• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.8
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• pp.1481-1487
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• 2008

In this paper, we propose a novel interactive 3D floating image pointing device for the use of 3D environment. The proposed system consists of the 3D floating image generation system by use of a floating lens array and the a user interface based on real-time finger detection. In the proposed system, a user selects single image among the floating images so that the interaction function are performed effectively by pressing the button event through the finger recognition using two cameras. To show the usefulness of the proposed system, we carry out the experiment and the preliminary results are presented.

• Journal of the Korea Society of Computer and Information
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• v.27 no.12
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• pp.231-238
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• 2022

In this paper, among short-range wireless communication technologies such as Beacon, Bluetooth, UWB (Ultra-wideband), ZigBee, NFC (Near Field Communication), Z-Wave, 6LoWPAN (IPv6 over Low power WPAN), D2D (Device to Device), etc., proposed an IoT service platform based on a beacon that can provide indoor positioning. And, a beacon-linked web server was designed by blocking indiscriminate beacon spam signals and applying REST web service technology with flexibility and scalability. Data accessibility between different devices was verified by testing the success rate of data transmission, the success rate of blocking beacon push, the success rate of IoT interlocking processing, the accuracy of location positioning, and the success rate of REST web service-based data processing. Through the designed IoT service platform, various proposals and research on short-distance-based business models and service platforms will be conducted in the future.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.3
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• pp.1-7
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• 2021

In this paper, by embedding a bare-die chip-type drive amplifier into the PCB composed of ABF and FR-4, it implements an embedded active device that can be applied in 28 GHz band modules. The ABF has a dielectric constant of 3.2 and a dielectric loss of 0.016. The FR-4 where the drive amplifier is embedded has a dielectric constant of 3.5 and a dielectric loss of 0.02. The proposed embedded module is processed into two structures, and S-parameter properties are confirmed with measurements. The two process structures are an embedding structure of face-up and an embedding structure of face-down. The fabricated module is measured on a designed test board using Taconic's TLY-5A(dielectric constant : 2.17, dielectric loss : 0.0002). The PCB which embedded into the face-down expected better gain performance due to shorter interconnection-line from the RF pad of the Bear-die chip to the pattern of formed layer. But it is verified that the ground at the bottom of the bear-die chip is grounded Through via, resulting in an oscillation. On the other hand, the face-up structure has a stable gain characteristic of more than 10 dB from 25 GHz to 30 GHz, with a gain of 12.32 dB at the center frequency of 28 GHz. The output characteristics of module embedded into the face-up structure are measured using signal generator and spectrum analyzer. When the input power (P_in) of the signal generator was applied from -10 dBm to 20 dBm, the gain compression point (P_1dB) of the embedded module was 20.38 dB. Ultimately, the bare-die chip used in this paper was verified through measurement that the oscillation is improved according to the grounding methods when embedding in a PCB. Thus, the module embedded into the face-up structure will be able to be properly used for communication modules in millimeter wave bands.

• Annual Conference of KIPS
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• 2013.11a
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• pp.253-256
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• 2013

Device-to-device (D2D) 통신 기술은 기지국 및 Access Point (AP)와 같은 인프라의 경유 없이 트래픽 교환이 단말기간에 직접적으로 이루어지도록 하는 기술이다. 오늘날 D2D 통신 기술은 셀룰러 망 과부하 문제의 해결책으로써 많은 관심을 받고 있다. 본 논문에서는 대표적인 D2D 통신 기술인 Wi-Fi Direct에 기반하여 형성된 네트워크에 존재하는 다수의 단말에게 동영상을 스트리밍하기 위한 안드로이드 라이브러리 개발 사례를 소개한다. 본 논문에서 소개하는 라이브러리는 의사 브로드캐스트(Pseudo-broadcast) 방식을 사용하여 다수의 단말에게 동영상을 스트리밍한다. 의사 브로드캐스트 방식은 빠른 전송 속도로 동영상을 스트리밍할 뿐만 아니라 한 번의 전송을 다수의 단말에게 동일한 데이터를 전송할 수 있는 장점이 있다.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.20 no.2
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• pp.77-84
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• 2016

Objectives This paper is focused on the development of supporting device for the direct moxibustion. This device makes one help to do moxibustion on one's head and back for oneself. Without this device, one can't avoid the other's help to do moxibustion on one's head and back. Methods The design protocols of the supporting device for the direct moxibustion are determined. And 3 dimensional simulation using Ultimaker's 3D printer was carried out. The parts of the supporting device for direct moxibustion are followings: 1. preparing of the main parts which are divided into an acupuncture touching sting and moxa holder. 2. preparing a grip part. Results 3 different lengths of the acupuncture touching sting such as 3mm, 4mm, and 5mm were experimented for the perfect burning of moxa. Among them, the acupuncture touching sting with 4mm length was best for the perfect burning and for the organic functional tests. Conclusion The supporting device for direct moxibustion will be helpful to minimize of the burning of skin, the pain, and the smoke.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.7
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• pp.1533-1546
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• 2013

