• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.4
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• pp.583-594
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• 1989

The strong nonliner dynamic behavior of mechanical systems in the presence of clearances are studied. The nonlinearity is induced from the assumed symmetric piecewise-linear characteristics for stiffness and damping by the contact and uncontact. Based on Stoker's assertion concering the reasoning beyond the occurrence of subharmonics, the nonlinear differential equation is converted to four nonlinear algebraic equations form the boundary conditions at the contact points. For a single contact per half exciting period, under the assumption of symmetric response, the steady-state solutions obtained are in agreement with those of numerical integration. Also a nondimen-sionalized formulation is made for the purpose of parametric studies.

• Journal of Korea Entertainment Industry Association
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• v.14 no.5
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• pp.27-35
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• 2020

In 2020, one after another, musicians started to hold non-contact online concerts as the pop music industry began to shrink due to the unprecedented "Covid-19" incident, in seeking for various channels and alternatives. Taking this into account, this study conducted a survey with BTS' "Bang Bang Con The Live" as the subject that was held June 2020 to see if they were qualified as an alternative format for quarantine-focused non-contact concerts. The survey was carried out with the content analysis of online concert videos participated by music experts and by collecting evaluations and alternative suggestions from the audiences. The study showed that the sample performance video well fulfilled the actual feels of offline concert elements (field visualization, face-to-face interaction, and responsive behavior), satisfaction, and convenience as an alternative concert format as an emergency correspondence. However, it was analyzed that there was a serious lack of empathy and realism with fans. Therefore, the study showed the possibility that BTS' "Bangbangcon The Live" will function as an alternative format for non-contact concerts, but suggests that measures such as supplementing digital communication systems and technology devices must be taken to be recognized as a level of settlement in the global music community as well as in Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.3
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• pp.317-322
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• 1998

Generally, the conventional fish size grading methods just adopt the mechanical technique. So the grading methods have a problem such that the graded fish is easy to hurt on the skin and in the internal organs. In this paper, a fish size grading machine is developed using an image processing method. The grading method is based on the principal axis theorem. The length and projected area of a fish are obtained by getting the principal axis and the product of inertia moment on the captured image of a target fish. The developed machine uses an uncontact technique that the target fishes go through the front side of the CCD camera. So the above stated problem can be improved. The performance of this method is discussed with the experimental results.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.1
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• pp.87-99
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• 2022

We propoes a study on the dynamic characteristics analysis and position control of 5-degree multi-joint manipulators for untact remote working at construction sites and manufacturing plants. The main frame of freedom multi-joint manipulator consists of five elements, boom cylinder, boom cylinder, arm cylinder, bucket cylinder, and rotation joint and link. In addition, the main purpose of the proposed system is to realize the work of the manufacturing process or construction site by remote control. Motion control of the entire system is a servo valve control method by hydraulic servo cylinders for one to four joints, and a servo motor control method is applied for five joints. The reliability of the proposed method was verified through performance experiments by computer simulation.

• Journal of Venture Innovation
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• v.4 no.1
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• pp.23-38
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• 2021

This paper will examine the service quality of online education on service value, learning immersion, major satisfaction. The result structural equation model show that service quality of online education had a positive impact on service value. First, system convenience, system quality, interaction had a positive impact on service value. Second, System convenience, system quality, interaction had a positive impact on learning immersion Third, Online education on service value had a positive impact on Major Satisfaction. Fourth, Learning immersion had a positive impact on Major Satisfaction.

• Journal of the Korea Convergence Society
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• v.11 no.10
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• pp.53-61
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• 2020

Recently, as the uncontact service is activated in earnest due to the Corona 19 virus, the necessity of system development to provide non-face-to-face contact remote medical service has increased. In this study, we propose a smart healthcare system, Rm_She(Remote Medical Smart Healthcare System). Rm_She can collect and manage various vital signs information by connecting various healthcare products that detect bio-signals based on IoT to one application. The health check app (HC_app) is used to connect vital sign measurement devices to a wireless LAN and receive vital sign values from the HC_app. Then, the vital signs are output to the user on the smartphone, and the corresponding information is transmitted to the healthcare management server. The healthcare server receives the measured values and stores them in a database, and the stored measured values are provided as a web service so that medical staff can remotely monitor them in real time.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.2
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• pp.231-236
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• 2020

In today's society, the majority of people use smartphones, and mobile ordering and payment systems for their convenience are gaining their attention. The mobile payment market is on the rise, with over 71% of the market that is already formed in China. Many mobile payment markets are growing in Korea, which is a system that is provided only in large franchises. In this paper, we propose a mobile ordering and payment system using short-range wireless communication technology that can be easily used not only in franchises but also in the small businesses, and for the convenience of users in modern society to make a system that enables ordering and payment through mobile to communicate between the devices developed by short range wireless communication technology, smartphone and the main server.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.4
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• pp.785-790
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• 2020

In addition to the Fourth Industrial Revolution, interest and research on medical information are actively being conducted. As the technologies using short-range low-power wireless communication are applied in connection with mobile devices, the utilization of them in medical institutions is gradually increasing, and the demand of customers who want to receive high-quality services using IT technology is increasing in the medical environment according to the development and change of technology. In addition, modern people who are familiar with smart equipment and consider the value of time is important do not waste their time through rapid service. In addition, as the recent epidemics including Coronavirus Disease 2019 (COVID-19) have become popular, interest in untapped (non-face-to-face) has increased, and social distance is needed as a preliminary measure against infectious diseases. For this reason, this study studied the untapped-based medical reception system to provide quick service to patients using short-range low-power wireless communication and to provide safer and more comfortable environment for medical staff and visitors.

• The Journal of the Korea Contents Association
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• v.21 no.10
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• pp.264-273
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• 2021

To study how digital content can be effectively developed and transformed in a post-COVID world in which the normal operations of museums have been disrupted, this paper analyzes the rapid development and limitations of VR exhibitions and proposes, as an alternative, the development of AR exhibitions. Studying VR/AR exhibitions that ran before and after COVID-19, this paper finds that VR, on the one hand, translates physical objects into digital video, which lacks aesthetic depth, and encounters operational problems originated by devices. By using mobile devices that are widely distributed and convenient to use, AR exhibitions can, on the other hand, be divided into three types: "museum-specific exhibitions" can present digital content in a specific indoor space, while "place-specific exhibitions" can be used in open outdoor spaces. The "non-place-specific exhibitions", can, as third type, combine digital content with printed material sent by postal mail. Among these three types, the specific/unspecified place type shows the highest "uncontact effect," which can suggest the best direction for effective museum content development in the pandemic era.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.6
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• pp.1031-1036
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• 2020

Untact marketing emerged as one of the top 10 marketing in 2018. Since then, the scale of the mobile payment market has expanded, and the ratio of payment through mobile is melting into life even offline. Various mobile apps such as Samsung Pay and Smart Order are already popular systems, and various other mobile payment systems are increasing. For such mobile payments, this paper aims to comprehensively design a general-purpose untouched offline payment system by designing a mobile payment system that applies a short-range wireless communication method along with a study on the currently available mobile payment-linked API. We propose an offline payment system with an untouch method to prevent the spread of infectious diseases and contribute to a healthy society by solving the problem and minimizing contact with others in the current situation like the Corona 19 Incident.