对计算水平分层介质响应正交归一化法的改进

汪荣江提出一个简单的正交归一化技术来克服经典的Thomson-Haskell传播矩阵方法中存在的数值不稳定问题.为了进一步提高计算效率,给出该方法的2种改进.一种改进方法是将传播矩阵中与频率无关的部分分离出来,对于某一固定的水平慢度,这些矩阵只需计算一次;另一个改进是利用Langer块对角化的技术,将传播矩阵分解为几个稀疏矩阵的乘积.我们将改进之后的算法应用于计算水平分层模型中的广义反射系数.较之原有方案,提出的改进能节省一半计算时间.     

基于ADS的微带抽头式发夹型带通滤波器的设计

微带滤波器在通信系统中起着非常重要的作用,其性能的好坏直接影响着整个通信系统的性能。传统的设计滤波器的方法要通过理论进行大量的计算,计算过程繁杂。文章简要介绍了微带抽头式发夹型带通滤波器的设计理论以及如何通过ADS软件进行设计和优化仿真,并结合具体实例验证其可行性。     

An efficient micromixer based on multidirectional vortices due to baffles and channel curvature

An efficient planar micromixer based on multidirectional vortices in a curved channel with radial baffles is proposed and examined in this work. The curvature of the microchannel and the radial baffles induce vortices in different directions. The multidirectional vortices and the converging-diverging flow caused by the baffles contribute together to the enhancement of mixing. The micromixer is fabricated with polydimethylsiloxane by a single planar microlithography process and the mixing behaviors are observed by a confocal spectral microscope imaging system to validate the simulation obtained by a commercial code. The simulation and experimental results are in reasonable agreement. The concentration distributions and flow patterns obtained reveal the following trends. (i) The mixing efficiency of the basic C-shaped micromixer with the first baffle attached to the internal cylinder and the second attached to the external cylinder is better than that of the C-shaped micromixer with inverted arrangement of baffles. (ii) When the radius of the curved channel and the width of the passage between the baffle and the cylindrical wall are small enough and the Reynolds number (Re) is large enough, an extra separation vortex develops in the downstream of the second baffle. This phenomenon is one of the reasons of trend (i). (iii) A micromixer consisting of a few basic C-shaped micromixers connected by straight channels may generate a high degree of mixing for the case with a large Re.     

基于文献的科学发现计算性研究

利用文献计量方法结合知识可视化技术,通过绘制科学知识图谱计量分析了"文献"与"发现"之间的关系,并系统地展示了基于文献的科学发现的发展与现状,明确了实现基于文献的科学发现计算性的现实基础,包括由Swanson所提出的以非相关文献为基础的知识发现理论的研究,以及以相关文献为基础的科学发现的研究,尤其是应用科学计量学方法对科学发展前沿和热点的感知与识别的研究,这些研究为科学发现计算性的实现提供了参考。最后,在研究现状分析的基础上,提出一种计算机模拟结合可视化技术计量文献的新视角,并且提出了实现基于文献的科学发现计算的途径。     

基于N/8点FFT核的MDCT/IMDCT快速实现方案

数字音频编解码系统采用MDCT/IMDCT实现时间－频率域的互换,以消除音频分帧引起的时间域混叠效应。本文提出一种新的MDCT/IMDCT快速实现方案,基于N/8点FFT变换核,采用奇偶双路并行和蝶型单元技术,与现有快速算法相比,运算速度和吞吐能力均提高一倍,并且该方案既可以实现MDCT正变换,也可以实现相应的反变换。为了验证方案的正确性,在Altera FPGA开发板上完成了N=256点MDCT的实验,结果表明,该实现方案在运算速度和数据吞吐率等方面取得很大的改进。     

An efficient simulation of the fractional chaotic system and its synchronization

The computational complexity of the numerical simulation of fractional chaotic system and its synchronization control is O(N²) compared with O(N) for integer chaotic system, where N is step number and O is the computational complexity. In this paper, we propose optimizing methods to solve fractional chaotic systems, including equal-weight memory principle, improved equal-weight memory principle, chaotic combination and fractional chaotic precomputing operator. Numerical examples show that the combination of these algorithms can simulate fractional chaotic system and synchronize the fractional master and slave systems accurately. The presented algorithms for simulation and synchronization of fractional chaotic system are up to 1.82 and 1.75 times faster than the original implementation respectively.     

