• The Journal of the Acoustical Society of Korea
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• v.43 no.1
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• pp.19-28
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• 2024

This paper proposes a method to improve the performance of ship identification through lofargram analysis of ship noise by applying the Hough Transform to a Convolutional Neural Network (CNN) model. When processing the signals received by a passive sonar, the time-frequency domain representation known as lofargram is generated. The machinery noise radiated by ships appears as tonal signals on the lofargram, and the class of the ship can be specified by analyzing it. However, analyzing lofargram is a specialized and time-consuming task performed by well-trained analysts. Additionally, the analysis for target identification is very challenging because the lofargram also displays various background noises due to the characteristics of the underwater environment. To address this issue, the Hough Transform is applied to the lofargram to add lines, thereby emphasizing the tonal signals. As a result of identification using CNN models on both the original lofargrams and the lofargrams with Hough transform, it is shown that the application of the Hough transform improves lofargram identification performance, as indicated by increased accuracy and macro F1 scores for three different CNN models.

• Journal of dental hygiene science
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• v.24 no.1
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• pp.9-21
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• 2024

Background: The purpose of this study was to utilize text network analysis and topic modeling to identify interconnected relationships among keywords present in patent information related to oral health, and subsequently extract latent topics and visualize them. By examining key keywords and specific subjects, this study sought to comprehend the technological trends in oral health-related innovations. Furthermore, it aims to serve as foundational material, suggesting directions for technological advancement in dentistry and dental hygiene. Methods: The data utilized in this study consisted of information registered over a 20-year period until July 31st, 2023, obtained from the patent information retrieval service, KIPRIS. A total of 6,865 patent titles related to keywords, such as "dentistry," "teeth," and "oral health," were collected through the searches. The research tools included a custom-designed program coded specifically for the research objectives based on Python 3.10. This program was used for keyword frequency analysis, semantic network analysis, and implementation of Latent Dirichlet Allocation for topic modeling. Results: Upon analyzing the centrality of connections among the top 50 frequently occurring words, "method," "tooth," and "manufacturing" displayed the highest centrality, while "active ingredient" had the lowest. Regarding topic modeling outcomes, the "implant" topic constituted the largest share at 22.0%, while topics concerning "devices and materials for oral health" and "toothbrushes and oral care" exhibited the lowest proportions at 5.5% each. Conclusion: Technologies concerning methods and implants are continually being researched in patents related to oral health, while there is comparatively less technological development in devices and materials for oral health. This study is expected to be a valuable resource for uncovering potential themes from a large volume of patent titles and suggesting research directions.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.4
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• pp.685-692
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• 2024

In this paper, we propose a new CNN model to improve the recognition performance of command voice signals. This method obtains a spectrogram image after performing a short-time Fourier transform (STFT) of the input signal and improves command recognition performance through supervised learning using a CNN model. After Fourier transforming the input signal for each short-time section, a spectrogram image is obtained and multi-classification learning is performed using a CNN deep learning model. This effectively classifies commands by converting the time domain voice signal to the frequency domain to express the characteristics well and performing deep learning training using the spectrogram image for the conversion parameters. To verify the performance of the speech recognition system proposed in this study, a simulation program using Tensorflow and Keras libraries was created and a simulation experiment was performed. As a result of the experiment, it was confirmed that an accuracy of 92.5% could be obtained using the proposed deep learning algorithm.

• Journal of Industrial Convergence
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• v.22 no.7
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• pp.103-112
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• 2024

The purpose of this study is to verify the effect of parent's support on the school adaptation of immigrant adolescents to school life, the mediating effect of self-esteem, and the moderating effect of cultural adaptation stress. The data used for the analysis were the second panel data (2020) among the multicultural youth panel survey data. As for the data analysis method, frequency analysis, descriptive statistics analysis, correlation analysis, PROCESS MACRO Model Number 4 and PROCESS MACRO Model Number 1 analysis were performed. As a result of the analysis, first, parental support showed a positive (+) effect on school life adaptation. Second, in the relationship between parent's support and school adaptation, self-esteem had a statistically significant indirect effect. Third, it was found that cultural adaptation stress had no moderating effect in the relationship between parent's support and school adaptation. Based on these results, policy and practical suggestions for improving the school adaptation of immigrant adolescents to school life were presented.

