• Title/Summary/Keyword: resolution methods

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High Resolution Melting Analysis for Epidermal Growth Factor Receptor Mutations in Formalin-fixed Paraffin-embedded Tissue and Plasma Free DNA from Non-small Cell Lung Cancer Patients

  • Jing, Chang-Wen;Wang, Zhuo;Cao, Hai-Xia;Ma, Rong;Wu, Jian-Zhong
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6619-6623
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    • 2013
  • Background:The aim of the research was to explore a cost effective, fast, easy to perform, and sensitive method for epidermal growth factor receptor (EGFR) mutation testing. Methods: High resolution melting analysis (HRM) was introduced to evaluate the efficacy of the analysis for dectecting EGFR mutations in exons 18 to 21 using formalin-fixed paraffin-embedded (FFPE) tissues and plasma free DNA from 120 patients. Results: The total EGFR mutation rate was 37.5% (45/120) detected by direct sequencing. There were 48 mutations in 120 FFPE tissues assessed by HRM. For plasma free DNA, the EGFR mutation rate was 25.8% (31/120). The sensitivity of HRM assays in FFPE samples was 100% by HRM. There was a low false-positive mutation rate but a high false-negative rate in plasma free DNA detected by HRM. Conclusions: Our results show that HRM analysis has the advantage of small tumor sample need. HRM applied with plasma free DNA showed a high false-negative rate but a low false-positive rate. Further research into appropriate methods and analysis needs to be performed before HRM for plasma free DNA could be accepted as an option in diagnostic or screening settings.

High Resolution ISAR Imaging Based on Improved Smoothed L0 Norm Recovery Algorithm

  • Feng, Junjie;Zhang, Gong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.12
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    • pp.5103-5115
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    • 2015
  • In radar imaging, a target is usually consisted of a few strong scatterers which are sparsely distributed. In this paper, an improved sparse signal recovery algorithm based on smoothed l0 (SL0) norm method is proposed to achieve high resolution ISAR imaging with limited pulse numbers. Firstly, one new smoothed function is proposed to approximate the l0 norm to measure the sparsity. Then a single loop step is used instead of two loop layers in SL0 method which increases the searching density of variable parameter to ensure the recovery accuracy without increasing computation amount, the cost function is undated in every loop for the next loop until the termination is satisfied. Finally, the new set of solution is projected into the feasible set. Simulation results show that the proposed algorithm is superior to the several popular methods both in terms of the reconstruction performance and computation time. Real data ISAR imaging obtained by the proposed algorithm is competitive to several other methods.

Atmospheric Correction Problems with Multi-Temporal High Spatial Resolution Images from Different Satellite Sensors

  • Lee, Hwa-Seon;Lee, Kyu-Sung
    • Korean Journal of Remote Sensing
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    • v.31 no.4
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    • pp.321-330
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    • 2015
  • Atmospheric correction is an essential part in time-series analysis on biophysical parameters of surface features. In this study, we tried to examine possible problems in atmospheric correction of multitemporal High Spatial Resolution (HSR) images obtained from two different sensor systems. Three KOMPSAT-2 and two IKONOS-2 multispectral images were used. Three atmospheric correction methods were applied to derive surface reflectance: (1) Radiative Transfer (RT) - based absolute atmospheric correction method, (2) the Dark Object Subtraction (DOS) method, and (3) the Cosine Of the Uun zeniTh angle (COST) method. Atmospheric correction results were evaluated by comparing spectral reflectance values extracted from invariant targets and vegetation cover types. In overall, multi-temporal reflectance from five images obtained from January to December did not show consistent pattern in invariant targets and did not follow a typical profile of vegetation growth in forests and rice field. The multi-temporal reflectance values were different by sensor type and atmospheric correction methods. The inconsistent atmospheric correction results from these multi-temporal HSR images may be explained by several factors including unstable radiometric calibration coefficients for each sensor and wide range of sun and sensor geometry with the off-nadir viewing HSR images.

