机掘巷道连掘、连支配套模式的研发应用

随着装备水平的提升，综掘机械化得到广泛应用，加上后配套运输系统逐步完善及机载临时支护装置的普及，使综掘机得到了充分的发挥，促进了综合单进水平的提高。但是，掘进、支护、运输不能平行作业成为制约机掘巷道单进水平提升的瓶颈，翟镇煤矿自主研发连体自移超前支架以及与综掘机配套装置，实现掘进一无支护一临时超前支护一永久性支护的连掘连支衔接过渡，真正意义上达到了掘、锚、支一体化平行作业。

割集、回路与网络图论

本文就实际电路拓扑结构进行了分析，结合电路基本理论教学中的体会，重点介绍了割集分析法。

66kV及以下电压等级系统故障分析的网络数学模型研究

本文根据66kV 及以下等级电力系统网络的特点,应用拓扑理论对其网络数学模型进行了有效的简化,大大地节省了计算机内存。特别是在故障分析计算中,当运行方式多变、需反复修改网络模型时,本文的方法可使计算速度明显加快。现已在沈阳地区电网继电保护计算机整定计算中应用,为推广使用微型计算机进行较大规模电网的故障分析计算创造了条件。

(α,β)-constraints connected dominating set algorithm in wireless sensor network

To cope with the constraint problem of power consumption and transmission delay in the virtual backbone of wireless sensor network, a distributed connected dominating set （CDS） algorithm with （α,β）-constraints is proposed. Based on the （α, β）-tree concept, a new connected dominating tree with bounded transmission delay problem（CDTT） is defined and a corresponding algorithm is designed to construct a CDT-tree which can trade off limited total power and bounded transmission delay from source to destination nodes. The CDT algorithm consists of two phases： The first phase constructs a maximum independent set（MIS）in a unit disk graph model. The second phase estimates the distance and calculates the transmission power to construct a spanning tree in an undirected graph with different weights for MST and SPF, respectively. The theoretical analysis and simulation results show that the CDT algorithm gives a correct solution to the CDTF problem and forms a virtual backbone with（ α,β）-constraints balancing the requirements of power consumption and transmission delay.

应用拓朴理论改进基尔霍夫定律的教学

一、目前基尔霍夫定律教学中存在的问题: 基尔霍夫定律是电工学中最基本的定律,它是电路理论的基础,是分析计算复杂电路的最重要的一种工具。 作者在历年电工学教学过程中,当讲到应用基尔霍夫定律解复杂电路时同学们往往提出下列两个问题: (一)设复杂电路的节点数为n,支路数为m,为了求得各支路的电流,需列出m个独立方程式,当应用节点电流定律列出n-1个方程后,为什么其余m-n+1个方程必可应用回路电压定律列出?换句话说,为什么电路的独立回路数既不大于、又不小于而是恰好等于m-n+1呢?

Finding a Smooth Frame Decomposition of a Graph

Let G be a graph and A be a subset of the edges of G. A frame decomposition of G is a pair (G-A,A) such t ha t G-A is connected. A smooth frame decomposition of G is a frame decompo sition satisfying the two conditions: (1) Every leaf of G-A has a connected cotree and (2) The set of bridges of G-B(G-A) is A, where B(G-A) is the set of bridges of G-A. An efficient algorithm on finding a smooth frame decompositi on of a graph is provided.

Application of LRB isolation technology in continuous girder bridges

This paper summarizes the superiority of lead-rubber beating （LRB） continuous girder bridges. The research method for isolation performance is discussed when pile-soil interaction is considered. By the finite element method and self-compiling program, a systematic study of the reliability of LRB continuous girder bridges is given by the use of different indicators, including the riding comfort of the LRB system, the pounding and dynamic stability when the LRB system is subjected to seismic excitations, and the reliability of the LRB system when subjected to other common horizontal loads. The results show that the LRB system has obvious advantages over the traditional continuous girder structure. The LRB isolation effect remains good even when pile-soil interaction is considered; the vertical rigidity of the LRB guarantees desirable riding comfort. The LRB demonstrates good reliability when subjected to the effects of braking, wind loads and temperature. However, it is also pointed out that the pounding of the LRB system subjected to earthquakes must be avoided, and the dynamic stability may be reduced when the LRB system has higher piers and generates a larger displacement in a strong earthquake. Useful advice and guidance are proposed for engineering application.

