• Title/Summary/Keyword: 문제의 구조

Search Result 9,973, Processing Time 0.04 seconds

(A Study on the Control Mechanism for Network Survivability in OVPN over IP/GMPLS over DWDM) (DWDM기반의 OVPN에서 네트워크 생존성을 위한 제어 메커니즘 연구)

  • Cho Kwang-Hyun;Jeong Chang-Hyun;Hong Kyung-Dong;Kim Sung-Un
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.42 no.9 s.339
    • /
    • pp.85-96
    • /
    • 2005
  • A ' Virtual Private Network (YPN) over Internet' has the benefits of being cost-effective and flexible. However, given the increasing demands for high bandwidth Internet and for reliable services in a 'VPN over Intemet,' an IP/GMPLS over DWDM backbone network is regarded as a very favorable approach for the future 'Optical VPN (OVPN)' due to the benefits of transparency and high data rate. Nevertheless, OVPN still has survivability issues such that a temporary fault can lose a large amount of data in seconds, moreover unauthorized physical attack can also be made on purpose to eavesdrop the network through physical components. Also, logical attacks can manipulate or stop the operation of GMPLS control messages and menace the network survivability of OVPN. Thus, network survivability in OVPN (i.e. fault/attack tolerant recovery mechanism considering physical structure and optical components, and secured transmission of GMPLS control messages) is rising as a critical issue. In this Paper, we propose a new path establishment scheme under shared risk link group (SRLG) constraint for physical network survivability. And we also suggest a new logical survivability management mechanism by extending resource reservation protocol-traffic engineering extension (RSVP-TE+) and link management protocol (LMP). Finally, according to the results of our simulation, the proposed algorithms are revealed more effective in the view point of survivability.

Space-Time Concatenated Convolutional and Differential Codes with Interference Suppression for DS-CDMA Systems (간섭 억제된 DS-CDMA 시스템에서의 시공간 직렬 연쇄 컨볼루션 차등 부호 기법)

  • Yang, Ha-Yeong;Sin, Min-Ho;Song, Hong-Yeop;Hong, Dae-Sik;Gang, Chang-Eon
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.39 no.1
    • /
    • pp.1-10
    • /
    • 2002
  • A space-time concatenated convolutional and differential coding scheme is employed in a multiuser direct-sequence code-division multiple-access(DS-CDMA) system. The system consists of single-user detectors (SUD), which are used to suppress multiple-access interference(MAI) with no requirement of other users' spreading codes, timing, or phase information. The space-time differential code, treated as a convolutional code of code rate 1 and memory 1, does not sacrifice the coding efficiency and has the least number of states. In addition, it brings a diversity gain through the space-time processing with a simple decoding process. The iterative process exchanges information between the differential decoder and the convolutional decoder. Numerical results show that this space-time concatenated coding scheme provides better performance and more flexibility than conventional convolutional codes in DS-CDMA systems, even in the sense of similar complexity Further study shows that the performance of this coding scheme applying to DS-CDMA systems with SUDs improves by increasing the processing gain or the number of taps of the interference suppression filter, and degrades for higher near-far interfering power or additional near-far interfering users.

A 12b 100MS/s 1V 24mW 0.13um CMOS ADC for Low-Power Mobile Applications (저전력 모바일 응용을 위한 12비트 100MS/s 1V 24mW 0.13um CMOS A/D 변환기)

  • Park, Seung-Jae;Koo, Byeong-Woo;Lee, Seung-Hoon
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.47 no.8
    • /
    • pp.56-63
    • /
    • 2010
  • This work proposes a 12b 100MS/s 0.13um CMOS pipeline ADC for battery-powered mobile video applications such as DVB-Handheld (DVB-H), DVB-Terrestrial (DVB-T), Satellite DMB (SDMB), and Terrestrial DMB (TDMB) requiring high resolution, low power, and small size at high speed. The proposed ADC employs a three-step pipeline architecture to optimize power consumption and chip area at the target resolution and sampling rate. A single shared and switched op-amp for two MDACs removes a memory effect and a switching time delay, resulting in a fast signal settling. A two-step reference selection scheme for the last-stage 6b FLASH ADC reduces power consumption and chip area by 50%. The prototype ADC in a 0.13um 1P7M CMOS technology demonstrates a measured DNL and INL within 0.40LSB and 1.79LSB, respectively. The ADC shows a maximum SNDR of 60.0dB and a maximum SFDR of 72.4dB at 100MS/s, respectively. The ADC with an active die area of 0.92 $mm^2$ consumes 24mW at 1.0V and 100MS/s. The FOM, power/($f_s{\times}2^{ENOB}$), of 0.29pJ/conv. is the lowest of ever reported 12b 100MS/s ADCs.

