• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.295-309
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• 2021

Maker education has recently been actively practiced under strong governmental support as a nation-wide policy for innovative education, which now had to confront the unexpected challenge and crisis of 'contactless educational environments' due to COVID-19 pandemic. In this context, this study aimed to develop a checklist needed for developing 'contactless maker education program' which still continues to maintain 'maker mindsets' as the goal and direction of maker education, since maker education has been regarded as an alternative educational environment suitable for the 4th industrial revolution age. For this purpose, this study first conducted literature review related to maker education and contactless (i.e. online) education environments, from which several characteristics of the contactless maker education have been extracted. And then, 5 maker education instructors currently conducting the contactless maker education programs in various settings provided feedback on the developed checklist draft, which actually became the final version of the checklist. Considering the current COVID-19 pandemic situation, the checklist for the contactless Maker education might be helpful in preventing to diminish or reduce the educational values and active application of maker education.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.678-681
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• 2000

Contactless battery charger with a "더" type core is proposed in this paper. The proposed take-apart transformer maintain a high coupling coefficient in spite of air gap. The ZV-ZCS method is used for the efficiency and stable opeation of the system.he system.

• Progress in Superconductivity and Cryogenics
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• v.22 no.3
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• pp.1-6
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• 2020

This paper presents the analysis results on the electrical output performance characteristics of a 746 W high temperature superconducting generator (HTSG). The HTS field winding is charged by non-contact excitation method, i.e., contactless superconducting field exciter (CSFE) which is originated by rotary flux pump based on permanent magnet. In this paper, the preliminary current charging test was carried out using a 70 A CSFE to evaluate the performance of field exciter and analyze its non-contact excitation characteristics for the full-scale HTS field winding of the 746 W HTSG. First, the various contactless current-charging tests were conducted using assembly with HTS field winding and CSFE. Then, in order to estimate the output power performance characteristics of the 746 W HTSG, finite element analysis was conducted based on field excitation information which is experimentally measured under various operating conditions. Finally, the electrical output characteristics in no-load and load models were simulated by two-dimensional transient solver in ANSYS electromagnetics 19.0 release.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.5
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• pp.407-417
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• 2003

Detachable transformers used in contactless battery chargers have poor power transfer characteristics because they have low coupling coefficients due to their gaps. The ㄷㅓ type core gives a high coupling coefficient in a contactless battery charger compared with standard cores such as EE, EC and UU. In this paper, characteristics of the ㄷㅓ type core is studied. Detailed analyses and comparisons are given based on the sinusoidal operation and square-wave operation. Reductions in output current, voltage and power are stated analytically and numerically. The analyses are verified by experiments conducted on a ZVS converter including a detachable transformer. The analyses and comparison method can be applied to other gaped transformer such as a PCB transformer.

• Progress in Superconductivity and Cryogenics
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• v.15 no.1
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• pp.40-44
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• 2013

The contactless power transfer (CPT) systems have been recently gaining popularity widely since it is an available option to realize the power delivery and storage with connector-free devices across a large air gap. Especially, the CPT with electromagnetic resonance coupling method is possible to exchange energy within 2 m efficiently. However, the power transfer efficiency of CPT in commercialized products has been limited because the impedance matching of coupled coils is sensitive. As a reasonable approach, we combined the CPT system with HTS wire technology and called as, superconducting contactless power transfer (SUCPT) system. Since the superconducting coils have an enough current density, the superconducting antenna and receiver coils at CPT system have a merit to deliver and receive a mass amount of electric energy. In this paper, we present the feasibility of the SUCPT system and examine the transmission properties of SUCPT phenomenon between room temperature and very low temperature at 77 K as long as the receiver is within 1.0 m distance.