Joint Channel Estimation and Decoding Design for 5G-Enabled V2V Channel

This paper addresses the problem of channel estimation in 5G-enabled vehicular-to-vehicular(V2V) channels with high-mobility environments and non-stationary feature. Considering orthogonal frequency division multiplexing(OFDM) system, we perform extended Kalman filter(EKF) for channel estimation in conjunction with Iterative Detector & Decoder(IDD) at the receiver to improve the estimation accuracy. The EKF is proposed for jointly estimating the channel frequency response and the time-varying time correlation coefficients. And the IDD structure is adopted to reduce the estimation errors in EKF. The simulation results show that, compared with traditional methods, the proposed method effectively promotes the system performance.

Area-Based Connected Dominating Set Construction and Maintenance Algorithm in Ubiquitous Stub Environment

In order to construct and maintain stability Connected Dominating Set over MANET in Ubiquitous Stub Network, this paper proposes a novel area-based CDS construction and maintenance algorithm. The algorithm is divided into three phases: 1) Area Partition; 2) Area Expansion; 3) Area Connection. In additional, maintenance strategy is proposed in each phase respectively to handle node mobility with timer. At last, the simulation is implemented with OPNET and MATLAB and the results are analyzed in detailed with Size of CDS, Message Overhead and other indexes.

Stress Concentration Factors at Saddle and Crown Positions on the Central Brace of Two-Planar Welded CHS DKT-connections

A set of parametric stress analyses was carried out for two-planar tubular DKT-joints under different axial loading conditions. The analysis results were used to present general remarks on the effects of the geometrical parameters on stress concentration factors （SCFs） at the inner saddle, outer saddle, and crown positions on the central brace. Based on results of finite element （FE） analysis and through nonlinear regression analysis, a new set of SCF parametric equations was established for fatigue design purposes. An assessment study of equations was conducted against the experimental data and original SCF database. The satisfaction of acceptance criteria proposed by the UK Department of Energy （UK DoE） was also checked. Results of parametric study showed that highly remarkable differences exist between the SCF values in a multi-planar DKT-joint and the corresponding SCFs in an equivalent uni-planar KT-joint having the same geometrical properties. It can be clearly concluded from this observation that using the equations proposed for uni-planar KT-connections to compute the SCFs in multi-planar DKT-joints will lead to either considerably under-predicting or over-predicting results. Hence, it is necessary to develop SCF formulae specially designed for multi-planar DKT-joints. Good results of equation assessment according to UK DoE acceptance criteria, high values of correlation coefficients, and the satisfactory agreement between the predictions of the proposed equations and the experimental data guarantee the accuracy of the equations. Therefore, the developed equations can be reliably used for fatigue design of offshore structures.

On Graphs with Equal Connected Domination and 2-connected Domination Numbers

A subset S of V is called a k-connected dominating set if S is a dominating set and the induced subgraph S has at most k components.The k-connected domination number γck（G） of G is the minimum cardinality taken over all minimal k-connected dominating sets of G.In this paper,we characterize trees and unicyclic graphs with equal connected domination and 2-connected domination numbers.

Study on new technique of rapidly following curtain filling

The present problem of mining of narrow and gentle dip vein was analyzed. A new technique of rapidly following curtain filling was put forward. The results show that the new technique is feasible, has the characteristic to make the whole curtain wall filter, makes relative density of the filling tailings slurry reach saturation of 78.0% 80.0% in 25 min, and keeps the roof of mined out space stable in 60 min. The new technique of the rapidly following curtain filling has solved the difficult problem of the filling body filtering slowly and promptly controlling underground pressure, which cannot be solved in traditional ways.

Signal classification system using global-local feature extraction algorithm

A continuous wavelet transform(CWT)and globallocal feature(GLF)extraction-based signal classificationalgorithm is proposed to improve the signal classification accuracy.First,the CWT is utilized to generate the timefrequency scalogram.Then,the GLF extraction method is proposed to extract features from the time-frequency scalogram.Finally,a classification method based on the support vector machine(SVM)is proposed to classify the extracted features.Experimental results show that the extended binary phase shift keying(EBPSK)bit error rate(BER)of the proposed classification algorithm is1.3x10_5under the environment of additional white Gaussian noise with the signal-to-noise ratio of-3dB,which is24times lower than that of the SVM-based signal classification method.Meanwhile,the BER using the GLF extraction method is13times lower than the one using the global feature extraction method and24times lower than the one using the local feature extraction method.

Development of an automated system for continuous monitoring of powered roof support in longwall panel

Described the development of an Intrinsically Safe System for continuous monitoring of load and convergence of powered roof supports installed at Iongwall faces. The system developed for monitoring of behavior of a powered support in a mechanized Iongwall sublevel caving face. The logging system can be programmed for logging the data from the sensors at different logging intervals ranging from 16 h to 1 ms for logging variation in hydraulic pressures in legs and convergence of the support during progressive face advance. For recording dynamic loads, the data logger can be programmed to start fast logging, say at 10 ms intervals, when the pressure in a leg reaches a pre-specified threshold value, and continue fast logging until the pressure drops below this threshold value. This fast logging automatically stops when the pressure drops below this threshold value.

