• 제목/요약/키워드: current reconstruction

검색결과 414건 처리시간 0.025초

Adaptive Algorithm in Image Reconstruction Based on Information Geometry

  • Wang, Meng;Ning, Zhen Hu;Yu, Jing;Xiao, Chuang Bai
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제15권2호
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    • pp.461-484
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    • 2021
  • Compressed sensing in image reconstruction has attracted attention and many studies are proposed. As we know, adding prior knowledge about the distribution of the support on the original signal to CS can improve the quality of reconstruction. However, it is still difficult for a recovery framework adjusts its strategy for exploiting the prior knowledge efficiently according to the current estimated signals in serial iterations. With the theory of information geometry, we propose an adaptive strategy based on the current estimated signal in each iteration of the recovery. We also improve the performance of existing algorithms through the adaptive strategy for exploiting the prior knowledge according to the current estimated signal. Simulations are presented to validate the results. In the end, we also show the application of the model in the image.

Autologous Microvascular Breast Reconstruction

  • Healy, Claragh;Ramakrishnan, Venkat
    • Archives of Plastic Surgery
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    • 제40권1호
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    • pp.3-10
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    • 2013
  • Autologous microvascular breast reconstruction is widely accepted as a key component of breast cancer treatment. There are two basic donor sites; the anterior abdominal wall and the thigh/buttock region. Each of these regions provides for a number of flaps that are successfully utilised in breast reconstruction. Refinement of surgical technique and the drive towards minimising donor site morbidity whilst maximising flap vascularity in breast reconstruction has seen an evolution towards perforator based flap reconstructions, however myocutaneous flaps are still commonly practiced. We review herein the current methods of autologous microvascular breast reconstruction.

Research on a Spectral Reconstruction Method with Noise Tolerance

  • Ye, Yunlong;Zhang, Jianqi;Liu, Delian;Yang, Yixin
    • Current Optics and Photonics
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    • 제5권5호
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    • pp.562-575
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    • 2021
  • As a new type of spectrometer, that based on filters with different transmittance features attracts a lot of attention for its advantages such as small-size, low cost, and simple optical structure. It uses post-processing algorithms to achieve target spectrum reconstruction; therefore, the performance of the spectrometer is severely affected by noise. The influence of noise on the spectral reconstruction results is studied in this paper, and suggestions for solving the spectral reconstruction problem under noisy conditions are given. We first list different spectral reconstruction methods, and through simulations demonstrate that these methods show unsatisfactory performance under noisy conditions. Then we propose to apply the gradient projection for sparse reconstruction (GRSR) algorithm to the spectral reconstruction method. Simulation results show that the proposed method can significantly reduce the influence of noise on the spectral reconstruction process. Meanwhile, the accuracy of the spectral reconstruction results is dramatically improved. Therefore, the practicality of the filter-based spectrometer will be enhanced.

Image Reconstruction Method for Photonic Integrated Interferometric Imaging Based on Deep Learning

  • Qianchen Xu;Weijie Chang;Feng Huang;Wang Zhang
    • Current Optics and Photonics
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    • 제8권4호
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    • pp.391-398
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    • 2024
  • An image reconstruction algorithm is vital for the image quality of a photonic integrated interferometric imaging (PIII) system. However, image reconstruction algorithms have limitations that always lead to degraded image reconstruction. In this paper, a novel image reconstruction algorithm based on deep learning is proposed. Firstly, the principle of optical signal transmission through the PIII system is investigated. A dataset suitable for image reconstruction of the PIII system is constructed. Key aspects such as model and loss functions are compared and constructed to solve the problem of image blurring and noise influence. By comparing it with other algorithms, the proposed algorithm is verified to have good reconstruction results not only qualitatively but also quantitatively.

Automated 3D Model Reconstruction of Disaster Site Using Aerial Imagery Acquired By Drones

  • Kim, Changyoon;Moon, Hyounseok;Lee, Woosik
    • 국제학술발표논문집
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    • The 6th International Conference on Construction Engineering and Project Management
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    • pp.671-672
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    • 2015
  • Due to harsh conditions of disaster areas, understanding of current feature of collapsed buildings, terrain, and other infrastructures is critical issue for disaster managers. However, because of difficulties in acquiring the geographical information of the disaster site such as large disaster site and limited capability of rescue workers, comprehensive site investigation of current location of survivors buried under the remains of the building is not an easy task for disaster managers. To overcome these circumstances of disaster site, this study makes use of an unmanned aerial vehicle, commonly known as a drone to effectively acquire current image data from the large disaster areas. The framework of 3D model reconstruction of disaster site using aerial imagery acquired by drones was also presented. The proposed methodology is expected to assist rescue workers and disaster managers in achieving a rapid and accurate identification of survivors under the collapsed building.

