• Journal of the Semiconductor & Display Technology
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• v.22 no.4
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• pp.87-92
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• 2023

As the elderly population increases, the number of patients with various joint diseases, including degenerative arthritis, is steadily increasing. CPM medical devices are needed to effectively treat degenerative arthritis that is common in the elderly population. Domestic CPM medical devices have limited functions and are highly dependent on imports for expensive imported medical devices. To solve this problem, we designed a ROM measurement function using a current sensor that is not present in existing composite joint CPM medical devices. The algorithm was designed using the fact that the force caused by joint stiffness greatly increases the current flowing through the DC motor. In addition, the need for digital healthcare in the medical field is gradually expanding as the proportion of chronically ill patients increases due to the spread of the non-face-to-face economy due to COVID-19 and the aging population. Therefore, this paper aims to improve the performance of CPM medical devices by allowing real-time confirmation of rehabilitation exercise information and operation range measurement results in accordance with digital healthcare trends through a Bluetooth application developed as an Android studio.

• Journal of the Korean Society for Heat Treatment
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• v.19 no.1
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• pp.10-19
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• 2006

Microstructure and morphology of precipitates in $Ni_3Al$- and TiAl-based intermetallics containing carbon have been investigated in terms of transmission electron microscopy(TEM). In an $L1_2$-ordered $Ni_3Al$ alloy with 4 mol.% of chromium and 0.2~3.0 mol.% of carbon, fine octahedral precipitates of $M_{23}C_6$ type carbide were formed in the matrix by aging at temperatures around 973 K after solution annealing at 1423 K. TEM examination revealed that the $M_{23}C_6$ phase and the matrix lattices have a cube-cube orientation relationship and keep partial atomic matching at the {111} interface. After prolonged aging or by aging at higher temperatures, the $M_{23}C_6$ precipitates then adopt a rod-like morphology elongated parallel to the <100> directions. In the $L1_0$-ordered TiAl containing 0.1~2.0 mol.% carbon, TEM observations revealed that needle-like precipitates, which lie only in one direction parallel to the [001] axis of the $L1_0$ matrix, appear in the matrix and preferentially at dislocations. Selected area electron diffraction(SAED) patterns analyses have shown that the needle-shaped precipitate is $Ti_3AlC$ of perovskite type. The orientation relationship between the $Ti_3AlC$ and the $L1_0$ matrix is found to be $(001)_{Ti3AlC}//(001)_{L10\;matrix}$ and $[010]_{Ti3AlC}//[010]_{L10\;matrix}$. By aging at higher temperatures or for longer period at 1073 K, plate-like precipitates of $Ti_2AlC$ with a hexagonal structure are formed on the {111} planes of the $L1_0$ matrix. The orientation relationship between the $Ti_2AlC$ and the $L1_0$ matrix is $(0001)_{Ti2AlC}//(111)_{L10\;matrix}$ and $_{Ti2AlC}//_{L10\;matrix}$.

• Journal of Convergence for Information Technology
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• v.11 no.11
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• pp.172-177
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• 2021

As part of the digital era, a digital twin that simulates the weak part of a product by performing a stress test that reduces the lifespan of some expensive equipment that cannot be done in reality by accurately moving the real world to virtual reality is being actively used in the manufacturing industry. Due to the development of IoT, the digital twin, which accurately collects data collected from the real world and makes it the same in the virtual space, is mutually beneficial through accurate prediction of urban life problems such as traffic, disaster, housing, quarantine, energy, environment, and aging. Based on its action, it is positioned as a necessary tool for smart city construction. Although digital twin is widely applied to the manufacturing field, this study proposes a smart city model suitable for the 4th industrial revolution era by using it to smart cities and increasing citizens' safety, welfare, and convenience through the proposed model. In addition, when a digital twin is applied to a smart city, it is expected that more accurate prediction and analysis will be possible by real-time synchronization between the real and virtual by maintaining realism and immediacy through real-time interaction.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.4
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• pp.257-268
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• 2021

As the variety and scale of facilities increase due to industrialization and urbanization, blind spots for facility safety management have occurred, resulting in numerous casualties.To meet safety and security needs of citizens living in smart cities, we present a procedure for establishing an integrated platform for facility safety management by combining 5G and digital twin technologies. It can be used to perform inspection according to risk factors and aging of facilities. In this paper, the current status of facility management and application directions of new 5G digital twin-based smart city technologies are reviewed and digital twin implementation procedures are presented. Five cities were selected as target areas: Osan, Gwangmyeong, Guri, Uijeongbu, and Anyang. Old and emergency facilities of each local government were selected. A total of 33 digital twin facilities reflecting policy directions of each city were selected. Focusing on facilities determined by each city, the purpose of this study was to define information technology infrastructure elements for the application of the 5G digital twin facility safety management integrated platform, define categories of implementation services, and suggest a concrete integrated platform configuration plan.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.5
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• pp.30-39
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• 2023

