基于MQTT协议的移动冷库智能监控系统设计

随着人们对生鲜果蔬需求的增加,我国冷链物流得到快速发展。移动冷库由于其综合成本低,使用方便灵活的优势得到广泛的应用。针对移动冷库分布式、全方位监控的需求,设计了基于MQTT协议的智能移动冷库监控系统。该系统将物联网技术、传感器技术和无线通信技术等诸多技术相结合,采用MQTT协议实现冷库与用户之间消息传递,可实时监测冷库的运行参数,并能远程控制冷库工作模式,设定目标温度,极大提高冷库的智能化水平,具有较大的应用价值。     

Group based DBF MUD in CDMA mobile communication system

For the CDMA wireless cellular communication system, a new methodology is proposed to combine digital beamforming (DBF) with multi user detection (MUD) technology which harnesses the co channel interference mitigation and obtains better performance. The proposed approach assigns all the users within a cell into separated groups according to their direction of arrival (DOA). Then, only one DBF branch is employed for a singular group so that the main lobe is steered to the desired users in the group and nulls are directed to the mobile stations in other group. Furthermore, inter group interference is degraded by MUD following the DBF. The new strategy simplifies the weight vector calculation and solves the unorthogonal channel problem. Additionally, it decreases the bit error rate. The analysis and simulation illustrate the fruits of the new mechanism.     

Highway Accessibility,Location Rents,and the Efficiency of Metropolitan Area Tax Base Sharing

One solution that has been proposed for the fiscal disparities in fragmented metropolitan areas is the sharing of taxes generated by commercial and industrial property. A criticism of this proposal is that it distorts the efficient pattern of business locations resulting when an implicit market for business locations is allowed to develop through the independent fiscal behavior of communities and the optimizing location behavior of businesses. Critics recognize that the efficiency argument against sharing a metropolitan area's business tax base must be qualified to the extent that local governments possess location advantages which enable them to extract rents from business firms. This paper presents an empirical analysis which permits a partition of the local property tax payments from industrial firms into accessibility location rents and compensation payments to the community for the negative externalities of industrial development. The empirical analysis suggests that approximately 40 percent of the industrial taxes received by communities in this analysis represents accessibility location rents. It is concluded that these receipts could be redistributed through a metropolitan area tax base sharing program without affecting the efficiency of the implicit market for business locations.     

Intrusion Detection Technology in Ad Hoc Network

With the rapid development of wireless network and mobile computing,the security of network becomes more important.As one of wireless mobile network,mobile Ad hoc network has new vulnerabilities that do not exist in a fixed wired network,and is susceptible to attacks.This paper introduces some methods which used in intrusion detection system and provides a new model of system based on multi-layer integrated distributed technology,especially recommend the protocol analyzing method in this system.     

Design and Realize the Short Message Service System

Along with the widely using of mobile telephone, the SMS (Short Message Service) has achieved more and more approbation of consumers. Besides the point-point application of SMS among mobile phones, a new application of SMS between information system and mobile phones is developed quickly now, and it is a new way to achieve information conveniently and duly for users. In this paper, we design a software based on SMS to solve some problems which exists in the communication among employees. We also give out the system's functions, key technology and application in the enterprises. This system has some important value in theory and application for building a digital enterprise.     

基于物联网的农田环境监测无线传感器网络的管理

针对农田环境监测无线传感器网络中网络节点电量和处理能力有限等特点,分别从网络拓扑管理、位置管理、能量管理和故障管理等4个方面提出了一套完整的网络管理方案,以对网络运行状况进行监测和管理。为了用户能够远程监控和管理无线传感器监测网络,开发了远程监控管理平台,该平台由后台数据库和前端监测管理软件组成。试验结果表明,所提出的网络管理方案,能够实时监测网络的运行情况,及时诊断网络中的异常,保障了网络正常运行、数据实时传输;所开发的远程监控管理平台人机交互界面良好、功能完善、运行稳定,实现了用户对无线传感器监测网络的远程管理和对农田环境的有效监测。     

移动Ad Hoc网络AODV路由协议的研究与优化

无线移动自组网是仅由移动节点所组成的网络,具有分布式控制、自组织、多跳等特点,由于该网络具有抗毁性能高、易铺设等性质,越来越受到业界的广泛关注。原始的路由协议已经满足不了现有网络不可预测、频繁变化的拓扑结构的需要,因此,在之前研究的基础上,对现有Ad Hoc网络AODV路由协议进行了研究,并设计出一种基于AODV协议的改进路由协议——基于认知的AODV协议(Cognitive-based AODV,CAODV)。通过NS2进行试验仿真,结果表明,CAODV协议具有比AODV协议更加优良的性质,可以有效降低重启路由发现频率,增加断裂链路的修复成功率,降低协议的控制负载,对现有网络的动态变化具有很强的适应能力。     

