“傻瓜模具胶”

山西运城大成模具工艺厂开发出了集加热法软模、常温法软模诸多优点为一体的“傻瓜模具胶”。它一经问世就受到了消费者青睐。目前,该产品与技术正在全国范围内热力推广。 据该公司技术人员介绍,“傻瓜模具胶”

Traffic-prediction-assisted dynamic power saving mechanism for IEEE 802.16e wireless MANs

How to reduce the energy consumption powered mainly by battery to prolong the standby time is one of the crucial issues for IEEE 802.16e wireless MANs.By predicting the next downlink inter-packet arrival time,three traffic-prediction-assisted power saving mechanisms based on P-PSCI,i.e.,PSCI-PFD,PSCI-ED and PSCI-LD,were proposed.In addition,the corresponding adjustment strategies for P-PSCI were also presented when there were uplink packets to be transmitted during sleep mode.Simulation results reveal that compared with the sleep mode algorithm recommended by IEEE 802.16e,the proposed mechanism P-PSCI can improve both energy efficiency and packet delay for IEEE 802.16e due to the consideration of the traffic characteristics and rate changes.Moreover,the results also demonstrate that PSCI-PFD (a=-2) significantly outperforms PSCI-ED,PSCI-LD,and the standard sleep mode in IEEE 802.16e is in terms of energy efficiency and packet delay.

Numerical simulation and model of control-efficiency of thermal crown of work rolls in cold rolling

Aiming at accuracy control of the thermal crown of work rolls in cold rolling,new parameters such as regulation domain and control-efficiency factors were proposed and a numerical analysis model of the thermal crown of work rolls was established using finite difference method to study roll's thermal deformation.Based on simulation results,the influences of control-efficiency factors on thermal crown are presented and the thermal crown of work rolls is analyzed after taking sub-cooling of sprinkling beam into consideration.It has been found that the control-efficiency factor of any position on the roll's surface is linear function of the temperature and the control ability of water temperature is stronger than other control parameters.In addition,the verification of the model has been carried out based on the producing technology data in some factories and the numerical simulation results coincide well with the experimental data.Therefore,this work has important value for on-line control of roll's crown in cold rolling.

Study on LQR control algorithm using superelement model

The conventional linear quadratic regulator(LQR) control algorithm is one of the most popular active control algorithms.One important issue for LQR control algorithm is the reduction of structure's degrees of freedom(DOF). In this work, an LQR control algorithm with superelement model is intended to solve this issue leading to the fact that LQR control algorithm can be used in large finite element(FE) model for structure. In proposed model, the Craig-Bampton(C-B) method, which is one of the component mode syntheses(CMS), is used to establish superelement modeling to reduce structure's DOF and applied to LQR control algorithm to calculate Kalman gain matrix and obtain control forces. And then, the control forces are applied to original structure to simulate the responses of structure by vibration control. And some examples are given. The results show the computational efficiency of proposed model using synthesized models is higher than that of the classical method of LQR control when the DOF of structure is large. And the accuracy of proposed model is well. Meanwhile, the results show that the proposed control has more effects of vibration absorption on the ground structures than underground structures.

Fog Computing Dynamic Load Balancing Mechanism Based on Graph Repartitioning

Because of cloud computing's high degree of polymerization calculation mode, it can't give full play to the resources of the edge device such as computing, storage, etc. Fog computing can improve the resource utilization efficiency of the edge device, and solve the problem about service computing of the delay-sensitive applications. This paper researches on the framework of the fog computing, and adopts Cloud Atomization Technology to turn physical nodes in different levels into virtual machine nodes. On this basis, this paper uses the graph partitioning theory to build the fog computing's load balancing algorithm based on dynamic graph partitioning. The simulation results show that the framework of the fog computing after Cloud Atomization can build the system network flexibly, and dynamic load balancing mechanism can effectively configure system resources as well as reducing the consumption of node migration brought by system changes.

Thermodynamic performance of Dual-Miller cycle(DMC) with polytropic processes based on power output, thermal efficiency and ecological function

This study reports a new model of an air standard Dual-Miller cycle(DMC) with two polytropic processes and heat transfer loss.The two reversible adiabatic processes which could not be realized in practice are replaced with two polytropic processes in order to more accurately reflect the practical working performance. The heat transfer loss is taken into account. The expressions of power output, thermal efficiency, entropy generation rate(EGR) and ecological function are addressed using finite-time thermodynamic theory. Through numerical calculations, the influences of compression ratio, cut-off ratio and polytropic exponent on the performance are thermodynamically analyzed. The model can be simplified to other cycle models under specific conditions, which means the results have an certain universality and may be helpful in the design of practical heat engines. It is shown that the entropy generation minimization does not always lead to the best system performance.

Airside fin efficiencies for finned-tube heat exchangers with forced convection

The heat transfer and mass transfer fin efficiencies were analyzed numerically to show that popular models for heat transfer fm efficiency for circular fins are not always reasonable. The numerical results show that the effective heat transfer area of a circular fin increases several times faster than that of a straight fin for the same tube radius. Then, a simple but accurate heat transfer fin efficiency model was developed and verified by numerical results for a wide range of fin designs. This model predicts the heat transfer fin efficiency with absolute errors of less than 1%. The heat transfer and mass transfer fin efficiencies were found to be quite different for typical air flow with low relative humidity. Thus, these two fin efficiencies should not be assumed to be equal and a mass transfer fin efficiency model was developed, based on the heat transfer fin efficiency model. These heat transfer and mass transfer fin efficiencies are very useful for more accurate prediction for a wide range of practical applications.