Large dams, which are critical infrastructures for disaster prevention, are exposed to various risks such as aging, floods, and earthquakes. Better dam safety inspection and diagnosis using digital transformation technologies are needed. Traditional visual inspection methods by human inspectors have several limitations, including many inaccessible areas, danger of working at heights, and know-how based subjective inspections. In this study, drone photogrammetry was performed on two large dams to evaluate the applicability of digital data-based dam safety inspection and propose a data management methodology for continuous use. High-quality 3D digital models with GSD (ground sampling distance) within 2.5 cm/pixel were generated by flat double grid missions and manual photography methods, despite reservoir water surface and electromagnetic interferences, and severe altitude differences ranging from 42 m to 99.9 m of dam heights. Geometry profiles of the as-built conditions were easily extracted from the generated 3D mesh models, orthomosaic images, and digital surface models. The effectiveness of monitoring dam deformation by photogrammetry was confirmed. Cracks and deterioration of dam concrete structures, such as spillways and intake towers, were detected and visualized efficiently using the digital 3D models. This can be used for safe inspection of inaccessible areas and avoiding risky tasks at heights. Furthermore, a methodology for mapping the inspection result onto the 3D digital model and structuring a relational database for managing deterioration information history was proposed. As a result of measuring the labor and time required for safety inspection at the SYG Dam spillway, the drone photogrammetry method was found to have a 48% productivity improvement effect compared to the conventional manpower visual inspection method. The drone photogrammetry-based dam safety inspection is considered very effective in improving work productivity and data reliability.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.4
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• pp.173-191
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• 2022

The global economic crisis, the trend of an aging society, and the rapid digital transformation are huge burdens and crises for our society. Due to these environmental changes and the economic recession, entrepreneurship and re-employment issues after retirement have emerged as social issues. This study was conducted to empirically analyze what factors affect seniors when they may start a business. In particular, as the fourth industrial revolution progresses, the focus was on the capability to utilize information and communication technology (ICT) and digital media that cannot be avoided. For empirical analysis, an online survey of seniors was conducted and 287 valid samples were analyzed. SPSS 24.0 and Macro Process 4.0 were used for statistical analysis. As a result of the empirical analysis of this study, self-efficacy and personal innovation for information technology acceptance(ICT), and communication capability using digital media had a significantly positive (+) effect on senior's entrepreneurial intention. However, the perceived usefulness of information technology and the capability to utilize digital media devices were not tested for significance. Among the variables that had a significant effect, personal innovation was found to have the greatest effect. Opportunity recognition was found to play a mediating role between self-efficacy, personal innovation, communication capabilities, and senior's entrepreneurial intention. The results of this study are of academic and practical significance in that digital media utilization capability is also an influential factor among various factors influencing the entrepreneurial intention of seniors.

• Journal of Digital Contents Society
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• v.19 no.4
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• pp.779-787
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• 2018

This study delves into how the equalizer can compensate for a sound pressure of lost frequencies. The targeted audiences are senior citizens who have difficulties hearing high-frequency because of a decline of audio frequency. Through investigations, this study confirms that the reason why reduction of high-frequency hearing increases depending on senescence. By considering the features of audio frequency of senior citizens, it also clarifies the necessity of equalizer reflecting features of audio frequency for the senior citizens, which have dramatically increased in Korea. There are application programs having functions, which provide several options of equalizer setup that people can adjust it depending on their own audio frequency. Some of them provide different equalizer setup depending on age. This study, however, reveals that they are not fully enough to compensate for the range of hearing loss of the senior citizens. Therefore, by pointing out limitations of existing functions and suggesting improvements, this study explores the way of improvements that enhance the sound transmissions of digital media contents for senior citizens.

• Journal of Digital Convergence
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• v.13 no.11
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• pp.433-440
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• 2015

This paper was to explore the effect of the locus of control on life satisfaction and preparation for old age among middle-aged adults in the time of Convergence. This survey was conducted from September to December 2013, and 284responses were used for the analysis. The data was analyzed by descriptive statistics, Pearson Correlation and Multiple Regression. The research findings could be summarized as the followings. First, the locus of control had significantly positive effect on life satisfaction, Second, the locus of control also had significant effect on preparation for old age among middle-aged adults. Third, life satisfaction between preparation for old age had positive correlations with life satisfaction.

• Journal of Computational Design and Engineering
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• v.3 no.3
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• pp.250-265
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• 2016

Owing to our rapidly aging society, accessibility evaluation to enhance the ease and safety of access to indoor and outdoor environments for the elderly and disabled is increasing in importance. Accessibility must be assessed not only from the general standard aspect but also in terms of physical and cognitive friendliness for users of different ages, genders, and abilities. Meanwhile, human behavior simulation has been progressing in the areas of crowd behavior analysis and emergency evacuation planning. However, in human behavior simulation, environment models represent only "as-planned" situations. In addition, a pedestrian model cannot generate the detailed articulated movements of various people of different ages and genders in the simulation. Therefore, the final goal of this research was to develop a virtual accessibility evaluation by combining realistic human behavior simulation using a digital human model (DHM) with "as-is" environment models. To achieve this goal, we developed an algorithm for generating human-like DHM walking motions, adapting its strides, turning angles, and footprints to laser-scanned 3D as-is environments including slopes and stairs. The DHM motion was generated based only on a motion-capture (MoCap) data for flat walking. Our implementation constructed as-is 3D environment models from laser-scanned point clouds of real environments and enabled a DHM to walk autonomously in various environment models. The difference in joint angles between the DHM and MoCap data was evaluated. Demonstrations of our environment modeling and walking simulation in indoor and outdoor environments including corridors, slopes, and stairs are illustrated in this study.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.1
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• pp.61-67
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• 2014

Conventional synchronous circuits in low power required systems such as sensor systems cannot only satisfy the timing requirement of the low voltage digital systems, but also they may generate wrong outputs under the influence of PVT variations and aging effects. Therefore, in the reliable ultra-low power design, asynchronous circuits have recently been reconsidered as a solution for scaling issues. However, it is not easy to totally replace synchronous circuits with asynchronous circuits in the digital systems, so the interfacing between the synchronous and asynchronous circuits is indispensable for the digital systems. This paper presents a new design for interfacing between asynchronous circuits and synchronous circuits, and the interface circuits are applied to a $4{\times}4$ multiplier logic designed using 0.11um technology.