Multiple Description Coding of H.264/AVC Motion Vector under Data Partitioning Structure and Decoding Using Multiple Description Matching (데이터 분할구조에서의 H.264/AVC 움직임 벡터의 다중표현 부호화와 다중표현 정합을 이용한 복호화)

  • Yang, Jung-Youp;Jeon, Byeung-Woo
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.44 no.6
    • /
    • pp.100-110
    • /
    • 2007
  • When compressed video data is transmitted over error-prone network such as wireless channel, data is likely to be lost, so the quality of reconstructed picture is severely decreased. It is specially so in case that important information such as motion vector or macroblock mode is lost. H.264/AVC standard includes DP as error resilient technique for protecting important information from error in which data is labeled according to its relative importance. But DP technique requires a network that supports different reliabilities of transmitted data. In general, the benefits of UEP is sought by sending multiple times of same packets corresponding to important information. In this paper, we propose MDC technique based on data partitioning technique. The proposed method encodes motion vector of H.264/AVC standard into multiple parts using MDC and transmits each part as independent packet. Even if partial packet is lost, the proposed scheme can decode the compressed bitstream by using estimated motion vector with partial packets correctly transmitted, so that achieving improved performance of error concealment with minimal effect of channel error. Also in decoding process, the proposed multiple description matching increases the accuracy of estimated lost motion vector and quality of reconstructed video.

Design and Implementation of a Real-time Bio-signal Obtaining, Transmitting, Compressing and Storing System for Telemedicine (원격 진료를 위한 실시간 생체 신호 취득, 전송 및 압축, 저장 시스템의 설계 및 구현)

  • Jung, In-Kyo;Kim, Young-Joon;Park, In-Su;Lee, In-Sung
    • Journal of the Institute of Electronics Engineers of Korea SC
    • /
    • v.45 no.4
    • /
    • pp.42-50
    • /
    • 2008
  • The real-time bio-signal monitoring system based on the ZigBee and SIP/RTP has proposed and implemented for telemedicine but that has some problems at the stabilities to transmit bio-signal from the sensors to the other sides. In this paper, we designed and implemented a real-time bio-signal monitoring system that is focused on the reliability and efficiency for transmitting bio-signal at real-time. We designed the system to have enhanced architecture and performance in the ubiquitous sensor network, SIP/RTP real-time transmission and management of the database. The Bluetooth network is combined with ZigBee network to distribute traffic of the ECG and the other bio-signal. The modified and multiplied RTP session is used to ensure real-time transmission of ECG, other bio-signals and speech information on the internet. The modified ECG compression method based on DWLT and MSVQ is used to reduce data rate for storing ECG to the database. Finally we implemented a system that has improved performance for transmitting bio-signal from the sensors to the monitoring console and database. This implemented system makes possible to make various applications to serve U-health care services.

Cyclostorm : The Cloud Computing Service for Uplifting Javascript Processing Efficiency of Mobile Applications based on WAC (Cyclostorm : WAC 기반 모바일 앱의 자바스크립트 처리 효율 향상을 위한 클라우드 컴퓨팅 서비스)

  • Bang, Jiwoong;Kim, Daewon
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.50 no.5
    • /
    • pp.150-164
    • /
    • 2013
  • Currently it is being gradually focused on the mobile application's processing performance implemented by Javascript and HTML (Hyper Text Markup Language) due to the dissemination of mobile web application supply based on the WAC (Wholesale Application Community). If the application software has a simple functional processing structure, then the problem is benign, however, the load of a browser is getting heavier as the amount of Javascript processing is being increased. There is a limitation on the processing time and capacity of the Javascript in the ordinary mobile browsers which are on the market now. In order to solve those problems, the Web Worker that is not supported from the existing Javascript technology is now provided by the HTML 5 to implement the multi thread. The Web Worker provides a mechanism that process a part from the single thread through a separate one. However, it can not guarantee the computing ability as a native application on the mobile and is not enough as a solution for improving the fundamental processing speed. The Cyclostorm overcomes the limitation of resources as a mobile client and guarantees the performance as a native application by providing high computing service and ascripting the Javascript process on the mobile to the computer server on the cloud. From the performance evaluation experiment, the Cyclostorm shows a maximally 6 times faster computing speed than in the existing mobile browser's Javascript and 3 to 6 times faster than in Web Worker of the HTML 5. In addition, the usage of memory is measured less than the existing method since the server's memory has been used. In this paper, the Cyclostorm is introduced as one of the mobile cloud computing services to conquer the limitation of the WAC based mobile browsers and to improve the existing web application's performances.

