• 제목/요약/키워드: Limited approach

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Substructural parameters and dynamic loading identification with limited observations

  • Xu, Bin;He, Jia
    • Smart Structures and Systems
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    • 제15권1호
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    • pp.169-189
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    • 2015
  • Convergence difficulty and available complete measurement information have been considered as two primary challenges for the identification of large-scale engineering structures. In this paper, a time domain substructural identification approach by combining a weighted adaptive iteration (WAI) algorithm and an extended Kalman filter method with a weighted global iteration (EFK-WGI) algorithm was proposed for simultaneous identification of physical parameters of concerned substructures and unknown external excitations applied on it with limited response measurements. In the proposed approach, according to the location of the unknown dynamic loadings and the partially available structural response measurements, part of structural parameters of the concerned substructure and the unknown loadings were first identified with the WAI approach. The remaining physical parameters of the concerned substructure were then determined by EFK-WGI basing on the previously identified loadings and substructural parameters. The efficiency and accuracy of the proposed approach was demonstrated via a 20-story shear building structure and 23 degrees of freedom (DOFs) planar truss model with unknown external excitation and limited observations. Results show that the proposed approach is capable of satisfactorily identifying both the substructural parameters and unknown loading within limited iterations when both the excitation and dynamic response are partially unknown.

Gaussian process approach for dose mapping in radiation fields

  • Khuwaileh, Bassam A.;Metwally, Walid A.
    • Nuclear Engineering and Technology
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    • 제52권8호
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    • pp.1807-1816
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    • 2020
  • In this work, a Gaussian Process (Kriging) approach is proposed to provide efficient dose mapping for complex radiation fields using limited number of responses. Given a few response measurements (or simulation data points), the proposed approach can help the analyst in completing a map of the radiation dose field with a 95% confidence interval, efficiently. Two case studies are used to validate the proposed approach. The First case study is based on experimental dose measurements to build the dose map in a radiation field induced by a D-D neutron generator. The second, is a simulation case study where the proposed approach is used to mimic Monte Carlo dose predictions in the radiation field using a limited number of MCNP simulations. Given the low computational cost of constructing Gaussian Process (GP) models, results indicate that the GP model can reasonably map the dose in the radiation field given a limited number of data measurements. Both case studies are performed on the nuclear engineering radiation laboratories at the University of Sharjah.

구인두암의 절제 및 재건수술에서 하악골 절개 접근법과 하악골 보존 접근법의 임상적 비교 (Clinical Evaluation between Mandibulotomy and Mandible Sparing Approaches in Oropharyngeal Cancer Operation and Reconstruction)

  • 김정태;이정우;조동인;이혜민
    • Archives of Plastic Surgery
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    • 제35권2호
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    • pp.152-158
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    • 2008
  • Purpose: Mandibulotomy approach and mandible sparing approach are most common methods for oropharyngeal cancer surgery. Good surgical view and convenience of flap inset are advantages of mandibulotomy approach but deformity of mandible contour, postoperative malocclusion and radionecrosis are its limitations. To make up for the limitations, mandible sparing method is commonly performed, but limited surgical view and difficulties of flap inset are the weak points of this approach. The purpose of the study is to compare mandibulotomy and mandible sparing approaches in postoperative complications and progression of the treatment in oropharyngeal cancer operation and reconstruction. Methods: Single reconstructive microsurgeon operated for oropharyngeal cancer patients with different surgeons of head and neck department who prefer mandibulotomy and mandible sparing approach respectively, and we compared the frequency of postoperative complication, operation time, duration of hospitalization and recurrence rate between two different surgical approaches. Results: Mandibulotomy approach was used in 18 patients and mandible sparing approach was used in 15 patients. In mandibulotomy approach, there happened one case of teeth injury and one case of necrosis of skin and gingiva, but there happened no malocclusion and radionecrosis. In mandible sparing approach, there were 3 cases of fistula and 2 cases of infection which are significantly higher than mandibulotomy approach. There were no significant differences between early regional recurrence and duration of hospitalization. Conclusion: In this study we compared two different methods for the surgical approach in oropharyngeal cancer surgery. As mandible sparing approach has difficulties of limited surgical view, it can be used for the limited indications of anterior tongue and mouth floor cancer. Mandibulotomy approach has advantages of good surgical view and convenience of flap inset. In this method preservation of gingival tissue, watertight fashion suture, delicate osteotomy and plate fixation to maintain occlusion are the key points for the successful results.

