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Through the analysis of previous theories about the cause of the accident, our study identified the main causes of accidents that are unsafe behaviors of human, unsafe conditions of objects and management factors. And the cause of an accident often is multifactorial not simply due to any one of the above three factors. Unsafe behavior of human, the unsafe condition of object, and management factors are taken as X, Y and Z axis respectively. Keeping the main reason for the accident, interlaced relations among the main reason and the basic laws of security, the accident control model based on three-dimensional coordinates was established. By analyzing the safety factor, accident factor and synthesis factor in the model, the security of the system will be analyzed qualitatively and quantitatively.

In order to solve the problem that the existing virtual multiple-input multiple-output (Virtual MIMO) routing algorithm isn't suitable to isomorphism wireless sensor network, virtual MIMO clustering (VMC) algorithm which is applicable to small and medium scale isomorphism WSN is proposed. By combining the energy-efficient virtual MIMO communication technology with the method that cluster heads are selected randomly and cyclically, energy load of network is balanced and life of WSN is extended. We build energy test platform of wireless sensor network with microcontroller MSP430F135 and wireless radio transceiver chip CC2420. The relation between transmitting power and the RSSI is researched by the experimental platform in greenhouse, the path loss factor is solved, and the energy model of virtual MIMO clustering network is created. Then, we focus on the effect of the network size, node density and path loss factor on the virtual MIMO WSN energy-saving performance. To achieve the optimization objective that the longest life of the network, we adopt the genetic algorithm to optimize the ratio of cluster head which is a key parameter of WSN. The simulation results show that the VMC has more energy-efficient and longer lifetime than LEACH. When the parameters of network structure are appropriate, the lifetime can be extended several times

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For the sake of evaluating the content of mineral oil and in water, and further more we can judge water quality pollution, we finally develop an infrared spectrometer based on STM32 which is on the basis of infrared spectrophotometry. The instrument realizes calculating the absorbance and concentration automatically with the help of high-precision pyroelectric infrared sensor and signal processing circuit. Besides it combines with built-in A/D converter and USB data transmission module, it can draw the standard curve on the host computer. Experiment results show that the instrument is accuracy enough and simple enough to use.