北方果树霜冻害远程监控与报警系统初步研究与实现

为提高北方果树防霜冻害管理水平,基于物联网架构,设计实现了北方果树霜冻害监测与报警系统。该系统结合实时获取果树生长环境数据,及果树霜冻害发生规律和专家知识库,为用户提供远程果树环境信息分析和霜冻害智能诊断服务。同时为满足不同生产条件需求,结合用户需求和环境状况,提供自动报警。根据用户随时随地获取信息的需求,基于多种网络技术等(如Internet、android等移动互联网),开发了可用于PC终端、移动终端(如智能手机、平板电脑等)多平台管理模式。通过提供现场综合远程实时监控、数据采集、网络传输、数据管理分析及报警预警等功能,系统实现了对果树生长的全方位多功能的远程监控与综合管理,有效提高了果树防霜冻害监控管理水平。     

The Location Behavior of the Multinational Enterprise: Some Analytical Issues

ABSTRACT In the international business literature location behavior has traditionally been analyzed using Dunning's (1977 ) OLI framework, which focuses on the nature, role, and behavior of multinational enterprise (MNE). In this paper it is argued that this approach is now no longer appropriate for discussing the spatial behavior of MNEs, because of the fundamental changes which have taken place either in MNE organization or in the global and institutional environment for foreign direct investment (FDI). At the same time, the paper argues that current location theory from regional economics and economic geography is also largely unsuitable for discussing these issues, such that the spatial behavior of the MNE provides a set of difficult challenges to location analysts. There appears to have been some response to these issues from the international business and management literature, most notably the Porter literature on clusters. However, it is also argued here that this literature provides few, if any, real answers to the problems set by the geographical behavior of the MNE. It is concluded that a fusion of traditional economic geography approaches with a focus on the information and organizational aspects of the firm and the region under consideration may be a way forward for both theory and empirical analysis.     

Application of Changing Dimension and Classifying Power Management to Large-scale MIS

While large-scale MIS is being developed, what relation schema and power management system to set up greatly influences its initial development and later use. First, to solve the setup of relation schema concerning constant change in the attribute of an entity, a changing dimension based on the relational theory in tradition has been used for the setup of relation schema with a wide adaptability; second, to achieve effective power management where there are different standards for business classification on account of too many users and frequent alteration, a classifying power management system has been adopted for the realization of classified self-management model, making the whole system compact and flexible.     

农资电商平台发展浅析

为了解决困扰农业产业升级中农资辨别、使用、销售、流通的难题,针对规模种植农户、农资经销商、农资生产企业和电子商务平台进行了调研与对比分析,表明：农资电商平台已成为今后农资销售的主要模式。农资电商平台将具有B2C、O2O、移动互联网、网上支付和移动支付、融入体验分享和社交元素等特征。最后,提出了农资电商平台发展中面临的问题在于：物流运输限制、种植业分散、与传统交易模式矛盾、信任机制欠缺等。     

Local Embeddedness,Market Focus,and Productivity: Evidence of Taiwanese Manufacturing MNE Subsidiaries in China

There has been considerable literature discussing the characteristics and importance of location‐specific factors in the context of Foreign Direct Investment (FDI), but very little literature linking location‐specific factors to productivity. This study explores, for each location‐specific factor, the relationship between the degree of local embeddedness and the labor productivity. We contribute to the body of literature on location‐specific factors by arguing that market focuses play a pivotal role in determining the impact of local embeddedness on productivity. Based on their strategic choices, we categorize Taiwanese manufacturing multinational enterprise (MNE) subsidiaries in China into two groups: the local‐market‐focus group and the export‐market‐focus group. The paper fits the Ordinary Least Squares (OLS) regression models to the export‐market‐focus group and the local‐market‐focus group separately. For these two groups, each local‐embeddedness variable exerts different effect on labor productivity. Results also suggest that local‐market‐focus FDI is more affected by the host country's local business environment than is export‐market‐focus FDI. Although this study cannot represent all foreign companies in China, its dynamism offers a rich context in which to explore a deeper understanding of foreign companies' business activities in China.     