Nickel-Titanium swan-like memory connector: a new tool to treat humeral shaft nonunion

Objective: To explore a new strategy to treat humeral shaft nonunion efficiently. Methods: In the light of mechanical characteristics of Nickel Titanium memory and the anatomic morphology of humeral shaft, we designed the swan like shape memory alloy connector (SMC). SMC was clinically applied in treating 55 cases of humeral shaft nonunion. Success rate of nonunion repair, reinterventions, complications, range of motion, and patient satisfaction were evaluated. Results: Fifty five humeral shaft nonunion patients were treated with autogenous bone grafting and SMC internal fixation. The average follow up period was 32 months. In 50 patients with complete follow up data, 49 were recovered from nonunion by lamellar bone healing. The excellent and good rate was 98%; one patient suffering from re fracture in a fall refused further treatment. Neither infection nor re fracture after SMC extraction or joint dysfunction was found in the whole group. Conclusion: SMC facilitates safe internal fixation and bone grafting; its memory biomechanic properties promote osteosynthesis, resulting in accelerated and high quality healing of humeral shaft nonunion. SMC internal fixation with bone grafting is creative, efficient and promising in treating humeral shaft nonunion.

The critical loading for lateral buckling of continuous welded rail

The most significant differences between continuous welded rails （CWRs） and general split-type connectors are axial compression in the longitudinal direction, buckling stability and other issues generated under the influence of thermal effect. Under thermal effect, a dynamical behavior similar to that of a beam fixed on two sides occurs in the central locked area of the welded rail, as there is axial compression but no possibility of sliding. Continuous welded rails do not contract or expand, and are supported by the dynamical system made up of ballasts and rail clips. The rail-support system mentioned above has the features of non-uniform material distribution and uncertainty of construction quality. Due to these facts, the dynamics method based on the linear elastic hypothesis cannot correctly evaluate the rail＇s buckling conditions. This study is aimed at applying Finite Difference Method （FDM） and Monte Carlo Random Normal Variables Method to the analysis of welded rail＇s buckling behavior during the train＇s acceleration and deceleration, under thermal effect and uncertain factors of ballast and rail clips. The analysis result showed that buckling occurs under the combined effect of thermal effect and the train＇s deceleration force co-effect and the variance ratio of ballast and rail clips is over 0.85, or under the combined effect of thermal effect and the train＇s acceleration force when the ariance ratio is over 0.88.

Analysis on the driving forces of different airports and routes

There has been a great deal of research on the driving force of aviation network.Moreover, the research methods and perspectives are also varied.This article mainly studies the driving force of aviation network,the influencing factors of main driving force are analyzed.The driving force analysis of different airport and route is carried out respectively.The results can better reveal the connection mechanism of solid routes.Because the sample space of the hub airport and the trunk airport is too small,the conclusions are not sufficiently illustrative,therefore, this article studies only the branch airports.The conclusions are compared with the results of the comprehensive analysis,and we see if the conclusions are the same or similar.

Adaptive Nonlinear Model Predictive Control Using an On-line Support Vector Regression Updating Strategy

The performance of data-driven models relies heavily on the amount and quality of training samples, so it might deteriorate significantly in the regions where samples are scarce. The objective of this paper is to develop an online SVR model updating strategy to track the change in the process characteristics efficiently with affordable computational burden. This is achieved by adding a new sample that violates the Karush–Kuhn–Tucker conditions of the existing SVR model and by deleting the old sample that has the maximum distance with respect to the newly added sample in feature space. The benefits offered by such an updating strategy are exploited to develop an adaptive model-based control scheme, where model updating and control task perform alternately.The effectiveness of the adaptive controller is demonstrated by simulation study on a continuous stirred tank reactor. The results reveal that the adaptive MPC scheme outperforms its non-adaptive counterpart for largemagnitude set point changes and variations in process parameters.

河南济源县承留汉墓的发掘

济源承留汉墓(JCM1)位于县城西南12公里的承留乡承留村西约100米,村西公路南侧的高地上(图一)。高地三面为丘陵所环抱,向东较开阔,高地四周常有汉墓发现。1985年初,该墓由省司法厅新济建材厂在当地施工时发现,同年3月,受新乡地区文管会和济源县文管所派遣,我们在承留乡党委、乡政府和新济建材厂的大力协助下,对该墓进行了发掘,现将有关情况简报如下。