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Comparison of different inversion methods of D-T_(2)two-dimensional nuclear magnetic resonance logging and applicability analysis 被引量:2
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作者 Li Cheng-Lin Tan Mao-Jin +4 位作者 Wang Ke-Wen Feng Zhou Liu Ying-Ming Zhang Hai-Tao and Xiao Li-Zhi 《Applied Geophysics》 SCIE CSCD 2022年第2期173-184,306,307,共14页
D-T_(2)two-dimensional nuclear magnetic resonance(2D NMR)logging technology can distinguish pore fluid types intuitively,and it is widely used in oil and gas exploration.Many 2D NMR inversion methods(e.g.,truncated si... D-T_(2)two-dimensional nuclear magnetic resonance(2D NMR)logging technology can distinguish pore fluid types intuitively,and it is widely used in oil and gas exploration.Many 2D NMR inversion methods(e.g.,truncated singular value decomposition(TSVD),Butler-Reds-Dawson(BRD),LM-norm smoothing,and TIST-L1 regularization methods)have been proposed successively,but most are limited to numerical simulations.This study focused on the applicability of different inversion methods for NMR logging data of various acquisition sequences,from which the optimal inversion method was selected based on the comparative analysis.First,the two-dimensional NMR logging principle was studied.Then,these inversion methods were studied in detail,and the precision and computational efficiency of CPMG and diffusion editing(DE)sequences obtained from oil-water and gas-water models were compared,respectively.The inversion results and calculation time of truncated singular value decomposition(TSVD),Butler-Reds-Dawson(BRD),LM-norm smoothing,and TIST-L1 regularization were compared and analyzed through numerical simulations.The inversion method was optimized to process SP mode logging data from the MR Scanner instrument.The results showed that the TIST-regularization and LM-norm smoothing methods were more accurate for the CPMG and DE sequence echo trains of the oil-water and gas-water models.However,the LM-norm smoothing method was less time-consuming,making it more suitable for logging data processing.A case study in well A25 showed that the processing results by the LM-norm smoothing method were consistent with GEOLOG software.This demonstrates that the LM-norm smoothing method is applicable in practical NMR logging processing. 展开更多
关键词 two-dimensional NMR logging D-T_(2)spectrum inversion method diffusion editing sequence data processing
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Source extension based on ε-entropy 被引量:3
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作者 张剑 《Journal of Chongqing University》 CAS 2005年第2期102-106,共5页
It is known by entropy theory that image is a source correlated with a certain characteristic of probability. The entropy rate of the source and ε- entropy (rate-distortion function theory) are the information conten... It is known by entropy theory that image is a source correlated with a certain characteristic of probability. The entropy rate of the source and ε- entropy (rate-distortion function theory) are the information content to identify the characteristics of video images, and hence are essentially related with video image compression. They are fundamental theories of great significance to image compression, though impossible to be directly turned into a compression method. Based on the entropy theory and the image compression theory, by the application of the rate-distortion feature mathematical model and Lagrange multipliers to some theoretical problems in the H.264 standard, this paper presents a new the algorithm model of coding rate-distortion. This model is introduced into complete test on the capability of the test model of JM61e (JUT Test Model). The result shows that the speed of coding increases without significant reduction of the rate-distortion performance of the coder. 展开更多
关键词 Rate-Distortion function LAGRANGIAN source extension Theory of information video coding image compression
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Human Cytomegalovirus UL138 Open Reading Frame Is Highly Conserved in Clinical Strains 被引量:6
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作者 Ying Qi Rong He Yan-ping Ma Zheng-rong Sun Yao-hua Ji Qiang Ruan 《Chinese Medical Sciences Journal》 CAS CSCD 2009年第2期107-111,共5页
Objective To investigate the variability of human cytomegalovirus (HCMV) UL138 open reading frame (ORF) in clinical strains. Methods HCMV UL138 ORF was amplified by polymerase chain reaction (PCR) and PCR amplif... Objective To investigate the variability of human cytomegalovirus (HCMV) UL138 open reading frame (ORF) in clinical strains. Methods HCMV UL138 ORF was amplified by polymerase chain reaction (PCR) and PCR amplification products were sequenced directly, and the data were analyzed in 19 clinical strains. Results LIL138 ORF in all 30 clinical strains was amplified successfully. Compared with that of Toledo strain, the nucleotide and amino acid sequence identifies of LIL138 ORF in all strains were 97.41% to 99.41% and 98.24% to 99.42%, respectively. All of the nucleofide mutations were substitutions. The spatial structure and post-translational modification sites of HL138 encoded proteins were conserved. The result of phylogenetic tree showed that HCMV HL138 sequence variations were not definitely related with different clinical symptoms. Conclusion HCMV UL138 ORF in clinical strains is high conservation, which might be helpful for UL138 encoded protein to play a role in latent infection of HCMV. 展开更多
