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The relationship between the axial structures of three-dimensional (3-D) targets and the signal of the remote-sensing techniques, such as the modulated echo waveform of the full-waveform light detection and ranging (FW-LiDAR), has been well established. However, the relationship between the lateral structures on modulated echo waveform has not been exploited in detail. For FW-LiDAR, the peak intensity, rather than the shape and width, of the echo waveform reflects lateral structural information. Using four typical two-dimensional shapes to approach the lateral structures, a mathematical formula bridging the peak intensity and the lateral structures is derived. Based upon the echo waveform simulated using the formula, modulations of the lateral structural information on the peak intensity are examined to establish a database of target properties, including shape, size and position. The physics regarding peak intensity dependence on target position is used for facile shape recognition. The modulation of the lateral shapes of ground and aerial targets on the FW-LiDAR can be assessed extensively following the procedure demonstrated in this paper. Owing to the conciseness, the peak intensity formula enables the retrieval of lateral structural information by inversion, promoting the applications of FW-LiDAR in domains including topological mapping, ecological monitoring and space debris detection and removal.

A front-end board (FEB) configuration test board is developed for examining the configuration interfaces of various application-specific integrated circuits (ASICs) developed for the ATLAS New Small Wheel project. In this paper, we present the development of a FEB configuration test board, and some functions are developed in terms of configurations of the key chips on the FEB-VMM3 and trigger data serializer (TDS2) using giga-bit transceiver-slow control adapter (GBT-SCA). Additionally, the protocols provided by GBT-SCA and the front-end board ASICs are used to verify the whole data link. The board provides technical reference for prototyping the FEB key chip configuration and data readout, as well as the final system configuration. The FEB(front end board) configuration test board is developed aiming at meeting the requirement of testing the new generation ASIC(application-specific integrated circuit) chips and its configuration system for ATLAS NSW(New Small Wheel) upgrade, In this paper, some functions are developed in terms of the configurations of the key chips on the FEB, VMM3 and TDS2 using GBT-SCA. Additionally, a flexible communication protocol is designed, verifying the whole data link. It provides technical reference for prototype FEB key chip configuration and data readout, as well as the final system configuration.

Machine-type communication (MTC) devices provide a broad range of data collection especially on the massive data generated environments such as urban, industrials and event-enabled areas. In dense deployments, the data collected at the closest locations between the MTC devices are spatially correlated. In this paper, we propose a k-means grouping technique to combine all MTC devices based on spatially correlated. The MTC devices collect the data on the event-based area and then transmit to the centralized aggregator for processing and computing. With the limitation of computational resources at the centralized aggregator, some grouped MTC devices data offloaded to the nearby base station collocated with the mobile edge-computing server. As a sensing capability adopted on MTC devices, we use a power exponential function model to compute a correlation coefficient existing between the MTC devices. Based on this framework, we compare the energy consumption when all data processed locally at centralized aggregator or offloaded at mobile edge computing server with optimal solution obtained by the brute force method. Then, the simulation results revealed that the proposed k-means grouping technique reduce the energy consumption at centralized aggregator while satisfying the required completion time.

Surface plasmon resonance (SPR) and quartz crystal microbalance (QCM) techniques are become increasingly popular in probing behaviors and properties of adsorbates at solid-liquid interfaces. Despite the numerous studies focusing on revealing various relations between their output signals and adsorbed mass, however, the mechanics of these specific relations remains elusive. In this paper, we showed that the universality of a proportional relation between SPR signal and surface mass stems from the catholicity of a linear relation between surface refractive index and surface concentration, and a small refractive index shift. The partial validity of a proportional relation between QCM signal and surface mass is due to that a linear relation between surface viscosity and surface concentration, and a small viscosity shift are not always true. The ratio of SPR and QCM signals to the surface mass is dominated by the refractive index increment and intrinsic viscosity, respectively. The weak sensitivity of refractive index increment to conformation, architecture, etc., makes the mass estimation from SPR technique very convenient. The strong sensitivity of intrinsic viscosity to these factors makes the mass evaluation from QCM technique very difficult, whereas endowing a powerful method in quantitatively probing the conformation of adsorbates at solid-liquid interfaces.

