• 제목/요약/키워드: ROSs

검색결과 525건 처리시간 0.033초

Responses of the Ross Sea to the Climate Change: Importance of observations in the Ross Sea, Antarctica (기후변화에 따른 남극 로스해 반응에 관한 고찰: 남극 로스해 관측의 중요성)

  • Yoon, Seung-Tae
    • Ocean and Polar Research
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    • 제44권1호
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    • pp.69-82
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    • 2022
  • The Ross Sea, Antarctica plays an important role in the formation of Antarctic Bottom Water (AABW) which is the densest water mass in global thermohaline circulation. Of the AABW, 25% is formed in the Ross Sea, and sea ice formation at the polynya (ice-free area) developed in front of ice shelves of the Ross Sea is considered as a pivotal mechanism for AABW production. For this reason, monitoring the Ross Sea variations is very important to understand changes of global thermohaline circulation influenced by climate change. In addition, the Ross Sea is also regarded as a natural laboratory in investigating ice-ocean interactions owing to the development of the polynya. In this article, I introduce characteristics of the Ross Sea described in previous observational studies, and investigate variations that have occurred in the Ross Sea in the past and those taking place in the present. Furthermore, based on these observational results, I outline variations or changes that can be anticipated in the Ross Sea in the future, and make an appeal to researchers regarding the importance and necessity of continuous observations in the Ross Sea.

The Ross Procedure in Pediatric Patients: A 20-Year Experience of Ross Procedure in a Single Institution

  • Yoon, Dong Woog;Yang, Ji-Hyuk;Jun, Tae-Gook;Park, Pyo Won
    • Journal of Chest Surgery
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    • 제50권4호
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    • pp.235-241
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    • 2017
  • Background: The Ross/Ross-Konno procedure is considered a good option for irreparable aortic valve disease in pediatric patients because of its hemodynamic performance and potential for growth of the pulmonary autograft. This study is a review of the long-term results of our 20-year experience with the Ross and Ross-Konno operations in a single institution. Methods: Between June 1995 and January 2016, 16 consecutive patients (mean age, $6.0{\pm}5.9years$; range, 16 days to 17.4 years) underwent either a Ross operation (n=9) or a Ross-Konno operation (n=7). The study included 12 males and 4 females, with a median follow-up period of 47 months (range, 6 to 256 months). Results: There were no cases of in-hospital or late mortality. Six reoperations were performed in 5 patients. Four patients underwent right ventricular-pulmonary artery (RV-PA) conduit replacement. Two patients underwent concomitant replacement of the pulmonary autograft and RV-PA conduit 10 years and 8 years after the Ross operation, respectively. The rate of freedom from adverse outcomes of the pulmonary autograft was 88% and 70% at 5 and 10 years, respectively. The rate of freedom from valve-related reoperations was 79% and 63% at 5 and 10 years, respectively. Conclusion: Pulmonary autografts demonstrated good durability with low mortality. The Ross/Ross-Konno procedure is a good option that can be performed safely in pediatric patients with aortic valve disease, even in a small-volume center.

Ross Operation with Aortic Ring Annuloplasty (대동맥판륜 성형술을 동반한 Ross 술식)

  • 이재원;정성호;김건일;송명근
    • Journal of Chest Surgery
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    • 제33권9호
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    • pp.744-747
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    • 2000
  • Pulmonic autograft replacement of the aortic valve(Ross procedure) has been to have potential for growth in children, no complication of antiocagulation, and enhanced durability. Therefore, Ross operation is indicated in the young, in patients with an active life style, and when anticoagulation is contraindicated. However, late autograft valve has occurrd more frequently in patients with significant size discrepancy between the pulmonay valve annulus and the aortic valve annulus. In order to resolve this problem, we performed aortic annuloplasty with Duran ring for more accurate and strong reinforcement. We report a case using the Duran ring as a method of aortic annuloplasty during Ross procedure.

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A Study on Effects of Breeding Combination for Feeding and Economic Analysis in Broiler Stock (육용종계의 교배조합이 실용계의 사양과 경제성에 미치는 영향)

