• Title/Summary/Keyword: Wi-gi

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A Novel Authentication Protocol for Secure WiBro Services (안전한 WiBro 서비스를 위한 새로운 인증 프로토콜)

  • Koo, Jung-Sook;Kim, Jin-Geun;Bak, Jong-Hyeok;Koo, Jung-Doo;Lee, Gi-Sung
    • Proceedings of the KAIS Fall Conference
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    • 2008.05a
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    • pp.224-227
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    • 2008
  • 사용자가 안전한 WiBro 서비스를 받기 위해서 사용자 단말과 ACR(Access Control Router) 간에 인증이 선행되어야 한다. 그렇지 않을 경우, 많은 공격 위험으로부터 노출될 수 있다. 따라서 한국정보통신기술협회(TTA)에서는 휴대인터넷(와이브로$^{TM}$) 서비스를 위한 상호 인증 절차 표준을 제정하였다. 이 표준 프로토콜은 PISIM(Portable Internet Subscriber Identity Module)을 이용하여 PE(Portable Equipment)와 ACR 간에 상호 인증을 수행한다. 그러나 표준은 인증에 필요한 메시지의 수가 대체적으로 많은 편이며 PISIM의 분실과 에러가 발생했을 경우에는 사용자는 무선인터넷 서비스를 사용할 수 없게 된다. 따라서 본 논문에서는 ACR과 PSS 간에 키 동의 프로토콜을 수행하여 PSS를 인증한다. 이때 PSS의 계산량을 지원하기 위한 PSD(Power Support Device)가 키 동의 프로토콜에 참여하게 된다. 이렇게 생성된 키는 ACR과 안전한 통신 세션을 맺고 있는 KAS(Key Authentication Server)에 PSS의 식별자와 키 정보를 암호화에서 저장한다. 끝으로 제안된 프로토콜의 안전성과 효율성을 분석한다.

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Indoor Location Data Construction Technique using GAN (GAN을 이용한 실내 위치 데이터 구성 기법)

  • Yoon, Chang-Pyo;Hwang, Chi-Gon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2021.10a
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    • pp.490-491
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    • 2021
  • Recently, technologies using Wi-Fi fingerprints and deep learning are being studied to provide accurate location-based services in an indoor environment. At this time, the composition of learning data is very important, and it is essential to collect sufficient data necessary for learning. However, the number of specific points for the collection of radio signal data within the area requiring positioning is infinite, and it is impossible to collect all of these data. Therefore, there is a need for a way to make up for insufficient learning data. This study proposes a method of constructing a sufficient number of location data necessary for learning based on insufficiently collected location data.

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Realization of FBAR Devices for Broadband WiMAX Applications

  • Mai, Linh;Lee, Jae-Young;Pham, Van Su;Yoon, Gi-Wan
    • Journal of information and communication convergence engineering
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    • v.6 no.1
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    • pp.34-37
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    • 2008
  • Effects of the addition of Cr adhesion layer to $W/SiO_2$ multilayer Bragg reflectors on the resonance characteristics of film bulk acoustic wave resonator (FBAR) devices are presented. Main resonance peaks could be significantly shifted to higher frequency, mainly due to the addition of Cr adhesion layer to multilayer Bragg reflectors and control of the bottom electrode thickness as well. The FBAR devices with the Cr adhesion layer in Bragg reflectors could result in much more improved resonance characteristics at about 3 GHz in terms of return loss and Q-factor.

Thermal Improvements for 2.75 GHz-FBAR Devices

  • Mai, Linh;Lee, Jae-Young;Pham, Van-Su;Kabir, S. M. Humayun;Dong, Hoai-Bac;Yoon, Gi-Wan
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.10a
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    • pp.196-199
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    • 2007
  • In this paper, we studied a ZnO-based film bulk acoustic wave resonator (FBAR) device fabricated on top of a novel multi-layered Bragg reflector with chromium adhesion layers $(0.03{\mu}m-thick)$ inserted. The performance of FBAR device could be significantly improved using proper thermal treatments. At ${\sim}2.75$ GHz, we could achieve good return loss and quality factor (Q). This device fabrication technique will be useful for the future mobile WiMAX applications.