This paper focuses on two opening reinforcement methods of spherical shells under uniform external pressure. To reduce the local weakening and buckling effects of openings in spherical shells, designs comprising the wall reinforcement and the combination of a wall and thick plate reinforcement were employed to minimize buckling instability. In addition, the equal-proportion models of two kinds of reinforcement methods were manufactured and tested. The geometry, thickness, buckling load, and final collapsed mode were measured for each spherical shell with opening reinforcement. The paper contains a comparison between theoretical predictions, numerical analysis results and experimental data for two reinforced spherical shells. The theoretical and numerical results were in good agreement. The numerical solution result, obtained by considering the real defect, was consistent with the experimental result, and the failure mode was consistent with the location of the defect.

This study examined the buckling of unstiffened cylindrical shells under external pressure. Six stainless steel cylindrical shell specimens were tested, with a length-to-radius ratio, L/R, ranging from 1 to 7. The wall thickness, diameter, axial length, and geometry of each specimen and the material properties of the corresponding sheets were measured. All cylindrical specimens were subjected to external pressure in a pressure chamber; the buckling load and final collapsed mode were recorded. This paper presents a comparison among theoretical calculations, finite element (FE) results, and experimental data for externally pressurized cylindrical shells. In the numerical calculations, true geometry, average wall thicknesses, and elastic–perfectly plastic modeling were considered. Deviation between theoretical and FE results was 0%to − 22%, and it increased with the length-to-radius ratio. Experimental results are consistent with FE results, with deviation of 2–9%, and final collapsed modes of all shells are consistent.

This paper focuses on spherical shells with openings and reinforcement under uniform external pressure. To reduce the local weakening and buckling effects of the openings on these spherical pressure shells, the opening reinforcement parameters were optimized to minimize the buckling instability. According to the result of the optimization, two laboratory-scale models were manufactured and tested. The geometry, spherical shell thickness, wall thickness, buckling load, and final collapsed mode were measured for each spherical shell with an opening; the material properties of the corresponding sheets were also measured. The buckling behavior of a simulated spherical shell with an opening was demonstrated numerically according to experimental data. Numerical calculations involved considering the real geometrical shape, average values of parameters, and elastic-plastic modeling of true stress–strain curves. Moreover, the effects of initial geometrical imperfections on the critical load of the simulated spherical shell were analyzed numerically. The scanning model was calculated according to deterministic imperfections obtained from measured geometrical shapes. The theoretical model was calculated according to the equivalent geometrical imperfection valued as the first buckling mode of linear buckling. The results of the experimental and numerical investigations were compared in tables and figures.

One of the principal metabolites in cattle excreta following the administration of Synovex® ONE, which contains estradiol benzoate and trenbolone acetate, is 17α-estradiol. As part of the environmental assessment of the use of Synovex ONE, data were generated to characterize the fate of 17α-estradiol in the environment. Studies were conducted to determine the degradation and transformation of 17α-[14 C]-estradiol in 2 representative water-sediment systems each under aerobic and anaerobic conditions. The same transformation products-estriol, 17β-estradiol, and estrone-were formed, principally in the sediment phase, under both conditions in both systems. From the production of these transformation products, the 50% disappearance time (DT50) values of estrone and 17β-estradiol were determined, along with the DT50 values of 17α-estradiol and the total drug (17α-estradiol + 17β-estradiol + estrone). The results indicate that 17 α-[14 C]-estradiol was more persistent under anaerobic conditions than under aerobic conditions and that 17 α-[14 C]-estradiol was less persistent than its transformation products. The DT50 values for the total system (aqueous and sediment phases) and for the total residues (17α-estradiol, 17β-estradiol, and estrone) were selected for use in modeling the environmental fate of estradiol benzoate. For aerobic degradation in the water-sediment system, the DT50 was 31.1 d, and it was 107.8 d for the anaerobic system. Environ Toxicol Chem 2017;36:621-629. © 2016 SETAC.

