Spectral resource defragmentation based on PCE in flexible bandwidth optical networks

The granularity of the flexible bandwidth optical network is the spectral slots,which is much smaller than that of the wavelength switch optical network.For the dynamic clients’ connections setup and tear down processes,it will give rise to fragmentation of spectral resources.It is the decline in the probability of finding sufficient contiguous spectrum for new connections that result in the fragmentation of spectral resource.To be more specific,these spectra may be unavailable and waste.In this case,the severe waste of the spectrum will lead to low efficiency in spectral utilization and will not adapt to large capacity requirements of transmission in the future.Because path computation element(PCE) framework has the characteristics of the central disposal and deployment of the spectrum resource,we construct the spectral resource allocation scenario based on PCE framework in the flexible bandwidth optical network to use spectrum resource effectively.Based on the principle of the generation of the fragmentation,we put forward a spectrum resource defragmentation algorithm to consolidate the available spectrum for clients’ connections.The simulation results indicate that this algorithm is able to reduce fragmentation of network,improve the continuity of spectral resource,reduce the blocking rate of services in the network and improve the spectral efficiency significantly.     

Woody Breast短期贮藏中肉质的变化

为研究近年来速生型肉鸡鸡胸肉硬度缺陷(woody/wooden breast,WB)俗称"木质肉"在短期贮藏中生肉肉质参数的变化。实验选取68只42日龄Cobb 500肉鸡作为研究对象,经宰杀后人工分级为低(normal,NORM)、高(severe,SEV)两组(n=34只/组)。在不同时间节点下(1、3、8 d)对所有样本测定质量、挤压力(compression force,CF)、滴水损失(drip loss,DL)、肌节长度(sarcomere length,SL)及肉破碎化指数(gravimetric fragmentation index,GFI)。对所有参数进行组间(不同WB等级间,不同时间节点)显著性分析,同时对各参数与WB等级间进行相关性分析。结果表明:SEV样本质量、CF、SL、GFI在贮藏时间节点处都显著高于NORM样本(P0.05),DL在1 d时NORM与SEV间无差异,在3~8 d时显著上升(P0.05)。CF、SL、GFI在1~3 d时,所有样本都显著减小(P0.05),3~8 d时CF无显著变化(P0.05),SL、GFI在NORM样本间无差异但在SEV样本间继续减小(P0.05)。相关性分析表明,CF、累积DL与WB等级极显著相关(P0.01),SL、GFI随时间变化与WB硬度减小存在联系。综上可知,SEV生肉肉质较NORM差,WB硬度随贮藏时间变长而减小,但其生肉品质并不会发生改变,因此对WB检测应在宰杀当天在线进行,且WB硬度由多种原因共同作用导致。     

Application of statistical modeling of image spatial structures to automated visual inspection of product quality

Automated visual inspection (AVI) attracts increasing interest in product quality control both academic and industrial communities, particularly on mass production processes, because product qualities of most types can be characterized with their corresponding surface visual attributes. However, many product images in AVI systems are comprised of stochastically accumulative fragmentations (particles) of local homogeneity, without distinctive foregrounds and backgrounds, which brings great challenges in computer analysis, e.g., rice images, fabric images, and consequently, in the intelligent identification of the product qualities. A method of Weibull distribution (WD)-based statistical modeling of image spatial structures (ISSs) to inspect automatically the product quality is presented. The ISS, obtained with multi-scale and omnidirectional Gaussian derivative filters (OGDFs), was demonstrated to be subject to a representative WD model of integral form based on the theory of sequential fragmentation in advance. The WD-model parameters (WD-MPs) of the ISS, with essential human perceptual significance, were extracted as the visual features for product quality identification. The classification performance of the proposed product quality inspection method, namely, the proposed WD-MP features integrated with an introduced spline regression (SR) classifier in this study, was verified on two case studies in the field of the AVI of product quality, namely, automated rice quality classification, and intelligent fabric quality assessment in the corresponding assembly lines of industrial scale. Experimental results indicate that the proposed WD-MP features can effectively characterize the statistical distribution profiles of ISS of complex grain images, piled with a large number of stochastically accumulative fragmentations. The proposed method provides an effective tool for grain image modeling and analysis and consequently lays a foundation for the intelligent perception of product qualities on assembly lines.     