• Journal of the Korea Society of Computer and Information
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• v.29 no.8
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• pp.123-131
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• 2024

The purpose of this study is to identify the prevalence of diabetes and related factors and thereby to provide fundamental data for the prevention and management of diabetes. This study is a secondary analysis based on the raw data from the Korea National Health and Nutrition Examination Survey (KNHANES) for the years 2011 and 2021. Analysis method was frequency analysis, complex samples Chi-square test, complex samples logistic regression analysis. As a result of the study, the factors related to diabetes were sex, age, education level, hypertension, dyslipidemia, and subjective health recognition in 2011(Negelkerke R²=.255), and sex, age, education level, hypertension, dyslipidemia, mother's diabetes, and subjective health recognition in 2021(Negelkerke R²=.327). This study is meaningful in that the factors related to diabetes were identified according to time trend, and the changes in the related factors were confirmed. Development and application of an intervention program to prevent diabetes are necessary.

• The Korean Journal of Emergency Medical Services
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• v.28 no.2
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• pp.99-108
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• 2024

Purpose: This study aimed to compare the effectiveness of one-hand compression method (one-hand) and two-thumb compression methods (two-thumb) using a 3-year-old pediatric mannequin. Methods: Participants in the experiment were randomly assigned to 21 people with one hand and 21 people with two thumbs, who had completed a basic life support training course. The mannequin used a few junior QCPR manikis (Laerdal, Norway), based on an age of 3. The study followed the guidelines for two-rescuer pediatric CPR, performing chest compressions and ventilations in a 15:2 ratio for 5 cycles, 10 minutes. The chest compression number, depth, speed rate, and recoil rate were measured after 1, 3, and 5 cycles, respectively. Data were analyzed using SPSS 23.0. Results: Comparing the efficiency of chest compressions performed during 1, 3, and 5 cycles, the depth of chest compressions was 40.84±3.10 mm for the two thumbs and 51.48±4.79 mm for the one-hand, which was significantly different (p<.001). According to pediatric CPR guidelines, the frequency corresponding to the compression depth range of 40.00-50.00 mm was statistically higher at 57.1% (12 people) of two thumb than at 23.8% (5 people) of one hand (p<.001). Conclusion: While the current guidelines recommend one- or two-thumb encircling hand compressions for larger children, the use of one- or two-handed wrapped thumb compressions should be considered for smaller children, depending on the rescuer's judgment, when distinguishing between a child and an infant is difficult.

• Korean Journal of Agricultural Science
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• v.49 no.4
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• pp.1067-1083
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• 2022

The objectives of this study were to classify the types of elderly households and to compare the characteristics of their dietary lifestyle. Panel data surveyed by Korea Rural Economic Institute (KREI) for Food Purchase Attitudes over three years (2019 - 2021) were utilized for the analysis. Through a factor analysis, five common factors were extracted out of 19 basic variables related to dietary style, which indicate two kinds of consumer competency index (safe diet, traditional diet) and three kinds of purchase frequency (healthy food, meat & fish, fresh seafood). Applying the cluster analysis method, by using socioeconomic variables along the five common factors, elderly households aged 60 or older were grouped into four types. As a result, Type 1 elderly households accounted for 50.8%, Type 2 for 16.2%, Type 3 for 27.8%, and Type 4 for 5.2% out of all 870 elderly households. Type 1 is characterized as a low-income vulnerable class with a poor diet, Type 2 as a middle-income class with a healthy food-oriented diet, whereas Type 3 was classified as a middle-income class with a meat-oriented diet, and Type 4 as a high-income class with diverse dietary culture. It is necessary to expand the agri-food voucher pilot project to the entire country and also increase the monthly subsidy for the Type 1 elderly households. Implementing community kitchen projects for elderly single-person households, promoting senior internships by providing incentives to companies that employ retirees, the provision of education by local governments on a safe and balanced diet for Types 2 and 3, and the promotion of an elderly-friendly social environment are also recommended.

