• 제목/요약/키워드: Wi-cheon

검색결과 65건 처리시간 0.052초

해상 무선통신을 위한 이중대역 마이크로 스트립 안테나 설계 (Design of Dual-Band Microstrip Antenna for Marine Telecommunication)

  • 최조천;이광복;김갑기;이성로
    • 한국통신학회논문지
    • /
    • 제39C권12호
    • /
    • pp.1314-1317
    • /
    • 2014
  • 본 논문에서는 LTE와 WiMAX 시스템에 적용 가능한 마이크로스트립 패치 안테나를 설계하였다. 제안된 모노폴 안테나의 기판은 FR-4이고 크기는 $70.88mm{\times}54.88mm$이다. 제안된 안테나는 평면형 모노폴 설계를 기본구조로 구성함으로서 LTE와 WiMAX 대역을 포함하는 이중대역 특성을 갖도록 설계하였다. 최적화된 파라메타를 얻기 위해 상용 툴(CST's Microwave Studio Program)을 사용하여 시뮬레이션 하였으며 안테나 성능에 민감하게 작용하는 파라메타를 찾아내서 최적화된 수치를 얻었다. 얻어진 최적화된 수치를 사용하여 제안된 안테나를 설계하였다. 따라서 제안된 안테나는 LTE와 WiMAX 대역을 동시에 만족하였다. 그리고 LTE와 WiMAX 대역에서 좋은 이득과 방사패턴의 특성을 얻었다.

WiBro 환경에서의 u-Healthcare 서비스를 위한 무선데이터 품질 측정 방안 연구 (A Study on Wireless Data Quality Measurement Method for u-Healthcare Service in WiBro Environment)

  • 심재성;윤성열;박석천
    • 한국산학기술학회논문지
    • /
    • 제13권2호
    • /
    • pp.834-841
    • /
    • 2012
  • 유 무선 통신망의 발전과 스마트폰 등 무선 단말을 이용한 모바일오피스 등 무선서비스 이용이 날로 증가하고, 이를 이용한 u-Healthcare 서비스가 각광 받고 있는데, 기존의 품질 측정 기준은 단순히 속도나 에러율 등만을 고려하였기 때문에 u-Healthcare의 안정성을 보장하기 위해서는 서비스별 품질관리가 필요하다. 본 논문에서는 u-Healthcare 무선서비스 사용자의 품질 보장 및 사용자 요구를 만족시키기 위한 방안으로 무선 환경을 고려한 무선서비스별 품질 측정 기준을 제시하였다. 관련 연구를 통해 3GPP, WiMAX 포럼, GSMA 등 국제 표준화 기관에서 제시한 주요성능 지표와 사업자 사례를 통해 최종 사용자 관점에서의 WiBro 환경에서 u-Healthcare를 제공하기 위한 서비스별 품질기준 체계를 확립하고 각 서비스별로 품질지표 수립의 타당성을 제시하였다.

수동 소자를 이용한 Wi-MAX용 트리플렉서 모듈 설계 (Design Of Compact Passive Triplexer Module for Wi-MAX Application)

  • 전재완;서재환;이승철;이상아;임종헌;천성종;박재영
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2009년도 제40회 하계학술대회
    • /
    • pp.2253_2254
    • /
    • 2009
  • 무선 모바일 통신 시장의 성장에 따라 수동 소자로 구성된 모듈에 대한 관심이 높아지고 있다. 본 논문에서는 수동소자를 이용한 Wi-MAX용 트리플렉서를 설계하였다. 트리플렉서는 Wi-MAX의 RF Front-end단 앞부분에 연결되며, IEEE 802.16에 따른 2GHz, 3GHz, 5GHz 대역을 선택, 분리해주는 역할을 한다. 제안된 트리플렉서는 저역통과필터, 대역통과필터, 고역통과필터로 구성하였으며, 수동소자의 최소화로 인해 삽입손실 향상을 중점으로 설계하였다. 회로해석 결과, 각 대역별 (2/3/5GHz) 삽입손실은 각각 -0.5dB, -0.6dB, -0.4dB 였으며, 반사손실은 -20dB, -20dB, -12dB, 격리도는 -20dB, -24dB, -25dB의 특성을 보였다. 수동 소자의 최소화 설계로 인해 모듈 및 시스템의 저가화를 기대할 수 있다.