Based on the sea depth of 1,500 m in the South China Sea, this paper focuses on the overall design ideas and methods of subsea manifolds with double flow line and double input. The layout scheme of different valves and pipelines and the space volume utilization were discussed, and the pipeline parameter design of the two phase fluid was completed. In this paper, three kinds of stress design criteria were analyzed. Stress analysis and deformation analysis of the designed piping system were carried out based on AutoPIPE software. The strength of the system was checked according to the relevant specifications of ASME. The results show that the circumferential stress was mainly affected by the internal and external pressure difference of the pipeline, and the longitudinal stress was mainly affected by the constraint form of the pipeline node and the temperature difference inside and outside the pipeline.

The functions and applications of flexible molecules rely heavily on their properties, such as conformation and dynamics. Despite numerous studies on the properties of flexible molecules in various conditions, the properties of discrete molecules in a dilute solution of nano-scale thickness sandwiched between a solid substrate and a bulk solution have not been sufficiently studied. In this study, based on the quartz crystal microbalance with dissipation monitoring, we demonstrate a facile way to investigate the conformation and dynamics of discrete polymer chains in nano-scale thickness solution by estimating the specific values of exclude volume exponent v and pre-factor k in the modified Mark-Houwink equation, respectively. Using poly(ethylene glycol) (PEG) as an example, the results suggest that the properties of a PEG with a molecular weight of 2 k are not significantly affected by the solid substrate. Moreover, for PEGs with molecular weights of 6 k and 20 k, the changes in conformation and dynamics are minimal and significant, respectively, in comparison with those in bulk solution. The proposed method can be further extended to probe the conformation, dynamics, and related phenomena of linear neutral polymers, and polyelectrolytes (including biopolymers) with a high salt condition.

Full-Batch update and mini-batch update are two most widely used algorithms in back-propagation(BP) neural network, to deal with the huge training time and computation cost in the learning process. Parallel computing can improve the computation efficiency and have implemented these two algorithms on Mapreduce framework. In this paper, we implement these two algorithms on Spark framework and evaluate the performance by extensive experimental results. We verify that, Spark framework outperforms Mapreduce in implementing full-batch update algorithm due to its innovative design philosophy and lazy evaluation mechanisms. In addition, mini-batch update algorithm will cost less training time than full-batch update and we also notice that the moderate batch size k will perform better, although accurate analysis is not completed. Our work obtain novel knowledge in recognizing the performance in Spark framework for these two algorithms.

When and why people change their cell phones are important issues in mobile communications industry because it will impact greatly on the marketing strategy and revenue estimation for both telecommunication operators and manufactures. In this paper, we evaluate the key features that affect the mobile phone changing based on statistical data of mobile users provided by one mobile communication operator. First, we investigate the impact of static features like user age, phone brands, and then the dynamic traffic features. We also discuss the effect that long term influence related factors by statistical analysis. According to statistical analysis, we recognize 8 important features for mobile phone changing events. Our work present an first step knowledge about the feature importance for the issue concerned, which are significant for further phone changing prediction tasks using various prediction models.

The metabolites 17α-trenbolone and 17α-estradiol are principal metabolites in cattle excreta following the administration of Synovex® ONE, which contains trenbolone acetate and estradiol benzoate. As part of the environmental assessment of the use of Synovex ONE, data were generated to characterize the fate of 17α-trenbolone, and its metabolite trendione in the environment. Predictions of the fate and environmental concentrations of these hormones after land application require accurate estimates of the sorption of these compounds in soils. The sorption and desorption of 17α-trenbolone and trendione were measured at 5 nominal concentrations in 5 soils from different geologic settings using a batch equilibrium technique following guideline 106 of the Organisation for Economic Co-operation and Development. Both the sorption and desorption of 17α-trenbolone and trendione to soils were adequately described by the Freundlich sorption model and by linear partition coefficients. The mean sorption coefficients were 9.04 mL/g and 32.2 mL/g for 17α-trenbolone and trendione, respectively. The corresponding mean Freundlich sorption exponents were 0.88 and 0.98, respectively. Sorption of 17α-trenbolone and trendione was correlated principally with soil organic carbon. Average sorption coefficients normalized to soil organic carbon content (KOC ) were 460 mL/g and 1804 mL/g for 17α-trenbolone and trendione, respectively. The mean desorption coefficients were 22.1 mL/g and 43.8 mL/g for 17α-trenbolone and trendione, respectively. Calculated hysteresis coefficients based on the difference in the area between sorption and desorption isotherms indicated that sorption equilibrium was not fully reversible and hysteresis of desorption isotherms occurred for both 17α-trenbolone and trendione. Environ Toxicol Chem 2017;36:613-620. © 2016 SETAC.

