• 제목/요약/키워드: Incomplete reduction

검색결과 97건 처리시간 0.037초

Generalized Incomplete Pochhammer Symbols and Their Applications to Hypergeometric Functions

  • Sahai, Vivek;Verma, Ashish
    • Kyungpook Mathematical Journal
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    • 제58권1호
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    • pp.67-79
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    • 2018
  • In this paper, we present new generalized incomplete Pochhammer symbols and using this we introduce the extended generalized incomplete hypergeometric functions. We derive certain properties, generating functions and reduction formulas of these extended generalized incomplete hypergeometric functions. Special cases of this extended generalized incomplete hypergeometric functions are also discussed.

불완전분해법을 전처리로 하는 공액구배법의 안정화에 대한 연구 (Study on Robustness of Incomplete Cholesky Factorization using Preconditioning for Conjugate Gradient Method)

  • 고진환;이병채
    • 대한기계학회논문집A
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    • 제27권2호
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    • pp.276-284
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    • 2003
  • The preconditioned conjugate gradient method is an efficient iterative solution scheme for large size finite element problems. As preconditioning method, we choose an incomplete Cholesky factorization which has efficiency and easiness in implementation in this paper. The incomplete Cholesky factorization mettled sometimes leads to breakdown of the computational procedure that means pivots in the matrix become minus during factorization. So, it is inevitable that a reduction process fur stabilizing and this process will guarantee robustness of the algorithm at the cost of a little computation. Recently incomplete factorization that enhances robustness through increasing diagonal dominancy instead of reduction process has been developed. This method has better efficiency for the problem that has rotational degree of freedom but is sensitive to parameters and the breakdown can be occurred occasionally. Therefore, this paper presents new method that guarantees robustness for this method. Numerical experiment shows that the present method guarantees robustness without further efficiency loss.

A CLASS OF MULTILEVEL RECURSIVE INCOMPLETE LU PRECONDITIONING TECHNIQUES

  • Zhang, Jun
    • Journal of applied mathematics & informatics
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    • 제8권2호
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    • pp.305-326
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    • 2001
  • We introduce a class of multilevel recursive incomplete LU preconditioning techniques (RILUM) for solving general sparse matrices. This techniques is based on a recursive two by two block incomplete LU factorization on the coefficient martix. The coarse level system is constructed as an (approximate) Schur complement. A dynamic preconditioner is obtained by solving the Schur complement matrix approximately. The novelty of the proposed techniques is to solve the Schur complement matrix by a preconditioned Krylov subspace method. Such a reduction process is repeated to yield a multilevel recursive preconditioner.

Effect of cone-beam computed tomography metal artefact reduction on incomplete subtle vertical root fractures

  • Andrea Huey Tsu Wang;Francine Kuhl Panzarella;Carlos Eduardo Fontana;Jose Luiz Cintra Junqueira;Carlos Eduardo da Silveira Bueno
    • Imaging Science in Dentistry
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    • 제53권1호
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    • pp.11-19
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    • 2023
  • Purpose: This study compared the accuracy of detection of incomplete vertical root fractures (VRFs) in filled and unfilled teeth on cone-beam computed tomography images with and without a metal artefact reduction (MAR) algorithm. Materials and Methods: Forty single-rooted maxillary premolars were selected and, after endodontic instrumentation, were categorized as unfilled teeth without fractures, filled teeth without fractures, unfilled teeth with fractures, or filled teeth with fractures. Each VRF was artificially created and confirmed by operative microscopy. The teeth were randomly arranged, and images were acquired with and without the MAR algorithm. The images were evaluated with OnDemand software (Cybermed Inc., Seoul, Korea). After training, 2 blinded observers each assessed the images for the presence and absence of VRFs 2 times separated by a 1-week interval. P-values<0.05 were considered to indicate significance. Results: Of the 4 protocols, unfilled teeth analysed with the MAR algorithm had the highest accuracy of incomplete VRF diagnosis (0.65), while unfilled teeth reviewed without MAR were associated with the least accurate diagnosis (0.55). With MAR, an unfilled tooth with an incomplete VRF was 4 times more likely to be identified as having an incomplete VRF than an unfilled tooth without this condition, while without MAR, an unfilled tooth with an incomplete VRF was 2.28 times more likely to be identified as having an incomplete VRF than an unfilled tooth without this condition. Conclusion: The use of the MAR algorithm increased the diagnostic accuracy in the detection of incomplete VRF on images of unfilled teeth.

