• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.108-109
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• 2022

In this study analyzed experimental data on noise interference caused by engine operating apply surface wave communication in the engine room. For the experiment, 7 areas of the engine room on 256 ton tug boat and measured noise during engine on off using signal analyzer for effect surface wave communication. In order to construct and actual communication network based on the analysis of the noise and confirm the characteristics of surface wave communication in the area made metal bulkheads the actual communication network installed communication equipment between three metal bulkheads and conducted a comparative experiment with wireless communication. The difference was confirmed. As a result, in the case of surface wave communication, there was no significant difference in the transmission and reception rates before and after engine operation in an environment with three bulkheads, but in the case of Wi-Fi using wireless, the performance deteriorated significantly during operation. was confirmed. As a result of analyzing the experimental data, it was confirmed that noise caused by engine operation affects wireless communication but does not affect surface wave communication. Therefore, even in the area with a lot of electromagnetic wave noise in the ship, when the surface wave communication system is configured using the ship's metal structure, it is possible to replace the wireless communication and furthermore, it is possible to apply the surface wave communication in the enclosed space and the engine room in the ship.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.57-58
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• 2023

The working time for loading and transporting containers in the container terminal is one of the factors directly related to port productivity, and minimizing working time for these operations can maximize port productivity. Among working time for container operations, the working time of yard tractors(Y/T) responsible for the transportation of containers between berth and yard is a significant portion. However, it is difficult to estimate the working time of yard tractors quantitatively, although it is possible to estimate it based on the practical experience of terminal operators. Recently, a technology based on IoT(Internet of Things), one of the core technologies of the 4th industrial revolution, is being studied to monitoring and tracking logistics resources within the port in real-time and calculate working time, but it is challenging to commercialize this technology at the actual port site. Therefore, this study aims to develop yard tractor working time prediction model to enhance the operational efficiency of the container terminal. To develop the prediction model, we analyze actual port operation data to identify factors that affect the yard tractor's works and predict its working time accordingly.

• Korean Journal of Culture and Social Issue
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• v.17 no.1
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• pp.63-79
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• 2011

The purpose of the present study is to examine effects of anger expression and perceived emotional competence on school anger in adolescents. The participants were 304 high school students (134 males, 170 females). They were administered the anger-related subscales (anger-out, anger-in, and anger control) of the Korean Version of the State-Trait Anger Expression Inventory (STAXI-K), the Korean Version of Trait Meta-Mood Scale (K-TMMS), and the Korean Version of School Anger Inventory(SAI-K). The results showed that school anger positively correlated with anger-out and anger-in, and negatively correlated with anger control and perceived emotional competence. Neither interaction effects of anger-out and perceived emotional competence nor interaction effects of anger-in and perceived emotional competence on school anger were significant. On the contrary, interaction effects of anger control and perceived emotional competence on school anger were significant. The results of post-hoc analysis revealed that the effect of anger control on school anger was significant in the case of high perceived emotional competence but not significant in the case of low perceived emotional competence. Based on these results, it was suggested that psychological programs designed to reduce school anger in adolescents need effective measures to enhance not only anger control skills but also perceived emotional competence.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.3
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• pp.56-63
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• 2023

In this paper, we studied the effect of electron beam irradiation on sol-gel indium-gallium-zinc oxide (IGZO) thin films under air and nitrogen atmosphere and carried out the electrical characterization of the s ol-gel IGZO thin film transistors (TFTs). To investigate the optical properties, crystalline structure and chemical state of the sol-gel IGZO thin films after electron beam irradiation, UV-Visible spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were carried out. The sol-gel IGZO thin films exhibited over 80% transmittance in the visible range. The XRD analysis confirmed the amorphous nature of the sol-gel IGZO films regardless of electron beam irradiation. When electron beam irradiation was conducted in a nitrogen (N₂) atmosphere, we observed an increased proportion of peaks related to M-O bonding contributed to the improved quality of the thin films. Sol-gel IGZO TFTs subjected to electron beam exposure in a nitrogen atmosphere exhibited enhanced electrical characteristics in terms of on/off ratio and electron mobility. In addition, the electrical parameters of the transistor (on/off ratio, threshold voltage, electron mobility, subthreshold swing) remained relatively stable over time, indicating that the electron beam exposure process in a nitrogen atmosphere could enhance the reliability of IGZO-based thin-film transistors in the fabrication of sol-gel processed TFTs.

• Smart Media Journal
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• v.12 no.8
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• pp.9-17
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• 2023

The development of information and communication technology and the improvement of the development and dissemination of smart devices have caused changes in the form of tourism, and the concept of smart tourism has since emerged. In this regard, researches related to smart tourism has been conducted in various fields such as policy implementation and surveys, but there is a lack of research on application reviews. This study collects Trip Advisor application review data in the Google Play Store to identify usage of the application and user satisfaction through Latent Dirichlet Allocation (LDA) topic modeling. The analysis results in four topics, two of which are positive and the other two are negative. We found that users were satisfied with the application's recommendation system, but were dissatisfied when the filters they set during search were not applied or that reviews were not published after updates of the application. We suggest more categories can be added to the application to provide users with different experiences. In addition, it is expected that user satisfaction can be improved by identifying problems within the application, including the filter function, and checking the application environment and resolving the error occurring during the application usage.