Measurements of Impervious Surfaces - per-pixel, sub-pixel, and object-oriented classification -

  • Kang, Min Jo;Mesev, Victor;Kim, Won Kyung
    • Korean Journal of Remote Sensing
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    • v.31 no.4
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    • pp.303-319
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    • 2015
  • The objectives of this paper are to measure surface imperviousness using three different classification methods: per-pixel, sub-pixel, and object-oriented classification. They are tested on high-spatial resolution QuickBird data at 2.4 meters (four spectral bands and three principal component bands) as well as a medium-spatial resolution Landsat TM image at 30 meters. To measure impervious surfaces, we selected 30 sample sites with different land uses and residential densities across image representing the city of Phoenix, Arizona, USA. For per-pixel an unsupervised classification is first conducted to provide prior knowledge on the possible candidate spectral classes, and then a supervised classification is performed using the maximum-likelihood rule. For sub-pixel classification, a Linear Spectral Mixture Analysis (LSMA) is used to disentangle land cover information from mixed pixels. For object-oriented classification several different sets of scale parameters and expert decision rules are implemented, including a nearest neighbor classifier. The results from these three methods show that the object-oriented approach (accuracy of 91%) provides more accurate results than those achieved by per-pixel algorithm (accuracy of 67% and 83% using Landsat TM and QuickBird, respectively). It is also clear that sub-pixel algorithm gives more accurate results (accuracy of 87%) in case of intensive and dense urban areas using medium-resolution imagery.

Spatial Downscaling of MODIS Land Surface Temperature: Recent Research Trends, Challenges, and Future Directions

  • Yoo, Cheolhee;Im, Jungho;Park, Sumin;Cho, Dongjin
    • Korean Journal of Remote Sensing
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    • v.36 no.4
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    • pp.609-626
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    • 2020
  • Satellite-based land surface temperature (LST) has been used as one of the major parameters in various climate and environmental models. Especially, Moderate Resolution Imaging Spectroradiometer (MODIS) LST is the most widely used satellite-based LST product due to its spatiotemporal coverage (1 km spatial and sub-daily temporal resolutions) and longevity (> 20 years). However, there is an increasing demand for LST products with finer spatial resolution (e.g., 10-250 m) over regions such as urban areas. Therefore, various methods have been proposed to produce high-resolution MODIS-like LST less than 250 m (e.g., 100 m). The purpose of this review is to provide a comprehensive overview of recent research trends and challenges for the downscaling of MODIS LST. Based on the recent literature survey for the past decade, the downscaling techniques classified into three groups-kernel-driven, fusion-based, and the combination of kernel-driven and fusion-based methods-were reviewed with their pros and cons. Then, five open issues and challenges were discussed: uncertainty in LST retrievals, low thermal contrast, the nonlinearity of LST temporal change, cloud contamination, and model generalization. Future research directions of LST downscaling were finally provided.

Random Access Method for the IEEE 802.16 Networks (IEEE 802.16 망을 위한 랜덤 액세스 기법)

  • Kim, Myeong-Hwan;Kook, Kwang-Ho;Lee, Kang-Won;Kim, Young-Il
    • Journal of the Korea Society for Simulation
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    • v.17 no.4
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    • pp.11-19
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    • 2008
  • To enhance the performance of the IEEE 802.16 broadband wireless access system, it is necessary to improve the efficiency of the radio link. The efficiency of the uplink can be improved by using more efficient random access method. As new random access methods, we propose a RA_NBRM method which is based on the number of bandwidth request messages and a RA_CRA method which is based on the conflict resolution algorithm. The simulation results show that the performance of the new methods is superior to that of the existing binary exponential backoff method.

