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For tractor operation on deformable terrains, accurate terrain profiles are critically needed to determine the dynamic tractor response, which is affected by the terrain roughness. Effective profiles for tractors operating on agricultural terrains were identified in this study. A novel technique, called independent component analysis (ICA), was used to estimate the effective profiles. ICA can use a known system dynamic response (observed signals) to identify road-induced excitation. In this context, tractor wheel vibration signals were used as observed signals, and the ICA method was used to estimate the source signals, which are the effective profiles of the terrain. The proposed approach was validated by comparing the estimated profiles with those measured by a profiling apparatus in the time and frequency domains. The calculated root mean square error RMSE and the relative error Ef between the measured and estimated profiles showed that the proposed approach can be used to accurately estimate road profiles. A group of grass-field roughness data was taken as an example to compare the characteristics of the original and effective profiles, and the parameters of the effective profiles, such as the RMS, roughness index C and waviness W were found to noticeably change during the interaction between the tractor wheel and the terrain soil.

Additional file 1: Table 1. Associations between tertile of thyroid indicators and the risk of GDMin subjects with TPO Ab negativity. Table 2. Associations between extremely 10th/90thpercentile of thyroid indicators and the risk of GDM. Table 3. Associations between extremely 2.5th/97.5thpercentile thyroid indicators and the risk of GDM in subjects with TPO Abnegativity. Table 4. Associations between extremely 10th/90thpercentile thyroid indicators and the risk of GDM in subjects with TPO Abnegativity.

Additional file 1: Age- and sex-specific body mass index cutoff points for Chinese children and adolescents.

Additional file 2: Informed consent forms.

How to accurately and efficiently measure the profiles of the terrain on which agricultural machines operate has been an ongoing research topic. In this study, a surface profiling apparatus (profiler) was developed to measure agricultural terrain profiles along parallel tracks. The profiler is mainly composed of sensor frames, an RTK-GNSS system (Real Time Kinematics-Global Navigation Satellite Systems), laser sensors, an Inertial Measurement Unit (IMU) sensor and a data acquisition system. Along with a full description of how the terrain profiles were produced, a methodology to compensate for the tractor motion was included in the sensor data analysis. In field profiling validation, two trapezoidal bumps with known dimensions were used to assess the ability of the terrain profiler to reproduce the vertical profiles of the bumps, resulting in root mean square error (RMSE) of 3.6-4.7 mm and 4.5-5.1 mm with profiling speeds of 1.02 and 2.56 km/h, respectively. In addition, a validation test was also conducted on an asphalt road by profiling a flat road with the measuring wheels of the profiler rolling on the flat section but with the tractor wheels driving over a trapezoidal bump to excite the tractor pitch and roll motion. The measured profiles then also exhibited a flat road, which showed the ability of the profiler to remove the tractor motion from the profiling measurements.

Background: Considering the limitations of cisplatin in clinical application, there is ongoing research to fabricate new platinum-containing prodrug which are highly effective to tumor cells and have low toxicity to normal cells. Methods: In this study, a cyclodextrin-based supramolecular platinum prodrug that is 6,6’-ophenylenediseleno- bridged bis (β-cyclodextrin)s (CD) and its potassium tetrachloroplatinate(II) complex was reported. The cytotoxicity experiments were performed to evaluate the anticancer activities of supramolecular prodrug in vitro by means of MTT assay. The practical application of supramolecular prodrug in tumor treatment in vivo were evaluated using BALB/c nude mice model bearing Hela cancer cells. Results: Compared with commercial anticancer drug cisplatin, the resultant cyclodextrin-based platinum prodrug exhibited comparative anticancer effect but with much lower toxicity side effects in vitro and in vivo. Conclusion: The cyclodextrin-based supramolecular platinum prodrug displayed antitumor activity comparable to the commercial antitumor drug cisplatin but with lower side effects both in vitro and in vivo, implying that the two adjacent cyclodextrin cavities not merely act as desired solubilizer, but also endowed the prodrug with cell permeability through the interaction of cyclodextrin with phospholipids and cholesterol on cell membrane.

