Alloy gene Gibbs energy partition function and equilibrium holographic network phase diagrams of AuCu_3-type sublattice system

Taking AuCu3-type sublattice system as an example, three discoveries have been presented: First, the third barrier hindering the progress in metal materials science is that researchers have got used to recognizing experimental phenomena of alloy phase transitions during extremely slow variation in temperature by equilibrium thinking mode and then taking erroneous knowledge of experimental phenomena as selected information for establishing Gibbs energy function and so-called equilibrium phase diagram. Second, the equilibrium holographic network phase diagrams of AuCu3-type sublattice system may be used to describe systematic correlativity of the composition?temperature-dependent alloy gene arranging structures and complete thermodynamic properties, and to be a standard for studying experimental subequilibrium order-disorder transition. Third, the equilibrium transition of each alloy is a homogeneous single-phase rather than a heterogeneous two-phase, and there exists a single-phase boundary curve without two-phase region of the ordered and disordered phases; the composition and temperature of the top point on the phase-boundary curve are far away from the ones of the critical point of the AuCu3 compound.

Alloy gene Gibbs energy partition function and equilibrium holographic network phase diagrams of Au_3Cu-type sublattice system

Taking Au3Cu-type sublattice system as an example, three discoveries have been presented. First, the fourth barrier to hinder the progress of metal materials science is that today’s researchers do not understand that the Gibbs energy function of an alloy phase should be derived from Gibbs energy partition function constructed of alloy gene sequence and their Gibbs energy sequence. Second, the six rules for establishing alloy gene Gibbs energy partition function have been discovered, and it has been specially proved that the probabilities of structure units occupied at the Gibbs energy levels in the degeneracy factor for calculating configuration entropy should be degenerated as ones of component atoms occupied at the lattice points. Third, the main characteristics unexpected by today’s researchers are as follows. There exists a single-phase boundary curve without two-phase region coexisting by the ordered and disordered phases. The composition and temperature of the top point on the phase-boundary curve are far away from those of the critical point of the Au3Cu compound; At 0 K, the composition of the lowest point on the composition-dependent Gibbs energy curve is notably deviated from that of the Au3Cu compounds. The theoretical limit composition range of long range ordered Au3Cu-type alloys is determined by the first jumping order degree.

Research on reliability index of a large communication network with domain partition and interconnection

In order to indicate the performances of a large-scale communication network with domain partition and interconnection today, a kind of reliability index weighed by normalized capacity is defined. Based on the route rules of network with domain partition and interconnection, the interconnection indexes among the nodes within the domain and among the domains are given from several aspects. It is expatiated on that the index can thoroughly represent the effect on the reliability index of the objective factor and the subjective measures of the designer, which obeys the route rules of a network with domain partition and interconnection. It is discussed that the defined index is rational and compatible with the traditional index.

Partition coefficient prediction of Baker's yeast invertase in aqueous two phase systems using hybrid group method data handling neural network

A hybrid GMDH neural network model has been developed in order to predict the partition coefficients of invertase from Baker's yeast. ATPS experiments were carried out changing the molar average mass of PEG(1500–6000 Da), p H(4.0–7.0), percentage of PEG(10.0–20.0 w/w), percentage of MgSO_4(8.0–16.0 w/w), percentage of the cell homogenate(10.0–20.0 w/w) and the percentage of MnSO_4(0–5.0 w/w) added as cosolute. The network evaluation was carried out comparing the partition coefficients obtained from the hybrid GMDH neural network with the experimental data using different statistical metrics. The hybrid GMDH neural network model showed better fitting(AARD = 32.752%) as well as good generalization capacity of the partition coefficients of the ATPS than the original GMDH network approach and a BPANN model. Therefore hybrid GMDH neural network model appears as a powerful tool for predicting partition coefficients during downstream processing of biomolecules.

Resource Partitioning and Routing Optimization in Relay Enhanced Cellular Network

A joint routing and resource partitioning scheme were proposed to improve cell capacity and user throughput of cellular network enhanced with two-hop fixed relay nodes (FRNs). Radio resources are partitioned under a reuse partitioning based framework, which guarantees effective and efficient inter-cell interference management. At the same time, each mobile terminal was assigned a channel-dependent route by the routing controller, which tries to maximize the cell capacity under the constraint imposed by reuse partitioning. Intensive computer simulations demonstrate the performance superiority of the FRN enhanced cellular network employing this scheme in comparison with conventional network, as well as the validity of the channel-dependent routing mechanism.

