Fast mode decision algorithm for spatial resolutions down-scaling transcoding to H.264

A fast mode decision algorithm is proposed in this paper to accelerate the process of transcoding videos into H.264with arbitrary rate spatial resolution down-scaling. The proposed algorithm consists of three steps. First, an early-stop technique is introduced to determine the 16× 16-mode blocks, which take up about 70% of all the macroblocks; then, a bottom-up merging process is performed to determine the mode of rest non-early-stopped blocks; and then, we adopt half-pixel motion estimation to further refine the acquired predictive motion vectors. In order to obtain the predictive motion vectors for early-stop and merging processes, we propose a motion vector composition scheme, which can reuse the information in the input pre-encoded videos to handle the spatial resolution down-scaling. Experimental results showed that our algorithm is about four times faster than the Cascaded-Decoder-Encoder method and has negligible PSNR drop and little bit rate increase.

An error resilient scheme for H.264 video coding based on distortion estimated mode decision and nearest neighbor error concealment

Although H.264 video coding standard provides several error resilience tools, the damage caused by error propagation may still be tremendous. This work is aimed at developing a robust and standard-compliant error resilient coding scheme for H.264and uses techniques of mode decision, data hiding, and error concealment to reduce the damage from error propagation. This paper proposes a system with two error resilience techniques that can improve the robustness of H.264 in noisy channels. The first technique is Nearest Neighbor motion compensated Error Concealment (NNEC) that chooses the nearest neighbors in the reference frames for error concealment. The second technique is Distortion Estimated Mode Decision (DEMD) that selects an optimal mode based on stochastically distorted frames. Observed simulation results showed that the rate-distortion performances of the proposed algorithms are better than those of the compared algorithms.

Study on Decision Method of Neutral Point Grounding Mode for Medium-Voltage Distribution Network

The neutral grounding mode of medium-voltage distribution network decides the reliability, overvoltage, relay protection and electrical safety. Therefore, a comprehensive consideration of the reliability, safety and economy is particularly important for the decision of neutral grounding mode. This paper proposes a new decision method of neutral point grounding mode for mediumvoltage distribution network. The objective function is constructed for the decision according the life cycle cost. The reliability of the neutral point grounding mode is taken into account through treating the outage cost as an operating cost. The safety condition of the neutral point grounding mode is preserved as the constraint condition of decision models, so the decision method can generate the most economical and reliable scheme of neutral point grounding mode within a safe limit. The example is used to verify the feasibility and effectiveness of the decision method.

Optimal Mode Decision Method for Interframe Prediction in H.264/AVC

Studies show that encoding technologies in H.264/AVC,including prediction and conversion,are essential technologies.However,these technologies are more complicated than the MPEG-4,which is a standard method and widely adopted worldwide.Therefore,the amount of calculation in H.264/AVC is significantly up-regulated compared to that of the MPEG-4.In the present study,it is intended to simplify the computational expenses in the international standard compression coding system H.264/AVC for moving images.Inter prediction refers to the most feasible compression technology,taking up to 60%of the entire encoding.In this regard,prediction error and motion vector information are proposed to simplify the computation of inter predictive coding technology.In the initial frame,motion compensation is performed in all target modes and then basic information is collected and analyzed.After the initial frame,motion compensation is performed only in the middle 8×8 modes,and the basic information amount shifts.In order to evaluate the effectiveness of the proposed method and assess the motion image compression coding,four types of motion images,defined by the international telecommunication union(ITU),are employed.Based on the obtained results,it is concluded that the developed method is capable of simplifying the calculation,while it is slightly affected by the inferior image quality and the amount of information.

