• Title/Summary/Keyword: D2D communication

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A Basic Study of Verbs List for Vocabulary Learning Based on Augmented Reality (증강현실 기반 어휘 지도에서 동사 목록에 대한 기초 연구)

  • Hwang, BoMyung;Kwon, SoonBok;Kim, SeonJong;Shin, BeomJoo
    • 재활복지
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    • v.21 no.2
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    • pp.233-246
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    • 2017
  • The present study is a basic study for application of Augmented Reality (AR) to verb teaching for children with language developmental disorders and is intended to examine validity for the list of verbs at the beginning of development. To confirm the validity of the verbs list, the appropriateness of the verbs was evaluated by three professors with certification of KSLP (Korean Speech-Language Pathologist) working in the department of Speech-Language Pathology at the university. The motion validity test was conducted by showing motion implemented as AR to eight master's students in Speech-Language Pathology major, having them record verbs that came to their mind, and evaluating in the conformity. The second motion validity test was conducted by using 5-point Likert scales to 87 undergraduates in Speech-Language Pathology major and having them see the motions in AR and marked the degrees to which them see the motions conform to the relevant verbs on the scales. Using the SPSS 21.0 program, descriptive statics analyses of the results were conducted. Through this all process, thirty verbs were selected as having content validity. It could be seen that when AR based communication system are applied, things and backgrounds that complement the insufficient movements of motions and help motion recognition should be also provided. In future studies, the 3D images of the AR based communication system will be complemented and the content validity will be verified with typically developing children and the children with language developmental disorders.

Implementation and Verification for the Low RCS Characteristics of Active Phased Array Antenna (능동위상배열 안테나의 저피탐 특성 구현 및 검증)

  • Joung-Myoung Joo;;Heeduck Chae;Jongkuk Park;Young-Jo Choi;Hyeong-Ki Lee;Jeongyun Han;Jeong-Hwan Jeon
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.23 no.2
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    • pp.87-94
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    • 2023
  • As the latest weapon systems and electronic equipments are increasingly demanding stealth technology to improve the survivability of allies, it is necessary to implement low-observability technology that reduces the radar cross section(RCS). In order to implement this stealth technology, a method for low RCS characteristics by applying a shape design or a electromagnetic wave absorber is widely used. However, active phased array antennas have structural limitations in shape design, also when a absorber is applied to it, the performance of the antenna is degraded. Therefore, in this paper, in order to realize the low RCS characteristics of the active phased array antenna operating in the X-band, individual radiating elements suitable for applying the radio wave absorber were selected, and a 13x13 array antenna was designed and manufactured. Next, by comparing the measured results of the relative RCS and electrical performance for the manufactured antenna according to the presence and type of the absorber, it is shown that the electrical performance is maintained at an equal or higher level while obtaining the low RCS characteristics. Thereby the method proposed in this paper for implementing the low RCS characteristics was validated. Finally, it was confirmed that when the wave absorber is applied to the array antenna, the limitation of its performance deterioration can be overcome.

An Analysis of Mathematical Processes in Elementary Mathematics Curricula of Korea, China, Japan, and the US (한국, 중국, 일본, 미국 초등 수학과 교육과정에서 강조하는 수학적 과정 요소에 대한 분석)

  • Pang, JeongSuk;Lee, JiYoung;Lee, SangMi;Park, YoungEun;Kim, SuKyong;Choi, InYoung;SunWoo, Jin
    • School Mathematics
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    • v.17 no.2
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    • pp.289-308
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    • 2015
  • This study analyzed mathematical processes elaborated in the mathematics curricula of Korea, China, Japan, and the US. Ten mathematical processes were extracted: (a) learning of concepts, principles, laws, and skills; (b) problem solving; (c) reasoning; (d) communication; (e) representation; (f) connections; (g) creativity; (h) character-building; (i) self-directed learning; and (j) positive attitude toward mathematics. This study specified the meaning of such processes and their sub-domains, noticing similarities and differences among the curricula. On the basis of the results, this study includes suggestions for the development of next mathematics curriculum in Korea.

