可重构智能表面辅助的四元数调制无线通信系统

四元数调制(Quaternion Modulation,QMod)是一种新型高传输速率的极化调制(Polarized Modulation,PMod)技术,是未来卫星通信系统中极具潜力的多元调制方案之一。QMod将数据块分成4块,其中两块是传输数据信号,另外两块则映射到极化状态部分。每个极化状态块均有一位比特,那么它们可以产生4个极化状态组合。这些状态组合可以用来确定传输数据块在四元数4个不同维度中的位置,从而获得两位额外的传输比特。相比于传统的PMod技术,QMod有着更高的频谱效率。为了进一步挖掘QMod的潜力,介绍了由可重构智能表面(Reconfigurable Intelligent Surface,RIS)辅助的QMod系统,同时推导了该系统的平均误码率理论上界,并在瑞利信道下进行了BER性能仿真。仿真结果表明,RIS辅助的PMod或者QMod系统即便在较低的SNR情况下仍有良好的BER性能,并且随着RIS单元数的增多,其BER性能会逐步提升。     

油品运输中减少能耗的精细化管理措施分析

油品具有两个基本的物理特性,第一个是挥发性,第二个是易燃性。这些物理特性使得油品在运输过程中的能耗现象非常常见,有时候还会引发安全事故。为了让油品在运输过程里面的能耗得到更加有效的控制,就应该对油品消耗管理体系加以改进,使能源能耗控制管理模式的层次不断提升。此外还要对水电气能源进行多层次管理,从而提升企业整体效益并实现节约能源的目标。本文主要对油品运输中优品损耗的精细化管理措施加以研究。     

Long-term performance analysis of chemical filters in clean rooms based on a prediction model

Chemical filters are the most important devices for removing gas-phase pollutants in clean rooms. However, the testing concentration of chemical filters is too high for reflecting their performance in a real clean room environment. This study tested the adsorption performance of chemical filters in the two most commonly used shapes at different concentrations. Then, the Langmuir equation and Wheeler-Jonas kinetic equation were combined to establish an adsorption performance prediction model of chemical filters under actual conditions. The predicted values of the model were in good agreement with the experimental results, which indicated the high accuracy of the prediction model. The model does not need to test the microscopic parameters of the adsorbent and can maintain high accuracy at low concentrations. A fast method for calculating the service life of chemical filters was also presented. Based on this model, the total cost of using a chemical filter with a high carbon content in microelectronic clean rooms could be decreased by 45% due to decreasing the number of filter replacements over 3 months. So a chemical filter with a high carbon content should be preferred over a filter with low resistance in microelectronic clean rooms.     

新型无机内保温涂层的性能及应用

根据水泥烧成热耗的组成，降低高温设备表面散热是降低水泥烧成热耗的重要途径之一，而减少高温窑炉墙壁的热传导可有效降低设备的表面散热。本文在介绍无机内保温涂层隔热原理的基础上，对保温涂层的应用效果进行了对比研究，通过在传统耐火隔热材料的基础上增加新型无机内保温涂层，可有效降低高温设备外表面温度，减少水泥生产中的散热损失，达到节能降耗的目的。     

Modeling unaccounted-for gas among residential natural gas consumers using a comprehensive fuzzy cognitive map

Residential natural gas consumption depends on several factors. Available tools and methods to identify, categorize, and validate effective factors have some limitations, making consumption modeling more complex. Once a comprehensive model of effective consumption factors is developed for residential gas consumers, it can predict consumption. In addition, such a model could be used to verify the accuracy of measuring devices in order to reduce unaccounted for gas (UFG). The key factors affecting residential gas consumption were identified based on previous studies and their mutual effects were analyzed using a fuzzy cognitive mapping (FCM) method. The most significant factors and their effects on natural gas consumption in the residential sector were determined. In this study, for the first time, the expected consumption for each consumer was estimated using a consumption index. Generally, if the estimated consumption is significantly different from the amount recorded by the meter, it could suggest a potential source of UFG. The proposed method was applied to the data collected from the residential gas consumers of a small region in Iran (Dasht-e Arjan region, Fars province), and the results demonstrate the effectiveness of the proposed method.     

Understanding consumer resistance to the consumption of organic food. A study of ethical consumption,purchasing, and choice behaviour

Although the demand for organic food is growing globally, the mainstream consumption of organic food is far less. The present study attempts to understand the underlying reasons for consumer resistance toward consuming organic food using the theoretical framework of innovation resistance theory (IRT). The study further examines the association between different consumer barriers and purchase decisions (purchase intentions, ethical consumption intentions, and choice behaviour) at different levels of buying involvement and environmental concerns. The collected data, consisting of 452 consumers, were analyzed by structural equation modeling approach. The results showed that value barrier shared a negative association with purchase intentions and ethical consumption intentions. Ethical consumption and purchase intention were found to have a direct influence on choice behaviour. Additionally, the relationship between ethical consumption intention and choice behaviour is mediated by purchase intention. However, no significant differences have emerged based on the level of buying involvement and environment concerns. The findings of the study provide insight into public policymakers, marketers, suppliers, and consumer associations by enhancing their current understanding of buying behaviour of the growing organic food community.     

A machine learning‐based operational control framework for reducing energy consumption of an amine‐based gas sweetening process

This study proposes a data‐driven operational control framework using machine learning‐based predictive modeling with the aim of decreasing the energy consumption of a natural gas sweetening process. This multi‐stage framework is composed of the following steps: (a) a clustering algorithm based on Density‐Based Spatial Clustering of Applications with Noise methodology is implemented to characterize the sampling space of all possible states of the operation and to determine the operational modes of the gas sweetening unit, (b) the lowest steam consumption of each operational mode is selected as a reference for operational control of the gas sweetening process, and (c) a number of high‐accuracy regression models are developed using the Gradient Boosting Machines algorithm for predicting the controlled parameters and output variables. This framework presents an operational control strategy that provides actionable insights about the energy performance of the current operations of the unit and also suggests the potential of energy saving for gas treating plant operators. The ultimate goal is to leverage this data‐driven strategy in order to identify the achievable energy conservation opportunity in such plants. The dataset for this research study consists of 29 817 records that were sampled over the course of 3 years from a gas train in the South Pars Gas Complex. Furthermore, our offline analysis demonstrates that there is a potential of 8% energy saving, equivalent to 5 760 000 Nm³ of natural gas consumption reduction, which can be achieved by mapping the steam consumption states of the unit to the best energy performances predicted by the proposed framework.     

基于深度EPG的智能导航平台建设

随着三网融合的大力推进以及双向互动业务的大力开展,运营商使用原有简单的EPG不足以支撑开展更多的增值业务,不能主动为用户推荐节目,不能为运营商带来新的收入机会。作为重要的创新能力支撑系统,介绍了江苏有线智能导航平台的设计与应用,为相关广电运营商提供一定的设计参考。