An efficient page ranking approach based on vector norms using sNorm(p) algorithm

In the whole world, the internet is exercised by millions of people every day for information retrieval. Even for a small to smaller task like fixing a fan, to cook food or even to iron clothes persons opt to search the web. To fulfill the information needs of people, there are billions of web pages, each having a different degree of relevance to the topic of interest (TOI), scattered throughout the web but this huge size makes manual information retrieval impossible. The page ranking algorithm is an integral part of search engines as it arranges web pages associated with a queried TOI in order of their relevance level. It, therefore, plays an important role in regulating the search quality and user experience for information retrieval. PageRank, HITS, and SALSA are well-known page ranking algorithm based on link structure analysis of a seed set, but ranking given by them has not yet been efficient. In this paper, we propose a variant of SALSA to give sNorm(p) for the efficient ranking of web pages. Our approach relies on a p-Norm from Vector Norm family in a novel way for the ranking of web pages as Vector Norms can reduce the impact of low authority weight in hub weight calculation in an efficient way. Our study, then compares the rankings given by PageRank, HITS, SALSA, and sNorm(p) to the same pages in the same query. The effectiveness of the proposed approach over state of the art methods has been shown using performance measurement technique, Mean Reciprocal Rank (MRR), Precision, Mean Average Precision (MAP), Discounted Cumulative Gain (DCG) and Normalized DCG (NDCG). The experimentation is performed on a dataset acquired after pre-processing of the results collected from initial few pages retrieved for a query by the Google search engine. Based on the type and amount of in-hand domain expertise 30 queries are designed. The extensive evaluation and result analysis are performed using MRR, [email protected], MAP, DCG, and NDCG as the performance measuring statistical metrics. Furthermore, results are statistically verified using a significance test. Findings show that our approach outperforms state of the art methods by attaining 0.8666 as MRR value, 0.7957 as MAP value. Thus contributing to the improvement in the ranking of web pages more efficiently as compared to its counterparts.     

An efficient algorithm for partial fraction expansion of the linear matrix pencil inverse

A new algorithm for computations of matrix partial fractions representing the inverse of linear matrix pencil is based on an appropriate expression in matrix form of the Pascal triangle. It concerns singular and nonsingular systems and starts with the inverse of regular matrix linear pencil M(s) = sA₀ - A where only A₀ is singular, or both A₀ and A are singular. Nonsingular systems are considered as a particular case of singular systems. The presented algorithm of the matrix partial fraction expansion is suitable to determine the matrix transfer function, and is computer oriented because all manipulations can be performed on matrices with constant entries only.     

An efficient method of Yarrowia lipolytica immobilization using oil- and emulsion-modified bacterial cellulose carriers

BackgroundYarrowia lipolytica is a nonconventional, dimorphic yeast with multiple biotechnological applications. Considering the size of Y. lipolytica cells and a plethora of its morphological forms (spherical cells or hyphae and pseudohyphae), it is highly difficult to select a suitable carrier for this useful microorganism. Bacterial cellulose (BC) is currently considered one of the most promising immobilization carriers. In the current study, the usefulness of oil- and emulsion-modified BCs as a carrier for Y. lipolytica immobilization was investigated. Static and agitated cultures were conducted in media supplemented with oil or emulsion to improve carrier porosity.ResultsIt was found that the application of oil- and emulsion-modified BCs correlated with significantly higher efficiency of Y. lipolytica immobilization and hence higher yield than the yield achieved with an unmodified carrier. Increased efficiency of immobilization correlated with BC porosity-related parameters, which, in turn, depended on the size of oil droplets introduced into the culture medium. Moreover, changes in porosity-related parameters caused by the addition of oil or emulsion to the medium were observed when the cultures were conducted only under static conditions and not under agitated conditions.ConclusionThe application of oil- and emulsion-modified BCs as carriers significantly increased the efficiency of Y. lipolytica immobilization as compared to unmodified BC. The addition of oil or emulsion to the culture medium can be a simple but effective method to modify the porosity of BC-based carriers.How to cite: Żywicka A, Wenelska K, Junka A, et al. An efficient method of Yarrowia lipolytica immobilization using oil- and emulsion-modified bacterial cellulose carrier. Electron J Biotechnol 2019;41. https://doi.org/10.1016/j.ejbt.2019.06.004.     