Design and Implementation of Optical Receiving Bipolar ICs for Optical Links

  • Nam Sang Yep;Ohm Woo Young;Lee Won Seok;Yi Sang Yeou1
    • Proceedings of the IEEK Conference
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    • 2004.08c
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    • pp.717-722
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    • 2004
  • A design was done, and all characteristic of photodetectr of the web pattern type which a standard process of the Bipolar which Si PIN structure was used in this paper, and was used for the current amplifier design was used, and high-speed, was used as receiving optcal area of high altitude, and the module which had a low dark current characteristic was implemented with one chip with a base. Important area decreases an area of Ie at the time of this in order to consider an electrical characteristic and economy than the existing receiving IC, and performance of a product and confidence are got done in incense. First of all, the receiving IC which a spec, pattern of a wafer to he satisfied with the following electrical optical characteristic that produced receiving IC of 5V and structure are determined, and did one-chip is made. On the other hand, the time when AR layer of double is $Si_{3}N_{4}/SiO_{2}=1500/1800$ has an optical reflectivity of less than $10{\%}$ on an incidence optical wavelength of 660 ,and, in case of photo detector which reverse voltage made with 1.8V runs in 1.65V, an error about a change of thickness is very the thickness that can be improved surely. And, as for the optical current characteristic, about 5 times increases had the optical current with 274nA in 55nA when Pc was -27dBm. A BJT process is used, and receiving IC running electricity suitable for low voltage and an optical characteristic in minimum 1.8V with a base with two phases is made with one chip. IC of low voltage operates in 1.8V and 3.0V at the same time, and optical link receiving IC is going to be implemented

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A Study on PAPR reduction in OFDM WPAN system using Millimeter Wave (Millimeter Wave를 이용하는 OFDM WPAN 시스템에서 PAPR 감소에 관한연구)

  • Kim, Wan-Tae;Yoo, Sun-Yong;Cho, Sung-Joon
    • Journal of Advanced Navigation Technology
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    • v.12 no.2
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    • pp.139-145
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    • 2008
  • There has been lots of studies on communication systems using millimeter wave recently in many countries, specially in newly assigned 57GHz ~ 64GHz ISM band. Among those studies, IEEE 802.15.3c standard proposes OFDM (Orthogonal Frequency Division Multiplexing) systems for high data rate transmission support. But OFDM method has the PAPR (peak-to-Average Power Radio) problem The PAPR problem is to decline the performance of the transmission system due to signals distorted severely when passing through nonlinear components such as ADC/DAC and power amplifiers. In order to solve the problem of P APR, this paper suggests SSC (Sine Soft Clipping) and analyzes the PAPR, CCDF, PSD, BER by applying SAW(Surface Acoustic Wave) filter and power amplifiers to IEEE 802.15.3.c OFDM WPAN systems.

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Robust Face and Facial Feature Tracking in Image Sequences (연속 영상에서 강인한 얼굴 및 얼굴 특징 추적)

  • Jang, Kyung-Shik;Lee, Chan-Hee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.9
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    • pp.1972-1978
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    • 2010
  • AAM(Active Appearance Model) is one of the most effective ways to detect deformable 2D objects and is a kind of mathematical optimization methods. The cost function is a convex function because it is a least-square function, but the search space is not convex space so it is not guaranteed that a local minimum is the optimal solution. That is, if the initial value does not depart from around the global minimum, it converges to a local minimum, so it is difficult to detect face contour correctly. In this study, an AAM-based face tracking algorithm is proposed, which is robust to various lighting conditions and backgrounds. Eye detection is performed using SIFT and Genetic algorithm, the information of eye are used for AAM's initial matching information. Through experiments, it is verified that the proposed AAM-based face tracking method is more robust with respect to pose and background of face than the conventional basic AAM-based face tracking method.

A Atudy on NCS-based Virtual Training Content Analysis (NCS기반 가상훈련 콘텐츠 분석에 관한 연구)

  • Song, Eun-Jee;Lee, Seok-Hee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.3
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    • pp.651-656
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    • 2017
  • Virtual Training generates virtual situation or environment with specific goals in order to instruct trainees as if they are in the real-world. Recently, the demand of experiencing certain incident, which we are not able to experience in real life, has been increased along with the fast developing Virtual Reality (VR) technology. Particularly, Virtual Training(VT) enables us to learn various fields those require high risk and high cost. The system of VT provides interaction and allows us absorb these learning materials better which augments learning effect. Based on the demand of Virtual Training system, this research analyzes current education paradigm National Competency Standards (NCS) in Korea and suggests possible education that utilizes Virtual Training system. At the end of the day, our future goal is to apply suggested Virtual Training contents to universities that reflect NCS curriculum like polytechnic university.

