Recent globalization in industries has increased the number of product failures and troubles caused by using them in unexpected ways. It is required to develop a methodology for obviating such troubles in advance in the product design phase by predicting various ways of usage and then analyzing their influences on the product. The authors have focused on the latter point and developed a set of methods for detecting failures considering each way of usage in the product design phase. This research aims at the former point. Definition of ways of usage is discussed. Generation processes of unexpected ways of usage are analyzed from the point of view of functions and “6W2H” and then classified into two classes. For one of the classes of unexpected ways, methods for predicting and modeling them are proposed.
Recently, getting more reduction of energy consumption is attracting the attention not only of society, but also of industries. The other hand, the industries need to apply high-mix low-volume productions in response to customer needs. Therefore, the industries have to simultaneously realize productivity applying high-mix low-volume productions, and reduction of energy consumption. Previous studies conducted on the formulation of energy consumption per production throughput. However, research on the formulation of considering production for the high-mix low-volume production line has not been conducted.
In this study, we propose a formulation of relationship between production conditions and energy consumption per production throughput for high-mix low-volume productions. We consider lot size, cycle time, and setting-up time as production conditions. Case studies for the printed circuit board production are carried out to verify our proposed formulation.
This research focused on a decomposition type optimization method that makes it easier to solve individual optimization problems by dividing the optimization problem into smaller optimization problems in multiple design spaces. Then, based on the parametric relationship of the product system model, a hierarchical optimization method to divide the optimization problem into optimizable optimization problems that can definitely define the objective function was studied. For this purpose, this research focused on the dependency relationship between the design variables of the optimization problem and the objective function and constructed an algorithm that divides and hierarchizes the optimization problem into an optimizable problem, which can be definitely defined by the objective function. By using this algorithm, this research adapted this method for 3DLSI rough design. As a result, we get the proper definition of optimization problem.
A flame combustion method enables the synthesis of diamond using acetylene-oxygen gas in ambient atmosphere. It has various advantages over other methods. We previously synthesized diamond films on a Mo substrate surface by the flame combustion method. To prevent diamond film delamination for the synthesis of good diamond films, a three-step synthesis method was proposed. However, the surface roughness of synthesized diamond films by this method became large, and it is necessary to reduce the surface roughness. In this study, to reduce the surface roughness, amount of diamond paste with the diamond seed particles as generation nuclei for the diamond seed attachment processing of synthesis of diamond films was carefully varied in the range of 0.050～0.150 g. To investigate the surface morphology and the surface roughness of synthesized diamond films, synthesized films were observed. Amount of diamond paste with the diamond seed particles affected the surface morphology and the surface roughness of synthesized diamond films. Amount of diamond paste with the diamond seed particles was increased, the surface roughness of the synthesized film was reduced by this study. The surface roughness in the Case 5 condition was the smallest in this experiment. Furthermore, to investigate influence of the surface roughness of synthesized diamond films, generation nuclei on the substrate in the synthetic initial stage and diamond seed particles on the substrate surface after the seeding treatment were observed. Relationship between number of diamond generation nuclei on the substrate in the synthetic initial stage and surface roughness and amount of diamond paste were confirmed.