Optimizing neural networks by genetic algorithms for predicting particulate matter concentration in summer in Beijing

We developed and tested an improved neural network to predict the average concentration of PM10 （particulate matter with diameter smaller than 10 μm） several hours in advance in summer in Beijing. A genetic algorithm optimization procedure for optimizing initial weights and thresholds of the neural network was also evaluated. This research was based upon the PM10 data from seven monitoring sites in Beijing urban region and meteorological observation data, which were recorded every 3 h during summer of 2002. Two neural network models were developed. Model I was built for predicting PM10 concentrations 3 h in advance while Model II for one day in advance. The predictions of both models were found to be consistent with observations. Percent errors in forecasting the numerical value were about 20%. This brings us to the conclusion that short-term fluctuations of PM10 concentrations in Beijing urban region in summer are to a large extent driven by meteorological conditions. Moreover, the predicted results of Model II were compared with the ones provided by the Models-3 Community Multiscale Air Quality （CMAQ） modeling system. The mean relative errors of both models were 0.21 and 0.26, respectively. The performance of the neural network model was similar to numerical models, when applied to short-time prediction of PM10 concentration.     

Synthesis and gel properties of sorbitol derivative gelators

1, 3：2, 4-di-p-methylbenzylidene-D-sorbitol （MDBS） is known to be an efficient sorbitol derivative gelator. Two new sorbitol derivative gelators were designed and synthesized in contrast to MDBS in order to study the gel properties of gelators with different structures. Their gelation behavior to 30 solvents was investigated. It was found that the gelation behavior was related to the molecular structure of gelators. Compared with MDBS, the gelator with more hydroxyl in the molecular structure could gel water and that with more aromatic ring could gel aromatic solvent. The fibrous and three-dimensional network of the gels was obtained by scanning electron microscopy （SEM）. Ultraviolet-visible （UV-Vis） spectroscopy revealed that π-π interaction was one of the main driving forces for the formation of gels. The π-π stacking of gelation increases with the number of aromatic rings in the molecular structure of gelator. Fourier transform infrared （FT-IR） spectroscopy revealed that the hydrogen bonding was also the main driving force for the formation of gels. The layered structure of the gels was studied by X-ray diffraction （XRD）.     

Perception of Nonverbal Communication Influenced by Culture

The concept of perception influenced by culture is pretty important in the study of intercultural communication.The perceptions of language and nonverbal language formed under various cultures intimate with each other during communication.This paper aims to explore the relationship between perception and culture in nonverbal communication through the study of eye language and body odor,and promote the communication among people of different culture as well.     

Seismic reliability and rehabilitation decision of water distribution system

in order to evaluate the seismic reliability of water distribution system and make rehabilitation decisions correspondingly, it is necessary to assess pipelines damage states and conduct functional analysis based on pipe leak- age model. When an earthquake occurred, the water distribution system kept serving with leakage. By adding a virtual node at the centre of the pipeline with leakage, an efficient approach to pressure-driven analysis was developed for simulating a variety of low relative scenarios, and a hydraulic leakage model was also built to perform hydraulic analy- sis of the water supply network with seismic damage. Then the mean-first-order-second-moment method was used to analyse the seismic serviceability of the water distribution system. According to the assessment analysis, pipes that were destroyed or in heavy leakage were isolated and repaired emergently, which improved the water supply capability of the network and would constitute the basis for enhancing seismic reliability of the system. The proposed approach to seismic reliability and rehabilitation decision analysis on water distribution system is demonstrated effective through a case study.     

Noisy chaotic neural network for resource allocation in high-speed train OFDMA system

High-speed train communication system is a typical high-mobility wireless communication network. Resource allocation problem has a great impact on the system performance. However, conventional resource allocation approaches in cellular network cannot be directly applied to this kind of special communication environment. A multidomain resource allocation strategy was proposed in the orthogonal frequency-division multiple access （OFDMA） of high-speed. By analyzing the effect of Doppler shift, sub-channels, antennas, time slots and power were jointly consid- ered to maximize the energy efficiency under the constraint of total transmission power. For the purpose of reducing the computational complexity, noisy chaotic neural network algorithm was used to solve the above optimization problem. Simulation results showed that the proposed resource allocation method had a better performance than the traditional strategy.     

