Key Engineering Materials Vols. 474-476

Abstract: Surface matching technique is a key technique in automatic generation of 3D finite element mesh. In this paper, a surface matching technique including surface-gap filling, boundary match and C-node match, is introduced. Eight types of free facet configurations and their corresponding matching rules are established. Then a combined method of priority nodes and relative position relationships for boundary match is presented, and an effective method for C-node match is given, too. The methods can achieve precise match between mesh boundaries and model boundaries, and establish reasonable geometry and topology connections of matched nodes. Several examples are provided to demonstrate the accuracy and efficiency of the algorithms presented in this paper.

Abstract: The heat convection was the main heat exchange in the autoclave by which composite pressure vessel was cured. To determine the heat convection coefficient, the combination of theoretical calculation and temperature test is absolutely necessary. In the theoretical calculation, the determination of the heat convection coefficient is considered as an inversion problem of thermal conduction. By adjusting convection coefficient value in the finite element calculation, optimization method was employed to obtain a good agreement between calculated temperature and measured temperature. In the temperature test, the metallic liner of pressure vessel was used as test component to record temperature data which was compared with the calculated temperature. The results present the equivalent thermal boundary condition for the simulation of curing process of pressure vessel.

Abstract: The data-acquisition of temperature is widely used in industrial control, household appliances, medical care, and other important areas often using the data acquisition. For industry, household appliances, and other unsuitable for the traditional wireless data acquisition situation, this paper presents a wireless system of data acquisition of temperature based on radio frequency, and the system can avoid a cable transmission’s the inherent high-cost, long production cycle, the restricted number of transceiver devices such shortcomings . This paper presents the principle, the major flow chart, features system which is mainly made up of MCU ATmega8 and RF chip nF905. Experiments show that this is the accurately and efficiently system of temperature data wireless acquisition and transmission.

Abstract: Given an undirected graph G=(V, E) with real nonnegative weights and + or – labels on its edges, the correlation clustering problem is to partition the vertices of G into clusters to minimize the total weight of cut + edges and uncut – edges. This problem is APX-hard and has been intensively studied mainly from the viewpoint of polynomial time approximation algorithms. By way of contrast, a fixed-parameter tractable algorithm is presented that takes treewidth as the parameter, with a running time that is linear in the number of vertices of G.

Abstract: Precise recognition of the weed by computer vision, furthermore raising the weeding efficiency, reducing the use of herbicide, and decreasing the pollution to the environment is one of the key technologies in the field of precision agriculture. To determine the optimal threshold in image automatic segmentation and solve one-dimensional histogram without obvious peak and valley distribution, image segmentation method based on fisher criterion and improved adaptive genetic algorithm is proposed. This method can preserve the multifamily of population and the astringency of the algorithm, and can overcome the problems of poor astringency and premature occurrence. The result shows that the proposed approach has better immunity to Salt and Pepper Noise and greatly shortens the time of image segmentation.

Abstract: The seepage of rock and soil is a common problem in geotechnical engineering, because of the uncertainty property of rock and soil, how to ascertain the seepage parameter of rock and soil becomes a problem to solve. Aiming to the problem, after introducing the theory of seepage parameter identification, the paper combines unstable seepage finite element method (FEM) and difference evolution (DE) arithmetic, constructs intelligent identification FEM method of seepage parameter, and develops the procedure. The hydraulic head distribution of seepage field can be calculated accurately by FEM and the optimal solution can be obtained by DE, the seepage FEM being embedded in DE, overcoming the local optimization problems of conventional methods and improving the precision of identification. A tam sample is calculated by the method, it states that the convergence speed is quick and result is satisfied. It is a powerful method for seepage parameter identification.

Abstract: This research explores the relation between TW-DRG and pharmacological information by using the concept of data warehouse as a basis. It is hoped to assist doctors, under the condition that patients’ rights will not be affected, to replace the high-priced pharmaceuticals with the pharmaceuticals which are low-priced yet with the same pharmacological and pharmacodynamic effects, in order to reduce the medication cost in medical institutions and hospitals. From this result, we learn that the differences among doctors’ medication habits can be offered to hospitals and doctors for policy analysis on medication. Also, doctors can make appropriate adjustments in medication acts and find out the replaceable pharmaceuticals so that the pharmaceutical cost can be lowered.

Abstract: A dissipative particle dynamics simulation method is used to get insight into molecular-level details of vesicle fusion in this study. For simplicity, the simulation system contains water and amphiphiles. The fusion mechanism is investigated in detail. It is found that the whole fusion process is in well agreement with the “stalk-pore” hypothesis. The dynamics of vesicle fusion is analyzed by monitoring the time evolutions of morphologies.

Abstract: A dissipative particle dynamics simulation method is used to investigate the vesicle fusion behavior in this study, especially to probe the driving force for vesicle fusion. Based on the former study, the fusion mechanism is investigated from the point of conservative energies. It is found that the total energy is decreasing during vesicle fusion, which is mainly caused by the reduction of conservative energy. Through further exploring the six interaction energies of particle-pairs, it is demonstrated that the energy reduction is attributed to the interaction energy between water and amphiphiles. The pressure variation confirms that vesicle fusion is a process of energy releasing.

Abstract: A method for reconstruction of tooth model based on rotate scanning using structured light match technology was proposed. And an algorithm of mesh simplification of the surface point of tooth model using section lines sampling with fixed angles was achieved, which can provide regular surface mesh points for finite element method (FEM). Experiments showed that the method and algorithm could generate accurate surface mesh model which can provide excellent data support for finite element biomechanical model analysis.