• International Journal of Knowledge Content Development & Technology
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• v.14 no.4
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• pp.65-84
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• 2024

The study was conducted on the awareness and application of internet of things in universities libraries in Kwara State, Nigeria. the study formulated used four research questions and used eighty five (85) samples as the population using total enumerative sampling techniques. A survey method was used in undertaking the study, in which answers were sought on the level of awareness of the internet of things in universities libraries in Kwara State, the extent of application of the internet of things in universities libraries in Kwara State, the benefit of internet of things in universities libraries in Kwara State, the challenges faced in the application of internet of things in universities libraries in Kwara State. The data collected from the study were analyzed using frequency tables and percentage. The study discovered that there the students are aware of the internet of things in universities libraries in Kwara State and the benefit of internet of a things include: Device in the IoT platforms are heterogeneous and are based on different hardware platforms and networks, It gives the high level of interoperability and interconnectivity, IoT platform has sensors which detect or measure any changes in the environment to generate data that can report on their status or even interact with the environment, IoT comes with the combination of algorithms and computation, software & hardware that makes it smart and Anything can be interconnected with the global information and communication infrastructure and the study identified data interpretation problem, Lack of skilled and specialized workers, Cost and Challenges in online security as well as Software complexity are major challenges faced in the application of internet of things in universities libraries in Kwara State. In conclusion the study made some recommendations which include that: Future libraries should be equipped with new technologies and networking devices as soon as possible. As this will be essential for users and librarians to have sufficient knowledge about IOT technologies.

• Journal of Advanced Navigation Technology
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• v.28 no.5
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• pp.706-712
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• 2024

For wirelessly connecting the RF sensing of the radar with a long distant object, the system must have antennas of a high gain. Conventionally, they adopt arrays and curved lenses, but have problems of conductor and dielectric loss in the feed and ending up with a large volume. This paper proposes an FR-4-substrate flat metasurface lens to intensify the RF signal, which undergoes design, fabrication and test. To verify the design method, the antenna sized 64×64mm² is prototyped by inexpensive FR-4 PCB etching process and its S₁₁ and radiated wave are measured. Gain increase of around 10 dB and high directivity are observed at the K-band.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.93-93
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• 2016

Large scale integrated circuits (LSIs) has been improved by the shrinkage of the circuit dimensions. The smaller chip sizes and increase in circuit density require the miniaturization of the line-width and space between metal interconnections. Therefore, an extreme precise control of the critical dimension and pattern profile is necessary to fabricate next generation nano-electronics devices. The pattern profile control of plasma etching with an accuracy of sub-nanometer must be achieved. To realize the etching process which achieves the problem, understanding of the etching mechanism and precise control of the process based on the real-time monitoring of internal plasma parameters such as etching species density, surface temperature of substrate, etc. are very important. For instance, it is known that the etched profiles of organic low dielectric (low-k) films are sensitive to the substrate temperature and density ratio of H and N atoms in the H2/N2 plasma [1]. In this study, we introduced a feedback control of actual substrate temperature and radical density ratio monitored in real time. And then the dependence of etch rates and profiles of organic films have been evaluated based on the substrate temperatures. In this study, organic low-k films were etched by a dual frequency capacitively coupled plasma employing the mixture of H2/N2 gases. A 100-MHz power was supplied to an upper electrode for plasma generation. The Si substrate was electrostatically chucked to a lower electrode biased by supplying a 2-MHz power. To investigate the effects of H and N radical on the etching profile of organic low-k films, absolute H and N atom densities were measured by vacuum ultraviolet absorption spectroscopy [2]. Moreover, using the optical fiber-type low-coherence interferometer [3], substrate temperature has been measured in real time during etching process. From the measurement results, the temperature raised rapidly just after plasma ignition and was gradually saturated. The temporal change of substrate temperature is a crucial issue to control of surface reactions of reactive species. Therefore, by the intervals of on-off of the plasma discharge, the substrate temperature was maintained within ${\pm}1.5^{\circ}C$ from the set value. As a result, the temperatures were kept within $3^{\circ}C$ during the etching process. Then, we etched organic films with line-and-space pattern using this system. The cross-sections of the organic films etched for 50 s with the substrate temperatures at $20^{\circ}C$ and $100^{\circ}C$ were observed by SEM. From the results, they were different in the sidewall profile. It suggests that the reactions on the sidewalls changed according to the substrate temperature. The precise substrate temperature control method with real-time temperature monitoring and intermittent plasma generation was suggested to contribute on realization of fine pattern etching.