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Implementation of Software Platform for STTC-OFDM based WiBro Systems (STTC-OFDM 기반의 WiBro 시스템 소프트웨어 플랫폼 구현)

  • Lee, Dong-Gi;Lee, Jong-Sik;Jun, Hwang-In;Lee, Seung-Hyun;Kim, Jin-Young
    • 한국정보통신설비학회:학술대회논문집
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    • 2008.08a
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    • pp.535-539
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    • 2008
  • Recently mobile devices can transmit mass data contained multi-media contents. According these flow, a demand for fast data transmission is being risen, so we acutely require remarkable technology that overcome mobile communication's poor environment and rise data transmission volume. Because it can be satisfied these needs, the OFDM(Orthogonal Frequency Division Multiplexing) that rise data transmission volume using efficient frequency, and MIMO(Multiple Input Multiple Output) that rise transmission confidence and data transmission volume using numbers of antenna is attended. Before design of MIMO-OFDM System we want to make an analysis for theory of its systems, and we want to design MIMO-OFDM simulator for verify an ability of modulation, data volume and numbers of antenna.

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A Study on Picture Meta Data Processing System Architecture based on Ubiquitous Environment (유비쿼터스 환경에 적용 가능한 사진 메타 데이터 처리 시스템 아키텍쳐 연구)

  • Kyung, Min-Gi;Min, Dugki
    • Proceedings of the Korea Information Processing Society Conference
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    • 2009.04a
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    • pp.954-956
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    • 2009
  • 디지털 카메라는 단순히 사진을 찍는 장치가 아니며 사진에 연관된 다양한 메타 데이터를 제공하기 위한 다양한 시스템이 사진을 찍는 CCD와 유기적으로 연계되어 있다. 사진에 연관된 메타 데이터들은 디지털 카메라로 찍은 사진을 분류하는 기능을 지원한다. 하지만 사진의 메타 데이터들은 사진에 대한 검색을 가능하게 하지만, 대부분 사람의 수작업으로 이루어지기 때문에 새로운 메타 데이터의 입력이 어렵다는 문제점이 있다. 사진의 메타 데이터를 쉽게 추가하기 위해 본 논문에서는 GPS 시스템과 Wi-Fi, 데이터베이스를 이용해서 사진의 메타 데이터를 Exif(Exchangeable image file format)에 추가하고자 한다. GPS 시스템은 사진을 찍는 사람들이 어디에 있는지를 제시하고, Wi-Fi와 데이터 베이스를 이용해서 사용자에게 사용자가 사진을 찍은 위치와 관련된 메타 데이터를 제공한다. 이를 기반으로 본 논문에서는 이러한 PreTag라는 사진 메타 데이터 추가 아키텍처를 제시한다.

A study on the Theory of 'Ja-Yeol(刺熱)' in 32nd Chapter of 'So Moon(素問) Yellow Emperior's Nei-Ching(黃帝內經)' (황제내경(黃帝內經) 소문(素問) 자열론(刺熱論)에 대한 연구(硏究))

  • Kwon, Kun-Hyuck;Hong, Won-Sik
    • Journal of Korean Medical classics
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    • v.3
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    • pp.151-217
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    • 1989
  • In this thesis, I intend to study the translational and clinical interpretation through the theory of Ja-Yeol, and reached the following conclusions. 1. Liver-Heat-Disease due to absess of the function of expelling and lifting off, that Liver-Yang cannot lift up to upper-warmer, and stagnate liver. I think the symptoms of yellowish urine, abdominal pain, somnolence, fever belong to the syndrome of 'Gi-Bun(氣分)', and the symptoms of ravings with surprising, distending pain of hypochondrium, restless involuntary movement of the limbs, unable to lie flat belong to the syndrome of 'Hyeol-Bun(血分)'. 2. Heart-Heat-Disease due that 'Eum-Gi(陰氣)' in heart cannot lay down and reach to stagnate at heart, inner part. I think the symptoms of unjoy, acute cardiac pain, fidgetiness, well-nausea, headeche, reddish face, anhidrosis, etc. reveal with Heart-Heat-Disease. 3. Spleen-Beat-Disease due that 'Eum-Gi' in spleen cannot lay down and Yin of spleen changs heat. I think the symptoms of heaviness of head, cheek pain, fidgetiness, cyanosis, well-nausea, fever, not to let flex and reflex with back pain, diarrhea with abdominal pain, left and right cheek pain reveal with Spleen-Heat-Disease. I think symptoms of fever, diarrhea with abdominal pain belong to the syndrome of Yin-exhausion. 4. Lung-Heat-Disease due to that 'Eum-Gi' in lung cannot lay down. When 'Wi-Gi(衛氣)' stagnates at external part, I think, the symptoms of intolerance to wind and cold, yellowish fur, fever reveal. When Wi-Gi stagnates at lung, inner part, I think, the symptoms of dispnea with cough, pain on chest and back, unable to breath deeply, hydrosis and chilling reveal. 5. Kidney-Heat-Disease, in that the symptoms of back pain, leg aching, extreme thirst and frequently drink, fever, pain and stiffness of nape, cooling and aching leg, heat on plantar pedis, not trying to speak reveal is regarded external heat disease of 'Tai-Yang-Gyeong's(太陽經)' disease that asthenic fever open 'Tai-Yang-Gyeong' and lift by not enough of 'Yang-Gi(陽氣)' lifeing up from Kidney space, the water space of five elements.