Additional file 1. Adverse events.

For most software systems, pair-wise combinatorial testing is highly practical and effective. This article mainly starts with the specific research status of the pair-wise covering combinatorial test and the main content of the software test, analyzes and compares the existing main implementation algorithms, and then evaluates their specific performance.

This study aimed to examine the association among parental moderate-to-vigorous physical activity (MVPA), parental support, and the MVPA of children by gender. Participants comprised of 172 boys and 151 girls aged seven to 11 years old from three primary schools in Shanghai. Their parents were also included as research respondents. Accelerometers were utilized to measure MVPA duration among the children. Questionnaires that focused on parental support and MVPA were completed by the parents. Results indicated that only 4% of the children met the recommended MVPA duration of 60 minutes per day based on objective data. Parental support consisted of two constructs: logistic support and explicit modelling. Boys engaged in more MVPA than girls although no gender differences were noted in terms of the logistic support and explicit modelling of parents and their MVPA. A regression analysis revealed that 23.3% of the variance in MVPA for boys was explained by explicit modelling and MVPA of fathers. Moreover, 10.5% of the variance for girls was explained by the explicit modelling of mothers. Thus, parents should be highly encouraged to support the MVPA of their children by acting as role models. They can also enhance the MVPA of their children using different methods based on gender.

This paper proposes a kind of intelligent kitchen management system which integrates various technologies such as sensor, ZigBee, embedded, database, Web application, Android mobile development and so on. The paper introduces the system structure, system function, design plan and system implementation of the system. The system provides many ways to check, manage, control and monitor the kitchen information for users intelligently. It has good practicability and extensibility, and improves the intelligentized level of people's life.

Given a start point s, a target point t, and k disjoint convex polygons in the given order in the plane, finding the shortest path of visiting the convex polygons sequence from s to t is the goal. In this paper, we present a fast algorithm to compute the shortest path based on the last step shortest path maps. Firstly, we locate the dividing-points quickly in the two adjacent polygons, which can reduce amounts of iteratively computation. Then, we convert this problem to solving the shortest path of visiting the disjoint line segments sequence which makes the solution much simpler. Furthermore, we analyze the complexity of new algorithm and obtain that it is superior to the previous solution. Finally, we implement this algorithm and show that it is correct.

In this paper, the problem of traveling disjoint segment sequences in the plane will be studied. The goal is to find the shortest path from the start point, then visiting each segment in the given order, and finally to the target point. By adopting the techniques of division of convex chain, combination optimization and binary search tree, we design a fast algorithm with the O(nlog2n) time complexity to solve it, denoted by BST algorithm, where n is the total number of all segments, and we introduce the main techniques used in this paper in detail. Furthermore, we generate a large amount of test data to test BST algorithm, and compare the efficiency of BST algorithm and Rubber-band algorithm, which is the better solution to this problem. The results show that BST algorithm is superior to Rubber-band algorithm, and it is the optimal algorithm for visiting the disjoint segment sequences so far.

Univariate and multivariate Cox analysis of prognostic factors associated with survival for diabetic patients with locally advanced cervical cancer who underwent neoadjuvant chemotherapy and radical hysterectomy. (DOCX 23Â kb)

Clipping algorithm is an effective method to reduce the Peak-to-Average Power Ratio for OFDM systems, but it introduces nonlinear distortions and causes the error rate of the system rising at the same time. To solve this drawback of clipping algorithm, this paper introduces CE-SLM algorithm to clipping, in other words when the PAPR of signal is greater than the threshold, and CE-SLM algorithm will be applied. CE-SLM algorithm uses the Cross Entropy (CE) to optimize the symbol sequence in SLM algorithm in order to reduce PAPR. This process doesn't introduce nonlinear distortions and can reduce the error rate of the system. Computer simulation results show that the union algorithm can reduce the error rate of the system under the condition of keeping the same PAPR reduction effect with clipping algorithm.

