• Educational Technology International
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• v.18 no.1
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• pp.49-71
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• 2017

The purpose of the study was to identify key design features of virtual reality with head-mounted displays (HMD) and touchless interface for the hearing-impaired and hard-of-hearing learners. The virtual reality based training program was aimed to help hearing-impaired learners in machine operating learning, which requires spatial understanding to operate. We developed an immersive virtual learning environment prototype with an HMD (Oculus Rift) and a touchless natural user interface (Leap Motion) to identify the key design features required to enhance virtual reality for the hearing-impaired and hard-of-hearing learners. Two usability tests of the prototype were conducted, which revealed that several features in the system need revision and that the technology presents an enormous potential to help hearing-impaired learners by providing realistic and immersive learning experiences. After the usability tests of hearing-impaired students' exploring the 3D virtual space, interviews were conducted, which also established that further revision of the system is needed, which would take into account the learners' physical as well as cognitive characteristics.

• Journal of Korea Multimedia Society
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• v.13 no.9
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• pp.1337-1347
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• 2010

Fingerprint recognition is a biometric technology to identify individual by using fingerprint features such ridges and valleys. Most fingerprint systems perform the recognition based on minutiae points after acquiring a fingerprint image from contact type sensor. They have an advantage of acquiring a clear image of uniform size by touching finger on the sensor. However, they have the problems of the image quality can be reduced in case of severely dry or wet finger due to the variations of touching pressure and latent fingerprint on the sensor. To solve these problems, the contactless capturing devices for a fingerprint image was introduced in previous works. However, the accuracy of detecting minutiae points and recognition performance are reduced due to the degradation of image quality by the illumination variation. So, this paper proposes a new LDP-based fingerprint recognition method. It can effectively extract fingerprint patterns of iterative ridges and valleys. After producing histograms of the binary codes which are extracted by the LDP method, chi square distance between the enrolled and input feature histograms is calculated. The calculated chi square distance is used as the score of fingerprint recognition. As the experimental results, the EER of the proposed approach is reduced by 0.521% in comparison with that of the previous LBP-based fingerprint recognition approach.

• The Journal of the Korea Contents Association
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• v.21 no.8
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• pp.79-88
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• 2021

COVID-19 is putting the entire performance industry in a dire situation. One of the approaches to overcome this crisis is contactless performance business using video media. But, these contactless performance videos are now found to have their own issues. First, with the increasing demands for these videos, the need for higher-quality video products is also increasing. However, there are many organizations that cannot afford such an investment. Second, it is not possible to have the same unique experience of a live performance with the videos. 360-degree VR performance videos are now gaining attention as an alternative to cope with this issue. As such, the researcher reviewed the production of 360 VR performance videos in general based on the cases of the play and a children's story concert As a result, the researcher could confirm the three benefits of simulated 'live experience through a sense of reality', 'convenience of filming' and 'continuity of acting'. Also, the issues related to this approach including 'Lack of professional filming companies', 'Expensive viewing equipment', 'Absence of Platform' and 'Limitations of Camera Technology', among others have been identified, etc. Based on these findings, the researcher could propose strategies for improvement in order to utilize 360-degree VR performance videos.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.1
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• pp.53-57
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• 2010

This study proposes the algorithm which drives the powerless without battery. The exiting wire or RF type dosimeter, which is the computation of the real time with battery on the dose radiation exposure, In the Wired dosimeter, it is trouble to need the maintenance and management by periods. Besides, the case of the RF typed dosimeter with battery, it is requested to size bigger and to replace battery frequently and so on. Especially RF typed dosimeter has trouble to need for the embody with large power consumption on the contactless typed dosimeter. As the method for the low power, the study designed to be down the operating clock of the MPC, to improve the efficiency of the rectifier, to eliminate the external memory and the DC-DC converter for the simplification of the circuit We convince our research contributes not only to understand the simplified circuit and miniaturization, but also to help the design and application technology of the powerless dosimeter.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.3
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• pp.639-646
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• 2016

In this study, the contactless measurement method with a optical displacement sensor(ODS, ADNS 9500) was proposed to overcome flaws in a rotary encoder based measurement under particular circumstances, such as a slippage and a case of little rotational inertia. The performance tests of the optical displacement sensor using data acquisition board and National Instruments's LabVIEW program were performed to accomplish accurate displacement measurements and the performance characteristics according to measurement direction, speed, acceleration, height and surface types were discovered through the repetitive tests. The experimental results indicate that, in order to get an accurate in-plane motion, the height(distance between the ODS and the target surface) has to be maintained at the range of 2.4 mm to 3.2 mm and the sensitivity(resolution) should be modified and applied to the formulae for displacement calculation, considering its measurement direction, speed and surface type.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.2
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• pp.387-392
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• 2022

