Applied Mechanics and Materials Vols. 513-517

Abstract: In this work, a monopole antenna with defect ground is proposed for ultra wideband EMC measurement in communication system. The antenna is fed by micro-strip. It is demonstrated that the antenna provides an impedance bandwidth ranging from 2.5 GHz to 13.5 GHz (for VSWR < 2) and supports an adequate pattern.

Abstract: Accurate road data is critical to vehicle ride comfort research. Trigonometric series (TS) method is widely used in road roughness construction, but the accuracy of the road data in time domain is not high and the power spectrum density (PSD) exits poor convergence problem. To solve the above problems, this paper has made two improvements: generate random frequency in each band using the local PSD function, optimize phase angle using the principle of minimum energy. The simulation results show that the improved method has higher precise and better convergence of PSD.

Abstract: Macroinvertebrates are important components of stream ecosystems. A field experiment was conducted to study the effects of substrate particle size, shape, and roughness on the composition and biodiversity of macroinvertebrates. The results show that the particle sizes, porosity, and interstial dimensions of the substrate affect the macroinvertebrate community, while the shape and surface roughness of the substrate do not strongly affect the macrobenthos composition and density. The macroinvertebrate composition in gravel is stable. The density and species richness in the gravels, leaf humus and are much higher than those in the black silt and sands.

Abstract: Nowadays, public safety has already attracted great attention, especially when natural disasters and other emergencies happen more and more frequently. So, personnel evacuation simulation research in the populated areas has become one of the core issues to reduce the social damage. To improve the simulation theory, this paper puts forward an improved cellular automata model using some idea of the classic Ant Colony Optimization Algorithm for reference when making rules for the evacuating personnel. And the improved model takes the interaction among the crowd and the influences exerted by the evacuating personnel upon the environment into account. The new model cares more specific details of both environment and the personnel, so it simulates the crowd psychology successfully and provides a more reliable theory that is to expand and improve the cellular automaton simulation model on personnel evacuation.

Abstract: With the rapid growth of location-based services, indoor positioning system has attracted significant interest. Due to the long reading range and multi-tag identification capability, RFID system has the potential to estimate the accurate location of indoor objects. In this paper a novel RFID indoor positioning system is proposed based on Doppler Effect of moving RFID antenna. The system is constructed with a rotary platform, which is used to record the motion and trajectory of moving antenna. Parallel to the antenna velocity data, the Doppler frequency of RFID signal is recorded to compute the relative velocity between the antenna and target tags. By comparing the antenna movement with the relative velocity data, the position of the target is estimated using triangulation.

Abstract: Nowadays, the demands of Location-based Service are growing fast. It contains huge business opportunities. This paper presents an efficient indoor localization scheme using Radio-Frequency Identification technology. The major idea of our method is Dead Reckoning, a method of navigation that using the best estimates of speed and direction to calculate users' motion trace. We implemented Dead Reckoning in indoor environment by taking advantage of features of RFID. We collected RFID tag phase value to calculate the velocity of users and recalibrate users' position by using known fixed RFID reader. We designed a series of experiments to verify the feasibility of our velocity calculation method, then we simulated the whole process of our system. The results show that our system can track user's motion effectively in indoor environment. We believe this is an encouraging result, holding promise for real-world deployment.

Abstract: Timely monitoring and controlling light intensity,temperature,air humidity, soil moisture by Siemens (LOGO!) and analyzing and regulating,which comprised the controlling system for vegetable greenhouse. Controlling greenhouse shutter, filling light, moisturizing, dehumidifying and ventilating for vegetables automatically or artificially, the robust growth of vegetables is achieved in relatively appropriate environment in greenhouse.

Abstract: Radio Frequency Identification (RFID) provides a non-line-of-sight and contactless approach for object identification. In the supply chain, objects are usually assembled into a group and RFID system enables us to quickly identify a group of objects. However, RFID system only provide the identified objects ID, unable to provide the missing objects IDs. This paper concerns the problem of missing objects detection and missing unique IDs recovery. In supply chain, a traditional method of items lost detection is encoding a group of objects ID before the shipment, and decoding when examine the integrity of the objects. In this paper, we propose a new scheme for missing objects detection and missing IDs recovery, which is called Linearly Independent Vectors Based Group Coding, abbreviated LIVGC. A numerical simulation reveals that the proposed method have higher recovery rate (>20%) than the EGC scheme in the same length of redundancy code.

Abstract: In a complex supply network composed of suppliers, manufactures and buyers, RFID tech is used to connect different items. RFID tech makes it possible to collect data in logistics with a low cost and it can optimize the traditional method more efficiently. A platform using EPCGlobal standards supplies the base environment for high-level applications, such as abnormal event detection in a supply chain, frequent path mining and the retail theft prediction. This paper studies abnormal events detection in the supply network. The data captured from the EPC information service is used to calculate a path and the machine learning method is adopted to cluster the path.

Abstract: With the development of science and technology, electronic equipments are widely applied in society. Electronic equipments make life more convenient and efficient. However, a variety of harmful electromagnetic radiation is generated when the electronic equipment is working. The electromagnetic radiation not only affects the normal operation of other electronic device but also pollutes the environment survival for human. Furthermore, electromagnetic radiation is harm to human. Therefore, it is important to take measures to prevent various electromagnetic radiations. Firstly this paper introduces relevant knowledge of electromagnetic radiation and standards on electromagnetic radiation. Then, it analyses the biological effect of electromagnetic radiations according to the radiation distribution of cell-phone. Finally, it proposes protective measures based on the study of the biological effect.