• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.4
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• pp.157-166
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• 2022

In the case of a die-casting process, defects that are difficult to confirm by visual inspection, such as shrinkage bubbles, may occur due to an error in maintaining a vacuum state. Since these casting defects are discovered during post-processing operations such as heat treatment or finishing work, they cannot be taken in advance at the casting time, which can cause a large number of defects. In this study, we propose an approach that can predict the occurrence of casting defects by defect type using machine learning technology based on casting parameter data collected from equipment in the die casting process in real time. Die-casting parameter data can basically be collected through the casting equipment controller. In order to perform classification analysis for predicting defects by defect type, labeling of casting parameters must be performed. In this study, first, the defective data set is separated by performing the primary clustering based on the total defect rate obtained during the post-processing. Second, the secondary cluster analysis is performed using the defect rate by type for the separated defect data set, and the labeling task is performed by defect type using the cluster analysis result. Finally, a classification learning model is created by collecting the entire labeled data set, and a real-time monitoring system for defect prediction using LabView and Python was implemented. When a defect is predicted, notification is performed so that the operator can cope with it, such as displaying on the monitoring screen and alarm notification.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.571-580
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• 2023

The purpose of this study is to evaluate the accessibility of the Cakewalk SI-Drum for the screen reader users. An evaluation was performed by testing the accessibility of the [Virtual Instrument Editing] that is a part of MIDI Production of the NCS(National Competency Standards) by using the SI-Drum and the Sense Reader. The results of this study are as follows. The SI-Drum has almost no basic accessibility for the screen users to do an above task. But the screen reader users can perform the tasks by using Sense Reader's Mouse Pointer function and Position Memory function. To use SI-Drum more efficiently, SI-Drum's basic accessibility have to be provided fully. Several suggestions are proposed to develop a fully accessible SI-Drum for the screen users.

• Journal of dental hygiene science
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• v.23 no.1
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• pp.1-12
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• 2023

Background: This study aimed to identify the present level and needs of clinical dental hygienists and to present the Borich needs assessment and the locus for focus model as integrated priorities. Methods: The participants of this study were dental hygienists working in dental clinics (hospitals). The final data of the 194 participants were analyzed using frequency analysis and a paired sample t-test. To analyze the need for clinical dental hygienists to perform work, the Borich priority determination formula was used. The x-y plane consisting of four quadrants was used to analyze the need using the locus for focus model, which helps to determine the priority while showing visual effects. Results: "Scaling" was the highest required level for clinical dental hygienists, and "panorama taking" was the highest present level. The priorities of educational needs were systematically and visually derived from dental hygienists who were currently working through the Borich needs assessment and the locus for focus model for each task performed in the clinical field. Through the priorities of these two models, a total of 13 items appeared in the common high-level area; "oral health care (disability)," "oral health care (systemic disease)," "applying a rubber dam," "professional mechanical tooth cleaning," "root planing," "taking vital signs," "medication counseling," "wire cutting," "removing cement after removing band/bracket," "delivering bracket," "preparing mini-screw implantation," "dental insurance claim," and "patient reception." Conclusion: Based on the results, the department of dental hygiene should maintain and improve the standardized clinical practice curriculum and clinical dental hygienists' practical skills and contribute to the realization of the legal scope of dental hygienists, reflecting the requirements of clinical fields.

• Communications of Mathematical Education
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• v.37 no.2
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• pp.257-276
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• 2023

Mathematical modeling can be described as a series of processes in which real-world problem situations are understood, interpreted using mathematical methods, and solved based on mathematical models. The effectiveness of mathematics instruction using mathematical modeling has been demonstrated through prior research. This study aims to explore insights for mathematical modeling instruction by analyzing the metacognitive characteristics shown in the mathematical modeling cycle, according to the mathematical thinking styles of elementary math gifted students. To achieve this, a mathematical thinking style assessment was conducted with 39 elementary math gifted students from University-affiliated Science Gifted Education Center, and based on the assessment results, they were classified into visual, analytical, and mixed groups. The metacognition manifested during the process of mathematical modeling for each group was analyzed. The analysis results revealed that metacognitive elements varied depending on the phases of modeling cycle and their mathematical thinking styles. Based on these findings, didactical implications for mathematical modeling instruction were derived.

