• Applied Chemistry for Engineering
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• v.35 no.2
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• pp.122-127
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• 2024

Cosmetic preservatives are an important class of ingredients in terms of ensuring sustainable use and providing customer satisfaction. Recently, a great deal of interest has been drawn to the production and use of toxic-free, naturally derived preservatives. In this work, a new naturally derived preservative (laurimino bispropanediol, LB) was developed to replace the most widely used diol preservatives, such as 1,2-hexanediol or 1,2-octanediol. The basic properties of the obtained preservative were measured, and the solution behavior of the preservative in an aqueous medium was examined. The feasibility of micelle formation in the preservative solution was investigated using the fluorescence (FL) based pyrene method. Micelle formation was feasible owing to the relatively long hydrophobic chains and increased hydroxyl groups in the preservative molecules. The emulsification capability of the preservative was assessed using the Rosano and Kimura method, showing that the preservative possessed emulsifying capability in an organic solvent (benzene) and soy bean oil. In addition, the dispersion stability of cosmetic formulations, including the new LB preservatives such as essence and lotion, was demonstrated by comparing the light transmittance of the formulations. This article provides important information for future research regarding the synthesis and practical applications of new toxic-free naturally derived preservatives.

• Journal of Music and Human Behavior
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• v.21 no.1
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• pp.69-87
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• 2024

This study investigated whether joint attention response behaviors in children with autism spectrum disorder (ASD) change in response to musical cues and reinforcing stimulus, and compared them with neurotypically developing (NT) children. The participants included 13 children with ASD and 14 NT children aged between 3 to 5 years. The study established six task conditions, involving cues (verbal vs. musical) for responding to joint attention (RJA) behaviors and reinforcing stimulus (verbal vs. sound vs. musical) for social referencing behaviors. These tasks were presented 12 times with two repetitions each. The results of the study showed that providing musical cues during the RJA phase increased levels of RJA in children with ASD, consistent with prior studies. Subsequently, musical reinforcing stimuli increased the frequency of social referencing behaviors in these children. This indicates that musical stimuli can extend beyond mere sensory cues, helping individuals to understand and respond to social and emotional cues from others. Moreover, these musical stimuli could serve as effective social reinforcement factors for this population.

• Industry Promotion Research
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• v.9 no.1
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• pp.149-157
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• 2024

The purpose of this study is to objectively examine the effects of integrated art therapy on cognitive function and depression in the early dementia elderly, and to identify and discuss the process of change in the early dementia elderly through a comprehensive analysis through behavior change observation diary. As a research method, a mixed study was designed using in-depth analysis through qualitative studies as well as quantitative studies on the effect of integrated art therapy on cognitive function and depression in the elderly with early dementia. The quantitative study conducted a pre-post examination of 20 elderly people with early dementia using the day care center in P-gu, Suwon, and the qualitative study analyzed the behavioral change observation diary of 10 elderly people with early dementia. These findings show that first, integrated art therapy had a significant effect on the cognitive function of the elderly with early dementia (p<.001, t=-5.871). Second, integrated art therapy had a significant effect on the depression of the elderly with early dementia (p<.001, t=5.325). Third, the integrated art therapy program changed to a positive attitude before and after cognitive function and depression of the elderly with early dementia. By revealing the effect of integrated art therapy on cognitive function and depression of the elderly with early dementia through the results of this study, it is meaningful as basic data for research related to the elderly with early dementia as well as providing effective information on integrated art therapy programs related to the elderly with early dementia.