In addition to complying with access standards for facilities that require infection control (operating rooms, delivery rooms, intensive care units, etc.) in accordance with the 2019 Medical Care Act Enforcement Regulations, entry, exit, contact information, etc. for entry and exit, the criteria for entering and exiting special rooms of medical institutions have been revised so that records of facts are kept for one year. However, even now, the inconvenience continues due to the fact that such contents are created by hand or due to errors. For this reason, this study designed and implemented a system that provides automatic opening, closing, and accessing record storage functions for authorized users using IoT devices and UWB technology, and we expected that the convenience of the visitors and systemized access control will be possible.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06d
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• pp.187-189
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• 2006

최근 지하철이나 버스 등의 교통수단을 이용하기 위해 지불방식의 편리, 지연시간의 단축 등 효율성이 높은 비접촉식 카드를 많이 사용하고 있다. 이러한 비접촉식 스마트 카드를 인증하기 위해서는 스마트카드ID가 스마트카드 단말기 내부에 저장하고 있어야 하며, 스마트카드ID가 변경될 때마다 서버으로부터 전송받아 최신의 정보로 갱신되어야 한다. 교통시스템에서 사용되는 통신매체는 RS-485를 사용하여 38.5Kbps로 통신하고 있고, 그로인해 스마트카드ID를 전송할 때 시간이 많이 소모되고, 스마트카드ID를 전승하는 동안에는 스마트카드 단말기의 사용이 제한되고 있어 단말기가 사용되지 않는 시간에 전송하고 있다. 이러한 교통시스템의 환경에서 점점 더 많아지고 있는 대량의 데이터를 스마트카드 단말기에 빠르게 전송하기 위해 스마트카드ID의 특성을 이용한 인코딩 기법을 적용하여 스마트카드ID의 크기를 줄여 전송함으로써 전송시간을 줄이는 방법을 제안하였다.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.6
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• pp.638-643
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• 2013

Laser beam machining (LBM) is fast, contactless and able to machine various materials. So it is used to cut metal, drill holes, weld or pattern the imprinted surface. However, after LBM, there still leave burrs and recast layers around the machined area. In order to remove these unwanted parts, LBM process often uses electrochemical etching (ECE). But, the total thickness of workpiece is reduced because the etching process removes not only burrs and recast layers, but also the entire surface. In this paper, surface coating was performed using enamel after LBM on metal. The recast layer can be selectively removed without decreasing total thickness. Comparing with LBM process only, the surface quality of enamel coating process was better than that. And edge shape was also maintained after ECE.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.393-396
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• 1996

This paper studies electrostatically suspended induction motors (ESIM). The ESIM possesses the rotating ability of an ordinary electrostatic induction motor, in addition to providing contactless support by electrostatic suspension. To accomplish these two functions, a feedback control strategy and the operating principle of an ordinary electrostatic induction motor are used. The stator possesses electrodes which exert the electrostatic forces to the rotor and are divided into a part responsible for suspension and one for rotation. Two rotor types are utilized: a polished glass disk without any surface treatment, and a polished glass disk covered with a thin layer of conductive material (ITO layer) on only one side. In this paper, the principle of the ESIM is described, followed by stator electrode design, experimental apparatus, control strategy for stable suspension. Experimental results show that the glass disk has been rotated with a speed of approximately 70 rpm while being suspended stably at a gap length of 0.3 mm.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.311-314
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• 1996

In contactless disk handling systems based on electrostatic suspension in which the stator is to be transferred, the limited stiffness in lateral direction severely restricts the achievable translational acceleration. In existing stator electrode pattern designs, the magnitude of the lateral force is determined by the magnitude of the control voltages which are applied to the individual electrodes to levitate the disk stably. As a result, the lateral force cannot be set arbitrarily. A new stator electrode pattern is presented for the electrostatic levitation of disk-shaped objects, in particular silicon wafers and aluminum hard disks, which allows the lateral forces to be controlled independently from the levitation voltages. Therefore, greater lateral forces can be obtained, compared with the existing stator designs. Experimental results will be presented for a 4-inch silicon wafer that clearly reveal the increased lateral stiffness by using the proposed stator electrode compared to the conventional electrode pattern.