Simulation of oxygen transfer in liquid lead under influence of nanoparticles by using lattice Boltzmann method

Oxygen transfer presents a serious challenge in the application of liquid lead as a nuclear coolant in advanced reactors. To mitigate corrosion by liquid lead in contact with steel, carefully controlling the oxygen concentration has been used as an effective way. Oxygen needs to mix in liquid lead uniformly and quickly. To enhance oxygen transport in liquid lead, nanoparticles are added to the liquid metal. In the current study, a lattice Boltzmann method is applied to investigate natural convection of copper/lead and aluminum oxide/lead in two-dimensional simplified container. Two thermal boundary cases are evaluated in order to check the effect of different natural convection flow patterns on oxygen transport. Some useful information are obtained such as improvement in natural convection and reduction in oxygen equilibrium time.

Local Government-owner Bidder and Corporate Control Transfer

In this study, we discuss the financial constraints and the behavior of local governments. We expect that governments in relative wealthy region will act as a helping hand for companies trader its control on average, while those in relative poor region will be a grabbing hand. By dividing local governments into 3 categories according to its GDP per capita and Fiscal Revenue per capita, we test the relationship between government attributes and the long-term performance of listed companies in corporate control market. We find that target companies who are later controlled by the wealthiest government achieve better performance, while those who were later controlled by the poorest governments also achieve significant better long-term performance.

THE CONTROL OF POLYMETHACRYLATE MOLECULAR STRUCTURE BY GROUP TRANSFER POLYMERIZATION

INTRODUCTION Group transfer polymerization (GTP) is a method for controlling the structure of acrylic polymers in which reactive chain ends are covalentiy bound to a trimethylsilyl group. In the presence of a catalyst, monomer inserts into these chain ends between the silyl group and the last monomer unit. The process is illustrated by equation (1) for methyl methacrylate. GTP is a living polymerization, i. e., there is little or no chain termination and no chain transfer. A significant advantage of GTP is that it

GENERALIZED TRANSFER FUNCTION OF CONTROL SYSTEM AND AN IMPROVEMENT ON THE DECISION METHOD OF MOVEMENT STABILITY

In this paper the definitions of generalized transfer functios of control system and itscontinuity are presented.Using generalized transfer function as a tool,a set of theorems fordeciding movement stability have been constructed.Thus basing understanding of thecharacteristics of a control dynamics system on its measured procedure will simplify thedecision method of movement stability problems.

Accelerated transmission in peer-to-peer network

The design and evaluation of accelerated transmission （AT） systems in peer-to-peer networks for data transmission are introduced. Based on transfer control protocol （TCP） and peer-to-peer （P2P） substrate networks, AT can select peers of high performance quality, monitor the transfer status of each peer, dynamically adjust the transmission velocity and react to connection degradation with high accuracy and low overhead. The system performance is evaluated by simulations, and the interrelationship between network flow, bandwidth utilities and network throughput is analyzed. Owing to the collaborative operation of neighboring peers, AT accelerates the process of data transmission and the collective network performance is much more satisfactory.

Authentication and Access Control in RFID Based Logistics-customs Clearance Service Platform

The content security requirements of a radio frequency identification （RFID） based logistics-customs clearance service platform （LCCSP） are analysed in this paper. Then, both the unified identity authentication and the access control modules are designed according to those analyses. Finally, the unified identity authentication and the access control on the business level are implemented separately. In the unified identity authentication module, based on an improved Kerberos-based authentication approach, a new control transfer method is proposed to solve the sharing problem of tickets among different servers of different departments. In the access control module, the functions of access controls are divided into different granularities to make the access control management more flexible. Moreover, the access control module has significant reference value for user management in similar systems.

BIFURCATIONS AND CHAOS CONTROL IN TCP-RED SYSTEM

Objective Analyzing the nonlinear dynamics of the TCP-RED congestion control system is of great importance. This study will help investigate the loss of stability in Internet and design a proper method for controlling bifurcation and chaos in such system. Methods Based on bifurcation diagram, the effect of parameter on system performance is discussed. By using the state feedback and parameter variation strategy, a simple real time control method is proposed to modify the existing RED scheme. Results With our control method, the parametric sensitivity of RED mechanism is attenuated. Moreover, a sufficient condition on the robust stability of the system is also derived to adjust the parameters in TCP-RED system. Conclusion The proposed method has the advantages of simple implementation and unnecessary knowledge of the exact system.

STUDY AND ENHANCEMENT ON BUFFER MANAGEMENT FOR SMOOTH HANDOVER IN MIPV6

For improving Transfer Control Protocol (TCP) performance in mobile environment,smooth handover with buffer management has been proposed to realize seamless handovers. However in our simulation, even if smooth handover in Mobile IPv6 (MIPv6) is implemented, TCP can not always achieve better performance due to packets forwarding burst. Based on the study of buffer management for smooth handover, this paper proposes an enhanced buffer management scheme for smooth handover to improve TCP performance. In this scheme, a packet-pair probing technology is adopted to estimate the available bandwidth of the new path from Previous router (Prtr) to Mobile Node (MN), which will be used by Prtr to control the buffered packets forwarding. The simulation results demonstrate that smooth handover with this scheme can achieve better TCP performance than the original scheme.

