• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.8
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• pp.975-980
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• 2019

In this paper, we propose a deep learning-based scheduling scheme for user selection in multi-user multi-antenna networks which is considered one of key technologies for the next generation mobile communication systems. We obtained 90,000 data samples from the conventional optimal scheme to train the proposed neural network and verified the trained neural network to check if the trained neural network is over-fitted. Although the proposed neural network-based scheduling algorithm requires considerable complexity and time for training in the initial stage, it does not cause any extra complexity once it has been trained successfully. On the other hand, the conventional optimal scheme continuously requires the same complexity of computations for every scheduling. According to extensive computer-simulations, the proposed deep learning-based scheduling algorithm yields about 88~96% average sum-rates of the conventional scheme for SNRs lower than 10dB, while it can achieve optimal average sum-rates for SNRs higher than 10dB.

• Journal of the Korea Convergence Society
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• v.12 no.4
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• pp.285-291
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• 2021

This study is a retrospective study attempted to determine the factors that influence the survival of patients with traumatic acute subdural hematoma. The study subjects were 207 patients with traumatic subdural hematoma who visited the emergency room from January 2017 to February 2019 at C University Hospital in G Metropolitan City. Data analysis was using the SPSS 23.0 program, and χ2-test, t-test, and logistic regression analysis. As a result of the study, the factors affecting the survival of the subjects were under disease, complications, and initial GCS. Therefore, it is necessary to establish a medical system to check the subject's history and to train medical staff to prevent complications. In addition, it is necessary to improve the transfer system so that the GCS of the subject can be measured from the stage before transfer to a medical institution and transferred to a hospital that can be treated quickly.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.6
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• pp.41-50
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• 2020

This paper deals with the Braille Education System which complements the shortcomings of the existing Braille Learning Products. An application dedicated to the blind is configured to perform full functions through touch gestures and voice guidance for user convenience. Braille kit is produced for educational purposes through Arduino and 3D printing. The system supports the following functions. First, the learning of the most basic braille, such as initial consonants, final consonant, vowels, abbreviations, etc. Second, the ability to check learned braille by solving step quizzes. Third, translation of braille. Through the experiment, the recognition rate of touch gestures and the accuracy of braille expression were confirmed, and in case of translation, the translation was done as intended. The system allows blind people to learn braille efficiently.

• Advances in nano research
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• v.10 no.1
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• pp.77-90
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• 2021

In the present study, novel chitosan coated magnetic magnetite (Fe3O4) nanoparticles were successfully biosynthesized from mushroom, Agaricus campestris, extract. The obtained bio-nanocomposite material was used to investigate ultra-fast and highly efficient for removal of Ni2+ ions in a fixed-bed column. Chitosan was treated as polyelectrolyte complex with Fe3O4 nanoparticles and a Fungal Bio-Nanocomposite Material (FBNM) was derived. The FBNM was characterized by using X-Ray Diffractometer (XRD), Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy (SEM-EDS), Fourier Transform Infrared spectra (FTIR) and Thermogravimetric Analysis (TGA) techniques and under varied experimental conditions. The influence of some important operating conditions including pH, flow rate and initial Ni2+ concentration on the uptake of Ni2+ solution was also optimized using a synthetic water sample. A Central Composite Design (CCD) combined with Response Surface Modeling (RSM) was carried out to maximize Ni2+ removal using FBNM for adsorption process. A regression model was derived using CCD to predict the responses and analysis of variance (ANOVA) and lack of fit test was used to check model adequacy. It was observed that the quadratic model, which was controlled and proposed, was originated from experimental design data. The FBNM maximum adsorption capacity was determined as 59.8 mg g-1. Finally, developed method was applied to soft drinks to determine Ni2+ levels. Reusability of FBNM was tested, and the adsorption and desorption capacities were not affected after eight cycles. The paper suggests that the FBNM is a promising recyclable nanoadsorbent for the removal of Ni2+ from various soft drinks.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.1
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• pp.55-63
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• 2022

A stranded ship means a ship which is stuck on a rock or a seabed, and cannot move by itself. The lightening plan is required to refloat the stranded ship. For this, we have to understand the forces and moments acting on the ship, which is composed of the gravity, buoyancy, and reaction force due to the touched area below the ship. This study defines those forces and moments, and proposed the calculation method to find the posture based on the static equilibrium. It is divided by two steps. In the first step, the magnitude and position of the reaction force are obtained based on the known information such as initial trim angle and draft of the ship. In the second step, the reaction force and the posture is calculated due to the three cases such as addition, reduction, and movement of the cargo. It is applied to three examples in order to calculate the reaction force, and the trim angle due to changes of the cargo. As a results, we successfully obtain the magnitudes and positions of forces acting on the stranded ship and to check the posture of the stranded ship.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.5
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• pp.161-170
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• 2022

The maintenance of bridges installed in rivers is carried out through facility safety inspection and repair & reinforcement procedures according to the results. Many studies have been so far conducted on the safety check of the bridge upperstructure because of the ease of access. However as it is impossible to directly investigate whether the pier foundation installed in the river has been scoured. Management of underwater foundations has remained based on theory. In this study, the scour of the bridge foundation installed in such a river was realized in 3D form by using an echo sounder and VRS. This made it possible to predict the scour pattern through comparison and analysis with the ground height of the riverbed at the time of the bridge installation. Based on these results, if the pier foundation is used as an initial data to determine whether or not local scour is present and to predict long-term scouring, bridge collapse due to foundation scour can be prevented.