Modeling and robustness of knowledge network in supply chain

The growth and evolution of the knowledge network in supply chain can be characterized by dynamic growth clustering and non-homogeneous degree distribution.The networks with the above characteristics are also known as scale-free networks.In this paper,the knowledge network model in supply chain is established,in which the preferential attachment mechanism based on the node strength is adopted to simulate the growth and evolution of the network.The nodes in the network have a certain preference in the choice of a knowledge partner.On the basis of the network model,the robustness of the three network models based on different preferential attachment strategies is investigated.The robustness is also referred to as tolerances when the nodes are subjected to random destruction and malicious damage.The simulation results of this study show that the improved network has higher connectivity and stability.     

Calculation of minimal dominating set in wireless sensor network with host switch-on/off

This paper proposes a simple and efficient distributed algorithm for calculating minimal dominating set in wireless sensor network. This method can avoid maintaining the connectivities between backbone hosts. Considering that the hosts in mobile networks have different characteristics, this paper proposes a method of calculating minimal dominating set with weight. The nodes can be chosen to form a minimal dominating set when the network topology changes. For the host switch on/off operation, the updating algorithm was provided. The change in the status of a host affects only the status of hosts in the restricted vicinity. Simulation results show that the proposed method can ensure fewer dominators but with higher weight to form the minimal dominating set and the nodes can be adaptive to the changes of network topology.     

Counselling as communication strategies in open and distance education： NOUN experience

The whole world is now referred to as a global village because of the technological revolution is taking place especially in the area of information and communication. In this paper, the author started the discussion with definition of communication, highlighted means of communication and purposes of communication, counselling as a form of communication, conceptual flame work for communication in ODL （open and distance education）, component of good communication, media selection and combination for effective counselling process in NOUN. The author in his recommendations, advocated that for a counsellor to be effective in discharging his responsibilities, he or she must attain a certain level of competency in communication skills, select appropriate media, and must be efficient in the use of communication devices especially computer. Also the media of counselling must be readily available to both the counsellor and counselees.     

RESEARCH ON BUS-ROUTE NETWORK PLANNING

A new method of bus-route network planning is presented by analyzing theservice characteristics of bus-route network.The following optimization objects areadopted:to minimize the total number of transfers from one route to another,to minimizethe total number of passenger-kilometers(or passenger-hours),to even passenger distri-bution on the network,and to make the directions of bus-routes consistent with the direc-tions of passenger flows.The algorithm is very simple.This method is suitable forlarge-sized and medium-sized cities and has been adopted in the transportation planningof Nanjing and Zhengzhou.The result is satisfactory.     

MANET在空间复用随机模型下的平均洪泛距离研究

The flooding distance is an important parameter in the design and evaluation of a routing protocol,which is related not only to the delay time in the route discovery,but also to the stability and reliability of the route.In this paper, the average flooding distance (AFD) for a mobile ad hoc network (MANET) in a random graph model was given based on the dynamic source routing (DSR) protocol.The influence of spatial reuse on the AFD was also studied.Compared with that in the model without the spatial reuse,the AFD in the model with the spatial reuse has much smaller value,when the connetivity probability between nodes in the network is small and when the number of reused times is large.This means that the route discovery with the spatial reuse is much more effective.     

网络出版的传播视角解读

网络出版传播是指出版者利用数字出版技术，借助互联网为流通渠道，将网络出版物向读者发行的社会传播活动。它具有便捷性、交互性、主动性、融合性等特点。网络出版传播的媒介主要是网络出版物，具体形式包括电子图书(e—book)、网络期刊、网络报纸、网络音像等。网络出版的传播主体应该是指包括网络出版者和读者即传收双方在内的传播参与者，与传统出版传播相比，其最大特点是自由性的扩大。     

