基于高维数据优化聚类的长周期峰谷时段划分模型研究

为了使峰谷时段划分结果客观反映出各时段的负荷差异,且能够在一个较长的时间周期(例如1a)内适用,本文提出一种以数据样本集高维化处理和K-均值聚类分析相结合的时段划分模型。首先,通过数据高维化的处理方法构建涵盖较长时间周期(例如1a)内所有负荷信息的数据样本集;其次,以K-均值算法为聚类分析工具,在高维数据样本集上构建峰谷时段划分模型。最后,结合某区全年负荷数据,对所构建的模型进行算例仿真,在验证模型的合理性基础上,最终输出时段划分结果。

高维信息可视化方法研究综述

文章按照高维信息的维数与可视化空间维数对应关系来分类高维信息可视化技术,对现有的高维信息可视化技术方法进行了总结归类,并对如何应用进行了展望。

改进的基于SOM的高维数据可视化算法

通过对高维数据可视化方法的系统研究,提出了一种新的基于自组织映射(Self-Organizing Map,SOM)的算法。为了表现该方法的特点,将其称为三维自组织映射(Three-Dimensional SOM,TDSOM)。它在对高维数据记录集进行SOM分析后将其投影到三维坐标系中的特定的点集上,最终形成三维模型。该模型弥补了传统模型难以清晰准确地展现高维数据的缺陷,并且新模型着重于在一个比二维平面更为广阔的三维立体空间中展现海量数据。使用者通常可以根据当前领域的专业知识在分析模型的基础上得出有意义的模式。新方法可以广泛使用在数据挖掘和模式识别等领域。

基于MSD的图像感兴趣区域自动提取方法研究

将单幅图像数据进行分割,获得高维化后的数据集合,再依据图像数据的最优分解来提取不同图像块之间的数字关联,利用多维尺度分析(MDS)方法来获取单幅图像数据不同块之间的低维表示。通过对此低维表示的自动分析,便可获得图像感兴趣区域的精确位置。的实例验证了方法的可行性、有效性。

铂电极BZ反应体系的系统动力学分析

在一定的条件下 ,将铂电极 BZ化学反应的六变量高维动力学系约化为三变量体系 ,同时对该体系进行了全面的系统动力学分析 .研究结果表明 ,通过改变耦合体系的外控参数条件 ,在将体相保持在均一稳定定态的参数范围内 ,电极反应相可能进入振荡区 ,而呈现出电极反应相与体相的动力学行为不一致性 .进一步计算出体相处于非振荡状态时 ,电极反应相产生电化学振荡的外控参数区域 .

VR高维度数据可视化前导认知教学平台的构建

高维度数据可视化是VR技术的重要组成部分,VR高维度数据可视化作为一门复合技术,融入了计算机图形、多媒体、人机交互、网络、立体显示以及仿真等多种科学技术。可视化的过程虽然受到了美学原理与设计规律的影响,但却没有与传统造型学科发生关联。国内对于传统视觉造型的理论和实践,是在建立的前导认知基础上,利用计算机的先进技术,使其可以在理论知识和实践操作上发挥出应有的作用,但结果并没有发挥出想要的效果。为此,可构建一款基于VR高维度数据可视化的前导认知教学平台,消除专业属性差异上的认知障碍,以高维度数据化造型的方式创新前导认知,提升学生的专业性。

Portal hypertension secondary to myelofibrosis with myeloid metaplasia:A study of 13 cases

AIM:To describe the clinical presentation and complications of portal hypertension (PH) secondary to myelofibrosis with myeloid metaplasia (MMM).METHODS: Medical records for 123 patients with MMM were reviewed.RESULTS: Thirteen patients with PH secondary to MMM were identified. Median ages at time of MMM and PH diagnosis were 61 and 66 years, respectively. The interval from MMM diagnosis to presentation with one of the PH features ranged from 1 to 11 years. Variceal bleeding and ascites were the most common presentations. Of the eight patients who presented with variceal bleeding, six patients underwent endoscopic variceal ligation (EVL) with no variceal recurrence or hematological worsening during a 12-mo follow up period.CONCLUSION: Patients with MMM might develop PH. Exact mechanisms leading to PH in MMM are still controversial. As in other etiologies, variceal bleeding and ascites are the most common presentations. Anemia may correlate with, and/or predict, the severity of the PH presentation in these patients. EVL can successfully control variceal bleeding in MMM. Further clinical studies are required.

