Key Engineering Materials Vols. 474-476

Abstract: Computer MIDI and multimedia system in university music teaching application is still at the development phase. Combining with the teaching practice, the articles analyzes and studies some problems focused on computer and multimedia systems in university MIDI music theory in the teaching of practical application.

Abstract: Despite the quality of engineers that still universities are forming, the existing system for educating engineers must change, provides the courses for engineering educators, and a large experience developing and implementing engineering programs, the engineering education research team has decided to develop and to offer a graduation level program for engineers dedicated to education. Through the application of computer-mediated communication educators or instructional designers in the field of engineering with an opportunity to share the ideas and experience of innovating curriculum and instructional methods of engineering education. In this paper, we briefly review the status of engineering education in China. Additionally, we provide details of how these concepts can be used in an educational model, a learning system is also believed to be the stepping stone to one that generates and rewards “active, independent, self-directed learning” for students to gather and assess data rigorously and critically.

Abstract: In the present study, we have demonstrated that alginate and collagen sponge can act as scaffolds in order to support 3-dimensional structure for the differentiated bone marrow derived mesenchymal stem cells (BMSCs) during chondrogenesis in vitro and in vivo. The chondrogenic induced BMSCs were well distributed and differentiation in scaffolds system before implantation, then they produced sufficient ECM in the implants to form chondroid aggregates in vivo. In our opinion, well-differentiated BMSCs is a crucial feature of cartilage repair and only can be achieved in scaffold matrix. Furthermore, when dealing with cartilage defects, alginate seem to be superior to collagen sponge, and the combinational strategy of pre-induced BMSCs combined with alginate 3D-culture might be useful in improving conventional autologous cells transplantation or free-cells scaffolds.

Abstract: Aseptic loosening induced by wear debris particles of artificial joint is characterized by a considerable suppression of osteogenesis. The objective of this investigation was to determine the effect of different-sized titanium particle on protein synthesis, and mineralization in bone marrow–derived mesenchymal stem cells(BMSCs) induced toward osteogenic differentiation in vitro. Rat bone marrow–derived mesenchymal stem cells (rBMSCs) induced toward osteogenesis were cultured in the presence or absence of titanium particles in varied size, 0.9µm, 2.7µm, 6.9µm, respectively. Flow cytometry characterization of rBMSCs proved 99% homogeneity by using with cell-surface antibody. The bone matrix protein synthesis evaluation showed that three size groups of titanium particles could suppress early, middle, and late markers of the osteogenic lineage, i.e., alkaline phosphatase activity, C-terminal type I procollagen and osteocalcin secretion repectively, in a dose- and time-dependent manner. The least detrimental particle size group was 0.9 μm, which is a reasonable finding as this group is more susceptible to phagocytosis due to smaller size. The cell-mediated matrix mineralization in terminally differentiated cultures by Alizarin Red S assay revealed a reduction in the number and area of mineralizing nodules, even mineralization calcium concentration in BMSCs cultures after titanium particles treatment. Collectively, the data suggest that different size titanium particles alters osteogenic differentiation in BMSCs cultures during lineage progression and provide further insight into wear debris-induced reduced bone formation.

Abstract: The 3D interaction design solution and implementation with VTK and QT were proposed in the system of virtual spinal fixation surgery. After discussing the background of 3D interaction technology, the principles of the interaction design about 3D interaction used in the system was given. According to the requirement of the system, the observer pattern and command pattern were adopted. And then 3D interactive design based on 3D Widgets was given in detail, the implementation view was shown. Finally, some implementation interface and five kinds of widgets design were displayed.

Abstract: To further improve the fault coverage and accuracy of fault location in SRAM based on FPGAs interconnect, an efficient method of fault detection and location is presented. Eight types of programming based on multiple times programmable FPGA is used, and further improved fault coverage and accuracy of fault location. Analysis showed that the proposed methods could cover all interconnect single faults and locate five single faults to specific switch or locate bridge fault to a pair of segments.

Abstract: In order to provide high Quality of Service (QoS), rational scheduling and resource allocation are needed when a great deal of tasks requesting grid resources. By quantifying some important properties of Grid QoS and maximizing cost-performance ratio of Grid system, a QoS-guaranteed self-adaptive grid resource selection algorithm based on SAGA which is named QoS-SGRSA is proposed, and the flow of the algorithm is introduced. In the low load condition, traditional resource selection algorithm is adopted, so an allocation policy is found rapidly. While in the high load condition, by means of using complementary advantages of GA and SA, it can guarantee that the search is on the optimization direction. Finally, we evaluated the effectiveness of QoS-SGRSA by emulation experiments.

Abstract: The expected rate of earnings and risk of high-tech projects are very fuzzy, and investors hope to get the expected rate of earnings maximization and risk minimization. Therefore, this paper establishes the model of fuzzy multi-objective programming method to select an optimal portfolio scheme. On the one hand, the objectives risk can be scattered, on the other hand investors can get ideal earnings. The example shows that this method to solve problems of portfolio investment decision is feasible and effective.

Abstract: This paper proposes a new cooperative GBN-ARQ（Go-Back-N Cooperative Automatic Repeat Request: GBN-CARQ）algorithm which is suitable for the single source and single relay wireless communication system based on TDMA, establishing the queuing model of single source and single relay wireless communication system based on TDMA and providing the expressions of its throughput and delay performance. By comparing with GBN-ARQ algorithm and normal cooperative ARQ（Cooperative ARQ：CARQ）algorithm, it is shown that GBN-CARQ algorithm has better average throughput performance.

Abstract: Based on the large spring/stiffness method (LSM), this paper develops an improved technique (I-LSM) applicable to structural dynamic analysis with the assumption of Rayleigh damping. To estimate the accuracy of the technique, the dynamic response is analyzed for a 2-DOFs model respectively subjected to uniform/nonuniform seismic excitations. It indicates that the traditional LSM is inapplicable when Rayleigh damping is adopted. And the errors increase monotonously with the aggrandizement of damping. It’s also validated that the I-LSM based on the modification of displacement considering the influences of Rayleigh damping presented in this paper is able to effectively yield results almost identical to those of theoretical methods with errors beneath 4%.