Efficient fast mode decision using mode complexity for multi-view video coding

The variable block-size motion estimation(ME) and disparity estimation(DE) are adopted in multi-view video coding(MVC) to achieve high coding efficiency. However, much higher computational complexity is also introduced in coding system, which hinders practical application of MVC. An efficient fast mode decision method using mode complexity is proposed to reduce the computational complexity. In the proposed method, mode complexity is firstly computed by using the spatial, temporal and inter-view correlation between the current macroblock(MB) and its neighboring MBs. Based on the observation that direct mode is highly possible to be the optimal mode, mode complexity is always checked in advance whether it is below a predefined threshold for providing an efficient early termination opportunity. If this early termination condition is not met, three mode types for the MBs are classified according to the value of mode complexity, i.e., simple mode, medium mode and complex mode, to speed up the encoding process by reducing the number of the variable block modes required to be checked. Furthermore, for simple and medium mode region, the rate distortion(RD) cost of mode 16×16 in the temporal prediction direction is compared with that of the disparity prediction direction, to determine in advance whether the optimal prediction direction is in the temporal prediction direction or not, for skipping unnecessary disparity estimation. Experimental results show that the proposed method is able to significantly reduce the computational load by 78.79% and the total bit rate by 0.07% on average, while only incurring a negligible loss of PSNR(about 0.04 d B on average), compared with the full mode decision(FMD) in the reference software of MVC.

Adaptive early termination of fast mode decision in MVC based on inter-view correlation

Variable size motion estimation （ME） and disparity estimation （DE） are employed to select the best coding mode for each macroblock （MB） in the current joint multiview video model （JMVM）. This technique achieves the highest possible coding efficiency, but it results in extremely large computation complexity which obstructs the multiview video coding （MVC） from practical application. This paper proposes an adaptive early termination of fast mode decision algorithm for MVC. It makes use of the coding information of the corresponding MBs in neighbor view based on inter-view correlation to early terminate the mode decision procedure. Experimental results show that the proposed fast mode decision algorithm can achieve computational 50% computation saving with no significant loss of rate distortion （RD） performance.

Fast mode decision for inter macroblocks in H. 264/AVC

In this paper, a fast mode decision algorithm for inter macroblocks in H.264/AVC is proposed, The algorithm is able to classify all modes by both gradient operator and comparison of space-time correlation. Because only part of modes is used to compare with each other the computational complexity can be reduced greatly. The simulation results show that it takes about 75 % of encoding time for other algorithm with similar visual quality.

Fast inter-mode decision method based on best matching block for H.264 encoding

In H.264 encoder, all possible coding modes should be checked to choose the most appropriate mode for every macroblock, which adds a heavy computation burden to the encoder. In this paper, a fast inter-mode decision method is presented to reduce computation complexity of an H.264 encoder. By detecting the best matching block （BMB） before transform and quantization, some coding modes can be skipped and the corresponding encoding steps can be omitted for these BMBs. Meanwhile this method can also be used to detect all-zero blocks. The experimental results show that this method achieves consistently significant reduction of encoding time while keeping almost the same rate-distortion performance.

Fast mode decision for Hierarchical-B pictures in scalable video coding

To decrease the computational complexity of adaptive inter-layer prediction and improve the encoding efficiency in sealable video coding, a mode decision algorithm is proposed by exploiting the part of used candidate modes of the co-located reference macrobloeks for Hierarchical-B pictures. This scheme reduces the amount of the candidate modes to generate a dynamic list for the current encoding macroblock according to the statistical information derived from the co-located reference macroblocks in different temporal levels. The experimental results show that this fast algorithm reduces approximately 31% encoding time on average with the negligible loss of encoding performance.

Edge Feature Based Fast Mode Decision Algorithm for H.264 Intra Prediction

A fast intra mode decision algorithm is proposed in this paper to reduce the complexity of H. 264 encoder. The proposed algorithm adopted the pre-processing method based on edge feature in pictures to filter out some impossible prediction modes. Context information and pre-computed threshold are used to determine whether it is necessary to check the DC mode. This method is able to get rid of most of candidate modes so that only 66--150 modes are left for the final mode decision, instead of 592 modes in the case of full search （FS） method of H. 264. Simulation results demonstrate that the coding time of the proposed algorithm falls down 71.7% compared with FS method, while the performance loss is trivial compared with FS mode decision scheme.