Is portal vein cavernous transformation a component of congenital hepatic fibrosis?

Congenital hepatic fibrosis (CHF) is an autosomal recessive disorder that belongs to the family of fibropolycystic liver diseases. This family includes a spectrum of disorders which are usually found in combination with each other and are usually inherited. Clinically fibropolycystic diseases have three effects being present in different proportions, those of a space occupying lesion, of portal hypertension and of cholangitis. In most patients, the first manifestations of CHF are signs and symptoms related to portal hypertension such as splenomegaly and varices. Portal hypertension in these patients has been attributed to the hypoplasia or compression of the portal vein radicles in the fibrous bands. Cavernous transformation of the portal vein (CTPV) is a relatively rare condition resulting from extrahepatic portal vein obstruction with recanalization or collateral vein formation to bypass the obstruction. It has been found that patients with CHF having an accompanying CTPV have relatively large splenomegaly and suffers more frequent episodes of bleeding from esophageal varices.We believe that CTPV is a congenital component of CHF and also one of the important causative factors of portal hypertension in these patients.

Hypergraph High-Dimension Clustering Algorithm for Optimized Cooperative Wireless Multicast

In order to guarantee the wireless multicast throughput at a minimum cost, we propose a layered hypergraph high-dimension clustering algorithm (LayerHC) considering the channels and statistical locations of mobile members. The algorithm can achieve a minimum multicast spanning tree to obtain a minimum number of relays and effective cooperative areas with low computational complexity.

Oxidizing Cellulose to 2,3-Dialdehyde Cellulose by Sodium Periodate

Study on oxidizing cellulose to 2.3-dialdehyde cellulose by sodium periodate （NalO4） was carried out. The effects of reaction conditions such as pH of solution, temperature, oxidant concentration, oxidation time. the particle size of 2,3-dialdehyde cellulose and alkali treatment temperature on the dialdehyde concentration ot cellulose were investigated in detail, The results show that the aldehyde group content was created while reaction temperature and alkali treatment temperature increased. The most principal factors affecting the aldehyde group content of 2,3-dialdehyde cellulose were found out and the best oxidation conditions were as follows： the pH was 2. the reaction temperature was 45℃. the mass ratio of cellulose to NalO4 was 1/2, the reaction time was 4 h, the alkali treatment temperature was 70℃ and smaller particle size was 0.80 mm.

Crystallization of calcium silicate at elevated temperatures in highly alkaline system of Na_2O–CaO–SiO_2–H_2O

In Na_2O–CaO–SiO_2–H_2O system,systematic investigations of phase and morphology of calcium silicate in hydrothermal conditions were concisely conducted for high-value utilization of silicon resource in high-alumina fly ash(HAFA).The results show that crystal composition and phase may be affected by relatively low concentration of NaOH,and sodium ions are rearranged into the structure to form NaCaHSiO_4 and Na_2Ca_3H_8Si_2O_(12) with different C/S ratio at high concentration of Na OH.In addition,phases in wollastonite group possess the morphology of nano fiber.Formation of nano fiber is attributed to the difference of surface energies between axial and radial direction,and higher temperatures lead to easier growth along radial direction.The preparation of C–S–H with different phases and morphologies can guide for the application of silicate solution with high alkalinity with different purposes.