An efficient IoT-based perspective view of food traceability supply chain using optimized classifier algorithm

The food industry is composed of a complex network of processing food and supply to the market. Supplying the food product to the market requires logistics with its operations. Nowadays the management of the food supply chain plays a vital role. In the food industry, supplying food with high quality and minimizing cost is required throughout the implementation of supply chain management. The quality of food is an essential thing for tracing the issues in food safety. Due to the increase in demand for quality food products by consumers IoT-based Food Supply Chain Management (FCM) is required for satisfying the consumer's needs. The IoT-based FCM helps the suppliers in the aspects of managing food safety procedures and tackling the issues in food safety, monitoring the lifespan of food on the manufacturing side, analyzing the process of reproduction or farming of raw material, warehousing, transporting the food product, sales in wholesaler etc. The main aim of using IoT is to receive sensor signals for monitoring the proper growth of crops in good quality soil, weather status, and so on. Also, in the transporting of food products, the sensors, and Radio-Frequency Identification (RFID) tags transmit the information to the server for monitoring the food safety parameters like temperature level, frozen level, etc. The issues are unsafe, ambiguous, the cost is high, low quality, and inaccurate. To overcome these issues, this paper proposed Internet of Things (IoT) based Food Supply Chain management is implemented. This paper proposes Tree-Augmented Naïve Bayes (TANB) with particle swarm optimization algorithm (TANB-PSO). This proposed work uses IoT which track, trace and manages the operations of food supply chain management. TANB-PSO handles optimized chronological data with IoT. The accuracy rate of three models in the FSCM of our proposed work TANB-PSO produces a higher accuracy rate of 95.02%. TANB got 92.44%, and PSO got 93.68%. The error rate of root mean square error (RMSE) and mean error (MAE) for the proposed work TANB-PSO is 0.017 and 0.031.     

创设高效体育课堂的思考

在体育课堂教学活动中,体育教师的备课、学生的学习兴趣、有效的课堂组织、教师的指导用语、经常的课后反思,这些是响体育课堂效率的因素。如何使学生在有限的教学单位时间内掌握良好的运动技能和学到更多的体育知识,使体育课堂教学达到最优效果,需要不断地去探索与研究。     

An efficient method for the retrieval of objects by topological relations in spatial database systems

In this paper, we present a new method to improve the performance of query processing in a spatial database. The previous approach can process the retrieval of spatial objects by topological relations using R-tree structures based on minimum bounding rectangles. In our approach, we add internal rectangle to the leaf nodes of the R-tree as additional information for helping objects retrieval. As a result, the number of false hits can be reduced and part of the true hits can be identified at the early stage of searching. The experiments demonstrated that the performance of database systems can be improved because both the number of objects accessed and the number of objects requiring detailed inspection are much less than those in the previous approach.     

Making the development of technological innovations more efficient: An exploratory analysis in the biotechnology sector

The current study analyzes the processes involved in obtaining technological innovations. Conclusive results are lacking in the literature, so this work defines and empirically tests a model of the relations between the firm's innovative capacity and the different ways of accumulating knowledge and the decision whether or not to codify it. Also, the model takes into account whether the innovations obtained are radical or incremental.The empirical study uses a sample of Spanish biotechnology firms, and the results show that accumulating knowledge using internal sources and not codifying it significantly improves the firm's capacity to develop radical innovations. The results also show that knowledge codification speeds up the development of incremental innovations. The relation between incremental innovations and the sources of knowledge is not so clear, although the results suggest the possible existence of a nonlinear relation between the two variables.     

