• Advances in Computational Design
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• v.6 no.1
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• pp.15-30
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• 2021

With improvement in innovative manufacturing technologies, it became possible to fabricate any complex shaped structural design for practical applications. This allows for the fabrication of curvilinearly stiffened pressure vessels and pipes. Compared to straight stiffeners, curvilinear stiffeners have shown to have better structural performance and weight savings under certain loading conditions. In this paper, an optimization framework for designing curvilinearly stiffened composite pressure vessels and pipes is presented. NURBS are utilized to define curvilinear stiffeners over the surface of the pipe. An integrated tool using Python, Rhinoceros 3D, MSC.PATRAN and MSC.NASTRAN is implemented for performing the optimization. Rhinoceros 3D is used for creating the geometry, which later is exported to MSC.PATRAN for finite element model generation. Finally, MSC.NASTRAN is used for structural analysis. A Bi-Level Programming (BLP) optimization technique, consisting of Particle Swarm Optimization (PSO) and Gradient-Based Optimization (GBO), is used to find optimal locations of stiffeners, geometric dimensions for stiffener cross-sections and layer thickness for the composite skin. A cylindrical pipe stiffened by orthogonal and curvilinear stiffeners under torsional and bending load cases is studied. It is seen that curvilinear stiffeners can lead to a potential 10.8% weight saving in the structure as compared to the case of using straight stiffeners.

• The Journal of Information Systems
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• v.31 no.3
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• pp.19-45
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• 2022

Purpose Since COVID-19, the demand for online class platforms has increased. However, those platforms have not been clearly defined, and related research is also limited. In the context of the knowledge marketplace (KMs), this study examined the effects of class information and trust in creators on class preferences from the perspective of consumption value theory. Design/methodology/approach By establishing a web crawler through Python, this study collected 1,174 class data in Korea's leading knowledge marketplace, Class 101, focusing on diverse class-related information and the number of Instagram followers for individual class creators. Based on class information, this research analyzed the effects of consumers' utilitarian value, social value, and hedonic value on class preference. In addition, this study examined whether consumers' trust in creators moderates the relationship between class information and class preference. Findings According to analysis results, it was found that the higher the consumers' consumption value for each class on KMs, the more positive their preference for the class. Also, it was confirmed that consumers' trust in creators moderates the relationship between class information and class preference.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.3
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• pp.272-280
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• 2022

The first step is to determine the principal dimensions of the design ship, such as length between perpendiculars, beam, draft and depth when accomplishing the design of a new vessel. To make this process easier, a database with a large amount of existing ship data and a regression analysis technique are needed. Recently, deep learning, a branch of artificial intelligence (AI) has been used in regression analysis. In this paper, deep learning neural networks are used for regression analysis to find the regression function between the input and output data. To find the neural network structure with the highest accuracy, the errors of neural network structures with varying the number of the layers and the nodes are compared. In this paper, Python TensorFlow Keras API and MATLAB Deep Learning Toolbox are used to build deep learning neural networks. Constructed DNN (deep neural networks) makes helpful in determining the principal dimension of the ship and saves much time in the ship design process.

• Communications of Mathematical Education
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• v.37 no.3
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• pp.467-482
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• 2023

In this paper, we present our new teaching and learning materials on gradient descent method, which is widely used in artificial intelligence, available for college mathematics. These materials provide a good explanation of gradient descent method at the level of college calculus, and the presented SageMath code can help students to solve minimization problems easily. And we introduce how to solve least squares problem using gradient descent method. This study can be helpful to instructors who teach various college-level mathematics subjects such as calculus, engineering mathematics, numerical analysis, and applied mathematics.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.47 no.3
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• pp.127-140
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• 2024

This study proposes a construction plan for the Korea Navy's next-generation TSCE(Total Ship Computing Environment) based destroyers to address rapidly evolving maritime threats and decreasing military manpower. It focuses on system integrated ship construction based on TSCE for quick response time with fewer operators, improving the efficiency of systems and Equipments installed in the ship. The methodology includes analyzing TSCE-based system integration theories and levels. also analyze system integration in U.S. Navy's Zumwalt destroyers and Littoral Combat Ships, conducting expert surveys to build consensus on system integration methods, proposing operational efficiency improvements through TSCE-based system integration. Additionally, we propose an architecture of TSCE with real time OA(Open Architecture) from both functional and physical perspectives, verified through Python simulations. The study suggests optimal crew sizes for next-generation destroyers through comparative analysis of TSCE based integration types. It emphasizes the importance of system integration in naval ship construction, presenting specific measures to enhance operational efficiency and optimize crew operations. The findings are expected to contribute significantly to enhance the future naval capabilities of the Korea Navy.