Evaluating the Importance of Business Location Factors: The Influence of Facility Type

This study examines two important issues concerning the evaluation of business location factors. First, in contrast to many analyses that seek to determine the influence of a single factor or set of factors on site selection, this study aims to measure the relative importance of a wide range of factors. Second, it investigates the extent to which the perceived importance of a given location factor varies based on the type of facility in question. While there is a substantial amount of research devoted to identifying industry‐specific location factors, little is known about the influence that facility type has on the assessment of location criteria. Drawing on original survey data collected from real estate professionals in the U.S., we found significant differences in the mean ratings for more than half of the 39 location factors on the basis of facility type. In particular, “corporate/office” respondents were significantly more likely than “manufacturing” or “retail” respondents to assign higher ratings to “quality‐of‐life” location factors, such as crime rates, amenities, housing, and schools. We discuss the implications of these findings for future research on location theory.     

农村市场开拓的广告传播分析

“农村市场”己不是地域的意义,而代表了一种消费能力和层次。农村市场消费需求的市场化、商品化程度提高;农民消费升级较快,消费亮点不断涌现,具有和城市消费不同的特点.企业在开拓农村市场时总体上采用“全面进攻+重点突破”的广告策略,具体地,做好五结合,即中央媒体与地方媒体相结合,商业广告与公益广告相结合,媒体广告与口碑营销相结合,固定媒体与移动媒体相结合,空中广告与地面推广相结合。     

粮情分析系统开发及应用实践(一)

针对目前计算机粮情检测系统粮情分析功能偏弱的情况,在总结了不同用户(保管员、仓储科长、上级主管人员)业务需求的基础上,介绍了粮情分析的主要内容以及分析软件的系统架构、功能模块、专家知识等粮情分析软件开发情况。     

基于无线传感器网络的森林火情实时监测系统

为了实现森林火情监测过程的自动化、智能化和网络化,提出基于无线传感器网络的森林火情实时监测系统。该系统由无线传感监测网络和监控中心2部分组成,可实时、在线、精确获取森林气象及火场环境信息,具有部署灵活、维护方便、成本低廉、扩展性好等优点。移动节点的引入进一步加强了消防人员的安全保障和监测系统的可靠性。将该系统应用在情况复杂多变、实时性要求很高的森林防火,能显著提高救灾效率,减少火灾所带来的人员和财产损失。     

The Effects of Environmental Regulation on Business Location in the United States

This article empirically examines whether variations in state environmental regulations have affected the location of manufacturing branch plants by the Fortune 500 companies. Using several measures of environmental regulation, no statistically significant effects of environmental regulation on business location are found. For most manufacturing industries, the estimates are precise enough to rule out the possibility of large effects of environmental regulation on business location. For highly polluting industries, however, the variance in the estimates is quite large. We cannot rule out the possibility of effects of environmental regulation on the location of highly polluting industries that are large enough to be important to policymakers.     

Multisited Versus Compact Producer Service Firms: Insights from the French Case

Much of the literature on the location of producer services is concerned with their uneven spatial development across regions. Although this approach is useful, it proves to be limited, and a complementary analytical framework is required. This paper uses data from France's Annual Survey of Services to address producer service location from a novel perspective, that of the firm. A basic distinction is made between single site (compact) and multisite (network) producer service firms, and the natures of these two types are analyzed in terms of business strategies, location and performance. Further analyses are then based upon the distinctions between sales and servuction networks, and between specialized and diversified networks. Although significant for producing higher output levels, a network structure does not necessarily ensure a higher level of profitability.     

RR-CETEN Algorithm: Making TC PMore Robust Against Spurious Retransmissions

Numerous studies have shown that packet reordering is common,especially at wireless and Satellite networks where there are high degree of parallelism and different link speeds.Packets reordering decreases TC Pperformance,because it leads to over estimation of network congestion.The CETEN(Cumulative Explicit Transport Error Notification) has solved the overestimation caused by packet corruption.However,it does not consider the reordering at wireless network,which makes the LEAST(Loss Estimations AlgorithmS for TCP) loss rate value imprecise.The solution is based on explicit spurious retransmit notification at receiver side,and signals the sender packet loss caused by reordering packet.This mechanism can improve precision of LEAST and make the TC Pmore robust.The method is showed efficient in experiment.     

Construction and Application of GPS Location-based Services System Based on JAVA

A method of constructing GPS-based positioning services system by means of JAVA technology is introduced in this paper. The position data, which are sent from GPS satellites, are received by GPS receiving terminal and are analyzed by mobile computing client developed on J2ME in accordance with the differential GPS algorithm. The client submits special position querying information to position server in way of wireless GPRS network. After computing and data querying, the server developed by J2EE returns results to the mobile device. Then, the mobile computing client displays the position map or carries out further processing. All of these form a highly precise location-based services system.