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Trends and Innovations in Autologous Breast Reconstruction

  • Nicole E. Speck;Vendela Grufman;Jian Farhadi
    • Archives of Plastic Surgery
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    • 제50권3호
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    • pp.240-247
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    • 2023
  • More than 40 years have passed since the description of the first "free abdominoplasty flap" for breast reconstruction by Holmström. In the meantime, surgical advances and technological innovations have resulted in the widespread adoption of autologous breast reconstruction to recreate the female breast after mastectomy. While concepts and techniques are continuing to evolve, maintaining an overview is challenging. This article provides a review of current trends and recent innovations in autologous breast reconstruction.

Analysis of the Phase Current Measurement Boundary of Three Shunt Sensing PWM Inverters and an Expansion Method

  • Cho, Byung-Geuk;Ha, Jung-Ik;Sul, Seung-Ki
    • Journal of Power Electronics
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    • 제13권2호
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    • pp.232-242
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    • 2013
  • To obtain phase currents information in AC drives, shunt sensing technology is known to show great performance in cost-effectiveness and therefore it is widely used in low cost applications. However, shunt sensing methods are unable to acquire phase currents in certain operation conditions. This paper deals with the derivation of the boundary conditions for phase current reconstruction in three-shunt sensing inverters and proposes a voltage injection method to expand the measurable areas. As the boundary conditions are deeply dependent on the switching patterns, they are typically analyzed on the voltage vector plane for space vector pulse width modulation (SVPWM) and discontinuous pulse width modulation (DPWM). In the proposed method, the voltage injection and its compensation are conducted within one sampling period. This guarantees fast current reconstruction and the injected voltage is decided so as to minimize the current ripple. In addition to the voltage injection method, a sampling point shifting method is also introduced to improve the boundary conditions. Simulation and experimental results are presented to verify the boundary condition derivation and the effectiveness of the proposed voltage injection method.

Evolution and current status of microsurgical tongue reconstruction, part II

  • Choi, Jong-Woo;Alshomer, Feras;Kim, Young-Chul
    • 대한두개안면성형외과학회지
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    • 제23권5호
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    • pp.193-204
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    • 2022
  • Tongue reconstruction remains a major aspect of head and neck reconstructive procedures. Surgeons planning tongue reconstruction should consider several factors to optimize the overall outcomes. Specifically, various technical aspects related to tongue reconstruction have been found to affect the outcomes. Multidisciplinary teams dedicated to oncologic, reconstructive, and rehabilitative approaches play an essential role in the reconstructive process. Moreover, operative planning addressing certain patient-related and defect-related factors is crucial for optimizing functional speech and swallowing, as well as quality of life outcomes. Furthermore, tongue reconstruction is a delicate process, in which overall functional outcomes result from proper flap selection and shaping, recipient vessel preparation and anastomosis, surgical approaches to flap insetting, and postoperative management. The second part of this review summarizes these factors in relation to tongue reconstruction.

이상유동의 동적 전기 임피던스 가시화에 대한 전류패턴의 영향 (Effect of input current patterns on dynamic electrical impedance imaging of two-phase flows)

  • 정순일;;;김신;김경연;김민찬
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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    • pp.475-478
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    • 2006
  • In electrical impedance tomography (EIT) an array of electrodes is attached on the boundary of an object and small alternating currents are injected through these electrodes, and then the resulting voltages are measured. An estimation for the cross-sectional resistivity distribution in the object is obtained by using these current and voltage data in a nondestructive manner. In this paper, the electrical impedance imaging of two-phase flows undergoing rapid transient is considered with a special emphasis on the effect of the current pattern on the image reconstruction. The trigonometric current pattern, which is commonly used in the conventional static electrical impedance imaging, shows poor performance in case of the dynamic imaging considered in this work. Extensive numerical experiments are conducted with various kinds of current patterns and their effects on the image reconstruction performance are examined.

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요전박유리피판을 이용한 하인두협착 재건 (A Case of Reconstruction of Hypopharyngeal Stricture with Radial Forearm Free Flap)

  • 김민식;선동일;이동희;조승호
    • 대한기관식도과학회지
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    • 제3권2호
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    • pp.307-312
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    • 1997
  • Reconstruction of the pharyngoesophagus is one of the most difficult challenges in head and neck surgery. The goals of pharyngoesophageal reconstruction include restoration of a person's ability to swallow and to speak with minimal morbidity, but no current reconstruction modality is clearly best. Following its first introduction as fasciocutaneous flap by Yang in 1981, the forearm flap based on radial artery has become recognized as a very reliable and relatively easy one to use. The forearm flap has thin, pliable and predominantly hairless skin and scant subcutaneous layer In addition, its vascular pedicle is long and of large caliber, which greatly increases the chance of successful revascularization. The forearm flap shows the potentiality for better functional rehabilitation in swallowing and speech as well as the possibility of three dimensional reconstruction. We experienced a case of radial forearm free flap for the reconstruction in a patient with the hypopharyngeal stricture. The early return of oral feeding was possible and successfully enough to return to the normal daily activity.

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