This paper proposes an optimization design method of vibration damping for an electron beam system. It realizes low cost and highly precise electron beam system. Semiconductor devices which are smaller and thinner are required by growing of smartphones and tablet PCs. However, semiconductor device factories have an issue that productivity is decreased by disturbance vibration. Especially, it is difficult to compensate both floor vibration and equipment's inner vibration. Furthermore, an active damper that does not make magnet field is required, because reducing distortion of deflection of electron beam is very important for an electron beam equipment. In such background, this paper proposes a design method for an active damping by using a state feedback controller with an estimator of column vibration. The proposed controller has negative feedback of chamber state and estimated electron beam column state. In addition, this paper proposes a design method for adapting to an environment of a semiconductor device factory by including variable parameters into the state feedback controller. Finally, this paper describes an experimental result of the design method of vibration damping.

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This paper proposes an analysis method for the fluctuation of the positional deviation in a feed drive system. In this analysis, the positional-deviation fluctuation due to position-dependent disturbances is separated from the total deviation. The cause of the disturbance is roughly determined. The positional deviation of an actual feed drive system with a ball screw drive was analyzed by the proposed method. The positional deviation and motor torque were measured at several constant feed rates. The measured data were analyzed in the wavelength domain to distinguish the positional-deviation fluctuation due to the position-dependent disturbance. In the positional deviation, seven periodic fluctuations were determined to be the position-dependent fluctuation. These fluctuations were caused by the circulation of balls in the ball screw, the run-out of the ball screw, the geometrical inaccuracy of the ball screw and the disturbance in the control system, including the servo motor. The fluctuation magnitude of the positional deviation due to the ball screw was almost 1/3 of the total magnitude. The magnitude of the positional-deviation fluctuation depended on the feed rate and the wavelength of the disturbance because of the frequency response of the feed drive system to the disturbance.

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This study considered the influence of task complexity on evolution of virtual creatures. Creatures consist of rigid primitives, joints, and neural controller and these parameters are evolved with real number coded genetic algorithm. Creatures are evaluated in a virtual environment that implemented physical forces for achieving various simple tasks such as walking, pursuit toward a target, and evasion from obstacles. Acquired shapes of creatures are classified into 4 types according to a feature value named “number of branches”. Experimental results showed that the creature has a specific number of branches obtained a high fitness.

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Most services depend on a great deal of individual skills. Therefore, skills of employee have a huge effect on service quality. OJT (On the Job Training) is put in place in the fields so that employees acquire skills required to provide a high quality service. However, employees cannot acquire skills effectively in most OJT sessions because firms don't carry out OJT sessions in well planned manner. Therefore, this paper proposes an employee participatory process of skill structure modeling for OJT planning. Specifically, the proposed method clarifies skills should be acquired and visualizes preconditions among the skills. The proposed method is verified through the application to a practical case.

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