• Journal of the Microelectronics and Packaging Society
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• v.31 no.2
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• pp.28-35
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• 2024

Corrosion inside electronic packages significantly impacts the system performance and reliability, necessitating non-destructive diagnostic techniques for system health management. This study aims to present a non-destructive method for assessing corrosion in copper interconnects using the Smith chart, a tool that integrates the magnitude and phase of complex impedance for visualization. For the experiment, specimens simulating copper transmission lines were subjected to temperature and humidity cycles according to the MIL-STD-810G standard to induce corrosion. The corrosion level of the specimen was quantitatively assessed and labeled based on color changes in the R channel. S-parameters and Smith charts with progressing corrosion stages showed unique patterns corresponding to five levels of corrosion, confirming the effectiveness of the Smith chart as a tool for corrosion assessment. Furthermore, by employing data augmentation, 4,444 Smith charts representing various corrosion levels were obtained, and artificial intelligence models were trained to output the corrosion stages of copper interconnects based on the input Smith charts. Among image classification-specialized CNN and Transformer models, the ConvNeXt model achieved the highest diagnostic performance with an accuracy of 89.4%. When diagnosing the corrosion using the Smith chart, it is possible to perform a non-destructive evaluation using electronic signals. Additionally, by integrating and visualizing signal magnitude and phase information, it is expected to perform an intuitive and noise-robust diagnosis.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.4
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• pp.324-331
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• 2024

The height of large car and truck carriers from the keel to the wheel house is 44 ~ 46 m, and as the car-carriers increases in size, it exhibits the 'top heavy' characteristic, where the upper section is heavier than the lower section. This study aims to estimate the maximum outward heel angle of the Golden Ray car-carrier (G-ship) during turning maneuvers for accident investigation and the prevention of similar accidents. The theoretically calculated maximum outward heel is 7.5° (at 19 kn, rudder angle 35°) with a GM of +3.0 m or higher, and 16.7° with a GM of +1.85 m. Meanwhile the experimentally modified maximum outward heel is 10.5° (at 19 kn, rudder angle 35°) with a GM of +3.0 m or higher, and 23.3° with a GM of +1.85 m. The G-ship is maneuvered during an accident at a speed of 13 kn, at starboard rudder angle of 10° to 20°, it changes course from 038°(T) to 105°(T) based on the instructions of the on-board pilot. At this time, the maximum outward heel is estimated to be between 7.8° and 10.9° at the port side, which is 2.2 times higher than the normal outward heel. In the IS code, cargo ships are required to exhibit a minimum GoM of +0.15 m or more. The maneuvered G-ship exhibits a GoM of +1.72 m. It is not maneuvered because it fails to satisfy the international GoM criteria and because its GoM is insufficient to counteract the heeling moment during the maneuver. This study is performed based on accident-investigation results from the Korea Maritime Safety Tribunal and the USCG.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.4
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• pp.365-372
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• 2024

The South Korean marine industry is emerging as a significant market, driven by the growing popularity of various water leisure activities, including sailing. This trend suggests a rising demand for sailing yachts. Consequently, since 2022, the design and development of a 28ft sailing yacht have been ongoing, supported by the government and the Ministry of Oceans and Fisheries, to promote yachting culture in South Korea. The Velocity Prediction Program (VPP) analysis was conducted using WinDesign during the preliminary design stage to evaluate performance and determine design parameters. The hydrodynamic model used for this vessel is based on regression methods developed from years of experience in naval architecture and yacht research at the Wolfson Unit, providing reliable estimates for most modern yachts. However, owing to the lack of specific hydrodynamic data from towing tank tests or CFD numerical analysis, verification of the hydrodynamic model has faced some challenges. Additionally, an incomplete weight estimate resulted in variable VCG values, potentially affecting stability and overall performance. The optimal boat speed for this vessel was determined at true wind speeds (TWS) of 4, 8, 12, 16, and 20 knots, using both the jib (up to 120° TWA) and the spinnaker (from 80° TWA). The optimized speed of the yacht was found to be comparable to that of international similar-class yachts.

