Vibration Control of A Flexible Marine Riser System Subject to Input Dead Zone and Extraneous Disturbances

An observer-based adaptive backstepping boundary control is proposed for vibration control of flexible offshore riser systems with unknown nonlinear input dead zone and uncertain environmental disturbances.The control algorithm can update the control law online through real-time data to make the controller adapt to the environment and improve the control precision.Specifically,based on the adaptive backstepping framework,virtual control laws and Lyapunov functions are designed for each subsystem.Three direction interference observers are designed to track the timevarying boundary disturbance.On this basis,the inverse of the dead zone and linear state transformation are used to compensate for the original system and eliminate the adverse effects of the dead zone.In addition,the stability of the closed-loop system is proven by Lyapunov stability theory.All the system states are bounded,and the vibration offset of the riser converges to a small area of the initial position.Finally,four examples of flexible marine risers are simulated in MATLAB to verify the effectiveness of the proposed controller.

Agricultural Input and Output in Jiangsu Province with Case Analysis

[Objective] The aim was to explore interrelationship between agricultural input and output in Jiangsu and the influence degrees of input factors on agricultur-al output. [Method] Quantitative analysis and evaluation were made on agricultural input and output in Jiangsu during 1990-2012 as per factor analysis and regression analysis. [Result] The result of factor analysis showed that since the 1990s, the comprehensive efficiency of agricultural input/output in Jiangsu was growing and in-put/output of agriculture, forestry, animal husbandry and fishery, crop farming, and of food production were extracted, whose scores reflect the changes of input/output ef-ficiencies in terms of agriculture, forestry, animal husbandry, fishery, crop farming and food production in the two decades. The results of regression analysis indicated that the effects of the three indices on agricultural output tended to be volatile and the influence degrees were concluded also by regression parameters. [Conclusion] The research provides theoretical references for agricultural input/output structure in Jiangsu Province.

On the Balance Between “Input” and “Output” in College English Teaching

The current college English teaching is usually associated with two discouraging words—"time-consuming"and"inefficient", which badly demands some urgent solutions. On the basis of Krashen's Input Hypothesis and Swain's Output Hypothesis, this paper elaborates the indispensable and critical roles respectively of input and output in language learning, and proposes a concept of balanced input and output in college English teaching. The paper also presents some personal suggestions as to how to bring the balance into teaching.

Input and Output Balance to Assist in Language Competence

Second Language Acquisition(SLA) education in China suffers from an imbalance between language input and output.Reading and listening are the dominate methods used in the classroom,while speaking and writing are used far less.This paper examines the results that are caused by this imbalanced development of comprehensible output and input.Alternative solutions are examined.The results show the limitations in students' abilities that are commonly based on the current methods of teaching.The implications are that policy makers,curriculum developers and teachers should strive to balance the amount of comprehensible input and output through various means.

The Study of Strategies in College English Translation Teaching from the Perspective of Input and Output Theory

Research on SLA gives highlights to English translation teaching. The second language acquisition is a cognitive process of understanding and outputting the second language by making use of strategies, which contains language input, learners' linguistic knowledge, and language output. This paper analyzes language input and output theory and then proposes that we should stress language input by practice and interaction and at the same time focus on the role of language output in college English translation teaching.

Influence of heat input on microhardness and microstructure across the welding interface between stainless steel and low alloy steel

The welding interface is crucial to the service safety of dissimilar metal weld(DMW)joints between stainless steel(SS)and low alloy(LA)steel.Different status of welding interfaces was prepared by cladding SS consumables to LA steel substrates with different heat inputs via tungsten inert gas arc welding(TIG),followed by a series of microstructural characterizations and hardness tests.Results showed that a hardening and transition layer(TL)would be generated along the welding interface,and the width and hardening degree of the TL would increase with the heat input.Meanwhile,heavy load hardness tests showed that highly severe inhomogeneous plastic deformation and the microcrack would be generated in the interfacial region and the welding interface respectively in the highest heat input sample(1.03 kJ/mm).These results indicate that the increase in heat input would deteriorate the bonding performance of DMW joints.Further microstructural observations showed that the higher hardening degree of the highest heat input sample was mainly attributed to the stronger grain boundary,solution,and dislocation strengthening effects.