• Journal of Korean society of Dental Hygiene
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• v.23 no.5
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• pp.343-350
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• 2023

Objectives: Water constitutes a majority of the human body and is essential for health. In addition, water intake can prevent dental caries by improving salivary lubrication and self-cleaning. This study aimed to determine the relationship between the amount of daily water intake and the symptoms of oral disease in Korean adolescents. Methods: We used data from the Korea Youth Risk Behavior Web-based Survey (KYRBS), conducted in Korea in 2021, and identified the relationship between daily water intake and oral disease symptoms in Korean adolescents. KYRBS is a nationwide cross-sectional survey conducted by the Korea Disease Control and Prevention Agency (KDCA), and a total of 54,848 participants were included in this study. Results: After adjusting for confounding factors, logistic regression analysis showed that tooth pain was more often experienced by those who drank less than two cups of water per day (odds ratio [OR]: 1.14; 95% confidence interval [CI]: 1.01-1.30) than those who drank five or more cups of water per day. Conclusions: A low daily water intake is associated with tooth pain, a symptom of dental caries. The results of our study suggest that increasing water intake may reduce dental caries. Therefore, adequate water intake may help prevent dental caries.

• Journal of Korea Port Economic Association
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• v.39 no.2
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• pp.59-76
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• 2023

In this study, we tried to find out port safety from various perspectives through news data that can be easily accessed by the general public and domestic academic journal data that reflects the insights of port researchers. Non-negative Matrix Factorization(NMF) based topic modeling was conducted using Python to derive the main topics for each data, and then semantic analysis was conducted for each topic. The news data mainly derived natural and environmental factors among port safety risk factors, and the academic journal data derived security factors, mechanical factors, human factors, environmental factors, and natural factors. Through this, the need for strategies to strengthen the safety of domestic ports, such as strengthening the resilience of port safety, improve safety awareness to broaden the public's view of port safety, and conduct research to develop the port industry environment into a safe and specialized mature port. As a result, this study identified the main factors to be improved and provided basic data to develop into a mature port with a port safety culture.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.4
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• pp.344-355
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• 2023

In complete denture fabrication, accurate preliminary impressions are crucial for obtaining an accurate final impression. However, it can be challenging in cases of atypical arch shapes. This case report compares diagnostic casts made with a stock tray and an intraoral scanner (IOS) in a patient with an atypical arch shape. A 58-year-old edentulous male patient with long, narrow, atypical arches was referred to the Oral and Maxillofacial Surgery department for complete denture fabrication. Compared to the diagnostic cast obtained using IOS with adequately captured anatomical parameters, the primary model obtained using a stock tray showed prominent overextended flanges on the labial and buccal sides of the maxillary arch and less prominent overextended flanges in the mandibular arch with pressure spots in the posterior palatal seal area. The custom tray fabricated from such a model required additional adjustment resulting in increased chair time during the final impression procedure.

• Resources Recycling
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• v.32 no.6
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• pp.34-44
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• 2023

In this work, column flotation using factorial design was performed for recovering high-grade molybdenite concentrate. First, the flotation concentrate from Samyang Mining Plant was regrinded to a mean size of 165, 116, 46.7, and 38.4 ㎛ for an increase of the liberation degree. Tests were carried out for various variables affecting column flotation, and then the concentrates with molybdenite grade and recovery of 98.3 % and 95.28 % were obtained, respectively. Also, regression was performed using the statistical analysis program (SPSS 25) with the factorial design and experimental data on particle size, flow wash-water velocity and depressant that affect high grade. From the results, a model equation was derived to predict the molybdenite grade (MG) and recovery (MR) with the relationship between column flotation variables. Factors such as depressant concentration + wash-water velocity and particle size + depressant concentration + wash-water velocity were smaller than the significance level (0.05) and had a significant effect on the dependent variable, grade, and in the recovery model, only particle size and wash-water velocity factors affected the dependent variable, recovery.

• Journal of Veterinary Clinics
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• v.40 no.5
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• pp.336-340
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• 2023

A dog (2-year old, female, Shih-Tzu) presented with hyperthermia and right-sided facial paralysis characterized by the inability to close the right eye and drooling from the right side of the mouth after H3N2 influenza vaccination [A/Canine/Korea/01/07(H3N2) strain; Caniflu-Max, Bionote, Hwaseong, Gyeonggi-do, ROK]. To determine the cause of the fever and neurological symptoms, physical examination, ophthalmic examination, thoracic and abdominal radiography, abdominal ultrasonography, complete blood counts, serum chemistry values, and electrolyte levels were determined. In addition, Cerebrospinal fluid analysis, antinuclear antibody test, fever of unknown origin polymerase chain reaction (PCR) panel, tick-borne pathogen PCR panel were performed. As a result, hyperthermia, leukocytosis, and elevated C-reactive protein were confirmed. In addition, neurological examination revealed decreased right eyelid reflexes, corneal reflexes, threat response, and facial sensation, it was possible to suspect problems with the trigeminal and facial nerves of the cranial nerve. Magnetic resonance imaging revealed a lesion suggestive of myositis in the right muscular lesion at atlanto-occipital junction level on site of vaccine injection. Therefore, right-sided facial paralysis was tentatively determined to be a secondary cause of nerve damage caused by myositis. The patient was treated with immunosuppressants such as prednisolone and mycophenolate mofetil. After 3 months of immunosuppressant therapy, the patient's symptoms improved.