Mathematical programming algorithms for bin packing problems with item fragmentation

In this paper we consider a class of bin packing problems from the literature having the following distinctive feature: items may be fragmented at a price. Problems of this kind arise in diverse application fields like logistics and telecommunications, and have already been extensively tackled from an approximation point of view. We focus on the case in which splitting produces no overhead, a fixed number of bins is given and the number of fragments or fragmentations needs to be minimized. We first investigate the theoretical properties of the problem. Then we elaborate on them to devise mathematical programming models and algorithms, yielding both exact optimization algorithms and effective heuristics. An extensive experimental campaign proves that our approach is very effective, and highlights which features make an instance computationally harder to solve.     

Study on the influence of joint spacing on rock fragmentation under TBM cutter by linear cutting test

Joint spacing is one of the most important geological factors influencing rock fragmentation by TBM cutters and TBM performance. In order to study the influence of joint spacing, full-scale linear cutting tests have been conducted for the Beishan granite samples with different joint spacing (i.e. one intact sample, two jointed samples with joint spacing of 100 mm and 400 mm). For different joint spacing, the influence of penetration depth on rock fragmentation was also explored by varying the penetration depth with an interval of 0.5 mm. During the test process, the three directional forces acting on the TBM cutter were recorded, and the rock chips formed by each cutting pass were weighed, respectively. By analysing the cutting force, crack initiation/propagation and rock chips, the influences of joint spacing on rock fragmentation process by TBM cutter were investigated. The test results showed that the increase of penetration depth cannot improve the TBM breakage efficiency after reaching a certain value for the intact rock sample, and the normal force for intruding the intact rock is larger than that for intruding the rock jointed samples. It is also found that the sample part below the joint plane is intact, thus joint can restrain the crack propagating cross the joint plane and facilitates the chips formation on the cutting surface. For the rock sample with joint spacing of 100 mm, two rock fragmentation modes were found during the cutting process. One mode is that the cracks initiate from the crushed zone under TBM cutter, and the cracks propagate to the joint plane, consequently form large rock chips. The other one is that the cracks initiate from the joint plane and then propagate to the rock cutting surface, and the cracks initiate before the formation of the crushed zone under the cutter. For the rock sample with joint spacing of 400 mm, there are two rock fragmentation stages, i.e., the normal rock fragmentation stage and the joint-controlled rock fragmentation stage. There is a transitional process between these two stages, and also the median crack can be promoted to propagate vertically to joint plane due to the joint existence. This study can provide useful guidance for operation optimization and performance prediction for TBM operating in jointed rock masses.     

Microstructure–strength models for heat treatment of Al–Si–Mg casting alloys I: microstructure evolution and precipitation kinetics

A comprehensive microstructure–strength mathematical model for the heat treatment of Al–Si–Mg casting alloys is presented. As part of the model development, the evolution of microstructure and mechanical properties during heat treatment of an industrially cast A356 aluminium alloy was studied in an extensive experimental investigation. For the solution treatment process, the changes in dendritic composition and eutectic morphology in the temperature range 773–833 K (500–560°C) were quantified using microprobe and image analysis techniques. For natural and artificial ageing, the kinetics of precipitation/clustering was determined using an isothermal calorimetry technique in conjunction with hardness and mechanical property measurements. Two other Al–Si–Mg model alloy compositions were used to study the effects of alloy chemistry on microstructure response during heat treatment. The overall aim of the experimental work presented here is to facilitate the development of a comprehensive microstructure–strength model for the heat treatment of Al–Si–Mg casting alloys that will be presented in part II of this paper.