Influence of heat input on the microhardness and microstructure of the welding interface between nickel-based alloy and low-alloy steel

The evolution of microstructure and local properties near the welding interface is essential for the service safety of dissimilar metal welded joints between nickel-based alloy(NA) and low-alloy steel(LA).In this work,NA filler metal was deposited on LA substrate under different heat inputs by tungsten inert gas(TIG) welding.Microstructural characterization and microhardness tests were carried out near the prepared cladding interfaces.Optical and scanning electron microscopes show the lack of evident hardening transition layer along the welding interface.As the heat input increases,the mean hardness of the deposited layer also increases remarkably due to the rising dilution rate.Microstructural characterization shows a significant composition gradient across the cladding interface,but the diffusion gradient is limited to a small range.Under high heat input,a planar grain zone is generated along the interface due to the large temperature gradient across the interface region.

Exact controllability of rational expectations model with multiplicative noise and input delay

This paper considers the rational expectations model with multiplicative noise and input delay,where the system dynamics rely on the conditional expectations of future states.The main contribution is to obtain a sufficient condition for the exact controllability of the rational expectations model.In particular,we derive a sufficient Gramian matrix condition and a rank condition for the delay-free case.The key is the solvability of the backward stochastic difference equations with input delay which is derived from the forward and backward stochastic system.

Adaptive Control Based on Neural Networks for an Uncertain 2-DOF Helicopter System With Input Deadzone and Output Constraints

In this paper, a study of control for an uncertain2-degree of freedom(DOF) helicopter system is given. The2-DOF helicopter is subject to input deadzone and output constraints. In order to cope with system uncertainties and input deadzone, the neural network technique is introduced because of its capability in approximation. In order to update the weights of the neural network, an adaptive control method is utilized to improve the system adaptability. Furthermore, the integral barrier Lyapunov function(IBLF) is adopt in control design to guarantee the condition of output constraints and boundedness of the corresponding tracking errors. The Lyapunov direct method is applied in the control design to analyze system stability and convergence. Finally, numerical simulations are conducted to prove the feasibility and effectiveness of the proposed control based on the model of Quanser's 2-DOF helicopter.

Research on consensus of multi-agent systems with and without input saturation constraints

In recent years,with the continuous development of multi-agent technology represented by unmanned aerial vehicle(UAV)swarm,consensus control has become a hot spot in academic research.In this paper,we put forward a discrete-time consensus protocol and obtain the necessary and sufficient conditions for the second-order consensus of the second-order multi-agent system with a fixed structure under the condition of no saturation input.The theoretical derivation verifies that the two eigenvalues of the Laplacian of the communication network matrix and the sampling period have an important effect on achieving consensus.Then we construct and verify sufficient conditions to achieve consensus under the condition of input saturation constraints.The results show that consensus can be achieved if velocity,position gain,and sampling period satisfy a set of inequalities related to the eigenvalues of the Laplacian matrix.Finally,the accuracy and validity of the theoretical results are proved by numerical simulations.

Neural adaptive chaotic control with constrained input using state and output feedback

This paper presents neural adaptive control methods for a class of chaotic nonlinear systems in the presence of constrained input and unknown dynamics. To attenuate the influence of constrained input caused by actuator saturation, an effective auxiliary system is constructed to prevent the stability of closed loop system from being destroyed. Radial basis function neural networks（RBF-NNs） are used in the online learning of the unknown dynamics, which do not require an off-line training phase. Both state and output feedback control laws are developed. In the output feedback case, high-order sliding mode（HOSM） observer is utilized to estimate the unmeasurable system states. Simulation results are presented to verify the effectiveness of proposed schemes.