The Effects of Tacrolimus versus Cyclosporine on Acute Graft Rejection Episode and Acute Renal Dysfunction Following Pancreas Transplantation (췌장이식환자에서 Tacrolimus와 Cyclosporine이 급성거부반응과 신장장애에 미치는 영향)

  • Oh, Jung Mi;Klassen, David
    • Korean Journal of Clinical Pharmacy
    • /
    • v.9 no.2
    • /
    • pp.81-87
    • /
    • 1999
  • 췌장이식의 성공률은 지난 10년 동안 상당히 상승되었다. International Pancreas Transplant Registry에 따르면 1995년 이래 미국에서만 매년 1,000건 이상의 췌장이식이 실시되고 있다. 장기이식후 나타나는 급성 거부반응은 이식 후 6개월 이내에 가장 높은 빈도수로 나타난다. 췌장이식환자에서는 신장을 이식한 것보다 두배나 높은 거부반응을 나타나며 이로 인한 입원율의 증가 항림프제(antilyinphocyte) 사용과 감염의 증가로 이환율이 높다. 더구나 Cyclosporine (CsA)을 기초로 한 면역억제제요법의 사용은 높은 급성 거부반응률(acute graft rejection)을 초래하여 이식한 장기의 조직손실이 문제가 되고 있다. 새로운 면역억제제인 Tacrolimus (FK506)의 사용은 이식환자에서의 거부반응을 감소시켜 생존율을 증가시키는 것으로 알려져 있다. Tacrolimus는 neutral macrolide로 cyclic peptide인 CsA과는 화학 구조는 매우 다르나 비슷한 면역억제 효과를 보인다. 하지만 Tacrolimus의 사용시 신경독성, 신독성, 특히 고혈당증의 발생률이 높아 일부 이식센터에서는 장기 이식 후에 사용하기를 꺼리기도 한다. 하지만 여러 연구논문에서 간과 신장 이식 후 급성 거부반응 예방에 Tacrolimus는 CsA에 비해 이점이 있는 결과를 발표하였다. 결과적으로, 현재 췌장이식 후 Tacrolimus를 기초로 한 면역억제의 효과에 대한 연구가 활발히 진행중이다. 따라서 본 연구에서는 1994-1996년 사이에 Tacrolimus 또는 CsA를 기초로 한 면역억제요법을 투여 받은 췌장이식환자 101명을 후향적으로 조사하여 Tacrolimus (n=54)와 CsA(n=57)의 급성 거부반응 예방 효과와 신부전 발생률을 비교하였다. 모든 환자는 항림프구 약물, Azathioprine, Prednisone을 이식 후 면역억제제로 투여 받았다 기준선으로부터 $20\%$ 이상의 혈청 creatinine의 상승이 있는 환자에서는 급성 신부전으로 정의하였고 신장생검법으로 거부반응을 진단하였다 Matched-pair analysis에 따르면 췌장이식환자의 6개월 생존율은 CsA군에서 $97\%$, Tacrolimus군에서 $96\%$로 별다른 차이가 없었으며 (p=0.57), 6개월간의 이식한 췌장의 보존율은 CsA군에서는 $88\%, Tacrolimus에서 $91\%$. 유의한 차이는 없었다(p=0.29). 췌장이식 후 6개월 동안 Tacrolimus의 사용은 생검으로 증명되는(biopsy-proven) 급성 거부반응의 발생빈도는 CsA보다 유의하게 낮았을 뿐만 아니라 (p<0.05) 거부반응 증상의 심각도 또한 감소시켰다 (p=0.03). 급성거부반응 발생빈도의 감소로 Tacrolimus군에서 antilymphocyte 치료가 유의하게 줄어들었다(p=0.01). CsA군에서 Tacrolimus보다 신부전의 발생률이 높았으나 통계학적 차이는 없었다. 췌장이식후의 최적의 면역억제요법의 결정하기 위해서는 향후 Tacrolimus와 CsA을 비교하는 전향적 무작위 연구가 필요하다.

