• Journal of the Korean Society of Industry Convergence
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• v.26 no.3
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• pp.471-481
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• 2023

Digital twin is considered as a key technology of industry 4.0, thus being essential for the future of industrial production. Despite the significance, a systematic analysis of its technological landscape is lacking. This study aims to investigate the technological development trends and newly emerging technological convergence opportunities in the domain of digital twin by exploiting patent information derived from U SPTO. For this purpose, this study visualized and predicted the convergence dynamics among patent classification codes by adopting patent co-classification analysis and link prediction approach. The findings show that the number of digital twin-related patent applications has increased significantly since 2018. The CPC code G06F showed the highest eigenvector centrality, while G05B was characterized by highest betweenness centrality. According to the predictive model, 41 novel links were revealed, acting as potential technology convergence opportunities. These links were then categorized into 11 different domains. The most dominant category was "digital data processing and artificial intelligence", which could play a foundational role in the diffusion of digital twin technology. The presence of digital twin technology is dominant in manufacturing, but its applications are expected to expand, including "climate change", "healthcare" and "aerospace engineering". The derived insights can support R&D managers and policy makers in formulating R&D strategies and directing future R&D investment decisions.

• Korean Journal of Acupuncture
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• v.40 no.4
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• pp.177-183
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• 2023

Objectives : One of the crucial combinations of acupoints for treating various disorders involves the Eight Confluent acupoints. The present study aims to investigate the selection patterns of the Eight Confluent acupoints in clinical trials and determine the most frequent pairings through network analysis. Methods : The frequencies of the Eight Confluent acupoints were extracted from the Acusynth database, which includes data from 421 clinical investigations. We examined the degree distribution, eigenvector centrality, proximity centrality, and betweenness centrality of these acupoint combinations using network analysis. Results : Data mining revealed that among the Eight Confluent acupoints, PC6 and TE5 were the most commonly applied in the treatment of 30 disorders. Additionally, we identified the most frequently co-occurring pairs of Eight Confluent acupoints by network analysis which included PC6-GV20, SP4-GV4, LU7-LI4, TE5-PC7, GB41-SP6, KI6-BL62, and SI3-BL62. Conclusions : Through the application of data mining and network analysis, we have elucidated the selection patterns and combinations of the Eight Confluent acupoints. These findings provide valuable insights that can enhance doctors' understanding of clinical database-driven Eight Confluent acupoint selection patterns.

• Journal of Korean Academy of Nursing
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• v.53 no.6
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• pp.635-651
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• 2023

Purpose: This study aimed to identify the main keyword, network structure, and main topics of the national petition related to "nursing" in South Korea. Methods: Data were gathered from petitions related to the national petition in Korea Blue House related to the topic "nursing" or "nurse" from August 17, 2017, to May 9, 2022. A total of 5,154 petitions were searched, and 995 were selected for the final analysis. Text network analysis and topic modeling were analyzed using the Netminer 4.5.0 program. Results: Regarding network characteristics, a density of 0.03, an average degree of 144.483, and an average distance of 1.943 were found. Compared to results of degree centrality and betweenness centrality, keywords such as "work environment," "nursing university," "license," and "education" appeared typically in the eigenvector centrality analysis. Topic modeling derived four topics: (1) "Improving the working environment and dealing with nursing professionals," (2) "requesting investigation and punishment related to medical accidents," (3) "requiring clear role regulation and legislation of medical and nonmedical professions," and (4) "demanding improvement of healthcare-related systems and services." Conclusion: This is the first study to analyze Korea's national petitions in the field of nursing. This study's results confirmed both the internal needs and external demands for nurses in South Korea. Policies and laws that reflect these results should be developed.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.1
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• pp.189-201
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• 2023

The purpose of this study is to analyze the ICT startup investment status in Korea and examine the relationship between startups and venture capitals by network analysis. In this study, the Gephi was used to analyze network attribute values and to compare the results of each centrality. As a result of the analysis, IMM investment, Altos Ventures, and Smilegate Investment were located in the top ranks in each centrality. It can present that venture capital companies ranked high in betweenness centrality, closeness centrality, eigenvector centrality have continuously invested in growing startups into unicorns from 2014 to 2019. These results can be used as data for startups want to receive funding from venture capital in the future in consider to the relation of startup and invest industry. This study provides information to develop strategies for the sustainable venture investment environment in Korea of stakeholders such as startups, venture capital, consumers, and the government; as a result, it can help various follow-up studies in the field of startups and venture capital.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.37 no.1
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• pp.41-47
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• 2024

