A novel intelligent approach for yaw position forecasting in wind energy systems

Yaw control systems orientate the rotor of a wind turbine into the wind direction, optimize the wind power generated by wind turbines and alleviate the mechanical stresses on a wind turbine. Regarding the advantages of yaw control systems, a k-nearest neighbor classifier (k-NN) has been developed in order to forecast the yaw position parameter at 10-min intervals in this study. Air temperature, atmosphere pressure, wind direction, wind speed, rotor speed and wind power parameters are used in 2, 3, 4, 5 and 6-dimensional input spaces. The forecasting model using Manhattan distance metric for k = 3 uncovered the most accurate performance for atmosphere pressure, wind direction, wind speed and rotor speed inputs. However, the forecasting model using Euclidean distance metric for k = 1 brought out the most inconsistent results for atmosphere pressure and wind speed inputs. As a result of multi-tupled analyses, many feasible inferences were achieved for yaw position control systems. In addition, the yaw position forecasting model developed was compared with the persistence model and it surpassed the persistence model significantly in terms of the improvement percent.     

Large variation in periphyton δ13C and δ15N values in the upper Great Lakes: Correlates and implications

Stable isotope ratios of carbon (δ¹³C) and nitrogen (δ¹⁵N) are frequently used to examine food web structure. Despite periphyton's importance to lake food webs, little is known about spatial variation of periphyton δ¹³C and δ¹⁵N values in the Great Lakes. We present periphyton δ¹³C and δ¹⁵N values from 28 sites the upper Great Lakes, including Lake Superior, the north shore of Lake Michigan, and Green Bay. We also examined variation in periphyton isotope values relative to several water quality parameters (TP, TN, TKN, NO₃⁻, K_d) as well as periphyton C:N. There was a large range in both periphyton δ¹³C (range = 13.5‰) and δ¹⁵N (range = 10.2‰) among sites. Periphyton in more eutrophic sites had more depleted δ¹³C and more enriched δ¹⁵N compared to more oligotrophic sites. Our finding of high variability in periphyton isotope values in the Upper Great Lakes has implications for stable isotope-based reconstructions of food web structure.     

Sanitary legislation governing Food Services in Brazil

The Technical Regulation of Good Practices for Brazilian Food Services (Regulamento Técnico de Boas Práticas para Serviços de Alimentação do Brasil) can be complemented by sanitary surveillance agencies at the state, district and municipal levels by tailoring it to location-specific requirements. The purpose of the present study was to survey sanitary legislation governing Brazilian Food Services. During the period from November 2011 to November 2012, a survey was conducted with the sanitary surveillance agencies from the various states, capitals and the Federal District. A previously prepared and tested tool was used for data collection, comprising 10 questions. Only 10 (19.2%) of the sanitary codes had been established prior to RDC Resolution n° 216/2004 and were not complementary. Of the legislation cited as complementary, only the states of Santa Catarina, Rio Grande do Sul and São Paulo and the capital of the state of São Paulo truly presented additional and location-specific aspects. No legislation that was specific to hospital kitchens was found. The majority of participating coordination, including the Evaluation List for Good Practices in Food Services, was also verified; however, it had not been published. In conclusion, a gap in sanitary surveillance services exists, which was caused by the lack of location-specific food service regulations.     

Pool boiling of saturated FC-72 on nano-porous surface

Pool boiling heat transfer from nano-porous surface immersed in a saturated FC-72 dielectric fluid has been experimentally studied at atmospheric pressure (101 kPa). The data obtained from nano-porous surface (Anodisc 25) of thickness about 70 μm made from aluminum oxide (Al₂O₃) obtained from Whatman, were compared to that of a plain surface (aluminum) of thickness about 105 μm. From the experimental data obtained it was evident that there is a reduction of about 30% in the incipient superheat for the applied power for nano-porous surface over plain surface. SEM photographs of the nano-porous coating were taken for determining the size of the pores.     

几种新型的光电器件

描述用ＳＯＩ技术制造的光耦合ＭＯＳ继电器和多量子阱长波和红外探测器，以及集成异质结晶体管和激光二管于一体的高增益，高灵敏的光电子开关器件，文中着重介绍这些器件的结构，制造工和器件特性，并对其进行了讨论。     

Full Or-Parallemism and Restricted And-Parallelism in BTM

BTM is a new And/Or parallel execution model for logic programs which exploits both full Or-parallelism and restricted And-parallelism.The advantages of high parallelism and low run time cost make BTJ,an experimental execution system of BTM implemented on a nonshared-memory multiprocessor system,achieve significant speedup for both And-paralled and Or-parallel logic programs.     

Variations in Spectral Slope in Lake Taihu,a Large Subtropical Shallow Lake in China

Spectral slope (S), describing the exponential decrease of the absorption spectrum over a given wavelength range, is an important parameter in the study of of chromophoric dissolved organic matter (CDOM) dynamics, and also an essential input parameter in remote sensing models. Furthermore, S is often used as a proxy for CDOM composition, including the ratio of fulvic to humic acids and molecular weight. The relative broad range in S values reported in the literature can be explained by the different spectral ranges and fitting methods used. A single exponential model is used to fit the S values for 17 investigations involving 458 samples in Lake Taihu from January to October in 2004. The average S value was 15.18 ± 1.39 μm⁻¹ for the range of 280–500 nm, which fell within the range reported in the literature. The frequency distribution of S value basically obeyed a normal distribution. Significant differences in S values between summer and other seasons showed that phytoplankton degradation was one of the important sources of CDOM in summer, whereas CDOM mainly came from the river input in other seasons. Furthermore, the estimated S value decreased with increasing wavelength range used in regression. The maximum and minimum values derived from the regression were 17.89 ± 1.25 μm⁻¹ and 13.62 ± 2.11 μm⁻¹ for the wavelength ranges of 280–380 nm and 400–500 nm, respectively, a decrease of 23.9%. S values significantly decreased with the increase of CDOM absorption coefficients. CDOM absorption coefficients could be more appropriately estimated from exponential model introducing the variation of S with absorption coefficients, making them useful for a remote sensing bio-optical model of Lake Taihu. DOC-specific absorption coefficient a*(λ) and the parameter M describing molecular size of the humic molecules could also be used as a proxy for the sources and types of CDOM. A general relationship was found between S and a*(λ), and M values. S increased with the decrease of DOC-specific absorption coefficient and the increase of M corresponding to the decrease of molecular weight.     

NCFW专家系统的汉语接口

NCFW系统是适合于花岗岩与变质岩地区的勘探地下水专家系统，系统的人机交互既可用菜单（亦称项目单）方式，亦可用汉语对话方式。这两种方式既可混合使用亦能灵活切换。本文着重描述了汉语接口的设计思想、实现中采用关键技术以及系统运行实例。