求多级串联理想混合流反应器的出口浓度——二级可逆反应

在多级串联理想混合流反应器中进行二级可逆反应时,可用图解法和代数法求各级反应器的出口浓度。但图解法不够精确,代数法又费时费力,而且,当反应器个数趋于无穷大时,以上两种方法则无法计算。针对上述两种方法的不足,开发了一种新的方法,即利用C++语言,依据递推关系式编制程序,该程序能够迅速求解,并与计算结果完全一致。该法具有精确、快捷、通用、方便的优点。可以显著提高计算效率,不仅在多级串联理想混合流反应器的设计中具有重要应用价值,而且在实际的化学工业生产中也具有重要意义。具有推广价值。

求多级串联全混流反应器的出口浓度-1/3级不可逆反应

在多级串联全混流反应器中进行1/3级不可逆反应时,可用作图法和代数法求每一段反应器的出口浓度。但图解法不够精确,代数法又较为繁琐,而且当反应器个数很多时,上述两种方法则无能为力。考虑以上两种方法的不足,就具体实例,寻求了另外一种方法,即依据第N段反应器的出口浓度的表达式,利用C++语言编制程序,通过该程序能够快速求出每一段反应器的出口浓度,结果与代数法计算结果基本一致。该法具有简便、精确、高效以及通用的优点,不仅在多级串联全混流反应器的设计中具有重要应用价值,而且在实际的化学工业生产中也具有重要意义。

Prediction of Injection-Production Ratio with BP Neural Network

Injection of water to enhance oil production is commonplace, and improvements in understanding the process are economically important. This study examines predictive models of the injection-to-production ratio. Firstly, the error between the fitting and actual injection-production ratio is calculated with such methods as the injection-production ratio and water-oil ratio method, the material balance method, the multiple regression method, the gray theory GM (1,1) model and the back-propogation (BP) neural network method by computer applications in this paper. The relative average errors calculated are respectively 1.67%, 1.08%, 19.2%, 1.38% and 0.88%. Secondly, the reasons for the errors from different prediction methods are analyzed theoretically, indicating that the prediction precision of the BP neural network method is high, and that it has a better self-adaptability, so that it can reflect the internal relationship between the injection-production ratio and the influencing factors. Therefore, the BP neural network method is suitable to the prediction of injection-production ratio.

基于电力系统中不对称故障的分析与探讨

在电力系统运行过程中,时常会发生故障,且大多是短路故障。短路问题是电力技术方面的基本问题之一。通过短路问题分析 不对称故障,以此作为合理选择电气接线、选用有足够热稳定度和动稳定度的电气设备及载流导体、确定限制短路电流的措施、在电力系统 中合理地配置各种继电保护并整定其参数等的重要依据。分析计算不对称短路方法很多,目前实际最常用的方法是对称分量法。而以对称 分量法为核心的计算方法又可有解析法和计算机程序算法等。本文通过对电力系统不对称故障的计算、不对称短路计算、解析法和计算机 程序法的分析比较得出计算机程序法更优的结果。对区域电力系统的合理规划设计以及对提高电网的安全稳定性水平起到了实质、有效的 作用。

Strategies and Principles of Distributed Machine Learning on Big Data

The rise of big data has led to new demands for machine learning （ML） systems to learn complex mod- els, with millions to billions of parameters, that promise adequate capacity to digest massive datasets and offer powerful predictive analytics （such as high-dimensional latent features, intermediate repre- sentations, and decision functions） thereupon. In order to run ML algorithms at such scales, on a distrib- uted cluster with tens to thousands of machines, it is often the case that significant engineering efforts are required-and one might fairly ask whether such engineering truly falls within the domain of ML research. Taking the view that ＂big＂ ML systems can benefit greatly from ML-rooted statistical and algo- rithmic insights-and that ML researchers should therefore not shy away from such systems design-we discuss a series of principles and strategies distilled from our recent efforts on industrial-scale ML solu- tions. These principles and strategies span a continuum from application, to engineering, and to theo- retical research and development of big ML systems and architectures, with the goal of understanding how to make them efficient, generally applicable, and supported with convergence and scaling guaran- tees. They concern four key questions that traditionally receive little attention in ML research： How can an ML program be distributed over a cluster？ How can ML computation be bridged with inter-machine communication？ How can such communication be performed？ What should be communicated between machines？ By exposing underlying statistical and algorithmic characteristics unique to ML programs but not typically seen in traditional computer programs, and by dissecting successful cases to reveal how we have harnessed these principles to design and develop both high-performance distributed ML software as well as general-purpose ML frameworks, we present opportunities for ML researchers and practitioners to further shape and enlarge the area that lies between ML and systems..

