Video watermarking plays a crucial role in protecting intellectual property rights and ensuring content authenticity.This study delves into the integration of Galois Field(GF)multiplication tables,especially GF(2^(4))...Video watermarking plays a crucial role in protecting intellectual property rights and ensuring content authenticity.This study delves into the integration of Galois Field(GF)multiplication tables,especially GF(2^(4)),and their interaction with distinct irreducible polynomials.The primary aim is to enhance watermarking techniques for achieving imperceptibility,robustness,and efficient execution time.The research employs scene selection and adaptive thresholding techniques to streamline the watermarking process.Scene selection is used strategically to embed watermarks in the most vital frames of the video,while adaptive thresholding methods ensure that the watermarking process adheres to imperceptibility criteria,maintaining the video's visual quality.Concurrently,careful consideration is given to execution time,crucial in real-world scenarios,to balance efficiency and efficacy.The Peak Signal-to-Noise Ratio(PSNR)serves as a pivotal metric to gauge the watermark's imperceptibility and video quality.The study explores various irreducible polynomials,navigating the trade-offs between computational efficiency and watermark imperceptibility.In parallel,the study pays careful attention to the execution time,a paramount consideration in real-world scenarios,to strike a balance between efficiency and efficacy.This comprehensive analysis provides valuable insights into the interplay of GF multiplication tables,diverse irreducible polynomials,scene selection,adaptive thresholding,imperceptibility,and execution time.The evaluation of the proposed algorithm's robustness was conducted using PSNR and NC metrics,and it was subjected to assessment under the impact of five distinct attack scenarios.These findings contribute to the development of watermarking strategies that balance imperceptibility,robustness,and processing efficiency,enhancing the field's practicality and effectiveness.展开更多
Evaluating the permeability and irreducible water saturation of tight sandstone reservoirs is challenging.This study uses distribution functions to fit measured NMR T_(2)distributions of tight sandstone reservoirs and...Evaluating the permeability and irreducible water saturation of tight sandstone reservoirs is challenging.This study uses distribution functions to fit measured NMR T_(2)distributions of tight sandstone reservoirs and extract parameters for characterizing pore size distribution.These parameters are then used to establish prediction models for permeability and irreducible water saturation of reservoirs.Results of comparing the fit of the T_(2)distributions by the Gauss and Weibull distribution functions show that the fitting accuracy with the Weibull distribution function is higher.The physical meaning of the statistical parameters of the Weibull distribution function is defined to establish nonlinear prediction models of permeability and irreducible water saturation using the radial basis function(RBF)method.Correlation coefficients between the predicted values by the established models and the measured values of the tight sandstone core samples are 0.944 for permeability and 0.851 for irreducible water saturation,which highlight the effectiveness of the prediction models.展开更多