• Journal of The Korean Institute of Defense Technology
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• v.5 no.3
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• pp.8-17
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• 2023

The current weapon system is operated as a complex weapon system with various standards and protocols applied, so there is a risk of failure in smooth information exchange during combined and joint operations on the battlefield. The interoperability of weapon systems to carry out precise strikes on key targets through rapid situational judgment between weapon systems is a key element in the conduct of war. Since the Korean military went into service, there has been a need to change the configuration and improve performance of a large number of software and hardware, but there is no verification system for the impact on interoperability, and there are no related test tools and facilities. In addition, during combined and joint training, errors frequently occur during use after arbitrarily changing the detailed operation method and software of the weapon/power support system. Therefore, periodic verification of interoperability between weapon systems is necessary. To solve this problem, rather than having people schedule an evaluation period and conduct the evaluation once, AI should continuously evaluate the interoperability between weapons and power support systems 24 hours a day to advance warfighting capabilities. To solve these problems, To this end, preliminary research was conducted to improve defense interoperability capabilities by applying natural language processing techniques (①Word2Vec model, ②FastText model, ③Swivel model) (using published algorithms and source code). Based on the results of this experiment, we would like to present a methodology (automated evaluation of interoperability requirements evaluation / level measurement through natural language processing model) to implement an automated defense interoperability evaluation tool without relying on humans.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.4
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• pp.781-790
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• 2024

As modern people's interest in exercise and health increases, the demand for exercise-related information and devices is increasing, and exercising in the wrong posture can lead to body imbalance and injury. Therefore, in this study, the purpose of this study is to correct the posture for health promotion and injury prevention through the correct exercise posture of users. It was developed using Arduino Uno R3, a pressure sensor, and an acceleration sensor as the main memory device of the system. The pressure sensor was used to determine the squat posture, and the acceleration sensor was used to determine three types of gait: normal step, nasolabial step, and saddle step. Data is transmitted to a smartphone through a Bluetooth module and displayed on an app to guide the user in the correct exercise posture. The gait was determined based on the 20˚ angle at which the foot was opened, and the correct squat posture was compared with the ratio of the pressure sensor values of the forefoot and hindfoot based on the data of the skilled person. Therefore, based on an experiment with about 90% accuracy when determining gait and 95% accuracy based on a 7:3 ratio of pressure sensor values in squat posture, a system was established to guide users to exercise in the correct posture by checking in real time through a smartphone application and correcting exercise in the wrong posture.

• Journal of the Korea Computer Graphics Society
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• v.30 no.3
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• pp.61-69
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• 2024

Mixed reality(MR) technology combines the advantages of virtual reality(VR) and augmented reality(AR) technology, allowing MR users to interact with virtual objects against the background of the real world. In addition, since virtual objects interact with the real world, users can experience a higher immersion. This study proposes electric circuit practical training content using Meta Quest Pro to produce immersive MR content based on reality. To this end, first, the development process for producing MR content by linking Meta Quest Pro equipment with the Unity 3D engine is organized. Then, based on the traditional electric circuit practical training method used in elementary school science classes, virtual electric circuit practical training content with the same training method and operation process is produced based on MR. Finally, survey experiments are conducted to analyze the presence and experience of the MR-based educational environment provided using the produced content. Through this, the usability of the proposed practical training content is evaluated and future research directions are suggested.

• Journal of the Health Care and Life Science
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• v.9 no.2
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• pp.303-308
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• 2021

Staphylococcus aureus and methicillin resistant S. aureus (MRSA) is a major cause of nosocomial infections and is one of the most commonly isolated bacterial species in the hospital and continues to be an important pathogens in both community and hospital-acquires infection. The purpose of this study is to investigate the carrier rate of S. aureus and MRSA in the community and molecular genetic characteristics of these organisms. The identification of S. aureus and MRSA were done by the procedures in Murray's manual of Clinical Microbiology and antibiotic susceptibility patterns by the Clinical and Laboratory Standards Institute(CLSI). MRSA strains were confirms by oxacillin disk diffusion method. forty-six strains (71.9%) of S. aureus were isolated from the nasal specimens of 64 students in health science university. twenty-two strains (22%) of 46 S. aureus were resistant to penicillin and oxacillin. twenty-two strains of the 46 S. aureus isolates were methicillin-resistant Staphylococcus aureus (MRSA). The mecA genes in MRSA were detected by polymerase chain reaction (PCR). Community and nosocomial infections caused by methicillin-resistant Staphylococcus aureus are a significant problem worldwide. There continuous epidemiological study is to investigate the prevalence of MRSA in community acquired infections.