  • 박준영;오세정
    • Korean Journal of Poultry Science
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    • 제7권1호
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    • pp.31-42
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    • 1980
  • In order to identify the best superior cross combination of breeder stocks for broiler production, combining ability test and analyses of phenotypic performances for parent stocks were examined on records of 1,440 broiler chicken which were produced from 4 parental strains and 3 maternal strains at Hanhyup Poultry Breeding Farm from September 28, 1978 to January 5, 1979. The results obtained were as follows; 1. There was not found heterosis effect in viability but it seems to be desirable to select Hubbard strain in paternal line to improve viability. 2. As the paternal and maternal lines, selection of Ross strain showed the best paternal and maternal performance and the best general combining ability in body weight at 8 weeks of age is expected to be able to improve body weight of it s crossbred And the most superior cross combinations based on the specific combining ability and performance of rack crossbred were identified as Hubbard x Ross ana Ross x Hypeco crossbreds. 3. The best paternal and maternal lines on the smallest feed consumption for 8 weeks were Hubbard and Ross strains, and Hypeco strain, respectively. Especially Hubbard x Hypeco cross combination was proved as the smallest feed consumption compared with other cross combinations. 4. In feed requirement per Kg body weight increase, Hubbard strain for paternal line, Hypeco strain for naternal line, and cross combinations of Hubbard x Hypeco, Hubbard x Ross and Ross x Hypeco were certified as the most superiors. 5. Also superior cross combinations of Hubbard x Hypeco and Hubbard x Ross earned the most profit per bird through economic analysis. According to results as shown above, this experiment seems to be able to reach a such conclusion that production of superior cross combinations Hubbard x Ross, Hubbard x Hypeco and Ross x Hypeco through selection of Ross and Hubbard strains to paternal line and Hypeco and Ross strains for maternal line may become to considerable improvement for important economic characters of broiler; viability, body weight, feed consumption and feed requirement.

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CERTAIN SUBCLASSES OF ANALYTIC FUNCTIONS ASSOCIATED WITH MILLER-ROSS-TYPE POISSON DISTRIBUTION SERIES

  • Bilal, SEKER;Sevtap, SUMER EKER;Bilal, CEKIC
    • Honam Mathematical Journal
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    • 제44권4호
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    • pp.504-512
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    • 2022
  • The purpose of the present paper is to obtain some sufficient conditions for analytic functions, whose coefficients are probabilities of the Miller-Ross type-Poisson distribution series, to belong to classes 𝓖(λ, 𝛿) and 𝓚(λ, 𝛿).

Modified Sign Test Using Reverse Ranked Ordering-Set Samples

  • Kim, Hyun-Gee;Kim, Dong-Hee
    • Communications for Statistical Applications and Methods
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    • 제13권2호
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    • pp.419-428
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    • 2006
  • The method of Reverse Ranked Ordering-Set Sampling(RROSS) as an opposed Ranked Ordering-Set Sampling(ROSS) and Ranked-Set Sampling(RSS) is discussed. We propose the test statistic using sign test on RROSS. This method is effective when observations are expensive and measurement is perhaps destructive or invasive. This method obtains more informations than ROSS and RSS. The asymptotic relative efficiencies of RROSS with respect to ROSS and RSS are always greater than 1 for all sample sizes. We consider a simple model to describe the effect of imperfect judgment errors.

Early Failure of the Shelhigh Pulmonary Valve Conduit in Ross Operation - Two case reports- (Ross 수술시 사용한 Shelhigh 폐동맥판 도관의 조기 실패 -2예 보고-)

  • Jang Woo Sung;Kim Dong Jung;Kim Jin Hyun;Han Kook Nam;Choi Chang Hyu;Kim Woong Han
    • Journal of Chest Surgery
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    • 제38권5호
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    • pp.382-384
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    • 2005
  • Background: It is very difficult to choose the ideal valved conduit used in right ventricle outflow reconstruction in child. We can use the cryopreserved homograft but there is a limit of application because of its difficulties in the size matching and supply capacity. The $Shelhigh^{(R)}$porcine-valved conduit is commercially available and used as an alternative choice in these days. We report two cases of early Shelhigh conduit failure in right ventricular outflow tract after Ross operation in congenital aortic stenosis.

Evaluation of Gap Heat Transfer Model in ELESTRES for CANDU Fuel Element Under Normal Operating Conditions (CANDU형 핵연료봉의 정상상태 계산용 ELESTRES 코드내 간극 열전달 모델 평가)

  • Lee, Kang-Moon;Ohn, Myung-Yong;Lim, Hong-Sik;Park, Jong-Ho;Hwang, Son-Tae
    • Nuclear Engineering and Technology
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    • 제27권3호
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    • pp.344-357
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    • 1995
  • The gap conductance between the fuel and the sheath depends strongly on the gap width and has a significant influence on the amount of initial stored energy. The modified Ross and Stoute gap conductance model in ELESTRES is based on a simplified thermal deformation model for steady-state fuel temperature calculations. A review on a series of experiments reveals that fuel pellets crack relocate, and are eccentrically positioned within the sheath rather than solid concentric cylinders. In this paper, the hue recently-proposed gap conductance models (offset gap model and relocated gap model) are described and are applied to calculate the fuel-sheath gap conductances under experimental conditions and normal operating conditions in CANDU reactors. The good agreement between the experimentally-inferred and calculated gap conductance values demonstrates that the modified Ross and Stoute model was implemented correctly in ELESTRES. The predictions of the modified Ross and Stoute model provide conservative values for gap heat transfer and fuel surface temperature compared to the offset gap and relocated gap models for a limiting power envelope.