The performance of using plastic scintillation fiber (PSF) array coupled with charge-coupled devices (CCD) for X-ray imaging and detection is described. The method is simple and low cost. The experimental setup is present and some obtained images are shown. Modulation Transfer Function (MTF) of the PSF array was also presented and compared to earlier reports. The results show that the system can be applicable under some environments to demonstrate the concept of radiation imaging or detection.

We describe a simple position sensitive γ-ray detector configuration and investigate its performance using a Monte Carlo simulation method. The detector is based on the characteristics of Compton scattering of high energy photons by electrons and the leakage of high energy photons from a rod shaped plastic scintillating fiber. Both energy and spatial resolution have been presented with energies in the range of 0.8–7 MeV, about 10% and a few centimeters, respectively. Cross-talk of the configuration has also been considered.

When and why people change their mobile phones are important issues in mobile communications industry, because it will impact greatly on the marketing strategy and revenue estimation for both mobile operators and manufactures. It is a promising way to take use of big data to analyze and predict the phone changing event. In this paper, based on mobile user big data, first through statistical analysis, we find that three important probability distributions, i.e., power-law, log-normal, and geometric distribution, play an important role in the user behaviors. Second, the relationships between eight selected attributes and phone changing are built, for example, young people have greater intention to change their phones if they are using the phones belonging to the low occupancy phones or feature phones. Third, we verified the performance of four prediction models on phone changing event under three scenarios. Information gain ratio was used to implement attribute selection and then sampling method, cost-sensitive together with standard classifiers were used to solve imbalanced phone changing event. Experiment results show our proposed enhanced backpropagation neural network in the undersampling scenario can attain better prediction performance.

Synovex® ONE is an extended-release implant containing the active ingredients estradiol benzoate and trenbolone acetate for use in beef steers and heifers. Trenbolone acetate is rapidly hydrolyzed in cattle to form 17β-trenbolone and its isomer, 17α-trenbolone, which are further transformed to a secondary metabolite, trendione. As part of the environmental assessment for the use of Synovex ONE, data were generated to characterize the fate of 17α-trenbolone, which is the principal metabolite found in cattle excreta, in the environment. A study was conducted to determine the degradation and transformation of [14 C]-17α-trenbolone in 2 representative water-sediment systems under aerobic conditions. The same transformation products, 17β-trenbolone and trendione, were formed, principally in the sediment phase, in both systems. From the production of these transformation products, the 50% disappearance time (DT50) values of 17β-trenbolone and trendione were determined, along with the DT50 values of the parent compound and the total drug (17α-trenbolone + 17β-trenbolone + trendione). The DT50 values for the total system (aqueous and sediment phase) and for the total residues (17α-trenbolone + 17β-trenbolone + trendione) in the 2 systems were 34.7 d and 53.3 d, respectively. Environ Toxicol Chem 2017;36:630-635. © 2016 SETAC.

The performance of a simple prototype X-ray detector composed of plastic scintillating fibers (PSF) coupled with a charge-coupled device (CCD) for X-ray imaging was evaluated using a Monte Carlo simulation. The advantage of this detector is its simplicity and very low cost. The results show that the imaging detector has a reasonable efficiency and sensitivity for imaging X-ray with energy below a few hundred keV. The resolution can be very good if the size of the PSF used is appropriately chosen. For higher energy X-ray, the efficiency is greatly reduced. Improvements are suggested which could make such imaging detector more suitable and even desirable under certain circumstances and when the low cost are essential.