Deformation behavior of high performance fiber reinforced cementitious composite prepared with asphalt emulsion

A novel engineered cementitious composite(ECC) was prepared with the complex binder of Portland cement and asphalt emulsion.By adjusting the amount of asphalt emulsion,different mixture proportions were adopted in experiments,including four-point bending test,compressive test,and scanning electric microscopy(SEM).The SEM observation was conducted to evaluate the contribution of polyvinyl alcohol(PVA) fiber and asphalt emulsion to the composite toughening mechanism.The tests results show that the most remarkable deflection-hardening behavior and saturated multiple cracking are achieved when the content of asphalt emulsion is 10%.However,excessive content of asphalt emulsion causes severe damages on the deformation behavior as well as loss in compressive strength of the mixture.SEM observation indicates that the influence of asphalt emulsion on the fiber/matrix interfacial property changes the dominant fiber failure type from rupture into pull-out mode,and thus causes beneficial effects for strain-hardening behavior.

Dynamic characteristics of high stressed red sandstone subjected to unloading and impact loads

In the process of deep projects excavation,deep rock often experiences a full stress process from high stress to unloading and then to impact disturbance failure.To study the dynamic characteristics of three-dimensional high stressed red sandstone subjected to unloading and impact loads,impact compression tests were conducted on red sandstone under confining pressure unloading conditions using a modified split Hopkinson pressure bar.Impact disturbance tests of uniaxial pre-stressed rock were also conducted(without considering confining pressure unloading effect).The results demonstrate that the impact compression strength of red sandstone shows an obvious strain rate effect.With an approximately equal strain rate,the dynamic strength of red sandstone under confining unloading conditions is less than that in the uniaxial pre-stressed impact compression test.Confining pressure unloading produces a strength-weakening effect,and the dynamic strength weakening factor(DSWF)is also defined.The results also indicate that the strain rate of the rock and the incident energy change in a logarithmic relation.With similar incident energies,unloading results in a higher strain rate in pre-stressed rock.According to the experimental analysis,unloading does not affect the failure mode,but reduces the dynamic strength of pre-stressed rock.The influence of confining pressure unloading on the shear strength parameters(cohesion and friction angle)is discussed.Under the same external energy impact compression,prestressed rock subjected to unloading is more likely to be destroyed.Thus,the effect of unloading on the rock mechanical characteristics should be considered in deep rock project excavation design.

Optimization algorithm for rapid 3D gravity inversion

The practical application of 3D inversion of gravity data requires a lot of computation time and storage space.To solve this problem,we present an integrated optimization algorithm with the following components:(1)targeting high accuracy in the space domain and fast computation in the wavenumber domain,we design a fast 3D forward algorithm with high precision;and(2)taking advantage of the symmetry of the inversion matrix,the main calculation in gravity conjugate gradient inversion is decomposed into two forward calculations,thus optimizing the computational efficiency of 3D gravity inversion.We verify the calculation accuracy and efficiency of the optimization algorithm by testing various grid-number models through numerical simulation experiments.

New Generalized Transformation Method and Its Application in Higher-Dimensional Soliton Equation

A new generalized transformation method is differential equation. As an application of the method, we presented to find more exact solutions of nonlinear partial choose the （3＋1）-dimensional breaking soliton equation to illustrate the method. As a result many types of explicit and exact traveling wave solutions, which contain solitary wave solutions, trigonometric function solutions, Jacobian elliptic function solutions, and rational solutions, are obtained. The new method can be extended to other nonlinear partial differential equations in mathematical physics.

High dimension feature extraction based visualized SOM fault diagnosis method and its application in p-xylene oxidation process

Purified terephthalic acid(PTA) is an important chemical raw material. P-xylene(PX) is transformed to terephthalic acid(TA) through oxidation process and TA is refined to produce PTA. The PX oxidation reaction is a complex process involving three-phase reaction of gas, liquid and solid. To monitor the process and to improve the product quality, as well as to visualize the fault type clearly, a fault diagnosis method based on selforganizing map(SOM) and high dimensional feature extraction method, local tangent space alignment(LTSA),is proposed. In this method, LTSA can reduce the dimension and keep the topology information simultaneously,and SOM distinguishes various states on the output map. Monitoring results of PX oxidation reaction process indicate that the LTSA–SOM can well detect and visualize the fault type.