缺电子Rh-BINAP催化剂催化氢化富电性底物的机理研究

合成了4种富电性的脱氢α-氨基酸衍生物,将缺电子催化剂Rh-3,5-CF3- (R) -BINAP用于这几种底物的不对称氢化反应中.讨论了底物上取代基及空间位阻对对映选择性的影响.     

An efficient solution of hamiltonian boundary value problems by combined gauss pseudospectral method with differential continuation approach

Our paper deals with an effective application of the pseudospectral method to solution of Hamiltonian boundary value problems in optimal control theory. The developed numerical methodology is based on the celebrated Gauss pseudospectral approach. The last one makes it possible to reduce the conventional Hamiltonian boundary value problem to an auxiliary algebraic system. The implementable algorithm we propose is computationally consistent and moreover, involves numerically tractable results for a relative small discretization grids. However, the solution of the obtained algebraic equations system may has a low convergence radius. We next use the differential continuation approach in order to weaken the necessity of the well-defined initial conditions for the above algebraic system. The presented solution procedure can be extremely useful when the generic shooting-type methods fail because of sensitivity or stiffness. We discuss some numerical results and establish the efficiency of the proposed methodology.     

An efficient smart data mining framework based cloud internet of things for developing artificial intelligence of marketing information analysis

Because of the big volume of marketing data, a human analyst would be unable to uncover any useful information for marketing that could aid in the process of making decision. Smart Data Mining (SDM), which is considered an important field from Artificial Intelligence (AI) is completely assisting in the performance business management analytics and marketing information. In this study, most reliable six algorithms in SDM are applied; Naïve Bayes (NB), Logistic Regression (LR), Random Forest (RF), Support Vector Machine (SVM), ID3, and C4.5 on actual data of marketing for bank that taken from Cloud Internet of Thing (CIoT). The objectives of this study are to build an efficient framework to increase campaign of marketing for banks by identifying main characteristics that affect a success and to test the performance of CIoT and SDM algorithms. This study is expected to enhance the scientific contributions to investigating the marketing information capacities by integrating SDM with CIoT. The performances of SDM algorithms are calculated by eight measures; accuracy, balance accuracy, precision, mean absolute error, root mean absolute error, recall, F1- Score and running time. The experimental findings show that the proposed framework is successful, with higher accuracies and good performance. Results revealed that customer service & marketing tactics are essential for a Company’ success & survival. Also, the C4.5 has accomplished better achievement than the SVM, RF, LR, NB, & ID3. At the end, CIoT Platform was evaluated by response time, request rate & processing of bank data.     

浅谈西红花对生长环境的适应性及其生药鉴别

西红花(藏红花、番红花)(Crocus sativus L.)，为鸢尾科植物西红花的柱头，是名贵的中药材，现我国部分地区引种成功，但西藏并没有种植栽培的历史。因此，研究和探讨西红花在西藏引种栽培成功的条件及其在性状和药理方面的优缺点，对以后发展以西红花为主要经济实体的实业具有十分重要的意义。     

基于日志式文件系统的数据修复模型

被入侵或遭受攻击后的计算机系统,其磁盘数据往往会遭到篡改、删除等恶意修改,而这些数据通常是非常宝贵的,因此数据恢复技术尤为重要。现有的数据恢复技术在很多方面存在不足,这是因为主流文件系统其设计本身并不利于数据恢复。针对上述问题,发现日志式文件系统设计有利于实施高效的数据恢复算法,从理论上分析了它有利于进行数据恢复的原因,设计了基于日志式文件系统的数据恢复算法模型,并在开发的日志式文件系统模拟器和真实环境中分别进行了算法测试。实验表明,日志式文件系统可以容易地实现恢复迅速、对系统性能影响轻微、无需额外存储机制的数据恢复算法。