• Journal of information and communication convergence engineering
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• v.22 no.3
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• pp.221-230
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• 2024

The aim of this study is to investigate the automatic recognition and analysis of Jeju marine-life images using artificial intelligence (AI) technology. The dataset of marine-life images was prepared using tools such as Python, TensorFlow, and Google Colab (Google Colaboratory). We also developed models by training deep learning AI in image recognition to automatically recognize the species found in these images and extract their associated information, such as taxonomy, characteristics, and distribution. This study is innovative in that it uses deep learning technology combined with imagerecognition technology for marine biodiversity research. In addition, these results will lead to the development of the marine-life industry in Jeju by supporting marine environment monitoring and marine resource conservation. Furthermore, this study is anticipated to contribute to academic advancement, specifically in the study of marine species diversity.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.4
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• pp.49-62
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• 2022

Borehole Data is geotechnical information provided so that workers can safely perform construction at the field. It creates 3D data and supports viewing as a 3D image. Currently, all Korean companies that develop programs using 3D visualization use the MVS program developed by C Tech Development Corporation. However, the MVS program is a commercial program, and it is difficult to use MVS in 3D related programs developed by Korean Companies. In this paper, we propose to develop a program that can replace MVS to generate a 3D stratum model from clustered borehole information using Python's Gempy open-source. The 3D stratum model program can creates point data for each stratum and can creates a surface for each stratum through interpolation. Then, the 3D stratum model program is completed by merging the surfaces of each stratum. It was confirmed that there was no difference when a 3D model was created and compared with the MVS program and the proposed program from the borehole data of a Goyang area.

• Journal of Satellite, Information and Communications
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• v.12 no.3
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• pp.108-113
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• 2017

The OBCP called 'operator on board' is that of a procedure to be executed on-board, which can be easily be loaded, executed, and also replaced, without modifying the remainder of the FSW. The use of OBCP enhances the on-board autonomy capabilities and increases the robustness to ground stations outages. The OBCP engine which is the core module of OBCP component in the FSW interprets and executes of the procedures based on script language written using a high-level language, possibly compiled, and it is relying on a virtual machine of the OBCP engine. FSW team in KARI has studied OBCP since 2010 as FSW team's internal projects, and made some OBCP engines such as Java KVM, RTCS/C and KKOMA on ERC32 processor target only for study. Recently we have been studying ESA's OBCP standard and implementing Lua and MicroPython on LEON2-FT/AT697F processor target as the OBCP engine. This paper presents the design and implementation of Lua for the OBCP engine on AT697F processor with VxWorks RTOS, and describes the evaluation result and performance of the OBCP engine.

• Journal of the Korea Convergence Society
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• v.12 no.8
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• pp.1-11
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• 2021

The purpose of this study was to analyze the trends and characteristics of 'stress urinary incontinence' research through word frequency analysis, and their relationships were modeled using word embedding. Abstract data of 9,868 papers containing abstracts in PubMed's MEDLINE were extracted using a Python program. Then, through frequency analysis, 10 keywords were selected according to the high frequency. The similarity of words related to keywords was analyzed by Word2Vec machine learning algorithm. The locations and distances of words were visualized using the t-SNE technique, and the groups were classified and analyzed. The number of studies related to stress urinary incontinence has increased rapidly since the 1980s. The keywords used most frequently in the abstract of the paper were 'woman', 'urethra', and 'surgery'. Through Word2Vec modeling, words such as 'female', 'urge', and 'symptom' were among the words that showed the highest relevance to the keywords in the study on stress urinary incontinence. In addition, through the t-SNE technique, keywords and related words could be classified into three groups focusing on symptoms, anatomical characteristics, and surgical interventions of stress urinary incontinence. This study is the first to examine trends in stress urinary incontinence-related studies using the keyword frequency analysis and word embedding of the abstract. The results of this study can be used as a basis for future researchers to select the subject and direction of the research field related to stress urinary incontinence.

• Therapeutic Science for Rehabilitation
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• v.13 no.1
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• pp.49-63
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• 2024

Objective : The purpose of this study was to investigate parental perspectives on cognitive rehabilitation using a combination of phenomenological research methodology and word cloud analysis. Methods : Interviews were conducted with five parents of children with developmental disabilities. Word cloud analysis was conducted using Python, and five researchers analyzed the meaning units and themes using phenomenological methods. Words with high frequency were considered as a heuristic tool. Results : A total of 43 meaning units and nine components related to the phenomenon of cognitive rehabilitation were derived, and three themes were finalized. The main themes encompassed the definition of cognitive rehabilitation, challenges associated with cognitive rehabilitation, and factors influencing the selection of a cognitive rehabilitation institute. Cognitive rehabilitation emerged as a treatment focused on improving learning, daily functioning, and cognitive abilities in children with developmental disabilities. The perceived issues with cognitive rehabilitation pertained to treatment methods, therapist expertise, and associated costs. In addition, parents highlighted the importance of therapist expertise, humane personality, and affordability of cost and schedule when choosing a cognitive rehabilitation institute. Conclusion : Parents expressed expectations for substantial improvements in their children's daily functioning through cognitive rehabilitation. However, challenges were identified in clinical practices. Going forward, we expect that cognitive rehabilitation will evolve into a better therapeutic support service addressing the concerns raised by parents.