铁路智能综合能源管理系统

针对当前铁路用能采集落后、管理粗放、信息缺失、数据挖掘能力差的缺陷,提出了铁路智能综合能源管理系统。该系统实现了对铁路运营主/子站电、水、气、环境、资产数据的统一采集和管理;实现了系统数据采集集中化、能源数据可视化、用能计划结构化、辅助决策智能化、用能管理一体化、核心模块国产化、界面展示场景化等功能。介绍了系统的总体架构、功能模块分类以及主要功能模块设计方案,提出了数据采集处理模块和能耗地图的实现架构,最后提出了能耗分析和决策的实现方法。

Airflow adjustment and minimization of the air power of ventilation network

It is often required to know which roadway （adjustment roadway） resistances and how much values of the resis- tances should be changed to make the airflow rates in roadways （target roadways） to certain required values in the practice of mine ventilation. In this case, the airflow rates of the target roadways and the resistances of the roadways other than the ad- justment roadways are the given conditions and the resistances of the adjustment roadways are the solutions to be found. No straightforward method to solve the problem has been found up to now. Therefore, trial and error method using the ventilation network analysis program is utilized to solve the problem so far. The method takes long calculation time and the best answer is not necessarily obtained. The authors newly defined ＂airflow element＂ as an element of the ventilation network analysis. The resistances that satisfy the airflow requirements can be calculated straight forwardly by putting the function of the airflow element into the ventilation network analysis. The air power required for the ventilation can be minimized while meeting the airflow requirements by the advanced application of the method. The authors made the computer program fulfill the method. The program was applied to actual ventilation network and it was found that the method is very practical and the time required for the analysis is short.

Parallelization and performance tuning of molecular dynamics code with OpenMP

An OpenMP approach was proposed to parallelize the sequential molecular dynamics(MD) code on shared memory machines. When a code is converted from the sequential form to the parallel form, data dependence is a main problem. A traditional sequential molecular dynamics code is anatomized to find the data dependence segments in it, and the two different methods, i.e., recover method and backward mapping method were used to eliminate those data dependencies in order to realize the parallelization of this sequential MD code. The performance of the parallelized MD code was analyzed by using some performance analysis tools. The results of the test show that the computing size of this code increases sharply form 1 million atoms before parallelization to 20 million atoms after parallelization, and the wall clock during computing is reduced largely. Some hot-spots in this code are found and optimized by improved algorithm. The efficiency of parallel computing is 30% higher than that of before, and the calculation time is saved and larger scale calculation problems are solved.

Intellectual Capital, Corporate Culture and Performance of Firms Listed on Nairobi Securities Exchange

The broad objective of this study was to establish the moderating effect of corporate culture on the relationship between intellectual capital and organizational performance of firms listed on Nairobi Securities Exchange. The review of literature provided conceptual and empirical gaps that formed the basis of the conceptual hypotheses. Two hypotheses were deduced from general objective： Intellectual capital has a significant influence on corporate performance; corporate culture moderates the relationship between intellectual capital and corporate performance. A cross-section research design was adopted. A survey questionnaire was the main tool of data collection and was distributed to the 50 heads of human resource departments in the different firms＇ period covering four financial years from 2009 to 2012. The study also utilized secondary data obtained from Capital Market Authority Statistical bulletins and Nairobi Securities Exchange Handbook 2012-2013 to collect data on financial performance （ROA, ROE, and Dividend Yield）. Data were tested for reliability results showing that study dimensions were reliable, apart from task-oriented culture that had a Cronbach alpha of 0.262, thus being not considered for further analysis; thus the study relied on employee-oriented culture as a measure of corporate culture. The hypotheses were tested using multiple regression analysis and hierarchical regression respectively. Multiple regression analysis showed that intellectual capital had a significant influence on non-financial performance and no significant influence on financial measures of performance （ROA, ROE, and Dividend Yield）. Test for moderation showed that the interaction term was not significant and thus, employee-oriented culture did not moderate the relationship between intellectual capital and corporate performance. The study demonstrates importance of the influence of intellectual capital on non-financial performance of firms listed on Nairobi Securities Exchange. The results show that interplay among human capital, social capital, and organization capital is important for firms listed on Nairobi Securities Exchange and that the firms should nurture the employees into sharing their knowledge by creating internal and external networks and also creating support system within the organization to retain the knowledge.