This paper utilizes computational asymptotic analysis to compute the boundary layer solution for composite beams and validates the findings through a comparison with ANSYS results. The boundary layer solution, presented as a sum of the interior solution and pure boundary layer effects, necessitates a mathematically rigorous formalization for both interior and boundary layer aspects. Computational asymptotic analysis emerges as a robust technique for addressing such problems. However, the challenge lies in connecting the boundary layer and interior solutions. In this study, we systematically separate the principles of virtual work and the principles of Saint-Venant to tackle internal and boundary layer issues. The boundary layer solution is articulated by calculating the Papkovich-Fadle eigenfunctions, representing them as linear combinations of real and imaginary vectors. To address warping functions in the interior solutions, we employed a least squares method. The computed solutions exhibit excellent agreement with 2D finite element analysis results, both quantitatively and qualitatively. This validates the effectiveness and accuracy of the proposed approach in capturing the behavior of composite beams.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.2
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• pp.188-202
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• 1997

The seasonal variability of the sea surface winds over the last Sea of Korea (Japan Sea) is investigated by means of empirical orthogonal function (EOF) analysis. The combined representation of fields of three climatic variables by empirical orthogonal functions is discussed. The eigenvectors are derived from daily sea level pressure, wind speed and 10-day mean sea surface temperature (SST) during 15 years $(1978\~1992)$. The spatial patterns of the mean pressure are characterized by the high pressure in the western part and the low pressure in the eastern part. The spatial distribution of the standard deviation (SD) of pressure are characterized by max SD of 6.6 mb near the Vladivostok, and minima along the coast of the Japan. In Vladivostok, the maxima of SD of SST and south-north wind (WV) were also occurred. The representation of fields of individual meteorological variables by EOF shows that the first mode of the west-east wind (WU) explain over $47.3\%$ of the variance and the second mode of WU represents $30\%$. Especially, the first mode of the WV explain $70.9\%$ of the variance and their time series coefficients show 1-cpy, 0.5-cpy frequency spectrum. The spatial distribution of the first mode eigenvectors of SST are characterized by maximum near Vladivostok. The combined representation of fields of several variables (pressure, wind, SST) reveals that the first mode magnitudes of the variance of the combined eigenvectors (WU-PR) are increased. By means of this result, the 1-year peak and the 6-months peak are remarkable. In the three combined patterns (wind, pressure, SST), the second mode of the eigenvector (wind) is affected by the SST. Their time coefficients of the first mode show noticeable 1-year peak. The spectral analysis of the second mode shows broad seasonal signal with the period of 4-months and a significant peak of variability at 3-month period.

• Journal of Korean Home Economics Education Association
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• v.33 no.1
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• pp.17-35
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• 2021

The purpose of this study is to derive implications for the development of the next home economics curriculum by comparing the 'function' and 'achievement standard' presented in the 14 subjects of the 2015 revised middle school common curriculum with the home economics curriculum. For this, keyword network analysis was conducted, and the results are as follows. First, in the 'function' of the 2015 revised middle school common curriculum, 'analysis, use, and expression' were found to be core function keywords with high Degree Centrality and the Eigenvector Centrality. Second, the functional keywords 'understanding, explanation, expression, analysis, and use' in the 'achievement standard' of the 2015 revised middle school common curriculum appeared with high frequency, and 'practice, problem-solving, search and reasoning' which are related to practical problem-solving ability appeared. It was confirmed that 'appreciation, solution and realization', which have relatively high Eigenvector Centrality, were core functional keywords used in the 'achievement standard'. Third, when the 'function' and 'achievement standard' of the 2015 revised middle school home economics curriculum were matched and compared, 7 out of 15 functions were not used in the statement of 'achievement standard', so the connection between 'function' and 'achievement standard' appeared to be insufficient. In addition, the diversity of functional keyword used in the 'achievement standard' was also found insufficient when compared to the middle school common curriculum. Therefore, this study propose strengthening the connectivity of 'function' and 'achievement standard' in the next home economics curriculum, using keywords such as 'analyze', 'express', 'compare', 'understand', 'interpret', 'explore', 'appreciate', and 'solve'.