Research on extended AHP method with the aid of RST

Analytic Hierarchy Process (AHP) method can be used to solve the tasks of multi-criterion decision system fields, but some complicated questions processed by AHP cannot be easily solved by means of the general method. It is because of being unsatisfied with consistency condition or judgment matrix too intricate to solve, which causes AHP invalidation. So in order to resolve this problem, AHP knowledge systems reduced with the aid of Genetic Algorithms (GA) were proposed, which directly acquired the order of AHP issue through the rule of Rough Sets Theory (RST) method, or solved the tasks reduced by RST with classical AHP method. On this condition, the compare decision system of region informatization level was solved, and the results solved were the same to those by classical AHP, which denoted that this method was more simple and reliable, besides the four rules of changing AHP system into RST Decision System.

Quality of service estimation based on maximum bottleneck algorithm for domain aggregation in backbone networks

This paper investigates the routing among autonomous systems (ASs) with quality of service (QoS) requirements. To avoid the intractability of the problem, abstract QoS capability must be informed among ASs, because the routhing which constrained QoS has been proved to be nondeterministic polynomial-time (NP) hard even inside an AS. This paper employs the modified Dijkstra algorithm to compute the maximum bottleneck bandwidth inside an AS. This approach lays a basis for the AS-level switching capability on which interdomain advertisement can be performed. Furthermore, the paper models the aggregated traffic in backbone network with fractional Brownian motion (FBM), and by integrating along the time axis in short intervals, a good estimation of the distribution of queue length in the next short intervals can be obtained. The proposed advertisement mechanism can be easily implemented with the current interdomain routing protocols. Numerical study indicates that the presented scheme is effective and feasible.

Geospacial information utilized under the access control strategy

This paper introduces a solution to the secure requirement for digital rights management （DRM） by the way of geospacial access control named geospacial access control （GeoAC） in geospacial field. The issues of authorization for geospacial DRM are concentrated on. To geospacial DRM, one aspect is the declaration and enforcement of access rights, based on geographic aspects. To the approbation of digital geographic content, it is important to adopt online access to geodata through a special data infrastructure （SDI）. This results in the interoperability requirements on three different levels： data model level, service level and access control level. The interaction between the data model and service level can be obtained by criterions of the open geospacial consortium （OGC）, and the interaction of the access control level may be reached by declaring and enforcing access restrictions in GeoAC. Then an archetype enforcement based on GeoAC is elucidated. As one aspect of performing usage rights, the execution of access restrictions as an extension to a regular SDI is illuminated.

Mining Frequent Closed Itemsets in Large High Dimensional Data

Large high-dimensional data have posed great challenges to existing algorithms for frequent itemsets mining.To solve the problem,a hybrid method,consisting of a novel row enumeration algorithm and a column enumeration algorithm,is proposed.The intention of the hybrid method is to decompose the mining task into two subtasks and then choose appropriate algorithms to solve them respectively.The novel algorithm,i.e.,Inter-transaction is based on the characteristic that there are few common items between or among long transactions.In addition,an optimization technique is adopted to improve the performance of the intersection of bit-vectors.Experiments on synthetic data show that our method achieves high performance in large high-dimensional data.

Cellular Automaton Simulation of Evacuation Process in Story

Computer simulations on the evacuation process in a story are launched with cellular automaton in this article. The story is composed of five rooms and one corridor. Influence of various parameters on the evacuation process is investigated. It shows that the width of the door of rooms has little influence but the width of the corridor and the maximum velocity of the pedestrian have great influence on the time for evacuation. The relation between evacuation time and the width of corridor is found as tc ∝ W^-0.84. It is also found that appropriate shape of the room is helpful to evacuation.

Monte Carlo Simulation for Slope Stabilization Using Drilled Shafts

A reliability based analysis method for a drilled shaft stabilized slope system is presented in this paper. The drilled shaft stabilization mechanisms for the slope were treated as the drilled shaft induced soil arching, which was quantified by the load transfer factor in the limited equilibrium analysis. However, due to the inherent uncertainties of the soil properties and the model error of the semi-empirical load transfer equation, an extension modification of the deterministic method into a probabilistic method is developed in this paper. The MCS （Monte Carlo simulation） with log-normal random variables has been employed to calculate the probability of failure （Pf） for the drilled shafts/slope system. The developed theories were coded into a computer program for analyzing complex slope geometry and slope profile conditions. Finally, a case study has been performed to illustrate the application analysis of the developed probability approach in drilled shafts/slope system.