  • PDF

경북 지역의 향사와 불천위제례의 진설과 제수 비교 - 대구와 안동지역 중심으로 - (Comparison of Hyang-Sa and Bulchunwee Rituals and Food in Kyungbuk - Focused on Daegu and Andong Areas -)

  • 최정희;박금순
    • 한국식품조리과학회지
    • /
    • 제24권6호
    • /
    • pp.801-810
    • /
    • 2008
  • The principal objective of this study was to assess Korea's traditional ritual food culture, and to compare two types of ancestral rites the Hyang-Sa and Bool-cheon-wi rites which were held in the Daegu and Andong regions of Korea. In this study, we describe the performance of the Bool-cheon-wi rites held by two head families located near the Andong area namely, the head family of Seoae Ryu Seong-Ryong(1542-1607)(Seoae) who was well-respected for his writings and personality, and the head family of Dangye Ha Wee-Ji(1412-1456)(Dangye) who was well-known and famous as one of the members of the Sa-ryuk-sin. This research was conducted via diredt engagement in these memorial services and several interviews with the families. The results were summarized as follows; Foods used in the Hyang-sa rites including Mae(bap), Kook, Jaban(Jogee), Po(dried fish), Juck, boiled and seasoned vegetables, fruits, confections, and liquor. Jobap and Ssalbap were used as Mae at SD(Seo Dalsung), and PMPH(Pahoi Myogul Habin Park) used Jo, Hyunmy, Pi and Susu in the raw. The dishes on the table were arranged as follows. A wine cup was placed in the first row, Po(a dried pollack), and jujube and nuts in the second row, Ryukpo(slices of dried beef), Sangeogogi were set at the third row, and Soegogi, pork, Mu, and Minary were placed in the fourth row, and the head of the pig was placed in the center of the table at SD. A wine cup, Soegogi, and pork were positioned in the first row, Mu, Minary, Pi and Susu were placed in the second row, and Jogee, Jo, and Hyunmy were placed in the third row at PMPH. The sacrificial foods offered for Bool-cheon-wi rites were as follows; Mae(bap) Kook noodle Jogee Tang(stew) Po Juck Tucks boiled, seasoned and salted vegetables Jeon fruit confectioneries liquor(chungju). The head family of Seoae Yu Seong-Ryong utilized 5 types of Tang(meat stew, fish stew, chicken stew, vegetable stew, seafood stew), whereas the head family of Dangye Ha Wee-Ji utilized 3 kinds of Tang(meat stew, fish stew, vegetable stew). As a basic Tuck, Shi-roo-tuck(a steamed rice cake), piled up to 25 layers, was primarily utilized. In particular, Jung-Gae(Seoae's favorite food) was placed on the table. For grilled-meat food(Juck), Yu's family used raw meat and Ha's family the half-cooked meat. The main types of Jucks used were meat-Juck, fish-Juck, chicken-Juck, and these were not served one by one. Hyang-sa and Bool-cheon-wi rites have an the educational function, in that they allow for the carrying out of filial duties by a heartfelt performance of performing the ceremony, by taking great care from the pre-rite preparations to the post-rite period. In addition, these rites have various meanings, as events that strengthen the ties of blood relations of ancestors and themselves, and to promote and harmonize family friendships, they may also have religious meaning in the culture, as prayers are offered that all the family's descendants may be blessed, live long and enjoy abundance whlie respecting their ancestors. As for the role of Hyang-sa and Bool-cheon-wi rites in today's nuclear family society, it can be said that these rites remain especially important as a method to strengthen community consciousness by fostering an understanding of the meaning of existence itself, and thus inspiring the roots of consciousness.

How to Combine Diffusion-Weighted and T2-Weighted Imaging for MRI Assessment of Pathologic Complete Response to Neoadjuvant Chemoradiotherapy in Patients with Rectal Cancer?