• Physical Therapy Korea
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• v.30 no.3
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• pp.221-229
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• 2023

Background: In modern society, the use of computers accounts for a large proportion of our daily lives. Although substantial research is being actively conducted on musculoskeletal diseases resulting from computer use, there has been a recent surge in interest in improving the working environment for prevention. Objects: This study aimed to examine the effects of posture correction feedback (PCF) on changes in neck posture and muscle activation during computer typing. Methods: The participants performed a computer typing task in two sessions, each lasting 16 minutes. The participant's dominant side was photographed and analyzed using ImageJ software to verify neck posture. Surface electromyography (EMG) was used to confirm the participant's cervical erector spinae (CES) and upper trapezius muscle activities. The EMG signal was analyzed using the percentage of reference voluntary contraction and amplitude probability distribution function (APDF). In the second session, visual and auditory feedback for posture correction was provided if the neck was flexed by more than 15° in the initial position during computer typing. A 20-minute rest period was provided between the two sessions. Results: The neck angle (p = 0.014), CES muscle activity (p = 0.008), and APDF (p = 0.015) showed significant differences depending on the presence of the PCF. Furthermore, significant differences were observed regarding the CES muscle activity (p = 0.001) and APDF (p = 0.002) over time. Conclusion: Our study showed that the feedback system can correct poor posture and reduces unnecessary muscle activation during computer work. The improved neck posture and reduced CES muscle activity observed in this study suggest that neck pain can be prevented. Based on these results, we suggest that the PCF system can be used to prevent neck pain.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.10
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• pp.2627-2642
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• 2023

Parkinson's disease (PD) is a typical, chronic neurodegenerative disease involving the concentration of dopamine, which can disrupt motor activity and cause different degrees of gait disturbance relevant to PD severity in patients. As current clinical PD diagnosis is a complex, time-consuming, and challenging task that relays on physicians' subjective evaluation of visual observations, gait disturbance has been extensively explored to make automatic detection of PD diagnosis and severity rating and provides auxiliary information for physicians' decisions using gait data from various acquisition devices. Among them, wearable sensors have the advantage of flexibility since they do not limit the wearers' activity sphere in this application scenario. In this paper, an attention-based temporal network (ATN) is designed for the time series structure of gait data (vertical ground reaction force signals) from foot sensor systems, to learn the discriminative differences related to PD severity levels hidden in sequential data. The structure of the proposed method is illuminated by Transformer Network for its success in excavating temporal information, containing three modules: a preprocessing module to map intra-moment features, a feature extractor computing complicated gait characteristic of the whole signal sequence in the temporal dimension, and a classifier for the final decision-making about PD severity assessment. The experiment is conducted on the public dataset PDgait of VGRF signals to verify the proposed model's validity and show promising classification performance compared with several existing methods.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.34 no.4
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• pp.275-282
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• 2023

Objectives: This study aimed to identify the psychiatric comorbidity status of adult patients diagnosed with attention-deficit hyperactivity disorder (ADHD) and determine the impact of comorbidities on neuropsychological outcomes in ADHD. Methods: The study participants were 124 adult patients with ADHD. Clinical psychiatric assessments were performed by two board-certified psychiatrists in accordance with the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. All participants were assessed using the Mini-International Neuropsychiatric Interview Plus version 5.0.0 to evaluate comorbidities. After screening, neuropsychological outcomes were assessed using the Comprehensive Attention Test (CAT) and the Korean version of the Wechsler Adult Intelligence Scale, Fourth Edition (K-WAIS-IV). Results: Mood disorders (38.7%) were the most common comorbidity of ADHD, followed by anxiety (18.5%) and substance use disorders (13.7%). The ADHD with comorbidities group showed worse results on the Perceptual Organization Index and Working Memory Index sections of the K-WAIS than the ADHD-alone group (p=0.015 and p=0.024, respectively). In addition, the presence of comorbidities was associated with worse performance on simple visual commission errors in the CAT tests (p=0.024). Conclusion: These findings suggest that psychiatric comorbidities are associated with poor neuropsychological outcomes in adult patients with ADHD, highlighting the need to identify comorbidities in these patients.

