一种全自动、全性能互感器校验仪整检装置的设计与实现

文中针对现有的互感器校验仪整检装置存在的准确度低、稳定性差、变频对误差有影响、工作回路电压(电流)检定点范围小等问题,采用直角坐标系与极坐标系的转换技术、高准确度自动测量反馈技术,设计了双路幅值和相位精密可调的数字程控标准信号源,实现了频率及负载改变后,功率源的相位幅值的自动补偿,实现了互感器校验仪和二次压降测试仪的全性能自动检定和校准。该装置经第三方机构检测,技术指标和功能达到设计要求。

基于《互感器校验仪通信协议》的全自动整检装置

按照JJG 169《互感器校验仪检定规程》的要求,一般采用互感器校验仪整体检定装置对互感器校验仪进行检定。目前各电科院、计量院使用的互感器校验仪整体检定装置都是采用电工式设计,采用手动方式对互感器校验仪进行检定。国家电网公司2013年颁布的企业标准Q/GDW 1897《互感器校验仪通信协议》明确了互感器校验仪的通信技术要求,也为对互感器校验仪的全自动检定提供了可能。本文介绍一种基于《互感器校验仪通信协议》的互感器校验仪整体检定装置,该装置采用电子式设计,完全满足《互感器校验仪检定规程》及《互感器校验仪通信协议》的技术要求,实现了对互感器校验仪的全自动检定。

新型互感器校验仪整检装置

目前国内互感器校验仪检定工作基本上采用多种应用不同标准比例电源,电工式标准比例电源、电子式标准比例电源及电工/电子式标准比例电源的互感器检定方法。为了适应国家校验仪新规程JJG169-2010的需要;校验仪要过载150%(南方电网要求过载200%)和校验仪抑制谐波的能力检测。本文介绍一种新型的检测装置。满足计量部门检测校验仪项目的需求。

弹性针布整检操作台的改造

为了满足弹性针布植针机扩台的生产需求,充分利用车间闲置空间及机台,分析了弹性针布的制造工艺流程,重点阐述了弹性针布整检设备的设计原理、主要机构设计与实现及其优缺点,指出新整检设计方案空间、人员、机台利用率高,运行稳定、成本低廉、安全性高,可有效提高工作效率,实用性强。

检整系统高技能人才培养思考

通过分析机务段检整系统技能人才现状,认清检整系统技能人才存在问题,提出检整系统技能人才培养思路,完善检整系统人才培养措施,为机务段高技能人才培养提供助力。

全自动互感器校验仪整体检定系统设计及应用

提出了一种由计算机控制的全自动互感器校验仪整体检定系统的设计方案,该装置由计算机、全自动互感器校验仪整检装置和标准通讯协议等组成,计算机硬件部分采用DSP处理芯片TMS320LF2407A为控制器,软件部分采用友好、直观的虚拟仪器软件为人机交互界面,同时该系统还采用高精度数控线性变频变压电源作为交流测试信号电源。目前本全自动互感器校验仪整检系统样机在江苏省电力公司电科院、国网电科院使用情况良好,极大地提高了工作效率。

互感器负荷箱测试仪的校准方法探讨

互感器负荷箱是使用互感器校验仪对互感器进行检定时常用的设备,起到模拟二次负荷的作用,目前一般采用负荷箱测试仪来对负荷箱进行校准。为确保该校准过程的规范性和准确性,需要保证负荷箱测试仪工作在较高的精准度上,因此作为计量器具,负荷箱测试仪同样需要定期进行检定。本文根据工作实践,提出了互感器负荷箱测试仪的误差校准方法以供探讨。

GRA BASED ANALYSIS ON FACTORS INFLUENCING CO_2 EMISSIONS IN CHINA

How to achieve the objective of reducing CO2 emissions has been an academic focus in China recently. The factors influencing CO2 emissions are the vital issue to accomplish the arduous target. Firstly, three influential factors, the energy consumption, the proportion of tertiary industry in gross domestic product （GDP）, and the degree of dependence on foreign trade, are carefully selected, since all of them have closer grey relation with China＇s COz emissions compared with others when the grey relational analysis （GRA） method is applied. The study highlights co-integration relation of these four variables using the co-integration analysis method. And then a long-term co-integration equation and a short-term error correction model of China＇s CO2 emissions are devel- oped. Finally, the comparison is exerted between the forecast value and the actual value of China＇s CO2 emissions based on error correction model. The results and the relevant statistics tests show that the pro- posed model has better explanation capability and credibility.