무지 외반증 재발의 한 원인으로 생각되는 종자골 정복에 영향을 주는 인자 (Incomplete Reduction that Influence Reduction of Sesamoid as a Cause for Recurrence of Hallux Valgus)

  • 윤영필;이철형;정현윤;김영우;정재용
    • 대한족부족관절학회지
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    • 제14권1호
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    • pp.21-24
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    • 2010
  • Purpose: The incomplete reduction of the sesamoid has lately been issued as cause for recurrence. In this study, we analysed factors that may influence reduction of sesamoid. Materials and Methods: The study consists of 50 cases operated by single surgeon. Eighteen cases were done by proximal chevron osteotomy, and 32 cases were done by scarf osteotomy. Hallux valgus (HV) angle and intermetatarsal (IM) angle were measured before and three months after the surgery. Sesamoid position (SP) was classified according to Hardy and Clapham grade system. Results: After the proximal chevron osteotomy, the correction of the mean HV angle was $19.5^{\circ}$, and IM angle was $6.2^{\circ}$. SP was changed from 5.6 to 3.4 grade. After the Scarf osteotomy, the correction of the mean HV angle was 25 degree, and IM angle was $9^{\circ}$. SP was changed from 5.5 to 2.8 grade. There was difference of sesamoid's correction between two different method of surgery (p=0.127). However, better correction of sesamoid was witnessed with bigger correction angle regardless of method of surgery (p=0.002, 0.001). Conclusion: We believe surgical method do not effect sesamoid's correction but more correction angle can result in better correction of sesamoid position.

Generalization of the statistical moment-based damage detection method

  • Zhang, J.;Xu, Y.L.;Xia, Y.;Li, J.
    • Structural Engineering and Mechanics
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    • 제38권6호
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    • pp.715-732
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    • 2011
  • A novel structural damage detection method with a new damage index has been recently proposed by the authors based on the statistical moments of dynamic responses of shear building structures subject to white noise ground motion. The statistical moment-based damage detection (SMBDD) method is theoretically extended in this paper with general application. The generalized SMBDD method is more versatile and can identify damage locations and damage severities of many types of building structures under various external excitations. In particular, the incomplete measurements can be considered by the proposed method without mode shape expansion or model reduction. Various damage scenarios of two general forms of building structures with incomplete measurements are investigated in consideration of different excitations. The effects of measurement noise are also investigated. The damage locations and damage severities are correctly identified even when a high noise level of 15% and incomplete measurements are considered. The effectiveness and versatility of the generalized SMBDD method are demonstrated.

부분 체중지지를 이용한 앞, 뒤로 걷기 운동이 불완전 척수손상환자의 보행에 미치는 효과 (Effect of Forward, Backward Walking using Partial Weight Bearing on Walking of the Patient with Incomplete Spinal Cord Injury)

  • 김석환;정재훈
    • PNF and Movement
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    • 제9권2호
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    • pp.29-37
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    • 2011
  • Purpose : The purpose of this study was to find out of an effect of forward, backward walking using partial weight bearing on walking of the patient with incomplete spinal cord injury. Methods : The average age, and the term of being sick of 6 patients who were selected as the subjects with incomplete spinal cord injury and who received medical attention in the National Rehabilitation Hospital, was 50.3 years old, and 10.7 months, and those were also the patients that were classified as ASIA-C or D by ASIA. The forward, backward walking using a partial weight bearing system as the research method, took total 6 weeks, 3 days per week, 3 times per day, total 45 minutes for each time(15 minutes for a time, 5 minutes for a breathing time), and the 15 minutes was used for forward walking 7.30 minutes, backward walking for 7.30 minutes, to find out before and after the test of WISCI, PCI, Walking Speed, Motor Score of Lower Limbs for the selected patients with incomplete spinal cord injury. Results : The result was showed WISCI from 17 points to 17 points that is, no change occurred at all, and PCI from $161.01{\pm}103.06$ to $74.97{\pm}58.19$, some amount of reduction that is not statistically significant(p<.05). Regarding walking speed, it increased from $24{\pm}.07m/sec$ to. $61{\pm}.35m/sec$, that is statistically significant(p<.05), and motor score of lower limbs showed statistically significant increase like from $33.17{\pm}7.08$ to $37{\pm}5.14$(P<.05). Conclusion : The 4 evaluation categories seem to have shown differences due to an insufficient number of subjects, and short test term, and it seems the more diverse task-oriented walking exercises should be studied in the coming days.