Wireless multicast is considered as an effective transmission mode for the future mobile social contact services supported by Long Time Evolution (LTE). Though wireless multicast has an excellent resource efficiency, its performance suffers deterioration from the channel condition and wireless resource availability. Cognitive Radio (CR) and Device to Device (D2D) are two solutions to provide potential resource. However, resource allocation for cognitive wireless multicast based on D2D is still a great challenge for LTE social networks. In this paper, a joint sub-carriers and power allocation model based on D2D for general cognitive radio multicast (CR-D2D-MC) is proposed for Orthogonal Frequency-Division Multiplexing (OFDM) LTE systems. By opportunistically accessing the licensed spectrum, the maximized capacity for multiple cognitive multicast groups is achieved with the condition of the general scenario of imperfect spectrum sensing, the constrains of interference to primary users (PUs) and an upper-bound power of secondary users (SUs) acting as multicast source nodes. Furthermore, the fairness for multicast groups or unicast terminals is guaranteed by setting a lower-bound number of the subcarriers allocated to cognitive multicast groups. Lagrange duality algorithm is adopted to obtain the optimal solution to the proposed CR-D2D-MC model. The simulation results show that the proposed algorithm improves the performance of cognitive multicast groups and achieves a good balance between capacity and fairness.

• Journal of Magnetics
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• v.17 no.4
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• pp.308-315
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• 2012

Experimental investigations of the magnetization, magnetostriction and magnetoelectric (ME) effects were performed on sandwich - type Metglas/PZT/Metglas laminate composites. The results have been analyzed by taking into account the demagnetization contribution. The study has pointed out that the magnetic flux concentration is strongly improved in piezomagnetic laminates with a narrower width leading to a significant enhancement of the ME effects. The piezomagnetic laminates with the optimal area dimension were integrated to form a 2-D geomagnetic device, which simultaneously can precisely detect the strength as well as inclination of the earth's magnetic field. In this case, a magnetic field resolution of better than $10^{-4}$ Oe and an angle precision of ${\pm}0.1^{\circ}$ were determined. This simple and low-cost geomagnetic-field device is promising for various applications.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.8
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• pp.643-650
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• 2000

Density-of-states effective mass(m*$_{d}$) and conductivity mass(m*$_{c}$)for Ge and Ge$_{0.8}$/Sn$_{0.2}$ are obtained by using 8$\times$8 k.p and strain Hamiltonians. It is shown that m*$_{d}$ and m*$_{c}$ for electrons in Ge/Ge$_{0.8}$/Sn$_{0.2}$(001) and Ge$_{0.8}$/Sn$_{0.2}$/Ge(001) are much smaller than those for electrons in relaxed Ge mainly due to the increase of interaction caused by the strain between the conduction band and valence bands at the $\Gamma$ point. The lift of degeneracy in Ge/Ge$_{0.8}$/Sn$_{0.2}$(001) and Ge/Ge$_{0.8}$/Sn$_{0.2}$(001) makes m*$_{d}$ and m*$_{c}$ for holes smaller than those in relaxed Ge and results in the decrease of the interband scattering as well as interband scattering. The decrease of the interband scattering is more obvious in Ge/Ge$_{0.8}$/Sn$_{0.2}$(001) because of its large splitting energy between the heavy hole and light hole band. Therefore, Ge/Ge$_{0.8}$/Sn$_{0.2}$(001) is expected to be good candidate for the development of ultra high-speed CMOS device.CMOS device.eed CMOS device.CMOS device.

• The Journal of the Korea Contents Association
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• v.19 no.9
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• pp.348-356
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• 2019

This study is was to suggest improvement of assistive device for the elderly according to investigate the satisfaction and the needs of assistive device for elderly. The subjects were 184 beneficiary older adults in long-term health insurance who used home care service in I city and D city. Data were analyzed using SPSS 20.0. With the exception of cognitive assistance grade, subjects were showed from 'normal' to ' satisfied' on a types of assistive device and services related to assistive device. I, II grade subjects needed assistive device for self-care. III, IV and V grade subjects needed assistive device for safety and health maintenance. In the service related assistive device, All subjects needed service on 'periodic follow-up service', 'expert on assistive device' and 'comprehensive evaluation'. This results is significant in that it suggest to needed assistive device in accordance with grade unlike previous studies. Results of this study will expected to utilize as a basic evidence for improvement of assistive device, service related to assistive device for elderly.

• Journal of Magnetics
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• v.12 no.1
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• pp.21-26
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• 2007

Si-based electromagnetic noise suppressors on coplanar waveguide transmission lines incorporated with a $SiO_2$ dielectric layer and a nanogranular Co-Fe-Al-O magnetic thin film are reported. Unlike glass-based devices, large signal attenuation is observed even in the bare structure without coating the magnetic thin film. Much larger signal attenuation is achieved in fully integrated devices. The transmission scattering parameter ($S_{21}$) is as small as -90 dB at 20 GHz at the following device dimensions; the thicknesses of the $SiO_2$ and Co-Fe-Al-O thin films are 0.1 $\mu$m and 1 $\mu$m, respectively, the length of the transmission line is 15 mm, and the width of the magnetic thin film is 2000 $\mu$m. In all cases, the reflection scattering parameter ($S_{11}$) is below -10 dB over the whole frequency band. Additional distributed capacitance formed by the Cu transmission line/$SiO_2$/Si substrate is responsible for these characteristics. It is considered that the present noise suppressors based on the Si substrate are a first important step to the realization of MMIC noise suppressors.