Multiple Kalman filters model with shaping filter GPS real-time deformation analysis

In order to detect the deformation in real-time of the GPS time series and improve its reliability, the multiple Kalman filters model with shaping filter was proposed. Two problems were solved: firstly, because the GPS real-time deformation series with a high sampling rate contain coloured noise, the multiple Kalman filter model requires the white noise, and the multiple Kalman filters model is augmented by a shaping filter in order to reduce the colored noise; secondly, the multiple Kalman filters model with shaping filter can detect the deformation epoch in real-time and improve the quality of GPS measurements for the real-time deformation applications. Based on the comparisons of the applications in different GPS time series with different models, the advantages of the proposed model were illustrated. The proposed model can reduce the colored noise, detect the smaller changes, and improve the precision of the detected deformation epoch.

Research on Agricultural Economic Development under the Background of Urbanization

Agriculture is the basic industry of China and the support of all other industries. In order to clarify the impact of urbanization on China＇s agriculture, a cointegration test was conducted between the urbanization rate and the total agricultural output value in China during the past 30 years of 1986-2015. The results showed that the development of urbanization and agricultural economy had no severe effect on weakening the agricultural economy in China, while on the contrary, there was a long-term equilibrium relationship between the two, which was only limited to a certain range, and in the future high development of urbanization of China, the development of agricultural economy would face great challenges. Therefore, China should specify cultivated land use, strengthen the supervision standard of land circulation; increase investment in science and technology, improve the efficiency of agricultural output; optimize financial support for agriculture, enhance the enthusiasm of farmers; cultivate new agricultural operators, promote the process of agricultural industrialization, so as to form economies of scale and explore a new road of urbanization which is not at the expense of the cost of agricultural economy.

An Empirical Study on the Environmental Kuznets Curve for China's Carbon Emissions:Based on Provincial Panel Data

Based on the Environmental Kuznets Curve theory, the authors choose provincial panel data of China in 1990-2007 and adopt panel trait root and co-integration testing method to study whether there is Environmental Kuznets Curve for China＇s carbon emissions. The research results show that： carbon emissions per capita of the eastern region and the central region of China fit into Environmental Kuznets Curve, but that of the western region does not. On this basis, the authors carry out scenario analysis on the occurrence time of the inflection point of carbon emissions per capita of different regions, and describe a specific time path.

A Study on the Monitoring System for the FMS

Introduces a new monitoring method in FMS explicated in some detail by means of the MSF(Monitoring System of FMS)under development by the au- thors.In order to push FMS technology forword,enhance machining flexibility and the flexibility of human operaters and equipment in a FMS,the authors have made some breakthroughs in traditional ways of single item,unit monitoring and self-han- dling,and suggested the idea of integrated inspection and put the MSF into more practicability.The working status of FMS can be monitored on the CRT of a micro- computer of the MSF,system troubles will be shown with icons,by the flash of the system characteristic symbol or by alarming,and so on.This explores a new way for FMS inspection in a wholly integrated manner.

Experimental study on characteristics of trapping and regulating sediment with an open-type check dam in debris flow hazard mitigation

Beam dams are a highly effective and commonly used open-type check dam in debris-flow hazard mitigation. In this study, dimensional analysis was used to obtain empirical equations for quantitatively determining the sediment-trapping and flow-regulating characteristics of a beam dam. To determine the coefficients of the empirical equations, flume experiments were conducted to simulate the trapping and regulating processes. The flow pattern, trapping, and regulating characteristics were investigated when debris flows passed through a beam dam. Debris-flow bulk density and peak discharge, and sediment-trapping ratios, were measured directly and indirectly. The results showed that three blocking actions occurred, and that blockage-breaking considerably influenced the trapping and regulating performance of the beam dam. The relative opening size and the sediment concentration were the two main factors affecting the performance of the beam dam. The ratio of trapping sediment decreased with relative opening, and increased with sediment concentration as well as reducing ratio of bulk density and reducing ratio of peak discharge. The sediment concentration and relative opening were the leading factors influencing the trapping and regulating sediment of a beam dam, followed by flume gradient. The results showed that the calculated values obtained using empirical equations were in good agreement with the values derived from the experiments, and that the deviation was acceptable. Finally, taking Zechawa Gully as an example, using the empirical equations we designed the opening size of a beam dam aimed to trap sediment and regulate peak discharge of debris flow in the main gully.

An Efficient Method for Checking the Integrity of Data in the Cloud

Cloud computing and storage services allow clients to move their data center and applications to centralized large data centers and thus avoid the burden of local data storage and maintenance.However,this poses new challenges related to creating secure and reliable data storage over unreliable service providers.In this study,we address the problem of ensuring the integrity of data storage in cloud computing.In particular,we consider methods for reducing the burden of generating a constant amount of metadata at the client side.By exploiting some good attributes of the bilinear group,we can devise a simple and efficient audit service for public verification of untrusted and outsourced storage,which can be important for achieving widespread deployment of cloud computing.Whereas many prior studies on ensuring remote data integrity did not consider the burden of generating verification metadata at the client side,the objective of this study is to resolve this issue.Moreover,our scheme also supports data dynamics and public verifiability.Extensive security and performance analysis shows that the proposed scheme is highly efficient and provably secure.

