Applied Mechanics and Materials Vols. 58-60

Abstract: Signal generator is an integral part of the electronic system, determines the system performance. With the rapid development of microelectronics technology and digital integrated circuits, the high-precision signal generators are demanded in the field of various kinds electronic systems. To meet this requirement, this paper discusses that DDS chip AD9912 produced linear frequency modulation is controlled by LPC2138 which is ARM chip and the results are displayed by the touch screen, which also used of setting waveform and frequency.

Abstract: In an actual system, the effects of nonlinear factors are inevitable. So in real practice, when a model for complex system is being built, all the features in it will be linearized. Though simplifying the designing and analyzing process, the model being built in this way is thought to be incapable of revealing the true characteristics of the system. In order to solve this problem, the paper analyzes a model combining both linear and nonlinear features while taking the parameter perturbation of the linear part into consideration, which enables the model to retain as many characteristics of the actual system as possible. Provided that the nonlinear function satisfies the Lipschitz constraint conditions, the robust guaranteed cost state feedback control law of nonlinear system is deduced using the Lyapunov function and then converted into the feasible solutions of linear matrix inequality (LMI). The proposed method optimizes the design of controller by modifying the previous oversimplified models that fail to reveal the real characteristics of the actual system, and the effectiveness of the proposed method is being verified through an algorithm simulation example.

Abstract: Coordination has been regarded as a critical factor of successful projects. Because construction projects are highly fragmented with many participants involved at different construction stages, coordination is more complicated for contractors. A coordination systems and procedure developed by simulating circulatory system could improve coordination effectiveness of construction projects due to the natural and effective physiological functions of the human body. To verify the applicability and effectiveness of the system and procedure, two tools to quantify coordination needs and supply were proposed and a case project was tested for ten months. The results showed that the more fit between coordination needs and supply, the better the task performance, meaning that the coordination system and procedure is effective. During construction the contractor can follow the coordination procedure and assign an engineer to evaluate variation of coordination needs and supply periodically or at emergent conditions. As coordination supply does not meet needs, time and frequency of coordination methods should be adjusted.

Abstract: A MILP model for optimization of byproduct gas supply in the iron and steel making process is proposed. This model can make the holder fluctuate keep in the normal range, prevent unfavorable byproduct gas emission or shortage, minimize oil consumption and switch the burners in the boil, and it can simultaneously maximize the efficiency of energy resource usage in the iron and steel making process.

Abstract: The method of using ultrasonic heating to aid high precision moulding of micro features has been studies. The study developed a method of using ultrasonic vibration to heat the polymer and hot embossing high precision micro features. A commercial ultrasonic welding machine is converted to provide the heating of polymer and mold then into precision micro features for study of ultrasonic heating and the microflow of polymer under ultrasonic agitation. A stainless steel microporous mold of 200µm thick with through holes of 50µm and 200µm in diameter were used. Using a frequency of 35kHz, the microflow behavior of PC (Polycarbonate) and PE (Polyethylene) in the microchannels were investigated. The differing properties of microflow for these two types of polymer give indication on the theoretical and practical agreement on prediction of microflow under ultrasonic energy.

Abstract: Since the Savonius rotor has a low starting torque and is adaptable for wind in various directions, it has received great attention in the past decades. In this paper, we present an overview of the state of the art in Savonius rotor design, according to three general strategies of design optimization: 1) Optimizing Savonius rotor structural parameters including overlap ratio, aspect ratio of the rotor, twist angle, Reynolds number, and the shaft of the rotor; 2)Adopting multi-level Savonius rotor or combining Savonius rotor with other type rotor to avoid negative torque of the rotor and improve both efficiency and starting torque; 3)Adding auxiliary devices such as curtain or guide-box to decrease the negative torque. We conclude with a discussion of the advantages and challenges associated with development of this promising technology.

Abstract: Probe of Cloud Droplet (CDP) based on forward scattering has the characteristics of high efficiency, simple structure, and it is the main instrument for small cloud particle (less than 50μm in diameter) detection. A CDP based on forward scattering was constructed in this paper. Calibration experiment and the measurement of the field of depth were conducted. To measure the depth of field, a pinhole adhered to a rotating disk which is fixed to multi-dimensional optical table is used. The pinhole can be seen as a particle appeared in the detection area periodically, as it moved across the laser beam, the depth of the field can be measured. Standard particles with known size were used to calibrate the system and Mie theory was used to calculate the intensity of forward scattering signal. In the end, combining the experiment results and the theoretical calculations, the response curve which can be used to inverse the size of cloud droplet was obtained.

Abstract: A new method for the prediction of protein quaternary structure is constructed based on Isomap (Isometric feature mapping) algorithm, which is a manifold learning-based data mining method. DC (Dipeptide Composition) is used as sequence encoding scheme for the construction of decision system. A DR (Dimensionality Reduction) algorithm, the so-called Isomap is introduced to reduce the decision system, which can be used to classify new objects. The results thus obtained in predicting the quaternary structure of proteins are quite encouraging.

Abstract: In this study, a novel sequence encoding scheme is introduced by fusing PseAA and PSSM. However, this sequence encoding scheme would correspond to a very high dimensional feature vector. A dimensionality reduction algorithm, the so-called NPE (Neighborhood Preserving Embedding) is introduced to extract the key features from the high-dimensional space. Finally, the K-NN (K-Nearest Neighbor) classifier is employed to identify the types of protein structures. Our jackknife test results thus obtained are quite encouraging, which indicate that the above methods are used effectively to deal with this complicated problem of predicting protein structural classes.

Abstract: This study proposed an integration process to incorporate sustainability issues into engineering design for construction projects. To facilitate use by engineers, the integration process was built on the traditional design process. Design work is the foundation for the integration process. Because engineers are familiar with design work and processes, the linkage between the eight design steps and six integration steps make the integration more concrete. The study results show that the integration process can help participants to incorporate sustainability issues, communicate with stakeholders, and achieve consensus, if followed rigorously. The integration steps, such as creation of the integration team and evaluation of alternatives, are similar to the elements dealt with in environmental impact assessment. Since sustainability integration is actually a decision-making and execution process, its management should have the attention of the government, construction owner, and integration team.