PurposeThe purpose of this paper is to research the influence of inflation and delay in payment on the inventory model on Weibull distribution and present a new method of inventory control model for fresh agricultural products.Design/methodology/approachThe previous researches deal with the inventory problems. However, these researches are based on deteriorating industrial products, so that the method for inventory model of agricultural products should be employed. According to agricultural products characteristics, the model assumes that deterioration is defined as fixed and demand is taken as Weibull distribution. An optimal order quantity and the minimum inventory total cost are formulated and solved under inflation and delay in payment.FindingsThe minimum inventory total cost and the optimal ordering quantity are convex with the length of the period with positive stock. When the delay period is longer than the length of the period with positive stock, the minimum inventory total cost and the optimal ordering quantity increase with permissible delay in payment increase and decrease with inflation rate increase, changing steeply with inflation rate and increasing permissible delay.Research limitations/implicationsThe market demand of fresh agricultural products is on two‐parameter Weibull distribution.Practical implicationsThe paper gives useful advice for agricultural supply chain managers.Originality/valueThe paper presents a new method of inventory control for fresh agricultural products.

An optoelectronic device current-voltage(I-V) testing platform was established based on the software LabVIEW,including a PCI-GPIB card from American National Instrument(NI) Corporation as well as 6517 Electrometer/High Resistance Meter from Keithley Corporation.Using the LabVIEW program to control Keithley6517,the system has the function of collecting,displaying,storing and analyzing the voltage and current data through the GPIB card.It can also draw the I-V characteristic curve according to the measured data and figure out the relevant parameters of different devices.In this paper,taking solar cell as an example,it figures out the open voltage(Voc),short current(Isc),maximum power(Pm),fill factor(FF) and percentage of conversion efficiency(PCE) of the solar cell.Through contrast test and correction,this system has a maximum error of 0.18%.This system not only has a high degree of automation,but also has a high degree of accuracy and reliability.And it not only can be used in laboratory teaching,also can be used in the factory for solar cell and thin film transistor products performance testing.

With the TEM and physical gas adsorption techniques, porous properties of nano-fibriform silica (MLD: 92.73%) from natural chrysotile are studied in this paper. The results indicate that porous nano-fibriform silica results from brucite octahedral sheets of nature chrysotile dissolved completely and Si-O tetrahedral sheets collapsed by acid leaching. Its length is at a micron or nanometer scale. There are two types of pores: pores among neighboring fibers and pores in nanofiber. These pores (less than 6.5 nm in diameter, mostly 2.1 nm and 3.8 nm) all belong to mesopores. The pores in fibers consist of those among SiO2 particles, those among aggregates, remnant nanotubes and capillary tubes. Nano-fibriform silica proves better than the traditional silica as a carrier of catalyzer and a filler for reinforce rubber and plastics.

PurposeIn the grid‐based simulation, the resource application needed is distributed in the grid environment as grid service, and time management is a key problem in the simulation system. Grid workflow provides convenience for grid user to management and executes grid services. But it emphasizes process and no time‐management, so a temporally constrained grid workflow model is pointed out based on grid flow with temporally constraint to schedule resources and manage time.Design/methodology/approachThe temporally constrained grid workflow model is distributed model: the federate has local temporal constraints and interactive temporal constraints among federates. The problem to manage time is a temporally distributed constraint satisfaction problem given deadline time and duration time of grid services. Multi‐asynchronous weak‐commitment search (AWS) algorithm is an approach to resolve DCSP, so a practical example of a simulation project‐based grid system was presented to introduce application of Multi‐AWS algorithm.FindingsThe temporally constrained grid workflow is based temporal reasoning and grid workflow description about grid services.Originality/valueThe new problem about scheduling resources and managing time in the grid‐based simulation is pointed out; and the approach to resolve the problem is applied into a practical example.