Data collected from a 3-yr controlled field study in Hamilton, New Zealand were used to examine whether the Root Zone Water Quality Model is capable of predicting water movement and pesticide fate in the field based on key lab-measured parameters and environmental variables. Acetochlor [2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methyl-phenyl) acetamide; 2.5 and 5.0 kg a.i. ha -1 ] and terbuthylazine (C 9 H 16 CIN 5 ; 1.5 and 3.0 kg a.i. ha -1 ) were applied onto nine field plots (3 by 9 m each). Soil core samples were taken to a depth of 1 m to determine soil water contents and pesticide concentrations. Dissipation of both pesticides in the field at both application rates followed first-order kinetics (adjusted r 2 > 0.91). The mean dissipation half-life was 16 d for acetochlor and 25 d for terbuthylazine. Relatively small amounts of the pesticides leached below 5 cm and none leached below 10 cm. Predicted soil water contents in the soil profile were not significantly different from those measured in the field (p > 0.84). Predicted acetochlor and terbuthylazine masses in the soil profile based on a linear instantaneous-equilibrium (I-E) partitioning model matched those measured in the field (adjusted r 2 > 0.93). However, predicted pesticide concentrations in the soil profile were less satisfactory, with 68 and 35% of the predicted concentrations being within a factor of 2 of the measured concentrations for 0- to 5- and 5- to 10-cm depths, respectively. Calibration of each pesticide sensitive parameter individually did not significantly improve the overall predictions of pesticide mass and concentrations in the soil profile when the I-E partitioning model was used. The predictions were improved when a two-site, equilibrium-kinetic (E-K) sorption model was used.

The Root Zone Water Quality Model (RZWQM) is a one-dimensional, numerical model for simulating water movement and chemical transport under a variety of management and weather scenarios at the field scale. The pesticide module of RZWQM includes detailed algorithms that describe the complex interactions between pesticides and the environment. We have simulated a range of situations with RZWQM, including foliar interception and washoff of a multiply applied insecticide (chlorpyrifos) to growing corn, and herbicides (alachlor, atrazine, flumetsulam) with pH-dependent soil sorption, to examine whether the model appears to generate reasonable results. The model was also tested using chlorpyrifos and flumetsulam for the sensitivity of its predictions of chemical fate and water and pesticide runoff to various input parameters. The model appears to generate reasonable representations of the fate and partitioning of surface- and foliar-applied chemicals, and the sorption of weakly acidic or basic pesticides, processes that are becoming increasingly important for describing adequately the environmental behavior of newer pesticides. However, the kinetic sorption algorithms for charged pesticides appear to be faulty. Of the 29 parameters and variables analyzed, chlorpyrifos half-life, the Freundlich adsorption exponent, the fraction of kinetic sorption sites, air temperature, soil bulk density, soil-water content at 33 kPa suction head and rainfall were most sensitive for predictions of chlorpyrifos residues in soil. The latter three inputs and the saturated hydraulic conductivity of the soil and surface crusts were most sensitive for predictions of surface water runoff and water-phase loss of chlorpyrifos. In addition, predictions of flumetsulam (a weak acid) runoff and dynamics in soil were sensitive to the Freundlich equilibrium adsorption constant, soil pH and its dissociation coefficient.

