Key Engineering Materials Vols. 467-469

Abstract: Genetic programming is an effective way to generate design candidates in an open-ended, but statistically structured, manner. A critical aspect of the procedure is a fitness measure, which guides candidate designs toward an optimal scheme in reasonable time. This paper has suggested a new definition of fitness base on Hungarian algorithm for automatically synthesizing designs for multi-domain, lumped parameter dynamic systems, and uses a type of embryo bond graph model with three modifiable sites to initialize population. Although the experiments run to date are not sufficient to allow making strong statistical assertions, it shows that the search capability of genetic programming combining Hungarian algorithm is good enough to make feasible automated design methodology proposed here for multi-domain systems.

Abstract: Based on the principal-agent theory, this paper constructs quality signaling game model in supply chain under the condition of asymmetric information. The supplier makes the production process investment decision and determines the type of production process level (high level type or low level type), who will also make quality prevention strategy and determine its products quality prevention level. The manufacturer makes the quality appraisal strategy and processing strategy when it accepts the intermediary components, who will also determine its products quality inspection level and processing level. In this paper, we analyze the supplier may signal the type of production process investment level to the manufacturer in order to obtain the optimal incentive contracts. We take use of the optimal theory to establish supplier’s production process quality prevention model and manufacturer’s products quality inspection model and investigate the manufacturer's information rents to motivate supplier to improve products quality level. This paper will prove that: the supplier may have the incentives to signal the type of production process investment level to the manufacturer, and improve its products quality prevention level in its production process. When the manufacturer observes supplier’s signals of products quality level, it will reduce quality inspection level and improve processing level. With the improvement of supplier’s quality prevention level, its warranty payments and price rebate will decrease, the manufacturer will increase its upfront payments and reduce apportionment ratio of external failure cost. Meanwhile the integrated supply chain’s joint expected profits will also increase, and then the manufacturer will reduce the supplier’s information rents obviously. Above all, we analyze the causes of ratchet effects and provide corresponding quantitative descriptions and proofs for our conclusions respectively.

Abstract: Actually modern systems have to ensure higher and higher operating standards, thus including monitoring and control subsystems for their achievement. In safety critical systems control is a crucial task in order to satisfy strict reliability requirements. But it is also necessary that the control system is itself reliable. As a consequence, adequate techniques are necessary in order to perform reliability evaluation of both the controlled and the control systems. Techniques that therefore should avoid over-simplistic assumptions and/or approximations that, for example, are usually introduced when dependencies, interferences and other dynamic reliability aspects are not taken into the right consideration. In this paper, a technique for carefully evaluating the reliability of such systems, also considering dynamic aspects and behaviors, is proposed. Firstly the technique is detailed through the specification of the dynamic reliability block diagrams notation, and therefore in order to demonstrate its effectiveness, it is applied to an example of a computing-based control system taken from literature, thus providing guidelines for the reliability representation and evaluation through DRBD.

Abstract: A deep understanding of adiabatic shear fracture (ASF) during serrated chip formation is essential to explore the material removal mechanism of high speed cutting (HSC). This paper aims to reveal the microscopic details of ASF in serrated chips. The material to investigate was AISI 1045 steel of different hardness grades, and the micro-structural analysis was conducted using optical and scanning electronic microscopes. The investigation showed that at the hardness of HRC50, most fractured surfaces were covered by a large number of dimples elongated along the shear direction, indicating that the fundamental cause of the serrated chip generation is the deformation localization of the adiabatic shear followed by ductile damage fracture in primary shear zones. The higher the material hardness is, the easier the adiabatic shear and ductile fracture take place. A new model was then proposed to interpret the ductile fracture due to adiabatic shear governed by the nucleation, growth and coalescence of micro-voids during serrated chip formation.

Abstract: How to exercise reasonable motion control on robot becomes a new research focus in robot technology research. This paper proposes the Rotate-Lookup-Summation according to the deficiency of traditional look-up table. This method first confirm the controlling factors P1，P2….Pn that would affect the control volume Z, and then the multi-dimensional control volumes and multi-dimensional control factors would be projected to sub-dimensional space. Finally, the same controlling factors of different sub-dimensional space would be rotated to a single sub-dimensional space and establish a corresponding table. According to the single sub-dimensional space value of the controlling factors, the corresponding control variable could be found in table and eventually complete the control process. Experiments show that the method could ensure the integrity and accuracy of table, reduce the table memory capacitance and lookup time, so as to realize the control of look-up table in micro-device.

Abstract: In perspective of maximizing the economic growth rate, this article examines the optimal size of China’s fiscal expenditure with theoretical and empirical methods. Based on exploring the Congested Public Goods Model and the Pure Public Goods Model, we estimate that during the year of 1978-2006 the optimal size of China’s fiscal expenditure is about 20-25% of GDP. According to this criterion, China's fiscal spending policies can be divided into three development stages: (1) the higher size phase (1978-1992); (2) the lower size phase (1993-2000); (3) the optimal size phase (2001-2006)

Abstract: In micro-cutting process, a remarkable characteristic of micro-Cutting is that cutting parameters level closing to the crystal grain msize of material. Though, the prediction formula of micro-cutting forces should reference to strain gradient plasticity theory in formula construction , while cutting edge radius had been regard as a important parameters in the process of micro-cutting. With advantedge FEM software for simulation of micro-cutting , the results show that, there was no significant effect of temperature on cutting force; strain gradient reaction will be decreased by feed rate’s reducing in process, cutting depth effected cutting force in linear mode, the max. workpiece temperature area is no longer the second deformation area but the primary deformation zone, while the max. temperature area of the tool would transfer to the tool tip from theoretical location of traditional cutting.

Abstract: Compressive performance of honeycomb paperboard with different number of paper-cores had been analyzed to meet the need of honeycomb paperboard produce. First, the models were built after buckling theory analysis. Dynamic characteristics of nonlinear collapse process under axial dynamic load were analyzed in the FEA software. It was indicated that: the collapsing process was divided into four parts: linear elastic phase, elastic-plasticity phase, plasticity collapse phase and densification phase. When the number of cores increased, the models had a bearing up on compressive strength. At last, the compressive performance had been verified by experiment.

Abstract: Using GIS(Geographic Information System), GPS(Global Positioning System), and GPRS(General Packet Radio Service), an digital mining control management system in an open pit has been designed and developed. A linear programming model is set up in a practical application. By the model, the system can automatically draw up production plan of ore blending well every day. The system can monitor and dispatch open-pit trucks and shovels well, and can play back their historical paths. It can monitor and control the process of mining production in real time. The system can also count the number of trucks’ delivery and shovels’ loading automatically. Experiments on real scenes show that the performance of this system is stable and can satisfy production standards of ore blending in open pits.

Abstract: Ribs with triangular cross section can be obtained by rolling process on copper tube surface. The ribs are the basis for machining 3D Integral External Finned Tube. Triangular ribs on a red copper tube with 12.6mm diameter and 1.25mm wall thickness are fabricated under, the feed rate of 0.15mm/r, the speed of 2m/min, and rolling depth from 0.1mm to 0.85mm.In this study, four kinds of ribs are obtained. After the analysis of the relationship between rolling depth and the rib structure, the optimal single triangular rib can be obtained on condition that the rolling depth is 0.75mm.