目的:探讨后路松解复位侧块关节植骨融合枕颈内固定术治疗颅底凹陷症合并难复性寰枢椎脱位的临床疗效。方法:回顾性分析2010年1月~2020年1月于我院行后路松解复位侧块关节植骨融合枕颈内固定术治疗颅底凹陷症合并难复性寰枢椎脱位患者...目的:探讨后路松解复位侧块关节植骨融合枕颈内固定术治疗颅底凹陷症合并难复性寰枢椎脱位的临床疗效。方法:回顾性分析2010年1月~2020年1月于我院行后路松解复位侧块关节植骨融合枕颈内固定术治疗颅底凹陷症合并难复性寰枢椎脱位患者的资料,其中男11例,女8例,年龄37.4±13.9岁(13~69岁),随访时间为54.7±29.4个月(25~131个月)。术前、术后1周、术后6个月、末次随访时分别通过视觉模拟(visual analogue scale,VAS)评分和日本骨科协会(Japanese Orthopaedic Association,JOA)评分评估患者的疼痛和神经功能情况。术前、术后1周、术后6个月、末次随访时在颈椎正中矢状位CT上测量寰齿前间距(atlantodental interval,ADI)、齿突尖至Chamberlain线的距离(distance of the top of odontoid to Chamberlain′s line,DOCL),在颈椎MRI上测量延髓脊髓角(cervico-medullary angle,CMA)。通过CT评估植骨融合情况,记录术后并发症。结果:所有患者手术顺利,手术时间136.1±29.0min(95~210min),出血量为189.7±85.0mL(100~455mL)。术前、术后1周、术后6个月及末次随访时VAS评分分别为6.06±1.21分、2.35±0.76分、1.24±0.81分、1.12±0.90分,JOA评分分别为9.26±2.24分、14.05±2.01分、15.05±1.57、15.16±1.42分;与术前相比,患者术后1周、术后6个月和末次随访时的VAS评分和JOA评分均显著改善(P<0.05)。影像学方面,术前、术后1周、术后6个月及末次随访时ADI分别为9.63±1.93mm、1.21±1.10mm、1.16±1.09mm、1.26±1.02mm,DOCL分别为11.47±3.93mm、2.53±3.30mm、2.32±3.20mm、2.26±2.73mm,CMA分别为114.31°±11.00°、144.16°±9.33°、145.31°±8.83、143.42°±9.12°;与术前相比,患者术后1周、术后6个月和末次随访时的ADI、DOCL和CMA均显著性改善(F=41.05,P<0.001)。所有患者均实现骨性融合,融合时间为10.3±2.7个月(5~15个月)。术后发生并发症2例(脑脊液漏1例,切口深部组织感染1例),给予对症支持治疗后均治愈。结论:后路松解复位侧块关节植骨融合枕颈内固定术是治疗颅底凹陷症合并难复性寰枢椎脱位安全有效的手术方式。展开更多
At any given time, a product stock manager is expected to carry out activities to check his or her holdings in general and to monitor the condition of the stock in particular. He should monitor the level or quantity a...At any given time, a product stock manager is expected to carry out activities to check his or her holdings in general and to monitor the condition of the stock in particular. He should monitor the level or quantity available of a given product, of any item. On the basis of the observation made in relation to the movements of previous periods, he may decide to order or not a certain quantity of products. This paper discusses the applicability of discrete-time Markov chains in making relevant decisions for the management of a stock of COTRA-Honey products. A Markov chain model based on the transition matrix and equilibrium probabilities was developed to help managers predict the likely state of the stock in order to anticipate procurement decisions in the short, medium or long term. The objective of any manager is to ensure efficient management by limiting overstocking, minimising the risk of stock-outs as much as possible and maximising profits. The determined Markov chain model allows the manager to predict whether or not to order for the period following the current period, and if so, how much.展开更多
文摘Video watermarking plays a crucial role in protecting intellectual property rights and ensuring content authenticity.This study delves into the integration of Galois Field(GF)multiplication tables,especially GF(2^(4)),and their interaction with distinct irreducible polynomials.The primary aim is to enhance watermarking techniques for achieving imperceptibility,robustness,and efficient execution time.The research employs scene selection and adaptive thresholding techniques to streamline the watermarking process.Scene selection is used strategically to embed watermarks in the most vital frames of the video,while adaptive thresholding methods ensure that the watermarking process adheres to imperceptibility criteria,maintaining the video's visual quality.Concurrently,careful consideration is given to execution time,crucial in real-world scenarios,to balance efficiency and efficacy.The Peak Signal-to-Noise Ratio(PSNR)serves as a pivotal metric to gauge the watermark's imperceptibility and video quality.The study explores various irreducible polynomials,navigating the trade-offs between computational efficiency and watermark imperceptibility.In parallel,the study pays careful attention to the execution time,a paramount consideration in real-world scenarios,to strike a balance between efficiency and efficacy.This comprehensive analysis provides valuable insights into the interplay of GF multiplication tables,diverse irreducible polynomials,scene selection,adaptive thresholding,imperceptibility,and execution time.The evaluation of the proposed algorithm's robustness was conducted using PSNR and NC metrics,and it was subjected to assessment under the impact of five distinct attack scenarios.These findings contribute to the development of watermarking strategies that balance imperceptibility,robustness,and processing efficiency,enhancing the field's practicality and effectiveness.