With the scheduled phasing out of methyl bromide, there is an urgent need for alternatives. We evaluated the efficacy of propargyl bromide as a potential replacement for methyl bromide for the control of barnyardgrass (Echinochloa crus-galli) and Fusarium oxysporum in an Arlington sandy loam, a Carsitas loamy sand and a Florida muck soil. Soil was mixed with barnyardgrass seeds or F oxysporum colonized on millet seeds, and treated with propargyl bromide at a range of concentrations. The mortality of the fungi and weed seeds was determined after 24 h of exposure at 30 degrees C. The concentrations required to inhibit 50% barnyard seed germination (LC50) were 2.8, 2.4 and 48.5 micrograms g-1 in the sandy loam, loamy sand and muck soil, respectively. In contrast, the LC50 values for F oxysporum were 11.2, 10.8 and 182.1 micrograms g-1 in the sandy loam, loamy sand and muck soil, respectively. The low efficacy of propargyl bromide in the muck soil was a result of the rapid degradation and high adsorption of the compound in the soil. The degradation half-life (t1/2) was only 7 h in the muck soil at an initial concentration of 6.8 micrograms g-1, compared to 60 and 67 h in the sandy loam and loamy sand, respectively. The adsorption coefficients (Kd) were 0.96, 0.87 and 5.6 cm3 g-1 in the sandy loam, loamy sand and muck soil, respectively. These results suggest that registration agencies should consider site-specific properties in recommending application rates for propargyl bromide.

The Brooks-Corey functions are commonly used in hydrologic models, with parameters obtained by fitting the functions directly to measured soil water retention data or by conversion methods from the van Genuchten functions which are continuous across the domain of matric suctions. Problems in fitting the BC functions directly to the retention data motivated use of the conversion methods. However, differences in converted parameters could significantly influence model predictions. We compared the direct fitting method and the conversion methods of Lenhard et al., Morel-Seytoux et al., and van Genuchten using measured water retention data during drainage and determined the influence of these methods on hydrological predictions when the converted parameters were used in the root zone water quality model. The conversion methods had significant influence on predictions of water retention, hydraulic conductivity, runoff, and evapotranspiration, with the observed level of significance (p ≤ 0.006) much lower than the test level of significance (α = 0.05). The method of Morel-Seytoux et al. inadequately described measured water retention data (p=0.027), whereas the other two methods adequately described the data at relatively high suctions (p ≥ 0.687), deviations occurred around the air-entry suction. The method of Lenhard et al. best reproduced the characteristics of the Brooks-Corey functions (p ≥ 0.31) and could be used to obtain the Brooks-Corey parameters simply and reproducibly.

A model of web data gathering and processing on Tibetan and Uyghur language is introduced in this paper, including page crawler, content extraction, word segmentation and frequency statistics and display. Firstly, It extracts the website's templates and use the template to extract the content and title of the web page, then the software transforms the HTML file to the XML file. The second step is to segment the content of XML file into words and to count the number of words, in order to store the statistics into database. Finally", "there is a web page to display the the result of the frequency statistics.

The purpose of the present study was to comprehensively evaluate available golf course water quality data and assess the extent of impacts, as determined by comparisons with toxicologic and ecologic reference points. Most water quality monitoring studies for pesticides have focused on agriculture and often the legacy chemicals. There has been increased focus on turf pesticides since the early 1990s, due to the intense public scrutiny proposed golf courses receive during the local permitting process, as well as pesticide registration evaluations by the U.S. Environmental Protection Agency under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Results from permit-driven studies are frequently not published and knowledge about them is usually not widespread. Forty-four studies involving 80 courses from a 20-year period passed our quality control and other review criteria. A total of 38,827 data entries (where one analysis for one substance in one sample equals a data entry) from pesticide, pesticide metabolite, total phosphorus, and nitrate analyses of surface water and groundwater were evaluated. Analytes included 161 turf-related pesticides and pesticide metabolites. Widespread and/or repeated water quality impacts by golf courses had not occurred at the sites studied, although concerns are raised herein about phosphorus. Individual pesticide database entries that exceed toxicity reference points for groundwater and surface water are 0.15 and 0.56%, respectively. These percentages would be higher if they could be expressed in terms of samples collected rather than chemicals analyzed. The maximum contaminant level ([MCL]; 10 mg/L) for nitrate-nitrogen was exceeded in 16/1,683 (0.95%) of the groundwater samples. There were 1,236 exceedances of the total phosphorus ecoregional criteria in five ecoregions for 1,429 (86.5%) data entries. (This comparison is conservative because many of the results in the database are derived from storm flow events.) Thus, phosphorus appears to present the greatest water quality problem in these studies. Pesticides detected in wells had longer soil metabolism half-lives (49 d) compared with those not detected (22 d), although the means were not significantly different.