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Analysis of Antenna Isolation Using Decoupling Structure (격리구조 기법을 이용한 안테나 격리도 변화 분석)

  • Lee, Junghun;Kim, Jihoon;Kim, Min-Gi;Kim, Hyung-Hoon;Kim, Hyeong-Dong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.26 no.12
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    • pp.1044-1049
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    • 2015
  • In this paper, isolation enhanced antenna using isolating resonator was proposed. Two loop type antennas were designed to operate at Wi-Fi band(2.4~2.5 GHz), in symmetry to the center, and are closely located to each other. In order to enhance isolation characteristics at Wi-Fi bands, isolating resonator was designed between the two loop type antennas. The proposed isolating resonator is a slot type antenna that enhances isolation with the control of the size, and by adjusting the value of capacitor($C_D$) the resonant frequency of the isolating resonator can easily be adjusted to enhance isolation characteristic at the target frequency.

Diligence/Indolence Management Scheme Using WiFi Access Points (와이파이 무선접근점을 이용한 근태관리 기법)

  • Jo, Hyun Joon;Park, Jin Soo;Lee, Dong Gi;Kim, Dong Hyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.6
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    • pp.1395-1400
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    • 2014
  • Diligence/Indolence records are the key data for a human resource management and the basic data to measure the salaries of the employees. However, existing mechanical or electro-magnetic diligence/indolence management systems have the problems that the systems are often incorrect or require much cost to build them. In this paper, we design and implement the diligence/indolence management system using a smart device of an employee. To measure the data of the diligence/indolence, the implemented system acquires the location data of the employee using the MAC addresses of both a smart device and access points of the WiFi and transfers the data of punching-in/out based on the acquired location to a server. The benefit of the proposed system is that it is easy for small business to use the proposed D/I management system with low cost because the system exploits smart devices and WiFi access points installed previously.

The Study on Clinical relations of Mamok and Abnormal sensations (마목(麻木)과 이상감각(異常感覺)과의 연관성에 관한 연구(1))

  • Ko, Seong-Kyu
    • The Journal of Korean Medicine
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    • v.18 no.1
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    • pp.251-266
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    • 1997
  • The results are as follows. 1. Oriental medical terms which express abnormal sensations are Bulin, Mamok, Mamokbulin. 2. Bulin, Oriental medical terminology, was used from Naegyeong's era to the Song Dynasty era and expressed as one of the symptoms in Jungpung(Stroke), Bi syndrome(Obstruction syndrom of Gi and Hyeol), Wi syndrome(Flaccid paralysis of the limbs), Hyeolbi(One of the Bi syndroms). But since the Keum Dynasty era, Mamok or Mamokbulin were more used than Bulin and that was refered as seperated disease. 3. Ma is paresthesia or dysthesia on the skin and the limbs, and the symtoms are not itchy, patients are felt like insect's crawling or bite. Mok is a stubborn symptom , the patients are felt like tree, which don't know pain and itching sensation. And therefore Ma is similar to positive phenomena and Mok is similar to negative phenomena in clinical aspect. 4. Mamok is GiHyeol(Gi is functional activities, Hyeol is blood) and Gyeonglak(Meridian system)'s disease. It's main causes are Giheo(Deficiency of Gi) and Hyeolhel(dificiency of Blood) and inducing tactors are Pung-Han-Seub(pathogenic wind-cold-dump) and Damtak(Phlegm-turbity), Eohyeol(Stagnated blood). 5. Mamok is induced from mononeuritis, multiple mononeuritis, polyneuropathy in the peripheral nervous lesions and also induced from cervical spondylosis, spinal tumour, multiple sclerosis, cerebrospinal vascular disease in central nervous systems.

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