应用改进混合蛙跳算法的实用语音情感识别

针对支持向量机(Support Vector Machine,SVM)的参数优化问题,提出了一种改进的混合蛙跳算法(Improved Shuffled Frog Leaping Algorithm,Im-SFLA),提高了其在实用语音情感识别中的学习能力。首先,我们在SFLA中引入了模拟退火(Simulated Annealing,SA)、免疫接种(Immune Vaccination,IV)、高斯变异和混沌扰动算子,平衡了搜索的高效性和种群的多样性;第二,利用Im-SFLA优化SVM的参数,提出了一种Im-SFLA-SVM方法;第三,分析了烦躁等实用语音情感的声学特征,重点分析了基音、短时能量、共振峰和混沌特征随情感类别的变化特性,构建出144维的情感特征向量并采用LDA降维到4维;最后,在实用语音情感数据库上测试了算法性能,将提出的算法与混合蛙跳算法(Shuffled Frog Leaping Algorithm,SFLA)优化SVM参数的方法(SFLA-SVM方法)、粒子群优化(Particle Swarm Optimization,PSO)算法优化SVM参数的方法(PSO-SVM方法)、基本SVM方法、高斯混合模型(Gaussian Mixture Model,GMM)方法和反向传播(Back Propagation,BP)神经网络法等进行对比。实验结果表明,采用Im-SFLA-SVM方法的平均识别率达到77.8%,分别高于SFLA-SVM方法、PSO-SVM方法、SVM方法、GMM方法和BP神经网络法各1.7%,2.7%,3.4%,4.7%,7.8%,并且对于烦躁这种实用情感的识别率提高效果最为明显,从而证实了Im-SFLA是一种有效的SVM参数选择方法,并且Im-SFLA-SVM方法能显著提升实用语音情感的识别率。     

Managing pharmaceuticals delivery service using a hybrid particle swarm intelligence approach

Medicines or drugs have unique characteristics of short life cycle, small size, light weight, restrictive distribution time and the need of temperature and humidity control (selected items only). Thus, logistics companies often use different types of vehicles with different carrying capacities, and considering fixed and variable costs in service delivery, which make the vehicle assignment and route optimization more complicated. In this study, we formulate the problem to a multi-type vehicle assignment and mixed integer programming route optimization model with fixed fleet size under the constraints of distribution time and carrying capacity. Given non-deterministic polynomial hard and optimal algorithm can only be used to solve small-size problem, a hybrid particle swarm intelligence (PSI) heuristic approach, which adopts the crossover and mutation operators from genetic algorithm and 2-opt local search strategy, is proposed to solve the problem. We also adapt a principle based on cost network and Dijkstra’s algorithm for vehicle scheduling to balance the distribution time limit and the high loading rate. We verify the relative performance of the proposed method against several known optimal or heuristic solutions using a standard data set for heterogeneous fleet vehicle routing problem. Additionally, we compare the relative performance of our proposed Hybrid PSI algorithm with two intelligent-based algorithms, Hybrid Population Heuristic algorithm and Improved Genetic Algorithm, using a real-world data set to illustrate the practical and validity of the model and algorithm.

     

Effects of gamma-irradiation and air annealing on Yb-doped Y3Al5O12 single crystal

The effects of gamma-irradiation on the air-annealed 10at.% Yb:Y(3)Al(5)O(12) (YAG) and air annealing on the gamma-irradiated 10at.% Yb:YAG have been studied by the difference absorption spectra before and after treatment. The gamma-irradiation and air annealing led to opposite changes of the absorption properties of the Yb:YAG crystal. After air annealing, the gamma-irradiation induced centers were totally removed and the concentration of Fe(3+) and Yb(3+) were lightly increased. For the first time, the gamma-irradiation induced valence changes between Yb(3+) and Yb(2+) ions in Yb:YAG crystals have been observed.     

Oxidative Dissolution of Resoles: A Versatile Approach to Intricate Nanostructures

Resoles are resins obtained by base‐catalyzed phenol–formaldehyde condensation with a three‐dimensional cross‐linked framework. They are considered as highly chemical‐resistant, and calcination is thus generally used in the treatment of resole‐type resins, which significantly limits the diversity of nanostructured materials that can be derived from resole‐type resins. Herein, we report that selected metal nitrate solutions can be used to dissolve various types of nanostructured resoles through an oxidative dissolution process. This strategy not only enables the controlled dissolution of resoles, but more importantly provides a new approach to selectively etch resole‐based nanocomposites to give rise to a variety of nanostructured materials with unprecedented architectures and great potential in bioapplications.     

How rigid are conjugated non-ladder and ladder polymers?