The purpose of the present study was to comprehensively evaluate available golf course water quality data and assess the extent of impacts, as determined by comparisons with toxicologic and ecologic reference points. Most water quality monitoring studies for pesticides have focused on agriculture and often the legacy chemicals. There has been increased focus on turf pesticides since the early 1990s, due to the intense public scrutiny proposed golf courses receive during the local permitting process, as well as pesticide registration evaluations by the U.S. Environmental Protection Agency under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Results from permit-driven studies are frequently not published and knowledge about them is usually not widespread. Forty-four studies involving 80 courses from a 20-year period passed our quality control and other review criteria. A total of 38,827 data entries (where one analysis for one substance in one sample equals a data entry) from pesticide, pesticide metabolite, total phosphorus, and nitrate analyses of surface water and groundwater were evaluated. Analytes included 161 turf-related pesticides and pesticide metabolites. Widespread and/or repeated water quality impacts by golf courses had not occurred at the sites studied, although concerns are raised herein about phosphorus. Individual pesticide database entries that exceed toxicity reference points for groundwater and surface water are 0.15 and 0.56%, respectively. These percentages would be higher if they could be expressed in terms of samples collected rather than chemicals analyzed. The maximum contaminant level ([MCL]; 10 mg/L) for nitrate-nitrogen was exceeded in 16/1,683 (0.95%) of the groundwater samples. There were 1,236 exceedances of the total phosphorus ecoregional criteria in five ecoregions for 1,429 (86.5%) data entries. (This comparison is conservative because many of the results in the database are derived from storm flow events.) Thus, phosphorus appears to present the greatest water quality problem in these studies. Pesticides detected in wells had longer soil metabolism half-lives (49 d) compared with those not detected (22 d), although the means were not significantly different.

The change of illumination problem is still a challenging and difficult problem in face recognition under complex illumination condition. There were many proposals that dealing with illumination problem in face recognition in the past decade. In this paper, we classify the existing methods into three main categories and introduce the representative algorithms and theories, then analyze the advantages and disadvantages of these algorithms correspondingly. As a result of this study we conclude direction of future research.

Due to the complex nature of pesticide transport, process-based models can be difficult to use. For example, pesticide transport can be effected by macropore flow, and can be further complicated by sorption, desorption and degradation occurring at different rates in different soil compartments. We have used the Root Zone Water Quality Model (RZWQM) to investigate these phenomena with field data that included two management conditions (till and no-till) and metribuzin concentrations in percolate, runoff and soil. Metribuzin degradation and transport were simulated using three pesticide sorption models available in RZWQM: (a) instantaneous equilibrium-only (EO); (b) equilibrium-kinetic (EK, includes sites with slow desorption and no degradation); (c) equilibrium-bound (EB, includes irreversibly bound sites with relatively slow degradation). Site-specific RZWQM input included water retention curves from four soil depths, saturated hydraulic conductivity from four soil depths and the metribuzin partition coefficient. The calibrated parameters were macropore radius, surface crust saturated hydraulic conductivity, kinetic parameters, irreversible binding parameters and metribuzin half-life. The results indicate that (1) simulated metribuzin persistence was more accurate using the EK (root mean square error, RMSE = 0.03 kg ha(-1)) and EB (RMSE = 0.03 kg ha(-1)) sorption models compared to the EO (RMSE = 0.08 kg ha(-1)) model because of slowing metribuzin degradation rate with time and (2) simulating macropore flow resulted in prediction of metribuzin transport in percolate over the simulation period within a factor of two of that observed using all three pesticide sorption models. Moreover, little difference in simulated daily transport was observed between the three pesticide sorption models, except that the EB model substantially under-predicted metribuzin transport in runoff and percolate >30 days after application when transported concentrations were relatively low. This suggests that when macropore flow and hydrology are accurately simulated, metribuzin transport in the field may be adequately simulated using a relatively simple, equilibrium-only pesticide model.