• 제목/요약/키워드: Reverse

검색결과 7,847건 처리시간 0.031초

혼합된 셀 크기를 갖는 CDMA 셀룰라 시스템에서 역방향 링크 용량 분석 (Reverse link analysis of CDMA cellular systems with mixed cell sizes)

  • 전형구;신성문;권수근;강창언
    • 한국통신학회논문지
    • /
    • 제25권4A호
    • /
    • pp.481-488
    • /
    • 2000
  • The demands for mobile communication service are growing rapidly. In heavily populated areas, cell split is unavoidable to increase the capacity of the cellular system. Cell splitting makes a cellular system to have mixed cell sizes. For cell planning, it is necessary to analyze the reverse link capacity of a CDMA cellular system with mixed cell sizes. In this paper, we propose a method to calculate the reverse link capacity of a CDMA cellular system with mixed cell sizes. When a macro cell is split into three micro cells, as an example, we calculate the reverse link capacities for the three micro cells and the neighboring macro cells. The results show that as the radius of a micro cell decreases, the reverse link capacity of the micro cell increases, while those of the neighboring macro cells decrease.

  • PDF

작은 곡률반경 파이프 벤딩을 위한 열간 파이프 벤딩공정 해석 및 설계 (Analysis and Process Design of Hot Pipe Bending Process With Small Bending Radius)

  • 류경희;김동진;김병민;이동주
    • 소성∙가공
    • /
    • 제10권4호
    • /
    • pp.329-337
    • /
    • 2001
  • The finite element simulation model and the program to calculate the reverse moment have been developed to analyse the stress state and deformation of pipe bending using local induction heating with small bending radius in this study. The reverse moment that is to be applied on the bending arm to control the wall thinning ratio of the bending outside to within a particular value. Even though the demand of pipes with small bending radius is increasing in power plants and ship buildings, the welded elbows are still widely used. The bending process with or without a reverse moment acting on the bending arm has been simulated. The reverse moments calculated from the developed program are in good agreement with the finite element simulations and the experiments.

  • PDF

재활용을 고려한 역공급사슬 시뮬레이션 모델 개발 (A Development of Reverse Supply Chain Simulation Model Considering a Recycling)

  • 임석진;박병태
    • 대한안전경영과학회지
    • /
    • 제11권4호
    • /
    • pp.193-199
    • /
    • 2009
  • Recently, an industrial production-distribution planning problem has been widely investigated in Supply Chain Management(SCM). One of the key issues in the current SCM research area is reverse logistics network. This study have developed a simulation model for the reverse logistics network. The simulation model analysis reverse logistics network issues such as inventory policy, manufacturing policy, transportation mode, warehouse assignment, supplier assignment. Computational experiments using commercial simulation tool ARENA show that the real problems. The model can be used to decide an appropriate production-distribution planning problem in the research area.

MPEG Bit Stream에서의 Reverse Trick Mode 알고리즘 (Reverse Trick Mode Algorithms of MPEG Bit Stream)

  • 신성욱;이동호
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2001년도 제14회 신호처리 합동 학술대회 논문집
    • /
    • pp.689-692
    • /
    • 2001
  • 대용량 hard disk를 내장하고 있는 DTV용 PVR(Personal video recorder)에서는 단순히 수신되는 방송 stream을 녹화하고 재생하는 기능 뿐만 아니라 다른 여러 가지의 부가적인 기능들을 지원하는 것이 필요하다. 그 중의 하나가 기존의 아날로그 VCR의 사용자들에게 친숙한 fast-forward play, reverse play, pause 등과 같은 trick mode play기능을 지원하는 것이다. 그러나 MPEG video는 화면간의 상관관계를 이용하여 압축하는 방식을 채택하고 있으므로 재생하고자 하는 frame이 intra frame이 아닌 한 독립적으로 재생할 수가 없어서 trick mode play 기능을 구현하기가 용이하지 않다. 특히 reverse trick mode의 경우에는 original stream에서의 마지막 frame이 먼저 display되어야 하는데 이를 위해 하나의 GOP가 모두 decoding되어야 하므로 더욱 그 구현이 어렵다. 본 논문에서는 reverse trick mode를 구현하기 위한 여러 알고리즘을 소개하고 이에 대한 system 복잡도, 메모리 사용량 성능 등을 분석하고자 한다.

  • PDF

Improved Charge Pump with Reduced Reverse Current

  • Gwak, Ki-Uk;Lee, Sang-Gug;Ryu, Seung-Tak
    • JSTS:Journal of Semiconductor Technology and Science
    • /
    • 제12권3호
    • /
    • pp.353-359
    • /
    • 2012
  • A highly efficient charge pump that minimizes the reverse charge sharing current (in short, reverse current) is proposed. The charge pump employs auxiliary capacitors and diode-connected MOSFET along with an early clock to drive the charge transfer switches; this new method provides better isolation between stages. As a result, the amount of reverse current is reduced greatly and the clock driver can be designed with reduced transition slope. As a proof of the concept, a 1.1V-to-9.8 V charge pump was designed in a $0.35{\mu}m$ 18 V CMOS technology. The proposed architecture shows 1.6 V ~ 3.5 V higher output voltage compared with the previously reported architecture.