  • Jong Keon Jang;Chul-min Lee;Seong Ho Park;Jong Hoon Kim;Jihun Kim;Seok-Byung Lim;Chang Sik Yu;Jin Cheon Kim
    • Korean Journal of Radiology
    • /
    • 제22권9호
    • /
    • pp.1451-1461
    • /
    • 2021
  • Objective: Adequate methods of combining T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) to assess complete response (CR) to chemoradiotherapy (CRT) for rectal cancer are obscure. We aimed to determine an algorithm for combining T2WI and DWI to optimally suggest CR on MRI using visual assessment. Materials and Methods: We included 376 patients (male:female, 256:120; mean age ± standard deviation, 59.7 ± 11.1 years) who had undergone long-course CRT for rectal cancer and both pre- and post-CRT high-resolution rectal MRI during 2017-2018. Two experienced radiologists independently evaluated whether a tumor signal was absent, representing CR, on both post-CRT T2WI and DWI, and whether the pre-treatment DWI showed homogeneous hyperintensity throughout the lesion. Algorithms for combining T2WI and DWI were as follows: 'AND,' if both showed CR; 'OR,' if any one showed CR; and 'conditional OR,' if T2WI showed CR or DWI showed CR after the pre-treatment DWI showed homogeneous hyperintensity. Their efficacies for diagnosing pathologic CR (pCR) were determined in comparison with T2WI alone. Results: Sixty-nine patients (18.4%) had pCR. AND had a lower sensitivity without statistical significance (vs. 62.3% [43/69]; 59.4% [41/69], p = 0.500) and a significantly higher specificity (vs. 87.0% [267/307]; 90.2% [277/307], p = 0.002) than those of T2WI. Both OR and conditional OR combinations resulted in a large increase in sensitivity (vs. 62.3% [43/69]; 81.2% [56/69], p < 0.001; and 73.9% [51/69], p = 0.008, respectively) and a large decrease in specificity (vs. 87.0% [267/307]; 57.0% [175/307], p < 0.001; and 69.1% [212/307], p < 0.001, respectively) as compared with T2WI, ultimately creating additional false interpretations of CR more frequently than additional identification of patients with pCR. Conclusion: AND combination of T2WI and DWI is an appropriate strategy for suggesting CR using visual assessment of MRI after CRT for rectal cancer.

차세대 RF 트랜시버 기술 동향 (Technical Trend of Next-Generation RF Transceiver for Mobile Terminals)

  • 김준형;정재호;권헌국;이광천
    • 전자통신동향분석
    • /
    • 제23권3호
    • /
    • pp.72-81
    • /
    • 2008
  • 차세대 이동통신 서비스나 Beyond 4G 이동통신 서비스의 단말기는 유비쿼터스 정보화 사회의 도래에 발맞춰 기존의 single mode 시스템에서 탈피하여 3G LTE, Mobile WiMAX(WiBro), DMB, IEEE 802.11b/g/n 등의 다중 이동통신 서비스를 지원하는 단말기로 발전하는 추세이다. 또한 고속 데이터 전송을 위한 MIMO 및 스마트 안테나 등의 다중 접속 기능은 다중 밴드/다중 모드/다중 경로 처리 구조의 RF transceiver를 요구하고 있다. 이러한 융합 universal 단말기를 구현하기 위해서는 여러 이동통신 서비스를 지원하는 "Reconfigurability and Convergence" RF transceiver가 필요하지만 현재의 집적 기술로는 0-수 GHz에 할당되어 있는 모든 이동통신 서비스를 지원하는 단말기 구현에 제약사항이 많기 때문에 미국 및 유럽의 국외 연구기관과 기업에서는 2-3개의 선택적인 이동통신 서비스를 지원하는 RF transceiver를 개발하여 세계 시장에서 경쟁 준비를 하고 있다. 본 고에서는 차세대 이동통신 단말기의 RF transceiver 칩 셋 기술과 국내외 개발 동향에 대해 살펴보고자 한다.

무선데이터 서비스 품질 측정 시스템의 신뢰성 검증 및 평가 (Assessment and Validation of the Reliability of Quality Measurement System for Wireless Data Services)

  • 최동환;박석천
    • 한국IT서비스학회지
    • /
    • 제11권1호
    • /
    • pp.239-246
    • /
    • 2012
  • The user increases around the WiBro and in which the mobile broad band service is the wireless internet base technology HSDPA, that is the cellular phone foundation technique, and moreover the issue about the user effective quality guarantee emerges but the quality control of the wireless network is the incomplete actual condition. Therefore, the reliability verification according to the development of the system for the performance measure for the continued wireless data service and it and evaluation are needed for the quality control. In this paper, the wireless data service quality measurement system was implemented with the design. The same test environment as the existing network performance measurement program was built for the reliability verification of the embodied device for measuring quality and evaluation and the cost performance was performed. It could confirm that design and embodied wireless data service quality measurement system operated accurately in this paper through the quality measure result value analysis.