普铝铸造自动控流和应急装置的开发和应用

为了提高铝锭铸造生产线的自动化程度,降低人员作业的安全风险,在国电投集团科创部的大力支持下,鸿骏铸造车间联合锦溪科技开展了普铝铸造的自动控流和应急系统开发应用,建成一条示范型全自动调控流铝锭铸造生产线,提高自动化程度,降低安全风险。项目获评内蒙古智能装备首台套,项目得到内蒙古科技强国转化专项资金。自此取得了一定的效果,供同行参考。

感应流道式自动控流阀控水原理及性能分析

基于计算流体力学方法(有限体积法),针对一种感应流道式自动控流阀的控制原理及其内部流体流动特征进行研究。结果表明:该自动控流阀对流体黏度具有较强的识别能力,见水后自动控流阀能够有效自动关闭,当原油黏度大于2 mPa·s,该自动控流阀即可开启生产;感应流道的长度与流体黏度敏感性呈正相关,感应流道截面大小对流体黏度敏感性影响较大;与浮板式AICD和螺旋通道型AICD试验结果对比发现,相同条件下自动控流阀产油量更高,控水效果更好。研究结果对感应流道式自动控流阀的优化设计提供了理论依据。

提高铸轧机铝液液面控制精度的方法

引用自动控流装置及气流报警装置,根据装置机理编制PLC控制程序,经过反复实验、调整,参数优化,确定最佳控制方式,从而提高了铝液液面控制精度,有效保证了产品质量。

Reachability analysis of web service compositions via NWA

In order to improve the design and implementation quality of web service compositions,formal methods are used to model them and certain properties are verified.WCFA （web service interface control flow automata）is used to model web services,especially the control flow and possible interactions with other web services.A web service composition consists of a set of interacting WCFA.The global behavior of web service compositions is captured by NWA（nested word automata）.A variation of the depth-first search algorithm is used to transform a set of WCFA into an NWA.State formulae and call stacks at each node of NWA are computed by a path-sensitive reachability analysis.Safety properties,call stack inspection properties and pre/post-conditions of service invocations are described by assertions.Then verification of these assertions is carried out by an automated SAT tool.

A Two-Lane Cellular Automata Model with Influence of Next-Nearest Neighbor Vehicle

In this paper, we propose a new two-lane cellular automata model in which the influence of the next-nearest neighbor vehicle is considered, The attributes of the traffic system composed of fast-lane and slow-lane are investigated by the new traffic model. The simulation results show that the proposed two-lane traffic model can reproduce some traffic phenomena observed in real traffic, and that maximum flux and critical density are close to the field measurements. Moreover, the initial density distribution of the fast-lane and slow-lane has much influence on the traffic flow states. With the ratio between the densities of slow lane and fast lane increasing the lane changing frequency increases, but maximum flux decreases. Finally, the influence of the sensitivity coefficients is discussed.

Soft sensor modeling based on Gaussian processes

In order to meet the demand of online optimal running, a novel soft sensor modeling approach based on Gaussian processes was proposed. The approach is moderately simple to implement and use without loss of performance. It is trained by optimizing the hyperparameters using the scaled conjugate gradient algorithm with the squared exponential covariance function employed. Experimental simulations show that the soft sensor modeling approach has the advantage via a real-world example in a refinery. Meanwhile, the method opens new possibilities for application of kernel methods to potential fields.

SC response characteristics of two kinds of coagulant

Automatic coagulant dosage control with streaming current (SC) technique is introduced in this paper. Aluminum and ferric coagulants are widely used in surface water treatment. The SC response characteristics of P AlCl 3 aluminum coagulant and P FeCl 3 ferric coagulant were investigated in this work. Bench scale water treatment results were obtained from jar tests including rapid mixing, flocculation and undisturbed sedimentation. Results showed that aluminum coagulant is more sensitive than ferric coagulant to SC response.

A Potential Flow Based Flight Simulator for an Underwater Glider

Underwater gliders are recent innovative types of autonomous underwater vehicles （AUVs） used in ocean exploration and observation. They adjust their buoyancy to dive and to return to the ocean surface. During the change of altitude, they use the hydrodynamic forces developed by their wings to move forward. Their flights are controlled by changing the position of their centers of gravity and their buoyancy to adjust their trim and heel angles. For better flight control, the understanding of the hydrodynamic behavior and the flight mechanics of the underwater glider is necessary. A 6-DOF motion simulator is coupled with an unsteady potential flow model for this purpose. In some specific cases, the numerical study demonstrates that an inappropriate stabilizer dimension can cause counter-steering behavior. The simulator can be used to improve the automatic flight control. It can also be used for the hydrodynamic design optimization of the devices.