  • PDF

Bond Strength Evaluation of RC Beams on the Rib Shape of Reinforcing Bars (철근 마디 형상에 따른 RC 휨부재의 부착강도 평가)

  • Hong, Geon-Ho;Kim, Jin-Ah;Choi, Oan-Chul
    • Journal of the Korea Concrete Institute
    • /
    • v.23 no.3
    • /
    • pp.393-400
    • /
    • 2011
  • The needs for high strength structural materials have recently increased, because construction and cost efficiencies are demanded by the costumers. But, the use of high strength reinforcing bars requires longer development and splice lengths compared to normal strength bars. This restriction may cause reduction in construction efficiency and require more complicated details. The purpose of this paper is to evaluate the bond strength on the rib shape of reinforcing bars to decrease development and splice lengths of high strength reinforcements. Total of 5 simple beam specimens were tested, and the main test variable was a rib shape of reinforcing bars. Test data was analyzed in the viewpoint of bond strength, load-deflection relationship, and crack pattern. Test results indicated that the bond strength of high relative rib area reinforcing bars increased up to 11% compared to normal strength reinforcements. And the improved rib shape reinforcements, which were formed with high and low height rib, increased the bond strength up to 23% even though the relative rib area was same as the high relative rib area reinforcements. Serviceability performances such as deflection number of cracking, and maximum crack width were similar in all specimens, so it is safe to conclude that the improved rib shape reinforcements can be applied to the structural members.

Local Festival and Culture Contents (지역축제와 문화콘텐츠)

  • Kim, Kyung Sook
    • Journal of the Korea Convergence Society
    • /
    • v.8 no.7
    • /
    • pp.183-189
    • /
    • 2017
  • This research aims to inquire about local festival culture contents of France which are considered a successful case of cultural contents industry and will make a diagnosis regarding the applicability and concomitant problems in our country. It reviews French local festival and culture contents, represented by Bordeaux wine Festival. This research analyses the structure of storytelling and the emotional factors as communication and experience tool of historical and cultural resources in terms of cultural semiotics. The findings are as follows: First, it is about a strategy linked with historical and cultural resources as a package touristic product made of the tradition, history, cultural heritage, arts and winery experience. Second, it is about a storytelling strategy. The status of Bordeaux wine holds a splendid story originated in long historical background and benefits of nature. Third, it is about a strategy oriented to communication and experience. Fourth, it is about a strategy inducing fun and fantasy. A festival is a form of a play, and the play is the culture itself. The revitalization of local festivals which allow the increment of one's most personal happiness index is estimated to have the most crucial values and significance. Finally, the cases of European local festivals are considered to be worth benchmarking in many different domains in the sense that they create new contents by making interesting stories adapted from the past history.

Preference Analysis on the Reconstruction and Remodeling of Old Aged Apartment in Daejeon Area (대전지역 노후화된 아파트의 재건축과 리모델링에 대한 선호도 분석)

  • Park, Sun-Gyu
    • Journal of the Korean Recycled Construction Resources Institute
    • /
    • v.4 no.2
    • /
    • pp.180-186
    • /
    • 2016
  • There are many apartment buildings with the government's policy of increasing the supply of residential houses in Korea. Roughly 60% of the Korea population are living in apartment buildings. Since the 1970s, the Korean economy has grown enormously, the economic and social structure was radically transformed to industrialization and urbanization step. A village has grown into a large town in Korea and apartment buildings was constructed to solve national housing shortage by the Korean government and the construction company. Since the 2000s, this apartment buildings which was built in the 1970s and 1980s had become gradually deteriorated. So, reconstruction and remodeling project of apartment buildings have been come into request in Korea. There are two way to improve the residential environment. The one is remodeling of apartment buildings and the other is reconstruction of that. Therefore, we carried out questionnaire and survey study of the preference on the reconstruction and remodeling of old aged apartment which were located in daejeon province. As a result, the preference rate of remodeling is increasing instead of reconstruction because reconstruction of apartment buildings takes more money and needs long construction period.