• Title/Summary/Keyword: Wrap-around

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Implementation of UPC algorithm in ATM network (ATM망에서의 UPC 알고리즘 구현)

  • 이요섭;조태경;최명렬
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.10e
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    • pp.88-90
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    • 2002
  • 본 논문에서는 ATM 망의 트래픽 제어 기능 중의 하나인 UPC(Usage Parameter Control) 알고리즘을 제안하고 VHDL을 이용하여 칩(chip)을 구현하였다. 제안한 알고리즘은 우선순위가 높은 셀의 손실을 최소로 하고, 트래픽의 다중화 및 역다중화 과정에서 발생되는 트래픽의 군집성을 해소할 수 있다는 장점을 갖고 있다. 구현한 칩은 입력 모듈과 UPC 모듈, 출력 모듈의 3부분으로 이루어지며, 편의상, UPC 모듈에서는 커넥션 테이블의 index를 VCI(Virtual channel Identifier)와 동일하게 할당하였다. 또한 UPC 모듈의VSA(Virtual Scheduling Algorithm)블럭에서 셀의 도착시간을 계수하는 카운터가 랩-어라운드(wrap-around)할 때 생기는 VSA의 오류를 보정하여 구현하였다.

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Morbidity of the Foot as a Free-Flap Donor Site (유리 피판 공여부로서 족부의 이병률)

  • Lee, Kwang-Suk;Wie, Dae-Gon;Han, Sang-Won
    • Archives of Reconstructive Microsurgery
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    • v.6 no.1
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    • pp.39-46
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    • 1997
  • The methods of clinical applications of the foot as a free-flap donor site includes microvascular toe-to-finger transfer, free neurovascular flap transfer, first web space flap transfer, and osteocutaneous free flap transfer. We have evaluated the results of treatment for 35 patients to be undergone a microvascular reconstructive procedure with the foot as a donor site from January 1982 to June 1996. The performed operations were 16 cases of thumb reconstruction with wrap around procedure, 3 cases of tenocutaneous flap transfer, 10 cases of dorsalis pedis flap transfer, 2 cases of first web space free flap and 4 cases of toe-to-finger transfer. The follow up study was 69 months in average. Regarding to the various donor sites, morbidity was divided into five different categories: Cosmesis, Functional loss, Sensory loss, Wound complication, and Pain. According to the results of examination(35 patients), the results was excellent(25), good(9), fair(1), and poor(0). Among the categories, morbidity was higher at cosmesis. The patients under 50 years were better outcome. Among the operative methods from the foot as a donor site, thumb reconstruction with wrap around procedure showed poorest outcomes. So, We conclude that the foot as a free flap donor site is a good source for the microvascular reconstructive surgery. But, Preoperative donor site evaluation, adequate operative technique and post operative management are essential to decrease the morbidity of donor site.

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Kirchhoff Prestack Depth Migration for the Complex Structure Using One-Way Wave Equation (일방향 파동방정식을 이용한 복잡한 구조의 키리히호프 중합전 심도구조보정)

  • Ko, Seung-Won;Yang, Seung-Jin
    • Geophysics and Geophysical Exploration
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    • v.5 no.1
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    • pp.18-22
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    • 2002
  • As a single arrival traveltime, maximum energy arrival traveltime has been known as the most proper operator for Kirchhoff migration. In case of the model having the simple structure, both the first arrival traveltime and the maximum energy arrival traveltime can be used as the correct operators for Kirchhoff migration. However for some model having the complex and high velocity contrast structure, the migration using the first arrival traveltime can't give the correct depth section. That is, traveltime to be required in Kirchhoff migration is the maximum energy traveltime, but, needs considerably more calculation time than that of first arrival. In this paper, we propose the method for calculating the traveltime approximated to the maximum energy arrival using one-way wave equation. After defining the WAS(Wrap Around Suppression) factor to be used for calculating the first arrival traveltime using one-way wave equation as the function of lateral grid interval and depth and considering the delay time of source wavelet. we calculate the traveltime approximated to the maximum energy arrival. to verify the validity of this traveltime, we applied this to the migraion for simple structure and complex structure and compared the depth section with that obtained by using the first arrival traveltime.

A Study on the Religious Costume in Ancient Mesopotamia (고대 메소포타미아 종교 복식에 관한 연구)

  • 임상임;류보영
    • Journal of the Korean Society of Costume
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    • v.50 no.8
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    • pp.113-128
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    • 2000
  • This essay examines the costumes for gods and priests in ancient Mesopotamia as they are depicted in various documents and artifacts of the period, and it is part of an ongoing project that studies the process in which the religious costumes, the means of religious communication, of ancient Mesopotamia had evolved. The study shows that the religious costunmes in ancient Mesopotamia have following characteristics. 1. The costumes for gods are the same as those for men, including warp-around skirts, tierd skirts, shawls, and tunics. However, there are some differences : costumes for gods include such distinguishing features as aprons and long tassels. 2. Both wear stylized headpieces that indicate their divinity and have long hair and long beard. 3. As for shoes, the Sumerian and Babilonian gods go barefoot, but the militant Assyrian gods wear sandals. 4. Sumerian and Babilonian figures do not have much, but the Assyrian gods wear various ornaments including earrings and bracelets that emphasize their muscular physique. 5. Priests wear weird skirts or wrap-around skirts but no top. They have shaved hair to indicate their role as purifiers, but some of them have long beards.