关键词 human cytomegalovirus UL 138 CONSERVATION
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Recognition of Multifunctional Coded Target in Single-camera Mobile 3D-vision Coordination Measurement
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作者 XU Zhi-hua XIA Ling-li YU Zhi-jing 《Semiconductor Photonics and Technology》 CAS 2009年第3期167-172,共6页
Single-camera mobile-vision coordinate measurement is one of the primary methods of 3D-coordinate vision measurement, and coded target plays an important role in this system. A multifunctional coded target and its rec... Single-camera mobile-vision coordinate measurement is one of the primary methods of 3D-coordinate vision measurement, and coded target plays an important role in this system. A multifunctional coded target and its recognition algorithm is developed, which can realize automatic match of feature points, calculation of camera initial exterior orientation and space scale factor constraint in measurement system. The uniqueness and scalability of coding are guaranteed by the rational arrangement of code bits. The recognition of coded targets is realized by cross-ratio invariance restriction, space coordinates transform of feature points based on spacial pose estimation algorithm, recognition of code bits and computation of coding values. The experiment results demonstrate the uniqueness of the coding form and the reliability of recognition. 展开更多
关键词 coded target mobile vision 3D-coordinates measurement pose estimate match of targets
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Complexity scalable control algorithm for intra coding in H.264 under energy constraints
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作者 Gao Xuejun Lam Kin Man +1 位作者 ZhuoLi ShenLansun 《High Technology Letters》 EI CAS 2010年第3期274-279,共6页
In this paper, the complexity of intra coding is first analyzed so as to achieve a weight of complexity measurement for each intra mode. Then, a new complexity scalable control algorithm for intra coding in H. 264 is ... In this paper, the complexity of intra coding is first analyzed so as to achieve a weight of complexity measurement for each intra mode. Then, a new complexity scalable control algorithm for intra coding in H. 264 is proposed, based on the rearrangement of the order of candidate modes and an efficient complexity allocation and control (CAAC) scheme at the macroblock (MB) level. The candidate modes of each MB are rearranged according to the local-edge information. Experimental results show that our proposed algorithm can make an appropriate cut-off point of the candidate modes sequence adaptively according to the current energy condition of a mobile device, so as to adjust the complexity at any level while maximizing the video quality, which can prolong the operational lifetime of the battery with minimum degradation in video quality. 展开更多
关键词 complexity scalable control complexity allocation rearrangement of candidate modes intra coding H. 264 energy constraints
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Exploring the Usefulness of Extensible Business Reporting Language (XBRL) for Reporting Intellectual Capital (IC): Evidence From Italian Preparers
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作者 Marco Papa Floriana Luisi 《Journal of Modern Accounting and Auditing》 2014年第5期537-550,共14页
Intellectual capital disclosure (ICD) has experienced a substantial increase in recent decades and many frameworks and guidelines have been issued to provide directions with regard to what constitutes "good" ICD. ... Intellectual capital disclosure (ICD) has experienced a substantial increase in recent decades and many frameworks and guidelines have been issued to provide directions with regard to what constitutes "good" ICD. Companies can use Extensible Business Reporting Language (XBRL) to "build" their own intellectual capital (IC) reports. This digital format has both technical and operating characteristics suitable for reporting non-financial information. This paper reports the findings of a survey of the views of 37 Italian preparers on the scope, the taxonomy, and the assurance of IC reporting via XBRL. It was found that respondents favor the adoption of an IC reporting framework and the standardization of IC indicators. Preferences reveal uncertainty about the level of flexibility for tagging IC information, while supporting the main benefits of XBRL and indicating a marked inclination for tagged information certified by an independent audit. Overall, despite a low awareness of XBRL, the importance placed on standardization of IC information and on the usefulness of the comparability and the speed attribute of XBRL supports the appealing features of this language for developing IC reporting. 展开更多
关键词 Extensible Business Reporting Language (XBRL) digital reporting intellectual capital disclosure (ICD) business reporting
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让随文练笔真正贯穿于阅读教学中
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作者 王思九 《写作(下)》 2018年第1期93-94,共2页
读写结合随文练笔早已成为广大语文教师的共识。本文结合多年的教学实践.拟从阅读与写作的关系中,梳理出一些读写相融合的契机。让随文练笔真正发挥效用.快速提升学生的语文素养。
关键词 随文练笔 仿写 编扩 感悟 阅读教学
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