• Journal of the Korean institute of surface engineering
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• v.55 no.2
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• pp.102-119
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• 2022

Gold plating is used as a coating of connecter in printed circuit boards, ceramic integrated circuit packages, semiconductor devices and so on, because the film has excellent electric conductivity, solderability and chemical properties such as durability to acid and other chemicals. As increasing the demand for miniaturization of printed circuit boards and downsizing of electronic devices, several types of electroless gold plating solutions have been developed. Most of these conventional gold plating solutions contain cyanide compounds as a complexing agent. The gold film obtained from such baths usually satisfies the requirements for electronic parts mentioned above. However, cyanide bath is highly toxic and it always has some possibility to cause serious problems in working environment or other administrative aspects. The object of this investigation was to develop a cyanide-free electroless gold plating process that assures the high stability of the solution and gives the excellent solderability of the deposited film. The investigation reported herein is intended to establish plating bath composition and plating conditions for electroless gold plating, with thiomalic acid as a complexing agent. At the same time, we have investigated the solution stability against nickel ion and pull strength of solder ball. Furthermore, by examining the characteristics of the plated Au plating film, the problems of the newly developed electroless Au plating solution were improved and the applicability to various industrial fields was examined. New type electroless gold-plating bath which containing thiomalic acid as a complexing agent showing so good solution stability and film properties as cyanide bath. And this bath shows the excellent stability even if the dissolved nickel ion was added from under coated nickel film, which can be used at the neutral pH range.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.11
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• pp.1531-1537
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• 2021

The quality of the game can be evaluated by its fun and functional stability. Among them, the quality area for fun is the essence of the game, so it is a very important factor to be considered from the point of view of a game designer. Usually, fun games with high originality and immersion are designed in the early stages of development, such as idea generation and concept setting. At this time, making it possible to verify the fun factor of the game has an important influence on the success of the game. In this study, the case of using PIT technique when teaching fun element design to students who are starting to study game design was introduced and the effect was analyzed. It is expected that the PIT technique will be used more actively in the game design education field for high-quality and fun game design.

• Journal of Biomedical Engineering Research
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• v.43 no.5
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• pp.361-368
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• 2022

The purpose of this study was to develop a hand rehabilitation training system for hemiplegic patients. We also tried to find out five hand postures (WF: Wrist Flexion, WE: Wrist Extension, BG: Ball Grip, HG: Hook Grip, RE: Rest) in real-time using multi-channel EMG-based deep learning. We performed a pre-processing method that converts to Spider Chart image data for the classification of hand movement from five test subjects (total 1,500 data sets) using Convolution Neural Networks (CNN) deep learning with an 8-channel armband. As a result of this study, the recognition accuracy was 92% for WF, 94% for WE, 76% for BG, 82% for HG, and 88% for RE. Also, ten physical therapists participated for the usability evaluation. The questionnaire consisted of 7 items of acceptance, interest, and satisfaction, and the mean and standard deviation were calculated by dividing each into a 5-point scale. As a result, high scores were obtained in immersion and interest in game (4.6±0.43), convenience of the device (4.9±0.30), and satisfaction after treatment (4.1±0.48). On the other hand, Conformity of intention for treatment (3.90±0.49) was relatively low. This is thought to be because the game play may be difficult depending on the degree of spasticity of the hemiplegic patient, and compensation may occur in patient with weakened target muscles. Therefore, it is necessary to develop a rehabilitation program suitable for the degree of disability of the patient.

• The Journal of the Convergence on Culture Technology
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• v.7 no.2
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• pp.333-338
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• 2021

Development of 5th generation mobile telecommunication technology is visualizing ideal hyper-connected social information and communication technology (ICT). In particular, virtual reality (VR) technology is at the starting point for new expansion and leaps. This work defines virtual reality as media in this context and collects and analyzes discourse on its scalability around space and communication theory. We first elaborated the concept, starting with the early discussions of the virtual reality concept in 1990, and discussed the relationship between the physical world and digital information, expression and interaction immersion as a medium, simulation, art creation theory, and finally evolutionary development. In conclusion, beyond the discourse on the technology of virtual reality, academic subjects were required to have theoretical frameworks on cognitive science, neuroscience, social science, and humanities issues (ethics, personality, etc.) for the development and evolution of virtual reality. In other words, it is time for the evolution of virtual reality to be discussed, which can be moved beyond.

• Journal of the Society of Disaster Information
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• v.18 no.3
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• pp.487-494
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• 2022

Purpose: This study proposes a Metaverse-based police education and training model that can efficiently improve the performance of various police activities according to changes in the environment of the times. Method: The structure of this system can generate Avatar Controller expressed using HMD and haptic technology, access the Network Interface, and educate and train individually or on a team basis through the command control module, education and training content module, and analysis module. Result: In the proposed model of this study, the command and control module was incorporated into individual or team-based education and training, enabling organic collaborative training among team members by monitoring the overall situation of terrorism or crime in real time. Conclusion: Metaverses-based individual or team-based police education and training can provide a more efficient and safe education and training environment based on immersion, interaction, and rapid judgment in various situations.