Comparative and Empirical Study on Vegetable Input-Output Efficiency of Suburban and Rural Areas

On the basis of comparative analysis on the vegetable input-output efficiency of suburban and rural areas in 2011- 2012,this paper made co-integration test,impulse response and variance decomposition for the vegetable input-output relationship of suburban areas in 1998-2012. Comparative analysis indicated that the vegetable input-output benefit of suburban area declines,while that of rural area rises; empirical analysis indicated that there is a long-term stable relationship between labor cost of vegetable planting and vegetable income and between material cost of vegetable planting and vegetable income,but the vegetable income itself has certain lag effect,followed by material cost,and the labor cost has minimum influence. Finally,it came up with recommendations for improving suburban vegetable input-output relationship,including improving vegetable input security mechanism,improving farmers' quality and innovation ability,and increasing technological input.

An evaluation of input/dissipation terms in WAVEWATCH Ⅲ using in situ and satellite significant wave height data in the South China Sea

A WAVEWATCH III version 3.14（WW3） wave model is used to evaluate input/dissipation source term packages WAM3, WAM4 and TC96 considering the effect of atmospheric instability. The comparisons of a significant wave height acquired from the model with different packages have been performed based on wave observation radar and HY-2 altimetry significant wave height data through five experiments in the South China Sea domain spanning latitudes of 0°–35°N and longitudes of 100°–135°E. The sensitivity of the wind speed correction parameter in the TC96 package also has been analyzed. From the results, the model is unable to dissipate the wave energy efficiently during a swell propagation with either source packages. It is found that TC96 formulation with the ＂effective wind speed＂ strategy performs better than WAM3 and WAM4 formulations. The wind speed correction parameter in the TC96 source package is very sensitive and needs to be calibrated and selected before the WW3 model can be applied to a specific region.

Grey analysis of the relationship between grain output and major input factor in Guizhou Province:1983-2005

Because conditions for the grain production are not favorable and the input in the production factors ofmodern agriculture is not sufficient, the grain supply has been less than the demand for a long time. By means of greycorrelation analysis, this paper deals with the correlation situation among such input factors as the grain sown area, thetotal power of agricultural machinery, the fertilizer utilization volume, the actual irrigation area, the damage area, thenumber of farming labor force, in order to understand the major restricting and driving forces that have affected thegrain output in the recent 23 years. The analysis shows that the grain sown area and fertilizer utilization volume are thetwo most important leading factors that affect grain production in Guizhou Province, while the damage area and the totalpower of the farming-used machines are the following factors. Fertilizer utilization volume and the actual agriculturalmachinery and irrigation area are the two increasingly influential factors that affect grain production. The influence of thefarming labor force upon grain production became less strong. The main measures to increase grain production outputin Guizhou Province are to stabilize the arable land, increase the actual irrigation area, expedite the transfer of thefarming labor force and increase the input of modern agriculture.

Fundamental Theories of Second Language Acquisition: The Input Hypothesis, the Output hypothesis, and the Interaction Hypothesis

In the field of applied linguistics,several hypotheses have been proposed for second language acquisition:the Input Hypothesis,the Output hypothesis,and the Interaction Hypothesis.They address the fundamental components of successful second language acquisition respectively.This paper introduces these hypotheses and constructs a comprehensive picture based on them。

The Role of Input, Interaction and Output in Second Language Learning

This article mainly talks about the role of input,interaction,and output in the second language acquisition.Input is believed as a trigger for learners’language learning.And the process from input to output is interaction.Through interaction,language learners can negotiate the meaning with the interlocutor and narrow down the gap between the target language and their own.All the hard work made in interaction is to produce output,which includes three functions:noticing function,hypothesistesting function,and metalinguistic function.Some teaching examples are shown to testify the hypothesis and its function in the process of second language acquisition.