• Journal of Intelligence and Information Systems
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• v.27 no.1
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• pp.23-46
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• 2021

Collaborative filtering, which is often used in personalization recommendations, is recognized as a very useful technique to find similar customers and recommend products to them based on their purchase history. However, the traditional collaborative filtering technique has raised the question of having difficulty calculating the similarity for new customers or products due to the method of calculating similaritiesbased on direct connections and common features among customers. For this reason, a hybrid technique was designed to use content-based filtering techniques together. On the one hand, efforts have been made to solve these problems by applying the structural characteristics of social networks. This applies a method of indirectly calculating similarities through their similar customers placed between them. This means creating a customer's network based on purchasing data and calculating the similarity between the two based on the features of the network that indirectly connects the two customers within this network. Such similarity can be used as a measure to predict whether the target customer accepts recommendations. The centrality metrics of networks can be utilized for the calculation of these similarities. Different centrality metrics have important implications in that they may have different effects on recommended performance. In this study, furthermore, the effect of these centrality metrics on the performance of recommendation may vary depending on recommender algorithms. In addition, recommendation techniques using network analysis can be expected to contribute to increasing recommendation performance even if they apply not only to new customers or products but also to entire customers or products. By considering a customer's purchase of an item as a link generated between the customer and the item on the network, the prediction of user acceptance of recommendation is solved as a prediction of whether a new link will be created between them. As the classification models fit the purpose of solving the binary problem of whether the link is engaged or not, decision tree, k-nearest neighbors (KNN), logistic regression, artificial neural network, and support vector machine (SVM) are selected in the research. The data for performance evaluation used order data collected from an online shopping mall over four years and two months. Among them, the previous three years and eight months constitute social networks composed of and the experiment was conducted by organizing the data collected into the social network. The next four months' records were used to train and evaluate recommender models. Experiments with the centrality metrics applied to each model show that the recommendation acceptance rates of the centrality metrics are different for each algorithm at a meaningful level. In this work, we analyzed only four commonly used centrality metrics: degree centrality, betweenness centrality, closeness centrality, and eigenvector centrality. Eigenvector centrality records the lowest performance in all models except support vector machines. Closeness centrality and betweenness centrality show similar performance across all models. Degree centrality ranking moderate across overall models while betweenness centrality always ranking higher than degree centrality. Finally, closeness centrality is characterized by distinct differences in performance according to the model. It ranks first in logistic regression, artificial neural network, and decision tree withnumerically high performance. However, it only records very low rankings in support vector machine and K-neighborhood with low-performance levels. As the experiment results reveal, in a classification model, network centrality metrics over a subnetwork that connects the two nodes can effectively predict the connectivity between two nodes in a social network. Furthermore, each metric has a different performance depending on the classification model type. This result implies that choosing appropriate metrics for each algorithm can lead to achieving higher recommendation performance. In general, betweenness centrality can guarantee a high level of performance in any model. It would be possible to consider the introduction of proximity centrality to obtain higher performance for certain models.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.37 no.2
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• pp.31-43
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• 2000

This paper presents a novel algorithm lot extraction of the eye and mouth fields (facial features) from 2D gray level face images. First of all, it has been found that Eigenfeatures, derived from the eigenvalues and the eigenvectors of the binary edge data set constructed from the eye and mouth fields are very good features to locate these fields. The Eigenfeatures, extracted from the positive and negative training samples for the facial features, ate used to train a MultiLayer Perceptron(MLP) whose output indicates the degree to which a particular image window contains the eye or the mouth within itself. Second, to ensure robustness, the ensemble network consisting of multiple MLPs is used instead of a single MLP. The output of the ensemble network becomes the average of the multiple locations of the field each found by the constituent MLPs. Finally, in order to reduce the computation time, we extracted the coarse search region lot eyes and mouth by using prior information on face images. The advantages of the proposed approach includes that only a small number of frontal faces are sufficient to train the nets and furthermore, lends themselves to good generalization to non-frontal poses and even to other people's faces. It was also experimentally verified that the proposed algorithm is robust against slight variations of facial size and pose due to the generalization characteristics of neural networks.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.1B
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• pp.41-51
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• 2012

Sometimes, there exist many alternatives for doing a SOC project. However, the limitation of the fund requires the determination of investment priority for the alternatives. This may be performed according to the degree of importance of individual alternatives. Especially, the river improvement project at the downstream of dams has complex and various values and this characteristics make it difficult decision-maker to do reasonable determination. This study aims to determine an investment priority of 33 alternatives in the river improvement project at the downstream of dams using PROMETHEE method which has advantages in determining the priority. In this study, we determined evaluation criteria and attributes by considering the functions and objectives of the river improvement project at the downstream of dams. The eigenvector method in AHP was used to estimate the relative importance of evaluation criterion. Based on the estimation, we determined investment priority of 33 alternatives by PROMETHEE method and the priority of alternatives was derived in the order of Juam regulation dam, Unmun dam, Yongdam dam and so on. The results of this study could provide a reasonable standard to the decision-maker for the determination of investment priority of alternatives.