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The Ross Procedure in Pediatric Patients: 10 Years Experience at the Asan Medical Center (소아 환자에서 Ross 수술 성적 보고: 아산병원 10년 경험)

  • Kim, Hee-Jung;Seo, Dong-Man;Yun, Tae-Jin;Park, Jeong-Jun;Park, In-Sook;Kim, Young-Hwue;Ko, Jae-Kon
    • Journal of Chest Surgery
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    • 제42권3호
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    • pp.305-310
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    • 2009
  • Background: The Ross procedure is known as a good surgical option for a young age group with aortic valve problems, but few reports on the Ross procedure are available in the Korean literature. This study is a review of our midterm results of 10 year experience with the pediatric Ross operation in Asan Medical Center. Material and Method: From March 1997 to October 2008, eighteen patients who were aged less than 16 years underwent the Ross procedure. There were 11 males and 7 females. The patients median age was 8.5 years (range: $0.5\sim14.0$). The aortic valve pathophysiology was 6 patients with aortic insufficiency, 4 patients with aortic stenosis, 7 patients with mixed aortic stenoinsufficiencey and 1 patient with infective endocarditis. The valve morphology was bicuspid in 11 and tricuspid in 7. All the patients were operated on with the root replacement technique. All the pumonic valves were replaced with an allograft except for one pericardial monocusp valve. The mean follow up duration was 52.8 months (range: 5.8$\sim$138.2 months). We reviewed the echocardiographic data with focusing on the, auto-graft dysfunction and reoperation. Result: There was no hospital mortality and late mortality. According to the last echocardiographic data, 2 autografts showed aortic regurgitation grade 2, 4 autografts showed aortic regurgitation grade 1 and the others were less than trivial. Reoperation of the pulmonic position conduit was performed 4 times in three patients. The rate of freedom from reoperation at 5 years was 72.2%. On the serial follow up, the Z-values of the aortic annulus/aortic sinus were changed from $1.6{\pm}1.7/0.9{\pm}1.7$ at preoperation to $1.8{\pm}1.6$(p=0.64)/$2.2{\pm}0.9$ (p=0.01) at the last follow-up. There was no significant relation between the growth of the neoaortic root and neoaortic insufficiency. Conclusion: Our midterm results of the Ross procedure in pediatric patients showed good autograft function and growth potential. Vet reoperation due to allograft dysfunction was a major concern.

Analysis of Tidal Deflection and Ice Properties of Ross Ice Shelf, Antarctica, by using DDInSAR Imagery (DDInSAR 영상을 이용한 남극 로스 빙붕의 조위변형과 물성 분석)

  • Han, Soojeong;Han, Hyangsun;Lee, Hoonyol
    • Korean Journal of Remote Sensing
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    • 제35권6_1호
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    • pp.933-944
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    • 2019
  • This study analyzes the tide deformation of land boundary regions on the east (Region A) and west (Region B) sides of the Ross Ice Shelf in Antarctica using Double-Differential Interferometric Synthetic Aperture Radar (DDInSAR). A total of seven Sentinel-1A SAR images acquired in 2015-2016 were used to estimate the accuracy of tide prediction model and Young's modulus of ice shelf. First, we compared the Ross Sea Height-based Tidal Inverse (Ross_Inv) model, which is a representative tide prediction model for the Antarctic Ross Sea, with the tide deformation of the ice shelf extracted from the DDInSAR image. The accuracy was analyzed as 3.86 cm in the east region of Ross Ice Shelf and it was confirmed that the inverse barometric pressure effect must be corrected in the tide model. However, in the east, it is confirmed that the tide model may be inaccurate because a large error occurs even after correction of the atmospheric effect. In addition, the Young's modulus of the ice was calculated on the basis of the one-dimensional elastic beam model showing the correlation between the width of the hinge zone where the tide strain occurs and the ice thickness. For this purpose, the grounding line is defined as the line where the displacement caused by the tide appears in the DDInSAR image, and the hinge line is defined as the line to have the local maximum/minimum deformation, and the hinge zone as the area between the two lines. According to the one-dimensional elastic beam model assuming a semi-infinite plane, the width of the hinge region is directly proportional to the 0.75 power of the ice thickness. The width of the hinge zone was measured in the area where the ground line and the hinge line were close to the straight line shown in DDInSAR. The linear regression analysis with the 0.75 power of BEDMAP2 ice thickness estimated the Young's modulus of 1.77±0.73 GPa in the east and west of the Ross Ice Shelf. In this way, more accurate Young's modulus can be estimated by accumulating Sentinel-1 images in the future.