Service-based flexible workflow system for virtual enterprise

Using the services provided by virtual enterprises, we presented a solution to implement flexible inter-enterprise workflow management. Services were the responses of events that can be accessed programmatically on the Internet by HTTP protocol. Services were obtained according to some standardized service templates. The workflow engine's flexible control to a request was bound to appropriate services and their providers by using a constraint-based, dynamic binding mechanism. Hence, a flexible and collaborative business was achieved. The workflow management system supports virtual enterprise, and the styles of virtual enterprises can be adjusted readily to adapt various situations.

Application of Fuzzy Discrete Event System in Air Conditioning Energy-saving

Air conditioning (AC) system is the one with asynchronous and uncertain nature. In this paper, the fuzzy discrete event system (FDES) is introduced to the research of AC energy-saving control. A fuzzy automaton modeling is given for AC energy-saving control and effectiveness optimization is made. To facilitate the implement of the control and energy saving, priorities have been assigned to the major control steps based on logical reasoning. Forward-looking tree modeling based on FDES has been simplified to help further optimization, and a simple and concrete example has been put forward illustrating energy-saving control in AC system.

Cellular Automaton Models of Highway Traffic Flow Considering Lane-Control and Speed-Control

As two kinds of management modes of highway tramc control, lane-control, and speed-control produce different effect under different conditions. In this paper, traffic flow cellular automaton models for four-lane highway system with two opposing directions under the above two modes are established considering car and truck mixed running. Through computer numerical simulating, the fundamental diagrams with different parameters are obtained, and after the analysis of density-flux diagrams, the variation discipline of flux with traffic density under different control models is gained. The results indicate that, compared with lane-control, utilization ratio of road can be further improved with speed-control when the truck number increases. The research result is of great significance for reasonable providing theoretical guidance for highway traffic control.

CMOS Automatic Gain Control Circuit with DC Offset Cancellation for FM/cw Ladar

This paper presented an automatic gain control （AGC） circuit suitable for FM/cw ladar. The proposed architecture was based on two-stage variable gain amplifier （VGA） chain with a novel DC offset canceller circuit, which contained an improved Gilbert cell and a Gm-C feedback loop. To keep the VGA with a linearity in dB characteristic, an improved exponential gain control circuit was introduced. The AGC was implemented in 0.18 gm standard CMOS process. Simulation and measurement results verified that its gain ranged from -20 dB to 30 dB, and band- width ranged from 100 kHz to 10 MHz. Its power consumption was 19.8 mW under a voltage supply of 3.3 V.

Dynamic Control of a Flexible Shaft Mounted in Adaptive or Active Bearing

The dynamic behavior of rotors is highly influenced by bearing characteristics. In previous works, the authors have shown that it may be beneficial to adapt the bearing behavior to the shaft behavior. Several adaptive and active components will be developed in this paper in order to control the shaft dynamical amplitude. Different models of hydrodynamic bearings behavior are described. The Reynolds equation resolution may be done by numerical or analytical solutions. A physical analysis of the equation of thin films will identify the most sensitive parameters. The shaft flexibility is taking into account by a modal approach. The fluid-structure coupling process is a simulation, step by step, of the rotor behavior. At each step, the nonlinear fluid force is numerically calculated to obtain the unbalanced shaft response. The results, presented in this paper, concern the dynamic response of unbalanced shaft mounted in adaptive or active bearings： bearings with variable clearance, variable viscosity or variable housing speed. It is shown that the fluid bearing parameters must be adapted to the rotor speed （in particular near or far a critical speed）. Then, the paper presents a new kind of active bearing. It works with a mechanical control of the housing position. Several parameters are tested and compared. The robustness of the dynamic control parameters is presented. In conclusion, the bearing adaptation could be very useful to control the shaft dynamic. This limits the effect of the critical speed, in particular by diminishing the shaft amplitude and the dynamic forces transmitted to the housing.

Arterial embolization for iatrogenic life.threatening bleeding from subcutaneous hypervascular tumor in prone position

Performing angiography in the prone position is a difficult technique; however it is useful in some emergency situation. We experienced a 60 years old male who was performed lipema excision on his back in his family doctor＇s clinic. Since massive arterial bleeding could not be controlled with manual astriction, he transferred to our hospital in prone position with hemodynamic instability. Operating field was not kept because of massive bleeding; therefore surgical treatment was impossible. We planed emergency arterial embolization （AE） in prone position. Hence we chose the left radial artery for vascular access. The left subclavicle arteriography showed many major and minor feeding arteries from left subclavicular and axillary arteries and a massive extravasation of the contrast medium. Three major feeding arteries were performed AE with gelatin sponge and steel coils, After AE, massive bleeding was controlled. He could discharge from our hospital on the 5th hospital day without any complication. Arterial embolization for lifethreatening bleeding from subcutaneous hypervascular tumor in the prone position is first report to our knowledge, and it is extremely rare. However we thought that this technique is useful for patients who could not turn in the supine position, e.g. massive bleeding during renal biopsy and penetrating trauma from back.