A holistic examination of the load rating design of longwall shields after more than half a century of mechanised longwall mining

It is a commonly asked question:how big should the longwall shields be? The answer is a key aspect of a longwall mining feasibility study when the consequences of inadequately rated shields are considered.This paper addresses this question based on the measured nature of the loading environment in which shields are required to operate,the various geological and geometrical controls of that environment and the various links between their load rating,a range of other relevant shield design factors and the loss event they are required to prevent a major roof collapse on the longwall face.The paper concludes that despite the tremendous advances that have been made in shield design and load rating over the past50 years,the same drivers that caused longwall miners of the past to seek improved roof control on the longwall face via the use of ever-higher rated shields,are still as relevant today.However at the current time,the limits of the largest available longwall shields have yet to be tested,therefore industry focus for the foreseeable future should possibly be in achieving the maximum level of roof control on the face via their optimum operational use rather than considering further shield rating increases and incurring the inevitable downsides in terms of capital cost and shield weight.

DCFl-Checker： Checking Kernel Dynamic Control Flow Integrity with Performance Monitoring Counter

It is a challenge to verify integrity of dynamic control flows due to their dynamic and volatile nature. To meet the challenge, existing solutions usually implant an ＂attachment＂ in each control transfer. However, the attachment introduces additional cost except performance penalty. For example, the attachment must be unique or restrictedly modified. In this paper, we propose a novel approach to detect integrity of dynamic control flows by counting executed branch instructions without involving any attachment. Our solution is based on the following observation. If a control flow is compromised, the number of executed branch instructions will be abnormally increased. The cause is that intruders usually hijack control flows for malicious execution which absolutely introduces additional branch instructions. Inspired by the above observation, in this paper, we devise a novel system named DCFI- Checker, which detect integrity corruption of dynamic control flows with the support of Performance Monitoring Counter （PMC）. We have developed a proof-of-concept prototype system of DCFI-Checker on Linux fedora 5. Our experiments with existing kemel rootkits and buffer overflow attack show that DCFI- Checker is effective to detect compromised dynamic control transfer, and performance evaluations indicate that performance penaltyinduced by DCFI-Checker is acceptable.

Automated visual position detection and adjustment for optical waveguide chips and optical fiber arrays

The alignment coupling between optical waveguide chips and optical fiber arrays is the basis of the alignment coupling of planar optical waveguide devices, and the precise position detection with angle and spacing adjustments is one of the key steps of alignment coupling. A methodology for position detection, and angle and spacing adjustment was proposed for optical waveguide chips and optical fiber arrays based on machine vision. The experimental results show angle detection precision levels higher than 0.05°, line detection precision levels higher than 0.1 μm, and detection time less than 2 s. Therefore, the system developed herein meets the precise requirements necessary for position detection, and angle and spacing adjustments for optical waveguide chips and optical fiber arrays.

International Price Shocks Transmission： The Case of Rice in Togo

The objective of the paper was to examine the relationship between the world rice price and the rice price in Togo using the linear and nonlinear co-integration tests. The author used the monthly prices for Togo local rice market and international market. The results show that the rice prices on the local market are integrated to international market. The elasticity of the long-term transmission is high. The threshold autoregression （TAR） model reveals an asymmetric transmission with a magnitude that varies depending on the nature of shock. Price increases in international markets are transmitted more rapidly to the local markets than price reductions. These results might be explained by the market power of traders, transport costs and government intervention.

Empirical Analysis on the Relation Between Electronic Industry Development and Energy Consumption

Data from 1996 to 2012 is used to conduct co-integration test, VAR model and Granger causality test in order to examine the relation between China＇ s electronic industry added-value and energy consumption. The result of co-integration test illustrates the long-term equilibrium of the relationship between the electronic industry development and energy consumption. The dynamic analysis of VAR model shows that there is a positive response from the economic growth of the electronics industry to energy consumption, while the impact of energy consumption on economic growth is a slightly negative response. It has been proved that the electronic industry development and energy consumption are mutual Granger causality. According to these conclusions, some suggestions are proposed in the end, including accelerating the development of China＇ s electronic industry to promote high-teeh electronic products, improving energy efficiency, enhancing research efficacy, creasing the effort for energy development and implementing rational energy policies.