Analyzing the Impacts of Minimum Wage Standards on Reducing the Working Poor in China

During the past decades, the transformation of the labor market has significantly impacted on workers＇ wage structures and their employment in China. Along with the widening wage gaps and the growing income inequalities, the size of non-standard jobs expanded rapidly in China＇s urban labor market. As a result of this, the concept of working poor has become increasingly applicable to social and labor market realities in China, Based on the household survey data and by using quantitative analysis, this paper attempts to examine the interaction between the compulsory minimum wage standards and the working poor in the period of China＇s economic transition. The results show that for those whose monthly wages higher than the compulsory minimum wage standards were less likely to work poor and that workers with wages lower than the minimum wage floor were vulnerable to working poor, which supported the expectation that the implementation of compulsory minimum wages would help to reduce the risk of being a member among the working poor in China＇s urban labor market.

Optimal design of modular dual-field modulated permanent magnet linear motors with thrust characteristics

To reduce thrust ripple and cost and improve the average thrust of permanent magnet linear motors,a modular dual-field modulation permanent magnet linear motor was studied,and the parameters were optimized.First,sensitive parameters were selected using the Taguchi method,and then the optimal variables were sampled using the optimal Latin hypercube experimental design method and an ensemble of surrogates model of optimization objectives,and its accuracy was verified.Next,a multi-objective particle swarm optimization algorithm was used to optimize the purpose of“maximum average thrust and minimum thrust ripple”,and the Pareto front of average thrust and thrust ripple was obtained.Finite element analysis showed that the optimized modular dual flux-modulation permanent magnet linear motor(MDFMPMLM)had a 29.5%reduction in thrust ripple and a 5%increase in average thrust compared to the original motor.This study provided an effective method for improving the performance of permanent magnet linear motors.

Design and integrated simulation of a pressurized feed system of the dual-thrust hybrid rocket motor

A new pressurized feed system of the dual-thrust hybrid rocket motor for flight is presented in this paper.The feed system supplies 90% hydrogen peroxide (90%H 2 O 2) with two different flows of 4.5 and 2 kg s 1.The oxidizer flow is changed through regulating the mass flow of the high-pressure gas and switching the performance modes of the unique oxidizer flow control valve simultaneously.The models of the gas storage container,pressure regulator valve,control orifice,propellant tank,oxidizer flow control valve and cavitating venturi are generated and used to compute the instantaneous pressure,temperature and mass flow rate.There is a good agreement between the simulated and experimental results.Parameter sensitivity analysis is also conducted.It is found that the throat diameter of the cavitating venturi in feed line 1 is the main factor affecting the mass flow in both boost and sustaining phase.Other parameters have limited effects on the mass flow rate and the transition time of the system.

A novel posture alignment system for aircraft wing assembly

A novel 6-degree of freedom (DOF) posture alignment system, based on 3-DOF positioners, is presented for the assembly of aircraft wings. Each positioner is connected with the wing through a rotational and adsorptive half-ball shaped end-effector, and the positioners together with the wing are considered as a 3-PPPS (P denotes a prismatic joint and S denotes a spherical joint) redundantly actuated parallel mechanism. The kinematic model of this system is established and a trajectory planning method is introduced. A complete analysis of inverse dynamics is carried out with the Newton-Euler algorithm, which is used to find the desired actuating torque in the design and path planning phase. Simulation analysis of the displacement and actuating torque of each joint of the positioners based on inverse kinematics and dynamics is conducted, and the results show that the system is feasible for the posture alignment of aircraft wings.

Thermodynamic analysis for a chemically recuperated scramjet

Endothermic hydrocarbon fuel is regarded as an optimal fuel for a scramjet with regenerative cooling,which provides extra cooling through endothermic chemical conversion to avoid the severly limited cooling capacity when conventional fuels are adopted for cooling.Although endothermic cooling is proposed from the view point that the heat sink of a conventional fuel is insufficient,the heat-absorbing through endothermic chemical reaction is actually a chemical recuperation process because the wasted heat dissipated from the engine thermal structure is recovered through the endothermic chemical reaction.Therefore,the working process of a scramjet with endothermic hydrocarbon fuel cooling is a chemical recuperative cycle.To analyze the chemical recuperative cycle of a chemically recuperated scramjet engine,we defined physical and chemical recuperation effectivenesses and heating value increment rate,and derived engine performance parameters with chemical recuperation.The heat value benefits from both physical and chemical recuperations,and it increases with the increase in recuperation effectiveness.The scramjet performance parameters also increase with the increase in chemical recuperation effectiveness.The increase in chemical recuperation effectiveness improves both the performances of the fuel cooling system and the combustion system.The results of analysis prove that the existence of a chemical recuperation process greatly improves the performance of the whole scramjet.