Mode decision for H.264 down-scaling video transcoding

Although the coding modes of H.264 coded video would be changed by the transcoding process of spatial resolution reduction, there exists good correlation in prediction modes and prediction directions between input and output video. In this paper, we first introduce a new spatial resolution reduction transcoding architecture of intra coded frames where the distortion can be calculated directly in compression domain. We then propose a fast mode decision algorithm in which only a small part of rate distortion optimization （RDO） calculation is needed for mode decision. For 4×4 luma block, the proposed scheme has average 21.3% computation saving, compared to the cascaded pixel-domain transcoding scheme with the fast intra mode decision algorithm proposed in JVT-G013. For 16×16 luma block, RDO calculation is completely avoided in our scheme while the scheme in JVT-G013 needs 2 RDO calculations. Experimental results show that our scheme outperforms that of JVT-G013 in terms of significantly computasavings with negligible loss of PSNR

Application of Fuzzy Decision-Making Theory and Conflict-Resolution Method to Failure Mode and Effect Analysis of Industrial Valve

It is not objective to rate the decision-making factors in the traditional failure mode and effect analysis,so fuzzy semantic theory is used in this paper.Six fuzzy semantic scales and their corresponding semantics are summarized,and a defuzzification method is studied to obtain the fuzzy value table of the six fuzzy semantic scales.For the conflicts between experts in the traditional failure mode and effects analysis,a conflict-resolution algorithm is studied to obtain the failure risk order.Finally,a certain type of industrial valve is used as an example to prove the validity of the theory proposed in this paper.

Research and Application of Maintenance Decision Method of Complex Equipment in Nuclear Power Plant

The determination of maintenance mode of complex equipment in nuclear power plant is an essential work for reliability analysis and maintenance decision. Currently, the main decision method of maintenance mode is reliability centered maintenance( RCM) logic decision-making process, but the process is a qualitative analysis process. Based on a comprehensive analysis of factors affecting equipment reliability and maintenance work, it adopts a fuzzy synthesis decision method to establish a maintenance decision model,which uses the maximum subordination principle and expert assessment method to determine the maintenance mode of complex equipment. Combined with a concrete example of generators in nuclear power plant,a description of maintenance decision method was proposed in the application of complex equipment. The research shows that the method is feasible and reliable.

基于多模态超声建构胎儿先天性心脏病决策树模型及其应用价值

目的:分析基于多模态超声建构胎儿先天性心脏病决策树模型及其应用价值。方法:随机选取2021年4月-2023年7月在本院产前超声检查孕中期孕妇300例,常规产科超声检查确定胎儿生长程度,核实孕周,采用超声多断面模式方法对胎儿心脏进行多断面检测,包括四腔心断面、三血管断面、主动脉弓断面、左室流出道断面、右室流出道断面。对正常分娩的新生儿进行心脏多断面超声检测。对300例胎儿进行多断面模式超声检测,分析胎儿是否伴有先天性心脏畸形,对比超声检查与随访结果符合情况。结果:超声检出21例先天性心脏畸形胎儿,8例选择引产,余13例正常分娩。超声诊断与随访结果对比,卵圆孔直径增大、法洛四联症、完全型心内膜垫缺损、二尖瓣闭锁、右室发育不良综合征、左室发育不良综合征、大动脉转位、永存动脉干、单心室、三尖瓣下移符合率均为100%,超声诊断室间隔缺损7例,随访发现室间隔诊断5例,诊断符合率71.4%。279例超声诊断无先天性心脏畸形胎儿出生后经超声诊断发现有1例卵圆孔未闭、3例室间隔缺损,共4例漏诊患儿,漏诊率0.54%。四腔心断面、三血管断面、主动脉弓断面、左室流出道断面、右室流出道断面诊断胎儿畸形率分别为3.95%、0.63%、2.76%、3.27%、3.25%。由决策树模型可得,产前超声检查发现胎儿心脏可疑异常、高龄孕妇、孕妇接受药物治疗或射线暴露、孕妇有先天性心脏病家族史是胎儿存在先天性心脏病的独立危险因素,其中产前超声检查发现胎儿心脏可疑异常的影响最为显著。结论:孕中期胎儿产前超声多断面模式筛查胎儿先天性心脏病,能够对多数胎儿先天性心脏病进行诊断。

