of medical health care including single pregnant mothers.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.613-615
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• 2013

Request to provide a service to XML word file recently has been increasing. In this paper, it is converted to an XML file data input (HWP, MS-Office) a Word file, stored in a database by extracting data directly input to the word processor user creates an XML mapping file I to provide a system that. This can be retrieved from the database the required data to previously created forms word processor, to generate a Word file from the application program a word processing document.

• Journal of Industrial Convergence
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• v.17 no.3
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• pp.17-22
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• 2019

As the value of big data is recognized as important, it is possible to advance decision making by effectively introducing and improving the development and utilization of JAVA and R programs that can analyze vast amounts of existing and unstructured data to governments, public institutions and private businesses. In this study, news data was collated and analyzed through text mining techniques in order to establish marketing strategies based on consumers' airline preferences. This research is meaningful in establishing marketing strategies based on analysis results by analyzing consumers' airline preferences using high-level big data utilization program techniques for data that were difficult to obtain in the past.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.4
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• pp.769-774
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• 2019

The development of information technology in a software-centered society as of today is a very important, and the training of software utilizing robots has become popular in recent years. This study proposes efficient SW convergence education by providing curriculum and contents for science + SW convergence education in conjunction with instruction block coding program. It also complements the limitations of existing unstructured chemistry experiment teaching aid, We have developed a 'chemical experiment paradigm' that integrates software education that can be linked with other classes.

• Nuclear Engineering and Technology
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• v.53 no.8
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• pp.2488-2498
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• 2021

The wall film-wise condensation plays an important role in the heat transfer processes of heat exchangers, refrigerators, and air conditioner. In the field of nuclear engineering, steam condensation is often utilized in safety systems to remove the core decay heat under both transient and accident conditions. In particular, passive containment cooling system (PCCS), are designed to ensure containment safety under severe accident conditions. A computational fluid dynamics (CFD) scale analysis has been conducted to calculate the heat transfer rate of the PCCS. However, despite the increase in computing power, there are challenges in the long-term transient simulation of containment using CFD scale codes. In this study, a heat structure coupling between the CFD and system analysis codes was performed to efficiently analyze PCCS. In addition, the component unstructured program for interfacial dynamics (CUPID) was improved to analyze the condensation behavior of ternary gas mixtures. Thereafter, the condensation heat transfer on the primary side was calculated using the improved CUPID and CFD code, whereas that on the secondary side was simulated using MARS. Both the coupled codes were validated against the CONAN facility database. Finally, conjugate heat transfer simulations with wall condensation in the presence of non-condensable gases were appropriately performed.

• The Journal of the Korea Contents Association
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• v.18 no.11
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• pp.30-37
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• 2018

The social media data and the broadcasting data related to onion as well as agri-food consumer panel data were collected and investigated if the amount of money spent to purchase onion in year 2014 when onion price plunged latest were correlated with the frequencies of onion-related keywords in the social media data and the broadcasting programs because onion price in year 2018 is expected to plunge due to overproduction and there has been needs to analyze impacts of social media and broadcasting program on onion purchase in the previous similar events, and identify potential factors that can promote onion consumption in advance. What we identified from our study include a) broadcasting news programs mentioning words "onion," were correlated with onion purchase with 3 - 6 weeks in advance; b) broadcasting entertainment programs mentioning words "onion and health," were correlated with onion purchase with 11 weeks in advance; c) blog mentioning words "onion and efficacy," were correlated with onion purchase with 5 weeks in advance. Our study provided a case on how social media and broadcasting programs could be analyzed for their effects on consumer purchase behavior using big data collection and analysis in the field of agriculture. We propose to use the findings from the study may be applied to promote onion consumption.

• Journal of the Korean earth science society
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• v.33 no.2
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• pp.200-215
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• 2012

The revitalization of science museum depends on the number of qualified docents who can meet the museum visitors' educational needs. However, the current unstructured docent system is not sufficient to meet the goal. Forty six docents currently working in science museums were surveyed about docent training program, current working conditions, and docent professional program in order to propose a viable system providing a docent profession. Data were collected through surveys with 46 docents, interviews with two experienced docents, and several artifacts from the science museum and selected docents. The surveys consisted of 47 items asking about personal biography, docent's perception, docents training program they took, current working conditions, and supplementary professional program. The conclusion of this study is as follows; First, there must be recognition about docents who can play educator's roles which are different from those of general volunteers in terms of recruiting and training system in science museum. Second, docents need to take training and supplementary professional courses that focus on observing and educating visitors in the field. Third, we need a docent management system by employing a well structured evaluating tools. A well established docent system will bring forth the enhancement of science museum education and the increase of science popularization by providing visitors with the quality educational services.

• Journal of The Korean Association For Science Education
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• v.17 no.3
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• pp.289-299
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• 1997

This study has been undertaken in the light of constructivist view of teacher education. Participant observation, unstructured interview and questionnaire were used to explore the process and the role of practicum in science teacher education. The subjects were 19 student teachers majoring in physics education; 8 had participated at boys junior high school, 11 at senior high school. The student teachers had very critical and negative perception on their school days' science lessons. They had expected to do 'better' in their practicum but there were only 3 to 5 opportunities of teaching under the umbrella of textbook. Explanation in the classroom and solving exercise problem were the main features of student teachers' lessons. Much of the lessons were similar when it is to same topic and the main reference for their lesson preparation was the textbook. The student teachers felt the design of teaching approach as the most difficult thing during their lesson preparation. They realized that teaching is harder than they thought and they should consider students' level and responses. Though they had become to have more positive perception on teaching job through their field experiences, their decision on job preference did not change. More than half did not want to be a teacher. The student teachers recognised the courses related with science education as the most useful to their teaching in practice among the program of college of education which they had taken. The experience of writing one lesson plan or teaching in front of their peers, designing a new demonstration equipment were recognised as valuable and helpful element of the courses. They proposed to reduce the amount of general education courses and to emphasize the courses relevant with science education and practicum. The limited opportunity of teaching in practicum was pointed out as problematic. Though the practicum was recognized as a 'good' experience to student teachers, it was confined by textbook and limited teaching opportunity. In conclusion, the practicum was not organized and implemented as a meaningful experience of science teaching and learning. There should be more structured studies on what kind of perceptions and experiences the student teachers had brought to the science teacher education program, how they interact with the elements of the program and how they affect to their science teaching. The structure and content of practicum also should be studied and developed so as to make practicum as a meaningful experience of science teaching and learning.