제한적 후방 도달법을 이용한 관절내 종골 골절의 치료 (Limited Posterior Approach for the Surgical Treatment of Intraarticular Fracture of Calcaneus)

  • 현윤석;송경원;신성일;이진영;이승용;김갑래;신건호;서은호;반태서
    • 대한족부족관절학회지
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    • 제11권1호
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    • pp.79-85
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    • 2007
  • Purpose: To evaluate the clinical efficacy of the limited posterior approach for the surgical treatment of intraarticular fracture of calcaneus. Materials and Methods: From March 2000 to February 2006, we studied retrospectively 186 patients, 203 cases who were treated with open reduction and internal fixation through limited posterior approach and were followed up for more than 1 year. The clinical results were evaluated with Creighton-Nebraska score and circle draw test after 1 year. We checked simple AP, lateral, axial and Broden's view preoperatively and 1 year after surgery, and compared $B{\ddot{o}}hler$ angle and Gissane angle. Results: By Creighton-Nebraska score, Sanders type 2 was 86.4, type 3 was 74.3, type 4 was 62.4. And by circle draw test, type 2 was 8.9 cm, type 3 was 7.2 cm, type 4 was 5.9 cm. $B{\ddot{o}}hler$ angle and Gissane angle were $7.6^{\circ}$, $102.4^{\circ}$, and it increased to $23.5^{\circ}$, $128.6^{\circ}$ after postoperative 1 year. Conclusion: Limited posterior approach for the surgical treatment of intraarticular fracture of calcaneus was considered to an effective treatment modality.

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Management of Andersson Lesion in Ankylosing Spondylitis Using the Posterior-Only Approach: A Case Series of 18 Patients

  • Shaik, Ismail;Bhojraj, Shekhar Yeshwant;Prasad, Gautam;Nagad, Premik Bhupendra;Patel, Priyank Mangaldas;Kashikar, Aaditya Dattatreya;Kumar, Nishant
    • Asian Spine Journal
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    • 제12권6호
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    • pp.1017-1027
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    • 2018
  • Study Design: This retrospective study was conducted including 18 patients who underwent posterior-only stabilization and fusion procedure for pseudoarthrosis in the ankylosed spine from October 2007 to May 2015. Purpose: This study aimed to describe the treatment outcomes in 18 patients with Andersson lesion (AL) who were managed using the posterior-only approach. Literature Review: AL is an unstable, localized, vertebral, or discovertebral lesion of the spine. It is observed in patients with ankylosing spondylitis. The exact etiology of this disorder remains unclear, and the treatment guidelines are not clearly described. Methods: We analyzed 18 patients with AL who were treated with posterior long segment spinal fusion without any anterior interbody grafting or posterior osteotomy. Pre- and postoperative radiography, computed tomography, and recent follow-up images were examined. The pre- and postoperative Visual Analog Scale score and the Oswestry Disability Index score were evaluated for all patients. Whiteclouds' outcome analysis criteria were applied at the follow-up. Moreover, at study completion, patient feedback was collected; all the patients were asked to provide their opinion regarding the surgery and were asked whether they would recommend this procedure to other patients and them self undergo the same procedure again if required. Results: The most common site was the thoracolumbar junction. The symptom duration ranged from 1 month to 10 years preoperatively. Most patients experienced fusion by the end of 1 year, and the fusion mass could be observed as early as 4 months. Pseudoarthrosis void of up to 2.5 cm was noted to be healed in subsequent imaging. In addition, clinically, the patients reported good symptomatic relief. No patient required revision surgery. Whiteclouds' outcome analysis score at the latest follow-up revealed goodto-excellent outcomes in all patients. Conclusions: ALs can be treated using the posterior-only approach with long segment fixation and posterior spinal fusion. This is a safe, simple, and quick procedure that prevents the morbidity of anterior surgery.

제한된 기상변수와 Polynomial Networks Approach를 이용한 일 증발접시 증발량의 모형화 (Modeling of Daily Pan Evaporation using the Limited Climatic Variables and Polynomial Networks Approach)

  • 김성원
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2010년도 학술발표회
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    • pp.1596-1599
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    • 2010
  • Group method of data handling neural networks model (GMDH-NNM) is used to estimate daily pan evaporation (PE) using limited climatic variables such as max temperature ($T_{max}$), min temperature ($T_{min}$), mean wind speed ($W_{mean}$), mean relative humidity ($RH_{mean}$) and sunshine duration (SD). And, for the performances of GMDH-NNM, it is composed of training and test performances, respectively. The training and test performances are carried out using daily time series data, respectively. From this research, we evaluate the impact of GMDH-NNM for the modeling of the nonlinear time series data. We should, thus, construct the credible data of the daily PE data using GMDH-NNM, and can suggest the methodology for the irrigation and drainage networks system. Furthermore, this research represents that the strong nonlinear relationship such as pan evaporation modeling can be generalized using GMDH-NNM.

