• 대한치과기공학회지
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• 제44권4호
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• pp.132-143
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• 2022

Purpose: The study aims to analyze differences in the satisfaction level of dental technology students regarding in-person and online classes. It also aims to provide fundamental resources for the improvement of major subject class methods that will improve students' self-directed learning abilities, thereby affecting their class satisfaction. Methods: In this study, a self-administered questionnaire was conducted from November 8 to November 30, 2021, for 256 dental technology students. The collected data were analyzed using the IBM SPSS Statistics ver. 21.0 statistical program. Frequency and percentage, mean, standard deviation, t-test, ANOVA, post-hoc test, correlation analysis, and linear regression analysis were performed to analyze the data. Results: In the self-directed learning abilities, the attitude of the learners was shown to have the highest positive (+) correlation in both in-person and online classes, with a statistically significant effect (p<0.001) on class satisfaction in major subject classes. Moreover, the explanatory power of the model was 52.2% and 39.7%, respectively. Conclusion: We concluded from the study that there is a need for professors to improve teaching methods to increase learners' self-directed learning competence, through problem-based learning, discussion learning, team-based collaborative learning, and mentor-mentee learning, thereby enabling learners to lead classes themselves.

• 대한치과기공학회지
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• 제43권3호
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• pp.132-137
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• 2021

Purpose: To study the perception and satisfaction of in-person and online classes for dental technology students. Methods: A total of 420 questionnaires were distributed to dental technology students between June 1 and June 30, 2021. Of these, 225 questionnaires were assessed using frequency analysis, one-way analysis of variance, Pearson's Chi-squared test, and independent t-tests via IBM SPSS Statistics ver. 22.0 (IBM). Results: For theory subjects, satisfaction was higher for online classes than in-person classes (p=0.001). For practical subjects, satisfaction was higher for in-person classes than online classes (p=0.002). Both the learning effect and motivation for learning were higher for in-person classes than online classes (p=0.001). Conclusion: When in-person and online classes become coexistent, there should be educational guidelines for improving the quality and effectiveness of learning in these different contexts.

• International journal of advanced smart convergence
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• 제7권4호
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• pp.27-39
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• 2018

Since the global positioning system (GPS) has been included in mobile devices (e.g., for car navigation, in smartphones, and in smart watches), the impact of personal GPS log data on daily life has been unprecedented. For example, such log data have been used to solve public problems, such as mass transit traffic patterns, finding optimum travelers' routes, and determining prospective business zones. However, a real-time analysis technique for GPS log data has been unattainable due to theoretical limitations. We introduced a machine learning model in order to resolve the limitation. In this paper presents a new, three-stage real-time prediction model for a person's daily route activity. In the first stage, a machine learning-based clustering algorithm is adopted for place detection. The training data set was a personal GPS tracking history. In the second stage, prediction of a new person's transient mode is studied. In the third stage, to represent the person's activity on those daily routes, inference rules are applied.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권2호
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• pp.751-770
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• 2019

Action recognition is an essential task in computer vision due to the variety of prospective applications, such as security surveillance, machine learning, and human-computer interaction. The availability of more video data than ever before and the lofty performance of deep convolutional neural networks also make it essential for action recognition in video. Unfortunately, limited crafted video features and the scarcity of benchmark datasets make it challenging to address the multi-person action recognition task in video data. In this work, we propose a deep convolutional neural network-based Effective Hybrid Learning (EHL) framework for two-person interaction classification in video data. Our approach exploits a pre-trained network model (the VGG16 from the University of Oxford Visual Geometry Group) and extends the Faster R-CNN (region-based convolutional neural network a state-of-the-art detector for image classification). We broaden a semi-supervised learning method combined with an active learning method to improve overall performance. Numerous types of two-person interactions exist in the real world, which makes this a challenging task. In our experiment, we consider a limited number of actions, such as hugging, fighting, linking arms, talking, and kidnapping in two environment such simple and complex. We show that our trained model with an active semi-supervised learning architecture gradually improves the performance. In a simple environment using an Intelligent Technology Laboratory (ITLab) dataset from Inha University, performance increased to 95.6% accuracy, and in a complex environment, performance reached 81% accuracy. Our method reduces data-labeling time, compared to supervised learning methods, for the ITLab dataset. We also conduct extensive experiment on Human Action Recognition benchmarks such as UT-Interaction dataset, HMDB51 dataset and obtain better performance than state-of-the-art approaches.

• 사상체질의학회지
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• 제34권3호
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• pp.31-40
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• 2022

Objectives Sasang constitutional medicine is a traditional Korean medicine that classifies humans into four constitutions in consideration of individual differences in physical, psychological, and physiological characteristics. In this paper, we proposed a method to classify Taeeum person (TE) and Non-Taeeum person (NTE), Soeum person (SE) and Non-Soeum person (NSE), and Soyang person (ST) and Non-Soyang person (NSY) using a convolutional neural network with only facial images. Methods Based on the convolutional neural network VGG16 architecture, transfer learning is carried out on the facial images of 3738 subjects to classify TE and NTE, SE and NSE, and SY and NSY. Data augmentation techniques are used to increase classification performance. Results The classification performance of TE and NTE, SE and NSE, and SY and NSY was 77.24%, 85.17%, and 80.18% by F1 score and 80.02%, 85.96%, and 72.76% by Precision-Recall AUC (Area Under the receiver operating characteristic Curve) respectively. Conclusions It was found that Soeum person had the most heterogeneous facial features as it had the best classification performance compared to the rest of the constitution, followed by Taeeum person and Soyang person. The experimental results showed that there is a possibility to classify constitutions only with facial images. The performance is expected to increase with additional data such as BMI or personality questionnaire.