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Comparison Packing Materials for Proper MAP of Mixed Sprout Vegetables (혼합 싹채소의 MAP를 위한 포장재 비교)

  • Kang, Ho-Min;Choi, In-Lee;Kim, Il-Seop
    • Journal of Bio-Environment Control
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    • v.17 no.3
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    • pp.226-230
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    • 2008
  • A comparison was made of the effect of different packaging materials on storability of mixed sprout vegetables (alfalfa, broccoli, cabbage, radish, and red radish) stored at $8^{\circ}C$. They were packaged by several kinds of films that were 50 fm thickness low-density polyethylene film (PE 50), 50 fm thickness polypropylene film (PP 50), $50{\mu}m$ thickness ceramic film (CE 50), $25{\mu}m$ thickness ceramic film (CE 25), $10\sim13{\mu}m$ thickness polyethylene film (wrap), and polyethylene terephthalate box with ventilation hole (box). The fresh weight of mixed sprouts packaged with different materials decreased below to 2% except box packages that decreased around 7% compared with initial weight. The atmospheres that were developed inside the different materials during storage differed significantly. The carbon dioxide and oxygen concentration of packages were kept properly with 5% in CE 25, but the PE 50 and CE 50 treatments showed higher carbon dioxide and lower oxygen concentration. So the off-flavor of mixed sprouts was more severe in the PE 50 and CE 50 treatment. The ethylene concentration of packages showed lowest in box treatment, followed by PP 50, wrap and CE 25 treatment. The overall quality of mixed sprouts was lower in PE 50 and CE 50 than CE 25 treatment after 10 days storage, supposed to be resulted from highest ethylene concentration and lowest oxygen concentration. Conclusionally, the CE 25 film that showed below 1% fresh weight loss, 5% carbon dioxide, 5% oxygen and below 4 ppm ethylene concentration in package may be a proper packaging material for mixed sprout vegetables.

System-Level Simulation for Efficient Displacement of Base Station Antennas for CDMA Uplink System in Urban Microcells (도심 마이크로셀에서 CDMA 시스템을 위한 효율적인 기지국 배치를 위한 모의실험)

  • Min, Seung-Wook
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.5A
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    • pp.517-525
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    • 2008
  • In this paper, we cary out system level simulations to investigate the effect of cell shape(i.e., different base station displacements in the two directions defined by the street grid) on minimizing transmitter power, interference power, and blocking probability for CDMA system in urban microcellular environments. In urban microcell, path loss to the base station depends on the orientation of the street where the mobile is located. Interference from mobile stations to the base station in the reference cell is considered up to second tier. The wrap around method is used to include the second tier interference with realistic computational complexity without reducing the accuracy of interference calculations. The investigation shows that the transmitter power, interference power, and blocking probability in a cell can be reduced by proper selection of the efficient cell shape.

Advanced Silicon Solar Cell Structures for Space Applications

  • Lee, S.H.;Kim, D.S.
    • Solar Energy
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    • v.17 no.2
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    • pp.23-33
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    • 1997
  • This paper reviews the advanced solar cell structures used in space. These are the structures which incorporate the back surface field and reflectors with very shallow and lightly doped emitters. Their use in space has shown that the thinner cells are more resistive to radiation damage than the thicker ones. It has been found that the charged particles affect both the surface and bulk of the cells used in space. This causes degradation in the output power, which in effect, can be explained by the degrading diffusion length of the cells. The PERL cells showed higher BOL(beginning of life) efficiency and almost the same EOL(end of life) efficiency as structures with wrap-around contact configuration fabricated on 10 ${\Omega}cm$ resistivity substrates. This observation lead to a conclusion that, the space cells do not necessarily need to have very high BOL efficiency except in specific missions which require such.

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An Experimental Study to Prevent Debdonding Failure of RC Beams Strengthened by Aramid Fiber Sheets (아라미드섬유쉬트로 휨 보강된 RC보의 부착파괴 방지 상세에 관한 실험적 연구)

  • Choi, Ki-Sun;You, Young-Chan;Kim, Keung-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.84-87
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    • 2004
  • Nominal flexural strength of RC members strengthened with FRP sheets is generally based on the tensile strength of composite materials obtained from coupon tests. This method is based on the assumption that bond failure does not occur until the FRP sheet reaches its rupture strength. According to the previous researches, however, bond failure often occurs before the FRP sheet reaches its rupture strength. Some attempts were made to control debonding failure by increasing the bonded length of sheet or wrapping the section around their side of the member(U-wrap). In this study, the flexural failure mechanism of RC beams strengthened with AFRP sheets with different bond lengths is investigated. Their strengthening details to prevent the premature debonding failure are also suggested and its effectiveness is verified.

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Error Analysis Caused by Using the Dftin Numerical Evaluation of Rayleigh's Integral (레일리 인테그랄의 수치해석상 오차에 대한 이론적 고찰)

  • Kim, Sun-I.
    • Journal of Biomedical Engineering Research
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    • v.10 no.3
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    • pp.323-330
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    • 1989
  • Large bias errors which occur during a numerical evaluation of the Rayleigh's integral is not due to the replicated source problem but due to the coincidence of singularities of the Green's function and the sampling points in Fourier domain. We found that there is no replicated source problem in evaluating the Rayleigh's integral numerically by the reason of the periodic assumption of the input sequence in Dn or by the periodic sampling of the Green's function in the Fourier domain. The wrap around error is not due to an overlap of the individual adjacent sources but berallse of the undersampling of the Green's function in the frequency domain. The replicated and overlApped one is inverse Fourier transformed Green's function rather than the source function.

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