肺癌多学科综合诊治现状及未来方向

尽管肺癌多学科诊疗(multidisciplinary team,MDT)模式能够提高患者的生活质量和生存预后,为何没有达到MDT诊疗模式所预期的目标呢?主要原因是肺癌MDT诊治模式相对滞后于各种治疗手段的进步。分析国内外肺癌MDT诊治最新研究成果,结合四川大学华西医院肺癌中心肺癌MDT诊治经验,本文将从以下几个方面对肺癌MDT的进展及未来发展方向进行讨论和总结:(1)肺癌MDT诊治模式的内涵和外延需要转变并适应新的诊治手段;(2)肺癌MDT诊治临床决策应当从“多学科会诊(multidisciplinary consultation,MDC)”向“MDT”转变;(3)肺癌MDT诊治过程要从“消防队模式”转向“防火墙模式”,并最终实行“个体化全程管理模式”;(4)肺癌MDT诊治路径要从“临时召集模式”向“肺癌单病种中心制模式”转变。

高校智库服务决策的模式构建与高质量发展——基于知识生产模式转型的视角

高校智库服务决策本质上是一种知识生产活动。知识生产模式转型背景下,高校智库服务决策的内涵更加丰富,目标情境、参与主体、研究范式、评价方式等不断变化,展现出诸多新特征。本研究通过对高校智库服务决策特征变化的分析,构建了高校智库服务决策的三种模式:学科中心学术情境下“学—政”互动的专家模式、跨学科应用情境下“智—政”互动的平台模式和超学科适应情境下多边互动的开放模式。在这三种模式演进和共生发展情境下,提出高校智库服务决策实现高质量发展的四条进路:树立符合国家需求与公共利益的服务决策理念,创新多边互动的服务决策组织形式,构建多层次的服务决策研究范式,建立开放多元的服务决策评价体系。

决策支撑服务:新时代高校智慧图书馆高质量转型发展的应然选择

决策支撑服务,既是新时代图书馆满足高校高质量发展所产生责任取向的意识形态,也是智慧图书馆走向高质量发展必须做出的主动选择与回应。如何以决策支撑服务赋能智慧图书馆向高质量发展推进,需要分析影响与制约其向“高”发展的制度政策、组织机制、服务模式、人才支撑、资源配置等核心变量。结合42所“双一流”高校图书馆转型实践,剖析了决策支撑服务所面临的宏观政策、中观治理与微观实践的三重困境,在此基础上,提出了创设前瞻化顶层设计、重构立体化制度体系、形成协同化治理机制、设计精分化服务面向、丰富动态化服务方式、建设智慧化人才队伍的赋能智慧图书馆高质量发展与客观突围的行动举措。

选择集规模对服装网购决策满意度的影响研究

针对企业在竞争激烈的环境下不断细分市场推出越来越多产品种类的问题,文章基于选择超负荷理论,以736名网购用户为被试,采用网页开发技术搭建模拟线上购物平台,通过2项实验重点考察了服装网购情景下选择集规模对决策满意度的影响,并探究消费者困惑和调节模式在这一关系中的作用。结果显示:1)选择集内选项数量与决策满意度的关系呈倒U形结构,且存在一个“最优值”;2)消费者困惑能够在选择集规模与决策满意度的关系中起部分中介作用;3)选择集规模对决策满意度的直接预测作用及消费者困惑在两者关系中的中介作用均会收到调节模式的调节。相比运动模式者,评估模式者从大选择集进行决策时决策满意度更低,更容易出现选择超负荷。

应用J_(mode)值单调性的快速P帧模式选择算法

为了提高编码速度,针对H.264/AVC中运算量较大的P帧模式选择部分,提出了一种新的快速选择算法。该算法依次通过Jmode值单调性检测、基于子块运动向量(MV)的水平与垂直方向选择,这两个步骤逐步缩小候选帧间模式检测范围,同时提出了基于最佳帧间模式的帧内模式选择方法,选择性地检测帧内模式,从而有效避免不必要的模式检测过程。实验结果表明,相对JM中模式全搜索算法,改进算法平均减小了约63.80%的编码时间,而只带来了微小的编码性能损失。

共享决策在剖宫产术后再次妊娠分娩方式中的应用进展

就再次妊娠妇女面临的分娩方式决策挑战以及共享决策在再次妊娠分娩方式中的实施过程、应用效果、阻碍因素和发展策略进行综述,以期为剖宫产术后再次妊娠妇女的分娩管理提供依据。