• Journal of the Ergonomics Society of Korea
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• v.31 no.4
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• pp.533-540
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• 2012

Objective: This paper targets a framework of a hand gesture based interface design. Background: While a modeling of contact-based interfaces has focused on users' ergonomic interface designs and real-time technologies, an implementation of a contactless interface needs error-free classifications as an essential prior condition. These trends made many research studies concentrate on the designs of feature vectors, learning models and their tests. Even though there have been remarkable advances in this field, the ignorance of ergonomics and users' cognitions result in several problems including a user's uneasy behaviors. Method: In order to incorporate compatibilities considering users' comfortable behaviors and device's classification abilities simultaneously, classification-oriented gestures are extracted using the suggested human-hand model and closed-loop classification procedures. Out of the extracted gestures, the compatibility-oriented gestures are acquired though human's ergonomic and cognitive experiments. Then, the obtained hand gestures are converted into a series of hand behaviors - Handycon - which is mapped into several functions in a mobile device. Results: This Handycon model guarantees users' easy behavior and helps fast understandings as well as the high classification rate. Conclusion and Application: The suggested framework contributes to develop a hand gesture-based contactless interface model considering compatibilities between human and device. The suggested procedures can be applied effectively into other contactless interface designs.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.103-111
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• 2021

In modern society, digital lifestyles are spreading to minimize contact with people and to receive contactless information. The spread trend has established an unmanned distribution system in which transactions through contactless technologies such as kiosks and chatbots are activated in face-to-face transactions with sellers and consumers. In order to streamline logistics supply worldwide, digital new deal based joint logistics hubs, unmanned courier storage platforms, and fresh logistics based last mile services have been developed into unmanned logistics systems, focusing on the intelligent logistics system automation process. Unmanned courier storage system installed in urban areas and home to daily logistics where volume is concentrated are provided with fresh logistics services through cold chain and receiving freights in contactless environments. Development is also underway to minimize safety accidents caused by courier services, such as managing various information based on the integrated control system. This paper defines the concept of integrated operation for the development of a platform for contactless unmanned courier storage device developed into next-generation logistics system. In addition, we intend to develop systems engineering-based output for deriving safety requirements and specifications by identifying risk sources that may occur in the operational scenario. Therefore, the goal is to establish a foundation for safety and reliability between interfaces of logistics systems to be installed in apartment and subway station environments that want to provide unmanned logistics services to various consumers.

• Informatization Policy
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• v.29 no.2
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• pp.66-90
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• 2022

The radical digital transformation and development of the contactless digital economy in the wake of the COVID-19 pandemic are increasing the need to solve various problems such as conflicts of interest among market participants and delays in related laws and regulations. This study investigates the concept and characteristics of the contactless digital economy and identifies the related regulatory issues and resolutions through literature review, news article analysis, and expert interviews. From the literature review, it is identified that the contactless digital economy has eight hyper-innovation characteristics: hyper-intelligence, hyper-connectivity, hyper-convergence, hyper-personalization, hyper-automation, hyper-precision, hyper-diversity, and hyper-trust. From news article analyses and expert interviews, this study identifies various regulatory issues, such as competition between incumbents and new entrants, the collision of constitutional rights, collision of social values, conflict between market participants, absence of laws and regulations, and existence of excessive market power, and then proposes a series of resolutions.

• The Journal of the Korea Contents Association
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• v.22 no.1
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• pp.47-57
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• 2022

Demands for tangible contents using VR/AR technologies are much bigger as contactless services such as sports, physical activity, and fitness are expanded after COVID-19. A variety of technologies such as an offer and analysis of tangible data through a sensor technology, users' physical movement sensing through a motion recognition sensor, a real-time measurement of a physical skeleton point a multiple access to a real-time video, and AI training are being utilized as main technologies. This case study utilized motion recognition technologies as the study on tangible contents necessary for indoor-based physical education, sports, and fitness in the contactless environment and suggested cases to develop the physical measurement contents by design approach for the measurement assessment necessary for the development in tangible contents. The research established lists of the measurement assessment based on professionals' consultations within the measurement assessment function through the test to plan tangible contents and developed tangible contents by reflecting them as assessment measurement elements of tangible contents. The research can be utilized as the design approach of industrial companies which intend to develop tangible contents as well as reference cases of the research on contactless tangible contents for the sports and physical education.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.703-706
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• 2011

Contactless systems use electromagnetic fields to transport power from railway substation to the traction system. In Korea Railroad Research Institute, KRRI, the RIPS (Railway Inductive Power Supply), has been developed. The RIPS is based on a contactless transformer with a fixed coreless primary and a moving core, compared with E shape and U shape, in the secondary. The primary coil is supply with 20 kHz current which produces a magnetic flux in the secondary core. Further this flux induces a current in the secondary coil.