Dynamic Nodes Partition Algorithm for Ad HOC Network

A dynamic nodes partition algorithm for the Ad Hoc network is proposed. Firstly, Roam cluster method is used to cluster 926 random nodes in a square region. Subsequently, the central moving model based on the simulated annealing algorithm and the least circle overlay model is constructed to remove the network redundancy of the circle number and circle radius respectively. Simulation results show that the algorithm can effectively maintain the stability of network structure and increase balancing capabilities of Ad Hoc network load. The future work is to study how to improve the adaptability for the application in the complicated areas.

Clustering in Wireless Multimedia Sensor Networks Using Spectral Graph Partitioning

Wireless multimedia sensor network (WMSN) consists of sensors that can monitor multimedia data from its surrounding, such as capturing image, video and audio. To transmit multimedia information, large energy is required which decreases the lifetime of the network. In this paper we present a clustering approach based on spectral graph partitioning (SGP) for WMSN that increases the lifetime of the network. The efficient strategies for cluster head selection and rotation are also proposed.

System Vulnerability Analysis Using Graph Pathfinding Strategies in Partitioned Networks

In this paper, a new method has been introduced to find the most vulnerable lines in the system dynamically in an interconnected power system to help with the security and load flow analysis in these networks. Using the localization of power networks, the power grid can be divided into several divisions of sub-networks in which, the connection of the elements is stronger than the elements outside of that division. By using our proposed method, the probable important lines in the network can be identified to do the placement of the protection apparatus and planning for the extra extensions in the system. In this paper, we have studied the pathfinding strategies in most vulnerable line detection in a partitioned network. The method has been tested on IEEE39-bus system which is partitioned using hierarchical spectral clustering to show the feasibility of the proposed method.

Reuse Partitioning-Based Frequency Assignment in Fixed Two-Hop Relay Cellular Network

In relay cellular network, relay links will consume extra frequency resources, which makes radio resource allocation become more complex and important. A new frequency allocation scheme is proposed to increase cell capacity and improve signal-to-interference ratio (SIR) of users located at cell edges. By dividing cell into different parts and configuring each of these parts with a unique reuse factor, this scheme improves spectral utilization efficiency and avoids inter-cell interference effectively. Optimal combinations of reuse factors and locations of relay nodes are also addressed and investigated. Computer simulation results show that, by employing the proposed scheme, maximum cell capacity gains of about 50%, 35% and 30% can be achieved in comparison with conventional cellular network scheme, traditional reuse partitioning scheme and reuse-adjacent-cell-frequencies scheme, respectively. Moreover, since in the proposed scheme resources are dynamically allocated among relay nodes, more benefits can be obtained in comparison with fixed resource allocation schemes under non-uniform traffic distribution.

Impact of joint resource partitioning and routing on performance of relay enhanced cellular networks

Radio resource assignment schemes and routing strategies in relay enhanced cellular networks are proposed in this paper. Under the reuse partitioning-based frequency planning framework, the intra-cell resource partitioning between the base station and relay nodes was addressed firstly by introducing a metric of effective reuse factor. Then, coverage-oriented and capacity-oriented rantings, as well as two link bandwidth assignment schemes＂ equal-bandwidth per link＂ and ＂equal-bandwidth per mobile station＂ were developed. These key issues and their impacts on the system performance were analyzed comprehensively and supported by simulations. Results show that the cell capacity and edge user throughput of the proposed network are superior to the traditional non-relay network when an appropriate effective reuse factor is adopted.

Fast CU Partition for VVC Using Texture Complexity Classification Convolutional Neural Network

Versatile video coding(H.266/VVC),which was newly released by the Joint Video Exploration Team(JVET),introduces quad-tree plus multitype tree(QTMT)partition structure on the basis of quad-tree(QT)partition structure in High Efficiency Video Coding(H.265/HEVC).More complicated coding unit(CU)partitioning processes in H.266/VVC significantly improve video compression efficiency,but greatly increase the computational complexity compared.The ultra-high encoding complexity has obstructed its real-time applications.In order to solve this problem,a CU partition algorithm using convolutional neural network(CNN)is proposed in this paper to speed up the H.266/VVC CU partition process.Firstly,64×64 CU is divided into smooth texture CU,mildly complex texture CU and complex texture CU according to the CU texture characteristics.Second,CU texture complexity classification convolutional neural network(CUTCC-CNN)is proposed to classify CUs.Finally,according to the classification results,the encoder is guided to skip different RDO search process.And optimal CU partition results will be determined.Experimental results show that the proposed method reduces the average coding time by 32.2%with only 0.55%BD-BR loss compared with VTM 10.2.