Single-nucleotide polymorphisms (SNPs) of exon 8 of the GHR gene were detected in Chinese Holstein cows by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). The results showed that exon 8 of the GHR gene digested byTasI could be divided into two kinds of alleles and three kinds of genotypes. The frequencies of allele A and T were 0.6339 and 0.3661, respectively. The frequencies of genotypes AA, AT and TT were 0.459, 0.350 and 0.191, respectively. Sequencing showed one single nucleotide mutation T→A at 4962 bp of the gene in genotype TT when compared with genotype AA, and this mutation resulted in an amino acid change of phenylalanine (TTT)→tyrosine (TAT). The result of χ2testing indicated that the genotypic frequency of the GHR gene digested byTasI did not fit with Hardy–Weinberg equilibrium in this population (PP

Poly caprolactone (PCL) was used to modify multiwall carbon nanotubes (MWNTs). The characterization results of TEM, FTIR, Raman, TG and 721 Spectrophotometer showed that PCL was covalently combined with MWNTs. The MWNTs/PVC composites were prepared by the addition of pristine and modified MWNTs into poly(vinyl chloride) through melting process. The addition of MWNT-PCL (0.28 vol%) increased the Young’s modulus, tensile strength, elongation at break, area of stress–strain curve and impact strength by 22.8%, 34%, 280%, 419% and 418%, respectively. The reinforcement values of Δ Y Δ V f = 77.84 ± 24 GPa , Δ σ Δ V f = 4.3 ± 1.6 GPa and Δ I Δ V f = 180 ± 0.01 GPa were observed. SEM image of the fracture surfaces showed that most of MWNT-PCL was pulled out of the matrix covered with a PVC layer, which showed high level of interfacial adhesion.

The optical spectra of Cu2+ in dioptase are calculated using crystal-field theory. Good agreement between measured and calculated energy values is obtained under D 4h point-symmetry approximation. The electron paramagnetic resonance g factors, g // and g ⊥, are also investigated from high-order perturbation formulae. The local structure of Cu2+ in dioptase is obtained using these formulae. Theoretical results are in perfect agreement with experimental findings.

The regeneration of exhausted solutions of electroless nickel plating wood veneer was realized using soluble calcium salt to precipitate and remove phosphite and then using fluoride to remove residual calcium ions from the solution. The effect of the pH value of the solution, treatment temperature and the molar ratio of calcium ions to phosphite ions on the removal efficiency of phosphite was investigated. Wood veneer was electroless plated using regenerated solutions. A coating with better electrical conductivity and electromagnetic shielding was obtained.

Electrical and electromagnetic shielding wood-metal composite was prepared by using electroless nickel plating. The effects of solution amount, plating time and plating temperature on surface resistivity and electromagnetic shielding effectiveness were investigated. And P content, microstructure and surface feature of layers obtained at different temperatures were analyzed by energy dispersion spectrometer (EDS), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that layers with higher electro-conductivity and electromagnetic shielding effectiveness were obtained under the optimum conditions that plating solution was 500 mL, plating time was 30 min and plating temperature was 62°C. The results showed by EDS analysis that P content increased gradually in a small extent with plating temperature increased. It was showed by XRD and SEM analysis that layers plated at different temperatures were all microcrystalline structure and uniform and successive, which had noticeable metal luster. Those indicated that plating temperature had little influence on microstructure and surface feature under pH value invariable.