Design of double-clad, dispersion-compensating single-mode fiber with parabolic-index profile for $\lambda$=1.55 $\mu$m ($\lambda$=1.55 $\mu$m에서 포물선분포-이중클래드, 분산보상 단일모드 광섬유의 설계)

  • 김동각;김창민;이상배;강희전
    • Korean Journal of Optics and Photonics
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    • v.8 no.2
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    • pp.134-141
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    • 1997
  • We design the single mode dispersion-compensating fibers (DCF) which may be necessary for upgrading the previously installed 1.31 ${\mu}{\textrm}{m}$ optical communication system to the 1.55 ${\mu}{\textrm}{m}$ system. To obtain the optimum index profile that allows large negative dispersion at 1.55 ${\mu}{\textrm}{m}$, parabolic-index, double-clad fibers are analyzed by applying the 1-D FEM to the scalar wave equation of optical fibers. In constideration of macro-bending loss, the fibers are designed so that the cutoff wavelength of the $LP_{01}$ mode is greateer than 1.80 ${\mu}{\textrm}{m}$. The computer simulations show that the lower bound of the dispersion at 1.55 ${\mu}{\textrm}{m}$ is limited to about -120 ps/nm . km for the fiber index profiles satisfying the $LP_{01}$'s cutoff condition.

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Front-End Design for Underwater Communication System with 25 kHz Carrier Frequency and 5 kHz Symbol Rate (25kHz 반송파와 5kHz 심볼율을 갖는 수중통신 수신기용 전단부 설계)

  • Kim, Seung-Geun;Yun, Chang-Ho;Park, Jin-Young;Kim, Sea-Moon;Park, Jong-Won;Lim, Young-Kon
    • Journal of Ocean Engineering and Technology
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    • v.24 no.1
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    • pp.166-171
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    • 2010
  • In this paper, the front-end of a digital receiver with a 25 kHz carrier frequency, 5 kHz symbol rate, and any excess-bandwidth is designed using two basic facts. The first is known as the uniform sampling theorem, which states that the sampled sequence might not suffer from aliasing even if its sampling rate is lower than the Nyquist sampling rate if the analog signal is a bandpass one. The other fact is that if the sampling rate is 4 times the center frequency of the sampled sequence, the front-end processing complexity can be dramatically reduced due to the half of the sampled sequence to be multiplied by zero in the demixing process. Furthermore, the designed front-end is simplified by introducing sub-filters and sub-sampling sequences. The designed front-end is composed of an A/D converter, which takes samples of a bandpass filtered signal at a 20 kHz rate; a serial-to-parallel converter, which converts a sampled bandpass sequence to 4 parallel sub-sample sequences; 4 sub-filter blocks, which act as a frequency shifter and lowpass filter for a complex sequence; 4 synchronized switches; and 2 adders. The designed front-end dramatically reduces the computational complexity by more than 50% for frequency shifting and lowpass filtering operations since a conventional front-end requires a frequency shifting and two lowpass filtering operations to get one lowpass complex sample, while the proposed front-end requires only four filtering operation to get four lowpass complex samples, which is equivalent to one filtering operation for one sample.

A Study on Opinion of Korean Feminine Seniors on the Life Support Appliances for Healthy Ageing - Medication Dispenser, Video Phone, Activity Monitor, Sleep Monitor - (재가노인 생활지원기기에 대한 한국 여성노인의 인식 - 알약분배기, 비디오폰, 활동모니터, 취침모니터를 중심으로 -)

  • Steggell, Carmen D.;Park, Kyoung-Ok;Kim, Sun-Joong;Kwon, Myoung-Hee
    • Journal of the Korean Home Economics Association
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    • v.46 no.4
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    • pp.83-96
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    • 2008
  • The purpose of this study is to grasp the opinion of Korean feminine seniors on the life support appliances for their healthy ageing: medication dispenser, video phone, activity monitor and sleep monitor. The focus group interviews, asking the usability of the appliances, were answered by each 6 feminine seniors of more than 65 years, residing in Corvallis of U.S.(group I), Cheongju(group II), and Ulsan(group III) of Korea. The results are as follows. (1) The medication dispenser proved to be very useful to all the respondents. All the seniors, who take more than one medicine a day, felt it helpful that the medication dispenser makes them to take medicines at fixed time. In addition, they hoped the medicine envelope to be developed for the dispenser use by the supply side. (2) The seniors showed interest in the manner the video phone works; to work by the voice, rather than by the finger. They expressed the hope of the video phone to display the communication contents, in consideration of their weakening hearing. (3) The seniors who live alone, especially, felt intimacy to the activity monitor, thinking as if some helpers were beside them. The fact that it can send emergency calls immediately when situations happen, gave the seniors emotional safety as a patron. (4) The sleep monitor, although essential to the serious cases without moving ability, was proved less necessary to the healthy seniors. They expressed the hope of this appliance to be evolved for the use with the mattress without bed.