Coupled pile soil interaction analysis in undrained condition

The effective stress method is developed to predict the axial capacity of piles in clay. The effective stress state changes due to the resulting pore pressure change and therefore, the strength and stiffness of the soil will change. In this work, the finite element method is utilized as a tool for the analysis of pile-soil systems in undrained condition. The computer program CRISP was developed to suit the problem requirements. CRISP uses the finite element technique and allows predictions to be made of ground deformation using critical state theories. Eight-node isoparametric element was added to the program in addition to the slip element. A pile loading problem was solved in which the pile-soil system is analyzed in undrained condition. The pile is modelled as elastic-plastic material, while the soil is assumed to follow the modified Cam clay model. During undrained loading condition, the settlement values increase by 22% when slip elements are used. The surface settlement increases by about three times when the load is doubled and the surface settlement at all points increases when using slip elements due to the mode of motion which allows smooth movement of the adjacent soil with respect to the pile. The vertical displacement increases as the distance decreases from the pile and negligible values are obtained beyond 10D (where D is the pile diameter) from the center of the pile and these values are slightly increased when slip elements are used. The vertical effective stress along a section at a distance D from the pile center is approximately the same for all load increments and lower values of effective vertical stress can be obtained when slip elements are used.

Calculation of Combustion Products by the New Iteration Method of Non-linear Equations

For a specific combustion problem involving calculations of several species at the equilibrium state, it is simpler to write a general computer program and calculate the combustion concentration. Original work describes, an adaptation of Newton-Raphson method was used for solving the highly nonlinear system of equations describing the formation of equilibrium products in reacting of fuel-additive-air mixtures. This study also shows what possible of the results. In this paper, to be present the efficient numerical algorithms for. solving the combustion problem, to be used nonlinear equations based on the iteration method and high order of the Taylor series. The modified Adomian decomposition method was applied to construct the numerical algorithms. Some numerical illustrations are given to show the efficiency of algorithms. Comparisons of results by the new Matlab routines and previous routines, the result data indicate that the new Matlab routines are reliable, typical deviations from previous results are less than 0.05%.

System design of touch type DC motor

This paper focuses on the use of the touchpad （key）, STC89C51RC monolithic integrated circuit PWM control signal, which changed the traditional mechanical buttons as a DC motor rotational speed and steering control method. Touch switch advantages compared with the traditional mechanical switches are： first, the quieter second, more sensitive; third, faster; four, long life and so on. Specialized chips are also used in the article the PWM signal system, and the principle of PWM signal, method and how the software adjust the duty cycle of the PWM signal to control its input signal waveforms are are described in detail. In addition, this article also introduced consisting of triode amplifier circuit of h-bridge amplifier as a DC motor driving module, enabling the control of DC motor speed. On the software side, PI was described in detail in the article arithmetic program initializes write ideas and specific programs such as program implementation.

求多级串联理想混合流反应器的出口浓度——1/2级不可逆反应

在多级串联理想混合流反应器中进行1/2级不可逆反应时,可用作图法和代数法求出各段反应器的出口浓度。但作图法不够精确,代数法求解又较为繁琐,而且,当反应器个数很多时,上述2种方法则无能为力。本文考虑以上2种方法的不足,就具体实例,开发了另外1种方法,即依据第N段反应器的出口浓度的表达式,利用C++语言编制程序,通过该程序能够快速求出每1段反应器的出口浓度,结果与代数法计算结果基本一致。该法具有简便、精确、高效以及通用的优点,不仅在多级串联理想混合流反应器的设计中具有重要应用价值,而且在实际的化学工业生产中也具有重要意义。

求多级串联理想混合流反应器的出口浓度——三级可逆反应

在多级串联理想混合流反应器中进行3级可逆反应时,求各级反应器的出口浓度,不仅在多级串联理想混合流反应器的设计中具有重要应用价值,而且在实际的化学工业生产中也具有重要意义,经济效益显著。可用图解法和代数法求解,但图解法不够精确,代数法又费时费力,而且,当反应器个数趋于无穷大时,以上2种方法则无法计算。针对上述2种方法的不足,本文利用C++语言,依据递推关系式编制程序,该程序能够迅速求解,并与计算结果完全一致。该法具有精确、快捷、通用、方便的优点。可以显著提高计算效率,具有推广价值。

求多级串联全混流反应器的出口浓度——2/3级不可逆反应

在多级串联全混流反应器中进行2,3级不可逆化学反应时,求每一段反应器的出口浓度,在多级串联全混流反应器的设计中不仅具有重要应用价值,而且在实际的化学工业生产中也具有重要意义,经济效益显著。前文研究表明:可用作图法和代数法求解,但作图法不够精确,代数法求解又较为繁琐,且当反应器个数很多时,上述2种方法则无能为力。而计算机程序法能克服以上2种方法的不足。本文结合具体实例,依据第N段反应器的出口浓度的表达式,利用C*语言编制程序。通过该程序能讯速的求解。该法具有简便、精确、高效以及通用的优点,可以显著的提高计算效率,具有推广价值。