A NOVEL MARKOV ANALYTICAL MODEL FOR THE TCP/AQM SYSTEMS

A novel closed-loop feedback TCP/AQM(Transfer Control Protocol/Active Queue Management) model is proposed in this paper using a discrete-time Markov chain,and a way to calculate the equilibrium distribution of this model is given.In the model,system time is divided into time slots,the bottleneck router queue model and TCP window size model in each slot are analyzed.Finally,by combining adjacent slots,an integrated TCP/AQM analytical model is developed.By this model,the average values of packets dropping ratio and queue length in the router and TCP sending rate can be estimated,hence,this model could be a useful tool for the analysis of AQMs and support the development of new AQM schemes theoretically.The proposed TCP/AQM model is extended to a TCP-UDP(Control User Datagram Protocol)/AQM model,to analyze the TCP/AQM system performance when UDP flows exist.By implementing this model on Matlab,we compare its solutions to NS2 simulated solutions,then the validity of the model to analyze the closed-loop feedback TCP/RED(Random Early Detection) system is verified.

Mass Media and Urban Tribes, Analysis of Their Relations by Stafford Beer＇s Viable System Model

This paper discusses the relations between mass media and urban tribes, by Stafford Beer＇s viable system model （VSM）. During 1950-2010, the influence of media and advertising over individual decision-making processes has deepened of age range to which have targeted advertising and expanded for Western world, leading the culture diversity, naturally given, toward only one standardized culture prevailing nowadays. In the 1960s they were the women, then the young people during 1970s, and then children in the 1980s and during the 1990s over early childhood, when we learnt to speak （3 years old）, achieving brand loyalty among very young children and the brands of products for this age group. From this perspective, urban tribes have taken control of the lives of young people, offering a false freedom, at the moment of choosing ＂How to be yourself＂ from options given in the market as a ＂catalogue of predesigned identities＂. A phenomenon is so complex, so it requires a holistic framework able to make explicit its components and relations between them and the relationship with internal and external environment. In particular, the VSM provides a way to analyze communication＇s problems thus clarifying： how, when and where, repair and controlling into the organization, identifying strategies to improve decision-making. Given the recursive nature of the VSM, it is possible to navigate within the phenomenon, through different recursions＇ levels. It will help to define more assertive and effective policies by health authorities, education and government in general, and also help someone among young people to see themselves inside of a dynamic consumption and thus can leave the domain and enter into a recta-domain, with more wisdom and consciousness.

The Application of NPs in WCDMA Systems

Recent efforts to add new services to the wide-band code division multiple accesses （WCDMA） system have increased interest in network processor （NP）-based routers that are easy to extend and evolve. In this paper, an application of NPs in routing engine module （REM） of radio network controller （RNC） in WCDMA system is proposed. The measuring results show that NPs have good performance and efficiency in routing traffic of the communication network and the simulation verifies the fast forwarding function of NPs.

How much control causes tunneling? Evidence from China

We study the dynamic causal effects of the shareholding ratio of controlling shareholder on tunneling behavior in China.We use control-right-transfers as the event to conduct the study.We obtain 394 control-right-transfer samples in China corporate control market from 2001 to 2008.We use related party transactions amount to capture control shareholders’tunneling activities,and make the following findings.Firstly,tunneling behavior is significantly affected by the shareholding ratio of controlling shareholder.Secondly,the relationship between tunneling and shareholding ratio of controlling shareholder takes an N shape(incline-decline-incline).There are at least two turning points in the relationship.Furthermore,firms with shareholding ratios of controlling shareholder that range from 34.46%to 39.01%(8.99–18.04%)exhibit the most(least)severe tunneling.Firm size is significantly positively related to tunneling activities.In addition,the shareholding ratios of the board and the tunneling activities are significantly negatively correlated.These findings imply the shareholding ratio decision of controlling shareholder in control transfers lead to agency problems manifested in China in a particular form of tunneling.

A seventh-order model for dynamic response of an electro-hydraulic servo valve

In this paper, taking two degrees of freedom on the armature–flapper assembly into account, a seventh-order model is deduced and proposed for the dynamic response of a two-stage electro-hydraulic servo valve from nonlinear equations. These deductions are based on fundamental laws of electromagnetism, fluid, and general mechanics. The coefficients of the proposed seventhorder model are derived in terms of servo valve physical parameters and fluid properties explicitly.For validating the results of the proposed model, an AMESim simulation model based on physical laws and the existing low-order models validated by other researchers through experiments are used to compare with the seventh-order model. The results show that the seventh-order model can reflect the physical behavior of the servo valve more explicitly than the existing low-order models and it could provide guidance more easily for a linear control design approach and sensitivity analysis than the AMESim simulation model.

Design method of supercritical hydrocarbon fuel injection for a scramjet

Both the fuel transfer control scheme and the knowledge of fuel temperature and pressure values before injection are important to a scramjet engine.A measurement method of the fluid temperature suitable for small channel is presented,and a fluid transfer control scheme of the area of injecting holes is designed using the balance equations of fluid mass,energy and entropy.A convective heat transfer experiment is conducted to evaluate the temperature measurement and the fluid transfer control design method of the heat absorbing supercritical hydrocarbon fuel.The results show that during the heating process the injecting pressure meets the requirement,and the fluid transfer control system works well.Such results suggest that the design method in the present work would be useful in the design of regenerative cooling for scramjet engines.