• Dementia and Neurocognitive Disorders
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• v.22 no.4
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• pp.148-157
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• 2023

Background and Purpose: Episodic memory is a system that receives and stores information about temporally dated episodes and their interrelations. Our study aimed to investigate the relevance of episodic memory to time perception, with a specific focus on simultaneity/order judgment. Methods: Experiment 1 employed the simultaneity judgment task to discern differences in time perception between patients with mild cognitive impairment or dementia, and age-matched normals. A mathematical analysis capable of estimating subjects' time processing was utilized to identify the sensory and decisional components of temporal order and simultaneity judgment. Experiment 2 examined how differences in temporal perception relate to performance in temporal order memory, in which time delays play a critical role. Results: The temporal decision windows for both temporal order and simultaneity judgments exhibited marginal differences between patients with episodic memory impairment, and their healthy counterparts (p = 0.15, t(22) = 1.34). These temporal decision windows may be linked to the temporal separation of events in episodic memory (Pearson's ρ = -0.53, p = 0.05). Conclusions: Based on our findings, the frequency of visual events accumulated and encoded in the working memory system in the patients' and normal group appears to be approximately (5.7 and 11.2) Hz, respectively. According to the internal clock model, a lower frequency of event pulses tends to result in underestimation of event duration, which phenomenon might be linked to the observed time distortions in patients with dementia.

• Korean Journal of Clinical Laboratory Science
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• v.56 no.1
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• pp.89-98
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• 2024

Gross examination techniques (GETs) of specimens collected from cancer surgery or endoscopy comprise the act of recording visual information about cancer for accurate histopathological diagnosis and collecting sections of the lesion to create microscopic specimens. GETs must include concise and accurate expressions, appropriate structuring, sufficient resections, error-free standardization of important information, and photo-diagramming of complex specimens. To increase the satisfaction of pathological interpretation, it is a task that must be performed accurately and carefully to gain confidence on a theoretical and practical basis with a sufficient understanding of gross examination. Based on the experience of clinical pathologists in the field of GETs, additional specimen types should be identified as viable candidates. Also, their needs and concerns regarding treatment should be carefully considered. In addition, departments at each institution should review the national focus on clinical partnerships, continuous professional training, diagnostic errors, and value-based healthcare provision.

• Archives of design research
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• v.19 no.1 s.63
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• pp.225-234
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• 2006

Product designers sketch various ideas of foreground figures(detail design) onto background figures(basic form) and evaluate numerous combinations of them in the late stages of design process. Designers have to test their ideas elaborately with a high-fidelity physical model that looks like a real product. However, due to the requirements of time and expense in making high-fidelity design models, it is impossible to evaluate such a number of combinatorial solutions of background and foreground figures. Contrary to digital models, physical design models are not easily modifiable and so designers cannot easily develope ideas through iterative design-evaluation process. To address these problems, we proposed a new concept 'Augmented Plasticity' that gives morphological editability to a rigid physical object using Augmented Reality technology and implemented the idea as Digital Skin system. Digital Skin system figures out the position and orientation of object surface with ARToolKit visual marker and superimposes a deformed surface image seamlessly using differential rendering method. We tried to apply Digital Skin system to detail design, redesign of product, and material exploration task. In consequence, it was found that Digital Skin system has potential to allow designers to implement and test their ideas very efficiently in the late stages of design process.