Abstract: Compared with common psychoacoustic model, this article uses wavelet packet decomposition to decompose a signal. This method improves the situation of insufficient time-frequency resolution which the uniform spectrum analysis causes. In addition, frequency division by wavelet packet decomposition is much closer to human’s critical band than the way common psychoacoustic model getting, it is more suitable to human’s hearing characteristics. So we can use wavelet packet decomposition replace FFT in MPEG, and get accurate psychoacoustic model.
Abstract: Radiometric interferometry is one of the main tools in support of spacecraft navigation. Because it does not lose sensitivity to spacecraft declination when the spacecraft is near earth's equatorial plane, as is the case for Doppler tracking. As a working mode, DOD measurement can acquire differential doppler information which is an important observation value used for orbit determination. To perform DOD tracking, the spacecraft needs to transmit high frequency sinewave tone which is usually specially designed. In this paper, we discussed algorithm of DOD measurement using traditional ranging tones. And experiment was performed with ranging tone of China CE'2, data was recorded with baseline which is combined with Shanghai station and Beijing station. Theoretical analysis testifies high accuracy of our algorithm.
Abstract: For the analysis of plane stress, there are two methods, transformation of equation and Mohr’s circle. With the former method, the two principle angles are found by taking derivative to determine the extreme value of stresses. However, it is unknown which one of the two principle angles corresponding to the maximum stress. Moreover, the relationship between the two methods is inexplicit, as the angle of the rotation of the element is eliminated to derive the equation of Mohr’s circle. Using trigonometric relations, considering two systems of sign conventions for shear stresses, simplified parametric transformation equations are obtained. A unique principle angle is easy to be found corresponding to a principle stress. It is obvious that the graph of the simplified equations is a circle. The relationship of the angle of the rotation of the element and the angular parameter of the circle is explicit.
Abstract: Standardization of mechanical parts across enterprise and in large scope is benefit to promote the reuse degree of parts and improve the specialization and co-ordination of industrial production. In this paper, a user-group requirements based approach for standardization of part is proposed. The main idea of the approach is to collect, statistic and analyze the users’ requirements of mechanical parts through the web-based parts library and then construct the evaluation index system to instead the traditional parts spectrum analysis which used in GT (Group Technology). The key steps and methods are discussed and the application case is introduced for verifying the proposed approach.
Abstract: The principle of the Markov chain model is described in this paper, based on the combination forecasting thought and Markov chain thinking, we combine joint forecasting model with the state of the Markov chain transfer model , which is better reflected the law of development of the system of things. We get with parameters in the joint model, and use the joint model to predict the Guangxi food production. Based on historical grain yields data from 1964 to 2011 and the nature of the growth curve regression equation, we establish parameter joint prediction model of Markov and the quadratic function growth curve, which can predict the future grain production of Guangxi province, and we could proof its feasibility. The accuracy of parameter joint model prediction is high, which can be validated by historical grain yields data.
Abstract: In the case of aircraft emergency landing, occupants’ safety analysis and research is one of the indispensable links in the verification of airworthiness safety. However, traditional experimental methods is time-consuming, complex and costly, seriously affect the development of new models to market. This paper established a finite element model of the full-size aircraft cockpit according to a certain type of amphibious light aircraft, and adding the dummy and safety belt occupant restraint system finite element model on this basis. In accordance with the requirements of CCAR-23 test conditions, using large dynamic finite element analysis software LS-DYNA numerical simulation was processed to study this aircraft’s emergency landing procedure. This paper investigated the dynamic response of the dummy and head injury criterion (HIC) value etc. The results provide certain reference for aircraft emergency landing safety design.
Abstract: As the number of household appliance increasing, and the number of waste products has increased dramatically, these waste electrical appliances’ processing not only bring huge economic expense, and a lot of waste electrical appliances influence ecological environment and the human health. Recycling economy requirements enterprise to reduce energy consumption, and improve the utilization of the resources Focused on the issue of recycling end-of-life appliances, this paper presents three modes of recycling end-of-life appliances, which are self-supporting mode, outsourcing mode and joint management mode, and analyzed the characteristics and application areas respectively. According to the characteristics of the three modes, this paper presents the evaluation index system, and compares each evaluation index. At last, this paper uses the AHP method to choose the mode of recycling end-of-life appliances.
Abstract: As an important part of the deep-water oil and gas field, the development process of subsea Christmas tree includes design, manufacture and test. The testing technology of subsea Christmas tree supplies reliability and security for the use of subsea Christmas tree, and it`s an important content of the localization of subsea Christmas tree. This paper takes Zhuhai deep water subsea engineering equipment manufacturing and testing base as the basis, in accordance with relevant specifications and engineering examples, mainly studies the factory acceptance testing and the system integration testing of subsea Christmas tree and puts forward the content and steps of the testing. Meanwhile, the site requirements are analysed which will provide technical support for the subsea Christmas tree testing research and provide references and recommendations for the establishment of Zhuhai base in China.
Abstract: Product design is a type of system engineering and Furniture product form in the furniture production system plays an extremely important role. By introducing the necessity of studying on the relation of the furniture product form and modeling elements, it analyzed the contents of the furniture product form, and then it discussed in detail the relationship between furniture product form and function, material, structure, color and texture with the concept of creating the humanized form based on the philosophical perspective of “the whole and part”. In the end, it pointed out that this relationship is reasonable, sensible and effective, which can provide the effective guiding ideology and implementation way in modern society for designing furniture products which are reasonable and sensible.
Abstract: On the basis of former researcher domestically and abroad about flexible production system technologies, the experiment platform for modular flexible manufacturing system (KNT-FMS) is designed and implemented according to customers’ requirements. After analysis of system requirements, the architecture of modular flexible manufacturing system (KNT-FMS) is constructed. Then the design and implementation of production status recognition and monitoring are focused on. Finally, the application of monitoring system is illustrated by an example of 11-stop experimental flexible manufacturing system. The experiment platform can train professional skills for the students and engineers before working through simulating the work conditions of factual production system so as to shorten the gaps between theory and practice and improve the comprehensive skills all around. Also it provides practical training equipments for training applicable skilled talent and is of application value.