Reverse Engineering을 위한 보간곡선, 곡면의 가공 및 오차 보정 (Manufacturing and error compensation of interpolated curves and surfaces for reverse Engineering)

  • 양재봉
    • 한국공작기계학회:학술대회논문집
    • /
    • 한국공작기계학회 1997년도 추계학술대회 논문집
    • /
    • pp.230-234
    • /
    • 1997
  • Reverse engineering involves digitizing a three-dimensional model or part converting the data to a CAD database description and manufacturing by CNC. Currently, the digitization is done through measurements taken manually by a CMM or touch probe mounted on a CNC machinetool. Some reverse engineering techniques require close integration between the data collection method and the surface-fitting algorithms. Accurate surface data are collected by input to the surface fitting method. This study has been found that both the smoothness of surfaces and accuracy of surface fitting are related with the degree of the interpolated surfaces.

  • PDF

Reverse Total Shoulder Arthroplasty in the Massive Rotator Cuff Tear

  • Jeong, Jin Young;Cha, Hong Eun
    • Clinics in Shoulder and Elbow
    • /
    • 제17권3호
    • /
    • pp.145-150
    • /
    • 2014
  • In the patients of retracted massive rotator cuff tears, there are much of difficulty to functional recovery and pain relief. Nevertheless the development of treatment, there are still debates of the best treatments in the massive rotator cuff tears. Recenlty various of treatments are introduced; these are acromioplasty with debridement, biceps tenotomy, great tuberoplasty with biceps tenotomy, partial repair, mini-open rotator cuff repair, arthroscopic rotator cuff repair, soft tissue augmentation, tendon transfer, flap, hemiarthroplasty, and reverse total shoulder arthroplasty. That there is no difference of result for reverse total shoulder arthroplasty between patients who have massive rotator cuff tear without arthritis and patients who have cuff tear arthropathy. Reverse total shoulder arthroplasty is one of reliable and successful treatment options for massive rotator cuff tear. Especially it is more effective for patients who have a pseudoparalysis.

받음각이 큰 평판 채널 내의 역류 유동 해석 (Flow Analysis of Reverse Flow in a Channel with High Angle of Attack)

  • 최승;손창현
    • 한국가시화정보학회지
    • /
    • 제5권1호
    • /
    • pp.37-42
    • /
    • 2007
  • Reverse flow occurs in a channel when there is an obstruction at the entry. However it has been shown recently that reverse flow can be realized without an obstruction, by staggering the sides of the channel and placing it at an angle of attack to the oncoming flow. In this study the latter flow is computationally investigated. Studies have been carried out for different widths (gap between the two walls forming the channel), and at an angle of attack of 30. The results have captured all the essential features of this complex phenomenon and show the time dependent pumping mechanism which leads to the occurrence of reverse flow.

Reverse Moat Pattern을 가진 STI CMP 공정에서 EPD 고찰 (A study on EPD of STI CMP Process with Reverse Moat Pattern)

  • 이경태;김상용;서용진;김창일;장의구
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2000년도 춘계학술대회 논문집 전자세라믹스 센서 및 박막재료 반도체재료 일렉트렛트 및 응용기술
    • /
    • pp.14-17
    • /
    • 2000
  • The rise throughput and the stability in fabrication of device can be obtained by applying of CMP process to STI structure in 0.18um semiconductor device. To employ in STI CMP, the reverse moat process has been added thus the process became complex and the defects were seriously increased. Removal rates of each thin films in STi CMP was not equal hence the devices must to be effected, that is, the damage was occured in the device dimension in the case of excessive CMP process and the nitride film was remained on the device dimension in the case of insufficient CMP process than these defects affect the device characteristics. We studied the current sensing method in STI-CMP with the reverse moat pattern.

  • PDF

Friend Virus 를 이용한 Reverse Transcriptase 억제제의 생체제의 약효검색

  • 안형수;황인숙;이상준;김동섭;허인회
    • 한국응용약물학회:학술대회논문집
    • /
    • 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
    • /
    • pp.278-278
    • /
    • 1994
  • HIV와 유사하게 retro virus의 일종인 Friend virus of Anemia strain (FVA)을 BALB/c mice 에게 감염시 reverse transcriptase 의 활성에 의해 비장의 erythroid progenitor cell 에서 증식되므로서 비장의 비대 및 빈혈을 초래하게 된다. 이를 지표로 하여 reverse transcriptase 억제작용을 지닌 항 virus 약물을 천연성분으로 부터 검색하고자 하였다. 우선, 대조약물로 사용한 기존의 항 AIDS 약물인 zidovudine (AZT) 을 FVA 가 감염된 BAB/c mice 에게 18일간 투여시 (약 100 mg/kg/day, p.o. ) 대조군에 비해 비장의 비대 및 reverse transcriptase 활성이 90% 이상 억제되었으며, 이들의 혈청을 정상 BALB/c mice 에게 재투여시에도 유사한 결과를 나타내어 reverse transcriptase 를 억제하므로서 항 virus 작용을 나타낸다는 것을 입증하였다. 그러나, 혈액중 Hemoglobin등 빈혈의 지수는 대조군과 유사한 수치를 나타내므로서 정상으로 회복되지를 못하였다. 이것은 zidovudine 자체가 지니는 골수억제에 의한 부작용 때문인 것으로 고려된다.

  • PDF