• Computers and Concrete
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• v.30 no.4
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• pp.277-287
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• 2022

Due to the scarcity of extortionate experimental data, fatigue failure of the reinforced concrete (RC) element might be achieved economically adopting nonlinear finite element (FE) analysis as an alternative approach. However, conventional implicit dynamic analysis is expensive, quasi-static method overlooks interaction effects and inertia, direct cyclic analysis computes stabilized responses. Apart from this, explicit dynamic analysis may provide a numerical operating system for factual long-term responses. The study explores the fatigue behavior based on a simplified explicit dynamic solution employing nonlinear time domain analysis. Among fourteen RC beams, one beam is selected to validate under static loading, one under fatigue with the experimental study and other twelve to check the detail fatigue behavior. The SWOT (Strength, Weakness, Opportunities, Threats) analysis has been carried out to pinpoint the detail scenario in the adoption of numerical approach as an alternative to the experimental study. Excellent agreement of FE and experimental results is seen. The 3D nonlinear RC beam model at service fatigue limits is truthful to be used as an expedient contrivance to envisage the precise fatigue behavior. The simplified analysis approach for RC beam under fatigue offers savings in computation to predict responses providing acceptable accuracy rather than the complicated laboratory investigation. At higher frequency, the flexural failure occurs a bit earlier gradually compared to the repeated loading case of lower frequency. The deflection increases by 6%-10% at the end of first cycle for beams with increasing frequency of cyclic loading. However, at the end of fatigue loading, greater deflection occur earlier for higher load range because of more rapid stiffness degradation. For higher frequency, a slight boost in concrete compressive strains at an initial stage of loading has been seen indicating somewhat stepper increment. Stiffness degradation in larger loading cycle at same duration escalates the upsurge of the rate of strain in case of higher frequency.

• Journal of Platform Technology
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• v.11 no.3
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• pp.76-82
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• 2023

Starting from the 4th industrial revolution, core technologies were applied to industries to build various smart environments. Smart factories in the manufacturing industry produce high-quality products by applying IIoT as a core technology that can collect and control a wide range of data for customized production. However, the network environment of the smart factory converted to open through IIoT was exposed to various security risks. In accordance with security breaches, IIoT has shown degradation in the quality of manufactured products and production processes due to network disturbance, use and maintenance of forged IIoT, and can cause reliability problems in business. Accordingly, in this study, a method for safe connection and utilization of IIoT was studied during the initial establishment of a smart factory. Specifically, a study was conducted to check the IIoT connection situation so that the practicality of the IIoT connected to the smart factory could be confirmed and the harmless environment established.

• Journal of Trauma and Injury
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• v.36 no.1
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• pp.15-21
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• 2023

Purpose: Dental avulsion injuries have a poor prognosis that largely depends on the immediate steps taken to manage the avulsed tooth. A lack of knowledge about the initial management can lead to tooth loss, with further adverse implications for esthetics, phonetics, and overall growth and function. Hence, the present study aimed to assess parents' knowledge regarding dental avulsion and the variables associated with their knowledge of avulsion injuries. Methods: A series of closed-ended questions on parents' knowledge regarding avulsion, such as immediate management, storage media, handling, and urgency of visiting the dentist, was asked. Univariate associations between the outcomes were assessed using the Pearson chi-square test. The chisquare goodness-of-fit test was used to check whether the sample data were representative of the population. Results: In total, 211 mothers and 149 fathers were included, of whom 46.7% had experienced dental trauma during their own childhood. Sixty-one percent of mothers believed that they knew everything necessary about tooth avulsion and its management. A significant number of participants who thought that they had a good level of knowledge about avulsion chose water, tissue, or paper wrap to transport the tooth, and preferred tap water, alcohol, or antiseptic to clean the avulsed tooth. Conclusions: Both mothers and fathers had poor knowledge about tooth avulsion, indicating that there is an immediate need for educational programs focusing on this issue. Since a substantial proportion of participants believed incorrect information, it is vital to disseminate accurate information.

• Journal of Oral Medicine and Pain
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• v.48 no.1
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• pp.31-36
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• 2023

This report presents the case of a 14-year-old male with rheumatoid arthritis (RA) in both temporomandibular joints (TMJs), in whom a bone scan and laboratory tests were used to confirm the diagnosis. The patient visited the Department of Orofacial Pain and Oral Medicine at the affiliation hospital with a complaint of a 1-year history of bilateral TMJ pain and sound. Clinical examination revealed bilateral TMJ and masseter muscle pain during mouth opening and palpation. Radiological examination revealed no significant morphological changes in either TMJ. The patient was prescribed medications at the first visit to address the pain, inflammation, and stiffness. A bone scan and laboratory tests were planned/scheduled for differential diagnosis between simple arthralgia and osteoarthritis. The bone scan revealed increased radiotracer uptake in both TMJs. The laboratory tests revealed a RA factor of 82.4 IU/mL, which is more than four times the normal range. The final diagnoses were bilateral TMJ early rheumatoid arthritis (ERA) and juvenile idiopathic arthritis. We created a stabilization splint and referred the patient to the Department of Rheumatology for further evaluation of the ERA. After fitting of the stabilization splint and giving instructions regarding its use, the patient has been receiving monthly follow-up checks for symptoms and undergoes follow-up blood tests every 3 months. About 14 months after the initial visit, the pain had significantly decreased from a Visual Analog Scale score of 5 to 1, and the RA factor decreased to 66.6 IU/mL. A regular follow-up check will continue until the end of growth.