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생산능력 제약하에 확률적 수요를 갖는 로트 크기 결정기법에 관한 연구 (A Study on the Capaciated Production Lot Sizing Problem with Probabilistic Demand)

  • 김만식;이호일
    • 대한산업공학회지
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    • 제15권2호
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    • pp.109-116
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    • 1989
  • In many cases, production-inventory systems involves significant demand variations. Actual demand is probabilistic and the production capacity is also limited. Finding the proper production lot sizes to this problem usually requires heavy computational procedures. Therefore a heuristic approach were under various assumptions is highly recommended. In this paper, an approach with consideration of probabilistic demand and limited production capacity is proposed.

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Pyramiding transgenes for potato tuber moth resistance in potato

  • Meiyalaghan, Sathiyamoorthy;Pringle, Julie M.;Barrell, Philippa J.;Jacobs, Jeanne M.E.;Conner, Anthony J.
    • Plant Biotechnology Reports
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    • 제4권4호
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    • pp.293-301
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    • 2010
  • The feasibility of two strategies for transgene pyramiding using Agrobacterium-mediated transformation was investigated to develop a transgenic potato (Solanum tuberosum L. cv. Iwa) with resistance to potato tuber moth (PTM) (Phthorimaea operculella (Zeller)). In the first approach, cry1Ac9 and cry9Aa2 genes were introduced simultaneously using a kanamycin (nptII) selectable marker gene. The second approach involved the sequential introduction (re-transformation) of a cry1Ac9 gene, using a hygromycin resistance (hpt) selectable marker gene, into an existing line transgenic for a cry9Aa2 gene and a kanamycin resistance (nptII) selectable marker gene. Multiplex polymerase chain reaction (PCR) confirmed the presence of the specific selectable marker gene and both cry genes in all regenerated lines. The relative steady-state level of the cry gene transcripts in leaves was quantified in all regenerated lines by real-time PCR analysis. Re-transformation proved to be a flexible approach to effectively pyramid genes for PTM resistance in potato, since it allowed the second gene to be added to a line that was previously identified as having a high level of resistance. Larval growth of PTM was significantly inhibited on excised greenhouse-grown leaves in all transgenic lines, although no lines expressing both cry genes exhibited any greater resistance to PTM larvae over that previously observed for the individual genes. It is anticipated that these lines will permit more durable resistance by delaying the opportunities for PTM adaptation to the individual cry genes.

Tobacco Retail License Recognition Based on Dual Attention Mechanism

  • Shan, Yuxiang;Ren, Qin;Wang, Cheng;Wang, Xiuhui
    • Journal of Information Processing Systems
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    • 제18권4호
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    • pp.480-488
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    • 2022
  • Images of tobacco retail licenses have complex unstructured characteristics, which is an urgent technical problem in the robot process automation of tobacco marketing. In this paper, a novel recognition approach using a double attention mechanism is presented to realize the automatic recognition and information extraction from such images. First, we utilized a DenseNet network to extract the license information from the input tobacco retail license data. Second, bi-directional long short-term memory was used for coding and decoding using a continuous decoder integrating dual attention to realize the recognition and information extraction of tobacco retail license images without segmentation. Finally, several performance experiments were conducted using a largescale dataset of tobacco retail licenses. The experimental results show that the proposed approach achieves a correction accuracy of 98.36% on the ZY-LQ dataset, outperforming most existing methods.

Hybrid RANS/LES simulations of a bluff-body flow

  • Camarri, S.;Salvetti, M.V.;Koobus, B.;Dervieux, A.
    • Wind and Structures
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    • 제8권6호
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    • pp.407-426
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    • 2005
  • A hybrid RANS/LES approach, based on the Limited Numerical Scales concept, is applied to the numerical simulation of the flow around a square cylinder. The key feature of this approach is a blending between two eddy-viscosities, one given by the $k-{\varepsilon}$ RANS model and the other by the Smagorinsky LES closure. A mixed finite-element/finite-volume formulation is used for the numerical discretization on unstructured grids. The results obtained with the hybrid approach are compared with those given by RANS and LES simulations for three different grid resolutions; comparisons with experimental data and numerical results in the literature are also provided. It is shown that, if the grid resolution is adequate for LES, the hybrid model recovers the LES accuracy. For coarser grid resolutions, the blending criterion appears to be effective to improve the accuracy of the results with respect to both LES and RANS simulations.