中学聋生网络交往情况的调查与分析

随着互联网的普及,网络为聋生的沟通与交往提供了一个全新的平台。网络交往作为一种新型的交往方式正深刻地影响着聋生的学习和生活。本文采用自编问卷,对83名中学聋生网络交往的情况进行调查和分析。调查结果显示：中学聋生普遍喜欢网络交往,他们的能力基本能满足网络交往的需要;网络交往对聋生语言能力、社会交往能力具有积极的影响;但学校网络资源配置相对缺乏,聋生网络交往对象局限于聋人。因此,应改善校园网络环境,重视聋生的网络交往,加强聋生网络交往指导,并构建聋生网络学习和交流平台。     

基于SIP的智能家居网关的设计与实现

提出一种基于SIP的智能家居网关的设计方案。该方案通过开发SIP UA来实现家庭内部网络与外部网络的集成通信,网关在家庭内部网络中集成了ZigBee通信和WiFi通信,利用SIP特性使网关支持媒体流的传输,还通过外载语音识别芯片为网关实现了语音控制功能。最后,通过实验证明了该方案的可行性。     

网络教育教师传播素养浅析

教师的传播素养是影响教育传播过程效果的关键因素之一。文章介绍了教师传播素养的概念和要素,对网络教育传播过程中教师的任务和网络教学对教师传播素养的要求进行了详细论述,分析了目前教师在网络教育传播实践中存在的问题,提出了网络教育中培养教师传播素养的三点策略。     

网络暴力的传播学论析

网络暴力在传播的过程中,表现出了很多特点：传播角色假借正义之名、传播活动自发形成、传播内容的社会敏感性、信息结构的开放性、恶劣影响虚拟促成和传播效果容易失控。网络暴力的这些传播学特点,与网络信息传播者的情绪有着很大的关系。     

网络环境下的人际传播

网络技术的普及为人际传播提供了丰富多彩的传播媒介。文章以我国网络环境下的人际传播活动为研究对象,分别从传统人际传播、网络人际传播的新方式及特点,以及网络人际传播的现实作用和问题等几个方面进行了分析阐述。文章尝试性地将网络人际传播特点总结为：具有多媒体性质,以文字传播为主,以及匿名性、随机性、平等性。提出应在发展完善网络人际传播的同时解决其发展过程中出现的问题,以使网络人际传播发挥更大的作用。     

和谐“网络社会”的构建及其途径

“网络社会”的崛起已成为不争的事实,它为人类提供了一种“数字化”的生存方式。“网络交往”是一种全新的交往方式,它既拓展了人的交往空间,给人类文明带来了巨大的进步,又产生了一系列伦理道德及法律问题。要构建和谐“网络社会”,应加强网络法规对网络社会问题的控制力;充分发挥科技在应对网络社会问题中的作用;构建网络社会交往的基本伦理准则。     

Personal Network Structure and Perceived Social Support in the Context of Intercultural Adjustment

The connections between an international student’s communication network, perceived social support, and intercultural adjustment are not well understood. This study aims to test the network–support–adjustment path among international students. With data collected from 215 international students studying at a large U.S. university, path model analyses showed that tie strength, a relational characteristic of one’s communication network, was positively associated with perceived emotional support, which in turn was positively related to sociocultural adjustment. In contrast, network density and proportion of U.S. ties were not associated with perceived informational support, although perceived informational support was found to contribute to enhanced psychological adjustment. Therefore, the network–support–adjustment path was only partially supported with the current data. This article discusses theoretical and practical implications of these findings.     

无线传感器网络跨层通信协议综述与分析

设计基于跨层机制的通信协议,以达到优化网络性能、有效分配网络资源的目的,是无线传感器网络研究中的一项关键技术.对现有的基于跨层设计的网络通信协议进行综述和分析,并以跨层通信协议设计的目的性为着眼点,对跨层通信协议划分为3类：提高互操作性和增强网络适应性为目的的跨层设计,提高某些性能标准为目的的跨层设计和无分层模型设计.该分类方式有助于网络设计人员进行更具有针对性和实用性跨层设计.     

人人网的成功对提高网络课程传播与互动绩效的启示

人人网是国内最大的SNS网站之一,它在传播和互动方面有着不可媲美的巨大优势,对网络课程建设有着一定的启示作用。该文分析了人人网在传播与互动上的成功之处,揭示了网络课程的不足,提出了加强网络课程传播与互动的策略和将商业化的成功模式与提高教育绩效有机整合的方法。