Wood is a kind of porous natural material with very poor electro-conductivity, and it has almost no function of electromagnetic shielding. The method of electroless nickel plating was used to produce wooden material with electrical and effective electromagnetic shielding properties. Ni−P alloy layer was obtained on wood surface. The surface feature of plated wood veneer was observed by SEM and the surface composition and microstructure of the layer under different conditions were investigated by EDS and XRD respectively. Mean-while, the relevant surface resistivity and electromagnetic shielding effectiveness were measured. Correlations of the phosphorous content in the layer to the structure of Ni−P alloy, electro-conductivity and electromagnetic shielding of plated veneers were discussed. SEM photos showed that the surface of electroless nickel plated veneers were covered with Ni−P alloy layer entirely, which made wood veneers more like metal. At the same time, the results showed that with the decreasing of the phosphorous content in the layer, the microstructure of Ni−P alloy layer transformed to be microcrystalline and electro-conductivity and electromagnetic shielding effectiveness were imrpoved. When the phosphorous content was less than 2.37wt pct in the layer, the microstructure of Ni−P alloy layer was microcrystalline structure and its surface resistivity and electromagnetic shielding effectiveness were nearly 0.5 Ω/⊥ and 55–60dB respectively.

Spin-transfer effects induced by spin-polarized current in the spin valve structures present a platform for studying different static and dynamic magnetization states sustained or driven by current. Especially, it can excite some new magnetic states and cause magnetization reversal and precession, which offers some promising applications in data processing and microwave emission. However, most of researches so far have focused on the spin valve structure with parallel or perpendicular anisotropy. Compared with the spin valve structure with parallel or perpendicular anisotropy device, the spin valve structure with a tilted polarizer is also hopeful for its potential application in fast-switching and high-density magnetic recording. Moreover, the tilted polarizer provides a new way to control the spin torquedriven magnetization dynamics in spin valve structure. In this paper, the magnetization reversal and precession driven by the spin-transfer torque in spin valve structures with a perpendicular free layer and a tilted polarizer layer are investigated theoretically. By linearizing the Landau-Lifshitz-Gilbert equation including the spin-transfer torque, two coupled dynamically evolutive equations and new equilibrium directions are obtained. Performing stability analysis for all new equilibrium directions and taking [Co/Ni]4 multilayers as an illustrative example, we obtain the phase diagrams of magnetic states defined in parameter space spanned by external magnetic field and current density. Several magnetic states, including quasi-parallel stable states, quasi-antiparallel stable states, out-of-plane precession, and bistable states are distinguished in the phase diagrams. Through adjusting the magnitudes of current density and external magnetic field, the switching from stable states to precessional ones and the reversal between two stable states can be realized, and the reversal current increases with the external magnetic field increasing. Meanwhile, we portray the phase diagram of magnetic states defined in parameter space spanned by current density and the direction of tilted polarizer. In this case, the out-of-plane precession does not emerge as the current density and external magnetic field are relatively small. Affected by the directions of spin polarizer, the reversal current of magnetization is lowest when the direction of spin polarizer is parallel to the easy axis of free-layer, and is largest when the direction of spin polarizer is perpendicular to the easy axis of free-layer. Selecting the different directions of the polarized-layer magnetization provides an alternative way to improve the efficiency of current-driven microwave emitting and magnetization reversal. By solving temporal evolution equations numerically, the behaviors of different magnetic states are shown and the validities of the phase diagrams are confirmed.

Cerium phosphate powders were synthesized by direct solid liquid reaction of cerium dioxide and phosphate acid at the Ce: P ratio of 1∶1. Phase-pure and fine grain size CePO4 powers could be obtained by calcining the as received powders at the temperature higher than 600°C. It is demonstrated that the grain size and morphology of the CePO4 powders were calcined at various temperatures. An interesting layered crystal structure and a series of microcracks that cross and occur along the extrusion stress direction on the extruded surface inside CePO4 were observed. The ductility and machinability of CePO4 ceramic are attributed to the layered structure. Continuous machining debris was observed on the turned surface.

