Hybrid intelligent framework for one-day ahead wind speed forecasting

Neural Computing and Applications - Nowadays wind power is considered as one of the fastest growing alternative energies, that is expected to continue to grow rapidly in the upcoming...     

Object segmentation and labeling by learning from examples

We propose a system that employs low-level image segmentation followed by color and two-dimensional (2-D) shape matching to automatically group those low-level segments into objects based on their similarity to a set of example object templates presented by the user. A hierarchical content tree data structure is used for each database image to store matching combinations of low-level regions as objects. The system automatically initializes the content tree with only "elementary nodes" representing homogeneous low-level regions. The "learning" phase refers to labeling of combinations of low-level regions that have resulted in successful color and/or 2-D shape matches with the example template(s). These combinations are labeled as "object nodes" in the hierarchical content tree. Once learning is performed, the speed of second-time retrieval of learned objects in the database increases significantly. The learning step can be performed off-line provided that example objects are given in the form of user interest profiles. Experimental results are presented to demonstrate the effectiveness of the proposed system with hierarchical content tree representation and learning by color and 2-D shape matching on collections of car and face images.     

Pilot-plant results of the electro-Fenton treatment of olive mill wastewaters followed by anaerobic digestion.

In this work, we investigated an integrated technology for the treatment of the recalcitrant contaminants of olive mill wastewaters (OMW), allowing water recovery and reuse for agricultural purposes. The method involves an electrochemical pre-treatment step of the wastewater using the electro-Fenton reaction followed by an anaerobic bio-treatment. The electro-Fenton pre-treatment process removed 66% of the total polyphenolic compounds and subsequently decreased the OMW toxicity from 100 to 66.9%, which resulted in improving the performance of the anaerobic digestion. A continuous laboratory-scale methanogenic reactor was operated at a loading rate of 10g COD/L per day without any apparent toxicity. Furthermore, in the combined process, a high overall reduction in COD, suspended solids, polyphenols and lipids content was achieved by the two successive stages. Moreover, this combined process which was experimented at a real scale (25 m3 digester) demonstrated its technical feasibility and opens promising perspectives for industrial application in the Mediterranean countries because of its easy conception and high energy (methane) production.     

On an evolutionary approach for constrained optimization problem solving

Over the last few decades, many different evolutionary algorithms have been introduced for solving constrained optimization problems. However, due to the variability of problem characteristics, no single algorithm performs consistently over a range of problems. In this paper, instead of introducing another such algorithm, we propose an evolutionary framework that utilizes existing knowledge to make logical changes for better performance. The algorithmic aspects considered here are: the way of using search operators, dealing with feasibility, setting parameters, and refining solutions. The combined impact of such modifications is significant as has been shown by solving two sets of test problems: (i) a set of 24 test problems that were used for the CEC2006 constrained optimization competition and (ii) a second set of 36 test instances introduced for the CEC2010 constrained optimization competition. The results demonstrate that the proposed algorithm shows better performance in comparison to the state-of-the-art algorithms.     

AES and XPS study on the tarnishing of silver in alkaline sulphide solutions

Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) were used to follow the changes that occur on the surfaces of silver sheets when reacting with sulphide solutions of pH 12. The results obtained enabled conclusions to be drawn about the nature of the Ag₂S films. Immersion in dilute sulphide solutions ( 3 × 10^–4 M) resulted in highly irregular films that were interrupted by shallow depressions (cavities). Inside these cavities AES analysis proved the existence of massive carbon species, the presence of which delayed healing of the cavities by the formation of Ag₂S film, thus allowing the silver metal interface to continue in contact with the solution oxygen. This explains why silver electrodes maintain the Ag/Ag₂O potential while immersed in dilute sulphide solutions. Equilibration of silver with more concentrated sulphide solutions (5 × 10^–4 to 5 × 10^–3 M) effected healing of the cavities through the formation of a continuous Ag₂S film. Once this continuous film is formed, the metal interface is no longer accessible to the solution oxygen. At this point the transition of potential from Ag/Ag₂O to Ag/Ag₂S occurs.     

