Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

无线传感器网络，作为全球未来十大技术之一，集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术，可实时感知、采集、处理、传输网络分布区域内的各种信息数据，在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议，并针对大规模的无线传感器网络设计了一种树状路由协议，它根据节点地址信息来形成路由，从而简化了复杂繁冗的路由表查找和维护，节省了不必要的开销，提高了路由效率，实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR（AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332007115216

Detection of Isoflavones Content in Soybean Based on Hyperspectral Imaging Technology

Because of many important biological activities, Soybean isoflavones which has great potential for exploitation is significant to practical applications. Due to the conventional methods for determination of soybean isoflavones having long detection period, used too many reagents, couldn’t be detected on-line, and other issues, we propose hyperspectral imaging technology to detect the contents of soybean isoflavones. Based on the 40 varieties of soybeans produced in Heilongjiang province, we get the spectral reflection datum of soybean samples varied from the soybean’s hyperspectral images which are collected by the hyperspectral imaging system, and apply high performance liquid chromatography (HPLC) method to determine the true value of the selected samples of isoflavones. The feature wavelengths for isoflavones content prediction (1516, 1572, 1691, 1716 and 1760 nm) were selected based on correlation analysis. The prediction model was established by using the method of BP neural network in order to realize the prediction of soybean isoflavones content analysis. The experimental results show that, the ANN model could predict isoflavones content of soybean samples with of 0.9679, the average relative error is 0.8032 %, and the mean square error (MSE) is 0.110328, which indicates the effectiveness of the proposed method and provides a theoretical basis for the applications of hyerspectral imaging in non-destructive detection for interior quality of soybean

Design of a Broadband Electrical Impedance Matching Network for Piezoelectric Ultrasound Transducers Based on a Genetic Algorithm

An improved method based on a genetic algorithm (GA) is developed to design a broadband electrical impedance matching network for piezoelectric ultrasound transducer. A key feature of the new method is that it can optimize both the topology of the matching network and perform optimization on the components. The main idea of this method is to find the optimal matching network in a set of candidate topologies. Some successful experiences of classical algorithms are absorbed to limit the size of the set of candidate topologies and greatly simplify the calculation process. Both binary-coded GA and real-coded GA are used for topology optimization and components optimization, respectively. Some calculation strategies, such as elitist strategy and clearing niche method, are adopted to make sure that the algorithm can converge to the global optimal result. Simulation and experimental results prove that matching networks with better performance might be achieved by this improved method

The Passive Surface Wave Methods for Shallow Engineering Exploration Based on the ESPAC Technology

ESPAC method is a rapidly emerging field of seismological research, which can reflect the physical properties of the Earth’s medium. In the process of using the ESPAC method, sometimes the noise of the original data is relatively large, and the raw data of each seismometer needs to be preprocessed, including operations such as de-averaging, de-trending, re-sampling, normalization, and filtering. The selection of the normalized method and the selection of the bandwidth of the filter are particularly important, and it will produce the wrong result if not handled properly. This article attempts to use the extended spatial autocorrelation (ESPAC) method to extract Rayleigh-wave phase velocity dispersion curves from the vertical component of the seismic stations’ microtremors, and proposes feasible and effective solutions to the selection of the normalized method and bandwidth of bandpass filtering

Modeling and Research on Power System of Distributed Sensor Networks for Long Streamers in Marine Seismic Exploration

The electric power system plays an important role in sensor networks. In the marine seismic exploration streamer system (MSESS), an underwater power system transmits high-voltage direct current to all nodes in the streamer through a daisy chain structure. As offshore oil exploration develops toward deep water, it is necessary to study long streamers with large-scale sensor networks for deep water exploration. When the length of a streamer is increased to a certain value, the output current of the power supply increases sharply. This results in the activation of the overcurrent protection and the power supply shuts down. This paper puts forward an accurate model for an underwater power system applied to MSESS. Using the Newton iteration algorithm and a reverse algorithm, equations established by the model are solved and laboratory test results are used to verify the accuracy of the model. Based on simulation and analysis of the model, we explain why the power system crashes when the streamer is too long. Software that can quickly calculate the maximum number of nodes (the maximum length with which the system works normally) is developed and it is significant for the design of MSESS. The method of research could also be applied to relevant work such as large-scale sensor networks with daisy-chaining power supply in land seismic exploration

Significant Daily CO₂ Source–Sink Interchange in an Urbanizing Lake in Southwest China

Inland lake water–air interfaces, particularly the partial pressure of CO2 (pCO2), have become key parameters in the study of global carbon cycle changes. However, there are few studies on short-term daily variations in pCO2 in urbanizing lakes. The fluctuations in pCO2 and CO2 fluxes (fCO2) were monitored biweekly on-site for pCO2 assessments during daytime hours (7:00–17:00 CST) from January to September 2020 in an urbanizing lake located in Southwest China. We found a pronounced and uninterrupted decline in the average levels of pCO2 and fCO2 from 7:00 to 17:00 CST. Notably, the mornings (7:00–12:00 CST) exhibited substantially elevated pCO2 and fCO2 values compared to the afternoons. Specifically, compared to 7:00, the mean pCO2 and fCO2 at 17:00 CST decreased by ca. 74% and 112%, respectively. The average daytime pCO2 was 707 ± 642 μatm, significantly higher than the typical atmospheric CO2 levels of 380–420 μatm, while the average pCO2 on 9 January, 1 April, and 27 July was lower than typical atmospheric CO2. Each month, all water environmental parameters showed significant differences. pCO2 and fCO2 reached maximums in September; water temperature and turbidity significantly increased; and pH, dissolved oxygen and transparency markedly decreased. Additionally, the correlation between pCO2 and environmental factors demonstrated that the nutrient levels, dissolved oxygen, pH, and transparency/turbidity had significant roles in CO2 dynamics in this lake. Therefore, this urbanizing lake could serve as a CO2 source and sink during the daytime

Room temperature DC magnetron sputtering deposition of hydrogenated aluminum doped zinc oxide thin films on polyethylene terephthalate substrates

In thiswork,aluminumdopedzincoxide(AZO)andhydrogenatedaluminumdopedzincoxide(HAZO) thin films weredepositedonpolyethyleneterephthalate(PET)substratesatroomtemperaturebyDC magnetron sputtering.Hydrogenationimprovedthecrystallinityandreducedsurfaceroughnessofthe AZO thin films. ThehydrogenatedAZO films revealedimprovedelectricalandopticalproperties comparing withtheAZO films preparedunderthesamedepositioncondition:theresistivitydecreased from 0.18 Ω cm to3.0 10？3 Ω cm, whichwasmostlyduetotheincreaseofthecarrierconcentration from 1.5 1019 cm？3 to 2.3 1020 cm？3. Theaveragetransmittanceinthevisiblerangeincreasedfrom 82.0% to84.5%.Thishydrogenatedprocessmayprovideaneasilyrealizedmethodtofabricatehigh qualityAZO films on flexiblesubstratesatroomtemperature