• Journal of Practical Engineering Education
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• v.14 no.2
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• pp.361-366
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• 2022

Recently, with the development of virtual and augmented reality technology, metaverse is emerging as a new paradigm that will lead the next-generation internet era, and social and economic activities are spreading around the game, entertainment, music, and content industries. Moreover, as non-face-to-face conversion accelerated after the outbreak of COVID-19, lifestyles and industrial sites are becoming untact and further rapidly becoming a metaverse. In particular, the application of metaverse to the education field is attracting attention because realistic classes using real-time voice conversations using avatars, 3D objects, and 360-degree images can increase immersion and overcome the limitations of distance education. This study examines the concept of metaverse and examines that education using metaverse can be an alternative that can increase the efficiency of education in the non-face-to-face era. In particular, it shows that it is effective in language education and suggests an actual metaverse-based Korea language education program.

• Journal of East Asia Management
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• v.3 no.2
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• pp.21-41
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• 2022

This study aims to analyze the characteristics of the management situation of the Korea Railroad Corporation(KORAIL) through the management innovation process of the KORAIL and to suggest its implications for military application. Despite stable demand, the railway passenger industry had the limitation of not being able to abolish deficit routes due to public service obligations. In addition, the launch of the Suseo High-Speed Line has introduced a competitive system, posing a threat to corporate management. KORAIL wanted to overcome this crisis by innovating its management through the utilization of big data, improvement of the freight business, decentralization of demand, the introduction of tourism railroads, and development of station influence areas. By utilizing big data, KORAIL was able to optimize the railway fare system while reducing fixed costs spent on railway maintenance. It also drastically reduced the station of cargo and created a base station to pursue economies of scale. On the other hand, the existing exclusive station system was abolished to solve the chronic saturation of the downtown area, and the railway demand was moved to Gwangmyeong Station and Suwon Station to optimize the passenger supply. In particular, it developed a new business model called the tourism railway by developing the mountain Byeokjin Line, which was a chronic deficit line, and sought to improve liquidity through the development of the station influence area. Such a process of innovation at KORAIL suggests an appropriate direction in seeking ways to innovate the military medical institutions. First of all, the necessity of improving organizational immersion through the development of a personnel structure suitable for the compulsory organization, while expanding the facilities of the division and corps, and reducing the time required for medical treatment and waiting through the establishment of a data-based medical system was suggested. Next, it was also discussed to integrate the National Health Medical College, which received accreditation as a medical facility through the designation of advanced general hospitals and is ultimately under discussion with the Medical Institution. Through this, we hope that the military medical institutions, which are facing various challenges, will overcome existing limitations and be re-lighted as innovative institution that provides comprehensive public health services.

• Food Science of Animal Resources
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• v.43 no.3
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• pp.428-440
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• 2023

Global meat consumption is increasing worldwide, however, supply remains lacking. Several alternative protein sources, such as cultured meat, plant-based protein production, and edible insects, have been proposed to overcome this shortage. Interestingly, edible insects are characterized by superior digestive and absorptive qualities that make them the ideal replacement for traditional protein production. This study aims to further the processing ability of insect protein by investigating the effects of various pre-treatment methods, such as blanching (HB), roasting (HR), and superheated steam (HS), on the nutritional properties and physicochemical characteristics of proteins extracted from Hermetia illucens larvae. The drying rate, pH value, color analysis, amino and fatty acid profile, as well as bulk density, shear force, and rehydration ratios of the above pre-treatment methods, were explored. HS was found to have the highest drying rate and pH value analysis showed that HB and HS samples have significantly higher values compared to the other modalities. Raw edible insects had the highest value in the sum of essential amino acid (EAA) and EAA index when compared to EAAs. HB and HS showed significantly lower bulk density results, and HS showed the highest shear force and the highest value in rehydration ratio, regardless of immersion time. Therefore, taking the above results together, it was found that blanching and superheated steam blanching pre-treatment were the most effective methods to improve the processing properties of H. illucens after hot-air drying.

• Composites Research
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• v.21 no.2
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• pp.8-14
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• 2008

Decrease of strength in composite material is generally caused by water absorption. It makes fracture of material, and loss of money or human lives. The objective of this study is to investigate the causes of decrease in strength by water absorption. Mechanism of water absorption was supposed as three steps. This mechanism is consisted of absorption into resin, absorption between resin and surface treatment agent, and delamination between fiber and resin. Conditions of test were supplied differently; kinds of fiber and resin, immersion time etc. Both of reversible reaction and irreversible reaction occurred simultaneously. Most of decrease in strength was finished at 2.5% water absorption, and the strength was recovered. At 4% water absorption, most of decrease was caused by irreversible reaction, therefore, there was a tendency not to be recovered in strength.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.2
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• pp.13-20
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• 2023

The process of microelectromechanical system (MEMS) fabrication involves surface treatment to impart functionality to the device. Such surface treatment method is the self-assembled monolayer (SAM) technique, which modifies and functionalizes the surface of MEMS components with organic molecule monolayer, possessing a precisely controllable strength that depends on immersion time and solution concentration. These monolayers spontaneously adsorb on polymeric substrates or metal/ceramic components offering high precision at the nanoscale and modifying surface properties. SAM technology has been utilized in various fields, such as tribological property control, mass-production lithography, and ultrasensitive organic/biomolecular sensor applications. This paper provides an overview of the development and application of SAM technology in various fields.