Effect of particle dimension on biocompatibility of carbon nanomaterials

With various emerging applications ranging from medicine to materials and electronics, the risk of exposure to nanomaterials is rapidly increasing. Several routes of exposure to nanomaterials exist; the most important being dermal contact and inhalation. In this dermal toxicity study, the cellular effects of carbon-based materials with diameters ranging from micro- to nano-dimension were investigated using mouse keratinocytes (HEL-30). The carbon materials tested included carbon fibers (CF; 10 μm diameter), carbon nanofibers (CNF; 100 nm diameter), multi-walled carbon nanotubes (MWCNT; 10 nm diameter), and single-walled carbon nanotubes (SWCNT; 1 nm diameter). CF and CNF did not significantly affect cell viability; however, MWCNT and SWCNT reduced cell viability in a time-dependent manner up to 48 h, with full recovery of mitochondrial function by the 72 h time point. After a 24 h exposure, cells exposed to MWCNT produced up to 3-fold higher increase in reactive oxygen species than those exposed to SWCNT. The results of this study suggest that high-aspect ratio carbon material toxicity is dependent on dimension and composition.     

Radiation crosslinking of linear polyethyleneimine-based nanoparticles grafted to poly(glycidyl methacrylate) via trimethylolpropane triacrylate as potential electronic packaging material

Linear polyethyleneimine (L-PEI)-based nanoparticles were synthesized via hydrolysis of poly-2-methyl-2-oxazoline (PMeOx), which was prepared by cationic ring-opening polymerization of the oxazoline five-membered ring. Herein, a kinetic study of the ring-opening polymerization reaction is discussed. The nuclear magnetic resonance spectrum of PMeOx verified the presence of repeating units and terminal groups in the polymer's structure. Molar ratios of PEI and PMeOx were characterized using size exclusion chromatography with low-polydispersity polymer chains as the controlled polymerization reaction. PEI and PMeOx exhibited narrow particle size distribution with hydrodynamic radii of 89 and 67 nm, respectively, as determined via dynamic light scattering analysis. In addition, atomic forces and scanning electron microscopy were used to investigate the topography of the PEI thin films. Poly(glycidyl methacrylate) P(GMA) was grafted onto a PEI chain in the presence of trimethylolpropane triacrylate (TMPTA) as the crosslinking agent to synthesize the P(GMA–PEI–TMPTA) tripolymer via free radical polymerization using gamma irradiation. The thermal characterization of the P(GMA–PEI–TMPTA) tripolymer was conducted using thermogravimetric analysis and differential scanning calorimeter. Generally, the thermal stability of the P(GMA–PEI–TMPTA) tripolymer was improved at low-glycidyl methacrylate concentrations. The prepared tripolymer could be used as effective packaging materials for electronics industries.     

搞定双核处理器“变”单核的问题

不久前笔者购买了一台电脑,采用Intel Pentium E2180双核处理器,在现场验机时,看到开机自检信息和系统属性中均显示出正确的处理器型号,于是就打包拿回了家。不料再开机使用时才发现,任务管理器中只有一颗核心的占用率信息（正常应该是两颗）,而且在CPU-Z和Everest检测软件中均显示处理器型号为Intel Pentium E2180,但核心却只有一个（图1、图2）。难道双核处理器也有假货吗？     

用大容量内存，注意主板的内存Bank限制

我最近购买了一块华硕P5QL-EM主板,该主板的规格上写有最大支持8GB内存容量,但我插上了6GB和8GB容量的内存时却出现了无法开机的情况,一旦将总内存容量降低到4GB就没有问题。难道主板也有4GB内存容量的限制吗？     

Microblogs recommendations based on implicit similarity in content social networks

With the development of online social networking applications, microblogs have become a necessary online communication network in daily life. Users are interested in obtaining personalized recommendations related to their tastes and needs. In some microblog systems, tags are not available, or the use of tags is rare. In addition, user-specified social relations are extremely rare. Hence, sparsity is a problem in microblog systems. To address this problem, we propose a new framework called Pblog to alleviate sparsity. Pblog identifies users’ interests via their microblogs and social relations and computes implicit similarity among users using a new algorithm. The experimental results indicated that the use of this algorithm can improve the results. In online social networks, such as Twitter, the number of microblogs in the system is high, and it is constantly increasing. Therefore, providing personalized recommendations to target users requires considerable time. To address this problem, the Pblog framework groups similar users using the analytic hierarchy process (AHP) method. Then, Pblog prunes microblogs of the target user group and recommends microblogs with higher ratings to the target user. In the experimental results section, the Pblog framework was compared with several other frameworks. All of these frameworks were run on two datasets: Twitter and Tumblr. Based on the results of these comparisons, the Pblog framework provides more appropriate recommendations to the target user than previous frameworks.