Community-detection-based Approaches for Distribution Network Partition

A rational partition is the key prerequisite for the application of distributed algorithms in distribution networks.This paper proposes community-detection-based approaches to a distribution network partition,including a non-overlapping partition and a border-node partitioning method.First,a novel electrical distance is defined to quantify the coupling relationships between buses and it is further used as the edge weight in a transformed equivalent graph.Then,a vertex/link partition community detection approach is applied to over-partition the network into high intra-cohesive and low inter-coupled subregions.Following this,a greedy algorithm and a tabu search method are combined to merge these subregions into target numbers according to the scale similarity principle.The proposed approaches take the influence of three-phase imbalance into consideration and they are decoupled from the power flow.Finally,the approaches are tested on an IEEE 123-bus distribution system and the results verify the effectiveness and the credibility of our proposed methods.

Betweenness-based algorithm for a partition scale-free graph

Many real-world networks are found to be scale-free. However, graph partition technology, as a technology capable of parallel computing, performs poorly when scale-free graphs are provided. The reason for this is that traditional partitioning algorithms are designed for random networks and regular networks, rather than for scale-free networks. Multilevel graph-partitioning algorithms are currently considered to be the state of the art and are used extensively. In this paper, we analyse the reasons why traditional multilevel graph-partitioning algorithms perform poorly and present a new multilevel graph-partitioning paradigm, top down partitioning, which derives its name from the comparison with the traditional bottom-up partitioning. A new multilevel partitioning algorithm, named betweenness-based partitioning algorithm, is also presented as an implementation of top-down partitioning paradigm. An experimental evaluation of seven different real-world scale-free networks shows that the betweenness-based partitioning algorithm significantly outperforms the existing state-of-the-art approaches.

基于CatBoost算法的配电网分区拓扑辨识

含多分布式电源配电网的拓扑结构具有多样性与多变性,影响拓扑辨识的实时性和准确性。提出一种基于CatBoost算法的配电网分区拓扑辨识方法。构建结合拓扑分区的配电网拓扑辨识框架,采用区域开关状态矩阵描述拓扑结构,以进行物理上的辨识降维;提出基于CatBoost算法的特征选择与拓扑辨识方法,通过分区并行离线训练得到历史拓扑和未知拓扑的区域拓扑辨识CatBoost模型,通过在线应用得到实时的区域开关状态矩阵标签,形成配电网开关状态矩阵,实现系统拓扑辨识。配电网算例系统测试结果验证了所提方法的有效性。

考虑次生故障差异化影响下韧性主动提升的输电系统网架重构策略

近年来,我国能源电力加速转型,极端自然灾害频发,国际形势不稳定,使得常规安全风险与非常规安全风险交织,大停电风险有增加的趋势。稳健可靠的网架重构方案对防止恢复中再次发生系统崩溃具有重要意义,针对当前研究中未有效计及恢复中次生故障的不足,该文提出一种考虑次生故障差异化影响下系统韧性主动提升的网架重构策略。首先,讨论在网架重构恢复方案中考虑次生故障影响的必要性;然后,基于分割多目标风险分析方法提出一种系统韧性指标,旨在差异化处理次生故障并突出高风险故障对恢复过程的影响;进一步建立考虑韧性主动提升的网架重构全局优化模型,以增强系统对高风险故障的抵御能力。为提高模型的求解效率,提出一种基于窗口滚动机制的求解策略,可给出兼顾快速性与稳健性的网架重构方案。最后,采用新英格兰10机39节点系统和IEEE 118节点系统验证所提出方法的有效性。