Based on the traditional trip attraction model, a new method of operation condition evaluation and supply scale forecasting for public parking facilities is proposed. It begins with the operation condition investigation of existing parking facilities, and then analyzes qualitatively the existing parking facilities supply scale by four indexes. finally, it can calculate the supply scale in predict year. Combined with concrete work of urban parking facilities planning in china, the evaluation index and prediction model were applied, and the parking facilities operation condition, demand, supply scale and internal structure are analyzed deeply. The method proposed in the paper can provide the theory basis for the public parking facilities planning in other cities. DOI: http://dx.doi.org/10.11591/telkomnika.v11i2.2069

High-yielding low-cost vanadium oxide nanotubes were prepared by hydrothermal self-assembling process from vanadium pentoxide and organic molecules as structure-directing templates. Moreover, a new method was discovered to determine the content of V (IV) in vanadium oxide nanotubes by thermogravimetric analysis (TGA). This method can be extended to determine the content of low oxidation state in other transition metal oxide nanomaterials.

Test data generation is a key part in software test area and it is of significance to realize the automation of software testing. The main contribution of this paper lies in that a practical model, which utilizes genetic algorithms as searching policy to generate software structural test data, is proposed. To achieve higher performance, such issues as encoding strategy, algorithms operator evolution, evaluation function construction and instrumentation are addressed in detail, a new method of initialization of population is introduced in order to make the initial population has higher adaptability, and much emphasis is put on algorithms operator evolution, which is a key factor which can highly affect algorithms efficiency, finally, the results show that the application of genetic algorithms in software test data generation is more efficient compared with other methods.

Pipe breaks and leaks in water distribution networks may bring about economic, environmental and safety issues. It is critical to evaluate the current and future condition of the system for maintenance decision-making. RBF neural network model was proposed for forecasting pipe leakage. Two models based on RBF neural network were established according to previous leakage data set. The goal of the pipe leakage time prediction model is to forecast the leakage time of each pipe and the goal of the leakage time series prediction model is to forecast the future leakage trend of pipelines. The date set used for analysis comes from a city of north China. The results show that the models provide good estimates for pipe leakage and can be useful for water utilities in pipe inspection and maintenance. Active leakage control in pipe networks can be achieved using the models and the blindness maintenance will be reduced.

It is a challenging task to design a trust model that can effectively evaluate the relationships between different entities under Grid computing environment. In recent years, integrating trust into grid computing systems has been a hot research spot. In this paper a dynamic trust model is proposed based on direct trust and recommendation trust. Due to the dynamic nature of grid environment, the trust value that one entity holds about another entity is also dynamic in this model. If the entity performed well, then its trust value should be increased and if the entity performed bad, its trust value should be decreased. The trust value is computed either using direct trust value or using recommendation trust value according to the interaction history of the entities. Simulation experiments are provided to assess the model.

The deterioration of pipes in water distribution systems can lead to pipe breaks and leaks which may result in a reduction in the water-carrying capacity of pipes and lead to economic, safety and environmental issues Leakage can be detected by correlating changes in flow characteristics to changes in a hydraulic model for the network. This paper presented a nonlinear model-based leak detection method making use of monitoring pressure heads obtained from a test network. The leakage was simulated by the test work. The software EPANET was used to perform the hydraulic simulation of the network. The model was optimized by the genetic algorithm. The results show that model built can estimate the leakage location and leakage amounts. It was suitable for estimating small pipe leakage and the results satisfied the engineering applications, which is useful for water utilities in pipe inspection and maintenance.

To explore the mechanism governing the reversal of multidrug resistance in human breast carcinoma cells by chelerythrine.Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to determine the expressions of protein kinase Cα (PKCα) and multidrug resistance-related genes ABCG2, ABCC1, MDR1, and P-glycoprotein (P-gp) in MCF-7Taxol cells after treatment with chelerythrine and phorbol-12-myristate-13-acetate (PMA). Also, the antitumor effect of PMA or chelerythrine and effects of PKCα activator or inhibitor in combination with paclitaxel or adriamycin on multidrug resistance in MCF-7Taxol cells were evaluated by MTT.RT-PCR or Western blot showed that the expressions of MDR1 and P-gp were significantly higher in MCF-7Taxol cells exposed to PMA stimuli (both P0.05).PKCα inhibitor chelerythrine can reverse multidrug resistance in breast carcinoma cells by inhibiting the expressions of MDR1 and P-gp expression in vitro.