Update the finite element model of Canton Tower based on direct matrix updating with incomplete modal data

  • Lei, Y.;Wang, H.F.;Shen, W.A.
    • Smart Structures and Systems
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    • 제10권4_5호
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    • pp.471-483
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    • 2012
  • In this paper, the structural health monitoring (SHM) benchmark problem of the Canton tower is studied. Based on the field monitoring data from the 20 accelerometers deployed on the tower, some modal frequencies and mode shapes at measured degrees of freedom of the tower are identified. Then, these identified incomplete modal data are used to update the reduced finite element (FE) model of the tower by a novel algorithm. The proposed algorithm avoids the problem of subjective selection of updated parameters and directly updates model stiffness matrix without model reduction or modal expansion approach. Only the eigenvalues and eigenvectors of the normal finite element models corresponding to the measured modes are needed in the computation procedures. The updated model not only possesses the measured modal frequencies and mode shapes but also preserves the modal frequencies and modes shapes in their normal values for the unobserved modes. Updating results including the natural frequencies and mode shapes are compared with the experimental ones to evaluate the proposed algorithm. Also, dynamic responses estimated from the updated FE model using remote senor locations are compared with the measurement ones to validate the convergence of the updated model.

Influence of end-joint methods on magnetization loss in striated helical conductors

  • Kim, Woo-Seok;Kim, Yungil;Choi, Kyeongdal;Lee, Ji-Kwang
    • 한국초전도ㆍ저온공학회논문지
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    • 제15권4호
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    • pp.39-43
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    • 2013
  • To reduce the magnetization loss of a coated conductor, the striation and the transposition have to be accomplished for magnetic decoupling. The loss reduction effect in incomplete as well as complete striated YBCO CCs was reported in previous research. At the case of the incomplete striated sample, the end region of the sample is non-striated. So, it is not jointed with each other. In power applications, the joint is needed because current leads must be connected with HTS coils. In this research, the influence of end-joint methods with copper and superconducting joint on magnetization loss in striated YBCO CC and spiral winding samples are presented and compared with non-striated measured result.

불완전 방사선치료 환자의 분석 (Why Do Patients Drop Out During Radiation Therapy? - Analyses of Incompletely Treated Patients -)

  • 허승재;우홍균;안용찬;김대용;신경환;이규찬;정원아;김현주
    • Radiation Oncology Journal
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    • 제16권3호
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    • pp.347-350
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    • 1998
  • 목적 : 본 연구는 계획된 방사선치료의 과정 도중에 방사선치료를 완료하지 못하는 환자들의 빈도를 조사하고 그 이유를 분석하고자 하였다. 대상 및 방법 :삼성서울병원 치료방사선과에서 방사선치료를 받은 환자 중에서 1996년 4월부터 1997년 5월까지 방사선치료를 시행 받은 1,100명의 환자들을 대상으로 하였다. 대상 환자들 중에서 최초 계획 방사선량의 95$\%$ 이하를 받은 경우를 불완전 방사선치료로 정의하여 그 빈도와 이유를 조사하였다. 결과 : 불완전 방사선치료의 빈도는 1,100명 중 128명으로 12$\%$였다. 불완전 방사선치료 환자들의 운동수행능력은 전체 환자들에 비하여 불량하였으며, 방사선치료의 목적은 고식적 목적이 많았다. 불완전 방사선치료의 가장 흔한 이유는 환자의 거부였으며 이는 주로 환자의 방사선치료에 대한 불신과 경제적 부담 때문이었다. 결론 : 불완전 방사선치료의 빈도를 줄이기 위해서는 방사선치료의 임상적 적응 여부는 물론 환자의 사회 경제적인 여건을 잘 고려하여 방사선치료의 대상 환자를 선정하는 것이 요망되며 이는 특히 고식적 방사선치료의 경우에 더욱 중요하다고 할 수 있겠다.

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