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Feature Based Multi-Resolution Registration of Blurred Images for Image Mosaic

  • Fang, Xianyong;Luo, Bin;He, Biao;Wu, Hao
    • International Journal of CAD/CAM
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    • v.9 no.1
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    • pp.37-46
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    • 2010
  • Existing methods for the registration of blurred images are efficient for the artificially blurred images or a planar registration, but not suitable for the naturally blurred images existing in the real image mosaic process. In this paper, we attempt to resolve this problem and propose a method for a distortion-free stitching of naturally blurred images for image mosaic. It adopts a multi-resolution and robust feature based inter-layer mosaic together. In each layer, Harris corner detector is chosen to effectively detect features and RANSAC is used to find reliable matches for further calibration as well as an initial homography as the initial motion of next layer. Simplex and subspace trust region methods are used consequently to estimate the stable focal length and rotation matrix through the transformation property of feature matches. In order to stitch multiple images together, an iterative registration strategy is also adopted to estimate the focal length of each image. Experimental results demonstrate the performance of the proposed method.

MEDIUM RESOLUTION SPECTRAL LIBRARY OF LATE-TYPE STELLAR TEMPLATES IN NEAR-INFRARED BAND

  • Le, Huynh Anh Nguyena;Kang, Won-Seok;Pak, Soo-Jong;Im, Myung-Shin;Lee, Jeong-Eun;Ho, Luis C.;Pyo, Tae-Soo;Jaffe, Daniel T.
    • Journal of The Korean Astronomical Society
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    • v.44 no.4
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    • pp.125-134
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    • 2011
  • We present medium resolution (R = 5000 - 6000) spectra in the near-infrared band, 1.4 - 1.8 ${\mu}m$, for template stars in G, K, and M types observed by the echelle spectrometer, IRCS, at the SUBARU 8.2 m telescope. The identification of lines is based on the spectra of Arcturus (K2 III) in the literature. We measured the equivalent of widths and compared our results to those of Meyer et al. (1998). We conclude that our spectral resolution (R = 6000) data can investigate more accurately the properties of lines in stellar spectra. The library of the template stellar spectra in ASCII format are available for download on the World Wide Web.

Suitability of Arbitration Regarding Types of Disputes in the Fashion Industry (패션산업의 분쟁 유형에 따른 중재적합성)

  • Lee, Jae-Kyoung
    • Journal of Arbitration Studies
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    • v.29 no.1
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    • pp.91-113
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    • 2019
  • The fashion industry has been growing in Korea, but the law and the dispute resolution have been less than effective so far. Copyright and patent law have proven only minimally effective in fashion, ending up with designers and fashion companies relying on their trademarks to protect their design. Litigating trademark disputes in the fashion industry presents a host of problems and leads to resorting to the Alternative Dispute Resolution (ADR). ADR methods, especially arbitration, however, are emerging as substitutes to litigation. Using these methods, the fashion industry should sincerely consider a self-regulating program in which its members-both fashion designers and corporations alike-can resolve disputes in a manner mutually beneficial to all parties in order to preserve the industry's growth, solidarity, and esteem. From 2016, KCAB's Fashion Industry Dispute Advisory Committee (FIDAC) for ADR has promoted a better solution for disputes in the fashion industry. Therefore, stakeholders in the fashion industry should commit to procuring innovation in fashion on a long-term basis by establishing a panel handling an alternate dispute resolution process. The ADR process can mitigate the uncertainty created by relevant legislation or any other disputes, which could result in shying away from any business in the fashion industry.

Super-Resolution Using NLSA Mechanism (비지역 희소 어텐션 메커니즘을 활용한 초해상화)

  • Kim, Sowon;Park, Hanhoon
    • Journal of the Institute of Convergence Signal Processing
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    • v.23 no.1
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    • pp.8-14
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    • 2022
  • With the development of deep learning, super-resolution (SR) methods have tried to use deep learning mechanism, instead of using simple interpolation. SR methods using deep learning is generally based on convolutional neural networks (CNN), but recently, SR researches using attention mechanism have been actively conducted. In this paper, we propose an approach of improving SR performance using one of the attention mechanisms, non-local sparse attention (NLSA). Through experiments, we confirmed that the performance of the existing SR models, IMDN, CARN, and OISR-LF-s can be improved by using NLSA.