Persistence length is commonly used to quantitatively describe the chain rigidity of macromolecules, which represents an important structural parameter governing many physical properties of polymers. Although the mathematical models and experimental measurements on the chain rigidity of conventional single stranded polymers have been well explored and documented, those of the more rigid yet highly intriguing multiple stranded polymers, especially conjugated ladder polymers, are yet not well established. This article introduces the fundamental concepts on macromolecular chain rigidity, as well as the corresponding experimental methods, models, and simulations. Subsequently, representative examples of works done on the chain rigidity of nonladder conjugated polymers and conjugated ladder polymers are reviewed. Last but not least, it provides outlooks on the challenges with respect to the less-investigated chain rigidity of conjugated ladder polymers, including new models to describe and predict chain conformation, synthetic control on structural defects, and insights into the correlation of rigidity and applications.     

Influence of embedded boron nitride nanosheets on Fe3+ diffusion in Fricke gel dosimeter and its response to γ rays

Journal of Radioanalytical and Nuclear Chemistry - The Fe3+ diffusion in Fricke gel dosimeter, widely used for the measurement of accurate dose distributions in radiotherapy, results in a gradual...     

N-Heterocyclic Carbene Stabilized Dicarbondiphosphides: Strong Neutral Four-Membered Heterocyclic 6π-Electron Donors

In contrast to cyclic π-conjugated hydrocarbons, the coordination chemistry of inorganic heterocycles is less developed. Dicarbondiphosphides stabilized by N-heterocyclic carbenes (NHCs) NHC→C₂P₂←NHC ( 1 a , b ) (NHC=IPr or SIPr) contain a four-membered C₂P₂ ring with an aromatic 6π-electron configuration. These heterocycles coordinate to a variety of complex fragments with metals from groups 6, 9, and 10, namely [M⁰(CO)₃] (M=Cr, Mo), [Co^I(CO)₂]⁺, or [Ni^IIBr₂], through an η⁴-coordination mode, leading to complexes 2 a , b , 3 a , b , 5 a , b , and 6 a , b , respectively. These complexes were characterized by X-ray diffraction methods using single crystals, IR spectroscopy, and DFT calculations. In combination these methods indicate that 1 a , b behave as exceptionally strong 6π-electron donors.     

Enhanced nigrostriatal neuron-specific,long-term expression by using neural-specific promoters in combination with targeted gene transfer by modified helper virus-free HSV-1 vector particles

Background  

Direct gene transfer into neurons has potential for developing gene therapy treatments for specific neurological conditions, and for elucidating neuronal physiology. Due to the complex cellular composition of specific brain areas, neuronal type-specific recombinant gene expression is required for many potential applications of neuronal gene transfer. One approach is to target gene transfer to a specific type of neuron. We developed modified Herpes Simplex Virus (HSV-1) particles that contain chimeric glycoprotein C (gC) – glial cell line-derived neurotrophic factor (GDNF) or brain-derived neurotrophic factor (BDNF) proteins. HSV-1 vector particles containing either gC – GDNF or gC – BDNF target gene transfer to nigrostriatal neurons, which contain specific receptors for GDNF or BDNF. A second approach to achieve neuronal type-specific expression is to use a cell type-specific promoter, and we have used the tyrosine hydroxylase (TH) promoter to restrict expression to catecholaminergic neurons or a modified neurofilament heavy gene promoter to restrict expression to neurons, and both of these promoters support long-term expression from HSV-1 vectors. To both improve nigrostriatal-neuron specific expression, and to establish that targeted gene transfer can be followed by long-term expression, we performed targeted gene transfer with vectors that support long-term, neuronal-specific expression.     

肽自组装水凝胶的制备及在生物医学中的应用

短肽自组装水凝胶作为一种新型的生物材料,具有生物相容性高、免疫原性低、含水量高、降解产物可被机体重吸收利用、结构与天然细胞外基质类似等优点,使其在材料科学、生物医药及临床医学等领域具有广阔的应用前景。在这篇综述中,我们主要介绍了常用的几种制备稳定的肽自组装水凝胶方法,包括酶催化的水凝胶化、化学/物理交联的水凝胶化以及光催化的水凝胶化。进一步,我们介绍一些关于肽自组装水凝胶在药物递送和抗肿瘤治疗、抗菌和伤口愈合以及3D生物打印和组织工程中的应用。我们希望通过本文的论述能引起更多的人对肽自组装水凝胶的关注,以推进其在生物医学领域应用的发展。     

Recent Advances in DNA-Based Cell Surface Engineering for Biological Applications

Due to its excellent programmability and biocompatibility, DNA molecule has unique advantages in cell surface engineering. Recent progresses provide a reliable and feasible way to engineer cell surfaces with diverse DNA molecules and DNA nanostructures. The abundant form of DNA nanostructures has greatly expanded the toolbox of DNA-based cell surface engineering and gave rise to a variety of novel and fascinating applications. In this review, we summarize recent advances in DNA-based cell surface engineering and its biological applications. We first introduce some widely used methods of immobilizing DNA molecules on cell surfaces and their application features. Then we discuss the approaches of employing DNA nanostructures and dynamic DNA nanotechnology as elements for creating functional cell surfaces. Finally, we review the extensive biological applications of DNA-based cell surface engineering and discuss the challenges and prospects of DNA-based cell surface engineering.