On présente un modèle mathématique détaillé de la microstructure-résistance du traitement thermique des alliages de moulage d'Al–Si–Mg. Faisant partie du développement du modèle, on a étudié l'évolution de la microstructure et des propriétés mécaniques lors du traitement thermique d'un alliage d'aluminium A356 moulé industriellement lors d'un examen expérimental de grande envergure. Pour le traitement de mise en solution, on a quantifié les changements de la composition dendritique et la morphologie de l'eutectique dans la gamme de température de 773 à 833 K (500 à 560 °C) en utilisant les techniques de la microsonde et de l'analyse d'image. Pour le vieillissement naturel et artificiel, on a déterminé la cinétique de précipitation/agrégation en utilisant une technique de calorimétrie isotherme en conjonction avec les mesures de dureté et de propriétés mécaniques. On a utilisé deux autres compositions de l'alliage modèle d'Al–Si–Mg pour étudier les effets de la chimie de l'alliage sur la réponse de la microstructure lors du traitement thermique. Le but global du travail expérimental présenté ici est de faciliter le développement d'un modèle détaillé de microstructure-résistance du traitement thermique des alliages de moulage d'Al–Si–Mg qui sera présenté dans la seconde partie de cet article.     

Mapping Cohesive Fracture and Fragmentation Simulations to Graphics Processor Units

A graphics processor units(GPU)‐based computational framework is presented to deal with dynamic failure events simulated by means of cohesive zone elements. The work is divided into two parts. In the first part, we deal with pre‐processing of the information and verify the effectiveness of dynamic insertion of cohesive elements in large meshes in parallel. To this effect, we employ a novel and simplified topological data structure specialized for meshes with triangles, designed to run efficiently and minimize memory occupancy on the GPU. In the second part, we present a parallel explicit dynamics code that implements an extrinsic cohesive zone formulation where the elements are inserted ‘on‐the‐fly’, when needed and where needed. The main challenge for implementing a GPU‐based computational framework using an extrinsic cohesive zone formulation resides on being able to dynamically adapt the mesh, in a consistent way, by inserting cohesive elements on fractured facets. In order to handle that, we extend the conventional data structure used in the finite element method (based on element incidence) and store, for each element, references to the adjacent elements. This additional information suffices to consistently insert cohesive elements by duplicating nodes when needed. Currently, our data structure is specialized for triangular meshes, but an extension to tetrahedral meshes is feasible. The data structure is effective when used in conjunction with algorithms to traverse nodes and elements. Results from parallel simulations show an increase in performance when adopting strategies such as distributing different jobs among threads for the same element and launching many threads per element. To avoid concurrency on accessing shared entities, we employ graph coloring. In a pre‐processing phase, each node of the dual graph (bulk elements of the mesh as graph nodes) is assigned a color different from the colors assigned to adjacent nodes. In that fashion, elements of the same color can be processed in parallel without concurrency. All the procedures needed for the insertion of cohesive elements along fracture facets and for computing nodal properties are performed by threads assigned to triangles, invoking one kernel per color. Computations on existing cohesive elements are also performed based on adjacent bulk elements. Experiments show that GPU speedup increases with the number of nodes and bulk elements. Copyright © 2015 John Wiley & Sons, Ltd.     

基于特征性离子快速筛查和识别色胺类新精神活性物质

采用气相色谱-质谱(GC-MS)法和超高效液相色谱-串联四极杆飞行时间质谱(UPLC-QTOF MS)法分析2015~2019年国内检测发现的11种色胺类新精神活性物质。GC-MS在电子轰击源(EI)模式下采集数据,UPLC-QTOF MS在电喷雾正离子(ESI⁺)-碰撞诱导解离(CID)模式下采集数据。通过对目标物质谱裂解产生的特征性离子进行分析,推测了色胺类新精神活性物质可能的碎裂途径,建立了一种快速、便捷筛查和识别色胺类新精神活性物质的方法。     

爆炸冲击能和膨胀能破岩作用机理研究

为研究岩石破碎过程中爆炸应力波与爆生气体膨胀的作用，进行了耦合装药爆破实验。结果表明，耦合装药爆破时爆炸冲击能（Ｅｓ）和部分膨胀能（Ｅｂ）进行冲击加载，在介质中依次激起原生和次生爆炸应力波。不同Ｅｓ／Ｅｂ比值条件下，介质爆破致裂效果与破碎质量出现明显差异的主要原因，是这两个应力波加载水平发生了变化，进而影响到介质的爆破破裂行为。由此认为，Ｅｓ和部分Ｅｂ在破岩过程中所起的主要作用，是通过应力波与缺陷相互作用使岩石产生破裂的方式进行的；以（准）静态形式存在的部分Ｅｂ的主要作用，是促使爆破块度与岩体分离。