Response of Terrigenous Sediment Input to Sea Level Change and East Asian Monsoon Evolution Since 30kyr in the Southwestern Taiwan Basin

The compositions of grain size,clay minerals,and geochemical elements in core sediments(TS4)from the southwestern Taiwan Basin(South China Sea)were investigated to assess the response of terrigenous sediment input to sea level change and the East Asian monsoon evolution since 30 kyr.The chronology was discussed based on foraminiferal AMS14C dates.Our results indi-cated that rivers in Taiwan have been the major sediment contributors since 30 kyr,followed by the Pearl River;and Luzon Island contribute little sediments to the southwestern Taiwan Basin.In this study,we reconstructed the variations in terrigenous sediment input by using the proxies such as Al2O_(3)(%),F1 score,and TiO_(2)/CaO.The F1 score can be used to indicate the flux of terrigenous sediments.The contribution of Taiwan Residents rivers and the Pearl River were evaluated by using the value of(illite+chlorite)/kaolinite.The variations of Al2O_(3)(%),F1 score,and TiO_(2)/CaO values along the core were clearly correlated to the evolution of the East Asian summer monsoon since 30 kyr.Based on these records,we recognized three evolutionary stages of terrigenous sediment input in the southwestern Taiwan Basin.During stage Ⅰ(29-24kyr),the input of terrigenous sediments continued to increase.During stage Ⅱ(24-11.5 kyr),the sediment input decreased at first and then increased,with the lowest value during the last glacial period(21-17kyr).Terrigenous sediment input during stage Ⅲ(11.5 kyr-)showed the decreasing first and then increasing trends,generally higher than those in the first and second stages.The variations of terrigenous sediment input in the study area corresponded well with the evolu-tion of the East Asian summer monsoon since 30 kyr.Increased terrigenous sediment input during 4-1.8 kyr was suggested to be caused by the enhanced ENSO activity.Sea level change does not alter the overall trend of terrigenous sediment input,but does change the relative contributions of rivers in Taiwan and the Pearl River.

Neural Network Based Scheduling for Variable-Length Packets in Gigabit Router with Crossbar Switch Fabric and Input Queuing

A high-speed and effective packet scheduling method is crucial to the performance of Gigabit routers. The paper studies the variable-length packet scheduling problem in Gigabit router with crossbar switch fabric and input queuing, and a scheduling method based on neural network is proposed. For the proposed method, a scheduling system structure fit for the variable-length packet case is presented first, then some rules for scheduling are given. At last, an optimal scheduling method using Hopfield neural network is proposed based on the rules. Furthermore, the paper discusses that the proposed method can be realized by hardware circuit. The simulation result shows the effectiveness of the proposed method.

Channel capacity of multiple-input multiple-output systems with transmit and receive correlation

In order to investigate the impact of channel model parameters on the channel capacity of a multipleinput multiple-output （MIMO） system, a novel method is proposed to explore the channel capacity under Rayleigh fiat fading with correlated transmit and receive antennas. The optimal transmitting direction which can achieve maximum channel capacity is derived using random matrices theory. In addition, the closed-form expression for the channel capacity of MIMO systems is given by utilizing the properties of Wishart distribution when SNR is high. Computer simulation results show that the channel capacity is maximized when the antenna spacing increases to a certain point, and furthermore, the larger the scattering angle is, the more quickly the channel capacity converges to its maximum. At high SNR （〉12 dB）, the estimation of capacity is close to its true wlue. And, when the same array configuration is adopted both at the transmitter and the receiver, the UCA yields higher channel capacity than ULA.

Environmental input-output model and its analysis with a focus on the solid waste management sectors

An environmental input output model (EIOM) was introduced to the regional solid waste management sectors, which can reflect the direct and indirect relations between the environment and the regional economy development. Some details about how to use the EIOM was discussed. The EIOM was applied to the Changsha City in China. The example results indicate that much useful information related to the environment and the regional economy development can be gained from the solution of the EIOM. Thus, the EIOM can be used as a useful tool for the sustainable development planning including the solid waste management sectors.