• Journal of Information Processing Systems
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• 제15권4호
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• pp.785-796
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• 2019

Due to the view point, illumination, personal gait and other background situation, person re-identification across cameras has been a challenging task in video surveillance area. In order to address the problem, a novel method called Joint Bayesian across different cameras for person re-identification (JBR) is proposed. Motivated by the superior measurement ability of Joint Bayesian, a set of Joint Bayesian matrices is obtained by learning with different camera pairs. With the global Joint Bayesian matrix, the proposed method combines the characteristics of multi-camera shooting and person re-identification. Then this method can improve the calculation precision of the similarity between two individuals by learning the transition between two cameras. For investigating the proposed method, it is implemented on two compare large-scale re-ID datasets, the Market-1501 and DukeMTMC-reID. The RANK-1 accuracy significantly increases about 3% and 4%, and the maximum a posterior (MAP) improves about 1% and 4%, respectively.

• 한국멀티미디어학회논문지
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• 제23권8호
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• pp.891-902
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• 2020

The Re-Identification(Re-ID) is one of the most popular researches in the field of computer vision due to a variety of applications. To achieve a high-level re-identification performance, recently other methods have developed the deep learning based networks that are specialized for only person or vehicle. However, most of the current methods are difficult to be used in real-world applications that require re-identification of both person and vehicle at the same time. To overcome this limitation, this paper proposes a deep neural network learning method that combines triplet and softmax loss to improve performance and re-identify people and vehicles simultaneously. It's possible to learn the detailed difference between the identities(IDs) by combining the softmax loss with the triplet loss. In addition, weights are devised to avoid bias in one-side loss when combining. We used Market-1501 and DukeMTMC-reID datasets, which are frequently used to evaluate person re-identification experiments. Moreover, the vehicle re-identification experiment was evaluated by using VeRi-776 and VehicleID datasets. Since the proposed method does not designed for a neural network specialized for a specific object, it can re-identify simultaneously both person and vehicle. To demonstrate this, an experiment was performed by using a person and vehicle re-identification dataset together.

• 한국컴퓨터정보학회논문지
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• 제27권3호
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• pp.1-12
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• 2022

해양조난사고 발생 시 해상 익수자의 안전과 생명 보장을 위해 구조자산을 활용한 신속한 탐색 및 구조작전은 매우 중요하다. 본 연구는 해양관측부이에서 수집되는 기상정보에 다중선형회귀분석, 의사결정나무, 서포트벡터머신, 벡터자기회귀, 순환신경망의 LSTM을 활용하여 울릉도 북서해역의 표층해류를 분석하고 유향과 유속에 대한 각각의 예측모형을 구축하여 예측된 유향과 유속정보를 통해 해상 익수자의 이동경로를 예측하는 모형들을 제안한다. 본 연구에서 적용한 다양한 기계학습 모형을 MAE와 RMSE의 성능 평가척도로 비교해 볼 때 LSTM이 가장 우수한 성능을 보였다. 또한, 익수자 이동지점과 예측모형의 예측지점 간 거리 차이에 있어서도 LSTM이 다른 모형들에 비해 탁월한 성능을 나타내었다.

• 의학교육논단
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• 제24권1호
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• pp.56-62
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• 2022

Despite current regulations requiring social distancing due to coronavirus disease 2019, problem-based learning (PBL) requires student interaction to achieve common goals and enhance critical thinking and deep learning abilities. Social presence in the online education environment reduces both perceptions of physical distance and psychological distance in interactions. This study aimed to compare PBL activities between in-person and videoconferencing classes, and to investigate social presence and learning satisfaction in a videoconferencing PBL environment. The PBL consisted of six modules for both the first and second years of Chonnam National University Medical School. As social distancing was strengthened, the second class of the fifth module in both years was converted to an online format and the fifth module was excluded. The first four PBL modules were conducted as in-person classes, but the last PBL module was administered via videoconferencing. After the final PBL module, 100 (81.3%) first-year medical students and 90 (79.6%) second-year students were asked to complete a self-administered questionnaire on social presence and learning satisfaction. There were no significant differences in the small group activities of tutorial sessions between in-person and videoconferencing classes. In the online videoconferencing class, students who had favorable attitudes toward the tutors' social role and interactions with peers showed high satisfaction with their learning. In conclusion, online videoconferencing allows students to simultaneously perceive their interactions with others and social presence, even at a distance. Tutors can enhance a sense of online community and collaborative learning as facilitators of online PBL.

• 한국간호교육학회지
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• 제23권1호
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• pp.118-130
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• 2017

Purpose: The purpose of this study was to identify the relationship between the satisfaction with clinical practice and clinical performance ability by types of self-directed learning ability of nursing students. Methods: This was a triangular study that was conducted to understand clinical performance ability. The subjects were 260 junior and senior students from a university in P city. The data were collected from April 22 to December 30, 2015. Data were collected by Q-card, Q-block an assessment tool, a structured self-reporting survey and a questionnaire. Results: We classified the self-directed learning abilities into four types: Type 1: a self-reflective person; Type 2: a person who prepares for the future; Type 3: a person with a sense of responsibility and obligation; and Type 4: an enthusiastic learner. We found that clinical performance ability was higher for Type 4 than Type 3. We found that clinical performance satisfaction with clinical practice was also higher for the Type 4 individual than a Type 3 person. Conclusion: To improve students' clinical performance ability, we need plans and support to lead students toward becoming an 'enthusiastic learner' type of person with self-directed learning ability. It is necessary to increase students' satisfaction with clinical practice.