In this paper, a feature perturbation by mutual information is proposed and multiple nearest neighbor classifiers are combined according to this way. Multiple nearest neighbor classifiers system based on feature perturbation can improve the performance of single nearest neighbor classifier biased with the curse of dimensionality. However, there are two problems in multiple nearest neighbor classifiers system based on feature perturbation: (i) how to determine the number of component classifiers, and (ii) how to select features for each component classifier. In this paper, the proposed method by mutual information is able to solve the two problems. (i) The number of component classifiers is set to be the number of classes, and (ii) the selected features for each component classifier are automatically determined by mutual information. In order to evaluate the effectiveness of the proposed method, three UCI datasets are selected. And the proposed method is compared with: (i) NNC, (ii) NNC after feature selection by mutual information, (iii) multiple nearest neighbor classifiers system based on feature perturbation by attribute bagging. The experimental results show that multiple classifiers system is superior to single classifier. And multiple nearest neighbor classifiers system based on feature perturbation by mutual information is better than any other combination methods. In addition, the number of component classifiers in the proposed method is less than any other methods.

The paper is based on the formula put forward by Shannon, which is used to measure the information flow generated from discrete variables, and also the maximum entropy rule put forward by Jaynes, which is used to describe the distribution of maximum entropy. Through analysing the characters of entropy function, we draw a conclusion of the relationship between the value of entropy function and the possibility of variables. At the end, compressed organization structure is proved to be superior to hierarchical structure.

Sewage treatment system is a complicated nonlinear system with multi-variables, chemical reaction, biological process and altered loads, hard to describe mathematically. Thus prediction of the effluent quality of sewage treatment plant through a mathematical model has being a challenge. In this paper we adopts regression support vector machine (SVM) to set up a prediction model of a sewage treatment plant with a popular process cyclic activated sludge system (CASS). Kernel function of the prediction model is radial basic function, and parameters of the kernel function are optimally determined by cross-validation. Then the prediction model is used to predict effluent quality of the sewage treatment plant with CASS process. Test result of the case study shows that the prediction model works well and the regression SVM is powerful in predicting effluent quality of CASS process sewage treatment plant with small sample learning ability and good generalization.

The frequency stability's definition in time domain is briefly introduced and four measurement methods are discussed in this paper, including direct counters, frequency difference multipliers, heterodyne method and dual mixer time difference method. Some detailed calculations on accuracies are given for a better comparison. What's more, for making precise measurements, an attempt to combine these four methods with the latest TDC and TAC techniques is made, and a block diagram is presented. Finally, we estimate the accuracies of these combinations: direct counters combined with the dual arctangent technique can reach 4 E-12/S, frequency difference multipliers with multi-phase clock TDC 2.5 E-13/S. When the multi-phase clock TDC technique applied on heterodyne method and dual mixer time difference method, the measurement accuracy respectively can reach 1.25 E-16/S and 2.5 E-17/S.

Digital product development process involves a good many function interoperations in Internet applications. But the heterogeneity of distributed applications affects their interoperability so as to reduce the accessibility and usability of product data. For the sake of the settle of this matter, an idea of application integration that looks upon service as core and a multi-layer integrated service model on the basis of intelligent service unit (ISU) are proposed to realize dynamic loose application integration. The structure of ISU is designed. The application of Web service technology in integration is also studied with the analysis of integration scenario on PDM/CAD, PDM/CAPP. Intelligent service units running integrated environment based on PDM are designed and realized. The feasibility of the techniques in this paper is validated by the developing of a PDM prototype system.