面向区域自治的配电网动态区域划分方法

具有间隙性及波动性特征的大量分布式光伏接入配电网,为配电网的源荷功率平衡及节点电压调节等带来了新的技术挑战。为充分利用配电网中多类型调节资源的调节能力,提高新能源高比例接入下配电网的自治能力,提出了一种面向区域自治的配电网动态区域划分方法。首先,结合分布式光伏和负荷预测数据,衡量配电网中多类型可调资源的调节能力,建立考虑模块度、电压调节能力和功率持续调节能力的综合指标体系。其次,采用遗传算法求解各区域最优综合指标,结合运行状态及调控需求设计分区结构更新触发机制,更新分区结果。最后,结合实际配电网典型日运行数据的仿真算例及对比分析验证了所提区域动态划分方法在提高区域电压调节能力和功率持续调节能力方面的优势,并分析了不同指标权重,不同触发阈值以及不同时间尺度对分区结果的影响。

基于碎片化分区的桥梁网络震后修复优先级分析与优化

为了研究区域性桥梁的抗震优化问题,针对城市桥梁网络的震后修复优先级,引入基于交通密度的网络碎片化分区方法(FaDPa),提出了考虑恢复性和经济性的双重韧性指标,并针对震后短时抢救以及长时修复的时段特征引入了分阶段优化方法,尤其在长时修复阶段基于不同的修复需求对其进行了分时期处理;在抢险救灾阶段和长时修复阶段分别融入碎片化理论,前者以恢复韧性、时间为目标对抢救顺序进行优化,后者以综合韧性、碎片恢复性、时间对修复顺序进行优化。研究结果表明:基于密度的碎片化理论对桥梁网络不同修复阶段的地震损伤程度做出了不同的划分,此基础上展开的分阶段修复工作在抢险救灾过程中对其综合韧性提升程度达到52.3%,在长期修复过程中不影响韧性优化的前提下增加了碎片恢复性,其功能水平提升可达20.3%;修复优化阶段,经过考虑不同修复方向的双重韧性指标以及分时期处理的优化理论可以根据决策者的需求进行灵活调整,且面临不同修复环境时都具有一定的适应性。

基于高低温分区热管网络的高轨通信卫星散热能力提升方法

针对我国高轨通信卫星不断提升的散热需求,提出采用基于高低温分区热管网络的热设计方法。在分析热管网络散热能力的基础上,进行设备分区布局设计、分区热管网络散热面设计和分区热管网络布局设计。该方法可在保证卫星仪器设备工作温度、不降低热设计可靠性、不增加分系统重量及功率需求的前提下,将卫星散热能力提升15%~20%。文章还结合近些年通信卫星研制中的经验和教训,归纳给出高低温分区热管网络设计中的注意事项,以期为相关工程设计提供有效指导。

考虑通信-物理耦合的有源配网故障后协调恢复策略

针对极端灾害可能使智能配电网信息物理系统中通信网络和物理网络同时发生故障,而现有故障恢复策略处理此类问题时效率低,得不到最优方案。文章提出一种考虑通信-物理耦合关系的有源配电网灾后故障恢复策略,首先利用图论的知识对通信网络和物理网络之间耦合关系进行建模,在此基础上,考虑孤岛划分、网络重构以及动态协调通信-物理系统的检修策略建立了有源配电网通信网络和物理网络协调恢复模型,求解此故障恢复策略得到最优的考虑通信-物理耦合关系的有源配电网灾后协调恢复方案。最后,以通信网与改进的IEEE33节点系统为例,对所提多种优化方案的结果进行分析,验证了该文所提策略的优越性。

极端条件下多源配电网主动孤岛研究综述与展望

高比例分布式电源接入后的故障配电网,具备主动恢复与自治能力,有利于提升电力系统适应气候变化和灾害风险管理的水平,顺应配电网技术的发展方向。当前,配电网主动孤岛自恢复和稳定运行的研究受到广泛关注。首先,概述多源配电网主动孤岛的内涵,以及多源配电网孤岛与微电网孤岛的区别,分析归纳配电网主动孤岛在分布式电源高比例接入下稳定运行存在的关键问题。其次,从主动孤岛划分、孤岛自组网波动平抑控制以及组网完成后主动孤岛小干扰稳定控制3个方面阐述国内外研究现状,并进行总结。最后,基于电力物联网、高电力电子化下的小干扰抑制以及能源互联网背景下的主动孤岛方案,对多源配电网主动孤岛的发展前景进行展望和总结。