Failure process and characteristics of three-dimensional high-stress circular tunnel under saturated water content

True-triaxial compression tests were carried out on cubic granite samples with a circular through hole using a true-triaxial testing system to investigate the influence of saturated water content(SWC) on the failure process and characteristics of a circular tunnel of surrounding rocks. The spalling failure under SWC can be divided into four periods: calm period, buckling deformation period, period of rock fragment gradual buckling and exfoliation, and period of formation of symmetrical V-shaped notches. When the horizontal axial and vertical stresses were constant, the spalling failure severity was reduced with the increase in lateral stress. Under natural water content, a strong rockburst with dynamic failure characteristics occurred on the circular hole sidewall. Under SWC, the failure severity was reduced and the circular hole sidewall experienced spalling failure, exhibiting progressive static failure characteristics.Therefore, water can reduce the failure severity of surrounding rocks in deep underground engineering, which has a certain guiding significance for the prevention and control of rockbursts.

Multiple esophageal variceal ruptures with massive ascites due to myelofibrosis-induced portal hypertension

A 75-year old man had been diagnosed at 42 years of age as having polycythemia vera and had been monitored at another hospital. Progression of anemia had been recognized at about age 70 years, and the patient was thus referred to our center in 2008 where secondary myelofibrosis was diagnosed based on bone marrow biopsy findings. Hematemesis due to rupture of esophageal varices occurred in January and February of 2011. The bleeding was stopped by endoscopic variceal ligation. Furthermore, in March of the same year, hematemesis recurred and the patient was transported to our center. He was in irreversible hemorrhagic shock and died. The autopsy showed severe bone marrow fibrosis with mainly argyrophilic fibers, an observation consistent with myelofibrosis. The liver weighed 1856 g the spleen 1572 g, indicating marked hepatosplenomegaly. The liver and spleen both showed extramedullary hemopoiesis. Myelofibrosis is often complicated by portal hypertension and is occasionally associated with gastrointestinal hemorrhage due to esophageal varices. A patient diagnosed as having myelofibrosis needs to be screened for esophageal/gastric varices. Myelofibrosis has a poor prognosis. Therefore, it is necessary to carefully decide the therapeutic strategy in consideration of the patient's concomitant conditions, treatment invasiveness and quality of life.

Kernelized fourth quantification theory for mineral target prediction

This paper presents a nonlinear multidimensional scaling model, called kernelized fourth quantifica- tion theory, which is an integration of kernel techniques and the fourth quantification theory. The model can deal with the problem of mineral prediction without defining a training area. In mineral target prediction, the pre-defined statistical cells, such as grid cells, can be implicitly transformed using kernel techniques from input space to a high-dimensional feature space, where the nonlinearly separable clusters in the input space are ex- pected to be linearly separable. Then, the transformed cells in the feature space are mapped by the fourth quan- tifieation theory onto a low-dimensional scaling space, where the sealed cells can be visually clustered according to their spatial locations. At the same time, those cells, which are far away from the cluster center of the majority of the sealed cells, are recognized as anomaly cells. Finally, whether the anomaly cells can serve as mineral potential target cells can be tested by spatially superimposing the known mineral occurrences onto the anomaly ceils. A case study shows that nearly all the known mineral occurrences spatially coincide with the anomaly cells with nearly the smallest scaled coordinates in one-dimensional sealing space. In the case study, the mineral target cells delineated by the new model are similar to those predicted by the well-known WofE model.

Surface Plasmon Polaritons of Two-Dimensional Three-Order Dendritic Structures

We study surface plasmon polaritons excited on two-dimensional three-order dendritic structures. Previous studies show that split ring resonators （SRRs） can be used to obtain magnetic resonance, thus sustairdng surface waves behaving like surface plasmon polaritons （SPPs）. In this paper, we obtain detailed results on surface plasmon polaritons of several different grating structures and theoretically prove that this kind of structures can sustain SPPs. Besides, since dendritic structures can be fabricated by double template-assisted electrochemical deposition, it is worth noting that fabrication of SPP-based materials might be much easier.