文摘Evaluating the permeability and irreducible water saturation of tight sandstone reservoirs is challenging.This study uses distribution functions to fit measured NMR T_(2)distributions of tight sandstone reservoirs and extract parameters for characterizing pore size distribution.These parameters are then used to establish prediction models for permeability and irreducible water saturation of reservoirs.Results of comparing the fit of the T_(2)distributions by the Gauss and Weibull distribution functions show that the fitting accuracy with the Weibull distribution function is higher.The physical meaning of the statistical parameters of the Weibull distribution function is defined to establish nonlinear prediction models of permeability and irreducible water saturation using the radial basis function(RBF)method.Correlation coefficients between the predicted values by the established models and the measured values of the tight sandstone core samples are 0.944 for permeability and 0.851 for irreducible water saturation,which highlight the effectiveness of the prediction models.
文摘目的:探讨后路松解复位侧块关节植骨融合枕颈内固定术治疗颅底凹陷症合并难复性寰枢椎脱位的临床疗效。方法:回顾性分析2010年1月~2020年1月于我院行后路松解复位侧块关节植骨融合枕颈内固定术治疗颅底凹陷症合并难复性寰枢椎脱位患者的资料,其中男11例,女8例,年龄37.4±13.9岁(13~69岁),随访时间为54.7±29.4个月(25~131个月)。术前、术后1周、术后6个月、末次随访时分别通过视觉模拟(visual analogue scale,VAS)评分和日本骨科协会(Japanese Orthopaedic Association,JOA)评分评估患者的疼痛和神经功能情况。术前、术后1周、术后6个月、末次随访时在颈椎正中矢状位CT上测量寰齿前间距(atlantodental interval,ADI)、齿突尖至Chamberlain线的距离(distance of the top of odontoid to Chamberlain′s line,DOCL),在颈椎MRI上测量延髓脊髓角(cervico-medullary angle,CMA)。通过CT评估植骨融合情况,记录术后并发症。结果:所有患者手术顺利,手术时间136.1±29.0min(95~210min),出血量为189.7±85.0mL(100~455mL)。术前、术后1周、术后6个月及末次随访时VAS评分分别为6.06±1.21分、2.35±0.76分、1.24±0.81分、1.12±0.90分,JOA评分分别为9.26±2.24分、14.05±2.01分、15.05±1.57、15.16±1.42分;与术前相比,患者术后1周、术后6个月和末次随访时的VAS评分和JOA评分均显著改善(P<0.05)。影像学方面,术前、术后1周、术后6个月及末次随访时ADI分别为9.63±1.93mm、1.21±1.10mm、1.16±1.09mm、1.26±1.02mm,DOCL分别为11.47±3.93mm、2.53±3.30mm、2.32±3.20mm、2.26±2.73mm,CMA分别为114.31°±11.00°、144.16°±9.33°、145.31°±8.83、143.42°±9.12°;与术前相比,患者术后1周、术后6个月和末次随访时的ADI、DOCL和CMA均显著性改善(F=41.05,P<0.001)。所有患者均实现骨性融合,融合时间为10.3±2.7个月(5~15个月)。术后发生并发症2例(脑脊液漏1例,切口深部组织感染1例),给予对症支持治疗后均治愈。结论:后路松解复位侧块关节植骨融合枕颈内固定术是治疗颅底凹陷症合并难复性寰枢椎脱位安全有效的手术方式。
文摘At any given time, a product stock manager is expected to carry out activities to check his or her holdings in general and to monitor the condition of the stock in particular. He should monitor the level or quantity available of a given product, of any item. On the basis of the observation made in relation to the movements of previous periods, he may decide to order or not a certain quantity of products. This paper discusses the applicability of discrete-time Markov chains in making relevant decisions for the management of a stock of COTRA-Honey products. A Markov chain model based on the transition matrix and equilibrium probabilities was developed to help managers predict the likely state of the stock in order to anticipate procurement decisions in the short, medium or long term. The objective of any manager is to ensure efficient management by limiting overstocking, minimising the risk of stock-outs as much as possible and maximising profits. The determined Markov chain model allows the manager to predict whether or not to order for the period following the current period, and if so, how much.