A Ray-Tracing Analysis of ICRH in Tokamaks

Power deposition profiles generated by Ion Cyclotron Resonance Heating （ICRH） in non-circular tokamaks are studied using a ray-tracing technique. The simulation results for the Experimental Advanced Superconductor Tokamak （EAST） D-shaped plasma are presented. It is indicated that the spatial distributions of plasma parameters （plasma density, species temperature, minority ion concentration, etc.） have an significant influence on the power deposition profiles. The findings may be highly useful to the planned plasma heating and experiments in EAST.     

Genetic algorithm approach to a production ordering problem in an assembly process with constant use of parts

An optimal production scheduling problem for an assembly process with buffers at the input and output sides of a machine is dealt with. The problem has two kinds of constraints. One constraint is that the buffers' capacity is limited. The other constraint is that the cycle time of the worker is constant without waiting time. An optimal production ordering is determined, subject to these constraints, in such a way that the rate of use of parts to produce each product should be as constant as possible. A procedure to apply the genetic algorithm to this problem is shown. The operations of reproduction, crossover and mutation are presented. It is observed from numerical results that the genetic algorithm gives a better suboptimal solution than the greedy method.     

A simulation study on autonomous decentralized mechanism in fish behaviour model

The behaviour of a fish school is considered an interesting phenomenon because a fish school behaves differently in various situations. The paper considers a fish school as an autonomous decentralized system and constructs a mathematical model for the autonomous decentralized mechanism. Simulation results show that, by varying the quantity of information exchange among members in school, the present model describes fish behaviour not only for a school with fixed configuration but also for that with variable form. Furthermore, a remarkable difference in fish trajectory is found between the two schools.     

A method for decomposing mixed-integer linear programs with staircase structure

An algorithm is presented for solving mixed-integer linear programs with a staircase structure. The basic idea of the algorithm is to decompose the original problem into a series form of small-scale mixed-integer problems. For each problem decomposed, the solution is obtained by the conventional branch-and-bound method. In this algorithm the feasibility of the solution is always assured, but in order to save computation time the optimality condition is checked restrictedly for the solution obtained. The difference between the optimal objective value and the objective value obtained can be estimated. By examining numerical results, it is observed that the algorithm is efficient, requiring less computation time than other methods.     

INFLUENCE OF DISSOLVED CARBON CONTENT ON RECRYSTALLIZATION γ TEXTURE IN ULTRA-LOW CARBON DEEP DRAWING STEEL WITH HIGH PURITY

借助三维取向分布函数探讨了高纯超低碳深冲钢板的固溶碳含量对再结晶γ织构的影响，分析了固溶碳与再结晶γ织构及其中的｛１１１｝＜１１２＞和｛１１１｝＜１１０＞织构之间的关系     

Fatigue life prediction of composites under two-stage loading

In order to predict the fatigue life under two-stage loading by formulating a cumulative fatigue damage rule for composite materials, the fatigue process in SiC–Al and glass-fibre reinforced plastics were investigated. A microcrack occurred within the composites which resulted in cumulative fatigue damage that increased linearly with the number of cycles. The mechanical conditions of damage growth and failure were determined by characterizing the microdamage governing the fatigue. The ultimate failure is shown to occur when the product of the stress amplitude ratio and microdamage density is beyond a critical value and an expression for the remaining fatigue life is derived. This revised version was published online in November 2006 with corrections to the Cover Date.     

Gel Forming Characteristics of Frozen Surimi from Chum Salmon in the Presence of Protease Inhibitors

When salted surimi paste of chum salmon was incubated at 20–60°C, a marked loss of the breaking strength of heat-induced gel occurred simultaneously with breakdown of myosin heavy chain, but this was effectively suppressed by addition of cysteine protease inhibitors or bovine plasma powder. In the presence of protease inhibitor, the surimi gels were formed at relatively low temperatures showing highest gel strength at incubations of 50 and 60°C. Chum salmon surimi showed no evidence of suwari and no myosin heavy chain cross-linking.     

Reference Design of ICRF Antenna for EAST

An antenna array suitable for plasma heating and current drive has been designed for the ion cyclotron resonance frequency range （ICRF） heating on the EAST superconducting tokamak. The ICRF heating is planned to operate in a frequency range of 30 MHz to 80 MHz and hence the antenna geometry is optimized for 55 MHz. The design is based on the conventional strap antenna element. The coupling properties of the antenna are calculated with a slab model of the plasma for the antenna simulation. The coupling code is extended for the analysis of the toroidal antenna array separated by septa.     

Electron Paramagnetic Resonance in R2O-Al2O3−SiO2 Glass Systems

Systematic detection of an EPR signal was conducted for three alkali oxide-Al₂O₃−SiO₂ glass systems. Observed EPR spectra, having a main line with g=2.03 and a broad and anisotropic shape, are attributed to the unsaturated bridging oxygen bond resulting from the breakup of the SiO₂ random network. This signal appears in the area AValkali atom ratio >1 for the Na₂0 and K₂O systems, indicating that the collapse of the Al 4-coordinated structure begins at an equimolar ratio when alumina is substituted for the alkali oxide, whereas somewhat different behavior was observed for the Li₂O system.     

An autonomous decentralized scheduling algorithm for a scheduling problem in a metal mould assembly process

This paper deals with a scheduling problem in a metal mould assembly process. The process is of job shop type with several additional constraints. One constraint is that precedence relations exist not only among operations but also among jobs. The other constraint is that the system has two types of machines in parallel. The single-function machine executes a specific operation of each job and the multi-function machine can execute several operations. Therefore selection of the machine is necessary for executing each operation. In addition the problem has two objective functions. One is to minimize the sum of the tardiness of each job, and the other is to maximize the working time of the multi-function machine because of reducing the operating cost of machines. An autonomous decentralized scheduling algorithm is proposed to obatin a compromise solution of the multi-objective problem. In this algorithm, a number of decision makers are called subsystems, which co-operate with one another in order to attain the goal of the overall system. In our algorithm, all jobs and the set of multi-function machine are defined as the subsystem because their objective functions are competitive. They determine the scheduling plan on the basis of their co-operation and the satisfaction of their own objective function levels. The effectiveness of the algorithm is investigated by examining numerical results.